• 전기학회논문지
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• 제67권11호
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• pp.1471-1476
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• 2018

In this paper, a high-gain antenna for satellite communication is proposed. The proposed antenna consists of septum polarizer, circular waveguide, Hat-feed structure that has a high-gain and efficiency. Especially, it is smaller and lighter than the conventional satellite communication antennas by applying a hat-feed structure. The measured results show that received gain of proposed antenna is better than 29.9 dBi and transmitted gain of proposed antenna is better than 30.5 dBi. The co-polarized and cross-polarized radiation patterns comply with ITU-RR Ap.8 and ITU-R S.731-1 that are recommended by International Telecommunication Union. The designed high-gain antenna for satellite communication is expected to be used for OTM and airborne satellite systems.

• 대한기계학회논문집A
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• 제37권7호
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• pp.929-935
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• 2013

본 논문은 사각 보강 패널에 사용되는 모자형 보강재의 크기 최적화에 대한 결과를 제시하였다. 보강 패널은 1500 ~ 2500 m/s 의 속도를 가지는 발사체와 충돌한다. 모자형 보강재의 크기를 결정하기 위해서 크기 최적화가 수행되었다. 크기 최적화를 수행하기 위해서는 3 개의 함수들로 구성되어 있다. 이 함수들은 목적함수, 제한함수 그리고 설계 함수로 이루어져 있다. 목적 함수는 보강 패널의 1 차 고유 진동수의 최대화가 되도록 하는 것이다. 제함 함수는 보강재의 부피가 사각 패널 부피의 10 % 이내가 되도록 하는 것이며, 설계 변수로는 모자형 보강재의 치수가 된다. 최적화된 모자형 보강재를 이용하한 보강 패널을 사용하여 초고속 충돌에 대한 시뮬레이션을 수행하였으며, 최적화된 보강재에 대해서 속도와 운동 에너지 변화에 대한 결과를 얻었다. 보강 패널의 충돌 저감을 평가하기 위해서 발사체의 운동 에너지와 속도를 무차원화 계산을 수행하여 비교 분석 하였다.

• 한국의류학회지
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• 제33권7호
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• pp.1038-1049
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• 2009

A hat is an important fashion accessory item for a total fashion coordination and the number of millineries is increasing in the current accessory market. This research provides basic information about the millinery in relation to consumer consumption behavior, preference, and satisfaction with hat products. A survey was conducted among 395 individuals age 20 and over who were quota sampled according to age and gender to investigate the differences between genders and different age groups. The collected data were statistically treated with the SPSS 12.0 program in terms of frequency, percentage, mean, standard error, cross tabulation, t-test, one-way ANOVA, and a Duncan-test. The results are as follows: 1. Respondents wear hats for ornamental purposes regardless of the season. They discard hats when they become out of style 2 to 3 years after the purchase. 2. In general, consumers prefer the baseball cap design among various hat product categories. Achromatic colors were the favorite color tone and the preferred material was woven cloth. 3. Consumers were most satisfied with colors and most dissatisfied with deformation after laundering. 4. There was a significant difference in preferences among the different age groups. Younger consumers were more concerned about individual image and style. Older consumers considered hats as a functional means such as protecting themselves from the sun. 5. There was a significant gender difference. Compared to males, female consumers were more concerned about the quality of sewing and colorfastness than male consumers.

• 패션비즈니스
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• 제18권4호
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• pp.28-44
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• 2014

The purpose of this study is to analyze the hat fashion worn by the British royal family. The research range has been limited to hats which Elizabeth II, Camilla Parker Bowles, and Kate Middleton wore from April 29, 2011 to April 11, 2014 when Kate Middleton married Windsor Prince William and became part of the royal family. The methods of the research were: previous studies and literature about the royal family were referred to, the function and types of hats were considered, and then the plasticity of the designs seen in hat fashion of the royal family were analyzed. The results are as follows: first, the shape of the hats of the British royal family: Three-dimensional shapes(84.2%) were the most frequent, the detailed shape of the hat Canotier(33.5%), Boater(12.7%) and Bowler(10.3%) had greater frequency. Second, the color of the hats were W(13.7%), Bk(10.5%), Y(9.8%), B(9.6%), YR/PB(9.4%) and RP(9.2%) color. The Color Combination is the Monochrome Color(62.3%), Analogous Color(16.1%), Accent Color(13.2%) and Complementary Color(8.4%) were most frequent. Third, the material of the hats were Felt(44.5%) and Straw(40.3%) were used most frequently. Finally, the decoration of hats were: Flowers(25.7%), String(25.0%), Ribbon(18.4%) and Feathers(17.9%) were the most common. This study can be utilized as basic data for effective styling and design ideas in the field of total fashion.

