A heterogeneous multiprocessor architecture for flexible mediaprocessing

Eclipse is a scalable architecture template for designing data-dependent stream-processing subsystems of media-processing SoCs. It combines application configuration flexibility with the efficiency of function-specific coprocessors that concurrently execute the tasks of one or more applications     

A highly flexible multiprocessor solution for ray tracing

The ray tracing algorithm continues to attract much research and development to improve the quality of the images that are generated, and to reduce the time taken to produce them. By identifying the key requirements of a development system from the user's point of view, we describe a general-purpose multiprocessor solution for ray tracing which may be used to reduce execution time without restricting development of the ray tracing code. The solution is based upon a distributed memory multiprocessor system in which each processor addresses a small amount of memory relative to the size of the model database. Methods for exploiting the coherence of references to entries in the database are described which use a combination of dynamic and static caching techniques. This scheme allows databases of arbitrary size to be supported on multiprocessors with limited distributed memory.     

Performance analysis of hybrid network multiprocessor architecture

In this paper we investigate architectures that combine message‐passing and shared‐memory technologies, called hereinafter hybrid architectures. We introduced hybrid architectures in which large buses of the shared‐memory are split into a number of small high‐performance shared‐memory blocks, which are connected via message‐passing architecture, such as hypercube, grid or ring. This way we avoid the possible degradation of the achieved performance due to the fact that the bus performance does not scale well when the number of processors it connects increases. We study the saturation situations of several hybrid network architectures, where adding processors does not reduce the overall execution time. We show that the use of hybrid network architectures leads to significant improvement of the systems price/performance ratio, by significantly improving the performance with almost no system cost increment. Therefore, the usage of hybrid architectures demonstrates how minimal ‘cost’ spending could significantly increase the system performance. In addition, we show that different types of applications have different best hybrid architectures. Copyright © 2000 John Wiley & Sons, Ltd.     

A multiprocessor architecture for viewing solid models

A simple way of using many processors in picture generation is to allocate each one to a region of the display screen. A device is proposed which uses such an architecture to produce pictures direct from set-theoretic solid models. Alternative strategies for partitioning the screen area between processors are advanced, and evaluated by means of a simulation.     

一种基于分布式平台的规则处理架构

采用字符串变换规则对字典进行变形变换是安全字符串恢复中的一种有效方法,然而,规则的处理过程复杂,现有的方式都是基于软件实现,针对处理性能、功耗等方面的现实需求,提出了一种基于分布式平台的规则处理架构,首次使用FPGA硬件来加速规则的处理过程,并通过将复杂的规则组合进行拆分,分布到并行结点上进一步加速规则的处理过程。在蚁群系统上的实验结果表明,采用该种架构的规则处理系统满足实际需求,性能和能效相比CPU和GPU都有显著提高,表明了该分布式规则处理架构的有效性。     

Assembling a resolution multiprocessor from interface,programming and distributed processing components

An effective resolution multiprocessor can be built from distributed processing, logic programming, and interface elements. Widely used, portable, components can be modularly composed into a portable parallel system that displays good resistance to premature obsolescence by software evolution. A virtual multiprocessor offering common message passing and configuration services integrates a distributed mesh of sequential resolution engines. Users configure and control the resolution engines and virtual multiprocessor through a GUI using an embedded command language to drive its facilities. Prolog programs either explicitly control parallel execution through message passing or would have to rely on program transformation techniques to extract parallelism implicitly.     

DIASPORA: A highly distributed web-query processing system

Current proposals for web querying systems have assumed a centralized processing architecture wherein data is shipped from the remote sites to the user's site. We present here the design and implementation of DIASPORA, a highly distributed query processing system for the web. It is based on the premise that several web applications are more naturally processed in a distributed manner, opening up possibilities of significant reductions in network traffic and user response times. DIASPORA is built over an expressive graph-based data model that utilizes simple heuristics and lends itself to automatic generation. The model captures both the content of web documents and the hyperlink structural framework of a web site. Distributed queries on the model are expressed through a declarative language that permits users to explicitly specify navigation. DIASPORA implements a query-shipping model wherein queries are autonomously forwarded from one web-site to another, without requiring much coordination from the query originating site. Its design addresses a variety of interesting issues that arise in the distributed web context including determining query completion, handling query rewriting, supporting query termination and preventing multiple computations of a query at a site due to the same query arriving through different paths in the hyperlink framework. The DIASPORA system is currently operational and is undergoing testing on our campus network. In this paper we describe the design of the system and report initial performance results that indicate significant performance improvements over comparable centralized approaches. This revised version was published online in August 2006 with corrections to the Cover Date.     

