• Journal of Institute of Control, Robotics and Systems
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• v.9 no.5
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• pp.407-412
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• 2003

An effective methodology is .reported for determining the optimal capacity (lot-size) of batch processing and storage networks which include material recycle or reprocessing streams. We assume that any given storage unit can store one material type which can be purchased from suppliers, be internally produced, internally consumed and/or sold to customers. We further assume that a storage unit is connected to all processing stages that use or produce the material to which that storage unit is dedicated. Each processing stage transforms a set of feedstock materials or intermediates into a set of products with constant conversion factors. The objective for optimization is to minimize the total cost composed of raw material procurement, setup and inventory holding costs as well as the capital costs of processing stages and storage units. A novel production and inventory analysis formulation, the PSW(Periodic Square Wave) model, provides useful expressions for the upper/lower bounds and average level of the storage inventory hold-up. The expressions for the Kuhn-Tucker conditions of the optimization problem can be reduced to two subproblems. The first yields analytical solutions for determining batch sizes while the second is a separable concave minimization network flow subproblem whose solution yields the average material flow rates through the networks. For the special case in which the number of storage is equal to the number of process stages and raw materials storage units, a complete analytical solution for average flow rates can be derived. The analytical solution for the multistage, strictly sequential batch-storage network case can also be obtained via this approach. The principal contribution of this study is thus the generalization and the extension to non-sequential networks with recycle streams. An illustrative example is presented to demonstrate the results obtainable using this approach.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1859-1864
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• 2004

An effective methodology is reported for the optimal design of multisite batch production/transportation and storage networks under uncertain demand forecasting. We assume that any given storage unit can store one material type which can be purchased from suppliers, internally produced, internally consumed, transported to or from other plant sites and/or sold to customers. We further assume that a storage unit is connected to all processing and transportation stages that consume/produce or move the material to which that storage unit is dedicated. Each processing stage transforms a set of feedstock materials or intermediates into a set of products with constant conversion factors. A batch transportation process can transfer one material or multiple materials at once between plant sites. The objective for optimization is to minimize the probability averaged total cost composed of raw material procurement, processing setup, transportation setup and inventory holding costs as well as the capital costs of processing stages and storage units. A novel production and inventory analysis formulation, the PSW(Periodic Square Wave) model, provides useful expressions for the upper/lower bounds and average level of the storage inventory. The expressions for the Kuhn-Tucker conditions of the optimization problem can be reduced to two sub-problems. The first yields analytical solutions for determining lot sizes while the second is a separable concave minimization network flow subproblem whose solution yields the average material flow rates through the networks for the given demand forecast scenario. The result of this study will contribute to the optimal design and operation of large-scale supply chain system.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.6
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• pp.537-544
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• 2004

An effective methodology is reported for determining the optimal lot size of batch processing and storage networks which include uncertain demand forecasting. We assume that any given storage unit can store one material type which can be purchased from suppliers, internally produced, infernally consumed, transported to or from other sites and/or sold to customers. We further assume that a storage unit is connected to all processing and transportation stages that consume/produce or move the material to which that storage unit is dedicated. Each processing stage transforms a set of feedstock materials or intermediates into a set of products with constant conversion factors. A batch transportation process can transfer one material or multiple materials at once between sites. The objective for optimization is to minimize the probability averaged total cost composed of raw material procurement, processing setup, transportation setup and inventory holding costs as well as the capital costs of processing stages and storage units. A novel production and inventory analysis formulation, the PSW(Periodic Square Wave) model, provides useful expressions for the upper/lower bounds and average level of the storage inventory. The expressions for the Kuhn-Tucker conditions of the optimization problem can be reduced to two sub-problems. The first yields analytical solutions for determining lot sires while the second is a separable concave minimization network flow subproblem whose solution yields the average material flow rates through the networks for the given demand forecast scenario. The result of this study will contribute to the optimal design and operation of the global supply chain.

