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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

Ontology alignment mechanisms for improving web-based searching

Taye, Mohammad Mustafa January 2009 (has links)
Ontology has been developed to offer a commonly agreed understanding of a domain that is required for knowledge representation, knowledge exchange and reuse across domains. Therefore, ontology organizes information into taxonomies of terms (i.e., concepts, attributes) and shows the relationships between them. In fact, it is considered to be helpful in reducing conceptual confusion for users who need to share applications of different kinds, so it is widely used to capture and organize knowledge in a given domain. Although ontologies are considered to provide a solution to data heterogeneity, from another point of view, the available ontologies could themselves introduce heterogeneity problems. In order to deal with these problems, ontologies must be available for sharing or reusing; therefore, semantic heterogeneity and structural differences need to be resolved among ontologies. This can be done, in some cases, by aligning or matching heterogeneous ontologies. Thus, establishing the relationships between terms in the different ontologies is needed throughout ontology alignment. Semantic interoperability can be established in ontology reconciliation. The original problem is called the ―ontology alignment‖. The alignment of ontologies is concerned with the identification of the semantic relationships (subsumption, equivalence, etc.) that hold between the constituent entities (which can be classes, properties, etc.) of two ontologies. In this thesis, an ontology alignment technique has been developed in order to facilitate communication and build a bridge between ontologies. An efficient mechanism has been developed in order to align entities from ontologies in different description languages (e.g. OWL, RDF) or in the same language. This approach tries to use all the features of ontologies (concept, attributes, relations, structure, etc.) in order to obtain efficiency and high quality results. For this purpose, several matching techniques have been used such as string, structure, heuristic and linguistic matchingtechniques with thesaurus support, as well as human intervention in certain cases, to obtain high quality results. The main aim of the work is to introduce a method for finding semantic correspondences among heterogeneous ontologies, with the intention of supporting interoperability over given domains. The approach brings together techniques in modelling, string matching, computation linguistics, structure matching and heuristic matching, in order to provide a semi-automatic alignment framework and prototype alignment system to support the procedure of ontology alignment in order to improve semantic interoperability in heterogeneous systems. This technique integrates some important features in matching in order to achieve high quality results, which will help when searching and exchanging information between ontologies. Moreover, an ontology alignment system illustrates the solving of the key issues related to heterogeneous ontologies, which uses combination-matching strategies to execute the ontology-matching task. Therefore, it can be used to discover the matching between ontologies. This thesis also describes a prototype implementation of this approach in many real-world case studies extracted from various Web resources. Evaluating our system is done throughout the experiments provided by the Ontology Alignment Evaluation Initiative. The system successfully achieved 93% accuracy for ontology matching. Finally, a comparison between our system and well-known tools is achieved so that our system can be evaluated.
12

A Low-cost Wireless Sensor Network System Using Raspberry Pi and Arduino for Environmental Monitoring Applications

Ferdoush, Sheikh Mohammad 05 1900 (has links)
Sensors are used to convert physical quantity into numerical data. Various types of sensors can be coupled together to make a single node. A distributed array of these nodes can be deployed to collect environmental data by using appropriate sensors. Application of low powered short range radio transceivers as a communication medium between spatially distributed sensor nodes is known as wireless sensor network. In this thesis I build such a network by using Arduino, Raspberry Pi and XBee. My goal was to accomplish a prototype system so that the collected data can be stored and managed both from local and remote locations. The system was targeted for both indoor and outdoor environment. As a part of the development a controlling application was developed to manage the sensor nodes, wireless transmission, to collect and store data using a database management service. Raspberry Pi was used as base station and webserver. Few web based application was developed for configuring the network, real time monitoring, and database management. Whole system functions as a single entity. The use of open source hardware and software made it possible to keep the cost of the system low. The successful development of the system can be considered as a prototype which needs to be expanded for large scale environmental monitoring applications.
13

