• Korean Journal of Construction Engineering and Management
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• v.15 no.4
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• pp.107-118
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• 2014

Electrical Construction industry uses Construction industry's statistical data for business outlook. Because there are not electrical construction business view's statistical data. It has own unique characteristic which is different from construction industry. So it must have a electrical construction Business Index. This study was focused on developing the business index of electrical construction business. Electrical construction business index consists of electrical construction composite Index(ECI) and the electrical construction business survey index(EBSI). This study experimentally analyzes the business views of electrical construction industry in 2/4 quarter of 2014. The leading Index of ECI indicates -0.4% compared with 1/4 quarter of 2014, coincidence index also shows that electrical construction industry's business cycle is in an economic downturn. EBSI is 83.5 in 2/4 quarter of 2014, down from 95.2 in 1/4 quarter of 2014. It means that electrical construction company has a pessimistic prediction. As a result we know that the Business Index of Electrical Construction Business shows similar results. It is expected to make contribution for electrical contractors to establish management strategies and prepare responses to economic changes by providing information about economic trends of electrical construction business and forecasting future economy.

• Korean Chemical Engineering Research
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• v.59 no.1
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• pp.60-67
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• 2021

This study presented techno-economic analysis of a 500 MWe oxy-coal power plant with CO2 capture. The power plant included a circulating fluidized-bed (CFB), ultra-supercritical steam turbine, flue gas conditioning (FGC), air separation unit (ASU), and CO2 processing unit (CPU). The dry flue gas recirculation (FGR) was used to control the combustion temperature of CFB. One FGR heat exchanger, one heat exchanger for N2 stream exiting ASU, and a heat recovery from CPU compressor were considered to enhance heat efficiency. The decrease in the temperature difference (ΔT) of the FGR heat exchanger that means the increase in heat recovery from flue gas enhanced the electricity and exergy efficiencies. The annual cost including the FGR heat exchanger and FGC cooling water was minimized at ΔT = 10 ℃, where the electricity efficiency, total capital cost, total production cost, and return on investment were 39%, 1371 M$, 90 M$, and 7%/y, respectively.

• Journal of Electrochemical Science and Technology
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• v.13 no.1
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• pp.148-158
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• 2022

The electrochemical CO₂ reduction (ECR) to produce value-added fuels and chemicals using clean energy sources (like solar and wind) is a promising technology to neutralize the carbon cycle and reproduce the fuels. Presently, the ECR has been the most attractive route to produce carbon-building blocks that have growing global production and high market demand. The electrochemical CO₂ reduction could be extensively implemented if it produces valuable products at those costs which are financially competitive with the present market prices. Herein, the electrochemical conversion of CO₂ obtained from flue gases of a power plant to produce diesel and formic acid using a consistent techno-economic approach is presented. The first scenario analyzed the production of diesel fuel which was formed through Fischer-Tropsch processing of CO (obtained through electroreduction of CO₂) and hydrogen, while in the second scenario, direct electrochemical CO₂ reduction to formic acid was considered. As per the base case assumptions extracted from the previous outstanding research studies, both processes weren't competitive with the existing fuel prices, indicating that high electrochemical (EC) cell capital cost was the main limiting component. The diesel fuel production was predicted as the best route for the cost-effective production of fuels under conceivable optimistic case assumptions, and the formic acid was found to be costly in terms of stored energy contents and has a facile production mechanism at those costs which are financially competitive with its bulk market price. In both processes, the liquid product cost was greatly affected by the parameters affecting the EC cell capital expenses, such as cost concerning the electrode area, faradaic efficiency, and current density.

• Journal of Sericultural and Entomological Science
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• v.2
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• pp.49-61
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• 1962

