• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.360-373
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• 2017

The BTO-a projects is the types, which has a demand risk among the type of PPP projects in Korea. When demand risk is realized, private investor encounters financial difficulties due to lower revenue than its expectation and the government may also have a problem in stable infrastructure operation. In this regards, the government has applied various risk sharing policies in response to demand risk. However, the amount of government's risk sharing is the government's contingent liabilities as a result of demand uncertainty, and it fails to be quantified by the conventional NPV method of expressing in the text of the concession agreement. The purpose of this study is to estimate the value of investment risk sharing by the government considering the demand risk in the profit sharing system (BTO-a) introduced in 2015 as one of the demand risk sharing policy. The investment risk sharing will take the form of options in finance. Private investors have the right to claim subsidies from the government when their revenue declines, while the government has the obligation to pay subsidies under certain conditions. In this study, we have established a methodology for estimating the value of investment risk sharing by using the Black - Scholes option pricing model and examined the appropriateness of the results through case studies. As a result of the analysis, the value of investment risk sharing is estimated to be 12 billion won, which is about 4% of the investment cost of the private investment. In other words, it can be seen that the government will invest 12 billion won in financial support by sharing the investment risk. The option value when assuming the traffic volume risk as a random variable from the case studies is derived as an average of 12.2 billion won and a standard deviation of 3.67 billion won. As a result of the cumulative distribution, the option value of the 90% probability interval will be determined within the range of 6.9 to 18.8 billion won. The method proposed in this study is expected to help government and private investors understand the better risk analysis and economic value of better for investment risk sharing under the uncertainty of future demand.

• 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.

• Journal of Environmental Science International
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• v.23 no.12
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• pp.2045-2056
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• 2014

In this study, pressure drop was measured in the pulse jet bag filter without venturi on which 16 numbers of filter bags (Ø$140{\times}850{\ell}$) are installed according to operation condition(filtration velocity, inlet dust concentration, pulse pressure, and pulse interval) using coke dust from steel mill. The obtained 180 pressure drop test data were used to predict pressure drop with multiple regression model so that pressure drop data can be used for effective operation condition and as basic data for economical design. The prediction results showed that when filtration velocity was increased by 1%, pressure drop was increased by 2.2% which indicated that filtration velocity among operation condition was attributed on the pressure drop the most. Pressure was dropped by 1.53% when pulse pressure was increased by 1% which also confirmed that pulse pressure was the major factor affecting on the pressure drop next to filtration velocity. Meanwhile, pressure drops were found increased by 0.3% and 0.37%, respectively when inlet dust concentration and pulse interval were increased by 1% implying that the effects of inlet dust concentration and pulse interval were less as compared with those changes of filtration velocity and pulse pressure. Therefore, the larger effect on the pressure drop the pulse jet bag filter was found in the order of filtration velocity($V_f$), pulse pressure($P_p$), inlet dust concentration($C_i$), pulse interval($P_i$). Also, the prediction result of filtration velocity, inlet dust concentration, pulse pressure, and pulse interval which showed the largest effect on the pressure drop indicated that stable operation can be executed with filtration velocity less than 1.5 m/min and inlet dust concentration less than $4g/m^3$. However, it was regarded that pulse pressure and pulse interval need to be adjusted when inlet dust concentration is higher than $4g/m^3$. When filtration velocity and pulse pressure were examined, operation was possible regardless of changes in pulse pressure if filtration velocity was at 1.5 m/min. If filtration velocity was increased to 2 m/min. operation would be possible only when pulse pressure was set at higher than $5.8kgf/cm^2$. Also, the prediction result of pressure drop with filtration velocity and pulse interval showed that operation with pulse interval less than 50 sec. should be carried out under filtration velocity at 1.5 m/min. While, pulse interval should be set at lower than 11 sec. if filtration velocity was set at 2 m/min. Under the conditions of filtration velocity lower than 1 m/min and high pulse pressure higher than $7kgf/cm^2$, though pressure drop would be less, in this case, economic feasibility would be low due to increased in installation and operation cost since scale of dust collection equipment becomes larger and life of filtration bag becomes shortened due to high pulse pressure.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.10
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• pp.1443-1451
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• 2014

