基于Internet的直接网络数据服务的基本概念与技术框架

直接网络数据服务为计算程序提供了一种通过Internet直接访问远程数据的手段 ,它在通讯和计算技术上分别以SOAP协议和Java跨平台计算能力为基础。本文分析了Internet应用技术的现状和发展 ,结合当前数据交换技术和化工数据应用的特点 ,提出了一种新的化工数据应用方法 ,即建立基于Internet的直接网络数据服务的计算模型。实现此计算体系涉及多方面的数据协议和计算技术 ,其中最重要的思想是通过构建一个易用的数据规范框架 ,以简化整个体系的用户使用界面 (包括编程接口和访问语法 )。该框架定义了数据的描述规范、存储规范、查询规范、传输规范和使用规范。该计算模型主要包括 3个部分 ,即服务器端的数据库模型、基于SOAP的数据传输模型和客户端的应用编程接口。该系统以远程程序为数据消费对象 ,最终将实现对数据库透明的访问能力和可扩充的分布服务能力。在此基础上 ,可以进一步发展为分布式计算服务体系     

Human-assistance robotic system based on distributed computing technology

Population aging is becoming an increasingly pressing problem for society. Thus, the timely development of supporting systems to improve care cost and the quality of life of the elderly is becoming particularly important. Because of the dispersal of the elderly and disabled, a standard software architecture that can implement network-distributed software sharing and improve the cost of writing and maintaining software is in high demand. This paper proposes using distributing computing technology CORBA to integrate network-distributed software and robotic systems for supporting the aged or disabled. Using CORBA as a communication architecture, we implemented a networkdistributed human-assistance robotic system. We developed a hardware base including a robot arm and an omnidirectional mobile robot, developed key technologies such as localization of a mobile robot, real-time recognition, real-time multimedia, and implemented several CORBA servers including a Web user management server, a task-level robot arm control server, a live image and video feedback server, a mobile robot control server, and an indoor Global Positioning System server. With the user controlling a robot arm with 5 d.o.f. to cooperate with an omnidirectional mobile robot, the developed system can provide basic services to support the aged and disabled.     

Real-Time Multimedia Applications in a Web-Based Robotic Telecare System

In this paper, real-time multimedia applications are integrated into a Web-based robotic telecare system. Using Java media framework (JMF), a video/audio conference system is developed to improve the interaction among caregivers, and switches remote robot manipulating privilege with the help of a centralized management server. This video/audio conference system is established on a similar profile of H.323 multipoint control unit (MCU). Access control is utilized to guarantee confidentiality of telecare users. Different telecare services are provided to meet requirements of various users. The whole telecare system is verified in a campus network.     

Internet-Based Robotic System Using CORBA as Communication Architecture

In this paper, we propose the Internet-based robotic system that uses Common Object Request Broker Architecture (CORBA) to implement networking connections between a client and a remote robotic system. The client can transparently invoke a method on a server across the network without any need to know where the application servers are located, or what programming language and operating system are used. This lets the system overcome the shortcomings of the other typical Internet robotic system. To cope with time delays on the communication path, we have implemented the robot control server, which allows the user to control the telerobotic system at a task-level. We have also implemented the live image feedback server, which provides live image feedback for a remote user. The proposed system gives the users the ability to operate the remote robotic system to retrieve and manipulate the desired tableware or other things to support the aged and disabled over the Internet by using the intuitive user interface.     

Mobile Edge Computing: Opportunities,solutions, and challenges

The emergence of several new computing applications, such as virtual reality and smart environments, has become possible due to availability of large pool of cloud resources and services. However, the delay-sensitive applications pose strict delay requirements that transforms euphoria into a problem. The cloud computing paradigm is unable to meet the requirements of low latency, location awareness, and mobility support. In this context, Mobile Edge Computing (MEC) was introduced to bring the cloud services and resources closer to the user proximity by leveraging the available resources in the edge networks. In this paper, we present the definitions of the MEC given by researchers. Further, motivation of the MEC is highlighted by discussing various applications. We also discuss the opportunities brought by the MEC and some of the important research challenges are highlighted in MEC environment. A brief overview of accepted papers in our Special Issue on MEC is presented. Finally we conclude this paper by highlighting the key points and summarizing the paper.     