An adaptable distributed query processing architecture

Traditionally, distributed query optimization techniques generate static query plans at compile time. However, the optimality of these plans depends on many parameters (such as the selectivities of operations, the transmission speeds and workloads of servers) that are not only difficult to estimate but are also often unpredictable and fluctuant at runtime. As the query processor cannot dynamically adjust the plans at runtime, the system performance is often less than satisfactory. In this paper, we introduce a new highly adaptive distributed query processing architecture. Our architecture can quickly detect fluctuations in selectivities of operations, as well as transmission speeds and workloads of servers, and accordingly change the operation order of a distributed query plan during execution. We have implemented a prototype based on the Telegraph system [Telegragraph project. Available from >]. Our experimental study shows that our mechanism can adapt itself to the changes in the environment and hence approach to an optimal plan during execution.     

A computer network based control architecture for autonomous distributed multirobot systems

This paper presents the specification and implementation procedure using a microcomputer network based autonomous distributed control architecture for industrial multirobot systems. The procedure is based on the concept of data flow network controlled by communicating sequential processes to perform coordinated tasks. Robots and other computerized industrial devices such as conveyors and manufacturing machines are defined as object-oriented Petri nets. A modular and hierarchical approach is adopted to define a set of Petri net type diagrams which represent concurrent activities of control processes for such devices. Asynchronous and synchronous interactions are modelled by places and transitions, respectively, in global process interaction nets. The control software is implemented on a computer network using Inmos transputers with true parallel processing and message passing primitives efficiently handled in hardware. Petri net based models are directly and efficiently transformed to corresponding codes in occam, the high level parallel programming language defined for the transputer.     

FASA: A software architecture and runtime framework for flexible distributed automation systems

Modern automation systems have to cope with large amounts of sensor data to be processed, stricter security requirements, heterogeneous hardware, and an increasing need for flexibility. The challenges for tomorrow’s automation systems need software architectures of today’s real-time controllers to evolve.This article presents FASA, a modern software architecture for next-generation automation systems. FASA provides concepts for scalable, flexible, and platform-independent real-time execution frameworks, which also provide advanced features such as software-based fault tolerance and high degrees of isolation and security. We show that FASA caters for robust execution of time-critical applications even in parallel execution environments such as multi-core processors.We present a reference implementation of FASA that controls a magnetic levitation device. This device is sensitive to any disturbance in its real-time control and thus, provides a suitable validation scenario. Our results show that FASA can sustain its advanced features even in high-speed control scenarios at 1 kHz.     

A local area network architecture for communication in distributed real-time systems

Distributed real-time systems of the future will require specialized network architectures that incorporate new classes of services and protocols in order to support time-constrained communication. In this paper, we propose a new local area network architecture for such systems. This four-layered architecture is characterized by new classes of connection-oriented and connectionless services that take into account the timing constraints of messages. We describe various aspects of the logical link control layer of the architecture and various real-time protocols that may be employed at the medium access control layer in order to support the new classes of services. We also describe a homogeneous approach to the implementation of medium access control protocols to support both connection-oriented and connectionless services, based on a uniform window splitting paradigm.     

A regular scalable fault tolerant interconnection network for distributed processing

Bounded degree networks like deBruijn graphs or wrapped butterfly networks are very important from VLSI implementation point of view as well as for applications where the computing nodes in the interconnection networks can have only a fixed number of I/O ports. One basic drawback of these networks is that they cannot provide a desired level of fault tolerance because of the bounded degree of the nodes. On the other hand, networks like hypercube (where degree of a node grows with the size of a network) can provide the desired fault tolerance but the design of a node becomes problematic for large networks. In their attempt to combine the best of the both worlds, authors in [IEEE Transactions on Parallel and Distributed Systems 4(9) (1993) 962] proposed hyper-deBruijn (HD) networks that have many additional features of logarithmic diameter, partitionability, embedding, etc. But, HD networks are not regular, are not optimally fault tolerant and the optimal routing is relatively complex. Our purpose in the present paper is to extend the concepts used in the above-mentioned reference to propose a new family of scalable network graphs that retain all the good features of HD networks and at the same time are regular and maximally fault tolerant; the optimal point to point routing algorithm is significantly simpler than that of the HD networks. We have developed some new interesting results on wrapped butterfly networks in the process.     

