• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.238-242
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• 2015

A steam jet vacuum system that will be implemented in a multi-effect desalination plant is numerically investigated. The objective of this study is to numerically investigate the performance characteristic of the steam jet vacuum system for the sea water distillation process. The effects of design parameter such as nozzle size and converging duct angle are discussed in order to get a better understanding of flow characteristics inside the steam ejector and subsequently pave the way for more optimum designs. The simulation results have been in good agreement with experimental data and have well reproduced the shock train phenomena of the throat region.

• Journal of the Korean Society for Railway
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• v.11 no.1
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• pp.45-53
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• 2008

With the growing international consensus regarding sustainable development of transportation, the plan of transportation infrastructure needs to meet various requirements toward enhancing environmental conditions. Accordingly, the upcoming long-term plan of high-speed rail network has to be reflecting the sustainability of transportation systems. In this paper, we demonstrate an application of methodologies based on multi-attribute utility theory for determining priorities of sustainable high-speed rail investment. The proposed methodologies identify indicators for sustainable transportation systems such as economic, environmental, and social ones and then, evaluate priority for planning a long-term sustainable high-speed rail network by comparing the relative importance among indicators. This will help transportation agencies to prioritize high-speed rail investment toward sustainable transportation systems.

• The Korean Journal of Financial Management
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• v.17 no.2
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• pp.1-28
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• 2000

본 연구에서는 경영자 소유지분과 자본적 투자지출의 관계를 이론과 실증분석의 양 차원에서 분석하였다. 우선 이론적인 분석에서는 경영자가 기업가치 극대화뿐만 아니라 규모극대화를 동시에 추구할 때, 기업의 자발적 투자지출은 경영자 소유지분의 함수라는 점을 보였다. 특히 2차효용함수의 가정하에서 자본적 투자지출과 경영자 소유지분의 관계는 경영자의 소유지분과 위험회피도, 확실성 등가에 의한 프로젝트의 순기대현금 흐름 수준에 따라 달라지는 것으로 나타났다. 또한 자본적 투자지출은 경영자의 효용함수 행태에 따라 경영자 소유지분이 낮은 수준에서는 소유지분의 감소함수이나 높은 수준에서는 증가함수로 반전되는 구조적인 전환점이 존재한다는 점을 밝혔다. 한편 90-95년 중 우리나라 상장 제조업의 자료를 바탕으로 규모극대화 기업과 규모비극대화 기업에 대하여 경영자 소유지분과 자본적 투자지출의 관계를 비교한 결과, 규모극대화 기업에서 경영자 지분이 약 30%인 구조적인 전환점을 중심으로 그 이전에서는 경영자 지분의 증가에 따라 자본적 투자지출이 감소하나 그 이후에는 증가함수로 단전되는 것으로 나타나 이론의 내용을 지지하였다. 그러므로 본 연구의 결과는 기존의 연구에서와는 달리 안주가설(entrenchment hypothesis)에 의하지 않더라도 경영자의 효용함수의 행태에 따라 일정한 경영자 소유지분 이상에서는 가치비극대화 행위가 지배할 있다는 점을 보여주고 있다.

• The Korean Journal of Applied Statistics
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• v.33 no.5
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• pp.541-553
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• 2020

The receiver operating characteristic (ROC) curve is expressed as both sensitivity and specificity; in addition, some optimal thresholds using the ROC curve are also represented with both sensitivity and specificity. In addition to the sensitivity and specificity, the expected usefulness function is considered as disease prevalence and usefulness. In particular, partial the area under the ROC curve (AUC) on a certain range should be compared when the AUCs of the crossing ROC curves have similar values. In this study, partial AUCs representing high sensitivity and specificity are proposed by using sensitivity and specificity lines, respectively. Assume various distribution functions with ROC curves that are crossing and AUCs that have the same value. We propose a method to improve the discriminant power of the classification models while comparing the partial AUCs obtained using sensitivity and specificity lines.

• Journal of Labour Economics
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• v.43 no.4
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• pp.87-116
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• 2020

This study empirically investigates the possible negative relationship between the number of job offers and the job satisfaction in the Korean labor market, using the Korea Labor Income Panel Study, where the number of job offers of young workers are collected in the third wave. Results show that the number of job offers is negatively related to every year job satisfaction, this effect is smaller for higher earning and older individuals, and there is a gender heterogeneity. We discuss that having more job offers does not necessarily increase the workers' utility, which is a general monotonic assumption in the traditional economics. We suggest that having a large number of job offers allowing them to choose the best option can be inefficient itself, and therefore it is better to focus on qualitative matching rather than increasing just the absolute number of job opportunities.

