Application of the internet technology and client/server paradigm for the implementation of REPI

There are many problems associated with Requirements Engineering such as defining the system scope, developing understanding among the communities involved in the system to be built, volatility of requirements etc. These problems may lead to poor requirements and therefore cancellation of the system development, or else the development of a system that is unsatisfactory, has high maintenance cost or is unacceptable. By improving Requirements Elicitation, the Requirements Engineering can be improved, leading to a better requirements specification and eventually a better product. Requirements Elicitation requires effective communication among the team members, as communication is the key factor. Easing communications between stakeholders and developers makes the process of Requirements Elicitation easier. REPI guides team members through the elicitation phase using the SEI\u27s framework. REPI forces stakeholders to explicitly describe the requirements resulting in reduced chances of misunderstood requirements, leading to better requirements specification

Network Computer Technology. Phase I: Viability and Promise within NASA's Desktop Computing Environment

Over the past several months, major industry vendors have made a business case for the network computer as a win-win solution toward lowering total cost of ownership. This report provides results from Phase I of the Ames Research Center network computer evaluation project. It identifies factors to be considered for determining cost of ownership; further, it examines where, when, and how network computer technology might fit in NASA's desktop computing architecture

Design and implementation of a web-based cooperative school information system.

by Tsui Yuen.Thesis (M.Phil.)--Chinese University of Hong Kong, 1999.Includes bibliographical references (leaves 144-151).Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Computer-assisted Education --- p.2Chapter 1.2 --- Motivation and Problems --- p.4Chapter 1.3 --- Objectives and Approaches --- p.7Chapter 1.4 --- Organization of Thesis --- p.9Chapter 2 --- Related Work --- p.10Chapter 2.1 --- Existing Research Projects --- p.10Chapter 2.2 --- Structural and Navigational Hypertext Presentation --- p.11Chapter 2.3 --- Multimedia Integration for Hypermedia Courseware --- p.13Chapter 2.4 --- Standalone Java Applets --- p.14Chapter 2.5 --- Software Tools Using Browser Plugins --- p.17Chapter 2.6 --- Chapter Summary --- p.18Chapter 3 --- SIS Education Scenarios --- p.19Chapter 3.1 --- Library System --- p.21Chapter 3.2 --- Groupware System --- p.24Chapter 3.3 --- Student-Monitoring System --- p.25Chapter 3.4 --- Management System --- p.26Chapter 3.5 --- Chapter Summary --- p.27Chapter 4 --- Software Architecture of SIS --- p.29Chapter 4.1 --- Client-server Model --- p.29Chapter 4.2 --- Software Configuration --- p.31Chapter 4.3 --- Software Design --- p.33Chapter 4.3.1 --- Module 1: Access Authorization Identifier (AAI) --- p.34Chapter 4.3.2 --- Module 2: Multimedia Presentation Tools (MPT) --- p.35Chapter 4.3.3 --- Module 3: Intelligent Questions Selector (IQS) --- p.38Chapter 4.3.4 --- Module 4: Online Examination Center (OEC) --- p.40Chapter 4.3.5 --- Module 5: Student History Recorder (SHR) --- p.41Chapter 4.3.6 --- Module 6: Student Performance Analyzer (SPA) --- p.42Chapter 4.3.7 --- Module 7: Electronic Mail Manager (EMM) --- p.43Chapter 4.3.8 --- Module 8: Result Querying Agent (RQA) --- p.44Chapter 4.3.9 --- Module 9: Group Activity Area (GAA) --- p.45Chapter 4.3.10 --- Module 10: Integrated Systems Logger (ISL) --- p.48Chapter 4.4 --- Chapter Summary --- p.50Chapter 5 --- Demonstration --- p.52Chapter 5.1 --- Login Dialog Boxes --- p.52Chapter 5.2 --- Services Menu for Students --- p.53Chapter 5.3 --- Teaching Materials for Students --- p.54Chapter 5.4 --- Teaching Materials for Students ´ؤ Chinese --- p.56Chapter 5.5 --- Teaching Materials for Students - English --- p.60Chapter 5.6 --- Teaching Materials for Students - Mathematics --- p.64Chapter 5.7 --- Tests for Students --- p.66Chapter 5.8 --- Tests for Students - Chinese --- p.66Chapter 5.9 --- Tests for Students - English --- p.68Chapter 5.10 --- Queries for Students --- p.70Chapter 5.11 --- Discussion Area for Students --- p.71Chapter 5.12 --- Educational Television for Students --- p.72Chapter 5.13 --- Flow of Services for Students --- p.75Chapter 5.14 --- Services Menu for Teachers --- p.76Chapter 5.15 --- Teaching Materials for Teachers --- p.77Chapter 5.16 --- Teaching Materials for Teachers - Chinese --- p.78Chapter 5.17 --- Teaching Materials for Teachers - English --- p.82Chapter 5.18 --- Tests Papers for Teachers --- p.86Chapter 5.19 --- Queries for Teachers --- p.87Chapter 5.20 --- Preparation of Test Papers for Teachers --- p.88Chapter 5.21 --- Modification of Questions for Teachers --- p.91Chapter 5.22 --- Flow of Services for Teachers --- p.95Chapter 5.23 --- Chapter Summary --- p.96Chapter 6 --- System Implementation --- p.97Chapter 6.1 --- Characteristics of Java --- p.97Chapter 6.2 --- Platform Independence --- p.98Chapter 6.3 --- Integration with Existing Packages for Java Technology --- p.100Chapter 6.4 --- Cryptography of User Passwords --- p.103Chapter 6.5 --- Transmission of Data Packages --- p.105Chapter 6.6 --- Multithreading for Multitasking --- p.108Chapter 6.7 --- Management of User Interfaces --- p.110Chapter 6.8 --- Data Structures for Temporary Storage --- p.112Chapter 6.9 --- Messages Broadcasting in Chat Rooms --- p.116Chapter 6.10 --- Playback of Audio and Video Data Files --- p.121Chapter 6.11 --- Progress of System Implementation --- p.125Chapter 6.12 --- Chapter Summary --- p.128Chapter 7 --- Discussion and Future Work --- p.129Chapter 7.1 --- Wide Spread of the World Wide Web --- p.129Chapter 7.2 --- Communication between Schools and Families --- p.130Chapter 7.3 --- Pedagogical Uses --- p.130Chapter 7.4 --- Virtual Student Community --- p.131Chapter 7.5 --- Differences between SIS and Other Web-based Educational Systems --- p.132Chapter 7.6 --- Future Work --- p.133Chapter 7.7 --- Chapter Summary --- p.138Chapter 8 --- Summary --- p.139Bibliography --- p.14

