• The Journal of Asian Finance, Economics and Business
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• v.9 no.4
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• pp.315-324
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• 2022

The goal of this study is to understand better the relationship between hospital bed occupancy rate and cost rigidity as a proxy for the degree of hospital bed congestion, as well as the relationship between the risk of changes in hospital bed occupancy rate and congestion cost, targeting public hospitals. As public hospitals for analysis, we selected hospital projects from the Public Enterprises Survey Reports published by the Department of Public Enterprises, Ministry of Finance, and obtained unbalanced panel data consisting of 1,505 hospitals and 15 years, totaling 12,595 hospitals and years. The analysis revealed that the risk of changes in the bed occupancy rate increases the degree of cost rigidity and leads to a decrease in the variable cost ratio; furthermore, an increase in the bed occupancy rate decreases the degree of cost rigidity and leads to an increase in the variable cost ratio. These findings suggest that although public hospitals are taking managerial actions to avoid congestion costs, congestion costs resulting from higher bed occupancy rates have not been eliminated. The regression analysis results show that even if congestion costs arise as the occupancy rate increases, they are covered by the increase in revenue associated with the increase in the occupancy rate.

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.1
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• pp.51-60
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• 2006

When the nature of measuring a performance variable is destructive or very expensive, it is attractive to use a surrogate variable which is highly correlated with the performance variable and less expensive to measure. In this paper, we propose rectifying screening procedures using the performance and surrogate variables. Two screening procedures are considered; a statistically-based screening procedure to reduce the current proportion of nonconforming items to a specified lower value after screening, and an economically-based screening procedure where the screening limit is determined so that the expected cost is minimized. It is assumed that the surrogate variable given the performance variable is normally distributed with known mean and standard deviation. For two screening procedures, methods of finding the optimal solutions are presented and numerical examples are also given.

• Journal of Applied Reliability
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• v.11 no.2
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• pp.187-212
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• 2011

KHP project sets total ownership cost as the target cost by applying CAIV and administrates total ownership cost through compromise analysis, a periodical estimate and management of design alternatives for each development. Based on expected cost results, sensibility of total ownership cost is analyzed complying with the change of reliability, availability, maintainability and other related factors. By considering potential total ownership cost saving methods, first of all, this paper identifies total ownership cost changing effects for each related factor, secondly, suggests total ownership cost and maintenance and operating cost saving methods via finding components that affect total ownership cost and lastly, suggests total ownership cost saving directions that may be applied to other projects in the future.

• Journal of Power Electronics
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• v.12 no.1
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• pp.75-82
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• 2012

Elimination of rotor position sensors mechanically coupled with the rotor shaft is attractive to variable speed drives primarily due to increased system reliability and cost reduction. In this regard, search for a simple and robust position sensorless control has been intensified in past few years specifically for low-cost, high-volume applications such as home appliances. This paper describes a new parameter insensitive position sensorless control for switched reluctance motor (SRM) drives satisfying such a need in this market segment. Two consecutive switch-on times of the controllable switch in hysteresis current control are compared to estimate the rotor position and speed. The proposed sensorless control algorithm is very simple to implement since it does not depend on extensive computation or any additional hardware. In addition, the proposed method is robust in that its dynamic performance is least affected by system parameter variations. The proposed approach is demonstrated on a single-controllable-switch-converter-driven SRM with two-phases that lends itself to a system with low cost and compact packaging which comes close to the intended applications. Analysis and simulation results followed by experimental verification are presented to demonstrate the feasibility of the proposed sensorless control method.

