• Korean Journal of Ichthyology
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• v.23 no.4
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• pp.278-287
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• 2011

Habitat environment, age and feeding ecology of Gobiobotia macrocephala were investigated to provide baseline data for ecological characteristics and recovery in the Seom River at Heungho- ri, Buron-myeon, Wonju-si, Gangwon-do, Korea from 2010 to 2011. G. macrocephala inhabited 10~40 cm in water depth, 8~20 cm bottom size and 40~120 cm/sec in current velocity, and pebble floor were factors to be important for inhabit density. Age group of G. macrocephala in May estimated from the standard length indicated that the 28~42 mm group is 1 year old, the 43~58 mm group is 2 years old, the 59~69 mm group is 3 years old and the 69~85 mm group is more than 4 years old, and the female was 4~10 mm larger than the male. G. macrocephala did mainly feeding with nocturnal fishes between 00 h to 06 h, and they fed mainly Trichoptera (57.7%), Diptera (26.0%) and Ephemeroptera (16.3%). And their small juvenile fed mainly Ephemeroptera and Diptera, however, they ate mainly Trichoptera while growing to adult fish.

• Journal of Animal Environmental Science
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• v.17 no.1
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• pp.33-38
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• 2011

Economic development involves increase in life expectancy as well as human health care. Consequently, demand for fish meal and fish oil is rapidly growing. In particular, Krill (Eupausia superba) oil product is in high demand due to its rich unsaturated-fatty acid, and thus stable supplies are necessary in the krill oil market. It is required for captured krills to be immediately frozen and stored during ship transport, since proteins of the krill are quickly denatured in natural temperature condition. However, the transportation cost has been sharply increased, which encourages researchers to involve in studies for development of efficient oil extraction process. In this study, a solid/liquid separation technique on boat for the krill oil was developed through triple separation tests using only a separator or using either brush or crusher prior to the separator. The separation tests revealed that the efficiency were 46.2, 60.2 and 60.4 % by the separator, combination with brush, and combination with crusher, respectively. In addition, it was found that byproduct, extracted cake, derived from the separation process could be used as a feed stuff. These results suggest that smashing using the brush or crusher prior to the separator is more efficient than using only the separator.

• Korean Journal of Environment and Ecology
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• v.25 no.5
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• pp.666-672
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• 2011

This study examined the different growth rate of larval salamander Hynobius leechii by the predation risk. We collected salamander's eggs from Mountain Inwang. Eggs were treated by two different conditions: (1) cue - which had a predation risk three times a day; (2) no cue - which had no predation risk. Predation risk was conducted by using chemical cue from Chinese minnows. The chemical cue treatment started from the next day after the collection and ended one week after the hatching. Between the first week and the second week after the hatching we fed salamander larvae with tubifex ad. libitium. After the treatment phase, we measured snout - vent length of the each larva on the first week and the second week after the hatching. The results showed that there was a significant difference in the growth rate by the predation risk. From these results we found that predation risk can cause the different growth rate to the larval salamander and these changes could be affect their mortality.

• Journal of Bio-Environment Control
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• v.10 no.1
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• pp.23-29
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• 2001

This experiment was conducted to investigate to investigate the effect of air circulation and forced ventilation of greenhouse on the development of fermented fruits in an oriental melon. An air circulation system and a forced ventilation system were operated during 09:30~17:00 at a 15 min. interval from Apr. 6, 5 days after fruit setting, to Jun. 29, everyday except rainy days. Wind velocities in the greenhouse were 0.06~0.08, 0.24~0.32, and 0.60~0.72m.s$^{-1}$ in the naturally ventilated (control), in the air circulated, and including leaf length and width, were observed between treatments. However, the amount of xylem exudate increased in the air circulated treatment as compared to the control. Percent of fermented fruits significantly decreased in the air circulated treatment as compared to the control. The forced ventilation treatment showed no significant difference in percent of fermented fruits as compared to the control or to the air circulated treatment.

• Journal of Bio-Environment Control
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• v.11 no.2
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• pp.56-60
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• 2002

Since the transmittance of solar radiation directly affected by the structural frames of greenhouse can be changed according to the ratio of diffuse to direct radiations, it is necessary to investigate the transmittance of greenhouse at the different weather conditions. We can easily get the data of total solar radiation from the Meteorological Administration, but we have to personally measure the photosynthetic photon flux (PPF). If the relationship between total solar radiation and PPF is established, the PPF can be simply acquired from the relationship. Sol it is required to develop the equation to calculate PPF depending on weather condition. This study was conducted to determine the transmittance of PPF at canopy level in glasshouse and the correlation between total solar radiation and PPF at clear and cloudy days. The variation phase of greenhouse transmittance at clear day was very different from that at cloudy day. It was concluded that the proper transmittance, depending on the weather condition, should be adopted to calculate the accurate total solar radiation and PPF in greenhouse. The transmittance of solar radiation was the same as that of PPF in greenhouse. It was confirmed that the ratio of PPF to total radiation increased as the amount of cloud increased. The correlation between the hourly total solar radiation and PPF was derived.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.6
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• pp.409-415
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• 2021