The value of handhelds in smart environments

The severe resource restrictions of computer-augmented everyday artifacts imply substantial problems for the design of applications in smart environments. Some of these problems can be overcome by exploiting the resources, I/O interfaces, and computing capabilities of nearby mobile devices in an ad-hoc fashion. We identify the means by which smart objects can make use of handheld devices such as PDAs and mobile phones, and derive the following major roles of handhelds in smart environments: (1) mobile infrastructure access point; (2) user interface; (3) remote sensor; (4) mobile storage medium; (5) remote resource provider; and (6) weak user identifier. We present concrete applications that illustrate these roles, and describe how handhelds can serve as mobile mediators between computer-augmented everyday artifacts, their users, and background infrastructure services. The presented applications include a remote interaction scenario, a smart medicine cabinet, and an inventory monitoring application.     

Robust one-time password authentication scheme using smart card for home network environment

Due to the exponential growth of the Internet users and wireless devices, interests on home networks have been enormously increased in recent days. In digital home networks, home services including remote access and control to home appliances as well as services offered by service providers are alluring. However, the remote control services cause digital home networks to have various security threats. Hence, for digital home networks, robust security services, especially remote user authentication, should be considered. This paper presents a robust and efficient authentication scheme based on strong-password approach to provide secure remote access in digital home network environments. The proposed scheme uses lightweight computation modules including hashed one-time password and hash-chaining technique along with low-cost smart card technology. It aims to satisfy several security requirements including stolen smart card attack and forward secrecy with lost smart card as well as functional requirements including no verification table and no time synchronization. Comparing with the existing representative schemes, it can be validated that the proposed scheme is more robust authentication mechanism having better security properties. We have conducted formal verification of the proposed scheme.     

Distributed Telerobotics System Based on Common Object Request Broker Architecture

This paper proposes using CORBA as communication architecture to integrate network-distributed software and robotic systems in support systems for the aged or disabled. The proposed method keeps system costs low and expands availability. Its high scaling and inter-operating ability allows clients and server objects that are written in different languages, run in different operating systems, and connected to different networks to inter-operate. It also enables the system to be extended and integrated with other technologies and applications distributed over the Internet. Based on CORBA, we developed hardware base including a robot arm and an omnidirectional mobile robot and application servers including a task-level robot arm control server, live feedback image server, mobile robot control server and iGPS server. By remotely controlling mobile robot to cooperate with the robot arm, the caregivers or family member can use the developed system for some basic services to the aged or disabled.     

A hybrid positioning system for technology‐independent location‐aware computing

Location‐aware computing is a form of context‐aware mobile computing that refers to the ability of providing users with services that depend on their position. Locating the user terminal, often called positioning, is essential in this form of computing. Towards this aim, several technologies exist, ranging from personal area networking, to indoor, outdoor, and up to geographic area systems. Developers of location‐aware software applications have to face with a number of design choices, that typically depend on the chosen technology. This work addresses the problem of easing the development of pull location‐aware applications, by allowing uniform access to multiple heterogeneous positioning systems. Towards this aim, the paper proposes an approach to structure location‐aware mobile computing systems in a way independent of positioning technologies. The approach consists in structuring the system into a layered architecture, that provides application developers with a standard Java Application Programming Interface (JSR‐179 API), and encapsulates location data management and technology‐specific positioning subsystems into lower layers with clear interfaces. In order to demonstrate the proposed approach we present the development of HyLocSys. It is an open hybrid software architecture designed to support indoor/outdoor applications, which allows the uniform (combined or separate) use of several positioning technologies. HyLocSys uses a hybrid data model, which allows the integration of different location information representations (using symbolic and geometric coordinates). Moreover, it allows support to handset‐ and infrastructure‐based positioning approaches while respecting the privacy of the user. The paper presents a prototypal implementation of HyLocSys for heterogeneous scenarios. It has been implemented and tested on several platforms and mobile devices. Copyright © 2009 John Wiley & Sons, Ltd.     

