46138782
Leveraging legacy codes to distributed problem-solving environments: a Web services approach
This paper presents WSOWG, a Web-services-oriented wrapper generator for automatically wrapping non-networked legacy codes as Web services for reuse in distributed problem-solving environments. Using WSOWG, a finite element based computational fluid dynamics (CFD) legacy code has been wrapped as a Web service. A problem-solving environment for simulating incompressible Navier-Stokes flows has also been implemented. A user makes use of the CFD service through a Web page without knowing the exact implementation of the service. In this way, a user's computing environment can be extended to a heterogeneous distributed computing environment. Performance evaluation shows that the overhead to invoke the CFD Web service generated by WSOWG using Simple Object Access Protocol (SOAP) and CORBA Internet Inter-ORB Protocol (IIOP) is reasonable compared with that of invoking another CFD Web service manually wrapped from the CFD legacy code using SOAP only.
14345064
A Wrapper Generator for Wrapping High Performance Legacy Codes as Java/CORBA Components
This paper describes a Wrapper Generator for wrapping high performance legacy codes as Java/CORBA components for use in a distributed component-based problem- solving environment. Using the Wrapper Generator we ave automatically wrapped an MPI-based legacycode as a single CORBA object, and implemented a problem- solving environment for molecular dynamic simulations. Performance comparisons between runs of the CORBA object and the original legacy code on a cluster of workstations and on a parallel computer are also presented.
905924
Resource Monitoring with Globus Toolkit 4
The past few years have seen the Grid rapidly evolving towards a service-oriented computing infrastructure. With the OGSA facilitating this evolution, it is expected that WSRF will be acting as the main an enabling technology to drive the Grid further. Resource monitoring plays a critical role in managing a large-scale Grid system. This paper presents GREMO, a lightweight resource monitor developed with Globus Toolkit 4 (GT4) for monitoring CPU and memory of computing nodes in a Windows and Linux environments.
5393650
PaDDMAS: parallel and distributed data mining application suite
Discovering complex associations, anomalies and patterns in distributed data sets is gaining popularity in a range of scientific, medical and business applications. Various algorithms are employed to perform data analysis within a domain, and range from statistical to machine learning and AI based techniques. Several issues need to be addressed however to scale such approaches to large data sets, particularly when these are applied to data distributed at various sites. As new analysis techniques are identified, the core tool set must enable easy integration of such analytical components. Similarly, results from an analysis engines must be sharable, to enable storage, visualisation or further analysis of results. We describe the architecture of PaDDMAS, a component based system for developing distributed data mining applications. PaDDMAS provides a tool set for combining pre-developed or custom components using a dataflow approach, with components performing analysis, data extraction or data management and translation. Each component is wrapped as a Java/CORBA object, and has an interface defined in XML. Components can be serial or parallel objects, and may be binary or contain a more complex internal structure. We demonstrate a prototype using a neural network analysis algorithm.
16993770
Service matchmaking with rough sets
With the wide adoption of open grid services architecture (OGSA) and Web services resource framework (WSRF), the grid is emerging as a service-oriented computing infrastructure for engineers and scientists to solve data and computationally intensive problems. It is envisioned that computing resources in a future grid environment will be exposed as services. Service discovery becomes an issue of vital importance for a wider uptake of the grid. This paper presents RSSM, a rough sets based service matchmaking algorithm for service discovery with an aim to tolerate uncertainty in identifying service properties. The evaluation results show that the RSSM algorithm is more effective in service discovery compared with other mechanisms such as UDDI and OWLS.
979117
The software architecture of a distributed problem-solving environment
This paper describes the functionality and software architecture of a generic problem-solving environment (PSE) for collaborative computational science and engineering. A PSE is designed to provide transparent access to heterogeneous distributed computing resources, and is intended to enhance research productivity by making it easier to construct, run, and analyze the results of computer simulations. Although implementation details are not discussed in depth, the role of software technologies such as CORBA, Java, and XML is outlined. An XML-based component model is presented. The main features of a Visual Component Composition Environment for software development, and an Intelligent Resource Management System for scheduling components, are described. Some prototype implementations of PSE applications are also presented. Copyright 2000 John Wiley & Sons, Ltd.
4784687
SERF: ODMG-based generic re-structuring facility
The age of information management and with it the advent of increasingly sophisticated technologies have kindled a need in the database community and others to re-structure existing systems and move forward to make use of these new technologies. Legacy application systems are being transformed to newer state-of-the-art systems, information sources are being mapped from one data model to another, a diversity of data sources are being transformed to load, cleanse and consolidate data into modern data-warehouses [CR99].
