Mobile agent-enabled framework for structuring and building distributed systems on the internet

Mobile agent has shown its promise as a powerful means to complement and enhance existing technology in various application areas. In particular, existing work has demonstrated that MA can simplify the development and improve the performance of certain classes of distributed applications, especially for those running on a wide-area, heterogeneous, and dynamic networking environment like the Internet. In our previous work, we extended the application of MA to the design of distributed control functions, which require the maintenance of logical relationship among and/or coordination of proc- essing entities in a distributed system. A novel framework is presented for structuring and building distributed systems, which use cooperating mobile agents as an aid to carry out coordination and cooperation tasks in distributed systems. The framework has been used for designing various distributed control functions such as load balancing and mutual ex- clusion in our previous work. In this paper, we use the framework to propose a novel ap- proach to detecting deadlocks in distributed system by using mobile agents, which dem- onstrates the advantage of being adaptive and flexible of mobile agents. We first describe the MAEDD (Mobile Agent Enabled Deadlock Detection) scheme, in which mobile agents are dispatched to collect and analyze deadlock information distributed across the network sites and, based on the analysis, to detect and resolve deadlocks. Then the design of an adaptive hybrid algorithm derived from the framework is presented. The algorithm can dynamically adapt itself to the changes in system state by using different deadlock detec- tion strategies. The performance of the proposed algorithm has been evaluated using simulations. The results show that the algorithm can outperform existing algorithms that use a fixed deadlock detection strategy.     

目标码动态测试框架的设计及实现

在提出了一种支持多种测试数据构造方式,具有异常监测及自动化分析模块的目标码动态测试框架。并按照该框架实现了对文件格式处理软件的安全性进行测试的原型系统DT,该系统实现了执行参数输入和缺陷注入两种测试方法。为了验证系统的有效性,以MS Office软件近两年来的公开漏洞为例对DT系统进行了测试,实验结果表明这些漏洞都可以通过测试发现。     

An implementation framework for HPF distributed arrays onmessage-passing parallel computer systems

Data parallel languages, like High Performance Fortran (HPF), support the notion of distributed arrays. However, the implementation of such distributed array structures and their access on message passing computers is not straightforward. This holds especially for distributed arrays that are aligned to each other and given a block-cyclic distribution. In this paper, an implementation framework is presented for HPF distributed arrays on message passing computers. Methods are presented for efficient (in space and time) local index enumeration, local storage, and communication. Techniques for local set enumeration provide the basis for constructing local iteration sets and communication sets. It is shown that both local set enumeration and local storage schemes can be derived from the same equation. Local set enumeration and local storage schemes are shown to be orthogonal, i.e., they can be freely combined. Moreover, for linear access sequences generated by our enumeration methods, the local address calculations can be moved out of the enumeration loop, yielding efficient local memory address generation. The local set enumeration methods are implemented by using a relatively simple general transformation rule for absorbing ownership tests. This transformation rule can be repeatedly applied to absorb multiple ownership tests. Performance figures are presented for local iteration overhead, a simple communication pattern, and storage efficiency     

On building a CNN-based multi-view smart camera for real-time object detection

Multi-view image sensing is currently gaining momentum, fostered by new applications such as autonomous vehicles and self-propelled robots. In this paper, we prototype and evaluate a multi-view smart vision system for object recognition. The system exploits an optimized Multi-View Convolutional Neural Network (MVCNN) in which the processing is distributed among several sensors (heads) and a camera body. The main challenge for designing such a system comes from the computationally expensive workload of real-time MVCNNs which is difficult to support with embedded processing and high frame rates. This paper focuses on the decisions to be taken for distributing an MVCNN on the camera heads, each camera head embedding a Field-Programmable Gate Array (FPGA) for processing images on the stream. In particular, we show that the first layer of the AlexNet network can be processed at the nearest of the sensors, by performing a Direct Hardware Mapping (DHM) using a dataflow model of computation. The feature maps produced by the first layers are merged and processed by a camera central processing node that executes the remaining layers. The proposed system exploits state-of-the-art deep learning optimization methods, such as parameter removing and data quantization. We demonstrate that accuracy drops caused by these optimizations can be compensated by the multi-view nature of the captured information. Experimental results conducted with the AlexNet CNN show that the proposed partitioning and resulting optimizations can fit the first layer of the multi-view network in low-end FPGAs. Among all the tested configurations, we propose 2 setups with an equivalent accuracy compared to the original network on the ModelNet40 dataset. The first one is composed of 4 cameras based on a Cyclone III E120 FPGA to embed the least expensive version in terms of logic resources while the second version requires 2 cameras based on a Cyclone 10 GX220 FPGA. This distributed computing with workload reduction is demonstrated to be a practical solution when building a real-time multi-view smart camera processing several frames per second.     

