• 대한화학회지
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• 제57권4호
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• pp.499-506
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• 2013

이 연구에서는 경북 지역의 사범대학에 개설된 화학교육론 강좌에 클리커로 알려진 교실 응답 시스템을 적용한 뒤 이에 대한 예비 화학교사들의 인식을 조사하였다. 강의 첫 시간에 클리커의 교육적 활용 방법과 사용법에 대해 소개한 뒤, 수업 중 평균 4-5개의 질문을 제시하였다. 이 질문에 대한 답을 예비교사들에게 클리커로 입력하게 한 뒤, 응답 분포를 확인하고 이에 대한 피드백을 제공하였다. 예비교사들에게 제시된 질문은 학습 내용을 회상하는 질문, 관련 내용에 대한 이해정도를 점검하는 질문, 어떤 사안에 대한 견해를 확인하는 질문, 이해가 어려운 내용에 대한 질문이 다양하게 포함되었다. 학기 말에 클리커 활용에 대한 예비교사들의 인식을 리커트 형식과 에세이 형식으로 조사한 결과, 예비 화학교사들은 클리커 활용의 인지적 효과, 정의적 효과, 그리고 매체 특성 측면 모두에서 긍정적으로 인식하였다. 8가지 클리커 질문 유형 중 예비교사들이 선호하는 유형은 개념 이해 질문과 학습 점검 질문이었다. 클리커를 활용한 구체적인 사례와 연구 결과에 대한 교육학적 함의도 포함되었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권1호
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• pp.344-357
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• 2015

With the increase in a number of access technologies and data rates, a continuous connection among different networks is demand of the future wireless networks. In the last decade, user connectivity among different access networks remained a challenging job. Therefore, in this article, we proposed a user-centric and user-perspective based network selection mechanism for fast handover management in heterogeneous wireless networks. The proposed scheme selects the most appropriate network among available networks on the basis of resources i.e. cost, data rate, and link quality. Initially, we load the Media Independent Information Service (MIIS) with the information of cost and data rate provided by different network operators. Similarly, Mobile Node (MN) is also loaded with the user preferred cost and data rate for different applications. The MN obtains the information of cost and data rate from MIIS server upon a predefined threshold, and make a decision for handover according to its current cost and data rate. Furthermore, we employ an optimal threshold mechanism for initiation of the handover execution phase to minimize false handover indications. The proposed scheme is based on a survey for network selection and its implementation in C programming language to validate its performance and accuracy. The simulation result shows that the proposed scheme performs superior then the schemes present in the current literature.

• 대한전자공학회논문지TE
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• 제42권4호
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• pp.7-14
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• 2005

최근의 통신매체로는 함축적이고 인식이 용이한 영상/비디오가 매우 선호되고 있다. 그러나 이들 데이터는 그 양이 과다해 영상/비디오 데이터의 압축의 큰 연구과제가 되어 왔다. 본 논문에서는 영상압축 시 성능을 크게 좌우할 수 있는 데이터 형식의 최적화에 관련되고, 웨이블릿 변환과 이를 이용한 JPEG2000을 기반으로 한다. 본 논문에서는 이산 웨이블릿 변환 시 이용되는 데이터 형식을 결정하는데 있어서의 기준을 주파수 변환 및 양자화 과정에서의 데이터 손실 양으로 설정하였으며, 이를 바탕으로 실험적으로 최적의 데이터 형식을 도출하였다. 그 결과, 필터계수는 (1, 9)의 10-비트 고정소수점 형식, 웨이블릿 계수는 (9, 7)의 16-비트 고정소수점 형식이 최적임을 확인하였다.

• 한국환경보건학회지
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• 제31권6호
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• pp.498-503
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• 2005

