http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Seung-Oh Hur,Jung-Hun Ok,Seon-Ah Hwang,Hee-Rae Cho,Yong-Seon Zhang,Hyup-Sung Lee 한국토양비료학회 2020 한국토양비료학회지 Vol.53 No.4
The soil temperature in the greenhouse reacts differently with changes of soil temperature affected by the outside temperature because it is heated in winter or cooled in summer to maintain the temperature. This study was conducted to analyze the changes of soil temperature by soil depth in the greenhouse and to create a model to predict soil temperature. As a result of measuring and analyzing from December 13, 2019, to May 28, 2020, the average soil temperature was lowest in January, and then continuously increased from February to May. The amplitude, which is the difference between the highest and lowest soil temperature, tends to decrease by the depth increases from 0-10㎝ to 50-60㎝. This tendency to decrease could be expressed as a function of exponential decrease by soil depth. As a result of comparison with the Fourier series and sinusoidal function models, the sinusoidal model shows statistically the same value with the Fourier series model and is more useful. However, since the sinusoidal function model is less accurate in predicting temperature change with a slope, a corrected model that can reflect the temperature change slope was required. As a result of the analysis, the following model could be used. [수식은 본문 참조] where, f(χ) is soil temperature, A₀ is initial temperature, An is amplitude, T is period, ø is phase, χ is time. This is a model in which a sine wave function representing periodicity is combined with a quadratic function that can take into account the slope of temperature change. If the quadratic function coefficient is positive, it can simulate the tendency to increase and decrease when the coefficient is negative. This model generally well-simulate soil temperature by soil depth during the measured period. The significance of this study is to analyze and predict the soil temperature in the greenhouse. Besides, the advantage of being able to take into account the gradient of temperature change can be used to predict soil temperature under outdoor conditions.
허승오(Seung-Oh Hur),류명진(Myong-Jin Ryu),류동기(Dong-Ki Ryu),정선옥(Sun-Ok Chung),허윤근(Yun-Kun Huh),최진용(Jin-Yong Choi) 충남대학교 농업과학연구소 2011 농업과학연구 Vol.38 No.4
Wireless technology has enabled farmers monitor and control protected production environment more efficiently. Utilization of USN (Ubiquitous Sensor Network) devices also brought benefits due to reduced wiring and central data handling requirements. However, wireless communication loses signal under unfavorable conditions (e.g., blocked signal path, low signal intensity). In this paper, performance of commercial wireless communication devices were evaluated for application to protected crop production. Two different models of wireless communication devices were tested. Sensors used in the study were weather units installed outside and top of a greenhouse (wind velocity and direction, precipitation, temperature and humidity), inside ambient condition units (temperature, humidity, CO2, and light intensity), and irrigation status units (irrigation flow and pressure, and soil water content). Performance of wireless communication was evaluated with and without crop. For a 2.4 GHz device, communication distance was decreased by about 10% when crops were present between the transmitting and receiving antennas installed on the ground, and the best performance was obtained when the antennas were installed 2 m above the crop canopy. When tested in a greenhouse, center of a greenhouse was chosen as the location of receiving antenna. The results would provide information useful for implementation of wireless environment monitoring system for protected crop production using USN devices.
