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Speeding up fractal image compression by genetic algorithms

MULTIDIMENSIONAL systems AND SIGNAL PROCESSING 2005年第2期16卷 217-236页

作者： Mohamed, F Aoued, B Department of Computer Science Evolutionary Engineering and Distributed Information Systems Laboratory EEDIS University of Sidi Bel-Abbès Algeria Department of Electronics Communications Networks Architectures and Multimedia Laboratory University of Sidi Bel Abbès Algeria

The main problem with all fractal compression implementation is execution time. Algorithms can spend hours to compress a single image. Most of the major variants of the standard algorithm for speeding up computation time have led to a bad-quality or a lower compression ratio. For example, the Fisher's [ 7] proposed classification pattern greatly accelerated the algorithm, but image quality was poor due to the search-space reduction imposed by the classification, which eleminates a lot of good solutions. By using genetic algorithms to address the problem, we optimize the domain blocks search. We explore all domain blocks present in the image but not in exhaustive way ( like a standard algorithm) and without omitting any possible block (solution) as a classification pattern does. A genetic algorithm is the unique method for satisfying these constraints. And it is a way to do be a random search because the genetic one is directed by fitness selection, which produces optimal solutions. Our goal in this work is to use a genetic algorithm to solve the IFS inverse problem and to build a fractal compression algorithm based on the genetic optimization of a domain blocks search. we have also implemented standard Barnsley algorithm, the Y. Fisher based on classification, and the genetic compression algorithm with quadtree partitioning. A population of transformations was evolved for each range block, and the result is compared with the standard Barnsely algorithm and the Fisher algorithm = based classification. We deduced an optimal set of values for the best parameters combination, and we can also specify the best combination for each desired criteria: best compression ratio, best image quality, or quick compression process. By running many test images, we experimentally found the following set of optimal values of all the algorithm parameters that ensure compromise between execution time and solutions optimality: Population size = 100, Maximum generations = 20, Crossover rat

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Predicting cement compressive strength using double-layer multi-expression programming

Predicting cement compressive strength using double-layer mu...

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4th International Conference on Computational and Information Sciences, ICCIS 2012

作者： Zhang, Qingke Yang, Bo Wang, Lin Zhu, Fuxiang Shandong Province Key Laboratory of Network Based Intelligent Computing University of Jinan Jinan China Computer Networks and Distributed Systems Laboratory Beijing Institute Technology Beijing China

ISBN: (纸本)9780769547893

This paper presents a novel algorithm named Double-layer Multi-expression Programming (DMEP). Then DMEP model is applied to the prediction of 28-day Portland cement compressive strength. We compare DMEP model with other four soft computing models, namely Multi-Expression Programming model (MEP), Gene Expression Programming model (GEP), Neural networks model (NN) and Fuzzy logic model (FL) on 28-day cement strength prediction. The experiment results show that DMEP model has a lower rate in RMSE and MAE, and the prediction average percentage error of the cement strength data using DMEP model is reduced to 2.18%, which is lower than other four models. The results obtained from the computational tests demonstrate that DMEP is a promising technique for the prediction of cement strength. © 2012 IEEE.

关键词： Soft computing

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Checkpointing distributed application running on mobile ad hoc networks

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International Journal of High Performance Computing and Networking 2018年第2期11卷 95-107页

作者： Mansouri, Houssem Badache, Nadjib Aliouat, Makhlouf Pathan, Al-Sakib Khan Department of Computer Science Faculty of Exact Sciences University of Bejaia Bejaia06000 Algeria Research Center on Scientific and Technical Information CERIST Ben-Aknoun Algiers16000 Algeria Laboratory of Networks and Distributed Systems Computer Science Department University of Ferhat Abbas Stif1 Stif19000 Algeria Faculty of Computer and Information Systems Islamic University in Madinah Madinah al-Munawwarah Saudi Arabia CSE Department University of Asia Pacific Bangladesh

Mobile ad hoc network (MANET) is a type of wireless network consisting of a set of self-configured mobile hosts that can communicate with each other using wireless links without the assistance of any fixed infrastructure. This has made it possible for us to create distributed mobile computing applications and has also brought several new challenges in the field of distributed algorithm design. Checkpointing is a well explored fault tolerance technique for the wired and cellular mobile networks. However, it is not directly applicable to MANET owing to its dynamic topology, limited availability of stable storage, partitioning and the absence of fixed infrastructure. In this paper, we propose an adaptive, coordinated and non-blocking checkpointing algorithm to provide fault tolerance in cluster-based MANET, where only a minimum number of mobile hosts in the cluster should take checkpoints. The performance analysis and simulation results show that the proposed scheme requires less coordinating-message cost and performs well compared to the related previous works. Copyright ? 2018 Inderscience Enterprises Ltd.

