the use of robotic arms in industrial and academic settings has grown exponentially, however, the process of simulating and operating these systems continues to be a significant challenge, particularly for users witho...
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Access to large numbers of data sources introduces new problems for users of heterogeneous distributed databases. End users and application programmers must deal with unavailable data sources. Database administrators ...
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ISBN:
(纸本)0818673982
Access to large numbers of data sources introduces new problems for users of heterogeneous distributed databases. End users and application programmers must deal with unavailable data sources. Database administrators must deal with incorporating new sources into the model. Database implementors must deal withthe translation of queries between query languages and schemas. the distributed Information Search COmponent (Disco) addresses these problems. Query processing semantics are developed to process queries over data sources which do not return answers. Data modeling techniques manage connections to data sources. the component interface to data sources flexibly handles different query languages and translates queries. this paper describes (a) the distributed mediator architecture of Disco, (b) its query processing semantics, (c) the data model and its modeling of data source connections, and (d) the interface to underlying data sources.
A token based algorithm for distributed mutual exclusion is presented. It uses a distributed counter to tolerate faults due to site failures and communication failures. this eliminates the need for expensive election ...
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ISBN:
(纸本)0818673982
A token based algorithm for distributed mutual exclusion is presented. It uses a distributed counter to tolerate faults due to site failures and communication failures. this eliminates the need for expensive election protocols that are commonly employed in existing token-based algorithms. As in many existing fault-tolerant mutual exclusion algorithms, timeouts are used to detect failures. Our algorithm has the unique property that even if timeout periods are incorrectly assumed, the safety requirement of mutual exclusion is still guaranteed. It is, therefore, suitable for highly asynchronous distributed environments. Performance analysis shows that the algorithm is also efficient in terms of the average number of messages required per critical section, and the average time delay to enter the critical section. Finally, we show how to obtain a bounded algorithm from the basic unbounded algorithm.
distributed programs are often instrumented for collecting information to assist in analyzing the behavior of an application. However, the act of monitoring a process introduces intrusive overhead that delays the time...
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ISBN:
(纸本)0818673982
distributed programs are often instrumented for collecting information to assist in analyzing the behavior of an application. However, the act of monitoring a process introduces intrusive overhead that delays the times at which actions occur in a monitored execution in comparison to the times at which they occur in an unmonitored execution. these delays can alter the actions of individual processes and the behavior of the system as a whole. the overall behavior of process scheduling is determined by the choices a scheduler makes in terms of when particular processes will be given access to the processor. Monitoring introduced delays can result in different scheduling choices being made which can in turn lead to changes in the behavior of processes throughout the distributed system. this paper presents intrusion removal techniques which are designed to accommodate monitoring delays in an attempt to minimize the intrusion on the scheduling and execution behavior of the monitored computation.
Wireless power transfer technologies lead the way towards new paradigms for pervasive networking and have already penetrated the mobile and portable user device research and market. their use is not only limited to ch...
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ISBN:
(纸本)9781728143514
Wireless power transfer technologies lead the way towards new paradigms for pervasive networking and have already penetrated the mobile and portable user device research and market. their use is not only limited to charging devices like smartphones wirelessly by using a central wireless charger, but it is also extended to peer-to-peer (P2P) wireless crowd charging, when a user device shares energy directly with another user device. this paper surveys the literature over the period 2014-2020 on both P2P and central wireless crowd charging from the point of view of algorithmic applications as it applies to ubiquitously networked user devices and identifies some open research challenges for the future.
A Virtual Hierarchical design optimization method has been developed to combine strength of the flat and the hierarchical optimization methods for efficient and quality optimization of multi-million gate designs in a ...
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ISBN:
(纸本)0769524079
A Virtual Hierarchical design optimization method has been developed to combine strength of the flat and the hierarchical optimization methods for efficient and quality optimization of multi-million gate designs in a distributedcomputing environment. A novel design representation "Virtual Hierarchy" is proposed for sub-design optimization in a distributedcomputing environment. the principle and the implementation details of the method are described. the method has been successfully applied to a number of designs.
Recently, large-scale distributedsystems are being developed. Since it is expensive to newly develop the system, it is required to adopt the system in use to the changes of the user requirements and the environments....
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ISBN:
(纸本)0818673982
Recently, large-scale distributedsystems are being developed. Since it is expensive to newly develop the system, it is required to adopt the system in use to the changes of the user requirements and the environments. therefore, it is essential to discuss how to upgrade the distributed programs. the system cannot be kept highly available by the conventional upgrading methods because multiple processes have to be suspended simultaneously. this paper discusses a new method which allows each process to invoke the upgrading procedure independently of the other processes. the key idea is that multiple versions of processes are allowed to co-exist temporarily. If the multiple versions of processes co-exist, such protocol errors as the unspecified receptions and the communication deadlocks can occur. Each pair of an old-version process and a new-version one is named a process group. the group communication protocol proposed in this paper supports message transmissions among the process groups. Moreover, the protocol errors can be detected and resolved by using checkpointing, timeout and rollback recovery.
As the amount data from IoT devices on transportation systems increases, developing a robust pipeline to stream, store and process data became critical. In this study, We explore prediction accuracy and computational ...
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ISBN:
(纸本)9781538666142
As the amount data from IoT devices on transportation systems increases, developing a robust pipeline to stream, store and process data became critical. In this study, We explore prediction accuracy and computational performance of various supervised and unsupervised algorithms perform on distributedsystems for developing a smart transportation data pipeline. Using a subset of New York City Taxi & Limousine Commission data, we evaluate Logistic Regression, Random Forrest Regressors and Classifiers, Principal Component Analysis, and Gradient Boosted Regression and Classification Tree machine learning techniques on a commodity computer as well as on a distributed system. Employing Amazon S3, EC2 and EMR, MongoDB, and Spark, we identify the conditions-data size and algorithm-under which the performance of distributedsystems excel.
Based on a brief history of the storage systems for Web applications, we motivate the need for a new storage system. We then describe the architecture of such a system, called Yesquel. Yesquel supports the SQL query l...
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ISBN:
(纸本)9781450329286
Based on a brief history of the storage systems for Web applications, we motivate the need for a new storage system. We then describe the architecture of such a system, called Yesquel. Yesquel supports the SQL query language and offers performance similar to NOSQL storage systems.
In this paper we present an evaluation of Angel, a single address space operating system, originally designed in 1992, which has been developed over the past few years. the purpose of this work was to examine how we c...
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ISBN:
(纸本)0818673982
In this paper we present an evaluation of Angel, a single address space operating system, originally designed in 1992, which has been developed over the past few years. the purpose of this work was to examine how we could simplify the kernel and service structure using the single address space as the enabling technology. We believe that in so doing, we could achieve far better performance and simpler extensibility compared to other micro-kernel architectures. We recently completed a prototype system based around the PC/486 architecture which has allowed us to evaluate our claims and postulations. An initial analysis of this prototype has been performed to examine the system's structure and performance characteristics. this demonstrates an architecture which is more flexible, faster and smaller than monolithic operating systems.
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