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Dissertations / Theses on the topic 'Basics of electronics'
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Mališkienė, Audronė. "DARBŲ PROGRAMOS KETVIRTOS KLASĖS SPECIALIŲJŲ UGDYMOSI POREIKIŲ MOKINIAMS PLĖTOTĖ." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2009. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2009~D_20090828_130334-47699.
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Darbe atlikta teorinė žemesniųjų lavinamųjų klasių mokinių psichosocialinės raidos, veiklos ypatumų, veiklos priemonių – žaislų bei elektronikos ugdymo svarbos ir turinio parinkimo ypatumų analizė.
Iškelta hipotezė, kad mokinių gebėjimas saugiai eksploatuoti jų aplinkoje sutinkamus elektroninius prietaisus bei prietaisus su elektronikos elementais sudaro optimalias prielaidas vaikų psichosocialinei raidai, o dažniausiai vaikų aplinkoje sutinkami elektroniniai daiktai yra žaislai bei buitiniai prietaisai.
Anketinės apklausos metodu buvo atliktas tyrimas, kurio tikslas - ištirti ko ir kaip pedagogai moko ketvirtų lavinamųjų klasių mokinius ugdydami jų elektronikos pradmenų gebėjimus. Parengtos darbų programos plėtotei rekomendacinės elektronikos pradmenų ugdymo temos, pravestas eksperimentinis mokymas, įvertinti mokinių gebėjimai tinkamai eksploatuoti elektronikos prietaisus iki eksperimentinio mokymo ir po jo.
Tyrime dalyvavo 30 specialiosios mokyklos žemesniųjų lavinamųjų klasių mokinių technologijų mokytojų ir 50 ketvirtų lavinamųjų klasių mokinių.
Empirinėje dalyje nagrinėjamas mokytojų suvokimas apie lavinamųjų klasių mokinių gebėjimą tinkamai eksploatuoti elektronikos prietaisus, nustatomi trys mokinių gebėjimų lygiai: gebančių naudoti elektronikos prietaisus savarankiškai, gebančių naudoti su pagalba ir negebančių naudoti. Nustatomi gebėjimų skirtumai tarp berniukų ir mergaičių.
Svarbiausios empirinio tyrimo išvados:
1. Pedagogai nurodo ugdantys mokinių... [toliau žr. visą tekstą]Analysis of scientific literature reveals that scientists actively discuss issues, regarding what electronic means and devices should children be familiar with, teach how to use them, so that there would be optimal possibilities for their adaptation in society. This motivates to change task program for schoolchildren with extensive and extremely extensive educational needs of fourth grade by including topics, regarding formation of this skills in this field. It is possible to hypothesize that ability to safely behave with electronic toys and house appliances could increase children motivation to play social roles’ games and the suggested topics for development of a program, regarding involvement of basics of electronics into the program, will not only meet children needs, wishes and interests, but will also allow for adequate communication with social environment. Research participants constituted of 30 crafts teachers of lower training grades in special schools and 50 schoolchildren with extensive and extremely extensive educational needs in specials schools. Most significant conclusions from empirical research are: ● Data from teachers’ questionnaire reveal that all of them follow the task program prepared by Kaukenaite for children with extensive and extremely extensive educational needs and two thirds of respondents indicate that they introduce these students to electronic devices and methods, even though these topics are not included into the program. ● Research on... [to full text]
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Kamasani, Jyotheesh Reddy, Uday Suhas Nakkapalli, and Sai Jaswanth Yadala. "Arduino Based Home Electronics Labs : Basic- & Advanced-Electronics and Sensors Approaches." Thesis, Blekinge Tekniska Högskola, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-20034.
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Background. Engineering is incomplete without the practical knowledge so laboratories and practical experiments play a quite vital role in the study. Engineering requires both practical knowledge and skills along with theoretical background. However, new technology provides opportunity to perform experiments on distance or at home, what in current situation of COVID-19 pandemic has created a great motivation to have a deep study on distance education of Engineering. This report proposes the Home Labs for basic course in electronics. It shows both technical and educational approaches in terms of communication between a student and instructor. Objectives. The main objective of this project is to design and implement three labs of dedicated to basic electronics, linear integrated circuit and sensors. Each lab consists of five experiments. All experiments need to be accessed from home. Surveillance of lab results is one of the keys of the Home Labs, which cannot be compromised. Miniaturization of commonly used heavy lab equipment is one of the main project issue. Documentation of each and every experiment should be prepared in feasible way to help students to perform their experiments easily. The reporting template should also be easy to understand and implement. Methods. Most of the experiments apply Arduino as control unit. The microcontroller does not only control the experiments and connect it to the Internet as an element of IoT concept, but it also take responsibility for measurements and visualisation. The Arduino kit along with electronic components is owned by each student and could be handle anytime. Some extra components such as mini digital oscilloscope facilitate the experiments. Conclusions. Laboratories are the prime requirement of the Engineering Programs for developing students' practical skills. As implementation of all the experiments shows they can be done by not only real time lab equipment but also with miniaturized components. The proposed Home Lab budget was so friendly and economical compared to the campus labs. The Arduino based home electronic labs is the replica of the real time lab for the students who are doing their distance education and cannot have proper resource of the campus labs.
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Huelskamp, Leo. "Order restricted A-basis and B-basis values." Thesis, Wichita State University, 2012. http://hdl.handle.net/10057/5399.
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In this thesis, the concept of A-basis and B-basis as it relates to the aviation industry
is studied. The rst assumption that will be made in order to help with the formulation of
the A-basis and B-basis values is that each of the samples from the obtained data is given
by a normal distribution. With this assumption, the paper begins by deriving the formulas
needed for obtaining A-basis and B-basis values. Once these formulas have been derived,
they will be put to use in programs that are capable of running simulations. Then the thesis
will examine the results and investigate if any problem areas arise. It will be discovered that
there is a problem with the formulas derived as it pertains to the aviation industry, so the
next step will be to nd where the error originates from and nd a suitable way to x this
error. The next item that will be looked at is how to successfully run simulations where
it is desirable to impose certain restrictions on the population mean of each factor that is
being taken into consideration. The thesis will conclude by looking at what happens when
combining both the method used to x the error discovered earlier and the method used
to apply the order restriction, and again will run simulations by means of programs that
take both methods into account. The results show how order restriction can be applied to
the population means of the breaking strength of composite materials to obtain results that
follow certain theories that have been determined by engineers.Thesis (M.S.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Mathematics and Statistics
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Ruggles, Tikhon(Tikhon James). "Electronics first : development of a basic electronics course of study for naval engineers." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/127048.
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Thesis: Nav. E., Massachusetts Institute of Technology, Department of Mechanical Engineering, May, 2020Thesis: S.M. in Naval Architecture and Marine Engineering, Massachusetts Institute of Technology, Department of Mechanical Engineering, May, 2020
Cataloged from the official PDF of thesis.
Includes bibliographical references (pages 109-110).
MIT's 2N program produces naval engineers for the U.S. Navy. It provides its students with a solid foundation of critical engineering, design, construction, and naval architecture concepts. However, within that curriculum, there is less of an emphasis on electrical engineering and electronics as it applies to shipboard systems. The purpose of this project is to outline a new course of study centered around laboratory assignments designed especially for the 2N program that will provide an accelerated introduction to electronics and electrical engineering for the naval engineer.
by Tikhon Ruggles.
Nav. E.
S.M. in Naval Architecture and Marine Engineering
Nav.E. Massachusetts Institute of Technology, Department of Mechanical Engineering
S.M.inNavalArchitectureandMarineEngineering Massachusetts Institute of Technology, Department of Mechanical Engineering
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Haas, Christopher. "The projector basis method for electronic band structure calculations." W&M ScholarWorks, 1996. https://scholarworks.wm.edu/etd/1539623886.
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Over the last several decades, two methods have emerged as the standard tools for the calculation of electronic band structures. These methods, the Car-Parinello plane wave method and the linear augmented plane wave method (LAPW), each have strengths and weaknesses in different regimes of physical problems. The Car-Parinello algorithm is ideal for calculations with soft pseudopotentials and large numbers of atoms. The LAPW method, on the other hand, easily handles all-electron and hard-core pseudopotential calculations with a small number of atoms. The projector basis method, presented here, is a hybrid mixed basis method which allows the calculation of moderately large ({dollar}\sim{dollar}200) numbers of atoms represented by hard pseudopotentials. This method will then be used to calculate two members of a relatively new mass of materials, called electrides, in which the anion has been replaced with a localized electron.
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Oudah, Alsafa. "Medication Reconciliation : Electronic medication list discrepancies – Cross sectional study." Thesis, Umeå universitet, Institutionen för integrativ medicinsk biologi (IMB), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-178901.
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Gu, Huanhuan. "Computed basis functions for finite element analysis based on tomographic data." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=107699.
