Decision Strategies for a P2P Computing System

Peer-to-Peer (P2P) computing (also called ‘public-resource computing’) is an effective approach to perform computation of large tasks. Currently used P2P computing systems (e.g., BOINC) are most often centrally managed, i.e., the final result of computations is created at a central node using partial results – what may be not efficient in the case when numerous participants are willing to download the final result. In this paper, we propose a novel approach to P2P computing systems. We assume that results can be delivered to all peers in a distributed way using three types of network flows: unicast, Peer-to-Peer and anycast. We describe our concept of the system architecture with a special focus on the decision strategies developed for system participants. Using our discrete realtime simulator we evaluate the proposed strategies in various scenarios and present a comprehensive analysis of obtained results. According to obtained results, the Peer-to-Peer flow provides lower operational cost of the computing system compared to unicast and anycast flows. Moreover, an appropriate selection of decision strategy can significantly reduce the operational cost

A P2P Computing System for Overlay Networks

A distributed computing system is able to perform data computation and distribution of results at the same time. The input task is divided into blocks, which are then sent to system participants that offer their resources in order to perform calculations. Next, a partial result is sent back by the participants to the task manager (usually one central node). In the case when system participants want to get the final result, the central node may become overloaded, especially if many nodes request the result at the same time. In this paper we propose a novel distributed computation system, which does not use the central node as the source of the final result, but assumes that partial results are sent between system participants. This way we avoid overloading the central node, as well as network congestion. There are two major types of distributed computing systems: grids and Peer-to-Peer (P2P) computing systems. In this work we focus on the latter case. Consequently, we assume that the computing system works on the top of an overlay network. We present a complete description of the P2P computing system, considering both computation and result distribution. To verify the proposed architecture we develop our own simulator. The obtained results show the system performance expressed by the operation cost for various types of network flows: unicast, anycast and Peer-to-Peer. Moreover, the simulations prove that our computing system provides about 66% lower cost compared to a centralized computing system

Decentralization of a Multi Data Source Distributed Processing System Using a Distributed Hash Table

A distributed processing system (DPS) contains many autonomous nodes, which contribute their own computing power. DPS is considered a unified logical structure, operating in a distributed manner; the processing tasks are divided into fragments and assigned to various nodes for processing. That type of operation requires and involves a great deal of communication. We propose to use the decentralized approach, based on a distributed hash table, to reduce the communication overhead and remove the server unit, thus avoiding having a single point of failure in the system. This paper proposes a mathematical model and algorithms that are implemented in a dedicated experimental system. Using the decentralized approach, this study demonstrates the efficient operation of a decentralized system which results in a reduced energy emission

Quantization with Knowledge Base Applied to Geometrical Nesting Problem

Nesting algorithms deal with placing two-dimensional shapes on the given canvas. In this paper a binary way of solving the nesting problem is proposed. Geometric shapes are quantized into binary form, which is used to operate on them. After finishing nesting they are converted back into original geometrical form. Investigations showed, that there is a big influence of quantization accuracy for the nesting effect. However, greater accuracy results with longer time of computation. The proposed knowledge base system is able to strongly reduce the computational time

Random Approach to Optimization of Overlay Public-Resource Computing Systems

The growing need for computationally demanding systems triggers the development of various network-oriented computing systems organized in a distributed manner. In this work we concentrate on one kind of such systems, i.e. public-resource computing systems. The considered system works on the top of an overlay network and uses personal computers and other relatively simple electronic equipment instead of supercomputers. We assume that two kinds of network flows are used to distribute the data in the public-resource computing systems: unicast and peer-to-peer. We formulate an optimization model of the system. After that we propose random algorithms that optimize jointly the allocation of computational tasks and the distribution of the output data. To evaluate the algorithms we run numerical experiments and present results showing the comparison of the random approach against optimal solutions provided by the CPLEX solver

