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Mayhoub, Mohammed Salah. "Hybrid lighting systems : performance, application and evaluation." Thesis, University of Liverpool, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.569655.
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Daylight was the main source of lighting in vernacular architecture, and building design accordingly responded to its strategic limitations. Needs for new types of buildings in conjunction with the great development of electric lamp led to the ascendancy of electric lighting. However, a return to the interest in natural lighting emerged with the energy crises in the 1970s. In order to meet the new requirements, new optical materials and technologies have been combined to produce innovative daylighting systems able to deliver daylight long distances into buildings. There is a need to maximize the utilization of daylight, to optimize the integration between davlighting and electric lighting systems so as to increase the potential application of daYlig~ing system. The development of the hybrid lighting systems (HLS) aims to satisfy these desires. / HLS seek to maximize the utilization of daylight by tracking sunrays, and in most cases they are concentrated to minimize the light guidance size, which eases the installation and in turn increases the potential application of HLS. Prior to delivery of daylight, electric lighting source is added to instantly top up any possible shortage of daylight. A control system works to regulate this process to minimize the energy consumption. The one output device for both sources used in the HLS made it possible to no longer need for two distinct lighting systems to be installed in one space. Investigations in this work have measured HLS performance in terms of light delivery, light quality, energy saving and economic performance. Potential applications of HLS in different buildings types and across a wide geographical region have been investigated. An overall evaluation of HLS has been carried out. Furthermore, methods to estimate illuminance data, where measured data is unavailable, have been developed to help investigating systems performance over different geographical locations. Illuminance data produced using the developed methods showed superiority over that produced using other available methods, with the additional advantages of simplicity and universal application. HLS performance and potential application are influenced by many variables including system characteristics, building types, and location features. The research showed that the most important variable is the concentration ratio of the light collector. This determines HLS ability to collect daylight, and thus its applicability in different geographical locations. It also stipulates light collector and guidance size, and thus HLS applicability in different building type, influences the delivered light quality, and thus occupants' perception of daylight, and influences HLS initial and running costs. Delivered light by HLS may not be perceived as daylight due to the absence of the outside view, the likely change in daylight colour because of the mixing with electric light, the fade awareness of the seasonal and diurnal changes in daylight colour and intensity because of the instant and continuous top up. The challenges of cost, light quality and integration in building design are the most serious barriers confronting HLS ability to penetrate the market and to be used widely. This work makes suggestions to overcome these problems.
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Xiao, Yu. "Evaluation of Test Vector Quality for Hybrid Systems." Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-347562.
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When testing is performed, a large number of test vectors representing series of signal values are input to the applications under development, and the results of the testing are then analyzed by checking violations of defined safety requirements. However, there is usually limited time, personnel and other resources. Selecting a subset of test vectors with better qualities is one of the possible ways in order to bring down the costs for testing-related activities.This thesis work aims at evaluating and quantifying the qualities of test vectors for a hybrid system. Two possible criteria for good qualities are proposed, evaluated and quantified for test vectors that are input to a hybrid application at Volvo Cars. For validation and analyses purposes, the semantics of Signal Temporal Logic (STL) and its robustness satisfaction are introduced and monitored with the Matlab/Simulink Toolbox Breach. The conclusion is that the method we proposed to evaluate and quantify the qualities of test vectors is able to satisfy the needs from Volvo Cars by far. With the experiences we have at present, however, it is not sufficiently proven that test vectors with higher qualities assessed by our method behave better when the robustness satisfaction of STL formulas is monitored. Nevertheless, it is a good beginning to relate the robustness satisfaction of STL semantics to test vector quality evaluation for people with similar goals to consider in the future.
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Du, Plessis Jacques J. P. "Performance evaluation of water collecting systems with a hybrid dephlegmator." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95920.
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Thesis (MEng) -- Stellenbosch University, 2014.<br>ENGLISH ABSTRACT: Water collection systems are used in wet-cooling towers (WCTs) with fill over
which water to be cooled flows and in evaporative air-cooled heat exchangers
(EACHEs) having deluged tube bundles over which water flows to transfer heat
from the tubes. They collect and remove water falling from the bottom of the fill
or heat exchanger tube bundle while allowing air to pass with limited flow
resistance. There are basically two types of collection systems, categorized as
trough and basin systems. Trough systems comprise of multiple, evenly spaced
parallel troughs extended in one direction with inclined capture plates to direct
water into the troughs. The water collects in the troughs and drains under gravity
to a collecting tank or manifold from where it is pumped to the sprayers. In basin
systems water falls directly into an open basin under gravity where it is collected
and can be pumped to the sprayers. The hybrid (dry/wet) dephlegmator (HDWD)
for air-cooled steam condensers, which is being developed at Stellenbosch
University as discussed by Heyns (2008), Owen (2013) and Anderson (2014),
requires a more effective water collection system with a lower pressure drop than
what current designs have to offer.
In this thesis, an existing trough system is systematically evaluated by means of
various high speed camera and flow experiments to determine its performance
characteristics and to find ways to improve its catchment effectiveness. A
modification is proposed which increases the effectiveness from approximately
92% to 100 % with a relatively small increase in pressure drop, by adding a small
deflector plate and reducing the spacing between adjacent troughs. Experimental
data and CFD models are used to determine the performance characteristics of the
modified trough system for design purposes.
For comparison, various basin system designs are proposed and investigated using
CFD, where the baseline model is validated by means of experimental data of
rectangular cooling tower inlets by Kröger (2004). Rectangular cooling tower
inlets are relevant as they have a similar re-circulating flow pattern to what is seen
with the water basin inlets at the vicinity of the inlet wall. The numerical data is
correlated to determine empirical relations for the flow performance
characteristics.
The comparison between the modified trough and the different basin systems
yields that the trough system requires significantly less fan and pumping power
than basin systems and the costs are also expected to be less.<br>AFRIKAANSE OPSOMMING: Wateropvangstelsels word gebruik in nat koeltorings en verdamping verkoelers,
waar waterdruppels in teen-vloei is met n lugstroom. Die stelsel vang die water
wat val op en verwyder dit uit die lugstroom met 'n minimale lugweerstand. Daar
is twee wateropvangstelsels wat as volg gekategoriseer word: trog stelsel en
wateropvangbak stelsel. 'n Trog stelsel bestaan uit eweredige gespasieerde trôe
parallel aan mekaar met 'n skuinsvlak om water in die kanaal op te vang. Water
dreineer as gevolg van swaartekrag na 'n opvangs tenk waarvan dit terug gepomp
word na die sproeiers. In 'n wateropvangbak stelsel val water direk in die bak en
word terug gepomp na die sproeiers. 'n Lugverkoelde kondenserstelsels met 'n
hibriede (droog/nat) deflegmator wat huidiglik by die Stellenbosch Universiteit
ontwikkel word benodig 'n meer effektiewe wateropvangstelsel met 'n lae drukval.
In hierdie tesis word bestaande trog stelsels sistematies geëvalueer deur middel
van verskeie toetse met 'n hoë spoed kamera en lugvloei eksperimente om die
werkverrigtingskarakteristieke te bepaal en om die opvangsvermoë te verbeter. 'n
Verbetering word voorgestel wat die opvangsvermoë verbeter van ongeveer 92 %
na 100 % met 'n relatiewe klein verhoging in die drukval deur 'n klein leilem by te
voeg en die spasiëring tussen trôe te verminder. Eksperimentele data en BVD
(berekeningsvloeidinamika) modelle word gebruik om die werkverrigtingskarakteristieke
te bepaal van die nuwe trog stelsel vir ontwerps doeleindes.
Die modelle is bekragtig deur gebruik te maak van literatuur van inlaatverlies
korrelasies vir reghoekige koeltorings, soos gedoen deur Kröger (2004). Die inlaat
van reghoekige koeltorings het soortgelyke vloeipatrone en vloeiwegbreking soos
wat by die inlaat van die wateropvangbak stelsel gesien word. Die numeriese data
word gebruik om 'n vergelyking vir die vloei karakteristieke te bepaal.
'n Vergelykende studie tussen die nuwe trog stelsel en die wateropvangbak stelsel
het bewys dat die trog stelsel noemenswaardig minder waaier drywing en pomp
drywing benodig.
