• 한국전자거래학회지
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• 제16권2호
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• pp.19-37
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• 2011

인터넷의 발달과 함께 온라인을 통한 상거래 활동은 급증해 왔다. 전자상거래 초기에 기존의 오프라인 업체들과 온라인 업체들 간의 가격수준 및 편차에 대한 연구들이 많이 이루어졌으나, 전자상거래가 활성화되고 성숙된 지금은 이러한 채널 유형별 비교보다는 전자상거래 업체들의 가격변화 행태에 대한 연구가 필요하다. 이에 따라 본 연구에서는 전자상거래 상에서 제품이 판매되기 시작한 시점부터 시간이 흐름에 따라 가격이 어떻게 변화하는지를 분석하였다. 가격비교 사이트로부터 가격자료를 수집하여 분석에 활용하였다. 이를 통해 시간이 흐를수록 최저가와 평균가격이 하락하는 것을 보였으며, 최고가는 시간이 흐를수록 오히려 상승하는 패턴을 보였다. 최고가의 상승에는 판매업체 수 증가가 양의 영향을, 출시 이후 기간이 음의 영향을 미치는 것을 보였으며 이 두 가지의 영향력에 따라 제품군별로 상이한 상승 패턴을 보였다. 또한, 제품군의 유형별로도 판매업체 수에 따라 상이한 가격변화 패턴을 보였다.

• 복식문화연구
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• 제25권4호
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• pp.433-447
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• 2017

This study reveals the components of college women's shopping orientations and compares the attributes of shoes accordingly. This study attempts to investigate the needs of consumers in the target market of young women by comparing the importance of shoe attributes with their shopping orientations and to provide basic data for efficient marketing strategies which could increase sales. Data was collected using a questionnaire survey. Of a total of 330 questionnaires, 319 were used for statistical analysis. The survey was carried out from July to August 2016. The 17 shopping orientation-related questions and 13 questions about shoe purchase attributes were measured using a five-point Likert Scale. SPSS 23 was used to carry out: descriptives, factor analysis, reliability analysis, cluster analysis, ANOVA, and Duncan's test. Shopping orientations were divided between brand orientation, pleasure orientation, trend orientation and utilitarian orientation. Shoe attributes were categorized into ostentation value, product value, economic value and aesthetic value. College women were divided into the following groups: active shopping, passive shopping, rational shopping and conforming shopping. According to the comparison of the importance of shoe attributes by consumer type among college women, a significant difference by group was found in ostentation value and aesthetic value only. Furthermore, the average scores on the importance of product value and economic value were very high without significant differences between groups. The study results would be available as basic data to help improving the visual image of shoes and product quality for brands targeting young women in the fashion industry.

• 환경영향평가
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• 제19권4호
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• pp.421-429
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• 2010

The reliability of the measurement of ambient trace species is an important issue, especially, in background area such as Gosan in Jeju Island. In a previous episodic study, it was suggested that the PM10 measurement result by the gravimetric method(GMM) was not in agreement with the result by the ${\beta}$-ray absorption method(BAM). In this study, a systematic comparison was carried out for the data between 2001 and 2008 at Gosan(GMM and BAM) and Jeju city (BAM) which is near to Gosan. It was found that at Gosan the PM10 concentration by BAM was higher than GMM and the correlation between them was low. The BAM results at Gosan and Jeju city showed similar trend implying the discrepancy at Gosan was not caused by instrumental problem of the BAM at Gosan. Based on the previous studies two probable reasons for the discrepancy are identified; (1) negative measurement error by the evaporation of volatile ambient species at the filter in GMM such as nitrate and ammonium and (2) positive error by the absorption of water vapor during measurement in BAM. There was no heater at the inlet of BAM at Gosan during the sampling period. Based on the size-segregated measurement data, it was identified that the evaporation error was minor, if any. The relationship between the two methods did not vary with the ambient relative humidity. Thus, at present, it is not clear why the discrepancy had been occurring and when using the PM10 data at Gosan, one should be aware the possible errors.

• 한국자기학회지
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• 제24권5호
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• pp.152-159
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• 2014

마그네틱 기어는 두 개 이상의 분리된 장치들 사이에서 기계적인 접촉 없이 토크를 전송한다. 특히, 희토류계 영구자석을 사용한 마그네틱 기어는 고 출력으로 인해 다양한 산업에 적용된다. 따라서 마그네틱 기어는 일반적인 기어를 대체할 수 있다. 본 논문에서는 이차원 유한요소해석을 이용해 평행방향과 할박 자화 마그네틱 기어의 기어비를 선정하고, 내측과 외측 영구자석 두께, 철심 각도, 할박 세그먼트 개수, 내측과 외측 영구자석 자화 패턴과 같은 설계 변수에 따라 토크 해석을 수행하였다. 해석 결과, 개선된 설계변수를 갖는 모델이 초기 설계 모델과 비교해 더 높은 토크를 가짐을 확인하였다.

