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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.
321

Immersive Representation of Building Information Model

Nseir, Hussam 2011 May 1900 (has links)
Building Information Modeling (BIM) is an emerging technology that utilizes 3D graphical representations to improve communication, collaboration, and data exchange. Immersive Visualization Environment (IVE) is another promising technology that enhances the 3D graphical representation to achieve a higher level of a sense of presence. The connection between the BIM technology that utilizes the 3D graphical representation and the IVE technology that enhances the 3D graphical representation has led many professionals to visualize BIM in immersive environments. This study is an attempt to overcome a systematic issue presented by available immersive visualization systems. The problem is that in order to visualize an information-rich BIM model from a commercial BIM application in an immersive visualization environment, the BIM model needs to pass through a tough conversion process and loss a large amount of its information. This research study utilizes the Application Programming Interface (API) of a commercially available BIM application to develop an immersive visualization environment. This approach was applied on Autodesk Navisworks software by developing a software program that utilizes Navisworks' API to control Navisworks' camera angle and generate an immersive visualization environment. A prototype of the approach was built in the Department of Construction Science at Texas A & M University and named BIM CAVE Prototype. The overall goal of this research was to prove that it is possible to transform a commercial BIM application into an immersive visualization system. A phenomenological study was utilized by interviewing subject matter experts from the construction industry. The intent of this effort was to explore and develop a phenomenological understanding of how research participants perceived the BIM CAVE system. The results show that the BIM CAVE can be considered an immersive visualization environment because it contains a majority of the immersive visualization environment features. However, a variety of technical limitations must be overcome before it can be called a fully immersive and functional visualization environment. Moreover, even though this investigation was to some extent successful, this research approach needs to be tested on other commercially available BIM applications before generalizations are made.
322

ZigBee in Industry

Wettergren, Andreas January 2007 (has links)
<p>Den här C-uppsatsens mål är att undersöka om den trådlösa tekniken ZigBee är lämplig att använda i en industriell miljö. Arbetet med uppsatsen har utförts i Trolhättan (Sverige) i företaget Binar Elektronik AB:s lokaler. Bakgrunden till detta samarbete är att Binar vill veta om ZigBee är ett lämpligt val för en av deras framtida produkter.</p><p>Uppsatsen är uppdelad i fyra delar, där den första och inledande delen översiktligt beskriver begreppet ZigBee. Den här delen innehåller även en marknadsundersökning rörande ZigBee-hårdvara. Uppsatsen fortsätter sedan med nästa del där en specialisering mot en specifik ZigBee-hårdvara tar vid. Den ZigBee-modul som valdes kallas Xbee och den blev utvald baserat på resultatet från marknadsundersökningen. Den här delen beskriver även den kod som utvecklats för att på ett effektivt sätt kommunicera med Xbee-modulen.</p><p>Uppsatsens tredje del består av ett antal praktiska tester i olika miljöer, vars mål är att påvisa vilka styrkor och svagheter som ZigBee-tekniken har i respektive miljö. Den här delen innehåller även ett räckviddstest av Xbee-modulen. Den sista och avslutande delen innehåller uppsatsens resultat och slutsatser. Dessa slutsatser visar tydlig att Xbee-modulen, och dess ZigBee-tekniken, har stor potential att uppfylla de krav som ställs på ett trådlöst system i en industriell miljö. Det måste dock noteras att denna slutsats ej bör tas ur sitt sammanhang och att den således endast är giltig för de testmiljöer som den här uppsatsen behandlat.</p> / <p>This Bachelor of Science thesis has the primary objective to investigate whether or not the wireless technology ZigBee is suitable for industry usage. The thesis work has been done in collaboration with Binar Elektronik AB (Trollhättan, Sweden). The background story for this collaboration is that Binar is interested in finding out if ZigBee is suitable for one of their upcoming products.</p><p>The thesis is divided into four main parts, beginning with a researching part concerning ZigBee as a concept and a market research on ZigBee hardware. The thesis continuous with a specialization towards one ZigBee hardware, the ZigBee module from MaxStream called Xbee. The Xbee module was chosen based on the result from the market research. This part also describes the code that has been developed for the Xbee module, which main purpose is to simplify communication with the module.</p><p>The next part of the thesis contains a number of different field tests that show how ZigBee communication is affected in different environments. This part also includes a range test with the Xbee module. The last part of the thesis contains the final results and conclusions, which clearly show that the ZigBee technology, and Xbee in particular, has a potential to satisfy the requirements for a wireless system in an industrial environment. This conclusion concerning the industrial usability of ZigBee should however be seen in the light of this particular thesis work, making this conclusion viable only for the field test environments.</p> / See hompage http://www.wettergren.se/zigbee/.
323

