• Proceedings of the Korean Information Science Society Conference
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• 2002.10d
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• pp.334-336
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• 2002

군집 분석은 데이터의 속성을 분석하여 서로 유사한 패턴을 가진 데이터를 묶는 방법이다. 군집 분석은 많은 응용 분야에서 쓰이고 있으나, 수행된 군집 분석 결과가 과연 정확한 결과이고 의미 있는 결과인지를 평가하는데 어려움이 있다. 본 논문에서는 군집이 형성된 데이터를 분석하여 군집 분석 결과를 평가하는 상대적 군집 평가 방법을 제안한다. 본 논문에서는 상대적 군집 평가 방법의 인덱스를 정의하고 형성된 군집 분석 결과에 적용해 최적의 군집, 의미 있는 군집을 찾을 수 있음을 보인다. 또한 실험을 통해 제안한 인덱스의 적합성을 보이며, 제안한 인덱스가 기존의 인덱스에 비해 최적의 군집, 의미 있는 군집을더 잘 찾을 수 있음을 보인다.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.2
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• pp.47-55
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• 2016

In this study, WUA (Weighted Usable Area) based on the Instream Flow Incremental Methodology (IFIM) was calculated to determine ecological flow at JeonJu-Cheon by using River2D model. To calibrate River2D, simulation results for low flow conditions of River2D were compared with calibrated HEC-RAS simulation results and the optimum parameters were determined. The results were RMSE (0.18), NSE (0.71) and coefficient of determination (0.78) for velocity and RMSE (0.02), NSE (0.71), coefficient of determination (0.73) for water depth. The result shows that the model successfully simulates the water flows. A selected target fish species to build the habitat suitability index were composed of Zaccoplatypus and Coreoleuciscus splendidus. These species showed the highest occurrences over the past decade in f ish monitoring. Also, The WUA-Discharge curve was calculated with the suitability index in a medium flow conditions. From the result, WUA is changed according to flowrate. In the flowrate-WUA/A graph, ecological flow can be determined at $1.8{\sim}2.0m^3/s$ for Zaccoplatypus $2.0m^3/s$ and Coreoleuciscus splendidus $1.8m^3/s$ at JeonJu-Cheon upstream. When compared with flow-duration analysis, it is demonstrative that simulation results fitted ecological flow considering quantity of available habitat for each fish species.

• Asia Marketing Journal
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• v.13 no.4
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• pp.139-158
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• 2012

This study was intended to classify tie-in promotion tools by the criteria of benefit-fit between consumer and tie-in promotions. Tie-in promotion tools include tie-in price reductions, tie-in coupons, tie-in memberships, tie-in contests, tie-in sweepstakes, tangible and intangible tie-in premiums, tie-in payment terms, tie-in samples, tie-in events(culture event, charity event, experience event) and tie-in fund·rebates. The fit between consumer pursuit benefit and tie-in promotion supplying benefit was used as a classification criteria on the basis of Lee et al.'s study in 2011. For the experiment, one stimuli and 12 scenarioes were developed. 100 pieces of data were obtained for each scenario. As a result, benefit fit was subsequently divided into two factors: hedonic-benefit fit and utilitarian-benefit fit. Tie-in promotion tools were then classified into 4 types: high hedonic benefit-added, high utilitarian benefit-added, low hedonic benefit-added, and low utilitarian benefit-added. In previous research, tie-in promotion type was mainly divided by the evaluative criteria on company's viewpoint such as horizontal/vertical or intra-company/ inter-company, which reflects mutual exclusiveness between two criteria. Whereas, in this study, tie-in promotion type was divided by evaluative criteria on consumer's viewpoint such as hedonic- benefit fit/utilitarian-benefit fit. The classifications in this study practically reflect benefit-added of tie-in promotion type superadded one benefit coexisting two benefits.

