• KIEE International Transactions on Power Engineering
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• 제5A권4호
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• pp.412-415
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• 2005

The recent requirement for faster and more frequent solutions has encouraged the consideration of parallel implementations using decentralized processors. Distributed multi-processor environments can potentially greatly increase the available computational capacity and decrease the communication burden, allowing for faster Optimal Power Flow (OPF) solutions. This paper presents a mathematical approach to implementing distributed OPF using the alternating direction method (ADM) to parallelize the OPF. Several IEEE Reliability Test Systems were adopted to demonstrate the proposed algorithm.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 PARALLEL CFD 2006
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• pp.21-26
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• 2006

A large-scale finite element simulation and modeling method is presented for environmental flows in urban area. Parallel stabilized finite element method based on domain decomposition method is employed for the numerical simulation. Several GIS and CAD data are used for the preparation of the shape model for landform and urban structures. The present method Is applied to the simulation of flood flow and wind flow In urban area. The present method is shown to be a useful planning and design tool for the natural disasters and the change of environments in urban area.

• 충청수학회지
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• 제22권1호
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• pp.117-121
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• 2009

For $1{\leq}p$, $q{\leq}{\infty}$ and $s{\in}\mathbb{R}$, it is proved that there exists a constant C > 0 such that for any $f{\in}B^{s+2}_{p,q}(\mathbb{R}^n)$ $${\parallel}f{\parallel}_{B^{s+2}_{p,q}(\mathbb{R}^n)}{\leq}C{\parallel}f\;-\;{\Delta}f{\parallel}_{B^{s}_{p,q}(\mathbb{R}^n)}$$, which tells us that the operator $I-\Delta$ is $B^{s+2}_{p,q}$-coercive on the Besov space $B^s_{p,q}$.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.529-535
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• 2000

This paper propose the method to obtain the inverse kinematics and the Jacobian of the 5-bar parallel robot and apply the nonlinear controller to the 5-bar parallel robot with the dynamic analyses using the Jacobian of the Passive joints with respect to the active ones and singular value decomposition(SVD). It also experimentally shows that we can do high-speed and accuracy tasks using nonlinear control method. And it explains the relation between the property of the position control and manipulability using a new performance index.

• 대한기계학회논문집A
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• 제21권12호
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• pp.2096-2105
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• 1997

A parallel approach using a network of engineering workstations is presented for the efficient computation in the elastoplastic analysis of strip rolling process. The domain decomposition method coupled with the frontal solver for elimination of internal degrees of freedom in each subdomain is used. PVM is used for message passing and synchronization between processors. A 2-D plane strain problem and the strip rolling process are analyzed to demonstrate the performance of the algorithm and factors that have a great effect on efficiency are discussed. In spite of much communication time on the network the result illustrates the advantages of this parallel algorithm over its corresponding sequential algorithm.

• 한국정밀공학회지
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• 제13권4호
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• pp.109-121
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• 1996

This paper presents how the input forces along the prismatic joints of a parallel manipulator are transmitted to the upper platform. In order to consider force transmission and moment transmission seperately the Jacobian matrix for parallel manipulators is splitted into two parts. Magnitudes of input forces on the six actuators at a given manipulator configuration which generate maximum/minimum output force with no moment generated on the platform are obtained through the singular value decomposition of a matrix involving the Jacobian. Similarly the directions of the input forces to obtain only the rotation of the platform have been analyzed. Using the singular values a simple equation for the volume of ellipsoid which is a good tool for manipulability measure is provided. Obtained results could be useful in determinimg design parameters like radius of plaform, angles between joints, etc. Simulations are porvided.

• 한국통신학회논문지
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• 제37A권10호
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• pp.841-849
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• 2012

본 논문은 max-log 근사화 하에서 연판정 최대 우도 (soft-output maximum-likelihood, soft-ML) 성능을 달성하기 위한 저복잡도 연판정 다중 안테나 (soft-output multiple-input multiple-output, soft-MIMO) 검출 알고리즘을 제안한다. 제안된 알고리즘은 병렬 트리-탐색 (parallel tree-search, PTS)을 기반으로 하며, 정렬 순서를 변경한 정렬된 QR 분해 (sorted-QR decomposition, SQRD)를 채널 순서화를 위해 적용한다. 비트별 로그-우도비 (log-likelihood ratio, LLR)를 계산하는 과정에서 발생할 수 있는 공집합 문제 (empty-set problem)는 탐색 레벨별로 추가적인 노드들을 삽입함으로써 해결한다. 제안된 노드 삽입 기법에서는 선택된 노드와 반대 비트 값을 가지면서 가장 가까운 노드만 삽입되기 때문에, 연산 복잡도 측면에서 상당히 효율적이다. 제안된 알고리즘의 연산 복잡도는 기존 알고리즘 대비 약 37-74% 수준이며, $4{\times}4$ 시스템에 대한 시뮬레이션 결과, 제안된 알고리즘은 soft-ML와 비교하여 0.1 dB 미만의 성능 저하를 보였다.

• 전기학회논문지
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• 제56권10호
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• pp.1721-1730
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• 2007

SThis paper proposes a new dispatch scheduling algorithm in interconnected regional system operations. The dispatch scheduling formulated as mixed integer non-linear programming (MINLP) problem can efficiently be computed by generalized Benders decomposition (GBD) algorithm. GBD guarantees adequate computation speed and solution convergency since it decomposes a primal problem into a master problem and subproblems for simplicity. In addition, the inter-temporal optimal power flow (OPF) subproblem of the dispatch scheduling problem is comprised of various variables and constraints considering time-continuity and it makes the inter-temporal OPF complex due to increased dimensions of the optimization problem. In this paper, regional decomposition technique based on auxiliary problem principle (APP) algorithm is introduced to obtain efficient inter-temporal OPF solution through the parallel implementation. In addition, it can find the most economic dispatch schedule incorporating power transaction without private information open. Therefore, it can be expanded as an efficient dispatch scheduling model for interconnected system operation.

• 한국CDE학회논문집
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• 제5권4호
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• pp.359-372
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• 2000

Current CAD systems are good enough to be used as a tool to manipulate three-dimensional shapes. This is a very important capability to be owned by a design tool because a major portion of designers'activities is spent on the shape manipulation in the design detailing process. However, the whole design process involves a lot more than the, shape manipulation. Currently, these remaining tasks, mostly logical reasoning process for the function realization together with structure decomposition in the top-down manner, are processed in the designer's brain. To support the top-down functional design process of a mechanical product, a system integrating the functional, structural and geometrical aspects of a product design in a unified environment is presented. Using this system, a designer can perform function decomposition, structure decomposition, and geometry detailing, and function verification activities in parallel and the whole design process it modeled resultantly. Once the whole design process is modeled, any redesign task can be automatically performed with the verification of the desired functions.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.321-322
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• 2007