• 한국토양비료학회지
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• 제49권2호
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• pp.115-124
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• 2016

The objectives of this study were to evaluate the soil fertility about plastic film house, upland, and orchard in Gyeongbuk Province, Korea. The surface chemical properties of soil samples were investigated every 4 year from 2000 year at upland, 2001 year at orchard, and 2002 year at plastic film house. During 12 year's monitoring, mean soil pH was increased by 0.7 and 0.8 pH unit from pH 5.7 in upland and orchard, respectively, 0.5 pH unit from pH 6.5 in plastic film house. About 50% of all the field samples occupied within the recommended pH range (pH 6-7). Although soil organic matter (SOM) was gradually increased by about $10g\;kg^{-1}$ for 12 years, 40% of orchard, 49% of plastic film house, and 77% of upland soil samples were still below the 3% SOM. The mean concentration of available phosphate for 12 years in upland, orchard, and plastic film house were 530, 600, and $760mg\;kg^{-1}$, respectively. The relative frequencies exceeding the recommended available phosphate range ($300-550mg\;kg^{-1}$) were 43%, 53%, and 66% at upland, orchard, and plastic film house soils, respectively. $NH_4OAc$ exchangeable $K^+$ of upland, orchard, and plastic film house in the last soil test were 0.8, 0.9, and $1.6cmol_c\;kg^{-1}$, respectively. The relative frequencies above the recommended K level were 56% and 70% of orchard and plastic film house soil samples, respectively. The levels of crop nutrients except exchangeable Ca and Mg in upland soil were tended to increase gradually in the three fields. Exchangeable Mg, EC, available phosphate, organic matter and soil pH could be used as principle components to differentiate the chemical properties of three land fields. This analysis revealed that the soil fertility was affected by cropping method and field management, although additional research is needed to assess the importance of management on soil chemical properties and many fields indicate an opportunity for improvement in fertilizer management.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.799-802
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• 2002

Continuously variable transmission(CVT) mechanisms considered here combine the functions of a K-H-V type differential gear unit and a V-belt type continuously variable unit(CVU). As combining the functions of a K-H-V type differential gear unit and a V-belt type CVU, 24 different mechanisms are presented. Some useful theoretical formula related to speed ratio, power flow and efficiency are derived and analyzed. These mechanisms have many advantages which are the decrease of CVT size, the increase of overall efficiency, the extension of speed ratio range, and the generation of geared neutral.

• 한국정밀공학회지
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• 제20권2호
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• pp.199-208
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• 2003

Continuously variable transmission (CVT) mechanisms considered here combine the functions of a K-H-V type differential gear unit and a V-belt type continuously variable unit (CVU). As combining the functions of a K-H-V type differential gear unit and a V-belt type CVU, 24 different mechanisms are presented. Some useful theoretical formula related to speed ratio, power flow and efficiency are derived and analyzed. These mechanisms have many advantages which are the decrease of CVT size, the increase of overall efficiency, the extension of speed ratio range, and the generation of geared neutral.

• 전력전자학회논문지
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• 제10권4호
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• pp.403-410
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• 2005

본 논문은 정지궤도 위성을 위한 완전조절방식을 갖는 태양전지 어레이 션트 전압조절기를 나타낸다. 스위칭 션트 전압조절기는 태양전지 어레이 전력을 조절하는 어레이 스위치 모듈들로 구성된다. 이러한 태양전지 어레이 션트 모듈들은 스위칭을 통해 버스에 태양전지 회로가 접속되거나 분리되며, 단지 FPGA 로직변경 만을 통해 이전의 회로설계로부터 간단하게 확장이 가능하다. 제안된 설계회로를 검증하기위해 제어로직 및 최악조건해석이 수행되었으며, 시뮬레이션 및 실험결과를 보여준다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 춘계학술발표회논문집(2)
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• pp.515-519
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• 1997

The purpose of this study is to reduce the fast neutron fluence at the reactor pressure vessel(RPV) and to provide a basis for plant-life extension. In this study, different neutron absorbers were employed in the core outer assemblies of Kori Unit 1 Cycle 14. The modified assemblies were used to calculate fast neutron fluence at the RPV and to evaluate reduction of outer assembly power and total power in core. By comparison with the case of no suppression fixture, the fast neutron fluence of a case with two rows stainless steel around the assembly with natural uranium pins is decreased by 85.8%. It is noted that the modification of outer assembly is more efficient than the previous low leakage loading pattern (LLLP) applied to Kori Unit 1. Also, compared fast neutron fluence in Cycle 1 with Cycle 14, fast neutron fluence at the RPV between Cycle 1 and Cycle 14 is not significantly different. It is found that LLLP applied to the Kori Unit 1 has not contributed to fast neutron fluence reduction at the RPV.

