• 생물환경조절학회지
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• 제22권2호
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• pp.146-153
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• 2013

토마토 접목순화장치 개발을 위한 기초실험의 일환으로 대목의 종류 및 활착실내의 온습도가 접목활착율에 미치는 영향을 조사하였다. 접목활착실의 온도는 $23^{\circ}C>17^{\circ}C>20^{\circ}C>26^{\circ}C$ 순으로 초기 활착율과 최종활착율이 높은 것으로 조사 되었으며, 상대습도는 높을수록 활착율은 양호한 결과를 나타냈다. 단 상대습도가 90% 이상 처리구에서는 곰팡이병에 의한 이병주 발생도 같이 증가하는 경향을 나타냈다. 대목의 종류에 따른 초기활착율은 'Kanbarune'의 $26({\pm}1)^{\circ}C$와 'Solution'의 $20({\pm}1)^{\circ}C$를 제외하고는 대목의 종류와 관계없이 모든 온도 처리구에서 83% 이상 양호한 활착율을 보였으나, 최종 활착율에서는 처리 온도간에 뚜렷한 유의적 차이를 나타내, $23({\pm}1)^{\circ}C$에서만 대목의 종류와 관계없이 85%에서 90%전후의 활착율을 보였고, $20({\pm}1)$와 $26({\pm}1)^{\circ}C$에서는 65~75% 정도로 활착율이 저하되었다. 특히, $27({\pm}1)^{\circ}C$에서는 이병주의 증가로 건묘생산율은 모든 대목처리구에서 65% 이하였다. 일반적으로 알려져 있는 고온기 접목활착 최적온도인 $23({\pm}1)^{\circ}C$에서는 대목의 종류에 따른 건묘생산율은 84~88% 전후로 대목 품종간 유의적 차이는 없었다. 접목활착실내 상대습도 조건에 따른 최종 접목활착율은 초기 2~3일간은 상대습도를 90%로 유지하고 나머지 7~8일간은 75% 정도로 유지하는 처리구에서 100% 접목활착 성공율을 나타냈고, 전기간 90%로 유지한 처리구와 1일 90%, 9일간은 75%로 유지한 처리구에서는 90%전후의 성공률을 나타냈다. 전반적으로 높은 상대습도 유지기간이 길수록 초기 활착율은 증가하는 경향을 보였으나, 고습도에서 장기간 묘를 양생할 경우, 곰팡이병 발생 등으로 최종 건묘생산율은 감소하므로, 초기 2~3일간만 90% 전후로 유지하고 나머지 구간은 75% 전후로 유지하는 것이 고온기 토마토 접목 활착율 향상을 위한 바람직한 조건이라 판단되었다. 각 처리간 묘소질에는 큰 차이를 나타내지 않았으나, 전반적으로 활착율이 양호했던 처리구에서 묘소질이 타 처리구에 비해 상대적으로 좋았으며, 이러한 경향은 특히 근권부의 형태적 특성을 조사한 결과에서 명료하게 나타났다. 이상의 결과 고온기 토마토 활착실내의 환경관리는 23도 전후의 온도에서 $80({\pm}5)%$의 상대습도로 관리하는 것이 건묘생산에 적합할 것으로 판단되었다.

• 응용통계연구
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• 제19권1호
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• pp.163-170
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• 2006

역학(epidemiology) 또는 임상(clinic) 자료를 분석하기 위한 주효 측도의 선택에 대한 연구가 계속되고 있지만, 주효 측도들이 일반적인 함수 형태로만 표현되는 경우에는 주효 측도들의 특징이나 관계를 이해하는 것이 쉽지 않다. 이 논문에서는 주효 측도의 선택 문제 보다는 이변량 자료에 대한 주효 측도 중에서 위험도차이(risk different: RD), 상대위험률(relative risk: RR), 그리고 교차비(odds ratio: OR)를 방사형 그림(radar diagram)을 사용하여 나타내고 이 그림을 이용하여 이들의 특성이나 관계를 살펴보았다. 방사형 그림은 이 측도들을 이해하는데 좋은 도구가 될 것이다.

