• Journal of the Korean Statistical Society
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• v.22 no.2
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• pp.235-247
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• 1993

The predictive density function of a potential future observation and its first four moments are obtained in this paper to study the effects of a non-normal prior of the unknown mean of a normal population. The derived predictive density function is modified to study changes in utility curves, used to choose the optimum treatment from a given set of treatments, at a given level of stimulus due to slight deviations from normality of the prior distribution. Numerical illustrations are provided to exhibit some effectsl.

• Industrial Engineering and Management Systems
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• v.12 no.1
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• pp.36-40
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• 2013

The paper discusses the problem of how to allocate the fund to a large number of individuals in a higher school so as to bring a higher utility return based on the theory of uncertain set. Suppose that experts can assign each invested individual a corresponding nondecreasing membership function on a close interval I according to its actual level and developmental foreground. The membership degree at the fund $x{\in}I$ is called utility degree from fund x, and product (minimum) of utility degrees of distributed funds for all invested individuals is called united utility degree from the fund. Based on the above concepts, we present an uncertain optimization model, called Maximal United Utility Degree (or Maximal Membership Degree) model for fund distribution. Furthermore, we use nondecreasing polygonal functions defined on close intervals to structure a mathematical maximal united utility degree model. Finally, we design a genetic algorithm to solve these models.

• Journal of Energy Engineering
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• v.8 no.1
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• pp.76-84
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• 1999

The demand of Small Self-generating System (SSS) including Small Cogeneration System (SCS) is constantly increasing with the need of electricity and/or thermal in office, hospital, hotel, and small factory, etc. It is especially recommended to operate SCS in the heat-following mode to maximize the efficiency of generator. In case of the heat-following mode SCS has got to be connected to distribution system so as to send surplus power to the utility or receive the short power from utility. But the interconnection of SSS with distribution system causes a few problems such as the bad power quality, and low security. If SSS is not promptly disconnected after faults occur (Islanding of SSS), it can not only damage equipment of utility and adjacent customers but also endanger life of human due to overvoltage or overcurrent. In this paper it has been deeply discussed if interconnection of engine self-generator/control system satisfies the protective requirement for SSS or not. 500 kW engine generator running in the Jodo island has been used to perform the analysis of interconnection.

• Journal of Electrical Engineering and Technology
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• v.8 no.4
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• pp.737-743
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• 2013

The small-scaled onsite generators such as photovoltaic power, wind power, biomass and fuel cell belong to decarbonization techniques. In general, these generators tend to be connected to utility systems, and they are called distributed generations (DGs) compared with conventional centralized power plants. However, DGs may impact on stabilization of utility systems, which gets utility into trouble. In order to reduce utility's burdens (e.g., investment for facilities reinforcement) and accelerate DG introduction, the advanced operation algorithms under the existing utility systems are urgently needed. This paper presents the advanced voltage regulation method in power systems since the sending voltage of voltage regulators has been played a decisive role restricting maximum installable DG capacity (MaxC_DG). For the proposed voltage regulation method, the difference from existing voltage regulation method is explained and the detailed concept is introduced in this paper. MaxC_DG estimation through case studies based on Korean model network verifies the superiority of the proposed method.

• KIEE International Transactions on Power Engineering
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• v.2A no.4
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• pp.166-173
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• 2002

Dispersed Generation (DG) units significantly effect the existing distribution protection practices. Therefore, new protection practices of the distribution system interconnected with DG units should be reevaluated and developed. In this paper, a new inter-tie protection scheme of DG units for distribution automatic reclosing is proposed. The impact of DG units on existing radial-sectionaliser coordination is analyzed. And the effects of the distribution reclosing type (radial and passive reclosing) on DG dynamics are analyzed and classified. From the results of the DG dynamic responses by the reclosing type, i.e. radial and passive reclosing, the inter-tie protection schemes of DG are introduced to improve the reliability and availability of utility interactive DG. The proposed schemes are proved and evaluated by a case study using PSCAD/EMTDC simulation.

