• ETRI Journal
• /
• 제43권5호
• /
• pp.825-834
• /
• 2021

Based on its simplicity and user-friendly characteristics, OpenMP has become the standard model for programming on shared-memory architectures. Checkpointing-aided parallel execution (CAPE) is an approach that utilizes the discontinuous incremental checkpointing technique (DICKPT) to translate and execute OpenMP programs on distributed-memory architectures automatically. Currently, CAPE implements the OpenMP execution model by utilizing the DICKPT to distribute parallel jobs and their data to slave machines, and then collects the results after executing these distributed jobs. Although this model has been proven to be effective in terms of performance and compatibility with OpenMP on distributed-memory systems, it cannot fully exploit the capabilities of multicore processors. This paper presents a novel execution model for CAPE that utilizes two levels of parallelism. In the proposed model, we add another level of parallelism in the form of multithreaded processes on slave machines with the goal of better exploiting their multicore CPUs. Initial experimental results presented near the end of this paper demonstrate that this model provides significantly enhanced CAPE performance.

• 한국정보처리학회논문지
• /
• 제6권11호
• /
• pp.2932-2945
• /
• 1999

As the Internet and Java technology have been growing up, parallel processing approach to utilize those idle resources connected to the Internet has become quite attractive. In this paper, JICE(Java Internet Computing Environment) was implemented as a parallel computing platform based on the Internet using multithreading and RMI mechanisms provided by Java. The basic model of JICE is constructed as three components, such as a client, a set of workers, and a broker. A worker communicates with other workers via a globally shared memory system. It provides users with master-slave programming model and a collection of library functions. The basic model of JICE is also extended as a multimanaging system. This multimanaging system is evaluated by analysis to show its effectiveness. According to numerical analysis and experiments with several benchmarks, it is shown that the performance of basic model depends on the shared memory reference ratio and user's library is a quite promising.

• Journal of Electrical Engineering and Technology
• /
• 제3권4호
• /
• pp.552-558
• /
• 2008

Optimal design of the direct-driven Permanent Magnet(PM) wind generator, combined with F.E.A(Finite Element Analysis) and Genetic Algorithm(GA), has been performed to maximize the Annual Energy Production(AEP) over the entire wind speed characterized by the statistical model of wind speed distribution. Particularly, the proposed parallel computing via internet web service has contributed to reducing excessive computing times for optimization.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
• /
• pp.362-369
• /
• 1998

The computational environment in which engineers perform their designs has been rapidly evolved from coarse serial machines to massively parallel machines. Although the recent development of high-performance computers are available for a number of years, only limited successful applications of the new computational environments in computational structural engineering field has been reported due to its limited availability and large cost associated with high-performance computing. As a new computational model for high-performance engineering computing without cost and availability problems, parallel structural analysis models for large scale structures on a network of personal computers (PCs) are presented in this paper. In structural analysis solving routine for the linear system of equations is the most time consuming part. Thus, the focus is on the development of efficient preconditioned conjugate gradient (PCG) solvers on the proposed computational model. Two parallel PCG solvers, PPCG-I and PPCG-II, are developed and applied to analysis of large scale space truss structures.

• ETRI Journal
• /
• 제39권5호
• /
• pp.632-642
• /
• 2017

Digital all-optical parallel computing is an important research direction and spans conventional devices and convergent nano-optics deployments. Optical bus-based interconnects provide interesting aspects such as relative information communication speed-up or slow-down between optical signals. This aspect is harnessed in the newly proposed All-Optical Linear Array with a Reconfigurable Pipelined Bus System (OLARPBS) model. However, the physical realization of such communication interconnects needs to be considered. This paper considers spatial layouts of processing elements along with the optical bus light paths that are necessary to realize the corresponding interconnection requirements. A metric in terms of the degree of required physical constraint is developed to characterize the variety of possible solutions. Simple algorithms that determine spatial layouts are given. It is shown that certain communication interconnection structures have associated intrinsic topologies.

• 한국CDE학회논문집
• /
• 제13권3호
• /
• pp.217-226
• /
• 2008

Web Services for CAD (WSC) aims at interoperation with CAD systems based on Web Services. This paper introduces one part of WSC which enables remote users to retrieve assembly model data using Web Services. However, retrieving assembly model data takes long time. To resolve this problem, this paper proposes using parallel Web Services. As assembly models comprise a set of part models, it is easy to separate the problem domain into smaller problems. In addition, Web Services inherently supports distributed computing. This characteristic makes the parallel processing of Web Services easy. Firstly, the implementation of WSC which retrieves assembly model data based parallel Web Services is shown. And then, for the comparison, the experiments on the retrieval of assembly model data based on single Web Services and parallel Web Services are shown.

