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Nel, Eugéne Johannes. "Multi-h synchronisation for codes with long constraints-length." Master's thesis, University of Cape Town, 1997. http://hdl.handle.net/11427/9471.
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Bibliography: p. 64.This dissertation investigates the synchronisation of Multi-h signals with a long constraint length. However, Multi-h codes exhibiting a long constraint length invariably also exhibit a large denominator q. Since traditional methods for synchronising Multi-h signals utilises a q-th power law device, where the frequency spectrum of the qth power of the signal renders all the necessary frequencies for synchronisation, we suspect that a large q could be detrimental. When simulated, it turns out that the qth power law device fails to deliver distinct (and useable) frequency components at a q size of about 8. Unfortunately, the most useful codes have denominators starting at a size of q equals 32. This called for a novel approach to synchronisation. One device that shows much potential is the new Massey-Hodgart coherent MSK demodulator. In a significant departure from standard quadrature structures, this MSK demodulator uses matched filter detection with a pair of reference signals at the two MSK signaling frequencies; an optimal maximum-likelihood bit decision is then formed over two bit intervals. The reference signals are recovered by a pair of decision-switched Costas loops, which are tightly integrated with the demodulator structure. The goal was to modify the Massey-Hodgart MSK demodulator into a Multi-h synchroniser that contained matched filter detection for all the frequencies in the Multi-h signal. The reference frequencies would still be decision switched and recovered by Costas loops.
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Sauer, Derek. "Telomere Length and Senescence in a Long-lived Fish (Ictiobus cyprinellus)." Thesis, North Dakota State University, 2019. https://hdl.handle.net/10365/29782.
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The pattern of shorter telomere lengths in older individuals has been observed across many vertebrates, but has not been well-documented in bony fishes. Bony fish (i.e., Class Osteichthyes) represent the most speciose and oldest group of vertebrates, and understanding their telomere dynamics can fill gaps in our understanding of the process and evolution of aging in vertebrates. In this study we quantified telomere length, immune function, and stress in bigmouth buffalo (Ictiobus cyrpinellus), a long-lived bony fish in the family Catostomidae, to characterize variation in telomeres and condition. We found that length of telomeres extracted from red blood cells was not related to age. We also found that the neutrophil/lymphocyte ratio was lower in older individuals, and immune function was greater in older individuals. Our findings suggest bigmouth buffalo may be capable of intrinsic regulation of telomere shortening and provide support for the existence of negligible senescence in some vertebrates.
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Forster, Richard John. "Development and applications of single frequency erbium doped fibre lasers." Thesis, University of Strathclyde, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248516.
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Olney, Cynthia Ann. "Development of recall from short-term and long-term memory: Effects of list length, word length, taxonomic relatedness, acoustic similarity, and modality." Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185567.
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An emerging theory of short-term memory, called fuzzy trace theory (FTT), postulates a link between memory and reasoning ability that might explain the relationship of performances on memory span tasks to other measures of intelligence. Two key assumptions regarding the encoding and retrieval of information in short-term memory (STM) are central to FTT. First, stored memory traces are assumed to vary along a continuum of verbatim detail to gist. Second, retrieval from STM is assumed to vary along a continuum of simple to reconstructive readout. The three experiments reported in this dissertation were designed to examine these two assumptions regarding encoding and retrieval by examining subjects' performances on memory span tasks. Memory span was the measure of choice for this series of experiments because span tasks have long been considered a pure measures of memory. Recall of items (item memory) and ordering of items for serial recall (order memory) were factored and treated as independent memory processes. The findings in the three experiments indicated that item memory relied more on simple readout of verbatim detail, while order memory relied on reconstruction from gist. More development was observed for order memory, indicating that age changes in memory span performance may be caused by development of gist extraction and reconstructive processes. It was suggested that children's ability to order items is the component of serial recall that explains the link between memory span performance and other measures of intelligence.
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Walding, Christina L. "Inappropriate hospital admission and length of inpatient stay : patients with long term neurological conditions." Thesis, University of Nottingham, 2010. http://eprints.nottingham.ac.uk/28918/.
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Introduction Studies have shown that a proportion of patients admitted to hospital do not require the intensity of services they provide. Also, the admission of patients can be for an inappropriate duration. Methods Three studies were conducted. The first study was a record review to determine the appropriateness of patient admissions and inpatient stays. The second examined the wider causes of inappropriate admissions/inpatient stays as perceived by clinicians, and identified interventions to reduce such admissions/stays. Data were collected using focus groups. The final study explored barriers to service use from the perspectives of clinicians and patients. Data were collected from clinicians via an online questionnaire and from both clinicians and patients using semi structured in-depth interviews. Results Of 119 patients, 32 were admitted inappropriately and 83 were admitted for an inappropriate duration. Risk factors for an inappropriate admission included living in the community compared to a nursing/residential home, and for an inappropriate length of stay included the number of presenting complaints, number of long term neurological conditions and whether the participant lived alone in their own home or with others. In the second study, the limited knowledge and a lack of health and social care resources in the community, were perceived as causes of inappropriate admission/lengths of stay. Interventions to prevent inappropriate admissions/lengths of stay included: sub-acute care facilities and patient held summaries of specialist consultations, among others. The final study found that the main barriers to use of services were out of hour's access and unfamiliarity of clinicians with local service provision. Conclusions The causes of inappropriate admissions/lengths of stay related, in main, to communication problems and accessibility of services. Interventions to improve transference of information and knowledge regarding long term condition management and service provision may be warranted.
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Brower, Cheyna Katherine. "Too Long and Too Boring: The Effects of Survey Length and Interest on Careless Responding." Wright State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=wright1524614764948287.
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Millard, Peter Henry. "Geriatric medicine : a new method of measuring bed usage and a theory for planning." Thesis, St George's, University of London, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320090.
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Cassel, Stanley David. "The effect of increasing length on the overall conductance and capacitance of long heat pipes." Diss., Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/19589.
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Wright, Jonathan C. "Evaluation of LOWTRAN and MODTRAN for use over high zenith angle/long path length viewing /." Online version of thesis, 1991. http://hdl.handle.net/1850/11352.
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Katz, Robert Adam. "The Long Term Stability of Mandibular Arch Length and Width Changes Following Rapid Maxillary Expansion." The Ohio State University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=osu1383819575.
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Hay, Tristyn Nicole. "Long-term fertilization effects on ectomycorrhizal community structure and fine root length in interior spruce forests." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/40275.
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Ever-present on the roots of appropriate host trees, ectomycorrhizas are pivotal in the survival and productivity of trees of interior British Columbia. Although ectomycorrhizal (ECM) fungi provide access to nutrients that would otherwise be unavailable to roots, nutrient supply can still limit above ground productivity of trees. Such nutrient constraints have led to the use of fertilization as standard practice for increasing tree yields in some parts of the world. Although much research has been completed on the short-term response of ECM communities to nitrogen enrichment, almost none has focused on responses to long-term fertilization treatments aimed at maximum tree productivity. In our study, the response of ECM fungal communities of three interior spruce (Picea glauca) stands in interior British Columbia to 10-15 yr of fertilization was studied. The treatments included (i) unfertilized control, (ii) annual fertilization (kg ha⁻¹); to maintain 1% foliar N (iii) periodic fertilization (kg ha⁻¹); 200N, 100P, 100K, 50 sulphur, 25 magnesium, 1.5 boron applied every 6 years. The study sites were located in three different biogeoclimatic zones: the moist, cold (SBSmc2), the moist cool (SBSmk1) and the wet cool (SBSwk1) variants of the Sub-Boreal Spruce zone of central interior British Columbia. Using morphological and molecular analysis, the identity of the dominant ECM fungal symbionts on the randomly-selected root tips was determined in order to characterize the ECM fungal community. Both ECM fungal diversity and richness differed amongst sites, but did not appear to be affected by fertilization. The relative abundance and frequency of Tylospora spp., one of the dominant genera in the community, were lower in plots exposed to annual fertilization at one of the sites. No overall effect on the ECM fungal community was observed in response to fertilization. As the periodic fertilization treatment more closely reflects operational modes of fertilization in these regions, these results suggest that large-scale fertilization could be established in the central interior of British Columbia without major disturbance to this important component of the soil microbial community.
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Taylor, Kelli M. "The effects of overlearning on long-term retention." [Tampa, Fla.] : University of South Florida, 2004. http://purl.fcla.edu/fcla/etd/SFE0000321.
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Gibson, Millan-John. "Fibre Length Distribution and Dispersion during the Injection Moulding Process: An experimental study evaluating fibre length attrition and dispersion during processing of long glass fibre reinforced polymer composites in injection moulding including an evaluation of long glass fibre measurement techniques." Thesis, University of Bradford, 2018. http://hdl.handle.net/10454/17360.
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This project evaluates fibre length dispersion and distribution within the injection moulding process of long glass fibre reinforced polypropylene, sponsored by Autodesk Simulation.
The primary material used in this investigation was a 15 mm long glass fibre reinforced polypropylene consisting of two fibre content levels, 20 wt. % and 40 wt. %.
A review of previous research was compiled in this study to evaluate various glass fibre measurement methods and fibre breakage studies to establish where along the injection moulding process fibre breakage predominantly occurs and which process parameters have the greatest influence on fibre length distribution along the screw.
Based on literature findings, a manual fibre length measurement method was developed and applied in this study and benchmarked against existing commercially available automated software programs and found to be more accurate in obtaining a reliable fibre length distribution within a glass fibre reinforced sample.
Fibre length measurements from the nozzle confirmed that the majority of fibre breakage had already occurred in the screw. Measurements taken along the screw showed a drastic decrease in weighted average glass fibre length from initial pellet form to the end of the metering zone with sudden transitions to lower weighted average values seen at the beginning of the feeding zone and along the compression zone.
Fibre dispersion results from the nozzle and along the screw through the use of a μ-CT scanner showed a complex fibre flow and orientation of fibres with the preservation of fibre clusters being seen all along the injection moulding process but chiefly in the feeding and compression zones of the screw.
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Saeedy, Neda Eva. "IN-GROUND PLASTIC HINGE ANALYSIS FOR PILES USED IN MARINE OIL AND LNG TERMINALS." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/949.
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The design and maintenance of Marine Oil and LNG Terminals is governed by the Marine Oil Terminal Engineering and Maintenance Standards (MOTEMS) which is part of the 2010 Title 24 California Code of Regulations, Part 2, California Building Code, Chapter 31F: Marine Oil Terminals. The purpose of this thesis is to evaluate the current recommendations for the in-ground plastic hinge length and depth for piles in section 7 of MOTEMS for all typical soil properties and pile dimensions found in Marine Oil and LNG Terminals. The pile types considered in this analysis are 24-inch octagonal prestressed concrete piles and 24-, 36-, and 48-inch steel pipe piles in varying soil conditions.
Existing recommendations for plastic hinges are incomplete and inadequate. MOTEMS does not have any recommendations for plastic hinge depth, only length, nor does it have any recommendations for in-ground plastic hinge for steel piles. Recommendations for steel piles are however found in the Port of Long Beach Wharf Design Criteria (POLB), but the recommendations in both MOTEMS and POLB have shown to be inadequate for both steel and prestressed concrete piles. MOTEMS also proves to be adequate for Level 2 earthquakes but not for Level 1. The plastic hinge length for Level 1 is much longer than that for Level 2. So the MOTEMS recommendations for Level 1 lead to conservatively small displacement capacity. POLB recommendations are also adequate for Level 2 but not Level 1 for concrete and are overly conservative for steal and therefore, not adequate for either level except in dense and medium sands during a Level 1earthquake. POLB does not take into account different soil characteristics and has one value for all soils, which is inadequate for most cases.
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Alghamdi, Majed Mohammed. "Investigations into long-standing problems in radical polymerization kinetics : chain-length-dependent termination rate coefficient and mode of termination." Thesis, University of Canterbury. Chemistry, 2014. http://hdl.handle.net/10092/10028.
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The present thesis investigates some long standing problems in radical polymerization (RP). The major aim is to consider the feasibility of using simple techniques to provide more insight into the kinetics of RP. This can contribute to fundamental knowledge of radical polymerizations, particularly with respect to the mode of termination (λ), average termination rate coefficient (
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Shavitranuruk, K. "Long Cavity Quantum Dot Laser Diode and Monolithic Passively Mode-Locked Operation." Doctoral diss., University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3392.
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Advantage of the single QD active layer is its potential for very low threshold current density, which in turn can produce low internal optical loss. The low threshold current density and low internal loss thus enable a significant increase in laser diode cavity length. Because of the importance of the threshold current density in heatsinking, future technology of broad-area monolithic laser diodes can be implemented. The dissertation describes the development and the unique characteristics of single QD active layer laser with long cavity. The data are presented on single layer QD laser diodes that reach threshold current densities values of 11.7 A/cm2 in a p-up mounted 2 cm long cavity and as low as 10 A/cm2, with CW output power of 2 W in a p-down mounted 1.6 cm long cavity. The 8.8 A/cm2 in a p-down mounted 2 cm long cavity is reported. To our knowledge the value 8.8 A/cm2 is the lowest threshold current density ever reported for a room temperature laser diode. These single layer QD laser diodes reach an internal loss of ~0.25 cm-1, which is also the lowest ever reported for a room temperature laser diode. These unique characteristics of single layer QD and laser diode size are potentially promising for the monolithic mode-locked laser because of relatively high peak power with a low repetition rate that is on the order of a few GHz, which can be the novel device for external clocking in the optical interconnect applications. In this dissertation, the stable optical pulse train in a 40 µm wide stripe with a repetition rate of 3.75 GHz with 1.1 cm cavity length through the passive mode-locked onto the monolithic two-section device fabricated from this single layer QD laser is observed.Ph.D.
