Dissertations / Theses on the topic 'Distributed computing'
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1
Datla, Dinesh. "Wireless Distributed Computing in Cloud Computing Networks." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/51729.
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The explosion in growth of smart wireless devices has increased the ubiquitous presence of computational resources and location-based data. This new reality of numerous wireless devices capable of collecting, sharing, and processing information, makes possible an avenue for new enhanced applications. Multiple radio nodes with diverse functionalities can form a wireless cloud computing network (WCCN) and collaborate on executing complex applications using wireless distributed computing (WDC). Such a dynamically composed virtual cloud environment can offer services and resources hosted by individual nodes for consumption by user applications. This dissertation proposes an architectural framework for WCCNs and presents the different phases of its development, namely, development of a mathematical system model of WCCNs, simulation analysis of the performance benefits offered by WCCNs, design of decision-making mechanisms in the architecture, and development of a prototype to validate the proposed architecture.
The dissertation presents a system model that captures power consumption, energy consumption, and latency experienced by computational and communication activities in a typical WCCN. In addition, it derives a stochastic model of the response time experienced by a user application when executed in a WCCN. Decision-making and resource allocation play a critical role in the proposed architecture. Two adaptive algorithms are presented, namely, a workload allocation algorithm and a task allocation - scheduling algorithm. The proposed algorithms are analyzed for power efficiency, energy efficiency, and improvement in the execution time of user applications that are achieved by workload distribution. Experimental results gathered from a software-defined radio network prototype of the proposed architecture validate the theoretical analysis and show that it is possible to achieve 80 % improvement in execution time with the help of just three nodes in the network.Ph. D.
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Li, Guangxing. "Supporting distributed realtime computing." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309077.
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Evers, David Martin. "Distributed computing with objects." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318049.
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Riddoch, David James. "Low latency distributed computing." Thesis, University of Cambridge, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619850.
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BOLDRIN, FABIO. "Web Distributed Computing Systems." Doctoral thesis, Università degli studi di Ferrara, 2011. http://hdl.handle.net/11392/2388764.
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The thesis presents the PhD study about a new approach in distributed computing based on the exploitation of web browsers as clents, using technologies and best practices of Javascript, AJAX and Flex. The described solution has two main advantages: it is client free, so no additional programs have to be installed to perform the computation, and it requires low CPU usage, so clientside computation is no invasive for users. The solution is developed with both AJAX and Adobe® Flex® technologies embedding a pseudoclient into a web page that hosts the computation in the form of a banner. While users browse the hosting web page, client side of the system query the server side part for a subproblem, called crunch, computes the solution(s) and sends back it to the server. All the process is always transparent for the users navigation experience and computer use in general. The thesis shows the feasibility of the system and the good performances that can be achieved, with details over tests and metrics that have been defined to measure the performance indexes. The new architecture has been tested through this performance metrics by implementing two examples of distributed computing, the cracking of the RSA cryptosystem through the factorization of the public key and the Pearson's correlation index between smples in genetic data sets. Results have shown good feasibility of this approach both in a closed environment and also in an Internet environment, in a typical real situation. A mathematical model has been developed over this solution. The main goals of the model are to describe and classify different categories of problems on the basis of the feasibility and o find the limits in the dimensioning of the scheduling systems to have convenience in the use of this approach.
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Calabrese, Chris M. Eng Massachusetts Institute of Technology. "Distributed inference : combining variational inference with distributed computing." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/85407.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 95-97).
The study of inference techniques and their use for solving complicated models has taken off in recent years, but as the models we attempt to solve become more complex, there is a worry that our inference techniques will be unable to produce results. Many problems are difficult to solve using current approaches because it takes too long for our implementations to converge on useful values. While coming up with more efficient inference algorithms may be the answer, we believe that an alternative approach to solving this complicated problem involves leveraging the computation power of multiple processors or machines with existing inference algorithms. This thesis describes the design and implementation of such a system by combining a variational inference implementation (Variational Message Passing) with a high-level distributed framework (Graphlab) and demonstrates that inference is performed faster on a few large graphical models when using this system.
by Chris Calabrese.
M. Eng.
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Higham, Lisa. "Randomized distributed computing on rings." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28839.
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The communication complexity of fundamental problems in distributed computing on an asynchronous ring are examined from both the algorithmic and lower bound perspective.
A detailed study is made of the effect on complexity of a number of assumptions about the algorithms. Randomization is shown to influence both the computability and complexity of several problems. Communication complexity is also shown to exhibit varying degrees of sensitivity to additional parameters including admissibility of error, kind of error, knowledge of ring size, termination requirements, and the existence of identifiers.
A unified collection of formal models of distributed computation on asynchronous rings is developed which captures the essential characteristics of a spectrum of distributed algorithms those that are error free (deterministic, Las Vegas, and nondeterministic), and those that err with small probability (Monte Carlo and nondeterministic/probabilistic). The nondeterministic and nondeterministic/probabilistic models are introduced as natural generalizations of the Las Vegas and Monte Carlo models respectively, and prove useful in deriving lower bounds. The unification helps to clarify the essential differences between the progressively more general notions of a distributed algorithm. In addition, the models reveal the sensitivity of various problems to the parameters listed above.
Complexity bounds derived using these models typically vary depending on the type of algorithm being investigated. The lower bounds are complemented by algorithms with matching complexity while frequently the lower bounds hold on even more powerful models than those required by the algorithms.
Among the algorithms and lower bounds presented are two specific results which stand out because of their relative significance.
1. If g is any nonconstant cyclic function of n variables, then any nondeterministic algorithm for computing g on an anonymous ring of size n has complexity [Formula Omitted] bits of communication; and, there is a is nonconstant cyclic boolean function [Formula Omitted], such that [Formula Omitted] can be computed by a Las Vegas algorithm in [Formula Omitted] expected bits of communication on a ring of size n.
2. The expected complexity of computing AND (and a number of other natural functions)
on a ring of fixed size n in the Monte Carlo model is [Formula Omitted] messages and bits where [Formula Omitted] is the allowable probability of error.Science, Faculty of
Computer Science, Department of
Graduate
8
Gao, Yiran. "Dynamic inter-domain distributed computing." Thesis, Queen Mary, University of London, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.510898.
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Bouchard, David S. M. Massachusetts Institute of Technology. "Embodied emergence : distributed computing manipulatives." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/41743.
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Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2007.Includes bibliographical references (p. 65-67).