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Ingverud, Patrik. "Complexity evaluation of CNNs in tightly coupled hybrid recommender systems." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-232027.
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In this report we evaluated how the complexity of a Convolutional Neural Network (CNN), in terms of number of filters, size of filters and dropout, affects the performance on the rating prediction accuracy in a tightly coupled hybrid recommender system. We also evaluated the effect on the rating prediction accuracy for pretrained CNNs in comparison to non-pretrained CNNs. We found that a less complex model, i.e. smaller filters and less number of filters, showed trends of better performance. Less regularization, in terms of dropout, had trends of better performance for the less complex models. Regarding the comparison of the pretrained models and non-pretrained models the experimental results were almost identical for the two denser datasets while pretraining had slightly worse performance on the sparsest dataset.<br>I denna rapport utvärderade vi komplexiteten på ett neuralt faltningsnätverk (eng. Convolutional Neural Network) i form av antal filter, storleken på filtren och regularisering, i form av avhopp (eng. dropout), för att se hur dessa hyperparametrar påverkade träffsäkerheten för rekommendationer i ett hybridrekommendationssystem. Vi utvärderade även hur förträning av det neurala faltningsnätverket påverkade träffsäkerheten för rekommendationer i jämförelse med ett icke förtränat neuralt faltningsnätverk. Resultaten visade trender på att en mindre komplex modell, det vill säga mindre och färre filter, gav bättre resultat. Även mindre regularisering, i form av avhopp, gav bättre resultat för mindre komplexa modeller. Gällande jämförelsen med förtränade modeller och icke förtränade modeller visade de experimentella resultaten nästan ingen skillnad för de två kompaktare dataseten medan förträning gav lite sämre resultat på det glesaste datasetet.
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Caseiro, Rui Miguel Fernandes. "Performance evaluation of hybrid millimeter wave systems under limited information." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/18711.
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Mestrado em Engenharia Eletrónica e Telecomunicações<br>Sem resumo disponível.<br>The increase of electronic devices with wireless connections, end up presenting
problems to the current architectures. The current 4G architecture
can not handle the demands that arise from the increase of users and it will
be necessary to deal with higher tra c and connections with higher transmission
rate. Consequently, to meet these requirements, new technologies
and techniques are needed for the next generation(5G).
Techniques such as the use of millimeter waves, combined with terminals
equipped with large antenna arrays or massive number of antennas, although
promising and presenting good results, bring with them new problems. Millimeter
waves due to the smaller wavelength will allow systems with massive
number of antennas. New transmit and receive signal processing (e.g. hybrid
beamforming) has been proposed for millimeter wave communications
combined with a massive number of antennas. However, transmit beamforming
requires the knowledge of channel state information prior to the
transmission. Therefore the design of e cient feedback techniques is of
paramount importance for pratical systems. This issue is more relevant for
massive MIMO based systems than for the conventional MIMO systems.
For the rst one the channel information to fed back is much higher.
In this dissertation a low-overhead feedback channel quantization scheme
is proposed. Then, a single-user mmW massive MIMO system is evaluated
under the developed quantization strategy. It was considered a transmitter
employing a hybrid analog-digital equalizer. The considered techniques
quantizes separately some channel parameters, such as complex fading amplitudes,
transmit and receive array response. After that, these quantized
parameters are fed back to the transmitter and the channel is reconstructed
in order to compute the transmit beamformers. The results have shown
that a very low number of bits is needed to obtain a performance close to
the one obtained with perfect channel information.
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Leyshock, Patrick Michael. "Optimizing Data Movement in Hybrid Analytic Systems." PDXScholar, 2014. https://pdxscholar.library.pdx.edu/open_access_etds/2089.
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Hybrid systems for analyzing big data integrate an analytic tool and a dedicated data-management platform, storing data and operating on the data at both components. While hybrid systems have benefits over alternative architectures, in order to be effective, data movement between the two hybrid components must be minimized. Extant hybrid systems either fail to address performance problems stemming from inter-component data movement, or else require the user to explicitly reason about and manage data movement. My work presents the design, implementation, and evaluation of a hybrid analytic system for array-structured data that automatically minimizes data movement between the hybrid components.
The proposed research first motivates the need for automatic data-movement minimization in hybrid systems, demonstrating that under workloads whose inputs vary in size, shape, and location, automation is the only practical way to reduce data movement. I then present a prototype hybrid system that automatically minimizes data movement. The exposition includes salient contributions to the research area, including a partial semantic mapping between hybrid components, the adaptation of rewrite-based query transformation techniques to minimize data movement in array-modeled hybrid systems, and empirical evaluation of the approach's utility. Experimental results not only illustrate the hybrid system's overall effectiveness in minimizing data movement, but also illuminate contributions made by various elements of the design.
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Sala, Dolors. "Design and evaluation of MAC protocols for hybrid fiber/coaxial systems." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/13268.
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Rüngeler, Matthias [Verfasser], Peter [Akademischer Betreuer] Vary, and Anke [Akademischer Betreuer] Schmeink. "Hybrid digital-analog transmission systems : design and evaluation / Matthias Rüngeler ; Peter Vary, Anke Schmeink." Aachen : Universitätsbibliothek der RWTH Aachen, 2015. http://d-nb.info/1156714559/34.
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Kiss, Steven Brent. "The Effectiveness of Pilot Response to Generate Concatenated Downlink Messages after Evaluation of Hybrid Graphic-Text Clearances." Wright State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=wright1369499745.
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Lindstrom, Joel David. "Design and evaluation of compact heat exchangers for hybrid fuel cell and gas turbine systems." Thesis, Montana State University, 2005. http://etd.lib.montana.edu/etd/2005/lindstrom/LindstromJ0505.pdf.
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Skoglund, Mattias. "Evaluation of test cycles for freight locomotives." Licentiate thesis, KTH, Elektriska maskiner och effektelektronik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-48066.
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Diesel locomotives provide versatility to the railway system as they do not depend on electric feeding. Worldwide they constitute important parts of locomotive fleets used for various tasks such as mainline services, shunting and terminal operations. The main drawbacks are emissions of CO2, NOx and other pollutants. The emissions to air are in general controlled by legislation. The European testing and approval procedure for locomotive engines is performed with the ISO 8178-F test cycle. It is alone meant to resemble all European locomotives. Good correlation was found between mainline operations and the ISO 8178-F test cycle. A good correlation was furthermore found between shunting operations and North American shunting test cycles. However, this thesis has shown that this results in inadequate description of for instance shunting operations. Typical characteristics for shunting are relatively high ratio of transient loading, low mean power output and high amount of idling. Therefore important aspects of diesel locomotive usage are thereby disregarded in certifications. Deficient correlation between test cycle and intended operations may lead to locomotives that are not properly optimised for the type of operation they are intended for. Improperly dimensioned and optimised locomotives cause impaired fuel economy and more emissions emitted. Many Swedish diesel locomotives are to a large extent used in shunting-like conditions in yards and industries for instance. Therefore, it is recommended to supplement the present ISO test cycle with a test cycle that includes the characteristic of shunting. Knowledge about duty cycles for specific operations can be of importance in locomotive acquisition, dimensioning of new locomotives or when estimating emissions and/or fuel consumption. It is essential to make proper dimensioning of propulsion systems as it can imply lower life cycle costs as well as fewer emissions. Appropriate dimensioning of the propulsion system is particularly important for non-conventional propulsion systems. If the application range of a test cycle is narrow, its emulating capability ought to be better at describing and representing the indented application. Today's test cycles state fractional power or torque as a function of engine speed. This may result in misleading duty cycles when the same kind of operation is undertaken with different locomotives that have widespread power ratings. A more powerful locomotive used for the very same load as a less powerful locomotive will result in a different duty cycle. Non-conventional propulsion systems are gaining popularity also in the railway industry where implementation of new technology usually is slow. Dual mode and hybrid systems are two examples. Related to test and duty cycles the build-up of these new propulsion systems change the prerequisites of the propulsion systems. From a duty cycle perspective it is reasonable to implement an additional test cycle for non-conventional propulsion systems if the popularity rises.<br>QC 20111115
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Bartole, Dennis. "Evaluation of the Seismic Performance Factors for Hybrid Coupled Core Wall Systems with Steel Coupling Beams." University of Cincinnati / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1627661636041797.