Optics and Photonics
Optics and Photonics
Optics PhD
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Badraghi, Naghimeh. "Productivity, Cost and Environmental Damage of Four Logging Methods in Forestry of Northern Iran." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-145790.
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Increasing productivity, reducing cost, reducing soil damage, reducing the impact of harvesting on standing tree and regeneration are all very important objectives in ground skidding system in the management of the Hyrcanian forest. The research carried out to obtain these objectives included four logging methods, tree length method (TLM), long length method (LLM), short length method (SLM), and wood extraction by mule (mule) in northern Iran. In order to determine the cost per unit, time study techniques were used for each harvesting method, time study data are shifted to logarithmic data based on 10. On the basis of the developed models simulated, 11 skidding turns are simulated and the unit cost are estimated depending on the diameter of the log (DL), skidding distance (SD), and the winching distance (WD) for 11 different cycles with TLM, LLM and SLM.
The results showed that on average, the net costs per extraction of one cubic meter of wood were 3.06, 5.69, 6.81 and 34.36 €/m3 in TLM, LLM, SLM and mule. The costs depending on diameter of log (DL), skidding distance (SD) and winching distance (WD) showed that the most economical alternative for Northern Iran is TLM. In the cut-to-length system, the costs of both alternatives LLM, SLM were significantly dependent on DL. , thus the result of this study suggests that as long as the diameter of the felled trees is less than 40 cm, the cut-to-length system is not an economical alternative, whilst the cut-to-length method can be applied for trees with a diameter more than 40 cm. Where diameters are more than 40 cm TLM it is more economical than SLM, however it was not significantly different. Depending on SD in short skidding distance SLM is preferable to LLM but in cases of long skidding distance LLM is more economical than SLM. The winching distance affect was not a factor on cost.
To assess the damage on seedlings and standing trees a 100% inventory method was employed in pre-hauling and post-hauling, alongside of skidding trails, winching strips and mule hauling with a 12m width. To chose the best alternative depending on standing damage the Analysis of multiple criterial approval (MA) was applied. The amount of trees damaged by winching operation were 11.89% in TLM, 14.44% in LLM 27.59%, SLM and 0 stem and by skidding operation were 16.73%, 3.13% and 8.78% of total trees in TLM, LLM and SLM. In the winching area about 14%, 20%, 21% and 6 % of the total regeneration was damaged by TLM, LLM, SLM and mule and the skidding operation damaged 7.5% in TLM, 7.4 % LLM and 9.4% in SLM. The friendliest alternative to residual standing was mule but in manual method (where the wood extraction is done by skidder) MA showed that the best alternative depending on residual damage is LLM.
To determine the degree of soil compaction a core sampling technique of bulk density was used. Soil samples collected from the horizontal face of a soil pit at 10 cm depth soil core, at 50m intervals on skid trials, in winching strips and control are (no vehicles pass) a soil sample was taken at 10m intervals in the hauling direction of the mule. In order to determine the post-harvesting extent of disturbance on skidding trails by skidding operations, the disturbed widths were measured at 50 m intervals along the skid trails. In the winching area, where the winched logs created a streak of displaced soil, the width of the displaced streak was measured at 5 m interval along the winching strip. In mule hauling operations the width of a streak created by a mule foot track was measured at 10 m intervals.
To compare increased average bulk density between alternatives one way The ANOVA, Duncan test and Dunnett t-test with a 95 % confidence level were used. A General linear model was applied to relate the increasing bulk density and the slope gradient. To realize the correlation between the increment of soil bulk density and the slope gradient and the correlation between the soil compaction and soil moisture content (%) The Pearson correlation test was applied. To choose the best alternative (in manual method) a MA test was applied again. The bulk density on the skidding trail increased 51 % for 30 skidding turn, 35 % for 31 skidding turn (one unloaded and one loaded pass) and 46% for 41 skidding turn. Results of ANOVA (p < 0.05) show significant differences of bulk density between alternatives. Duncan test and the Dunnett t-test indicated that the increasing soil bulk density was not significant between control samples and winching strip of TLM and extraction by mule samples.
The general linear modeling and Pearson correlation test results indicated that the slope gradient had an insignificant effect on soil compaction, whilst the Pearson test indicates a medium negative correlation between soil compaction and percentage of soil moisture. By ground-based winching operation 0.07%, 0.03%, 0.05% and 0.002% of the total area and by ground based skidding operation 1.21%, 1.67%, 0.81% and 0.00% of total area was disturbed and compacted in TLM, LLM, SLM and mule. The Pearson correlation results show that the width of disturbed area was significantly influenced by the diameter of logs and length of logs (p ˂ 0.05), but there is no significant correlation between soil disturbance width and slope. The results of analysis of MA showed that soil compaction was not related to logging method but sensitivity analysis of MA shows that LLM and TLM are both preferable to SLM.
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Östlund-Lagerström, Lina. "Effect of long-term ultra-endurance training on telomere length and telomere regulatory protein expressions in vastus lateralis of healthy humans." Thesis, Örebro universitet, Hälsoakademin, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-15859.
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Johansson, Mikael. "Skriva för framtiden : En studie om flerspråkiga elevers skrivutveckling i årskurs 5." Thesis, Linnéuniversitetet, Institutionen för svenska språket (SV), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-54454.
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Abstract The aim of this study was to investigate how a group of pupils developed in their written language in grade 5. The study proceeds from my hypothesis that a number of textual variables, such as average text length, average sentence length, the average length of the initial clause constituent, and the proportion of long words, ought to rise during a term. The material consists of over 600 texts written by 14 pupils. All the texts are analysed with the LIX tool available on the Internet. The texts are entered into the LIX counter which then returns a value for the studied variables. This procedure was performed for all the variables except initial clause constituent length. That is instead calculated manually by counting the number of words per initial clause constituent. The result shows that all the variables except the proportion of long words increase during the term. The average text length is the variable with the most noticeable increase during the whole term. The proportion of long words, however, did decrease during the same period. The results also show a great correspondence with earlier research on upper secondary pupils’ writings. This means that the group of 11 years old multilingual pupils in this study write with the same proficiency as 16–19 years old pupils, as regards the variables average text length, average sentence length and the average length of the initial clause constituent.
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Leitch, David B. "Predictive patterns of institutional misconduct, pro-social behavior, and length of stay of incarcerated youth in a secure, long-term, juvenile rehabilitation facility." Kent State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=kent1529614192152508.
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Parveen, Bushra. "Fibre Orientation and Breakage in Glass Fibre Reinforced Polymer Composite Systems: Experimental Validation of Models for Injection Mouldings. Validation of Short and Long Fibre Prediction Models within Autodesk Simulation Moldflow Insight 2014." Thesis, University of Bradford, 2014. http://hdl.handle.net/10454/14865.
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End-gated and centre gated mouldings have been assessed with varying thickness and sprue geometries for the centre gate. Alternative image analysis techniques are used to measure the orientation and length of injection moulded short and long fibres composite components. The fibre orientation distribution (FOD) measurements for both geometries have been taken along the flow path. In shear flow the FOD changes along the flow path, however the FOD remains relatively constant during expansion flow. The core width and FOD at the skin within a long glass fibre (LGF) specimen is different in comparison to a short glass fibre (SGF) specimen. Fibre length measurements have been taken from the extrudate, sprue and 2 positions within the centre gate cavity. The size of the sprue has little influence on fibre breakage if the moulding is more than 1 mm thick The SGF FOD prediction models within Autodesk Simulation Moldflow Insight 2014 (ASMI) have been validated against measured SGF data. At present, by default, the models over-predict the < cos2θ > for most geometries. When the coefficients are tailored for each model, drastic improvements are seen in the FOD prediction. The recently developed SGF RSC model accurately predicts the FOD in shear, in a thin geometry, whereas the Folgar-Tucker model predicts the FOD accurately in expansion flow. The measured LGF fibre length distribution (FLD) and FOD have been validated against the LGF prediction models. The LGF models are currently under predicting the breakage and over-predicting < cos2θ >. The breakage prediction improves if measured FLD of the extrudate is input into the model.
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Allen, Beverlin. "Pressure ulcers and nutritional deficits in elderly long-term care patients : effects of a comprehensive nutritional program on pressure ulcer healing, length of hospital stay and charges to patients." FIU Digital Commons, 2010. http://digitalcommons.fiu.edu/etd/1095.
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The elderly are at the highest risk of developing pressure ulcers that result in prolonged hospitalization, high health care costs, increased mortality, and decreased quality of life. The burden of pressure ulcers will intensify because of a rapidly increasing elderly population in the United States (US). Poor nutrition is a major predictor of pressure ulcer formation. The purpose of this study was to examine the effects of a comprehensive, interdisciplinary nutritional protocol on: 1) pressure ulcer wound healing 2) length of hospital stays, and 3) charges for pressure ulcer management. Using a pre-intervention/post intervention quasi-experimental design the study sample was composed of 100 patients 60 years or older, admitted with or acquiring a pressure ulcer. A pre-intervention group (n= 50) received routine pressure ulcer care (standard diet, dressing changes, and equipment). A post-intervention group received routine care plus an interdisciplinary nutrition intervention (physical therapy, speech therapy, occupational therapy, added protein and calories to the diet). Research questions were analyzed using descriptive statistics, frequencies, Chi-Square Tests, and T-tests. Findings indicated that the comprehensive, interdisciplinary nutritional protocol had a significant effect on the rate of wound healing in Week3 and Week4, total hospital length of stay (pre-intervention M= 43.2 days, SD=31.70 versus M=31.77, SD=12.02 post-intervention), and pressure ulcer length of stay (pre-intervention 25.28 days, SD5.60 versus 18.40 days, SD 5.27 post-intervention). Although there was no significant difference in total charges for the pre-intervention group ($727,245.00) compared to the post-intervention group ($702,065.00), charges for speech (m=$5885.12, SD=$332.55), pre albumin (m=$808.52,SD= $332.55), and albumin($278 .88, SD=55.00) were higher in the pre-intervention group and charges for PT ($5721.26, SD$3655.24) and OT($2544 .64, SD=1712.863) were higher in the post-intervention group. Study findings indicate that this comprehensive nutritional intervention was effective in improving pressure ulcer wound healing, decreasing both hospital length of stay for treatment of pressure ulcer and total hospital length of stay while showing no significant additional charges for treatment of pressure ulcers.
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Persson, Maria, and Emma Ericsson. "Bra jobbat pojkar! : En kvantitativ studie av skillnader i flerspråkiga flickors och pojkars skrivande." Thesis, Linnéuniversitetet, Institutionen för svenska språket (SV), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-70973.
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Syftet med studien är att undersöka eventuella skillnader i flickors och pojkars skrivande under grundskolans tidigare år. I studien undersöks dagbokstexter skrivna av flerspråkiga flickor och pojkar i årskurs tre. Fokus ligger på att undersöka elevernas text- och meningslängd, långord samt nominalkvot. Tidigare forskning utförd på elever i årskurs nio samt på gymnasiet visar att pojkar tagit ett steg närmare flickorna i vissa aspekter i sin skriftliga komplexitet. Vår studie om elevers skrivande i årskurs tre talar till och med för att pojkarna gått förbi flickorna. Materialet består av tio dagböcker skrivna av sex flickor och fyra pojkar. I studien delar vi in eleverna som skriver texterna i flickor och pojkar, och vi förutsätter därmed att det finns vissa skillnader mellan dem som påverkar deras skriftspråksutveckling. Vi utgår från en positivistisk vetenskapsteori med en viss kvantitativ ansats och med tydligt mätbara textaspekter. De skillnader som studien visar är att pojkar skriver längre texter, har högre nominalkvot samt använder fler långord. Flickorna skriver däremot längre meningar än pojkar.
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Sanz, Martín Marina. "Effects of CO2 and long day length on primary productivity in the Arctic Ocean: a perspective on climate change = Efectos del CO2 y largos fotoperiodos en la productividad primaria del Océano Ártico: una perspectiva sobre el cambio climático." Doctoral thesis, Universitat de Barcelona, 2018. http://hdl.handle.net/10803/563077.
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Climate change, caused by anthropogenic emissions of carbon dioxide (CO2) and other greenhouse gasses into the atmosphere, is producing profound impacts on ecosystems. The Arctic Ocean is one of the most vulnerable regions of the world and is experiencing the most substantial effects of climate change. This region is characterized by strong seasonality with highly productive episodes, called phytoplankton blooms, that together with the entrance of ice-melt, reduce the CO2 concentration in seawater (from about 370 to 130 μatm). During spring and summer, the low CO2 concentrations might limit the photosynthesis of marine plants and algae. However, during these periods the increase of atmospheric and oceanic CO2 may stimulate the primary productivity in the Arctic Ocean.
Increased atmospheric CO2 is directly related with Arctic warming and the consequent acceleration of glaciers and sea-ice melting. During spring and summer, the ice cover retreat increases the light irradiance in submersed areas and ice-free areas become more frequent. An increase of ice-free waters may probably favour the expansion of marine vegetation into the Arctic and the migration of subarctic species to northern regions, characterized by long day length in summer.
