• 한국작물학회지
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• 제45권3호
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• pp.190-194
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• 2000

남부지방 노지에서 식용 풋옥수수 2기작 적정 재식 거리를 구명하기 위하여 1997년까지부터 1998년까지 2년간에 걸쳐 풋옥수수로 적합한 찰옥 2호를 7월 10일 파종하였다. 재식 밀도는 ha당 55.5천본, 66.6천본, 83.3천본, 111.1천본으로 달리하여 주요 생육특성 및 수량반응을 검토한 결과를 요약하면 다음과 같다. 1. 간장은 재식밀도가 ha당 55.5천본일때 평균 154cm이었으나, 재식밀도가 증가할 수록 커져 111.1천본에서는 168cm로 컸다. 또한 착수고와 중심고도 유사한 경향을 보였으며, 재식밀도 차이에 따른 도복은 없었다. 2. 출사기에 조사한 단위면적당 건물중은 재식밀도의 증가에 따라 무거워졌고, 엽면적지수도 건물중과 비슷한 경향이었다. 3. 2기작에서 출사기는 재식밀도간에 차이가 없이 8월 27일로 동일하였다. 4. 이삭길이와 이삭폭은 재식밀도간에 유의적인 차이가 없었으나, 착립장은 가장 밀식인 ha당 111.1 천본에서 짧았다. 이삭수는 재식밀도가 증가함에 따라 많아졌으나, 이삭중은 ha당 83.3천본에서 2개년 평균 11.2 MT으로 가장 무거워 적정 재식밀도는 약 80천본으로 추정되었다.

• 한국해안해양공학회지
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• 제16권3호
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• pp.152-161
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• 2004

우리나라 연안 조위자료의 확률밀도함수 형태로 쌍봉형 정규분포 함수 형태를 제안하였다. 빈도분포 해석은 국립해양조사원에서 제공하는 인천, 군산, 목포, 제주, 여수, 마산, 가덕도, 부산, 포항, 속초 검조소의 1시간 간격 조위자료를 사용하였다. RMS 오차 및 결정계수($R^2$) 값을 비교ㆍ분석한 결과, 조위자료의 확률밀도함수로 본 연구에서 제안한 쌍봉형 함수가 기존에 사용하던 정규분포형 함수보다 더 적합한 함수로 파악되었다. 본 연구에서 제안된 함수의 매개변수는 Newton 방법을 수정한 Levenberg-Marquardt 방법으로 추정하였으며, 추정된 매개변수는 분석지점 검조소 자료의 비조화 상수와 밀접한 관계가 있는 것으로 파악되었다.

• 한국작물학회지
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• 제51권spc1호
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• pp.255-258
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• 2006

홍화 재배시 종실의 수량 감소가 적으면서 꽃잎 수량을 증가시키기 위해 밀식과 적심을 통하여 시험한 결과를 요약하면 아래와 같다. 개화기는 관행이 6월 23일인데 비해 적심 처리구는 2일 늦은 6월 25일에 개화하였으며 밀식처리구는 같았다. 유효분지수는 2열 밀식재배와 3열 밀식재배가 적심이나 대조구에 비해 많았으며, 유효화두수는 3열밀식재배에서 270개/$m^2$로 가장 많았으나 적심은 $186{\sim}223$개/로 적었다. 종실 수량은 대조구 10a당 220 kg에 비해 2열밀식재배는 231 kg으로 5% 증수 되었다. 채화 화두수는 3열밀식이 가장 많았으나 건조된 꽃잎 수량은 2열밀식과 3열밀식이 10a당 25.4 kg, 26.9 kg으로 대조구의 22.0 kg에 비해 각각 15%, 22% 증수되었다.

