FORMI: Integrating Adaptive Fragmented Objects into Java RMI

Distributed object-oriented applications are commonly implemented atop middleware platforms such as CORBA, .NET Remoting, and Java remote method invocation (RMI). These platforms provide a simple mechanism to invoke methods of remote objects. Increasingly more applications are demanding nonfunctional properties such as fault tolerance, high availability, and adaptivity, which require extensions to distributed objects' basic interaction model. A fragmented-object model, such as the one Marc Shapiro proposed, can provide the required flexibility. It's far more generic and flexible than the traditional client-server approach. A fragmented object is a truly distributed object; it consists of multiple fragments located on multiple nodes. Such a model allows arbitrary partitioning of state and functionality on these fragments, and arbitrary internal interaction between fragments of a single object. We have investigated integrating a fragmented-object model into CORBA (AspectIX), which requires internal modifications to the CORBA object request broker. Our approach for transparently integrating fault-tolerant objects into .NET Remoting is also useful for seamlessly integrating fragmented objects. Our FORMI architecture integrates fragmented objects into Java RMI without requiring internal modifications to the RMI runtime     

The Signal Passing Interface and Its Application to Embedded Implementation of Smart Camera Applications

Embedded smart camera systems comprise computation- and resource-hungry applications implemented on small, complex but resource-hardy platforms. Efficient implementation of such applications can benefit significantly from parallelization. However, communication between different processing units is a nontrivial task. In addition, new and emerging distributed smart cameras require efficient methods of communication for optimized distributed implementations. In this paper, a novel communication interface, called the signal passing interface (SPI), is presented that attempts to overcome this challenge by integrating relevant properties of two different, yet important, paradigms in this context—dataflow and message passing interface (MPI). Dataflow is a widely used modeling paradigm for signal processing applications, while MPI is an established communication interface in the general-purpose processor community. SPI is targeted toward computation-intensive signal processing applications, and due to its careful specialization, more performance-efficient for embedded implementation in this domain. SPI is also much easier and more intuitive to use. In this paper, successful application of this communication interface to two smart camera applications has been presented in detail to validate a new methodology for efficient distributed implementation for this domain.      

Extending the IEEE 802.1 MAC Bridge standard to remote bridges

The IEEE 802.1 MAC Bridge specification describes transparent local bridges, called spanning tree bridges, that interconnect 802-type local area networks (LANs). The author discusses experience with adapting the spanning tree algorithm to the remote bridge environment, including the addition of a distributed algorithm for utilizing backbone networks while they are configured as backup paths by the spanning tree. This results in local and remote bridge configurations that automatically detect and recover from all failures/restorals in a deterministic way. Once the support of the same spanning tree algorithm is pervasive, it is also possible to add distributed algorithms that allow spanning tree backup paths to be utilized     

Study of key technology for reconfigurable satellite platform supporting network interconnection

Reconfigurable satellite platform is a new spacecraft design concept.The application of distributed computing in reconfigurable integrated satellite platform was studied,the standard mechanical interface,electrical interface for the separation or separation between main platform and a variety of payloads to form a new combination and achieve the expansion of platform functions and efficient use was proposed.Including the security control protocol,scalable design,distributed computing and management models and other aspects of a detailed design,the key technologies of reconfigurable integrated satellite platforms supporting network interconnection were studied to meet the existing communications,remote sensing and navigation satellites’ needs.It will be promoted for the spacecraft design to the integrated business and in the orbit reconfiguration direction of continuous development,which will enhance the stability of the orbit operation,survivability and maintainability and provide a reliable technical foundation for the world of integrated network research.     

Distributed resource management and connection control for a multi-access interface to a broadband ISDN (BISDN)

A customer premises network (CPN) provides a common communications fabric to efficiently integrate the traffic of multiple terminals on a common access interface to a BISDN. An important consideration in choosing a CPN architecture is to facilitate terminal portability and application transparency, so as to accommodate standard broadband terminals and applications, requiring only minor modification to adapt them from the standard BISDN interface to the multi-terminal environment. This paper explores the multi-faceted issues of CPN transparency with an emphasis on the evolving BISDN control and management architecture. We introduce a control architecture that conforms to a rigorous separation between ‘call control’ and ‘connection management’. This allows the CPN to be transparent to the user to network signalling exchange, and to participate only in the connection management via a remote resource management protocol. More generally, this scheme allows a call control entity located in a local exchange node (LEN) to manage a distributed set of resources such as switches and multiplexors (and CPNs). This is achieved through the definition of a standard interoperable interface between the central call control entity and the connection control entities which may be remotely located in various network elements. The features and functionality for such an interface, which we term the bearer connection control interface, are described within the framework of the OSI remote management architecture. A standard remote resource management protocol allows for the co-operative sharing of resources across administrative domains. Although the importance of such a scheme is particularly visible as applied to remote CPN management, it is useful in other application domains where it is advantageous to distribute management processes.     