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Ben, Makhlouf Ibtissem [Verfasser]. "Comparative Evaluation and Improvement of Computational Approaches to Reachability Analysis of Linear Hybrid Systems / Ibtissem Ben Makhlouf." Aachen : Shaker, 2016. http://d-nb.info/1094396621/34.
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Ficker, Kyle A. M. S. "Evaluation of the Seismic Performance Factors for Hybrid Coupled Core Wall Systems with Steel Fuse Coupling Beams." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1396454864.
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Ding, Yao. "Evaluation of New Seismic Performance Factors for Special Hybrid Coupled Core Wall Systems with Steel Coupling Beams." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1573225104906633.
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Brandsma, Age. "Performance Evaluation for a Solar Assisted Air Conditioning System in Taipei." Thesis, Högskolan Dalarna, Energiteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:du-26878.
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This report shows the study performed at Taipei National University of Technology in Taipei to evaluate the performance of a solar air conditioning system. The performance is evaluated under Taiwan climate conditions. The research is performed under summer weather conditions. No influence is done on these conditions. A solar air conditioning system currently available on the market is used. No changes are made to the system. The work to be done is divided into different phases in order to guide the process. First, a literature research is done to find similar research done on this topic and to gain a basic understanding of the topic. Then several measurement plans are made to investigate different parts of the system.. Measurements are done. It is tried to developing a computer model in order to be able to simulate the system performance. The overall objective was to gain knowledge about a solar assisted air-conditioning system and develop a model to simulate the system. Initially a list of research questions was made in order to quantify ‘gaining knowledge’ about the system. The plan was to answer them by using measurement data and creating a model to perform simulations. There are measurements done in this report, however due to too many ‘unknowns’* it is difficult to draw conclusions from them. A lot of research questions are still open and they are also not included in this report. It is also not succeeded to make a working model of a solar assisted air conditioner. It is succeeded in making a model to predict the performance of the evaporator. This model is currently within 11% accurate.
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Inal, Mine. "Ethyl Lactate Production By Hybrid Processes: Determination Of Phase Diagrams And Evaluation Of Performance Of Organophilic Pervaporation Membranes." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/4/1121243/index.pdf.
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Ethyl lactate is a promising, and environmentally benign chemical, which requires efficient separation techniques to overcome the equilibrium limitations in its production. Pervaporation based hybrid systems are successful in these type of equilibrium limited reactions, where product and/or by-product are removed from reaction medium by pervaporation unit(s) so as to drive reaction to completion. For the production of ethyl lactate four possible semi-batch hybrid systems were previously proposed. However, in order to select the suitable hybrid system within the proposed layouts phase equilibrium and reaction kinetics of the system must be well defined in addition to the performance data of the pervaporation membranes. Therefore, vapor pressure curve of ethyl lactate, VLE curves of ethanol-ethyl lactate and ethyl lactate-water were determined and performances of commercial hydrophobic membranes were investigated experimentally for the separation of ethanol-ethyl lactate mixtures.
As a result of vapor pressure and VLE experiments, azeotrope was observed at 71wt% of water for ethyl lactate-water binary mixture at 80mmHg pressure. Furthermore, dependence of vapor composition on pressure was found to be slight for ethanol-ethyl lactate mixtures.
Two commercial hydrophobic membranes, and an organoselective one were used in the separation of ethyl lactate-ethanol mixtures. It is found that hydrophobic membranes have sufficient fluxes and reasonable selectivities. Moreover, it is observed that as temperature increase flux increases and selectivity decreases. Finally, it is concluded that it would be possible to produce ethyl lactate by using the previously proposed integrated PV-esterification reactor systems.
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Svensson, Louise. "Evaluation of quantitative assessment extensions to a qualitative riskanalysis method." Thesis, Linköpings universitet, Databas och informationsteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-143597.
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The usage of information systems (IS) within organizations has become crucial. Information is one of the most vulnerable resources within an enterprise. Information can be exposed, tampered or made non-accessible, where the integrity, confidentiality or availability becomes affected. The ability to manage risks is therefore a central issue in enterprises today. In order to manage risks, the risks need to be identified and further evaluated. All kind of threats with the possibility to negatively affect the confidentiality, integrity, or availability of the organization need to be reviewed. The process of identifying and estimating risks and possible measures is called risk analysis. There are two main categories of risk analysis, qualitative and quantitative. A quantitative method involves interpreting numbers from data and is based on objective inputs. A qualitative method involves interpreting of subjective inputs such as brainstorming and interviews. A common approach is to apply a qualitative method, however a lot of criticism has been raised against using subjective inputs to assessing risks. Secure State is a consulting company with specialist expertise in the field of information security. They help their customers to build trust in the customers systems and processes, making their customers businesses operate with consideration to information security. One service offered by Secure State is risk analysis, and currently they perform qualitative risk analysis. Given all criticisms against a qualitative approach for assessing risks, this study developed a quantitative risk analysis method for Secure State. According to participants, who attended at a risk analysis where the developed quantitative risk analysis method was used, the quantitative risk analysis method improved the risk assessment. Since risks and their effects are decomposed into smaller components in the proposed quantitative risk analysis method, interpretations of risks and their meaning during assessments less likely differed. Therefore, the common understanding of a risk increases, which makes the quality of the evaluation of risks increase. Furthermore, the usage of statistical data increases in the developed quantitative risk analysis method. Additionally, the quantitative method handles the fact that all data used is imperfect. The data is imperfect since it is used to describe the future, and the future has not happened yet.
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Barnawi, Abdulwasa. "Hybrid PV/Wind Power Systems Incorporating Battery Storage and Considering the Stochastic Nature of Renewable Resources." University of Toledo / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1470357709.
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Andersson, Morgan. "Personal news video recommendations based on implicit feedback : An evaluation of different recommender systems with sparse data." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-234137.
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The amount of video content online will nearly triple in quantity by 2021 compared to 2016. The implementation of sophisticated filters is of paramount importance to manage this information flow. The research question of this thesis asks to what extent it is possible to generate personal recommendations, based on the data that news videos implies. The objective is to evaluate how different recommender systems compare to complete random, each other and how they are received by users in a test environment. This study was performed during the spring of 2018, and explore four different algorithms. These recommender systems include a content-based, a collaborative-filter, a hybrid model and a popularity model as a baseline. The dataset originates from a news media startup called Newstag, who provide video news on a global scale. The data is sparse and includes implicit feedback only. Three offline experiments and a user test were performed. The metric that guided the algorithms offline performance was their recall at 5 and 10, due to the fact that the top list of recommended items are of most interest. A comparison was done on different amounts of meta-data included during training. Another test explored respective algorithms performance as the density of the data increased. In the user test, a mean opinion score was calculated based on the quality of recommendations that each of the algorithms generated for the test subjects. The user test also included randomly sampled news videos to compare with as a baseline. The results indicate that for this specific setting and data set, the content-based recommender system performed best in both the recall at five and ten, as well as in the user test. All of the algorithms outperformed the random baseline.<br>Mängden video som finns tillgänglig på internet förväntas att tredubblas år 2021 jämfört med 2016. Detta innebär ett behov av sofistikerade filter för att kunna hantera detta informationsflöde. Detta examensarbete ämnar att svara på till vilken grad det går att generera personliga rekommendationer baserat på det data som nyhetsvideo innebär. Syftet är att utvärdera och jämföra olika rekommendationssystem och hur de står sig i ett användartest. Studien utfördes under våren 2018 och utvärderar fyra olika algoritmer. Dessa olika rekommendationssystem innefattar tekniker som content-based, collaborative-filter, hybrid och en popularitetsmodell används som basvärde. Det dataset som används är glest och har endast implicita attribut. Tre experiment utförs samt ett användartest. Mätpunkten för algoritmernas prestanda utgjordes av recall at 5 och recall at 10, dvs. att man mäter hur väl algoritmerna lyckas generera värdefulla rekommendationer i en topp-fem respektive topp-10-lista av videoklipp. Detta då det är av intresse att ha de mest relevanta videorna högst upp i sin lista av resultat. En jämförelse gjordes mellan olika mängd metadata som inkluderades vid träning. Ett annat test gick ut på att utforska hur algoritmerna presterar då datasetet blir mindre glest. I användartestet användes en utvärderingsmetod kallad mean-opinion-score och denna räknades ut per algoritm genom att testanvändare gav betyg på respektive rekommendation, baserat på hur intressant videon var för dem. Användartestet inkluderade även slumpmässigt generade videos för att kunna jämföras i form av basvärde. Resultaten indikerar, för detta dataset, att algoritmen content-based presterar bäst både med hänsyn till recall at 5 & 10 samt den totala poängen i användartestet. Alla algoritmer presterade bättre än slumpen.
