• 한국콘텐츠학회논문지
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• 제19권10호
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• pp.226-236
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• 2019

본고는 춘천문화방송의 재무 및 편성자료를 바탕으로 지역방송사 경영성과와 편성의 상관관계 및 경영상황의 변화에 따른 제작 형태의 변화를 분석하였다. 분석 결과, 지역방송사의 영업이익률과 자체제작비율은 정의상관관계가 있는 것으로 나타났다. 한편, 경영상황 변화에 따른 제작 형태의 변화를 분석한 결과, 경영여건이 악화된 시기에는 프로그램의 출연자 수가 줄고, 야외 촬영 형태가 늘었음이 확인되었다. 지역방송사들은 수익이 지속적으로 감소하는 상황에서 출연자수를 줄이고, 내부 스튜디오 녹화 보다는 외부 녹화 형태를 취함으로써 인건비와 세트 제작비를 절감해온 것으로 분석된다.

• Journal of Korea Trade
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• 제24권5호
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• pp.35-54
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• 2020

Purpose - It seems common sense that corporate social responsibility (CSR) is a key driver of business sustainability. Nevertheless, there has been little research on the performance of socially responsible activities, including economic and environmentally responsibility activities, in internationally diversified firms. Design/methodology - The purpose of this study was to evaluate the effects of CSR activities on management performance. For this evaluation, an empirical analysis was conducted with total of 2,520 cases, selected from companies listed on the Korea Composite Stock Price Index market for six years from 2013 to 2018. As proxies for management performance, financial data such as a total asset net profit ratio and a total asset operating ratio were used. A multivariate regression analysis was conducted to test hypotheses. Findings - The results of this analysis indicated that firms in the CSR outstanding group were ranked significantly higher than other groups in management performance. In addition, CSR activities of internationally diversified firms positively influenced the total asset net profit ratio and total asset operating ratio. Originality/value - The results suggest that the CSR activities of these firms can play a significant role in enhancing management performance in the economic status of Korea, where the degree of export dependency is high.

• Membrane and Water Treatment
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• 제10권5호
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• pp.361-372
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• 2019

Effect of different alkane based solvents on the stability of emulsion liquid membrane was investigated using normal alkanes (n-hexane, n-heptane, n-octane and n-decane) under various operating parameters of surfactant concentration, emulsification time, internal phase concentration, volume ratio of internal phase to organic phase, volume ratio of emulsion phase to external phase and stirring speed. Results of stability revealed that emulsion liquid membrane containing n-octane as solvent and span-80 (5 % (w/w)) as emulsifying agent presented the highest amount of emulsion stability (the lowest breakage) compared with other solvents; however, operating parameters (surfactant concentration (5% (w/w)), emulsification time (6 min), internal phase concentration (0.05 M), volume ratio of internal phase to organic phase (1/1), volume ratio of emulsion phase to external phase (1/5) and stirring speed (300 rpm)) were also influential on improving the stability (about 0.2% breakage) and on achieving the most stable emulsion. The membrane with the highest stability was employed to extract acridine orange with various concentrations (10, 20 and 40 ppm) from water. The emulsion liquid membrane prepared with n-octane as the best solvent almost removed 99.5% of acridine orange from water. Also, the prepared liquid membrane eliminated completely (100%) other cationic dyes (methylene blue, methyl violet and crystal violet) from water demonstrating the efficacy of prepared emulsion liquid membrane in treatment of dye polluted waters.

• The Journal of Asian Finance, Economics and Business
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• 제8권3호
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• pp.251-265
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• 2021

It seems a common sense that corporate social responsibility (CSR) is a key driver to attain business sustainability. Nevertheless, there has been little research on the performance of socially responsible activities, including economic and environmental responsibility activities in internationally diversified firms. The purpose of this study was to evaluate the effects of CSR activities on management performance. For this evaluation, an empirical analysis was conducted with a total of 2,520 cases, selected from companies listed on the Korea Composite Stock Price Index market for six years from 2013 to 2018. As proxies for management performance, financial date such as a total asset net profit ratio and a total asset-operating ratio were used. A multivariate regression analysis was conducted to test hypotheses. The results of this analysis indicated that firms in the CSR outstanding group are significantly higher than other groups in management performances. In addition, CSR activities of internationally diversified firms positively influence their total asset net profit ratio and total asset-operating ratio. The results suggested that CSR activities of these firms can play a significant role in enhancing management performances amid the economic status of Korea, where a degree of export dependency is high.

• 한국병원경영학회지
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• 제11권1호
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• pp.54-90
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• 2006

Medical clinics are core institutes that cover the primary medical care in Korea. Financial viability of the clinics is essential for them to conduct their roles and functions, and can be improved by increasing their operating profitability. On this ground, this study aimed at finding important factors that affect the operating profitability, and thereby at suggesting strategic alternatives that can contribute to the improvement of the profitability. Operating margin was set as a dependent variable, and such factors as general management conditions, number of visits, medical revenue, marketing activities, input resources, medical cost as independent variables. Nineteen hypotheses related to the variables were established and tested using data collected from 138 sample clinics for the year 2003. The results of the study are as follows : Firstly, such variables as percent ratio of the depreciation plus rent costs to total administration costs, type of clinical department manifested whether medical, surgical, or quasi-surgical, percent ratio of the interior facility investment to total fixed assets, and total number of outpatient visit are important factors that affect, positively or negatively, the medical profitability of the clinics. Secondly, following measures are needed to be established and implemented to improve the medical profitability. (1) Administration costs share 53.2% of the total medical costs, and depreciation plus rent costs 16.3% of the total administration costs. This implies that such measures as reinforcement of marketing activities, establishment of the cooperative utilizing system of the facility and equipment, or group practice are needed to increase cost-effectiveness. (2) Occupancy rate of the clinics with inpatient bed is as low as 45.5%, causing high fixed costs and low medical profitability. For its improvement, the resource input structure should be reorganized. Thirdly, in the future, a study that can increase sample representativeness of the study and explanation power of the variables should be performed for each type of clinical department to find more specific determinant factors and to contribute to the improvement of the medical profitability of the clinics.