Accelerating network applications by distributed interfaces on heterogeneous multiprocessor architectures

Hosts with several, possibly heterogeneous and/or multicore, processors provide new challenges and opportunities to accelerate applications with high communications bandwidth requirements. Many opportunities to scale these network applications with the increase in the link bandwidths are related to the exploitation of the available parallelism provided by the presence of several processing cores in the servers, not only for computing the workload of the user application but also for decreasing the overhead associated to the network interface and the system software.     

A distributed multi-layer MEC-cloud architecture for processing large scale IoT-based multimedia applications

Multimedia Tools and Applications - The enormous growth of the Internet of Things (IoT) devices gave governments, businesses, and individual users new means to accomplish their missions. Several...     

A survey of skyline processing in highly distributed environments

During the last decades, data management and storage have become increasingly distributed. Advanced query operators, such as skyline queries, are necessary in order to help users to handle the huge amount of available data by identifying a set of interesting data objects. Skyline query processing in highly distributed environments poses inherent challenges and demands and requires non-traditional techniques due to the distribution of content and the lack of global knowledge. This paper surveys this interesting and still evolving research area, so that readers can easily obtain an overview of the state-of-the-art. We outline the objectives and the main principles that any distributed skyline approach has to fulfill, leading to useful guidelines for developing algorithms for distributed skyline processing. We review in detail existing approaches that are applicable for highly distributed environments, clarify the assumptions of each approach, and provide a comparative performance analysis. Moreover, we study the skyline variants each approach supports. Our analysis leads to a taxonomy of existing approaches. Finally, we present interesting research topics on distributed skyline computation that have not yet been explored.     

A model of distributed recovery for the SUPRENUM multiprocessor

SUPRENUM (Superrechner für numerische Anwendungen) is a German supercomputer project. This paper describes a model for distributed recovery on the SUPRENUM multiprocessor. First we describe the architecture of the SUPRENUM multiprocessor in some definitions. In the next section the distribution of global system checkpoints and an algorithm for distributed reconfiguration is given.     

A multiprocessor architecture for solving nonlinear partial differential equations

This paper presents the architecture of a special-purpose multiprocessor system, which we call the Broadcast Cube System (BCS), for solving non-linear Partial Differential Equations (PDEs). The BCS has the following important features: (a) Being based on the conceptually simple bus interconnection scheme it is easily understood. The use of homogeneous Processing Elements (PEs) which can be realized as standard VLSI chips makes the hardware less costly. (b) The interconnection network is simple and regular. The network can easily be extended to vast number of PEs by adding buses with new PEs on them and by slightly increasing the number of PEs on existing buses. The interconnection pattern is highly redundant to support fault tolerance in the event of PE failures. (c) In terms of the switching delays, the delay a message undergoes between a pair of PEs connected to a common bus is zero. The maximum delay between any pair of PEs is one unit and thus a strong localization of communicating tasks is not needed to avoid long message delays even in networks of thousands of PEs. The effectiveness of the BCS has been demonstrated by both analytical and simulation methods using heat transfer and fluid flow simulation, which requires solution of non-linear PDEs, as a benchmark program.     

A flexible architecture for distributed knowledge based systems with nomadic access through handheld devices

Nowadays any Knowledge Based System (KBS) realization needs of intercommunication among distributed components and to use non-connected and distributed data sources, which poses several challenges to the classical Artificial Intelligence field of KBS.

The multiagent paradigm and the use of ontologies are considered to be suitable tools to face the problems of designing and developing today KBS. On the other hand, using such networked KBS through handheld devices makes more efficient exploitation and interaction with the system.

This paper presents an open and flexible architecture for a distributed KBS and an application of it to construct a system for Psychological Disorders consulting, the so called PDA² (Psychological Disorder Assistant through PDA). We analyze the main features of the architecture as well as the agent tools we may use to construct it. Additionally, we present a support ontology for Psychological Disorders.