The Experts below are selected from a list of 2682 Experts worldwide ranked by ideXlab platform
Jawad A Salehi - One of the best experts on this subject based on the ideXlab platform.
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energy efficient routing and spectrum assignment with regenerator placement in elastic optical networks
Journal of Lightwave Technology, 2014Co-Authors: Ahmad Fallahpour, Hamzeh Beyranvand, Alireza S Nezamalhosseini, Jawad A SalehiAbstract:In this paper, we present a dynamic energy efficient routing and spectrum assignment algorithm with regenerator placement (RP) capability for elastic optical networks. In this algorithm, a virtual graph is considered for a given network topology graph, whereby the cost functions of virtual graph is computed according to the energy consumption of the corresponding links and intermediates routers. Furthermore, the arrived connection Request is served by finding the most energy-efficient path among the possible candidate paths. Then, the quality of transmission (QoT) of the selected path is evaluated in terms of bit error rate. If the estimated QoT is higher than a predetermined threshold, the designated path is assigned to the Incoming Request, otherwise, the RP algorithm is utilized to place a regenerator at the most energy-efficient position. In addition, the demanded transmission rate and required QoT are fulfilled by assessing different modulation formats and selecting appropriate modulation format in terms of power consumption and blocking probability (BP). We evaluate the proposed algorithms through extensive numerical simulations. The results of simulations reveal that the proposed algorithms have better performance than other existing schemes in terms of network total energy consumption and acceptable BP.
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a quality of transmission aware dynamic routing and spectrum assignment scheme for future elastic optical networks
Journal of Lightwave Technology, 2013Co-Authors: Hamzeh Beyranvand, Jawad A SalehiAbstract:In this paper, we present a quality-of-transmission (QoT) aware dynamic routing, modulation level, and spectrum assignment scheme referred to as QoT-aware RSA. The proposed QoT-aware RSA has three stages: path computation with QoT-aware modulation level assignment, path selection, and spectrum assignment. Two schemes are presented in the path computation stage namely, modified Dijkstra and K-shortest-path algorithms. A closed-form expression is derived to model the fiber nonlinearity effects and the impairments of intermediate routers. This expression is utilized to estimate the network dependent QoT and the transmission reach of the modulation levels. We propose to select the best path in terms of optical signal-to-noise ratio (OSNR) metric. Furthermore, the traffic-balancing spectrum assignment method is utilized to serve the Incoming Request. The proposed scheme is evaluated using extensive numerical simulations based on both random and deterministic traffic models. The results of simulation reveal that the path selection and spectrum assignment methods can affect the average OSNR performance. Furthermore, the results show that the proposed path selection and spectrum assignment schemes outperform other existing alternatives in the literature.
Krzysztof Zatwarnicki - One of the best experts on this subject based on the ideXlab platform.
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ICCCI - Global Distribution of HTTP Requests Using the Fuzzy-Neural Decision-Making Mechanism
Computational Collective Intelligence. Semantic Web Social Networks and Multiagent Systems, 2009Co-Authors: Leszek Borzemski, Anna Zatwarnicka, Krzysztof ZatwarnickiAbstract:This paper presents the HTTP Request global distribution using the fuzzy-neural decision making mechanism. Two efficient algorithms GARDiB and GARDiB2 are proposed to support HTTP Request routing to the Websites. The algorithms use the fuzzy-neural decision-making method to assign each Incoming Request to the Website with the least expected response time. The response time includes the transmission time over the network; as well as the time elapsed on the responding Website server. Simulation experiments showed that GARDiB performed slightly better than GARDiB2 and both proposed algorithms outperformed other competitive distribution algorithms in all simulated workload scenarios.
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ICAISC - Performance evaluation of fuzzy-neural HTTP Request distribution for web clusters
Artificial Intelligence and Soft Computing – ICAISC 2006, 2006Co-Authors: Leszek Borzemski, Krzysztof ZatwarnickiAbstract:In this paper we present the performance evaluation of our fuzzy-neural HTTP Request distribution algorithm called FNRD, which assigns each Incoming Request to the server in the Web cluster with the quickest expected response time. The fuzzy mechanism is used to estimate the expected response times. A neural-based feedback loop is used for real-time tuning of response time estimates. To evaluate the system, we have developed a detailed simulation and workload model using CSIM19 package. Our simulations show that FNRD can be more effective than its competitors.
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Performance Evaluation of Fuzzy-Neural HTTP Request Distribution for Web Clusters
Lecture Notes in Computer Science, 2006Co-Authors: Leszek Borzemski, Krzysztof ZatwarnickiAbstract:In this paper we present the performance evaluation of our fuzzy-neural HTTP Request distribution algorithm called FNRD, which assigns each Incoming Request to the server in the Web cluster with the quickest expected response time. The fuzzy mechanism is used to estimate the expected response times. A neural-based feedback loop is used for real-time tuning of response time estimates. To evaluate the system, we have developed a detailed simulation and workload model using CSIM19 package. Our simulations show that FNRD can be more effective than its competitors.
Hamzeh Beyranvand - One of the best experts on this subject based on the ideXlab platform.
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energy efficient routing and spectrum assignment with regenerator placement in elastic optical networks
Journal of Lightwave Technology, 2014Co-Authors: Ahmad Fallahpour, Hamzeh Beyranvand, Alireza S Nezamalhosseini, Jawad A SalehiAbstract:In this paper, we present a dynamic energy efficient routing and spectrum assignment algorithm with regenerator placement (RP) capability for elastic optical networks. In this algorithm, a virtual graph is considered for a given network topology graph, whereby the cost functions of virtual graph is computed according to the energy consumption of the corresponding links and intermediates routers. Furthermore, the arrived connection Request is served by finding the most energy-efficient path among the possible candidate paths. Then, the quality of transmission (QoT) of the selected path is evaluated in terms of bit error rate. If the estimated QoT is higher than a predetermined threshold, the designated path is assigned to the Incoming Request, otherwise, the RP algorithm is utilized to place a regenerator at the most energy-efficient position. In addition, the demanded transmission rate and required QoT are fulfilled by assessing different modulation formats and selecting appropriate modulation format in terms of power consumption and blocking probability (BP). We evaluate the proposed algorithms through extensive numerical simulations. The results of simulations reveal that the proposed algorithms have better performance than other existing schemes in terms of network total energy consumption and acceptable BP.
