• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.738-739
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• 2006

This paper will describe a powder and processing method that facilitates single press-single sintered densities approaching $7.5g/cm^3$. At this sintered density, mechanical properties of the powder metal (P/M) component are significantly improved over current P/M technologies and begin to approach the performance of wrought steels. High performance gears have the added requirement of rolling contact fatigue durability that is dependent upon localized density and thermal processing. Combining high density processing of engineered P/M materials with selective surface densification enables powder metal components to achieve rolling contact fatigue durability and mechanical property performance that satisfy the performance requirements of many high strength automotive transmission gears. Data will be presented that document P/M part performance in comparison to conventional wrought steel grades.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.11a
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• pp.57-60
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• 2020

순위다중패턴매칭문제는 길이가 n인 텍스트 T와 패턴들의 집합 P' = {P₁,P₂…,P_k}가 주어졌을 때, P'에 속하는 패턴들과 상대적인 순위가 일치하는 T의 모든 부분문자열들의 위치를 찾는 문제이다. P'에서 가장 짧은 패턴의 길이가 m, 가장 긴 패턴의 길이를 $\bar{m}$, 모든 패턴들의 길이의 합을 M, q개의 연속된 문자들을 q-그램이라 할 때, 기존에 텍스트의 핑거프린트를 이용하여 순위다중패턴매칭문제를 $O(q!+nqlogq+Mlog\bar{m}+nM)$ 시간에 해결하는 알고리즘이 제시되었다. 본 논문에서는 텍스트의 핑거프린트를 활용하여 O(max(q!,M,n))개의 스레드를 이용하여 순위다중패턴매칭문제를 평균적으로 $O(\bar{m}+qlogq+n/q!)$ 시간에 해결하는 병렬 구현 방법을 제시한다. 실험 결과, n = 1,000,000, k = 1,000, m = 5, q = 3일 때, 본 논문에서 제시하는 병렬 구현 방법은 기존의 순차 알고리즘보다 약 19.8배 빠르게 수행되었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.1403-1404
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• 2011

본 논문에서는 동영상과 다양한 데이터들을 매쉬업하여 통합미디어컨텐츠(UMC : United Media Contnets)를 수월하게 제작하고 재생시켜주는 E.M.P.Z(Editor Media Player Zone)의 개발에 대해 기술한다. E.M.P.Z는 에디터를 사용하여 다양한 데이터를 편집하는 기능과 UMC를 재생하기 위한 플레이어 기능, 그리고 웹기반환경에서 검색 및 플레이기능 등을 제공하며, 학습을 위한 동영상강의, 스포츠중계, 광고 등의 다양한 분야에서 활용 가능하다.

• Journal of Powder Materials
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• v.21 no.4
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• pp.294-300
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• 2014

The connecting rod is one of the most important parts in automotive engines, transforming the reciprocal motion of a piston generated by internal combustion into the rotational motion of a crankshaft. Recent advances in high performance automobile engines demand corresponding technological breakthroughs in the materials for engine parts. In the present research, the powder metallurgy (P/M) process was used to replace conventional quenching and/or tempering processes for mass production and ultimately for more cost-efficient manufacturing of high strength connecting rods. The development of P/M alloy powder was undertaken not only to achieve the improvement in mechanical properties, but also to enhance the machinability of the P/M processed connecting rods. Specifically $MoS_2$ powders were added as lubricants to non-normalizing Fe-Cr-Mn-V-C alloy powder to improve the post-sintering machinability. The effects of $MoS_2$ addition on the microstructure, mechanical properties, and machining characteristics were investigated.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.3
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• pp.349-356
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• 2014

The objective of this study was to evaluate the effects of molasses and propionic acid on the fermentation quality and aerobic stability of total mixed ration (TMR) silages prepared with whole-plant corn in Tibet. TMR (354 g/kg DM) was ensiled with four different treatments: no additive (control), molasses (M), propionic acid (P), and molasses+propionic acid (PM), in laboratory silos (250 mL) and fermented for 45 d. Silos were opened and silages were subjected to an aerobic stability test for 12 days, in which chemical and microbiological parameters of TMR silages were measured to determined the aerobic deterioration. After 45 d of ensiling, the four TMR silages were of good quality with low pH value and ammonia/total N (AN), and high lactic acid (LA) content and V-scores. M silage showed the highest (p<0.05) LA content and higher dry matter (DM) recovery than the control and P silages. P silage had lower (p<0.05) LA content than the control silage. During aerobic exposure, lactic acid contents decreased gradually in the control and M silages, while that of P and PM silages increased, and the peak values were observed after 9 d. M silage had similar yeast counts with the control silage (> $10^5$ cfu/g FM), however, it appeared to be more stable as indicated by a delayed pH value increase. P and PM silages showed fewer yeasts (< $10^5$ cfu/g FM) (p<0.05) and were more stable than the control and M silages during aerobic exposure. It was concluded that M application increased LA content and improved aerobic stability of TMR silage prepared with whole-plant corn in Tibet. P application inhibited lactic acid production during ensiling, and apparently preserved available sugars which stimulated large increases in lactic acid during aerobic exposure stage, which resulted in greater aerobic stability of TMR silage.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.1211-1214
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• 2008

