• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.763-768
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• 2002

This study was performed in the airlift bioreactor using the nitrifier consortium entrapped in polyvinyl alcohol(PVA) for removing low concentration total ammonia nitrogen(TAN). At the superficial air velocity of 0.83 cm/sec, TAN removal rate and removal efficiency was $316.6{\pm}7.2g/m^3{\cdot}day$ and $92.8{\pm}2.2%$ respectively. Removal rate was continuously increased with decreasing hydraulic residence time(HRT) from 0.5 hr to 0.05 hr, whereas removal efficiency decreased with decreasing HRT. The optimum temperature for nitrification was $30^{\circ}C$ at which removal efficiency was $95.5{\pm}1.5%$. Nitrification was effectively performed at low temperature, $10^{\circ}C$. In the pH range from 7 to 9 in the bioreactor, removal rate and removal efficiency was $310{\pm}10g/m^3{\cdot}day$ and $94{\pm}3%$ respectively.

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.247-252
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• 2015

ZSM-5 crystals grew on the surface of ${\alpha}$-SiC and ${\beta}$-SiC particles by hydrothermal synthesis method. SiC particles which were > $50{\mu}m$ of size were used, and oxide layer were developed on the surface of the particles to induce growth of ZSM-5 from the surface. Then, synthesis time and temperature condition were considered growing ZSM-5. In this study, oxide layer was formed on ${\beta}$-SiC at $900^{\circ}C$ in air, and it was controlled to grow ZSM-5 grew from the ${\beta}$-SiC surface with $150^{\circ}C$ synthesis condition. This is due to Si-O-Si or Si-O-Al bond, which is basic framework of ZSM-5 can be easily formed, from the silicon oxide film on the surface of ${\beta}$-SiC. When the synthesis temperature was $200^{\circ}C$, the size of ZSM-5 was increased, and it covered much area of the SiC surface with better crystal shapes with longer synthesis time.

• 한국문화재보존과학회:학술대회논문집
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• 2004.10a
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• pp.15-24
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• 2004

The Seokgatap pagoda composed of mainly alkali granite and other minor pink-feldspar granite, fine-grained granite, granodiorite, diorite, gabbro, and tuff. Despite the small loss and damage derived from joints, its peel-off and exfoliation are serious enough to cause the heavy deterioration on the stone surface. The chemical and petrological weathering has partly replaced the original rock-forming minerals with clay minerals and iron oxyhydroxides. Based on the petrogenesis, rock materials of the pagoda is very similar to rocks of Dabotap pagoda and the Namsan granite in the Gyeongju. The central fart of the pagoda has sunken highly, which caused all the corners to split and the structural transformation to become worse. The reverse V-shaped gaps between the materials have broken stones filled in a coarse way. The iron plates inserted between the upper flat stone laid on other stones and tile pagoda body in the north and east side has been exposed in the air and corroded, discoloring of the adjacent stones. The overall diagnosis of the Seokgatap pagoda is the deteriorated functions of the stone materials, which calls for a long-term monitoring and plans to reinforce the stone surfaces. But the main body including the pagoda roof stone needs washing on a regular basis, and the many different cracks should be fixed with glue by using the fillers or hardeners designed for stone cultural properties after removing the cement mortar. In case of the replacement of the stone materials with new stones, it's necessary to examine the pagoda for the center of gravity and support intensity of the materials. The structural stability of the pagoda can be attained by taking a reinforce measure in geotechnical engineering and making a drainage. The ground humidity, which has aggravated weathering and structural instability, should be resolved by setting up a humidity reduction facility. The contamination of lichens and bryophyte around the pagoda and on the surface is serious. Thus biochemical treatments should be given too in order to prevent further biological damages and remove the vegetation growing on the discontinuous planes.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.118-128
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• 2016

As the interest on the air-pollution is gradually rising up at home and abroad, automotive and fuel researchers have been working on the exhaust emission reduction from vehicles through a lot of approaches, which consist of new engine design, innovative after-treatment systems, using clean (eco-friendly alternative) fuels and fuel quality improvement. This research has brought forward two main issues : exhaust emission and PM (particulate matter) particle emissions of gasoline vehicle. Exhaust emission and PM particle of automotive had many problem that cause of ambient pollution, health effects. In addition, researcher studied the environment problems of the MTBE contained in the fuel as oxygenate additives. The researchers have many data about the health effects of ingestion of MTBE. However, the data support the conclusion that MTBE is a potential human carcinogen at high doses. Based on the oxygenated fuel additive types (MTBE, Bio-ETBE, Bio-ethanol, Bio-butanol), this paper discussed the influence of oxygen contents on gasoline fuel properties and evaporative emission characteristics. Also, this paper assessed the acceleration and power performance of gasoline vehicle for the fuel property.

