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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.
11

OpenGL ES-based Emulator with Performance Tuning in the 3DApplication Development Platform for Embedded Systems

Hung, Chih-Yang 04 September 2009 (has links)
Developing 3D application for low-performance embedded system often contains some limitations as hardware specifications (e.g. memory and processing efficiency). Existing OpenGL ES emulators are designed to provide the development environment for programmers, but these emulators often are lack of cross-platform performance tuning analysis for embedded systems and are only suitable for a designated hardware. In this thesis, we present an OpenGL ES emulator with performance tuning for developing 3D application of embedded systems without conforming to a specific hardware. It can further help programmers to emulate 3D application on PC for different development platforms.
12

JAVA VIRTUAL MACHINE DESIGN FOR EMBEDDED SYSTEMS: ENERGY, TIME PREDICTABILITY AND PERFORMANCE

Sun, Yu 01 December 2010 (has links)
Embedded systems can be found everywhere in our daily lives. Due to the great variety of embedded devices, the platform independent Java language provides a good solution for embedded system development. Java virtual machine (JVM) is the most critical component of all kinds of Java platforms. Hence, it is extremely important to study the special design of JVM for embedded systems. The key challenges of designing a successful JVM for embedded systems are energy efficiency, time predictability and performance, which are investigated in this dissertation, respectively. We first study the energy issue of JVM on embedded systems. With a cycle-accurate simulator, we study each stage of Java execution separately to test the effects of different configurations in both software and hardware. After that, an alternative Adaptive Optimization System (AOS) model is introduced, which estimated the cost/benefit using energy data instead of running time. We tuned the parameters of this model to study how to improve the dynamic compilation and optimization in Jikes RVM in terms of energy consumption. In order to further reduce the energy dissipation of JVM on embedded systems, we study adaptive drowsy cache control for Java applications, where JVM can be used to make better decision on drowsy cache control. We explore the impact of different phases of Java applications on the timing behavior of cache usage. Then we propose several techniques to adaptively control drowsy cache to reduce energy consumption with minimal impact on performance. It is observed that traditional Java code generation and instruction fetch path are not efficient. So we study three hardware-based code caching strategies, which attempt to write and read the dynamically generated Java code faster and more energy-efficiently. Time predictability is another key challenge for JVM on embedded systems. So we exploit multicore computing to reduce the timing unpredictability caused by dynamic compilation and adaptive optimization. Our goal is to retain high performance comparable to that of traditional dynamic compilation and, at the same time, obtain better time predictability for JVM. We study pre-compilation techniques to utilize another core more efficiently. Furthermore, we develop Pre-optimization on Another Core (PoAC) scheme to replace AOS in Jikes JVM, which is very sensitive to execution time variation and impacts time predictability greatly. Finally, we propose two new approaches that automatically parallelizes Java programs at run-time, in order to meet the performance challenge of JVM on embedded systems. These approaches rely on run-time trace information collected during program execution, and dynamically recompiles Java byte code that can be executed in parallel. One approach utilizes trace information to improve traditional loop parallelization, and the other parallelizes traces instead of loop iterations.
13

Intelligent Stereo Video Monitoring System for Paramedic Helmet

Liu, Yang January 2017 (has links)
During the first aid process, when patients are threatened by poor medical conditions, ambulance paramedics are required to administer emergency treatment based on instruc- tions provided by a remote emergency doctor through voice communication. However, such voice communication is always limited in expressing abundant detailed information for the patient. This thesis presents a framework for a stereoscopic and intelligent telemedicine sys- tem that can provide 3D live video communication between paramedics and emergency doctors. The proposed system captures 3D video from the paramedic headset carried by the paramedics, transmits the video through wireless live streaming, and displays the video with a 3D effect for emergency doctors in the hospital. The video can be analyzed to extract information about the patient through embedded algorithm such as face de- tection algorithm. In this thesis, the hardware, functional mechanism and face detection algorithm are introduced separately. The hardware of the system consists of a paramedic headset, a server box and a 3D PC, which are used to capture 3D video, transmit video through live streaming and display video with a stereo effect, respectively. The functional mechanism includes two subsystems, which work for pushing the stereo video to multiple live streams and displaying the 3D video from the live stream. In order to detect the patient information from the video, a multi-task face detection algorithm is applied to analyze the stereo video using deep learning technology. We improved the neural networks of face detection by utilizing 1 ⇥ 1 convolutional layers and retrain the network based on the transfer learning to achieve better and faster performance. This system has achieved good and stable performance in network delay (0.0489ms) and objective video quality evaluations. The face detection algorithm has achieved no- table accuracy (91.78% In FDDB dataset) and efficiency (19.71 ms/frame).
14

