• 임산에너지
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• 제19권1호
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• pp.1-6
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• 2000

본 연구는 소나무(Pinus densifora S. et Z.) 유묘의 발아전 단계, 자엽 단게 및 1차엽 발생후 단계 등 각각의 생육단계에서의 UV-B 증가 환경에 노출될 때의 생장반응을 탐구하고자 16주 동안 3수준의 UV-B(ambient UV-BBE, ambient + 3.2, ambient + 5.2 KJm-2s-1) 조사량이 설치된 야외 포장에서 실시되었다. UV-B 조사에 의하여 소나무 유묘의 수고생장, 근원경생장 및 건물생산량은 감쇠되었으며 T/R율은 증가하였다. 유묘에 대한 UV-B 처리시작 단계 차이에 따른 생장차이도 관찰되었는데, ambient +3.2 처리구내에서 보면 발아전 단계부터 UV-B 처리를 받은 유묘의 수고생장 및 근원경생장이 상대적으로 높았다. 주 수준의 UV-B 증가 처리구에서 모두 자엽단계부터 처리를 잗은 유묘의 건물생산량이 각 처리구내에서 가장 낮앗다. 한편 UV-B 증가에 의해 소나무 유묘 침엽의 엽롭소 함량은 감소하였으며 엽록소 a/b율은 증가하였다.

• 화훼연구
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• 제17권2호
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• pp.141-145
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• 2009

동절기 산취(Chamecereus silvestrii) '희망'의 주 야 온도를 달리하며 처리한 결과 초장은 주간온도 $20^{\circ}C$와 야간온도 $15^{\circ}C$에서 가장 크게 나타났다. 구경은 주간온도 $25^{\circ}C$에서 구직경과 구고의 생육이 우수하였고, 주간온도 $25^{\circ}C$에서는 모든 야간온도에서 구직경 생육이 양호하였으며 구고는 주간온도 $25^{\circ}C$에서는 $20^{\circ}C$에 비해 야간온도가 $25^{\circ}C$로 높을수록 생육이 좋았다. 주 야간온도 조합의 합산온도가 높을수록 구직경과 구고신장이 증가하는 경향을 나타났다. 색도에서 Hunter 'a' 값은 야간온도가 높을수록 낮아졌으나 'b' 값은 높아져 야간온도가 높으면 탁도가 증가하였다. 또한 구직경과 구고변화의 증가가 다시 시작되는 기점은 정식 후 15일로 나타났다.

• Plant Resources
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• 제4권1호
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• pp.13-25
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• 2001

Growth and yield of licorice were investigated under the different conditions of photoperiod and shading in order to establish its cultural practice for the domestic production with the aim to substitute the import. The photoperiod was adjusted to 8,10, and 12 h by shielding plants from the light with blackout curtain. Large seedlings(11-20g) appeared to be affected by photoperiod since around 65 days. Most of growth parameters, including plant height, number of leaf, fresh and dry weight of plant and root, were the highest in 12 h photoperiod among all the photoperiod levels, excepting stem diameter which was the highest in 10 h photoperiod(4.5mm). Each photoperiod was similar to each other in root length and diameter. Small seedlings(4-l0g) showed a similar trend to large seedlings. The results from field photoperiod experiment demonstrated that 12 h photoperiod was also the best among three photoperiod treatments in plant height, stem diameter, number of leaf, root length, fresh and dry weight of plant and root. The effect of shading was tested under the three levels of control (0%), half-shading (55%), and full shading (90%). Shading remarkably suppressed the growth and yield, compared to no-shading. Although plant height and root length were little affected by the shading, stem and root diameters were heavily reduced.

• 한국산학기술학회논문지
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• 제21권12호
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• pp.411-416
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• 2020

산림 현장조사는 현장에서 측정된 데이터를 야장에 수기로 기입하는 방법으로 이루어지고 있으며, 현장 조사 후 결과를 다시 정리해야하는 번거로움이 있다. 이에 본 연구에서는 객체 모델링과 AR을 활용한 방법을 적용하여 시험림에 대한 수목조사에 효율성을 제고하고자 하였다. 3D 레이저 스캐너를 이용하여 연구대상지 1ha 면적의 387개 수목에 대한 데이터를 취득하였으며, 수목 객체의 추출 및 모델링을 통해 수목에 대한 좌표, 수고 및 흉고직경을 산정하였다. 이 방법은 현장에서 데이터 취득에 소요되는 시간을 감소시킬 수 있으며, 디지털화 된 성과물 생성이 가능하기 때문에 관련 시스템 구축을 위한 기초자료로 활용이 가능하다. 또한 수목에 대한 모델링 결과와 GNSS 및 AR 기법을 이용한 조사는 현장에서 조사하는 수목에 대한 좌표와 수고 및 흉고직경 등의 속성정보를 확인할 수 있어 특정 객체의 위치와 속성값을 현장에서 확인하기 어려웠던 기존 조사 방법의 단점을 개선할 수 있었다. 향후 포인트클라우드와 AR 기술을 활용한 방법은 현장조사에 소요되는 인력과 시간을 감소시킬 수 있어 수목조사 및 모니터링의 효율성을 크게 향상시킬 것이다.