• Journal of the Ergonomics Society of Korea
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• v.27 no.4
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• pp.37-44
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• 2008

To design the cockpit of Korean helicopter, anthropometric data for Korean helicopter pilots as a target population is necessary. The present study measured the body sizes of Korean helicopter pilots to design the cockpit of Korean helicopter, and compared the measurements with those of Korean civilian and the US Army. The sample size was 100 which determined by a statistical analysis. Anthropometric measurements were collected for 100 samples (male = 94, female = 6; age group = 20~40) of Korean helicopter pilots by applying standard measurement protocol. To compare three anthropometric data, Korean civilian and US Army data were controlled by considering age group (20~40) and gender ratio (male: female = 9:1) of Korean helicopter pilots. The average body sizes of Korean helicopter pilots were mostly similar to those of Korean civilian, however, lower limb related variables (hip breadth, popliteal height and thigh clearance) and shoulder-to-elbow length were significantly greater (1~7%) at α=0.05. Furthermore, the average body sizes for Korean helicopter pilots regarding lower limb length and thickness were significantly smaller than those of the US Army (1~12%); however, the average body sizes for Korean helicopter pilots regarding upper body related variables (sitting height, sitting eye height, and acromial height) and hip breadth were significantly greater (0.7~1.9%). Lastly, size variability for Korean helicopter pilots was significantly smaller than those of Korean civilian and the US Army. Anthropometric data for Korean helicopter pilots of the present study was applied to design and evaluate a Korean helicopter cockpit.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.2
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• pp.82-95
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• 2011

The objective of this paper is to analyze the GIS-based water cycle system: rainfall, evapotranspiration, surface run-off of Gyeongsanam-do for the effective rainwater management. The rainfall(1999~2008) analyzed by a spatial interpolation method, showed relatively higher amount in Hadong-gun, Sanchung-gun, and Sacheon-gun on the southwest coast than in Changnyeong-gun, Miryang-si, and Changwon-si in the mideast inland. The evapotranspiration was calculated by the three independent variables: air temperature, landuse, and NDVI(normalized difference vegetation index). The analysis showed that Namhae-gun had the highest evapotranspiration of 93.71mm, and Jinhae-si and Changwon-si had the lowest values of 81.78mm and 84.37mm. The surface run-off was analysed by a run-off equation based on the SCS hydrologic soil classification and landuse. The amount of surface run-off showed that Hadong-gun had the highest value, of 90.40mm, and Geochang-gun had the lowest, of 46.69mm. The analysis results of the GIS-based water cycle system will be used to support the establishment of the effective rainwater management plan in Gyeongasngnam-do.

• Journal of Korea Port Economic Association
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• v.27 no.4
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• pp.73-90
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• 2011

Global companies regard the conditions of a location as one of the most crucial factors to assess the competitiveness of ports and the port hinterland, as well as emphasize creation of throughput and the importance of value added logistics in the hinterland under diffusing Supply Chain Management(SCM). This study deals with the evaluation of competitiveness in 7 hinterlands and the establishment of assessment model in hinterland. This study analyzes the importance of factors for the port hinterland competitiveness using AHP method. As a result, logistics factor, accounting for 62.3%, is shown as the relative more important factor, followed by hinterland's economy factors(27.3%) and city/policy factor(10.4%). The result implicates that measures to activate logistics factors with relatively high importance are essentially needed in order to improve the competitiveness of the hinterland of Busan New Port. Especially, it is needed to establish service routes of the port and air networks and to expand infrastructure for support. This study also assesses the competitiveness of hinterlands for the seven domestic and foreign ports based on importance of assessment factors for the hinterland competitiveness using AHP analysis. Busan(3.903) is ranked fourth behind Singapore(4.570), Hong Kong(4.357) and Shanghai(4.042) in assessment.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.253-263
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• 2016