Increasing cost and scarcity of maize has stimulated the use of alternative feed sources (AFS) in the diets of cattle. In this study, we investigated the effects of partial or total replacement of maize on nutrient digestibility, growth performance, blood metabolites, and economics in Limousin crossbred feedlot cattle. Forty-five $Limousin{\times}Luxi$ crossbred bulls were randomly assigned to the three treatment groups, orthodox diet (OD; 45.0% maize), partial replacement diet (PRD; 15% maize, 67% AFS), total replacement diet (TRD; 0% maize, 100% AFS). The growth feeding trial lasted for 98 days. Dry matter intake (DMI) and average daily gain (ADG) were recorded. The digestion trial was carried out after the end of the growth trial. Total faeces and feed samples were measured daily. Digestibilities of dry matter (DM) and organic matter (OM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) were calculated. After the feeding trial, blood metabolites were measured in 12 animals from each group. Initial and final body weights did not differ significantly among treatment groups (p>0.05). The ADG and DMI were 1.72 and 8.66, 1.60 and 9.10, and 1.40 and 9.11 kg/d for OD, PRD, and TRD, respectively. The PRD and TRD exhibited lower ADG (p<0.01) and higher DMI (p<0.01) than OD. The DMI (%body weight) was comparable between groups (p>0.5). Feed efficiency of PRD and TRD were lower than OD (p<0.01). The DM digestibility decreased with reduced level of maize (p = 0.10), OM digestibility was higher in OD (p<0.05), and CP, NDF and ADF digestibilities were similar for all groups (p>0.05). Blood urea nitrogen (mg/dL) in PRD and TRD was higher than OD (p<0.01), while other blood parameters did not differ significantly. Feed costs ($/head/d) were 1.49, 0.98, and 0.72 for OD, PRD, and TRD, respectively (p<0.01). Feed costs per kg gain ($) were significantly lower for PRD (0.63) and TRD (0.54) than OD (0.89; p<0.01). Overall profit ($/head) and daily profit ($/head/d) did not differ significantly between treatments (p>0.05), although TRD showed the highest economic benefits overall (p<0.01). While a traditional diet maximized the growth rate, partial or total replacement of dietary maize with AFS proved economically feasible due to their lower costs and comparable nutrient digestibilities of DM, CP, NDF, and ADF. Partial replacement may prove economically competitive in the current situation of China.

• Environmental and Resource Economics Review
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• v.13 no.3
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• pp.519-547
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• 2004

This paper analyze problems about scope of specific trade obligations(STOs), principle of dispute settlement procedure, and non-parties in context of the Cartagena Protocol on Biosafety(POB), which based on sub-paragraph 31(i) of DDA WTO Ministrial Declaration. The implications based on result of this study are as follows. First, to accept the wider scope of STOs under POB in Korea, importing country, won't be harmful to LMOs and Bioindustry. Instead, it will ensure a high level of biosafety concerning the import of LMOs. Exporters can take different kinds of trade measures to countervail adverse effect on the export of LMOs in this case. Therefore importer will endure the aftereffect. However, if korea were in exporter's place, to accept the wider scope STOs under POB will not have a good influence on the export of LMOs. Korea, therefore, should devise scheme for responding to debate about the STOs in MEAs, which have to be based on cost-benefit analysis and scenarios taking into account of speed and level in biotechology progress, status and trend of LMOs R&D and production, and condition of other industries. Second, it is not easy to agree with applying to what's rule between the POB and WTO for settlement dispute. Because there is the incompatibility between the POB characterized according to social rationality and WTO's rules for safety and environmental protection characterized according to scientific rationality. This issue have to be discussed for long period due to gap like that. Accordingly Korea, one of major LMOs importing countries, should suggest continuously that the effort is needed to ensure an adequate level of protection in transboundary movements of LMOs and scientific, environmental and socio-economic study. Third, in case of dispute between party and non-party of the POB, the duties under the WTO of non-party of the POB(if WTO member country) is valid. The country, therefore, will try to settle dispute based on WTO's rules. However, international society have to ensure for sound and safe use of LMOs in the field of transboundary movements. Accordingly Korea should devise scheme for preventing the possibility of dispute between party and non-party of the POB(if WTO member country), which is supported by policy options under the POB.