• 전기전자학회논문지
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• 제2권2호
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• pp.239-246
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• 1998

영상 압축을 위한 방법으로서 수리형태학적 상세부분(details)의 추출을 위한 방법인 post-it 변환 과정 중에서 기존에는 상세부분(details)를 추출하는 단계의 참조영상을 일반 top-hat 결과로 취함으로서 상세부분(details)의 정보량이 많아 지고 밝고 어두운 상세부분(details)을 뺀 smoothed 영상이 평활화 되지 않고 오히려 공간주파수가 높아지는 단점이 있으므로 본 논문에서는 그러한 단점을 극복하기 위해 참조영상을 일반 top-hat이 아닌 재생 top-hatd의 사용을 제안함으로서 상세부분(details) 영상과 smoothed 영상의 압축효율 증대와 재생과정상의 반복연산수 감소 효과가 발생함을 보인다. 그러나 이러한 결과는 단독적으로 사용되는것이 아니라 동화상의 고효율 압축시 그 일부 과정으로 이용하며 이러한 변형 post-it 변환을 분할기반 부호화와 연계하여 동화상 비디오 시퀸스에 적용함으로서 본래 목적하였던 초저속 동화상 전송을 위한 고효율 압축을 실현하고자 한다.

• Journal of applied mathematics & informatics
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• 제30권5_6호
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• pp.993-1003
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• 2012

The family of graphs $\hat{W}_{4n}$ is defined by taking the simple whee graph $W_{n+1}$ with $n$ rim vertices and then adding three extra vertices on every rim edge of the wheel. In this paper, the critical group of this whole family of graphs is investigated.

• 품질경영학회지
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• 제17권1호
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• pp.107-115
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• 1989

This study is suggested tn find a methodology of influential subset detecting by using diagonal elements of the hat matrix, $h_{ij}$, and off-diagonal elements of the modified hat matrix, $h_{ij^*}$. And this study shows that elements of two matrix is very useful to detect a masking subset in various situations by analytic and emperical explanations. Also a desirable procedure to detect the significant subset and the calibration points for $h_{ij}$ and $h_{ij^*}$ are recommended.

• Journal of the Korean Data and Information Science Society
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• 제10권1호
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• pp.11-18
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• 1999

To estimate the mean and the variance of a lognormal distribution, Finney (1941) derived the uniformly minimun variance unbiased estimators(UMVUE) in the form of infinite series. However, the conditions ${\sigma}^{2}\;>\;n\;and\;{\sigma}^{2}\;<\;\frac{n}{4}$ for computing $E(\hat{\theta}_{AM})\;and\;E(\hat{\eta}^{2}_{AM})$ are necessary. In this paper, we give an alternative derivation of the UMVUE's.

• Korean Journal of Mathematics
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• 제16권2호
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• pp.215-231
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• 2008

Let E be a uniformly convex Banach space with a uniformly $G{\hat{a}}teaux$ differentiable norm, C a nonempty closed convex subset of E, and $T:C{\rightarrow}{\mathcal{K}}(E)$ a multivalued nonself-mapping such that $P_T$ is nonexpansive, where $P_T(x)=\{u_x{\in}Tx:{\parallel}x-u_x{\parallel}=d(x,Tx)\}$. For $f:C{\rightarrow}C$ a contraction and $t{\in}(0,1)$, let $x_t$ be a fixed point of a contraction $S_t:C{\rightarrow}{\mathcal{K}}(E)$, defined by $S_tx:=tP_T(x)+(1-t)f(x)$, $x{\in}C$. It is proved that if C is a nonexpansive retract of E and $\{x_t\}$ is bounded, then the strong ${\lim}_{t{\rightarrow}1}x_t$ exists and belongs to the fixed point set of T. Moreover, we study the strong convergence of $\{x_t\}$ with the weak inwardness condition on T in a reflexive Banach space with a uniformly $G{\hat{a}}teaux$ differentiable norm. Our results provide a partial answer to Jung's question.

• 한국응용곤충학회지
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• 제23권3호
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• pp.153-157
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• 1984

포장조건하에서 수잉기와 출수기에 벼멸구를 인위적으로 가해시킨 후 출수후 고사시기별로 수량수율을 조사하여 다음과 같은 결과를 얻었다. 1. 출수후 23일경에 고사된 벼는 무접종구에 비하여 등숙율은 $32.2\~37.5\%$ 현미천립중은$ 3.2\~3.5g$ 감소되었다. 2. 고사시기가 같아도 수잉기부터 가해구는 출수기부터 가해구보다 등숙율 현미천립중, 현미수량이 낮았다. 3. 고사된 벼의 감수율은 무접종에 비하여 고사시기에 따라 $24\~62\%$였으며 출수후 고사일수(X)와 수량(Y)간에는 다음과 같은 관계가 있었다. o 수잉기이후가해 : $\hat{Y}=10.145X-16.374(r=0.9726^{**})$ o 출수기이후가해 : $\hat{Y}=9.792X+26.936(r=0.8850^{**})$.