• 대한임베디드공학회논문지
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• 제12권6호
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• pp.377-384
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• 2017

The scope of the matrix application is so broad that it can not be limited. A typical matrix application area in computer science is image processing. Particularly, radar scanning equipment implemented on a small embedded system requires real-time matrix transposition for image processing, and since its memory size is small, a general matrix transposition algorithm can not be applied. In this case, matrix transposition must be done in disk space, such as flash disk, using a limited memory buffer. In this paper, we analyze and improve a recently published flash disk-based matrix transposition algorithm named as asymmetric sub-matrix transposition algorithm. The performance analysis shows that the asymmetric sub-matrix transposition algorithm has lower performance than the conventional sub-matrix transposition algorithm, but the improved asymmetric sub-matrix transposition algorithm is superior to the sub-matrix transposition algorithm in 13 of the 16 experimental data.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.187-190
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• 2005

There have been many studies to improve the performance of a database system focused on modifying data structure, data partitioning, and materializing strategy. The main contribution of this study is to propose a new alternative towards improving database performance by designing single table schema or processing queries virtually in main memory space. Material Requirement Planning(MRP) part explosion process has shown almost 2 times shorter under DB schema we suggested, and even more than 10 times shorter when separating and filtering policy of DB archiving process are assumed. Several experimental results are shown to illustrate the excellence of our solution.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2001년도 춘계 학술대회논문집
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• pp.38-44
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• 2001

An efficient Gauss-Seidel time integration scheme is developed for solving the Euler and Navier-Stokes equations on unstructured meshes. Roe's FDS is used for the explicit residual computations and van Leer's FVS for evaluating implicit flux Jacobian. To reduce the memory requirement to a minimum level, off-diagonal flux Jacobian contributions are repeatedly calculated during the Gauss-Seidel sub-iteration process. Computational results based on the present scheme show that approximately $15\%$ of CPU time reduction is achieved while maintaining the memory requirement level to $50-60\%$ of the original Gauss-Seidel scheme.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2005년도 추계 학술대회논문집
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• pp.157-162
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• 2005

Parallel implementation and performance assessment of the grid assembly in a structured chimera grid approach is studied. The grid assembly process, involving hole cutting and searching donor, is parallelized on the PC cluster. A message passing programming model based on the MPI library is implemented using the single program multiple data(SPMD) paradigm. The coarse-grained communication is optimized with the minimized memory allocation because that the parallel grid assembly can access the decomposed geometry data in other processors by only message passing in the distributed memory system such as a PC cluster. The grid assembly workload is based on the static load balancing tied to flow solver. A goal of this work is a development of parallelized grid assembly that is suited for handling multiple moving body problems with large grid size.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1098-1100
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• 2005

The floorplanning problem is an essential design step in VLSI layout design and it is how to place rectangular modules as density as possible. And then, as the DSM advances, the VLSI chip becomes more congested even though more metal layers are used for routing. Usually, a VLSI chip includes several buses. As design increases in complexity, bus routing becomes a heavy task. To ease bus routing and avoid unnecessary iterations in physical design, we need to consider bus planning in early floorplanning stage. In this paper, we propose a floorplanning method for topological constraint consisting of bus constraint and memory constraint. The proposed algorithms based on Genetic Algorithm(GA) is adopted a sequence pair. For selection control, new objective functions are introduced for topological constraint. Studies on floor planning and cell placement have been reported as being applications of GA to the LSI layout problem. However, no studies have ever seen the effect of applying GA in consideration of topological constraint. Experimental results show improvement of bus and memory constraint.

• 대한전자공학회논문지
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• 제27권5호
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• pp.699-708
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• 1990

This paper proposes two test procedures for detecting functional faults in semiconductor random access memories (RAM's) and a new testimg scheme to execute the proposed test procedures. The first test procedure detects stuck-at faults, coupling faults and decoder faults, and requires 19N operations, which is an improvement over conventional procedures. The second detects restricted patternsensitive faults and requires 69N operations. The proposed scheme uses Built-In Self Testing (BIST) techniques. The scheme can write into more memory cells than I/O pins can in a write cycle in test mode. By using the scheme, the number of write operations is reduced and then much testing time is saved.

• 한국가시화정보학회지
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• 제14권2호
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• pp.25-30
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• 2016

The wafer temperature and its uniformity inside the LPCVD chamber were analyzed. The temperature uniformity at the end of the wafer load depends on the heat-insulating cap. The finite difference method was used to investigate the radiation and conduction heat transfer mechanisms, and the temperature field and heat diffusion in the LPCVD chamber was visualized. It was found that the temperature uniformity of the wafers could be controlled by the size and distance of the heat-insulating cap.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.238.1-238.1
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• 2014

이번 연구는 system-on-panel에 적용하기 위한 비휘발성 메모리의 메모리 윈도우 특성 향상에 관한 연구이다. 이를 위해 SiO2/SiNX/SiOXNY의 메모리 구조를 이용하였으며, 채널층으로 투명한 비정질 인듐-주석-아연-산화물을 이용하였다. N형 물질의 특성인 수많은 전자로 인해 erasing의 어려움이 발생하는데 이는 빛과 전압의 동시 인가로 해결하였다. 전하트랩층은 비휘발성 메모리에서 가장 널리 이용되는 질화막을 이용하였으며, SiH4과 NH3의 비율은 8대 1에서 1대 2까지 이용하였다. 이번 연구에서 SiH4과 NH3의 비율이 2대 1일 때 쓰기 전압 +13V와 지우기 전압 -6V에서 약 3.7V의 높은 메모리 윈도우를 얻을 수 있었다.

• Journal of information and communication convergence engineering
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• 제13권1호
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• pp.27-35
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• 2015

Multiprecision multiplication is the most expensive operation in public key-based cryptography. Therefore, many multiplication methods have been studied intensively for several decades. In Workshop on Cryptographic Hardware and Embedded Systems 2011 (CHES2011), a novel multiplication method called 'operand caching' was proposed. This method reduces the number of required load instructions by caching the operands. However, it does not provide full operand caching when changing the row of partial products. To overcome this problem, a novel method, that is, 'consecutive operand caching' was proposed in Workshop on Information Security Applications 2012 (WISA2012). It divides a multiplication structure into partial products and reconstructs them to share common operands between previous and next partial products. However, there is still room for improvement; therefore, we propose a finely designed operand-caching mode to minimize useless memory accesses when the first row is changed. Finally, we reduce the number of memory access instructions and boost the speed of the overall multiprecision multiplication for public key cryptography.

• 대한전기학회논문지:전력기술부문A
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• 제52권11호
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• pp.647-654
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• 2003

As electrical power system has become complicated and enlarged to cope with the increasing electric demand, it has to be expected that higher speed, higher reliability, higher function and higher arithmetic ability in protective relay should be realized. Therefore, in this papers, by hardware design and implementation used DMA controller that transfer blocks of data to any location in the memory map without interfering with CPU operation, CPU utilization is increased effectively, as a result it made possible to implement multi-function digital protective relay which has high trust and high function of protection as well as control and metering for power transformers using single processor(DSP).