• 산업경영시스템학회지
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• 제40권2호
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• pp.51-59
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• 2017

Due to the rapid change of global business environment, the growth of China's steel industry and the inflow of cheap products, domestic steel industry is faced on downward trend. The change of business paradigms from a quantitative growth to a qualitative product is needed in this steel industry. In this environment, it is very important for domestic steel distribution companies to secure their competitiveness by selecting good supply companies through a efficient procurement strategy and effective method. This study tried to find out the success factors of steel distribution industry based on survey research from experts. Weighted values of each factors were found by using AHP (analytic hierarchy process) analysis. The weighted values were applied to DEA(data envelopment analysis) model and eventually the best steel supply company were selected. This paper used 29 domestic steel distribution firms for case example and 5 steps of decision process to select good vendors were suggested. This study used quality, price, delivery and finance as a selection criteria. Using this four criterions, nine variable were suggested. Which were product diversity, base price, discount, payment position, average delivery date, urgency order responsibility and financial condition. These variables were used as a output variable of DEA. Sales and facilities were used as an input variable. Pairwise comparison was conducted using these variables. The weighted value calculated by AHP pairwise comparison were used for DEA analysis. Through the analysis of DEA efficiency process, good DMU (decision making unit) were recommended as a steel supply company. The domestic case example was used to show the effectiveness of this study.

• Nuclear Engineering and Technology
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• 제27권3호
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• pp.403-417
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• 1995

1970년대 초반에 한국의 원자력 발전소 계획이 시작된 반면, 미국에서는 1970년대 후반 이래로 신규원자력 발전소 건설은 실질적으로 중단되었다. 신규 발전소 건설 현황을 고려해 보면, 발전소가 원자력과 화력의 적절한 조합에서, 모두 화력 발전소로 옮겨가는 것으로 보인다. 그렇지만, 천연자원의 고갈이라는 관점에서, 경쟁관계인 두 발전소를 투입된 에너지의 측면에서 고찰하는 것이 필요하다. 본 논문에서는 원자력과 화력의 두 발전소를 에너지 투자의 측면에서 비교 분석하였다. 비교 방법은 순에너지분석(NEA)이다. 그러한 분석을 통하여 산업체와 상품들에 대한 입력-출력 분석(IOA)을 수행하였다. 이러한 정보를 이용하여 순에너지비율(net energy ratio)을 계산하고 비교하였다. 한국의 자료가 불충분하기 때문에 미국의 발전소를 대상으로 NEA를 수행하였다. 순에너지분석이 결론적인 해답을 주지는 못하지만, 이 방법은 의사 결정 과정중의 제거절차(screening process)로 쓰일 수 있다. 에너지 계통을 고려할 때, 이러한 분석 결과는 일반적인 지침으로 사용될 수 있다. 이러한 분석은 다른 계통의 에너지사용에 대한 고찰을 하는 데도 적용될 수 있을 것이다.

• 디지털콘텐츠학회 논문지
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• 제19권1호
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• pp.157-163
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• 2018

SNS를 이용하는 사람들은 매일 자신의 다양한 생각을 SNS에 게시한다. SNS에 게시된 데이터는 수많은 사람들의 생각과 의견이 담겨있다고 할 수 있다. 특히 트위터에서 서비스되는 인기 화제어는 사용자가 올린 글에서 자주 등장한 단어의 횟수를 집계해 순위를 결정한다. 하지만 이와 같은 방법은 단순히 중복된 단어가 나열된 불필요한 데이터에 민감하다. 제안하는 방법은 단어간의 관계도를 이용한 단어의 화제성을 기반으로 순위를 결정하므로 불필요한 데이터의 영향을 적게 받고 주요단어를 안정적으로 추출할 수 있다. 성능 비교를 위하여 내림차순 화제어 순위와 상위 20개중에서 의미 없는 화제어의 비율 측면에서 형태소 분석과 PageRank 기반의 제안 방식과 단순 등장 횟수 기반의 기존 방식을 비교한다. 제안하는 방안과 기존 방안은 상위 20개중에서 무의미한 화제어를 각각 55%과 70%를 순위권에 포함시켰으며 제안한 방법이 기존 방법과 비교할 때 15% 정도 향상된다.

