• 한국환경복원기술학회지
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• 제12권2호
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• pp.29-39
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• 2009

Research was initiated to investigate a vegetation characteristics of the winter season by seeding periods. 3 seeding periods (Mid-December seeding plot, Late January seeding plot and Early March seeding plot) and 3 zones (the top zone, the middle zone and the bottom zone) in each plot were treated with 3 replications on the experimented slope. Data such as vegetation coverage (%), soil hardness (MPa), temperature ($^{\circ}C$) and moisture (%) content were analyzed. The vegetation coverage was high in Early March seeding plot, medium in Mid-December, and low in Late January seeding plot. Early March seeding plot was effective in moisture content, soil hardness, and temperature for the growth of vegetation when compared to Late January seeding plot and Mid-December seeding plot. From the standpoint of coverage ratio of plant species, the coverage of Dianthus sinensis and Albizzia julibrissin were high in the Late January seeding plot whereas the coverage of Lotus corniculatus and Cool-season turfgrass were high in Early March seeding plot. These results indicated that the high vegetation coverage of Dianthus sinensis and Albizzia julibrissin in Early March seeding plot was caused by scarification during winter season. There was no difference observed in plant height regardless of seeding periods except in early surveying time of May and June after seeding. As far as each zone of the plot was concerned, the vegetation coverage was high. in the bottom zone, medium in the middle zone and low in the top zone. The bottom area of the experimented slope was high in moisture content when compared to the middle zone and the top zone.

• Journal of Biosystems Engineering
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• 제34권3호
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• pp.190-196
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• 2009

The temperature of root zone is known as an important factor for the growth of crops and reduction of energy in greenhouse. The purpose of this study was to design the solar energy supply system to keep the optimum condition of root zone by soil warming. As a result of this study, soil warming compared with no warming changed on a large scale temperature rise effect by depth of soil. The greenhouse's inner temperature have an effect on the temperature of surface up to 15 cm, rised to about 1 hour after warming. In case of the temperature fluctuation, soil temperature was about $12^{\circ}C$ up to 15${\sim}$25 cm and it was $13.4^{\circ}C$ at greater depths. This results showed that the position of root zone was very different after 3 weeks of growth.

• 설비공학논문집
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• 제13권10호
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• pp.947-959
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• 2001

We propose a control scheme to control the indoor zone temperature via variable air volume (VAV) unit. To control the room temperature, state space model of the conditioned zone which is partitioned into nine artificial sectional regions is derived. The nonlinearity of the damper motion and actuator are considered for the practical use in the state space system description. The temperature control of the room temperature is performed by manipulating the degree of openness of the damper in relation to the local room temperature and the supplied air flow rate. In general, since a local temperature in the conditioned zone is measured, it is required to estimate the temperature values in each regions for the precise temperature control. We thus design a state observer to estimate the regional temperature, and use these values in the controller. The overall control system consists of the state observer based state feedback with the integral control. We compared the control results of the proposed scheme with those of cascade proportional and integral (PI) control, and showed that the scheme achieved precise control of the conditioned system.

• 생물환경조절학회지
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• 제10권1호
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• pp.30-35
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• 2001