• 한국벤처창업학회:학술대회논문집
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• 2021.11a
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• pp.189-195
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• 2021

최근 고령화로 인한 수명연장은 노후생활비용 부담의 가중을 통해 고령자들의 노후파산 가능성을 높이는 핵심 위협요인이 되고 있기 때문에 이를 위한 사적자산의 안정적, 장기적인 관리와 증식이 필수적이다. 자산관리 자문/일임 서비스를 이용하는 것은 이를 해결할 수 있는 좋은 대안이지만 과거에는 서비스 이용가능 대상이 대형 금융기관을 거래하는 거액자산가들로 국한되어 있었다. 그런데 최근 기술혁신과 더불어 플랫폼을 기반으로 하는 웰스테크(디지털 자산관리) 서비스가 빠른 속도로 대중화되고 있어, 이를 활용하면 보다 많은 고령자들이 자산관리에 대한 부담을 경감할 수 있을 것으로 예상된다. 본 연구에서는 이런 이유로 최근 주목받는 웰스테크(디지털 자산관리) 자문/일임 서비스에 대한 고령자들의 사용의도에 영향을 미치는 특성 및 요인들을 파악하고자 한다. 이를 위해 기술수용이론 중 소비자가 얻는 혜택과 희생을 모두 고려하는 '가치기반수용모델(Value Based Model)'을 기본 모형으로 하되 웰스테크(디지털 자산관리) 자문/일임서비스의 특성을 고려하여 '가격효용성'을 혜택 요인에 추가하였다. 또한 고령자의 특성을 고려하여 희생 요인에 '인지된 위험'을, 별도의 요인으로 '사회적 영향'을 각각 추가하였다. 예상되는 연구결과로는 지각된 혜택에 해당하는 유용성, 즐거움, 가격효용성은 모두 인지된 가치에 유의한 (+)의 영향을 미칠 것으로 예상되는 반면, 지각된 희생에 해당하는 기술성과 인지된 위험은 모두 인지된 가치에 유의한 (-)의 영향을 미칠 것으로 예상된다. 또한 추가변수인 사회적 영향은 인지된 가치에 유의한 (+)의 영향을 미칠 것으로 예상된다.

• The Journal of the Korea Contents Association
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• v.15 no.7
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• pp.489-499
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• 2015

The purpose of this study is to identify factors affecting piracy of online digital contents, focusing on relative awareness of illegal duplications, compared to legal duplication. To do this, the current study integrates factors proposed in existing literature and the previous studies based on the theory of planned behavior and accesses them from cost-benefit point of view. Main findings are summarized as followed;- First, with regard to relative benefits gained by illegal duplication, it is shown that monetary and psychological utility have positive effects on attitudes and behaviors of illegal duplication. Particularly, it is found that monetary incentive is the main cause of illegal duplication as monetary gains are major factors affecting illegal duplication behaviors. Second, it is suggested that ethical cost is a definitive factor that has negative effects on illegal duplication behaviors while technological cost has also significant effects on illegal duplication behaviors. Third, it is confirmed that there is a significant relationship between attitudes and behaviors of illegal duplication. This result shows that an attitude to illegal duplication is antecedent of behaviors as the belief and the value regarding illegal duplication can lead actual behaviors.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.3
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• pp.36-46
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• 2011

At present, the number of local governments using the Traffic Information Center are increasing and drivers are utilizing its traffic information from VMS installed on roads in cities. However, the cases of the user's utility of VMS about urban roads with special characteristics different from expressways and urban highways haven't been evaluated so far. Because VMS is a medium installed from a budget to provide traffic information, it is necessary to evaluate and manage the efficiency of users. This study judged that the efficiency of the drivers using VMS of urban roads most influences the duty on alternative route information provision so that it established its evaluation criteria. In addition, it needs to raise its value by many drivers' observation of VMS. Therefore, in case of the same conditions, the installation location of VMS should be a road section with much traffic volume so its the evaluation criteria was established. At present, the study results can be utilized to raise the user's utility of VMS installed in the urban roads.

• Proceedings of the Korean DIstribution Association Conference
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• 2006.05a
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• pp.35-56
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• 2006

The objective of this research is to identify the factors affecting the quality perception of consumer about the private brand and to investigate how the monetary utility of the private brand affects the consumer's preference. The main finding can be summarized in three points. The consumer's usage experience with PB have a positive but store image has no significant effect on the quality perception of PB. The perceived quality and monetary utility of PB has a significant effect on the quality perception while the perceived quality has stronger effect. The competitiveness of the national brand in the same store, post-usage attitude, the perceived quality, and perceived value have significant effect on the preference toward PB but monetary utility does not. The perceived effect has the strongest effect. This result suggests that even the value-seeking consumers prefer PB only when the perceived quality exceeds a certain limits. This study provides the strategic implications for retail managers and theoretical implication for the researcher studying PB.

• Journal of Digital Convergence
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• v.18 no.1
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• pp.103-109
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• 2020

As part of the sharing economy service, the present study is not only about the positive aspects of O2O services, but also about the consumer ethical perceptions of recent conflicts with existing business and labor markets, trust of platform, and service utility on consumer satisfaction and intention to recommend O2O services. To test hypotheses, data were collected and analyzed for 149 samples, focusing on the car sharing service, an example of the sharing economy service, which is becoming an issue. As a result, the ethical self-identity of the consumer, the trust of the platform, and the service utility, all affected the service satisfaction, whereas only the hedonic utility and trust of the platform had a positive effect on the intention to recommendation. This study is meaningful in that it examines the influence of service utility focusing on ethical consciousness and social perspective of consumers, rather than on the point of consumption such as ethical consumption position and trust of platform based on sharing economy service.