• 한국의류학회지
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• 제26권8호
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• pp.1165-1176
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• 2002

This study intended to provide more refined information on color preferences by systematizing the concept of the color preference(general color preference, apparel color preference) and revealing different trends in the color preference and the actual possession of apparels. We collected data from 303 females in the ages between 20 and 40 in Seoul and analyzed by paired t-test. The results were as follows: 1. The analysis on general color preference, apparel color preference, and apparel possession color revealed that the cold colors such as blue and violet marked higher, and the warm colors such as yellow and orange marked lower in general color preference. For apparel color preference, neutral and brown were among the highest and the rest of the colors were in the same trend as general color preference. Apparel possession color showed defined accordance with apparel color preference. In terms of tones, pale tone marked the highest in general color preference and was followed by vivid, dull, and dark tones in decreasing order. For apparel color preference, pastel, dul1, and dark tones were among the highest. 2. Comparison between general color preference and apparel color preference in terms of hue showed that, except for orange, every hue showed disagreement in general color preference and apparel color preference. Neutral and brown hues marked higher in apparel color preference than in general color preference where as a]1 the other hues marked higher in general color preference. Comparison between apparel color preference and apparel possession color in terms of hue revealed that in most hues, apparel possession color was lower than apparel color preference. In terms of tones, vivid and pale tones marked higher in general color preference than in apparel color preference while dull and dark tones marked higher in apparel color preference than in general color preference.

• 대한방사선치료학회지
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• 제10권1호
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• pp.11-22
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• 1998

The absolute absorbed dose can be determined according to the measurement conditions ; measurement material, detector, energy and calibration protocols. The purpose of this study is to compare the absolute absorbed dose due to the differences of measurement condition and calibration protocols for photon beams. Dosimetric measurements were performed with a farmer type PTW and NEL ionization chambers in water, solid water, and polystyrene phantoms using 6MV photon beams from Siemens linear accelerator. Measurements were made along the central axis of $10{\times}10cm$ field size for constant target to surface distance of 100cm for water, solid water and polystyrene phantom. Theoretical absorbed dose intercomparisons between TG21 and IAEA protocol were performed for various measurement combinations on phantom, ion chamber, and electrometer. There were no significant differences of absorbed dose value between TG2l and IAEA protocol. The differences between two protocols are within $1\%\;while\;the\;average\;value\;of\;IAEA\;protocol\;was\;0.5\%$ smaller than TG2l protocol. For the purpose of comparison, all the relative absorbed dose were nomalized to NEL ion chamber with Keithley electrometer and water phantom, The average differences are within $1\%,\;but\;individual\;discrepancies\;are\;in\;the\;range\;of\;-2.5\%\;to\;1.2\%$ depending upon the choice of measurement combination. The largest discrepancy of $-25\%$ was observed when NEL ion chamber with Keithley electrometer is used in solid water phantom. The main cause for this discrepancy is due to the use of same parameters of stopping power, absorption coefficient, etc. as used in water phantom. It should be mentioned that the solid water phantom is not recommended for absolute dose calibration as the alternative of water, since absorbed dose show some dependency on phantom material other than water. In conclusion, the trend of variation was not much dependent on calibration protocol. However, It shows that absorbed dose could be affected by phantom material other than water.

• Structural Engineering and Mechanics
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• 제76권3호
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• pp.311-324
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• 2020

Until now, a comparative study on fully and partially-connected steel shear walls leading to enhancing strength and stiffness reduction of partially-connected steel plate shear wall structures has not been reported. In this paper a number of 4-story and 8-story steel plate shear walls, are considered with three different connection details of infill plate to surrounding frame. The specimens are modeled using nonlinear finite element method verified excellently with the experimental results and analyzed under monotonic loading. A comparison between initial stiffness and shear strength of models as well as percentage of shear force by model boundary frame and infill plate are performed. Moreover, a comparison between energy dissipation, ductility factor and distribution of Von-Mises stresses of models are presented. According to the results, the initial stiffness, shear resistance, energy dissipation and ductility of the models with beam-only connected infill plates (SSW-BO) is found to be about 53%, 12%, 15% and 48% on average smaller than those of models with fully-connected infill plates (SPSW), respectively. However, performance characteristics of semi-supported steel shear walls (SSSW) containing secondary columns by simultaneously decreasing boundary frame strength and increasing thickness of infill plates are comparable to those of SPSWs. Results show that by using secondary columns as well as increasing thickness of infill plates, the stress demands on boundary frame decreases substantially by as much as 35%. A significant increase in infill plate share on shear capacity by as much as 95% and 72% progress for the 4-story SSW-BO and 8-story SSSW8, respectively, as compared with non-strengthened counterparts. A similar trend is achieved by strengthening secondary columns of 4-story SSSW leading to an increase of 50% in shear force contribution of infill plate.