Enhanced SOAP Performance for Low Bandwidth Environments

Phan, Thi Khoi Anh, khoianh81@yahoo.com January 2007 (has links)
It is desirable that SOAP performs efficiently in environments where there are a large number of transactions. However, SOAP is based on XML and therefore inherits XML's disadvantage of having voluminous messages. Firstly, the performance of different SOAP bindings is investigated. A benchmark of different SOAP bindings in wireless environments demonstrates the unsuitability of HTTP and TCP bindings in limited bandwidth environments. UDP is recommended as an alternative transport protocol for SOAP. Secondly, the thesis examines the use of multicast in reducing the traffic caused by SOAP messages in low bandwidth environments to deal with challenges described. A novel SOAP-level multicast protocol based on the similarity of SOAP messages, called SMP (Similarity-based SOAP Multicast Protocol), is proposed. In particular, issues of traffic, network optimization, response time and scalability are investigated. Lastly, two extensions of SMP are proposed to further improve the performance of SMP. SMP's extensions are two algorithms, greedy and incremental tc-SMP, for traffic-constrained similarity-based SOAP multicast. Tc-SMP optimizes network traffic by building its own spanning trees instead of using the one built by traditional methods, such as Dijkstra's algorithm. A new client is added to a tc-SMP tree through an existing tc-SMP node that causes minimal additional traffic for that connection. Detailed analytical models and experimental evaluations of the proposed methods demonstrate that combining SOAP messages of similar content and multicasting them as aggregated messages can significantly lower total network traffic. These improvements are advantageous for Web service applications that involve a high number of simultaneous similar transactions such as stock quotes, weather and sport event reports.
14

Building Learning Content Sharing and Management System Based on Web Service and SCORM

Hsu, Ming-chen 21 September 2007 (has links)
The Internet technology maturity, the fast influence our life, is not having the national boundary, not time, region limit network characteristic, also changed the school edition traditional teaching way, the teaching from the classroom, the school, extends to the Internet, studies is not restricted in the same time and the same learning environment. Along with e-learning¡¦s development, the teaching material more and more multi-dimensional, but those material restricted by the learning platform, the teaching material itself exchangeability also reduces along with it. In this thesis, a learning content management system (LCMS) based on SCORM (sharable content object reference model) which shares learning object by Web Service is proposed. The whole system can be divided into four subsystems. Learning object management subsystem manages learning objects and those metadata. Content Upload subsystem provides the functionality of converting ordinary files to learning objects and parse SCORM content into the system. Content authoring subsystem assembles these objects to form abigger learning object or a courseware. Content provider can share learning objects by web-service searching subsystem. Users can use content authoring subsystem to construct new learning contents, and web-service searching subsystem to search and share learning objects easily.
15

A £k-calculus Based Approach for Web Services Composition in Choreography Environment

Kuo, Wei-ting 30 July 2012 (has links)
Nowadays, Web Services technology has become a standard to integrate business processes across organizations. In general, there are two approaches for web service composition: Orchestration and Choreography. Orchestration is used to develop a single process that integrates services within or across an organization to achieve a business goal. On the other hand, Choreography is often used for cross-organizational communication and serves as a specification for communication. In a choreographed environment, each Web service is an independent entity, and each service selects the partner services using its own selection policy without knowing all the other services in the choreography. In this thesis, we use £k-calculus for modeling the Web Services. Afterwards, we propose an approach for each constituent process to choose and invoke other processes using the limited information provided by its partners. In our method, each service proclaims the requirments of its potential service providers (or consumers) and itself and provides to its partners. Subsequently each service will generate a local view using the information provided by its service consumers and providers to guide the selection. We evaluate our method by simulating 100,000 executions with different degrees of service availability. The experimental results indicate that our proposed method can indeed improve the success rate of the entire choreography.
16

Exploiting Semantics and Syntax for Service Specification and Signature Matching: The S5 Web Service Matchmaker

Mehdi, Syed Farrukh 25 November 2011 (has links)
In this thesis, we present a hybrid semantic web service discovery framework that exploits both the signatures and specifications of a web service, whilst adopting logical and non-logical service matching methods. For signature level service matching, we have developed two techniques: (i) logical similarity measures applied to the services’ input/output concepts; and (b) non-logical matching based on a Structure Preserving Semantic Matching algorithm. For specification level service matching, we have applied a unique short sentence matching approach on the textual-description of a web service. We evaluated the performance of our S5 Web Service Matchmaker using the OWLS-TC dataset, and furthermore compared its performance with the OWLS-MX discovery model. Our results indicate that S5 Web Service Matchmaker offers an improved web service matching performance with a significant increase in recall and subtle improvements in precision. / Web services are independent software systems designed to offer machine-to-machine interactions over the WWW to achieve well-described operations. The description of a web service entails (a) a syntactic component detailing the service’s operations and data structures in terms of the Web Services Description Language (WSDL), and (b) a semantic component that offers a semantic description, in terms of an ontology, of the services’ data and operations. Typically, service providers expose their services to the public by providing brief descriptions of the service’s operations; the challenge is to discover the right service based on rather sparse service descriptions in response to a specific service request. In this thesis, we present a hybrid semantic web service discovery framework that offer semantic web service discovery at both the signature and specification levels of a web service, whilst exploiting logical and non-logical service matching methods. For signature level service matching, we have developed two techniques: (i) logical similarity measures applied to the services’ input/output concepts; and (b) non-logical matching based on a Structure Preserving Semantic Matching algorithm. For specification level service matching, we have applied a unique short sentence matching approach on the textual-description of a web service. The cumulative similarly measures determine the overall similarity of a services’ description with the service request. We evaluated the performance of our S5 Web Service Matchmaker using the OWLS-TC dataset, and furthermore compared its performance with the OWLS-MX discovery model. Our results indicate that S5 Web Service Matchmaker offers an improved web service matching performance with a significant increase in recall and subtle improvements in precision.
17