Distributed systems and the emergent properties that can arise out of simple localized interactions have fascinated scientists and artists alike for the last century. They challenge the notions of control and creativity, producing outcomes that can be beautiful, engaging and surprising at the same time. While extensive work has been done using computer simulations of such systems in fields like artificial life and generative art, their physically embodied counterparts are still in their infancy, in part due to the complexity of building and deploying such systems. In this thesis, I will discuss how simple tangible nodes can enable playful and creative experimentation with the concept of emergent behavior. Specifically, I will address how embodied interaction scenarios involving parallel systems can be implemented and how a range of sensing and actuating possibilities can be leveraged to generate novel and engaging experiences for the end users. In particular, the use of sound will be explored as a medium for representation. Finally, I will argue that there is value in making the transition from software simulations to a situated and manipulable instantiation of these concepts, both for the designer of a system and its users.
by David Bouchard.
S.M.
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Vaikuntanathan, Vinod. "Distributed computing with imperfect randomness." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/34354.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.Includes bibliographical references (p. 41-43).
Randomness is a critical resource in many computational scenarios, enabling solutions where deterministic ones are elusive or even provably impossible. However, the randomized solutions to these tasks assume access to a pure source of unbiased, independent coins. Physical sources of randomness, on the other hand, are rarely unbiased and independent although they do seem to exhibit somewhat imperfect randomness. This gap in modeling questions the relevance of current randomized solutions to computational tasks. Indeed, there has been substantial investigation of this issue in complexity theory in the context of the applications to efficient algorithms and cryptography. This work seeks to determine whether imperfect randomness, modeled appropriately, is "good enough" for distributed algorithms. Namely, can we do with imperfect randomness all that we can do with perfect randomness, and with comparable efficiency ? We answer this question in the affirmative, for the problem of Byzantine agreement. We construct protocols for Byzantine agreement in a variety of scenarios (synchronous or asynchronous networks, with or without private channels), in which the players have imperfect randomness. Our solutions are essentially as efficient as the best known randomized Byzantine agreement protocols, which traditionally assume that all the players have access to perfect randomness.
by Vinod Vaikuntanathan.
S.M.
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Fan, Rui 1977. "Lower bounds in distributed computing." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/43030.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (p. 167-170).
Distributed computing is the study of achieving cooperative behavior between independent computing processes with possibly conflicting goals. Distributed computing is ubiquitous in the Internet, wireless networks, multi-core and multi-processor computers, teams of mobile robots, etc. In this thesis, we study two fundamental distributed computing problems, clock synchronization and mutual exclusion. Our contributions are as follows. 1. We introduce the gradient clock synchronization (GCS) problem. As in traditional clock synchronization, a group of nodes in a bounded delay communication network try to synchronize their logical clocks, by reading their hardware clocks and exchanging messages. We say the distance between two nodes is the uncertainty in message delay between the nodes, and we say the clock skew between the nodes is their difference in logical clock values. GCS studies clock skew as a function of distance. We show that surprisingly, every clock synchronization algorithm exhibits some execution in which two nodes at distance one apart have Q( lo~gD clock skew, where D is the maximum distance between any pair of nodes. 2. We present an energy efficient and fault tolerant clock synchronization algorithm suitable for wireless networks. The algorithm synchronizes nodes to each other, as well as to real time. It satisfies a relaxed gradient property. That is, it guarantees that, using certain reasonable operating parameters, nearby nodes are well synchronized most of the time. 3. We study the mutual exclusion (mutex) problem, in which a set of processes in a shared memory system compete for exclusive access to a shared resource. We prove a tight Q(n log n) lower bound on the time for n processes to each access the resource once. .
(cont.) Our novel proof technique is based on separately lower bounding the amount of information needed for solving mutex, and upper bounding the amount of information any mutex algorithm can acquire in each step. We hope that our results offer fresh ways of looking at classical problems, and point to interesting new open problems
by Rui Fan.
Ph.D.
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Xu, Lei. "Cellular distributed and parallel computing." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:88ffe124-c2fd-4144-86fe-47b35f4908bd.
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This thesis focuses on novel approaches to distributed and parallel computing that are inspired by the mechanism and functioning of biological cells. We refer to this concept as cellular distributed and parallel computing which focuses on three important principles: simplicity, parallelism, and locality. We first give a parallel polynomial-time solution to the constraint satisfaction problem (CSP) based on a theoretical model of cellular distributed and parallel computing, which is known as neural-like P systems (or neural-like membrane systems). We then design a class of simple neural-like P systems to solve the fundamental maximal independent set (MIS) selection problem efficiently in a distributed way, by drawing inspiration from the way that developing cells in the fruit fly become specialised. Building on the novel bio-inspired approach to distributed MIS selection, we propose a new simple randomised algorithm for another fundamental distributed computing problem: the distributed greedy colouring (GC) problem. We then propose an improved distributed MIS selection algorithm that incorporates for the first time another important feature of the biological system: adapting the probabilities used at each node based on local feedback from neighbouring nodes. The improved distributed MIS selection algorithm is again extended to solve the distributed greedy colouring problem. Both improved algorithms are simple and robust and work under very restrictive conditions, moreover, they both achieve state-of-the-art performance in terms of their worst-case time complexity and message complexity. Given any n-node graph with maximum degree Delta, the expected time complexity of our improved distributed MIS selection algorithm is O(log n) and the message complexity per node is O(1). The expected time complexity of our improved distributed greedy colouring algorithm is O(Delta + log n) and the message complexity per node is again O(1). Finally, we provide some experimental results to illustrate the time and message complexity of our proposed algorithms in practice. In particular, we show experimentally that the number of colours used by our distributed greedy colouring algorithms turns out to be optimal or near-optimal for many standard graph colouring benchmarks, so they provide effective simple heuristic approaches to computing a colouring with a small number of colours.
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Farooqui, Kazi. "Group-based distributed computing: Programming and distributed platform model." Thesis, University of Ottawa (Canada), 2000. http://hdl.handle.net/10393/8518.
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Much research has been done in the past in the area of group communication. However most of this research exists in the low-level support for group communication, such as different types of ordered and reliable multicast protocols, membership management protocols, virtual synchrony, replication techniques, etc. Most of this research provides only low-level pieces of the complete puzzle. The big picture involves a vision of group-based distributed computing . This vision calls for a shift of focus from low-level issues of group communication to the high-level issues of an overall distributed environment capable of supporting group-based distributed computing applications . This thesis is focussed on the dual models of the distributed environment---the distributed programming model and the distributed platform model, required for the support of group-based distributed computing applications. The thesis presents the software architecture of an agent-based and policy-driven group support platform in an implementation independent manner. This is an extensible, configurable and programmable software architecture which permits the separation of group coordination aspects from the application issues. The goal is to enhance the level of middleware support provided by the current generation of distributed platforms such as CORBA. The thesis identifies a set of "middleware-level" group support services (GSSs), such as message distribution service, collation service, synchronisation service, filtering service, etc. commonly required by group-based applications and the corresponding group support agents (GSAs). The thesis presents a framework for the organisation of these group support agents. This framework is called the group support machine (GSM). This thesis is based upon the architectural principles underlying object-based distributed systems architectures such as RM-ODP, ANSA, ROSA, OMA, etc., and is scoped within the ODP computational and engineering models. (Abstract shortened by UMI.)
