• The KSFM Journal of Fluid Machinery
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• v.17 no.5
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• pp.19-26
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• 2014

The cross flow turbine attracts more and more attention for its relatively wide operating range and simple structure. In this study, a novel type of micro cross flow turbine is developed for application to a step in an irrigational channel. The head of the turbine is only H=4.3m and the turbine inlet channel is open ducted type, which has barely been studied. The efficiency of the turbine with inlet open duct channel is relatively low. Therefore, a guide nozzle on the turbine inlet is attached to improve the performance of the turbine. The guide nozzle shapes are investigated to find the best shape for the turbine. The guide nozzle plays an important role on directing flow at the runner entry, and it also decreases the negative torque loss by reducing the pressure difference in Region 1. There is 12.5% of efficiency improvement by attaching a well shaped guide nozzle on the turbine inlet.

• The KSFM Journal of Fluid Machinery
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• v.17 no.5
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• pp.67-71
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• 2014

Recently, the cross flow turbine attracts more and more attention for its good performance over a large operating regime at off design point. This study adopts a very low head cross flow turbine that has barely been studied before, and investigates the effect of air layer on the performance of the cross flow turbine. As open duct is applied in this study and free surface model is used between the air layer and water, an engineering definition of efficiency, instead of traditional definition of efficiency, is used. As torque at the runner fluctuates up and down at a reasonable limit, statistical method is used. Pressure and water volume fraction contours are shown to present the characteristics of air-water flow. With constant air suction in the runner chamber, the water level gradually drops below the runner and efficiency of the turbine can be raised by 10 percent. All considered, the effect of air layer on the performance of turbine is considerable.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.575-578
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• 2013

Rice cultivation in the paddy field and the burning of crop residues have been identified as the important sources of methane emission in agricultural sector. This study aimed at assessment of the methane emission from croplands in the year of 2011 with the IPCC guideline methodology. Methane from rice cultivation was emitted 6,813 $CO_2$-eq Gg in 2011. According to the water management, methane emission amounts by continuously flooded and intermittently flooded were 1,499 and 5,314 $CO_2$-eq Gg, respectively. Methane emission by crop residues burning was highest in red pepper and followed by rice straw, pulses and barely in 2011. Methane emission by field burning was very little compared with rice cultivation.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.6
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• pp.671-680
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• 2013

This study was conducted to examine the consumption realities of processed food and the perception of food labeling with targets of university students attending schools in Daegu and Gyeongbuk areas. The reason for buying processed food was because it is easy to cook. As for the number of using processed food, it was answered that everyday dairy products, noodles, breads and snacks for 3~4 times a month, and meat processed foods, canned foods, sauces and frozen foods for 2~3 times a month. With regard to selecting processed products, both male and female students answered with taste and price first, barely considering the safety and nutritional elements. It turned out that they check the price, expiration date and country of origin in order upon buying processed foods. Most of them recognized food labeling, but answered that they checked it sometimes in order to check the 'expiration date' and the 'calories'. They were aware of the food nutritional contents indication. It was turned out that male students check it for nutrients and female students for weight control. The effect of the processed food indication was that it is easy to choose the necessary foods for health and as well as for comparing the food with other products. The satisfaction of the food labeling system was mediocre. The results indicated that the food indication system needs to be educated or promoted.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.5
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• pp.654-664
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• 2017

The temperature profiles upon high speed impact of reactive structural materials were analyzed. A two color pyrometer, which included high-speed camera, spectral splitter, and band pass filters, was utilized to measure transient temperature profiles during and after reactive metal samples impacted into steel plate with velocities of 1600~1700 m/s. The spatial temperature distribution was analyzed from the ratio of spectral radiances at two different wavelength in infrared zone, i.e. 700 and 900 nm. The measured temperatures were calibrated with black body source. Two different types of metal samples, namely aluminum and nickel, were employed to understand reaction behavior upon the impact of samples in ambient condition. According to our experiments, the Ni sample appeared to barely react with ambient air producing an instant small fireball, while Al sample reacts violently with air generating a relatively prolong fireball.