Applications of internet technology for requirements elicitation

During the Requirements Elicitation part of a project various stakeholders need to be able to communicate their requirements to the developers, and the developers need to be able communicate their understanding back to the stakeholders. Communication between the various members of the project is the key factor during the Requirements Elicitation part of a project. Easing communications between stakeholders and developers makes the process of eliciting requirement easier, leading to better requirements specification and eventually a better product. The Requirements Elicitation Process through Internet (REPI) web site has been designed and implemented to explore this idea. The prototype version of REPI guides project members through the elicitation phase using the Software Engineering Institute\u27s framework for Requirements Elicitation. The REPI web site forces stakeholders to explicitly describe the requirements and encourage early discussion between stakeholders and developers. This decreases the likelihood of misunderstood requirements, leading to better requirements specification

An Automated Method for Identifying Inconsistencies within Diagrammatic Software Requirements Specifications

The development of large-scale, composite software in a geographically distributed environment is an evolutionary process. Often, in such evolving systems, striving for consistency is complicated by many factors, because development participants have various locations, skills, responsibilities, roles, opinions, languages, terminology and different degrees of abstraction they employ. This naturally leads to many partial specifications or viewpoints. These multiple views on the system being developed usually overlap. From another aspect, these multiple views give rise to the potential for inconsistency. Existing CASE tools do not efficiently manage inconsistencies in distributed development environment for a large-scale project. Based on the ViewPoints framework the WHERE (Web-Based Hypertext Environment for requirements Evolution) toolkit aims to tackle inconsistency management issues within geographically distributed software development projects. Consequently, WHERE project helps make more robust software and support software assurance process. The long term goal of WHERE tools aims to the inconsistency analysis and management in requirements specifications. A framework based on Graph Grammar theory and TCMJAVA toolkit is proposed to detect inconsistencies among viewpoints. This systematic approach uses three basic operations (UNION, DIFFERENCE, INTERSECTION) to study the static behaviors of graphic and tabular notations. From these operations, subgraphs Query, Selection, Merge, Replacement operations can be derived. This approach uses graph PRODUCTIONS (rewriting rules) to study the dynamic transformations of graphs. We discuss the feasibility of implementation these operations. Also, We present the process of porting original TCM (Toolkit for Conceptual Modeling) project from C++ to Java programming language in this thesis. A scenario based on NASA International Space Station Specification is discussed to show the applicability of our approach. Finally, conclusion and future work about inconsistency management issues in WHERE project will be summarized

