• Journal of the Korean association of regional geographers
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• 제2권1호
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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.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 한국방사성폐기물학회 2005년도 춘계 학술대회
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• pp.110-120
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• 2005

For utilizing vitrification to treat low and intermediate level waste, industrial pilot plant was designed and constructed in October 1999 at Daejon, Korea through the joint research program among NETEC, MOBIS and SGN. More than 70 tests were performed on simulated IER, DAW etc. including key nuclide surrogate(Cs, Co); this plant has been shown to vitrify the target waste effectively and safely, however, some dust are generated from the HTF(High Temperature Filter) as a secondary waste. In case of long term operation, it is also concerned that pipe plugging can be occurred due to deposited dust in cooling pipe namely, connecting pipe between CCM(Cold Crucible Melter) and HTF. In this regard, we have developed the special complementary system of the off-gas treatment system to recycle the dust from HTF to CCM and to remove the interior dust of cooling pipe. Main concept of the dust recycling is to feed the dust to the CCM as a slurry state; this system is regarded as of an important position in the viewpoint of volume reduction, waste disposal cost and glass melt control in CCM. The role of DRS(Dust Recycling System) is to recycle the major glass components and key nuclides; this system is served to lower glass viscosity and increase waste solubility by recycling B, Na, Li components into glass melt and also to re-entrain and incorporate into glass melt like Cs, Co. Therefore dust recycling is helpful to control the molten glass; it is unnecessary to consider a separate dust treatment system like a cementation equipment. The effects of Dust Cleaner are to prevent the pipe plugging due to dust and to treat the deposited dust by raking the dust into CCM. During the pilot vitrification test, overall performance assessment was successfully performed; DRS and Dust Cleaner are found to be useful and effective for recycling the dust from HTF and also removing the dust in cooling pipe. The obtained operational data and operational experiences will be used as a basis of the commercial facility.

• Journal of the Korea institute for structural maintenance and inspection
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• 제18권5호
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• pp.1-8
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• 2014

Structures requiring chemical resistance are usually coated with surface protecting agents, but the cost for maintenance and re-construction is incurred due to the low durability. Therefore, in this study, sulfur was polymerized and the performance was examined so that it could be used as the concrete surface protecting agents for structures requiring chemical resistance. The evaluation results indicated that for the spray of the sulfur polymer surface coating agents, the application of the gravity type was appropriate; and for the number of coating times, about 3 cycle spray gave the best results. For the surface condition of the concrete to be coated with the surface protecting agents, outstanding quality was obtained above room temperature ($20{\sim}30^{\circ}C$), and the bond strength increased as the temperature increased. The evaluation results of the strength characteristics depending on the filler content of the surface protecting agents indicated that about 20~40% filler mixing contributed to the strength improvement as it reduced the shrinkage of the sulfur polymer. Also, the mixing of silica showed larger increase in the bond strength than the mixing of fly ash, and the most outstanding bond strength characteristics could be obtained by the mixing of both silica and fly ash. In the case of the chemical resistance, the strength reduction was minimized and outstanding chemical resistance was obtained when the fly ash and silica were substituted by 20%, respectively. The performance evaluation of the chloride ion penetration indicated that for the specimens coated with the sulfur polymer surface protecting agents, the chloride ion penetration resistance increased by 29~48% compared to the specimen without the coating of the surface protecting agent. The examination of the coating condition of the surface protecting agents, compressive strength, bond strength, chemical resistance, and salt damage resistance indicated that in the range of this study, the optimal level was when the silica and fly ash were substituted by 20%, respectively, as the filler for the sulfur polymer.

• Journal of Bio-Environment Control
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• 제9권3호
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• pp.166-170
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• 2000

Three methods for heat collection, which were the flat solar collector, two fan with radiator, and square pipe method, were studied to sue efficiently solar energy in the three different glasshouses for two years. The flat plate solar collector method was made use of the commercial solar collector with collection area of 24$m^2$, the method of two fans with radiators collected solar energy at the top of the glasshouse. An thermal storage tank was constructed underneath in teach glasshouses. When an area of 1,000$m^2$ was heated to the minimum temperature of 9$^{\circ}C$, the decrease rate of heating fuel for the flat plate solar collector, the fan attached radiator and the square pipe methods were 7%, 19% and 28% respectively. The flat plate solar collector method, which could be heated approximately 40-50$m^2$, was currently used by most of the farmer. Under the condition, the decrease rate of annual heating fuel was 14% which was not better for an economic annual heating fuel. If the fan with radiator method was operated, the use of installation and maintenance were required. So, it could not be good economic efficiency of solar heating. The heating efficiency of the square pipe method was relatively better thant those of the flat plate solar collector or the fan attached radiator. Since the cost of materials and its installation of the use of square pipe method was lower than any other method. However, corrosion of the pipe, greater shade in the greenhouse and strength against the square pipe were problems that should be overcome in the square pipe method.

