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  • 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

Simulador pediátrico InCor: desenvolvimento de um modelo hidráulico do sistema circulatório pediátrico com ajustes automatizados de pressões. / InCor pediatric simulator: development of a pediatric mock circulation loop with an automated adjustment of pressures.

Daniel Seidenberger Torres 14 May 2018 (has links)
Os dispositivos de assistência ventricular (DAVs) podem ser utilizados para a estabilização hemodinâmica de pacientes à espera do transplante cardíaco. Os avanços nas tecnologias e a utilização de materiais biocompatíveis vem contribuindo para o desenvolvimento de dispositivos com dimensões reduzidas e menor trauma ao sangue. A avaliação do desempenho desses dispositivos demanda a utilização de simuladores hidráulicos do sistema circulatório que reproduzam as pressões e fluxos existentes nas condições fisiológicas de interesse. Este trabalho tem como objetivo o desenvolvimento de um simulador da circulação pediátrica com ajustes automatizados de pressões. O simulador é composto por um circuito hidráulico modelando os laços sistêmico e pulmonar e um sistema microcontrolado com uma interface de usuário para medição e visualização dos fluxos e pressões ventriculares e automatização dos ajustes das pressões arteriais aórtica e pulmonar (PAo, PAP) e das pressões atriais esquerda e direita (PAE, PAD). Duas bombas pulsáteis com 15 ml de volume de ejeção são utilizadas para modelar os comportamentos mecânicos dos ventrículos esquerdo e direito. As complacências da aorta e da artéria pulmonar e as pré-cargas dos ventrículos são simuladas por câmaras com volumes ajustáveis de ar e líquido (análogo sanguíneo) utilizando uma bomba de ar. As resistências hidráulicas dos laços são ajustadas por oclusores motorizados. Os sinais instantâneos dos fluxos de entrada e saída dos DAVs e das pressões arteriais, atriais e ventriculares são obtidos por transdutores e digitalizados em um microcontrolador que comanda os oclusores e a bomba de ar. Foram desenvolvidos algoritmos para ajustes das resistências, complacências e pré-cargas. Uma interface gráfica de usuário apresenta os sinais em tempo real (ou gravados) permitindo a escolha dos parâmetros e condições de simulação. O desempenho do sistema de automatização foi avaliado nas simulações de: 1) condições definidas pelo aplicativo da interface e 2) condições fisiológicas (normal e redução na contratilidade do miocárdio). No modelo hidráulico sistêmico as pressões foram ajustadas em ambas as situações com erro máximo de 0,5% para a PAo e 5% para a PAE em aproximadamente 80 segundos. No modelo completo da circulação o erro máximo para as simulações de condições fisiológicas foi de 4% para as pressões arteriais e 5% para as atriais. Os resultados obtidos demonstram que o simulador desenvolvido permite reproduzir adequadamente as características da circulação pediátrica essenciais para a avaliação do desempenho de dispositivos de assistência mecânica. O simulador é portátil, de fácil utilização e pode ser utilizado como ferramenta didática ou para o treinamento de profissionais da saúde envolvidos em assistência a pacientes com suporte circulatório. / Ventricular assist devices (VADs) can be used for the hemodynamic stabilization of patients waiting for heart transplantation. Advances in the technologies and the use of biocompatible materials have contributed to the development of devices with reduced dimensions and blood trauma. Evaluation of the performance of these devices demands the use of hydraulic simulators of the circulatory system that reproduce pressures and flows existing in physiological conditions of interest. This work aims to develop a simulator of the pediatric circulation with automated adjustments of pressures. The simulator consists of a hydraulic circuit modeling the systemic and pulmonary branches and a microcontrolled system with a user interface for monitoring flows and ventricular pressures, and automating adjustments of aortic and pulmonary arterial pressures (AoP, PAP) and left and right atrial pressures (LAP, RAP). Two pulsatile pumps with 15 ml ejection volume are used to model the mechanical behavior of the left and right ventricles. Aortic and pulmonary arterial compliances and preloads of the ventricles are simulated by chambers with adjustable volumes of air and fluid (blood analog) using an air pump. Motorized clamps adjust the hydraulic resistances of the loops. Instantaneous signals of VAD input and output flows and of arterial, atrial and ventricular pressures are obtained by transducers and digitalized in a microcontroller that commands the clamps and the air pump. Algorithms were developed to adjust the resistances, compliances and preloads. A graphical user interface displays signals in real time (or recorded) and allows selection of simulation parameters. The performance of the automation system was tested setting pressures in two situations: 1) simulations of random conditions defined by the interface software and 2) simulations of physiological conditions (normal and low myocardial contractility). In the systemic model, the pressures were adjusted in both cases (maximum error of 0.5% for AoP and 5% for LAP) in approximately 80 seconds. In the complete model, the maximum error for simulations of physiological conditions was 4% for arterial pressures and 5% for atrial pressures. The results obtained demonstrate that the simulator developed allows mimicking the relevant features of the systemic and pulmonary branches of the circulation needed to assess the performance of mechanical circulatory assist devices. The simulator is portable, easy to operate and can be applied in teaching and training of health professionals working with mechanical circulatory support of patients.
82

