Wee-Keong Ng

G-Portal: a map-based digital library for distributed geospatial and georeferenced resources

As the World Wide Web evolves into an immense information network, it is tempting to build new digital library services and expand existing digital library services to make use of web content. In this paper, we present the design and implementation of G-Portal, a web portal that aims to provide digital library services over geospatial and georeferenced content found on the World Wide Web. G-Portal adopts a map-based user interface to visualize and manipulate the distributed geospatial and georeferenced content. Annotation capabilities are supported, allowing users to contribute geospatial and georeferenced objects as well as their associated metadata. The other features included in G-Portals design are query support, content classification, and content maintenance. This paper will mainly focus on the architecture design, visualization and annotation capabilities of G-Portal.

Regression models for estimating product life cycle cost

Product life cycle cost (LCC) is defined as the cost that is incurred in all stages of the life cycle of a product, including product creation, use and disposal. In recent years, LCC has become as crucial as product quality and functionality in deciding the success of a product in the market. In order to estimate LCC of new products, researchers have employed several (parametric) regression analysis models and artificial neural networks (ANN) on historical life cycle data with known costs. In this article, we conduct an empirical study on performance of five popular non-parametric regression models for estimating LCC under different simulated environments. These environments are set by varying the number of cost drivers (independent variables), the size of sample data, the noise degree of sample data, and the bias degree of sample data. Statistical analysis of the results recommend best LCC estimation models for variable environments in stages of the product life cycle. These findings are validated with real-world data from previous work.

Hierarchical Text Classification Methods and Their Specification

Hierarchical text classification refers to assigning text documents to the categories in a given category tree based on their content. With large number of categories organized as a tree, hierarchical text classification helps users to find information more quickly and accurately. Nevertheless, hierarchical text classification methods in the past have often been constructed in a proprietary manner. The construction steps often involve human efforts and are not completely automated. In this chapter, we therefore propose a specification language known as HCL (Hierarchical Classification Language). HCL is designed to describe a hierarchical classification method including the definition of a category tree and training of classifiers associated with the categories. Using HCL, a hierarchical classification method can be materialized easily with the help of a method generator system.

XStamps: a multiversion timestamps concurrency control protocol for XML data

With the tremendous growth of XML data over the Web, efficient management of such data becomes a new challenge for database community. Several data management solutions, proposed in recent years, extend the capability of traditional database systems to meet the needs of XML data while alternative approaches introduce new generation databases, named as native XML database management systems. Although traditional databases have mature transaction management and concurrency control techniques, there is still a need to tailor techniques for native XML databases in order to deal with distinct characteristics of XML. In this paper, we propose XStamps, a multiversion timestamps concurrency control protocol for XML data, which is integrated in NextDB, a native XML database management system. XStamps is designed based on multiversion timestamps protocol, and additional features are added to enable the flexible control of the isolation level of transactions and allow such transactions to commit early. Experimental results have shown that XStamps works well with XML data and provides performance gain over other concurrency protocols like tree and two-phase locking.

Financial advisor agent in a multi-agent financial trading system

Agent based technology has gained a lot of importance over recent years as is evident from the rapidly growing number of Web sites using agents. In the future, the level of automation would be such that work delegated to an agent could be accomplished by collaborating with other agents. Conventional financial trading systems alert the user based on the analysis of financial instruments based on user inputs. The authors take it a step further: an agent may initiate actions up to a limit defined by the user on the belief that in light of the analysis information available, the user would have taken the same action. The paper describes a multi agent financial trading system that helps to manage a financial portfolio by monitoring variables such as stock prices. Agents alert their owner or take autonomous actions when the information being monitored satisfies certain user-established criteria. All agents collaborate with one another to retrieve financial information, perform analysis, and take appropriate actions such as investing at the best rates trying to optimize the client portfolio.

Categorization of Standards, Guidelines and Tools for Secure System Design for Critical Infrastructure IT in the Cloud

With the increasing popularity of cloud computing, security in cloud-based applications is gaining awareness and is regarded as one of the most crucial factors for the long term success of such applications. Despite all benefits of cloud computing, its fate lies in its success in gaining trust from its users achieved by ensuring cloud services being built in a safe and secure manner. This work evaluates existing security standards and tools for creating Critical Infrastructure (CI) services in cloud environments -- often implemented as cyber physical systems (CPS). We also identify security issues from a literature review and from a show case analysis. Furthermore, we analyse and evaluate how mitigation options for identified open security issues for CI in the cloud point to individual aspects of standards and guidelines to support the creation of secure CPS/CI in the cloud. Additionally, we presented the results in a multidimensional taxonomy based on the mapping of the issues and the standards and tools. We show which areas require the attention as they are currently not covered completely by existing standards, guidelines and tools.

Deriving configuration knowledge and evaluating product variants through intelligent techniques

Mass customization has become a crucial business strategy for product manufacturers that aims at satisfying individual customer needs with near mass production efficiency. Companies must develop the necessary infrastructure to derive valid product configurations that satisfy the requirements of lifecycle cost along with customer’s constraints. In this paper, to overcome the drawback of current product configurators, we apply a rule mining approach to automatically generate configuration knowledge, and present a hybrid approach based on Activity Based Costing (ABC) and machine learning techniques to estimate LCC of derived product variants from a constraintbased configurator at the design stage. The proposed intelligent techniques would benefit companies in enhancing product development capability in a shorter lifecycle.