최근 Path-diversity에 근거한 통신 방식은 다양한 P2P streaming 어플리케이션에 대역폭 고갈 현상을 해결하는 쪽으로 연구가 진행 중이다. 이 논문에서는 네트워크의 대역폭 확보와 효과적인 데이터 전송을 위해서 다소 직관적인 방법인 다중시간이론을 소개하고, 이를 P2P 네트워크에 적용할 수 있는 방법을 제시한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.1441-1443
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• 2008

최근 들어 미디어 스트리밍 서비스 제공 시 서버의 부하 및 비용을 줄이기 위해 P2P 기반의 오버레이 네트워크를 이용하여 미디어 스트리밍 콘텐츠를 분배하는 방안이 등장하고 있다. 하지만 이 방안은 그 효율성만큼이나 보안 취약성도 많이 존재하는 방안이다. 본 논문에서는 P2P 기반의 미디어 스트리밍 서비스에 대한 보안 위협과 이에 대응하기 위한 보안 고려사항을 분석하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.1A
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• pp.80-88
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• 2002

Visual media(image, graphic, and video) processing poses challenge from several perpectives, specifically from the point of view of real-time implementation and scalability. There have been several approaches to obtain speedups to meet the computing demands in multimedia processing ranging from media processors to special purpose implementations. A variety of parallel processing strategies are adopted in these implementations in order to achieve the required speedups. We have investigated a parallel processing system for improving the processing speed o f visual media related applications. The parallel processing system we proposed is similar to a pipelined memory stystem(MAMS). The multi-access memory system is made up of m memory modules and a memory controller to perform parallel memory access with a variety of combinations of 1${\times}$pq, pq${\times}$1, and p${\times}$q subarray, which improves both cost and complexity of control. Facial recognition, Phong shading, and automatic segmentation of moving object in image sequences are some that have been applied to the parallel processing system and resulted in faithful processing speed. This paper describes the parallel processing systems for the speedup and its utilization to three time-consuming applications.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.3
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• pp.102-109
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• 2001

In this paper, a new multiplication algorithm which describes the methods of constructing a multiplierover GF(p$^{m}$ ) was presented. For the multiplication of two elements in the finite field, the multiplication formula was derived. Multiplier structures which can be constructed by this formula were considered as well. For example, both GF(3) multiplication module and GF(3) addition module were realized by current-mode CMOS technology. By using these operation modules the basic cell used in GF(3$^{m}$ ) multiplier was realized and verified by SPICE simulation tool. Proposed multipliers consisted of regular interconnection of simple cells use regular cellular arrays. So they are simply expansible for the multiplication of two elements in the finite field increasing the degree m.

• Food Science of Animal Resources
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• v.36 no.6
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• pp.769-778
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• 2016

In this study, we improved the eggshell-membrane separation process by separating the shell and membrane with EDTA solution, evaluating effects of three different extraction solutions (acetic acid, EDTA, and phosphate solution), and co-purifying multiple eggshell proteins with two successive ion-exchange chromatography procedures (CM Sepharose Fast Flow and DEAE Sepharose Fast Flow). The recovery and residual rates of eggshell and membrane separated by the modified method with added EDTA solution were 93.88%, 91.15% and 1.01%, 2.87%, respectively. Ovocleidin-116 (OC-116) and ovocalyxin-36 (OCX-36) were obtained by loading 50 mM Na-Hepes, pH 7.5, 2 mM DTT and 350 mM NaCl buffer onto the DEAE-FF column at a flow rate of 1 mL/min, ovocleidin-17 (OC-17) was obtained by loading 100 mM NaCl, 50 mM Tris, pH 8.0 on the CM-FF column at a flow rate of 0.5 mL/min. The purities of OCX-36, OC-17 and OC-116 were 96.82%, 80.15% and 73.22%, and the recovery rates were 55.27%, 53.38% and 36.34%, respectively. Antibacterial activity test suggested that phosphate solution extract exhibited significantly higher activity against the tested bacterial strains than the acetic acid or EDTA extract, probably due to more types of proteins in the extract. These results demonstrate that this separation method is feasible and efficient.