The insect Diplosis mori Yokoyama is causing extensive destruction of mulberry trees in Korea with a resultant loss in silk production. This study was made to determine an effective method of control. Methods and Materials Used Preliminary studies were made to determine more exactly the life cycle of the insect. Based on this information, various control measures were tested, including the use of spray methods with BHC and control of larvae by tilling. Results Obtained 1. Life cycle studies (a) In the Suwon area, this-insect has 5 generations per year. The first starts in the later part of June and the final cycle ends in the later part of September. (b) The adult insects appear about 7: 00-8: 00 P.M. and live for 2-5 days. Females live in longer periods than the male. (c) Larvae lives inside the second and third stipules (A. B.) before mulberry leaf development. They cause extensive damage to the leaves at the point where they are attached to the stem. (d) Weather conditions considerably affect the life cycle. The pupa particularly are affected and not be able to change into the moth stage when there is a long period of no rain. (e) Larvae are large......0.3 to 2.0mm......and are milky-white immediately after hatching but turn to pinkish as the worm matures. The matured worm has a jumping ability up to 15-20cm. The worm burrows into the ground 1.5 to 3.0 cm before changing into the pupal stage. (f) The pupal stage usually lasts 7-8 days, in summer weather conditions and the pupa is surrounded with a coarse cocoon. (g) These insects, as a general rule, overwinter as pupae but sometimes as larvae. 2. Control measures (a) BHC dust applied on the ground seem most effective. It should be done 4-5 days after the worm has burrowed into the ground. For this control, it is recommended that 6kg of a 2% formation Tanbo(l0ares) be used. (b) For the effective spraying against the fly, it is recommended that a formulation of liquid BHC spray terials be used at the rate of 400-600 liters per Tanbo. (c) Tillage methods which provide a cover of soil 5cm or more in depth above infested areas will effect-maively prevent the emergence of the fly from the pupal stage. 3. Conclusions Methods of control against Diplosis mori Yokoyama can be tied more closely to the life cycle of the insect with more effective results. Further studies are needed to complete information on possible controls during or after hibernation. Economic studies on the cost of these control measures are also needed.

• International Area Studies Review
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• v.21 no.4
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• pp.41-63
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• 2017

FDI can either be absorbed in the production cycle with domestic investment and create an inducement effect or it can remain as an exogenous factor and increase the volatility of GDP. The purpose of this paper is to research these different impacts that FDI could have. For that, the endogenous growth theory was employed. The statistic method used are the panel model for sectoral analysis, and GARCH model and VAR for time series analysis. Myanmar was selected as this paper's research subject because it is one of countries which had a colossal amount of FDI inflow recently. The panel analysis did not confirm the causality between sectoral FDI and sectoral GDP. The reason for this could be in the lack of data, since sectoral data exists yearly only during 2006-2016. Therefore this study conducted the times series analysis. According to the results, during 2006 until 2010, it showed signs of GARCH but the effect of FDI on GDP was nonexistent, which means FDI was not integrated into the domestic production cycle but stayed in residual terms. During 2011 to 2016, FDI seemed to affect the growth of Myanmar's GDP. The estimation confirmed the existence of GARCH and the Granzer causality test confirmed that FDI influenced the GARCH, which signified FDI increased the volatility of GDP. The VAR analysis showed responses of GDP to FDI was small(about 0.0007). This research assumes that FDI can be divided in two parts: one part which can be assimilated in the domestic production cycle and the other where it stays outside of the production cycle. The former creates production inducement effect and the latter only increases the volatility of GDP. According to this study, the latter outweighs the former impact in Myanmar.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.2
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• pp.210-230
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• 1995

To compare the wear resistance of four kinds of commercial acrylic resin teeth [SR-Orthosit PosterioresR(Ivoclar Co., Liechtenstein), Endura PosteriorR(Shofu Inc. Japan), trubyte IPN teethR(Dentsply International Inc., York,), Trubyte BiotoneR(dentsply Inermational Inc. Brazil) by means of the toothbrush abrasion method, the artificial resin teeth were embedded in epoxy resin with the occlusal surfaces aligned in one plane for a total of 40 blocks. There after, each lock was mounted in the arm of the toothbrush abrasion machine(K 236, Japan). Wear measurements were made on the three preconditioned states. Those were as follows : no treatment specimens, thermocycled specimens, and thermocycled specimens which were immeresed applied load of 400g during the buring the brushing cycle. At the end of the 30,000-stroke cycle, each specimen was removed, and weighed. The microhardness of four kinds of commercial resin teeth were determined by means of microhardness tester. Microhardness tests were performed on te no treatment specimens, thermocycled specimens, and thermocycled specimens with immersion in the denture cleansing solution. Finally, the comparison of thermal properties were perfomed using differential scanning calorimeter(DSC-1500). The following results were obtained : 1. In the case of no treatment teeth, the wear amount of endura Posterior(EN) was the greatest among the others(p<0.01), and the wear amount of three kinds of artificial resin teeth was increased in the order of Trubyte IPN teeth(IN), Trubyte Biotone(BN), SR-Orthosit Posteriores(SN) but there was no statistic significance(p>0.01). 2. The wear amount of Trubyte IPN teeth(IT) and Trubyte Biotone(BT), was increased due to thermocycling effect, but that of Endura Posteriores(ET) was decreased conversely(p<0.01). 3. Except for the SR-Orthosit Posteriores(STC), the wear amount of three kinds of artificial resing teeth(that is, ETC, ITC, BTC) was increased due to denture cleansing solution$(Cledent^R)$, but there was no statistic significance(p>0.01). But the wear amount of the SR-Orthosit Posteriores(STC) was the greatest among the others(p<0.01). 4. The wear amount of toothbrush was the greatest in case of contact with occlusal surface of SROrthosit Posteriores resin teeth(p<0.01). 5. the microhardness values(KHN) of the SR-Orthosit Posteriores was the highest among the experimental artificial resin teeth(p<0.01). 6. There was no relationship between microhardness valuse(KHN) and wear amount of four kinds of experimental artificial resin teeth(p<0.01). 7. The differential canning calorimetric property of four kinds of artificial resin teeth did not show endothermal or exothermal peak in the range of $100^{\circ}C$

