E-commerce is the current approach for doing any type of business online, which uses the superior power of digital information to understand the requirements and preferences of each client and each partner, to adapt products and services for them, and then to distribute the products and services as swiftly as possible.

The purpose of this project was to explore the use of Web services to solve enterprise computing problems. XML-based Web services allow complex information systems to be subdivided. In order to explore this architectural paradigm, two systems were built: an employee records sytem, and a vacation system.

E-commerce is the current approach for doing any type of business online, which uses the superior power of digital information to understand the requirements and preferences of each client and each partner, to adapt products and services for them, and then to distribute the products and services as swiftly as possible.

Several technologies and languages exist for the development and implementation of distributed systems. Furthermore, several models for teaching computer programming and teaching programming in a distance-based educational environment exist. Limited literature, however, is available on models for teaching distributed computing in a distance-based educational environment. The focus of this study is to examine how distributed computing should be taught in a distance-based educational environment so as to ensure effective and quality learning for students. The required effectiveness and quality should be comparable to those for students exposed to laboratories, as commonly found in residential universities. This leads to an investigation of the factors that contribute to the success of teaching distributed computing and how these factors can be integrated into a distance-based teaching model. The study consisted of a literature study, followed by a comparative study of available tools to aid in the learning and teaching of distributed computing in a distance-based educational environment. A model to accomplish this teaching and learning is then proposed and implemented. The findings of the study highlight the requirements and challenges that a student of distributed computing in a distance-based educational environment faces and emphasises how the proposed model can address these challenges. This study employed qualitative research, as opposed to quantitative research, as qualitative research methods are designed to help researchers to understand people and the social and cultural contexts within which they live. The research methods employed are design research, since an artefact is created, and a case study, since “how” and “why” questions need to be answered. Data collection was done through a survey. Each method was evaluated via its own well-established evaluation methods, since evaluation is a crucial component of the research process. / Computing / M. Sc. (Computer Science)

最近幾年來，網際網路的出現及應用面的廣泛，改變了企業的資訊架構。從Client/Server擴展到以Web為應用程式的平台，企業面臨了資訊架構的重整，企業網路、電子商務都是現今最新的應用。由於全球資訊網採開放架構，並以HTML、HTTP為標準，使得資訊業者有所依循，開發出許多產品來滿足企業的需求。隨著Web的廣泛使用，應用程式架構、介面與行為特質都將與以往有著大大的不同，元件及交易導向的Web應用程式是勢在必行的路。 對此變革，企業最重要的課題之一是，如何建構完整的企業網路環境以增強競爭力。資料庫系統是企業各種資訊軟體的基礎，在以Web為應用程式的平台的架構下，它仍是其中重要的關鍵元件。選擇資料庫系統必須考慮許多因素，而且現有的資料庫系統的產品很多，各項產品的特性與優點均有不同，每一種產品甚至可再細分成許多元件，可依照需要選用，因此資料庫產品的選擇變成一種複雜的過程。若選擇錯誤則不僅是金錢耗費的損失，更深遠地影響整個企業的順利運作，甚至是企業競爭力的下降，更可能嚴重到影響企業的存續。故資料庫系統的選擇不可不慎。 本文提出一網際網路資料庫體系選擇模式，協助企業在全球資訊網的開放架構及多階層應用系統環境下，評選出符合企業本身狀況及需求的網際網路資料庫系統。此模式內容包含，需求分析與確認、第一至四級網際網路資料庫體系需求屬性之彙整、兩階段的廠商篩選及含加權機制之廠商評比。 最後並將此模式運用於，行政院衛生署藥物食品檢驗局之購置網際網路資料庫設備計劃。 / Internet technology has drastically changed the enterprise computing and platform. Database management and systems represent the core of the change and the key of the new revolution of the information technology and infrastructure. Business information and models have been stored and manipulated through the use of the database technology. Due to the fast growing speed and variety of the database products in the marketplace, managers are having difficult making the right decision in selecting and maintaining the Internet database management and systems. To tackle this issue, we propose a requirements-based software selection model from the user’s viewpoint. In this research, we develop a five-step choice model with an emphasis on the requirement analysis and rank analysis. We collect and compile the functional and non-functional characteristics and features of the Internet database management and systems. We classify and organize them into a four-layer hierarchy and work with the weight mechanism in the rank analysis. This choice model adopts another five-part rank policy in order to produce the final suggestion of software selection. In the end, we apply the new model in a field case study of the Web Database Systems Procurement Project with the National Laboratories of Foods and Drugs, Department of Health, Executive Yuan.