• Geomechanics and Engineering
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• 제14권1호
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• pp.1-8
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• 2018

This paper presents an investigation of the liquefaction characteristics and particle crushing of isotropically consolidated silica sand specimens at a wide range of confining pressures varying from 0.1 MPa to 5 MPa during undrained cyclic shearing. Different failure patterns of silica sand specimens subjected to undrained cyclic loading were seen at low and high pressures. The sudden change points with regard to the increasing double amplitude of axial strain with cycle number were identified, regardless of confining pressure. A higher cyclic stress ratio caused the specimen to liquefy at a relatively smaller cycle number, conversely producing a larger relative breakage $B_r$. The rise in confining pressure also resulted in the increasing relative breakage. At a specific cyclic stress ratio, the relative breakage and plastic work increased with the rise in the cyclic loading. Less particle crushing and plastic work consumption was observed for tests terminated after one cyclic loading. Majority of the particle crushing was produced and majority of the plastic work was consumed after the specimen passed through the phase transformation point and until reaching the failure state. The large amount of particle crushing resulted from the high-level strain induced by particle transformation and rotation.

• 설비공학논문집
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• 제9권1호
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• pp.14-22
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• 1997

The position of propeller fan from duct inlet is one of basic parameters for the design of propeller fan. To investigate the effect of its position on fan characteristics, the inlet flow fields and relative flow angles were measured by a 5-hole pitot tube. The experimental results indicate that the ratio of radial flow introduced from propeller circumference to total inlet flow increases with the increase of propeller distance from duct inlet. When fan operates without duct, the total flow rate and the radial flow ratio are higher than those of any other positions of propeller relative to duct inlet. The radial flow ratio decreases as a flow coefficient and the propeller distance decrease. Therefore the front flow fields can be adjusted in some extent by varying the propeller distance according to a fan loading. The inlet flow angles are decreasing a little as a rotational speed and the propeller distance decrease. In the present case it was judged that the deviation angle of outlet flow became negative owing to a flow separation near a trailing edge.

• 대한가정학회지
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• 제30권1호
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• pp.237-255
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• 1992

The purpose of this study was to investigate relations of resources and demands, family financial management and financial statement of urban households by applying a system approach. The results of this study were as follows; Saving rate had significant differences according to resources variables such as age, family life cycle, occupation of househead and housewife, ratio of employed to family member, and to demands variabels such as subjective prospect of business cycle, and value orientation, whereas total saving amount had significant differences according to resources vaiables such as age, family life cycle, educational level, percapita income, occupation of househead, type of income and to demand variable, perception of relative income. Also average monthly saving amount had significant differences according to resources vaiables such as educational level, per capita income, occupation of housewife, housing ownership, ratio of employed to family member, ratio of dependent to employed, and to demands variable, perception of relative income. The stocks had significant differences according to resources variables such as age, family life cycle, educational level, per capita income, occupation of househead, type of income, and housing ownership. Finally, real estate had significant differences according to resources variables such as age, family life cycle, educational level, percapita income, occupation of househead, type of income, housing ownership, and to demands variable, perception of relative income. Financial Statement among urban households according to family financial management had significant differences. And among all variables affecting financial statement among urban households, per capita income had the highest effect and perception of relative income was the second.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.768-773
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• 2004

When a gas expands through a convergent nozzle in which the ratio of the ambient to the stagnation pressures is higher than that of the critical one, the issuing jet from the nozzle is underexpanded. If a flat plate is placed normal to the jet at a certain distance from the nozzle, a detached shock wave is formed at a region between the nozzle exit and the plate. In general, supersonic moist air jet technologies with nonequilibrium condensation are very often applied to industrial manufacturing processes. In spite of the importance in major characteristics of the supersonic moist air jets impinging to a solid body, its qualitative characteristics can not even know. In the present study, the effect of the nonequilibrium condensation on the underexpanded moist air jet impinging on a vertical flat plate is investigated experimentally. Flow visualization and impact pressure measurement are performed for various relative humidities and flat plate positions. The obtained results show the plate shock and Mach disk are dependent on the nozzle pressure ratio and the relative humidity, but for a given nozzle pressure ratio, the diameters of the plate shock and Mach disk depend on the stagnation relative humidity. The impact pressure deviation from the flow of without condensation is large, as the relative stagnation humidity increases.