Since pelagic and benthic ecosystems contribute largely to the primary productivity of the Arctic Ocean, in this thesis I investigate the experimental effects of two abiotic factors: increased CO2 and long day length. These effects have been tested on planktonic communities in surface waters and benthic macrophytes in subarctic and Arctic ecosystems. In parallel, I investigate the relationship between planktonic primary production rates estimated with three different methods: the O2 mass balance, the 18O method and the 14C method. This comparison of methods has been carried out for the first time in the Arctic Ocean, specifically in the north and northwest of the Svalbard shelf, and we conclude that the 14C method, with incubations of 24 h, underestimate the gross primary productivity measured with the O2-based methods, although the relationships change seasonally. In spring, the O2-based methods are the most appropriate methods to estimate the gross primary productivity while in summer both C and O2-based method are adequate. Therefore, the O2-based methods were applied to investigate the possible limitation of CO2 in planktonic communities in two regions of the Arctic Ocean. With this aim, we carried out experiments of CO2 additions in spring and summer in the west and northwest of the Svalbard shelf and observed that the stimulation was restricted to highly productive episodes, when CO2 concentrations were already low and nutrients concentrations were low but still present in seawater.
To determine the periods of CO2 limitation, I carried out weekly experiments of increased CO2 during the development of a phytoplankton bloom, from March to late May in 2016 in Godthåbsfjord, southwestern of Greenland. We observed that during approximately two weeks after the bloom reached its maximum production, called the peak bloom stage, the phytoplankton community was limited by the low CO2 concentrations. During this window of time the net primary production rates increased with increasing CO2 concentrations in presence of dissolved inorganic nutrients.
Additionally, we experimentally evaluated the effects of long day length, characteristic of Arctic summers, and the effect of increased CO2. on three subarctic macrophytes species: Ascophyllum nodosum, Fucus vesiculosus and Zostera marina. We observed that their photosynthetic activity, measured as the electron transport rate, were highest at long day length. Increased CO2 also had a positive, though non-significant effect on the macroalgae species A. nodosum and on the seagrass Z. marina. Therefore, these species will benefit from increased day length as they expand in the Arctic and migrate poleward with decreasing ice cover.
The results of the present thesis suggest that present and future increases of CO2 concentrations are likely to enhance the contribution of the spring bloom to the annual primary production budget in Arctic and subarctic waters. Moreover, long day length will benefit the expansion and poleward migration of the subarctic species investigated. In this thesis, I present experimental evidence of the effects of climate change in pelagic and benthic ecosystems in two regions of the Arctic Ocean, contributing to the field of climate change ecology in the marine environment. Besides, the comparative study of primary production methodologies contributes to the field of Arctic oceanography by which aids in developing further investigation and expectations conducive to forming conclusions on how climate change will affect the Arctic Ocean in the future.El cambio climático, causado por la emisión antropogénica de dióxido de carbono (CO2) y otros gases de efecto invernadero a la atmósfera, está produciendo grandes cambios en los ecosistemas. El Océano Ártico es una de las regiones más vulnerables del mundo y por ello en esta región se están produciendo cambios sustanciales. El Ártico se caracteriza por una fuerte estacionalidad con episodios altamente productivos, llamados floraciones o blooms de fitoplancton, que, junto con la entrada de agua de deshielo, reducen la concentración de CO2 en el agua de mar (de 370 a 130 μatm aproximadamente). Durante primavera y verano, las bajas concentraciones de CO2 pueden limitar la fotosíntesis de plantas y algas marinas. Sin embargo, durante estos periodos, el aumento global de CO2 atmosférico y oceánico podría estimular la producción primaria en aguas árticas y subárticas. El aumento de CO2 atmosférico está directamente relacionado el calentamiento del Ártico y la consecuente aceleración de la pérdida de glaciares y hielo marino. El retroceso de la cubierta de hielo en primavera y en verano está aumentado la entrada de luz en zonas sumergidas, y las zonas libres de hielo son más frecuentes. El aumento de aguas sin hielo marino podría favorecer la expansión de vegetación marina en el Ártico y la migración de especies subárticas hacia el norte, donde las horas de luz diaria alcanzan las 24 h. Debido a la importante contribución de ecosistemas pelágicos y bentónicos a la productividad primaria del Océano Ártico, en esta tesis he investigado los efectos experimentales de dos factores abióticos: el aumento de CO2 y largos fotoperiodos. Estos efectos han sido evaluados en comunidades planctónicas de aguas superficiales y en macrófitos bentónicos de ecosistemas subárticos y Árticos. De forma paralela, he investigado la relación de las tasas de producción primaria planctónica estimadas a través de tres métodos diferentes: el método de balance de oxígeno, el método de 18O y el método de 14C. Esta comparación se ha realizado por primera vez en el Océano Ártico y concluimos que el método de 14C, con incubaciones de 24 h, subestima la producción primaria bruta medida con los métodos basados en oxígeno, aunque las relaciones cambian estacionalmente. En primavera, periodo de alta producción, los métodos basados en oxígeno son los más apropiados para estimar de la producción primaria bruta mientras que en verano ambos métodos, basados en carbono y en oxígeno, son adecuados. Por ello, estos métodos se emplearon para investigar la posible limitación de CO2 en comunidades planctónicas del Océano Ártico. Con este objetivo realizamos experimentos de adición de CO2 en primavera y en verano en el oeste y noroeste de Svalbard y observamos que la estimulación estaba restringida a episodios de alta productividad, cuando las concentraciones de CO2 ya habían bajado y los nutrientes inorgánicos seguían presentes en el agua a bajas concentraciones. Para determinar el periodo de limitación de CO2, realicé experimentos semanales de aumento de CO2 durante el desarrollo de una floración de fitoplancton, desde Marzo hasta finales de Mayo de 2016 en Godthåbsfjord, al suroeste de Groenlandia. En estos experimentos, observamos que durante dos semanas aproximadamente y después de que la floración alcanzase su máxima producción, el llamado peak bloom stage, la comunidad fitoplanctónica está limitada por las bajas concentraciones de CO2. Durante este periodo de tiempo, las tasas de producción primaria neta aumentaron con el aumento de la concentración de CO2 en presencia de nutrientes inorgánicos disueltos. Además, hemos evaluado experimentalmente el efecto de largos fotoperiodos, característicos de la temporada de verano en el Océano Ártico, y el efecto del aumento de CO2 en tres especies de macrófitos subárticos: Ascophyllum nodosum, Fucus vesiculosus y Zostera marina. Hemos observado que la actividad fotosintética, medida como la tasa de transporte de electrones, era mayor en el fotoperiodo de luz continua. El aumento de CO2 también tuvo un efecto positivo, pero no significativo, en la especie de macroalga A. nodosum y en la fanerógama Z. marina. Por ello, estas tres especies se beneficiarán del aumento de horas de luz a medida en que se expandan y migren hacia el norte, siguiendo el retroceso de la cubierta de hielo. Los resultados de esta tesis sugieren que el presente y el futuro aumento de las concentraciones de CO2 incrementan la contribución de la floración de fitoplancton primaveral al balance de la producción primaria anual en aguas Árticas y subárticas. Además, el fotoperiodo de luz continua favorecerá la expansión y la migración hacia el norte de tres especies de macrófitos subárticos. En esta tesis presento evidencias experimentales sobre los efectos del cambio climático en comunidades planctónicas superficiales y en tres especies de macrófitos bentónicos en dos regiones del Océano Ártico, contribuyendo al conocimiento de la disciplina de la ecología del cambio climático en el medio marino y contribuyendo a la disciplina de la oceanografía ártica con el estudio comparativo de las metodologías de producción primaria en esta región, fomentando el desarrollo de futuros estudios y predicciones de los efectos del cambio climático en el Océano Ártico.
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Santos, Ana Rita Oliveira dos. "Impacto dos casos sociais no tempo de internamento hospitalar em Portugal." Master's thesis, Instituto Superior de Economia e Gestão, 2018. http://hdl.handle.net/10400.5/17085.
Full textAbstract:
Mestrado em Métodos Quantitativos para a Decisão Económica e EmpresarialOs pacientes internados no hospital com um prolongamento da alta hospitalar por razões não clínicas têm sido um tema importante no contexto da sustentabilidade dos sistemas nacionais de saúde. Na primeira parte é apresentada uma revisão da literatura na definição e perfil internacional destes pacientes. A segunda parte explora a situação portuguesa utilizando dados de 2015 referentes a meio milhão de pacientes em Portugal Continental. A terceira parte consiste na estimação de um modelo da Binomial Negativa para identificar as diferenças no tempo de internamento entre um paciente Caso Social e um Não Social. Da revisão da literatura realizada, constata-se que não existe uma definição única universal de Casos Sociais. Estes pacientes representam uma população de idade avançada, com diversas comorbilidades, apresentando estado de fragilidade e dependência, muitas vezes vivendo sozinhos ou em instituições residenciais. O prolongamento de alta destes pacientes está associado a fatores organizativos, socioeconómicos e clínicos. O perfil do Caso Social português é semelhante ao perfil internacional. Estima-se que a nível nacional correspondam a 3% dos pacientes internados. Em 2015, 50% destes pacientes concentra-se em Lisboa e as principais causas associadas prendem-se a falta de cuidador informal e o facto de o paciente viver sozinho. Os resultados do modelo confirmam que os Casos Sociais tendem a ter um tempo de internamento superior aos casos não sociais, mas a diferença é reduzida. Pode ser de interesse uma análise mais detalhada para pacientes outliers com mais de 30 dias de internamento onde a incidência de Casos Sociais é maior.
Hospital patients with a prolonged length of stay due to non-medical reasons have become a important topic of discussion in the context of sustainability of national health systems. The first part of this paper provides an extensive literature review on the definitions and international profile of these patients. The second part explores the Portuguese situation using 2015 data of half a million inpatients in mainland Portugal. The third part consists in the estimation of a binomial negative model to identify the differences in length of stay between Social Cases and a Non-Social cases. Given the existing literature, there is no unique and universal definition for these patients. Social cases tend to represent an older population, with several comorbidities, in a frail and dependent state, oftentimes living alone or in nursing homes. Their extended length of stay is mainly associated with organizational, clinical and socio-economic factors. Social cases in Portugal have a profile similar to their international counterparts and represent 3% of total inpatients in public hospitals. In 2015, 50% of them are concentrated in Lisbon area and the main causes for being considered social cases is lack of a caregiver and living alone. The model confirms that social case patients tend to have a longer length of stay compared to non-social cases, but the difference tends to be small. It could be of interest to conduct a more detailed analysis on outlier patients with more than 30 days of bed, where the incidence of social cases is more significant.
info:eu-repo/semantics/publishedVersion
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Bernotaitytė, Aistė. "Lietuvos ir pasaulio šuolininkių į tolį moterų paskutiniųjų bėgimo žingsnių ir atsispyrimo biomechaninių parametrų įtaka šuolio į tolį sportiniam rezultatui." Bachelor's thesis, Lithuanian Academic Libraries Network (LABT), 2013. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2013~D_20130910_083047-89152.
Full textAbstract:
Tyrimo objektas. Žingsnių greitis ir ilgis bei išlėkimo greitis ir kampas.
Tyrimo tikslas. Ištirti Lietuvos ir Pasaulio šuolininkių į tolį moterų paskutiniųjų bėgimo žingsnių greičio ir ilgio bei išlėkimo greičio ir kampo įtaką sportiniam rezultatui.
Tyrimo uždaviniai: 1. Nustatyti ir palyginti Pasaulio ir Lietuvos šuolininkių į tolį paskutiniųjų įsibėgėjimo žingsnių greičio kitimą ir jo įtaką sportiniam rezultatui. 2. Nustatyti ir palyginti Pasaulio ir Lietuvos šuolininkių į tolį paskutiniųjų įsibėgėjimo žingsnių ilgio kitimą ir jo įtaką sportiniam rezultatui 3. Nustatyti ir palyginti Pasaulio ir Lietuvos šuolininkių į tolį išlėkimo greitį ir jo įtaką sportiniam rezultatui. 4. Nustatyti ir palyginti Pasaulio ir Lietuvos šuolininkių į tolį išlėkimo kampą ir jo įtaką sportiniam rezultatui.
Tiriamieji. Buvo analizuojamos Pasaulio šuolininkės dalyvavusios 12 Pasaulio lengvosios atletikos čempionate Berlyne (n=8). Lietuvos šuolininkių testavimas atliktas Lietuvos studentų čempionate (2012 m.) Kauno manieže (n=10).
Hipotezė. Didelę įtaką šuolio į tolį rezultatui turi bėgimo greitis paskutiniuose metruose prieš atsispyrimą bei išlėkimo greitis ir kampas.
