• Journal of the Korean Operations Research and Management Science Society
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• v.29 no.3
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• pp.79-98
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• 2004

Despite its contribution to the Korean medical service industry the question of how efficiently the Korean public hospitals have operated has been unresolved. This study gauges and analyzes the overall efficiency and the Malmquist productivity index in the industry over the period 1992 through 2001. In addition to cost efficiency. we also measure technical, allocative, pure technical and scale efficiencies. Furthermore. the Malmquist index is decomposed into efficiency and frontier changes. We identify several important factors which seem to have strong relationship with various inefficiency estimates. The results indicate that on average the public hospitals has wasted a significant amount of resources and costs over the period. Unlike many other industries, the low level of cost efficiency of the public hospital industry is mainly due to allocative inefficiency rather than technical inefficiency. The Maimquist productivity indices seem both due to the frontier change and efficiency change, but with more effect by the former. The results also indicate that the turnover of hospital beds has played an important role in determining efficiency and productivity of this important industry.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.9C
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• pp.877-886
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• 2005

Various frame recovery algorithms have been suggested to overcome the communication quality degradation problem due to Internet-typical impairments on Voice over IP(VoIP) communications. In this paper, we propose a new receiver-based recovery method which is able to enhance recovered speech quality with almost free computational cost and without an additional increment of delay and bandwidth consumption. Most conventional recovery algorithms try to recover the lost or erroneous speech frames by reconstructing missing coefficients or speech signal during speech decoding process. Thus they eventually need to modify the decoder software. The proposed frame recovery algorithm tries to reconstruct the missing frame itself, and does not require the computational burden of modifying the decoder. In the proposed scheme, the Vector Quantization(VQ) codebook indices of the erased frame are directly estimated by referring the pre-computed VQ Codebook Index Interpolation Tables(VCIIT) using the VQ indices from the adjacent(previous and next) frames. We applied the proposed scheme to the ITU-T G.723.1 speech coder and found that it improved reconstructed speech quality and outperforms conventional G.723.1 loss recovery algorithm. Moreover, the suggested simple scheme can be easily applicable to practical VoIP systems because it requires a very small amount of additional computational cost and memory space.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.8
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• pp.779-791
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• 1990

This paper presents a knowledge based system to solve reactive power/voltage control problem in a power system. A need is recognized for new methods to alleviate a bus voltage limit violation more quickly when a power system becomes an emergency state due to contingency. To cope with this object, a set of indices concept which is used to make bus order list of reactive power injection priority is introduced. A set of indices, based on the overall system conditions, consists of steady state stability index, reactive power transmittance indes, voltage severity index and generator fuel cost index. This scheme and empirical rules of the knowledge on the basis of the human expert result in fast decision-making of the reactive power compensation devices since only the amount of devices is determined by the inference in the knowledge based system when the voltage violation is detected. In this approach, control devices such as shunt capacitor (reactor), transformer tap settings and generator voltages are utilized. Also the developed system herein can be used to minimize control action taken or generator fuel cost according to the user's option on the weighting factor. The results of a case study are also presented.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.6
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• pp.667-683
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• 2015

Since aged water treatment facilities could threaten the sustainable water supply, asset management system has been adopted for their systematic management. Level of Service(LoS) is one of critical components of asset management and could be quantified through benchmark index(BMI). Water supplier could estimate consumer's satisfaction and their performance through BMI to improve the LoS. We developed BMI for water treatment facilities from customer's satisfaction survey. BMI, represented with the Total Service Score(TSS), was assessed with water quality, water pressure, taste and odor, water rate, and service quality with weighing factors. BMI could, further, be used to assist the analysis of the life cycle cost to increase the unit of LoS.

• Women's Health Nursing
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• v.17 no.4
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• pp.328-336
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• 2011

Purpose: The purpose of this study is to develop the optimal nursing fee for nurse-midwifery center (MC) in the national health insurance system. Methods: The three methodologies used to calculate the conversion factors for the MCs in the national health insurance include cost accounting method, sustainable growth rate (SGR) model, and index model. In this study, the macro-economic indicators and the national statistics were used to estimate the conversion factors for the MCs. Results: The optimal nursing fee for the MCs in 2011 was estimated to be an increase of 57.7% by cost accounting analysis, a decrease of 17.1% by SGR model, and a decrease of 16.1% by index model. The results from SGR model and index model could had been biased due to the upswing of medical spendings in the short-term period (2008~2009). A sensitivity analysis of pre-delivery subsidy program for OB & GYN hospitals and clinics showed that the program has substantially diminished the demand for the MC services. Conclusion: More reliable methodologies to estimate nursing fees precisely are required to prove the value of nurses' services and a government subsidy program for the MC services should be followed from a social perspective.

