The Experts below are selected from a list of 10227 Experts worldwide ranked by ideXlab platform
H. Harada - One of the best experts on this subject based on the ideXlab platform.
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Preliminary evaluation of Dynamic Load Balancing using loop re-partitioning on Omni/SCASH
CCGrid 2003. 3rd IEEE ACM International Symposium on Cluster Computing and the Grid 2003. Proceedings., 2003Co-Authors: Yoshiki Sakae, S. Matsuoka, M Sato, H. HaradaAbstract:Increasingly large-scale clusters of PC/WS continue to become majority platform in HPC field. Such a commodity cluster environment, there may be incremental upgrade due to several reasons, such as rapid progress in processor technologies, or user needs and it may cause the performance heterogeneity between nodes from which the application programmer will suffer as Load imbalances. To overcome these problems, some Dynamic Load Balancing mechanisms are needed. In this paper, we report our ongoing work on Dynamic Load Balancing extension to Omni/SCASH which is an implementation of OpenMP on Software Distributed Shared Memory, SLASH. Using our Dynamic Load Balancing mechanisms, we expect that programmers can have Load imbalances adjusted automatically by the runtime system without explicit definition of data and task placements in a commodity cluster environment with possibly heterogeneous performance nodes.
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CCGRID - Preliminary evaluation of Dynamic Load Balancing using loop re-partitioning on Omni/SCASH
CCGrid 2003. 3rd IEEE ACM International Symposium on Cluster Computing and the Grid 2003. Proceedings., 2003Co-Authors: Yoshiki Sakae, S. Matsuoka, M Sato, H. HaradaAbstract:Increasingly large-scale clusters of PC/WS continue to become majority platform in HPC field. Such a commodity cluster environment, there may be incremental upgrade due to several reasons, such as rapid progress in processor technologies, or user needs and it may cause the performance heterogeneity between nodes from which the application programmer will suffer as Load imbalances. To overcome these problems, some Dynamic Load Balancing mechanisms are needed. In this paper, we report our ongoing work on Dynamic Load Balancing extension to Omni/SCASH which is an implementation of OpenMP on Software Distributed Shared Memory, SLASH. Using our Dynamic Load Balancing mechanisms, we expect that programmers can have Load imbalances adjusted automatically by the runtime system without explicit definition of data and task placements in a commodity cluster environment with possibly heterogeneous performance nodes.
E. Yanmaz - One of the best experts on this subject based on the ideXlab platform.
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GLOBECOM - Location dependent Dynamic Load Balancing
GLOBECOM '05. IEEE Global Telecommunications Conference 2005., 2020Co-Authors: E. Yanmaz, O.k. TonguzAbstract:The performance of most Dynamic Load Balancing schemes, proposed to solve the hot spot problem in cellular systems, depends on the user distribution within a cell. In this paper, we first study the impact of user distribution on the call blocking probability performance that can be achieved by two key Dynamic Load Balancing schemes (i.e., channel borrowing without locking (CBWL) and integrated cellular and ad hoc relay (iCAR) system (H. Jiang and S.S Rappaport, 1994)-(H. Wu et al., 2001)). We show that the achievable call blocking probability performance is location-dependent, and iCAR and CBWL schemes might not be able to achieve 2% call blocking probability for all user distributions, unless major modifications are made to CBWL or iCAR to overcome local congestion problems. Therefore, in this paper, we propose to use a joint Dynamic Load Balancing scheme that combines the features of CBWL and iCAR schemes. Our objective is to guarantee a low call blocking probability in congested cells irrespective of user location.
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The Mathematical Theory of Dynamic Load Balancing in Cellular Networks
IEEE Transactions on Mobile Computing, 2008Co-Authors: O.k. Tonguz, E. YanmazAbstract:While many interesting Dynamic Load Balancing schemes have been proposed for efficient use of limited bandwidth and to increase the capacity of congested or hot spots (or cells) in wireless networks, to date, a comprehensive mathematical framework which encompasses all of these schemes does not exist. In this paper, we provide a unified mathematical framework for Dynamic Load Balancing, which leads to closed-form performance expressions for evaluating the performance of some of the most important Dynamic Load Balancing strategies proposed in the literature. To the best of our knowledge, this is the first generic theoretical framework that can be used to evaluate the performance of many different Dynamic Load Balancing schemes with simple closed-form results. The accuracy of the results predicted by these analytical expressions derived from the theoretical framework is checked by comparing these results with simulation results provided in the literature for well-known schemes.