• Health Policy and Management
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• v.18 no.1
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• pp.1-20
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• 2008

How health care providers compete and how competition among them affects their behavior are crucial questions in theory and health policy. In ordinary markets, competition improves social welfare, However in health care markets facing uncertainty and information asymmetry, competition can take the form of wasteful quality competition and result in cost increase. The purpose of this study is to examine the characteristics of hospital service markets and examine the impact of hospital competition on hospital behavior, more specifically hospital cost and the size of personnel. Based on patient discharge data of 2002 by the Ministry of Health and Welfare and Korea Institute for Health and Social Affairs, and health insurance EDI claims data of 2002, this study measures the degree of competition in the inpatient service market of hospitals, using variable radius method and Herfindahl index. The result of the study shows that the hospital service market consists of on average 3.13 government administrative units(shi, gun, or gu). Compared with hospitals, general or general specialized hospitals cover larger markets and operate in more competitive markets. Nearly 60% of patients use hospitals, which are not located in their government administrative units, meaning that market definition based on variable radius is better than the conventional method of market definition based on government administrative units. The results of multivariate analysis show that competition is not associated with high cost index of hospitals. But hospitals in more competitive markets employ larger(more intensive) input of personnel per 100 beds, implying that hospital competition in Korea can have the form of quality and cost-increasing competition.

• Journal of the Korean Statistical Society
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• v.29 no.3
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• pp.319-336
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• 2000

A mixed model with a white noise process and an IMA(0,1,1) process is considered as a process model. It is assumed that the process is a white noise in the absence of a special cause and the process changes to an IMA(0,1,1) due to a special cause. One useful scheme in measuring the process level is to use the variable measurement interval (VMI) between measurement times according to the value of the previous chart statistic. The advantage of the VMI scheme is to measure the process level infrequently when in control to save the measurement cost and to measure frequently when out of control to save the off-target cost. This paper considers the VMI scheme in order to detect changes in the process model from a white noise to an IMA(0,1,1). The VMI scheme is shown to be effective compared to the standard fixed measurement interval (FMI) scheme in both statistical and economic contexts.

• The Journal of Fisheries Business Administration
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• v.39 no.1
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• pp.63-85
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• 2008

The objective of this study is to review the methodology of economic analysis of fishing ports by examining the economical feasibilities of a national fishing port (Jeongja Port) in Ulsan. This study utilized market value evaluation method to measure the benefits and costs related to the development of ports. The benefit variables are income effects resulting from the developments while the cost variables are sum of construction costs and maintenance costs. The income effects are measured in two ways: (1) income from individual project resulting from the developments, (2) the income effects by utilizing investment multipliers. The results shows that the BC ratio (Benefits/Costs) of Jeongja port by using (1) income from individual project resulting from the developments was 1.07 while the BC ratio by using (2) the income effects by utilizing investment multipliers was 1.10 due to a relative short period of useful life for investment multipliers. However, the income variable utilizing investment multipliers is more sensitive to the period of duration than the income variable from individual project.

• Land and Housing Review
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• v.10 no.3
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• pp.9-16
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• 2019

This study aimed at developing control algorithms for operating a variable refrigerant flow (VRF) heating and cooling system with optimal system parameter set-points. Two artificial neural network (ANN) models, which were respectively designed to predict the heating energy cost and cooling energy amount for upcoming next control cycle, was developed and embedded into the control algorithms. Performance of the algorithms were tested using the computer simulation programs - EnergyPlus, BCVTB, MATLAB in an incorporative manner. The results revealed that the proposed control algorithms remarkably saved the heating energy cost by as much as 7.93% and cooling energy consumption by as much as 28.44%, compared to a conventional control strategy. These findings support that the ANN-based predictive control algorithms showed potential for cost- and energy-effectiveness of VRF heating and cooling systems.

• The Transactions of the Korea Information Processing Society
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• v.7 no.11
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• pp.3462-3469
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• 2000

In this paper,new image vector quantization method for improvemtnt computation cost and compression ratio is proposed. A proposed method could saved the cornputatio cost of codebook eneration and encoding using partial codebook search, partial codevector elements, and interuplion criterion. And to improve cornpression ratio of codegook index lossless coding, codebook rearrangement, and variable length coding scheme are used.

• IE interfaces
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• v.2 no.2
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• pp.25-32
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• 1989

We study the joint cost allocation based on the book profit producing power of the output through the A-S price mechanism. We show what part of the A-S book profit is allocated to the joint cost and what part is allocated to the variable total book profit of the short-run book profit function. Also we compare some other classical joint cost allocation methods with this A-S price method.