关键词： Fault tolerance

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A Communication-Induced Checkpointing Algorithm for Consistent-Transaction in distributed Database systems 1

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8th International Symposium on Security in Computing and Communications, SSCC 2020

作者： Mansouri, Houssem Pathan, Al-Sakib Khan Laboratory of Networks and Distributed Systems Computer Science Department Faculty of Sciences Ferhat Abbas Setif University 1 Setif Algeria Department of Computer Science and Engineering Independent University Dhaka Bangladesh

ISBN: (数字)9789811604225

ISBN: (纸本)9789811604218

For better protection of distributed systems, two well-known techniques are: checkpointing and rollback recovery. While failure protection is often considered a separate issue, it is crucial for establishing better secure distributed systems. This article is dedicated to the proposal of a new checkpointing algorithm for saving a consistent-transaction state in distributed databases ensuring that database management systems are able, after a failure, to recover the state of the database. The proposed communication-induced algorithm does not hamper the normal transaction processing and saves a global consistent-transaction state that records only the fully completed transactions. Analysis and experimental results of our proposal show that the proposed scheme saves a minimum number of forced checkpoints and has some performance gains compared to the alternative approaches. © 2021, Springer Nature Singapore Pte Ltd.

关键词： distributed database systems

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i-DBF: an Improved Bloom Filter Representation Method on Dynamic Set

i-DBF: an Improved Bloom Filter Representation Method on Dyn...

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International Conference on Grid and Cooperative Computing Workshops (GCCW)

作者： Jiacong Wang Mingzhong Xiao Jing Jiang Bonan Min Computer Networks and Distributed Systems Laboratory Peking University China

Bloom filter is a simple space-efficient randomized data structure for representing a set in order to support membership queries, which uses an m-bit array to represent a data set. Dynamic bloom filter (DBF) can support concisely representation and approximate membership queries of dynamic set instead of static set. It has been proved that DBF not only possess the advantage of standard bloom filter, but also has better features when dealing with dynamic set. But DBF also has a disadvantage: the addition operation which mapped element x into bloom filter s will become no sense, if some of the first s-1 bloom filters have already responded that element x is in set A with some false positive probability. We point out this shortcoming and improve the addition operation with a new algorithm. We call this improved dynamic bloom filter i-DBF. Finally, we prove that this i-DBF has better performance both in the storage space and in the false positive probability

关键词： Data structures Peer to peer computing Costs computer networks Laboratories Protocols Information filtering Information filters Bandwidth Grid computing

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A Resilient Hierarchical Checkpointing Algorithm for distributed systems Running on Cluster Federation 1

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7th International Symposium on Security in Computing and Communications, SSCC 2019

作者： Mansouri, Houssem Pathan, Al-Sakib Khan Laboratory of Networks and Distributed Systems Computer Science Department Faculty of Sciences Ferhat Abbas Setif University 1 Sétif Algeria Department of Computer Science and Engineering Southeast University Dhaka Bangladesh

ISBN: (数字)9789811548253

ISBN: (纸本)9789811548246

In distributed systems, checkpointing method can be used to ensure fault-tolerance, which in turn could help the system’s security and stability. In simple terms, checkpointing means saving status information of a system. In this work, a novel hierarchical checkpointing algorithm for distributed systems is proposed, which runs on cluster federation. This algorithm is based on two well-known techniques in the literature and it ensures that a locally consistent state is always maintained in each cluster with a global optimistic logging technique between clusters. The proposed algorithm synchronizes the intra- and inter-cluster checkpointing process in such way that each checkpoint taken locally in any cluster is a segment of the consistent global state. Compared to other works, our scheme has low message cost as it makes sure that only few processes in each cluster record checkpoints for any execution operation. © Springer Nature Singapore Pte Ltd. 2020.

