• Journal of Korean Society for Quality Management
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• v.25 no.1
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• pp.1-16
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• 1997

In this paper, we illustrate how to design screening inspections for minimizing a total quality costs in a multi-stage manufacturing systems. The total quality cost model consists of inspection costs, internal failure costs, external failure costs, and Taguchi's loss function. Although, the use of automatic test equipment such as machnie vision and CMM has greatly increased inspection speed and accuracy, screeing(100% inspection) could be considered only as a short-term method to remove nonconforming items from a population, not for a long-term quality improvement. However, screeing should be used for certain situations such as before costly operations and after unsatisfied operations. This paper ends with an example that demonstrates the usefulness of the model.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.151-158
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• 1998

This paper presents an optimal decision model for minimizing the life-cycle cost of steel box girder bridges. The point is that it takes into account service life process as a whole, and the life-cycle costs include initial (design, testing, and construction) costs, maintenance costs and expected failure costs. The problem is formulated as that of minimization of expected total life-cycle cost with respect to the design variables. The optimal solution identifies those values of the decision variables that result in minimum expected total cost. The performance constraints in the form of flexural failure and shear failure are those specified in the design code. Based on extensive numerical investigations, it may be positively stated that the optimum design of steel box girder bridges based on life-cycle cost approach proposed in this study provides a lot more rational and economical design, and thus the proposed approach will propose the development of new concepts and design methodologies that may have important implications in the next generation performance-based design codes and standards.

• Journal of Korean Institute of Industrial Engineers
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• v.13 no.1
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• pp.1-10
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• 1987

This paper deals with a single-facility multiproduct lot-size model requiring consideration of setup costs. Each product is demanded at the constant rate per unit time in the next particular period. Due to the limitation of the production capacity, some productions of total demand requirement in that period must be pre-produced. The aim of this project is to determine when and how much of each product to make in order to minimize the total setup costs and inventory carrying-costs of all products. Also this paper contains the further realistic treatment of inventory carrying-costs.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.796-802
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• 2014

South Korea is recently under serious situation in supplying electricity with enough power reserve. A single fault of power plant at a peak-load time may lead to a total blackout for whole area connected by a single electric grid and isolated from other grids. Despite of the seriousness of blackout, however, there are scarce studies with ex-ante analysis of the economic costs from blackout. In order to evocate the seriousness, we calculate the economic costs for both industrial and household sectors with using some survey data and statistical methodologies. As a result, total economic costs are 39.23 trillion KRW (35.83 trillion KRW for industrial sector, 3.40 trillion KRW for household sector).

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.65
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• pp.23-30
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• 2001

In this paper, we consider an inventory system in case the toleration to be inventory stortage under the price discount. It has been observed that suppliers suggest a free addition of marketing policy like a price discount. A major reason for a supplier to offering a free addition to a customers is to stimulate the demand and to decrease a total cost. but, If we not adapting to the toleration to be inventory-lacking, we will a burden holding costs in a relation to the holding of inventory. This paper, is a combination of the toleration of inventory shortage and the condition of discount price. The costs are defined as the sum of the ordering, holding, shortage, purchasing and opportunity costs. Based on numerical results, conclusions follow about the total of operation costs the division of the shortage rate of inventory.

• Journal of the Korean Operations Research and Management Science Society
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• v.4 no.1
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• pp.69-77
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• 1979

A single machine stochastic scheduling problem is considered. Associated with each job is its random processing time and random deferral cost. The criterion is to order the jobs so as to minimize the sum of the deferral costs. The expected sum of the deferral costs is theroretically derived under the stochastic situation for each of several scheduling decision rules which are well known for the deterministic environment. It is also shown that certain stochastic problems can be reduced to equivalent deterministic problems. Two examples are illustrated to show the expected total deferral costs.