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Farooqui, Kazi. "Group-based distributed computing, programming & distributed platform model." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0015/NQ57039.pdf.
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Olson, Chandra. "Jini an investigation in distributed computing /." [Florida] : State University System of Florida, 2001. http://etd.fcla.edu/etd/uf/2001/ank7122/chandra.PDF.
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Thesis (M.E.)--University of Florida, 2001.Title from first page of PDF file. Document formatted into pages; contains viii, 71 p.; also contains graphics. Vita. Includes bibliographical references (p. 69-70).
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Kore, Anand. "Using idle workstations for distributed computing." Ohio : Ohio University, 1998. http://www.ohiolink.edu/etd/view.cgi?ohiou1176488008.
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Wulf, Lars. "Interaction and security in distributed computing." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362116.
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Wong, Ying-ying, and 王瑩瑩. "Process migration for distributed Java computing." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B43085386.
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Wagealla, Waleed. "Reliable mobile agents for distributed computing." Thesis, Nottingham Trent University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272441.
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The emergence of platform-independent, mobile code technologies has created big opportunities for Internet-based applications. Mobile agents are being utilized to perform a variety of tasks from personalized computing to business-critical transactions. Unfortunately, these advances were not matched by correspondent research into the reliability of these new technologies. This work has been undertaken to investigate the faulttolerance of this new paradigm. Agent programs' mobility and autonomy of execution has introduced a new class of failures different to that of traditional distributed systems. Therefore, fault tolerance is one of the main problems that must be resolved to improve the adoption of an agents' paradigm. The investigation of mobile agents reliability in this thesis resulted in the development of REMA (REliable Mobile Agents), which guarantees the reliable execution, migration, and communication of mobile agents in the presence of faults that might affect the agents hosts or their communication network. We introduced an algorithm for the transparent detection of faults that might affect agent execution, migration, and communication. A decentralized structure was used to divide the agent dynamic distributed system into network-partitioning proof spaces. Lightweight messaging was adopted as the basic error detection engine, which together with the loosely coupled detection managers provided an efficient, low overhead detection mechanism for agent-based distributed processing. The problem of taking checkpoint of agent execution is hampered by the lack of the accessibility of the underlying structure of the JVM. Thus, an alternative solution has been achieved through the REMA Checkpoint and Recovery (REMA-CR) package. REMA-CR provides the developer with powerful classes and methods that allow for capturing the critical data of agents' execution. The developed recovery protocol offers a communication-pairs, independent checkpointing strategy at a low-cost, that covers all possible faults that might invalidate reliable agent execution, migration and communication and maintains the exactly once execution property. The results and the performance of REMA confirmed our objectives of providing a fault tolerant wrapper for agents and their applications with acceptable overhead cost.
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Browne, James D. "Masterless Distributed Computing Over Mobile Devices." Thesis, Monterey, California. Naval Postgraduate School, 2012. http://hdl.handle.net/10945/17328.
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Approved for public release; distribution is unlimitedIt is obvious that information is becoming increasingly important in todays society. This can be seen by the widespread availability of high-speed Internet in homes and the ubiquity of smart phones. This new information centric paradigm is possible because of a large supporting infrastructure without which the Internet, the volumes of information, and the speed we can access them would not exist. The military has recognized the potential value of this trend because the greatest hindrance that any commander has is the fog of warthe absence of the information necessary to make critical decisions. On a battlefield, a commander would like to know the status and location of all of his soldiers, the same for enemy troops, and optimal strategies to accomplish their mission. Unfortunately this needed information is currently impossible to obtain in a timely manner. This thesis addresses these problems by presenting an architecture for ad-hoc distributed computing among mobile devices. Our results show that our system does indeed, as devices are added, speed up a distributed calculation and does it in a way that does not rely on the presence of a routable network. We also show that the speedup obtained nears optimal as the size of the computation necessary to calculate an update increases. Additionally, we have shown that we can chain distributed computations together resulting in a decreased amount of time needed to perform an SVD, an important step in many data-mining algorithms.
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Zhang, Jun. "Flexible distributed computing with volunteered resources." Thesis, Queen Mary, University of London, 2010. http://qmro.qmul.ac.uk/xmlui/handle/123456789/358.
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Nowadays, computational grids have evolved to a stage where they can comprise many volunteered resources owned by different individual users and/or institutions, such as desktop grids and volunteered computing grids. This brings benefits for large-scale computing, as more resources are available to exploit. On the other hand, the inherent characteristics of the volunteered resources bring some challenges for efficiently exploiting them. For example, jobs may not be able to be executed by some resources, as the computing resources can be heterogeneous. Furthermore, the resources can be volatile as the resource owners usually have the right to decide when and how to donate the idle Central Processing Unit (CPU) cycles of their computers. Therefore, in order to utilise volunteered resources efficiently, this research investigated solutions from different aspects. Firstly, this research proposes a new computational Grid architecture based on Java and Java application migration technologies to provide fundamental support for coping with these challenges. This proposed architecture supports heterogeneous resources, ensuring local activities are not affected by Grid jobs and enabling resources to carry out live and automatic Java application migration. Secondly, this research work proposes some job-scheduling and migration algorithms based on resource availability prediction and/or artificial intelligence techniques. To examine the proposed algorithms, this work includes a series of experiments in both synthetic and practical scenarios and compares the performance of the proposed algorithms with existing ones across a variety of scenarios. According to the critical assessment, each algorithm has its own distinct advantages and performs well when certain conditions are met. In addition, this research analyses the characteristics of resources in terms of the availability pattern of practical volunteer-based grids. The analysis shows that each environment has its own characteristics and each volunteered resource’s availability tends to possess weak correlations across different days and times-of-day.
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Dye, Brian. "Distributed computing with the Raspberry Pi." Thesis, Kansas State University, 2014. http://hdl.handle.net/2097/17612.