• Journal of Korea Water Resources Association
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• v.48 no.7
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• pp.567-579
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• 2015

This study performed the non-stationary flood frequency analysis considering time-varying parameters of a probability density function. Also, return period and risk under non-stationary condition were estimated. A stationary model and three non-stationary models using Generalized Extreme Value(GEV) were developed. The only location parameter was assumed as time-varying parameter in the first model. In second model, the only scale parameter was assumed as time-varying parameter. Finally, the both parameters were assumed as time varying parameter in the last model. Relative likelihood ratio test and Akaike information criterion were used to select appropriate model. The suggested procedure in this study was applied to eight multipurpose dams in South Korea. Using relative likelihood ratio test and Akaike information criterion it is shown that the inflow into the Hapcheon dam and the Seomjingang dam were suitable for non-stationary GEV model but the other six dams were suitable for stationary GEV model. Also, it is shown that the estimated return period under non-stationary condition was shorter than those estimated under stationary condition.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.808-814
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• 2021

The International Maritime Organization (IMO) explicitly stipulates the required performance of satellite based radio-navigation systems available for navigational purposes. Until 2019, the IMO had only recognized systems that could be serviced globally for satellite based radio-navigation. However, India's regional navigation satellite system has been approved recently, and other regional navigation satellite systems have also been made available for maritime navigation. Thus far, the IMO has approved the use of a total of five satellite navigation systems, such as the GPS, GLONASS, Galileo, BeiDou, and NavIC. In Korea, in addition to the four satellite based radio-navigation systems that are used excluding NavIC, Japan's regional navigation satellite system that has not yet been approved can be received. Japan has requested the IMO to recognize the QZSS as a WWRNS to formalize its use for ocean navigations. Given that the service coverage of the QZSS is not limited to Japanese territorial waters and also includes Korean waters, the suitability analysis of the QZSS for domestic navigation is important for maritime safety. This study aims to analyze the suitability of using the QZSS for domestic navigation. Accordingly, this work explores the status and plans of the QZSS as well as the performance required by the IMO for recognition as a WWRNS. The methods and environmental conditions examined in this work are described, and the analyzed results are presented in terms of positioning accuracy and availability.

• Journal of Food Hygiene and Safety
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• v.39 no.2
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• pp.83-94
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• 2024

The proportion of plant-based meat alternative (PBMA) consumers has recently increased in Korea. This is due to several reasons including protecting the environment, satisfying preferences, maintaining health, and improving eating habits. Accordingly, many companies produce and sell alternative meat using various materials. Alternative meats are classified into plant (such as soybeans and wheat), seaweed, insect, and cultured meats, depending on the raw materials used in manufacturing. PBMA is sold after undergoing processes such as grinding, seasoning, and molding. Therefore, monitoring the presence of any hazardous elements during this process is essential. Accordingly, in this study, we analyzed the harmful components of nine domestically distributed PBMA that are most easily accessible to consumers. After extracting fat from the samples and analyzing the rancidity level, samples F, G, and I were highly rancid. Trace amounts of aflatoxin were detected in samples A and B, but confirmed to be within the range. Cd and Pb were not detected in any sample. We hope that this study will help establish methods to ensure the safety of domestically sold PBMA.

• Korean journal of communication and information
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• v.61
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• pp.28-51
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• 2013

The present study analyzed the effects of brand extension on the existing parent brand by applying the media brand extension model which previous studies had suggested based on consumer based brand equity model. Based on previous studies, the present study constructed a research model in which pre-brand extension parent brand evaluation, brand portfolio quality variance, perceived number of brand extensions, perceived fit between parent brand and brand extended channel, and brand extended channel evaluation are supposed to affect post-brand extension brand extension evaluation, and tested the media brand extension feedback effects model through structural equation modeling. The analysis results show that pre-brand extension parent brand evaluation, brand portfolio quality variance, perceived fit, and brand extended channel evaluation affect post-brand extension parent brand evaluation while the effect of perceived number of brand extensions is not significant.