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This thesis proposes a novel way to find the electromagnetic fields when the computational domain is defined by a fine grid of pixels (2D) or voxels (3D). This happens quite often in bioelectromagnetic problems, since tissue shapes are usually obtained by tomography.The proposed method is a finite element method in which, in 3D, each element is simply a set of p × p × p voxels, where p is an integer. It therefore avoids the heavy burden of surface extraction and meshing. Since there may be multiple materials within one element, conventional basis functions are not suitable. Instead, basis functions are computed using the voxel grid, so that the internal discontinuities are respected.The idea is first tested on problems consisting of nested squares (2D) and cubes (3D) of dielectric, with a charge pair placed inside. The results obtained by using different element sizes p agree well with those obtained by commercial software: when p = 4, the root-mean-square (RMS) difference is 1.5 % of the maximum potential.Then the new method is applied to solve an electroencephalography (EEG) problem, in which the head is modelled as a volume conductor and neural activity by current dipoles. The head model consists of 180×217×181 voxels. The computed electric potential is sampled along a contour on the outer side of the scalp, for different element sizes p. These results, again, agree well with a reference solution: for p = 4, the RMS difference is about 1% of the maximum potential. Solving one FE problem with p = 4 is 4.7 times faster than when using each voxel as an element, i.e., p = 1. When the solution is required for multiple righthand sides, as is common, the speedup is greater. For example, with 24 righthand sides, the p = 4 solution is 40 times faster than when p = 1.Cette thése propose une nouvelle technique pour trouver les champs électromagnétiques lorsque le domaine de calcul est défini par un dense quadrillage de pixels (2D) ou voxels (3D). Un scénario qui arrive souvent dans le domaine de bioelectromagnetic, puisque les géométries des tissus sont généralement obtenues par tomographie.La technique proposée dans cette thése est une méthode des éléments finis dans laquelle, chaque élément 3D est un ensemble de p × p × p voxels (p est un nombre entier). Par conséquent, cette technique évite la difficile tâche de l'extraction de surface et de maillage. Comme un élément peut être composé de différents matériaux, les fonctions de base classiques ne sont plus pertinentes. Ainsi, les fonctions de base sont calculées en utilisant les grilles de voxels, afin de respecter des discontinuités internes. L'idée est d'abord testée sur des problèmes comprenant des carrés imbriqués (2D) et des cubes (3D) de diélectrique, avec une paire de charge placée à l'intérieur. Les résultats obtenus en utilisant différentes tailles d'élément (p) sont en bon accord avec ceux obtenus par un logiciel commercial: pour p = 4, la différence quadratique moyenne (RMS) est 1,5% du potentiel maximum. Ensuite, la nouvelle méthode est appliquée pour résoudre un problème électroencéphalographie (EEG), dans lequel la tête est modélisée par un volume conducteur et l'activité neuronale par des dipôles. Le modèle de tête se compose de 180×217×181 voxels. Le potentiel électrique calculée est échantillonné sur un contour sur le côté extérieur du cuir chevelu, pour différentes tailles d'élément, p. Ces résultats sont toujours en bon accord avec une solution de référence: pour p = 4, la quadratique moyenne (RMS) est d'environ 1% du potentiel maximum. Résoudre un problème des éléments finis avec p = 4 est 4,7 fois plus rapide que le cas que chaque voxel est considéré comme un seul élément, c'est à dire, p = 1. Lorsque le résoudre pour plusieurs côtés droits est recherché, qui est vrais dans plupart des cas, l'accélération est plus grande. Par exemple, avec 24 côtés droits, la solution pour p = 4 est 40 fois plus rapide que le cas de p = 1.
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Phillips, Jesse D. "Scripted artificially intelligent basic online tactical simulation." abstract and full text PDF (free order & download UNR users only), 2008. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1453606.
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Dikmen, Bora. "Numerical Studies Of The Electronic Properties Of Low Dimensional Semiconductor Heterostructures." Phd thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/2/12605473/index.pdf.
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An efficient numerical method for solving Schrödinger'
s and Poisson'
s equations using a basis set of cubic B-splines is investigated. The method is applied to find both the wave functions and the corresponding eigenenergies of low-dimensional semiconductor structures. The computational efficiency of the method is explicitly shown by the multiresolution analysis, non-uniform grid construction and imposed boundary conditions by applying it to well-known single electron potentials. The method compares well with the results of analytical solutions and of the finite difference method.
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Hallani, Rawad Kamal. "Designing Anthradithiophene Derivatives Suitable For Applications in Organic Electronics and Optoelectronics." UKnowledge, 2015. http://uknowledge.uky.edu/chemistry_etds/61.
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Anthradithiophene (ADT) derivatives have proven to be a front-runner in the world of small molecule semiconductors for organic electronics and optoelectronics. This is mainly due to the improved stability, easy tuning of chemical and physical properties, and impressive device performance that these molecules possess, especially in organic field effect transistors (OFET) and organic photovoltaics (OPV). The second chapter of this dissertation shows that reducing the amount of alkylsilylethynyl groups, used for functionalizing and solubilizing the ADT backbone, does alter the chemical, physical and crystallographic properties of ADTs. These changes offer the opportunity to study and observe different intermolecular interactions as well as monitoring their influence on sulfur scrambling in solid state. Additionally, from the early days ADTs and functionalized ADTs have been synthesized as isomeric mixtures. In chapter three, I demonstrate a new and simple method that can separate the syn and anti isomers of the F-TES-ADT and F-TEG-ADT chromatographically. The effects of isomeric purity on crystal packing and field effect transistor performance were studied extensively.
Chapter four of this dissertation reveals a new generation of acceptor (electron poor) ADT derivatives obtained by attaching cyanide as electron withdrawing group (EWG) to the ADT chromophore. An extensive study was conducted on CN-ADT (acceptor) molecules in small molecule (F-TES-ADT) donor/ small molecule (CN-ADT) acceptor binary BHJ blends as well as P3HT/CN-ADT/PCBM ternary BHJ blends. Photophysical studies of the Donor/ acceptor blends (interface, domains, and crystal orientation) were conducted to obtain a better understanding of the film morphology and its effect on solar cell performance.
Finally, the last part of the dissertation, Chapter five, focus on studying singlet fission in ADT derivatives, as well as the effect of varying the size of the alkylsilylethynyl functional group (used for solubilizing the ADT backbone) on altering the electronic couplings and how can that potentially affect the singlet fission rate in these molecules. We also tried to inspect the extent of the correlation between long-range order in crystal packing and singlet fission by monitoring singlet fission rate and efficiency for ADT derivatives with different thin film morphologies.
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Song, Liying Tugnait Jitendra K. "Channel estimation and equalization for doubly-selective channels using basis expansion models." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SPRING/Electrical_and_Computer_Engineering/Dissertation/Song_Liying_29.pdf.
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Joffe, Neil Raymond. "A study of multilevel partial response signalling for transmission in a basic supergroup bandwidth." Master's thesis, University of Cape Town, 1989. http://hdl.handle.net/11427/8334.
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Includes bibliographical references.The work in this thesis is primarily directed toward the design, construction and testing of an experimental multilevel partial response signalling baseband system. The system will find practical application in existing frequency division multiplexed-frequency modulated microwave links. The basic supergroup bandwidth of these links is 240 kHz. The design requires a transmission rate of 1.024 Mb/s in this bandwidth. Class-4 15 partial response signalling is the coding technique suitable to achieve this. A pilot tone scheme is used to facilitate symbol timing recovery at the demodulator. A sixth order Butterworth low pass filter approximates the ideal raised-cosine Nyquist channel. A theoretical discussion on impairments caused by deviation from this channel is given. Since the experimental system was non-ideal, it produced a degradation in the channel signal to noise ratio. This degradation, coupled with other factors, showed that further development was necessary for the system to be suitable for connection into an existing microwave link.
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Vasudeva, Vikas. "Characterization of MEMS devices on the basis of their frequency response function (FRF)." abstract and full text PDF (free order & download UNR users only), 2007. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1447635.
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Worgan, Simon F. "Modelling the emergence of a basis for vocal communication between artificial agents." Thesis, University of Southampton, 2010. https://eprints.soton.ac.uk/79524/.
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Understanding the human faculty for speech presents a fundamental and complex problem. We do not know how humans decode the rapid speech signal and the origins and evolution of speech remain shrouded in mystery. Speakers generate a continuous stream of sounds apparently devoid of any specifying invariant features. Despite this absence, we can effortlessly decode this stream and comprehend the utterances of others. Moreover, the form of these utterances is shared and mutually understood by a large population of speakers. In this thesis, we present a multi-agent model that simulates the emergence of a system with shared auditory features and articulatory tokens. Based upon notions of intentionality and the absence of specifying invariants, each agent produces and perceives speech, learning to control an articulatory model of the vocal tract and perceiving the resulting signal through a biologically plausible artificial auditory system. By firmly establishing each aspect of our model in current phonetic theory, we are able to make useful claims and justify our inevitable abstractions. For example, Lindblom’s theory of hyper- and hypo-articulation, where speakers seek maximum auditory distinction for minimal articulatory effort, justifies our choice of an articulatory vocal tract coupled with a direct measure of effort. By removing the abstractions of previous phonetic models we have been able to reconsider the current assumption that specifying invariants, in either the auditory or articulatory domain, must indicate the presence of auditory or articulatory symbolic tokens in the cognitive domain. Rather we consider speech perception to proceed through Gibsonian direct realism where the signal is manipulated by the speaker to enable the perception of the affordances within speech. We conclude that the speech signal is constrained by the intention of the speaker and the structure of the vocal tract and decoded through an interaction of the peripheral auditory system and complex pattern recognition of multiple acoustic cues. Far from passive ‘variance mopping’, this recognition proceeds through the constant refinement of an unbroken loop between production and perception.
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Hargood, Charlie. "Semiotic term expansion as the basis for thematic models in narrative systems." Thesis, University of Southampton, 2011. https://eprints.soton.ac.uk/273228/.
