An architectural application framework for evolving distributed systems

In this paper, we present an object-oriented application framework to support the development of evolving distributed systems. The framework combines concepts of the object-oriented paradigm with those of architectural design. The result is a framework which supports extensible and reusable configurations of distributed components. The framework addresses the problem of evolution by allowing the addition, replacement and extension of components of a configuration. Evolution is also possible at run time, where a configuration can change dynamically depending on a particular event. The paper outlines the fundamental aspects of our framework and presents a case study, which illustrates its application.     

A distributed parallel programming framework

This paper presents Visper, a novel object-oriented framework that identifies and enhances common services and programming primitives, and implements a generic set of classes applicable to multiple programming models in a distributed environment. Groups of objects, which can be programmed in a uniform and transparent manner, and agent-based distributed system management, are also featured in Visper. A prototype system is designed and implemented in Java, with a number of visual utilities that facilitate program development and portability. As a use case, Visper integrates parallel programming in an MPI-like message-passing paradigm at a high level with services such as checkpointing and fault tolerance at a lower level. The paper reports a range of performance evaluation on the prototype and compares it to related works     

Design and implementation of a framework for building distributed smart object systems

A smart object system encompasses the synergy between computationally augmented everyday objects and external applications. This paper presents a software framework for building smart object systems following a declarative programming approach centered around custom written documents that glue the smart objects together. More specifically, in the proposed framework, applications’ requirements and smart objects’ services are objectified through structured documents. A runtime infrastructure provides the spontaneous federation between smart objects and applications through structural type matching of these documents. There are three primary advantages of our approach: firstly, it allows developers to write applications in a generic way without prior knowledge of the smart objects that could be used by the applications. Secondly, smart object management (locating, accessing, etc.) issues are completely handled by the infrastructure; thus application development becomes rapid and simple. Finally, the programming abstraction used in the framework allows extension of functionalities of smart objects and applications very easily. We describe an implemented prototype of our framework and show examples of its use in a real life scenario to illustrate its feasibility.     

基于局部并行搜索的分布式约束优化算法框架

针对当前局部搜索算法在求解大规模、高密度的分布式约束优化问题（DCOP）时,求解困难且难以跳出局部最优取得进一步优化等问题,提出一种基于局部并行搜索的分布式约束优化算法框架（LPOS）,算法中agent通过自身的取值并行地搜索局部所有邻居取值来进一步扩大对解空间的搜索,从而避免算法过早陷入局部最优。为了保证算法的收敛性与稳定性,设计了一种自适应平衡因子K来平衡算法对解的开发和继承能力,并在理论层面证明了并行搜索优化算法可以扩大对解空间的搜索,自适应平衡因子K可以实现平衡目的。综合实验结果表明,基于该算法框架的算法在求解低密度和高密度DCOP时性能都优于目前最新的算法。特别是在求解高密度DCOP中有显著的提升。     

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 effective speedup metric for measuring productivity in large-scale parallel computer systems

With the parallel computer systems scaling-up, the measure index for performance of the systems demands a shift from traditional “high performance” to “high productivity.” This brings a new challenge to defining a synthetic, yet meaningful, measure index of multiple productivity variables; namely computing performance, reliability, energy consumption, parallel software development, etc. Traditional measures for large-scale parallel computer systems merely focus on computing performance, and are incapable of measuring the multiple productivity variables simultaneously in an effective manner. A recently proposed market-related money model, which pursues high utility/cost ratio, relies on money as a measure to consider the multiple productivity variables. Differing from the previous models, this paper proposes a novel system productivity speedup metric for large-scale parallel computer systems. The metric uses speedup instead of money to comprehensively unify the measures of multiple productivity variables. Finally, we propose a trade-off productivity measurement to weigh different productivity variables, to address different design targets. The measurement can facilitate the system evaluation, expose future technique tendencies, and guide future system design.     

A software architecture for distributed computer control systems

Distributed computer control systems have a number of potential advantages over centralized systems, especially where the application is itself physically distributed. A computer station can be placed close to the plant being controlled, and a communications network used to enable the stations to communicate to coordinate their actions. However, the software must be carefully designed to exploit the potential advantages of distribution. This paper describes the software architecture of CONIC, a system to support distributed computer control applications. This architecture emphasizes the distinction between the writing of individual software components and the construction and configuration of a system from a set of components. A modular structure is used to separate programming from configuration. Typed entry and exit ports are used to clearly define module interfaces. Ports, analagous to the plugs and sockets of hardware components, permit modules to be interconnected in different ways. On-line modification and extension of the system is supported by permitting the dynamic creation and interconnection of modules. Message passing primitives are provided to permit modules to coordinate and synchronize control actions.     