基于CORBA的分布式多神经元群测量方法

神经科学是非常复杂的系统科学,它的研究涉及到大数据量的计算和分析,少量电脑往往很难完成这样复杂的计算分析任务,在处理效率上也难以满足科研需要.所以,在研究过程中,运用分带式方法是非常必要的.CORBA是目前比较流行的分布式技术之一,随着技术的不断成熟,应用范围越来越广.另外,运用CORBA技术搭建分布式框架具有许多优势...     

Developing next-generation distributed applications with QoSenabled DPE middleware

This article describes how recent advances in distributed object computing middleware are enabling the creation of common quality-of-service capabilities that support next-generation distributed applications. DOC middleware helps to simplify and coordinate applications in order to leverage the underlying network and end-system QoS architectures more effectively. This article also describes a QoS-enabled middleware framework used to customize the CORBA audio/video streaming service for applications on multiple operating system platforms     

Improving the Performance of Hyperspectral Image and Signal Processing Algorithms Using Parallel,Distributed and Specialized Hardware-Based Systems

Advances in sensor technology are revolutionizing the way remotely sensed data is collected, managed and analyzed. The incorporation of latest-generation sensors to airborne and satellite platforms is currently producing a nearly continual stream of high-dimensional data, and this explosion in the amount of collected information has rapidly created new processing challenges. For instance, hyperspectral signal processing is a new technique in remote sensing that generates hundreds of spectral bands at different wavelength channels for the same area on the surface of the Earth. Many current and future applications of remote sensing in Earth science, space science, and soon in exploration science will require (near) real-time processing capabilities. In recent years, several efforts have been directed towards the incorporation of high-performance computing (HPC) systems and architectures in remote sensing missions. With the aim of providing an overview of current and new trends in parallel and distributed systems for remote sensing applications, this paper explores three HPC-based paradigms for efficient implementation of the Pixel Purity Index (PPI) algorithm, available from the popular Kodak’s Research Systems ENVI software package, as a representative case study for demonstration purposes. Several different parallel programming techniques are used to improve the performance of the PPI on a variety of parallel platforms, including a set of message passing interface (MPI)-based implementations on a massively parallel Beowulf cluster at NASA’s Goddard Space Flight Center in Maryland and on a variety of heterogeneous networks of workstations at University of Maryland; a Handel-C implementation of the algorithm on a Virtex-II field programmable gate array (FPGA); and a compute unified device architecture (CUDA)-based implementation on graphical processing units (GPUs) of NVidia. Combined, these parts deliver an excellent snapshot of the state-of-the-art in those areas, and offer a thoughtful perspective on the potential and emerging challenges of adapting HPC systems to remote sensing problems.     

Client and legacy integration in object oriented Web engineering

To be successful, e-commerce and Web information systems depend on systematic analysis and design processes. Even more important, our method is based on standard techniques like UML, XML, and Corba. It also allows for the integration of different kinds of clients from Java over HTML to WAP into a distributed environment. Through the smooth integration of highly heterogeneous legacy software and databases, our object oriented Web design provides techniques to achieve this goal     

SPEECH‐MAC: Special purpose energy‐efficient contention‐based hybrid MAC protocol for WSN and Zigbee network

Energy‐efficient Zigbee‐based wireless sensor network (WSN) occupies a major role in emergency‐based applications. The foremost drawback of such applications is maintaining the battery power because frequent changing is not possible in those conditions. In the earlier days, several researches created new model MAC protocols in terms of increase the lifetime of the WSN. But still, there is a research gap particularly in emergency applications. In order to improve the lifetime of such applications, we introduced a novel hybrid MAC protocol, namely, special purpose energy‐efficient contention‐based hybrid MAC (SPEECH‐MAC) protocol. This protocol includes dual hop concept considerably to save the energy. Both the single hop network and the dual hop networks are developed, and the results are analyzed. Prioritization mechanism for SPEECH‐MAC protocol is introduced to analyze the emergency conditions in detail. In summary, according to the simulation, the calculated parameters are total residual energy, end‐to‐end delay, packet drop, packet delivery ratio, and network throughput.     