• Management & Information Systems Review
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• v.32 no.2
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• pp.339-357
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• 2013

A purpose of this study is to examine the effects of job embeddedness on job satisfaction and turnover intention of construction IT worker and to verify the effects of job satisfaction as intervening variable on turnover intention. To achieve the purpose of this study, field survey was performed. To summarize the results of this study is as follows. First, if job embeddedness of construction IT worker (fit, links, sacrifice) in a workplace is high, turnover intention will be low; the result shows that there is a relation in relation level 0.00. Second, if job embeddedness of construction IT worker (fit, links, sacrifice) in a workplace is high, job satisfaction will be high it was excluded in working period links as there was no relation, but there was a statistical relation in service links, fit, and sacrifice for an organization. Third, if job satisfaction of construction IT worker in a workplace is high, turnover intention will be low this hypothesis can be adopted as there was a statistical relation. Fourth, job satisfaction works on the effect of job embeddedness (fit, links, sacrifice) on turnover intention as intervening variable.

• Journal of the Korean Society for Railway
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• v.19 no.1
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• pp.29-37
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• 2016

The type approval system of the railway safety law, which was enforced in 2014, has been preferentially applied to the field of railway vehicles. The type approval system addresses railway vehicles and railway constituents. Unlike the previous system, it requires serial verification stages divided, in consecutive order, into verification of design compatibility and conformity and type test. These stages are in accord with international certification systems including TSI certification of the European commission. This study has been carried out to find and meet the design requirements for a coupler head, which is a part of the automatic coupler system; requirements were drawn from TSI and technical specifications that are subordinate to the domestic railway approval system. Through this study, it has been found that there exist 34 design requirements to acquire a complete coupler head. Among those requirements, 32 were verified by document inspection and two were able to be verified by performing FEA and gathering range analysis data.

• Journal of Korean Society of Transportation
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• v.20 no.2
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• pp.125-134
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• 2002

도시화물수요예측모형에는 화물기반모형과 트럭통행기반모형이 있는데 화물기반모형은 화물체계가 기본적으로 화물운송과 관계가 있다는 개념에 기초를 두고 있으며, 차량이 아닌 화물의 움직임을 주요 분석대상으로 삼고 있다. 반면에, 트럭통행기반모형은 집합화된 독립변수를 이용하여 각 죤(Zone)에 유·출입하는 트럭의 통행을 분석하는 것이다. 본 연구의 목적은 트럭통행기반모형의 O-D 추정시 화물통행과 트럭통행 사이의 관계식을 산출하고 이를 설명할 수 있는 통행거리분포함수(Trip Length Distribution : TLD)를 추정함에 있다. 본 연구의 자료는 교통개발연구원에서 수행한 '서울시 물류조사 및 물류종합계획수립구상(1998)'의 화물 물동량 조사 자료를 이용하였으며, 이를 통해 통행거리분포에 따르는 화물 및 차량의 비율을 함수로서 나타내었다. 본 연구를 통하여 트럭통행기반모형에서 트럭통행거리분포를 이용하여 화물기반모형에서 도출할 수 있는 화물의 통행거리분포를 추정할 수 있었으며, 또한 각각의 통행거리분포는 감마분포를 이용하여 함수식으로 도출하고 상기한 두 가지 분포모형을 하나의 관계식을 통해 재산정할 수 있는 이론적인 틀을 제공하였다는 데 의의가 있다고 하겠다. 트럭통행거리분포, 화물통행거리분포 모두 통계적인 검증을 통해 적합한 것으로 분석되었으며, 전체화물의 통행거리분포와 매개함수를 통해 재산정된 모형의 결과 값 또한 통계적으로 유의하였다. 품목별 적용에서는 잡공업품과 화학공업품은 본 연구의 매개함수식을 통해 화물거리분포 모형이 적합하였으나 금속공업 품과 경공업품은 다소 차이가 있는 것으로 분석되었다.