Pagrindiniai rezultatai. Pasaulio šuolininkių į tolį greitis paskutiniajame žingsnyje yra 9.33±0,19 m/s, Lietuvos 7.76±0,41 m/s. Pasaulio šuolininkių priešpaskutinis žingsnis yra 2,31±0,17 m, Lietuvos 2,09±0,15 m, paskutinis žingsnis sutrumpėja palyginus su priešpaskutiniuoju 0,24 m, ir 0,06 m atitinkamai. Lietuvos... [toliau žr. visą tekstą]Research object: Speed and length of the running steps, take off speed and angle. Research goal: To analyze Lithuanian and World female long jumpers –discuss influence of the speed of last running steps as well as takeoff to the performance in the competition. Research tasks: 1. To identify and compare speed ofLithuanian and World long jumpersin the last runningsteps and its influence to the performance in the competition. 2. To identify and compare length of Lithuanian and World long jumpersin the last runningsteps and its influence to the performance in the competition. 3. To identify and compare take off speed of Lithuanian and World long jumpers and its influence to the performance in the competition. 4. To identify and compare take off angle of Lithuanian and World long jumpers and its influence to the performance in thecompetition. Subjects of this research: World’s top female long jumpers who participated at the 12th Athletics Championship in Berlin (n=8). Lithuanian long jumpers who were tested at the Student Athletics Championship in Kaunas in 2012 (n=10). Hypothesis: Significant influence to the result in the long jumps comes from the running speed in the last meters before the take off, also take off speed and angle. Main results: Speed of top World top female long jumpers in the last running step is 9.33±0,19 m/s, meanwhile of Lithuanians 7.76±0,41 m/s. Length of the last step of the World female long jumpers is 2,31±0,17 m, Lithuanians 2,09±0,15 m. The last step... [to full text]
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Gouveia, Bruno Pauka. "Modelo de mistura padrão com tempos de vida exponenciais ponderados." Universidade Federal de São Carlos, 2010. https://repositorio.ufscar.br/handle/ufscar/4544.
Full textAbstract:
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In this work, we brie_y introduce the concepts of long-term survival analysis. We dedicated ourselves exclusively to the standard mixture cure model from Boag (1949) and Berkson & Gage (1952), showing its deduction and presenting the imunes probability function, which is taken from the model itself and we investigated the identi_ability issues of the mixture model. Motivated by the possibility that a experiment design can lead to a biased sample selection, we studied the weighted probability distributions, more speci_cally the weighted exponential distributions family and its properties. We studied two distributions that belong to this family; namely, the length biased exponential distribution and the beta exponential distribution. Using the GAMLSS package in R, we made some simulation studies intending to evidence the bias that occur when the possibility of a weighted sample is ignored.
Neste trabalho apresentamos brevemente os conceitos que de_nem a análise de sobreviv ência de longa duração. Dedicamo-nos exclusivamente ao modelo de mistura padrão de Boag (1949) e Berkson & Gage (1952), sendo que nos preocupamos com sua formulação, apresentamos a função probabilidade de imunes, que é derivada do próprio modelo e investigamos a questão da identi_cabilidade. Motivados pela possibilidade de que um planejamento experimental leve a uma seleção viciada da amostra, estudamos as distribui ções ponderadas de probabilidade, mais especi_camente a família das distribuições exponenciais ponderadas e suas propriedades. Estudamos duas distribuições pertencentes a essa família, a distribuição exponencial length biased e a distribuição beta exponencial. Fazendo uso do pacote GAMLSS em R, realizamos alguns estudos de simulação com o intuito de evidenciar o erro cometido quando se ignora a possibilidade de que a amostra seja proveniente de uma distribuição ponderada.
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Eckfeldt, Lars. "Möglichkeiten und Grenzen der Berechnung von Rissbreiten in veränderlichen Verbundsituationen." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2005. http://nbn-resolving.de/urn:nbn:de:swb:14-1138179912681-09751.
Full textAbstract:
Die vorliegende Arbeit reflektiert die aktuelle Diskussion von Modellen zur Vorhersage von Rissbreiten und versucht, objektive Vergleichskriterien aufzustellen sowie Folgerungen für mögliche Lösungswege zu ziehen. Am Beginn steht eine ausführliche Auseinandersetzung mit dem Verbundmechanismus zwischen Betonstahl und Beton und den Möglichkeiten der Verbundanalyse. Ausgehend von eigenen Versuchen an kurzen Verbundlängen zur Untersuchung des Verbundverhaltens von Bewehrung in hochfesten Betonen wird in der Arbeit nach Möglichkeiten zur Vorhersage von Gleit- und Sprengbrüchen gesucht. Für Sprengbrüche, also Längsrissbildung, ist ein verbesserter Versuchsaufbau entwickelt worden, der Rückschlüsse auf die Verformungsentwicklung in der potentiellen Sprengbruchfläche und den Aufbau eines Verbundwiderstands unter Belastung ermöglicht. Es stellte sich trotz der Fortschritte in der Versagensanalyse dieser Versuche heraus, dass es wenig sinnvoll ist, die gewonnenen Verbundgesetze direkt auf lange Verbundlängen zur Ermittlung von Rissbreiten anzuwenden. Zur Simulation der mit Bauteilsituationen vergleichbaren langen Verbundlängen wird dagegen eine Hypothese über den Widerstand einer potentiellen Längsbruchfläche verwendet. Dabei wird die mögliche Reaktion von gekoppelten und voneinander abhängigen Betonzugringen um einen Betonstahl, vom Lasteintrag beginnend, sukzessive fortschreitend aufgebaut. Die Aufteilung der Zugringe folgt dabei einer Annahme über die Entwicklung von lokalen Verbundrissen nach Goto. Damit ist die Zugringtheorie von Tepfers auf lange Verbundlängen übertragbar und Simulationen von Zugstäben nahe an Tepfers theoretischen Ansätzen werden so ermöglicht. Die Rechnersimulationen an langen Verbundlängen im Vergleich zur Prognose nach MC 90 wurden für Einzelrissbildung und abgeschlossene Rissbildung an zylindrischen Dehnkörpergeometrien durchgeführt. Zur Verifizierung der zeitabhängigen Einflüsse wie Zwängungen aus Schwinden und Zugkriechen sind einfache Ansätze entwickelt worden. Am Ende dieser Analysen steht eine Neubewertung normativer Ansätze (MC 90/DIN 1045-1 sowie EN 1992-1-1) zur Berechnung einer charakteristischen Rissbreite. Eine Schlüsselstellung nimmt die richtige Prognose des wirksamen Rissabstands in allen Berechnungsmodellen ein. Anhand eines neu zusammengestellten Datensatzes und vorhandener Vergleichsdatensätze wurde die Performance der Modelle untersucht. Anwendungsbereiche, die problematisch erscheinen, konnten eingegrenzt werden. Es war zu folgern, dass die Ansätze für den effektiven Bewehrungsgrad und die Verbundspannung zu verbessern sind. Die daraufhin mit einem additiven Sicherheitselement und einem variablen Mindestwert entwickelte Modellalternative gegenüber den normativen Vorschlägen ist nun zielgerichteter und kann dabei eine effektivere und zuverlässigere Prognose der Rissbreite und damit der konstruktiven Bewehrungslösung liefern. Die Anforderungen an die Performance eines Rechenwertes der Rissbreite wk sind um ein Effektivitätskriterium für den Rissabstand srk ergänzt worden, dessen Vorhersagequalität entscheidend für effiziente und zuverlässige Vorhersagen der Rissbreite ist. Die Zuverlässigkeit des DIN-Ansatzes für Mindestbewehrung im Grenzzustand der Gebrauchstauglichkeit ist ebenfalls geprüft worden. Umfangreiche Zusammenstellungen, Beispiele und Parameterstudien sind im Anhang der Arbeit hinzugefügt, um die theoretischen Ergebnisse zu stützen und Lesern Vergleichsmöglichkeiten zu bieten. Dazu gehören auch zwei Ablaufpläne und Hilfsmittel für einfache Absicherungen, die die zu erwartenden Schwierigkeiten bei der Verwendung des normativen DIN 1045-1 Ansatzes zur Beschränkung auf kleine Rissbreiten ausgleichen könnenThe doctoral thesis reflects the recent discussion on the finding of suitable verification models for crack width control. It tries to assemble criteria for the comparison in order to draw conclusions from the outcome. In the very beginning stands a widespread analysis of the bond mechanisms between the reinforcing steel and the concrete. Starting from own testing on short embedment lengths in HPC, opportunities are researched for the prediction of a sliding or splitting failure of the surrounding concrete during bar pull-out. An improved test setup is developed by the Author to verify the splitting failure mechanism that finally leads to longitudinal cover cracking. It enables to obtain better indications for the inner strain development in the later failure plane, showing the development of the bond resistance during loading. Although progress were made in the quality of analysis, it turned out that, a direct implementation of obtained bond laws is less successful to take care of the apparent problem of long embedment lengths. The description of that problem is essential within the crack width verification. Differently, a method is suggested to simulate a probable longitudinal splitting plane and its potential to resist an applied longitudinal load. In that method, the possible reaction of interlinked concrete tension rings around a steel bar is thought to form a growing global resistance with every added resistance ring in a sequential chain that are decreasingly loaded if the distance to the load application increases. The segmentation follows an approximation of the possibly development of local bond cracks acc. to Goto. In this, the application of the tension ring theory from Tepfers were successfully overtaken to the problem of long embedment lengths. It enables for simulations close to the original theory of tensile rings formed by concrete around the reinforcing steel. Comparing the results with MC 90, the simulation of long embedment lengths were performed using imaginary cylindrical test-specimen, enabling the verification of single and stabilized cracking. Simplified methods were developed in order to implement time-dependent influences like restraint from creep and shrinkage.An extensive evaluation of the normative methods (MC 90/ DIN 1045-1 and EN 1992-1-1) for verifications of a characteristic crack width stands at the end of the studies. A key position within the models is held by the realistic prognosis of the accountable crack distance. Using a newly compiled dataset and already existing data for comparison, the performances of current models were verified for predicting crack widths or distances. Complicated fields of its application could be marked and isolated. It was concluded that, the approaches for the determination of the effective reinforcement ratio and the bond stress should be improved. The developed alternative for calculation is assembled with an added safety feature and a variable minimum for the crack distance. It can lead to a more reliable prognosis for crack distances and the depending crack widths in order to design a more efficient reinforcement detailing. The requirements on the performance of a determined characteristic crack width wk are extended by the application of a criteria of effectiveness for the calculated crack distance srk. The reliability of the MC 90 -approach and the DIN-approach for minimum reinforcement has also been checked. Extensive compilations of data, examples and parameter studies are added to the appendix in order to backup the theoretical results and to invite others to compare. Two calculation flow charts and helptools are integrated to ensure the quality of crack width calculations also in cases where smaller crack widths must be verified, using informative and normative methods in MC 90/ DIN 1045-1
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Eckfeldt, Lars. "Möglichkeiten und Grenzen der Berechnung von Rissbreiten in veränderlichen Verbundsituationen." Doctoral thesis, Technische Universität Dresden, 2004. https://tud.qucosa.de/id/qucosa%3A24631.
