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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.
21

Query Processing for Peer Mediator Databases

Katchaounov, Timour January 2003 (has links)
<p>The ability to physically interconnect many distributed, autonomous and heterogeneous software systems on a large scale presents new opportunities for sharing and reuse of existing, and for the creataion of new information and new computational services. However, finding and combining information in many such systems is a challenge even for the most advanced computer users. To address this challenge, mediator systems logically integrate many sources to hide their heterogeneity and distribution and give the users the illusion of a single coherent system.</p><p>Many new areas, such as scientific collaboration, require cooperation between many autonomous groups willing to share their knowledge. These areas require that the data integration process can be distributed among many autonomous parties, so that large integration solutions can be constructed from smaller ones. For this we propose a decentralized mediation architecture, peer mediator systems (PMS), based on the peer-to-peer (P2P) paradigm. In a PMS, reuse of human effort is achieved through logical composability of the mediators in terms of other mediators and sources by defining mediator views in terms of views in other mediators and sources.</p><p>Our thesis is that logical composability in a P2P mediation architecture is an important requirement and that composable mediators can be implemented efficiently through query processing techniques.</p><p>In order to compute answers of queries in a PMS, logical mediator compositions must be translated to query execution plans, where mediators and sources cooperate to compute query answers. The focus of this dissertation is on query processing methods to realize composability in a PMS architecture in an efficient way that scales over the number of mediators.</p><p>Our contributions consist of an investigation of the interfaces and capabilities for peer mediators, and the design, implementation and experimental study of several query processing techniques that realize composability in an efficient and scalable way.</p>
22

Graph visualization with OpenGL

Ahlgren, Hannes January 2005 (has links)
<p>Vizz3D is a 3D graphics code analysis tool, developed at Växjö University that optionally can use Java3D or OpenGL. However, initially Java3D was the only programming interface used. No other version was considered. Therefore the applications structure was built with the Java3D way of thought in mind. But code visualization with 3D graphics can be a demanding task for the computers processor and its graphics hardware and Java3D is known to be somewhat inefficient. So an OpenGL version was introduced.</p><p>This thesis reflects on the work restructuring the application’s code to fit both versions within Vizz3D in a structured and object-oriented way. The thesis shows the efforts to be taken to make an existing ever evolving tool easily extendible to other API’s. Additional aspects of OpenGL specific implementations are discussed throughout the thesis.</p>
23

Graph visualization with OpenGL

Ahlgren, Hannes January 2005 (has links)
Vizz3D is a 3D graphics code analysis tool, developed at Växjö University that optionally can use Java3D or OpenGL. However, initially Java3D was the only programming interface used. No other version was considered. Therefore the applications structure was built with the Java3D way of thought in mind. But code visualization with 3D graphics can be a demanding task for the computers processor and its graphics hardware and Java3D is known to be somewhat inefficient. So an OpenGL version was introduced. This thesis reflects on the work restructuring the application’s code to fit both versions within Vizz3D in a structured and object-oriented way. The thesis shows the efforts to be taken to make an existing ever evolving tool easily extendible to other API’s. Additional aspects of OpenGL specific implementations are discussed throughout the thesis.
24

Positionsindikering i bilder och video för WITAS dialogsystem / Position specification in images and video for the WITAS dialog system

Lindblom, Hannes January 2004 (has links)
Denna rapport beskriver arbetet med en utökning av ett dialogsystem till en UAV (Unmanned Aerial Vehicle, obemannad flygande farkost). Arbetet är utfört i WITAS-projektet (Wallenberg laboratory for research on Information Technology and Autonomous Systems), ett projekt som har som mål att utveckla en helikopter som ska kunna verka autonomt i t.ex. en trafikmiljö. Syftet med dialogsystemet är att en operatör med talspråk ska kunna ge kommandon till och få information från helikoptern. Detta examensarbete har som mål att utöka dialogen till att bli multimodal, dvs. att även innefatta pekningar och rörelser med musen. Operatören ska alltså kunna peka ut platser och objekt i en karta för att komplettera ett talat kommando eller få data utritat i kartan som svar på en förfrågan.
25

Hur fungerar datorer? : En fallstudie av att utveckla pedagogisk multimedia för ett datorhistoriskt museum. / How do computers work? : A case study of developing educational multimedia for a museum of computer history.