The influence of interfaces on the understanding of Mathematics in secondary schools in Afghanistan

Mojadadi, Abdul Rahman January 2010 (has links)
<p>he focus of this research is to establish whether there is a difference in the way the genders perceive the visualization of mathematics, with specific reference to set theory. The influence of the computing experience of students on their perceptions was also investigated. Interfaces were created for the teaching of set theory for learners in the first class of secondary school. Since the mother tongue of most the pupils is Dari the interface was made available in both Dari and English. The interfaces were used to gather the data for the researc</p>
83

Construction and realisation of measurement system in a radiation field of 10 standard suns.

Makineni, Anil Kumar January 2012 (has links)
A measurement system is to be presented, which is used to obtain the I-V characteristics of a solar cell and to track its temperature during irra-diation before mounting it into a complete array/module. This project presents both the design and implementation of an Electronic load for testing the solar cell under field conditions of 10000 W/m^2, which is able to provide current versus voltage and power versus voltage charac-teristics of a solar cell using a software based model developed in Lab-VIEW. An efficient water cooling method which includes a heat pipe array system is also suggested. This thesis presents the maximum power tracking of a solar cell and the corresponding voltage and current values. In addition, the design of the clamp system provides an easy means of replacing the solar cell during testing.Keywords: Solar cell, Metal Oxide Semiconductor Field Effect Transistor (MOSFET), I-V characteristics, cooling system, solar cell clamp system, LabVIEW, Graphical User Interface (GUI).
84

Hipertekstinės grafinės vartotojo sąsajos kūrimas aukšto abstrakcijos lygmens deklaratyvia sintakse / Hypertext graphical user interface definition using high abstraction level declarative syntax