• 복식
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• 제58권1호
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• pp.9-16
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• 2008

Six of the Imdang tombs containing remains with imprints of ancient fabrics and textiles were investigated. Within the tombs, a total of 120 pieces of imprinted fabrics and textiles were investigated, all of which belongs to $5{\sim}6C$ Shilla period. All of the hemp textiles examined exhibited similar characteristics found in ancient hemp textiles: they were woven by plain weave technique with s-twist threads. The examined silk could be categorized into plain woven silk, cho, and double woven brocade, all of them made with non-twisted threads and degummed silk. The density of the plain woven silk ranged from 39 threads to 144 threads. Cho was also found, which showed similar characteristics to those of Gaya and Bakjae tombs. One piece of 2/1 twill weave on plain ground and 12 pieces of double woven brocade were found and their average density was $97.4{\times}33.4/cm$ with denser warp than weft. The various thickness of the threads were observed in the examined plain braid. The silk with twining technique showed thicker warp than weft. This is similar to the techniques of fabrics found in the King Muryeoung's Tomb of the Bakjae period. Fabrics with the purple-like color were observed in the some of the double woven brocades and also on the plain woven silk imprinted on the remains. The purple-like color was revealed to be purple with a tint of violet. The two tombs from which the imprinted fabrics with purple-like color were found belonged to top-class social level of the Shilla period, which informs that the purple color was used exclusively for the people of higher social status. The floss silk was found between the double woven brocade and plain woven silk of the belt, which is an important evidence that the floss silk was used for stuffing in the early 6th century.

• Investigative Magnetic Resonance Imaging
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• 제20권2호
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• pp.95-104
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• 2016

Purpose: To evaluate the knee joint after double-bundle anterior cruciate ligament (ACL) reconstruction with three-dimensional (3D) isotropic magnetic resonance (MR) image, and to directly compare the ACL graft findings on 3D MR with the clinical results. Materials and Methods: From January 2009 to December 2014, we retrospectively reviewed MRIs of 39 patients who had reconstructed ACL with double bundle technique. The subjects were examined using 3D isotropic proton-density sequence and routine two-dimensional (2D) sequence on 3.0T scanner. The MR images were qualitatively evaluated for the intraarticular curvature, graft tear, bony impingement, intraosseous tunnel cyst, and synovitis of anteromedial and posterolateral bundles (AMB, PLB). In addition anterior tibial translation, PCL angle, PCL ratio were quantitatively measured. KT arthrometric values were reviewed for anterior tibial translation as positive or negative. The second look arthroscopy results including tear and laxity were reviewed. Results: Significant correlations were found between an AMB tear on 3D-isotropic proton density MR images and arthroscopic proven AMB tear or laxity (P < 0.05). Also, a significant correlation was observed between increased PCL ratio on 3D isotropic MRI and the arthroscopic findings such as tear, laxities of grafts (P < 0.05). KT arthrometric results were found to be significantly correlated with AMB tears (P < 0.05) and tibial tunnel cysts (P < 0.05). Conclusion: An AMB tear on 3D-isotropic MRI was correlated with arthroscopic results qualitatively and quantitatively. 3D isotropic MRI findings can aid the evaluation of ACL grafts after double bundle reconstruction.

• Geomechanics and Engineering
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• 제16권1호
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• pp.71-83
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• 2018

Compacted bentonites were chosen as the backfill material and buffer in high level nuclear waste disposal due to its high swelling pressure, high ion adsorption capacity and low permeability. It is essential to estimate the swelling pressure in design and considering the safety of the nuclear repositories. The swelling pressure model of expansive clay colloids was developed based on Gouy-Chapman diffuse double layer theory. However, the diffuse double layer model is effective in predicting low compaction dry density (low swelling pressure) for certain bentonites, and invalidation in simulating high compaction dry density (high swelling pressure). In this paper, the new relationship between nondimensional midplane potential function, u, and nondimensional distance function, Kd, were established based on the Gouy-Chapman theory by considering the variation of void ratio. The new developed model was constructed based on the published literature data of compacted Na-bentonite (MX80) and Ca-bentonite (FoCa) for sodium and calcium bentonite respectively. The proposed models were applied to re-compute swelling pressure of other compacted Na-bentonites (Kunigel-V1, Voclay, Neokunibond and GMZ) and Ca-bentonites (FEBEX, Bavaria bentonite, Bentonite S-2, Montigel bentonite) based on the reported experimental data. Results show that the predicted swelling pressure has a good agreement with the experimental swelling pressure in all cases.

