• Journal of the Optical Society of Korea
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• 제20권4호
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• pp.451-463
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• 2016

The misalignment errors and fluctuations in irradiance due to atmospheric turbulence can severely degrade the performance of free-space optical (FSO) systems. In this paper, we investigate the asymptotic bit error rate (BER) performance and diversity orders of FSO links using parallel transmit-diversity schemes. The BER expressions of FSO links with the switch-and-examine transmit (SET), switch-and-examine transmit with post-selection (SETps), dual-branch transmit laser selection (Dual-TLS), and group transmit laser selection (Group-TLS) schemes are derived, based on an approximate channel model. Then numerical simulations for these four schemes in the region of high average signal-to-noise ratio (SNR) are presented under different channel conditions. The results show that the four transmit-diversity schemes can reduce system complexity and overcome the limitation of peak power, without much BER deterioration.

• 한국항공운항학회지
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• 제14권4호
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• pp.101-109
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• 2006

This study investigates what criterion airline customers recognize important when evaluating airline firms. Specifically it is surveyed if different criterion are used by different groups of airline customers when choosing an airline firm. In addition customer group with high loyalty to 'K' airline, national carrier of Korea, is differently evaluate 'K' airline for the selection criterion over customer group without loyalty. Frequent flyer program is suggested most important by most of the customers being followed by flight schedule. Flight schedule, in-flight food and air fare of 'K' airline are differently evaluated according to level of royalty to the airline. However there appears no difference in the evaluation of seat and entertainment between two groups, customers with high loyalty and customers without loyalty.

• 수산해양교육연구
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• 제26권6호
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• pp.1442-1450
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• 2014

The aim of this study is to develop a model for the alternative selection in port privatization using Brainstorming, the ISM and AHP methods. For this, 30 detailed attributing factors were identified by both previous studies and port users, Also, 13 attributing evaluation factors were identified by a group of port experts using the brainstorming method. These were made into a model of hierarchical structure with 3 levels, taking 1 goal factor, 5 evaluation factors and 7 alternative factors using the ISM method. The collected date of questionnaires through the AHP method were analyzed with a group of port experts for an empirical analysis. The result of the hierarchical level 2 shows that profitability is the most important factor, followed by public interest, management professionality, service quality and financial soundness. The analysis results of hierarchical level 3 shows that commercialization is the most important factor.

• 복식문화연구
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• 제20권6호
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• pp.895-911
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• 2012

The purpose of this study was to examine consumers' perceptions of eco-friendly children's-wear and their impact on the selection criteria for children's-wear and stores. A descriptive survey method using a self-administered questionnaire was employed. The sample consisted of mothers with children under the age of 13 residing in Seoul and the Gyeonggi area. Data were collected from September 2011 to October, 2011. The collected data were analyzed to find the differences between purchasers and non-purchasers of eco-friendly children's-wear in terms of their perceptions of eco-friendly children's-wear, as well as the influence of these perceptions on the consideration degree of criteria for the selection of children's wear and store. The results indicate that perceptions of eco-friendly children's-wear implied five key factors related to quality reliability, expected value, style, degree of recognition, and dissatisfaction with design and price. The results also revealed some differences between the group purchasing eco-friendly children's-wear and the group not purchasing eco-friendly children's-wear. These different perceptions were related to the aspects of quality reliability, expected value, style, degree of recognition. In general, the non-purchasing group displayed a lower mean score than the purchasing group. Both groups showed a low interest in aesthetic appreciation and the degree of recognition factor. The results showed that consumer's perceptions of eco-friendly children's-wear had an influence on the criteria for the selection of children's-wear and store type in both groups. Considering the findings of the study, it is clear that both purchasers and non-purchasers of eco-friendly children's-wear showed differences in their perceptions and purchasing behavior. Therefore, marketing strategies to appeal to the non-purchasing group should be differentiated from strategies used to ensure the loyalty of the purchasing group.

• 한국식생활문화학회지
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• 제32권1호
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• pp.27-38
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• 2017

This study aimed to analyze the beverage usage behavior according to the food-related lifestyle in Seoul, Gyeonggi province area. Group 1, named 'health & safety seeking' group, consists of high percentage of women in their 40s, as well as a high percentage of high income and highly educated. Group 2, was group of 'high interest in dietary life', consists of a high percentage of women in their 30s, highly educated, earned 3~5 million won. Group 3, named 'convenience seeking' group, had a high percentage of men and of those in their 20s who earned less than 2 million won. In verifying the difference between food-related lifestyle groups in terms of their behaviors and attitudes towards the usage of beverage specialty shop, group 1 showed significantly high score in the number of visit beverage specialty shops, the intention to spend higher average expenditure per visit per person, importance of selection attributes of beverage specialty shop.

