Modeling of CO₂ Emission from Soil in Greenhouse

Lee, Dong-Hoon,Lee, Kyou-Seung,Choi, Chang-Hyun,Cho, Yong-Jin,Choi, Jong-Myoung,Chung, Sun-Ok Korean Society of Horticultural Science 2012 원예과학기술지 Vol.30 No.3

Greenhouse industry has been growing in many countries due to both the advantage of stable year-round crop production and increased demand for fresh vegetables. In greenhouse cultivation, $CO_2$ concentration plays an essential role in the photosynthesis process of crops. Continuous and accurate monitoring of $CO_2$ level in the greenhouse would improve profitability and reduce environmental impact, through optimum control of greenhouse $CO_2$ enrichment and efficient crop production, as compared with the conventional management practices without monitoring and control of $CO_2$ level. In this study, a mathematical model was developed to estimate the $CO_2$ emission from soil as affected by environmental factors in greenhouses. Among various model types evaluated, a linear regression model provided the best coefficient of determination. Selected predictor variables were solar radiation and relative humidity and exponential transformation of both. As a response variable in the model, the difference between $CO_2$ concentrations at the soil surface and 5-cm depth showed are latively strong relationship with the predictor variables. Segmented regression analysis showed that better models were obtained when the entire daily dataset was divided into segments of shorter time ranges, and best models were obtained for segmented data where more variability in solar radiation and humidity were present (i.e., after sun-rise, before sun-set) than other segments. To consider time delay in the response of $CO_2$ concentration, concept of time lag was implemented in the regression analysis. As a result, there was an improvement in the performance of the models as the coefficients of determination were 0.93 and 0.87 with segmented time frames for sun-rise and sun-set periods, respectively. Validation tests of the models to predict $CO_2$ emission from soil showed that the developed empirical model would be applicable to real-time monitoring and diagnosis of significant factors for $CO_2$ enrichment in a soil-based greenhouse.

Modeling of CO₂ Emission from Soil in Greenhouse

Dong Hoon Lee,Kyou Seung Lee,Chang Hyun Choi,Yong Jin Cho,Jong-Myoung Choi,Sun-Ok Chung 한국원예학회 2012 원예과학기술지 Vol.30 No.3

Greenhouse industry has been growing in many countries due to both the advantage of stable year-round crop production and increased demand for fresh vegetables. In greenhouse cultivation, CO₂ concentration plays an essential role in the photosynthesis process of crops. Continuous and accurate monitoring of CO₂ level in the greenhouse would improve profitability and reduce environmental impact, through optimum control of greenhouse CO₂ enrichment and efficient crop production, as compared with the conventional management practices without monitoring and control of CO₂ level. In this study, a mathematical model was developed to estimate the CO₂ emission from soil as affected by environmental factors in greenhouses. Among various model types evaluated, a linear regression model provided the best coefficient of determination. Selected predictor variables were solar radiation and relative humidity and exponential transformation of both. As a response variable in the model, the difference between CO₂ concentrations at the soil surface and 5-㎝ depth showed are latively strong relationship with the predictor variables. Segmented regression analysis showed that better models were obtained when the entire daily dataset was divided into segments of shorter time ranges, and best models were obtained for segmented data where more variability in solar radiation and humidity were present (i.e., after sun-rise, before sun-set) than other segments. To consider time delay in the response of CO₂ concentration, concept of time lag was implemented in the regression analysis. As a result, there was an improvement in the performance of the models as the coefficients of determination were 0.93 and 0.87 with segmented time frames for sun-rise and sun-set periods, respectively. Validation tests of the models to predict CO₂ emission from soil showed that the developed empirical model would be applicable to real-time monitoring and diagnosis of significant factors for CO₂ enrichment in a soil-based greenhouse.

혐기성소화에서 Aeration에 의한 수소생성에 관한 연구

이명주,김상철,장현섭,황선진 경희대학교 2005 環境硏究 論文集 Vol.14 No.-

Hydrogen gas was continuously produced by treating glucose-containing synthetic wastewater with sewage digester sludge. This research investigated the effect of aeration on biological hydrogen production in anaerobic digestion process. Aeration of 0.8, 2.5, 5, 10, 20 L-O₂/g-SS were used. After aeration, the batch reactor at 35℃ was operated on a mineral salts-glucose(20g/L). The maximum hydrogen production rate of 570 ml/L-area. was found at oxygen dosage of 5 L-O₂/g-SS and pH uncontrolled. When the reactor was controlled at pH 5.5 with 6N Noah and 4N CHI, hydrogen production rate is 3 times higher than that of the control.