Medical waste management is becoming increasingly important, specifically in light of the current COVID-19 pandemic, as hospitals, clinics, quarantine centers, and medical research institutes are generating tons of medical waste every day. Previously, a traditional incineration process was utilized for managing medical waste, but the lack of landfill sites, and accompanying environmental concerns endanger public health. Consequently, an innovative sterilization shredding system was developed to resolve this problem. In this research, we focused on the design and numerical analysis of a shredding system for hazardous and infectious medical waste, to establish its operational performance. The shredding machine's components were modeled in a CAD application, and finite element analysis (FEA) was conducted using ABAQUS software. Static, fatigue, and dynamic loading conditions were used to analyze the structural stability of the cutting blade. The blade geometry proved to be effective based on the cutting force applied to shred medical waste. The dynamic stability of the structure was verified using modal analysis. Furthermore, an S-N curve was generated using a high cycle fatigue study, to predict the expected life of the cutting blade. Resultantly, an appropriate shredder system was devised to link with a sterilization unit, which could be beneficial in reducing the volume of medical waste and disposal time, thereof, thus eliminating environmental issues, and potential health hazards.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.6
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• pp.642-649
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• 2001

Precision parts and instruments are tested to evaluate performance in development-process and product-step to prement a potential defect due to a failure design. In this paper, Environmental test technology, which is the basis of reliability analysis, is introduced with examples of test criterion, test method for products, encoder and traffic signal controller, and measuring instruments. Recently, as the importance of the environmental test technology is recognised. It is proposed that tranining of test technician and technology of jig design and failure analysis are very essential.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10a
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• pp.433-435
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• 1998

인터넷이 그 규모 및 정보의 내용에서의 대형화를 지향하면서 분산환경에서 사용자들의 정보에 대한 요구가 날로 증가하고 있고, 이를 만족시킬 수 있는 저 단계로 정보 수집이라는 것이 새로운 문제로 떠오르고 있다. 이에 에이전트를 기반으로 구성된 분산 디지털 도서관상에서 웨 정보 서비스를 제공하기 위한 로봇 에이전트를 설계.구현하였다. 구현된 로봇은 JAVA와 RMI를 기반으로 에이전트화를 통해 분산환경 구조를 갖추고 있으며, 멀티 쓰레드와 로봇 제어 알고리즘을 통해 정보의 수집 및 관리에 있어서 로봇의 신뢰도를 향상 시켰고 DBMS와 에이전트의 연계를 통한 대용량 처리 기능과 관리자의 관리의 편리성을 도모하기 위해 자동화 기능을 갖추었으며, 로봇과 관련되어 발생할 수 있는 부하를 최소화 할 수 있도록 하였다.

• Journal of Environmental Science International
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• v.10 no.6
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• pp.437-444
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• 2001

The characteristic features of surface ozone concentration and the forecasting procedure of high ozone days have been studied. The ozone concentration was continuously measured during 3 years (1997~1999) at air quality monitoring stations in five major cities in Korea. The diurnal variation of surface ozone concentration on high ozone days is characterized by low ozone concentration at night. The ozone concentration Increases continuously after sunrise, In reach a peak at 1500~1600 LST. Thereafter it decreases steadily to a low concentration at sunset. The diurnal and annual maximum of the surface ozone concentration at Seoul were observed in May and June, respectively. The favorable synoptic condition for the high ozone day is divided into 4 different synoptic weather patterns: a high-pressure system from the Sea of Okhotsk, the Pacific subtropical high extending westward, a moving high-pressure system covering the Korean peninsula. and a synoptic system In front of a typhoon. Most of high ozone days occur under the high pressure system in Korea.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.221-222
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• 2003

최근 농촌지역의 생물질 소각으로 인해 일시적이나마 시정의 급속한 악화, 호흡곤란과 같은 심각한 대기오염문제가 발생하고 있다. 우리 나라의 경우 이러한 생물질 소각은 주로 농사활동과 깊은 관련이 있는데 봄철과 가을철에 많이 발생한다. 본 연구의 측정 지점의 선행 연구결과를 보면 생물질 소각이 활발히 전개된 시기 12시간 포집된 PM2.5의 질량농도가 200$\mu\textrm{m}$/m$^3$까지 이르는 것으로 나타났고(박승식, 2002), 비록 연구시기는 다르지만 작년 6월 측정결과에 따르면 생물질 소각이 없었던 날에 비교하여 PM10, PM2.5 질량분포가 각각 340%, 360%증가하는 것으로 조사되었다(유성윤, 2002). (중략)