The design and application of an extensible operating system

Tanenbaum, A.S. [Promotor

Advancing Operating Systems via Aspect-Oriented Programming

Operating system kernels are among the most complex pieces of software in existence to- day. Maintaining the kernel code and developing new functionality is increasingly compli- cated, since the amount of required features has risen significantly, leading to side ef fects that can be introduced inadvertedly by changing a piece of code that belongs to a completely dif ferent context. Software developers try to modularize their code base into separate functional units. Some of the functionality or “concerns” required in a kernel, however, does not fit into the given modularization structure; this code may then be spread over the code base and its implementation tangled with code implementing dif ferent concerns. These so-called “crosscutting concerns” are especially dif ficult to handle since a change in a crosscutting concern implies that all relevant locations spread throughout the code base have to be modified. Aspect-Oriented Software Development (AOSD) is an approach to handle crosscutting concerns by factoring them out into separate modules. The “advice” code contained in these modules is woven into the original code base according to a pointcut description, a set of interaction points (joinpoints) with the code base. To be used in operating systems, AOSD requires tool support for the prevalent procedu- ral programming style as well as support for weaving aspects. Many interactions in kernel code are dynamic, so in order to implement non-static behavior and improve performance, a dynamic weaver that deploys and undeploys aspects at system runtime is required. This thesis presents an extension of the “C” programming language to support AOSD. Based on this, two dynamic weaving toolkits – TOSKANA and TOSKANA-VM – are presented to permit dynamic aspect weaving in the monolithic NetBSD kernel as well as in a virtual- machine and microkernel-based Linux kernel running on top of L4. Based on TOSKANA, applications for this dynamic aspect technology are discussed and evaluated. The thesis closes with a view on an aspect-oriented kernel structure that maintains coherency and handles crosscutting concerns using dynamic aspects while enhancing de- velopment methods through the use of domain-specific programming languages