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Ben, Makhlouf Ibtissem [Verfasser], Stefan [Akademischer Betreuer] Kowalewski, and Goran [Akademischer Betreuer] Frehse. "Comparative evaluation and improvement of computational approaches to reachability analysis of linear hybrid systems / Ibtissem Ben Makhlouf ; Stefan Kowalewski, Goran Frehse." Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1130326780/34.
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Ben, Makhlouf Ibtissem Verfasser], Stefan [Akademischer Betreuer] Kowalewski, and Goran [Akademischer Betreuer] [Frehse. "Comparative evaluation and improvement of computational approaches to reachability analysis of linear hybrid systems / Ibtissem Ben Makhlouf ; Stefan Kowalewski, Goran Frehse." Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1130326780/34.
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Friberg, Joy. "Evaluation of cross-platform development for mobile devices." Thesis, Linköpings universitet, Interaktiva och kognitiva system, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-103817.
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Developing an application for several platforms can be time consuming because each platform has its own operating system and different developing language. Cross-platform development makes it possible to develop an ap-plication that will work on several platforms. This report will evaluate this kind of development by doing a case study for the company CGI. The case study will evaluate which cross-platform methodology is the preferred choice for this specific vacation booking application I developed for CGI. The different methodologies I studied were web, hybrid, interpreted and cross-compiled. The preferred methodology for this vacation booking application I developed was in this case the hybrid alternative. When selecting this methodology I also chose two different tools and those two were Icenium and jQuery Mobile. The purpose of this report was to find out if cross-platform development can be a substitute to native programming and by evaluating and developing cross-platform I found out that it can be a substitute if the application is not to complex. In this specific case I also believe that hybrid development is a good substitute to native development for this kind of applications.
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Linde, Daniel. "Evaluation of a Flat-Plate Photovoltaic Thermal (PVT) Collector prototype." Thesis, Högskolan Dalarna, Energiteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:du-24061.
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This Master thesis, in collaboration with Morgonsol Väst AB, was completed as a part of the Solar Energy engineering program at Dalarna University. It analyses the electrical and thermal performance of a prototype PVT collector developed by Morgonsol Väst AB. By following the standards EN 12975 and EN ISO 9806 as guides, the thermal tests of the collector were completed at the facility in Borlänge. The electrical performance of the PVT collector was evaluated by comparing it to a reference PV panel fitted next to it. The result from the tests shows an improved electrical performance of the PVT collector caused by the cooling and a thermal performance described by the linear efficiency curve ηth=0.53-21.6(Tm-Ta/G). The experimental work in this thesis is an initial study of the prototype PVT collector that will supply Morgonsol Väst with important data for future development and research of the product.
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Cordes, Florian [Verfasser], Frank [Akademischer Betreuer] Kirchner, Frank [Gutachter] Kirchner, and Udo [Gutachter] Frese. "Design and Experimental Evaluation of a Hybrid Wheeled-Leg Exploration Rover in the Context of Multi-Robot Systems / Florian Cordes ; Gutachter: Frank Kirchner, Udo Frese ; Betreuer: Frank Kirchner." Bremen : Staats- und Universitätsbibliothek Bremen, 2018. http://d-nb.info/1183252072/34.
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Green, Robert C. II. "Novel Computational Methods for the Reliability Evaluation of Composite Power Systems using Computational Intelligence and High Performance Computing Techniques." University of Toledo / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1338894641.
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Boeuf, Vianney. "Dynamics of a two-level system with priorities and application to an emergency call center." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLX120/document.
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Dans cette thèse, nous analysons la dynamique de systèmes à événements discrets avec synchronisation et priorités, au moyen de réseaux de Petri et de réseaux de files d'attente.Nous appliquons cela à l'évaluation de performance d'un centre d'appels d'urgence.Notre motivation de départ est pratique. Pendant la durée de ce travail, un nouveau centre d'appels d'urgence a été mis en place pour l'agglomération parisienne, traitant les appels pour la police et les pompiers.La nouvelle organisation traite les appels en deux niveaux.Un premier niveau d'opérateurs répond aux appels, identifie les appels urgents et traite les appels non urgents.Les opérateurs de second niveau sont spécialistes (policiers ou pompiers) et traitent les demandes d'intervention.Quand un appel est identifié au niveau 1 comme très urgent, l'opérateur reste en ligne avec l'appelant jusqu'à ce qu'un opérateur de niveau 2 réponde. De plus, l'appel est prioritaire.Une conséquence de cette procédure est que, lorsqu'aucun opérateur de niveau 2 n'est disponible, les opérateurs de niveau 1 attendent avec ces appels très urgents, et la capacité du niveau 1 diminue.Nous nous intéressons à l'évaluation de performance de divers systèmes correspondant à cette description générale, dans des situations de saturation.Nous proposons trois modèles différents pour traiter ce type de systèmes.Les deux premiers sont des modèles de réseaux de Petri temporisés.Nous enrichissons les classiques réseaux de Petri à choix libres en autorisant des situations de conflit où le routage est résolu par des priorités.La principale difficulté est alors que l'opérateur de la dynamique n'est plus monotone.Dans un premier modèle, nous proposons une dynamique discrète pour cette classe de réseaux de Petri, avec des temps de séjour constants sur les places.Nous prouvons que les variables compteurs d'une exécution du réseau sont les solutions d'un système affine par morceaux, avec retards.Nous étudions les régimes stationnaires de cette dynamique, et caractérisons les régimes affines comme solutoins d'un système affine par morceaux, qui peut être vu comme un système sur le semi-corps de germes tropical (min plus).Les applications numériques montrent cependant que la convergence ne se fait pas toujours vers ces régimes stationnaires affines.Le second modèle est une transformation continue du précédent. Pour la même classe de réseaux de Petri, nous proposons une dynamique sous forme d'équations différentielles discontinues.Nous établissons l'existence et l'unicité de la solution.L'objectif de cette modélisation est d'obtenir un système plus simple dans lequel les pathologies du temps discret disparaissent. Nous montrons que les régimes stationaires sont les mêmes que ceux de la dynamique discrète. Les simulations numériques semblent montrer que la convergence s'obtient effectivement dans ce cas.Nous modélisons aussi le centre d'appels d'urgence comme un réseau de files d'attente, prenant ainsi en compte le caractère aléatoire des différentes variables du centre d'appel.Pour ce système, nous prouvons que la dynamique, après une transformation d'échelle, converge vers une limite fluide, qui correspond au système d'équations différentielles précédent.Cela conforte notre seconde modélisation.Les principaux outils de la preuve de convergence sont le calcul stochastique pour les processus de Poisson, les formulations de Skorokhod généralisées, ou encore des arguments de couplage.Ainsi, nos trois modèles d'un même centre d'appels d'urgence définissent un même comportement asymptotique schématique, décrivant différentes phases de congestion du centre.Dans une seconde partie de cette thèse, nous analysons des simulations poussées, prenant en compte les nombreux détails de notre étude de cas. Les simulations confirment le comportement schématique prédit par nos modèles mathématiques. Nous discutons aussi des interactions complexes provenant de la nature hétérogène du niveau 2<br>In this thesis, we analyze the dynamics of discrete event systems with synchronization and priorities, by the means of Petri nets and queueing networks.We apply this to the performance evaluation of an emergency call center.Our original motivation is practical. During the period of this work, a new emergency call center became operative in Paris area, handling emergency calls to police and firemen.The new organization includes a two-level call treatment. A first level of operators answers calls, identifies urgent calls and handles (numerous) non-urgent calls.Second level operators are specialists (policemen or firemen) and handle emergency demands.When a call is identified at level 1 as extremely urgent, the operator stays in line with the call until a level 2 operator answers. The call has priority for level 2 operators.A consequence of this procedure is that, when level 2 operators are busy, level 1 operators wait with extremely urgent calls, and the capacity of level 1 