Authenticated key agreement scheme for fog-driven IoT healthcare system

The convergence of cloud computing and Internet of Things (IoT) is partially due to the pragmatic need for delivering extended services to a broader user base in diverse situations. However, cloud computing has its limitation for applications requiring low-latency and high mobility, particularly in adversarial settings (e.g. battlefields). To some extent, such limitations can be mitigated in a fog computing paradigm since the latter bridges the gap between remote cloud data center and the end devices (via some fog nodes). However, fog nodes are often deployed in remote and unprotected places. This necessitates the design of security solutions for a fog-based environment. In this paper, we investigate the fog-driven IoT healthcare system, focusing only on authentication and key agreement. Specifically, we propose a three-party authenticated key agreement protocol from bilinear pairings. We introduce the security model and present the formal security proof, as well as security analysis against common attacks. We then evaluate its performance, in terms of communication and computation costs.

     

基于CORBA的应用级容错系统的设计与实现

CORBA是一种当前流行的基于对象技术的中间件平台，它对应用屏蔽了分布式系统的异构性。但是目前的CORBA产品大多缺乏客错机制，而客错机制是分布式应用的关键问题之一。针对已有研究的缺陷和不足，文章设计并实现了一种新颖的应用级容错CORBA系统，采用对象复制技术和热备份技术来对抗服务对象失效，并有效保证了CORBA良好的互操作性。     

A Distributed Framework for Parallel Data Mining Using HPJava

Java has become a language of choice for applications executing in heterogeneous environments utilising distributed objects and multithreading. To handle large data sets, scalable and efficient implementations of data mining approaches are required, generally employing computationally intensive algorithms. Conventional Java implementations do not directly provide support for the data structures often encountered in such algorithms, and they also lack repeatability in numerical precision across platforms. This paper describes a distributed framework employing task and data parallelism, and implemented in high performance Java (HPJava). Issues of interest for data mining algorithms are identified, and possible solutions discussed for overcoming limitations in the Java Virtual Machine. The framework supports parallelism across workstation clusters, using the message-passing interface as middleware, and can support different analysis algorithms, wrapped as Java objects, and linked to various databases using the Java database connectivity interface. Guidelines are provided for implementing parallel and distributed data mining on large data sets, and a proof-of-concept data mining application is analysed using a neural network.     

Reliable Anchor-Based Sensor Localization in Irregular Areas

Localization is a fundamental problem in wireless sensor networks and its accuracy impacts the efficiency of location-aware protocols and applications, such as routing and storage. Most previous localization algorithms assume that sensors are distributed in regular areas without holes or obstacles, which often does not reflect real-world conditions, especially for outdoor deployment of wireless sensor networks. In this paper, we propose a novel scheme called Reliable Anchor-based Localization (RAL), which can greatly reduce the localization error due to the irregular deployment areas. We first provide theoretical analysis of the minimum hop length for uniformly distributed networks and then show its close approximation to empirical results, which can assist in the construction of a reliable minimal hop-length table offline. Using this table, we are able to tell whether a path is severely detoured and compute a more accurate average hop length as the basis for distance estimation. At runtime, the RAL scheme 1) utilizes the reliable minimal hop length from the table as the threshold to differentiate between reliable anchors and unreliable ones, and 2) allows each sensor to determine its position utilizing only distance constraints obtained from reliable anchors. The simulation results show that RAL can effectively filter out unreliable anchors and therefore improve the localization accuracy.     

