• Journal of Korean Society of Transportation
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• v.27 no.2
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• pp.157-168
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• 2009

The random utility theory and the multinomial logit model (including a more recent variant--the mixed multinomial logit) derived from it have constituted a back bone for theoretical and empirical analyses of various travel demand features including mode choice. In their empirical applications, however, it is customary to specify random utilities which are linear in modal attributes such as time and cost, and in socio-economic variables. The linearity helps easy derivation of important information such as value of travel time savings by calculating marginal rate of substitution between time and cost. In this paper the author focuses on the very linearity of the random utilities. Taking into account the fact that the mode chooser is also labour supplier, commodity consumer as well as leisure-seeker, the author sets up a maximization model of the traveller, which encompasses various economic activities of the traveller. The author derive from the model the indifference curve defined on the space of modal attributes, time and cost and investigate under what conditions the random utility of the traveller becomes linear. It turns out that there exist the conditions under which the random utility is really linear in modal attributes, but the property does not hold when the traveller has a corner solution on the space of modal attributes, or when the primary utility function of the traveller is directly affected by labour provided and/or the travel time itself. As a corollary of the analysis, a random utility is suggested, approximated up to the second order of the variables involved for empirical studies of the field.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.290-295
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• 1999

This paper describes Trans-less type utility interactive system that is combined with buck/boost chopper applying partial resonant method, which remove Trans, and high efficient PWM inverter. Therefore, it is possible to make it lightweight, to cut down the cost, and to improve its reliability. What the merits of this system are that we con transmit arbitrary power to load and utility regardless of generating voltage magnitude and we can always obtain high factor controlling by equal phase signal with utility.

• Journal of the military operations research society of Korea
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• v.24 no.1
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• pp.98-109
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• 1998

This study develops a maintenance strategy for a reparable 2-unit standby system. The maintenance strategy implies the waiting time to call the repair facility when the unit-1 fails. Almeida and Souza set up the multi-attribute utility function consisting of system availability and repair cost for several maintenance strategies and decide the optimal maintenance strategy that maximize the expected value of the utility function. We decide the optimal maintenance strategy satisfying the following two criteria about the utility function : maximum variance using Almeida and Souza's utility function. It both criteria are not satisfied at the same time for every strategies, the strategy maximizing the lower confidence limit for expected utility function is regarded as an optimal one.

• Journal of the Optical Society of Korea
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• v.12 no.3
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• pp.166-169
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• 2008

The submersion monitoring system based on a reflective side-polished optical fiber submersion sensor with an optical fiber mirror was shown to be an effective alarm system with remote monitoringwhen the drainage capacity of a common utility duct is exceeded due to heavy rainfall. The proposed sensor was connected to an existing installed optical fiber network at a height of 250mm in a common utility duct, and then tested under sample materials(distilled water, river water, sea water, foul water, muddy water, petroleum, edible oil) at a distance of 1km from the sensor for remote sensing. In experiments, the proposed real-time sensor system reduced maintenance cost and improved monitoring efficiency by using a reflection-type side-polished optical fiber submersion sensor efficient for remote monitoring of a common utility duct.

• Journal of the Korea Safety Management & Science
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• v.18 no.1
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• pp.203-208
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• 2016

Bioinformatics service is very new and emerging in market that provides information such as whether or not occurrence of a particular disease through the base of DNA(Deoxyribonucleic Acid) & RNA(Ribo Nucleic Acid) sequence analysis. Recently, interest growing rapidly in utilization of the industrial purpose, but provision of commercialization like pricing and service packaging is not enough to go to market. For go-to-market, firstly refine the services and perform cost calculation of services in cost-plus method then estimate consumer utility by conducting conjoint analysis. Collectively, with cost and consumer utility result, optimal service price can be calculated.

• Korea Journal of Hospital Management
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• v.23 no.4
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• pp.15-25
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• 2018

Purposes: The objectives of this study present the direction of the criteria for the separately reimbursement of therapeutic medical device. Methodology: We summarized experts' opinion using Delphi survey and Analytic Hierarchy Process(AHP). 48 experts were gathered from Medical Insurance Review Nurses Association, medical device industry, academy and association, Medical Device Expert Evaluation Committee. Descriptive statistics, consistency index, content validity ratio were analyzed. Findings: Clinical utility, patient safety, infection control, cost-homogeneity, cost-effectiveness showed high feasibility and importance, but market contribution and functional utility showed low feasibility and importance in a relative sense. The results of functional utility differed between clinical and non-clinical experts. Measurability was low across the whole area. Among the criteria for the separately reimbursement of therapeutic medical device. Patient safety/infection control and clinical utility showed the highest relative importance values, analyzed using AHP. Practical Implications: Patient safety and infection control are needed to be considered as one of Value Assessment Criteria. It is important to find out how to improve the measurability of therapeutic medical device.