Stability of soybean isoflavone isomers according to extraction conditions such as temperature, pH, and extracting solvents was investigated. Heating induced three chemical reactions to occur for malony1 derivatives of isoflavones, namely decarboxylation of malony1 groups into acety1 derivatives, deesterification of malony1 residues, and hydrolysis of $\beta$-glycosidic bonds. Among the twelve isoflavone isomers, change in concentrations of acety1glycosides were most pronounced: Acety1 derivatives were present only in trace amounts in unheated hypocotyls, but the content increased dramatically during heating. As for the glycosides, concentrations of daidzin and glycitin increased due to heat treatment, though that of genistin remained almost unchanged. Heat decomposition rates and the patterns differed among the three malony1 derivatives. After 120 min at $80^{circ}C$, the relative concentrations of daidzin, glycitin and genistin were increased from $9.2\%$, $12.4\%$ and $3.3\%$ to $19.3\%$, $21.9\%$ and $6.2\%$, respectively. When crude isoflavones were solubilized in glycine buffer (pH 10.0) and incubated at $80^{circ}C$, deesterification occurred faster than at pH 7.0. When the pH of isoflavone solution was increased, the malony1glycosides were hydrolyzed to their respective glycosides at increased rate. Both acetyl and aglycone forms were unchanged and only de-esterification reactions occurred. At the acidic pH, malonylglycosides were much stable both at 60 and $80^{circ}C$. However at pH 10, $80^{circ}C$ and 1 hr, $75-80\%$ of malonylglycosides were transformed to their deesterified glycosides. When isoflavones were extracted with $60\%$ aqueous ethanol at $60^{circ}C$, isoflavone isomers were stable and the deesterification reactions did not occur in these conditions. However, at $80^{circ}C$ deesterification of malonyiglycosides occurred significantly with $15-20\%$ of malonylglycosides being hydrolyzed into their respective glycosides. This experiment showed that malonylglycosides undergo decomposition when heated or exposed to alkaline conditions. Also, aqueous ethanol was preferred to aqueous methanol as solubilizing media for obtaining extract with minimum degradation of malonylglycosides.

• 방송공학회논문지
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• 제25권4호
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• pp.569-575
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• 2020

전기화재의 원인중의 하나는 직렬 아크이다. 최근까지 아크 신호를 검출하기 위해 다양한 기법들이 진행되고 있다. 시간 신호에 푸리에 변환, 웨이블릿 변환, 또는 통계적 특징 등을 활용하여 아크 검출을 하는 방법들이 소개되었지만, 변환 및 특징 추출은 부가적인 처리 시간이 요구되는 단점이 있다. 반면에 최근의 딥러닝 모델은 종단간 학습으로 특징 추출 과정없이 직접 원시 데이터를 활용한다. 따라서, 1-D 시간 신호를 직접 활용하여 아크를 검출하는 것이 좋은데, 인공신경망의 분류 성능이 저하되는 문제점이 있다. 본 논문에서는 연속 입력 1-D 신호를 2-D로 변환한 후에, 합성곱신경망으로 분류하는 방법을 제안한다. 실험 데이터에 적용한 결과 합성곱신경망의 사용이 인공신경망보다 약 8.6%의 아크 분류 성능을 향상시켰다. 또한 2-D 데이터의 부족을 보완하기 위해서 데이터증강을 이용하여, 14%의 분류 성능을 개선하였다.

• 한국생활과학회지
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• 제18권4호
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• pp.879-889
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• 2009

The purpose of this study was to analyze the dimensions of clothing benefits sought of male and female consumers in their twenties. It also aimed to investigate the demographic characteristics associated with customers types and the relationship among the related variables by the consumers types. The data were analyzed by factor analysis, one-way ANOVA, Duncan test, cluster analysis, and $X^2$-test. The results of this study are as follows: 1) The clothing benefits consisted of five factors, which were the pursuit of style, individuality, popular brand, vogue, and practicality. Based on these five factors, respondents were classified into four consumer types, which were style-and-trend-oriented, practicality-oriented, popular brand-oriented, and fashion indifference consumers. 2) In terms of the demographics, there were significant differences in age, gender, and total income among the consumer types of clothing benefits. 3) There was a significant difference in single brand loyalty in terms of the consumers types of clothing benefits. The popular brand-oriented group showed the highest mean in the single brand loyalty, while the practicality-oriented group did the lowest. 4) There were significant differences in the selection of the stores among consumers types of clothing benefits. Specifically, the style-and-trend-oriented group the most selected department stores, while practicality-oriented group chose fashion outlets or online shopping malls the most. Additionally, in terms of the information sources, the style-and-trend-oriented group the most frequently used magazine ads, while the popular-brand-oriented group preferred commercials on TV or radio, direct mail, or flyers from department stores. On the other hand, the fashion indifference group the most frequently used mass media.