Scalable Services over DAB and DVB-T from a Receiver Point of View

Almgren, Hanna, Vestin, Johanna January 2002 (has links)
<p>TV and radio services have always been distributed over analogue broadcasting networks and been received on a TV -set or a radio receiver. Today this situation is changing due to digitalization and convergence between broadcasting, telecommunications and data communications. Other terminals, such as a PC, can also receive TV and radio services. Digital TV and radio can offer additional services such as e-commerce, electronic program guides and content synchronized to the TV and radio shows. If these services are to be received by several receiving terminals with different properties, the services must be adapted to the terminals. This can be done by scaling the services, meaning that the appearances and functionality of the services vary depending on the terminals’ properties. In this thesis scalable services are examined from a terminal point of view. Present and future receivers, platforms and possible methods to achieve scalability are presented, and their effects on scalable services are discussed.</p> / <p>TV- och radiosändningar har fram till nyligen endast distribuerats över analoga TV- och radionät och tagits emot av traditionella TV- och radioapparater, men detta håller på att ändras i och med att sändningarna digitaliseras och konvergens sker mellan broadcasting, telekom och datakom. Nu kan även andra terminaler fungera som mottagare, t.ex. en PC med ett digital-TVkort eller ett digital-radiokort. Digital TV och radio erbjuder tilläggstjänster som t.ex. ehandel, tjänster kopplade till radio- eller TV-program och elektroniska programguider. Om samma tjänst ska kunna tas emot på flera olika mottagarterminaler med olika egenskaper, måste tjänsten anpassas efter terminalerna. Detta kan göras genom att skala tjänsten, dvs. utseendet och funktionerna varierar beroende på bl.a. terminalens kapacitet. I detta arbete har terminalaspekterna på skalbara tjänster undersökts. Aktuella och framtida terminaler, plattformar och eventuella skalbarhetslösningar presenteras, och deras påverkan på skalbara tjänster diskuteras.</p>
324

Vérification des propriétés temporisées des automates programmables industriels

Bel Mokadem, Houda 28 September 2006 (has links) (PDF)
De nombreux sytèmes critiques comportent des aspects temporisés, où interviennent de manière cruciale des contraintes quantitatives sur les délais séparant certaines actions. Un automate programmable industriel (API) constitue un composant fondamental d'un système souvent critique destiné à réagir et à communiquer en temps réel avec son environnement. Ma thèse se situe dans le contexte de la vérification de propriétés temporisées des APIS. Plus précisement, on propose une sémantique formelle à base d'automates temporisés pour la modélisation d'une sous classe de programmes Ladder comportant des blocs TON. On fournie une logique temporisée dont la sémantique permet de considérer seulement les événements "signifcatifs" (c'est à dire les événements qui durent suffisamment longtemps). On propose deux sémantiques différentes pour cette logique: sémantique "locale" et sémantique "globale". Pour la sémantique "locale", on a obtenu plusieurs résultats d'expressivité et grâce à une nouvelle relation d'équivalence, on montre que son model checking reste décidable sans modifier la complexité théorique. En revanche, pour la sémantique "globale", le model checking devient indécidable.
325

Framework for Flexible Connectors with Java Reflection Proxies

Tao, Bo, Jiang, Xiaoming January 2009 (has links)
<p>This report presents the results of a master level thesis project that analyzes and designs about the issue “Framework for Flexible Connectors with Java Reflection Proxies”. In this project, there are two main issues; first one is about finding a way to implement the function of a connector. And the other one is to build a framework for flexible connectors.</p><p>By studying on Java’s dynamic proxy, we find we can use it to implement the function of a connector. When building a connector chain, we use an important Java technique--Java Reflection API.</p>
326

Webserver-Techniken (eingebettete Interpreter mod_perl, mod_dtcl ...)

Schmidt, Jürgen 08 May 2000 (has links)
Gemeinsamer Workshop von Universitaetsrechenzentrum und Professur Rechnernetze und verteilte Systeme (Fakultaet fuer Informatik) der TU Chemnitz. Workshop-Thema: Infrastruktur der ¨Digitalen Universitaet¨ Es gibt viele Möglichkeiten, dynamische Web Inhalte zu erzeugen. Dieser Vortrag soll einen Überblick über Erweiterungsmöglichkeiten auf der Serverseite geben. Mit Hinblick auf Performance werden im Vergleich zum CGI eingebettete Interpreter beleuchtet und spezielle Scriptsprachen wie PHP,Perl oder Tcl genannnt.
327

Risk-based Reliability Assessment of Subsea Control module for Offshore Oil and Gas production