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Narratives are a method of communicating information that comes naturally to people and is present in much of our digital and non-digital lives. While work has been undertaken investigating the nature of plot and content within narrative systems little has been done to model subtext or themes. In this thesis a machine understandable thematic model is presented for representing themes within narrative. Each instance of this model forms a definition of a theme and how it may be deconstructed into other thematic elements and their related features. The model is based on semiotic term expansion where terms may be shown to denote motifs which in turn connote themes. An authoring method has been developed to allow for instances of the model to be created. The effectiveness of this approach is demonstrated in four experiments presented within this thesis centred around the concept of creating thematic definitions and generating thematically relevant images. The first experiment explored a semiotic term expansion method for creating thematic definitions in terms of the model and a guide to support authors in doing so. This demonstrated that, though further support for authors is needed, creating valid definitions of themes was possible using the method. The following two experiments used a system called the Thematic Montage Builder; a prototype using definitions of the model to create themed photo montages. The first of these experiments compares the ability of this system to generate montages relevant to specific titles containing themes to Flickr keyword searches while the second compares this system to a term expansion system based on co-occurrence. In both cases the TMB generates montages that are judged by participants to better represent the theme in question. In the final experiment the effect of thematic emphasis on narrative cohesion is investigated. In this experiment a set of variables for measuring narrative cohesion are identified and the impact of using themed illustrations from the TMB on short stories is measured. The illustrations reduced the thematic noise of the short stories and further analysis shows a correlation between thematic cohesion and the perceived `logical sense' and `genre cohesion' of the narratives. This work shows that better machine understandable models of narrative can benefit from an understanding of themes, and that semiotic term expansion may be used to build successful thematic models.
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Lee, Dongjin 1956. "Automatic development of circuit and interconnection equations on the basis of topology and library of network components: SPICE approach." Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/277894.
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The modules for processing of interconnection specifications which are provided in an input file of circuit analyzer were developed. A software package for creation of appropriate computer models on the basis of topology and library of network components was also constructed and implemented using SPICE program. A computer program, called LSPICE, has been developed by combining SPICE numerical techniques and the modal analysis of coupled transmission lines. This program can be used for simulating the transient response of networks containing coupled lossless transmission lines. Several example networks have been simulated using this program. The results have been compared with those generated by the circuit simulator program called UANTL. The LSPICE has several advantages over UANTL and SPICE in simulating the transient response of network containing coupled lossless transmission lines. A description of LSPICE and a summary of the results of numerical experiments are included.
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Alshahrani, Sahar. "A Theoretical Study of the Electronic Structures of Tetrahedral Boron-Halogen Complexes." DigitalCommons@Robert W. Woodruff Library, Atlanta University Center, 2019. http://digitalcommons.auctr.edu/cauetds/180.
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This study addresses the structure and the bonding in the family of tetrahedral boranes. The specific molecules studied are the series B4X4 (X=H, F, Br, Cl, I), the series B4BrCl3, B4Br2Cl2, and B4Br3Cl and tetra-tert-butyl-tetraborane, t-Bu4B4. The research presented herein employs the Hartree-Fock Self Consistent Field (HFSCF), the Moller-Plesset second-order perturbation theory (MP2), and the Density Function Theory (DFT). A variety of basis sets was employed. Our calculations are the first theoretical studies of B4Br4, B4I4, B4BrCl3, B4Br2Cl2, and B4Br3Cl, and are also the first calculations for the D4h structures of any of these molecules, except for B4H4. These results were compared with experimental results, where such comparisons can be made. The most energetically stable structure for all the B4X4 and B4BrnClm molecules has symmetry Td.
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Adolphs, Kai. "Wettbewerbsvorteile im Electronic Retailing : theoretische Grundlagen und empirische Ergebnisse auf der Basis der Resource-Advantage-Theorie /." Wiesbaden : Dt. Univ.-Verl, 2004. http://www.gbv.de/dms/zbw/470715952.pdf.
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Bansah, Daniel K. "Assessing the uncertainty associated with regional groundwater model development for the Fernley/Wadsworth hydrographic basins, Nevada." abstract and full text PDF (free order & download UNR users only), 2006. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1439813.
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Landry, Kenneth D. "Instructional footprinting : a basis for exploiting concurrency through instructional decomposition and code motion /." Diss., This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-06062008-165834/.
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Lundbeck, Kim, and Wille Eriksson. "Graph Learning as a Basis for Image Segmentation." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-295622.
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Graph signal processing is a field concerning theprocessing of graphs with data associated to their vertices, oftenin the purpose of modeling networks. One area of this fieldthat has been under research in recent years is the developmentof frameworks for learning graph topologies from such data.This may be useful in situations where one wants to representa phenomenon with a graph, but where an obvious topologyis not available. The aim of this project was to evaluate theusefulness of one such proposed learning framework in thecontext of image segmentation. The method used for achievingthis consisted in constructing graph representations of imagesfrom said framework, and clustering their vertices with anestablished graph-based segmentation algorithm. The resultsdemonstrate that this approach may well be useful, although theimplementation used in the project carried out segmentationssignificantly slower than state of the art methods. A numberof possible improvements to be made regarding this aspect arehowever pointed out and may be subject for future work.Grafsignalbehandling är ett ämnesområde vars syfte är att behandla grafer med data associerat till deras noder, ofta inom nätverksmodelleringen. Inom detta område pågår aktiv forskning med att utveckla tekniker för att konstruera graftopologier från sådana data. Dessa tekniker kan vara användbara när man vill representera ett fenomen med grafer, men då uppenbara grafstrukturer inte finns tillgängliga. Syftet med detta projekt var att utvärdera användbarheten hos en sådan teknik när den appliceras inom bildsegmentering. Metoden som användes bestod i att konstruera grafrepresentationer av bilder med hjälp av denna teknik, för att sedan behandla dessa med en etablerad, grafbaserad segmenteringsalgoritm. Resultaten påvisar att detta tillvägagångssätt under rätt förutsättningar kan producera tillfredsställande bildsegmenteringar. Dock är implementeringen som nyttjats i projektet betydligt långsammare än de metoder som vanligen används inom området. Ett antal förslag till prestandaförbättring utpekas, och kan vara föremål för framtida studier.
Kandidatexjobb i elektroteknik 2020, KTH, Stockholm
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Monu, Ruban. "Design and implementation of a basic laboratory information system for resource-limited settings." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34792.
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Basic Laboratory Information System (BLIS) is a joint initiative of C4G @ Georgia Tech, the Centers for Disease Control and Prevention (CDC) and Ministries of Health in several countries in Africa. The vast majority of health laboratories in Africa, engaged in routinely testing samples drawn from patients (for HIV, malaria etc.), have been using non-standardized paper logs and manual entries for keeping track of patients, test samples and results. Besides the obvious burden of tedious record-keeping, these methods increase the chances of errors due to transcription and mismatches, making it difficult to track patient history or view critical population-wide data. In 2008, PEPFAR (the United States President's Emergency Plan for AIDS Relief) together with the CDC was reauthorized with a $48 billion budget over five years to combat HIV/AIDS, tuberculosis, and malaria. The focus of PEPFAR has shifted from rapid scale-up to the quality and reliability of the clinical health programs and having an effective laboratory management system is one of its goals.
C4G BLIS is a robust, customizable and easy-to-use system that keeps track of patients, samples, results, lab workflow and reports. It is meant to be an effective and sustainable enhancement to manual logs and paper-based approaches. The system is designed to work in resource-constrained laboratories with limited IT equipment and across sites with good, intermittent or no internet availability. With varied practices, workflow and terminology being followed across laboratories in various African countries, the system has been developed to enable each laboratory or country to customize and configure the system in a way that suits them best. We describe various aspects of BLIS including its flexible database schema design, configurable reports and language settings, end-user customizability and development model for rapid incorporation of user feedback. Through BLIS, we aim to demonstrate a sustainable ICT solution brought about by the early and constant involvement of the target laboratory staff and technicians, identifying their short- and long-term needs, and ensuring that the system can match these needs. We will present preliminary evaluation results from laboratories in Cameroon, Ghana, Tanzania and Uganda.
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Schalk, Martin. "Ultra-fast electronic pulse control at cryogenic temperatures." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAY061.
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Synchronisation ultra-rapide, mise en forme d’impulsions et commutation efficace sont au cœur des mesures précises. L’objectif de ce projet de thèse est d’apporter le contrôle électronique ultra-rapide aux circuits nanométriques refroidis à des températures de l’ordre du mK. L’opération quantique rapide rapprochera le domaine de l’optique électronique quantique de son homologue photonique avec des applications pour un contrôle électronique rapide et efficace des dispositifs quantiques. Les dispositifs expérimentaux développés au cours de ce projet de thèse sont décrits et testés de manière à esquisser également les possibilités d’intégration dans les technologies quantiques. Dans un premier temps, une impulsion de tension de forme lorentzienne Γ = (76 ± 2) ps est mesurée de manière résolue dans le domaine temporel à des températures cryogéniques. Ensuite, les dérives de phase et d’amplitude sont analysées et optimisé avec le spectre de bruit. Un nouveau dispositif de génération d’impulsions utilisant un générateur de peigne est ensuite décrit et testé. Enfin, un futur réalisation d’une expérience d’interférence quantique par manipulation et détection dans un conducteur quantique est décrite, de même que les défis posés pour les dispositives quantiques à basse température et ses interconnexionsUltra-fast synchronization, pulse shaping, and efficient switching are at the heart of precise measurements. The aim of this thesis project is to bring ultra-fast electronic control to small nano-metric circuits cooled down to mK temperatures. The fast quantum operation will bring the field of quantum-electronic optics closer to its photoniccounterpart with applications for fast and efficient electronic control in quantum devices. To this end, the experimental setups developed during the thesis project are described and tested in a way to outline also possible device integration for scalable solid-state quantum technology. As a first step, a Lorentzian-shaped voltage pulse with a full width half maximum Γ = (76 ± 2) ps is measured in a time-resolved manner at cryogenic temperatures. Secondly, the phase and amplitude drifts are analyzed and optimized together with the noise spectrum. A new pulse generation setup using a microwave frequency comb generator is then described and tested. Finally, a future realization of a quantum interference experiment by manipulating and detecting electronic pulses in a quantum conductor is described along with challenges for low-temperature quantum hardware and interconnects
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Vautrin, Christopher. "Electronic spin precession in all solid state magnetic tunnel transistor." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0075/document.