J-CAR: An efficient joint channel assignment and routing protocol for IEEE 802.11-based multi-channel multi-interface mobile Ad Hoc networks

The capacity of an IEEE 802.11-based multi-hop wireless network is limited. By effectively utilizing multiple non-overlapping channels and multiple interfaces, collision and co-channel interference can be reduced. This allows more concurrent transmissions and thus enhances the network capacity. In this paper, we introduce an efficient distributed joint channel assignment and routing protocol, called J-CAR¹. Unlike existing schemes, J-CAR allows a data interface to dynamically change its working mode between send and receive on a call-by-call basis, which enhances the utilization of both interface and channel. In J-CAR, channels are negotiated and assigned to active links in conjunction with the on-demand routing process. At each hop, J-CAR conducts a local optimization by selecting the least interfered channel according to the channel interference index. The channel interference index is designed by taking both the protocol and physical interference models into consideration. To find the least interfered path for network load balancing on a global scale, J-CAR employs a length-constrained widest-path routing. The “width” of a path is determined by the interference level of its bottleneck link. With an adjustable threshold on the path length (with respect to the shortest-path), the excessively long path can also be avoided. We show that with a comparable complexity as the existing schemes, J-CAR provides much higher system goodputs and shorter end-to-end packet delays.     

基于Web的通信电源远程监控系统的设计与研究

随着基于Web的嵌入式技术的出现、发展和不断完善,嵌入式设备可以直接接入Internet通过Web进行监控,文中利用动态交换技术和TCP/IP技术,集成了Web对象技术和分布式对象技术,通过OPC接口和ActiveX控件实现通信电源远程监控。     

Service-Oriented Architecture for Distributed Publish/Subscribe Middleware in Electronics Production

The Computer Aided Manufacturing using XML (CAMX) framework enables integrating electronics production systems using message-oriented middleware, offering standards-based communication among machines and control software applications. CAMX frameworks implement publish/subscribe of XML messages through an entity called the message broker (MSB), which provides the messaging service using a web-based interface. A challenge for MSB-based systems is that they must scale to handle large volumes of messaging traffic, which is a characteristic of modern information-intensive manufacturing systems. This paper first tackles this challenge by presenting an array of architecture patterns for creating distributed MSB frameworks, focusing mainly on globally distributed federations and locally distributed clusters. A unified architecture is subsequently presented that leverages the different patterns by combining federated frameworks with locally distributed clusters into a unified set of architecture elements and interactions. A service-oriented approach is followed to provide a uniform interface for distributed MSB elements, whether federated or locally distributed. The service-oriented approach is also used to dynamically discover resources and automatically invoke the (re)configuration and messaging services. The services are enriched with semantics in order to facilitate automatic discovery and selection of services using the semantic web services formal ontology. Semantic service advertisements are propagated using a peer-to-peer discovery protocol. The approach presented in this paper is not limited to the CAMX case and is generally applicable to distributed event-based manufacturing systems     

Private computing on public platforms: portable application security

As cellular telephones and high capacity memory sticks emerge as users' primary repository for data and applications, users will often run applications and display data on remote hosts. The biggest challenge in supporting this mobile data, mobile applications, stationary platform model is ensuring the security and privacy of user applications and data during execution on the remote platforms. Private computing on public platforms (PCPP) is a new application security approach which isolates applications to allow for secure and private execution on third party systems. This paper introduces PCPP and details its five basic building blocks which together ensure that the PCPP protected application's executable code, context, and data remain unaltered, unmonitored, and unrecorded before, during, and after exposure to the remote platform. Copyright © 2009 John Wiley & Sons, Ltd.     

Internet/Intranet互联环境中的安全认证和密钥分配

本文提出了解决Internet/Intranet互联环境安全性问题的模式,针对不同的Intranet的网络结构,提出了适用的安全模式,设计了相应的认证和密钥分配协议,并考虑了协议在开放系统互联OSI结构的安全管理问题.协议采用分层机制,在低层采用改进的Kerberos协议实现局域网内的认证和密钥分配,而高层的网间认证和密钥分配协议则根据安全模式的不同要求采用单钥体制,或公钥体制来设计。协议能够为Internet的各种远程访问提供安全保护。     

Flow admission control for multi-channel multi-radio wireless networks

Providing Quality of Service (QoS) is a major challenge in wireless networks. In this paper we propose a distributed call admission control protocol (DCAC) to do both bandwidth and delay guaranteed call admission for multihop wireless mesh backbone networks, by exploiting the multi-channel multi-radio (mc-mr) feature. We propose a novel routing metric for route setup, and present an efficient distributed algorithm for link reservation that satisfies the required bandwidth and reduces the delay by a local scheduling that minimizes one hop delay. To the best of our knowledge, this is the first distributed protocol that embeds mc-mr feature in Time Division Medium Access (TDMA) to do QoS call admission in wireless backbone networks. Extensive simulation studies show that our protocol significantly improves network performance on supporting QoS sessions compared with some widely used protocols.