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Master of ScienceDepartment of Computing and Information Sciences
Mitchell Neilsen
The Raspberry Pi is a versatile computer for its size and cost. The research done in this project will explore how well the Raspberry Pi performs in a clustered environment. Using the Pi as the components of a Beowulf cluster will produce an inexpensive and small cluster. The research includes constructing the cluster as well as running a computationally intensive program called OpenFOAM. The Pi cluster's performance will be measured using the High Performance Linpack benchmark. The Raspberry Pi is already used for basic computer science education and in a cluster can also be used to promote more advanced concepts such as parallel programming and high performance computing. The inexpensive cost of the cluster combined with its compact sizing would make a viable alternative for educational facilities that don't own, or can't spare, their own production clusters for educational use. This also could see use with researchers running computationally intensive programs locally on a personal cluster. The cluster produced was an eight node Pi cluster that generates up to 2.365 GFLOPS.
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Jiang, Haotian. "WEARABLE COMPUTING TECHNOLOGIES FOR DISTRIBUTED LEARNING." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1571072941323463.
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Wong, Ying-ying. "Process migration for distributed Java computing." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43085386.
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Kandaswamy, Partheepan. "System on fabrics utilising distributed computing." Thesis, Loughborough University, 2018. https://dspace.lboro.ac.uk/2134/33381.
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The main vision of wearable computing is to make electronic systems an important part of everyday clothing in the future which will serve as intelligent personal assistants. Wearable devices have the potential to be wearable computers and not mere input/output devices for the human body. The present thesis focuses on introducing a new wearable computing paradigm, where the processing elements are closely coupled with the sensors that are distributed using Instruction Systolic Array (ISA) architecture. The thesis describes a novel, multiple sensor, multiple processor system architecture prototype based on the Instruction Systolic Array paradigm for distributed computing on fabrics. The thesis introduces new programming model to implement the distributed computer on fabrics. The implementation of the concept has been validated using parallel algorithms. A real-time shape sensing and reconstruction application has been implemented on this architecture and has demonstrated a physical design for a wearable system based on the ISA concept constructed from off-the-shelf microcontrollers and sensors. Results demonstrate that the real time application executes on the prototype ISA implementation thus confirming the viability of the proposed architecture for fabric-resident computing devices.
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Rahafrouz, Amir. "Distributed Orchestration Framework for Fog Computing." Thesis, Luleå tekniska universitet, Institutionen för system- och rymdteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-77118.
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The rise of IoT-based system is making an impact on our daily lives and environment. Fog Computing is a paradigm to utilize IoT data and process them at the first hop of access network instead of distant clouds, and it is going to bring promising applications for us. A mature framework for fog computing still lacks until today. In this study, we propose an approach for monitoring fog nodes in a distributed system using the FogFlow framework. We extend the functionality of FogFlow by adding the monitoring capability of Docker containers using cAdvisor. We use Prometheus for collecting distributed data and aggregate them. The monitoring data of the entire distributed system of fog nodes is accessed via an API from Prometheus. Furthermore, the monitoring data is used to perform the ranking of fog nodes to choose the place to place the serverless functions (Fog Function). The ranking mechanism uses Analytical Hierarchy Processes (AHP) to place the fog function according to resource utilization and saturation of fog nodes’ hardware. Finally, an experiment test-bed is set up with an image-processing application to detect faces. The effect of our ranking approach on the Quality of Service is measured and compared to the current FogFlow.
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Guerrieri, Alessio. "Distributed Computing for Large-scale Graphs." Doctoral thesis, Università degli studi di Trento, 2015. https://hdl.handle.net/11572/368736.
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The last decade has seen an increased attention on large-scale data analysis, caused mainly by the availability of new sources of data and the development of programming
model that allowed their analysis. Since many of these sources can be modeled as graphs, many large-scale graph processing frameworks have been developed, from vertex-centric models such as pregel to more complex programming models that allow asynchronous computation, can tackle dynamism in the data and permit the usage of different amount of resources. This thesis presents theoretical and practical results in the area of distributed large-
scale graph analysis by giving an overview of the entire pipeline. Data must first be pre-processed to obtain a graph, which is then partitioned into subgraphs of similar size. To analyze this graph the user must choose a system and a programming model that matches her available resources, the type of data and the class of algorithm to execute. Aside from an overview of all these different steps, this research presents three novel approaches to those steps. The first main contribution is dfep, a novel distributed partitioning algorithm that divides the edge set into similar sized partition. dfep can obtain partitions with good quality in only a few iterations. The output of dfep can then be used by etsch, a graph processing framework that uses partitions of edges as the focus of its programming model. etsch’s programming model is shown to be flexible and can easily reuse sequential classical graph algorithms as part of its workflow. Implementations
of etsch in hadoop, spark and akka allow for a comparison of those systems and the discussion of their advantages and disadvantages. The implementation of etsch in akka
is by far the fastest and is able to process billion-edges graphs faster that competitors such as gps, blogel and giraph++, while using only a few computing nodes. A final
contribution is an application study of graph-centric approaches to word sense induction and disambiguation: from a large set of documents a word graph is constructed and then processed by a graph clustering algorithm, to find documents that refer to the same entities. A novel graph clustering algorithm, named tovel, uses a diffusion-based approach inspired by the cycle of water.
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Guerrieri, Alessio. "Distributed Computing for Large-scale Graphs." Doctoral thesis, University of Trento, 2015. http://eprints-phd.biblio.unitn.it/1613/1/main.pdf.
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The last decade has seen an increased attention on large-scale data analysis, caused mainly by the availability of new sources of data and the development of programming
model that allowed their analysis. Since many of these sources can be modeled as graphs, many large-scale graph processing frameworks have been developed, from vertex-centric models such as pregel to more complex programming models that allow asynchronous computation, can tackle dynamism in the data and permit the usage of different amount of resources. This thesis presents theoretical and practical results in the area of distributed large-
scale graph analysis by giving an overview of the entire pipeline. Data must first be pre-processed to obtain a graph, which is then partitioned into subgraphs of similar size. To analyze this graph the user must choose a system and a programming model that matches her available resources, the type of data and the class of algorithm to execute. Aside from an overview of all these different steps, this research presents three novel approaches to those steps. The first main contribution is dfep, a novel distributed partitioning algorithm that divides the edge set into similar sized partition. dfep can obtain partitions with good quality in only a few iterations. The output of dfep can then be used by etsch, a graph processing framework that uses partitions of edges as the focus of its programming model. etsch’s programming model is shown to be flexible and can easily reuse sequential classical graph algorithms as part of its workflow. Implementations
of etsch in hadoop, spark and akka allow for a comparison of those systems and the discussion of their advantages and disadvantages. The implementation of etsch in akka
is by far the fastest and is able to process billion-edges graphs faster that competitors such as gps, blogel and giraph++, while using only a few computing nodes. A final
contribution is an application study of graph-centric approaches to word sense induction and disambiguation: from a large set of documents a word graph is constructed and then processed by a graph clustering algorithm, to find documents that refer to the same entities. A novel graph clustering algorithm, named tovel, uses a diffusion-based approach inspired by the cycle of water.