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Ce travail porte sur la précession du spin d’électrons chauds polarisés en spin. Celle-ci est induite par le champ d’échange d’une couche mince ferromagnétique dans une structure multicouche. La précession du spin électronique a déjà été mesurée dans des matériaux ferromagnétiques mais uniquement pour des électrons qui possèdent une énergie supérieure à 4eV au-dessus du niveau de Fermi. L’objectif premier de cette thèse est de mesurer la précession du spin de l’électron pour des faibles énergies, comprises entre 0.7eV et 2eV au-dessus du niveau de Fermi. Pour ce faire, un transistor tunnel magnétique comportant trois couches magnétiques avec les aimantations qui pointent dans les trois directions de l’espace doit être construit. Les électrons sont injectés à basse énergie grâce à une jonction tunnel. Une diode Schottky (interface entre du Cu et du Si) filtre en énergie les électrons incidents, permettant uniquement aux électrons balistiques de contribuer au courant mesuré dans le semi-conducteur. Le premier travail a consisté à obtenir une couche magnétique exhibant une anisotropie perpendiculaire. Ainsi, nous avons réussi à faire croître une multicouche de Co et Ni sur une diode Schottky qui possède une anisotropie perpendiculaire jusqu’à 5 répétitions. Le deuxième travail réalisé dans cette thèse était d’optimiser le magnéto-courant d’une la vanne de spin. En effet, le magnéto-courant détermine la sensibilité de notre transistor tunnel magnétique. Nous avons notamment démontré ici que le magnéto-courant augmente avec le nombre de répétitions de la multicouche [Co/Ni], pour atteindre quasiment le maximum de 100% théoriquement prédit dans une vanne de spin à aimantations croisées. Enfin, le troisième travail de cette thèse résidait dans l’étude de la précession du spin de l’électron dans différents matériaux ferromagnétiques. Cet effet a été mis en évidence ici pour des couches à aimantation planaire composée de Co, de CoFeB, ainsi que pour un alliage de CoAl et ceci en fonction de leur épaisseurThis work is about polarised hot electrons spin precession. This phenomenon is induced by the exchange field of a ferromagnetic thin film in a multilayer structure. The electronic spin precession has already been measured in ferromagnetic materials, but only for electrons whose energy is more than 4eV over the Fermi level. The initial aim of this PhD work is to measure the electron spin precession for weak energies, between 0.7 eV and 2eV over the Fermi level. In order to achieve that, a magnetic tunnel transistor composed of three magnetic layers with their magnetisations directions perpendicular to each other has to be elaborated. The electrons are injected at low energy by means of a tunnel junction. A Schottky diode (interface between Cu and Si) filters the incident electrons by their energies, which enables only ballistic electrons to contribute to the measured current in the semi-conductor. The first task consisted in obtaining a magnetic layer showing perpendicular magnetic anisotropy. We succeeded in growing cobalt nickel multilayers exhibiting a perpendicular magnetic anisotropy up to five repetitions. The second part of the job carried out during this PhD was to optimise the magneto-current of a spin valve. Indeed, it determines the magnetic tunnel transistor sensitivity. We have demonstrated that the magneto-current increases with the number of repetitions of the [Co/Ni] multilayer up to a maximum of nearly a hundred percent, which is the maximum theoretically predicted in a spin valve with crossed magnetisations. Eventually, the third task of this PhD was the study of the electron spin precession in various ferromagnetic materials. This effect has been evidenced here for thin layers with in-plane magnetisations composed of Co, CoFeB, and also for a CoAl alloy depending on the thickness of the layers
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Velte, Linda Maria. "Electronic health record repository based on the openEHR standard." Master's thesis, Universidade de Aveiro, 2011. http://hdl.handle.net/10773/7479.
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Mestrado em Engenharia de Computadores e TelemáticaAn Electronic Health Record (EHR) aggregates all relevant medical information regarding a single patient, allowing a patient centric storage approach. This way the complete medical history of a patient is stored together in one record, making it possible to save time and work by allowing the sharing of information between health care institutions. To make this sharing possible there has to be agreed on the format in which the information is saved. There are many standards to de ne the way health information is stored, exchanged and retrieved. One of this standards is the Open Electronic Health Record (OpenEHR). The goal of this thesis is to create a repository which allows to store and manage patient records which follow the OpenEHR standard. The result of the implementation consists in three software parts, being them a Extensible Markup Language (XML) repository to store health information, a set of services allowing to manage and query the information stored and a web interface to demonstrate the implemented functionalities.
Um registo electrónico de saúde agrega toda a informação médica relevante de um paciente, permitindo uma filosofia de armazenamento orientada ao mesmo. Desta forma todo o historial médico do paciente encontra-se armazenado num único registo, permitindo a optimização de custos e tempo gasto nas diferentes tarefas, através de partilha de informação entre diferentes instituições médicas. Para possibilitar esta partilha é necessário definir um formato comum em que a informação é armazenada. Para tal foram definidas diversas normas que ditam as regras de armazenamento, troca e recuperação de informação médica. Uma destas normas é o Open Electronic Health Record (OpenEHR). O objectivo desta dissertação e criar um reposit orio que permite o armazenamento de registos médicos que sigam a norma OpenEHR. A implementação dá origem a três componentes de software, sendo eles uma base de dados Extensible Markup Language (XML) para armazenamento de registos médicos, um conjunto de serviços para gestão e pesquisa da informação armazenada e uma interface web para demonstração das funcionalidades implementadas.
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Buth, Christian. "Advanced electronic structure theory: from molecules to crystals." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2005. http://nbn-resolving.de/urn:nbn:de:swb:14-1132580113554-34509.
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In dieser Dissertation werden ab initio Theorien zur Beschreibung der Zustände von perfekten halbleitenden und nichtleitenden Kristallen, unter Berücksichtigung elektronischer Korrelationen, abgeleitet und angewandt. Als Ausgangsbasis dient hierzu die Hartree-Fock Approximation in Verbindung mit Wannier-Orbitalen. Darauf aufbauend studiere ich zunächst in Teil I der Abhandlung den Grundzustand der wasserstoffbrückengebundenen Fluorwasserstoff und Chlorwasserstoff zick-zack Ketten und analysiere die langreichweitigen Korrelationsbeiträge. Dabei mache ich die Basissatzextrapolationstechniken, die für kleine Moleküle entwickelt wurden, zur Berechnung von hochgenauen Bindungsenergien von Kristallen nutzbar. In Teil II der Arbeit leite ich zunächst eine quantenfeldtheoretische ab initio Beschreibung von Elektroneneinfangzuständen und Lochzuständen in Kristallen her. Grundlage hierbei ist das etablierte algebraische diagrammatische Konstruktionsschema (ADC) zur Approximation der Selbstenergie für die Bestimmung der Vielteilchen-Green's-Funktion mittels der Dyson-Gleichung. Die volle Translationssymmetrie des Problems wird hierbei beachtet und die Lokalität elektronischer Korrelationen ausgenutzt. Das resultierende Schema wird Kristallorbital-ADC (CO-ADC) genannt. Ich berechne damit die Quasiteilchenbandstruktur einer Fluorwasserstoffkette und eines Lithiumfluoridkristalls. In beiden Fällen erhalte ich eine sehr gute Übereinstimmung zwischen meinen Resultaten und den Ergebnissen aus anderen MethodenIn this dissertation, theories for the ab initio description of the states of perfect semiconducting and insulating crystals are derived and applied. Electron correlations are treated thoroughly based on the Hartree-Fock approximation formulated in terms of Wannier orbitals. In part I of the treatise, I study the ground state of hydrogen-bonded hydrogen fluoride and hydrogen chloride zig-zag chains. I analyse the long-range contributions of electron correlations. Thereby, I employ basis set extrapolation techniques, which have originally been developed for small molecules, to also obtain highly accurate binding energies of crystals. In part II of the thesis, I devise an ab initio description of the electron attachment and electron removal states of crystals using methods of quantum field theory. I harness the well-established algebraic diagrammatic construction scheme (ADC) to approximate the self-energy, used in conjunction with the Dyson equation, to determine the many-particle Green's function for crystals. Thereby, the translational symmetry of the problem and the locality of electron correlations are fully exploited. The resulting scheme is termed crystal orbital ADC (CO-ADC). It is applied to obtain the quasiparticle band structure of a hydrogen fluoride chain and a lithium fluoride crystal. In both cases, a very good agreement of my results to those determined with other methods is observed
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Champagne, Maurice C. "Basic writing, binaries, and bridges [electronic resource] : difference and power in the production and reception of representations of students /." College Park, Md.: University of Maryland, 2008. http://hdl.handle.net/1903/8493.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2008.Thesis research directed by: Dept. of English Language and Literature. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Lindhult, Johan. "Operational Semantics for PLEX : A Basis for Safe Parallelization." Licentiate thesis, Västerås : School of Innovation, Design and Engineering, Mälardalen University, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-631.
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Forster, Florian. "Die Auswirkungen elektronischer Vertriebsmedien auf stationäre Reisebüros eine empirische Analyse des Entscheidungsverhaltens der Konsumenten auf Basis der touristischen Wertschöpfungsstruktur ; Tourismus und Internet." Göttingen Cuvillier, 2010. http://d-nb.info/1001835700/04.
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Arretche, Felipe. "Excitações eletrônicas por impacto de pósitrons via Método Schwinger multicanal." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/278345.
