• 소성∙가공
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• 제16권3호
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• pp.178-186
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• 2007

Rheo-forging process of aluminum alloy is suitable for large parts of net shape without defects and excellent mechanical properties in comparison with conventional die casting and forging process. To control the microstructure of the product with high mechanical properties in rheo-forming, solid fraction is required to prevent porosity and liquid segregation. Therefore, in rheo-forging process, die shape, pressure type and solid fraction are very important parameters. The defects such as porosity, liquid segregation and unfitting phenomena occur during rheo-forging process. To prevent these defects, mechanical properties and microstructure analysis of samples versus the change of pressure are carried out and the problem and its solutions are proposed. Also, the mechanical properties versus various pressures were compared with and without heat treatment. The alloys used for rheo-forming are A356 and 2024 aluminum alloy. The rheology material is fabricated by electromagnetic process with controlling current and stirring time.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.101-102
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• 2019

The use of high fluidity concrete has been added in recent construction work. In this study, we analyzed segregation resistance due to admixture substitution of the system high fluidity concrete that was hardened. The research results show that the resistance to segregation at the time of admixture replacement is improved. The best results were shown with a ternary system mixed like FA and BS.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 추계 학술논문 발표대회
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• pp.38-39
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• 2014

In this research, the evaluation method of segregation resistance is suggested using the ratio of maximum and minimum values of concrete slump flow. As a result, in the case of normal concrete range from 80 to 210 mm of slump, it is considered that managing the EIS-N value to less than 1.10 is the most favorable for segregation determination.

• 제어로봇시스템학회논문지
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• 제15권9호
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• pp.922-928
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• 2009

This thesis puts forward a suggestion of measuring inner crack and center segregation in steel processing by using scanner and image processing with sulfur printer. To sum up, there are three points in this system. First, it scans sulfur printer and process the image by using histogram, image processing, and the mask. Second, it measures crack and center segregation by the fictitious image and output the length, thickness, exponent and grade on the mornitor. And finally, it gathers the measurement result image and data at the server and this information is used as data for the next casting.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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• pp.247-249
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• 2000

Transient phenomena cause delay in control response and must be studied and eliminated, if possible, suppressed. The difficulty in analyzing transient phenomena in ac machines comes from the large number of windings involved. But, it is possible that only one phase is used to represent three phases of the induction motor as called phase segregation method. The phase segregation method provides equivalent circuits for both the steady and transient states of induction motor. In this paper, analysis of the torque transient of the induction motor be carried out the phase segregation method and confirmed in the possibility of transientless torque control.

• International Journal of Advanced Culture Technology
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• 제10권1호
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• pp.55-66
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• 2022

As the number of immigrants staying in Korea has gradually increased since the mid-1990s, the rate of chronicle migration from certain countries such as China and Vietnam remain high. Registered foreign residents have formed ethnic communities depending on their countries of origin, and the purpose of stay, Korean language literacy, rent, and accessibility have resulted in their self-congregation or forced segregation. This study aims to explore the direction in which immigrants' residential distribution move over time, and whether the ethnic communities show any differences in the level of congregation or segregation. It focuses on identifying the residential distribution of Korean-Chinese, Chinese, and Vietnamese at the city, county, and district level across the country in Korea and examining the congregation and residential changes of three groups over the past decade using centrographic method. Comparing the location as well as the level of residential congregation or dispersion of three groups, which account for the majority of non-professional immigrants in Korea, it will provide a basis for further research on residential congregation or segregation of immigrants in the future.

• Journal of the Korean Statistical Society
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• 제6권2호
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• pp.167-177
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• 1977

유전적 질환이 있는 가계에서 출생하는 자녀중에서 유전적인 질환을 보유할 수 있는 확률을 예측하는 방법의 하나로서 우도추정치(likelihood estimator)를 사용하는 것은 분리분석(segregation analysis)에서 중요한 역할을 하고 있다. Elston과 Stewart(1971)는 이러한 분석방법의 일반적인 통계모형을 정립하였으며 필자(1974)와 Morton 등 (1974)은 complex segregation이 될 때에 분석되는 4가지의 통계모형을 주장하였다. 본 연구의 목적은 multiple ascertainment $\pi$가 존재하는 경우 분리확률모수(segregation parameter) $\theta$의 우도추정치를 구하고 둘째로 oligogenic case에 대한 이론적인 배경을 구명하고자 한다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.113-114
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• 2022

The aim of the research is to evaluate the segregation resistivity of the mixture conditions by changing the PVA and borax solutions for thixotropic property on concrete mixture. Since the water addition caused by producing solutions of PVA and borax induces segregation of the concrete mixture, the unit water was reduced by replacing the water amount for PVA and borax solution. By replacing the water from PVA and borax solutions, the segregation was prevented with prefixed concrete mix design and thixotropic properties were also occurred.

• 한국경제지리학회지
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• 제19권4호
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• pp.729-742
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• 2016

최근 세계화와 산업구조조정으로 인해 가속되는 사회경제적 양극화는 학력자본의 세대 간 대물림으로 고착될 위험에 처해 있다. 본 연구는 학력자본의 대물림은 거주지 분리를 매개로 이루어진다는 인식 하에 중년층의 교육수준별 거주지 분리에 따른 근린주거환경의 격차를 서울시를 사례로 분석하였다. 국지적 거주지 분리 측도를 통해 근린별 거주지 분리를 측정하고 자연, 주택, 지역인구, 생활 편의 교통, 교육, 복지문화 등 다양한 분야의 근린주거환경을 가늠하는 변수들을 활용했다. 분석 결과 학력층별 집중-집적지 간에는 뚜렷한 근린주거환경의 격차가 나타났다. 특히 저학력층과 고학력층 집중-집적지 사이에는 주택환경과 교육환경 측면에서 정반대의 성격을 보였다. 이러한 결과는 한국 도시의 계층별 거주지 분리의 원인에 대한 주장을 뒷받침하는 증거가 되기도 한다.

• 한국잠사곤충학회지
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• 제17권1호
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• pp.47-53
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• 1975

잠 육종용 기초품종으로 한성형잠을 얻고저 일본으로부터 도입된 교잡종 보옥$\times$춘산에 열성반문 희잠을 수대 Back crossing하여 다음 결과를 얻었다. 1. 한성형잠 목적형(♀ ：형반잠, ♂：희반잠)을 F$_4$에서 분리확인했다. 2. 목적형 Genotype은 ♀ ： (W.＋p)/Z.P/P, ♂ ： Z/Z.P/P로 반문의 유전은 분리계획 추정모식도와 일치했다. 3. 분리선발중 전좌염색체의 해이현상인 W/Z.P/P의 자잠이 나타났다. 4. 분리선발중 이상성비가 나타났으며 그의 기권에 대하여는 계속 추구중이다. 5. 분리 한성계통의 자웅잠의 계량형질의 차는 모품종보다 분리계통이 일반품종의 그것과 가까웠다.