• KIEAE Journal
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• v.15 no.1
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• pp.53-60
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• 2015

Increase in energy consumption in building is a big concern world over. In Nepal, energy crisis is a big issue but energy demand in buildings is barely even thought about. In the southern part of Nepal, where the weather is mostly hot during the year, cooling in buildings is very important. This is an initial study regarding building design strategies which focuses on cooling energy consumption in the building. It can be seen from the study that simple passive strategies can be applied in building design which can support in decreasing cooling load. Different passive cooling strategies like orientation, building size, thermal mass, window design and two direct cooling strategies have been investigated in this study. Direct cooling strategies like shading and natural cooling helps in passive cooling. Different desing strategies have different impact on the cooling energy requirement and the study shows that thermo physical property of building materials has the maximum effect on the energy consumption of the building. Each design strategy creates and average of 20% decrease in energy consumption, whereas the thermal conductivity can have as much as 10 times more effect on the energy consumption than other design strategies.

• Journal of Dental Anesthesia and Pain Medicine
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• v.15 no.1
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• pp.1-4
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• 2015

In pediatric dentistry, chloral hydrate is habitually selected for sedation of uncooperative children. Although chloral hydrate has been used for decades, various adverse effects are reported and necessity for new alternative drugs has increased. Dexmedetomidine was approved by FDA for sedation at intensive care units (ICU) in 1999. Compared to conventional sedative drugs, dexmedetomidine has not only analgesic and sedative effects but also it barely suppresses the respiratory system. Due to these characteristics, dexmedetomidine is known as safe sedative drug for children and elderly patients. Furthermore, approved by KFDA in 2010 in Korea, the frequency of sedation using dexmedetomidine is increasing. However, due to its intravenous administration method, it was difficult to apply in pediatric dentistry. Recently, intranasal administration method was introduced which might be a new possible alternative of oral sedation. In this study, we compare the mechanisms, pros and cons of chloral hydrate and dexmedetomidine, introducing new possibilities.

• Journal of Korea Multimedia Society
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• v.18 no.8
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• pp.980-987
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• 2015

Most of cultural area which people enjoy and consume is kitsch culture, though the culture is barely acknowledged. In this multimedia era, people create, publish and enjoy contents of 'webtoon(web+cartoon)', which is relatively faster and more convenient to enjoy comparing to published cartoon. Contrarily to its physical growth, the webtoon shows difficulty in advancing with other genres, is full of irritative factors and contents, and has tough time to become more sophisticated one. This study derived characteristics of kitsch in webtoon, suggested the way of webtoon as an art by analyzing conditions and usage motivation of webtoon. The conditions of kitsch are uniformity of mass consumption, popular vein, catharsis, vicarious satisfaction, immediate feedback-requiring image flood, and reproduction of techniques. The usage motivations of webtoon are studied as pursuit of information, entertainment, relaxation, socialization, convenience, and effectiveness. Usage motivation factors in webtoon and kitsch culture are almost identical. Contrary to its past of being underestimated and vulgarly considered, kitsch is acknowledged as an 'kitsch art'. By studying the process of becoming an art, the study has its purpose to suggest the experimental and developing way to make webtoon be acknowledged as 'webtoon art'.

• Journal of Korean Society of Transportation
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• v.18 no.1
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• pp.27-34
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• 2000

This study analyzes the price elasticities of airline Passenger demand through the 'Stated Preference' technique which uses survey data. Because the domestic airfare has been regulated by the government. it is not easy to derive Price elasticity through the usual regression analysis with aggregate data and thus a special methodology is required for elasticity estimation. Therefore, in this study we estimated the Price elasticities of domestic air passenger demand and the modal share change rates to the alternative modes with logit model and sample enumeration method, by analyzing the survey data on air Passengers' demand behavior about the mode choice between air-rail. air-bus, and air-car. As the results, the estimated price elasticities are in the range of -0.6~-0.9, and rail is mainly chosen as an alternative mode. bus is chosen Partly, and car is barely used.

• Journal of the Korean housing association
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• v.21 no.2
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• pp.41-48
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• 2010

This study shows how the water space outside the housing impacts the indoor thermal environment. CFD simulation was used for this experiment to analyze the interior environment focusing on the effect of temperature control and the thermal comfort. A shape of perfect square, which creates the very basic space formation, was used and the simulation was processed looking at the size, distance, and the location of the water space. The results of the experiment are as follows. Firstly, introducing a water space with the same floor area size of the simulation model decreased the indoor temperature by 1 Celsius (3.72%). It was determined the interior environment was considered as a comfort zone when the water space was greater than 70% of the floor area. Secondly, there was not much influence to the level of thermal comfort of the interior environment when the distance to the water space from the housing was greater than 2 meters. Lastly, interpreting the location of water space, the effect of controlling the total areas' temperature was the greatest following with the surrounding of the formation. There barely was any change to the temperature considering the side and the rear of the area.