• Fire Science and Engineering
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• v.16 no.1
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• pp.66-76
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• 2002

This paper includes new nozzle design, basic design factors of water mist system that minimize a thermal damage of cable causing business interruption and applying underground utility tunnel. A underground concrete structure (2.5 m(H)$\times$2.5 m(W)$\times$25 m(D)) is constructed in order to test a nozzle performance. Under the designing fire scenario, critical thermal damage of cable sheath ($400^{\circ}c$) reached within a 2 minutes with unsuppressed fire, but type 1 nozzle (SMD 470 $\mu{m}$) and type 2 nozzle (SMD 650 $\mu{m}$) control cable temperature below $400^{\circ}c$. A system performance and fundamental design factors; K factor, flow rate, spray angle, size distribution, nozzle pressure, spray density are analyzed and proposed for system optimization.

• Journal of the Korean Society of Costume
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• v.28
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• pp.137-150
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• 1996

The objectives of this study were to classify daily clothing selection motives and to group men into life style types and to examine the differences in daily clothing selection motives according to the life style types. Questionnaire comprised of three sections: 36 Likert type items of life style measure; 29 Likert type items of daily clothing selection motives measure: and 4 demographic variables. Samples were 267 salary men in gheir 20's to 30's in Seoul Korea. The data were analyzed using factor analy-sis cluster analysis one-way ANOVA Dun-can's multiple range test and t-test. 1. Five factors of life style were derived by factor analysis ; F. 1 'appearance oriented' f. 2. 'positive activity' F. 3 'economy oriented': F.4 'active-leisure';F. 5 'contemporary' Four types of life style of men were defined by cluster analysis of the five factors: T. 1'posi-tive activity'; T. 2.'economy interest'; T. 3'contemporary' : T 2'economy interest' T.3'contemporary' ; T. 4 'appearance interest' 2. Four factors of daily clothing selection motives were derived by factor analysis: F.1 'clothing harmony'; F.2 'clothing utility'; F.3 'psychological influence'; F.4 'exogenous situ-ation adaptation 3. There were significant differences in daily clothing selection motives according to the life style types. The types of positive activity economy interest and contemporary had 'clothing utility' motive more than appearance interest type. Economy interest type had 'hpsychological influence' motive more than other three types. Economy interest type and appearance interest type had 'exogenous situ-ation adaptation' motive more than other two types 4. 20's and unmarried men had'psychological influence' motive more than 30's and married. Upper class had 'clothing harmony' and 'ex-ogeneous situation adaptation' motives more than middle and low. Men with less education had ' clothing utility' and 'exogenous situation adaptation' motives more than did more edu-cation.

• Journal of Korean Society for Quality Management
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• v.51 no.2
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• pp.171-184
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• 2023

Purpose: First, this paper suggests an alternative approach to find optimal portfolio (stocks, bonds and ESG stocks) under the maximizing utility of investors. Second, we include ESG stocks in our optimal portfolio, and compare improvement of welfares in the case with and without ESG stocks in portfolio. Methods: Our main method of analysis follows Brennan et al(2002), designed under the continuous time framework. We assume that the dynamics of stock price follow the Geometric Brownian Motion (GBM) while the short rate have the Vasicek model. For the utility function of investors, we use the Power Utility Function, which commonly used in financial studies. The optimal portfolio and welfares are derived in the partial equilibrium. The parameters are estimated by using Kalman filter and ordinary least square method. Results: During the overall analysis period, the portfolio including ESG, did not show clear welfare improvement. In 2017, it has slightly exceeded this benchmark 1, showing the possibility of improvement, but the ESG stocks we selected have not strongly shown statistically significant welfare improvement results. This paper showed that the factors affecting optimal asset allocation and welfare improvement were different each other. We also found that the proportion of optimal asset allocation was affected by factors such as asset return, volatility, and inverse correlation between stocks and bonds, similar to traditional financial theory. Conclusion: The portfolio with ESG investment did not show significant results in welfare improvement is due to that 1) the KRX ESG Leaders 150 selected in our study is an index based on ESG integrated scores, which are designed to affect stability rather than profitability. And 2) Korea has a short history of ESG investment. During the limited analysis period, the performance of stock-related assets was inferior to bond assets at the time of the interest rate drop.