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Handover performance of Dynamic Load Balancing schemes in cellular networks
10th IEEE Symposium on Computers and Communications (ISCC'05), 2005Co-Authors: E. Yanmaz, O.k. TonguzAbstract:In this paper, we propose to use a Dynamic Load Balancing scheme that utilizes fixed relay stations placed in a cellular geographical coverage area to improve the handover performance in cellular networks. To this end, we develop closed-form performance expressions and derive the handover dropping probability in terms of the main system parameters, such as the new call and handover arrival rates, the number of fixed and Load-Balancing channels per cell, the Load Balancing probability for new and handover calls, etc. Our results show that by employing a Dynamic Load Balancing scheme, not only the new call blocking probability, but also the handover dropping probability can be improved substantially, without reserving any channels or assigning any priority to handover calls. In fact, employing Dynamic Load Balancing without any guard channels outperforms a conventional system that employs the well-known guard channel method (GCM).
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ISCC - Handover performance of Dynamic Load Balancing schemes in cellular networks
10th IEEE Symposium on Computers and Communications (ISCC'05), 2005Co-Authors: E. Yanmaz, O.k. TonguzAbstract:In this paper, we propose to use a Dynamic Load Balancing scheme that utilizes fixed relay stations placed in a cellular geographical coverage area to improve the handover performance in cellular networks. To this end, we develop closed-form performance expressions and derive the handover dropping probability in terms of the main system parameters, such as the new call and handover arrival rates, the number of fixed and Load-Balancing channels per cell, the Load Balancing probability for new and handover calls, etc. Our results show that by employing a Dynamic Load Balancing scheme, not only the new call blocking probability, but also the handover dropping probability can be improved substantially, without reserving any channels or assigning any priority to handover calls. In fact, employing Dynamic Load Balancing without any guard channels outperforms a conventional system that employs the well-known guard channel method (GCM).
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Is there an optimum Dynamic Load Balancing scheme?
GLOBECOM '05. IEEE Global Telecommunications Conference 2005., 2005Co-Authors: E. Yanmaz, O.k. Tonguz, R. RajkumarAbstract:Several Dynamic Load Balancing schemes have been proposed in the literature to solve the hot spot problem in cellular networks. In O. K. Tonguz and E. Yanmaz (2003), a unified theoretical framework for the performance analysis of Dynamic Load Balancing schemes in cellular networks have been developed, and closed-form expressions for the call blocking probability of several existing Dynamic Load Balancing schemes have been derived. However, to the best of our knowledge, an analysis showing which one of these Dynamic Load Balancing schemes is optimum, in terms of the achievable call blocking probability, has not been reported before. In this paper, we explore, for the first time, if a global optimum Dynamic Load Balancing scheme exists, and we examine if and under which conditions the existing Dynamic Load Balancing schemes can achieve optimality.
O.k. Tonguz - One of the best experts on this subject based on the ideXlab platform.
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GLOBECOM - Location dependent Dynamic Load Balancing
GLOBECOM '05. IEEE Global Telecommunications Conference 2005., 2020Co-Authors: E. Yanmaz, O.k. TonguzAbstract:The performance of most Dynamic Load Balancing schemes, proposed to solve the hot spot problem in cellular systems, depends on the user distribution within a cell. In this paper, we first study the impact of user distribution on the call blocking probability performance that can be achieved by two key Dynamic Load Balancing schemes (i.e., channel borrowing without locking (CBWL) and integrated cellular and ad hoc relay (iCAR) system (H. Jiang and S.S Rappaport, 1994)-(H. Wu et al., 2001)). We show that the achievable call blocking probability performance is location-dependent, and iCAR and CBWL schemes might not be able to achieve 2% call blocking probability for all user distributions, unless major modifications are made to CBWL or iCAR to overcome local congestion problems. Therefore, in this paper, we propose to use a joint Dynamic Load Balancing scheme that combines the features of CBWL and iCAR schemes. Our objective is to guarantee a low call blocking probability in congested cells irrespective of user location.