<p>Stress responsive genes play a key role in shaping the manner in which plants process and respond to environmental stress. Their gene products are linked to DNA transcription and its consequent translation into a response product. However, whilst these genes play a significant role in manufacturing responses to stressful stimuli, transcription factors coordinate access to these genes, specifically by accessing a gene&rsquo / s promoter region which houses transcription factor binding sites. Here transcriptional elements play a key role in mediating responses to environmental stress where each transcription factor binding site may constitute a potential response to a stress signal. Arabidopsis thaliana, a model organism, can be used to identify the mechanism of how transcription factors shape a plant&rsquo / s survival in a stressful environment. Whilst there are numerous plant stress research groups, globally there is a shortage of publicly available stress responsive gene databases. In addition a number of previous databases such as the Generation Challenge Programme&rsquo / s comparative plant stressresponsive gene catalogue, Stresslink and DRASTIC have become defunct whilst others have stagnated. There is currently a single Arabidopsis thaliana stress response database called STIFDB which was launched in 2008 and only covers abiotic stresses as handled by major abiotic stress responsive transcription factor families. Its data was sourced from microarray expression databases, contains numerous omissions as well as numerous erroneous entries and has not been updated since its inception.The Dragon Arabidopsis Stress Transcription Factor database (DASTF) was developed in response to the current lack of stress response gene resources. A total of 2333 entries were downloaded from SWISSPROT, manually curated and imported into DASTF. The entries represent 424 transcription factor families. Each entry has a corresponding SWISSPROT, ENTREZ GENBANK and TAIR accession number. The 5&rsquo / untranslated regions (UTR) of 417 families were scanned against TRANSFAC&rsquo / s binding site catalogue to identify binding sites. The relational database consists of two tables, namely a transcription factor table and a transcription factor family table called DASTF_TF and TF_Family respectively. Using a two-tier client-server architecture, a webserver was built with PHP, APACHE and MYSQL and the data was loaded into these tables with a PYTHON script. The DASTF database contains 60 entries which correspond to biotic stress and 167 correspond to abiotic stress while 2106 respond to biotic and/or abiotic stress. Users can search the database using text, family, chromosome and stress type search options. Online tools have been integrated into the DASTF&nbsp / database, such as HMMER, CLUSTALW, BLAST and HYDROCALCULATOR. User&rsquo / s can upload sequences to identify which transcription factor family their sequences belong to by using HMMER. The website can be accessed at http://apps.sanbi.ac.za/dastf/ and two updates per year are envisaged.</p>

A distributed application may be considered as a set of nodes which are spread across the network, and need to communicate with each other. The design and implementation of these distributed applications is greatly simplified using Group Communication Systems (GCSs) which provide multipoint to multipoint communication. Hence, GCSs can be used as building blocks for implementing distributed applications. The GCS is responsible for reliable delivery of group messages and management of group membership. The peer-to-peer model and the client-server model are the two models of distributed systems for implementing GCSs. In this thesis, our focus is on improving the capability of GCS based on the client-server model. Security is an important requirement of many distributed applications. For such applications, security has to be provided m the GCS itself. The security of a GCS includes confidentiality, authentication and non-repudiation of messages, and ensuring that the GCS is properly meeting its guarantees. The complexity and cost of implementation of the above three types of security guarantees greatly depend on whether the GCS servers are trusted by the group members or not. Making use of the GCS services provided by untrusted GCS servers becomes necessary when the GCS servers are managed by a third party. In this thesis, we have proposed algorithms for ensuring the above three security guarantees for GCSs in which servers are not trusted. As part of the solution, we have proposed a new digital multisignature scheme which allows group members to verify that a message has indeed been signed by all group members. The various group key management algorithms proposed in literature differ from each other with respect to the following four metrics: communication overhead, computational overhead, storage at each member and distribution of load among group members. We identify the need for a distributed group key management algorithm which minimizes the computational overhead on group members and propose an algorithm to achieve it.