Ahl, Linda January 2004 (has links)
Få människor vet hur datorer fungerar, vilka komponenter de är uppbyggda av och hur dessa samverkar. I detta examensarbete har en prototyp till en multimediepresentation utvecklats. Presentationen kommer att placeras på ett datorhistoriskt museum och dess syfte kommer där att vara att hjälpa människor förstå hur datorer fungerar. Prototypen är baserad på bilder och enklare animationer som förklarar samverkan och funktion hos de olika datorkomponenterna, bland annat genom att visa scenarier som många människor troligtvis känner igen från sin vardag. Målet med arbetet har varit att inskaffa kunskap kring hur multimedia kan användas för att illustrera tekniska processer, samt kunskap kring hur multimediepresentationer skall utveck-las. Därför har en systemutvecklingsmetod tagits fram som är anpassad till denna typ av system och som använts vid utvecklingen av prototypen. Systemutvecklingsmetoden är av iterativ modell, eftersom det visat sig att ett iterativt arbetssätt är att föredra framför ett linjärt vid multimedieutveckling. Detta beror på att det i denna typ av arbete där det till en början oftast är oklart vilka krav och önskemål som finns på slutprodukten är svårt att gå enkelriktat genom utvecklingsprocessen, d v s att göra ett steg helt färdigt innan nästa påbörjas. När det gäller multimedia är en slutsats att det med fördel kan användas för att visa och förklara tekniska förlopp och att det verkar vara ett användbart hjälpmedel inom utbildning och museiverksamhet.
26

Kunddatabas i Java och MySQL / Customer database using Java and MySQL

Kimmefors, Ann, Nilsson, Niclas January 2003 (has links)
The purpose with this work that is the basis for this thesis was to help Nattavaara Economical association to develop a program for handling invoices, customer information, and storage. The program and this thesis have been done in cooperation with the economical association in Nattavaara. Some of the demands on the program are that it shall handle customer information, storage status, invoices and diesel consumption. The program must be able to printout invoices, reminders, delivery notes, a customer list and a storage list. All information will be stored in a database. The program was implemented in the program language Java and with a MySQL database; since they both are platform independent and we have previous experience using them. The program is window based and built around the usage of tabbed windows; there every tab represents an own functionality, this to create a foreseeable and easy navigated program. User friendliness is something that has been taken into consideration in the process of developing this program, among other things through grouping of adjacent information and the placement of buttons. One of the conclusions with this work is that Java can with advantage be used to create graphical interfaces with connections to databases. Further development of the program could be for example to improve the quality of the printouts and the handling of the database initiation.
27

A user interface for the ontology merging tool SAMBO

Abdulahad, Bassam, Lounis, Georgios January 2004 (has links)
Ontologies have become an important tool for representing data in a structured manner. Merging ontologies allows for the creation of ontologies that later can be composed into larger ontologies as well as for recognizing patterns and similarities between ontologies. Ontologies are being used nowadays in many areas, including bioinformatics. In this thesis, we present a desktop version of SAMBO, a system for merging ontologies that are represented in the languages OWL and DAML+OIL. The system has been developed in the programming language JAVA with JDK (Java Development Kit) 1.4.2. The user can open a file locally or from the network and can merge ontologies using suggestions generated by the SAMBO algorithm. SAMBO provides a user-friendly graphical interface, which guides the user through the merging process.
28

Unobtrusive Augmentation  of Physical Environments : Interaction Techniques, Spatial Displays and Ubiquitous Sensing

