• The KIPS Transactions:PartA
• /
• v.12A no.6 s.96
• /
• pp.499-506
• /
• 2005

Recently, Hyper-Star network HS(m,k) which improves the network cost of hypercube has been proposed. In this paper, we show that the bisection width of regular Hyper-Star network HS(2n,n) is maximum (2n-2,n-1). Using the concept of container, we also show that k-wide diameter of HS(2n,n) is less than dist(u,v)+4, and the fault diameter is less than D(HS(2n,n))+2, where dist(u,v) is the shortest path length between any two nodes u and v in HS(2n,n), and D(HS(2n,n)) is its diameter.

• Journal of KIISE:Computer Systems and Theory
• /
• v.37 no.2
• /
• pp.61-65
• /
• 2010

The twisted cube has received great attention because it has several superior properties to the hypercube that is widely known as a versatile parallel processing system. In this paper, we show that node-disjoint $2^{n-1}$ meshes of size $2^n{\times}2^m$ can be embedded into a twisted cube with dilation 1 where $1{\leq}n{\leq}m$. The expansion is 1 for even m and 2 for odd m.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.7
• /
• pp.1756-1769
• /
• 1999

Parallel paths in an interconnection network have some significance in that message transmission time can be reduced because message is divided into packets and transmitted in parallel through several paths, and also an whose nodes has 2n binary bit string, is an interconnection network which has a lower network cost than hypercube and its variation. In this paper, we analyze node disjoint parallel path in Folded Hyper-Star graph FHS(2n,n) proposed as the topology of parallel computers and, using the result, prove that the fault diameter of a Folded Hyper-Star graph FHS(2n,n) is 2n-1.

• Proceedings of the KIEE Conference
• /
• 1990.11a
• /
• pp.457-459
• /
• 1990

• Convergence Security Journal
• /
• v.6 no.2
• /
• pp.81-89
• /
• 2006

System level diagnosis algorithms use the properties of t-diagnosable system where the maximum number of the faults does not exceed t. The existing diagnosis algorithms have limit when dealing with large fault sets in large multiprocessor systems. Somani and Peleg proposed t/k-diagnosable system to diagnose more faults than t (dimension) by allowing upper bounded few number of units to be diagnosed incorrectly. In this paper, we propose hypercube diagnosis algorithm using t/k-diagnosable system. When the number of faults exceeds t, we allow k faults to be diagnosed incorrectly. Simulation shows that the performance of the proposed algorithm is better than Feng's HADA algorithm. The proposed algorithm also gives similar performance compared to HYP-DIAG algorithm.

• Journal of KIISE:Computer Systems and Theory
• /
• v.26 no.9
• /
• pp.1064-1072
• /
• 1999

The well-known Dimension Exchange Method(DEM) to quantized loads may result in difference in assigned loads to processors as large as logn~units, in the worst case, after balancing for a hypercube of size n. In order to limit the increase of the accumulation of these differences, this paper proposes a method that limits the accumulation of the difference by redistributing an unit load (odd or even) of the same type, if possible, when there is a load distribution between two processors. We reduced the maximum difference to LCEIL logn over {2} RCEIL . The result shows the simulation experiments which show about 30% improvement in speedup compare to the DEM.

• Journal of KIISE:Computer Systems and Theory
• /
• v.28 no.12
• /
• pp.632-641
• /
• 2001

In this paper, we introduce new methods for hiding computation overheads involved in load redistributing for parallel computer of hypercube, mesh and tree topologies. The basic idea is either coalescing some phases of load redistributing to overlap the transfer on different links or dividing each phase into steps to pipeline the transfer of load unit by unit for maximum utilization of links. They proved effective in making links busy transmitting load as soon as possible, hence reducing the computation overheads involved in balancing. Proposed techniques experimented on hypercube, mesh or tree topologies reduce communication overheads by 20% to 50% compared with known methods.

• Journal of the Korea Society of Computer and Information
• /
• v.13 no.2
• /
• pp.221-233
• /
• 2008

In general, we use a Parallel processing computer manufactured specially for the purpose of parallel processing to do high performance computings. But we can depoly and use a PC cluster composed of several common PCs instead of the very expensive parallel processing computer. A common way to get a PC cluster is to adopt the star topology network connected by a switch hub. But in this paper, we grope efficient implementations of hypercube networks based on TCP/IP to connect 8 PCs directly for more useful parallel processing environment, and make evaluations on functionality and efficiency of them using ping, netperf, MPICH. The two proposed methods of implementation are IP configuration based on link and IP configuration based on node. The results of comparison between them show that there is not obvious difference in performance but the latter is more efficient in simplicity of routing table. For verification of functionality, we compare the parallel processing results of an application in them with the same in a star network based PC cluster. These results also show that the proposed hypercube networks support a perfect parallel processing environment respectively.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.9
• /
• pp.1065-1071
• /
• 2012

Wind energy is becoming one of the most preferable alternatives to conventional sources of electric power that rely on fossil fuels. For stable electric power generation, constant rotating speed control of a wind turbine is performed through pitch control and stall control of the turbine blades. Recently, variable pitch control has been implemented in modern wind turbines to harvest more energy at variable wind speeds that are even lower than the rated one. Although wind turbine pitch controllers are currently optimized using a step response via the Ziegler-Nichols auto-tuning process, this approach does not satisfy the requirements of variable pitch control. In this study, the variable pitch controller was optimized by a genetic algorithm using a neural network model that was constructed by the Latin Hypercube sampling method to improve the Ziegler-Nichols auto-tuning process. The optimized solution shows that the root mean square error, rise time, and settle time are respectively improved by more than 7.64%, 15.8%, and 15.3% compared with the corresponding initial solutions obtained by the Ziegler-Nichols auto-tuning process.

• Proceedings of the IEEK Conference
• /
• 1998.10a
• /
• pp.475-478
• /
• 1998

The matrix hypercube MH(2,n) is the interconnection network which improves the network cost of the hypercube. In this paper, we propose an algorithm for one-to-all broadcasting in the matrix hypercube MH(2,n). The algorithm can broadcast a message to 22n nodes in O(n) time. The algorithm uses the rich structure of the matrix hypercubes and works by recursively partitioning the original matrix hypercubes into smaller matrix hypercubes.