본 연구는 겨울철 토마토 펄라이트경에서 야간 근권온도를 1$0^{\circ}C$, 15$^{\circ}C$, 2$0^{\circ}C$, $25^{\circ}C$ 및 대구조로 설정하여 생육과 근활력 및 양분의 흡수 특성을 조사코자 수행하였다. 터널 피복내 온도는 근권온도가 높을수록 다소 증가하였으나 대구조에 비해 3$^{\circ}C$ 이상 증가되지 않았다. 초장, 엽장, 엽폭 등의 생육은 2$0^{\circ}C$ 처리구에서 가장 좋았다. 경엽의 생체중 및 건물중은 2$0^{\circ}C$ 처리구에서 가장 높았으나, 뿌리의 생체중 및 건물중은 대조구에서 가장 낮았다. 근활력은 제 1화방 개화기에는 근권온도가 높을수록 증가하는 경향이었으나, 과실 수확기에는 2$0^{\circ}C$ 처리구가 가장 높았고 15$^{\circ}C$, $25^{\circ}C$, 1$0^{\circ}C$ 및 대조구 순으로 높았다. 칼륨 함량은 경엽과 뿌리 모두 근권온도가 높을수록 많았으나, 질소와 마그네슘 함량은 처리간에 차이가 없었다. 인산과 칼슘 함량은 경엽에서는 근권온도가 높을수록 증가하였으나, 뿌리에서는 감소하는 경향을 나타냈다. 주당 착과수와 평균과중은 온도가 높을수록 많고 무거운 경향이었으나 $25^{\circ}C$ 처리구에서는 15$^{\circ}C$ 또는 2$0^{\circ}C$ 처리구에서보다 적고 가벼웠다. 이러한 결과로 10a당 수량은 2$0^{\circ}C$ 처리구가 6.960 kg으로 가장 많았으며 15$^{\circ}C$, $25^{\circ}C$, 1$0^{\circ}C$, 대조구 순으로 많았다. 2$0^{\circ}C$ 처리구보다 낮은 온도에서의 수량감소는 기형과의 발생의 많은 것에, 그리고 $25^{\circ}C$ 처리구에서의 수량감소는 착과수가 적은 것에 기인되었다.

• 원예과학기술지
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• 제29권1호
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• pp.10-15
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• 2011

본 연구는 근권 온도가 팔레놉시스의 화경 발생과 생육에 미치는 영향을 알아보고자 시험을 수행하였다. 근권 온도는 15, 20, 25 그리고 $30^{\circ}C$로 처리하였으며, 기온은 실험기간 동안 $28^{\circ}C$ 이상으로 유지하였다. 팔레놉시스의 $CO_2$ 흡수, 생체중, 건물중 그리고 분지근수는 $25^{\circ}C$에서 가장 높고, $15^{\circ}C$에서 가장 낮았다. 하지만 안토시아닌 함량은 $15^{\circ}C$에서 가장 높고 $25^{\circ}C$에서 가장 낮았다. 3개월간 근권을 $25^{\circ}C$ 이하로 저온처리해도 화경은 발생하지 않았다. K, Ca, Mg의 함량은 근권온도에 따라 변했으나, N과 P의 함량은 차이가 없었다. Ca과 Mg은 $25^{\circ}C$에서 가장 높았던 반면, K은 $20^{\circ}C$에서 가장 높았다. 본 실험결과 팔레놉시스의 온도 감응 부위는 지상부이며, 영양생장에 적합한 근권 온도는 $25^{\circ}C$이다.

• 대한가정학회지
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• 제30권2호
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• pp.81-86
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• 1992

The purpose of this study was to investigate the psychophysical correponding to temperature and to establish the comfort zone of thermal environment for Korean in winter. An experimental investigation was carried out in climate chamber maintaining the air temperature at 20, 22, 24, 26℃ and subjects were 128 college-age Korean(64 males and 64 females) in good health. Data were analyzed by SPSS PC＋ packages. 'Neutral' on the thermal sensation ratings was most frequently indicated at 24℃ by subjects was 23.1℃ (male 24.0℃, female 22.7℃), therefore the comfort zone of thermal environment in winter was considered as 23∼24℃.

• 한국습지학회지
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• 제13권2호
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• pp.265-273
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• 2011

지하수-지표수 혼합구간(Hyporheic zone)은 지표수와 지하수의 온도변화에 민감하게 반응하는 구간이다. 지표수의 경우 대기온도에 영향을 받아 온도의 변화주기가 짧은 반면, 상대적으로 지하수는 온도 변화주기가 길다. 본 연구에서는 지하수-지표수 혼합구간의 유동강도와 방향을 고려하여 깊이별 온도의 수직적 분포특성 분석하였다. 현장자료를 이용한 1차원 열전달 해석 수행결과, 지하수-지표수 혼합구간에서 지하수 유출과 지표수의 유입이 일어나는 지점에서 온도의 분포는 상이한 양상을 보였다. 혼합구간의 수직적 온도 분포의 변화는 하천기저에서 가장 두드러지게 나타났다. 또한 열전달 해석 결과를 바탕으로 연구지 혼합구간의 온도분포는 유동강도보다 유동방향에 지배받았다.