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The Mathematical Theory of Dynamic Load Balancing in Cellular Networks
IEEE Transactions on Mobile Computing, 2008Co-Authors: O.k. Tonguz, E. YanmazAbstract:While many interesting Dynamic Load Balancing schemes have been proposed for efficient use of limited bandwidth and to increase the capacity of congested or hot spots (or cells) in wireless networks, to date, a comprehensive mathematical framework which encompasses all of these schemes does not exist. In this paper, we provide a unified mathematical framework for Dynamic Load Balancing, which leads to closed-form performance expressions for evaluating the performance of some of the most important Dynamic Load Balancing strategies proposed in the literature. To the best of our knowledge, this is the first generic theoretical framework that can be used to evaluate the performance of many different Dynamic Load Balancing schemes with simple closed-form results. The accuracy of the results predicted by these analytical expressions derived from the theoretical framework is checked by comparing these results with simulation results provided in the literature for well-known schemes.
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Handover performance of Dynamic Load Balancing schemes in cellular networks
10th IEEE Symposium on Computers and Communications (ISCC'05), 2005Co-Authors: E. Yanmaz, O.k. TonguzAbstract:In this paper, we propose to use a Dynamic Load Balancing scheme that utilizes fixed relay stations placed in a cellular geographical coverage area to improve the handover performance in cellular networks. To this end, we develop closed-form performance expressions and derive the handover dropping probability in terms of the main system parameters, such as the new call and handover arrival rates, the number of fixed and Load-Balancing channels per cell, the Load Balancing probability for new and handover calls, etc. Our results show that by employing a Dynamic Load Balancing scheme, not only the new call blocking probability, but also the handover dropping probability can be improved substantially, without reserving any channels or assigning any priority to handover calls. In fact, employing Dynamic Load Balancing without any guard channels outperforms a conventional system that employs the well-known guard channel method (GCM).
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ISCC - Handover performance of Dynamic Load Balancing schemes in cellular networks
10th IEEE Symposium on Computers and Communications (ISCC'05), 2005Co-Authors: E. Yanmaz, O.k. TonguzAbstract:In this paper, we propose to use a Dynamic Load Balancing scheme that utilizes fixed relay stations placed in a cellular geographical coverage area to improve the handover performance in cellular networks. To this end, we develop closed-form performance expressions and derive the handover dropping probability in terms of the main system parameters, such as the new call and handover arrival rates, the number of fixed and Load-Balancing channels per cell, the Load Balancing probability for new and handover calls, etc. Our results show that by employing a Dynamic Load Balancing scheme, not only the new call blocking probability, but also the handover dropping probability can be improved substantially, without reserving any channels or assigning any priority to handover calls. In fact, employing Dynamic Load Balancing without any guard channels outperforms a conventional system that employs the well-known guard channel method (GCM).
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Is there an optimum Dynamic Load Balancing scheme?
GLOBECOM '05. IEEE Global Telecommunications Conference 2005., 2005Co-Authors: E. Yanmaz, O.k. Tonguz, R. RajkumarAbstract:Several Dynamic Load Balancing schemes have been proposed in the literature to solve the hot spot problem in cellular networks. In O. K. Tonguz and E. Yanmaz (2003), a unified theoretical framework for the performance analysis of Dynamic Load Balancing schemes in cellular networks have been developed, and closed-form expressions for the call blocking probability of several existing Dynamic Load Balancing schemes have been derived. However, to the best of our knowledge, an analysis showing which one of these Dynamic Load Balancing schemes is optimum, in terms of the achievable call blocking probability, has not been reported before. In this paper, we explore, for the first time, if a global optimum Dynamic Load Balancing scheme exists, and we examine if and under which conditions the existing Dynamic Load Balancing schemes can achieve optimality.