Full textAbstract:
Die vorliegende Arbeit reflektiert die aktuelle Diskussion von Modellen zur Vorhersage von Rissbreiten und versucht, objektive Vergleichskriterien aufzustellen sowie Folgerungen für mögliche Lösungswege zu ziehen. Am Beginn steht eine ausführliche Auseinandersetzung mit dem Verbundmechanismus zwischen Betonstahl und Beton und den Möglichkeiten der Verbundanalyse. Ausgehend von eigenen Versuchen an kurzen Verbundlängen zur Untersuchung des Verbundverhaltens von Bewehrung in hochfesten Betonen wird in der Arbeit nach Möglichkeiten zur Vorhersage von Gleit- und Sprengbrüchen gesucht. Für Sprengbrüche, also Längsrissbildung, ist ein verbesserter Versuchsaufbau entwickelt worden, der Rückschlüsse auf die Verformungsentwicklung in der potentiellen Sprengbruchfläche und den Aufbau eines Verbundwiderstands unter Belastung ermöglicht. Es stellte sich trotz der Fortschritte in der Versagensanalyse dieser Versuche heraus, dass es wenig sinnvoll ist, die gewonnenen Verbundgesetze direkt auf lange Verbundlängen zur Ermittlung von Rissbreiten anzuwenden. Zur Simulation der mit Bauteilsituationen vergleichbaren langen Verbundlängen wird dagegen eine Hypothese über den Widerstand einer potentiellen Längsbruchfläche verwendet. Dabei wird die mögliche Reaktion von gekoppelten und voneinander abhängigen Betonzugringen um einen Betonstahl, vom Lasteintrag beginnend, sukzessive fortschreitend aufgebaut. Die Aufteilung der Zugringe folgt dabei einer Annahme über die Entwicklung von lokalen Verbundrissen nach Goto. Damit ist die Zugringtheorie von Tepfers auf lange Verbundlängen übertragbar und Simulationen von Zugstäben nahe an Tepfers theoretischen Ansätzen werden so ermöglicht. Die Rechnersimulationen an langen Verbundlängen im Vergleich zur Prognose nach MC 90 wurden für Einzelrissbildung und abgeschlossene Rissbildung an zylindrischen Dehnkörpergeometrien durchgeführt. Zur Verifizierung der zeitabhängigen Einflüsse wie Zwängungen aus Schwinden und Zugkriechen sind einfache Ansätze entwickelt worden. Am Ende dieser Analysen steht eine Neubewertung normativer Ansätze (MC 90/DIN 1045-1 sowie EN 1992-1-1) zur Berechnung einer charakteristischen Rissbreite. Eine Schlüsselstellung nimmt die richtige Prognose des wirksamen Rissabstands in allen Berechnungsmodellen ein. Anhand eines neu zusammengestellten Datensatzes und vorhandener Vergleichsdatensätze wurde die Performance der Modelle untersucht. Anwendungsbereiche, die problematisch erscheinen, konnten eingegrenzt werden. Es war zu folgern, dass die Ansätze für den effektiven Bewehrungsgrad und die Verbundspannung zu verbessern sind. Die daraufhin mit einem additiven Sicherheitselement und einem variablen Mindestwert entwickelte Modellalternative gegenüber den normativen Vorschlägen ist nun zielgerichteter und kann dabei eine effektivere und zuverlässigere Prognose der Rissbreite und damit der konstruktiven Bewehrungslösung liefern. Die Anforderungen an die Performance eines Rechenwertes der Rissbreite wk sind um ein Effektivitätskriterium für den Rissabstand srk ergänzt worden, dessen Vorhersagequalität entscheidend für effiziente und zuverlässige Vorhersagen der Rissbreite ist. Die Zuverlässigkeit des DIN-Ansatzes für Mindestbewehrung im Grenzzustand der Gebrauchstauglichkeit ist ebenfalls geprüft worden. Umfangreiche Zusammenstellungen, Beispiele und Parameterstudien sind im Anhang der Arbeit hinzugefügt, um die theoretischen Ergebnisse zu stützen und Lesern Vergleichsmöglichkeiten zu bieten. Dazu gehören auch zwei Ablaufpläne und Hilfsmittel für einfache Absicherungen, die die zu erwartenden Schwierigkeiten bei der Verwendung des normativen DIN 1045-1 Ansatzes zur Beschränkung auf kleine Rissbreiten ausgleichen können.The doctoral thesis reflects the recent discussion on the finding of suitable verification models for crack width control. It tries to assemble criteria for the comparison in order to draw conclusions from the outcome. In the very beginning stands a widespread analysis of the bond mechanisms between the reinforcing steel and the concrete. Starting from own testing on short embedment lengths in HPC, opportunities are researched for the prediction of a sliding or splitting failure of the surrounding concrete during bar pull-out. An improved test setup is developed by the Author to verify the splitting failure mechanism that finally leads to longitudinal cover cracking. It enables to obtain better indications for the inner strain development in the later failure plane, showing the development of the bond resistance during loading. Although progress were made in the quality of analysis, it turned out that, a direct implementation of obtained bond laws is less successful to take care of the apparent problem of long embedment lengths. The description of that problem is essential within the crack width verification. Differently, a method is suggested to simulate a probable longitudinal splitting plane and its potential to resist an applied longitudinal load. In that method, the possible reaction of interlinked concrete tension rings around a steel bar is thought to form a growing global resistance with every added resistance ring in a sequential chain that are decreasingly loaded if the distance to the load application increases. The segmentation follows an approximation of the possibly development of local bond cracks acc. to Goto. In this, the application of the tension ring theory from Tepfers were successfully overtaken to the problem of long embedment lengths. It enables for simulations close to the original theory of tensile rings formed by concrete around the reinforcing steel. Comparing the results with MC 90, the simulation of long embedment lengths were performed using imaginary cylindrical test-specimen, enabling the verification of single and stabilized cracking. Simplified methods were developed in order to implement time-dependent influences like restraint from creep and shrinkage.An extensive evaluation of the normative methods (MC 90/ DIN 1045-1 and EN 1992-1-1) for verifications of a characteristic crack width stands at the end of the studies. A key position within the models is held by the realistic prognosis of the accountable crack distance. Using a newly compiled dataset and already existing data for comparison, the performances of current models were verified for predicting crack widths or distances. Complicated fields of its application could be marked and isolated. It was concluded that, the approaches for the determination of the effective reinforcement ratio and the bond stress should be improved. The developed alternative for calculation is assembled with an added safety feature and a variable minimum for the crack distance. It can lead to a more reliable prognosis for crack distances and the depending crack widths in order to design a more efficient reinforcement detailing. The requirements on the performance of a determined characteristic crack width wk are extended by the application of a criteria of effectiveness for the calculated crack distance srk. The reliability of the MC 90 -approach and the DIN-approach for minimum reinforcement has also been checked. Extensive compilations of data, examples and parameter studies are added to the appendix in order to backup the theoretical results and to invite others to compare. Two calculation flow charts and helptools are integrated to ensure the quality of crack width calculations also in cases where smaller crack widths must be verified, using informative and normative methods in MC 90/ DIN 1045-1.
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Olmstead, Claudia. "How long is long enough? : fourth grade English language learners' scores on a state's test and lengths of stay /." Thesis, Connect to this title online; UW restricted, 2004. http://hdl.handle.net/1773/7719.
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Engel, Sebastian. "Chemisch deponierte Schichtsysteme zur Realisierung von YBa2Cu3O7−d-Bandleitern." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1244452357143-40430.
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Die vorliegende Arbeit beschäftigt sich mit der Entwicklung neuer Schichtsysteme für die Realisierung biaxial texturierter hochtemperatursupraleitender Bandleiter. Bisher sind eine Vielzahl von Bandleiterarchitekturen bekannt, die sowohl durch physikalische Depositionsmethoden als auch mittels Abscheidung aus der chemischen Lösung hergestellt werden können. Während die Funktion von YBCO-Bandleitern mit Hilfe physikalischer Depositionsmethoden in den letzten Jahren demonstriert werden konnte, zeigen auf chemischem Wege deponierte Bandleiter schlechtere Eigenschaften. Seitens der Industrie besteht ein starkes Interesse, die hohen Produktionskosten, die im Hinblick auf physikalische Depositionsmethoden mit einem hohen Anlagenaufwand verbunden sind, anhand der kostengünstigen chemischen Synthese von Einzelschichten oder der gesamten Bandleiterarchitektur zu senken. Gelöst wurde diese Aufgabe innerhalb der vorliegenden Arbeit durch die Entwicklung metallorganischer Vorstufenlösungen zur Deposition von CaTiO3-, SrTiO3-Pufferschichten und supraleitender YBa2Cu3O7-Schichten.
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Engel, Sebastian. "Chemisch deponierte Schichtsysteme zur Realisierung von YBa2Cu3O7−d-Bandleitern." Doctoral thesis, Technische Universität Dresden, 2008. https://tud.qucosa.de/id/qucosa%3A23824.
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Die vorliegende Arbeit beschäftigt sich mit der Entwicklung neuer Schichtsysteme für die Realisierung biaxial texturierter hochtemperatursupraleitender Bandleiter. Bisher sind eine Vielzahl von Bandleiterarchitekturen bekannt, die sowohl durch physikalische Depositionsmethoden als auch mittels Abscheidung aus der chemischen Lösung hergestellt werden können. Während die Funktion von YBCO-Bandleitern mit Hilfe physikalischer Depositionsmethoden in den letzten Jahren demonstriert werden konnte, zeigen auf chemischem Wege deponierte Bandleiter schlechtere Eigenschaften. Seitens der Industrie besteht ein starkes Interesse, die hohen Produktionskosten, die im Hinblick auf physikalische Depositionsmethoden mit einem hohen Anlagenaufwand verbunden sind, anhand der kostengünstigen chemischen Synthese von Einzelschichten oder der gesamten Bandleiterarchitektur zu senken. Gelöst wurde diese Aufgabe innerhalb der vorliegenden Arbeit durch die Entwicklung metallorganischer Vorstufenlösungen zur Deposition von CaTiO3-, SrTiO3-Pufferschichten und supraleitender YBa2Cu3O7-Schichten.
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Heikkinen, J. (Juuso). "Recovery of calf muscle isokinetic strength after acute Achilles tendon rupture." Doctoral thesis, Oulun yliopisto, 2017. http://urn.fi/urn:isbn:9789526216195.
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Abstract Achilles tendon rupture (ATR) conservative treatment result usually good clinical outcome, but despite the treatment method calf muscle strength deficit persist. Recent evidence suggests that surgery might surpass conservative treatment in restoring strength after ATR, but structural explanations for surgery-related improved strength remain uncertain. The purposes of this thesis were to compare calf muscle isokinetic strength recovery, calf muscle volume, fatty degeneration and AT elongation after conservative treatment or after open surgical repair of ATR. An additional aim was to assess the role of fascial augmentation in terms of calf muscle isokinetic strength recovery, AT elongation, calf muscle volume atrophy and fatty degeneration, and their relationship with calf muscle isokinetic strength in long-term follow-up after ATR surgery. Surgery resulted in 10% to 18% greater plantar flexion strength (P = 0.037) compared to conservative treatment. The mean differences between affected and healthy soleus muscle volumes were -18% after surgery and -25% after conservative treatment (P = 0.042). At 18 months, AT were, on average 19 mm longer in patients treated conservatively compared to surgery (P < 0.001). At 18 months, patients with greater (2–3) fatty degeneration had lower soleus muscle volumes and plantar flexion strength in the healthy leg. In long term, augmentation did not affect any of the strength variables, but the injured side showed 12% to 18% strength deficit compared with the healthy side (P < 0.001). The AT was, on average, 12 mm longer in the affected leg than in the healthy leg (P < 0.001). The mean soleus muscle volume was 13% lower in the affected leg than in the healthy leg (P < 0.001). The mean volumes of the medial- and lateral gastrocnemius muscles were 12% and 11% lower in the affected leg than in the healthy leg, respectively (P < 0.001). AT elongation correlated substantially with plantar strength deficit (ρ = 0.51, P < 0.001) and with both gastrocnemius (ρ = 0.46, P = 0.001) and soleus muscle atrophy (ρ = 0.42, P = 0.002). Calf muscle fatty degeneration was more common in the affected leg compared healthy leg (P ≤ 0.018). In conclusion, surgery of ATR restored calf muscle isokinetic strength earlier and more completely than conservative treatment. Conservative treatment resulted in greater soleus muscle atrophy and AT elongation compared surgery, which may partly explain the surgery related better strength results. Augmentation provided no long-term benefits compared with simple suturation, and a 12 to 18% plantar flexion strength deficit compared to the healthy side persisted. AT elongation may explain the smaller calf muscle volumes, greater fatty degeneration, and plantar flexion strength deficit observed in long-term follow-up after surgical repair of ATRTiivistelmä Akillesjännerepeämän (ATR) konservatiivisella ja leikkaushoidolla hoidolla saavutetaan hyvät kliiniset tulokset. Viimeisimmät tutkimukset kuitenkin viittaavat leikkaushoidolla saavutettavan paremmat voimat kuin konservatiivisella hoidolla, mutta rakenteelliset selitykset leikkaushoidon paremmalle pohjelihaksen voimille ovat epäselviä. Työn tarkoituksena oli verrata pohjelihaksen isokineettisten voimien palautumista, pohjelihastilavuuksia, rasvadegeneraatiota ja akillesjänteen (AT) pidentymistä ATR:n konservatiivisen- ja leikkaushoidon jälkeen. Tarkoituksena oli arvioida lihaskalvovahvikkeen merkitystä pohjelihaksen isokineettisten voimien palautumisessa pitkäaikaisseurannassa. Lisäksi tutkimme AT pidentymisen, pohjelihastilavuuksien ja rasvadegeneraation suhdetta pohjelihaksen isokineettisiin voimiin ATR:n leikkaushoidon jälkeen 14 v seurannassa. Leikkaushoidolla saavutettiin 10–18 % paremmat pohjelihaksen voimat verrattuna konservatiiviseen hoitoon. Leikkaushoidon jälkeen soleuslihasten tilavuuksien puoliero terveen jalan hyväksi oli 18 % ja konservatiivisen hoidon jälkeen 25 %. 18 kk kohdalla konservatiivisesti hoidettujen AT oli 19 mm pidempi verrattuna leikkauksella hoidettuihin. 18 kk kohdalla potilaat, joilla vamma jalan soleuslihaksen rasva-degeneraatio oli korkea (2–3), kärsivät suuremmasta soleuslihaksen atrofiasta ja pohjelihaksen voima puolierosta. Voimat eivät muuttuneet 12 kk ja 14 v kontrollien välillä. Lihaskalvovahvikkeella ei ollut merkitystä voimien palautumisessa pelkkään suoraan ompeluun verrattuna, mutta vammapuoli jäi 10–18 % heikommaksi verrattuna terveeseen jalkaan. Vammajalan akillesjänne oli 12 mm pidempi terveeseen jalkaan verrattuna. Vammajalan kolmipäisen pohjelihaksen tilavuus oli 11–13 % pienempi verrattuna terveeseen jalkaan. Akillesjänteen pituus korreloi pohjelihaksen voimapuolieron sekä pohjelihasatrofian kanssa. Akillesjännerepeämän leikkaushoidolla pohjelihaksen isokineettiset voimat palautuvat nopeammin ja täydellisemmin kuin konservatiivisella hoidolla. Leikkaushoitoon verrattuna konservatiivinen hoito johtaa suurempaan soleuslihaksen atrofiaan ja akillesjänteen pidentymään, mikä selittää osittain leikkaushoidon paremmat voimatulokset. 14 v seurannassa lihaskalvovahvikkeesta ei ole etua akillesjännerepeämän leikkaushoidossa. Akillesjännerepeämän leikkaushoidosta huolimatta potilaalle jää terveeseen jalkaan verrattuna 10–18 % pohjelihasten voimapuoliero. Akillesjänteen pidentyminen mahdollisesti selittää pohjelihasten atrofian, rasvadegeneraation ja pysyvän pohjelihasten voimapuolieron akillesjännerepeämän leikkaushoidon jälkeen 14 v seurannassa
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Roothaer, Xavier. "Approche multi-échelle du comportement mécanique des os porteurs et non-porteurs : vers une personnalisation des modèles numériques EF de l'être humain." Thesis, Valenciennes, Université Polytechnique Hauts-de-France, 2019. http://www.theses.fr/2019UPHF0020.