<p>Stress responsive genes play a key role in shaping the manner in which plants process and respond to environmental stress. Their gene products are linked to DNA transcription and its consequent translation into a response product. However, whilst these genes play a significant role in manufacturing responses to stressful stimuli, transcription factors coordinate access to these genes, specifically by accessing a gene&rsquo / s promoter region which houses transcription factor binding sites. Here transcriptional elements play a key role in mediating responses to environmental stress where each transcription factor binding site may constitute a potential response to a stress signal. Arabidopsis thaliana, a model organism, can be used to identify the mechanism of how transcription factors shape a plant&rsquo / s survival in a stressful environment. Whilst there are numerous plant stress research groups, globally there is a shortage of publicly available stress responsive gene databases. In addition a number of previous databases such as the Generation Challenge Programme&rsquo / s comparative plant stressresponsive gene catalogue, Stresslink and DRASTIC have become defunct whilst others have stagnated. There is currently a single Arabidopsis thaliana stress response database called STIFDB which was launched in 2008 and only covers abiotic stresses as handled by major abiotic stress responsive transcription factor families. Its data was sourced from microarray expression databases, contains numerous omissions as well as numerous erroneous entries and has not been updated since its inception.The Dragon Arabidopsis Stress Transcription Factor database (DASTF) was developed in response to the current lack of stress response gene resources. A total of 2333 entries were downloaded from SWISSPROT, manually curated and imported into DASTF. The entries represent 424 transcription factor families. Each entry has a corresponding SWISSPROT, ENTREZ GENBANK and TAIR accession number. The 5&rsquo / untranslated regions (UTR) of 417 families were scanned against TRANSFAC&rsquo / s binding site catalogue to identify binding sites. The relational database consists of two tables, namely a transcription factor table and a transcription factor family table called DASTF_TF and TF_Family respectively. Using a two-tier client-server architecture, a webserver was built with PHP, APACHE and MYSQL and the data was loaded into these tables with a PYTHON script. The DASTF database contains 60 entries which correspond to biotic stress and 167 correspond to abiotic stress while 2106 respond to biotic and/or abiotic stress. Users can search the database using text, family, chromosome and stress type search options. Online tools have been integrated into the DASTF&nbsp / database, such as HMMER, CLUSTALW, BLAST and HYDROCALCULATOR. User&rsquo / s can upload sequences to identify which transcription factor family their sequences belong to by using HMMER. The website can be accessed at http://apps.sanbi.ac.za/dastf/ and two updates per year are envisaged.</p>

A software product line is a set of software-intensive systems that share a common, managed set of features satisfying the specific needs of a particular market segment or demand. Software product lines capitalize commonality and manage variation to reduce the time, effort, cost and complexity when creating and maintaining products in a product line. Therefore reusing core assets, software product line can address problems such as cost, time-to-market, quality, complexity of developing and maintaining variants, and need to quickly respond to market’s demands. The development of a software product line is different from conventional software development and in the area of education and research of product line there is a lack of a suitable purposefully designed and developed software product line (SPL) that can be used for educational or research purposes. In this thesis we have developed a software product line for turn-based two players distributed board games environment that can be used for educational and research purposes. The software product line supports dynamic runtime update, including games, chat, and security features, via OSGi framework. Furthermore, it supports remote gameplay via local area network and dynamic runtime activity recovery. We delivered a product configuration tool that is used to derive and configure products from the core assets based on feature selection. We have also modeled the software product line’s features and documented its requirements, architecture and user guides. Furthermore, we performed functional and integration tests of the software product line to ensure that the requirements are met according to the requirements specification prescribed by the stakeholders.

Universiẗat, Diss.--Heidelberg, 1996.