• 한국수학사학회지
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• 제14권1호
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• pp.101-108
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• 2001

There are two uses of zero which are both important but are different. One use of zero is as a number itself. The number zero is an abstract concept measuring the size of set with no elements in it. The second use of it is as an empty place indicator in our place-value number system. It is the notation. In this paper, we study a history of zero and the mistakes from a few earlier works in connection with some arithmetical operations involving the number zero.

• 한국정보통신학회논문지
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• 제2권1호
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• pp.157-163
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• 1998

아날로그와 디지틀 합산 가능한 신경회로망회로를 제안한다. 제안된 회로는 Hopfield 신경회로망 모델을 사용하였으며, 연결강도들은 에너지함수를 이용해서 구하였다. NMOS를 이용하여 뉴론을 만들었고, 시뮬레이션결과는 거의 대부분의 경우가 전체 최소점으로 수렴함을 보였다.

• Journal of the Korean Statistical Society
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• 제31권2호
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• pp.163-175
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• 2002

An extended version of the minimax eccentricity factor estimation for multiple set case is proposed. In addition, two more simple methods for multiple set factor analysis exploiting the concept of generalized canonical correlation analysis is suggested. Finally, a certain connection between the generalized canonical correlation analysis and the multiple set factor analysis is derived which helps us clarify the relationship.

• 품질경영학회지
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• 제15권1호
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• pp.2-12
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• 1987

Warranty cost usually involves complex factors paticularly when the product concerned consists of a great deal of parts. In spite of that it can be assessed by means of rather simple mathematical expression, it is possible to realistically appraise the sensitivity to any type of quality policy. This paper thus presents the mathematical concept related to the warranty cost and the general relationship showing that quality policy can be established in connection with the economic quality level.

• 대한수학회지
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• 제35권4호
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• pp.1045-1060
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• 1998

Recently, Chung and et al. ([11], 1991c) introduced a new concept of a manifold, denoted by ＊g-SE $X_{n}$ , in Einstein's n-dimensional ＊g-unified field theory. The manifold ＊g-SE $X_{n}$ is a generalized n-dimensional Riemannian manifold on which the differential geometric structure is imposed by the unified field tensor ＊ $g^{λν}$ through the SE-connection which is both Einstein and semi-symmetric. In this paper, they proved a necessary and sufficient condition for the unique existence of SE-connection and presented a beautiful and surveyable tensorial representation of the SE-connection in terms of the tensor ＊ $g^{λν}$. This paper is the first part of the following series of two papers: I. The SE-curvature tensor of ＊g-SE $X_{n}$ II. The contracted SE-curvature tensors of ＊g-SE $X_{n}$ In the present paper we investigate the properties of SE-curvature tensor of ＊g-SE $X_{n}$ , with main emphasis on the derivation of several useful generalized identities involving it. In our subsequent paper, we are concerned with contracted curvature tensors of ＊g-SE $X_{n}$ and several generalized identities involving them. In particular, we prove the first variation of the generalized Bianchi's identity in ＊g-SE $X_{n}$ , which has a great deal of useful physical applications.tions.

• Earthquakes and Structures
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• 제8권5호
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• pp.1039-1054
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• 2015

The purpose of this study was to evaluate the seismic performance of weak-axis column-tree type connections used in steel moment frames. These connections are composed of a shop-welded and fieldbolted steel structure and can improve welding quality. On this basis, column-tree type connections are widely used in steel moment resisting frames in Korea and Japan. In this study, splices designed with a semirigid concept regarding the seismic performance of column-tree connections were experimentally evaluated. The structures can absorb energy in an inelastic state rather than the elastic state of the structures by the capacity design method. For this reason, the plastic hinge might be located at the splice connection at the weak-axis column-tree connection by reducing the splice plate thickness. The main variable was the distance from the edge of the column flange to the beam splice. CTY series specimens having column-tree connections with splice length of 600 mm and 900 mm were designed, respectively. For comparison with two specimens with the main variable, a base specimen with a weak-axis column-tree connection was fabricated and tested. The test results of three full-scale test specimens showed that the CTY series specimens successfully developed ductile behavior without brittle fracture until 5% story drift ratio. Although the base specimen reached a 5% story drift ratio, brittle fracture was detected at the backing bar near the beam-to-column connection. Comparing the energy dissipation capacity for each specimen, the CTY series specimens dissipated more energy than the base specimen.