diminishes.We are interested in the performance evaluation of various systems corresponding to this general description, in stressed situations.We propose three different models addressing this kind of systems.The first two are timed Petri net models.We enrich the classical free choice Petri nets by allowing conflict situations in which the routing is solved by priorities.The main difficulty in this situation is that the operator of the dynamics becomes non monotone.In a first model, we consider discrete dynamics for this class of Petri nets, with constant holding times on places.We prove that the counter variables of an execution of the Petri net are solutions of a piecewise linear system with delays.As far as we know, this proof is new, even for the class of free choice nets, which is a subclass of ours.We investigate the stationary regimes of the dynamics, and characterize the affine ones as solutions of a piecewise linear system, which can be seen as a system over a tropical (min-plus) semifield of germs.Numerical experiments show that, however, convergence does not always holds towards these affine stationary regimes.The second model is a ``continuization'' of the previous one. For the same class of Petri nets, we propose dynamics expressed by differential equations, so that the tokens and time events become continue.For this differential system with discontinuous righthandside, we establish the existence and uniqueness of the solution.By using differential equations, we aim at obtaining a simpler model in which discrete time pathologies disappear. We show that the stationary regimes are the same as the stationary regimes of the discrete time dynamics.Numerical experiments tend to show that, in this setting, convergence effectively holds.We also model the emergency call center described above as a queueing system, taking into account the randomness of the different call center variables.For this system, we prove that, under an appropriate scaling, the dynamics converges to a fluid limit which corresponds to the differential equations of our Petri net model.This provides support for the second model.Stochastic calculus for Poisson processes, generalized Skorokhod formulations and coupling arguments are the main tools used to establish this convergence.Hence, our three models of an identical emergency call center yield the same schematic asymptotic behavior, expressed as a piecewise linear system of the parameters, and describing the different congestion phases of the system.In a second part of this thesis, simulations are carried out and analyzed, taking into account the many subtleties of our case study (for example, we construct probability distributions based on real data analysis).The simulations confirm the schematic behavior described by our mathematical models.We also address the complex interactions coming from the heterogeneous nature of level 2
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Lee, Young Duk [Verfasser], George [Akademischer Betreuer] Tsatsaronis, Felix [Akademischer Betreuer] Ziegler, Kook Young [Akademischer Betreuer] Ahn, and Tetyana [Akademischer Betreuer] Morozyuk. "Thermodynamic, economic and environmental evaluation of solid-oxide fuel-cell hybrid power-generation systems / Young Duk Lee. Gutachter: Felix Ziegler ; George Tsatsaronis ; Kook Young Ahn ; Tetyana Morozyuk. Betreuer: George Tsatsaronis." Berlin : Technische Universität Berlin, 2015. http://d-nb.info/1075807468/34.
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Wiziack, Nadja Karolina Leonel. "Desenvolvimento de sistemas multissensoriais híbridos, língua e narizes eletrônicos para a avaliação de combustíveis." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/3/3140/tde-21102010-104248/.
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A utilização simultânea de diferentes tecnologias de sensores é um método eficiente para aumentar o desempenho de sistemas sensoriais. Com o intuito de contribuir para um melhor controle da qualidade de combustíveis brasileiros, foram desenvolvidos neste trabalho sensores para serem utilizados em Língua e Narizes Eletrônicos. Estes sistemas multissensoriais foram utilizados separadamente, bem como simultaneamente, integrando-os para a avaliação da qualidade de gasolina e etanol. Desse modo, foram fabricados dois tipos de sistemas multissensoriais híbridos. O primeiro sistema foi composto pela integração de uma Língua Eletrônica (LE) e de um Nariz Eletrônico (NE), denominado SH-1. Neste sistema multissensorial, a impedância elétrica do conjunto dos diferentes sensores, baseados em filmes nanoestruturados de diferentes polímeros condutores depositados sobre diferentes microeletrodos de ouro, foi medida simultaneamente no líquido e no vapor de amostras de combustíveis. Já o segundo sistema multissensorial híbrido, SH-2, foi composto pela união de dois tipos de NEs e foi fabricado integrando sensores produzidos a partir de microbalanças de quartzo e de uma matriz de capacitores, ambos funcionalizados com os mesmos materiais sensoativos, polímeros condutores e metaloporfirinas. A frequência de oscilação do cristal de quartzo, bem como a capacitância da matriz de capacitores foram medidas no vapor de combustíveis. Estes sistemas híbridos são de fácil fabricação, simples operação e sensíveis a uma grande variedade de substâncias químicas de interesse. Foram empregadas ferramentas de análise multivariada de dados para a calibração e validação dos sensores, bem como para a interpretação dos resultados obtidos.<br>The simultaneous use of different sensor technologies is an efficient method to increase the performance of sensor systems. Aiming to contribute to a better quality control of Brazilian fuels, sensors were developed in this work to be used in electronic tongue and electronic noses. These multisensor systems were used separately and simultaneously integrating them to evaluation the quality of gasoline and ethanol. Thus, two types of multisensor hybrid systems were manufactured. The first system was composed by the integration of an Electronic Tongue (LE) and an Electronic Nose (NE), called SH-1. In this multisensor system, the electrical impedance of all the different sensors, based on nanostructured films of conducting polymers deposited on different gold microelectrodes, was measured simultaneously in both liquid and vapor fuel samples. The second multisensor hybrid system, SH-2, was composed by the union of two types of NEs and was fabricated by integrating sensors made from quartz microbalance and an array of capacitors, both functionalized with the same sensitive materials, conducting polymers and metalloporphyrins. The oscillation frequency of quartz crystal, and the capacitance of the array of capacitors were measured in the fuel vapor. These hybrid systems are easy to fabricate, simple to operate and sensitive to a wide variety of chemicals of interest. Tools for multivariate analysis were used for calibration and validation of the sensors, as well as for the interpretation of results.
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Meyer, Frank. "Systèmes de recommandation dans des contextes industriels." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00767159.
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Cette thèse traite des systèmes de recommandation automatiques. Les moteurs de recommandation automatique sont des systèmes qui permettent, par des techniques de data mining, de recommander automatiquement à des clients, en fonction de leurs consommations passées, des produits susceptibles de les intéresser. Ces systèmes permettent par exemple d'augmenter les ventes sur des sites web marchands : le site Amazon a une stratégie marketing en grande partie basée sur la recommandation automatique. Amazon a popularisé l'usage de la recommandation automatique par la célèbre fonction de recommandation que nous qualifions d'item-to-items, le fameux : " les personnes qui ont vu/acheté cet articles ont aussi vu/acheté ces articles. La contribution centrale de cette thèse est d'analyser les systèmes de recommandation automatiques dans le contexte industriel, et notamment des besoins marketing, et de croiser cette analyse avec les travaux académiques.
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Birkhold, Jörg-Michael [Verfasser], and A. [Akademischer Betreuer] Albers. "Komfortobjektivierung und funktionale Bewertung als Methoden zur Unterstützung der Entwicklung des Wiederstartsystems in parallelen Hybridantrieben = Objectification of comfort and functional evaluation as methods to support the development of restarting systems in parallel hybrid drivetrains [[Elektronische Ressource]] / Jörg-Michael Birkhold. Betreuer: A. Albers." Karlsruhe : KIT-Bibliothek, 2013. http://d-nb.info/1038256712/34.
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Greppi, Matteo <1985>. "Numerical optimization,modeling and system evaluation of a thermophotovoltaic hybrid panel." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5415/.
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Photovoltaic (PV) solar panels generally produce electricity in the 6% to 16% efficiency range, the rest being dissipated in thermal losses. To recover this amount, hybrid photovoltaic thermal systems (PVT) have been devised. These are devices that simultaneously convert solar energy into electricity and heat. It is thus interesting to study the PVT system globally from different point of views in order to evaluate advantages and disadvantages of this technology and its possible uses.