Olwal, Alex January 2009 (has links)
The fundamental idea of Augmented Reality (AR) is to improve and enhance our perception of the surroundings, through the use of sensing, computing and display systems that make it possible to augment the physical environment with virtual computer graphics. AR is, however, often associated with user-worn equipment, whose current complexity and lack of comfort limit its applicability in many scenarios. The goal of this work has been to develop systems and techniques for uncomplicated AR experiences that support sporadic and spontaneous interaction with minimal preparation on the user’s part. This dissertation defines a new concept, Unobtrusive AR, which emphasizes an optically direct view of a visually unaltered physical environment, the avoidance of user-worn technology, and the preference for unencumbering techniques. The first part of the work focuses on the design and development of two new AR display systems. They illustrate how AR experiences can be achieved through transparent see-through displays that are positioned in front of the physical environment to be augmented. The second part presents two novel sensing techniques for AR, which employ an instrumented surface for unobtrusive tracking of active and passive objects. These techniques have no visible sensing technology or markers, and are suitable for deployment in scenarios where it is important to maintain the visual qualities of the real environment. The third part of the work discusses a set of new interaction techniques for spatially aware handheld displays, public 3D displays, touch screens, and immaterial displays (which are not constrained by solid surfaces or enclosures). Many of the techniques are also applicable to human-computer interaction in general, as indicated by the accompanying qualitative and quantitative insights from user evaluations. The thesis contributes a set of novel display systems, sensing technologies, and interaction techniques to the field of human-computer interaction, and brings new perspectives to the enhancement of real environments through computer graphics. / <p>QC 20100805</p>
29

IT som stöd för strategiska beslut : en studie av datorimplementerade modeller av verksamhet som stöd för beslut om anskaffning av JAS 1982

Odar, Susanne January 2002 (has links)
Värdet av utvecklingen och användningen av värderingsmodeller inför beslutet om anskaffning av JAS 1982 beskrivs och analyseras i denna avhandling. Inom försvaret har datorimplementerade modeller av verksamhet - värderingsmodeller - använts som stöd för beslut sedan 1960-talet. Litteratur som belyser värdet av värderingsmodeller är dock sparsam. Kunskapen om värderingsmodellers möjligheter för att stödja lärande, kommunikation och beslut är begränsad. IT-utvecklingen ger nya tekniska möjligheter och intresset för värderingsmodeller ökar. Det finns därför en ökad risk för felinvesteringar. Det övergripande syftet med avhandlingen är att söka förståelse för hur värderingsmodeller kan bidra till att skapa, utveckla och kommunicera mentala modeller av verksamhet som stöd för beslut. Vilket värde värderingsmodellerna hade i det valda fallet och hur det skapades beskrivs och analyseras utgående från teorier om kunskap, kommunikation och beslutsfattande samt utgående från intervjuer med aktörer som medverkade i beslutsprocessen. Det framkommer att de som utveckla och använde modellerna utvecklade gemensam kunskap om flygplansalternativens förmåga, som kunde användas som underlag för beslut. Modellerna bidrog till detta. men de aktörer som medverkade och det arbetssättet som tillämpades var avgörande för det värde som skapades. En slutsats är att värderingsmodeller kan bidra till att skapa, utveckla och kommunicera mentala systemmodeller av verksamhet, men att de krävs mycket för att de skall göra det. Det ställs framförallt stora krav på beslutsfattarna och på de aktörerna som utvecklar och använder modellerna för att de skall vara av värde.
30

System-on-Chip test scheduling with defect-probability and temperature considerations

He, Zhiyuan January 2007 (has links)
Electronic systems have become highly complex, which results in a dramatic increase of both design and production cost. Recently a core-based system-on-chip (SoC) design methodology has been employed in order to reduce these costs. However, testing of SoCs has been facing challenges such as long test application time and high temperature during test. In this thesis, we address the problem of minimizing test application time for SoCs and propose three techniques to generate efficient test schedules. First, a defect-probability driven test scheduling technique is presented for production test, in which an abort-on-first-fail (AOFF) test approach is employed and a hybrid built-in self-test architecture is assumed. Using an AOFF test approach, the test process can be aborted as soon as the first fault is detected. Given the defect probabilities of individual cores, a method is proposed to calculate the expected test application time (ETAT). A heuristic is then proposed to generate test schedules with minimized ETATs. Second, a power-constrained test scheduling approach using test set partitioning is proposed. It assumes that, during the test, the total amount of power consumed by the cores being tested in parallel has to be lower than a given limit. A heuristic is proposed to minimize the test application time, in which a test set partitioning technique is employed to generate more efficient test schedules. Third, a thermal-aware test scheduling approach is presented, in which test set partitioning and interleaving are employed. A constraint logic programming (CLP) approach is deployed to find the optimal solution. Moreover, a heuristic is also developed to generate near-optimal test schedules especially for large designs to which the CLP-based algorithm is inapplicable. Experiments based on benchmark designs have been carried out to demonstrate the applicability and efficiency of the proposed techniques. / <p>2007</p>

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