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Orientador: Marco Aurelio Pinheiro LimaTese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin
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Resumo: Nesta tese investigamos a modelagem teórica de colisões pósitron-molécula no regime de baixas energias utilizando o método Schwinger multicanal. Nosso objetivo inicial foi sofisticar o procedimento de cálculo do parâmetro de aniquilação¸ Zeff . Esta quantidade é diretamente proporcional a taxa de aniquilação de pósitrons com elétrons da nuvem molecular. Infelizmente o método subestima Zeff com relação aos dados experimentais. Uma investigação mais detalhada sugere que esta deficiência está ligada a uma descrição pobre do cúspide elétron-pósitron na função de onda de espalhamento. Para tanto, inserimos um potencial complexo tipo delta de Dirac na Hamiltoniana de espalhamento com o objetivo de melhorar o cálculo de aniquilação direta e possivelmente adaptá-lo para descrever o canal de formação do positrônio real. Aplicação a sistemas modelo como átomo de He e molécula de H2 mostraram que esta técnica alternativa produz resultados similares ao cálculo perturbativo usual. Neste sentido a discrepância entre o parâmetro de aniquilação teórico obtido via método Schwinger multicanal e os dados experimentais continua em aberto. Recentemente o grupo da Universidade de San Diego, na Califórnia, desenvolveu um aparato experimental para medir seções de choque de excitação eletrônica de átomos e moléculas por impacto de pósitrons. O método Schwinger multicanal é o único que tem atacado sistematicamente este problema para moléculas na literatura. Neste trabalho, damos continuidade a este programa de pesquisa calculando seções de choque de excitação eletrônica para as moléculas de H2 e CO com variados níveis de aproximação. Nossos resultados indicam que as seções de choque integrais são insensíveis ao nível de acoplamento multicanal utilizado na modelagem da colisão e que efeitos de polarização podem ser particularmente importantes para energias imediatamente acima dos limiares de excitação eletrônica. Finalmente, e este sem dúvida é o maior resultado desta tese, aprendemos a tratar as bases variacionais usadas no cálculo de espalhamento. A evidência de que tal nível de maturidade foi atingido é a convergência das seções de choque com relação aos métodos de cálculo dos elementos de matriz da função de Green, anteriormente obtida somente por ajuste (popularmente conhecido como "chute") do conjunto de primitivas Gaussianas utilizado no cálculo de espalhamento
Abstract: In this thesis we investigate the theoretical modelling of positron-molecule collisions in low energy regime using the Schwinger multichannel method. Our initial objective was to sophisticate the procedure of calculation of the annihilation parameter Zeff. This quantity is directly proportional to the annihilation rate of positrons with molecular cloud electrons. Unhapilly the method underestimates Zeff compared to the experimental data. A more detailed investigation suggests that this deficiency is connected with a poor description of the electronpositron cusp of the scattering wave function. To this end, we inserted a complex potential of Dirac delta type in the scattering Hamiltonian with the major objective of improving the direct annihilation calculation and possibly to adaptate it to describe the real positronium formation channel. Aplication to model systems like He atom and H2 molecule showed that this alternative technique produce similar results compared to the usual perturbative calculation. In this sense, the discrepancy between the theoretical annihilation parameter generated by Schwinger multichannel method and the experimental data remains as an open problem. Recently the research group of San Diego University, in California, developed an experimental apparatus to measure electronic excitation cross sections for atoms and molecules by positron impact. The Schwinger multichannel method is the only that has sistematicaly attacked the problem for molecules in the literature. In this work, we continue this research program calculating electronic excitation cross sections for H2 and CO molecules with varied degrees of approximation. Our results indicate that integral cross sections are insensible to the level of multichannel coupling used in the collision model and that polarization effects can be particularly relevant for energies immediately above electronic excitation thresholds. Finally, and this doubtless is the greater result of this thesis, we learnt to treat the variational basis used in the scattering calculation. The evidence that such level of maturity was reached is the convergence of the cross sections by the methods of computation of the Green¿s function matrix elements, obtained before only by "guessing" of the set of primitive Gaussians employed in the scattering calculation
Doutorado
Física Atômica e Molecular
Doutor em Ciências
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Bancal, Sylvain. "Basic design of an HVDC interconnection in Brazil." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187693.
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HVDC technologies are very effective on long distance power transmission but generally raise large interrogations as how to determine an effective configuration. This thesis propose part of an optimization process in order to determine an optimal configuration for an HVDC installation, emphasizing in this report the impact of the conductor selection and of the filter design. The conductor selection, including varying voltages raises concern about the knowledge of the energy cost evolution in order to determine its optimum and a sensitivity analysis is proposed to evaluate the impact of this factor on the final design. The conductor selection approach made it possible to determine the key parameters in choosing a conductor which are the radius and number of conductors. Different types of conductors and configurations were compared with different scenari for energy cost in order to determine the most economical conductor. Filter design is a matter that concerns both the internal components and the AC components of the HVDC station but can also be considered as an optimization process, considering the total losses of the filters and the total harmonic distortion and using a minimax approach. The optimization approach, based on a Newton-Raphson algorithm, made it possible to determine an optimal combination of filters in order to account for all the power range in the HVDC link. It was observed that even though the actual choice for the design was close to the final design selected, it was not optimal for low power harmonics.HVDC är en mycket effektiv teknik för kraftöverföring av elektrisk energi på långa avstånd, men ställer generellt stora krav på hur man genomför en effektiv konfiguration. Denna avhandling föreslår en del av en optimeringsprocess för att bestämma en optimal konfiguration för en HVDC-anläggning. Det som betonas i denna rapport är effekterna av val av ledare och design av filter. Ledarvalet, inklusive val av spänning, kräver en prognostisering av energikostnadernasutvecklingen för att optimera designen och göra en känslighetsanalys för att utvärdera effekterna av dessa faktorer på den slutliga utformningen. Tillvägagångssättet för ledarval gjorde det möjligt att fastställa de viktigaste parametrarna att välja en ledare som är radien och antal delledare. Olika typer av ledare och konfigurationer jämfördes med olika scenario för energikostnaden för att bestämma denmest ekonomiska ledaren. Filterdesignen är en fråga som berör både de inre komponenterna och AC komponenter i HVDC-stationen, men kan också betraktas som en optimeringsprocess, med avseende på de totala förlusterna av filtren och total harmonisk distorsion och med hjälp av en minimax tillvägagångssätt. Optimeringsstrategin som bygger på en Newton-Raphsons algoritm, gjorde det möjligt att fastställa en optimal kombination av filter för att ta hänsyn till alla effektområden i HVDC-förbindelsen. Det observerades att även om det faktiska valet för konstruktionen var nära den slutliga utformning som valdes, så var den inte optimala för låga övertoner.
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Harvey, Shaun. "Charged particle induced soft errors in 1 Mbit and 4 Mbit DRAMs as the basis for a portable radiation detector system." Thesis, University of Surrey, 1998. http://epubs.surrey.ac.uk/843953/.
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A portable high speed digital electronic DRAM radiation detection system was designed and constructed at the University of Surrey. The electronics system was designed around a Fully Programmable Gate Array (FPGA) acting as the DRAM controller. The system was controlled by a Personal Computer (PC) which also acquired and stored the data. The system control software was developed using the C language and written at the University of Surrey, the system was designed for use with 4 different types of Dynamic Random Access Memory (DRAM) chips acting as detectors mounted on separate boards from the controller. This was so that the main electronics could be placed in a shielded area whilst the detector is exposed to a radiation field. This is especially important in neutron fields where activation of components can be a significant problem. The radiation response of decapsulated 1 Mbit and 4 Mbit DRAMs to alpha particles was examined. There were six different devices in all, three 1 Mbit standard power devices, two 4 Mbit standard power devices and one 4 Mbit low power DRAM. These DRAMs were tested under different operating conditions of operating voltage, memory data pattern, cycle time and incident a-particle energy. Each DRAM was examined and their peak responses in terms of these factors was determined and compared to previous experiments with earlier DRAMs, all six devices were found to show an increase in soft error rate (SER) when the operating voltage of the DRAM was decreased. This was in agreement with previous experiments. This continued until an optimum was reached, if the operating was decreased below the optimum then the SER of the devices would quickly fall to zero, which was an unexpected effect. Two devices, the Hyundai 1 Mbit device and the Hitachi 4 Mbit ZIG-ZAG device exhibited a strong dependence on memory pattern with the Hyundai having no response with a 0000 pattern and a peak SER with a 1111 pattern. The Hitachi device had it's highest SER at 0000 and it's lowest at 1111. The other devices all exhibited some pattern dependence but it was not as marked as in these two devices. The devices all showed a lower SER for higher energy alpha particles (~5 MeV) with the SER increasing as the incident alpha particle energy decreased until a maximum SER was reached. As the incident energy was decreased further the SER would begin to fall again. This was also in agreement with previous DRAM experiments. The highest SER of the DRAMs tested was that of the 4 Mbit low power DRAM (manufactured by Toshiba), which had an SER of 224.25 s-1, more than 25 times that of the next most sensitive device, the 1 Mbit Hyundai standard power DRAM with a peak SER of 8.27 s-1. Unfortunately, due to an undetected fault in the low power header board the Toshiba device was not available to be used in the positron and neutron experiments. The 1 Mbit standard power devices (as they were more sensitive than the 4 Mbit standard power devices) were taken to the MRC Cyclotron Unit in London to try and detect a variety of positron emitters (11C, 15O, 18F 68Ge). Unfortunately, these experiments were not successful and the 1 Mbit devices did not appear to have enough sensitivity to be able to detect any of these particles. The 1 Mbit devices were also taken and irradiated in a neutron beam from the CONSORT-II research reactor at Imperial College, the devices were irradiated both bare and coated with a thermal neutron to charged particle converter material, the converter used was 6LiF and was deposited directly onto the bare silicon die of the DRAM, in both cases thermal neutrons were detected by the DRAMs. Further possible experiments with a larger range of low power DRAMs to investigate their apparently high SER rates are discussed, including further experiments with positrons and neutrons. The implications of further miniaturisation of the controller and header boards for remote inspection purposes are also discussed.
