• The Journal of Asian Finance, Economics and Business
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• 제7권2호
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• pp.221-228
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• 2020

This study suggests an alternative to the conventional collaborative filtering method for predicting consumer choice, using case-based reasoning. The algorithm of case-based reasoning determines the similarity between the alternative sets that each subject chooses. Case-based reasoning uses the inverse of the normalized Euclidian distance as a similarity measurement. This normalized distance is calculated by the ratio of difference between each attribute level relative to the maximum range between the lowest and highest level. The alternative case-based reasoning based on similarity predicts a target subject's choice by applying the utility values of the subjects most similar to the target subject to calculate the utility of the profiles that the target subject chooses. This approach assumes that subjects who deliberate in a similar alternative set may have similar preferences for each attribute level in decision making. The result shows the similarity between comparable alternatives the consumers consider buying is a significant factor to predict the consumer choice. Also the interaction effect has a positive influence on the predictive accuracy. This implies the consumers who looked into the same alternatives can probably pick up the same product at the end. The suggested alternative requires fewer predictors than conjoint analysis for predicting customer choices.

• ETRI Journal
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• 제38권1호
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• pp.1-8
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• 2016

A large incoherent crosstalk (IC) caused by amplified spontaneous emission (ASE) noise power from Tx-disabled optical network units and a differential path loss has been shown to degrade upstream transmission performance in time-division multiplexing passive optical networks. This paper considers the IC-induced power penalty of an upstream signal both in an XG-PON and in a TWDM-PON. We investigate the degradation of the extinction ratio and relative intensity noise through a simulation and experiments. For the XG-PON case, we observe a 9.6 dB difference in the level of ASE noise power from Tx-disabled ONUs (hereafter known simply as ASE noise) between our result and the ITU-T XG-PON PMD recommendation. We propose an optical filtering method to mitigate an IC-induced power penalty. In the TWDM-PON case, the IC-induced power penalty is naturally negligible because the ASE noise is filtered by a wavelength multiplexer at the optical line terminal. The results provide design guidelines for the level of ASE noise in both XG-PONs and TWDM-PONs.

• 가정∙방문간호학회지
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• 제18권1호
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• pp.13-19
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• 2011

Purpose: The aim of this study was to evaluate patient satisfaction and indirect marketing effects (recommendation, hospital re-visit intention) and additionally to calculate the expected incomes by clinical nurse specialists (CNS). Methods: Sixty-six patients who had lower varicose vein removal surgery performed at two general hospitals from August 1 to November 30, 2008, were recruited. The effects were evaluated by degree of patient satisfaction, the number of personal recommendations given, rate of hospital re-visit intention, and indirect marketing effects. Indirect marketing effects were calculated as the total cost of surgery multiplied by the score of other variables. Results: The patient satisfaction score was 0.82 for CNS and 0.43 for general nurses (GN). The number of personal recommendations given was 2.5 for CNS and 1.1 for GN. The rate of hospital re-visit intention was 0.31 for CNS and 0.21 fot GN. The ratio of expected incomes between CNS and GN is 2.07 to 1. Conclusion: We found that when a CNS serves a patient, satisfaction, number of personal recommendations, hospital re-visit intention, and indirect marketing effects were higher than those of GN. These results show that CNS have dominant roles and functions and that the effects of CNS employment can be measured using economics parameters.

• KIEAE Journal
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• 제7권6호
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• pp.99-106
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• 2007

Tower crane is a large construction equipment which is extremely tall for its section when it is erected, with its high slenderness ratio, and it has a heavy load by itself due to large lifting stuff to handle. In line with the construction projects in these days which increasingly tend to become higher, larger and complex, the stuff and height subject to lifting are also getting larger and higher, which has also increased the risk of disastrous accidents. A stable foundation design thus to deal with the increasing self load becomes more important. When a typhoon Maemi swept the nation in 2003, as many as 43 tower cranes fell down or collapsed, causing a severe damage to the people and the properties. Considering such fatal damages, a technical evaluation of the stability to prevent the safety accident with the tower crane must be very crucial. Tower cranes operation in domestic construction sites, in fact, have been simply dependent on personal experience and intuition of the engineers. Particularly when it comes to the foundation design, it mostly depends on manufacturer's recommendation. The study hence was intended to develop the fundamental measures for granting the objective stability, instead of following the individual's experience only. The simulation model recommended in the study is expected to make a good commitment to achieving an effective lifting work as well as preventing the safety accident.

