• Health Policy and Management
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• v.10 no.4
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• pp.75-98
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• 2000

This study applied Data Envelopment Analysis(DEA) and Ratio Analysis and Regression Analysis to a set of Korean Public Corporation Medical Centers to evaluate their relative human resource efficiencies. The output measure used in this study was based on health insurance system which was used in both in-patient departments and out-patient departments. Inputs included working time of the doctors, nurses, technicians, and managerial department staff. Based on the data provided on the inputs and outputs, the analysis showed 23 of the 34 hospitals to be relatively inefficient. Each hospital with an efficiency rating of less than 1 was considered relatively inefficient. In addition, managerial strategies based on dual variables were constructed to indicate the manner In which inefficient hospitals may be made efficient. A subsequent analysis of t-test revealed that the bed occupancy rate, medical revenue per 100beds, value added revenue per staff, medical revenue per staff were statistically significant. The results of this study suggest the DEA is a promising tool for evaluating relative human resource efficiency in hospitals which have multiple inputs and outputs and where the efficient production function is not specifiable with any precision. But it is considered that efficiency evaluations may be most effective]y accomplished by Incorporating a combination of methodologies such as ratio analysis and regression analysis.

• Health Policy and Management
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• v.25 no.2
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• pp.118-128
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• 2015

Background: We measured productivity changes of regional public hospitals using both global Malmquist productivity index-based on global production possibility set over all the periods-and the traditional Malmquist productivity index and analyzed the factors of productivity change. Methods: The data used in this study is two annual inputs and two annual outputs of 32 regional public hospitals in Korea from 2005 to 2009 and the results such as distances and Malmquist productivity index and global Malmquist productivity index are obtained by an R program written for this study. Results: The results can be summarized as follows. Firstly, technical efficiencies of regional public hospitals are affected largely by scale efficiency than pure technical efficiency. Second, productivity progressed and technological change has more significant influence on productivity advance over the period between 2005 and 2009. Third, the circularity problem of the traditional Malmquist index is confirmed, and so the global Malmquist index without this problem are valid for the analysis. Conclusion: Though this study also has some limitations with the data of regional public hospitals with a short time span, it is the first study of hospitals using global Malmquist productivity index and later it can be expanded to private hospitals and longer time periods.

• International Journal of Oral Biology
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• v.30 no.4
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• pp.131-134
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• 2005

In the present study, performances of several in vitro maturation (IVM) systems for porcine follicular oocytes were evaluated, and an efficient chemically defined IVM system for porcine oocytes was proposed. The proposed one-step culture system supplemented with polyvinylalcohol (PVA) gave competitive efficiencies in terms of oocyte maturation and blastocyst development after parthenogenetic activation and in vitro culture, compared with the conventional two-step culture system by a supplementation of porcine follicular fluid (pFF). Additionally, it is identified that the proposed chemically defined one-step culture system yielded the comparable level of blastocyst production to the conventional maturation system in porcine somatic cell nuclear transfer (SCNT). Therefore, one can eliminate un-expected effects accompanied by supplementation of pFF. No medium replacement during whole maturation period is an additional benefit by applying this new system. Thus, these data support that the developed PVA supplemented chemically defined one-step IVM system for porcine follicular oocyte might be used in porcine SCNT program.

• The Journal of Fisheries Business Administration
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• v.43 no.1
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• pp.11-18
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• 2012

This study is aimed to estimate a dynamic productive efficiency by vessel of large purse seine fishery and analyze changes of them over times using a window/DEA method. In addition, based on estimation results, it aims to suggest production management implications for an viable development of fisheries. Results indicated that an annual efficiency change of large purse seine fishery was estimated at 0.77 for 2007~2008, 0.83 for 2008~2009, and 0.77 for 2009~2010, showing a decreasing trend. As returns on sales of vessels of large purse seine fishery showed a decreasing trend, the degree of efficiency of a vessel might be closely related to the fishing profitability. The Window/DEA method was used in this study to estimate the efficiencies of vessels for large purse seine fishery. This method is well known and widely used to analyze the dynamic efficiency and it can provide useful implications for management of input factors. As a limitation of this study, it was not able to provide detailed management ways to reduce inefficiencies. However, they can be investigated with data on managerial factor, human factor, distribution factors as a future study.

• KSBB Journal
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• v.8 no.4
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• pp.336-340
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• 1993

Zoogloea ramigera 115, well known type of bacteria to produce slime in sewage plants, was selected for biopolymer production. The extracted biopolymer showed high uptake capacity of metals such as cadmium and zinc. Especially the fermentor broth itself showed high adsorption of metal and could be used a biosorbent without an additional separation process. Biopolymer was immobilized into beads of calcium alginate and used in a packed bed reactor for the purpose of valued metals recovery. The biopolymer showed high removal efficiencies of 80% or greater for Cu, Cd, Mn and Zn, and high stability in sorption-desorption-resorption experiments. The immobilized biopolymer systems were found to be comparable to other metal removal systems such as ion exchange resins and to be of potential industrial application value.

