• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 497
  • 427
  • 114
  • 74
  • 33
  • 32
  • 31
  • 26
  • 21
  • 21
  • 10
  • 9
  • 7
  • 3
  • 2
  • Tagged with
  • 1422
  • 290
  • 267
  • 181
  • 179
  • 138
  • 136
  • 125
  • 100
  • 97
  • 92
  • 90
  • 88
  • 84
  • 84
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Integrating SciSPARQL and MATLAB

He, Xueming January 2014 (has links)
Nowadays many scientific experiment results involve multi-dimensional arrays. It is desirable to store these results in a persistent way and make queries against not only well-structured data objects like arrays but also the metadata that describe the experiments. SPARQL is a Semantic Web standard query language for data and metadata stored in terms of RDF. SciSPARQL is an extended version of SPARQL designed for scientific applications. It includes numeric multi-dimensional array operations and user-defined functions. The SciSPARQL Database Manager (SSDM) is a query processing engine for SciSPARQL. MATLAB is a popular and powerful scientific computing application programming language. We implemented an interface between MATLAB and SciSPARQL called MATLAB SciSPARQL Link (MSL). MSL provides SciSPARQL queries in MATLAB through a client/server interface. It optionally also provides an interface to enable calls to MATLAB in SciSPARQL queries.  With MSL MATLAB users can populate, update, and query SSDM databases it in terms of SciSPARQL queries. For the implementation we use C interfaces of MATLAB and SSDM, and the networking capabilities of SSDM. The DLL we made extends MATLAB with MSL interface functions.
82

Kompiuterinių matematinių sistemų animacijos tyrimas / Animation in computer systems for advanced mathematics

Girnytė, Diana 11 June 2004 (has links)
Many variety computer systems for advanced mathematics are now being used by hundreds of thousands of engineers, scientists and students across a broad range of exact science disciplines to perform calculations, drawing, to interface with other programs, and to publish their “live” documents on the Web. Maple, Mathcad and Matlab are computer systems for advanced mathematics and a rich problem-solving environments that gives you a wide choice of tools and supports a variety of analysis and visualization techniques. They provide many ways of representing data and mathematical expressions graphically using plots. They also have unique animating of graphs. Animation feature allows you to see a plot change in real time when the value of a variable changes. In this paper, we investigated and compared the creating, controling and using animation in Maple, Mathcad and Matlab and give animation examples for teaching mathematics. The main stress of this research work was to clear and to explain ways for practical use of animation as this area of computer systems has not been investigated in Lithuania yet.
83

MATLAB vaizdinio programavimo galimybės / MATLAB visual programming possibilities

Šeškutė, Kristina 08 June 2005 (has links)
For the user’s comfort in modern programs are created system of means, which are called graphical user interface (GUI). GUI is the window, created by user, with lay out graphical elements: command push button, edit text, list boxes, checkboxes, menu and etc. User graphical interface technology started to implant also in modern computer systems, from which the most advanced one – MATLAB. This work examines two ways of MATLAB graphical user interface creation, looks over graphical elements, MATLAB visual possibilities are compared with one the most popular programming medium C++Builder. In applied example are presented the discrete-time signal examples and real sound “a” signal, witch is possible not even depict, but also to hear out. This example demonstrates graphical user interface created by MATLAB.
84

Developing MATLAB Tools for Data Based Alarm Management and Causality Analysis

Amin, Md Shahedul Unknown Date
No description available.
85

Type Inferencing and MATLAB to Modelica Translation

Mohammad, Jahanzeb January 2014 (has links)
Matlab is a proprietary, interactive, dynamically-typed language for technical computing. It is widely used for prototyping algorithms and applications of scientific computations. Since it is a dynamically typed language, the execution of programs has to be analyzed and interpreted which results in lower computational performance. In order to increase the performance and integrate with Modelica applications it is useful to be able to translate Matlab programs to statically typed Modelica programs. This project presents the design and implementation of Matlab to Modelica translator. The Lexical and Syntax analysis is done with the help of the OMCCp (OpenModelica Compiler Compiler parser generator) tool which generates the Matlab AST, which is later used by the translator for generating readable and reusable Modelica code.
86

