34215309
Jini-enabled high performance computing
The vision of computational grids promises an exciting future for high performance computing (HPC). In the project presented we make a small but practical step toward the grand vision of pervasive HPC by using some of the prevailing Internet technologies to enable access of HPC anytime and anywhere. Specifically, the project focuses on HPC that could be accessed by using the World Wide Web. We have conducted experiments based on engineering/scientific applications. Examples include simulations of automated guided vehicles (hereafter AGVs for short) in container port operations, N-body and molecular simulations. We initially build systems based on an ad-hoc approach, whose merits and demerits are identified. Then, we employ Jini technology to reconstruct the system architecture and present a more efficient and robust model. Performance studies are also presented. The objectives are to explore and address relevant issues, evaluate various approaches, demonstrate a workable version and conduct experiments with actual Web-enabled applications. The result is that now we are able to partially realize the dream of using the HPCs anytime and anywhere through devices such as a wireless/mobile computer, as long as they are armed with a common Web browser.
11497838
On organizing and accessing geospatial and georeferenced Web resources using the G-Portal system
In order to organise and manage geospatial and georeferenced information on the Web making them convenient for searching and browsing, a digital portal known as G-Portal has been designed and implemented. Compared to other digital libraries, G-Portal is unique for several of its features. It maintains metadata resources in XML with flexible resource schemas. Logical groupings of metadata resources as projects and layers are possible to allow the entire metadata collection to be partitioned differently for users with different information needs. These metadata resources can be displayed in both the classification-based and map-based interfaces provided by G-Portal. G-Portal further incorporates both a query module and an annotation module for users to search metadata and to create additional knowledge for sharing respectively. G-Portal also includes a resource classification module that categorizes resources into one or more hierarchical category trees based on user-defined classification schemas. This paper gives an overview of the G-Portal design and implementation. The portal features will be illustrated using a collection of high school geography examination-related resources.
1037934
A visual tool for building logical data models of websites
Information sources over the WWW contain a large amount of data organized according to different interests and values. Thus, it is important that facilities are there to enable users to extract information of interest in a simple and effective manner. To do this, We propose the Wiccap Data Model, an XML data model that maps Web information sources into commonly perceived logical models, so that information can be extracted automatically according to users' interests. To accelerate the creation of data models, we have implemented a visual tool, called the Mapping Wizard, to facilitate and automate the process of producing Wiccap Data Models. Using the tool, the time required to construct a logical data model for a given website is significantly reduced.
17450841
An information concierge for the Web
WWW Information Collection, Collaging and Programming (WICCAP) system is a software system for the generation of logical views of web resources, and the extraction of desired information in the form of a structured document. It is designed to enable people to obtain information of interests in a simple and effective manner as well as to make information from the WWW accessible to applications so as to afford automation, inter-operation and Web-awareness among services. A key factor in making this system useful in practice is that it provides tools to automate and facilitate the process of constructing logical representation of websites, to identify and define information of interest, and to retrieving them. In this paper we present the design of the WICCAP system and its two main components, namely Mapping Wizard and Network Extraction Agent.
7602869
Intergenerational Partnerships in the Design of a Digital Library of Geography Examination Resources
This paper describes the engagement of intergenerational partners in the design of a digital library of geographical resources (GeogDL) to help prepare Singapore students for a national examination in geography. GeogDL is built on top of G-Portal, a digital library providing services over geospatial and georeferenced Web content. Scenario-based design and claims analysis were employed as a means of refinement to the initial design of the GeogDL prototype.
7550543
A digital library for geography examination resources
We describe a Web-based application developed above a digital library of geographical resources for Singapore students preparing to take a national examination in geography. The application provides an interactive, non-sequential approach to learning that supplements textbooks.
3730862
Distributed Resource Allocation in Stream Processing Systems
Distributed stream processing architecture has emerged as appealing solution to coping with the analysis of large amount of data from dispersed sources. A fundamental problem in such stream processing systems is how to best utilize the available resources so that the overall system performance is optimized. We consider a distributed stream processing system that consists of a network of cooperating servers, collectively providing processing services for multiple data streams. Each stream is required to complete a series of operations on various servers. We assume all servers have finite computing resources and all communication links have finite available bandwidth. The problem is to find distributed schemes to allocate the limited computing resources as well as the communication bandwidth in the system so as to achieve a maximum concurrent throughput for all output streams. We present a generalized multicommodity flow model for the above problem. We develop a distributed resource allocation algorithm that guarantees the optimality. We also provide detailed analysis on the complexity of the algorithm and demonstrate the performance using numerical experiments.
11533242
Multi-robot mobility enhanced hop-count based localization in ad hoc networks
The localization problem is important in mobile robots and wireless sensor network and has been studied for many years. Among many localization methods, the hop-count based approach is simple and scalable; however, the localization accuracy is not satisfactory if the node density is low. To solve this problem, in this paper a multi-robot approach is proposed to utilize the cooperation and mobility of the robots to improve the node distribution (density), thus enhancing the hop-count based localization. By an auction-based task allocation scheme, the robots can negotiate with the static sensor nodes and then select the most suitable robots to move to the area of sparse node density, thus increasing the localization accuracy for the static sensor nodes. On the other hand, the robots also can localize themselves with the help of the static sensor nodes. The efficacy of this approach is shown by simulation.
16274304
Face detection and tracking in video using dynamic programming
Face detection and tracking are important in video content analysis since the most important objects in most video are human beings. This paper proposes a new approach for combined face detection and tracking in video. The face detection algorithm is a fast template matching procedure using iterative dynamic programming (DP). Although the face detection algorithm is designed for frontal face, the same mechanism can also be applied to track non-frontal faces with online adapted face models. Due to the essence of template matching, the algorithm is capable of comparing the similarity among different faces, which makes it suitable for tracking the same face that occur at disjointed temporal locations in video. While the proposed face detection method provides comparable accuracy as the neural network based approach, it is much faster.
17231470
Dynamic scheduling of parallel computations
Structures of parallel programs are usually represented by task graphs in the scheduling literature. Such graphs are sometimes obtained at compile time. In many other cases, however, they can be determined only at run time. In this paper, we consider the scheduling of parallel computations whose task graphs are generated at run time. We analyze the case where the task graph is a random out-tree. When the number of offspring of a task has a geometric distribution whose parameter is decreasing and convex in the level, then the breadth-first policy stochastically minimizes the makespan. If, however, this parameter is increasing and concave, then the depth-first policy stochastically minimizes the makespan.
1204986
A floating-point CORDIC based SVD processor
An SVD processor system is presented in which each processing element is implemented using a simple CORDIC unit. The internal recursive loop within the CORDIC module is exploited, with pipelining being used to multiplex the two independent microrotations onto a single CORDIC processor. This leads to a high performance and efficient hardware architecture. In addition, a novel method for scale factor correction is presented which only need be applied once at the end of the computation. This also reduces the computation time. The net result is an SVD architecture based on a conventional CORDIC approach, which combines high performance with high silicon area efficiency.