• 한국환경교육학회지:환경교육
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• 제20권1호
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• pp.42-61
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• 2007

This study investigated the effect of the environmental issue analysis instruction on the decision making ability of middle school students. A pretest-posttest control group design was employed. The participants for the research were 288 1st grade male students in middle school in Seoul, the environmental issue analysis lesson group consisted of 142 members and the non-environmental education group consisted of 146 members. The cognitive level of the students were divided into three groups-concrete, transition, formal-as the result of GALT test. Students take issue analysis lessons during 6 weeks, one lesson per a week. Students had studied through worksheets reconstructed and developed by researcher on basis of issue analysis suggested by Ramsey et al. (1997). The results of the research were followings: After lesson for environmental issue analysis, all of the students were improved in decision-making ability regardless of cognitive level (p<.05). Especially, decision-making ability of the transition group students was improved to a high degree. Scores of searching relevant information, generation of alternatives, identification of values for selection criteria, the evaluation of alternatives' merits and demerits, prediction of consequence were increased in experimental group (p<.05). But the ability of selection of alternatives according to value was not reached statistically meaningful improvement. The decision-making ability of the control group students was not improved but ability of selection of alternatives, the evaluation of consequence were increased (p<.05).

• 한국주거학회논문집
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• 제17권6호
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• pp.9-18
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• 2006

The purpose of this study is to find out the selection of housing type and the characteristics of dwelling of foreign students' residence in order to provide some information for better housing plans for foreign students in Korea. To analyze characteristics of dwelling, a questionnaire survey was conducted with 171 students who study in the university located in seoul, Korea. The results are summarized as follows: Overseas students in Korea can get from their house to school within 30 minutes and they spend more than 9 hours a day at home on average. Housing is one of the most important factors for oversea students. For the dormitory group, they chose their houses based on fee, distance from the school, stability, etc. The lodging group, chose their houses based on fee, distance from school, and Korean culture experience. The Go-Si-Won group chose their houses based on fee, distance from the school, privacy and so on.

• Journal of Communications and Networks
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• 제15권2호
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• pp.164-172
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• 2013

We consider the problem of secure and robust clustering for quantized target tracking in wireless sensor networks (WSN) where the observed system is assumed to evolve according to a probabilistic state space model. We propose a new method for jointly activating the best group of candidate sensors that participate in data aggregation, detecting the malicious sensors and estimating the target position. Firstly, we select the appropriate group in order to balance the energy dissipation and to provide the required data of the target in the WSN. This selection is also based on the transmission power between a sensor node and a cluster head. Secondly, we detect the malicious sensor nodes based on the information relevance of their measurements. Then, we estimate the target position using quantized variational filtering (QVF) algorithm. The selection of the candidate sensors group is based on multi-criteria function, which is computed by using the predicted target position provided by the QVF algorithm, while the malicious sensor nodes detection is based on Kullback-Leibler distance between the current target position distribution and the predicted sensor observation. The performance of the proposed method is validated by simulation results in target tracking for WSN.

• 한국콘텐츠학회논문지
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• 제21권6호
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• pp.81-93
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• 2021

본 연구는 화장품 선택속성 및 소비자의 구매의도와 추천의도 간의 영향 관계를 살펴보았다. 또한 소비자의 할인추구성향에 따른 조절효과를 검증하였다. 마지막으로 정보원천에 따라 연구 모형 경로에 대한 차이를 검증하기 위해 다중집단분석을 실시하였다. 본 연구를 통해서 화장품을 구매하는 소비자의 선택속성을 명확화하고, 이러한 선택속성이 할인추구성향에 따른 구매의도와 추천의도에 미치는 영향구조를 정보원천별로 규명함을 통해 보다 세부적이고 실효성 높은 전략적 통찰에 목말라 하는 산업업계의 필요와 요구에 부응하고자 한다. 이러한 필요성에 기인한 연구목적 달성을 위해 한국 여성 소비자 258명의 설문지를 수집하고 연구에 활용하였다. 분석결과는 제품 선택속성, 구매의도와, 추천의도 모두 긍정적인 영향관계에 있는 것으로 나타났다. 또한 소비자의 할인추구성향에 따른 조절효과 분석결과 화장품 선택속성과 구매의도 사이, 선택속성과 추천의도 사이, 구매의도와 추천의도 사이에서 조절효과를 나타내는 결과를 보였다. 마지막으로 모형의 개별 경로들이 정보원천에 따라 차이가 있는지를 검증하기 위해 다중집단분석을 실시한 결과 부분적으로 채택되었다.

• 대한가정학회지
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• 제23권4호
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• pp.1-7
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• 1985

The aim of this study is to find out the relation-ship between personality and te factors for clothing selection. For the test, 396 high school girl students in Seoul were selected, respectively. The general personality test sheets by Kim Giseok and the questionnaire besed on Park Eunju's study on the factors for clothing selection were given to the sample group. RESULTS : 1. Behavior of clothing selection according to expression of individuality is sign ificantly correlated with ascendancy and sociability at the level of .001, and with emotional stability at .50. 2. Behavior of clothing selection according to utility is significantly correlated with resopnsibility and emotional stability at the level of .01. 3. Behavior of clothing selection according to economy is significantly correlated with ascendancy and self-confidence at the level of .01, and with responsibility and sociablity at .05. 4. Behavior of clothing selection according to modesty is significantly correlated with ascendancy and sociability at level of .001, and with self-confidence at .01. 5. Behavior of clothing selection according to conformity is significantly correlated with ascendancy, emothional stability, and self-confidence at the level of .001, and with sociability at .05.