Extraction of anthropological data with ultrasound

Heys, Richard January 2007 (has links)
Human body scanners used to extract anthropological data have a significant drawback, the subject is required to undress or wear tight fitting clothing. This thesis demonstrates an ultrasonic based alternative to the current optical systems, that can potentially operate on a fully clothed subject. To validate the concept several experiments were performed to determine the acoustic properties of multiple garments. The results indicated that such an approach was possible. Beamforming is introduced as a method by which the ultrasonic scanning area can be increased, the concept is thoroughly studied and a clear theoretical analysis is performed. Additionally, Matlab has been used to demonstrate graphically, the results of such analysis, providing an invaluable tool during the simulation, experimental and results stages of the thesis. To evaluate beamfoming as a composite part of ultrasonic body imaging, a hardware solution was necessary. During the concept phase, both FPGA and digital signal processors were evaluated to determine their suitability for the role. An FPGA approach was finally chosen, which allows highly parallel operation, essential to the high acquisition speeds required by some beamforming methodologies. In addition, analogue circuitry was also designed to provide an interface with the ultrasonic transducers, which, included variable gain amplifiers, charge amplifiers and signal conditioning. Finally, a digital acquisition card was used to transfer data between the FPGA and a desktop computer, on which, the sampled data was processed and displayed in a coherent graphical manner. The beamforming results clearly demonstrate that imaging multiple layers in air, with ultrasound, is a viable technique for anthroplogical data collection. Furthermore, a wavelet based method of improving the axial resolution is also proposed and demonstrated.
87

Simulering av elektriska förluster i en vindkraftpark : Utveckling av programvaran Wind Farm ElectricSystem Calculator (WFESC)

Thalin, Emil January 2013 (has links)
When planning new wind farms, the cost for the internal electrical grid is estimated to account for 8-9 % of the total investment cost. On top of that, the cost for accumulated reduced income over several years (due to electrical losses), has to be added. The economic lifespan is relatively long (about 20 years) which means that an error in the loss calculation could lead to a bad decision basis. The accumulated reduced incomes due to electrical losses can be higher than the initial investment cost for the internal electrical grid. Today, Statkraft Sweden is using a template number when estimating the electrical losses in a wind farm. The actual losses are probably lower than the template number which could lead to an unnecessary high loss cost when planning a new wind farm. The aim of this M.Sc. thesis is to develop a better method than the one currently used to estimate the electrical losses in an early stage of the planning process. With necessary information of the proposed wind farm, an early calculation can be done.The user will then have the option to make changes in the wind farm to minimize losses, long before the wind farm is actually built. In the initial stage of the thesis, the components generating losses was modeled using available literature. Next, a MATLAB-program was constructed where the user could build a proposed wind farm consisting of wind turbines, cables and transformers. The program was named Wind Farm Electric System Calculator (WFESC). Finally, WFESC was verified with measurement data from one of Statkraft’s wind farms in Småland, Sweden. WFESC can simulate the electrical losses and production from a wind farm. The simulation takes turbine information, cable types and transformer specifications into account. The user gets detailed information about the different types of losses which makes it possible to minimize losses in the wind farm. In a comparison, WFESC presents a result that differs 5 % from measured data acquired from one of Statkraft’s wind farms in Sweden. The difference between data produced with WFESC and measured data emerges from approximations done in WFESC and difficulties in estimating cable temperatures in a wind farm. The conclusion is that WFESC estimates the internal electrical losses well and can be used when planning a wind farm.
88

Μελέτη παραμέτρων και σχεδίαση συστήματος αυτόματης αναγνώρισης/παρακολούθησης σήματος για δορυφορικές επικοινωνιακές εφαρμογές

