• 한국수학교육학회지시리즈A:수학교육
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• 제41권1호
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• pp.79-90
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• 2002

In this article we study on connecting paper 131ding activities of triangle with mathematical proof Folding median, bisector of angle, and hight of paper triangle, we from and extract some ideas that help us to proof some important theorems of plane geometry. In this study using formed ideas in the process of paper folding activities, we suggest some interesting new mathematical proofs of the following theorems: 1. three medians of triangle are intersect in a point; 2. three bisectors of interior angles of triangle are intersect in a point; 3. three heights of triangle are intersect in a point.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2007년 추계학술발표대회 개요집
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• pp.232-234
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• 2007

This study conducts numerical simulations of Isotropic conductive adhesives using low melting point alloy fillers during the reflow process. The CIP method and predictor-corrector method are used to simulate more accurately on free surface flow of low melting point alloy fillers. For finding out optical conditions to obtain reliable conduction paths, the present study conducts extensive numerical simulations.

• Journal of the Korean Data and Information Science Society
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• 제15권2호
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• pp.387-394
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• 2004

Zero-Inflated Poisson distribution is Poisson distribution with excess zeros. Recently defects of product hardley happen in the manufacturing process. In this case it is desirable to apply to the Zero-Inflated Poisson distribution rather than Poisson. Our target of this paper is to study the tests for changes of rate of defects after the unknown change-point. We are going to compare the powers of the two proposed tests with likelihood tests by the simulations.

• 정보과학회 논문지
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• 제44권2호
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• pp.132-138
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• 2017

본 연구에서는 뉴메모리 기반 컴퓨팅 시스템의 신뢰성을 높이기 위해 프로세스 단위로 체크포인팅하는 시스템을 설계하고 구현한다. 프로세스 체크포인팅을 위하여 일반적인 프로세스 실행에서 문맥전환이 일어나는 시점마다 결함이 발생하기 이전의 안전한 상태로 되돌아갈 수 있는 롤백 시점을 만든다. 본 연구에서는 롤백 시점의 안전한 프로세스 상태에 대한 새로운 프로세스를 만들며 이를 P-process(Persistent-process)라고 명명한다. P-process를 만드는 주기를 세밀한 간격인 문맥전환 때마다 만들기 때문에 결함이 발생하였을 때 롤백으로 인한 프로세스 실행시간 손실을 작게 만들 수 있다. P-process를 만드는 오버헤드를 줄이기 위하여 프로세스의 메모리 상태에서 변경된 부분만 저장할 수 있도록 COW(Copy-On-Write) 메커니즘을 이용하였다. 문맥전환 때마다 P-process를 생성하였을 때 PARSEC 벤치마크의 11개 워크로드 중 8개의 워크로드에서 5% 내의 실행 시간 오버헤드가 발생하였으며 오버헤드가 많이 발생한 워크로드도 P-process의 생성 주기의 조정으로 오버헤드를 감소시킬 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제11권4호
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• pp.700-703
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• 2001

The influence of process conditions on highly branched glucooligosaccharides production by mixed culture of Leuconostoc mesenteroides ATCC 13146 and Lipomyces starkeyi ATCC 74054 was studied. We divided the batch culture fermentations into two groups according to inoculation method. One-point inoculation was performed by coinoculation of L. mesenteroides and L. starkeyi at the ration of 10 to 1, and two-point inoculation by L. mesenteroides inoculation first and L. starkeyi inoculation after L. mesenteroides grew to the end of the log phase of growth. Two-point inoculation improved the yield of oligosaccharide by 1.5 to 20 fold more than one-point inoculation. In this process, the highest yield of oligosaccharides (48% of theoretical yield) and productivity (0.85 g/l/h) were obtained with starch as an initial substrate for L. starkeyi growth. The estimated composition of the end product consisted of 31.5% oligosaccharides, 17.6% dextran, and 46.5% mannitol.