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a quality of transmission aware dynamic routing and spectrum assignment scheme for future elastic optical networks
Journal of Lightwave Technology, 2013Co-Authors: Hamzeh Beyranvand, Jawad A SalehiAbstract:In this paper, we present a quality-of-transmission (QoT) aware dynamic routing, modulation level, and spectrum assignment scheme referred to as QoT-aware RSA. The proposed QoT-aware RSA has three stages: path computation with QoT-aware modulation level assignment, path selection, and spectrum assignment. Two schemes are presented in the path computation stage namely, modified Dijkstra and K-shortest-path algorithms. A closed-form expression is derived to model the fiber nonlinearity effects and the impairments of intermediate routers. This expression is utilized to estimate the network dependent QoT and the transmission reach of the modulation levels. We propose to select the best path in terms of optical signal-to-noise ratio (OSNR) metric. Furthermore, the traffic-balancing spectrum assignment method is utilized to serve the Incoming Request. The proposed scheme is evaluated using extensive numerical simulations based on both random and deterministic traffic models. The results of simulation reveal that the path selection and spectrum assignment methods can affect the average OSNR performance. Furthermore, the results show that the proposed path selection and spectrum assignment schemes outperform other existing alternatives in the literature.
Leszek Borzemski - One of the best experts on this subject based on the ideXlab platform.
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ICCCI - Global Distribution of HTTP Requests Using the Fuzzy-Neural Decision-Making Mechanism
Computational Collective Intelligence. Semantic Web Social Networks and Multiagent Systems, 2009Co-Authors: Leszek Borzemski, Anna Zatwarnicka, Krzysztof ZatwarnickiAbstract:This paper presents the HTTP Request global distribution using the fuzzy-neural decision making mechanism. Two efficient algorithms GARDiB and GARDiB2 are proposed to support HTTP Request routing to the Websites. The algorithms use the fuzzy-neural decision-making method to assign each Incoming Request to the Website with the least expected response time. The response time includes the transmission time over the network; as well as the time elapsed on the responding Website server. Simulation experiments showed that GARDiB performed slightly better than GARDiB2 and both proposed algorithms outperformed other competitive distribution algorithms in all simulated workload scenarios.
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ICAISC - Performance evaluation of fuzzy-neural HTTP Request distribution for web clusters
Artificial Intelligence and Soft Computing – ICAISC 2006, 2006Co-Authors: Leszek Borzemski, Krzysztof ZatwarnickiAbstract:In this paper we present the performance evaluation of our fuzzy-neural HTTP Request distribution algorithm called FNRD, which assigns each Incoming Request to the server in the Web cluster with the quickest expected response time. The fuzzy mechanism is used to estimate the expected response times. A neural-based feedback loop is used for real-time tuning of response time estimates. To evaluate the system, we have developed a detailed simulation and workload model using CSIM19 package. Our simulations show that FNRD can be more effective than its competitors.
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Performance Evaluation of Fuzzy-Neural HTTP Request Distribution for Web Clusters
Lecture Notes in Computer Science, 2006Co-Authors: Leszek Borzemski, Krzysztof ZatwarnickiAbstract:In this paper we present the performance evaluation of our fuzzy-neural HTTP Request distribution algorithm called FNRD, which assigns each Incoming Request to the server in the Web cluster with the quickest expected response time. The fuzzy mechanism is used to estimate the expected response times. A neural-based feedback loop is used for real-time tuning of response time estimates. To evaluate the system, we have developed a detailed simulation and workload model using CSIM19 package. Our simulations show that FNRD can be more effective than its competitors.
C. Eswaran - One of the best experts on this subject based on the ideXlab platform.
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Performance Comparison of Various Garbage Collectors on JVM for Web Services
2006 International Symposium on Communications and Information Technologies, 2006Co-Authors: Hai-shuan Lam, G.s.v.r.k. Rao, C. EswaranAbstract:The current demand of e-commerce has increased the requirement of efficiency on Java server-side applications. Hence, the continuous availability and the good response-time of the Java Virtual Machine are needed to satisfy the continuous Incoming Request from remote clients. This project studied the optimization of garbage collector in Java Virtual Machine particularly on 3-tier Java server-side application to increase the throughput of real times processing, full utilization of CPU time and more memory efficiency to handle more workloads. The characteristics and the architectures of five JikesRVM garbage collectors were studied. They are CopyMS, GenMS, SemiSpace, GenCopy and MarkSweep. The best performing garbage collectors was determined and the main causes of their overheads were identified. The benchmarking suite, SPECjbb2000 was used to emulate a 3-tier Java server-side application. The performance of the five different garbage collectors on SPECjbb2000 for large and small memory size was compared. In conclusion, CopyMS is found to have the best average throughput for large heap size whereas, GenMS has the best overall performance in memory constraint and can handle the most workloads. On the other hand, GenCopy and SemiSpace demonstrated higher efficiency in handling light workloads. The performance of garbage collectors is proportional to the heap size used. Memory fragmentation and long pause time are two main challenges to be overcome for increasing the application performance. Future works for optimizing garbage collectors are recommended at the end of this report.
