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관개방법에 따른 논에서의 수문 및 수질특성에 미치는 영향
전지홍,윤춘경,최진규,윤광식 한국육수학회 2005 생태와 환경 Vol.38 No.1
관개방법이 논에서의 수문 및 수질특성에 미치는 영향을 파악하기 위하여 관개용수가 풍부한 지표수 관개지역과 관개용수가 부족한 지하수관개지역에서의 물수지 및 영양물질수지 분석을 실시하였다. 지표수 관개논은 영농기간동안 지속적으로 관개가 이루어졌으나, 지하수 관개논은 영농초기에만 이루어졌으며 그 이후에는 강우에 의해 담수심이 유지되어 지표유출은 지표수 관개논에 비해상대적으로 낮은 빈도를 나타내었다. 지표수의 영양물질 농도는 시비에 의해 크게 영향을 받는 것으로 나타났으며, 특히 다량의 시비가 이루어지는 영농초기(5~6월 중순)에는 높은 영양물질 농도를 나타내어 이 시기에 논에서 유출이 이루어진다면 하류 수계에 영향을 줄 것으로 판단되었다. 물수지 분석결과 지하수 관개논의 관개량, 지표유출량 등이 상대적으로 지표수 관개논에 비해 낮은 값을 나타내었다. 영양물질수지분석 결과 대부분의 유입은 시비에 의해 이루어졌으며, 유출은 지표유출이 많은 비중을 차지하였으나 지표유출과 침투유출사이의 비율은 토양의 특성에 좌우되는 것으로 판단된다. 외부에서의 유입을 제외하고 시스템내에서의 유출입만 고려한다면, 물관리가 효율적으로 이루어진 지하수 관개논에서 낮은 부하량을 나타내었다. 그러나 기비가 이루어지고 인위적인 낙수나 강우에 의한 유출이 발생할 경우, 높은 부하량 뿐만 아니라 고농도의 영양물질질이 수계로 유입되는 것으로 나타났다. 논에서의 비점오염관리를 위한 대안으로 현재 시행되고 있는 시비량 감소 뿐 아니라, 효율적인 물관리기법 개발이 포함되어야 할 것으로 판단된다. 특히 영농초기의 강우특성과 논에서의 담수기능을 고려해 볼 때 시비에 의한 높은 영양물질 농도를 나타내는 논 표면수의 유출을 효율적으로 억제할 수 있을 것으로 판단된다. 물꼬높이의 증가와 천수간단관개 영농초기의 강우에 의한 유출을 억제시킴으로써 부족한 관개용수의 절약 뿐만아니라 하류수계의 수질보호에 기여를 할 것으로 판단되며, 다양한 조건에 따른 환경적인 측떤 뿐 아니라 벼의 생리적인 측면은 장기적인 모니터링을 통해 반드시 고려되어 야 할 것이다. The comparison of water balance and nutrient loading from paddy field with different irrigation management were carried out during 1999-2002 at two different sites; one is irrigated with groundwater and the other is irrigated with surface water. For the surface water irrigated paddy field, irrigation was performed continuously during growing season. Whereas, initial irrigation with groundwater was applied during initial growing season, and the ponded water depth was maintained by natural precipitation since initial irrigation. The runoff frequency of groundwater irrigated paddy field was less than that of surface water irrigated paddy field. The nutrient concentration of ponded water was high by fertilization at early cultural periods, so reducing surface drainage during fertilization period can reduce nutrient loading from paddy fields. Amount of irrigation water to surface water irrigated paddy field was higher than to groundwater irrigated paddy field and evapotranspiration was similar because it is influenced by climate. Overall input in and output from paddy field irrigated with goundwater were less than that with surface water. This study indicate that efficient water management can reduce surface drainage outflow, save water, and protect water quality. It might be important BMPs for paddy field.
