An adaptive communication mechanism for heterogeneous distributed environments using XML and servlets.

Cheung Wing Hang.Thesis (M.Phil.)--Chinese University of Hong Kong, 2001.Includes bibliographical references (leaves 107-112).Abstracts in English and Chinese.Abstract --- p.iiAbstract in Chinese --- p.ivAcknowledgments --- p.vChapter 1 --- Introduction --- p.1Chapter 1.1 --- Firewall Issue in Distributed Systems --- p.2Chapter 1.2 --- Heterogeneous Communication Protocols --- p.4Chapter 1.3 --- Translator for Converting Interface Definition to Flexible XML --- p.8Chapter 1.4 --- An Implementation of a Scalable Mediator Query System --- p.9Chapter 1.5 --- Our Contributions --- p.9Chapter 1.6 --- Outline of This Thesis --- p.10Chapter 2 --- Related Work and Technologies --- p.12Chapter 2.1 --- Overview of XML Technology --- p.12Chapter 2.1.1 --- XML Basic Syntax --- p.13Chapter 2.1.2 --- DTD: The Grammar Book --- p.15Chapter 2.1.3 --- Representing Complex Data Structures --- p.17Chapter 2.2 --- Overview of Java Servlet Technology --- p.18Chapter 2.3 --- Overview of Simple Object Access Protocol --- p.20Chapter 2.4 --- Overview of XML-RPC --- p.21Chapter 2.5 --- Overview of XIOP --- p.22Chapter 3 --- Using XML and Servlets to Support CORBA Calls --- p.24Chapter 3.1 --- Objective --- p.24Chapter 3.2 --- General Concept of Our Mechanism --- p.25Chapter 3.2.1 --- At Client Side --- p.27Chapter 3.2.2 --- At Server Side --- p.28Chapter 3.3 --- Data in Transmission --- p.30Chapter 3.3.1 --- Using XML --- p.30Chapter 3.3.2 --- Format of Messages in Transmission --- p.30Chapter 3.4 --- Supporting Callbacks in CORBA Systems --- p.33Chapter 3.4.1 --- What is callback? --- p.33Chapter 3.4.2 --- Enhancement to Allow Callbacks --- p.34Chapter 3.5 --- Achieving Transparency with Add-on Components --- p.37Chapter 4 --- A Translator to Convert CORBA IDL to XML --- p.39Chapter 4.1 --- Introduction to CORBA IDL --- p.39Chapter 4.2 --- Mapping from IDL to XML --- p.40Chapter 4.2.1 --- IDL Basic Data Types --- p.41Chapter 4.2.2 --- IDL Complex Data Types --- p.42Chapter 4.2.3 --- IDL Interface --- p.48Chapter 4.2.4 --- Attributes --- p.48Chapter 4.2.5 --- Operations (Methods) --- p.49Chapter 4.2.6 --- Exceptions --- p.50Chapter 4.2.7 --- Inheritance --- p.51Chapter 4.2.8 --- IDL Modules --- p.52Chapter 4.2.9 --- A Sample Conversion --- p.52Chapter 4.3 --- Making a Request or Response --- p.53Chapter 4.4 --- Code Generation for Add-on Components --- p.54Chapter 4.4.1 --- Generation of Shadow Objects --- p.54Chapter 4.4.2 --- Generation of Servlet Components --- p.55Chapter 5 --- Communication in Heterogeneous Distributed Environments --- p.58Chapter 5.1 --- Objective --- p.58Chapter 5.2 --- General Concept --- p.60Chapter 5.3 --- Case Study 1 - Distributed Common Object Model --- p.61Chapter 5.3.1 --- Brief Overview of Programming in DCOM --- p.61Chapter 5.3.2 --- Mapping the Two Different Interface Definitions --- p.63Chapter 5.3.3 --- Sample Architecture of Communicating Between DCOM and CORBA --- p.66Chapter 5.4 --- Case Study 2 - Java Remote Methods Invocation --- p.67Chapter 5.4.1 --- Brief Overview of Programming in Java RMI --- p.67Chapter 5.4.2 --- Mapping the Two Different Interface Definitions --- p.69Chapter 5.4.3 --- Sample Architecture of Communicating Between JavaRMI and CORBA --- p.71Chapter 5.5 --- Be Generic: Binding with the WEB --- p.72Chapter 6 --- Building a Scalable Mediator-based Query System --- p.74Chapter 6.1 --- Objectives --- p.74Chapter 6.2 --- Introduction to Our Mediator-based Query System --- p.76Chapter 6.2.1 --- What is mediator? --- p.76Chapter 6.2.2 --- The Architecture of our Mediator Query System --- p.77Chapter 6.2.3 --- The IDL Design of the Mediator System --- p.79Chapter 6.2.4 --- Components in the Query Mediator System --- p.80Chapter 6.3 --- Helping the Mediator System to Expand Across the Firewalls --- p.83Chapter 6.3.1 --- Implementation --- p.83Chapter 6.3.2 --- Across Heterogeneous Systems with DTD --- p.87Chapter 6.4 --- Adding the Callback Feature to the Mediator System --- p.89Chapter 6.5 --- Connecting our CORBA System with Other Environments --- p.90Chapter 6.5.1 --- Our Query System in DCOM --- p.91Chapter 6.5.2 --- Our Query System in Java RMI --- p.92Chapter 6.5.3 --- Binding Heterogeneous Systems --- p.93Chapter 7 --- Evaluation --- p.95Chapter 7.1 --- Performance Statistics --- p.95Chapter 7.1.1 --- Overhead in other methods --- p.97Chapter 7.2 --- Means for Enhancement --- p.98Chapter 7.2.1 --- Connection Performance of HTTP --- p.98Chapter 7.2.2 --- Transmission Data Compression --- p.99Chapter 7.2.3 --- Security Concern --- p.99Chapter 7.3 --- Advantages of Using Our Mechanism --- p.101Chapter 7.4 --- Disadvantages of Using Our Mechanism --- p.102Chapter 8 --- Conclusion --- p.10

