• FLOWER RESEARCH JOURNAL
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• v.17 no.3
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• pp.185-189
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• 2009

This study was carried out to investigate the effect of shading (50% or not) and pruning height (3cm, 6cm, and 9cm) of remained above-ground plant part on shoot emergence aspect, mortality rate, flowering and cut flower characteristics of two years old Gypsophila paniculata plants. Days to shoot emergence (80%) advanced, emerged shoot number increased and mortality rate surveyed on late October decreased in 50% shading treatment. In addition to, mortality rate decreased, as above-ground plant part was highly pruned. Blooming was earlier with highly pruning the remained above-ground pan and under non-shading condition than shading. Growth traits such flower stalk length, primary branches number, stem diameter, and cut flower yield were the best and also non-particulate rate and rosette formation rate were the lowest in pruning height of 9cm under non-shading condition.

• Journal of the Korea Organic Resources Recycling Association
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• v.6 no.1
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• pp.53-66
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• 1998

This study was carried out to investigate the typical composition of food waste from municipal solid wastes (MSW) and unit food waste generation rates from different sources in the model cities and to study the food waste management system from unit household to composting facilities. The annual average food waste composition of MSW was determined as 49% in Taejon and 52% in Chungnam Province, respectively. No big difference in food waste composition was found among the different sources. Since the paper waste generally occupied the half of food waste, over 75% of MSW was found to be compostable or biodegradable. Per capita food waste generation rate, 200~250g/capita day was determined by the direct measurement from 32 households, while 380g/capita day for Chungnam Province and 400 g/capita day for Taejon were estimated by the load count analysis In the sanitary landfills. This difference means people contribute generating food waste at outside house approximately twice as much as that at inside house. Per capita food waste generation rates from several sources were determined as follows; 166~215g/capita day at municipalities, 400g/visitor day at a first class hotel, 170g/student day at a university restaurant. Food waste generation from restaurant was strongly dependant upon it's level or quality; 670g/capita day at the high level restaurant, 190g/capita day at the middle class and 60 g/capita day at the lower class restaurant. The food waste reduction rate in a In situ fermentor showed 30~40g/kg day.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.1130-1135
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• 2009

Avian Influenza is an infectious desease of birds. The infection can cause a wide spectrum of symptoms in birds, ranging from mild illness to a rapidly fatal diseases which might bring a tremendous economic loss to poultry farms[1]. It can also give fatal diseases to human. Therefore it is important to surveil wildbirds that are primary transportation of avian influenza. This report showed a relationship between avian influenza and a habitat of wildbirds using system dynamics, and concluded with suggestion for surveilance.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.151-152
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• 2000

광양만권역은 석유화학산업과 제철공업등 대규모 공단에서 배출되는 질소산화물, 탄화수소류에 의한 오존 농도가 증가되고 있으며, 산성비 등의 2차 오염생성물질에 의한 광역지역의 대기오염 현상도 이들의 물질들이 깊이 관여하고 있다. 따라서, 광양만권의 대기질 개선을 위해서는 대기오염물질의 배출원 및 배출량 분포를 정확하고 세밀한 파악이 무엇보다도 중요하다. 따라서, 본 연구에서는 광양만권의 광화학 옥시단트(Ox) 예측모델의 개발에 사용될 오염물질 배출량을 고정발생량 및 이동발생량으로 구분하 산출하였다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.330-332
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• 2003

현대 사회는 인구, 산업, 경제, 활동이 도시에 집중되어 발달되고 있으며, 도시에서의 활동증가로 인한 교통량도 급격히 증가하고 있다. 급격히 증가된 인간의 생활환경 변화로 인한 오염물질의 배출도 역시 증가하여 우리의 주변환경을 심각하게 오염시키고 있다. 대기중에 존재하는 에어로졸 입자는 자연발생원에서 직접 대기중에 배출되는 해염입자, 토양입자 등과 같은 1차 입자(Primary particle)와 주로 연소, 소각 등에 의해 인위적으로 발생된 가스상 물질의 대기중에서 다양한 물리ㆍ화학적인 반응을 통해 생성되는 2차입자(Secondary particle)로 크게 구별할 수 있다. (중략)

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.195-195
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• 2011

플라즈마를 이용한 반도체 이온 주입 공정(Plasma Immersion Ion Implantation)에서 이온 도즈량(DOSE) 측정은 공정 신뢰성 및 재현성 확보를 위해 중요하다. 본 연구에서는 도즈량 측정을 위해 패러데이컵과 같이 측정 장비를 챔버에 직접 삽입 시키지 않고 챔버 외부에서 이온 주입을 위한 바이어스 전극의 직류 펄스 전압 및 전류 신호 측정을 통해 실시간으로 도즈량을 추출하는 방법을 개발하였다. 펄스 전압 신호에서 전압 신호 상승, 하강 시간에 의해 발생된 변위 전류와 플라즈마 발생 소스의 RF잡음등을 제거한 후 이온 포격으로 인한 2차 전자 방출 계수를 고려하여 펄스 동작 기간 추출을 통해 실시간으로 측정하는 알고리즘을 구현하였다.