• Applied Chemistry for Engineering
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• 제28권1호
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• pp.101-111
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• 2017

Mineral carbonation is a technology in which carbonates are synthesized from minerals including serpentine and olivine, and industrial wastes such as slag and cement, of which all contain calcium or magnesium when reacted with carbon dioxide. This study aims to develop the mineral carbonation technology for commercialization, which can reduce environmental burden and process cost through the reduction of carbon dioxide using steel slag and the slag reuse after calcium extraction. Calcium extraction was conducted using NH4Cl solution for air-cooled slag and convert slag, and ${\geq}98%$ purity calcium carbonate was synthesized by reaction with calcium-extracted solution and carbon dioxide. And we conducted experimentally to minimize the quantity of by-product, the slag residue after calcium extraction, which has occupied large amount of weight ratio (about 80-90%) at the point of mineral carbonation process using slag. The slag residue was used to replace silica sand in the manufacture of cement panel, and physical properties including compressive strength and flexible strength of panel using the slag residue and normal cement panel, respectively, were analyzed. The calcium concentration in extraction solution was analyzed by inductively coupled plasma optical emission spectrometer (ICP-OES). Field-emission scanning electron microscope (FE-SEM) was also used to identify the surface morphology of calcium carbonate, and XRD was used to analyze the crystallinity and the quantitative analysis of calcium carbonate. In addition, the cement panel evaluation was carried out according to KS L ISO 679, and the compressive strength and flexural strength of the panels were measured.

• Journal of the Korean Geographical Society
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• 제42권1호
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• pp.133-155
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• 2007

The sustainable urban development has emerged as a new paradigm of urban studies in recent years. A review of the literature of land use and transport policies in relation to sustainable development reveals a consensus that the main objectives of sustainable strategy should decrease the numbers and length of journeys, and change the land use pattern towards mixed use and high density. However, there is a lack of empirical research as to what types of policies might influence effectively the reduction in the energy consumption and emission of $CO_2$. in order to sustain urban development. This paper tries to construct the conceptual structure of the PSS(planning support system), which is designed to the simulation of the probable effects of policies and planning of different kinds in cities, and evaluate the sustainablilty level according to construct the structure of the PSS(planning support system), which is designed to the simulation of the probable effects of policies and planning of different kinds in cities, and evaluate the sustainablilty level according to the alternative scenarios. The PSS is composed of three components (input-modeling-output). The core of PSS is integrating land use-transport-environment modeling. The advantages of integrating land use-transport-environment modeling are well known, but there are very few such integrated modeling packages in practice. So this paper tries to apply TRANUS software, which is an integrated land use and transport model. The TRANUS system was calibrated to city of Yongin for the base year. The purpose of the application of TRANUS to Yongin is to examine the operability of TRANUS system in Korea. From the outputs and results of operating the system, TRANUS may be effectively used to evaluate the effects of alternative sustainable urban development policies, since sustainablilty indicators can be extracted from several aspects such as land use consumption, total trips, distance and cost, energy consumption, ratio of transport split.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• 제22권7호
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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.

• Journal of Korean Society of Environmental Engineers
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• 제28권10호
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• pp.1016-1023
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• 2006

The water content of dewatered cake produced from belt press dewatering equipment was about 75 wt% which was some high to handle it, so the equipment contained a limit at the economical and environmental aspect. The thermal dewatering equipment built as an alternative to overcome several problems was set up at the sludge treatment field and estimated some feasibility as comparison with the dewatering performance of belt press. First, dewatering properties of waterworks sludge was analyzed by monthly. The sludge of a water shortage season contained a high organic content which led to be difficult to dewater the cake, the other side the sludge of rainwater season was ease to dewater because of low organic content. According to the results to analysis the water content of dewatered cake produced from two equipments on the base of the seasonal dewatering properties, the water content of dewatered cake produced from thermal dewatering for sludge of water shortage season was $41.6{\sim}48.3$ wt% and $71{\sim}84$ wt% from belt press. In the case of rainwater season, the water content of dewatered cake produced from thermal dewatering was $34{\sim}37.7$ wt% and $57{\sim}70$ wt% from belt press. It was understood that thereduction of water content of cake by thermal dewatering was larger than belt press. The economical aspect for two equipments was evaluated on considering the reduction of cake treatment amount as the decrease of water content of cake. When putting the cost index of thermal dewatering into 100, belt press was 121. This meant that thermal dewater was more economical than belt press by about 20% in the side of construction and operation. In conclusion, thermal dewatering equipment was estimated by producing the low water content dewatered cake as well as being operated with low coat.