석회암 유래 토양의 침투 및 투수속도 평가에 따른 수문유형 분류
허승오(Seung-Oh Hur),정강호(Kang-Ho Jung),손연규(Yeon-Kyu Sonn),하상건(Sang-Keun Ha),김정규(Jeong-Gyu Kim),김남원(Nam-Won Kim) 한국토양비료학회 2009 한국토양비료학회지 Vol.42 No.2
강원도 남부(영월)와 충북 제천, 단양 등지에 널리분포하는 석회암에서 유래된 토양은 점토 및 철분함량이 많은 식질계 토양이며 pH와 염기포화도(basesaturation)가 높은 붉은색 토양이다. 이 토양은 식양질과 식질 등의 세립(細粒)질로만 구성이 되어 있고자갈이 있는 토양으로 분류된다. 따라서, 토양의 침투및 투수속도가 우리나라 토양의 주 모재인 화강암이나 화강편마암 유래 토양과는 다른 양상을 보인다. 본연구는 세립질 특성을 보이는 석회암 유래 토양의 지표면에서의 침투속도와 토양층위별 투수속도를 측정해 복잡하게 세분되어 있는 토양의 종류를 수문학적 인 목적에 따라 단순화하기 위해 만든 수문학적 토양유형으로 분류하고자 하였다. 실험을 위해 이용된 토양은 과림, 모산, 장성, 마지, 안미, 평안의 6개 토양통이었고 장력 침투계(disctension infiltrometer)와 투수속도 측정계(Guelphpermeameter)로 침투 및 투수속도를 측정했다. 현장측정 이후 토양층위별로 시료를 채취하여 실험실조건에서 입도분포, 유기물함량을 측정했다. 토양통별 침투 및 투수속도를 측정한 결과는 유기물 층이 존재하는 과림통은 공극이 많고 토층 내에 나무 및 식물뿌리가 존재해 전체적으로 침투 및 투수속도가 빠른 특성을 보여 수문유형을 A로 분류하였다. 모산통은 토층 내에 자갈함량이 아주 높고 투수속도가 다른 토양에 비해 월등히 빠른 특성을 나타냈으나 50 cm이내에서 암반층이 존재하는 관계로 수문유형이 B/D로 분류되었다. 토층이 깊지 않은 장성통은 토층 내에 나무 및 식물뿌리가 많고 암석노출지가 존재해 침투속 도가 빠름에도 불구하고 C/D 수문유형으로 분류됐다. 자갈이나 잔돌이 많은 마지통은 잔자갈이 존재하고 침투나 투수속도가 빠른 편으로 B유형이었다. 논으로사용되는 안미통은 다른 석회암 유래토양에 비해 토층이 깊은 편이며 석회암 충적층에서 유래된 토양으로 선상지 및 곡간지에 분포한다. 관개된 상태에서 로타리 작업에 의해 표토의 특성이 교란되는 논으로 이용되는 특성 때문에 침투 및 투수속도는 느려 D유형으로 분류됐다. 잔돌이 존재하는 평안통은 석회암 붕적, 퇴적층으로부터 유래된 토양으로 산록경사지 및 선상단구에 분포하며 표토층인 A층에서 중 입상구조를 보이며 공극이 많고 작물뿌리가 매우 많아 침투속도는 빠르나 B층에서는 점토 함량이 감소했다 증가하면서 토성이 급격히 바뀌는 특성을 나타내 투수속도는 느린 값을 나타내 수문학적 토양유형은 D유형으로 분류됐다. Soils originated from limestone, located at the southern part of Kangwon province and Jecheon, Danyang of Chungbuk province are mainly composed of fine texture, and have different properties from soils originated from granite and granite gneiss, especially for water movement. This study was conducted for classification of hydrologic soil group (HSG) of soils originated from limestone by measuring the infiltration rate of surface soils and percolation rate of sub soils. Soils used for the experiment were 6 soils in total : Gwarim, Mosan, Jangseong, Maji, Anmi and Pyongan series. Infiltration and percolation rate were measured by a disc tension infiltrometer and a Guelph permeameter, respectively. Particle size distribution and organic matter content of the soils were analyzed. HSG, which was made by USDANRCS(National Resources Conservation Service) for hydrology, of Gwarim series with O horizon of accumulated organic matter was classified as type A which show the properties of low runoff potential, rapid infiltration and percolation rate. HSG of Mosan series, which has high gravel content and very rapid permeability, was classified as type B/D because of the impermaeble base rock layer under 50cm from surface. HSG of Jangseong series with shallow soil depth was classified as type C/D owing to the impermaeble base rock layer under 50cm from surface. HSG of Maji series was type B, and HSG of Anmi series used as paddy land was type D because of slow infiltration and percolation rate caused by the disturbance of surface soil by puddling. HSG of Pyeongan series having a sudden change of layer in soil texture was type D because of the slow percolation rate caused a the layer.