Μπελεσιώτης, Αναστάσιος 16 April 2013 (has links)
Στόχος της παρούσας εργασίας είναι η υλοποίηση ενός αλγορίθμου για την ανίχνευση και παρακολούθηση του δορυφορικού σήματος υπό διάφορες συνθήκες διάδοσης στο κανάλι. Αρχικά αναλύεται η δομή ενός δορυφορικού συστήματος επικοινωνιών και περιγράφονται τα σημαντικότερα στοιχεία του τόσο στο επίγειο όσο και στο διαστημικό τμήμα. Στη συνέχεια παρουσιάζεται το περιβάλλον του καναλιού μέσα στο οποίο γίνεται η διάδοση των ηλεκτρομαγνητικών κυμάτων και αναλύονται οι σημαντικότεροι παράγοντες εξασθένισης και αλλοίωσης του σήματος. Τέλος, γίνεται αναφορά στα σημαντικότερα υπάρχοντα συστήματα παρακολούθησης των δορυφορικών κεραιών σε ένα από τα οποία βασίστηκε και ο αλγόριθμος παρακολούθησης που δημιουργήθηκε μέσω του προγράμματος Matlab. / The main purpose of this thesis is the development of a basic algorithm capable of tracking the satellite signal under various propagation scenarios. At first, an analytical presentation of both earth and the space segment of the satellite system is being held. Afterwards, the basic elements of the satellite link are explained, as well as their negative effects on the radio-wave propagation mechanism. Finally, a brief reference on the most used antenna tracking systems is made, before we move on to the development of our own step-tracking algorithm in order to simulate the antenna tracking procedure under realistic transmission conditions.
89

Modelagem da propagação sonora em dutos : abordagem matemática no domínio da frequência e do tempo utilizando transformada de laplace

Cardoso, Saieny Hauak 29 February 2016 (has links)
Dissertação (mestrado)—Universidade de Brasília, Faculdade UnB Gama, Faculdade de Tecnologia, Programa de Pós-graduação em Integridade de Materiais da Engenharia, 2016. / Submitted by Fernanda Percia França (fernandafranca@bce.unb.br) on 2016-05-06T16:33:30Z No. of bitstreams: 1 2016_SaienyHauakCardoso.pdf: 6463926 bytes, checksum: f6beaa161a830b4ffcaf8a92d185413f (MD5) / Approved for entry into archive by Marília Freitas(marilia@bce.unb.br) on 2016-05-26T16:39:16Z (GMT) No. of bitstreams: 1 2016_SaienyHauakCardoso.pdf: 6463926 bytes, checksum: f6beaa161a830b4ffcaf8a92d185413f (MD5) / Made available in DSpace on 2016-05-26T16:39:16Z (GMT). No. of bitstreams: 1 2016_SaienyHauakCardoso.pdf: 6463926 bytes, checksum: f6beaa161a830b4ffcaf8a92d185413f (MD5) / Em meio ao crescimento urbanístico vivenciado atualmente, é fácil notar a presença de um elemento estrutural comum, seja no meio residencial ou industrial: os dutos. Estes são componentes essenciais no nosso cotidiano, presente desde o processo de transporte de matérias prima imprescindíveis para a sobrevivência humana, na mobilidade sistema de exaustão dos veículos automotores, até a utilização destes no contexto do conforto humano, sistemas de aquecimento, ventilação e ar condicionado. Apesar de ser de extrema importância nas aplicações de engenharia, os dutos são considerados como um dos principais responsáveis por transportar para o meio externo o ruído gerado por importantes fontes sonoras, como motores e ventiladores. Técnicas passivas e ativas de controle de ruído são comumente aplicadas aos dutos com o intuito de mitigar o ruído irradiado. No entanto, para um projeto efetivo deste controle, se faz necessário o conhecimento do comportamento acústico das ondas sonoras que se propagam em seu interior. Um importante exemplo pode ser citado: o projeto de um controlador ativo de ruído (CAR) em dutos, no qual a completa identificação do sistema acústico se faz necessário, por exemplo, para evitar instabilidades no sistema de controle e consequentemente aumentar sua eficiência. Neste trabalho, as funções de transferência (FT) acústicas entre fonte de ruído e microfone localizado no interior do duto, são estimadas para algumas configurações e condições de contorno. A FT analítica é desenvolvida no domínio da frequência, derivada da equação fundamental da onda e utilizando a transformada de Laplace e suas propriedades. Para isto, considera-se meio fluido contínuo, homogêneo, perfeitamente elástico, processo isentrópico, e ainda sistema linear e invariante no tempo. Além disso, o modelo de elementos finitos do sistema considerado é desenvolvido para comparação dos resultados. Ambos os modelos apresentaram respostas semelhantes, embora a condição de contorno aberto adicione algumas diferenças entre as FTs quando do aumento da frequência de análise. No contexto do CAR, este trabalho também apresenta o desenvolvimento matemático para estimativa da pressão sonora no domínio do tempo no interior de dutos acústicos. Partindo de FTs no domínio da frequência, utiliza-se transformada inversa de Laplace para estimativa da pressão sonora em determinada localização no interior do duto, devido a uma fonte sonora caracterizada pela sua velocidade de volume. As equações resultantes são implementadas em Matlab e os gráficos são discutidos em termos dos fenômenos físicos envolvidos. ______________________________________________________________________________________________ ABSTRACT / Amidst the urban growth currently experienced, it is easy to notice the presence of a common structural element, whether in residential or industrial environment: the ducts. These are essential components in our daily lives, present from the transport process of raw materials essential for human survival in the exhaust system mobility of vehicles, to the use of these in the context of human comfort, heating, ventilation and air conditioning . Despite being extremely important in engineering applications, the products are considered as one of the main responsible for transport to the outside noise generated by major noise sources such as motors and fans. Technical passive and active noise control are commonly applied to products in order to mitigate the radiated noise. However, for effective design of this control, the knowledge of the acoustic behavior of sound waves that propagate inside is necessary. An important example can be cited: the design of an active noise control (CAR) in pipelines, in which the complete identification of the acoustic system is necessary, for example, to prevent instabilities in the control system and thus increase efficiency. In this work, the transfer function (TF) between acoustic noise source and microphone located inside the duct, are estimated for some configurations and boundary conditions. The analytical FT is developed in the frequency domain derived from the fundamental equation of wave and using the Laplace transform and its properties. For this, it is considered continuous medium fluid, homogenous, perfectly elastic, isentropic process, and further linear time-invariant system. In addition, the finite element model of the system under consideration is designed to compare the results. Both models showed similar response, although the open boundary condition add some differences between TFs when increasing the frequency analysis. In the context of the CAR, this work also presents the mathematical development to estimate the sound pressure in the time domain within acoustic ducts. From the TFs in the frequency domain, it uses inverse Laplace transform to estimate the sound pressure in a particular location within the pipeline due to a sound source characterized by a volume velocity. The resulting equations are implemented in Matlab and graphics are discussed in terms of physical phenomena involved.
90