• The Korean Journal of Food And Nutrition
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• v.26 no.3
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• pp.404-413
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• 2013

This study was conducted to assess the dietary habits and behaviors of college students in the Northern Gyeonggi-do Region(Republic of Korea). To accomplish this, a survey was conducted to investigate the preference, intake frequency and menus of breakfast, lunch, dinner and snacks by male and female students. Most male and female students had irregular breakfasts with the main reasons for skipping a meal 'not enough time' (47.3, 45.5%) and 'irritating' (19.0, 21.9%), respectively. The principal breakfast menu for both was 'rice and side dishes'. The lunch time for male and female students was regular, and the lunch cost made up most of their spending money. The snack time of male and female students was mostly 'between lunch and dinner'. The snack menus of male and female students were 'cookies' (25.8, 19.0%), 'drinks' (18.0, 14.4%), and 'breads' (16.9, 13.2%), respectively. For male students, the reasons of snack intake were 'hunger' (46.1%), 'boredom' (15.7%), and 'habitual' (9.0%). For female students, the reasons were 'hunger' (28.2%), 'habitual' (22.4%), 'boredom' (15.5%). Half of the college students had regular delivery foods for reasons of 'hygiene', 'taste', and 'nutrition' in the order and in consideration of being the elderly. The facility foodservice was also used half of the college students for the reasons of being 'economic' (30.9, 22.6%), and 'liberated from preparing meals' (21.4, 23.8%), respectively. Both male and female students were found to have less knowledge of the facility foodservice in the elderly. Based on these results, greater efforts should be made to provide meaningful information regarding the dietary habits and behaviors of college students, especially, when elderly.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.1
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• pp.2-15
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• 1982

In this report, a total domestic demand for major commercial fertilizer for crop production in Korea up to 1996 was estimated. The agricultural products and area for demand for both 1982 and 1986 was quoted from the estimate of the 5th Five-year Economic plan. And the demands estimated for 1991 and 1996 reflected possible changes of diet from cereal to meat and their indirect effects on the increase of cereal consumption. As the advanced countries followed, consequently, the demands for soybean, corn and other feed grains were expected to be increased as well as the land for growing those crops. 1. Total annual demands for nitrogen, phosphorus and potassium fertilizers were estimated 1,050,000M/T, 1,110,000M/T, 1,280,000M/T and 1,010,000M/T for the year 1982, 1986, 1991, and 1996 respectively. 2. It was assumed that there would be difficulties in self-sufficiency of grains at the cost of the maximum utilization of land and fertilizers in 1996. 3. It was clear that the increase of the productivity per unit area is possible by improving the conditions of arable land which could resulted a self-sufficiency of food in Korea. As a consequence, the demand for fertilizers at that time would exceed the level of estimates. 4. The recent decrease in demand for commercial fertilizers (currently estimated 850,000M/T) was due to an inadequate application of fertilizers for respective crop reqirement. This inadequacy should be checked and encouraged the consumptions of fertilizers to be increased by supporting the price of grain.

• Journal of the Korean association of regional geographers
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• v.2 no.1
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• pp.25-38
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• 1996