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Le squelette humain a pour fonction de protéger les organes internes tout en participant au système de locomotion. Afin d’en assurer la rigidité mécanique, l’os cortical est présent dans toutes les parties du squelette. Le remodelage osseux, processus dynamique, est actif tout au long de la vie. Il permet à l’os cortical d’adapter sa géométrie et son architecture interne en fonction des contraintes qui lui sont appliquées. Étant un processus complexe, le remodelage osseux est amené à dysfonctionner chez les personnes âgées et fragiliser leurs os. Ainsi, cette thèse étudie les os porteurs et non porteurs humains en se concentrant sur le fémur et l’humérus. La revue de la littérature, effectuée dans le chapitre 1, met en évidence plusieurs verrous scientifiques à résoudre. En effet, pour diverses raisons pratiques, le fémur est très largement étudié, délaissant l’étude des autres os. Cela a pour effet d’en impacter les données matériaux utilisées par les modèles numériques du corps humain, souvent extraites d’études très anciennes et obsolètes dont les sujets humains diffèrent. De plus, les études architecturales sont, pour la plupart, limitées à des analyses en 2D et ne sont pas adaptées par rapport à l’architecture osseuse complexe. Par conséquent, le second chapitre décrit une méthode innovante capable d’analyser et de quantifier l’architecture en 3D à partir de scans tomographiques. Les canaux, connectivités et BMUs, berceaux du remodelage osseux, sont automatiquement détectés. 77 échantillons, prélevés sur humérus et fémurs gauche et droit, sont scannés et quantifiés à partir de cette méthode. Étant donné que de nombreuses caractéristiques, jamais mesurées auparavant, sont obtenues, des essais de traction et d’indentation sont effectués afin de comprendre et de mettre en évidence l’impact de l’architecture sur le comportement mécanique. Par conséquent, l’intégralité des échantillons, précédemment scannée, est testée. Dans l’objectif d’extraire des tendances générales, les humérus et fémurs sont comparés suivant différents tests statistiques. De même, l’impact de la latéralité est aussi étudié. Pour terminer, une étude de corrélation, suivie d’une étude de régressions, est effectuée afin de fournir des fonctions polynomiales destinées à prédire le comportement mécanique à partir d’une simple étude architecturaleThe human skeleton aims at participating to the locomotor system, protecting and serving as brackets for the internal organs. To ensure the mechanical stiffness of the entire body, the cortical bone can be found in every part of the skeleton. A dynamic process occurs throughout the life and is named bone remodelling. This process adapts the cortical bone architecture and the shape of bones according to their functions. Due to its complexity, bone remodelling can defect in the elderly and weakens bones. This thesis studies the bearing and non-bearing long human bones by focusing on the humerus and femur. A survey of the state of the art, detailed in the first chapter, reveals several lacks. First, the femur is widely investigated compared to the other bones and this unbalance creates a lack of data for the other bones. Therefore, inputs for numerical human models come from deprecated and contradictory studies where the extra-individual differences impact the trends. Second, architectural studies are mainly limited to in-plane assessment whereas the vascular network is complex and needs more robust analyses. Thus, the second chapter describes an innovative method to 3D assess the cortical vascular network from tomographic data. This Python script automatically detects canals, connectivity and Bone Multicellular Units (BMUs), cradle of the bone remodelling activity. Then, 77 samples from left and right femurs and humeri of ten human cadavers are scanned and analysed using this method. As this method provides numerous novel features of the cortical architecture, tensile and indentation tests are also carried out in order to understand and exhibit the impact of the architecture on the mechanical behaviour. Hence, all the scanned samples are tested and available for statistical analysis. So as to identify global trends, humerus and femur are compared using different statistical tests. Likewise, the bias impact is also investigated. Finally, a correlation study followed by a regression study is described so as to provide polynomial functions in order to be used to predict the mechanical behaviour from an architectural study
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Simonetti, Camila. "Análise teórico-experimental da deformação instantânea e lenta de vigas de concretos auto-adensáveis." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/15722.
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A consolidação das técnicas de dosagem e fabricação de concretos auto-adensáveis com reduzida relação a/c pode ser considerada como um dos desenvolvimentos mais impactantes da nova tecnologia do concreto. No Brasil a utilização deste tipo de concreto, apesar de estar aumentando consideravelmente, ainda é relativamente modesta. Projeta-se, todavia, uma considerável expansão nos próximos anos, em função das vantagens que este material oferece. Por isso, várias instituições têm buscado aprofundar o conhecimento sobre o concreto auto-adensável (CAA), através de estudos e pesquisas sobre o comportamento e características desse novo material. Visando colaborar para um melhor conhecimento sobre as propriedades de concretos autoadensáveis no estado endurecido, foi efetuado um estudo sobre o comportamento, em termos de deformação instantânea e lenta, de vigas fabricadas com CAA. O programa experimental compreendeu a análise de seis vigas de concreto armado dimensionadas segundo as exigências da NBR 6118/2003.Para fabricação das mesmas foi utilizado um concreto convencional, com teor de argamassa de 55%, que serviu como referência, e dois concretos auto-adensáveis, com teores de argamassa de 55% (similar ao do convencional) e 60% (típico de concretos auto-adensáveis). As vigas permaneceram em carga durante aproximadamente cinco meses, durante os quais foi registrada a evolução dos deslocamentos transversais do centro e do terço médio. Os resultados experimentais foram comparados com valores numéricos obtidos através da norma brasileira e do emprego de um modelo computacional baseado em elementos finitos. De uma forma geral, verificou-se que concretos auto-adensáveis possuem comportamento similar ao concreto convencional, podendo ser utilizada, para o dimensionamento de peças com este concreto, a mesma norma utilizada para estruturas de concreto convencional. Verificou-se, porém, que o modelo simplificado da norma brasileira vigente para estimativa da deformação total de longo prazo não apresentou dados coerentes com os resultados coletados em ensaio, subestimando os valores obtidos. Uma análise mais precisa foi possível através de um modelo de elementos finitos. Verificou-se, todavia, que para avaliar o comportamento de vigas de concreto armado em ambiente similar ao do ensaio, é imprescindível a inclusão dos efeitos da retração.Self-compacting concrete (SCC) is considered by many researchers and field engineers as one of the most important recent developments in concrete technology. Despite the considerable advantages that are associated with the use of this special concrete, its use in Brazil is still limited, although there is a growth trend. A strong market expansion is expected in a short period, reproducing what is now happening in Europe and the US. Therefore, many research institutions have been trying to increase the scientific knowledge about SCC, trough studies and researches focused on this new material. In this paper, a study about the immediate and long-term deflections of reinforced concrete beams using SCC is presented, aiming to increase the knowledge about the properties of the self-compacting concrete in its hardened state. In the experimental part of this study, a comparison between the maximum deflections registered in concrete beams under constant load, made with conventional and SCC concrete, is carried out. The experimental program involved the casting and testing of six beams with the same geometry, longitudinal and transversal reinforcement, and subjected to the same load pattern. The beam prototypes were designed according to the Brazilian standard NBR 6118/2003, with a 210cm span and an 18x10cm cross-section. Two types of concrete with different mortar contents have been used: one conventional concrete with a mortar content of 55%, and two SCCs with mortar contents of 55% and 60%. The beams were put under load during approximately five months. The mechanical properties of concrete have been determined and the maximum deflections have been measured throughout this period. The experimental results have been compared with numerical estimates obtained using procedures recommended by the Brazilian standard and with estimates from a FEM computational model. Overall, it was found that self-compacting concrete has a similar behavior to conventional concrete, for the same mortar content, and can be designed with the same criteria used for conventional concrete structures. The estimates obtained using the Brazilian standard, however, underestimated the maximum deflections in relation to the experimental data collected. Better estimates were obtained using the FEM model, when temperature and humidity data was used to account for the shrinkage.
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Ayet, Alex. "Flux de quantité de mouvement à l'interface air-mer : approche théorique du couplage entre turbulence et vagues de vent On the Impact of Long Wind-Waves on Near-Surface Turbulence and Momentum Fluxes, in Boundary-Layer Meteorology volume 174, March 2020 Scalewise return to isotropy in stratified boundary layer flows, in JGR Atmospheres 125 (16), August 2020 Scaling laws for the length scale of energy‐containing eddies in a sheared and thermally stratified atmospheric surface layer, in Geophysical Research Letters 47(23), December 2020." Thesis, Brest, 2020. http://www.theses.fr/2020BRES0038.
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Malgré de nombreuses études, le lien de causalité entre vent et vagues fait toujours l’objet de controverses : cela est dû entre autres au caractère multi-échelle d'une surface océanique réaliste, et à la présence de déferlements, qui modifient radicalement sa topologie. Dans cette thèse, ces deux questions sont abordées sous un angle théorique, à travers un modèle phénoménologique, qui relie les propriétés spectrales et moyennées de la turbulence proche de paroi en utilisant la géométrie de tourbillons attachés à celle-ci. La première partie de la thèse revisite ce modèle phénoménologique en questionnant ses hypothèses sous-jacentes et révèle, en particulier, des incohérences dans les modèles utilisés pour décrire le terme de redistribution d'énergie entre composantes turbulentes (modèle de Rotta). Le modèle phénoménologique est ensuite utilisé pour étudier le couplage entre vagues de vent longues (de l'ordre de 10m) et turbulence. Les résultats démontrent que la déformation des tourbillons attachés induite par cette interaction pourrait expliquer une partie de la variabilité des flux de quantité de mouvement à un vent moyen donné. Finalement, le couplage entre la turbulence et les vagues courtes et déferlantes est abordé en définissant une sous-couche rugueuse dans laquelle les propriétés des tourbillons attachés sont définies par la vitesse des fronts déferlants dominants pour un vent donné. Ces deux études posent les bases d'un nouveau paradigme, permettant d'étudier le couplage multi-échelle entre le spectre turbulent et le spectre des vagues. Celui-ci pourrait permettre de mieux prendre en compte l'influence de paramètres environnementaux sur les flux de quantité de mouvement et de chaleur. Il ouvre ainsi de nouvelles perspectives pour les études théoriques et pour l’exploration des données expérimentalesDespite numerous works, the causal link between wind and waves is still a controversial subject. This is due, among others, to the multi-scale nature of a realistic ocean surface and to wave breaking, which changes its topology. In this thesis, such problems are studied from a theoretical perspective, using a phenomenological model linking the spectral and averaged properties of wall-bounded turbulence through the geometry attached eddies.The first part of the thesis revisits this phenomenological model by questioning its underlying assumptions and, in particular, reveals inconsistencies in the models used for the energy redistribution between turbulence components (the Rotta model). The phenomenological model is then used to study the coupling between long wind-waves (of order 10m) and turbulence. Results indicate that the deformation of attached eddies, induced by this interaction, could explain some of the variability in momentum fluxes for a given mean wind. Finally, the study of the coupling between turbulence and short breaking waves is approached by defining a roughness sublayer, in which the properties of the attached eddies depend solely on the speed of the dominant breaking fronts for a given wind. These two studies from the basis of a new paradigm to study the multi-scale coupling between the turbulent and wave spectra. This would allow accounting for the influence of environmental parameters on momentum and heat fluxes, and opens new paths both from a theoretical perspective and for the analysis of experimental data
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Métivier, David. "Modèles cinétiques, de Kuramoto à Vlasov : bifurcations et analyse expérimentale d'un piège magnéto-optique." Thesis, Université Côte d'Azur (ComUE), 2017. http://www.theses.fr/2017AZUR4074/document.
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Les systèmes en interaction à longue portée sont connus pour avoir des propriétés statistiques et dynamiques particulières. Pour décrire leur évolution dynamique, on utilise des équations cinétiques décrivant leur densité dans l'espace des phases. Ce manuscrit est divisé en deux parties indépendantes. La première traite de notre collaboration avec une équipe expérimentale sur un Piège Magnéto-Optique. Ce dispositif à grand nombre d'atomes présente des interactions coulombiennes effectives provenant de la rediffusion des photons. Nous avons proposé des tests expérimentaux pour mettre en évidence l'analogue d'une longueur de Debye, et son influence sur la réponse du système. Les expériences réalisées ne permettent pour l'instant pas de conclure de façon définitive. Dans la deuxième partie, nous avons analysé les modèles cinétiques de Vlasov et de Kuramoto. Pour étudier leur dynamique de dimension infinie, nous avons examiné les bifurcations autour des états stationnaires instables, l'objectif étant d'obtenir des équations réduites décrivant la dynamique de ces états. Nous avons réalisé des développements en variété instable sur cinq systèmes différents. Ces réductions sont parsemées de singularités, mais prédisent correctement la nature de la bifurcation, que nous avons testée numériquement. Nous avons conjecturé une réduction exacte (obtenue via la forme normale Triple Zero) autour des états inhomogènes de l'équation de Vlasov. Ces résultats génériques pourraient être pertinents dans un contexte astrophysique. Les autres résultats s'appliquent aux phénomènes de synchronisation du modèle de Kuramoto pour les oscillateurs avec inertie et/ou interactions retardéesLong-range interacting systems are known to display particular statistical and dynamical properties.To describe their dynamical evolution, we can use kinetic equations describing their density in the phase space. This PhD thesis is divided into two distinct parts. The first part concerns our collaboration with an experimental team on a Magneto-Optical Trap. The physics of this widely-used device, operating with a large number of atoms, is supposed to display effective Coulomb interactions coming from photon rescattering. We have proposed experimental tests to highlight the analog of a Debye length, and its influence on the system response. The experimental realizations do not allow yet a definitive conclusion. In the second part, we analyzed the Vlasov and Kuramoto kinetic models. To study their infinite dimensional dynamics, we looked at bifurcations around unstable steady states. The goal was to obtain reduced equations describing the dynamical evolution. We performed unstable manifold expansions on five different kinetic systems. These reductions are in general not exact and plagued by singularities, yet they predict correctly the nature and scaling of the bifurcation, which we tested numerically. We conjectured an exact dimensional reduction (obtained using the Triple Zero normal form) around the inhomogeneous states of the Vlasov equation. These results are expected to be very generic and could be relevant in an astrophysical context. Other results apply to synchronization phenomena through the Kuramoto model for oscillators with inertia and/or delayed interactions
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Frizzarin, Rejane Mara. "Desenvolvimento de procedimentos analíticos em fluxo explorando difusão gasosa ou extração em ponto de nuvem. Aplicação a amostras de interesse agronômico e ambiental." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/64/64135/tde-30032015-160404/.