• KDI Journal of Economic Policy
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• 제30권2호
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• pp.129-155
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• 2008

The rate of antibiotics prescription for an acute airway infection significantly varies depending upon the diagnosis type, specialty, and the location of the hospital along with many other related factors. The objective of this study is to empirically investigate the possible relationship between the antibiotics prescription rates for an acute airway infection and the degree of competition in the hospital market regions of mainly the providers of primary medical care services such as clinics, internal medicines, pediatrics and otorhinolaryngology department. Using the data from Health Insurance Review and Assessment Service (HIRA) regarding the hospitals' antibiotics prescription rates for the acute airway infection and controlling for selected variables of demand and supply sectors, this study tries to figure out that the degree of competition in the hospital market, regardless of what type of competition indexes we employed, has a statistically significant effect on the variations of antibiotics prescription rate of the clinics in local areas. This result implies that as an economic consideration itself, the change in the degree of competition in the hospital market can play a crucial role influencing the treatment behaviors of the medical doctors. More specifically, this study reveals that as the degree of competition increases the antibiotics prescription rate goes up. This result means that if the market becomes more competitive in a specific region so that it might cause a reduction in doctor's income, doctors with rational decision-making process, recognize that the benefit created from inducing patients' seemingly unnecessary demand for medical care (income effect) would be higher than the costs associated with sustaining their targeted income (substitution effect). It is because that the doctors are more likely to prescribe antibiotics which create relatively higher margins than other medical care services in order to sustain their targeted income when the hospital market competition becomes tighter. Even though this study empirically confirms that antibiotics prescription can be affected by the economic incentives, it still raises following issues as limitations of the study: first issue is about the representativeness of the hospital regions segregated for this study, which might be weak in explaining whether these regions are mutually exclusive in reality. Patients actually consider the quality of services, transportation cost, time costs, and any other related factors choosing the doctors or hospitals, and in that sense, this study rules out 'border-crossing' in using the medical care services. Second issue arises in capturing the data of antibiotics prescription rate. Since we use the average rate for each medical institution, we cannot figure out the average rate for each patient so that we are not able to control for the variation of patients' medical conditions. It is because of the unavailability of data regarding each patient's medical condition from HIRA. Thirdly, since this study mainly analyzes the medical institutions providing primary care such as clinics, internal medicines, pediatrics, and otorhinolaryngology department, it is skeptical of whether those institutions can represent the hospital market in respective regions and truly reflect the degree of competition. It needs to extend the study areas and disease types as well as any micro data for future studies.

• Korean Journal of Plant Resources
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• 제25권5호
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• pp.624-632
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• 2012

As there have been lately many worldwide resource challenges such as potential exhaustion of fossil fuels, sudden rise of oil price and ever-rising grain pricing due to global food crisis, there have been more interests focused on recycling vegetable oils and fats into clean natural fuel and producing new resources based on waste cooking oil as a part of reusing waste resources. An Experiment was performed by using ratio of 50:50, 75:25 (w/w) mixture of based rapeseed oil, camellia oil, and olive oil. 50:50, 25:75 (w/w) mixture of based palm oil. The result was that the oleic acid ($C_{18:1}$) got the lowest percentage of 42.8%, when we combined the mixture of rapeseed oil and soybean oil. While the highest percentage of 72.1% was when the mixture of camellia oil and rapeseed oil were combined at 50:50 ratio. In 75:25 (w/w) case, mixture of rapeseed oil and soybean oil got the lowest. The highest ratio was the mixture of camellia oil and olive oil. Based on the component of palm oil, the total saturated fatty acid was decreased. It is expected that stabilizing oxidation through controlling of fatty acid after mixture and that liquidity at a low temperature. The acid value indicated that stabilizing oxidation got a range of highest to lowest. Camellia oil ranked as the highest, followed by olive oil, and the oil seeds as the lowest in rank. Controlling iodine value through mixture and improvement of stabilizing oxidation will provide a good quality. The quality of color has no significant change about mixture in ratio and maintenance. The reduction of the cost of refining process is expected by controling of mixture ratio at biodiesel production in the future.