Designing object-oriented interfaces for medical data repositories

Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (leaves 113-116).by Patrick J. McCormick.S.B.and M.Eng

CBSE: an implementation case study

Over the last couple of years, the shift towards component based software engineering (CBSE) methods has become a cost effective way to get an application to implementation stage much earKer. Adoption of Component Based Development methods acknowledges the use of third party components wherever possible to reduce the cost of software development, shorten the development phase and provide a richer set of processing options for the end user. The use of these tools is particularly relevant in Web based applications, where commercial off the shelf (COTS) products are so prevalent. However, there are a number of risks associated with the use of component based development methods. This thesis investigates these risks within the context of a software engineering project and attempts to provide a means to minimise and or at least manage the risk potential when using component based development method

Integration of Heterogeneous Digital Libraries with Semi-automatic Mapping and Browsing: From Formalization to Specification to Visualization

In this paper, we formalize the digital library (DL) integration problem and propose an overall approach based on the 5S framework. We apply 5S to domain-specific (archaeological) DLs, illustrating our solutions for key problems in DL integration. We use ETANA-DL as a case study to describe the process of semi-automatically generating a union catalog and a unified browsing service in an archaeological DL. A visual schema mapping tool is developed for union catalog creation. A pilot user study aids tool evaluation. Our approach is further validated through application of a general browsing component to two integrated DLs

Use of the Internet for Remote Train Monitoring

Railways and mass transit transportation systems are experiencing a new growth that will have an important social impact in the global transport domain. Therefore new important steps are required to advance the urgent needs, such as interoperability at train and vehicle levels, support for commissioning and maintenance, communication with ground infrastructure and introduction of new services. The ROSIN project aims at the validation of a complete and open platform, which will be the basis for a new generation of vehicles, consisting of an on-board network that interconnects all various on-board systems and subsystems. Taking advantage of a 10 year effort to specify a standard Train Communication Network (TCN), carried out within the International Electrotechnical Commission (IEC) by Technical Committee 9, Working Group 22, the ROSIN project aims to work out a comprehensive solution that closely addresses users requirements and has been validated and demonstrated extensively, using available technology, in a wide range of applications. The project covers all aspects of the on-board networking problems, addressing key areas such as passenger trains, freight trains and mass-transit (metros and trams). Communication and application requirements are considered, including maintenance needs and openness toward ground networks. Internet technologies are used to bring ubiquitous and low cost access to train data

Building Distributed Systems for the Pragmatic Object Web

We review the growing power and capability of commodity computing and communication technologies largely driven by commercial distributed information systems. These systems are built from CORBA, Microsoft\u27s COM, JavaBeans, and rapidly advancing Web approaches. One can abstract these to a three-tier model with largely independent clients connected to a distributed network of servers. The latter host various services including object and relational databases and of course parallel and sequential computing. High performance can be obtained by combining concurrency at the middle server tier with optimized parallel back end services. The resultant system combines the needed performance for large-scale HPCC applications with the rich functionality of commodity systems. Further the architecture with distinct interface, server and specialized service implementation layers, naturally allows advances in each area to be easily incorporated. We illustrate how performance can be obtained within a commodity architecture and we propose a middleware integration approach based on JWORB (Java Web Object Broker) multi-protocol server technology. We illustrate our approach on a set of prototype applications in areas such as collaborative systems, support of multidisciplinary interactions, WebFlow based visual metacomputing, WebFlow over Globus, Quantum Monte Carlo and distributed interactive simulations

Forum Session at the First International Conference on Service Oriented Computing (ICSOC03)

The First International Conference on Service Oriented Computing (ICSOC) was held in Trento, December 15-18, 2003. The focus of the conference ---Service Oriented Computing (SOC)--- is the new emerging paradigm for distributed computing and e-business processing that has evolved from object-oriented and component computing to enable building agile networks of collaborating business applications distributed within and across organizational boundaries. Of the 181 papers submitted to the ICSOC conference, 10 were selected for the forum session which took place on December the 16th, 2003. The papers were chosen based on their technical quality, originality, relevance to SOC and for their nature of being best suited for a poster presentation or a demonstration. This technical report contains the 10 papers presented during the forum session at the ICSOC conference. In particular, the last two papers in the report ere submitted as industrial papers

A Secure Network Node Approach to the Policy Decision Point in Distributed Access Control

To date, the vast majority of access control research and development has been on gathering, managing, and exchanging information about users. But an equally important component which has yet to be fully developed is the Policy Decision Point - the system that decides whether an access request should be granted given certain attributes of the requestor. This paper describes the research and implementation of a new PDP system for an undergraduate honors project. This PDP system employs three unique features which differentiate it from existing technology: collaboration capabilities, trusted management, and interoperability with other access control systems. Security considerations and future research areas are also discussed

Current usage of Component based Principles for Developing Web Applications with Frameworks: A Literature Review

Component based software development has become a very popular paradigm in many software engineering branches. In the early phase of Web 2.0 appearance, it was also popular for web application development. From the analyzed papers, between this period and today, use of component based techniques for web application development was somewhat slowed down, however, the recent development indicates a comeback. Most of all it is apparent with W3C’s component web working group. In this article we want to investigate the current state of web application development with component approach. Most of all we are interested in which way components are used, which web development frameworks are being used, for which domains is component based web development most popular and successful, etc. How many current web development frameworks explicitly refer to component-based approach? To answer this question, we performed a literature review