• The Korean Journal of Applied Statistics
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• v.8 no.1
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• pp.105-117
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• 1995

An asymptotically distribution-free procedure is proposed for paralleism of k regression lines against umbrella alternatives. Asymptotic properties are discussed, and comparative results relative to Kim and Lim(1994)'s tests show that our procedure is generally more powerful.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.410-410
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• 2003

실에 2차원 혹은 3차원적인 권축변형을 부여하고 이 변형을 적절한 방법으로 고정하며 섬유간의 상호 평행성을 저하시킴으로써 벌키성과 신축성이 부여된 실을 벌크가공사(bulk textured yarn)라고 부른다. 원리적으로는 물리적 변형을 이용하여 섬유간 평행성을 저하시키며, 이를 어떠한 수단으로 고정하는 것이다. 폴리에스터 원사에 대하여 널리 사용되는 방법 중 하나로 가연가공(false twist texturing)법을 들 수 있으며, 본보에서는 가연가공 히터의 온도변화에 따른 원사의 물성 변화에 대하여 분석하고 향후 이러한 기본적인 특성과 외관특성과의 상관성 유무를 확인하고자 한다. (중략)

• The Korean Journal of Applied Statistics
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• v.8 no.2
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• pp.77-86
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• 1995

For the problem of testing the parallelism of two regression lines, a robust procedure is proposed and examined. The proposed test statistic is based on the one-step GM-estimators of slope parameters proposed by Song et al. (1994b). These GM-estimators used the Least Trimmed Squares estimates as an initial values so as to obtain high breakdown point. Through a small-sample Monte Carlo simulation the empirical levels and powers of the proposed test are compared with other tests under various error distributions.

• Communications for Statistical Applications and Methods
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• v.16 no.1
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• pp.75-83
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• 2009

Parallelism tests are proposed for slope in the simple linear regression models. In this paper, we suggest the parametric test using HSD testing method (Tukey,1953) and distribution-free test using Kruskal-wallis (1952) for more than three slopes. Monte Carlo simulation study is adapted to compare the power of the proposed methods with Wilks' Lambda multivariate procedure.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1989.04a
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• pp.28-32
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• 1989

In the recent years, parallelogrammic shape structures were often introduced in the Civil Engineering. Especially parallelogrammic shape highway slabs, which were used in the portions of Interstate-75, U.S.A., were a unique one to result in only one wheel crossing the joint at any one time. In this reserch, major efforts were made to provide an appropriate subroutine program and to study an analytical behavior of paralleloqrammic plate bending element by developing the stiffness and load matrices.

• Communications of Mathematical Education
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• v.27 no.1
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• pp.81-97
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• 2013

In this study, we investigated how the relationship between 'parallel' lines and 'identical' lines is stated in mathematics textbooks of the 2007 revised national curriculum. In school mathematics, 'parallel' lines and 'identical' lines are explicitly distinguished in the perspective of 'coincidence', whereas 'identical' lines are implicitly regarded as a special case of 'parallel' in the perspective of 'slope'. These different treatments could bring out a confusion as was in the mock mathematics test for 2012 College Scholastic Ability Test. To resolve this confusion, it needs to be considered that the relationship between 'parallel' lines and 'identical' lines are more clearly stated in the context of 'slope' such as in some textbooks for the 4th and 5th curriculum and a textbook of Japan.

• Journal of Elementary Mathematics Education in Korea
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• v.23 no.4
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• pp.481-506
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• 2019

Perpendicularity and parallelity are important concepts in Mathematics as well as real-life contexts. However, those concepts are rather reduced in 2015 revised curriculum compared to previous 2009 revised curriculum. This study firstly analyzed teaching method related to perpendicularity and parallelity in a series of mathematics textbooks of Korea, Singapore and Japan. Moreover, the unit of perpendicularity and parallel was redesigned in a way to understand the concepts meaningfully and to give opportunities for students to explore how to make perpendicular and parallel lines. The results showed that noticeable changes has been as the curriculum was revised in Korea. Also, three countries showed some differences in concepts definition and learning activities. This study is expected to suggest implications for how to teach perpendicularity and parallelity in elementary school mathematics.

• The Korean Journal of Applied Statistics
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• v.7 no.1
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• pp.19-34
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• 1994

In this paper we propose nonparametric tests of parallelism against umbrella alternatives of slopes in k-regression lines and investigate the asymptotic properties of the proposed test statistics. For the known peak and unknown peak, we suggest the test statistics and show that, from Monte Carlo study, the proposed test statistics have good empirical powers for heavy tailed distributions than the likelihood ratio tests.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.10
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• pp.1036-1043
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• 2003

In this paper, novel lumped equivalent circuits for a conventional parallel directional coupler are proposed. This novel equivalent circuits only have self inductance and self capacitance, so we can design exact lumped equivalent circuit. The equivalent circuit and design formula for the presented lumped element coupler is derived based on the even- and odd-mode properties of a parallel-coupled line. By using the derived design formula, we have designed the 3 dB and 10 dB lumped element directional couplers at the center frequency of 100 MHz and 2 GHz, respectively a chip type directional coupler has been designed with multilayer configurations by employing commercial EM simulator. Designed chip-type directional couplers have a 3 dB-coupling value at the center frequency of 2 GHz and fabricated lumped directional coupler on fr4 organic substrate has a 3 dB, 10 dB-coupling values at the center frequency of 100 MHz. Excellent agreements between simulation results and measurement results on the designed directional couplers show the validity of this paper. Furthermore, in order to adapt to multi-layer process such as Low Temperature Cofired Ceramic (LTCC), chip-type lumped element couplers have been designed by using this method.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2003.05a
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• pp.52-52
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• 2003

경기육괴 서남부에 위치한 홍성지역의 기반암은 선캠브리아 화강암질 편마암으로 이루어진 것으로 알려져 왔으나, 적어도 일부는 신원생대(약820 Ma) 시기에 관입한 토날라이트질 심성암체로 구성된다. 토날라이트의 주 구성광물은 석영, 사장석, 흑운모, 각섬석이며, 저어콘, 스핀, 녹니석, 인회석 등이 소량으로 산출한다. 이 연구에서는 야외 및 미세구조 관찰을 통해, 홍성 화강암질암에서 나타나는 구조적 요소들이 화성기원임을 보고한다. 홍성 토날라이트에서 관찰되는 구조들이 화성기원인 증거는: (1) 엽리가 연속성이 부족하고 주향과 경사가 불규칙하며, 드물게는 사층리처럼 보이기도 한다. (2) 자형 내지 반자형의 장석과 각섬석이 엽리면에 평행 또는 준평행하게 배열되어 있으며, 반정 주변에는 음영대(pressure shadow)가 발달하지 않는다 (3) 고철질 포획체(mafic enclave)는 주변암의 엽리에 평행하게 신장되어 있고, 완전히 고화 되지 않은 상태에서 형성되는 불꽃 구조(flame structure)가 드물게 관찰된다. (4) 고철질 포획체의 주 구성광물인 흑운모와 각섬석은 주변암의 엽리와 평행하게 배열되어 있으나, 소성변형의 증거를 보이지 않는다. 홍성 토날라이트에서 관찰되는 모든 조직들이 화성기원이라고 주장하기는 어렵지만, 모두 고체상태에서의 변형작용으로 설명하기는 더욱 힘들다. 후자가 화성기원의 조직에 어느 정도 영향을 주었는지는 추후의 연구를 통해 밝혀져야 할 것이다.