A Distributed Processing Platform With Reconfigurable Autonomous Nodes

Distributed processing is a fast growing area of interest due to the exploding popularity of Internet of Things (IoT) and Unmanned Aerial Vehicles (UAV) technologies. IoT is a distributed processing structure by nature, while UAVs evolve from single-UAV applications towards multiple-UAV (teams). The demand for processing capabilities is expanding as well. The general purpose processors (e.g. CPUs) can be used for any type of application, however this flexibility is at the cost of operational efficiency. Application Specific Integrated Circuits (ASICs) are designed for certain types of application and have great operational efficiency, but they rarely can be used for other applications. The reconfigurable chips – Field Programmable Gate Arrays (FPGAs) provide high operational efficiency along with the application flexibility – as they can be reprogrammed with the functionality that is required at the given time. All the above listed aspects are combined in the distributed processing system that is expected to consume low amount of electrical energy. This dissertation proposes a comprehensive solution for the problem of distributed processing equipped with reconfigurable units. The complete and detailed architecture is provided for each element. The design includes operational algorithms that together with the architecture constitute a complete solution for the stated problem. The design of the units is flexible and allows any number and combination of CPUs, ASICs or FPGAs. Units in the proposed design are autonomous – the decisions are taken by individual units, instead of the central node, which is marginalized. The decentralized and autonomous approach provides more flexible and reliable design that is especially important for IoT and teamed UAV applications. The efficiency of the proposed solutions is defined as electrical energy consumption and operation timespan, and is measured using dedicated experimentation system through numerous simulations

Heuristic Algorithms for Optimization of Task Allocation and Result Distribution in Peer-to-Peer Computing Systems

Recently, distributed computing system have been gaining much attention due to a growing demand for various kinds of effective computations in both industry and academia. In this paper, we focus on Peer-to-Peer (P2P) computing systems, also called public-resource computing systems or global computing systems. P2P computing systems, contrary to grids, use personal computers and other relatively simple electronic equipment (e.g., the PlayStation console) to process sophisticated computational projects. A significant example of the P2P computing idea is the BOINC (Berkeley Open Infrastructure for Network Computing) project. To improve the performance of the computing system, we propose to use the P2P approach to distribute results of computational projects, i.e., results are transmitted in the system like in P2P file sharing systems (e.g., BitTorrent). In this work, we concentrate on offline optimization of the P2P computing system including two elements: scheduling of computations and data distribution. The objective is to minimize the system OPEX cost related to data processing and data transmission. We formulate an Integer Linear Problem (ILP) to model the system and apply this formulation to obtain optimal results using the CPLEX solver. Next, we propose two heuristic algorithms that provide results very close to an optimum and can be used for larger problem instances than those solvable by CPLEX or other ILP solvers

Software Development Approach for Discrete Simulators

Simulation is the most common approach to perform the problem research. Among several types of simulation, the most common way is the discrete simulation, which assumes the division of the time scale into fixed length time slots. Depending on investigated problem, simulation packages may be used or it could be necessary to design and create own simulation system. In this paper, we propose the complete pre-study scheme and the most commonly appearing implementation problems with suggested solutions. We also describe how to implement the exemplary simulator in C++

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http://archive.org/details/evaluationofhuma00okeeNAN

Introduction to the poetics of an oral language: the Mixtec in the low mountain (Guerrero, Mexico)

La lengua mixteca en la actualidad está en proceso de normalización lingüística, a través de instituciones educativas (Secretaría de Educación Pública: SEP) y de una Academia fundada en 1997. El área dialectal que he investigado (Rancho Nuevo de la Democracia y Metlatónoc) corresponde a la zona más empobrecida de la Mixteca y la que ha sufrido marginación durante siglos, por lo que no ha sido tenida en cuenta durante ese proceso. Por distintos motivos, sería beneficioso para los demás mixtecos que fuera mejor integrada. Humanamente, es una exigencia ética y política. Técnicamente, se encuentra en el cruce entre los tres grandes dialectos del mixteco, los cuales se remontan al s. XVI. Con el fin de facilitar su integración, he preparado une estudio integral de su lengua y su cultura, que estará pronto disponible para los investigadores. En este texto ofrezco un resumen de los rasgos más relevantes en cada uno de los niveles lingüísticos, con la intención específica de que puedan ser comparados fácilmente con otras áreas. Pero lo hago desde una perspectiva que me parece sugerente: la poeticidad de la lengua oral.Nowadays, the Mixtec language is advancing towards linguistic normalization, by means of education institutions (SEP) and the Academy founded in 1997. The dialectal area in which I have researched (Rancho Nuevo de la Democracia and Metlatonoc) is the most impoverished among Mixteca regions. It has suffered relegation for centuries, causing its alienation in the policy of normalization. For several reasons, it would be advantageous for the other Mixtecs that the region be taking into account. From the human point of view is an ethical and political must. From the technical, such area is the crossroad of the three major Mixtec dialects. In order to contribute to its cultural and social integration, I have prepared an integral survey of their culture and their language, that soon will be available for researchers. Hear I offer a summary of the main characteristics for each linguistical level, so that they may be easily compared with other dialectical areas. But I have chosen a stimulating perspective, or I think so: the poeticity of an oral language