关键词： Fault tolerance

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Rapid mobile development with ARC: Application framework for robust communications for disaster risk reduction and management

Rapid mobile development with ARC: Application framework for...

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IEEE International Conference on Wireless and Mobile Computing, Networking And Communications (WiMob)

作者： Jan Vincent Santos Danah Veronica Torres Monica Kathrina Villanoy Cedric Angelo Festin John Norman Doctor Roel Ocampo Networks and Distributed Systems Group University of the Philippines Computer Networks Laboratory University of the Philippines

ISBN: (纸本)9781509007257

In disaster situations communication and power infrastructure could be damaged, disrupting their associated services. This could delay relief efforts and cost more lives. In situations where connections are damaged and unreliable, peer-to-peer (P2P) and delay-tolerant networking (DTN) technologies can help provide alternative communication modes particularly in support of rescue and relief operations. Combining the benefits of the store-and-forward capability of DTN and the data propagation techniques of Wi-Fi Direct, we have created a flexible framework called ARC which allows users to create applications that could meet their specific requirements, particularly those in support of emergency communications. To demonstrate our framework, we created a simple application using ARC, and used this application to evaluate its DTN and Wi-Fi Direct group recovery capabilities.

关键词： IEEE 802.11 Standard Smart phones Libraries Mobile communication Protocols Routing

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MMC01-2: A Replica-Conscious Load Balancing Strategy for Large-Scale Multimedia Storage systems

MMC01-2: A Replica-Conscious Load Balancing Strategy for Lar...

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IEEE Globecom 2006

作者： Zeng Zeng Bharadwaj Veeravalli Computer Networks and Distributed Systems Laboratory National University of Singapore Singapore

In distributed multimedia storage systems where client requests for different multimedia objects may have different demands, placement and replication of the objects is an important factor, as it may result in an imbalance in server loading across the system. Replica management and load balancing is all the more a crucial issue for large-scale multimedia systems. We design and analyze a heuristic static strategy to determine the placement, number of replicas of the objects, and balance the client requests among the servers, to minimize the average waiting time (AWT) of the requests. Our strategy exploits clever virtual routing technique to strike a balance among the servers for load balancing. We validate the performance via rigorous simulations with respect to several influencing factors and compare with a system that uses hashing function only for load balancing.

关键词： Load management Large-scale systems Multimedia systems Network servers Streaming media Web server computer networks Laboratories Bandwidth Routing

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Self-Organizing systems 1

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丛书名： Lecture Notes in computer Science

1000年

作者： Thrasyvoulos Spyropoulos Karin Anna Hummel

ISBN: (数字)9783642108655

ISBN: (纸本)9783642108648

This book constitutes the refereed proceedings of the 4th International Workshop on Self-Organizing systems, IWSOS 2009, held in Zurich, Switzerland, in December 2009. The 14 revised full papers and 13 revised short papers presented were carefully selected from the 34 full and 27 short paper submissions. The papers are organized in topical sections on ad hoc and sensor networks; services, storage, and internet routing; peer-to-peer systems; theory and general approaches; overlay networks; peer-to-peer systems and internet routing; wireless networks; and network topics.

关键词： computer Communication networks Artificial Intelligence Simulation and Modeling Special Purpose and Application-Based systems Data Mining and Knowledge Discovery Information Storage and Retrieval

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A dynamic reconfiguration model for a distributed web crawling system

A dynamic reconfiguration model for a distributed web crawli...

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International Conference on computer networks and Mobile Computing (ICCNMC)

作者： Yan Hongfei Wang Jianyong Li Xiaoming Computer Networks and Distributed Systems Laboratory Department of Computer Science and Technology Peking University China

A web crawling system employing a parallel and distributed architecture needs to have a mechanism to bring the whole system in a coordinated state when the nodes are added to or removed from the system. This paper presents an efficient dynamic reconfiguration model that can be used in such a system. The study shows that this model leads to some nice properties, such as load balance and low traffic in the system, which contribute to high performance. Currently this model is being implemented in WebGather, a well-known Chinese and English web search engine.

关键词： Service oriented architecture Search engines Crawlers computer networks Laboratories computer science computer architecture Web search Telecommunication traffic Traffic control

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