• 충청수학회지
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• 제21권2호
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• pp.269-278
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• 2008

Let ${\partial}D$ be the boundary of the open unit disk D in the complex plane and $L^p({\partial}D)$ the class of all complex, Lebesgue measurable function f for which $\{\frac{1}{2\pi}{\int}_{-\pi}^{\pi}{\mid}f(\theta){\mid}^pd\theta\}^{1/p}<{\infty}$. Let P be the orthogonal projection from $L^p({\partial}D)$ onto ${\cap}_{n<0}$ ker $a_n$. For $f{\in}L^1({\partial}D)$, ${\hat{f}}(z)=\frac{1}{2\pi}{\int}_{-\pi}^{\pi}P_r(t-\theta)f(\theta)d{\theta}$ is the harmonic extension of f. Let ${\hat{P}}$ be the composition of P with the harmonic extension. In this paper, we will show that if $1, then ${\hat{P}}:L^p({\partial}D){\rightarrow}H^p(D)$ is bounded. In particular, we will show that ${\hat{P}}$ is unbounded on $L^{\infty}({\partial}D)$.

• 한국응용곤충학회지
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• 제59권4호
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• pp.303-309
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• 2020

차먼지응애(Polyphagostarsonemus latus)는 잎들깨에서 잎을 직접적으로 가해하여 농가 소득에 치명적인 피해를 야기하고 있지만 표본단위가 설정되어 있지 않아 적절한 표본 조사가 이루어지지 못하는 상황이다. 따라서, 본 연구에서는 잎들깨의 주내분포 연구를 통하여 표본단위와 최적표본수를 제시하고자 수행하였다. 차먼지응애는 하나의 들깨잎에서 엽병 부위를 중심으로 개체가 형성되어 전체잎으로 퍼져나가는 특징을 보였으며, 이때 기간은 접종 후 25일이 소요되었다. 단위면적당 차먼지응애의 밀도를 조사한 결과, 접종 후 경과 기간에 관계없이 신초에서의 밀도가 중엽과 성엽보다 높아 대표성을 띠기 때문에 표본단위는 신초가 적합할 것으로 판단되었다. 주당 표본수는 1개의 신초에 있는 알과 약성충 모두를 조사할 경우 정밀도 0.25를 충족할 것으로 추정되었다. 따라서, 시설 잎들깨에서 차먼지응애의 표본조사는 주당 1개의 신초에서 알과 약성충을 조사 할 때 가장 정확도가 높고 경제적이었다.

• 한국건설관리학회논문집
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• 제12권3호
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• pp.131-139
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• 2011

본 연구는 공공시설공사에서 VE의 코스트모델과 공사현장의 진도관리, 그리고 공사비 분쟁에서 공간정보의 부재로 인한 공종별 공사비 내역 정보의 한계를 인식하고, 이를 극복하기 위하여 공사비의 인식체계를 공간단위로 전환하는 개선 방안의 하나로 제안하는 건축물 세부공간단위의 공사비 원가계산방법에 관한 것이다. 본 연구를 통해 제시한 공간단위의 공사원가 산정 시스템은 공사비를 구성하는 모든 공간 단위에서, 모든 공종, 공종을 구성하는 모든 자재, 노무 및 모든 비용 항목에 대한 정밀하고도 다차원적인 파악이 가능하게 하는 것이다.

• 대한치과보철학회지
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• 제31권3호
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• pp.303-316
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• 1993

The purpose of this study was to analysis the stress distribution induced by three unit PFM bridges and various cantilever bridges replacing maxillary latersal incisor. The simplified two-dimensional photoelastic models used for this study was contructed in the folio- wing way. CR/R ratio was designed to be 1 : 1, 1 : 1.25 and 1 : 1.5. The pontics of cantilever bridge supported by maxillary canines consisted of wrap-around type, rest-extension type, and simple type. 3-unit PFM bridge was constructed with traditional method. 1kg vertical static load was applied on the center of the incisal edge of the pontic. The stress pattern was examined and recorded by photography. The results obtained were as follows ; 1. The magnitude of stress on the abutment root apex area of a traditional 3-unit bridge was the lowest. 2. The model of cantilevered pontic with a rest showed the relatively well distributed stress around the abutment tooth. The model with simple pontic generated the greatest stress concentration in the supporting structure of the abutment tooth. 3. As the height of bone level reduced, the rotational and vertical force increased around the abutment tooth. 4. The stress concentration of the 3-unit bridges occured on the root apex and stress concentration of the cantilever briage occured on the root apex and cervix area, 5. In the case of the cantilever bridge, stress concentrated distally on the root apex area of the abutment tooth and additional stress was observed mesially on the upper part of the root. Especially in the case of the simple pontic, was phenomenon was more apparent than the others. 6. Force applied to cantilevered pontic was transmitted to the adjacent central incisor through the contact surface. Stress was markedly observed on the mesial cervix area in the case of simple pontic and on the root apex area in the case of wrap-around type and rest-extension type.

• East Asian mathematical journal
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• 제21권1호
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• pp.123-135
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• 2005

We have extended the $H^p$ space and estabilished the derivative of inner functions, Blaschke product on weighted Hardy spaces for the unit disc in complex plane.