As the proportion of women's participation in economic activities is rising, the increase of husband and wife both working and nuclear families makes children up-bringing a social problem. But many families have difficulties by the shortage of day nurseries which can solve it. As we can see in the research, the most urgent problem is the extension of nurseries in quantity. In Taegu, since it became a wide-area city, there are 473 nurseries. But in the respect of distribution, only less than 10% of Dongs have more than 7 nurseries and more than 90% of Dongs have less than 7 nurseries. Consequently nurseries are extremely insufficient. Moreover 29 Dongs don't have any nurseries at all and they take 18.6% of Dongs. The second problem is the unbalanced distribution of nurseries. West and north ward which are industrial complex and swarmed with low-income families, and Tal-sung county which is recently included in the wide-area city keenly need the establishment of nurseries. Besides, Bi-san 1 Dong and Non-gong which have only $1{\sim}2$ nurseries though they have high proportion of children and women who can be pregnant are also the areas which take precedence of nursery establishment. The third problem is that government support must be increased in the areas which have many small, petty and profit-making private nurseries so that good quality teachers can make breeding activities in nice facilities and environment. In materials which are obtained by the interviews with publich servants in charge of family welfare in some ward offices. Young and unexperienced persons who aquired certificate of qualification take day-nursery permits and run nurseries only a few months. and if the profits are insufficient, they sell the nurseries for premiums to third persons who are not qualified. Then the third managers only think of profits without thought of good quality childcare. As the result, the nurseries become asylums not nurseries. That is why the conditions of nursery establishment must be restricted to suitable scale and experienced persons. The fourth problem is that the nurseries in work places are extremely insufficient. The women who have jobs have many things to do before they go to work such as preparing meals and leaving children in the care of someone. Hence the childcare problem of working women must be solved. In nuclear families, childcare is the most serious problem for working women. The fifth one is the reduction of childcare expenses. Women must sacrifice themselves a lot to make social activities. To say nothing of physical and mental burden, they have to spend much of their salaries on childcare. And yet they don't take the benefit of good quality childcare. For the participation of women in public affairs, society must support the childcare problem to have then be devoted to their jobs without worries about their children. Therefore Taegu wide-area city must select west, north ward which are industrial complex and the low-income swarmed area before everything and establish many national, public and corporate nurseries which cost less expenses.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.7
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• pp.492-507
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• 2010

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2009. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends of thermal and fluid engineering have been surveyed as groups of general thermal and fluid flow, fluid machinery and piping, and new and renewable energy. Various topics were covered in the field of general thermal and fluid flow such as an expander, a capillary tube, the flow of micro-channel water blocks, the friction and anti-wear characteristics of nano oils with mixtures of refrigerant oils, etc. Research issues mainly focused on the design of micro-pumps and fans, the heat resistance reliability of axial smoke exhaust fans, and hood systems in the field of fluid machinery and piping. Studies on ground water sources were executed concerning two well type geothermal heat pumps and multi-heat pumps in the field of new and renewable energy. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included the heat transfer in thermoelectric cooling systems, refrigerants, evaporators, dryers, desiccant rotors. In the area of industrial heat exchangers, researches on high temperature ceramic heat exchangers, plate heat exchangers, frosting on fins of heat exchangers were performed. (3) In the field of refrigeration, papers were presented on alternative refrigerants, system improvements, and the utilization of various energy sources. Refrigeration systems with alternative refrigerants such as hydrocarbons, mixed refrigerants, and $CO_2$ were studied. Efforts to improve the performance of refrigeration systems were made applying various ideas of suction line heat exchangers, subcooling bypass lines and gas injection systems. Studies on heat pump systems using unutilized energy sources such as river water, underground water, and waste heat were also reported. (4) Research trend in the field of mechanical building facilities has been found to be mainly focused on field applications rather than performance improvements. In the area of cogeneration systems, papers on energy and economic analysis, LCC analysis and cost estimating were reported. Studies on ventilation and heat recovery systems introduced the effect on fire and smoke control, and energy reduction. Papers on district cooling and heating systems dealt with design capacity evaluation, application plan and field application. Also, the maintenance and management of building service equipments were presented for HVAC systems. (5) In the field of architectural environment, various studies were carried to improve indoor air quality and to analyze the heat load characteristics of buildings by energy simulation. These studies helped to understand the physics related to building load characteristics and to improve the quality of architectural environment where human beings reside in.

• Korean Journal of Agricultural Science
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• v.20 no.1
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• pp.25-33
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• 1993

This study was conducted to obtain necessary informations for improving of wildlife rearing management. The data was gathered by surveying with questionaire. One hundred and eighty farmers which was 60 of deer and pheasant, 30 of wild boar and fox rearing farmers respectively were investigated during the summer in 1992. The results of this study are as follows : 1. Most of managers considered their rearing as a side job but agriculture was appointed as a main job from most of them except wild boar managers. 2. The major cost items were breeding stock and feeding which occupied over than half. 3. The yearly profit was the highest in deer(25.5%) but the lowest in wild boar(10.3%). 4. The break-even point was the highest in wild boar(24 mil. won) but the lowest in pheasant(7.3 mil. won). 5. The optimum sales scale for a year was deer(11 heads), Pheasant(1,027 heads), Wild boar(69 heads) and Fox (102 heads).