• 대한수학교육학회지:수학교육학연구
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• 제25권2호
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• pp.177-188
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• 2015

본 논문은 평면과 공간에서 두 벡터의 곱에 대한 역사적 발달 과정을 살펴보고, 이를 바탕으로 벡터의 내적과 외적을 연결하기 위한 교육적 시사점을 도출하였다. 역사적 분석의 결과, 평면에서 방향이 다른 두 선분의 곱을 정의하려는 노력은 두 선분의 길이의 곱과 방향각의 합이라는 기하학적 의미와 함께 복소수의 연산 규칙을 확립함으로써 복소수를 수학적 대상으로 승인하는 계기를 제공하였음을 확인하였다. 또한 3차원 공간에서 방향이 다른 두 선분의 곱을 정의하려는 노력은 사원수의 도입을 이끌었으며, 사원수의 곱으로 나타나는 실수부분과 벡터부분이 각각 벡터의 내적과 외적의 현대적인 정의로 발전하였음을 확인하였다. 이러한 분석 결과를 토대로 기하학적 관점에서 벡터의 내적과 외적을 각각 다른 방식으로 정의하여 서로 관련이 없는 것으로 인식하도록 만드는 현재의 전개방식에 대해 반성하고, 이 두 곱을 연결시키기 위한 한 가지 방안을 제시하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제19권11호
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• pp.1665-1670
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• 2006

The objective of this research was to provide the characterization and method for producing anti-E. coli O157:H7 antibodies in egg-laying hens and to determine if the antibody can restrain the proliferation of E. coli O157:H7 in-vitro. Selected antigenic fractions (whole cell, outer membrane protein and lipopolysaccharide (LPS)) from E. coli O157:H7 were injected to hens in order to produce anti-E. coli O157:H7 antibodies. The immune response and the egg yolk antibodies of laying hens against the whole cell, outer membrane protein and LPS antigens were monitored by ELISA. The level of antibodies against whole cell antigen monitored through ELISA sharply increased after the initial immunization, and it was found to be maximum on day 49 however, the level was maintained up to day 70. Antibodies (5 mg/ml) directed against the whole cell inhibited E. coli proliferation 10-13 times more than outer membrane protein or LPS. The antibody response against the whole cell antigens appeared to have higher activity in restraining the proliferation of E. coli O157:H7 than antibody against outer membrane protein or LPS. Results reflected that increasing the IgY's in the egg yolk could prevent greater economic losses due to human and animal health from pathogenic bacteria i.e. E. coli O157:H7.

• 대한수학회논문집
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• 제17권2호
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• pp.253-260
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• 2002

For an outer action $\alpha$ of a finite group G on a factor M, it was proved that H is a, normal subgroup of G if and only if there exists a finite group F and an outer action $\beta$ of F on the crossed product algebra M $\times$$_{\alpha}$ G = (M $\times$$_{\alpha}$ F. We generalize this to infinite group actions. For an outer action $\alpha$ of a discrete group, we obtain a Galois correspondence for crossed product algebras related to normal subgroups. When $\alpha$ satisfies a certain condition, we also obtain a Galois correspondence for fixed point algebras. Furthermore, for a minimal action $\alpha$ of a compact group G and a closed normal subgroup H, we prove $M^{G}$ = ( $M^{H}$)$^{{beta}(G/H)}$for a minimal action $\beta$ of G/H on $M^{H}$.f G/H on $M^{H}$.TEX> H/.

• 대한기계학회논문집
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• 제17권6호
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• pp.1389-1403
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• 1993

본 논문에서는 초기 변형소재가 이미 결정된 상태에서 제품의 최적 성형 방향 을 구하는 방법을 기술하였다. 초기 변형소재는 블랭크 호울더 곡면에 의해 변형된 중간 단면들에서의 형상을 에너지 최소화 개념을 적용하여 스플라인 곡선으로 나타내 고 이것들로 부터 곡선망을 구성한 후 최종적으로 양방향 스키닝기법(bi-directional skinning technique)에 의해 구현 하였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.441-444
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• 2009

In this research, a hot and cold combined forging process for manufacturing net-shape one-way clutch bearing outer race of an automobile automatic transmission unit is developed. The process is composed of hot forging for manufacturing an optimized gear-like perform and precision cold forging for sizing the perform into final net-shape product. Finite element simulation techniques are applied to find the optimized process designs including blank and die shapes. The predictions and experiments are compared, revealing that they are in good agreement with each other. The dimensional test showed that the important dimensional requirements on gear tooth-like shape of the forged product were fulfilled.