以規則分類機制來建立一個具可信度的網路服務架構

陳世庭, Se-Ting Chen Unknown Date (has links)
可信度是網路服務首要解決的問題,我們從數位憑證,認證、授權、委任授權等安全層面去研究代理者可信度,並提出一套完整可信度規則分類機制當作信任度判斷的依據。在此篇論文中,我們論證如何將規則概念應用在代理者的溝通協定、服務流程控制上。我們並同時整合語意網規則和本體論的技術,以達到可信的網路服務環境。 / Trust is one of the most important issues for Web Services. We studied the agent trust problem based on security technologies, such as digital certificates, authentication, authorization, and delegation, etc. Furthermore, we propose a complete trust rule taxonomy mechanism to assistant us on the evaluation of agent trustworthiness. In this thesis, we justify the feasibility of using rule concepts on the agent communication protocol and service process control. We also demonstrated how to integrate the semantic web rules and ontologies to have a trusted web services environment.
18

EXTRACT TRANSFORM AND LOADING TOOL FOR EMAIL

Lawanghare, Amit Rajiv 01 September 2019 (has links)
This project focuses on applying Extract, Transform and Load (ETL) operations on the relational data exchanged via emails. An Email is an important form of communication by both personal and corporate means as it enables reliable and quick exchange. Many useful files are shared as a form of attachments which contains transactional/ relational data. This tool allows a user to write the filter conditions and lookup conditions on attachments; define the attribute map for attachments to the database table. The Data Cleansing for each attribute can be performed writing rules and their matching state. A user can add custom functions for the data transformation. The aggregation of the data is done in the form of reports after the operation of data loading into the database is complete. The tool needs one-time setup per file template and its automated from that point.
19

A pattern-based approach to the specification and validation of web services interactions

Li, Zheng, n/a January 2007 (has links)
Web services are designed for composition and use by third parties through dynamic discovery. As such, the issue of interoperability between services is of great importance to ensure that the services can work together towards the overall application goals. In particular, the interaction protocols of a service need to be implemented and used properly so that the service composition can conduct itself in an orderly fashion. There have been significant research efforts in providing rich descriptions for Web services, which includes their behaviour properties. When describing the interaction process/protocols of a service, most of them adopt a procedural or programming style approach. We argue that this style of description for service interactions is not natural to publishing service behaviour properties from the viewpoint of facilitating third-party service composition and analysis. Especially when dealing with service with diverse behaviour, the limit of these procedural approaches become apparent. In this thesis, we introduce a lightweight, pattern/constraint-based declarative approach that better supports the specification and use of service interaction properties in the service description and composition process. This approach uses patterns to describe the interaction behaviour of a service as a set of constraints. As such, it supports the incremental description of a service's interaction behaviour from the service developer's perspective, and the easy understanding and analysis of the interaction properties from the service user's perspective. It has been incorporated into OWL-S for service developers to describe service interaction constraints. We also present a framework and the related tool support for monitoring and checking the conformance of the service's runtime interactions against its specified interaction properties, to test whether the service is used properly and whether the service fulfils its behavioural obligations. The tool involves interception of service interactions/messages, representation of interaction constraints using finite state automata and finite state machine, and conformance checking of service interactions against interaction constraints. As such, we provide a useful tool for validating the implementation and use of services regarding their interaction behaviour.
20

Från sensor tillhttp : en fallstudie av integrationen mellan inbyggda system och Web Services

Genc, Erkan, Axfjord, Dennis January 2003 (has links)
No description available.

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