• 한국기계가공학회지
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• 제19권6호
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• pp.80-87
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• 2020

The currently observed trend in car manufacturing is to increase energy-efficiency by producing lighter cars. This study examines the replacement of particular parts, specifically around the impact beam, with material composites 30% lighter than conventional steel currently used. The shape of the impact beam was determined as the trapezoidal cross-sectional area with central reinforcement, using three-point bending analysis. A prototype was fabricated based on the findings of our study and its performance was evaluated by the three-point bending analysis; 2 ply of aramid applied for its displacement. The performance of the final prototype for the door assembly was evaluated using a side-door strength test, which resulted to measured initial strength of 10.5 KN and intermediate strength of 15.6 KN. This research provides a promising solution for better impact beam manufacturing.

• 한국안전학회지
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• 제30권3호
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• pp.13-19
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• 2015

Railway vehicle equipment goes back again to the state just before when failure by the repair. In repairable system, we are interested in the failure interval. As such, a statistical model of the point process, NHPP power law is often used for the reliability analysis of a repairable system. In order to derive a quantitative reliability value of repairable system, we analyze the failure data of the air brake system of the train line 7. The quantitative value is the failure intensity function that was modified, converted into a cost-rate function. Finally we studied the optimal number and optimal interval in which the costs to a minimum consumption point as cost-rate function. The minimum cost point was 194,613 (won/day) during the total life cycle of the braking system, then the optimal interval were 2,251days and the number of optimal preventive maintenance were 7 times. Additionally, we were compared to the cost of a currently fixed interval(4Y) and the optimum interval then the optimal interval is 3,853(won/day) consuming smaller. In addition, judging from the total life, "fixed interval" is smaller than 1,157 days as "optimal interval".

• 소성∙가공
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• 제27권4호
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• pp.236-243
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• 2018

A multi-point forming die (MPFD), which has been used for producing curved plates, is capable of forming various curved plates with just one MPFD. However, in real industries, an MPFD is difficult to be adopted since the structural properties, punch strength, elastic recovery correction and dimensional accuracy become problems. In order to overcome these problems, the hot multi-point forming die (HMPFD) was proposed in this study. This HMPFD commonly provide more less spring-back and forming load than conventional MPFD. Nevertheless, this process is very difficult to form the curved plate, because the final curved shape of the plate depends on many process variables such as the punch/nozzle arrangement (height and distance), the radius of punch, contact conditions between plate and punch. In this study, the forming characteristics of HMPFD and conventional MPFD are compared with each other through the finite element analysis.

• 한국식품과학회지
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• 제27권2호
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• pp.164-169
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• 1995

퍼지 이론을 적용하여 압출성형공정을 제어하는 모의실험을 수행하였다. 압출물의 두께(팽화율)가 측정변수로 피드백 입력되고 퍼지제어기를 통하여 스크류 회전속도의 set point가 출력되었다. 얻어진 set point로 가상의 압출성형기가 작동하여 또 다른 두께값이 측정값으로 입력되었다. 이와같은 일련의 과정이 반복되면서 최종적으로 원하는 두께값을 얻을 수 있었고 피지제어기의 알고리즘은 압출성형 전문가로부터 얻어진 기본 법칙을 이용하여 작성 하였다.

• 인터넷정보학회논문지
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• 제6권2호
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• pp.37-47
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• 2005

대부분 소프트웨어 규모 추정 기법들은 사용자에게 제공될 기능에 기반을 두고 있으며, 기능에 대한 점수를 부여하는 과정에서 복잡도를 함께 고려하고 있다. 완전기능점수 기법은 데이터 처리, 실시간 시스템과 알고리즘 소프트웨어 등 광범위한 분야에 적용되는 장점을 갖고 있는 반면에 규모를 추정하는데 필요한 기능 요소들에 대한 가중치를 부여하지 않는 단점도 갖고 있다. 본 논문은 신규로 개발되는 프로젝트와 유지보수 프로젝트들에 적용되는 완전기능점수 계산 방법에 각기능 요소들에 대한 복잡도를 고려하여 소프트웨어 규모를 추정할 수 있는 방법을 제안하였다. 이를 위해 기능 점수 기반으로 실측된 데이터를 이용하여 제안된 방법의 타당성을 검증하였다. 검증한 결과, 소프트웨어의 규모 추정에 사용되는 속성들인 기능 요소들에 다른 가중치를 적용하였을 경우 보다 좋은 규모 추정이 가능하였다.