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Burgwinkel, Daniel J. "Ein Vorgehens- und Gestaltungsmodell für die Standardisierung und Einführung von digitalen Verträgen auf Basis der XML-Technologie." [S.l. : s.n.], 2004. http://www.unisg.ch/www/edis.nsf/7acbc805e9219074c1256d28004777d9/52bcae94ad811ed3c1256e49006e5954?OpenDocument&Highlight=2,burgwinkel,daniel.
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Biggs, Brandi L. "Basic computer literacy training to increase comfort levels with computers and improve behaviors of technological integration." Diss., Click here for available full-text of this thesis, 2006. http://library.wichita.edu/digitallibrary/etd/2006/t014.pdf.
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Giffin, Joy M. "Sediment production, storage, and transport processes studied in two semi-arid basins and in a recently burned region of the Mojave National Preserve." abstract and full text PDF (free order & download UNR users only), 2006. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1438923.
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Louderback, Lisbeth A. "Changes in vegetation and human adaptation from the latest Pleistocene to late Holocene in the eastern Great Basin : the Blue Lake pollen record /." abstract and full text PDF (UNR users only), 2007. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1446788.
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Thesis (M.A.)--University of Nevada, Reno, 2007."May 2007" Includes bibliographical references (leaves 138-151). Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2008]. 1 microfilm reel ; 35 mm. Online version available on the World Wide Web.
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Torres, Escalona Javier. "Electronic properties study on hydrazines and nitriles complexed by Lewis acids. Towards chemical hydrogen storage." Thesis, Pau, 2017. http://www.theses.fr/2017PAUU3051.
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Dans la problématique de l'utilisation de nouvelles énergies non polluantes, l'hydrogène est l'un des principaux carburants verts du futur. Les dérivés d'hydrazine et de borane sont potentiellement intéressants pour le stockage chimique de l'hydrogène. Les complexes entre hydrazines ou nitriles avec des boranes ou des alanes sont à la base de cette étude. Ces composés ont été synthétisés afin d'étudier leur structure électronique avant et après la création de la liaison entre les acides et les bases de Lewis. La spectroscopie photoélectronique à rayonnement UV (UV-SPE) est utilisée comme outil principal de caractérisation fournissant des énergies d'ionisation (IE). L’interprétation des résultats expérimentaux est supportée par des calculs quantiques comme ΔSCF + TD-DFT, OVGF, P3 et SAC-CI. Des simulations et des expériences par Flash Vacuum Thermolysis (FVT) ont été effectuées, portant sur l’élimination d'hydrogène à partir de dérivés d'hydrazine boraneWithin the problematic of the use of new non-polluting energies, hydrogen is one of the main green fuels of the future. Hydrazine borane derivatives are potentially interesting chemical hydrogen storage materials. Complexes between hydrazines or nitriles with boranes or alanes are the basis of this study. These compounds were synthesized in order to study their electronic structure before and after creation of the bond between the Lewis acids and bases. Ultraviolet Photoelectron Spectroscopy (UV-PES) is used as a main characterization tool, providing Ionization Energies (IE). The interpretation of the experimental results is supported by Quantum Chemical Calculations as ΔSCF+TD-DFT, OVGF, P3 and SAC-CI methods. Simulations and experiments by Flash Vacuum Thermolysis (FVT) were carried out on hydrogen release from hydrazine borane derivatives
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Chen, Yu-Ting. "REAL-TIME IMAGE PATTERN SENSOR FOR WELD POOL PENETRATION THROUGH REFLECTION IN GTAW." UKnowledge, 2018. https://uknowledge.uky.edu/ece_etds/130.
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In gas tungsten arc welding (GTAW), weld pool surface contains crucial information for welding development. In this research, simulate skilled welders to control the welding process and determine the penetration stages based on the weld pool reaction.
This study focuses on solving the uncertainty of the liquid weld pool in joint bases. The weld pool penetration process is highly depending on how the weld pool surface shape. To observe the weld pool, reflect the weld pool surface by the laser and image on the shield glass. The experiments show that the penetration can’t be determine by the reflecting grayness due to the variability of base metal. To control the joint bases diversity, fed a tip of the wire after the arc is established. Crate the new pattern of the weld pool penetration. Experiments verified the feasibility of this method.
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Kanakala, Raghunath. "Exploring the synthesis of hexaborides the basis of a new chemistry for the preparation of electro-chemical materials /." abstract, 2008. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3339123.
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Pham, Dinh Huong. "Bases mixtes ondelettes-gaussiennes pour le calcul de structures électroniques." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAM029/document.
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Cette thèse apporte une contribution aux méthodes numériques pour la simulation moléculaire ab initio, et plus spécifiquement pour le calcul de structures électroniques par l’équation de Schrödinger, ou par des formalismes comme la théorie de Hartree-Fock ou la théorie de la fonctionnelle de la densité. Elle propose une stratégie pour construire des bases mixtes ondelettes-gaussiennes dans l’approximation de Galerkin, combinant les qualités respectives de ces deux types de bases avec l’objectif de mieux capturer les points de rebroussement de la fonction d’onde. Les nombreux logiciels actuellement disponibles à l’usage des chimistes dans ce domaine (VASP, Gaussian, ABINIT...) se différencient par divers choix méthodologiques, notamment celui des fonctions de base pour exprimer les orbitales atomiques. Nouvel arrivant sur le marché, le code massivement parallèle BigDFT a opté pour les bases d’ondelettes. Comme le nombre de niveaux de résolution y est limité pour des raisons de performance,ces fonctions ne peuvent déployer pleinement leur puissance. La question posée est alors de savoir comment accroître la précision des calculs tous électrons au voisinage des singularités de type cusp de la solution, sans augmenter excessivement la complexité de BigDFT. La réponse que nous suggérons consiste à enrichir la base de fonctions d’échelles (niveau de résolution bas des bases d’ondelettes) par des fonctions gaussiennes centrées sur chaque position de noyau. La difficulté principale dans la construction d’une telle base mixte réside dans la détermination optimale du nombre de gaussiennes requises et de leurs écarts-types, de sorte que ces gaussiennes supplémentaires soient le mieux possible compatibles avec la base existante sous la contrainte d’un seuil d’erreur donné à l’avance. Nous proposons pour cela l’utilisation conjointe d’un estimateur a posteriori sur la diminution du niveau d’énergie et d’un algorithme glouton, ce qui aboutit à une suite incrémentale quasi-optimale de gaussiennes supplémentaires. Cette idée est directement inspirée des techniques de bases réduites. Nous développons les fondements théoriques de cette stratégie sur deux modèles 1-D linéaires qui sont des simplifications de l’équation de Schrödinger pour un électron,posée en domaine infini ou domaine périodique. Ces modèles prototypes sont étudiés en profondeur dans la première partie. La définition de l’estimateur a posteriori de type norme duale du résidu, ainsi que la déclinaison de la philosophie glouton en différents algorithmes concrets, sont présentées en seconde partie, accompagnées de résultats numériques. Les algorithmes proposés vont dans le sens d’une économie croissante du temps de calcul.Ils sont aussi de plus en plus empiriques, au sens où ils reposent de plus en plus sur les intuitions avec lesquelles les chimistes sont familiers. En particulier, le dernier algorithme pour plusieurs noyaux s’appuie en partie sur la validité du transfert atome/molécule et rappelle dans une certaine mesure les bases d’orbitales atomiquesThis thesis aims to be a contribution to numerical methods for ab initio molecular simulation, and more specifically for electronic structure calculations by means of the Schrödingerequation or formalisms such as the Hartree-Fock theory or the Density Functional Theory. It puts forward a strategy to build mixed wavelet-Gaussian bases for the Galerkinapproximation, combining the respective advantages of these two types of bases in orderto better capture the cusps of the wave function.Numerous software programs are currently available to the chemists in this field (VASP,Gaussian, ABINIT... ) and differ from each other by various methodological choices,notably that of the basis functions used for expressing atomic orbitals. As a newcomer tothis market, the massively parallel BigDFT code has opted for a basis of wavelets. Dueto performance considerations, the number of multiresolution levels has been limited andtherefore users cannot benefit from the full potential of wavelets. The question is thus howto improve the accuracy of all-electron calculations in the neighborhood of the cusp-typesingularities of the solution, without excessively increasing the complexity of BigDFT.The answer we propose is to enrich the scaling function basis (low level of resolutionof the wavelet basis) by Gaussian functions centered on each nucleus position. The maindifficulty in constructing such a mixed basis lies in the optimal determination of the numberof Gaussians required and their standard deviations, so that these additional Gaussiansare compatible in the best possible way with the existing basis within the constraint of anerror threshold given in advance. We advocate the conjunction of an a posteriori estimateon the diminution of the energy level and a greedy algorithm, which results in a quasi-optimal incremental sequence of additional Gaussians. This idea is directly inspired bythe techniques of reduced bases.We develop the theoretical foundations of this strategy on two 1-D linear models thatare simplified versions of the Schrödinger equation for one electron in an infinite domainor a periodic domain. These prototype models are investigated in depth in the firstpart. The definition of the a posteriori estimate as a residual dual norm, as well as theimplementation of the greedy philosophy into various concrete algorithms, are presented inthe second part, along with extensive numerical results. These algorithms allow for moreand more saving of CPU time and become more and more empirical, in the sense thatthey rely more and more on the intuitions with which chemists are familiar. In particular,the last proposed algorithm partly assumes the validity of the atom/molecule transfer andis somehow reminiscent of atomic orbitals bases
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Kumar, Sanjeev. "A formal semantics of teamwork and multi-agent conversations as the basis of a language for programming teams of autonomous agents /." Full text open access at:, 2006. http://content.ohsu.edu/u?/etd,17.