• Health Policy and Management
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• v.13 no.3
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• pp.129-147
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• 2003

This study is to grasp a trend of profitability classified by characteristics of hospitals and to analyze related factors. Subjects are 145 hospitals which have gotten the standardization audit by Korean Hospital Association during 1998-200l. Profitability was measured in the aspect of operation profit rate with operating margin to gross revenue as proxy variables. Independent variables were classified by general factors (ownership, number of beds, period of establishment, competition), financial factors (liabilities to total assets, current ratio, fixed ratio, total asset turnover, inventories turnover), and factors related to patient treatment (average length of stay, bed occupancy rate, new outpatient ratio, admission ratio of outpatients, number of patients per specialist, personnel costs per adjusted inpatient, administrative costs per adjusted inpatient). Hierarchical multiple regression analysis model was used in this study. As a result of hierarchical multiple regression analyzation of operating margin to gross revenue, adjustive $R^2$ of general factors was relatively more powerful. The factors had significant effect on operating margin to gross revenue were ownership(+), number of beds(+), competition(+), current ratio(+), fixed ratio(+), total asset turnover(+), personnel costs per adjusted inpatient(-).

• International Journal of Contents
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• v.13 no.2
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• pp.14-20
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• 2017

The purpose of this study was to investigate the association of obesity with medical care use and costs according to overall diseases, cerebrovascular diseases (CVD), ischemic heart disease (IHD), hypertension (HTN) and diabetes mellitus (DM). The final sample was a group of persons who were free of diseases mentioned above and were not underweight. Their baseline screening program data and health insurance contribution data were connected with a 7-year medical claim database. The participants were classified according to their baseline BMI into normal, overweight, obese, and severely obese groups. Given the disease type, the total costs of DM showed the largest difference in each obesity group in both males and females. Also, the pharmacy costs for DM were more relevant than any other type of service to the obesity level. Considering the high prevalence of obesity and the relevantly increased medical care use and costs, there is a need for reduction in medical costs through obesity prevention efforts.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.3
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• pp.44-53
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• 2007

Forming central warehouses for a number of stores can save costs in the continuous review inventory model due to economy of scale and information sharing. In this paper, transportation costs are included in this inventory model. Hence, the tradeoff between inventory-related costs and transportation costs is required. The main concern of this paper is to determine the number and location of central warehouses. Transportation costs are dependent on the distance from several central warehouses to each store. Hence, we develop an efficient simulated annealing algorithm using distance-based local search heuristic and merging heuristic to determine the location and the number of central warehouses. The objective of this paper is to minimize total costs such as holding, setup, penalty, and transportation costs. The performance of the proposed approach is tested by using some computational experiments.

• Health Policy and Management
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• v.17 no.3
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• pp.1-25
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• 2007

Relative value scales introduced in 2001 remarkably improved health insurance fee schedule, but current relative value scales have many problems. In the beginning the government intended to introduce 'resource based relative value scales(RBRVSs)' like USA, but political adjustment of RBRVS studied in 19.17 weakened the relationship between relative value scale and resource consumption. So unbalance of health insurance fees are existing till now. Also relative value was not divided to physician work and practice expense, and malpractice fee was not divided separately. To correct the unbalance of current relative value scales, the refinement project of health insurance relative value scales started in 2003. The project team divided relative value scales into three components, which are physician work, practice expense, malpractice fee. Physician work was studied by professional organizations like Korean medical association. To develop the practice expense relative value, project team organized clinical practice expert panels(CPEPs) composed of physicians, nurses, and medical technicians. CPEPs constructed direct expense data like labor costs, material costs, equipment costs about each medical procedures. The practice expense relative values of medical procedures were developed by the allocation of the institution level direct & indirect costs according to CPEPs direct costs. Institution level direct & indirect costs were collected in 21 hospitals, 98 medical clinics, 53 dental clinics, 78 oriental clinics, and 46 pharmacies. The malpractice fee relative values were developed through the survey of malpractice related costs of hospitals, clinics, pharmacies. Putting together three components of relative values in one scale, the final relative values were made. The final relative values were calculated under budget neutrality by medical departments, that is, total relative value score of a department was same before and after the revision. but malpractice fee relative value scores were added to total scores of relative values. So total score of a department was increased by the malpractice fee relative value score of that department This project failed in making 'resource based' relative value scales in the true sense of the word, because the total relative value scores of medical departments were fixed. However the project team constructed the objective basis of relative value scale like physician's work, direct practice expense, malpractice fee. So step by step making process of the basis, the fixation of total scores by the departments will be resolved and the resource based relative value scale will be introduced in true sense.