In particular in Chapter II, the development of the PVT absorber numerical optimization by a genetic algorithm has been carried out analyzing different internal channel profiles in order to find a right compromise between performance and technical and economical feasibility.
Therefore in Chapter III ,thanks to a mobile structure built into the university lab, it has been compared experimentally electrical and thermal output power from PVT panels with separated photovoltaic and solar thermal productions.
Collecting a lot of experimental data based on different seasonal conditions (ambient temperature,irradiation, wind...),the aim of this mobile structure has been to evaluate average both thermal and electrical increasing and decreasing efficiency values obtained respect to separate productions through the year.
In Chapter IV , new PVT and solar thermal equation based models in steady state conditions have been developed by software Dymola that uses Modelica language.
This permits ,in a simplified way respect to previous system modelling softwares, to model and evaluate different concepts about PVT panel regarding its structure before prototyping and measuring it.
Chapter V concerns instead the definition of PVT boundary conditions into a HVAC system . This was made trough year simulations by software Polysun in order to finally assess the best solar assisted integrated structure thanks to F_save(solar saving energy)factor.
Finally, Chapter VI presents the conclusion and the perspectives of this PhD work.
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Khallat, Mohamed Ali. "A methodology for evaluating photovoltaic-fuel hybird energy systems." Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/53626.
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A major issue encountered in the large scale use of Photovoltaic (PV) energy sources for the production of electricity is the variability of the resource itself. Extensive fluctuations of the PV generation may cause dynamic operational problems for an electric utility. In order to remedy this situation it is proposed that fuel cell power plants be operated in parallel with PV arrays. This hybrid operation will help to smooth out the fluctuating PV output. Because of its high ramping capability the fuel cell will be able to absorb such fluctuations.
An overall methodology is presented to evaluate the PV system in a large utility. This methodology has two parts-planning and operation. The aim of the planning study is to determine the capacity credit of a PV system based on the loss of load probability (LOLP). Long term SOLMET data is used to determine the nature of available insolation at a particular site. The expected value of hourly insolation is used in the planning study. The aim of the operation study is to validate the results of planning study in the shorter operational time frame, and determine the fuel cell requirements and associated operating cost savings for each penetration level of PV.
A technique to find the maximum penetration level of PV, without causing any economic penalty, is presented. It is found that the penetration level can be increased up to 15.62% of peak load by adding fuel cells to the system under consideration. The annual peak load for this system is taken as 6400 MW. It must be mentioned here that, similar evaluations for other systems may yield somewhat different results. This technique is general enough such that it can be used for other intermittent sources of generation as well.<br>Ph. D.
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Liu, Fengyuan. "Design, fabrication and evaluation of a hybrid biomanufacturing system for tissue engineering." Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/design-fabrication-and-evaluation-of-a-hybrid-biomanufacturing-system-for-tissue-engineering(13717125-61ac-4f95-a83b-62a706a5ea15).html.
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The combined use of additive manufacturing (AM), biocompatible and biodegradable materials, cells and biomolecular signals is the most common biomanufacturing strategy applied in scaffold fabrication. AM processes offer a better control and the ability to actively design the porosity and interconnectivity of the scaffolds. When combined with clinical imaging data, these fabrication techniques can be used to produce constructs that are customised to the shape of the defect or injury. However, due to the hydrophobicity of the commonly used synthetic biopolymers, cell-seeding and proliferation efficiency are limited. Moreover, due to the tortuosity of the scaffolds, non-uniform cell distribution with rare cell adhesion in the core region also commonly exists. Additionally, the commercial available machines are not able to create multi-material and material gradient scaffolds that are required to mimic the nature of nature tissues. To overcome the above limitations, this thesis describes the development of a hybrid bio-additive manufacturing system, called plasma-assisted bioextruson system (PABS), to produce smart scaffold by combining multi-head polymer extrusion and the plasma surface modification layer by layer, in the same chamber. PABS allows not only multiple biomaterials printing with the multi-extrusion heads, but also enables in-process plasma surface modification for zonal plasma-treated scaffolds fabrication. The in-house user interface enables a high degree of scaffold design freedom as it allows users to create single or multi-material constructs with uniform pore size or pore size gradient by changing process parameters such as lay-down pattern, filament distance, feed rate and layer thickness. Water contact angle tests and in vitro biological tests confirm that the hydrophilicity of synthetic polymers is improved and cell attachment and proliferation are enhanced after the in-process plasma modification. The effect of plasma treatment is also investigated by using different plasma modification strategies and various plasma modification parameters, including the plasma deposition velocity and the distance between the plasma jet and the printed scaffolds. The biological results also show dependence between the surface modification strategies and cell proliferation. The mechanical compression results show that for a fixed plasma deposition velocity, the effect of changing the distance between the plasma head and the deposited material is not significant. However, for a fixed distance, the compressive modulus increases with the increase in the plasma deposition velocity.
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Tamagna-Darr, Lucas. "Evaluating the effectiveness of an intrusion prevention system-honeypot hybrid /." Online version of thesis, 2009. http://hdl.handle.net/1850/10837.
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Wilson, Jonathan David. "A hybrid SOFC-microturbine combined-cycle system: modeling, efficiency evaluation and power management." Thesis, Montana State University, 2012. http://etd.lib.montana.edu/etd/2012/wilson/WilsonJ0512.pdf.
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As centralized electricity generation and transmission issues continue to complicate electricity demand, interest in distributed generation solutions is increasing. Solid oxide fuel cells are high temperature and efficiency electrochemical devices that can operate on natural gas as well as hydrogen. When in combined cycle operation with a microturbine, the system has the ability to utilize the unused fuel from the solid oxide fuel cell and waste heat to increase the electrical energy, overall efficiency, and feasibility of market penetration of the system. The waste heat can also be repurposed outside the system, known as combined heat and power, for heating residential water supplies. This thesis presents the modeling, efficiency evaluation and power management of a hybrid solid oxide fuel cell/microturbine system in combined cycle operation with combined heat and power functionality for residential applications in islanded and grid-connected modes. The response of the system to load changes is also examined. The dynamic models of the solid oxide fuel cell and microturbine are integrated using power electronic interfacing and simulated in Matlab/Simulink. Simulation results demonstrate an efficiency increase of the system in combined cycle operation and the dynamic behavior of the system in stand-alone operation under different load conditions.
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Perez-Collazo, Carlos. "Evaluation of the WEC sub-system of a hybrid wind-wave energy converter." Thesis, University of Plymouth, 2017. http://hdl.handle.net/10026.1/9485.
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The sustainable development of the offshore wind and wave energy sectors requires optimising the exploitation of the resources, and it is in relation to this and the shared challenge for both industries to reduce their costs that the option of integrating offshore wind and wave energy arose during the past decade. The relevant aspects of this integration are addressed in this work, and in particular the evaluation of the Wave Energy Converter (WEC) sub-system of a hybrid wind-wave energy converter: the state of the art of combined technologies; the definition of a novel hybrid prototype, based on a preliminary feasibility analysis of a conceptual proposal; and the evaluation of a simplified version of this prototype by means of physical and numerical modelling as a mean to set the reference and define new tools and methods for future evaluation and optimisation of the prototype. Because of the novelty of combined wave and offshore wind systems, fundamental knowledge was lacking as, for example a comprehensive review and classification, which was published as a journal paper framed in the present work. In particular, the core of this PhD thesis deals with the WEC sub-system of a hybrid device that integrates an Oscillating Water Column (OWC) device into the typical monopile substructure of an offshore wind turbine. A new prototype of the hybrid energy converter has been proposed, and a patent application was filled. Furthermore, an experimental set-up was designed, built and tested at a wave flume. On the basis of this experimental campaign the performance of the device is analysed. Finally, a full 3D-numerical mirror of the experimental set-up, including the hybrid energy converter, is defined and validated, and the flume enclosure effects studied for regular waves.
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Liu, Liman. "Evaluation of four sorghum hybrids in a gluten-free noodle system." Thesis, Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1599.