• 품질경영학회지
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• 제44권4호
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• pp.883-895
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• 2016

Purpose: The demand for ordinary mail services supplied by 'Korea POST' is decreasing due to the opening of mail service market and the growth of alternative communication media such as e-mail and SNS. To overcome this situation it is urgent to introduce new services that can be able to appeal customers and to improve existing services. Methods: A field survey is conducted to corporate customers who send ordinary mails and individual customers who receive these mails, respectively. Quality attributes of ordinary mail services are classified by two-dimensional perspectives in terms of Kano model. Decision tree model is utilized for classifying the quality attributes. Comparative analyses are done whether there are perceived differences on each quality attributes between corporate customers and individual customers. Results: Quality attributes such as 'discount postal charges', 'sending small packages by simply dropping it into a mail box', 'sending a mail of any appearance', 'delivering a mail anywhere', and 'receiving a mail at a preferred time where a customer is located ' are classified differently according to some market segments, while most of the quality attributes are classified as attractive or one-dimensional. Conclusion: Decision tree model has been found to be most effective to classify quality attributes for each market segment especially when trying to classify quality attributes belonging to 'gray areas'. Based on the perceived differences on quality attributes among customers, strategic implications are suggested to obtain potential customers and to have competitive advantages.

• 방송공학회논문지
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• 제15권4호
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• pp.527-539
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• 2010

대부분의 비디오 부호화 시스템은 YCbCr 색 공간에서 부호화가 수행되나 초고화질 비디오가 사용되는 분야에서는 YCbCr 색 공간에서 부호화하는 것이 RGB 색 공간에서 부호화는 것에 비해 높은 압축 효율을 제공하지 않기 때문에 RGB 공간에서 부호화하는 것이 선호된다. RGB 비디오 신호의 압축 부호화 효율을 증대시키기 위하여 본 논문은 잔여신호의 적응적 주파수-선택 가중 예측 기법을 제안한다. RGB 비디오 신호의 색 평면간 상관도를 최대한 활용하기 위해, 제안 기법은 잔여신호 평면 사이의 주파수 영역에서의 부호 일치도와 상관 강도에 근거하여 적응적으로 잔여신호 평면 간 예측될 주파수 영역과 그에 상응하는 예측 가중치를 선택한다. 실험 결과는 최신의 비디오 압축 표준인 H.264/AVC에서 4:4:4 비디오 부호화의 공통 모드에 비해 약 13% 정도 압축 부호화 성능을 개선시켰음을 보여준다.

• 한국식생활문화학회지
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• 제32권4호
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• pp.275-286
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• 2017

The purpose of this study was to provide basic data for development of a recipe for muslim-friendly halal Korean foods through investigation of awareness of Korean foods, taste evaluation, and menu preferences. After Korean foods' menu range and standard were set up for the survey and in-depth interviews with three halal food experts were conducted, 35 kinds of halal Korean foods were examined. The present study conducted a survey on 205 foreign Muslims living in Jeonju-si, Jeonbuk and Gimpo-si, Gyeonggi who ate Korean foods. Foreign Muslims were male workers in their 20's residing in company housing, and their monthly mean income was 1.01~2 million KRW. The majority of subjects responded that meal problems were the most difficult in everyday life. Concerning the taste of Korean foods, the response rate of 'sweet' and 'spicy' was high while 'Korean food is healthy' and 'Korean food ingredients is fresh' were high for awareness of Korean foods. 'Bulgogi' was the most preferred among the selected Korean foods, which was in line with the results of previous research. There is a need to provide information on Korean foods that can be made with food ingredients certified as halal and their recipes through various media for foreign Muslims who have limitations on in meals due to religious factors.

• 복식문화연구
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• 제16권3호
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• pp.588-594
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• 2008

Lookism is spread largely because many people think beautiful people are treated better and receive more favors. This trend has been influenced by mass media and impacted by commercial marketing strategy. The expectation for the beauty have risen higher than ever. People expect beautiful body and beautiful face which are more difficult to meet the standard of beauty. People desire tall and skinny body. The purpuse of this study was to find out body image from college females in the age which they are very sensitive to appearance. This research focused to find out how they perceived their own body shape and their perception of the most ideal body shape. Measuring tool for the research was 9 pictures of body silhouette from very skinny to very fat. To analyse the respondents' objective body image, Body Mass Index were employed. The result of this research indicated that there were distinct differences between their subjective body images and ideal body images. This result indicated that they were not satisfied with their own body shape and hence they were not confident towards their body images. Even though their objective bodies were normal or under weight, they still felt they were over weight. This meant their body images were misrepresented. They preferred thinner bodies even though their bodies were perfectly normal and healthy. But these misrepresented body images could be unhealthy physically, psychologically, or socially. These results showed that college females were overly obsessive with superficial appearance rather than improving ones capability to be more competitive in the society. From this research, I tried to find out perception of body image and it's distortion which was debated a lot in our society. I also want to provide basic reference material for establishing the body image study.