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Procedimentos analíticos espectrofotométricos foram desenvolvidos empregando etapas de separação e pré-concentração em sistemas de análises em fluxo com multi-impulsão ou lab-in-syringe, com aplicação a amostras de interesse agronômico (ferro em materiais vegetais e alimentos) e ambiental (cianeto dissociável em ácidos, ferro e antimônio em águas). A determinação de cianeto explorou a descoloração do complexo formado entre Cu(I) e ácido 2-2´-biquinolino-4,4´-dicarboxílico (BQA) pela presença de CN-, após a separação de HCN por difusão gasosa. Espectrofotometria com longo caminho óptico foi empregada para aumentar a sensibilidade, com resposta linear entre 5 e 200 g L-1, limite de detecção, coeficiente de variação (n = 10) e frequência de amostragem de 2,0 g L-1, 1,5% e 22 h-1, respectivamente. O procedimento consumiu apenas 48 ng de Cu(II), 5,0 g de ácido ascórbico e 0,9 g de BQA por determinação e gerou 2,6 mL de efluente. Tiocianato, nitrito e sulfito não afetaram a determinação de cianeto e peróxido de hidrogênio evitou a interferência de sulfeto até 200 g L-1. Os resultados para as amostras de águas naturais foram concordantes com o procedimento fluorimétrico em fluxo com 95% de confiança. Novas estratégias foram propostas para a extração em ponto nuvem (EPN) em fluxo: (i) a fase rica em surfactante foi retida diretamente na cela de fluxo, evitando a diluição; (ii) microbombas solenoide foram exploradas para melhorar a mistura e modular a vazão na retenção e remoção da fase rica, evitando a eluição com solvente orgânico e (iii) o calor liberado e os sais fornecidos por uma reação de neutralização em linha foram explorados para indução do ponto nuvem, sem dispositivo externo de aquecimento. Estas inovações foram demonstradas pela determinação espectrofotométrica de ferro baseada no complexo com 1-(2-tiazolilazo)-2-naftol (TAN). Resposta linear foi observada entre 10 e 200 g L-1, com limite de detecção, coeficiente de variação e frequência de amostragem de 5 g L-1, 2,3% (n = 7) e 26 h-1, respectivamente. O fator de enriquecimento foi de 8,9 com consumo apenas de 6 g de TAN e 390 g de Triton X-114 por determinação. Os resultados para amostras de águas foram concordantes com o procedimento de referência e os obtidos para digeridos de materiais de referência de alimentos concordaram com os valores certificados. A determinação espectrofotométrica de antimônio foi realizada explorando pela primeira vez a EPN em sistema lab-in-syringe. O complexo iodeto e antimônio forma um par iônico com H+, que pode ser extraído com Triton X-114. Planejamento fatorial demonstrou que as concentrações de ácido ascórbico, H2SO4 e Triton X-114, bem como as interações de segunda e de terceira ordem foram significativas (95% de confiança). Planejamento Box-Behnken foi aplicado para a identificação dos valores críticos. Robustez com 95% de confiança, resposta linear entre 5 e 50 g L-1, limite de detecção, coeficiente de variação (n = 5) e frequência de amostragem foram estimados em 1,8 g L-1, 1,6% e 16 h-1, respectivamente. Os resultados para amostras de águas naturais e medicamentos anti-leishmaniose foram concordantes com os obtidos por espectrometria de absorção atômica com geração de hidretos (HGFAAS) com 95% de confiançaSpectrophotometric analytical procedures were developed by exploiting separation and preconcentration steps in flow systems based on multi-pumping or lab-in-syringe approaches with application to agronomic (iron in plant materials and food) and environmental samples (acid dissociable cyanide, iron and antimony in waters). Cyanide determination exploited bleaching of the Cu(I)/2,2\'-biquinoline 4,4\'-dicarboxylic acid (BCA) complex by the analyte, after separation of HCN by gas diffusion. Long path length spectrophotometry was successfully exploited to increase sensitivity, thus achieving a linear response from 5 to 200 g L-1, with detection limit, coefficient of variation (n = 10) and sampling rate of 2 g L-1, 1.5% and 22 h-1, respectively. Each determination consumed 48 ng of Cu(II), 5 g of ascorbic acid and 0.9 g of BCA. As high as 100 mg L-1 thiocyanate, nitrite or sulfite did not affect cyanide determination and sample pretreatment with hydrogen peroxide avoided sulfide interference up to 200 g L-1. The procedure is environmentally friendly and presented one of the lowest detection limits associated to high sampling rate. The results for freshwater samples agreed with those obtained with the flow-based fluorimetric procedure at the 95% confidence level. Novel strategies were proposed for on-line cloud point extraction (CPE): (i) the surfactant-rich phase was retained directly into the flow cell to avoid dilution prior to detection; (ii) solenoid micro-pumps were explored to improve mixing and for flow modulation in the retention and removal of the surfactant-rich phase, thus avoiding the elution step with organic solvents and (iii) the heat released and the salts provided by an on-line neutralization reaction were exploited to induce cloud point without an external heating device. These approaches were demonstrated for the spectrophotometric determination of iron based on complex formation with 1-(2-thiazolylazo)-2-naphtol (TAN). A linear response was observed from 10 to 200 g L-1, with detection limit, coefficient of variation, and sampling rate of 5 g L-1, 2.3% (n = 7) and 26 h-1, respectively. The enrichment factor was 8.9 and the procedure consumed only 6 g of TAN and 390 g of Triton X-114 per determination. The results for freshwater samples agreed with the reference procedure and those obtained for certified reference materials of food agreed with the certified values. Spectrophotometric determination of antimony was performed for the first time exploiting CPE in the lab-in-syringe system. The antimony/iodide complex forms an ion-pair with H+, which can be extracted with Triton X-114. Factorial design showed that the concentrations of ascorbic acid, H2SO4 and Triton X-114, as well as the second and third order interactions were significant (95% confidence). The Box-Behnken design was applied to identify the critical values. The system is robust with 95% confidence and a linear response was observed from 5 to 50 g L-1, with detection limit, coefficient of variation (n = 5) and sampling rate of 1.8 g L-1, 1.6% and 16 h-1, respectively. The results for water samples and antileishmanial drugs agreed with those obtained by hydride generation atomic absorption spectrometry at the 95% confidence level
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Dias, Daniel Ventura. "Tecido adiposo e enxerto com tubo de polietileno poroso usados na técnica de tubulização influenciaria na reinervação de músculos de contração lenta e rápida de ratos?" Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/25/25149/tde-12062012-153642/.
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Problemas relacionados a lesões de nervos periféricos com consequentes perdas sensitivas e motoras tornaram-se frequentes no dia a dia da prática clínica e hospitalar, em consequência do aumento da violência urbana, dos acidentes de trânsito, acidentes profissionais e domésticos. Por esta razão, a busca por estratégias e técnicas que possam reparar a lesão nervosa e restabelecer a função do tecido lesado é importante e de grande valia no âmbito da saúde. Para reparar lesões nervosas com perda de tecido nervoso, várias técnicas cirúrgicas têm sido utilizadas, uma das técnicas mais comum é o uso do enxerto autógeno, mas técnicas alternativas têm sido propostas a fim de evitar as complicações ao local doador e acelerar o processo de regeneração nervosa como, por exemplo, a da tubulização. O uso desta técnica tem sido mais utilizado para o preenchimento dos tubos com substâncias que acelerem ou induzam o crescimento axonal. Baseado no exposto anteriormente pensou-se na realização desta pesquisa com o objetivo de verificar se uso de tubo de polietileno poroso preenchido ou não com tecido adiposo na técnica de tubulização alteraria a recuperação dos músculos sóleo (de contração lenta) e Extensor longo dos dedos (de contração rápida). Para isso foram utilizados 45 ratos (Rattus norvegicus),Wistar, machos, que foram divididos em cinco grupos, sendo, três controles, e dois experimentais. Nos grupos experimentais foram realizados a tubulização de polietilieno poroso preenchido ou não com tecido adiposo (GECP e GESP, respectivamente). Os tubos foram testados para avaliar a eficácia em reduzir a lacuna crítica de 10 mm do nervo isquiático. Os animais dos grupos experimentais foram sacrificados 150 dias após a cirurgia. Dos três grupos controles, dois não sofreram intervenção cirúrgica, e receberam o nome de inicial (GCI) e final (GCF) e foram sacrificados com 80 e 230 dias de vida respectivamente. E no outro grupo controle, denominado desnervado (GCD) os animais foram submetidos à secção do nervo isquiático. Antes do sacrifício os animais foram submetidos à análise funcional da marcha. Durante o sacrifício foram retiradas amostras dos músculos sóleo e Extensor longo dos dedos, que foram submetidas à coloração de Hematoxilina e Eosina, Tricrômico de Masson, e também a reações de m-ATPase e NADH-Tr. Imunomarcações foi utilizada para a expressão de Myod e miogenina. Os dados foram submetidos ao tratamento estatístico. Os resultados mostraram que nos animais dos grupos experimentais tiveram melhor recuperação muscular do que os dos animais desnervados e foi inferior quando comparado com o grupo controle final (GCF). Baseado nestes dados pode-se concluir que o uso do tubo de polietileno poroso com preenchimento de tecido adiposo interferiu positivamente na recuperação tanto do músculo sóleo quanto o extensor longo dos dedos.Problems related to injuries of peripheral nerves with consequent sensory and motor losses are seen more frequently in daily clinical and hospital practice due to an increase in urban violence, traffic accidents, domestic and labour accidents. For this reason, the search for strategies and techniques that can repair nerve damage and restore function of damaged tissue is important and of great value in health care. To repair nerve damage with loss of nerve tissue, several surgical techniques have been used, one of the common techniques is the use of the autograft, but alternative techniques have been proposed to avoid complications to the donor site and accelerate the process of nerve regeneration, such as tubulization. The use of this technique has been further utilized by filling the tubes with substances that speed up or induce axonal growth. Based on the previous work, in this research we wanted to see whether tubilization with the help of porous polyethylene tube filled with and without adipose tissue alter the recovery of the soleus (slow twitch) and extensor digitorum longus (fast twitch) muscles. For this we used 45 male Wistar rats (Rattus norvegicus), who were divided into five groups, three control and two experimental. In the experimental groups, tubulization was performed using porous polyethylene filled with (GECP) and without adipose tissue (GESP). The conduits were tested for efficacy in bridging the critical gap length of 10 mm in sciatic nerves.The animals of experimental groups were sacrificed 150 days after surgery. Of the three control groups, two did not undergo surgery, and were named as (GCI) for Initial and (GCF) for final group in which the animals were sacrificed at 80 and 230 days old respectively. And another control group, called denervated (GCD), the animals were subjected to sciatic nerve section. Prior to sacrifice the animals were subjected to functional analysis of gait. During the sacrifice, samples were taken from soleus and extensor digitorum longus muscles, which were stained with Hematoxylin and Eosin, Masson\'s trichrome and were also subjected to reactions of m-ATPase and NADH Tr. Immunostaining was also utilised for the expression of MyoD and myogenin. The data were analyzed statistically. The results showed that animals of experimental groups have better muscle recovery than those of denervated animals however the recovery was inferior when compared with the final control group (GCF).Based on these data we can conclude that the use of porous polyethylene tube filled with adipose tissue had a positive influence on the recovery of both the soleus and extensor digitorum longus.
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Bacques, Guillaume. "Étude de variations spatio-temporelles de glissements asismiques le long de failles majeures par Interférométrie RADAR Différentielle satellitaire : Cas du séisme lent de 2009-2010 de Guerrero (Mexique) : Cas de la déformation postsismique suite au séisme de Parkfield (2004, Mw6, Californie)." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENU044/document.