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Oesterle, Jonathan. "Holistic approach to designing hybrid assembly lines A comparative study of Multi-Objective Algorithms for the Assembly Line Balancing and Equipment Selection Problem under consideration of Product Design Alternatives Evaluation of the influence of dominance rules for the assembly line design problem under consideration of product design alternatives Hybrid Multi-objective Optimization Method for Solving Simultaneously the line Balancing, Equipment and Buffer Sizing Problems for Hybrid Assembly Systems Comparison of Multiobjective Algorithms for the Assembly Line Balancing Design Problem Efficient multi-objective optimization method for the mixed-model-line assembly line design problem Detaillierungsgrad von Simulationsmodellen Rechnergestützte Austaktung einer Mixed-Model Line. Der Weg zur optimalen Austaktung." Thesis, Troyes, 2017. http://www.theses.fr/2017TROY0012.
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Le travail présenté dans cette thèse concerne la formulation et la résolution de deux problèmes d'optimisation multi-objectifs. Ces problèmes de décision, liés à une approche holistique, ont pour but de sélectionner la meilleure configuration « produit/ligne d’assemblage » à partir d'un ensemble de design produits, et de ressources. Concernant le premier problème, un modèle de coût a été développé afin de traduire les interdépendances complexes entre la sélection d’un design produit et les caractéristiques des ressources. Une étude empirique est proposée et vise à comparer, selon plusieurs indicateurs de qualité multi-objectifs, différentes méthodes de résolution - comprenant des algorithmes génétiques, de colonies de fourmis, d’optimisation par essaims particulaires, des chauves-souris, de recherche du coucou et de pollinisation des fleurs. Plusieurs règles de dominance et une recherche locale spécifique au problème ont été appliquées aux méthodes de résolution les plus prometteuses. Concernant le second problème, qui se penche également sur le dimensionnement des stocks tampons, les méthodes de résolution sont à un modèle de simulation à événements discrets, dont la fonction première est l’évaluation des valeurs des différentes fonctions objectives. L’approche holistique associée aux deux problèmes a été validée avec deux cas industriels<br>The work presented in this thesis concerns the formulation and the resolution of two holistic multi-objective optimization problems associated with the selection of the best product and hybrid assembly line configuration out of a set of products, processes and resources alternatives. Regarding the first problem, a cost model was developed in order to translate the complex interdependencies between the selection of specific product designs, processes and resources characteristics. An empirical study is proposed, which aimed at comparing, according to several multi-objective quality indicators, various resolution methods – including variants of evolutionary algorithms, ant colony optimization, particle swarm optimization, bat algorithms, cuckoo search algorithms, and flower-pollination algorithms. Several dominance rules and a problem-specific local search were applied to the most promising resolution methods. Regarding the second problem, which also considers the buffer sizing, the developed algorithms were enhanced with a genetic discrete-event simulation model, whose primary function is to evaluate the value of the various objective functions. The demonstration of the associated resolution frameworks for both problems was validated through two industrial-cases
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Taylor, Brian Jonathan Hart. "Evaluating methods for multi-level system design of a series hybrid vehicle." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/44836.
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In design and optimization of a complex system, there exist various methods for defining the relationship between the system as a whole, the subsystems and the individual components. Traditional methods provide requirements at the system level which lead to a set of design targets for each subsystem. Meeting these targets is sometimes a simple task or can be very difficult and expensive, but this is not captured in the design process and therefore unknown at the system level. This work compares Requirements Allocation (RA) with Distributed Value Driven Design (DVDD).
A computational experiment is proposed as a means of evaluating RA and DVDD. A common preliminary design is determined by optimizing the utility of the system, and then a Subsystem of Interest (SOI) is chosen as the focal point of subsystem design. First the behavior of a designer using Requirements Allocation is modeled with an optimization problem where the distance to the design targets is minimized. Next, two formulations of DVDD objective functions are used to approximate the system-level value function. The first is a linear approximation and the second is a nonlinear approximation with higher fidelity around the preliminary design point. This computational experiment is applied to a series hybrid vehicle where the SOI is the electric motor.
In this case study, RA proves to be more effective than DVDD on average. It is still possible that the use of objectives is superior to design targets. This work shows that, for this case study, a linear approximation as well as a slightly higher fidelity approximation are not well suited to find the design alternative with the highest expected utility.
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Barajas, Leandro G. "Process Control in High-Noise Environments Using A Limited Number Of Measurements." Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/7741.
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The topic of this dissertation is the derivation, development, and evaluation of novel hybrid algorithms for process control that use a limited number of measurements and that are suitable to operate in the presence of large amounts of process noise.
As an initial step, affine and neural network statistical process models are developed in order to simulate the steady-state system behavior. Such models are vitally important in the evaluation, testing, and improvement of all other process controllers referred to in this work. Afterwards, fuzzy logic controller rules are assimilated into a mathematical characterization of a model that includes the modes and mode transition rules that define a hybrid hierarchical process control. The main processing entity in such framework is a closed-loop control algorithm that performs global and then local optimizations in order to asymptotically reach minimum bias error; this is done while requiring a minimum number of iterations in order to promptly reach a desired operational window.
The results of this research are applied to surface mount technology manufacturing-lines yield optimization. This work achieves a practical degree of control over the solder-paste volume deposition in the Stencil Printing Process (SPP). Results show that it is possible to change the operating point of the process by modifying certain machine parameters and even compensate for the difference in height due to change in print direction.
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Gorman, Craig T. "Initial measurements and test system development for evaluation of a novel, hybrid reverse osmosis-electrodialysis process." Diss., Connect to online resource, 2005. http://wwwlib.umi.com/cr/colorado/fullcit?p1428735.
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Skoglund, Anders. "A Simulation-based Evaluation of a Hybrid Storage System Combining P2P, F2F, and Cloud storage with a Distributed Reputation System." Thesis, Linköpings universitet, Databas och informationsteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-103191.
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As the amount of valuable data that the average person owns increases, there is a growing need for personal low cost backup services. A variety of methods have been developed to fulfill this need, from cloud based backup services to cooperative methods where users share spare resources to store each other’s data, either using a peer-to-peer (P2P) network to store data among a large number of diverse peers, or a friend-to-friend (F2F) network to store data among a smaller number of trusted friends. There are several advantages to each method, but they all have issues that can make them unsuitable for this task. The purpose of this thesis is to explore the possibility of avoiding these issues by creating a hybrid system that stores files using a combination of cloud storage and trust aware P2P and F2F networks. This should also give the user greater control over the distribution of files and make it more resilient towards malicious peers. A simple file storage system was designed that uses a combined P2P and F2F network together with a reputation system for determining how trustworthy a peer is based on its past behavior, as well as having the option of falling back on cloud storage. The user decides for each file how much data shall be stored using normal peers, friend peers, and cloud storage, and any requirements that the peers used must fulfill. A partial implementation of the system was created as part of a simulator used to evaluate how well the combined P2P and F2F networks and reputation system behaves in various circumstances, and using different distribution policies. While it is difficult to compare the performance of this system to that of other backup and file storage systems without more thorough testing, the results obtained show that it is in fact possible to construct a trustaware hybrid system, that it should perform better than a pure P2P or F2F system, and that it should perform well even if a majority of all peers were to act maliciously.
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Miller, Andrew Jared. "A Hybrid Method for Auralizing Vibroacoustic Systems and Evaluating Audio Fidelity/Sound Quality Using Machine Learning." BYU ScholarsArchive, 2021. https://scholarsarchive.byu.edu/etd/8946.
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Two separate methods are presented to aid in the creation and evaluation of acoustic simulations. The first is a hybrid method that allows separate low and high-frequency acoustic responses to be combined into a single broadband response suitable for auralization. The process consists of four steps: 1) creating separate low-frequency and high-frequency responses of the system of interest, 2) interpolating between the two responses to get a single broadband magnitude response, 3) adding amplitude modulation to the high-frequency portion of the response, and 4) calculating approximate phase information. An experimental setup is used to validate the hybrid method. Listening tests are conducted to assess the realism of simulated auralizations compared to measurements. The listening tests confirm that the method is able to produce realistic auralizations, subject to a few limitations. The second method presented is a machine learning approach for predicting human perceptions of audio fidelity and sound quality. Several algorithms are compared and various audio features considered in developing the machine learning models. The developed models accurately predict human perceptions of audio fidelity and sound quality in three distinct applications: assessing the fidelity of compressed audio, evaluating the fidelity of simulated audio, and comparing the sound quality of loudspeakers. The high accuracies achieved confirm that machine learning models could potentially supplant listening tests, significantly decreasing the time required to assess audio quality or fidelity.
