• Journal of Drive and Control
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• v.19 no.1
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• pp.69-75
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• 2022

This study aimed to develop solutions for the intermittent performance deterioration of self-propelled spinach harvesters through analysis model. The study was conducted in the following manner. First, changes in performance deterioration and surplus flow, which result from oil temperature changes, were analyzed by simulating actual sequential harvesting movements, which involve driving with actuators operated simultaneously, by analysis model developed in a previous study. Second, fundamental solutions for surplus flow problems were presented. Third, the solutions were applied to a virtual environment to present their practicality and quantitative effects. The two solutions based on the study results were as follows. First, a closed center-type directional control valve was applied to the hydraulic circuit. Second, an unloading system was set up through an on-off solenoid valve.

• International Commerce and Information Review
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• v.15 no.4
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• pp.97-122
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• 2013

Korea's trade balance in service showed surplus in 2012 on the basis of BPM5. This is recorded by 14 years since 1999. This owes to decrease of deficit in tourism balance, increase of surplus in construction and transportation, and shift from deficit to surplus, even in small portion, in personal cultural recreational services balance. While externally the global economic growth becomes inactive and the Korean Won has appreciated, internally Korean service industry is very weak and is not equipped with international competitiveness. This study intends to look into service surplus items and services deficit items and to present measures that will be able to strengthen competitiveness in service industry. As a short case study, German and Japan was benchmarked, as they are the countries which are developed on the basis of manufacturing like Korea. And in this study, by analyzing surplus items and deficit items in trade balance sheet, it is attempted to suggest policies which would be available for strengthening service industry. As the service industry is a highly value-added one, it is necessary to designate promising categories and intensively foster as strategic industry. Service industry has their own characteristics distinguished with manufacturing goods. It has very different logistics and payment system with manufacturing industry. It means there must be independent support systems which reflect the nature of industrial classification in service industry. It is necessary to provide export support system, to organize export market development group, to support marketing, to set common logistics center, to support diplomatic means, to provide legal service and so on.

• Journal of agriculture & life science
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• v.46 no.1
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• pp.195-206
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• 2012

This study is about an analysis of surplus solar energy by important greenhouse types as well as setting temperature different by using Typical Meteorological Year data which was secured in order to provide basic data for designing an optimum thermal storage system to accumulate surplus solar energy generating in greenhouses during the daytime. Depending on the setting temperatures of $15{\sim}19^{\circ}C$ for greenhouse heating during day and night, surplus heat amounts were varied at the rate of about $0.2{\sim}6.9%/4^{\circ}C$ with some variations according to the greenhouse types and regions. On the other hand, the variations of supplemental heat requirements were about $29.7{\sim}50.0%/4^{\circ}C$. Depending on the setting temperatures for greenhouse ventilations(low $25{\sim}29^{\circ}C$ and high $27{\sim}31^{\circ}C$), surplus heat amounts were varied at the rate of about $-9.9{\sim}-35.6%/4^{\circ}C$ in auto-type greenhouse. But in single-type greenhouses, they were about $-5.1{\sim}-13.4%/4^{\circ}C$. There were not significant changes in supplemental heat amounts depending on setting temperatures of ventilation for both greenhouse types and regions.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.4
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• pp.115-124
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• 2022

Unlike the semi-public system of city buses, Seoul's townbus are operated on a private operating system, which is poor condition to the changes in the environment. Sales decreased due to a decrease in the number of passengers due to COVID-19 and a demand for conversion due to the advent of competitive transportation methods, and the financial support of Seoul Metropolitan Government is continuously increasing. In this study, to analyze the characteristics of townbus operated by a private operating system, the townbus sales and surplus companies were analyzed by what factors were affected. For the analysis data, townbus financial statements of Seoul in 2018 were used, and townbus sales and surplus companies were applied as dependent variables, and townbus operation system, satisfaction survey, humanities and social variables, and subway and public bicycle characteristics were applied as independent variables. As a result of the analysis, the sales is affected by operating hours per vehicle, in-vehicle safety, the number of households, the number of elderly people, and public bicycle variables, and surplus companies are affected by in-vehicle safety, reliability, and public bicycle variables. In particular, public bicycles, a competitive means of transportation, had an impact on industry sales, and the townbus business environment is expected to become more difficult as time goes by. The industry is seeking self-rescue measures, and Seoul is required to strengthen financial support so that townbus can operate stably.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.353-360
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• 2017