Paškevičius, Paulius 13 August 2010 (has links)
Tezėse nagrinėjamas hipertekstinės grafinės vartotojo sąsajos aprašymas aukšto abstrakcijos lygmens elementais, juos apibrėžiant deklaratyvia sintakse. Siūloma architektūra aprašo hipertekstinę grafinę vartotojo sąsają aukšto abstrakcijos lygmens elementais. Apibrėžiamas 20-ties esminių grafinių elementų rinkinys, deklaratyvi XML notacija ir suprojektuojama HTML grafinės vartotojo sąsajos biblioteka, veikianti JavaScript pagrindu bei užtikrinanti ženkliai greitesnį ir paprastesnį grafinės vartotojo sąsajos kūrimą. Pateiktas metodas neturi viešų analogų ir yra skirtas sudėtingiems grafinės vartotojo sąsajos sprendimams. Eksperimentiniais tyrimais parodoma, kad deklaratyvi notacija ir aukštas abstrakcijos lygmuo gali sumažinti programinį kodą nuo 3,1 karto trivialiems GUI elementams iki 204,1 karto sudėtingiems GUI sprendimams. Eksperimentai patvirtina, kad didėjant grafinę vartotojo sąsają sudarančių HTML elementų kiekiui, galima tikėtis dar geresnių efektyvumo rodiklių. Sukurta architektūra yra integruota į programinės įrangos projektavimo modelį, kuriame vartotojo sąsajos ir logikos kūrimas iš dalies automatizuotas naudojant UML modelį. Tradicinis tekstinis redaktorius pakeistas duomenimis paremtu projektavimo įrankiu, panaudos atvejai vystomi scenarijais su grafiniu redaktoriumi, duomenų infrastruktūra generuojama iš modelio, o realizacija pateikiama keliomis programavimo technologijomis. / In master theses hypertext graphical user interface definition using high abstraction level declarative syntax is analyzed and architecture model is suggested. Suggested architecture defines graphical user interface using high abstraction level elements. Basic element set of more than 20 elements is defined, declarative XML notation is suggested and graphical user interface library for HTML is developed with JavaScript to ensure much faster and easier standard-based graphical user interface development. Provided method has no public analogues yet and is suggested for complex graphic user interfaces. Experimental studies proved that declarative syntax and high abstraction level can reduce programming language code from 3.1 times on trivial GUI elements to 204.1 times on complex GUI solutions. Studies have showed that when the number of HTML elements composing graphical user interface grows, even better effectiveness can be achieved. Developed architecture is integrated in software development model where graphical user interface and logic are semi-automated using UML model. Traditional text editor is changed by data driven design tool, use-cases are developed using graphical editor, data infrastructure is build from the model and solution is delivered in several programming technologies.
85

The influence of interfaces on the understanding of Mathematics in secondary schools in Afghanistan

Mojadadi, Abdul Rahman January 2010 (has links)
<p>he focus of this research is to establish whether there is a difference in the way the genders perceive the visualization of mathematics, with specific reference to set theory. The influence of the computing experience of students on their perceptions was also investigated. Interfaces were created for the teaching of set theory for learners in the first class of secondary school. Since the mother tongue of most the pupils is Dari the interface was made available in both Dari and English. The interfaces were used to gather the data for the researc</p>
86

Teksto redaktorių sąsajų efektyvumo palyginimas vertinant akies ir rankos judesius / The comparison of text editors graphical user interface (GUI) efficiency estimating eye and hand movements

Kavaliauskas, Kazimieras 04 August 2011 (has links)
Darbo tikslas yra palyginti teksto redaktorių grafinių vartotojų sąsajų efektyvumą vertinant akių ir rankos judesius. Šiame darbe yra apžvelgtos grafinės vartotojų sąsajos charakteristikos, akių ir rankų judesių matavimo metodai ir atlikti tyrimai. Atlikti tyrimai su teksto redaktorių vartotojų sąsajom. Tyrimų metu atlikti akių ir rankos judesių matavimai, išanalizuoti tyrimų rezultatai ir panaudoti nustatant vartotojo sąsajų efektyvumo palyginimui. Pagal gautus rezultatus nustatyti vartotojų sąsajų efektyvumai ir atlikta jų palyginimo analizė. Gautos išvados, kad su Microsoft Office 2007 teksto redaktoriais užduotims atlikti buvo sugaišta mažiausiai laiko ir pasiektas didžiausias greitis. Eksperimentiniais tyrimais patvirtinta, kad Microsoft Office 2007 redaktoriaus vartotojo sąsajos efektyvumas buvo didžiausias. / The goal of thesis is to compare the effectiveness of text editors graphical user interface estimating eye and hand movements. In this thesis the characteristics of GUI, the methods and techniques of eye and hand movements measurement are reviewed and researches are done. Researches were carried out with text editor user interfaces. Eye and hand movements measurements were made, results analyzed and used to compare user interface efficiency. According to the results the efficiencies of user interface were made and the analysis of comparison was carried out. It was conluded that with the Microsoft Office 2007 text editors the least time was spent and the maximum speed reached in order to do tasks. Experimental studies proved that the Microsoft Office 2007 User Interface Editor efficiency was highest.
87