Yoshiki Sakae - One of the best experts on this subject based on the ideXlab platform.
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Preliminary evaluation of Dynamic Load Balancing using loop re-partitioning on Omni/SCASH
CCGrid 2003. 3rd IEEE ACM International Symposium on Cluster Computing and the Grid 2003. Proceedings., 2003Co-Authors: Yoshiki Sakae, S. Matsuoka, M Sato, H. HaradaAbstract:Increasingly large-scale clusters of PC/WS continue to become majority platform in HPC field. Such a commodity cluster environment, there may be incremental upgrade due to several reasons, such as rapid progress in processor technologies, or user needs and it may cause the performance heterogeneity between nodes from which the application programmer will suffer as Load imbalances. To overcome these problems, some Dynamic Load Balancing mechanisms are needed. In this paper, we report our ongoing work on Dynamic Load Balancing extension to Omni/SCASH which is an implementation of OpenMP on Software Distributed Shared Memory, SLASH. Using our Dynamic Load Balancing mechanisms, we expect that programmers can have Load imbalances adjusted automatically by the runtime system without explicit definition of data and task placements in a commodity cluster environment with possibly heterogeneous performance nodes.
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CCGRID - Preliminary evaluation of Dynamic Load Balancing using loop re-partitioning on Omni/SCASH
CCGrid 2003. 3rd IEEE ACM International Symposium on Cluster Computing and the Grid 2003. Proceedings., 2003Co-Authors: Yoshiki Sakae, S. Matsuoka, M Sato, H. HaradaAbstract:Increasingly large-scale clusters of PC/WS continue to become majority platform in HPC field. Such a commodity cluster environment, there may be incremental upgrade due to several reasons, such as rapid progress in processor technologies, or user needs and it may cause the performance heterogeneity between nodes from which the application programmer will suffer as Load imbalances. To overcome these problems, some Dynamic Load Balancing mechanisms are needed. In this paper, we report our ongoing work on Dynamic Load Balancing extension to Omni/SCASH which is an implementation of OpenMP on Software Distributed Shared Memory, SLASH. Using our Dynamic Load Balancing mechanisms, we expect that programmers can have Load imbalances adjusted automatically by the runtime system without explicit definition of data and task placements in a commodity cluster environment with possibly heterogeneous performance nodes.
Lu Xinda - One of the best experts on this subject based on the ideXlab platform.
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Utilization of cluster of PCs for the study of Dynamic Load Balancing
2002 IEEE Region 10 Conference on Computers Communications Control and Power Engineering. TENCOM '02. Proceedings., 2002Co-Authors: M.a.m. Ibrahim, Lu XindaAbstract:The main concern of this paper is the utilization of an inexpensive cluster of PCs to study Dynamic Load Balancing technique (DLB) for parallel tree computation. Dynamic Load Balancing is not only a central issue in the cluster of computers model, but also is required for many algorithms such as parallel search tree. The basic conclusion of the paper is that excellent performance can be achieved by proper implementation of the Dynamic Load Balancing round robin (RR) scheme.
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Performance of Dynamic Load Balancing algorithm on cluster of workstations and PCs
Fifth International Conference on Algorithms and Architectures for Parallel Processing 2002. Proceedings., 2002Co-Authors: M.a.m. Ibrahim, Lu XindaAbstract:Heterogeneous parallel systems are becoming increasingly more common, especially with the increasing use of cluster computers, such as PCs and networks of workstations for parallel computing. The main concern of this paper is measuring and evaluating the performance of such parallel systems, based on a Dynamic Load Balancing algorithm for the parallel search algorithm: a depth-first search algorithm. The implementation of Dynamic Load Balancing is running under the message passing interface that allows parallel execution on the cluster of heterogeneous 6 SUN workstations, operating with the Solaris operating system and a cluster of 10 PCs operating with the Linux operating system, the parallel program of Dynamic Load Balancing is written in C language.