• Korean Journal of Optics and Photonics
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• v.3 no.4
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• pp.239-243
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• 1992

We have investigeted the interference phenomena of the second harmonic waves of Nd:YAG laser generated at KDP single crystals and the nitrogen CARS signals. To get the phase difference between the successively generated nonlinear optical signals, a phase shifting unit made of BK-7 glass and a high pressure gas cell are used. Coherence lengths of several samples for the nonlinear signals are measured. Adjusting the thickness of the phase shifting unit where the CARS signals make destructive interference completely, the CARS spectrum of nitrogen suppressed over wide wavelength range is obtained. Also, we have observed the change in degree of suppression of the spectrum for the variation of the thickeness of the phase shifting unit.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.359-359
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• 2019

2011년 4대강 다기능보 설치에 따라 배수영향을 받는 구간은 기존의 측정방법으로는 유량측정이 어려워 보 구간별로 자동유량측정시설을 설치하여 실시간으로 유량을 생산하고 있다. 하지만 현재 수질개선 및 하천 자연화를 위해 보 운영수위를 저하시켰다. 이에 수위 저하에 따른 측정영역 한계로 정상적인 운영에 어려움이 발생하고 있다. 본 연구에서는 낙동강 합천창녕보 영향 구간 내 합천군(율지교), 합천군(적포교) 지점을 대상으로 상하류 유량관계를 활용하여 결측 및 오측자료를 보완하고자 한다. 대상지점은 2018년 수문개방에 따른 수위저하로 인한 결측과 부유물에 걸림에 의한 유속자료 오측으로 자료의 보완이 필요하였다. 이로 인해 자료 보완을 위하여 각 지점의 환산유량을 이용하여 경향성 검토를 하였으며, 상하류 환산유량과 검보정 측정성과와의 관계를 활용한 관계식을 개발하여 유량을 산정하였다. 산정된 유량과 검보정 측정결과 상관도(R2)는 0.95 이상으로 나타나 매우 합리적으로 판단되나 수문조작 시에 일부 편차는 보인다는 결과를 나타냈다. 단기적인 자료보완은 품질관리를 통해 다양한 방법으로 가능하지만 상하류 유량관계를 활용한 방법이 장기적인 자료를 보완하는 방법으로 적절하다고 판단된다. 향후 보완방법을 다른 보 구간의 지점에도 적용하여 보 수위저하에 따른 시설물 개선공사가 진행되는 동안 실시간 유량자료의 제공으로 연속적인 유량자료 생산이 가능하도록 하고자 한다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.6
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• pp.659-677
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• 2022

Hydrogen is emerging as a next-generation energy source and development and supply of FCEV (hydrogen fuel cell electric vehicle) is expected to occur rapidly. Accordingly, measures to respond to hydrogen car accidents are required and researches on the safety of hydrogen cars are being actively conducted. In this study, In this study, we developed a hydrogen car accident scenarios suitable for domestic conditions for the safety evaluation of hydrogen car in road tunnels through analysis of existing experiments and research data and analyzed and presented the hazard distance according to the accident results of the hydrogen car accident scenarios. The accident results according to the hydrogen car accident scenario were classified into minor accidents, general fires, jet flames and explosions. The probability of occurrence of each accident results are predicted to be 93.06%, 1.83%, 2.25%, and 2.31%. In the case of applying the hydrogen tank specifications of FCEV developed in Korea, the hazard distance for explosion pressure (based on 16.5 kPa) is about 17.6 m, about 6 m for jet fire, up to 35 m for fireball in road tunnel with a standard cross section (72 m²).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.2
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• pp.167-173
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• 2015

Green manure crops are organic materials that can supply organic matter and substitute chemical fertilizer, yet emit methane while being decomposed. Therefore, we experimented with different kinds of Green manure crops and tillage depth in order to decrease the amount of methane emitted when utilizing Green manure crops in paddy soil. The amount of methane emitted during the cultivation period of rice started to increase after transplanting and peaked at 63, and 74 days after transplanting, than decreased to almost none starting from 106 days. According to the kind of Green manure crop, it was highest in barley, then hairy vetch and chemical fertilizer. Depending on the tillage depth, the amount of methane emitted decreased by 22.5% in chemical fertilizer, 12.4% in hairy vetch and 11.7% in barley in 20cm tillage compared to 10cm tillage. The air temperature of methane test period was $30{\sim}40^{\circ}C$, and the soil temperature was more than about $2{\sim}10^{\circ}C$ lower than the air temperature. Due to the irrigation started before transplanting, the oxidation-reduction potential (Eh) of soil was rapidly reduced, and showed negative (-) values. Eh values mostly kept the range of -300~-500 mV during rice cultivation. It rapidly increased 106 days after transplanting. Rice yield the highest in hairy vetch and did not show differences according to tillage depth. Methane emission could be effectively reduced if the paddy soil was tilled by 20 cm during the application of hairy vetch.