A Content-Aware Design Approach to Multiscale Navigation

Pindat, Cyprien 20 December 2013 (has links) (PDF)
Computer screens are very small compared to the size of large information spaces that arise in many domains. The visualization of such datasets requires multiscale navigation capabilities, enabling users to switch between zoomed-in detailed views and zoomed-out contextual views of the data. Designing interfaces that allow users to quickly identify objects of interest, get detailed views of those objects, relate them and put them in a broader spatial context, raise challenging issues. Multi-scale interfaces have been the focus of much research effort over the last twenty years.There are several design approaches to address multiscale navigation issues. In this thesis, we review and categorize these approaches according to their level of content awareness. We identify two main approaches: content-driven, which optimizes interfaces for navigation in specific content; and content-agnostic, that applies to any type of data. We introduce the content-aware design approach, which dynamically adapts the interface to the content. The latter design approach can be used to design multiscale navigation techniques both in 2D or 3D spaces. We introduce Arealens and Pathlens, two content-aware fisheye lenses that dynamically adapt their shape to the underlying content to better preserve the visual aspect of objects of interest. We describe the techniques and their implementation, and report on a controlled experiment that evaluates the usability of Arealens compared to regular fisheye lenses, showing clear performance improvements with the new technique for a multiscale visual search task. We introduce a new distortion-oriented presentation library enabling the design of fisheye lenses featuring several foci of arbitrary shapes. Then, we introduce Gimlens, a multi-view detail-in-context visualization technique that enables users to navigate complex 3D models by drilling holes into their outer layers to reveal objects that are buried into the scene. Gimlens adapts to the geometry of objects of interest so as to better manage visual occlusion problems, selection mechanism and coordination of lenses.
88

Ανάπτυξη προγραμματιστικού περιβάλλοντος για τη μελέτη ασύγχρονων νευρωνικών δικτύων

Ανδριακοπούλου, Ειρήνη 14 February 2012 (has links)
Εκτός από τα Τεχνητά Νευρωνικά Δίκτυα, ένα άλλο παρεμφερές πρόβλημα είναι αυτό της μοντελοποίησης των δομικών και λειτουργικών χαρακτηριστικών διαφόρων τμημάτων του Κεντρικού Νευρικού Συστήματος καθώς και των διαφόρων εγκεφαλικών λειτουργιών. Στόχος αυτής της διπλωματικής είναι η δημιουργία ενός μοντέλου του φυσιολογικού νευρώνα και της συγκρότησης νευρωνικών δικτύων που εμπλέκονται σε κάποια εγκεφαλική λειτουργία. Στην ανάπτυξη του μοντέλου λήφθηκαν υπόψη τα ιδιαίτερα νευροανατομικά χαρακτηριστικά και νευροφυσιολογικά χαρακτηριαστικά και οι ιδιότητες που σχετίζονται με τις υπό μελέτη εγκεφαλικές καταστάσεις. Επίσης διερευνήθηκε η αλληλεπίδραση και η αναπτυσσόμενη δυναμική, τόσο σε κυτταρικό επίπεδο όσο και σε συστημικό επίπεδο, καθώς και η δυναμική αλληλεπίδραση νευρωνικών δικτύων. Πραγματοποιήθηκε μακροσκοπική προσέγγιση με τη χρήση μαθηματικών μοντέλων και αναπτύχθηκε ένα GUI περιβάλλον για τη διαχείριση του προγράμματος από το χρήστη. / Apart from the Artificial Neural Networks, another similar problem is the modeling of structural and functional characteristics of different parts of the Central Nervous System and the various brain functions. The aim of this diploma is to create a model of normal neuron and the establishment of neural networks involved in some brain function. In developing the model were taken into account the specific neuroanatomical and neurophysiological characteristics and properties related to the studied brain states. We also investigated the interaction and the growing momentum, both at the cellular level and system level, and the dynamic interaction of neural networks. An macroscopic approach using mathematical models and developed a GUI environment for the management of the program by the user.
89