• Korean Journal of Health Education and Promotion
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• v.6 no.2
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• pp.23-39
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• 1989

There have been a lot of considerable. discussion and debate surrounding the management model in the health insurance management system and opinions regarding the management operating cost. It is a well known fact that there have always been dissenting opinions and debates surrounding the issue. The management operating cost varies according to the scale of the management organization and component members characteristics of the insurance carrier. Therefore, it is necessary to examine and compare the management operating cost to the simulated management models developed to cover those eligible for the health insurance scheme in this country. Since the management operating cost can vary according to the different models of management, four alternative management models have been established based on the critical evaluation of existing theories concerned, as well as on the basis of the survey results and simulation attempts. The first alternative model is the Unique Insurance Carrier Model(Ⅰ) ; desigened to cover all of the people with no classification of insurance qualifications and finances from the source of contribution of the insured, nationwide. The second is the Management Model of Large-scale District Insurance Carrier(Ⅱ) ; this means the Korean society would be divided into 21 large districts; each having its own insurance carrier that would cover the people in that particular district with no classification of insurance qualifications arid finances as in Model I. The third is the Management Model of Insurance Carrier Divided by Area and Classified with Occupation if Largescale (Ⅲ) ; to serve the self-employed in the 21 districts divided as in Model Ⅱ. It would serve the employees and their dependents by separate insurance carriers in large-scale similar to the area of the district-scale for the self-employed, so that the insurance qualifications and finances would be classified with each of the insurance carriers: The last is the Management Model of the Multi - insurance Carrier (Ⅳ) based on the Si. Gun. Gu area which will cover their own self- employed people in the area with more than 150 additional insurance carriers covering the employees and their dependents. The manpower necessary to provide services to all of the people according to the four models is calculated through simulation trials. It indicates that the Management Model of Large-scale District Insurance Carrier requires the most manpower among the four alternative models. The unit management operating costs per the insured individuals and covered persons are leveled with several intervals based on the insurance recipients. in their characteristics. The interval levels derived from the regression analysis reveal that the larger the scale of the insurance carriers is in the number of those insured and covered. the more the unit management operating cost decreases. significantly. Moreover. the result of the quadratic functional formula also shows the U-shape significantly. The management operating costs derived from the simulated calculation. on the basis of the average salary and related cost per staff- member of the Health Insurance Societies for Occupational Labours and Korean Medical Insurance Corporation for the Official Servants and Private School Teachers in 1987 fiscal year. show that the Model of Multi-insurance Carrier warrants the highest management operating cost. Meanwhile the least expensive management operating cost is the Management Model of Unique Insurance Carrier. Insurance Carrier Divided by Area and Classified with Occupation in Large-scale. and Large-scale District Insurance Carrier. in order. Therefore. it is feasible to select the Unique Insurance Carrier Model among the four alternatives from the viewpoint of the management operating cost and in the sense of the flexibility in promoting the productivity of manpower in the human services field. However. the choice of the management model for health insurance systems and its application should be examined further utilizing the operation research analysis for such areas as the administrative efficiency and factors related to computer cost etc.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.130-137
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• 2017

To maintain traffic safety during the target lifetime of bridges, it is essential to secure an appropriate maintenance budget and allocate that budget appropriately. This paper proposes a reasonable budget allocation system that considers various impact factors to improve the conventional budget allocation method simply considering the bridge scale. The maintenance action rate model and the unit cost model based on the prior maintenance history were developed to allocate appropriately the bridge maintenance budget for the total bridges of the management organization with the target management level. A method to determine the optimal budget allocation ratio for each management subject was proposed and case analysis was conducted using the proposed model. Proper budget allocation was made considering the bridge types, current safety level, and service life as well as the bridge size as an impact factor of the budget allocation of the bridge. The developed method can prevent budget waste and provide a rational basis for budget allocation by implementing the rational budget distribution.

• Applied Chemistry for Engineering
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• v.29 no.2
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• pp.209-214
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• 2018

In this paper, the techno-economic analysis of glycerol steam reforming for $H_2$ production capacity of $300m^3\;h^{-1}$ was carried out. The process of glycerol steam reforming was constructed by using Aspen $HYSYS^{(R)}$, a commercial process simulator, and parametric studies for the effect of the operating temperature on $H_2$ production was performed. Moreover, the economic analysis was conducted through an itemized cost estimation, sensitivity analysis (SA) and cash flow diagram (CFD), and the unit $H_2$ production cost was 5.10 $ ${kgH_2}^{-1}$ through the itemized cost estimation of glycerol steam reforming for $H_2$ production capacity of $300m^3\;h^{-1}$. SA was employed to identify key economic factors and various economic indicators such as net present value (NPV), discounted payback period (DPBP), and present value ratio (PVR) were found according to $H_2$ selling price using CFD.