• 한국초등과학교육학회지:초등과학교육
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• 제27권4호
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• pp.356-370
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• 2008

The study aims to explore sequence of earth science content in elementary school science curriculum in Korea and the U.S.. The analysis is focused on a) general content structure of earth science part; b) concept relationship between grades in the specific field of 'geology'; c) longitudinal connection of concepts and content in 'geology.' The findings are as follows. First, earth science curriculum content in Korea is structured according to sub-scientific disciplines centering on not science concepts but topics or inquiry activities whereas the U.S. curricular content is organized through integrative earth science topics with basic concepts and sub-concepts. Second, it is a common feature that basic concepts are interrelated to sub-concepts in all grades in both countries. However, basic concepts are scattered all over the grades, presented in a linear pattern in Korea while those are provided together in 3rd grade and repeated with extended concepts in a spiral structure in the U.S.. Last, it is not clear how concepts and content are longitudinally connected between grades in Korean curriculum. On the contrary, concepts and content in the U.S. curriculum have a strong longitudinal connection between grades with conceptual hierarchy. Such results indicate that Korean elementary school science curriculum would limit students' comprehensive understanding of science concepts through grades. The study suggests Korean science content should strengthen interrelationship among concepts as well as longitudinal connection between grades, in order to achieve the ultimate goal of science education, 'scientific literacy'.

• 한국강구조학회 논문집
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• 제23권1호
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• pp.1-12
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• 2011

강구조 접합부 설계에 '전강도 접합' 개념이 도입됨에 따라 비선형 정적 해석의 결과를 이용한 설계가 주목을 받고 있다. 그러나 현재 실무에 적용하기에는 생소한 개념이어서 어려움이 있다. 또한 대부분의 기존 연구가 가상의 고층 구조물에 대한 내용 이어서 실제 대다수 설계가 이루어지는 중 저층 산업용 구조물에 대한 연구는 부족하다. 이에 본 연구에서는 실제 진행 중인 중 저층 산업용 구조물의 비선형 정적 해석을 위한 간단 명료한 하중 패턴을 3차원 해석 모델에 대해 제시하여 해석을 수행하였고, 실무에서의 유용성을 위해 2차원 해석 모델에 대한 보다 간단한 하중 패턴을 제시하였다. 또한 해석 결과를 이용하여 접합부를 설계하는 과정에서 나타날 수 있는 문제점에 대해 비선형 정적 해석에 사용하는 힌지 특성을 간단한 유추를 통해 새롭게 제시하였다. 제시된 하중 패턴은 서로 다른 방법으로 구하였으나 동일한 결과를 보여 상호 신뢰성을 입증하였으며, 제시된 힌지 특성을 적용한 구조물의 해석 결과로부터 합리적인 결과를 얻어 그 타당성을 검증하였다.

• 한국의사학회지
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• 제32권1호
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• pp.77-86
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• 2019

The Diary of Muk-Jae is a historical record that describes many social aspects of the Joseon period in the 16th century. It records many scenes of its author, Lee Mun-Geon, treating patients. This paper uses The Diary of Muk-Jae to examine changes in the perception of the concept of cold damage and the text of the Shanghanlun (Treatise on Cold Damage) in the Joseon period in the 16th century. In The Diary of Muk-Jae, cold damage is understood in connection with two categories: 'dangerous disease' and 'disease caused by cold'. The Diary of Muk-Jae also presents the Shanghanlun not as a work limited to the concept of cold damage, but as a medical text that could be widely used for many different diseases. Thus, The Diary of Muk-Jae may represent a point of transition between in the perception of cold damage as seen in the Uibang Yuchui (The Collection of Medical Procedures) of the 15th century and the Donguibogam of the 17th century.

• 한국의류학회지
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• 제19권2호
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• pp.203-215
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• 1995

The funning process in the symbolism of dress can be approached by the semiotics of C. S. Pierce. According to Pearce\ulcorners theory, symbiosis consists of sign, its object, and interpret ant. Especially Pierce classifies the sign into three categories; icon, index, and symbol. The icon is based on the similarity in properties and forms, and the index is based on the actual connection with their objects, while the symbol is based on the association of interpret ant. This classification method can be considered as a theoretical base for symbol of ritual dress. On the other hand, it was discussed the analyzing method of the concept of dress same (symbolic element) by introducing the isolate concept of structuralism for explaining how the symbol reveals itself. So it is discussed the several concepts of structuralism; the concept of relation syntagmatique and relation paradigmatique, the relation binaries, and the units. It would be also necessary to consider dimension of context in addition to dimension of dress itself for the dimension of total symbolic elements of ritual dress. It is proposed that the above developed dress symbol elements should be used for under\ulcornerstanding the society or culture that includes the elements by introducing the symbolic anthropology such as V. Turner's three dimensions of symbol.