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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.
151

The Device Discovery in Bluetooth Scatternet Formation Algorithm

Jedda, Ahmed 25 May 2010 (has links)
The Bluetooth Scatternet Formation (BSF) problem can be defined as the problem of forming wireless networks of Bluetooth devices in an efficient manner. A number of restrictions imposed by the Bluetooth specifications make the BSF problem challenging and unique. Many interesting solution algorithms have been proposed in the literature to solve this problem. In this thesis, we investigate the BSF problem. We concentrate on problems introduced by the procedures of device discovery of the Bluetooth specifications and on the different solutions used by BSF algorithms to deal with these problems. We study also in this thesis problems introduced by the specifications of link establishment in Bluetooth due to their close interaction with the device discovery specifications. We survey and categorize the different device discovery techniques used by BSF algorithms. This categorization is then used as a basis to identify the different theoretical computational models used to study BSF algorithms. We argue, in this thesis, that the currently available models for Bluetooth wireless networks do not model adequately, in most cases, the complexities of the Bluetooth specifications and we show that these models were oversimplified in many cases. A general computational model will be useful as a starting point to design BSF algorithms and to compare the different and numerous BSF algorithms – especially in term of the execution time efficiency. In this thesis, we provide a set of suggestions that will help in the creation of such model. We survey a number of studies that examined in more depth the specifications of device discovery in Bluetooth. We survey also other studies that attempted to simplify the Bluetooth network model, either by suggesting modifications on the Bluetooth specifications or by the use of communication technologies other than Bluetooth. Finally, we present some experiments accompanied with analyzes to show the complexities of the Bluetooth specifications and their sensitivity to minor changes (whether in the specifications or in their implementation).
152

Model Driven Service Description and Discovery Framework for Carrier Applications

Giannopoulos, Nikolaos January 2007 (has links)
The most dominant architecture in the contemporary business domain is Service Oriented Architecture (SOA). The large number of the existing service description and discovery systems available today, including the ones proposed in research proposals, reveals an increasing need for adaptive, semantically enriched and context-aware, wide-area service discovery. This need will become more intense in the years to come as the number of available services increases rapidly. The main reason behind the existence of a plethora of such systems is that before these initiatives, the standard in service discovery was taking into account only the syntactic descriptions of the services, causing conflicts when services, with similar syntactic descriptions, needed to be evaluated. The research solutions available today offer efficient and accurate discovery at the syntactic, functional semantic and non-functional semantic level. However, the problem is that there is no general consensus yet regarding service discovery. Research by its very nature, leads to point solutions rather than complete systems. Based on these observations, we propose an adaptive service description and discovery framework for carrier applications, enabling the model-driven specification of services and client profiles, and also, for allowing the dynamic configuration of the services to meet specific quality requirements defined by the clients. The framework was implemented in the context of Model Driven Development, to ensure platform independence at the level of the specification of services. The framework takes the union of the point solutions offered by research proposals in the area of service description and discovery, creates an abstract model, and can compile that model to platform specific code. More specifically, services for carrier applications can be specified in a platform independent way both in terms of service signatures (syntactic properties) and in terms of the functionality and the QoS service characteristics (semantic properties). A model transformation framework allows for the creation of a platform specific model for the description of services in a specific technology platform (e.g., Web services). The framework is extensible to accommodate future extensions. In addition, as a proof of concept, we designed and developed an Eclipse Rich Client Platform (RCP) prototype tool, implementing our proposal.
153

Subventions à la découverte 2003-2004 - Discovery Grants 2003-2004

Sawyer, Patrice 04 1900 (has links)
Un recueil de toutes les subventions à la découverte du CRSNG détenues à l'université Laurentienne durant 2003-2004. A booklet of all NSERC Discovery grants held at Laurentian University in 2003-2004. / CRSNG et l'université Laurentienne NSERC and Laurentian University
154

Model Driven Service Description and Discovery Framework for Carrier Applications