Ingénierie des exigences pour la conception d'architectures de sécurité de systèmes embarqués distribués / A requirement engineering driven approach to security architecture design for distributed embedded systems

Idrees, Muhammad Sabir 21 September 2012 (has links)
Au cours des dix dernières années, l’impact des questions de sécurité sur le développement et la mise en oeuvre des systèmes embarqués distribués n’a jamais cessé de croître. Ceci est principalement lié à l’interconnexion toujours plus importante de ces systèmes qui les rend vulnérables aux attaques, ainsi qu’à l’intérêt économique d’attaquer ces systèmes qui s’est simultanément accru. Dans un tel contexte, méthodologies et outils d’ingénierie des exigences de sécurité sont devenus indispensables pour prendre des décisions appropriées quant a` la sécurité, et ce le plus tôt possible. L’ingénierie des exigences devrait donc fournir une aide substantielle à l’explicitation et à la spécification des problèmes et solutions de sécurité des logiciels bien avant que concepteurs et développeurs ne soient engagés dans une implantation en particulier. Toutefois, et c’est particulièrement vrai dans les systèmes embarqués, les exigences de sécurité ne doivent pas être considérées seulement comme l’expression abstraite d’un ensemble de propriétés indépendamment de l’architecture système ou des menaces et des attaques qui pourraient y survenir. Nous estimons que cette considération est d’une importance capitale pour faire de l’ingénierie des exigences un guide et un moteur de la conception et de la mise en œuvre d’un système sécurisé. Notre approche s’appuie en particulier sur une approche centrée sur les connaissances de l’ingénierie des exigences de sécurité, applicable dès les premières phases de conception du système jusqu’à la mise en application des exigences de sécurité dans l’implantation. / During the last ten years, the impact of security concerns on the development and exploration of distributed embedded systems never ceased to grow. This is mainly related to the fact that these systems are increasingly interconnected and thus vulnerable to attacks, and that the economic interest in attacking them has simultane- ously increased. In such a context, requirement engineering methodologies and tools have become necessary to take appropriate decisions regarding security early on. Security requirements engineering should thus strongly support the elicitation and specifica- tion of software security issues and solutions well before designers and developers are committed to a particular implementation. However, and that is especially true in embedded systems, security requirements should not be considered only as the abstract expression of a set of properties independently from the system architecture or from the threats and attacks that may occur. We believe this consideration is of utmost importance for security requirements engineering to be the driving force behind the design and implementation of a secure system. We thus describe in this thesis a security engineering requirement methodology depending upon a constant dialog between the design of system functions, the requirements that are attached to them, the design and development of the system architecture, and the assessment of the threats to system assets. Our approach in particular relies on a knowledge-centric approach to security requirement engineering, applicable from the early phases of system conceptualization to the enforcement of security requirements.
15

An implementation of an autonomous IoT system for real-time water quality monitoring with 4G and satellite connection : CatFish - Embedded systems