Highly Interactive Web-Based Courseware

Zukünftige Lehr-/Lernprogramme sollen als vernetzte Systeme die Lernenden befähigen, Lerninhalte zu erforschen und zu konstruieren, sowie Verständnisschwierigkeiten und Gedanken in der Lehr-/Lerngemeinschaft zu kommunizieren. Lehrmaterial soll dabei in digitale Lernobjekte übergeführt, kollaborativ von Programmierern, Pädagogen und Designern entwickelt und in einer Datenbank archiviert werden, um von Lehrern und Lernenden eingesetzt, angepasst und weiterentwickelt zu werden. Den ersten Schritt in diese Richtung machte die Lerntechnologie, indem sie Wiederverwendbarkeit und Kompabilität für hypermediale Kurse spezifizierte. Ein größeres Maß an Interaktivität wird bisher allerdings noch nicht in Betracht gezogen. Jedes interaktive Lernobjekt wird als autonome Hypermedia-Einheit angesehen, aufwändig in der Erstellung, und weder mehrstufig verschränk- noch anpassbar, oder gar adäquat spezifizierbar. Dynamische Eigenschaften, Aussehen und Verhalten sind fest vorgegeben. Die vorgestellte Arbeit konzipiert und realisiert Lerntechnologie für hypermediale Kurse unter besonderer Berücksichtigung hochgradig interaktiver Lernobjekte. Innovativ ist dabei zunächst die mehrstufige, komponenten-basierte Technologie, die verschiedenste strukturelle Abstufungen von kompletten Lernobjekten und Werkzeugsätzen bis hin zu Basiskomponenten und Skripten, einzelnen Programmanweisungen, erlaubt. Zweitens erweitert die vorgeschlagene Methodik Kollaboration und individuelle Anpassung seitens der Teilnehmer eines hypermedialen Kurses auf die Software-Ebene. Komponenten werden zu verknüpfbaren Hypermedia-Objekten, die in der Kursdatenbank verwaltet und von allen Kursteilnehmern bewertet, mit Anmerkungen versehen und modifiziert werden. Neben einer detaillierten Beschreibung der Lerntechnologie und Entwurfsmuster für interaktive Lernobjekte sowie verwandte hypermediale Kurse wird der Begriff der Interaktivität verdeutlicht, indem eine kombinierte technologische und symbolische Definition von Interaktionsgraden vorgestellt und daraus ein visuelles Skriptschema abgeleitet wird, welches Funktionalität übertragbar macht. Weiterhin wird die Evolution von Hypermedia und Lehr-/Lernprogrammen besprochen, um wesentliche Techniken für interaktive, hypermediale Kurse auszuwählen. Die vorgeschlagene Architektur unterstützt mehrsprachige, alternative Inhalte, bietet konsistente Referenzen und ist leicht zu pflegen, und besitzt selbst für interaktive Inhalte Online-Assistenten. Der Einsatz hochgradiger Interaktivität in Lehr-/Lernprogrammen wird mit hypermedialen Kursen im Bereich der Computergraphik illustriert.The grand vision of educational software is that of a networked system enabling the learner to explore, discover, and construct subject matters and communicate problems and ideas with other community members. Educational material is transformed into reusable learning objects, created collaboratively by developers, educators, and designers, preserved in a digital library, and utilized, adapted, and evolved by educators and learners. Recent advances in learning technology specified reusability and interoperability in Web-based courseware. However, great interactivity is not yet considered. Each interactive learning object represents an autonomous hypermedia entity, laborious to create, impossible to interlink and to adapt in a graduated manner, and hard to specify. Dynamic attributes, the look and feel, and functionality are predefined. This work designs and realizes learning technology for Web-based courseware with special regard to highly interactive learning objects. The innovative aspect initially lies in the multi-level, component-based technology providing a graduated structuring. Components range from complex learning objects to toolkits to primitive components and scripts. Secondly, the proposed methodologies extend community support in Web-based courseware – collaboration and personalization – to the software layer. Components become linkable hypermedia objects and part of the courseware repository, rated, annotated, and modified by all community members. In addition to a detailed description of technology and design patterns for interactive learning objects and matching Web-based courseware, the thesis clarifies the denotation of interactivity in educational software formulating combined levels of technological and symbolical interactivity, and deduces a visual scripting metaphor for transporting functionality. Further, it reviews the evolution of hypermedia and educational software to extract substantial techniques for interactive Web-based courseware. The proposed framework supports multilingual, alternative content, provides link consistency and easy maintenance, and includes state-driven online wizards also for interactive content. The impact of great interactivity in educational software is illustrated with courseware in the Computer Graphics domain

A New Protection Model for Component-Based

Protected operating systems multiplex programs onto resources such that they are isolated from one another — that is, concurrently executing programs cannot interfere with each other. A layer of software known as the kernel provides this protection to the software layers above it. Untrusted, ‘user’ programs are prevented from controlling the protection hardware because they are executed when the processor is in user mode — a mode of reduced privilege. In user mode, instructions that can be used to circumvent protection are unavailable; the processor’s instruction-set is reduced. This thesis introduces a new operating system protection mechanism termed SISR — Software-based Instruction Set Reduction (pronounced scissor). Here, all software (including the kernel) executes in the same processor mode, while both language independence and protection are maintained. Untrusted (that is, ‘user level’) code is prevented from issuing privileged instructions not by reducing the processor’s instruction set, but by scanning code prior to its loading; any code found to contain privileged instructions is not loaded. Memory protection is provided through segmentation. SISR leads to improved architectures (that is, simpler and more modular), and improves performance significantly. Its low overheads make fine-grained protection practical, making it especially well-suited to component-based operating systems. A prototype system has been built for x86-based PCs as a ‘proof-of-concept’. Significant improvements in architectures have been delivered. Tasks that have previously been inextricably linked (such as interrupt handling and CPU scheduling) have been separated into distinct components. Experiments have demonstrated significant improvements in performance, compared even to the leanest research operating systems