Giannopoulos, Nikolaos January 2007 (has links)
The most dominant architecture in the contemporary business domain is Service Oriented Architecture (SOA). The large number of the existing service description and discovery systems available today, including the ones proposed in research proposals, reveals an increasing need for adaptive, semantically enriched and context-aware, wide-area service discovery. This need will become more intense in the years to come as the number of available services increases rapidly. The main reason behind the existence of a plethora of such systems is that before these initiatives, the standard in service discovery was taking into account only the syntactic descriptions of the services, causing conflicts when services, with similar syntactic descriptions, needed to be evaluated. The research solutions available today offer efficient and accurate discovery at the syntactic, functional semantic and non-functional semantic level. However, the problem is that there is no general consensus yet regarding service discovery. Research by its very nature, leads to point solutions rather than complete systems. Based on these observations, we propose an adaptive service description and discovery framework for carrier applications, enabling the model-driven specification of services and client profiles, and also, for allowing the dynamic configuration of the services to meet specific quality requirements defined by the clients. The framework was implemented in the context of Model Driven Development, to ensure platform independence at the level of the specification of services. The framework takes the union of the point solutions offered by research proposals in the area of service description and discovery, creates an abstract model, and can compile that model to platform specific code. More specifically, services for carrier applications can be specified in a platform independent way both in terms of service signatures (syntactic properties) and in terms of the functionality and the QoS service characteristics (semantic properties). A model transformation framework allows for the creation of a platform specific model for the description of services in a specific technology platform (e.g., Web services). The framework is extensible to accommodate future extensions. In addition, as a proof of concept, we designed and developed an Eclipse Rich Client Platform (RCP) prototype tool, implementing our proposal.
155

Development of a 3D Tissue Engineered Bone Tumor Model

Burdett, Emily 16 September 2013 (has links)
3D ex vivo tumor models are required which better replicate the microenvironment encountered by tumor cells in vivo. In this study, we applied bone tissue engineering culture techniques to develop an ex vivo 3D bone tumor model. Ewing sarcoma cells were cultured on poly(ε-caprolactone) (PCL) microfiber scaffolds, and cellular growth kinetics, morphology, and infiltration were assessed. Cell/scaffold constructs were then exposed to anticancer drugs for up to 16 days and drug response was compared to 2D controls. Ewing sarcoma cells were capable of attachment and proliferation on PCL scaffolds and dense scaffold infiltration up to 200 micrometers. Constructs could be maintained in culture for up to 32 days, and high density 3D cell growth conferred an increased resistance to anticancer drugs over 2D controls. This 3D tumor model shows potential for use in future studies of bone tumor biology, especially as it pertains to the development of new anticancer drugs.
156

Development of a novel co-culture based in vitro model system to study the wound healing process

Abraham, Suraj 07 September 2010 (has links)
Drug development research on wound repair is challenging and inefficient due to the complex nature of wound healing and scarring processes and the limitations of available in vitro or in vivo models used for preclinical drug testing. Many patients who undergo elective back surgery develop post-surgical complications resulting from excess peridural scarring in and around the site of operation. We tested the effects of two anti-inflammatory compounds, quercetin and L-2-oxothiazolidine-4-carboxylate (OTC), in ameliorating peridural scar formation following spinal laminectomy surgery in laboratory rats. Western blot and immunocytochemical analyses indicated that the peridural scar tissue contained MyoD-positive myoblast cells and expressed prolyl-4-hydroxylase (P4H), a fibroblast marker. Treatment with 1 mM OTC reduced activation of ERK1/2 and p38 mitogen-activated protein kinases (MAPK) at 21 days post-surgery suggesting potential anti-scarring mechanism. However, large animal to animal variation in the expression levels of collagen biosynthesis markers made it difficult to demonstrate any efficacy of quercetin or OTC in reducing peridural scar formation. The shortcomings of this live animal approach led us to develop a novel three-dimensional (3-D) <i>in vitro</i> wound repair model for evaluating quercetin and OTC effects. High-density micromass co-cultures seeded at a 1:3 ratio of FR 3T3 fibroblast cells and L8 myoblast cells formed 3-D microtissues <i>in vitro</i> that expressed MyoD, P4H, and á-smooth muscle actin. The micromass tissue layer remained adherent to the culture plate when inflicted with a single laceration injury, which allowed monitoring of cell migration into the wound site. Wounded cultures were treated with quercetin, OTC and other agents (TGF- â1, mitomycin, p38 inhibitor SB202190, ERK inhibitor PD184352) to determine their effects on collagen accumulation, wound closure rates, MAPK activation, and gene transcript expression. Both OTC and quercetin treatments reduced collagen biosynthesis in dose-dependent manner. In addition, 1.5 mM OTC accelerated wound closure and significantly reduced p38 MAPK activation without affecting ERK1/2. In contrast, 40 µM quercetin delayed wound closure in micromass co-cultures and reduced ERK1/2 activation. Our in vitro findings suggest that OTC might have potential as an anti-scarring agent. Importantly, our novel micromass co-culture system shows promise as an improved 3-D scaffold-free in vitro model for use in preclinical drug development research.
157

A Semantic-based Approach to Web Services Discovery

Tsai, Yu-Huai 13 June 2011 (has links)
Service-oriented Architecture is now an important issue when it comes to program development. However, there is not yet an efficient and effective way for developer to obtain appropriate component. Current researches mostly focus on either textual meaning or ontology relation of the services. In this research we propose a hybrid approach that integrates both types of information. It starts by defining important attributes and their weights for web service discovery using Multiple Criteria Decision Making. Then a method of similarity calculation based on both textual and ontological information is applied. In the experiment, we collect 103 real-world Web services, and the experimental results show that our approach generally performs better than the existing ones.
158