Escalonamento de tarefas job-shop realistas utilizando algoritmos genéticos em MATLAB

Beck, Felipe Luís January 2000 (has links)
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Elétrica. / Made available in DSpace on 2012-10-18T01:17:35Z (GMT). No. of bitstreams: 0Bitstream added on 2014-09-25T17:12:43Z : No. of bitstreams: 1 182500.pdf: 4247647 bytes, checksum: 0d4e57bcc3bd8849bd1c880bb4c11cca (MD5) / Esta dissertação aborda o desenvolvimento e a implementação de um sistema para escalonamento de tarefas do tipo job-shop. Com o sistema que foi desenvolvido, é possível o tratamento não apenas de problemas clássicos, como também de problemas realistas, que levam em conta um grande número de características reais, ignoradas em problemas clássicos de escalonamento. Estes problemas realistas possuem um elevado número de operações e máquinas, se comparados a problemas clássicos, além de recursos adicionais, multiplicidade de máquinas do mesmo tipo, e vários modos possíveis de execução, entre outras características. Com o sistema desenvolvido é, também, possível o tratamento de problemas de escalonamento dos tipos flow e open-shop e, inclusive, de problemas que mesclem estes três tipos. Tendo sido desenvolvido utilizando MATLAB e uma toolbox genética, mostra-se que um sistema simples, construído a partir de software amplamente disponível, é satisfatório para a utilização em problemas de escalonamento. Os resultados obtidos em testes comprovam a eficiência do sistema criado no tratamento de problemas de escalonamento clássicos, e também a sua boa performance quando são tratados problemas realistas.

Page generated in 0.0396 seconds