• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.6
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• pp.177-193
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• 2022

In the near future, it is expected that the use of autonomous mobility-on-demand services will increase. Considering its complicated service components, including vehicle convenience, driving and matching speed, and platform convenience, the priorities of them will need to be determined for a successful establishment. In this context, this study examined the importance rank of each service component through an online survey of potential users of autonomous mobility-on-demand services. As a result of the AHP (Analytic Hierarchy Process) with respect to the upper-level components, driving and matching speed component is selected as most important, followed by platform convenience and vehicle convenience. Mean rank analysis with respect to lower-level components showed that the in-vehicle congestion level of vehicle convenience, waiting time of driving and matching speed, and pre-booking availability of platform convenience each ranked first. Additional analysis regarding each group was conducted to establish a group-specific strategy. As a result, it would be better to focus on a vehicle than a mobile platform when designing services for the region with a high proportion of the older. Moreover, it is recommended to speed up the driving and matching speeds more than the current public transport, alleviate in-vehicle congestion, and enable the users to book the schedule in advance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.73-78
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• 2016

In this study, GTAW was carried out on austenitic STS316 stainless steel. Overlay welding with the stellite-base filler metal was implemented using a double torch. The response variable was calculated on the measured Vickers hardness for process optimization using the Taguchi method and its response variable was then analyzed about effect on overlay welding characteristics. The optimal process design by the Taguchi method is extremely effective in the overlay welding process for the multiple response variables. In addition, the effects of contribution rate about each response variable was analyzed easily. The conditions of the optimal process were 105A, 18V, pre-heat treatment at $200^{\circ}C$, and post weld heat treatment at $100^{\circ}C$. The Vickers hardness of the specimens produced under the optimal condition of GTAW by the double torch was 8.19% higher than that by a single torch.

• Information Systems Review
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• v.21 no.2
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• pp.69-89
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• 2019

Recently, consumers are increasingly interested in the sharing economy, which utilizes various resources by sharing unused or under-used products/services with others. This study focuses on Airbnb, a representative sharing economy platform, to identify the success factors of the sharing accommodation services. The key properties of sharing accommodation services are extensively surveyed from extant literature and are classified them into the three important factors (economic, convenience, and trust) that influence the success of room-sharing services. The research data include 1,673 Airbnb hosts who offered accommodations in New York City, USA, in June 2018. The research variables of economic-, convenience-, and trust-related factors are utilized in the empirical analyses. The results of this study show that the number of available facilities, flexibility of refunds, the response rate and time to customer requests, and the status of Super host are positively associated with guest satisfaction from sharing accommodation services. This study bears significant managerial implications by suggesting a set of practical guidelines to participants in sharing accommodation services.

• Journal of the Korea Convergence Society
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• v.8 no.12
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• pp.291-298
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• 2017

In recent years, the increase of secondary controls within vehicles requires a mechanism to integrate various controls into a single device. This paper presents control performance of an integrated magnetorheological (MR) haptic device which can adjust various in-vehicle comfort instruments. As a first step, the MR fluid-based haptic device capable of both rotary and push motions within a single device is devised as an integrated multi-functional instrument control device. Under consideration of the torque and force model of the proposed device, a magnetic circuit is designed. The proposed MR haptic device is then manufactured and its field-dependent torque and force are experimentally evaluated. Furthermore, an inverse model compensator is synthesized under basis of the Bingham model of the MR fluid and torque/force model of the device. Subsequently, haptic force-feedback maps considering in-vehicle comfort functions are constructed and interacts with the compensator to achieve a desired force-feedback. Control performances such as reflection force are experimentally evaluated for two specific comfort functions.

• 한국정보교육학회:학술대회논문집
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• 2006.08a
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• pp.215-221
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• 2006

교육인적자원부는 교육행정 전반의 효율성을 높이고 교원 업무 환경 개선을 위해 교육행정정보시스템(NEIS)을 도입하여 시행하고 있다. 그러나 개인정보보호 문제로 여러 단체와 갈등을 빚어오던 중, 2003년 12월 교무 학사, 입 진학, 보건 등 3개영역을 분리하여 별도 시스템을 구축하기로 결정하고 2005년 시범학교 운영을 거쳐, 2006년에는 시스템을 전면적으로 운영하게 되었다. 본 연구는 교무업무시스템의 운영 현황을 분석하고, 당면한 문제점과 관련 과제를 제시하고자 하였다. 연구 결과, 70%이상의 교사들이 교무업무시스템을 1일 평균 1-2회 접속하는 것으로 밝혀졌으며, 기존의 수기장부가 약간 줄어들은 것으로 평가되었다. 교사들은 교무업무시스템의 기능, 디자인, 편의성, 효율성 등에 대해 긍정적이었으며, 재택 처리가 가능해진 것을 가장 좋은 점이라고 응답했다. 또한 개인정보보호에 대한 중요성을 알고 전자인증서를 관리한다는 응답이 많았으며, 가장 큰 문제점으로 접속의 어려움과 느린 시스템 속도 등 시설 측면의 개선이 요구되었다. 다수의 교사들이 시스템의 정착 후 교원의 업무가 경감되고 효율적으로 바뀔 것이라고 긍정적으로 응답했으나, 복잡해지고 이중 부담이 예측된다는 응답이 뒤를 이었다. 이러한 문제점을 개선하기 위해, 다양한 연수프로그램 제공, 학교 시설의 전반적인 개선, 수기장부의 감축을 통한 실제적인 업무 경감 등이 필요한 것으로 나타났다.