Elfing, Johan, Persson, Daniel January 2022 (has links)
This thesis is about implementing an Internet of Things system for measuring water quality in rivers and other aquatic environments with an autonomous water drone, where the data from various components are collected and sent wirelessly to the database in real-time. A Raspberry Pi is connected to the internet through a 4G modem and a wireless satellite communication connection called RockBlock for emergency calls and notifications. In addition, a sonar is also implemented to collect data for the unmanned surface vehicle's (USV) avoidance of collisions. Finally, batteries are connected to solar panels to auto-generate energy and provide the USV with its requested current and voltage. The minimum parameters to measure water quality are four: potential hydrogen, dissolved oxygen, nitrates, and colored dissolved organic matter. As a result, the system in this thesis measures the four parameters mentioned above, plus turbidity and temperature, since the interconnected sensors can also measure those. In addition, optical sensors were chosen because of their exceptional accuracy and precision when measuring water quality. The environment, mainly the aquatic, will benefit from this project and change for the better with time. / Den här vetenskapliga artikeln handlar om att implementera ett Internet of Things system avsett för att mäta vattenkvaliteten i floder och andra vattenmiljöer med en autonom vattendrönare, där datan från diverse komponenter samlas in och skickas trådlöst till databasen i realtid. En Raspberry Pi är ansluten till internet via ett 4G-modem samt en trådlös satellitkommunikationsanslutning som kallas RockBlock för nödmeddelanden och notifikationer. Dessutom implementeras ett ekolod för insamling av data till den autonoma vattendrönaren för undvikande avkollisioner. Slutligen är batterierna anslutna till solcellspaneler för att automatiskt generera energi och förse den autonoma vattendrönaren med tillräcklig ström samt spänning.Det minsta antalet parametrar för att mäta vattenkvalitet är fyra: potentiellt väte, löst syre, nitrat, och färgat löst organiskt material. Som ett resultat mäter systemet i denna avhandling de fyra parametrarna nämnda ovan, plusgrumlighet och temperatur, eftersom de sammankopplade sensorerna ocksåkan mäta dessa. Dessutom valdes optiska sensorer på grund av deras exceptionella noggrannhet och precision vid vattenkvalitetsmätning. Miljön, speciellt vattenmiljön, kommer att gynnas av detta projekt samt förändras till det bättre med tiden.
16

Intelligente Himbeere - Der Raspberry Pi

Heik, Andreas, Sontag, Ralph 08 May 2013 (has links) (PDF)
Aus der Vision, Computertechnik für den schmalen Geldbeutel technisch interessierten Jugendlichen verfügbar zu machen entstand ein kreditkartengroßer Einplatinencomputer, der Raspberry Pi. Wir möchten den Raspi im Vortrag etwas näher vorstellen und in einer kleinen Demonstration Anregungen für eigene Projekte geben. Gespannt sind wir auch auf Projekte, welche die Zuhörer bereits mit dem Raspberry Pi umgesetzt haben.
17

ARM i inbyggt system : med prototyp / ARM in Embedded System : with Prototype

Abdulhadi, Sami January 2009 (has links)
Inbyggda system blir allt vanligare i dagens samhälle. De inbyggda systemen finns i nästan allt nuförtiden, från diverse fordon till leksaker för barn. Dagens teknik innebär bland annat att gårdagens lösningar kan realiseras på en bråkdel av den tidigare ytan. Allt mer blir ytmonterat med mindre och mer komplexa kretsar. Detta är inte alltid till utvecklarnas fördel då montering av prototypkort blir en svår och/eller dyr process. Målet är att ta fram ett inbyggt system med en ARM-processor. Systemet ska innehålla USB-OTG, ethernet, minne av olika slag som FRAM och microSD samt en display med pekskärm för användargränssnitt. Projektet omfattar allt från komponentval till test och verifiering med programkod. Tiden räckte inte till för att få med alla delar som planerats. Resultatet av projektet blev ett prototypkort och två små programsekvenser, en som blinkar två lysdioder på kortet och en som skriver ut en bild på displayen. Detta inbyggda system är i första hand till för utvärdering av ARM-processorer för Mikrodidakt AB. / Embedded systems has become more and more common in today's society. The embedded systems are included in almost everything today, from various vehicles to children's toys. Today's technology means that yesterday's solutions can be realised on a fraction of the area. More and more become surface mounted with smaller and more complex circuits. This is not always an advantage for the developers when assembling and soldering prototype circuit boards become a more difficult and/or an expensive process. The goal is to create an embedded system with an ARM-processor. The system will consist of USB-OTG, ethernet, various memory like FRAM and microSD and a display with touchscreen for user interface. The project includes everything from choice of components to test and verification with program code. The time was too short to include all the parts that was planned. The result of the project was a prototype card and two small program sequences, one that blinks the two light diodes on the card and one that writes a picture on the display. This embedded system is intended for evaluating ARM-processors by Mikrododakt AB.
18