• Advances in environmental research
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• v.5 no.4
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• pp.251-262
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• 2016

The biodegradability and decomposition efficiencies increase with the pre-treatment of sludge in a digestion process. In this study, the feasibility of ultrasound coupled with potassium permanganate oxidation as a disintegration method and digestibility of aerobic reactor fed with disintegrated sludge with ultrasound coupled potassium permanganate were investigated. The first stage of the study focused on determining the optimum condition for ultrasonic pre-treatment for achieving better destruction efficiency of sludge. The second part of the study, the aerobic digestibility of sludge disintegrated with ultrasound and potassium permanganate oxidation alone and combined were examined comparatively. The results showed that when 20 min of ultrasonic pre-treatment applied, the specific energy output was 49384 kJ/kgTS with disintegration degree of 58.84%. During the operation of aerobic digester, VS/TS ratios of digesters fed with disintegrated sludge decreased indicating that disintegration methods could obviously enhance aerobic digestion performance. The highest reduction in volatile solids was 75% in the digester fed with ultrasound+potassium permanganate disintegrated sludge at the end of the operation compared to digester fed with raw sludge. Total Nitrogen (TN) and Total Phosphorus (TP) levels in sludge supernatant increased with this combined method significantly. Besides, it promoted the production of ${\bullet}OH$, thus enhancing the release of Carbon (C), Nitrogen (N) and Phosphorus (P) from the sludge. Disintegration with all methods used in this study could not improve Capillary Suction Time (CST) reduction in disintegrated digesters during the operation. The results demonstrated that the combined ultrasound treatment and potassium permanganate oxidation method improves the biodegradability compared to control reactor or their single application.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.5 no.1
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• pp.67-77
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• 1995

Abstract The principal factor affecting the increased penetration of photovoltaics into the marketplace is cost. For traditional crystalline silicon modules, half of the cost is that of the silicon wafers. As a result much effort has centered on reducing this cost by the use of thin film technologies. Substantial technical progress has been made towards improving the efficiencies of polycrystalline thin film solar cells to reduce the production costs. Progress in semiconductor deposition techniques has also been rapid. The most mature of these are based on polycrystalline silicon (p - Si), amorphous silicon (a - Si), copper indium diselenide $SuInSe_2$(CIS), and cadmium telluride (CdTe). This paper explores the recent advances in the development of polycrystalline thin film solar cells.

• Journal of Applied Reliability
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• v.12 no.1
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• pp.35-46
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• 2012

Wood pellet is one of biomass energy fuels, which is produced by compressing woody biomass such as sawdust, planer shavings, and whole-tree removal or tree tops and branches leftover after logging into cylindrical form. Latterly much attention has been paid to wood pellet boiler which is suitable for use at various scales in domestic and industrial furnaces for heat production to replace conventional fossil fuel energy sources since the use of wood pellet that is carbon neutral can alleviate global warming. This study presents the result of developing a high efficiency wood pellet boiler with 55MJ/h capacity. Efficiency has been improved by using a rotating disk burner with a shorter screw feeder. Special attention has been paid to the improvement of the safety of the wood pellet boiler from backfire by adopting a double protecting system composed of a shutter and an air curtain. The result shows that the efficiencies of the wood pellet boiler are 97.2% and 89.2% based on lower and higher heating values, respectively, at 15.1kW of heating output.

• Journal of Environmental Science International
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• v.5 no.1
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• pp.25-33
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• 1996

This study was conducted to Investigate the biological treatment capability of MMCMAS(Movinig Media Complete Mixing Activated Sludge) reactor for high strength organic wastewater (Average BOD=800mg/l). And this experimental results were compared previous study for low strength organic wastewater (Average HOD=150mg/l) by the same reactor. In this study, we abtained following conclusions ; (1) The laboratory MMCMAS reactor demonstrated that SBOD removal efficiencies of more than 90% can be achieved at organic Bonding rates of 30.9 gBOD/$m^2$/d for high strength organic wastewater and 39.4 gBOD/$m^2$/d for low strength organic wastewater, respectively. (2) The nitrification rates of MMCMAS reactor was found same results of similiar organic loading rates. (3) The ratio of attached biomass to total biomass on the moving media varied in the range of 40 to 63% and 32 to 94% for high and low strength organic wastewater, respectively. And it was varied at the various concentration of influents for the similiar organic loading rates. The sludge production rates was found approximately 0.37 gVSS/$gBOD_{rem}$. in MMCMAS reactor.

• Preventive Nutrition and Food Science
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• v.3 no.1
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• pp.98-104
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• 1998

As an efffort ot construct LAB (latice acid bacteria), capable of utilizing starch as fermentation substrate without the aid of externally supplied enzymes, plasmid vectors containing the amyL($\alpha$-amylase/pullulansase gene) from Clostridium thermophydrosulfuricum, and glucoamylase cDNA from Asperigillus shirousamii were constructed and introduced itno E. coli and L. lactis. For expression in procaryotes , 1.9kb glucoamylase cDNA encoding the mature form of enzyme was PCR amplified and translationaly fused to a PCR amplified 260 bp fragment containing the promotor and secretion signals of amyl in the same reading frame. The production of $\alpha$-amylase, Apu, and glucoamlase in E. coli and L. lactis was confirmed by enzyme assay and zymography . Enzymeswere detected in both cellpellets and supernatants, indicating theworking of scretion signals in heterologous hosts. The efficiencies of secretion were varibale depending on the gene and host. The highest $\alpha$- amylase acitivity observed was 1.1 units and most activiity was detected from thecell pellets. The degree of gene expression in both hosts and the effect on the growth of hosts were examined.