• Journal of the Korean Data and Information Science Society
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• v.10 no.2
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• pp.473-483
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• 1999

We introduce a way to construct a supercomputing capable system with some networked PCs, running the Linux operating system and computing power comparable with expensive commercial workstations, and with the Parallel Virtual Machine (PVM) software which enables one to control the total CPUs and memories of the networked PCs. By benchmarking the system using a PVM parallel program, we find that the system's parallel efficiency is close to 90 %.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.10
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• pp.1688-1695
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• 2008

Recently, it is common in a distribution system of Korea Electric Power Corporation (KEPCO) to find instances where distribution lines are parallel. A traditional method of an induced voltage calculation is not suitable for parallel distribution lines. For more actual analysis of induced voltage on telecommunication lines in parallel distribution lines, a new calculation method is needed. This paper presents a new calculation method of an induced voltage on telecommunication line using equivalent ${\pi}$ circuits matrix in parallel distribution lines. The advantages of the calculation method are using actual neutral current value and not using screening factor for considering the overhead ground wire and the neutral wire. To verify the effectiveness and the accuracy of the method, various case studies are performed with EMTP(Electro-Magnetic Transients Program).

• Journal of the Korean Society for Precision Engineering
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• v.20 no.2
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• pp.184-191
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• 2003

A parallel manipulator has high stiffness and all the joint errors on the device are not accumulated at the end -effector unlike a serial manipulator. These are the reasons why the parallel manipulator has been widely used in many fields of industry. In the parallel manipulator, it is very important to predict the exact pose of the end-effector when we want to control the end-effector motion. Installation errors have to be determined in order to predict and control the actual position and pose of the end-effector. This paper presents an algorithm to find the whole 36 joint error components with joint clearance errors and measurement errors considered, when a link length measurement sensor is used and data more than 36 times are acquired for 36 different configurations. A simulation test using this algorithm is performed with a Matlab program which uses the Levenberg-Marquardt method that is known to be efficient for non-linear optimization.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.697-700
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• 2002

In this paper, we proposed the micro web-server Implementation on Strong ARM processor with embedded Linux. The parallel port connecting parallel I/O is controlled via HPPT protocol and web browser program. HTTP protocol is ported into Linux and the micro web server program and port control program are installed on-board memory using CGI to be accessed by web browser, such as Internet Explore and Netscape. 8bit LED and DIP switches are connected to the processor port and the switch input status is monitored and the LED output is controlled from remote hosts vie internet. The result of the proposed embedded micro-web server can be used in automation systems, remote distributed control via internet using web browser.

• The Transactions of the Korea Information Processing Society
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• v.6 no.5
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• pp.1263-1271
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• 1999

This paper designs the performance analysis layer for the various performance analysis of parallel programs using event expressions are similar to the normal program language to analyze the events which display a dynamic state exchange of a program. The event expressions suggest operations for overloading and functions which are needed in performance analysis, such as a filtering operation, data format translation functions, performance analysis, static functions, and etc. By using the event expressions, the programmer can modify the event trace data to analyze the performance and analyze more easily and variously than the pre-developed tools.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2672-2674
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• 2003

In this paper, web based monitoring systems are implemented using embedded systems. A parallel port connecting parallel I/O is controlled via HTTP protocol and web browser program. HTTP protocol is ported into Linux. A micro web server program and port control program installed on-board memory using CGI to be accessed by web browser. Experimental results of proposed web based monitoring systems can be used in automation systems and remote distributed control systems via internet using web browser.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.1
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• pp.71-79
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• 2014

A parallelization of the bi-conjugate gradient solver for the pressure equation of the CUPID (component unstructured program for interfacial dynamics) code, which was developed for analyzing the components of a pressurized water-cooled reactor, was studied in a symmetric multi-processing system. The parallel performance was investigated for three typical parallel programming models (MPI, OpenMP, Hybrid) by solving incompressible backward-facing step flow at various grid resolutions. It was confirmed that parallel performance was low when problem size was small or the memory requirement for each thread was considerably higher than the cache memory. Furthermore, it was shown that MPI was better than OpenMP regardless of the problem size, and Hybrid was the best when the number of threads was relatively small.

• International Journal of Computer Science & Network Security
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• v.21 no.12spc
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• pp.570-578
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• 2021

Recently, in the field of engineering and scientific and technical calculations, problems of mathematical modeling, real-time problems, there has been a tendency towards rejection of sequential solutions for single-processor computers. Almost all modern application packages created in the above areas are focused on a parallel or distributed computing environment. This is primarily due to the ever-increasing requirements for the reliability of the results obtained and the accuracy of calculations, and hence the multiply increasing volumes of processed data [2,17,41]. In addition, new methods and algorithms for solving problems appear, the implementation of which on single-processor systems would be simply impossible due to increased requirements for the performance of the computing system. The ubiquity of various types of parallel systems also plays a positive role in this process. Simultaneously with the growing demand for parallel programs and the proliferation of multiprocessor, multicore and cluster technologies, the development of parallel programs is becoming more and more urgent, since program users want to make the most of the capabilities of their modern computing equipment[14,39]. The high complexity of the development of parallel programs, which often does not allow the efficient use of the capabilities of high-performance computers, is a generally accepted fact[23,31].

• The KIPS Transactions:PartA
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• v.18A no.3
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• pp.99-108
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• 2011

Processor technology is currently continued to parallel processing techniques, not by only increasing clock frequency of a single processor due to the high technology cost and power consumption. In this paper, a SIMD (Single Instruction Multiple Data) based parallel processor is introduced that efficiently processes massive data inherent in multimedia. In addition, this paper proposes pixel subword parallel processing instructions for the SIMD parallel processor architecture that efficiently operate on the image and video pixels. The proposed pixel subword parallel processing instructions store and process four 8-bit pixels on the partitioned four 12-bit registers in a 48-bit datapath architecture. This solves the overflow problem inherent in existing multimedia extensions and reduces the use of many packing/unpacking instructions. Experimental results using the same SIMD-based parallel processor architecture indicate that the proposed pixel subword parallel processing instructions achieve a speedup of $2.3{\times}$ over the baseline SIMD array performance. This is in contrast to MMX-type instructions (a representative Intel multimedia extension), which achieve a speedup of only $1.4{\times}$ over the same baseline SIMD array performance. In addition, the proposed instructions achieve $2.5{\times}$ better energy efficiency than the baseline program, while MMX-type instructions achieve only $1.8{\times}$ better energy efficiency than the baseline program.

• Computational Structural Engineering
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• v.28 no.1
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• pp.35-41
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• 2015