Umofia, Anietie Nnana 09 1900 (has links)
Offshore oil and gas exploitation is principally conducted using dry or wet tree systems, otherwise called the subsea Xmas tree system. Due to the shift to deeper waters, subsea production system (SPS) has come to be a preferred technology with attendant economic benefits. At the centre of the SPS is the subsea control module (SCM), responsible for the proper functioning and monitoring of the entire system. With increasing search for hydrocarbons in deep and ultra-deepwaters, the SCM system faces important environmental, safety and reliability challenges and little research has been done in this area. Analysis of the SCM reliability then becomes very fundamental due to the huge cost associated with failure. Several tools are available for this analysis, but the FMECA stands out due to its ability to not only provide failure data, but also showcase the system’s failure modes and mechanisms associated with the subsystems and components being evaluated. However, the technique has been heavily challenged in various literatures for several reasons. To close this gap, a novel multi-criteria approach is developed for the analysis and ranking of the SCM failures modes. This research specifically focusses on subsea tree-mounted electro-hydraulic (E-H) SCM responsible for the underwater control of oil and gas production. A risk identification of the subsea control module is conducted using industry experts. This is followed by a comprehensive component based FMECA analysis of the SCM conducted with the conventional RPN technique, which reveals the most critical failure modes for the SCM. A novel framework is developed using multi-criteria fuzzy TOPSIS methodology and applied to the most critical failure modes obtained from the FMECA evaluation using unconventional parameters. Finally, a validation of these results is performed using a stochastic input evaluation and SCM failure data obtained from the offshore industry standard reliability database, OREDA.
328

Standardization of the Instrumentation Hardware Abstraction Language in IRIG 106

Hamilton, John, Fernandes, Ronald, Darr, Timothy, Jones, Charles H., Faulstich, Ray 10 1900 (has links)
ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, California / Previously, we have presented an approach to achieving standards-based multi-vendor hardware configuration using the Instrumentation Hardware Abstraction Language (IHAL) and an associated Application Programming Interface (API) specification. In this paper we describe the current status of the IHAL standard. Since the first introduction of IHAL at ITC 2006, the language has undergone a number of additions and improvements. Currently, IHAL is nearing the end of a 2-year standardization task with the Range Commanders Council Telemetry Group (RCC TG). This paper describes the standardization process in addition to providing an overview of the current state of IHAL. The standard consists of two key components: (1) the IHAL language, and (2), the IHAL API specification.
329

ReserveTM: Optimizing for Eager Software Transactional Memory

Jain, Gaurav January 2013 (has links)
Software Transactional Memory (STM) helps programmers write correct concurrent code by allowing them to identify atomic sections rather than focusing on the mechanics of concurrency control. Given code with atomic sections, the compiler and STM runtime can work together to ensure proper controlled access to shared memory. STM runtimes use either lazy or eager version management. Lazy versioning buffers transaction updates, whereas eager versioning applies updates in-place. The current set of primitives suit lazy versioning since memory needs to be accessed through the runtime. We present a new set of runtime primitives that better suit eager versioned STM. We propose a novel extension to the compiler/runtime interface, consisting of memory reservations and memory releases. These extensions enable optimizations specific to eager versioned runtimes. A memory reservation allows a transaction to perform instrumentation-free access on a memory address. A release allows a read-only address to be modified by another transaction. Together, these reduce the instrumentation overhead required to support STM and improve concurrency between readers and writers. We have implemented these primitives and evaluated its performance on the STAMP benchmarks. Our results show strong performance and scalability improvements to eager versioned algorithms.
330

Comparison between two procedures of interproximal cleaning in periodontitis patients: a six month, single blind, randomized controlled clinical trial / Vergleich zwischen zwei Vorgehensweisen der Approximalraumreinigung bei Parodontitispatienten: eine randomisierte, klinisch kontrollierte, einfach verblindete 6- Monatsstudie

Schmidt, Bastian 06 November 2014 (has links) (PDF)
Purpose: Periodontitis generally initiates in the interdental area, where biofilm development is difficult to interrupt. Mechanical cleaning with interdental brushes (IDB) offers an effective method for plaque control and prevents gingivitis and periodontitis. This study aimed to determine whether mechanical cleaning with interdental brushes combined with the use of cetylpyridinium chloride (0.3% CPC) gel was more effective at plaque control compared with mechanical cleaning with interdental brushes alone. Materials and Methods: Forty individuals (30 - 70 years) with at least 20 teeth and moderate chronic periodontitis who had no experience with interdental cleaning aids were randomly assigned to a treatment group (brush + gel, n = 20) or a control group (brush, n = 20). Both groups were examined by a dentist at baseline and at 3 and 6 months for changes in interdental plaque [interproximal plaque index (API)] levels, gingival inflammation [sulcus bleeding index (SBI)], probing depth (PD), and bleeding on probing (BOP). Results: No baseline differences in age, gender, or number of teeth were observed between the two groups. During the study period, improvements in API and BOP were comparable between groups. However, improvements in SBI and PD were significantly greater in the test group than in the control group (P = 0.046 and P = 0.029, respectively). Conclusion: Mechanical interdental plaque control with interdental brushes combined with the use of CPC gel significantly improved 6-month gingival and periodontal outcomes (SBI and PD) compared with mechanical cleaning with interdental brushes alone.

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