基于CCM的构件组装技术的研究与应用

随着计算机网络技术的应用发展,分布式构件技术成为分布式计算领域的热点,CCM就是主流的分布式构件技术之一。分析了CORBA构件模型（CCM）的特点：即通过端口定义构件对外提供的功能、通过端口定义构件所需要的外部功能,构件通过端口进行组装。在产品生命周期管理（PLM）中的供应链管理系统（SCM）中充分应用了CCM及其端口组装方法,实现在分布式环境下软件构件的即插即用功能,使SCM系统具有良好的可移植性和平台无关性。     

基于Web Services应用集成技术的研究及实现

将现存的中间件技术如CORBA与新兴的Web服务实现互操作,可实现新的、增值的服务。文中阐述了如何将CORBA对象发布为Web服务以及Web客户如何能在不改变原有程序模式的情况下访问CORBA服务。     

Bayanihan: building and studying web-based volunteer computing systems using Java

Project Bayanihan is developing the idea of volunteer computing, which seeks to enable people to form very large parallel computing networks very quickly by using ubiquitous and easy-to-use technologies such as web browsers and Java. By utilizing Java’s object-oriented features, we have built a flexible software framework that makes it easy for programmers to write different volunteer computing applications, while allowing researchers to study and develop the underlying mechanisms behind them. In this paper, we show how we have used this framework to write master-worker style applications, and to develop approaches to the problems of programming interface, adaptive parallelism, fault-tolerance, computational security, scalability, and user interface design.     

Wireless network extension using mobile IP

Over the last two decades, we have seen a dramatic shift in computing systems, away from the monolithic mainframe and toward increasingly distributed, client-server systems. One of the key elements enabling the success of the distributed computing environment was the interconnecting network technology. High-speed, reliable network hardware and protocols evolved to support client-server applications. Network technology has now progressed to the point that applications are being written to specifically exploit the capabilities of the network. The explosion of World Wide Web applications is the latest example of the fact that the network is now the focus of the distributed computing environment. In a concurrent development, personal computing platforms placed increasingly powerful systems in ever smaller form factors. Users have embraced these advances: Mobile computers, in the form of laptops, palmtops, and personal digital assistants (PDAs), are a significant element of the current computing environment. However, to be fully productive, the mobile computer user requires access to the network. Further, access to a network is not sufficient. Mobile users need access to the same network-the same resources and services and communications capabilities-that they would if they were at their desktops. We refer to this concept of providing home network access to the mobile user as network extension. Addressing many requirements for practical wireless access, this Internet technology aids the development of advanced data services for wireless networks, including the integrated dispatch enhanced network     

CORBA/SOAP互操作技术的研究及实现

将现存的中间件技术如CORBA与新兴的Web服务实现互操作可实现新的、增值的服务。其中需要解决的两个关键技术就是如何自动高效地将CORBA对象的IDL描述转换为Web服务的WSDL描述以及Web客户如何能在不改变原有程序模式的情况下访问CORBA服务。对这两个关键技术进行了研究和实现。     

The Weka4WS framework for distributed data mining in service‐oriented Grids

The service‐oriented architecture paradigm can be exploited for the implementation of data and knowledge‐based applications in distributed environments. The Web services resource framework (WSRF) has recently emerged as the standard for the implementation of Grid services and applications. WSRF can be exploited for developing high‐level services for distributed data mining applications. This paper describes Weka4WS, a framework that extends the widely used open source Weka toolkit to support distributed data mining on WSRF‐enabled Grids. Weka4WS adopts the WSRF technology for running remote data mining algorithms and managing distributed computations. The Weka4WS user interface supports the execution of both local and remote data mining tasks. On every computing node, a WSRF‐compliant Web service is used to expose all the data mining algorithms provided by the Weka library. The paper describes the design and implementation of Weka4WS using the WSRF libraries and services provided by Globus Toolkit 4. A performance analysis of Weka4WS for executing distributed data mining tasks in different network scenarios is presented. Copyright © 2008 John Wiley & Sons, Ltd.     

Ada and real-time robotics: lessons learned

The Supervisory Telerobotics Laboratory (Steler) at the Jet Propulsion Laboratory (JPL) has developed a prototype telerobotic system to demonstrate the type of technology that will be used aboard Space Station Freedom Although the concept of telerobotics for space exploration is not new, the Steler system broke new ground in its demonstration of the feasibility of a local-remote architecture, including ground-remote control, for space applications. A remote space environment poses some interesting computational challenges to ground-remote control of space applications. A remote site has limited computation facilities, is burdened by minimal bandwidth and by round-trip communication delays of as much as 8 seconds, and yet is expected to respond quickly, predictably, and with recoverability to any anomalous situation. Additional design constraints are imposed by NASA's limitations on software, including on-board programs for the robot, being uploaded to the remote site without prior flight qualification. The authors discuss the use of Ada to meet the computational requirements of this project     