• Advances in Energy Research
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• 제7권1호
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• pp.21-34
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• 2020

Energy storage devices have received a keen interest throughout the world due to high power consumption. A large number of research activities are being conducted on electrochemical double layer capacitors (EDLCs) because of their high power density and higher energy density. In the present study, an EDLC was fabricated using natural graphite based electrodes and ionic liquid (IL) based gel polymer electrolyte (GPE). The IL based GPE was prepared using the IL, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (1E3MITF) with the polymer poly(vinyl chloride) (PVC) and the salt magnesium trifluoromethanesulfonate (Mg(CF₃SO₃)₂ - MgTF). GPE was characterized by electrochemical impedance spectroscopy (EIS), DC polarization test, linear sweep voltammetry (LSV) test and cyclic voltammetry (CV) test. The maximum room temperature conductivity of the sample was 1.64 × 10^-4 Scm^-1. The electrolyte was purely an ionic conductor and the anionic contribution was prominent. Fabricated EDLC was characterized by EIS, CV and galvanostatic charge discharge (GCD) tests. CV test of the EDLC exhibits a single electrode specific capacitance of 1.44 Fg^-1 initially and GCD test gives 0.83 Fg^-1 as initial single electrode specific discharge capacitance. Moreover, a good stability was observed for prolonged cycling and the device can be used for applications with further modifications.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권10호
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• pp.461-469
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• 2005

In this paper, a double-excitation type single sheet tester is developed to measure the magnetic characteristics of the electrical steel sheets. The developed system has the uniform magnetic field area of 20$\times$20mm$^{2}$, and can be applied to the measurement of the magnetic characteristics of the Non-oriented and Grain oriented electrical steel sheets. In the developed system, the magnetic flux density and magnetic field intensity are measured by using B-coil and H-coil, respectively. The B-coil has 1 turn search coil for each direction, and H-coil has 640 and 640 turns for rolling direction and transverse direction on the Im thickness Glass-Epoxy basement, respectively. Through experiments, it Is shown that the system can measure the magnetic characteristics up to 1.87 of magnetic flux density in the rolling direction in case of the Grain oriented electrical steel sheet. The measured results are compared with those measured in Okayama university, .Japan.

• 한국재료학회지
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• 제27권11호
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• pp.617-623
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• 2017

Mesoporous carbon nanofibers as electrode material for electrical double-layer capacitors(EDLCs) are fabricated using the electrospinning method and carbonization. Their morphologies, structures, chemical bonding states, porous structure, and electrochemical performance are investigated. The optimized mesoporous carbon nanofiber has a high sepecific surface area of $667m^2\;g^{-1}$, high average pore size of 6.3 nm, and high mesopore volume fraction of 80 %, as well as a unifom network structure consiting of a 1-D nanofiber stucture. The optimized mesoporous carbon nanofiber shows outstanding electrochemical performance with high specific capacitance of $87F\;g^{-1}$ at a current density of $0.1A\;g^{-1}$, high-rate performance ($72F\;g^{-1}$ at a current density of $20.0A\;g^{-1}$), and good cycling stability ($92F\;g^{-1}$ after 100 cycles). The improvement of the electrochemical performance via the combined effects of high specific surface area are due to the high mesopore volume fraction of the carbon nanofibers.

• 설비공학논문집
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• 제2권2호
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• pp.119-126
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• 1990

In this study, the overall heat transfer coefficients are calculated on fluidized bed double pipe heat exchanger and single phase double pipe heat exchanger at the same condition. The effect of the particle size, its material, fluidizing velocity and static bed height on overall heat transfer coefficient has been investigated. The main conclusions obtained from the experiment are as follows. 1. The overall heat transfer coefficient of the fluidized bed heat exchanger is higher than that of single phase forced convective heat exchanger (maximum 2.3 times) 2. The value of the overall heat transfer coefficient increase with an increase in static bed height and decrease with an increase in particle size. 3. For the same particle size, the particle of low density can obtain higher overall heat transfer coefficient than that of high density.