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Kim, Song Hun. "Distributed Reconfigurable Simulation for Communication Systems." Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/29700.
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The simulation of physical-layer communication systems often requires long execution times. This is due to the nature of the Monte Carlo simulation. To obtain a valid result by producing enough errors, the number of bits or symbols being simulated must significantly exceed the inverse of the bit error rate of interest. This often results in hours or even days of execution using a personal computer or a workstation.
Reconfigurable devices can perform certain functions faster than general-purpose processors. In addition, they are more flexible than Application Specific Integrated Circuit (ASIC) devices. This fast yet flexible property of reconfigurable devices can be used for the simulation of communication systems. However, although reconfigurable devices are more flexible than ASIC devices, they are often not compatible with each other. Programs are usually written in hardware description languages such as Very High Speed Integrated Circuit (VHSIC) Hardware Description Language (VHDL). A program written for one device often cannot be used for another device because these devices all have different architectures, and programs are architecture-specific.
Distributed computing, which is not a new concept, refers to interconnecting a number of computing elements, often heterogeneous, to perform a given task. By applying distributed computing, reconfigurable devices and digital signal processors can be connected to form a distributed reconfigurable simulator.
In this paper, it is shown that using reconfigurable devices can greatly increase the speed of simulation. A simple physical-layer communication system model has been created using a WildForce board, a reconfigurable device, and the performance is compared to a traditional software simulation of the same system. Using the reconfigurable device, the performance was increased by approximately one hundred times. This demonstrates the possibility of using reconfigurable devices for simulation of physical-layer communication systems.
Also, an middleware architecture for distributed reconfigurable simulation is proposed and implemented. Using the middleware, reconfigurable devices and various computing elements can be integrated. The proposed middleware has several components. The master works as the server for the system. An object is any device that has computing capability. A resource is an algorithm or function implemented for a certain object. An object and its resources are connected to the system through an agent. This middleware system is tested with three different objects and six resources, and the performance is analyzed. The results shows that it is possible to interconnect various objects to perform a distributed simulation using reconfigurable devices. Possible future research to enhance the architecture is also discussed.Ph. D.
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Pritchard, Lane L. "Distributed computing environment for Mine Warfare Command." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1993. http://handle.dtic.mil/100.2/ADA268799.
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Ahmetspahic, Emir. "Distributed Computing in Peer-to-peer Networks." Thesis, Linköping University, Department of Computer and Information Science, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2575.
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Concepts like peer-to-peer networks and distributed computing are not new. They have been available in different forms for a long time. This thesis examines the possibility of merging these concepts. The assumption is that non-centralized peer-to-peer networks can be used for effective sharing of computing resources. While most peer-to-peer systems today concentrate on sharing of data in various forms, this thesis concentrates on sharing of clock cycles instead of files.
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Kaya, Ozgur. "Efficient Scheduling In Distributed Computing On Grid." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607928/index.pdf.
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Today many computing resources distributed geographically are idle much of time. The aim of the grid computing is collecting these resources into a single system. It helps to solve problems that are too complex for a single PC. Scheduling plays a critical role in the efficient and effective management of resources to achieve high performance on grid computing environment. Due to the heterogeneity and highly dynamic nature of grid, developing scheduling algorithms for grid computing involves some challenges. In this work, we concentrate on efficient scheduling of distributed tasks on grid. We propose a novel scheduling heuristic for bag-of-tasks applications. The proposed algorithm primarily makes use of history based runtime estimation. The history stores information about the applications whose runtimes and other specific properties are recorded during the previous executions. Scheduling decisions are made according to similarity between the applications. Definition of similarity is an important aspect of this approach, apart from the best resource allocation. The aim of this scheduling algorithm (HISA-History Injected Scheduling Algorithm) is to define and find the similarity, and assign the job to the most suitable resource, making use of the similarity. In our evaluation, we use Grid simulation tool called GridSim. A number of intensive experiments with various simulation settings have been conducted. Based on the experimental results, the effectiveness of HISA scheduling heuristic is studied and compared to the other scheduling algorithms embedded in GridSim. The results show that history injection improves the performance of future job submissions on a grid.
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Arvidsson, Andreas, and Anders Andreasson. "Distributed computing for the public transit domain." Thesis, Karlstads universitet, Institutionen för matematik och datavetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-27747.
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DeSa, Colin Joseph. "Distributed problem solving environments for scientific computing." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-08042009-040307/.
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Algire, Martin. "Distributed multi-processing for high performance computing." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=31180.
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Parallel computing can take many forms. From a user's perspective, it is important to consider the advantages and disadvantages of each methodology. The following project attempts to provide some perspective on the methods of parallel computing and indicate where the tradeoffs lie along the continuum. Problems that are parallelizable enable researchers to maximize the computing resources available for a problem, and thus push the limits of the problems that can be solved. Solving any particular problem in parallel will require some very important design decisions to be made. These decisions may dramatically affect portability, performance, and cost of implementing a software solution to the problem. The results gained from this work indicate that although performance improvements are indeed possible---they are heavily dependent on the application in question and may require much more programming effort and expertise to implement.
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Craft, D. H. "Resource management in a distributed computing system." Thesis, University of Cambridge, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254104.
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Bridges, Christopher P. "Agent computing platform for distributed satellite systems." Thesis, University of Surrey, 2009. http://epubs.surrey.ac.uk/770399/.