软件分布式开发中协同工作支持框架的设计与实现

为了有效地支持软件分布式开发,提高软件协同开发环境的易用性和有效性,从协同理论和应用工具两方面入手,在集成了多种协同应用软件的同时,融入了对参与者的形式描述,提高了开发环境的智能性和可定制性,进而提高了协同开发的质量和效率。     

一种分布式系统中线程池的设计与实现

随着网络和分布式计算的日益发展,负载数量迅速增长,如何在大负载情况下保证高效的吞吐率是构建服务器时所面临的问题,目前广泛采用的技术之一是线程池。借鉴Leader／Followers模式,设计并实现了一类高效的线程池,并针对分布式系统环境做了进一步的改进。此方法已经应用到分布事务监控器OnceTX的实现中,并取得了很好的效果。     

A framework of auto-adapting distributed object for mobile computing

The low bandwidth hinders the development of mobile computing.Besides providing relatively higher bandwidth on communication layer,constructing adaptable upper application is important.In this paper,a framework of autoadapting distributed object is proposed,and evaluating methods of object performance are given as well.Bistributed objects can abjust their behaviors automatically in the framework and keep in relatively good performance to serve requests of remote applications.It is an efficient way to implement the performance transparency for mobile clients.     

基于BOM动态测试框架的设计与实现

为基于基本对象模型(BOM)的仿真模型测试提供测试平台,提高模型可靠性,为仿真系统的集成提供可靠的仿真模型,缩短仿真系统集成联试的周期,设计了独立的模型测试平台,在测试平台中提供BOM模型运行所需要的对象管理、数据分发、时间管理等服务,通过仿真模型在平台中的运行结果分析,验证模型接口以及功能。模型测试平台可为各种类型的模型提供仿真运行环境,平台运行效率可达到超实时仿真要求,模型集成效率提高。在大规模作战仿真系统开发中,可推广使用模型测试平台,提高模型可靠性,降低集成成本,缩短集成周期。     

基于智慧校园的党建管理系统的设计与实现

为切实解决党员发展程序不规范、上交材料难、信息不对称及数据统计难等问题,“智慧江财”项目,采用Java WEB的标准开发模式MVC,设计实现了基于智慧校园的党建管理系统。该系统将传统的党建工作与现代化信息技术手段有机融合,实现了线上线下良性互动的党建工作新格局。电脑PC端和手机移动端做到同步使用,集中管理、分散操作,极大地提升了校基层党务管理的工作效率和服务水平。     

A framework for designing ATM management systems by way of abstract information models and distributed object architectures

ATM network management has not yet reached the level of versatility and comprehensiveness exhibited by other aspects of this networking technology. Since the currently dominant general standards for broadband network management, primarily targeted towards large carrier networks, are too complex and intricate for smaller environments, e.g. LANs or corporate networks, ATM equipment manufacturers, in their effort to provide systems that exploit the power of ATM and yet remain practical and simple, usually resort to devising ad hoc proprietary extensions of simpler management frameworks, originally developed for other networking technologies. Such incompatible extensions, however, remain useless in the common case where the network is heterogeneous. The notion of abstract information modeling may be employed for improving on this situation.Building on this concept, the paper proposes a framework for developing ATM management systems intended for heterogeneous small- to medium-size networks. The general guidelines are illustrated through discussing a specific compliant management application intended for the remote monitoring of ATM network platforms and developed in the framework of a European research project. The application features a WWW interface and, as such, provides an example of the compatibility of information abstraction with the Web-based management techniques and of the benefits arising from the combination of the two notions.Lastly, and as the concept of abstracting information is inherent to recent frameworks for designing and programming distributed object systems, the paper explores this relation by discussing an alternative design of the monitoring application as a distributed object system.     

A framework for automated distributed implementation of component-based models

Although distributed systems are widely used nowadays, their implementation and deployment are still time-consuming, error-prone, and hardly predictable tasks. In this paper, we propose a method for producing automatically efficient and correct-by-construction distributed implementations from a model of the application software in Behavior, Interaction, Priority (BIP). BIP is a well-founded component-based framework encompassing high-level multi-party interactions for synchronizing components (e.g., rendezvous and broadcast) and dynamic priorities for scheduling between interactions. Our method transforms an arbitrary BIP model into a Send/Receive BIP model that is directly implementable on distributed execution platforms. The transformation consists in (1) breaking the atomicity of actions in components by replacing synchronous multiparty interactions with asynchronous Send/Receive interactions; (2) inserting distributed controllers that coordinate the execution of interactions according to a user-defined partition of interactions, and (3) adding a distributed algorithm for handling conflicts between controllers. The obtained Send/Receive BIP model is proven observationally equivalent to its corresponding initial model. Hence, all functional properties of the initial BIP model are preserved by construction in the implementation. Moreover, the obtained Send/Receive BIP model can be used to automatically derive distributed executable code. The proposed method is fully implemented. Currently, it is possible to generate C++ implementations for (1) TCP sockets for conventional distributed communication, (2) MPI for multi-processor platforms, and (3) POSIX threads for deployment on multi-core platforms. We present four case studies and report experimental results for different design choices including partition of interactions and choice of algorithm for distributed conflict resolution.     

