• Journal of the Korean Operations Research and Management Science Society
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• v.7 no.1
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• pp.51-57
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• 1982

During the course of history, more and more reliable birth control methods have become available. Hence, to a certain degree, the possibility of avoiding any or additional children, and of spacing the family building process has arisen. The advancement of six predetermination technology, whereby couples can influence the sex of their children, gives couples, another decision variable. Assuming a rational acting couple, we present a general decision-theoretic model which describes the family building process and its optimization through maximizing the expected utility concerning the spacing, ordering, sex, and number of their children.

• Journal of Energy Engineering
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• v.8 no.4
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• pp.505-511
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• 1999

One of the major challenges confronting a multiservice electric utility is the establishment of the right prices, for its services. The key objectives of particular pricing schemes are reasonableness of company earnings. Economic efficiency, the responsiveness of supply and of the allocation of sources to the desires of consumers, and maintenance of some degree of competition. This paper proposes a value-based pricing mechanism amenable to the current deregulation situation in electricity market allowing service differentiation. The proposed pricing mechanism can be implemented ina nodal auction model, and can also be applied to direct load control.

• IE interfaces
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• v.18 no.4
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• pp.370-381
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• 2005

This study is concerned with seeking the optimal allocation(disposition) for maximizing utility of consolidating old fashioned and new air defense weapon system like SAM-X(Patriot missile) and developing efficient solution algorithm based on simulated annealing(SA) algorithm. The SED(selection by effectiveness degree) procedure is implemented with an enhanced SA algorithm in which neighboring solutions could be generated only within the optimal feasible region by using a specially designed PERTURB function. Computational results conducted on the problem sets with a variety of size and parameters shows the significant efficiency of our SED algorithm over existing methods in terms of both the computation time and the solution quality.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.195-201
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• 1989

Voltage collapse is a serious concern to the electirc utility industry. It is common to associate steady-state stability with the ability of the transmission system to transport real power and to associate voltage collapse with the inability to provide reactive power at the necessary locations within the system. An algorithm to directly calculate the critical point of system voltage collapse was presented by the authors. The method (based on the ordinary power flow equations and explicit requirement of singularity of the Jacobian matrix) is basically one degree of freedom with proper load distribution factors. This paper suggests a modified algorithm to increase the degree of freedom, introducing the nonlinear programming technique. The objective function is a distance measure between the present operating point and the closest voltage collapse point. Knowledge of the distance and the most vulnarable bus from the voltage collapse point of view may be used as a useful index for the secure system operation.

• Journal of the Korean Operations Research and Management Science Society
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• v.23 no.3
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• pp.63-73
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• 1998

The paper deals with interactive multiple criteria decision making procedure when decision maker (DM) specifies her or his preference in incomplete ways. Usually DM is willing or able to provide only incomplete information, because of time pressure and lack of knowledge or data. Under incomplete information on utility and attribute weight, the pairwise dominance checks result in strict or weak dominance values. Considering only strict dominance values sometimes fails to Prioritize alternatives because of fuzziness of preference information. Further there exists some information loss useful if used, otherwise. In this paper, we consider the outranking concept which implies the willingness of DM's taking some risk under the least favorable situation because she has enough reasons to admit the results. By comparing the magnitude of net preference degree of alternatives which is defined by difference between outrankings and outranked degree of each alternative, we can prioritize alternatives.

• The Journal of Korean Physical Therapy
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• v.14 no.4
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• pp.412-422
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• 2002

The use of biochemical markers of bone turnover may be particular interest in the investigation of bone disorders with osteoporosis. Serum osteocalcin(OC), total alkaline phosphatase and procollagen C, reflecting bone formation, and urinary pyridinium cross-links excretion, reflecting bone reabsorption have been measured in hyperthyroidism, postmenopause women, after testosterone supplementation, androgen, testosterone and estrogen deficiency, bone mineral density degree, age duration. Bone marks which is reflect to metabolic bone disorders are biochemical indices method to measure enzyme activity about bone formation, bone absorption and bone components in blood or urine. Bone metabolism biochemical marks are correlated with osteophorotic agents and also represent significantly different between bone mineral density and bone biochemical marks. Therefore if we develope and use bone metabolism marks which have higher sensitivity and specificity in bone formation and bone absorption, I think that these bone biochemical marks can have utility in the clinical application to predict osteoporosis risk group, bone loss, bone fracture and response degree to treatment of osteoporosis risk groups.