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Space and satellite systems are considered to be the most extreme environment to design for and are fraught with engineering difficulty. Performance metrics such as fault tolerance, reliability, pre-determinism and heritage are still high on the list of requirements for all satellite missions. The advent of modem day electronics and miniaturisation, state-of-the-art computing and networking technologies has enabled research into 'distributed satellite systems', where multiple spacecraft work collaboratively to perform a mission using intersatellite connectivity. A satellite can be considered one of many nodes in an autonomous and decentralised system, analogous to a mobile ad-hoc network, enabling opportunities in multiple-point sensing, greater communications capabilities, and spacecraft redundancy. Existing satellite constellations can implement distributed satellite system scenarios but provide unpredictable relative ranges and rates due to various space perturbations. This creates a disconnected environment making it difficult to perform distributed mission operations. Without orbit maintenance, limited onboard resources in power and mass could mean lower processing and networking capabilities which need to rise dramatically to meet requirements for these new missions. This thesis investigates the use of an Agent-based distributed computing platform to enable ad-hoc satellites networking. Agents for real-time systems and their applications conclude that, despite being utilised in complex control systems, most Agent middleware is unsuited for mission critical, real-time, networked, embedded systems. Two constellation scenarios are simulated for distributed satellite missions highlighting orbital issues such as relative distance and mission lifetime. Computing requirements for such distributed computing opportunities using intersatellite connectivity and Agent technologies have led to a novel system-on-a-chip design, including a general purpose processor core and a dedicated Java co-processing core to enable hard real-time Agent functionalities and software Agent applications at minimal overhead. Common Agent middleware platforms are compared and a software configuration is chosen with relevant Agent services. A distributed image compression case study is also presented. A picosatellite testbed is also designed to provide realistic computing and power constraints.
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Chow, Ka-po, and 周嘉寶. "Load-balancing in distributed multi-agent computing." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B3122426X.
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張立新 and Lap-sun Cheung. "Load balancing in distributed object computing systems." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B31224179.
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Xiang, Yonghong. "Interconnection networks for parallel and distributed computing." Thesis, Durham University, 2008. http://etheses.dur.ac.uk/2156/.
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Parallel computers are generally either shared-memory machines or distributed- memory machines. There are currently technological limitations on shared-memory architectures and so parallel computers utilizing a large number of processors tend tube distributed-memory machines. We are concerned solely with distributed-memory multiprocessors. In such machines, the dominant factor inhibiting faster global computations is inter-processor communication. Communication is dependent upon the topology of the interconnection network, the routing mechanism, the flow control policy, and the method of switching. We are concerned with issues relating to the topology of the interconnection network. The choice of how we connect processors in a distributed-memory multiprocessor is a fundamental design decision. There are numerous, often conflicting, considerations to bear in mind. However, there does not exist an interconnection network that is optimal on all counts and trade-offs have to be made. A multitude of interconnection networks have been proposed with each of these networks having some good (topological) properties and some not so good. Existing noteworthy networks include trees, fat-trees, meshes, cube-connected cycles, butterflies, Möbius cubes, hypercubes, augmented cubes, k-ary n-cubes, twisted cubes, n-star graphs, (n, k)-star graphs, alternating group graphs, de Bruijn networks, and bubble-sort graphs, to name but a few. We will mainly focus on k-ary n-cubes and (n, k)-star graphs in this thesis. Meanwhile, we propose a new interconnection network called augmented k-ary n- cubes. The following results are given in the thesis.1. Let k ≥ 4 be even and let n ≥ 2. Consider a faulty k-ary n-cube Q(^k_n) in which the number of node faults f(_n) and the number of link faults f(_e) are such that f(_n) + f(_e) ≤ 2n - 2. We prove that given any two healthy nodes s and e of Q(^k_n), there is a path from s to e of length at least k(^n) - 2f(_n) - 1 (resp. k(^n) - 2f(_n) - 2) if the nodes s and e have different (resp. the same) parities (the parity of a node Q(^k_n) in is the sum modulo 2 of the elements in the n-tuple over 0, 1, ∙∙∙ , k - 1 representing the node). Our result is optimal in the sense that there are pairs of nodes and fault configurations for which these bounds cannot be improved, and it answers questions recently posed by Yang, Tan and Hsu, and by Fu. Furthermore, we extend known results, obtained by Kim and Park, for the case when n = 2.2. We give precise solutions to problems posed by Wang, An, Pan, Wang and Qu and by Hsieh, Lin and Huang. In particular, we show that Q(^k_n) is bi-panconnected and edge-bipancyclic, when k ≥ 3 and n ≥ 2, and we also show that when k is odd, Q(^k_n) is m-panconnected, for m = (^n(k - 1) + 2k - 6’ / ‘_2), and (k -1) pancyclic (these bounds are optimal). We introduce a path-shortening technique, called progressive shortening, and strengthen existing results, showing that when paths are formed using progressive shortening then these paths can be efficiently constructed and used to solve a problem relating to the distributed simulation of linear arrays and cycles in a parallel machine whose interconnection network is Q(^k_n) even in the presence of a faulty processor.3. We define an interconnection network AQ(^k_n) which we call the augmented k-ary n-cube by extending a k-ary n-cube in a manner analogous to the existing extension of an n-dimensional hypercube to an n-dimensional augmented cube. We prove that the augmented k-ary n-cube Q(^k_n) has a number of attractive properties (in the context of parallel computing). For example, we show that the augmented k-ary n-cube Q(^k_n) - is a Cayley graph (and so is vertex-symmetric); has connectivity 4n - 2, and is such that we can build a set of 4n - 2 mutually disjoint paths joining any two distinct vertices so that the path of maximal length has length at most max{{n- l)k- (n-2), k + 7}; has diameter [(^k) / (_3)] + [(^k - 1) /( _3)], when n = 2; and has diameter at most (^k) / (_4) (n+ 1), for n ≥ 3 and k even, and at most [(^k)/ (_4) (n + 1) + (^n) / (_4), for n ^, for n ≥ 3 and k odd.4. We present an algorithm which given a source node and a set of n - 1 target nodes in the (n, k)-star graph S(_n,k) where all nodes are distinct, builds a collection of n - 1 node-disjoint paths, one from each target node to the source. The collection of paths output from the algorithm is such that each path has length at most 6k - 7, and the algorithm has time complexity O(k(^3)n(^4)).
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PINA, FELIPE FREIXO. "UTILIZATION OF DHT IN DISTRIBUTED COMPUTING SYSTEMS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2011. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=19132@1.
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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIORArquiteturas P2P destacam-se pela descentralização e pelo incentivo a cooperação entre nós. Essas características permitem que sistemas baseados nesta arquitetura sejam tolerantes a falhas e que os recursos sejam distribu ídos entre os nós (via replicação). A utilização da técnica de DHT na criação de redes P2P permite que os sistemas sejam escaláveis. Ao contrário do uso mais comum em sistemas de distribuição de conteúdo, este trabalho investiga aplicacações da técnica de DHT em sistemas de computação distribu ída, onde o recurso compartilhado é a capacidade de processamento de cada nó. Quatro protocolos de roteamento de mensagens foram analisados para identificar os mais adequados aos sistemas de computação distribuída e aplicou-se o conceito de grupo de nós com o objetivo de aumentar a tolerância a falhas e distribuir tarefas entre os nós da rede.