• 산업공학
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• 제23권4호
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• pp.311-318
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• 2010

In the daily multi-reservoir operating problem, monthly storage targets can be used as principal operational guidelines. In this study, we tested the use of a simple back-propagation Artificial Neural Network (ANN) model to derive monthly storage guideline for daily Coordinated Multi-reservoir Operating Model (CoMOM) of the Han-River basin. This approach is based on the belief that the optimum solution of the daily CoMOM has a good performance, and the ANN model trained with the results of daily CoMOM would produce effective monthly operating guidelines. The optimum results of daily CoMOM is used as the training set for the back-propagation ANN model, which is designed to derive monthly reservoir storage targets in the basin. For the input patterns of the ANN model, we adopted the ratios of initial storage of each dam to the storage of Paldang dam, ratios of monthly expected inflow of each dam to the total inflow of the whole basin, ratios of monthly demand at each dam to the total demand of the whole basin, ratio of total storage of the whole basin to the active storage of Paldang dam, and the ratio of total inflow of the whole basin to the active storage of the whole basin. And the output pattern of ANN model is the optimal final storages that are generated by the daily CoMOM. Then, we analyzed the performance of the ANN model by using a real-time simulation procedure for the multi-reservoir system of the Han-river basin, assuming that historical inflows from October 1st, 2004 to June 30th, 2007 (except July, August, September) were occurred. The simulation results showed that by utilizing the monthly storage target provided by the ANN model, we could reduce the spillages, increase hydropower generation, and secure more water at the end of the planning horizon compared to the historical records.

• 경영과학
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• 제28권2호
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• pp.17-29
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• 2011

The purpose of this paper is to schedule elective surgery patients using a stochastic programming approach and to illustrate how operating room utilization behaves when a decision-maker varies costs associated with utilization. Because of the uncertainty in surgery durations, the underage and overage costs that a decision-maker considers plays an important role in allocating surgery cases into available operating room capacity. We formulate the problem as a stochastic mixed integer programming and propose a sampling-based approximation method for a computational purpose. Newsvendor model is employed to explain the results from numerical experiments that are conducted with the actual data from a hospital. The results show that the operating room utilization is more sensitive when the unit overtime cost is relatively larger than the unit cost for underutilized time.

• Journal of Advanced Marine Engineering and Technology
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• 제17권4호
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• pp.11-19
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• 1993

The experimental study was carried out to investigate the stability and the performance characteristics of the aero-valved pulsating combustion system with maximum operating capacity of 60KW. The effect of geometry of combustion system on the stable condition, the flammability limit, the total pressure oscillation amplitude, and the operating frequency can be identified, and the maximum turn-down-ratio is obtained up to 3.3. The total pressure oscillation amplitude can be controlled by tunning the length of the air inlet pipe. The empirical equation with which the operating frequency can be approximated is proposed and the discrepancy is within 5%. The volumetric efficiency is identified to be one of the important parameters determining the upper flammability limit and the maximum value of which is approximately 22%.

• 설비공학논문집
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• 제12권7호
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• pp.649-658
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• 2000

Thermodynamic modeling of low-pressure scroll compressor was developed by combining continuity and energy conservation equation. Suction gas heating was considered using energy balance inside the low pressure shell. Pressure, temperature and mass of refrigerant-22 as a function of orbiting angle were calculated by solving the governing equations using fourth order Rung-Kutta scheme. Motor efficiency was taken by experiments with a variation of frequency. The developed model was applied to the analysis of an inverter driven scroll compressor with a variation of frequency, pressure ratio and operating conditions. The model was verified with the experimental results at the same operating conditions. The developed model was adequate to predict performance of the inverter driven scroll compressor as a function of operating conditions. Calculated parameters from the model were discharge temperature, mass flow rate, power input, COP, and thermodynamic properties with respect to orbiting angle. To enhance the performance of a scroll compressor, it is essential to diminish leakage at low frequency level and improve the mechanical efficiency at high frequency level.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
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• pp.33-35
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• 2013

The present work is an experimental investigation on potential operating range using directly injected gasoline fuel in a single-cylinder compression ignition (CI) engine. The objectives of present study were to apply auto-ignited combustion to gasoline fuel and to evaluate potential operating range. In order to auto-ignite gasoline fuel in CI engine, the fuel direct-injection system and the intake air system were modified that a flow rate and temperature of intake air were regulated. The heat-release rate (HRR), net indicated mean effective pressure (IMEP), start of combustion (SOC), and combustion duration were derived from in-cylinder pressure data in a test engine, which has 373.33cc displacement volume and 17.8 compression ratio. The exhaust emission characteristics were obtained emission gas analyzer and smoke meter on the exhaust line system.