• Nuclear Engineering and Technology
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• 제50권5호
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• pp.639-647
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• 2018

In this study, the effects of selecting water/silver nanofluid as both a coolant and a reactivity controller during the first operating cycle of a light water nuclear reactor are investigated. To achieve this, coupled neutronic-thermo-hydraulic analysis is employed to simulate the reactor core. A detailed VVER1000/446 reactor core is modeled in monte carlo code (MCNP), and the model is verified using the porous media approach. Results show that the maximum required level of silver nanoparticles is 1.3 Vol.% at the beginning of the cycle; this value drops to zero at the end of cycle. Due to substitution of water/boric acid with water/Ag nanofluid, reactor operation time at maximum power extends to 357.3 days, and the energy generation increases by about 27.3%. The higher negative coolant temperature coefficient of reactivity in the presence of nanofluid in comparison with the water/boric acid indicates that the reactor is inherently safer. Considering the safety margins in the presence of the nanofluid, minimum departure from nucleate boiling ratio is calculated to be 2.16 (recommendation is 1.75).

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권7호
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• pp.3550-3565
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• 2019

This paper proposes a new measurement method for the effective measurement of the 99% occupied bandwidth (OBW) at monitoring stations. Although the OBW measurement of radio signal is recommended by the International Telecommunication Union Radio (ITU-R) with several methods, there still does not exist a clear measurement recommendation or standard for terrestrial DTV signal on-air environment. Modified adjacent channel power ratio (MACPR), which can be applied to 8-VSB (Vestigial Side Band) DTV (Digital Television) signal, is herein defined to verify the results of measurements obtained using the proposed measurement method. MACPR is a proper measuring parameter for determining the measuring area of a monitoring station. From measurement results obtained in real field environment, it has been found that the OBW of 8-VSB DTV signal can be effectively measured in areas where the MACPR value is over 35 dB and when the measurements are repeated more than 600 times in the same reception site. It also has been verified that measured results are within an error range of +/-0.1% compared to results directly obtained at a transmission station. It is expected that the proposed method is able to be employed in order to determine the proper location of monitoring station and provide a reliable OBW measurement procedure for 8-VSB DTV signal on-air environment.

• Human Ecology Research
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• 제61권3호
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• pp.475-492
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• 2023

This study investigated player responses to microtransactions in freemium Massively multiplayer online roleplaying games (MMORPG), specifically focusing on the game LostArk using English language review data. To this end, structural topic modeling was employed and the following six microtransaction-relevant topics were identified: microtransactions, developer issues, real money trade (RMT), random number generator (RNG) upgrade system, game content, and collectibles & adventure. The first four topics were classified as being "not recommended". However, the proportions of microtransaction-related topics were relatively lower than the other topics. Additionally, this study did not extract keywords related to unfairness and unethical issues in previous microtransaction research. The last two topics, game content, and collectibles & adventure were "recommended" topics, indicating positive functions of microtransactions such as enhancing the game experience by purchasing virtual items. Moreover, it was found that players who do not engage in microtransactions can still be satisfied through continuous game content updates. Additionally, an examination of the interaction effect between time and recommendation status revealed that while the frequency with which the six microtransaction-related topics were mentioned increased over time in the reviews, the ratio of recommendations to non-recommendations varied differently. This study contributes to game-related research by revealing players' authentic opinions on microtransactions in freemium MMORPGs, thereby providing practical implications for game companies.