• Journal of Society of Preventive Korean Medicine
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• v.12 no.3
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• pp.21-34
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• 2008

Objectives : This paper analysed the alternative methods of calculating conversion factor for oriental medicine in the National Health Insurance and estimated the conversion factor(reimbursing price level) of the oriental medical services, based on health insurance claims data and macro economic data. Methods : Comparing cost accounting method, SGR model, and index model to estimate conversion factor in the national health insurance, six empirical models were derived depending on the scope of revenue considered in financial indicators. Classifications of data and sources used in the analysis were identified as officially released by the government. Results and Conclusion : Cost accounting analysis and SGR model showed a two digit decrease in the physician fee schedule of oriental medical services in the national health insurance, while index model indicated a positive increase in the fee reimbursed. As expected, SGR model measured an overall trend of health expenditures rather than an individual financial status of medical institutions, and index model properly estimated the level of payments to oriental medical doctors. Upon a declining share of health expenditures on oriental medicine, a global budget system fixed to a flat rate of total budget could be an opportunity as well as a challenge.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.4 s.175
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• pp.811-823
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• 2000

In design and manufacturing airframe structures which are composed of a lot of sub-assemblies and large complex profile shapes it is difficult to reduce so called hardware variations. Accordingly cost increasing factors for manufacturing airframe parts are much more than other machine parts because of the variability of fabricated details and assemlies. To improve cost and quality, accurate assembly methods and DPD techniques are proposed in this paper which are based upon using CAD/CAM techniques, the concept of KC's and the coordinated datum and index throughout the design, tooling, manufacturing and inspection. The proposed methods are applied to produce fuselage frame assemblies and related engineering aspects are described regarding the design of parts and tools in the context of concurrent digital definition. First articles and consequent mass production of frame assemblies shows a great improvement of the process capability ratio from 0.7 by the past processes to 1.0 by the proposed methods in addition to the cost reduction due to the less number of tools, reduced total assembly times and the space compaction needed by massive inventory. The need to achieve better Cpk, however, and future studies to be investigated will be addressed briefly.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.3
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• pp.251-261
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• 2004

Recently, the corrosion and aging of bridge structures are of great concern impractical The uncertainties of the corroded reinforced bars in concrete influence not only the safety of the bridge structures, but also the flexural strength of reinforced concrete members. This paper considers these uncertainties by providing a reliability-based framework and show that the identification of the optimum maintenance scenario is a straightforward process. This is achieved by using a computer pro망am for Life Cycle Cost Analysis of Deteriorating Structures (LCCADS). This program can consider the effects of various types of actions on the reliability index profile of a deteriorating structures.

• Proceedings of the KIEE Conference
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• 2005.07e
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• pp.37-39
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• 2005

When we have been estimated construction costs, till now, we are used to costs accumulating method of each items based on standard labors rates. But there are some problems of its methods. Our governments are applied to a historical construction costs estimation system for building construction and civil engineering works from January 2004. The electrical construction works are forecasted that applied to historical construction cost estimation systems. This paper is showed to development of electrical construction cost index for estimation of historical costs and contract prices.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.2189-2196
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• 2016

This paper proposes a new finite control set-model predictive control (FCS-MPC) method for induction motors. In the method, the reference state that satisfies the given torque and rotor flux requirements is derived. Cost indices for the FCS-MPC are defined using the state tracking error, and a linear matrix inequality is formulated to obtain a proper weighting matrix for the state tracking error. The on-line procedure of the proposed FCS-MPC comprises of two steps: select the output voltage vector of the two level inverter minimizing the cost index and compute the optimal modulation factor of the minimizing output voltage vector in order to reduce the state tracking error and torque ripple. The steady state tracking error is removed by using an integrator to adjust the reference state. The simulation and experimental results demonstrated that the proposed FCS-MPC shows good torque, rotor flux control performances at different rotating speeds.