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Magwa, Nomampondo Penelope. "A spectroscopic study of the electronic effects on copper (II) and copper (I) complexes of ligands derived from various substituted benzyaldehyde- and cinnamaldehyde- based schiff bases." Thesis, Rhodes University, 2010. http://hdl.handle.net/10962/d1006712.
Full textAbstract:
Several Schiff base ligands, N, N‟-(aryl)benzyaldiimine ligands (R-BEN); N, N‟-(aryl)benzyaldiamine dihydrochloride ligands (R-BENH•2HCl); N, N‟-(aryl)benzyaldiamine ligands (R-BENH); N, N‟-bis(cinnamaldiimine) ligands (R-CA2EN) were synthesized for the investigation of the electronic effect of the substituents at para-position of the Schiff base ligands and their copper complexes. The synthesis of Schiff bases was carried out by reacting a series of para-substituted benzyaldehyde, and para-substituted cinnamaldehyde with ethylenediamine. The imine group of Schiff bases, N, N‟-(aryl)benzyaldiimine ligands and N, N‟-bis(cinnamaldiimine)ligands were reduced to corresponding amines with sodium borohydride in methanol These ligands, N, N‟-(aryl)benzyaldiamine ligands (H-BENH), N, N‟-bis(cinnamaldiimine)ligands (CA2EN) were reacted with copper(II) dihalide and copper(I) monohalide ions respectively to form complexes. The ligands and their complexes were analysed using elemental analyses, FT-IR spectroscopy (mid-IR), UV/vis in aprotic and protic solvents,while mass spectrometry, 1H-NMR and 13C-NMR were used to further analyse the ligands. By using substituent parameters, both the single and dual substituent parameters with the spectroscopic data obtained from the spectroscopic techiques mentioned above, it was hoped to monitor and determine whether the electronic effects (resonance or inductive effcets) was predominantly within the Schiff base ligands and copper complexes. The NMR studies with dual substituent parameters suggest that the effects of the substituents are transimitted through the ligands, via resonance effects and that the phenyl group is nonplanar with the azomethine in N, N‟-(aryl)benzyaldiimine ligands. The presence of an extra double bond in Schiff base {(N, N‟-bis(cinnamaldiimine) ligand)} altered the electron density. The UV/vis studies showed that the symmetry of the N, N‟-bis(4-R-benzyl)-1, 2-diaminoethanedihalidecopper(II) complexes were predominantly tetrahedral for both chloro and bromo complexes. The correlation studies from mid-infrared were beneficial in monitoring the effect experienced by N, N‟-(aryl)benzaldiimine ligands, the studies suggest that the inductive effect is more pronounced at the C=N.
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Poti, Allison Tamara S. "Building a multi-tier enterprise system utilizing visual Basic, MTS, ASP, and MS SQL." Virtual Press, 2001. http://liblink.bsu.edu/uhtbin/catkey/1221293.
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Multi-tier enterprise systems consist of more than two distributed tiers. The design of multi-tier systems is considerably more involved than two tier systems. Not all systems should be designed as multi-tier, but if the decision to build a multi-tier system is made, there are benefits to this type of system design. CSCources is a system that tracks computer science course information. The requirements of this system indicate that it should be a multi-tier system. This system has three tiers, client, business and data. Microsoft tools are used such as Visual Basic (VB) that was used to build the client tier that physically resides on the client machine. VB is also used to create the business tier. This tier consists of the business layer and the data layer. The business layer contains most of the business logic for the system. The data layer communicates with the data tier. Microsoft SQL Server (MS SQL) is used for the data store. The database containsseveral tables and stored procedures. The stored procedures are used to add, edit, update and delete records in the database. Microsoft Transaction Server (MTS) is used to control modifications to the database. The transaction and security features available in the MTS environment are used. The business tier and data tier may or may not reside on the same physical computer or server. Active Server Pages (ASP) was built that accesses the business tier to retrieve the needed information for display on a web page. The cost of designing a distributed system, building a distributed system, upgrades to the system and error handling are examined.Ball State UniversityMuncie, IN 47306Department of Computer Science
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Lozano, Rubí Raimundo. "A metamodel for clinical data integration. Basis for a new EHR model driven by ontologies." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/399855.
Full textAbstract:
Durante las últimas décadas se ha extendido la implantación de sistemas de información en las organizaciones sanitarias, proporcionando un adecuado soporte a los principales procesos de las mismas. Sin embargo, a pesar de los avances producidos durante los últimos años en las tecnologías de la información y la comunicación, los sistemas actuales no son capaces de proporcionar un verdadero soporte a los profesionales sanitarios en su práctica diaria y sus actividades de investigación. Como consecuencia de la variedad de organizaciones sanitarias existentes y la heterogeneidad de los sistemas de información en uso, los sistemas actuales de Historia Clínica Electrónica no son capaces de mostrar a los profesionales sanitarios una visión conceptualmente consolidada del estado de salud de los pacientes. Los datos clínicos de los pacientes se encuentran fragmentados tanto entre diferentes sistemas de información como dentro de los mismos, de modo que los profesionales deben interpretar las relaciones entre los mismos así como inferir relaciones ausentes. En este escenario, la interoperabilidad semántica es considerada por la comunidad científica como un factor esencial para que los sistemas de HCE constituyan una ayuda para mejorar la calidad y seguridad de la atención a los pacientes, la salud pública, la investigación clínica y la gestión sanitaria.
En esta tesis proponemos OntoEHR, una arquitectura conceptual para un nuevo sistema de HCE semánticamente interoperable, enfocado sobre el proceso clínico y dirigido por ontologías. Tanto los elementos conceptuales como estructurales del sistema son definidos explícitamente mediante ontologías OWL, conforme a un metamodelo declarativo que dirige el sistema. Los datos clínicos procedentes de diferentes fuentes son almacenados e integrados en un repositorio clínico, conforme con la norma CEN/ISO 13606, que es capaz de comunicar los datos clínicos mediante extractos CEN/ISO 13606. Por último, proponemos un modelo de Historia Clínica Orientada por Problemas, basada en la norma CEN/ISO 13940, para representar los datos clínicos de los pacientes, asegurando una continuidad asistencial segura y eficiente.
Esta tesis no propone ningún sistema de HCE específico y completo, sino las bases para construir tales sistemas.The deployment of information systems in healthcare facilities has become widespread in recent decades and the main processes at Healthcare facilities are generally well supported. However, in spite of great advances in information and communication technologies domain during last years, current systems fail to provide true support to healthcare professionals in their daily practice and research activities. As a consequence of the variety of organizations providing healthcare and the heterogeneity of information systems used, current Electronic Health Record systems are not capable to show to healthcare professionals a conceptually consolidated view of the patients’ health state. Patient’s health data are fragmented inside information systems and over different information systems, and the professional should interpret and infer lacking relationships among them. In this scenario, semantic interoperability is pointed out by scientific community as an essential factor in achieving benefits from EHR systems to improve the quality and safety of patient care, public health, clinical research, and health service management. In this thesis we propose OntoEHR, a conceptual architecture for a new semantically interoperable EHR system, focused on the clinical process and driven by ontologies. Conceptual and structural elements of the system are explicitly defined in OWL ontologies, conforming a declarative metamodel that drive all the system. Clinical data coming from different sources are stored and integrated in a clinical repository conforming to CEN/ISO 13606 standard, which is able to communicate clinical data using CEN/ISO 13606 extracts. Lastly, we propose a Problem Oriented Medical Record model, founded on CEN/ISO 13940 standard, to represents patients’ clinical data, assuring a safe and efficient continuity of care. This thesis do not propose a specific and complete EHR system, but the foundation to build such systems.
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Wegener, Michael. "Konstruktion einer Markterfolgsanalysemethodik für Mobile-Entertainment-Anbieter : Ableitung einer eklektischen Methodik auf Basis einer stufenweisen Fokussierung des Analyseobjektes und einer forschungshistorischen Reflektion inhaltlicher und methodischer Erkenntnisgewinne relevanter Markterfolgsanalysemethodiken des Marketing und strategischen Management /." München ; Mering : Hampp, 2006. http://deposit.d-nb.de/cgi-bin/dokserv?id=2832291&prov=M&dok_var=1&dok_ext=htm.
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Dempsey, Kim Marie. "The impact of additional time on LSAT scores does time really matter? : The efficacy of making decisions on a case-by-case basis /." View full text, 2003.
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Vural, Hulya. "Comparison Of Rough Multi Layer Perceptron And Rough Radial Basis Function Networks Using Fuzzy Attributes." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605293/index.pdf.
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The hybridization of soft computing methods of Radial Basis Function (RBF) neural networks, Multi Layer Perceptron (MLP) neural networks with back-propagation learning, fuzzy sets and rough sets are studied in the scope of this thesis. Conventional MLP, conventional RBF, fuzzy MLP, fuzzy RBF, rough fuzzy MLP, and rough fuzzy RBF networks are compared. In the fuzzy neural networks implemented in this thesis, the input data and the desired outputs are given fuzzy membership values as the fuzzy properties &ldquolow&rdquo
, &ldquo
medium&rdquo
and &ldquo
high&rdquo
. In the rough fuzzy MLP, initial weights and near optimal number of hidden nodes are estimated using rough dependency rules. A rough fuzzy RBF structure similar to the rough fuzzy MLP is proposed. The rough fuzzy RBF was inspected whether dependencies like the ones in rough fuzzy MLP can be concluded.