• 대한예방한의학회지
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• 제20권3호
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• pp.1-8
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• 2016

Objectives : There is a correlation between student's satisfaction of education and their occupation satisfaction. Therefore, Korean medical school students' satisfaction toward their education is important for their medical ability in Traditional Korean Medicine(TKM). The purpose of this study is to investigate TKM school students' satisfaction of education and their perceptions of TKM level. Methods : The questionnaire used in this study is consisted of questions about students' satisfaction and their perception toward issues about TKM. 168 cases were collected, and I analyzed 164 cases. Results : 43.9% of students think that the ratio of western medical courses to TKM courses in TKM school's curriculum is 'Proper'. 54.3% of students do not satisfy their curriculum. But, 51.2% of students would recommend high school students for entrance to TKM school. 77.9% of students think 'TKM doctor should use modern medical device'. 92.7% and 61.9% of students think 'Needed' toward 'Cooperation of western medicine and Korean medicine', and 'Medical unification' each. There are correlations ; (1)'recognition toward ratio of curriculum', (2)'satisfaction of curriculum', (3)'degree of recommendation to enter the TKM School', (4)'relation between TKM and Traditional Chinese Medicine(TCM) or Complementary and Alternative Medicine(CAM)'. Conclusions : Student's satisfaction of education is not quite high than satisfaction of TKM study itself. Most of respondents agreed usage of medical devices. The more they thought that they had curriculum for western medicine, the lesser they thought that medical unification was ont needed. Further studies are needed to assess satisfactions of students for their education with more accuracy results.

• 정보과학회 논문지
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• 제41권12호
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• pp.1075-1080
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• 2014

전쟁에서의 승리를 담보하는 핵심적 역할 중 하나는 최적의 군수지원을 통해 전투력을 극대화하고 지속능력을 가능한 장기적으로 유지하는 것이다. 주요 무기체계의 효과적인 사용을 위한 다양한 군수지원 방법론이 지속적으로 제안되고 있으나, 모든 군수지원 요소를 종합적으로 고려한 군수지원 접근법에 대한 연구는 전무한 실정이다. 본 논문에서는 기존 군수지원의 주요 방법론 이었던 고장률 분석을 통한 접근법에서 벗어나, 비용, 수송, 고장률, 정비, 시스템 복잡도 등 군수지원의 다양한 요소를 종합적으로 식별하여, 각각의 영향력을 결합할 수 있는 방법론과 stationary 분포를 이용한 최적의 군수지원 우선순위를 결정하여 추천하는 알고리즘을 최초로 제안한다.

• 한국콘텐츠학회논문지
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• 제18권10호
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• pp.507-517
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• 2018

본 연구는 한국을 재방문하는 외래 관광객의 특성을 분석하였다. 한국을 재방문하는 외래 관광객의 특성을 분석한 결과 인구통계학적 특성에 있어서 외래 관광객의 방문 횟수에 따라 성별, 나이, 국가별로 통계적으로 유의미한 차이가 있는 것으로 나타났으며 여행 특성에 있어서는 외래 관광객의 방문 횟수에 따라 여행형태, 동반자수, 방문 목적, 이용 숙박 시설, 주요 방문지, 방문 권역에서 통계적으로 유의미한 차이 있는 것으로 나타났다. 또한 여행지출 경비에 있어서는 외래 관광객의 방문횟수에 따라 1인당 개별 숙박비, 1인당 본인 거주국 지불 경비에서, 만족도에 있어서는 외래 관광객의 방문 횟수에 따라 출입국 절차, 대중교통, 숙박, 음식, 쇼핑, 관광지 매력, 관광 안내 서비스, 치안에서 통계적으로 유의미한 차이가 있는 것으로 나타났다. 그리고 여행 후 행동의도 및 이미지 평가에 있어서는 외래 관광객의 방문 횟수에 따라 향후 3년 내 재방문 의향, 타인 추천 의향, 여행 전 한국 이미지, 여행 후 한국 이미지에서 통계적으로 유의미한 차이가 있는 것으로 나타났다. 따라서 외래 관광객의 재방문율을 높이기 위해서는 이러한 특성을 고려한 관광 상품을 개발하는 것이 관광 수익을 극대화 하는데 필요하다.