P2P architectures are recognized for decentralization and incentive for the cooperation among nodes. These characteristics allow for fault tolerance and resource distribution among the nodes (by replication) to systems based on the P2P architecture. Systems based in P2P networks built using the DHT technique are scalable. Since this architecture is commonly used in content distribution systems, in this work we investigate the utilization of the DHT technique in distributed computing systems, where the shared resources are the node’s computational power. Four routing protocols were analyzed to identify the most appropriated for use in distributed computing systems and applied the group concept to archive fault tolerance and resource distribution among nodes.
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Saias, Alain Isaac. "Randomness versus non-determinism in distributed computing." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/37022.
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Mallett, Jacky 1963. "Kami : an anarchic approach to distributed computing." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/61847.
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Thesis (S.M.)--Massachusetts Institute of Technology, Program in Media Arts & Sciences, 2000.Includes bibliographical references (p. 83-84).
This thesis presents a distributed computing system, Kami, which provides support for applications running in an environment of heterogeneous workstations linked together by a high speed network. It enables users to easily create distributed applications by providing a backbone infrastructure of localized daemons which operate in a peer-to-peer networking environment, providing support for software distribution, network communication, and data streaming suitable for use by coarse grained distributed applications. As a collective entity, kami daemons, each individually run on a single machine, form a cooperating anarchy of processes. These support their applications using adaptive algorithms with no form of centralized control. Instead of attempting to provide a controlled environment, this thesis assumes a heterogeneous and uncontrolled environment, and presents a model for distributed computation that is completely decentralized and uses multicast communication between workstations to form an ecology of co-operating processes, which actively attempt to maintain an equilibrium between the demands of their users and the capabilities of the workstations on which they are running.
by Jacky Mallett.
S.M.
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Kelley, Ian Robert. "Data management in dynamic distributed computing environments." Thesis, Cardiff University, 2012. http://orca.cf.ac.uk/44477/.
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Data management in parallel computing systems is a broad and increasingly important research topic. As network speeds have surged, so too has the movement to transition storage and computation loads to wide-area network resources. The Grid, the Cloud, and Desktop Grids all represent different aspects of this movement towards highly-scalable, distributed, and utility computing. This dissertation contends that a peer-to-peer (P2P) networking paradigm is a natural match for data sharing within and between these heterogeneous network architectures. Peer-to-peer methods such as dynamic discovery, fault-tolerance, scalability, and ad-hoc security infrastructures provide excellent mappings for many of the requirements in today’s distributed computing environment. In recent years, volunteer Desktop Grids have seen a growth in data throughput as application areas expand and new problem sets emerge. These increasing data needs require storage networks that can scale to meet future demand while also facilitating expansion into new data-intensive research areas. Current practices are to mirror data from centralized locations, a technique that is not practical for growing data sets, dynamic projects, or data-intensive applications. The fusion of Desktop and Service Grids provides an ideal use-case to research peer-to-peer data distribution strategies in a hybrid environment. Desktop Grids have a data management gap, while integration with Service Grids raises new challenges with regard to cross-platform design. The work undertaken here is two-fold: first it explores how P2P techniques can be leveraged to meet the data management needs of Desktop Grids, and second, it shows how the same distribution paradigm can provide migration paths for Service Grid data. The result of this research is a Peer-to-Peer Architecture for Data-Intensive Cycle Sharing (ADICS) that is capable not only of distributing volunteer computing data, but also of providing a transitional platform and storage space for migrating Service Grid jobs to Desktop Grid environments.
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O'Keeffe, Daniel Brendan. "Distributed complex event detection for pervasive computing." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609012.
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Mohd, Nazir M. A. N. "Cost-effective resource management for distributed computing." Thesis, University College London (University of London), 2011. http://discovery.ucl.ac.uk/1331897/.
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Current distributed computing and resource management infrastructures (e.g., Cluster and Grid) suffer from a wide variety of problems related to resource management, which include scalability bottleneck, resource allocation delay, limited quality-of-service (QoS) support, and lack of cost-aware and service level agreement (SLA) mechanisms. This thesis addresses these issues by presenting a cost-effective resource management solution which introduces the possibility of managing geographically distributed resources in resource units that are under the control of a Virtual Authority (VA). A VA is a collection of resources controlled, but not necessarily owned, by a group of users or an authority representing a group of users. It leverages the fact that different resources in disparate locations will have varying usage levels. By creating smaller divisions of resources called VAs, users would be given the opportunity to choose between a variety of cost models, and each VA could rent resources from resource providers when necessary, or could potentially rent out its own resources when underloaded. The resource management is simplified since the user and owner of a resource recognize only the VA because all permissions and charges are associated directly with the VA. The VA is controlled by a ’rental’ policy which is supported by a pool of resources that the system may rent from external resource providers. As far as scheduling is concerned, the VA is independent from competitors and can instead concentrate on managing its own resources. As a result, the VA offers scalable resource management with minimal infrastructure and operating costs. We demonstrate the feasibility of the VA through both a practical implementation of the prototype system and an illustration of its quantitative advantages through the use of extensive simulations. First, the VA concept is demonstrated through a practical implementation of the prototype system. Further, we perform a cost-benefit analysis of current distributed resource infrastructures to demonstrate the potential cost benefit of such a VA system. We then propose a costing model for evaluating the cost effectiveness of the VA approach by using an economic approach that captures revenues generated from applications and expenses incurred from renting resources. Based on our costing methodology, we present rental policies that can potentially offer effective mechanisms for running distributed and parallel applications without a heavy upfront investment and without the cost of maintaining idle resources. By using real workload trace data, we test the effectiveness of our proposed rental approaches. Finally, we propose an extension to the VA framework that promotes long-term negotiations and rentals based on service level agreements or long-term contracts. Based on the extended framework, we present new SLA-aware policies and evaluate them using real workload traces to demonstrate their effectiveness in improving rental decisions.
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Liu, H. "Support for flexible and transparent distributed computing." Thesis, University College London (University of London), 2010. http://discovery.ucl.ac.uk/19725/.