바이오 휘드백 훈련을 통한 이완요법이 생리통 및 스트레스반응경감에 미치는 영향

이소우,김금순,최명애,이명선 서울대학교 간호대학 간호과학연구소 1999 간호학 논문집 Vol.13 No.1

The purpose of this study was to investigate the effects of a 4-week relaxation therapy using biofeedback on menstrual pain and stress for 35 sophomore and junior baccalaureate nursing students. A quasi-experimental pretest-posttest control group design was used. The relaxation therapy group included training sessions using respiration therapy augmented with biofeedback techniques for self-relaxation. A significant reduction of pain (P<.05) on the 1st and 2nd day of menstruation was reported on the visual analogue scale by the experimental groups, while that the control groups remained relatively unchanged. Also a significant reduction of pain (P<.05) was reported on the delivery pain scale by the experimental groups on the 2nd day of menstruation, while that of the control groups remained unchanged. However, there were no significant differences of pain on the 3rd and 4th day of menstruation between the two groups. A significant reduction of state of anxiety (P<0.5) was reported by experimental groups, while that of the control groups remained relatively unchanged. There were no significant changes in stress measured by the symptom of stress. The results of the study support the benefits of relaxation therapy using biofeedback on pain relief and stress.

Porter의 산업구조분석모형을 이용한 TFT-LCD 사업매력도 분석

이선규,이웅희,서명지,허연호,홍민정 금오공과대학교 산업기술개발연구원 2001 産業技術開發硏究 Vol.17 No.-

This study examined the key success factors and the degree of industry attractiveness in the TFT-LCD industries. The five competitive force factors include: barriers o entry, industry rivalry, threat of substitutes, supplier power and buyer power. As the result of this study, it was found that the key success factors were customer needs, high screen quality, low price, high performance, convenience and stability concerning with display device. This study provides another link in the chain of understanding of the industry attractiveness and key success factors in the TFT-LCD markets.

건조제를 이용한 벽부형진열장 밀폐도 간접측정

유혜선,김명남,이승은 국립중앙박물관 2001 박물관보존과학 Vol.3 No.-

박물관 진열장의 기밀성은 일반적으로 CO₂ 추적가스를 이용한 밀폐도를 측정함으로서 조사되어 왔지만 진열장 내부에 구멍을 내야하는 점은 사용 전이나 사용 중인 진열장에 대한 밀폐도 측정에 적용하는데 문제점으로 지적되어 왔다. 이에 진열장의 형상을 변화시키지 않고, 진열장의 밀폐도를 간접측정함으로서 사용 전이나 필요에 따라서는 전시중인 진열장에 대한 밀폐도를 측정할 수 있는 대안을 제시하고자 하였다. 밀폐도 간접측정법은 진열장 내부의 온습도 변화와 습도조절제(Art-sorb)의 중량변화를 통해 진열장의 기밀도를 간접적으로 알아보는 방법이다. 실험은 동일장소에 시공된 3개의 벽부형진열장을 대상으로 진열장내 조명을 켜지 않고 Art-sorb와 온습도 수집기를 넣고 12일간 진행하였다. 각 진열장내 온도와 습도 변동분을 주변변동분으로 나눠 변동율로 나타냈으며, 그 결과 온도 변동율에서는 벽부장A(0.67)가 벽부장B(0.69)나 벽부장C(0.79)보다 변동율이 적었으며 습도 변동율에서도 벽부장A(0.12)가 벽부장B(0.19)나 벽부장C(0.72)보다 변동율이 적어 기밀도가 가장 양호함을 알 수 있었다. 또한 CO₂추적가스를 이용한 직접 밀폐도 측정에서의 공기교환율에 대하여 간접 밀폐도 측정에서의 습도변동율을 대입해 보았다. The airtightness of museum cases in museums was measured by using CO₂ tracing gas, but it has been pointed that it has a problem with measuring the airtightness of a museum case which has a hole inside before it is used or while is being used. So studies tried to come up with alternatives which make it possible to measure the airtightness of a museum case before it is used or while it is being used if necessary by indirectly measuring the airtightness of the museum case without changing its form. Indirect measuring is done by measuring the change of Art-sorb weight and the change of temperature and humidity inside the museum case. Experiments were made for 12 days with three builtin wall case installed at the same place without turning on the lights but with Art sorb and the data logger of temperature and humidity put into museum case. The change rate was produced with the change of temperature and humidity inside the museum case divided by that of those around museum case. As a result, the temperature change rate of museum case A(0.67) was lower than that of museum case B(0.69) or museum case C(0.79). The humidity change rate of museum case A(0.12) was lower than that of museum case B(0.19) or museum case C(0.72) showing that its airtightness was the best. Also in the direct airtightness measurement by CO₂ tracing gas, the air exchange rate was compared with the humidity change rate by Art-sorb in the indirect measurement.