• Health Policy and Management
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• v.9 no.3
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• pp.53-69
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• 1999

In this study. we present a modified rational addiction model which incorporates social-psychological factors. This is done through a utility function which includes social-psychological factors as its component. We apply this model to a cigarette consumption function in Korea using the data from the Korean Household Panel Study(KHPS). The results provide relatively strong support for the rational addiction model. However. the impact of social-psychological factors and the short-run and long-run price elasticities are statistically insignificant.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.7
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• pp.1205-1214
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• 1997

The purpose of this study is to positively investigate if the theory of self-monitoring among various individual trait theories would be a theoretical concept which can explain about the differences of clothing behavior under given social situations among Female university students in Korea. For this purpose, the following research problem were set up; 1. Self-monitoring levels and changing differences of self-image as per situation would be reviewed. 2. Self-monitoring levels and changing differences of clothing selection factors as per situation would be reviewed. The results of this study can be summarized as follows; First, as a result of analyzing the differences of situational self-image pursuits within per situation depending on individuals self-monitoring levels, the differences were found significant by. Namely, the adjectives for situational self-image which corresponded to those who had high self-monitoring than low self.monitoring were "womanly", "refined", "sensual", "lively" and "elegant". Second, as a result of analyzing the differences of priority of clothing selection factors within per situation depending on individuals self-monitoring levels, the differences were found significant by. Those who had high self-monitoring level put a higher priority on fashionability, aesthetics and status.symbol of clothing within per situation, while those who had low self-monitoring thought important for economy or utility within per situation.rtant for economy or utility within per situation.

• Asia pacific journal of information systems
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• v.34 no.1
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• pp.1-25
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• 2024

Consumer demand for e-commerce services has skyrocketed due to the introduction of social distancing standards and lockdown measures that countries have taken to combat the pandemic. There has been a notable surge in the popularity of on-demand delivery services, with a significant influx of new users turning to the e-platform for assistance. This research paper tries to identify the enablers of E-commerce Utility and Service Quality and establish a connection using total interpretive structural modelling (TISM). Enablers are the building blocks for providing customers with an enhanced and more consistent service experience contributing to service quality. The enablers and the linkages thus established hold valuable insights for e-commerce marketers, aiding them in effectively reaching their customers, and achieving desired growth outcomes. The TISM- based model and the MICMAC analysis identified two barriers; website design and personalization as the decisive attributes of e-commerce service quality, possessing strong driving power and weak dependence. Furthermore, the factors of reliability, responsiveness, information, and ease of use form the linkage zone, indicating that any action taken on these factors would not only influence other factors but also have a reciprocal effect on them.

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.127-135
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• 2009

Most traffic information that drivers receive while driving are stored in their short-term memory and disappear within a few seconds. Contemporary modeling approaches using a dummy variable can't fully explain this phenomenon. As such, this study proposes to use utility functions of real-time in-vehicle traffic safety information (IVTSI), analyzing its safety impacts based on empirical data from an on-site driving experiment at signalized intersection approach with a limited visibility. For this, a driving stability evaluation model is developed based on driver's driving speed choice, applying an ordered probit model. To estimate the specified utility functions, the model simultaneously accounts for various factors, such as traffic operation, geometry, road environment, and driver's characteristics. The results show three significant facts. First, a normal density function (exponential function) is appropriate to explain the utility of IVTSI proposed under study over time. Second, the IVTSI remains in driver's short-term memory for up to nearly 22 second after provision, decreasing over time. Three, IVTSI provision appears more important than the geometry factor but less than the traffic operation factor.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.3
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• pp.437-447
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• 2017

In current, there has not been the evaluation model for the optimum design of the multi-utility tunnel by considering urban type and size, the function of surrounding road and feasibility analyses with respect to construction method, and arrangement of accommodation facilities inside multi-utility tunnel. Thus, in this study, we developed the evaluation model for the optimum design of the multi-utility tunnel before and after the decision of the multi-utility tunnel installation. In this paper, we have selected the Deming cycle which is used in various fields among several decision methods for optimizing the design. For the purpose of reflecting the various factors in the design of the multi-utility tunnel, 11 higher indicators were set up to lead to more detailed approaches. In addition, based on the "Plan-Do-Check-Action (PDCA)" circulation method, we can realize the installation of the multi-utility tunnel and design more efficiently through the first phase for conception and the second phase for optimization, and develop the program for the evaluation model accordingly.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.52
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• pp.311-322
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• 1999

Major problems involved in an electrical utility expansion planning within a time horizon are how to efficiently deal with objectives considering multiple factors and uncertainty. But justification factors in study these days have considered only quantitative factors except qualitative factors. Therefore, the purpose of this paper is to develop a new model for economic evaluation of nuclear power plants through the scoring model with the quantitative and qualitative factors under uncertainty. The quantitative factors use a levelized generation cost method considering time value of money. Especially, the environmental, risk, and safety factors in this paper have been also explained for the rational economic justification of the qualitative factors under uncertainty. This paper not only proposes a new approach method using the scoring model in evaluating economy of the nuclear power plant in the long term, but also provides the more efficient decision making criterion for nuclear power plants under uncertainty.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1627-1633
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• 2004

Safety and punctuality in the subway are considered as critical factors. This system is composed of many factors like signals, rails, electrical power sources, rolling stocks. The effective inspection should be carried out at all the times for the safety and punctuality. Purpose of the rolling stocks maintenance is to offer the optimum condition of vehicles, and minimize the maintenance expenses. This paper suggests appropriate maintenance period of rolling stocks to enhance the utility efficiency in SMSC.