• 전기학회논문지
• /
• 제56권12호
• /
• pp.2109-2115
• /
• 2007

The wind generators have been installed with high output power to increase the energy production and efficiency. Hence, Optimal design of the direct-driven PM wind generator, coupled with F.E.M(Finite Element Method) and Genetic Algorithm(GA), has been performed to maximize the Annual Energy Production(AEP) over the whole wind speed characterized by the statistical model of wind speed distribution. Particularly, the parallel computing via internet web service has been applied to loose excessive computing times for optimization. The results of the optimal design of Surface-Mounted Permanent Magnet Synchronous Generator(SPMSG) are compared with each other candidates to verify the usefulness of the maximizing AEP model.

• 한국수소및신에너지학회논문집
• /
• 제22권6호
• /
• pp.868-877
• /
• 2011

This paper presents a parallel computing methodology for polymer electrolyte fuel cells (PEFCs) and detailed simulation contours of a real-scale fuel cell. In this work, a three-dimensional two-phase PEFC model is applied to a large-scale 200 $cm^2$ fuel cell geometry that requires roughly 13.5 million grid points based on grid-independence study. For parallel computing, the large-scale computational domain is decomposed into 12 sub-domains and parallel simulations are carried out using 12 processors of 2.53 GHz Intel core i7 and 48GB RECC DDR3-1333. The work represents the first attempt to parallelize a two-phase PEFC code and illustrate two-phase contours in a representative industrial cell.

• 한국컴퓨터산업학회논문지
• /
• 제3권2호
• /
• pp.209-216
• /
• 2002

웹은 브라우저를 통한 단순한 정보의 전달과 정보의 공유수단으로서가 아니라, 수많은 컴퓨터 자원이 연결되어 있는 병렬 컴퓨팅을 위한 기반구조로서 이용될 수 있는 잠재적인 가능성을 가지고 있다. 웹을 기반으로 한 병렬컴퓨팅의 접근방법은 기존의 다른 방법들에 비하여 일반 사용자들의 접근에 대한 용이성, 확장성, 비용대비 효과적인 병렬시스템 구축의 용이성, 기존의 네트워크를 활용할 수 있다는 측면에서 많은 장점을 가진다. 자바언어에서의 이동코드(mobile code)의 개념을 가지고 있는 applet은 많은 계산을 필요로 하는 프로그램이 독립된 병렬작업으로 분할되어 웹 상의 여러 노드들로 이동되어 실행이 되어질 수 있는 가능성을 제시하여 주고 있다. 그러나 자바 applet은 보안에 대한 모델상의 제약으로 인하여 제한된 범위 내에서만 실행이 가능하며 클라이언트가 applet을 포함하고 있는 호스트들에 접속을 해야 한다는 점에서 유연성이 부족하다. 따라서 본 논문에서는 applet의 개념에 자치적으로 작업을 처리할 수 있는 기능을 추가하여 이동형 에이전트라 할 수 있는 Aglet(Agile applet)을 이용하여 웹 기반 병렬 컴퓨팅 환경을 설계하였으며, 웹 기반 병렬컴퓨팅 환경을 구축할 때 필요한 기술과 구조가 분석되었다. 또한 applet 기반의 방식과 비교하여 간단한 시뮬레이션과 분석이 이루어졌다.

• Structural Engineering and Mechanics
• /
• 제38권4호
• /
• pp.405-416
• /
• 2011

An efficient two-level domain decomposition parallel algorithm is suggested to solve large-DOF structural problems with nonlinear material models generating unsymmetric tangent matrices, such as a group of plastic-damage material models. The parallel version of the stabilized bi-conjugate gradient method is developed to solve unsymmetric coarse problems iteratively. In the present approach the coarse DOF system is solved parallelly on each processor rather than the whole system equation to minimize the data communication between processors, which is appropriate to maintain the computing performance on a non-supercomputer level cluster system. The performance test results show that the suggested algorithm provides scalability on computing performance and an efficient approach to solve large-DOF nonlinear structural problems on a cluster system.