냉수 가글링과 젖은 거즈를 이용한 구강간호가 비강수술 환자의 갈증 및 구강상태에 미치는 효과 비교

이인선,심명숙,나은희,강재연,김지혜,황민영,윤계숙,성영희 병원간호사회 2006 임상간호연구 Vol.11 No.2

Purpose: This study researched the comparison of oral care methods between the wet gauze and the water gargling for nasal surgery patients. It executed to find out more effective method to relieve thirst. Method: We divided two groups; the wet gauze and the cold water garaling. We assessed patient's oral cavity state and sebjective oral dryness for three times; firstly before the intervention, secondly 15 minutes after 1st intervention and thirdly 15 minutes afrer 2nd intervention. Result: As the intervention, there was no difference on oral condition subhectvely, but there was a difference on thirsty reduction objectively. As the aral dryness has relieved through both methods. It showed the repeated gargling helps more to relieve oral dryness effectively than the wet gauge. At PACU, post nasal surgery patient's oral dryness was decreased with gauze more than two times, patient's oral dryness was relieved. Whereas the dryness was relieved after applying the cold water gargling for just one time. Conclusion: The water gargling is more effective intervention than the wet gauze. Especially, oral dryness was improved in the section of objetive oral assessment index.

구두의 제품관여과 구매동기에 관한 연구

이명희,이지선,송원영 誠信女子大學校 生活文化硏究所 2003 生活文化硏究 Vol.17 No.-

The objectives of this study were to classify the contents of purchase motives of shoes, to investigate the difference of purchase motives according to product involvement level and to examine how post-purchase satisfaction of shoes was influenced by purchase motives and demographic variables. Samples were 405 college women in the metropolitan area of Seoul. The data were analyzed by using factor analysis, Cronbach's a-reliability test, descriptive analysis, x^2-test, one-way ANOVA, Duncan's multiple range test, and discriminant analysis. The results of this study were as follows. First, The factors of purchase motives derived by factor analysis: F.1 'advertisement and impulsive buying', F.2 'quality and appearance', F.3 'economy and deficiency'. Second, there were significant differences in purchase motives according to product involvement level. Females high in product involvement expressed the highest advertisement and impulsive buying motive among involvement groups. Females medium in product involvement expressed the highest economy and deficiency motive. Third, females high in the motive of advertisement and impulsive buying purchased well known brand shoes more than females low in the motive. The more the purchase quantity of shoes, the higher the score on advertisement and impulsive buying and the higher the score on quality and appearance motive. Forth, there were significant differences in purchase motives and product involvement level according to major and social stratification of college women. Fifth, quality and appearance motive was the most important in discriminating post-purchase satisfaction dissatisfaction groups followed, by the motive of advertisement and impulsive buying, and social stratification. The accuracy rate of the predicting the groups by 3 variables was 65.4%. Quality and appearance motive and social stratification had positive effects to post-purchase satisfaction, and the motive of advertisement and impulsive buying had a negative effect.

경연 대회를 통한 초ㆍ중고생의 창의력 신장 효과에 관한 연구

이희복,육근철,류해일,김현섭,김희수,박달원,유병환,김선효,김여상,서광수,변두원,서명석,배성효,박종석,심규철,이성희 공주대학교 과학교육연구소 2001 과학교육연구 Vol.32 No.1

미래 사회를 대비하기 위한 개인의 개성을 존중과 창의적인 능력을 지닌 인간을 양성을 목적으로 충청남도 지역의 초 ㆍ 중고등학생들을 대상으로 한 창의력 경연대회가 공주대학교 과학교육연구소에서 개최되었다. 충청남도 초 ㆍ중 ㆍ 고등학생들을 대상으로 실시한 창의력 경연대회는 창조적 아이디어를 내어 스스로 문제를 해결해 나갈 수 있는 교육 프로그램을 제공하는 좋은 기회였음이 확인되었으나, 일부의 팀에서만 참신하고 재미있는 아이디어들이 제안되었다. 여학생의 참가자 수가 상당히 증가하였으며, 대체적으로 입상권의 학생들의 상당 부분이 여학생이라는 것이 특이할만하다. 학년이 올라감에 따라서 창의적인 아이디어를 내는 양이나 질에 있어서 뒤떨어지는 것으로 분석되었으며, 토론 학습의 적응력이 미흡하고 발표력 및 청취력에 있어서도 떨어지는 것으로 나타났다. 따라서 중 ㆍ고등학교의 학교교육에서도 학생들에게 프로젝트형 탐구학습 프로그램의 적용은 물론 토론식 수습을 통한 학생들의 사고의 전환의 기회를 제공해야 할 것으로 사료된다. The creativity competition was held to foster the creativity of elementary and secondary school students in the Institute of Science Education, Kongju national University. It was found that the creativity competition effected on the improvement of inventing creative ideas and problem solving activities. But, only some competitors participated in semifinal and final contests, presented original and interesting ideas. More female students participated in competition than last year. More female participants were awarded a prize than males. Totally, participants were defective in discussion and communication, and presentation and listening ideas. Increasing grades correlated inversely with creativity and originality. There is need of inquiry project teaming programs and presenting opportunities of conversion of thinking by discussing instructions in school

달리기 운동 프로그램이 시각장애인의 건강관련 체력에 미치는 영향

이명수,양점홍,홍순미,최재현,박원익,이창준 釜山大學校 附設 體育科學硏究所 2004 體育科學硏究所 論文集 Vol.20 No.-

The purpose of this study was to find out the effect of jogging(LSD ; Long Slow Distance) and walking training on health-related fitness of the blind.....