• International Journal of Contents
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• v.9 no.3
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• pp.29-34
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• 2013

This study attempted to compare usability of auditory interfaces, which is a comprehensive concept that includes safety, utility, effectiveness, and efficiency, in personal computing environments: verbal messages (speech sounds), earcons (musical sounds), and auditory icons (natural sounds). This study hypothesized that verbal messages would offer higher usability than earcons and auditory icons, since the verbal messages are easy to interpret and understand based on semiotic process. In this study, usability was measured by a set of seven items: ability to inform what the program is doing, relevance to visual interfaces, degree of stimulation, degree of understandability, perceived time pressure, clearness of sound outputs, and degrees of satisfaction. Through the experimental research, the results showed that verbal messages provided the highest level of usability. On the contrary, auditory icons showed the lowest level of usability, as they require users to establish new coding schemes, and thus demand more mental effort from users.

• Korean Journal of Human Ecology
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• v.14 no.2
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• pp.277-292
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• 2005

The objectives of this study are to examine the degree of propensity for symbolic consumption among adolescents and its factors, and to investigate the effects of demographic variables - sex, grade, father's education, mother's education, father's job, mother's job, monthly allowance, monthly household income - self-esteem, and socialization agents variables - parents, friends, mass media - on the propensity. In this study, the propensity for symbolic consumption is defined as the propensity to consume products through their affective, subjective, and symbolic value rather than through their practical and utility value. The data used in this study were collected from 509 adolescents who are in the 2nd grade of middle or high schools in Pusan. The research results can be summarized as follows: 1. The propensity for symbolic consumption were found to have significant differences according to sex, father's education, mother's education, mother's job, and monthly allowance. 2. It differs significantly according to adolescents' self-esteem. That is, the lower self-esteem adolescents have, the higher propensity for symbolic consumption they show. 3. It also differs significantly according to the degree of communication with parents, the degree of accepting friends' view, the degree of communication with friends, the degree of informative influence from friends, and the degree of taking in mass media.

• Korean Journal of Child Studies
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• v.13 no.2
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• pp.203-216
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• 1992

The purpose of this study was to investigate the utility of the Luria-Nebraska Battery-Children's Revision (LNNB-CR) in the clinical situation in Korea: LNNB-CR was applied clinically in order to examine how well it differentiates brain damaged children from normals. Subjects were 30 children with the average age of 10 years. Among them 15 were diagnosed as the 'brain damaged' group, and the remaining 15 were normal. All subjects of the two groups were tested on all items in accordance with LNNB-CR manual. Data were analyzed by percentage, correlation coefficient, and t-test. The results were (1) the degree of consistency between testers averaged 97.2％ which confirmed the stability of the scoring system. (2) Split-half reliability was ranged from .75 on the Tactile Scale (C3) to .95 on the Memory Scale (C10). Thus, consistency of items within the scales appeared high. (3) Internal consistency reliability ranged from .74 on the Visual Scale (C4) to .98 on the Reading Scale (C9). Thus, the homogenity of items within the scales appeared high. (4) In the diagnostic discriminative power test between the two groups, both individual scales and total scores showed significant differences at the level of p<.001. (5) The discriminative power test between two groups on all items showed significant differences at the level of p<.05 or better in 126(85％) out of 149 items. These results are supportive of the diagnostic utility of the application of LNNB-CR to the clinical situation in Korea. However, extensive additional research is needed in order to prove its worth.

• Korean System Dynamics Review
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• v.5 no.1
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• pp.49-71
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• 2004

Demand-side Management can be defined as'any utility activity aimed at modifying customers' use of energy to produce desired changes in the utility's load shape'. Customers benefit by being able to control energy costs and improve quality of life and become more productive. Utilities benefit from DSM's value as a resource that enhances asset utilization and reduces both fuel costs and environmental emissions. The scope of DSM includes load management through rate schedules and conservation by improving energy effciency and using electricity consumption effectively. This paper study the DSM resource evaluation and customer behavior analysis todesign the DSM Program plan in response to customer needs. We develop basic system dynamics model to analysis the customer behavior based on a survey research. The DSM Program participants in the Hi- efficiency Inverter, Electric motor and efficient lighting applicancies operating by Conservation program 2002 become the survey objects. DSM resource evaluation evaluate firstt the distribution potentialities of each machine and then forecast the degree of diffusion. We apply the system dynamic approach to simulate the dynamic DSM market situation at the domestic beginning. This model will give the energy Planner the opportunity to create different scenarios for DSM program planning. Also it will lead to increased understanding of the dynamic DSM market