• 에너지공학
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• 제10권3호
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• pp.223-232
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• 2001

보염기 후류에 형성되는 화산회생의 보염특성을 고찰하기 위하여 연료 분출각의 변화, 난류발생격자의 설치, 재순환영역 내에 보조 연료의 공급에 따른 화염의 안정범위, 재순환영역의 길이 및 온도, 재순환영역주변의 난류강도 분포를 측정, 고찰하였다. 재순환영역의 길이는 주 연료 분출량의 변화에 따른 영향을 받지 않지만, 연료 분출각 및 주류유속의 변화, 보조 연료의 공급 난류발생격자의 설치 등에 따라 영향을 받는다. 확산화염의 경우 일반적으고 재순환영역의 길이가 길수록 보염성이 불량하지만, 난류발생격자를 설치한 경우에는 재순환영역의 길이가 길수록 보염성이 양호하다. 재순환영역의 온도는 연료 분출각의 변화, 보조 연료의 공급, 난류발생격사의 설치 등에 따라 영향을 받으며, 이론 혼합기 상태에서 최고값에 도달한다. 일반적으로 재순환영역의 온도가 낮을수록 보염성이 양호하지만. 난류발생격자를 설치한 경우에는 재순환영역의 온도가 낮을수록 보염성이 불량하다. 화염이 형성되는 보염기 후류 영역에 대한 난류강도는 격자의 직경이나 구속비가 큰 난류발생 격자를 설치한 경우에 크게 나타나며, 난류강도가 강 할수록 보염성이 불량하다. 연료 분출각의 변화, 난류발생격자의 설치, 재순환영역 내에 보조 연료의 공급 등의 방법으로 확산화염의 보염특성을 제어할 수 있다.

• 한국안전학회지
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• 제30권2호
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• pp.63-69
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• 2015

Recoilless weapons, which lead strong back blast and impulse noise more than 160 dB, have been used in compliance with the regulation of the safety zone for the safe operations. However, the safety zone regulations for the newly developed weapons should be prepared since the existing guidelines do not provide any information concerning the reason for the safety zone. In this study, the outdoor launch tests were performed to collect the data such as noise, pressure and temperature of the back blast. An assessment method using data obtained from launch tests has been proposed to determine the safety zone. The safety zone has been determined with consideration for the following criteria: Impulse noise, temperature and pressure of the back blast and blast angle. As a results, new safety zones for them have been established for the recoilless weapon developed by ADD (Agency for Defense Development). We expect that this research can be used as a guideline for establishing a new safety zone regulation of similar weapon to be developed.

• 대한기계학회논문집B
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• 제24권10호
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• pp.1294-1299
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• 2000

The combustion characteristics have been investigated to develop the 50 kW-class gas turbine combustor. The combustor design program was developed and applied to design this combustor. The combustion air which has the temperature of 45, 200, $300^{\circ}C$ were supplied to combustor for elucidating the effect of inlet air temperature on CO, NOx emissions and flame temperature. The exit temperature and NO were increased and CO was decreased with increasing inlet air temperature. Also, the effect of equivalence ratio was considered to verify the combustor performance. The emissions of CO and NO with inlet air temperature can be analyzed qualitatively by measuring the temperature inside the combustor. The combustion performance with fuel schedule was evaluated to get the informations of the starting and part loading process of gas turbine. The combustion was stable above the equivalence ratio of 0.18. The pattern factor which is the important parameter of combustor performance was satisfied with the design criterion. Consequently the combustor was proved to meet the performance goal required for the target gas turbine system.