The history and development of caravels

Schwarz, George Robert 15 May 2009 (has links)
An array of ship types was used during the European Age of Expansion (early 15th to early 17th centuries), but one vessel in particular emerges from the historical records as a harbinger of discovery: the caravel. The problem is that little is known about these popular ships of discovery, despite the fair amount of historical evidence that has been uncovered. How big were they? How many men did it take to operate such a vessel? What kind of sailing characteristics did they have? How and by whom were they designed? Where did they originate and how did they develop? These questions cannot be answered by looking at the historical accounts alone. For this reason, scholars must take another approach for learning about caravels by examining additional sources, namely ancient shipbuilding treatises, archaeological evidence, surviving archaic shipbuilding techniques, and iconographic representations from the past. Information gained from the available sources reveals many of the caravel’s characteristics through time. This ship type outclassed its contemporaries during the age of exploration because of its highly adaptive characteristics. These traits were, principally, its shallow draught, speed, maneuverability, and ability to sail close to the wind. This combination of attributes made the caravel the ideal ship for reconnaissance along the rocky African coastline, as well as for making the transatlantic voyages to the New World. It was built in a Mediterranean way during its post-medieval phases, a method that still survives in some parts of the world today. During the Age of Discovery (ca. 1430 to 1530), the caravel sat low in the water, had one sterncastle, and was either lateen-rigged or had a combination of square and lateen sails. This vessel reflects the advanced shipbuilding technology that existed in Europe at this time, and played and important role in the voyages which allowed the Europeans to expand their territories around the world. The results of the studies presented in this thesis provide a history and development of the caravel, which was gradual and often obscure. What has been gained from this work is a body of information that can be applied to other studies about ancient seafaring, and can serve as a starting point for further research.
159

Insider trading at the turn of the century: two essays

Tartaroglu, Semih -. 15 May 2009 (has links)
Insider trading may convey information to the market and promote accurate pricing of stocks. In this dissertation, I investigate insider trading at the turn of the century. In the first essay, I investigate insider trading activity in technology stocks during the high price - high volatility period of the late 1990s. I document that insiders of technology firms were heavy sellers during the ten month pre-peak period in which stock prices more than doubled. The technology stocks that were sold by insiders more extensively in the pre-peak period had lower returns in the post-peak period. I furthermore investigate the relation between the net order flows (buyer initiated minus seller initiated trades) and abnormal insider trading activity. I document that the net order flow is positively related to abnormal insider trading activity. However, this positive relation becomes weaker in the peak period; which implies less price discovery through insider trading during the rise of technology stock prices. In the second essay, I document that disclosure requirements significantly affect insider trading behavior. The Sarbanes-Oxley Act of 2002 requires expedited and on-line disclosure of insider transactions. This increase in the visibility of insider trading reduces informational advantage of insiders and increases the likelihood of facing legal sanctions for insiders. I document that insider purchases significantly declined after the Sarbanes- Oxley Act. In addition, the incidences of insider purchases (sales) prior to positive (negative) earnings surprises declined after the Act. Finally, I document that the earnings announcements become more informative after the Act, which is consistent with less price discovery through insider trading prior to earnings announcements. However, the evidence that the decline in insider trading contributes to more informative earnings announcements is pronounced for insider purchases but not for insider sales.
160

Missing Link Discovery In Wikipedia: A Comparative Study

Sunercan, Omer 01 February 2010 (has links) (PDF)
The fast growing online encyclopedia concept presents original and innovative features by taking advantage of information technologies. The links connecting the articles is one of the most important instances of these features. In this thesis, we present our work on discovering missing links in Wikipedia articles. This task is important for both readers and authors of Wikipedia. Readers will bene&amp / #64257 / t from the increased article quality with better navigation support. On the other hand, the system can be employed to support authors during editing. This study combines the strengths of different approaches previously applied for the task, and proposes its own techniques to reach satisfactory results. Because of the subjectivity in the nature of the task / automatic evaluation is hard to apply. Comparing approaches seems to be the best method to evaluate new techniques, and we offer a semi-automatized method for evaluation of the results. The recall is calculated automatically using existing links in Wikipedia. The precision is calculated according to manual evaluations of human assessors. Comparative results for different techniques are presented, showing the success of our improvements. Our system employs Turkish Wikipedia (Vikipedi) and, according to our knowledge, it is the &amp / #64257 / rst study on it. We aim to exploit the Turkish Wikipedia as a semantic resource to examine whether it is scalable enough for such purposes.

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