Consensus-based evaluation framework for distributed information retrieval systems

Multi-agent systems have been attacking the challenges of information retrieval tasks on distributed environment. In this paper, we propose a consensus choice selection method based framework to evaluate the performance of cooperative information retrieval tasks of the multiple agents. Thereby, two well-known measurements, precision and recall, are extended to handle consensual closeness (i.e., local and global consensus) between the sets of retrieved results. We show that in a motivating example the proposed criteria are prone to solve the rigidity problem of classical precision and recall. More importantly, the retrieved results can be ranked with respect to the consensual score, and the ranking mechanism has been verified to be more reasonable.

Towards a complete framework for parallel implementation of logic languages: the data parallel implementation of SEL

Although logic languages, due to their non-declarative nature, are widely proclaimed to be conducive in theory to parallel implementation, in fact there appears to be insufficient practical evidence to stimulate further developments in this field. The paper puts forward various complications which arise in assuming a solely process parallel approach as a possible explanation for this situation. As an alternative, data parallelism is posited as an underutilized forte of logic programming. The paper illustrates a data parallel implementation of a particular language called SEL which is based on sets. Thus, SEL (set equational language) is introduced as an example of logic language which lends itself to an efficient data parallel implementation. The strategy of this implementation assumes an abstract machine called SAM (set-oriented abstract machine) which is based on the WAM (Warren abstract machine). SAM serves as an intermediary between the SEL language and the target machine for the implementation, the Connection Machine. Finally, some preliminary benchmarks are presented.     

A tridiagonal solver for massively parallel computer systems

This paper describes a parallel solver of tridiagonal systems appropriate for distributed memory computers and implemented on an array of chain-connected T800 Transputers. Each processor in the chain uses the same program to solve its own subset of equations. This implementation is suited, for instance, for solving the heat conduction equation in one-dimensional hydrodynamic codes. The procedure performs a parallel cyclic reduction, a recursive Gaussian elimination on a reduced number of equations and a parallel backward unfolding scheme, with a direct substitution in the reduced equations. The code has been written in Occam2 language. A one-way communication of values between adjacent processors is required at each cycle of both the reduction and the unfolding steps. Due to the number of floating point operations and the amount of communications the implementation described here works efficiently on arrays with more than 4 processors and for more than 50 equations per processor.     

多主并行处理加固计算机设计和实现

采用Intel Xeon LV处理器,利用先进的EDA工具和仿真软件进行高速串行总线的合理布局布线,实现了一种支持多主并行处理的加固计算机。根据应用,构建了基于高速互连网络的计算机硬件系统,结合成熟的商用并行软件,对计算机系统并行能力进行了测试;针对抗恶劣环境应用,特别是热设计,通过热分析、建模仿真(Icepak)等手段,实现计算机系统的环境设计。     

An implementation framework for seru production

Seru production, which merges the flexibility of job shops, efficiency of mass production, and environment friendly characteristics of sustainable manufacturing, largely for electronics assembly, is the latest manufacturing mode developed in Japan. It is receiving attention from Japanese practitioners and researchers. However, some attempts to implement seru production are unsuccessful, especially outside Japan. This is because of lack of knowledge of the specific means to implement seru production. The purpose of this paper is to provide a general framework and some basic principles that should be followed while implementing seru production for practitioners from a practical perspective. This work is based on a systematic analysis of many implementation experiences of seru production in Japanese manufacturing factories as well as a broad investigation of the popular literature information. The proposed framework can serve as a concise guide to help implement seru production in the manufacturing industry. In addition, constructive information is provided for researchers who would like to know and study the advanced manufacturing mode of seru production but do not understand the Japanese language.     

Braess-like paradoxes in distributed computer systems

We consider optimal distributed decisions in distributed computer systems. We identify a Braess like paradox in which adding capacity to the system may degrade the performance of all users. Unlike the original Braess paradox, we show that this behavior occurs only in the case of finitely many users and not in the case of infinite number of users