• 한국의류학회지
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• 제25권4호
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• pp.773-782
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• 2001

This study was to investigate the value changes in Korean women by analyzing the ads of womens magazines. The contents of ads were classified into two types of values: general and consumption values. The general values, composed of inner-directedness and outer-directrdness, might predict consumer behavior in general. The consumption values, utilitarians and hedonic, were expected to affect the consumer purchasing attitude to a specific product. Factors affecting the cultural values were per capita income and womens social status. Total 2969 illustrated ads with verbal theme from 32 Korean womens magazines were used. The content analysis, chi-square test, logistic regression were done for the analysis. The results showed that inner-directedness was dominant general value in Korean womens culture and increased over time. Younger consumers were more inner-directed than older ones were, and inner-directed values increased with income growth. For the consumption values, utilitarian values were higher than hedonic ones and went up over time. For the product types, utilitarian ads were frequent in cosmetics while hedonic ads were high for apparels. Those results implied that Korean womens culture became more inner-directed with increased income. Also consumption values were likely to differ between product groups. Per capita income was shown to increase inner-directedness while womens social status was to increase outer-directedness.

• 소성∙가공
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• 제32권4호
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• pp.208-214
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• 2023

This paper discusses the deformation characteristics of a scaled-down automotive outer door panel with vacuum-assisted incremental sheet forming. The vacuum condition between the die and Al6052-H32 sheet with a thickness of 1.0 mm is reviewed with the goal of improving the geometrical accuracy of the target product. The material flow according to the forming tool path, including the multi-tool path and conventional contour tool path, is investigated considering the degradation of the pillow effect. To reduce friction between the tool and the sheet during incremental forming, automotive engine oil (5W-30) is used as a lubricant, and the strain field on the surface of the formed product is analyzed using ARGUS. By comparing the geometry and material flow characteristics of products under different test conditions, it is confirmed that the product surface quality can be significantly improved when the vacuum condition is employed in conjunction with a multi-tool path strategy.

• 정보처리학회논문지B
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• 제16B권6호
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• pp.497-502
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• 2009

본 논문에서는 상품평의 효율적인 분석을 위한 평가 항목 추출 시스템을 제안한다. 시스템은 크게 상품평 수집-보정과 평가 항목 추출의 두 단계로 구성된다. 상품평 수집-보정에서는 인터넷 쇼핑몰에서 상품평을 수집하고 상품평 특유의 구어체 표현과 맞춤법 오류 등을 처리한다. 평가 항목 추출에서는 스커트 상품 카테고리의 경우 ‘사이즈', ‘스타일'과 같이 상품을 평가하는 기준이 되는 항목을 상품평과 인터넷 상의 웹 문서를 활용하여 자동으로 추출한다. 상품평에 나타나는 명사들을 평가 항목 후보로 설정하고, 각 후보 명사의 상품평에서의 어휘 통계인 내부연관도와, 후보 명사와 상품 카테고리명의 웹 문서에서의 공기 빈도에 기반하여 계산된 외부연관도를 결합하여 상품과 평가 항목 후보의 연관도를 계산한다. 본 논문의 평가 항목 추출 방식은 평균 재현율 90%를 보여 기존 연구보다 우수한 결과를 보였다.

• 패션비즈니스
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• 제26권2호
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• pp.48-66
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• 2022

This study aimed to investigate and analyze the overall color utilization characteristics as design elements of advanced men's premium outer brands. From the analysis of a total of 889 color samples, PB showed the highest distribution in color, Bk, R, and P. The use of ltg and p of high and low chroma was high, centering on dkg of low value and low chroma, and g of medium chroma. The men's premium outer brand displays a luxurious color image centered on color planning due to color contrast between dark and grayish shades. The characteristics of colors and color distribution by brand were considered. The brands that utilized the most diverse colors and shades were Herno, which pursues sportswear of the Elegance image, and Stone Island, which pursues casual images of workwear style. These results show that systematic planning using colors and shades are utilized by all premium outer brand concept. The results of this study are meaningful because they can be used as basic data for effective product planning, men's outer design development, and color planning of outer clothing brands are they represent premium outer brands for men, and identifies color characteristics as differentiated design elements.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2000년도 춘계학술대회논문집
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• pp.83-87
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• 2000

The die for cold forging gets a ver high axial load and radial pressure during processing and hence deforms considerably in the radial direction. This radial deformation of die becomes a important factor influencing the dimensional accuracy of a product. In order to obtain a product with highly accurate dimension therefore it is essential to acquire some information on elastic deformation of the die and the product. The study has been performed for the relation of the deformation between a die and a product in backward extrusion. The strain of the die has been given by the simple experiment using the strain gauges attached to the outer surface of the die. Also the history of the deformation of the die and the product has been given by the experiment and Lames' formula. The results has been compared with the previous another method. The study has given useful results for the deformation history of the die and the product through the experiment and Lame's formula in backward extrusion which can be applied in the die design for the product with accurate dimension