• 한국환경보건학회지
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• 제32권3호
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• pp.240-248
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• 2006

The purposes of this study were to investigate the symptoms, diseases and deaths of residents living near the municipal solid waste landfill site, and to compare the relative risk ratio of their adverse health effects with control group. In self-evaluation, the scores were especially severe lowest in residents of v2 and v3 villages(which were located about 500 m toward under the landfill site) such as 32.2 and 16.7 for village-environment, 24.8 and 16.0 for management of landfill site, and 23.5 and 16.5 for confidence of environmental policy, respectively. On symptoms, relative risk ratios were also highest as 3.53 and 3.55 for breathing difficulty, and 3.36 and 3.00 for respiratory symptom in v2 and v3 villages, respectively. On morbidity, they were slightly high as much as 1.39 and 1.24 in v5 and v2 villages, respectively. On mortality, relative risk ratios were $1.15{\sim}2.46$ in experimental villages. They were especially high as much as 2.46 in v3 village where located near under the landfill site, and also 2.14 in v5 village where located at area affected with the landfill site, but near the sea. The rate of cancer causing death was average 35.2% of total deaths. It was very highest as much as 61.1 % in v2 village, where was closely located near under the landfill site. Cancers causing death in this village were lung cancer(3 cases), larynx cancer(2 cases), stomach cancer(2 cases), pancreatic cancer(1 case), thryoid cancer(1 case), leukemia(1 case) and other(1 case). Our data, although based on limited number of cases and geographical coverage, suggest that residents living near landfill site have the increasing relative risks of various symptoms and mortality causing cancer. No causal mechanisms are available to explain these findings. But the possibility of a causal association between the increased adverse health effects and the municipal solid waste landfill site cannot be fully excluded.

• Journal of electromagnetic engineering and science
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• 제2권1호
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• pp.1-4
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• 2002

Performance improvement of the DS-CDMA system by the spectrum-overlap is important for better service quality or more system capacity. In this paper, an analysis thor capacity improvement is newly considered when the Lanczos chip waveform is used for the spectrum-overlapped DS-CDMA system. RC(relative capacity) is the ratio of the capacity of overlapping system to that of non-overlapping system, which is used for the expression of the capacity improvement. The optimal overlapping ratio is numerically found to make the maximum capacity improvement When the rectangular chip waveform is used far the overlapping system, maximum capacity improvement is increased by about 10% at the required BER=$10^{-3}$TEX> and the optimal overlapping ratio is 1.23. When the 95 % power bandwidth is considered for the Lanczos chip waveform, maximum capacity improvement is increased by 34.4% at overlapping ratio of 1.55 when the required BER is $10^{-3}$TEX>. The lower required BER far the better communication quality makes gradually smaller capacity improvement.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.1108-1117
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• 2005

RAP(rammed aggregate pier) method which is intermediate foundation of deep and shallow foundation is used to improve the ground with high compaction energy. This method is widely spread around the world, but there are few examples and systemic researches for failure mechanism and bearing capacity of this method are not organized yet. In this paper, soil laboratory tests were carried out to evaluate the applicability of RAP method as the foundation of a structure. And the bearing capacity and the failure mechanism of RAP method were studied with respect to various relative densities(35%, 65%, 90%), diameters(45mm, 60mm) and lengths(20cm, 30cm, 40cm). As results, stress concentration ratio decreased as diameter of RAP was increasing or length of RAP was decreased or relative density was decreased. however these results were not always constant. because systematic interaction between relative density and diameter and length of RAP can affect stress concentration ratio, more studies on stress concentration ratio are needed throughout laboratory and field tests.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2003년도 제20회 춘계학술대회 논문집
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• pp.87-90
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• 2003

압축성 유동장의 주된 특징은 유동장의 형성과정에 의존한다는 것은 잘 알려져 있다. 본 연구의 목적은 비평형 응축을 수반하는 초음속 제트유동장의 발달에 미치는 제트의 시간이력을 조사하는 것이다. 특히 초음속 습공기 제트에서 마하디스크 직경과 위치의 거동이 노즐압력비와 초기 상대습도의 항으로 소개된다. 대기흡입식 풍동설비에 장착된 노즐의 출구에서 부족팽창된 습공기 제트를 얻기 위해 노즐의 압력비와 초기상대습도를 변화시켰다. 마하디스크의 직경은 동일한 압력비에서 상대습도가 증가함에 따라 증가하지만, 그 위치는 상류로 이동하는 것으로 나타났다. 또한 노즐의 작동압력비가 증가하는 경우의 마하디스크 직경과 발생위치가 감소하는 경우보다 더 크다.