In this study, the design and performance test of the air to water heat pump capable of producing hot water for greenhouse heating by using the surplus solar heat inside the greenhouse and the air heat outside greenhouse as the selective heat source were conducted. The heat storage operations using the surplus solar heat and the outside air heat were designed to be switched according to the setting temperature of the greenhouse in consideration of the optimum temperature range of the crop. In the developed system, it was possible to automatically control the switching of heat storage operation, heating and ventilation by setting 12 reference temperatures on the control panel. In the selective heat storage operation with the surplus solar heat and outside air heat, the temperature of thermal storage tank was controlled variably from $35^{\circ}C$ to $52^{\circ}C$ according to the heat storage rate and heating load. The heat storage operation times using the surplus solar heat and outside air heat were 23.1% and 30.7% of the experimental time respectively and the heat pump pause time was 46.2%. COP(coefficient of performance) of the heat pump of the heat storage operation using the surplus solar heat and outside air heat were 3.83 and 2.77 respectively and was 3.24 for whole selective heat storage operation. For the comparative experiment, the heat storage operation using the outside air heat only was performed under the condition that the temperature of the thermal storage tank was controlled constantly from 50 to $52^{\circ}C$, and COP was analyzed to be 2.33. As a result, it was confirmed that the COP of the heat storage operation using the surplus solar heat and outside air heat as selective heat source and the variable temperature control of the thermal storage tank was 39% higher than that of the general heat storage operation using the outside air heat only and the constant temperature control of the thermal storage tank.

• Journal of the Korean Institute of Educational Facilities
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• v.10 no.1
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• pp.84-91
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• 2003

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.426-430
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• 2008

Hot shear-welding is a process of bonding two plates together by using shearing stress in a controlled manner. This study dealt with the hot shear-welding process of two aluminum plates. These two plates were piles up in the shear-welding mold. Due to the shearing stress, these two plates were cut off longitudinally, and meantime they were welded together. During this process the control of the surplus material flow is very important, and it can be realized by designing the overlapping length and the shape of the cavity. The commercial software Deform-3D was employed to predict the effect of these two factors. The overlapping length and the shape of the cavity that presents the optimum design was then developed to get a good shear-welding process.

• Journal of the Korea Institute of Building Construction
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• v.4 no.4
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• pp.135-142
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• 2004

The purpose of this study is to predict remodeling timing of Permanent Rental Housing through historic data and cash flow analysis. For this aim, the study has estimated cash flow of Permanent Rental Housing considering initial construction costs, government supporting fund, rental incomes and maintenance expenses. Based on the expected cash flow analysis, reasonable remodeling timing is predicted for Permanent Rental Housing. The results of this study are as follows: (1) it is analyzed that building a8e of about 27 years is the best time for remodeling because cumulative surplus amounts reach maximum level, (2) it is required that remodeling should be made before 34 years of age roughly because cumulative surplus amounts change into minus from this time.

• The Korean Journal of Health Service Management
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• v.6 no.3
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• pp.219-229
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• 2012

In these days, the interest on medical industry is increasing around the world. This paper attempts to estimate the economic effects of the medical and measuring instrument industry through the Input-Output Analysis. Especially, 78*78 Sector Tables were used as the first analysis tool. So then, 79*79 Sector Tables adjusted were used for that industry. The main analysis tools of this study are comparing and analyzing backward and forward linkage effect, the induced effect of the self industry and other industries and the induced coefficients such as products, value-added, employee's pay, sales surplus, employment. According to the result of analysis, the medical and measuring instrument industry has great economic impacts which affects the major macroeconomic factors such as production and backward linkage effect. And the induced effects of the self medical and measuring instrument industry are significant compared to other industries in aspects of production, employee's pay and sales surplus.

• Ocean and Polar Research
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• v.39 no.3
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• pp.213-219
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• 2017

In this study, we analyzed the economic feasibility of the swimming crab (Portunus trituberculatus) fry releasing program in the West Sea of Korea. The catch rate of released fry in 2010, measured by genetic markers, was applied to the economic surplus method to estimate benefits. As a result of our analysis, the B/C ratio, as an indicator of economic evaluation, was determined to be 2.168, which means that the releasing program was economically feasible. And it was shown that the benefits to consumers is six times greater than the benefits to producers, confirming the necessity of the releasing program as a public work.