• Korean Journal of Clinical Pharmacy
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• v.20 no.3
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• pp.268-277
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• 2010

This study was conducted to analyze the cost-utility of ramosetron monotherapy, trimebutine monotherapy and trimebutine+loperamide combination therapy in male diarrhea-predominant patients with irritable bowel syndrome (IBS) in Korean healthcare setting. We constructed a decision-analytical model to estimate both total costs for each state of health and outcomes such as IBS-symptoms improvement for 3 and 6 months time horizon. Base analysis found that for ramosetron treatment with the price of KW910 for 5 ${\mu}g$ tablet, incremental cost effectiveness ratios (ICERs, cost per quality-adjusted life day) were KW85,000 and KW62,000 for 3 months and 6 months, respectively, compared with trimebutine. But ramosetron was a dominant strategy when compared with trimebutine+loperamide for both 3 months and 6 months. Sensitivity analyses showed robust results for drug acquisition costs till ramosetron price of KW950/tablet. In conclusion, ramosetron was a cost-effective regimen compared with trimebutine or trimebutine+loperamide from the societal perspective.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.5
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• pp.529-540
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• 2014

As sewerage systems have obsolete, as quality and service level standards increase, and as rain characteristics change, the sewerage utility authorities are challenged to develop cost recovery strategies that assure financial sustainability. In this study, we conducted scenario analysis to examine the effect of three alternatives of partial or full sewerage cost recovery in Seoul during 2014-30 periods. It turned out that the alternative 1 is optimal and recommended. According to alternative 1, we had better increase annually sewerage fee by 14.8% until 2020 and thereafter apply only the inflation rate in setting sewerage fee. It would gradually decrease the deficit after 2019. The accumulated deficit of 13 billion Won in 2030 was estimated. We expect that this kind of analysis may provide useful informations to help sewage utility staffs, decision makers, and regulatory authorities understand, develop and implement ultimate full cost recovery strategy for many municipalities.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.2
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• pp.13-25
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• 2022

Purpose : This study compared the cost-effectiveness ratio of physical therapy in health centers and home physical therapy, two physical therapy methods for home-bound stroke patients, and clarified the economic validity regarding the effect of home physical therapy. Methods : To measure and compare the cost and effectiveness of the two physical therapy methods for stroke patients, subjects were recruited based on in-hospital and home physical therapy. Among the entire data collected, 82 and 90 participants were selected for in-hospital and home physical therapy, respectively. To measure costs, regarding both in-hospital and home physical therapy, direct cost and indirect cost for patients, family, medical institutes, and the government were measured. In addition, activities of daily living were measured in both methods to measure their effectiveness. Through collected data, the cost-effectiveness and incremental cost-effectiveness ratios were analyzed. Results : Based on the analysis of cost-effectiveness, home physical therapy showed lower cost-effectiveness than in-hospital physical therapy. Furthermore, the incremental cost-effectiveness ratio also showed a difference, which implied home physical therapy could have high effectiveness compared to cost. Conclusion : Based on these results, home physical therapy could be considered as an alternativeto other methods of physical therapy, for home-bound stroke patients. In addition, the result of thisstudy contribute by providing evidence that home physical therapy offers economic benefits and canbe more effective in treating home-bound patients when policy decisions are made to establish a home physical therapy system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.5 no.7
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• pp.33-42
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• 1982

The standard theory of production treats human and non-human inputs in the same way. Inert Areas Theory drops this assumption. One distinction is obvious. Human capital, the source of human inputs, can not be purchased outright by firms. Usually what is purchased are units of labor time. What is critical is directed effort, at or beyond some level of skill. Direct effort, however, involves choice and motivation, and these are the critical variables left out of the standard theory. Leibenstein introduces the concept of "inert areas" by which he means "a set of effort positions whose associated levels of utility are not equal but in which the action required to go from a lower to a higher utility level involves a utility cost that is not compensated for by the gain in utility." This idea is used when discussing the behavior of firm's management.f firm's management.