• Journal of Korean Society of Environmental Engineers
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• v.39 no.4
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• pp.169-179
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• 2017

This study was conducted to supply information that can be utilized as data for desalination plant construction in the future by estimating unit cost of water production in the potential site of Incheon, Daesan, Yeosu, Busan, Ulsan and Sokcho in Korea. The production costs in Sokcho and Ulsan were similar to those of Busan and Yeosu. Those four sites showed better economic range due to low construction cost for intake facility compared to Incheon and Daesan. Although the salinity measured in the above 6 sites did not show perceptible effect on the production cost, the difference of seasonal seawater temperature needs to be considered due to the change of flux in reverse osmosis (RO) membrane. It turned out that the most critical parameters are the amortization in a year by the analysis of life cycle and the capacity of plant. Incheon and Daesan showed the difference of production cost up to 29% at the condition of amortization in 25 year, and up to 22% depending on plant capacity. However, the production cost in this study did not take into account of other indirect costs, therefore, this should be considered as the minimum cost.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.257-265
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• 2020

Parts obsolescence is a component type, in which raw materials or parts that make up a weapons system, are developed and produced according to demand, but they age due to changes in technology or market conditions. The weapon system equipment currently being used by the military is having difficulty in procurement, maintenance, and operation because of the obsolescence of parts. Parts obsolescence during the life cycle of a weapons system affects not only the combat readiness of the military but also the economic loss of material, parts, and equipment manufacturers and suppliers. On the other hand, advanced technology has reduced the life span of electronic components that make up the weapons system. In addition, because of the nature of the weapons system, the obsolescence of components takes decades from development to disposal, which has a serious adverse effect on equipment readiness and life cycle costs. Therefore, it is necessary to manage systematically the parts obsolescence from development until the disposal of the weapons system equipment. This study examined the system of component control in developed countries to present a proper management plan for local situations and propose development plans for the early settlement of component control.

• Journal of Labour Economics
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• v.26 no.3
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• pp.149-179
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• 2003

This study is analysing the factors determining individuals' behavior of selecting self-employment not only at the micro-level but also at the macro-level to put a particular emphasis on the financial constraint and unemployment rate representing business cycle. The data used in this study are "Korean Labor and Income Panal Study" of the Korea Labor Institute and "Economically Active Population Survey" of National Statistical Office. The main findings are as follows. First, human capital such as educational attainment and job experience has positive effects on male's selection of self-employment. The effects of job experience, however, changed negative for female's selection of self-employment. Second, real estate is significantly enhancing the selection probabilities of employer selection while the income from financial assets has negative effects. Third, entrepreneurial culture and environment are also raising the self-employment selection probability. Lastly, the regional unemployment rate representing the business cycle has positive effects on the self-employment selection after the financial crisis in 1997 both at the micro and macro level. Moreover, the coefficient of regional unemployment rate has changed positive in the structural model of self-employment selection controlling for selection bias and income opportunities, which means that individual's behavior of self-employment selection is rather complex when accounting for the uncertainties of income opportunities and diverse characteristics of self-employment workforce.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.2
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• pp.54-68
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• 2015

The advantage of electric taxies is that people who are not familiar with electric vehicle(EV) can have easily experience to ride EV. So, EV taxi would be a reasonable strategy for triggering EV market expansion. However, the EV taxi can be adopted by taxi companies with financial benefits. Therefore the feasibility study should be required by analyzing the cost with the points of view of the taxi company. In this study we suggested the methodology for feasibility study of the EV taxi based on the real taxi data and presented political implication. According to the study result, EV taxies could have economic value under the specific conditions such that the government subsidy is added to the purchase price of the vehicle. Also, the charging time should be used as drivers' rest time or mealtime in order not to consider the loss cost. We suggest that the new feasibility study which compares an EV taxi with other alternative vehicles such as PHEV or with an old EV taxi is needed as the future works.