Chrysanthemum production would benefit from crop growth simulations, which would support decision-making in crop management. Chrysanthemum is a typical short day plant of which floral initiation and development is sensitive to photoperiod. We developed a model to predict phenological development and leaf appearance of chrysanthemum (cv. Baekseon) using daylength (including civil twilight period), air temperature, and management options like light interruption and ethylene treatment as predictor variables. Chrysanthemum development stage (DVS) was divided into juvenile (DVS=1.0), juvenile to budding (DVS=1.33), and budding to flowering (DVS=2.0) phases for which different strategies and variables were used to predict the development toward the end of each phenophase. The juvenile phase was assumed to be completed at a certain leaf number which was estimated as 15.5 and increased by ethylene application to the mother plant before cutting and the transplanted plant after cutting. After juvenile phase, development rate (DVR) before budding and flowering were calculated from temperature and day length response functions, and budding and flowering were completed when the integrated DVR reached 1.33 and 2.0, respectively. In addition the model assumed that leaf appearance terminates just before budding. This model predicted budding date, flowering date, and leaf appearance with acceptable accuracy and precision not only for the calibration data set but also for the validation data set which are independent of the calibration data set.

• Journal of the Korean Electrochemical Society
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• v.8 no.2
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• pp.88-93
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• 2005

Anode-supported solid oxide fuel cell (SOFC) was investigated to increase the cell power density at intermediate temperature through control of the cathode structure. The anode-supported SOFC cell were fabricated by wet process, in which the electrolyte of $8mol\%\;Y_2O_3-stabilized\;ZrO_2 (YSZ)$ was coated on the surface of anode support of Ni/YSA and then the cathode was coated. The cathode has two- or three- layered structure composed of $(La_{0.85}Sr_{0.15})_{0.9}MnO_{3-x}(LSM),\;LSM/YS$ composite (LY), and $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_3{LSCF)$ with different thickness. Their single cells with different cathode structures were characterized by measuring the cell performance and ac impedance in the temperature range of 600 to $800^{\circ}C$ in humidified hydrogen with $3\%$ water and air. The cell with $LY\;9{\mu}m/LSM\;9{\mu}m/LSCF\;17{\mu}m$ showed best performance of $590mW/cm^2$, which was attributed to low polarization resistance due to LY and to low interfacial resistance due to LSCF.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.4
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• pp.109-120
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• 2016

This study aims to assess vulnerability in urban thermal environments of Seoul by using indicators frequently used in previous studies as well as effective indicators for spatial planning like urban and environmental planning. For this purpose, fifteen indicators that influence urban thermal environments such as heat waves, urban heat island effects, and urban micro-climates were identified based on literature reviews. Indicators for presenting urban structure and spatial properties were included; for example, building volume as 'exposure to climate', buildings completed before 1980 as 'sensitivity', and green space areas as 'adaptive capacity'. Among them, twelve indicators were applied to assess vulnerability in urban thermal environments of Seoul by using a GIS spatial analysis combined with fuzzy logic. The results show that the Gangnam area is identified as more vulnerable to a heat environment as compared to the Gangbuk area. In the Gangnam area, Seocho-gu, Gangnam-gu, Dongjak-gu, Yeongdeungpo-gu, Gangseo-gu were relatively high in vulnerability, while Dongdaemun-gu, Gangbuk-gu, Gwangjin-gu, Jungrang-gu were relatively high in the Gangbuk area. Gwanak-gu, Dobong-gu, Eunpyeong-gu, and Nowon-gu, which include forested areas, have low vulnerability in the sectors of 'exposure to climate' and 'sensitivity' due to the impact of Gwanaksan and Bukhansan. However, some areas with high vulnerability like Seocho-gu and Gangnam-gu may have lower vulnerability if the indicator 'status of air conditioning' from the sector of 'adaptive capacity' is used. This study could support the establishment of a practicable thermal environment policy and spatial planning to reduce heat-related risks in the field of urban and environmental planning.