An antibody network inspired evolutionary framework for distributed object computing

In order to meet the increasing scale and users requirements for the distributed object computing (DOC) systems, their infrastructures are highly desirable to be redesigned. Based on the principles of immune system and the evolution mechanisms learned from an antibody network model, a novel evolutionary framework for DOC (E-DOC) is proposed. The antibody network model as well as the evolution process including clonal proliferation, immune elimination, and immune memory is studied. Then, E-DOC framework based on the antibody network is proposed, whose simulation platform is designed and implemented. On the platform, the evolutionary features are studied by: (1) diversity and stability of antibodies and genotypes, (2) detection and elimination of antigens, (3) effect of immune memory, and (4) tendency of eliminated and stimulated antigens. The experiment results show that the proposed framework can achieve the evolution ability and the promising performance, which are critical to DOC systems. E-DOC is extendable for the future design of distributed object middleware, such as WebSphere Application Server and BEA WebLogic Application Server.     

分布式业务网管中安全服务框架的设计与实现

在分布式架构的业务网络管理系统中,保证业务数据在分布式节点间高效、实时和安全传输是系统可靠运行的关键问题之一.针对分布式业务网管对安全服务的具体需求,在分析传统网络管理系统安全解决方案的基础上,综合运用了XML签名与XML加密等多种安全技术,设计并实现了一种安全服务框架.提出了该框架的体系架构,详细介绍了框架的层次结构、功能模块和处理流程,并对框架中的关键模块,给出了详细的解决方案和基于Java技术的实现示例.     

智能相机的设计研究

提出了一种整机采用DSP＋FPGA＋AVR结构，基于低级算法和高级算法相结合的智能相机，设计制作了实验用样机。并用其对钢珠缺陷进行了检测，对该相机的性能进行了较为系统的测试和研究，提出了如何改进结构和算法以提高性能。实验证明该相机的正确识别率较高，相机的设计方案有广泛的适应性，对软件的结构和算法稍作修改即可应用于不同的工作场合。     

智能相机的设计研究

提出了一种整机采用DSP FPGA AVR结构,基于低级算法和高级算法相结合的智能相机,设计制作了实验用样机。并用其对钢珠缺陷进行了检测,对该相机的性能进行了较为系统的测试和研究,提出了如何改进结构和算法以提高性能。实验证明该相机的正确识别率较高,相机的设计方案有广泛的适应性,对软件的结构和算法稍作修改即可应用于不同的工作场合。     

QoS customization in distributed object systems

Applications built on networked collections of computers are increasingly using distributed object platforms such as CORBA,Java Remote Method Invocation (RMI), and DCOM to standardize object interactions. With this increased use comes the increased need for enhanced quality of service (QoS) attributes related to fault tolerance, security, and timeliness. This paper describes an architecture called CQoS (configurable QoS) for implementing such enhancements in a transparent, highly customizable, and portable manner. CQoS consists of two parts: application‐ and platform‐dependent interceptors and generic QoS components. The generic QoS components are implemented using Cactus, a system for building highly configurable protocols and services in distributed systems. The CQoS architecture and the interfaces between the different components are described, together with implementations of QoS attributes using Cactus and interceptors for CORBA and Java RMI. Experimental results are given for a test application executing on a Linux cluster using Cactus/J, the Java implementation of Cactus. Compared with other approaches, CQoS emphasizes portability across different distributed object platforms, while the use of Cactus allows custom combinations of fault‐tolerance, security, and timeliness attributes to be realized on a per‐object basis in a straightforward way. Copyright © 2003 John Wiley & Sons, Ltd.     

Economic power dispatch in smart grids: a framework for distributed optimization and consensus dynamics

By using the distributed consensus theory in multi-agent systems, the strategy of economic power dispatch is studied in a smart grid, where many generation units work cooperatively to achieve an optimal solution in a local area. The relationship between the distributed optimization solution and consensus in multi-agent systems is first revealed in this paper, which can serve as a general framework for future studies of this topic. First, without the constraints of capacity limitations, it is found that the total cost for all the generators in a smart grid can achieve the minimal value if the consensus can be reached for the incremental cost of all the generation units and the balance between the supply and demand of powers is kept. Then, by designing a distributed consensus control protocol in multi-agent systems with appropriate initial conditions, incremental cost consensus can be realized and the balance for the powers can also be satisfied. Furthermore, the difficult problem for distributed optimization of the total cost function with bounded capacity limitations is also discussed. A reformulated barrier function is proposed to simplify the analysis, under which the total cost can reach the minimal value if consensus can be achieved for the modified incremental cost with some appropriate initial values. Thus, the distributed optimization problems for the cost function of all generation units with and without bounded capacity limitations can both be solved by using the idea of consensus in multi-agent systems, whose theoretical analysis is still lacking nowadays. Finally, some simulation examples are given to verify the effectiveness of the results in this paper.