Widowhood and Depressive Symptoms Among Korean Elders: The Role of Social Ties
Jeon, Gyeong-Suk,Jang, Soong-Nang,Kim, Dong-Sik,Cho, Sung-Il Oxford University Press 2013 JOURNALS OF GERONTOLOGY SERIES B-PSYCHOLOGICAL SCI Vol.68 No.6
<P><B>Objectives.</B></P><P>This study examines the impact of social ties on the relationship between widowhood and depressive symptoms among the older Korean population.</P><P><B>Method.</B></P><P>Data were derived from the baseline survey of the Korean Longitudinal Study of Aging. The sample consisted of 1,953 men and 2,469 women aged ≥60 years who were married and had at least 1 child. The 10-item Center for Epidemiological Studies Depression Scale was the outcome measure. Multiple linear regression was used to evaluate the influence of social ties as the mediators and moderators on the relationship between widowhood and depressive symptoms.</P><P><B>Results.</B></P><P>The quality of relationship between women and their children accounted for 51.52% of the difference in depressive symptoms between married and widowed women, but only 11.36% between married and widowed men. The interaction of widowhood and the quality of relationships with children was significant only among men, and the interaction of this status and cohabitation with married children was significant only among women.</P><P><B>Discussion.</B></P><P>The quality of relationship with children plays an important mediating role in the relationship between widowed status and depressive symptoms among Korean men and women elders. Cohabitation with children may buffer mental distress for such women, and qualitatively good relationships with children may be important as moderators for the mental health of older Korean men after bereavement.</P>
Song, Gyeong Ju,Kim, Kyung-Bum,Cho, Jae Yong,Woo, Min Sik,Ahn, Jung Hwan,Eom, Jong Hyuk,Ko, Sung Min,Yang, Chan Ho,Hong, Seong Do,Jeong, Se Yeong,Hwang, Won Seop,Woo, Sang Bum,Jhun, Jeong Pil,Jeon, De Elsevier 2019 APPLIED ENERGY Vol.247 No.-
<P><B>Abstract</B></P> <P>We propose a piezoelectric energy harvesting technology installed in a roadway speed bump. We have installed a module that can charge mobile phones utilizing a speed bump piezoelectric harvester (SBPH), which is easy to apply to roads. A highly integrated module with 40 piezo-generators was fixed and installed at the center of the speed bump. When a medium-sized vehicle passed the module at a speed of 30 km/h, an output voltage of 144 V<SUB>max</SUB>, output current of 45.2 mA<SUB>max</SUB>, and output power of 4086.08 mW<SUB>max</SUB> (6.81 W/m<SUP>2</SUP>) were measured at a load resistance of 2 kΩ. When the vehicle passed over the SBPH nine times, it charged a capacitor (10,000 μF) to provide 6 V for about 200 s, and the charged electrical energy was enough to operate a cellphone. The self-controlled battery charging system via electricity generated by the piezoelectric module could be applied to a speed bump installed on an actual road.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The harvester was installed in common speed bump on an actual road. </LI> <LI> The harvesting module produces 4086.08 mW<SUB>max</SUB> and 6.81 W/m<SUP>2</SUP>. </LI> <LI> The harvester successfully charged a mobile phone without external energy source. </LI> <LI> These technologies can improve self-controlled charging system on actual road. </LI> </UL> </P>
한국형 패시브하우스를 위한 단열블럭시스템의 열성능 평가
전현석(Jeon Hyun-Seok),최경석(Choi Gyeong-Seok),강재식(Kang Jae-Sik),이승언(Lee Seung-Eon) 대한건축학회 2009 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.29 No.1(계획계)
Thermal insulation performance of building envelope is a key factor to reduce building energy consumption. Currently, most residential buildings are constructed by internal insulation method. Internal insulation method causes heat loss through thermal bridge effect, while it is economic and excellent in construction efficiency. In particular, heating energy loss is inevitable in 'ondol' system. External insulation method can minimize heat loss through thermal bridge effect. But domestic technologies for external insulation is not competitive in construction method and materials compare to developed countries. Thus, in spite of rising market demand for external insulation method to achieve energy efficiency, applicable technologies are insufficient. Therefore, this study evaluated the thermal performance of high density EPS insulation block wall system, which was developed to design a Korean passive house, during winter season as a mock-up test.
전현석(Jeon Hyun-Seok),최경석(Choi Gyeong-Seok),강재식(Kang Jae-Sik),이승언(Lee Seung-Eon) 대한건축학회 2009 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.29 No.1(계획계)
Lately, construction of large and high-rise buildings has steadily increased and in accordance with this trend, various envelope systems were developed. However. insulation methods applying to the envelope are insufficient, which cause interstitial condensation, energy losses, and discoloration of walls resulted from unappropriated construction. In this study, Ventilated Insulation System was used to consider conduction, convection, and radiation simultaneously. This research performed a field experiment to evaluate insulating performance comparing Ventilated Insulation System with Non-Ventilated Insulation System in winter.