• Applied Chemistry for Engineering
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• v.29 no.5
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• pp.589-593
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• 2018

In this paper, an economic evaluation with the uncertainty analysis using a Monte-Carlo simulation method was performed for the glycerol steam reforming to produce $H_2$ at a capacity of $300m^3h^{-1}$. Fluctuations in a unit $H_2$ production cost were identified based on the variation of key economic factors at ${\pm}10-{\pm}40%$ and the probability of 30.9% was obtained for a previously reported unit $H_2$ production cost of 5.10 $ $kgH{_2}^{-1}$. In addition, fluctuations in the B/C ratio were obtained by varying the fixed capital investment (${\pm}20%$), cost of manufacturing (${\pm}20%$), revenue (${\pm}20%$), and discount rate (2-10%) and the probability ranging from 17 to 55% was observed to meet a minimum B/C ratio of 1 for the economic feasibility of the glycerol steam reforming to produce $H_2$.

• Korean Journal of Construction Engineering and Management
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• v.15 no.6
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• pp.63-70
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• 2014

Deconstruction of the building must be applied firstly in order to improve recycling and reuse of construction wastes. In this study have done a case study for deconstruction of an apartment. All construction waste(CW) which will be generated during deconstruction was examined in each part of the building. Because drawing did not exist in most of the old building, we drew up floor plans of buildings. After analyzing these drawings, estimated quantities of CW. It was measured working time of labor and equipments for deconstruction and general demolition on each building of the apartment. In addition, it was proposed in the volume and weight per unit after analyzing detailed measurement of CW which was generated in the process of deconstruction and traditional demolition. It suggested recovery rate at a site, volume and weight conversion factors, and waste basic unit per area that based on the results of comparative analysis on the amount of CW which is calculated from drawing and generated at a site. These factors will be used fundamental materials for estimating quantities and treatment cost of CW, and scheduling of works.

• Journal of Wetlands Research
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• v.19 no.2
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• pp.240-245
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• 2017

In this study, we developed a method to assess quantitatively the amount and the economic value of water quality regulating service of ecosystem services. Numbers of species and aquatic organisms such as fish increased because of the improved water, but it was due to complex factors such as water quality regulation services of ecosystems, installation of environmental facilities for water quality treatment, and water quality regulation. Therefore we sought ways to quantitatively estimate the value of ecosystem regulation services. In this study, we propose a method to estimate the quantitative value of water quality regulation service of ecosystem by utilizing the total amount of water pollution. In addition, the economic value evaluation method was proposed by multiplying the estimated the quantitative value of water quality regulation service of ecosystem by the unit cost per unit capacity. Finally, the ecosystem water quality regulation service was estimated by using the evaluation method for BOD and T-P in Nakdong river watershed.

• Health Policy and Management
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• v.8 no.2
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• pp.58-75
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• 1998

The hospital is characterized by it's remarkable labor industry and human resources input by unit. Recently, the administrative personnel are recognized as important staff to provide a hospital guidance to consumer and also easiness for consumer's visit to hospital. The objectives of this study is to find the performance of the administrative personnel in hospitals. The unit of analysis is the hospitals and data was collected form 144 staffs in 5 hospitals. Self administered questionnaire was given to analyze the general characteristics of staft such as age, sex, education, experience, and performance level in terms of frequency, ability, necessity of tasks. The major findings are as follows: 1. The 5 major tasks such as general affairs, insurance related affairs, hospital statistics, admission/discharge, and analysis of treatment cost were analyzed. Performance level of these tasks were not showed consistent level. It means that the same task was showed both high level performance and low level one. 2. The higher rates of performance level, ability and necessity were found, below 29 years of age, junior college graduates and university hospital than that of general one. 3. Factors mostly affected to performances were found as characteristics of hospital, age and education. 4. Concerning the various manpower management, On the job training, incentive mechanism and colose relationship among units were somewhat lack. In conclusion, most responded administrative personnel have performed actively in dealing with their tasks. however, the performance level and ability of the same task were showed differently, it means that such routine works were not standardized. Therefore, standardization and specification of tasks should be developed to strength the performance. Finally, this study is the first attempt to find out the performance of the administrative staffs and the study results imply that further study could be neeed to promote the performance of administrative personnel efficiently and effectively.