• Transactions of Materials Processing
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• v.16 no.3 s.93
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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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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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.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.9
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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.

• Proceedings of the KIEE Conference
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• 2000.11b
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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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• v.10 no.1
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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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• v.6 no.2
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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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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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.

• Journal of the Economic Geographical Society of Korea
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• v.19 no.4
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• pp.729-742
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• 2016

Socio-economic polarization in Korea partly due to recent globalization and industrial restructuring could reduce social mobility significantly through passing down educational achievement to one's children. Under the notion that residential segregation is geographical frame for the reproduction of educational inequality, this research investigates residential segregation by educational attainment and neighborhood disparity with a case study of Seoul. The statistical analyses employed local segregation measures such as Location Quotient and Local Moran's I and a variety of variables that reflect neighborhood characteristics. As a result, it found that there are sharp and clear contracts between low- and high-educational group concentrations/clusters particularly in terms of housing characteristics and educational facilities. This results provide some evidences that support the arguments about the causes of residential segregation by class in Korean Cities.

• Journal of Sericultural and Entomological Science
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• v.17 no.1
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• pp.47-53
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• 1975

This experiment was carried out to obtain a marked larvae in sex-limited inheritance, using F$_1$ hybrid Bo ok X Chun san introduced from Japan. Sequence of backcrossing has been done through the earlier generation with a recessive character of plain marked larvae. 1. It is noted that genotypic segregation of sex-limited larval marking was observed in F$_4$ generation; female possesses larval marking and male shows a plain marking. 2. Larval marking heredity follows a diagram of segregation with an expected genotype such as ♀ ： (W$.$＋p)/Z$.$P/P and ♂ ： Z/Z$.$P/P. 3. It is observed that dissociation was occurred to produce female with a genotype of W/Z$.$P/P in segregation ana selection. 4. Abnormal ratio of sexuality is observed in the course of segregation and segregation and analysis of it is continuously under way. 5, It is observed that the difference of qualitative characteristics between female and male obtained from the original variety shows the same tendency as the normal marked variety.