Re-structuring is thus a critical task for a variety of applications. For this reason, most object-oriented database systems (OODB) today support some form of re-structuring support [Tec94, Obj93, BKKK87]. This existing support of current OODBs [BKKK87, Tec94, Obj93] is limited to a pre-defined taxonomy of simple fixed-semantic schema evolution operations. However, such simple changes, typically to individual types only, are not sufficient for many advanced applications [Bré96]. More radical changes, such as combining two types of redefining the relationship between two types, are either very difficult or even impossible to achieve with current commercial database technology [Tec94, Obj93]. In fact, most OODBs would typically require the user to write ad-hoc programs to accomplish such transformations. Research that has begun to look into the issue of complex changes [Bré96, Ler96] is still limited by providing a fixed set of some selected (even if now more complex) operations.
To address these limitations of the current restructuring technology, we have proposed the SERF framework which aims at providing a rich environment for doing complex user-defined transformations flexibly, easily and correctly [CJR98b]. The goal of our work is to increase the usability and utility of the SERF framework and its applicability to re-structuring problems beyond OODB evolution. Towards that end, we provide re-usable transformations via the notion of SERF Templates that can be packaged into libraries, thereby increasing the portability of these transformations. We also now have a first cut at providing an assurance of consistency for the users of this system, a semantic optimizer that provides some performance improvements via enhanced query optimization techniques with emphasis on the re-structuring primitives [CNR99]. In this demo we give an overview of the SERF framework, its current status and the enhancements that are planned for the future. We also present an example of the application of SERF to a domain other than schema evolution, i.e., the web restructuring.
12850359
Recognition of operator motions for real-time assistance using virtual fixtures
Hidden Markov Models (HMMs) are used for automatic segmentation and recognition of user motions. A new algorithm for real-time HMM recognition was developed. The segmentation results are used to provide appropriate assistance in a combined curve following and object avoidance task. This assistance takes the form of a virtual fixture, whose compliance can be altered online. Recognition and assistance experiments were performed using force and position data recorded from a cooperative manipulation system, where a robot and a human operator hold an instrument simultaneously. Recognition accuracy exceeds 90%, even when the users training the HMMs differ from those executing the task. For a task consisting of both path following and avoidance motions, an HMM-based virtual fixture switches the compliance from low to high when the user is trying to move away from the path. The HMM method improves operator performance in comparison with a constant virtual fixture and no virtual fixture.
53306617
Human-Machine Collaborative Systems for Microsurgical Applications
Human-machine collaborative systems (HMCSs) are systems that amplify or assist human capabilities during the performance of tasks that require both human judgment and robotic precision. We examine the design and performance of HMCSs in the context of microsurgical procedures such as vitreo-retinal eye surgery. Three specific problems considered are: (1) development of systems tools for describing and implementing HMCSs, (2) segmentation of complex tasks into logical components given sensor traces of human task execution, and (3) measurement and evaluation of HMCS performance. These components can be integrated into a complete workstation with the ability to automatically “parse” traces of user activities into task models, which are loaded into an execution environment to provide the user with assistance using on-line recognition of task states. The major contributions of this work include an XML task graph modeling framework and execution engine, an algorithm for real-time segmentation of user actions using continuous hidden Markov models, and validation techniques for analyzing the performance of HMCSs.
17270817
Grid Computing in China
Abstract
Grid computing presents a new trend to distributed computation and Internet applications, which can construct a virtual single image of heterogeneous resources, provide uniform application interface and integrate widespread computational resources into super, ubiquitous and transparent aggregation. In the adoption of Grid computing, China, who is facing more resource heterogeneity and other specific demands, has put much effort on both research and practical utilization. In this paper, we introduce the major China Grid research projects and their perspective applications. First we give the overview of the four government-sponsored programs in Grid, namely the China National Grid, ChinaGrid, NSFC Grid, and ShanghaiGrid. Then we present six representative ongoing Grid systems in details, which are categorized into Grid middleware and Grid application. This paper provides the general picture of Grid computing in China, and shows the great efforts, devotion and confidence in China to use Grid technology to boost the society, economics and scientific research.

14317372
Construct piecewise Hermite interpolation surface with blending methods
Three methods are proposed to construct a piecewise Hermite interpolation surface (PHIS), which is a piecewise algebraic surface interpolating a set of given points with associated normal directions. The surface is obtained by blending together some low-degree surface patches. Both the first and the second methods are completely local and give a surface with G/sup n/-continuity. In the third construction, we reduce the number of surface patches by joining as many cubic patches as possible. This method gives a global solution with G/sup 1/-continuity. These three different methods can be used to meet different requirements of the designers.