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La caractérisation des distributions spatio-temporelles des déformations transitoires le long de failles actives constitue actuellement l’un des axes privilégiés de recherches visant la compréhension des processus contrôlant le cycle sismique. Dans ce contexte, nous nous intéressons à deux sites d’études aux caractéristiques comportementales distinctes: la lacune sismique de Guerrero, siège de 4 séismes lents depuis 1997 (zone de subduction, d’une longueur de 100 km à l’ouest d’Acapulco au Mexique, dernière rupture en 1911, temps de récurrence ~4 ans) et le segment de Parkfield (segment de 20-30 km le long de la faille de San Andreas, Californie, 7 ruptures successives -Mw6- depuis 1857, temps de récurrence de ~22 ans). Dans le cas du Mexique, nous portons notre attention sur le séisme lent de 2009-2010 survenu au niveau de la lacune sismique et, dans le cas du segment de Parkfield, nous décrivons la déformation post-sismique suite au séisme du 28 septembre 2004, dernière rupture en date de ce segment, sur la période 2005-2010. Nous utilisons l’interférométrie radar différentiel satellitaire (DINSAR), complété de données GPS, pour estimer les faibles déformations (centimétriques) générées en surface par ces types de déformations. À l’issue de ce travail, dans le cas de la lacune sismique de Guerrero, nos mesures semblent montrer que le séisme lent de 2009-2010 affecte la partie sismogène de la lacune tout en affectant une portion de la subduction qui dépasse les limites géographiques de celle-ci. Dans le cas de Parkfield, nous parvenons à mettre en avant une prolongation temporelle jusqu’en 2010 du glissement post-sismique en plus d’une extension spatiale de ce glissement qui dépasse les limites de la rupture de 2004. Ces nouveaux éléments permettent de discuter plus en avant l’impact de ces déformations transitoires sur le comportement de ces systèmes de failles situés tout deux, sur des sites d’intérêts scientifiques majeursCharacterizing the spacio-temporal evolution of transient deformations along active faults is, by now, one of the most promising ways to better understand the mechanisms that drive the seismic cycle. In this context, we focused our attention on two areas that exhibit different characteristic behaviour types: the Guerrero seismic gap, a location of 4 consecutive slow slip events since 1997 (subduction zone, 100 km long westward from Acapulco, Mexico, last ruptured in 1911, repeating time ~4 years) and the Parkfield segment (20-30 km long segment, San Andreas fault, California, 7 successive breaks -Mw6- since 1857, repeating time ~22 years). In the case of Mexico, we particularly focused our attention on the 2009-2010 slow slip event that occurred at the gap location. In the case of Parkfield, we described the post-seismic deformation related to the 28th September 2004 Mw6 event (last recorded break) from 2005 to 2010. We used space-based differential radar interferometry (DINSAR) in addition to GPS data, to assess surface displacements at centimeter scale that are in relation with those two phenomena. As an outcome of the work, in the Guerrero seismic gap case, our measurements indicate that the 2009-2010 slow slip event has affected the seismogenic part of the gap and extents outside the spatial limits of it. In the case of Parkfield, our measurements indicate that the Parkfield segment has a post-seismic behaviour that lasts until 2010 at least and spatially extends outside the edge the 2004 coseismic trace along the fault line. These elements allow us to discuss the implication of such transient deformations in the two particular cases of the Guerrero seismic gap and the Parkfield segment, both of first scientific interest
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Wu, Chih-Wei, and 吳智偉. "Study on Short-Length FFT Design for Recursive Long-Length FFT Architecture." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/51442062097845654913.
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碩士國立交通大學
電機與控制工程系所
94
With the growing trend on many specific applications adopting long-length FFT, the performance of FFT processors is more and more important. Generally, the long-length FFT is implemented with recursive short-length FFT in order to save the cost and complexity. This thesis presents a study on different short-length FFT designs for recursive architecture long-length FFT. Under recursive architecture, latency of each short-length FFT iteration will be the bottleneck of overall performance. A new structure with CORDIC (COordinate Rotation DIgital Computer) and DA (Distributed Arithmetic) technique is proposed in order to achieve low latency. A case study on realizing an 802.11a 64-point FFT processor is also presented. The specified FFT processor computes 16-bit input data at a throughput rate of 20MHz. The two chips, the proposed 64-point CORDIC-DA FFT processor and the other one with fully parallel 8-point FFT structure, were fabricated using TSMC 0.18-um single-poly six-metal CMOS process. After simulation, analysis, and refinement, we make a conclusion that the parallel 8-point FFT structure is most suitable for recursive architecture FFT.
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Lin, Hsiu-Hung, and 林修鴻. "A configurable very long codeword length LDPC decoder." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/37158994606532437704.
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碩士國立臺灣大學
資訊工程學研究所
98
It is well known the minimal LDPC code distance is increases by the code-length. Generally speaking, it is good to use a long code length but there are problems in long code-length hardware design. In my design, I use the density evolution to decide the suitable node degree distribution pair in several code-lengths and make the parity check matrix with as long as possible girth when I generated it. Then, I designed a decoder with an external DDR2 SDRAM. It provides the ability to storage the big matrix and the large number of variable information received in channel. Throwing the re-write external memory, it provides the ability to configure and can decode various LDPC codes. At least, in order to have as less as possible coding gain loss, I use the sum-product to be the decoding algorithm and do smallest coding gain lose in hardware design.
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Tu, Shih-Hsiung, and 杜世雄. "Sequential Decoding for a Long Constraint Length Convolutional Codes." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/27475968025674189069.
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Yang, Ming-Feng, and 楊明峰. "A Cost-Efficient Folding Technique for Long-Length FIR Filter Implementation." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/82193171684134765388.
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碩士國立交通大學
電機與控制工程系所
93
This thesis presents two hardware efficient folding techniques for limited-resource implementation of long-length FIR filtering. Under the requirement of the throughput rate, we fold the FIR with the minimal number of processing elements (PEs) while the complexity of scheduler is low. The proposed folded architecture is highly scalable as the application parameters change.Cost functions are derived and these are used to address two related issues. The first issue focuses on memory requirements in folded architectures. The second is power consumption. The result of memory requirements and power estimation show that Parallel-In folding technique can turn out less memory area and power dissipation than do other folding techniques. Finally, the chip is implemented by using the UMC 0.18 μm 1P6M CMOS technology.
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VINNA and 林美妏. "Application of Long-Focal-Length Microlens Array on Shack-Hartmann Wavefront Sensor." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/99990610682162077498.
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碩士國立臺灣大學
光電工程學研究所
99
In adaptive optics, microlens array (MLA) is used to detect and divide the incidence wavefront into small parts which will be focused on the image sensor (CMOS) of Shack-Hartmann wavefront sensor (SHWS). In this paper, we present the fabrication method of long focal length (millimeter range) MLA with various structure and arrangement based on thermal reflow process. In order to extend the focal length, we used Polydimethysiloxane (PDMS) cover on our glass substrate of MLA. Because of the small refractive index difference between PDMS and MLA interface (UV-resin), the incidence light is less bended and focused in further distance. Besides, other specific focal lengths could be realized by modifying the refractive index difference. After the long-focal-length MLA film was fabricated, it could be integrated with an image sensor to build a SHWS. A longer focal length MLA will provide high sensitivity in determining the average slope across each lenslet under a given wavefront, and the spatial resolution of the wavefront sensor is increased by the number of lenslets across the detector. Thus, the accuracy improves with greater sensitivity and spatial resolution. The experimental result of the system is discussed and compared between the long focal length, the shorter focal length and the commercial SHWS.
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Li, Hui-ching, and 李慧卿. "The Study of the Medium / Long-Length Adolescent Novels ofKuan Chia-Chi’s." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/53001936350758200357.
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碩士國立臺南大學
國語文學系國語文教學碩士班
97
Kuan Chia-Chi is not only famous for her collection of “fairy tales” but also famous for her adolescent novels. These novels are masterpieces which are adopted from her genuine feelings and thoughts toward life-experiences. Some of them have been awarded both at home and abroad. This article aims at exploring the thematic patterns, characters, and writing techniques which reveals primary styles and characteristics in Kuan Chia-Chi’s adolescent novels. There are diverse thematic patterns in Kuan Chia-Chi’s adolescent novels, including love in the family, love between men and women, peer interaction, and so on. While portraying characters, Kuan Chia-Chi places equal emphasis on internals and externals. As for writing techniques, she shows her excellent skills based on the analysis of various perspectives, plots, scenes, and narrators.
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Hsu, Pao-Hua, and 許寶華. "Analysis of Long-term Trend and factors associated with Emergency Department Length of Stay." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/42325851920512106761.
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碩士國立陽明大學
醫務管理研究所
97
Background: Emergency department(ED) overcrowding not only decreases quality of care but also threatens patient’s safety. Research has shown that long ED stays prior to admission is one of the main causes of ED crowding. There are limited research on the trend and factors associated with Emergency department length of stay (ED LOS) for admitted patients in Taiwan hospitals. Objectives: This thesis aims to examine the trend and factors associated with ED LOS for admitted patients. Methods: This is a retrospective study. The data consist of hospital claim data from the Bureau of National Health Insurance (BNHI), with study subjects being the admitted patients from the Taipei District. The study period is 1999 to 2007. Factors associated with ED LOS are determined using logistic regression. Results: The number of patients admitted via the ED increased over time. 266,924 ED visits were admitted in 2007 and increased by 37.21% from 1999. In 2007, 21.59% and 4.52% of the patients stayed in the ED with a waiting time greater than 6 and 48 hours respectively, representing 25.67% and 94.83% increase since 1999. In 2004-07, the odds ratio of staying in the ED for admission over 6 hours was 1.18 to 1.5 and that over 48 hours was 1.95 to 3.06, compared with 2002(the year the BNHI implemented Hospital Global Budget Payment System). The contributing factors of staying in the ED for admission were associated with patients’ characteristics (age, gender, social-economic status), severity of disease, season, admitted during holiday, and hospital characteristics (scale, ownership, location). For females, ED visits during the third season and private hospital ED visits tend to have higher relative risk, to stay in the ED over 6 hours; being male, ED visit during the first season and public hospital ED visits tend to have higher relative risk for stay in the ED over 48 hours. The relative risk of staying in the ED both over 6 hours and over 48 hours were higher for older age, low income, ED visits during non-holiday, high disease severity, the medical center ED visits and ED visits at the remote island (Kinmen County, Lienchiang County). Conclusions: The relative risk of staying in the ED for admission in the Taipei District of BNHI increased dramatically since 2004 and this is particularly obvious for medical centers. We suggest that the government and medical service providers should face this phenomenon. Systemic review and strategies should be studied and executed in order to increase the efficiency and quality of emergency medical service.
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Lian, Chin-Kuang, and 廖欽寬. "A Partially Parallel Low-Density Parity Check Code Decoder with Reduced Memory for Long Code-Length." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/27023195850205517433.
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碩士國立中央大學
電機工程研究所
95
In recent years, low-density parity-check (LDPC) codes have attracted a lot of attention due to the near Shannon limit coding gains when iteratively decoded. Thus, the LDPC codes have been well recognized as an excellent error correction coding scheme for many digital communication systems, such as the next generation digital video broadcasting (DVB-S2), MIMO-WLAN (802.11n), WMAN (802.16e), mobile broadband wireless access (MBWA) (802.20) systems, and etc. Based on the message-passing algorithm, the LDPC decoder uses memories to store intermediate data between bit nodes and check nodes. In fact, the quantity of the stored data is related to the non-zero entries in H matrix. In other words, the memory size required by the LDPC decoder with the partially parallel architectures may significantly increase for large code length LDPC codes. In this thesis, we present an alternative approach which significantly reduces the memory size requirement and the salient feature of memory size reduction becomes significance particular for DVB-S2 applications.
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Shih, Tsung-Jung, and 施宗融. "Determination of the Earth’s Zonal Response in Length-of-day Variation to the Long-period Tides." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/48971881582520107562.
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碩士國立臺灣大學
海洋研究所
100
We estimate the Earth’s zonal tidal response coefficient κ from modern observed length-of-day (LOD) data for the period 1977-2009. Its magnitude and phase of κ contain important information about the Earth’s internal structure and dynamics. The influence of the atmospheric angular momentum (AAM) is firstly removed from the LOD data in order to better reveal the signals of long-period tides of periods ranging from 5 to 35 days. Numerical estimates of κ magnitude and phase lag are then obtained for 11 tides with sufficiently high signal to noise ratio (SNR). These estimates are compared with the theoretical baseline value, κ = 0.315, which is the value for a spherically symmetric Earth model under the additional assumptions of equilibrium long-period ocean tides and complete decoupling of the fluid core from the mantle. Comparison of our results with theoretical model computations is discussed in terms of possible frequency dependence of κ. Our κ amplitude and phase estimates are found to be consistent with two non-equilibrium ocean tide models, which are assimilated with precise sea surface height measurements provided by TOPEX/Poseidon satellite mission.
50
Hsu, Di-cheng, and 許迪程. "Implementation of Long Word-length RNS Arithmetic Operations Using Custom Instructions on an Altera SOPC System." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/53393002563872348329.
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碩士逢甲大學
資訊工程所
98
In designing mobile embedded systems, due to the requirement for low cost, low power, and high performance, 32-bit fixed-point processors with RISC architecture are used in these systems. As a result, the precision of these 32-bit processors is not sufficient for high-precision applications. To overcome this precision problem, this thesis proposes to implement long word-length arithmetic instructions on a 32-bit processor by adopting residue number system (RNS) arithmetic with moduli set {2n+1-1,2n,2n-1,2n-1-1}. By using custom instructions, we designed the function blocks of RNS addition, subtraction, multiplication, binary-to-residue conversion, and residue-to-binary conversion, and added these instructions to the Nios II processor on an Altera DE2 board. Due to the carry-free and independent properties, the speed of the long word-length (64-bit) arithmetic operations can be enhanced. To compare the performance of our designed 64-bit RNS instructions with the 64-bit fixed-point instructions, we choose matrix multiplications for our experiment. In most cases, the speed of the 64-bit RNS instructions can be 1.07 to 2.46 times the speed of the fixed-point instructions with 32-bit multiplier or pure software implementation. However, if 64-bit multipliers are used in the fixed-point instructions, the RNS instructions will be a little slower. This results show that the proposed long word-length RNS instructions have some speed advantage in performing consecutive multiplication and addition operations.