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.
315976
Resource Annotation Framework in a Georeferenced and Geospatial Digital Library
G-Portal is a georeferenced and geospatial digital library that aims to identify, classify and organize geospatial and georeferenced resources on the web and to provide digital library services for these resources. Annotation service is supported in G-Portal to enable users to contribute content to the digital library. In this paper, we present a resource annotation framework for georeferenced and geospatial digital libraries and discuss its application in G-Portal. The framework is flexible for managing annotations of heterogeneous web resources. It allows users to contribute not only the annotation content but also the schema of the annotations. Meanwhile, other digital library services, such as visualization and classification, can be provided over the annotations since they are treated as first class objects. This paper mainly focuses on the design of the resource annotation framework.
2945218
On querying geospatial and georeferenced metadata resources in G-Portal
G-Portal is a Web portal system providing a range of digital library services to access geospatial and georeferenced resources on the Web. Among them are the storage and query subsystems that provide a central repository of metadata resources organized under different projects. In G-Portal, all metadata resources are represented in XML (Extensible Markup Language) and they are compliant to some resource schemas defined by their creators. The resource schemas are extended versions of a basic resource schema making it easy to accommodate all kinds of metadata resources while maintaining the portability of resource data. To support queries over the geospatial and georeferenced metadata resources, a XQuery-like query language known as RQL (Resource Query Language) has been designed. We present the RQL language features and provide some experimental findings about the storage design and query evaluation strategies for RQL, queries.
16103436
Web-Based Parallel Simulation of AGVs Using Java and JINI
The vision of Computational Grids promises an exciting future for the distributed simulation community. In this project we make a small but practical step toward the grand vision of distributed simulation by using certain prevailing Internet technologies to enable access of simulation services anytime and anywhere. Specifically, this project focuses on accessing distributed simulation of AGVs (Automated Guided Vehicle) in container port operations through the World Wide Web. The objectives are to explore and address relevant issues, evaluate various approaches, demonstrate a workable version. We initially construct the AGV simulation system in an indirect communication model and identify its merits and demerits. Then, we explore the use of JINI technology for an efficient and robust direct communication architecture.
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.
31153136
An Adaptive Scheduling Algorithm for Molecule Docking Design on Grid
Grid provides a promising platform for the efficient execution of drug molecular docking design. Scheduling such applications is challenging for the heterogeneity, autonomy, and dynamic adaptability of grid resources. Assuming resource owners have a preemptive priority, we propose an adaptive algorithm of jobs scheduling based on time balancing strategy, which solves parallel molecular docking task by using the idle resources in the Grid. A mathematical model is developed to predict performance, which also considers systems with heterogeneous machine utilization and heterogeneous service distribution. According to the time balancing policy, ligands are partitioned into several subtasks and scheduled. The expected value of molecular docking completion time is predicted with performance model. To get better parallel computing performance, an optimal subset of heterogeneous resources with the shortest parallel executing time of tasks can be selected with the algorithm.
16029762
Preemptive Scheduling with Variable Profile, Precedence Constraints and Due Dates
Abstract This paper is concerned with the problem of scheduling preemptive tasks subject to precedence constraints in order to minimize the maximum lateness and the makespan. The number of available parallel processors is allowed to vary in time. It is shown that when an earliest due date first algorithm provides an optimal nonpreemptive schedule for unit-execution-time (UET) tasks, the preemptive priority scheduling algorithm, referred to as smallest laxity first, provides an optimal preemptive schedule for real-execution-time (RET) tasks. When the objective is to minimize the makespan, we get the same kind of result between highest level first schedules solving nonpreemptive tasks with UET and the longest remaining path first schedule for the corresponding preemptive scheduling problem with RET tasks. These results are applied to four specific profile scheduling problems and new optimality results are obtained.
14780024
Fuzzy causal networks: general model, inference, and convergence
In this paper, we first propose a general framework for fuzzy causal networks (FCNs). Then, we study the dynamics and convergence of such general FCNs. We prove that any general FCN with constant weight matrix converges to a limit cycle or a static state, or the trajectory of the FCN is not repetitive. We also prove that under certain conditions a discrete state general FCN converges to its limit cycle or static state in O(n) steps, where n is the number of vertices of the FCN. This is in striking contrast with the exponential running time 2/sup n/, which is accepted widely for classic FCNs.
9219349
Flexible Secure Multicasting in Active Networks
In this paper we describe an alternative, flexible approach to multicast security in active networks. Traditional schemes for securing multicast communication have key management and scalability problems for many typical applications. In addition, traditional mechanisms are not capable of expressing flexible, situational security policies for multicast sessions and participants. Our scheme exploits the computational power of active networks to provide dynamic, flexible security for multicast applications. One of the main advantages of our scheme is the low communication and key distribution overhead associated with multicast group management. Our approach is based on the Seraphim security architecture implementation, which uses active capabilities for access control. Seraphim is an extensible, reconfigurable security architecture that is flexible and accommodates a wide variety of security policies and mechanisms. It also provides applications and users the ability to create dynamically and enforce highly customized and situational policies. Using these policies we have developed several secure multicast applications that demonstrate the flexible nature and low overheads associated with our architecture.
1313086
Image-based surface detail transfer
Changing an object's appearance by adding geometric details is desirable in many real-world applications. Bump mapping has acted as an alternative to adding geometrical details, to an otherwise smooth object. But constructing visually interesting bump maps requires practice and artistic skills. Computer vision techniques have helped for modeling real-world objects and their surface details. In our approach, for cases where we only want to transfer geometrical details from one object to another, we might not need to explicitly compute 3D structures. In particular, our novel technique captures the geometrical details of an object from a single image in a way that is independent of the object's reflectance property. We can then transfer geometrical details to another surface, producing the appearance of a new surface with added geometrical details while preserving the object's reflectance property. Our method's advantages are that it's simple to implement, requires only a single image for each object, and produces effective results.