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Modern distributed computing developed from the traditional supercomputing community rooted firmly in the culture of batch management. Therefore, the field has been dominated by queuing-based resource managers and work flow based job submission environments where static resource demands needed be determined and reserved prior to launching executions. This has made it difficult to support resource environments (e.g. Grid, Cloud) where the available resources as well as the resource requirements of applications may be both dynamic and unpredictable. This thesis introduces a flexible execution model where the compute capacity can be adapted to fit the needs of applications as they change during execution. Resource provision in this model is based on a fine-grained, self-service approach instead of the traditional one-time, system-level model. The thesis introduces a middleware based Application Agent (AA) that provides a platform for the applications to dynamically interact and negotiate resources with the underlying resource infrastructure. We also consider the issue of transparency, i.e., hiding the provision and management of the distributed environment. This is the key to attracting public to use the technology. The AA not only replaces user-controlled process of preparing and executing an application with a transparent software-controlled process, it also hides the complexity of selecting right resources to ensure execution QoS. This service is provided by an On-line Feedback-based Automatic Resource Configuration (OAC) mechanism cooperating with the flexible execution model. The AA constantly monitors utility-based feedbacks from the application during execution and thus is able to learn its behaviour and resource characteristics. This allows it to automatically compose the most efficient execution environment on the fly and satisfy any execution requirements defined by users. Two policies are introduced to supervise the information learning and resource tuning in the OAC. The Utility Classification policy classifies hosts according to their historical performance contributions to the application. According to this classification, the AA chooses high utility hosts and withdraws low utility hosts to configure an optimum environment. The Desired Processing Power Estimation (DPPE) policy dynamically configures the execution environment according to the estimated desired total processing power needed to satisfy users’ execution requirements. Through the introducing of flexibility and transparency, a user is able to run a dynamic/normal distributed application anywhere with optimised execution performance, without managing distributed resources. Based on the standalone model, the thesis further introduces a federated resource negotiation framework as a step forward towards an autonomous multi-user distributed computing world.
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Chen, Xuetao. "Resource Allocation for Wireless Distributed Computing Networks." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/77054.
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Wireless distributed computing networks (WDCNs) will become the next frontier of the wireless industry as the performance of wireless platforms is being increased every year and wireless industries are looking for "killer" applications for increased channel capacity. However, WDCNs have several unique problems compared with currently well-investigated methods for wireless sensor networks and wired distributed computing. For example, it is difficult for WDCNs to be power/energy efficient considering the uncertainty and heterogeneity of the wireless environment. In addition, the service model has to take account of the interference-limited feature of wireless channels to reduce the service delay.
Our research proposes a two-phase model for WDCNs including the service provision phase and the service access phase according to different traffic patterns and performance requirements. For the service provision phase, we investigate the impact of communication channel conditions on the average execution time of the computing tasks within WDCNs. We then discuses how to increase the robustness and power efficiency for WDCNs subject to the impact of channel variance and spatial heterogeneity. A resource allocation solution for computation oriented WDCNs is then introduced in detail which mitigates the effects of channel variations with a stochastic programming solution.
Stochastic geometry and queue theory are combined to analyze the average performance of service response time and to design optimal access strategies during the service access phase. This access model provides a framework to analyze the service access performance and evaluate whether the channel heterogeneity should be considered. Based on this analysis, optimal strategies to access the service nodes can be determined in order to reduce the service response time. In addition, network initialization and synchronization are investigated in order to build a multiple channel WDCN in dynamic spectrum access (DSA) environments. Further, an efficient primary user detection method is proposed to reduce the channel vacation latency for WDCNs in DSA environments.
Finally, this dissertation presents the complete design and implementation of a WDCN on COgnitive Radio Network (CORNET). Based on SDR technologies, software dedicated to WDCNs is designed and implemented across the PHY layer, MAC layer, and application layer. System experiments are carried out to demonstrate the performance issues and solutions presented in this dissertation. Wireless distributed computing networks (WDCNs) will become the next frontier of the wireless industry as the performance of wireless platforms is being increased every year and wireless industries are looking for "killer" applications for increased channel capacity. However, WDCNs have several unique problems compared with currently well-investigated methods for wireless sensor networks and wired distributed computing. For example, it is difficult for WDCNs to be power/energy efficient considering the uncertainty and heterogeneity of the wireless environment. In addition, the service model has to take account of the interference-limited feature of wireless channels to reduce the service delay.
Our research proposes a two-phase model for WDCNs including the service provision phase and the service access phase according to different traffic patterns and performance requirements. For the service provision phase, we investigate the impact of communication channel conditions on the average execution time of the computing tasks within WDCNs. We then discuses how to increase the robustness and power efficiency for WDCNs subject to the impact of channel variance and spatial heterogeneity. A resource allocation solution for computation oriented WDCNs is then introduced in detail which mitigates the effects of channel variations with a stochastic programming solution.
Stochastic geometry and queue theory are combined to analyze the average performance of service response time and to design optimal access strategies during the service access phase. This access model provides a framework to analyze the service access performance and evaluate whether the channel heterogeneity should be considered. Based on this analysis, optimal strategies to access the service nodes can be determined in order to reduce the service response time. In addition, network initialization and synchronization are investigated in order to build a multiple channel WDCN in dynamic spectrum access (DSA) environments. Further, an efficient primary user detection method is proposed to reduce the channel vacation latency for WDCNs in DSA environments.
Finally, this dissertation presents the complete design and implementation of a WDCN on COgnitive Radio Network (CORNET). Based on SDR technologies, software dedicated to WDCNs is designed and implemented across the PHY layer, MAC layer, and application layer. System experiments are carried out to demonstrate the performance issues and solutions presented in this dissertation.Ph. D.
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Karra, Kiran. "Wireless Distributed Computing on the Android Platform." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/35256.
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The last couple of years have seen an explosive growth in smartphone sales. Additionally, the computational power of modern smartphones has been increasing at a high rate. For example, the popular iPhone 4S has a 1 GHz processor with 512 MB of RAM [5]. Other popular smartphones such as the Samsung Galaxy Nexus S also have similar specications. These smartphones are as powerful as desktop computers of the 2005 era, and the tight
integration of many dierent hardware chipsets in these mobile devices makes for a unique mobile platform that can be exploited for capabilities other than traditional uses of a phone, such as talk and text [4].
In this work, the concept using smartphones that run the Android operating system for distributed computing over a wireless mesh network is explored. This is also known as wireless distributed computing (WDC). The complexities of WDC on mobile devices are different from traditional distributed computing because of, among other things, the unreliable wireless communications channel and the limited power available to each computing node. This thesis develops the theoretical foundations for WDC. A mathematical model representing the total amount of resources required to distribute a task with WDC is developed. It is shown that given a task that is distributable, under certain conditions, there exists a theoretical minimum amount of resources that can be used in order to perform a task using WDC. Finally, the WDC architecture is developed, an Android App implementation of the WDC architecture is tested, and it is shown in a practical application that using WDC to perform
a task provides a performance increase over processing the job locally on the Android OS.Master of Science
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SHINDE, KAUSTUBH ARUN. "FUNCTION COMPUTING IN VERTICALLY PARTITIONED DISTRIBUTED DATABASES." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1163574762.
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