• The Journal of Industrial Distribution & Business
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• v.10 no.2
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• pp.39-49
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• 2019

Purpose - Customer loyalty and citizenship behavior are key success factors of franchise system. They make the management of franchisee more effective and efficient. Prior studies, however, mainly dealt with only acquisition utility of customer, such as perceived product/service quality and brand reputation to explain customer loyalty and citizenship behavior, which explains only on one side. We tried to investigate the effect of exchange utility of customer, such as relationship strength and psychological obligation together with the acquisition utility. In addition, we tried to investigate the relationship between customer loyalty and citizenship behavior in franchise context. Research design, data, and methodology - This study used data collected from the dining franchisee managers of 342 franchisors in South Korea. The franchisors consist of more than ten franchisees, the majority of which participated directly in the transaction with franchisor and have worked for more than six months. To test the hypotheses, the study used structural equation model analysis. Results - H1-1, 1-2, 1-3 predicted that acquisition utility would increase customer loyalty to franchisee. In support of H1-1, 1-2, 1-3, the results indicated that acquisition utilities such as perceived product value, perceived service value, and franchise brand reputation had positive effects on customer loyalty. H2-1, 2-2 predicted that exchange utility would increase customer loyalty to franchisee. In support of H2-2, the result indicated that psychological obligation had positive effects on customer loyalty like other acquisition utilities. However, H2-1 was not supported. Relationship strength had no significant effect on customer loyalty. H3 predicted that customer loyalty would increase customer citizenship behavior. In support of H3, the results indicated that customer loyalty had positive effect on customer citizenship behavior. Overall, the evidences generally supported the hypotheses. Conclusion - The results of the study show that not only acquisition utility but also exchange utility increases customer loyalty to franchisee and also show that customer loyalty increases customer citizenship behavior. Interestingly, however, relationship strength has no significant effect on customer loyalty. These results have two implications. The one is that increasing exchange utility can improve customer loyalty as acquisition utility can. The other one is that both of customer utilities can improve customer citizenship via customer loyalty.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.147-155
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• 2008

The economics of most chemical plants are heavily dependent upon the management of the utilities used in the plants. The utilities are supplied by the centralized utility system of the plant. Among the various utilities the steam is by far the most important energy source and the management of the electricity and the process water are greatly affected by the steam. Therefore it is necessary to educate students and new employees the basic concepts about the effective distribution of the utilities and the fundamental strategies to apply the concepts in actual plant operations. The OOUS (Optimal Operation of Utility System) is an GUI educational system designed to educate the effective generation of the steam and the optimal steam distribution schemes within short period. The OOUS deals with various utility equipments and processes and shows how to save operation costs by displaying the optimal operation conditions based on the process models and the operational knowledgebase.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.10-12
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• 2001

This paper presents a study of transient overvoltages caused by capacitor switching on the utility distribution system. Capacitor banks used for power factor correction and voltage regulation can improve efficiency of the power system. But transient voltages due to capacitor switching on the utility system affect the sensitive customer load equipments. If Distributed Generation System (DGS) is involved in the system, the problems become more serious. In this paper, effect of transient voltages at the customer load created by utility capacitor switching is analyzed by simulations Solutions to this problem are presented.

• 한국전산유체공학회:학술대회논문집
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• 2003.10a
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• pp.225-226
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• 2003

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1088-1090
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• 1998

The cogeneration facilities (COGN) into the power distribution system can cause operational problems - reenergization of distribution feeders under repair by utility personnel, voltage variation and regulation because of output power of COGN, and lost of coordination at emergency state - on an electrical utility system. This paper deals with momentary voltage dips as the parallel interconnection operation of COGN in the power distribution system. PSCAD/EMTDC simulation tool is used to show the behavior of momentary voltage dips. In addition, restraint solution for momentary voltage variation is presented.