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Maia, Júnior Francisco Franciné. "Cristais anidros das bases do ADN são semicondutores de Gap largo." reponame:Repositório Institucional da UFC, 2011. http://www.repositorio.ufc.br/handle/riufc/8105.
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MAIA JÚNIOR, Francisco Franciné. Cristais anidros das bases do ADN são semicondutores de Gap largo. 2011. 243 f. Tese (Doutorado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2011.Submitted by francisco lima (admir@ufc.br) on 2014-03-18T13:34:36Z No. of bitstreams: 1 2011_Tese_ffmaiajunior.pdf: 27698119 bytes, checksum: f4553d0bed3b17a38cc9b90fb8e55c88 (MD5)
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Guanine (G), adenine (A), cytosine (C), and thymine (T) nucleotide bases are the essential building blocks of DNA (deoxyribonucleic acid), which contains the genetic information used to build living cells. DNA strands are also promising candidates to fabricate molecular nanodevices, since they are stable polymers easy to replicate. Despite the early suggestion of the possibility of using DNA as a nanoscale conductor almost ten years after the elucidation of its helical structure, charge carrier transport through DNA-based structures is still a matter of debate. Here, we present the structural, electronic and optical properties of anhydrous crystals of DNA nucleobases found after DFT (Density Functional Theory) calculations, as well as experimental measurements of optical absorption for powders of these crystals. Experimental measurements of the UV absorption spectra for the anhydrous crystals were carried out on these pellets using a Varian Cary 5000 UV-visible NIR spectrophotometer. The absorption spectrum of the samples was recorded in the wavelength range between 200 and 800 nm (50000-12500 cm-1). The computational simulations of the present work were performed using the CASTEP code, which is based in the DFT approach. The Local Density Approximation (LDA) exchange-correlation potential developed by Ceperley and Alder and parametrized by Perdew and Zunger was adopted as well. With respect to our choice of functional, a note of caution must be made: in anhydrous DNA bases crystals, van der Waals interactions along the molecular stacking axis and hydrogen bonding between molecules in the same stacking plane are relevant to explain their structural features, and it is well known that pure DFT methods are unable to give a good description of dispersive forces. Besides, the LDA approximation is not the best option to provide an accurate account of hydrogen bonds. However, some DFT studies of layered crystals such as graphite as well as guanine hydrated crystals have shown that the LDA gives reasonable values for atomic distances, notwithstanding the limitations of this functional. This and the relatively low cost of LDA computations have motivated us to its adoption instead of more sophisticated (and computationally expensive) means. Guanine and cytosine (adenine and thymine) anhydrous crystals are predicted from the DFT simulations to be direct (indirect) band gap semiconductors, with values 2.68 eV and 3.30 eV (2.83 eV and 3.32 eV), respectively, while the experimentally estimated band gaps we have measured are 3.7 eV and 3.8 eV (3.5 eV and 4.0 eV), in the same order. Our LDA figures for the energy gaps are smaller than experimental values, as expected, and the gaps estimated from the optical absorption measurements presented in this work are in general smaller than experimental data available in the literature (except for guanine). The LDA ordering of increasing band gaps is G < A < C < T, while the ordering of gaps obtained experimentally is not settled: our work finds (from optical absorption measurements) A < G < C < T in contrast with the X-ray measurements, that indicate the energy gap sequence G < C < A < T. For electrons and holes moving along selected hydrogen bonds (parallel to the molecular plane of a given nucleobase), effective masses are in general large, exception made to thymine. When the same electrons move along the pi-stacking axis, however, effective masses stay between 4.0 and 6.3 free electron masses (m0), which suggests that stackings of nucleobases behave like wide gap semiconductors for electrons. The perpendicular transport of holes is also favored for nucleobase stackings without thymine. Finally, the complex dielectric function was calculated for each anydrous DNA base crystal, and a very pronounced anisotropy was observed for polarized incident light in the cases of guanine, adenine, and thymine, but not for cytosine.
As bases nucleotídicas guanina (G), adenina (A), citosina (C) e timina (T) são bases nucleotídicasos blocos essenciais da molécula do ácido desoxiribonucleico (ADN), que contém a as informações genéticas usadas pelas células vivas. Filamentos de ADN são também candidatos promissores para fabricação nanodispositivos moleculares, visto que polímeros estáveis e de fácil replicação. Apesar desta sugestão inicial da possibilidade de usar o ADN como condutor em nanoescala apenas dez anos após a elucidação da estrutura helicoidal do ADN, o transporte de portadores de cargas através de estruturas baseadas no ADN ainda são matéria de debate. Aqui, são apresentadas as propriedades estruturais, eletrônicas e ópticas dos cristais anidros das bases do ADN obtidas após cálculos baseados na teoria do funcional da densidade (DFT, do inglês Density Functional Theory), assim como medidas de absorção ótica para o pó desses cristais. Os experimentos do espectro absorção UV para os cristais foram realizadas sobre pastilhas usando o espectrometro Varian Cary 5000 UV-visible NIR, considerando o intervalo de 200 and 800 nm (50000-12500 cm-1). Os cálculos teóricos da presente tese foram desenvolvidos usando o pacote CASTEP, baseado na teoria DFT. Na descrição do potencial de troca e correlação, foi utilizada aproximação local da densidade (LDA, do inglês Local Density Approximation) desenvolvida por Cerpeley e Alder e parametrizado por Perdew e Zunger (CA-PZ). Sobre a escolha do funcional, uma observação deve ser feita: nos cristais anidros das bases do ADN, interações de van der Waals ao longo do eixo de empilhamento molecular e as ligações de hidrogênio entre as moléculas do mesmo plano são relevantes na explicação das suas características, e é bem conhecido que os métodos de DFT puro são incapazes de uma boa descrição das forças dispersivas. Além disso, a aproximação LDA não é a melhor opção para cálculos precisos das ligações de hidrogênio. Entretanto, alguns trabalhos DFT de cristais formados por camadas tais como grafite e o cristal hidratado da guanina mostraram que o funcional LDA fornece valores razoáveis para as distâncias atômicas, contrariando as limitações desse funcional. Isso e o baixo custo computacional foram as motivações que levaram a sua escolha em vez da adoção de funcionais mais sofisticados (e computacionalmente mais pesados). Os cristais de guanina e citosina (adenina e timina) são previstos terem gaps diretos (indiretos), com os valores experimentais estimados a partir da absorção de 3,7 eV e 3,8 eV (3,8 eV e 4,0 eV), na mesma ordem. Os resultados LDA mostraram gaps de energia menores do que os valores experimentais, como esperado, e os gaps experimentais estimados a partir da absorção ótica são, em geral, menores do que os valores experimentais disponíveis na literatura (exceto, para a guanina). A ordem crescente nos valores calculados dos gaps de energia para os cristais é dada por G < A < C < T, enquanto os valores experimentais obtidos nesta tese (a partir da absorção óptica) seguem a ordem A < G < C < T em contraste com as medidas de raios-x, que indicam a sequência G < C < A < T. Para os elétrons e buracos se movendo das ligações de hidrogênio (paralelas ao plano molecular da base), as massas efetivas são geralmente elevadas, exceto para a timina. Quando os mesmos elétrons se movimentam ao do eixo de empilhamento molecular, entretanto, as massas efetivas ficam entre 4,0 e 6,3m0, sugerindo estes cristais se comportam como semicondutores de gap largo ao longo das direções de empilhamento molecular. O transporte de buracos também é favorecido ao longo da direção de empilhamento, exceto para a timina. Finalmente, a função dielétrica complexa foi calculada para cada cristal anidro das bases do ADN, sendo observada uma forte anisotropia para a incidência de luz polarizada nos casos da guanina, adenina e timina, mas não para a citosina.
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Smith, Beth P. "Prehistoric crescentic tools from the Great Basin and California a spatial and temporal analysis /." abstract and full text PDF (UNR users only), 2008. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1456402.
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Isaac, Jolly Peter. "Comparing Basic Computer Literacy Self-Assessment Test and Actual Skills Test in Hospital Employees." ScholarWorks, 2015. http://scholarworks.waldenu.edu/dissertations/1294.
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A new hospital in United Arab Emirates (UAE) plans to adopt health information technology (HIT) and become fully digitalized once operational. The hospital has identified a need to assess basic computer literacy of new employees prior to offering them training on various HIT applications. Lack of research in identifying an accurate assessment method for basic computer literacy among health care professionals led to this explanatory correlational research study, which compared self-assessment scores and a simulated actual computer skills test to find an appropriate tool for assessing computer literacy. The theoretical framework of the study was based on constructivist learning theory and self-efficacy theory. Two sets of data from 182 hospital employees were collected and analyzed. A t test revealed that scores of self-assessment were significantly higher than they were on the actual test, which indicated that hospital employees tend to score higher on self-assessment when compared to actual skills test. A Pearson product moment correlation revealed a statistically weak correlation between the scores, which implied that self-assessment scores were not a reliable indicator of how an individual would perform on the actual test. An actual skill test was found to be the more reliable tool to assess basic computer skills when compared to self-assessment test. The findings of the study also identified areas where employees at the local hospital lacked basic computer skills, which led to the development of the project to fill these gaps by providing training on basic computer skills prior to them getting trained on various HIT applications. The findings of the study will be useful for hospitals in UAE who are in the process of adopting HIT and for health information educators to design appropriate training curricula based on assessment of basic computer literacy.