• Environmental and Resource Economics Review
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• v.28 no.4
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• pp.645-673
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• 2019

The hypothetical nature of stated preferences can lead to a hypothetical bias that might work as a normative pressure, influencing survey responses. This paper aims to test the impact of social desirability bias by comparing economic estimates based on both subjective and objective valuation questions. The case study is about an urban riverine restoration project in Deajeon, South Korea. As valuation methods both contingent valuation and choice experiments were comparatively applied. Based on a nationally representative sample of 1,000 respondents, the test results offered contrasting conclusions between two test approaches. Accroding to the estimation results based on the conventional valuation, the marginal willingness to pay estimates are 10,500 KRW from CV; and 18,600 KRW for improving water quality, 2,200 KRW for the inside view, 8,900 KRW for the outside view, and 5,800 KRW for biodiversity from CE. A segmentation-based approach is a conventionally used method, which showed a limited impact of social desirability on willingness to pay estimates. The alternative parameterization-based approach measures a model-wide impact of social desirability, proving a significant bias. Although the study positioned a cheap-talk statement before the valuation section of the survey questionnaires, which might have pre-screened the bias, the overall implications of the results suggest a caution in reducing and observing hypothetical bias. There might remain a significant and substantial hypothetical bias even after cheap-talk, particularly in situations with strong social desirability, so that the potential role of objective valuation questions is guaranteed.

• Environmental and Resource Economics Review
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• v.24 no.2
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• pp.435-461
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• 2015

Recently, Korean development Institute includes water for environmental improvement as an additional water demand category in water resources development project. In response to this change, this paper is to measure benefits of providing additional water in Yeondok Ohsip River by applying contingent valuation method. This study extended the conventional CVM design by incorporating distance variable into WTP function of dichotonomous choice responses and treated protest bids by estimating sample-selection models. The empirical analysis exhibited that more than 30% of respondents were categorized as protest bids and the mean of WTP from sample selection models were three times higher than that of the whole sample. In addition, the distance variable had significantly negative impact on sample WTP regardless of variables forms, and the geographical market area were more 400km, which implies that beneficiaries of water service would the households from the whole nation.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.17-18
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• 2011

최근 빠른 응답성과 정확성을 요구하는 임베디드 시스템의 사용이 증가됨에 따라 임베디드 시스템의 시간 정확성을 만족 시키는 경성 실시간성의 중요성이 커지고 있다. 이러한 임베디드 시스템의 운영체제로는 응용프로그램 개발의 편의성을 위해 범용 운영체제인 Linux를 많이 사용하며, Linux에 실시간성 제공을 위해 RT-Linux(Real Time - Linux)를 사용하고 있다. RT-Linux의 경우 경성 실시간성을 제공하지만 어셈블러를 사용해야 하므로 개발자가 다루기 힘들다는 단점이 존재한다. 이에 따라 Linux에 경성 실시간성을 제공하고 개발자에게 개발의 편의성을 제공하는 방법에 대한 연구가 필요하다. 본 논문에서는 범용운영체제인 Linux에 경성 실시간성을 제공하기 위해 x86기반의 Window에 실시간성을 제공하는 RTiK(Real-Time implanted Kernel)을 Linux에 모듈 형태로 적재하여 실시간성을 제공할 수 있는 방법을 설계 및 구현하였다.

• Environmental and Resource Economics Review
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• v.20 no.3
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• pp.595-628
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• 2011

This study investigates the issues and suggests reform measures in applying CV methods to the Korea Development Institute's (KDI's) Preliminary Feasibility Test (PFT) of public projects. Most public projects on culture, science and environment evaluated under the PFT system belong to the category of "nonstandard" projects whose outputs are non-marketed, and CV is currently the main tool used for their benefit estimation. A careful discussion and investigation is recommended for the selection of target population, payment vehicle, and number of payment times. Operating expert reviews, focus group interviews, and pre-tests is highly recommended to reduce the potential bias involved in the CV studies. A single or double bounded dichotomous choice format is the most popular design of questionnaire, but we identify several undissolved issues in designing and implementing the format. Some other forms of inducing WTPs may still deserve our consideration. Various specifications of the WTP function need to be tried and tested based on their stability, in particular. Employing a nonparametric approach is also recommended. Treatments of 0 or negative WTPs and protest bids are shown to be the most serious issues that affect the estimation results significantly. We review diverse measures of handling those issues and summarize their advantages and shortcomings.

• Proceedings of the Korea Contents Association Conference
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• 2018.05a
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• pp.361-362
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• 2018

본 연구는 대학 웹페이지의 Q&A(질의응답) 게시판에 게재된 비정형화 된 데이터를 수집한 후 텍스트마이닝과 네트워크 분석을 활용하여 자주 등장하는 키워드 간 연관 패턴을 파악하고자 한다. 분석결과를 바탕으로 FAQ(자주하는 질문) 게시판을 구성한다면 반복적인 질문에 대한 민원을 간소화함으로써 수요자의 편의성과 행정의 효율성 향상에 기여하고 나아가 원활한 양방향 소통이 가능할 것으로 기대한다.