• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.12
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• pp.1150-1156
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• 2007

Multidisciplinary design optimization methodologies play an essential role in modern engineering design which involves many inter-related disciplines. These methodologies usually require very long computing time and design tasks are hard to finish within a specified design cycle time. Parallel processing can be effectively utilized to reduce the computing time. The research on the parallel computing performance of MDO methodologies has been just begun and developing. This study investigates performances of MDF, IDF, SAND and CO among MDO methodologies in view of parallel computing. Finally, the best out of four methodologies is suggested for parallel processing purpose.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.10
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• pp.38-45
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• 2004

In this paper, a parallel visualization algorithm is proposed for efficient visualization of the massive data generated from large-scale parallel finite element analysis through investigating the characteristics of parallel rendering methods. The proposed parallel visualization algorithm is designed to be highly compatible with the characteristics of domain-wise computation in parallel finite element analysis by using the sort-last-sparse approach. In the proposed algorithm, the binary tree communication pattern is utilized to reduce the network communication time in image composition routine. Several benchmarking tests are carried out by using the developed in-house software, and the performance of the proposed algorithm is investigated.

• Industrial Engineering and Management Systems
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• v.4 no.2
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• pp.117-122
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• 2005

An assembly system (AS), a valuable tool for mass production, is generally composed of a number of workstations and a transport system. While the workstations perform some preplanned operations, the transport system moves the assemblies by special designed pallets from one station to another. One common problem associated with automatic assembly systems is that some assembly operations may have relatively long cycle times. As a consequence, the productivity, as determined by the operations with the longest cycle time, can be reduced significantly. Therefore, special forms of parallel workstations were developed to improve the performance of an assembly system. In this paper, three most commonly used parallel stations: on-line, off-line and tunnel-gated stations in a free transfer assembly system are studied via discrete event simulation. Our findings revealed that the off-line parallel system has the best performance because the two independent parallel stations can lower the buffer requirement; reduce the sensitivity to variability of processing time and balance of a line. On-line parallel systems were found to have a relatively poor performance, because the operations of two parallel stations block each other, and higher buffer capacity is required to achieve similar capacity. The tunnel-gated system was more efficient than the on-line system since the first parallel station can operate independently. More importantly, we have quantified the productivity of the three different strategies mentioned. Engineers can choose the optimal strategies for installing parallel stations under their working environment.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.810-815
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• 2004

In this paper, we propose new parallel mechanism of a 3 dimensional biped robot whose each leg is composed of two 3-dof parallel platforms linked serially. This proposed parallel mechanism is able to move freely in the man-made environment and is applied to various fields, such as medical, welfare, and so on. And a total weight of each leg is expected to be lighter than serial linked leg. One side leg consists of a 3-dof orientation platform and 3-dof asymmetric parallel platform. The former consists of three active linear actuators and seven passive joints, and the latter of two active linear actuators, one active rotational actuator and eight passive joints. Thus, there are two kinds of parallel platforms each chain's elements and active joint's positions are different for the biped robot to move freely like a serial link without the kinematics constraints. The effectiveness and the performance of the proposed parallel mechanism and locomotion trajectory are shown in computer simulations with a 12-DOF parallel biped robot.

• Journal of the Korea Society of Computer and Information
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• v.17 no.1
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• pp.171-181
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• 2012

This paper defines the AES password algorithm used as a symmetric-key-based password algorithm, and proposes the design of parallel password algorithm to utilize the resources of multi-core processor as much as possible. The proposed parallel password algorithm was confirmed for parallel execution of password computation by allocating the password algorithm according to the number of cores, and about 30% of performance increase compared to AES password algorithm. The encryption/decryption performance of the password algorithm was confirmed through binary comparative analysis tool, which confirmed that the binary results were the same for AES password algorithm and proposed parallel password algorithm, and the decrypted binary were also the same. The parallel password algorithm for multi-core environment proposed in this paper can be applied to authentication/payment of financial service in PC, laptop, server, and mobile environment, and can be utilized in the area that required high-speed encryption operation of large-sized data.

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

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.3
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• pp.251-260
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• 2002

The parallel/distributed processing with a lot of the idle hosts on the web has the high coot-performance ratio for large-scale applications. It's processing has to show the solutions for unpredictable status such as heterogeneity of hosts, variability of hosts, autonomy of hosts, the supporting performance continuously, and the number of hosts which are participated in computation and so on. In this paper, we propose the strategy of adaptive tack reallocation based on performance the host job processing, spread out geographically Also, It shows the scheme of dynamic host management with dynamic environment, which is changed by lots of hosts on the web during parallel processing for large-scale applications. This paper implements the PDSWeb (Parallel/Distributed Scheme on Web) system, evaluates and applies It to the generation of rendering image with highly intensive computation. The results are showed that the adaptive task reallocation with the variation of hosts has been increased up to maximum 90% and the improvement in performance according to add/delete of hosts.

• The Journal of the Acoustical Society of Korea
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• v.32 no.3
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• pp.252-261
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• 2013

The common speech recognition system displays higher recognition performance in a quiet environment, while its performance declines sharply in a real environment where there are noises. To implement a speech recognizer that is robust in different speech settings, this study suggests the method of Parallel Model Combination adaptation using frequency-variant based on environment-awareness (FV-PMC), which uses variants in frequency; acquires the environmental data for speech recognition; applies it to upgrading the speech recognition model; and promotes its performance enhancement. This FV-PMC performs the speech recognition with the recognition model which is generated as followings: i) calculating the average frequency variant in advance among the readily-classified noise groups and setting it as a threshold value; ii) recalculating the frequency variant among noise groups when speech with unknown noises are input; iii) regarding the speech higher than the threshold value of the relevant group as the speech including the noise of its group; and iv) using the speech that includes this noise group. When noises were classified with the proposed FV-PMC, the average accuracy of classification was 56%, and the results from the speech recognition experiments showed the average recognition rate of Set A was 79.05%, the rate of Set B 79.43%m, and the rate of Set C 83.37% respectively. The grand mean of recognition rate was 80.62%, which demonstrates 5.69% more improved effects than the recognition rate of 74.93% of the existing Parallel Model Combination with a clear model, meaning that the proposed method is effective.

• Journal of the Korea Computer Industry Society
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• v.3 no.2
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• pp.209-216
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• 2002

World Wide Web has potential possibility of infrastructure for parallel computing environment connecting massive computing resources, not just platform to provide and share information via browser. The approach of Web-based parallel computing has many advantages of the ease of accessibility, scalability, cost-effectiveness, and utilization of existing networks. Applet has the possibility of decomposing the independent/parallel task, moving over network, and executing in computers connected in Web, but it lacks in the flexibility due to strict security semantic model. Therefore, in this paper, Web-based parallel computing environment using mobile agent, Aglet (Agile applet) was designed and possible implementation technologies and architecture were analyzed. And simple simulation and analysis was done compared with applet-based approach.

• Journal of applied mathematics & informatics
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• v.6 no.2
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• pp.649-659
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• 1999

This paper presents a parallel implementation of stiff-ness matrix calculation based on the processor farm model on a net-work of workstations running PVM programming environment. As the computational characteristics of stiffnes matrix exhibits good po-tentials for effective prallel computation the performance improve-ment is show to be almost linear with the number of sorkstations involved in the computation.