Design of an Autonomous Underwater Vehicle with Vision Capabilities

Jebelli, Ali January 2016 (has links)
In the past decade, the design and manufacturing of intelligent multipurpose underwater vehicles has increased significantly. In the wide range of studies conducted in this field, the flexibility and autonomy of these devices with respect to their intended performance had been widely investigated. This work is related to the design and manufacturing of a small and lightweight autonomous underwater vehicle (AUV) with vision capabilities allowing detecting and contouring obstacles. It is indeed an exciting challenge to build a small and light submarine AUV, while making tradeoffs between performance and minimum available space as well as energy consumption. In fact, due to the ever-increasing in equipment complexity and performance, designers of AUVs are facing the issues of limited size and energy consumption. By using a pair of thrusters capable to rotate 360o on their axis and implementing a mass shifter with a control loop inside the vehicle, this later can efficiently adapt its depth and direction with minimal energy consumption. A prototype was fabricated and successfully tested in real operating conditions (in both pool and ocean). It includes the design and embedding of accurate custom multi-purpose sensors for multi-task operation as well as an enhanced coordinated system between a high-speed processor and accustomed electrical/mechanical parts of the vehicle, to allow automatic controlling its movements. Furthermore, an efficient tracking system was implemented to automatically detect and bypass obstacles. Then, fuzzy-based controllers were coupled to the main AUV processor system to provide the best commands to safely get around obstacles with minimum energy consumption. The fabricated prototype was able to work for a period of three hours with object tracking options and five hours in a safe environment, at a speed of 0.6 m/s at a depth of 8 m.
90

Desenvolvimento de uma toolbox para aplicação de inteligência computacional em sistemas de controle clássico / Development of a toolbox for application of computational intelligence in classic control systems

Dantas, Emmanuel Ramon Marques 27 December 2013 (has links)
Made available in DSpace on 2016-08-31T13:33:39Z (GMT). No. of bitstreams: 1 EmmanuelRMD_DISSERT.pdf: 3141928 bytes, checksum: 608c0b50b8f95185573646571b1dde6f (MD5) Previous issue date: 2013-12-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A new tool based on the use of computational intelligence applied in control systems is presented. This type of application has attracted the interest of researchers due the advantages in relation to others methods for controlling settings, especially when the system has a complex dynamics to be adjusted by traditional methods. The proposed computational tool GACT (Genetic Algorithm Control Tool) was developed to work as a Toolbox of MATLAB® software for use in control systems and is based on the joint application of Genetic Algorithms (GA) and the classical control theory. The GACT based on the advancement of the operating systems that are no longer fully handled by command lines, and now have an interactive graphical user interface. That is, the referred Toolbox allows the implementation of an intelligent control system in a way more simplified and interactive. The graphical user interface (GUI) was designed using the software GUIDE, integrated with MATLAB® in order to connect with the source code and block diagrams of the system to be controlled at the SIMULINK® / Uma nova ferramenta baseada no uso da inteligência computacional aplicada em sistemas de controle é apresentada. Esse tipo de aplicação tem despertado o interesse de pesquisadores por apresentar vantagens em relação aos outros métodos de ajustes para controladores, principalmente quando o sistema apresenta uma dinâmica complexa de ser ajustada pelos métodos tradicionais. A ferramenta computacional proposta GACT (Genetic Algorithm Control Tool) foi desenvolvida para funcionar como uma Toolbox do software MATLAB® para aplicação em sistemas de controle e fundamenta-se na aplicação conjunta de Algoritmos Genéticos (GA do inglês Genetic Algorithm) com a teoria de controle clássico. O GACT baseia-se no avanço dos sistemas operacionais que deixaram de ser totalmente manuseados por linhas de comando e passaram a ter uma interface gráfica interativa. Ou seja, a referida Toolbox possibilita a implementação de um sistema de controle inteligente de maneira mais simplificada e interativa. A interface gráfica foi concebida através do software GUIDE, integrado ao MATLAB® de maneira a relacionar-se com os códigos fontes e os diagramas de blocos do sistema a ser controlado no SIMULINK®

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