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Zeng, Xianwu. "Improving the Energy Density of Hydraulic Hybrid Vehicle (HHVs) and Evaluating Plug-In HHVs." University of Toledo / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1239319863.
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Weritz, Wulf. "Fall- und problemorientiertes Lernen in hybriden Lernarrangements theoretische Grundlagen, Entwicklung und empirische Evaluation von Studienmaterialien für die Lehrerausbildung an einer Präsenzuniversität." Frankfurt, M. Berlin Bern Bruxelles New York, NY Oxford Wien Lang, 2007. http://d-nb.info/990483614/04.
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Syahrina, Alvi. "Online Machine Translator System and Result Comparison." Thesis, Högskolan i Borås, Institutionen Handels- och IT-högskolan, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-20869.
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Translation from one human language to another has been using the help of the capabilities of computer advances. There are a lot of machine translators nowadays, each adapts to different machine translator approaches. This thesis presents the distinction between two selected machine translator approaches, statistical machine translator (SMT) and hybrid machine translator (HMT). The research focuses on creating evaluation for two machine translator of different approaches by both textual studies and evaluation experiment. The result of this research is an evaluation of the translator system and also the translation result. This result is then hoped to add information into the history of machine translators.<br>Program: Kandidatutbildning i informatik
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Broy, Perrine. "Evaluation de la sûreté de systèmes dynamiques hybrides complexes : application aux systèmes hydrauliques." Phd thesis, Université de Technologie de Troyes, 2014. http://tel.archives-ouvertes.fr/tel-01006308.
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Ces travaux s'intéressent à l'estimation de la fiabilité des évacuateurs de crues vannés. Le comportement fiabiliste de ces systèmes hydrauliques dépend à la fois d'événements aléatoires discrets, mais aussi de l'évolution d'une variable déterministe continue : ce sont des systèmes dynamiques hybrides. Pour ces systèmes, l'événement redouté est réalisé lorsque le niveau de la retenue atteint un seuil de sûreté. La démarche de fiabilité dynamique proposée dans cette thèse vise à prendre en compte l'information temporelle, de la modélisation à la synthèse d'indicateurs fiabilistes pour l'aide à la décision et développe deux contributions : 1) L'élaboration d'une base de connaissances dédiée à la description des évacuateurs de crues en termes de fiabilité dynamique. Chaque classe de composants est décrite par un automate stochastique hybride dont les états sont les différentes phases de son fonctionnement. 2) Le suivi de la simulation de Monte Carlo, le traitement et l'analyse des "histoires" (séquence de tous les états activés et des dates d'activation) obtenues en simulation. Cela permet de construire des indicateurs de fiabilité classique (probabilité d'occurrence de l'évènement redouté, identification des coupes équivalentes prépondérantes, ...). Des indicateurs de fiabilité dynamique basés sur la classification des histoires en fonction des dates de défaillance des composants concernés et sur l'estimation de l'importance dynamique sont aussi proposés.
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Höge, Bo [Verfasser], and Matthias [Akademischer Betreuer] Rötting. "Entwicklung und Evaluation eines Shared-Vision-Systems im Kontext hybrider Leistungsbündel / Bo Höge. Betreuer: Matthias Rötting." Berlin : Universitätsbibliothek der Technischen Universität Berlin, 2011. http://d-nb.info/1017593566/34.
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Njoya, Motapon Souleman. "Design and simulation of a fuel cell hybrid emergency power system for a more electric aircraft : evaluation of energy management schemes." Mémoire, École de technologie supérieure, 2013. http://espace.etsmtl.ca/1157/1/NJOYA_MOTAPON_Souleman.pdf.
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Dans le but de réduire la consommation de combustibles fossiles et les coûts liés à la maintenance, l’industrie aéronautique vise à remplacer la plupart des systèmes hydrauliques et pneumatiques des avions conventionnels par des systèmes électriques. Ces nouveaux avions du futur sont appelés « avion plus électrique ». Dans ces avions plus électrique, l’augmentation de la demande électrique rend l’utilisation du système de secours actuel basé sur une éolienne traditionnelle impossible. Surtout lors des atterrissages et décollages où la puissance fournie par celle-ci est presque nulle. L’une des solutions considérée par les avionneurs est de remplacer l’éolienne par un système hybride basé sur une pile à hydrogène, assistée par les batteries et/ou les super condensateurs.
Afin de s’assurer que le système hybride pourra satisfaire à la demande, il doit être correctement conçu et une stratégie efficace de gestion d’énergie doit être testée avec un vrai profil de vol. Ce travail vise à concevoir un système d’alimentation de secours basé sur une pile à hydrogène pour un avion plus électrique, et à comparer différentes stratégies de gestion d’énergie; avec pour but de s’assurer que la demande en situation d’urgence est entièrement satisfaite, et ce, dans les limites de chaque source d’énergie. Le système hybride considéré est constitué d’une pile à hydrogène, d’un bac de batteries aux ions de lithium et de super condensateurs, ainsi que leur convertisseurs CC-CC et CC-CA associés. Les stratégies de gestion d’énergie considérées sont les plus courantes de l’état de l’art, utilisées dans les véhicules hybrides, à savoir: la stratégie de commande par état de la machine, la stratégie basée sur la logique floue, la stratégie de commande par régulateur PI, la stratégie de commande basée sur le découplage de la fréquence et la stratégie de minimisation de la consommation équivalente (ECMS). D’autre part, une nouvelle stratégie optimale basée sur la maximisation de l’énergie instantanée des batteries/super condensateurs, est proposée afin d’en améliorer l’économie en hydrogène. En plus, un algorithme basé sur l’optimisation hors-ligne a été également développé afin de valider la stratégie proposée.
Les critères principaux de comparaison des différentes stratégies sont les suivants: la consommation d’hydrogène, l’état de charge des batteries/super condensateurs et l’efficacité globale du système. En plus, le niveau de sollicitations de chaque source d’énergie, qui influence énormément leur cycle de vie, est mesuré avec une nouvelle approche basée sur la transformée en ondelettes de leur puissance instantanée.
Un modèle de simulation et un banc d’essai expérimental ont été développés pour valider toutes les analyses et les différentes performances. Les principaux résultats obtenus sont les suivants : la stratégie de commande par état de la machine a fourni une performance légèrement meilleure en termes d’efficacité globale et du niveau de sollicitations des batteries et des super condensateurs. La stratégie de commande par régulateur PI et celle proposée ont eu la plus basse consommation d’hydrogène, mais avec un taux d’utilisation de l’énergie des batteries plus élevé. Comme prévu, le plus bas niveau de sollicitations de la pile à hydrogène ainsi que le plus bas taux d’utilisation de l’énergie des batteries ont été réalisés avec la stratégie de commande basée sur le découplage de la fréquence, mais aux dépens d’une consommation d’hydrogène plus élevée et d’une efficacité globale plus faible. Pour toutes les stratégies, la tension du bus DC ou des super condensateurs est presque maintenue constante. En outre, la stratégie proposée a été légèrement meilleure comparée à l’ECMS en termes de consommation d’hydrogène et d’efficacité globale avec une augmentation sur l’économie en hydrogène de 3 %.
La stratégie de gestion d’énergie appropriée au système de secours des avions plus électrique devrait être de type multi-stratégies telle que chaque stratégie est choisie basée sur un critère spécifique prioritaire. Par exemple, selon la durée de fonctionnement de chaque source d’énergie, la stratégie de gestion d’énergie peut être choisie avec pour but de réduire au minimum le niveau de sollicitations du système de pile à hydrogène, des batteries ou des super condensateurs, ainsi augmentant le cycle de vie du système d’alimentation hybride. Par ailleurs, si la cible est de réduire la consommation d’hydrogène, la stratégie proposée ou celle classique par régulateur PI sont de meilleurs candidats.