A security evaluation framework for cloud security auditing

Cloud computing is clearly one of today’s most enticing technologies due to its scalable, flexible, and cost-efficient access to infrastructure and application services. Despite these benefits, cloud service users (CSUs) have serious concerns about the data security and privacy. Currently, there are several cloud service providers (CSPs) offering a wide range of services to their customers with varying levels of security strengths. Due to the vast diversity in the available cloud services, from the customer’s perspective, it has become difficult to decide which CSP they should use and what should be the selection criteria. Presently, there is no framework that can allow CSUs to evaluate CSPs based on their ability to meet the customer’s security requirements. We propose a framework and a mechanism that evaluate the security strength of CSPs based on the customer’s security preferences. We have shown the applicability of our security evaluation framework using a case study.     

The implementation and evaluation of the use of CORBA in an engineering design application

Many computer applications today require some form of distributed computing to allow different software components to communicate. Several different commercial products now exist based on the Common Object Request Broker Architecture (CORBA) of the Object Management Group. The use of such tools, however, often requires the modification of existing systems, rather than the development of new applications. The objective of this research has been to integrate the use of a CORBA tool into an existing engineering design application for the purpose of (1) evaluating the amount of re‐engineering that is involved to effectively integrate distributed object computing into an existing application, and (2) evaluating the use and performance of distributed object computing in an engineering domain, which often requires the transfer of large amounts of information. The results of this work demonstrate that CORBA technology can be easily integrated into existing applications. The ease of the integration as well as the efficiency of the resulting system, however, depends upon the degree of modification that developers are willing to consider in the re‐engineering process. The most transparent approach to the use of CORBA requires less modification and generally produces less efficient performance. The less transparent approach to the use of CORBA can potentially require significant system modification but produce greater performance gains. This work outlines issues that must be considered for the partitioning of functionality between the client and the server, development of an IDL interface, development of client and server‐side wrappers, and support for concurrent, multi‐user access. In addition, this work also provides performance and implementation comparisons of different techniques for the use of wrappers and for the transfer of large data files between the client and the server. Performance comparisons for the incorporation of concurrent access are also presented. Copyright © 1999 John Wiley & Sons, Ltd.     

A model-based authorware for the construction of distributed multimedia systems

Distributed multimedia systems typically involve a sophisticated user interaction. Further, objects are allocated on physically distributed computing systems, and multimedia data must be transferred across heterogeneous networks in a timely manner. These systems often have complex requirements on a user interaction, quality of service and temporal order among media streams. The design and implementation of these requirements are inherently complex and present an extraordinary design and programming challenge. Generally, these complex requirements cannot be adequately captured using a single model or a design notation. The challenge amounts to (i) identification of multiple, often orthogonal models, each capturing a specific aspect of the requirements, and (ii) provision of an authorware that supports the composition of these models. In this paper, we propose to capture the multimedia requirements in three different models: configuration, user control and presentation, and demonstrate how the composition of these models can be supported by an authorware using the Java and CORBA technologies. The concepts are illustrated using a real-life example based on a virtual city tour application that features distributed controls, collaborative work and multimedia presentations. Various distributed multimedia applications like video phone, video conferencing and distributed presentation have been successfully constructed using the proposed multiple models and authorware. The results are encouraging and the approach can shorten the development of multimedia applications considerably.     

Contract RBAC in cloud computing

Cloud computing is a fast growing field, which is arguably a new computing paradigm. In cloud computing, computing resources are provided as services over the Internet and users can access resources based on their payments. The issue of access control is an important security scheme in the cloud computing. In this paper, a Contract RBAC model with continuous services for user to access various source services provided by different providers is proposed. The Contract RBAC model extending from the well-known RBAC model in cloud computing is shown. The extending definitions in the model could increase the ability to meet new challenges. The Contract RBAC model can provide continuous services with more flexible management in security to meet the application requirements including Intra-cross cloud service and Inter-cross cloud service. Finally, the performance analyses between the traditional manner and the scheme are given. Therefore, the proposed Contract RBAC model can achieve more efficient management for cloud computing environments.