THE STUDY OF EMBEDDED INTELLIGENT VEHICLE NAVIGATION SYSTEM*

Shengxi, Ding, Bo, Zhang, Jingchang, Tan, Dayi, Zeng 10 1900 (has links)
International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / The intelligent vehicle navigation system is the multifunctional and complex integrate system that involved in auto positioning technology, geography information system and digital map database, computer technology, multimedia and wireless communication technology. In this paper, the autonomous navigation system based on the embedded hardware and embedded software platform is proposed. The system has advantages of low cost, low power consumption, multifunction and high stability and reliability.
19

ENERGY-AWARE OPTIMIZATION FOR EMBEDDED SYSTEMS WITH CHIP MULTIPROCESSOR AND PHASE-CHANGE MEMORY

Li, Jiayin 01 January 2012 (has links)
Over the last two decades, functions of the embedded systems have evolved from simple real-time control and monitoring to more complicated services. Embedded systems equipped with powerful chips can provide the performance that computationally demanding information processing applications need. However, due to the power issue, the easy way to gain increasing performance by scaling up chip frequencies is no longer feasible. Recently, low-power architecture designs have been the main trend in embedded system designs. In this dissertation, we present our approaches to attack the energy-related issues in embedded system designs, such as thermal issues in the 3D chip multiprocessor (CMP), the endurance issue in the phase-change memory(PCM), the battery issue in the embedded system designs, the impact of inaccurate information in embedded system, and the cloud computing to move the workload to remote cloud computing facilities. We propose a real-time constrained task scheduling method to reduce peak temperature on a 3D CMP, including an online 3D CMP temperature prediction model and a set of algorithm for scheduling tasks to different cores in order to minimize the peak temperature on chip. To address the challenging issues in applying PCM in embedded systems, we propose a PCM main memory optimization mechanism through the utilization of the scratch pad memory (SPM). Furthermore, we propose an MLC/SLC configuration optimization algorithm to enhance the efficiency of the hybrid DRAM + PCM memory. We also propose an energy-aware task scheduling algorithm for parallel computing in mobile systems powered by batteries. When scheduling tasks in embedded systems, we make the scheduling decisions based on information, such as estimated execution time of tasks. Therefore, we design an evaluation method for impacts of inaccurate information on the resource allocation in embedded systems. Finally, in order to move workload from embedded systems to remote cloud computing facility, we present a resource optimization mechanism in heterogeneous federated multi-cloud systems. And we also propose two online dynamic algorithms for resource allocation and task scheduling. We consider the resource contention in the task scheduling.
20

ENERGY EFFICIENT EMBEDDED SYSTEM DESIGN FOR MEDICAL CARE SYSTEM USING WIRELESS SENSOR NETWORK

LI, QI 05 December 2008 (has links)
Recent surveys on medical service systems show that the cost of patient monitoring has grown significantly. The widespread use of portable digital medical device makes it possible to provide a more comprehensive tracking of patient conditions. However, the development of a full scale, distributed health monitoring system is much delayed due to the lack of efficient wireless communication in a large distributed network. This becomes a challenging research topic which is to find a way to provide accurate and real time patient information to medical experts in a fast, efficient and cost effective fashion. This paper proposes a novel solution on building a system which links patients and doctors together using embedded system technology and wireless sensor network. The content presented in this thesis introduces the design and implement of such a system.

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