• 농업과학연구
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• 제49권3호
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• pp.483-493
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• 2022

It is important to improve the efficiency of plant breeding and crop yield to fulfill increasing food demands. In plant phenotyping studies, the capability to correlate morphological traits such as plant height, stem diameter, leaf length, leaf width, leaf angle and size of panicle of the plants has an important role. However, manual phenotyping of plants is prone to human errors and is labor intensive and time-consuming. Hence, it is important to develop techniques that measure plant phenotypic traits accurately and rapidly. The aim of this study was to determine the feasibility of point cloud data based on a 3D light detection and ranging (LiDAR) system for plant phenotyping. The obtained results were then verified through manually acquired data from the sorghum samples. This study measured the plant height, plant crown diameter and the panicle height and diameter. The R² of each trait was 0.83, 0.94, 0.90, and 0.90, and the root mean square error (RMSE) was 6.8 cm, 1.82 cm, 5.7 mm, and 7.8 mm, respectively. The results showed good correlation between the point cloud data and manually acquired data for plant phenotyping. The results indicate that the 3D LiDAR system has potential to measure the phenotypes of sorghum in a rapid and accurate way.

• 한국환경과학회지
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• 제31권6호
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• pp.479-490
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• 2022

This study was to evaluate the utilization of terrestrial light detection and ranging for forest inventory in coniferous forests. Heights and diameter of the stand trees were measured manually using the traditional measurement method and the method using terrestrial LiDAR. The results of two methods were compared and analyzed to evaluate accuracy and feasibility. The terrestrial LiDAR used fixed and handy types to compare the accuracy between different operational methods. Comparative analyses used a paired t-test and Bland-Altman plot analysis. In the case of tree heights, the average of difference between the traditional method and terrestrial LiDAR for each plot was 0.81 m, -0.07 m, and 0.13 m for fixed type; 2.88 m, 1.19 m, and 0.93 m for the handy type. In the case of tree diameter at breast height, the average value of the difference between traditional methods and terrestrial LiDAR for each plot was 0.13 cm, -0.66 cm, and -0.03 cm for fixed type; 2.36 cm, 2.13 cm, and 1.92 cm for the handy type. The values from the method using the fixed type was highly consistent with that using the traditional measurement methods; the average difference was closer to zero. The crown density influences the precision of the height measurement using terrestrial LiDAR in coniferous forests. Therefore, future studies should focus on verifying the accuracy of terrestrial LiDAR in forests and on expanding the utilization of terrestrial LiDARs according to their operational methods.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.973-978
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• 2002

This study was performed to verify the effect of various testing conditions affecting measured compressive strength of concrete core and to compute the correction coefficients for it. Conditions of specimens affecting test results include size(diameter), height-diameter ratio, humidity of specimen, amount and arrangement of bar, core direction from structure and method of end preparation. In testing core strength of concrete, special cares should be taken on various testing conditions whose effects have been latent in conventional concrete.

• Structural Engineering and Mechanics
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• 제13권3호
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• pp.345-353
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• 2002

Three noded plate and shell finite element and 3D beam element in conjunction with Lanczos method are used for studying the effect of boat tail angle on the free vibration characteristics of a typical payload fairing for three different cylinder diameters with height to diameter ratio 1.5. Configurations without boat tail structural member are also studied. One half of the one side fairing structure is considered for the analysis and symmetric boundary conditions are used.

• 대한기계학회논문집
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• 제1권4호
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• pp.182-189
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• 1977

The propagating flame temperature of the Propane-Air premixture by using 30.$\mu$ and 50.$\mu$ diameter platinum sensing wires, that is, Two Wires Correction Method, Through the constant volume burining inside the 150mm diameter, 30mm height combustion chamber under the circumstances of the atomospheric pressure, and the room temperature was determined. Also the temperature distribution across High Temperature Region, i.e. Flame Front, and the temperature profile behind the flame the front have been obtained.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.355-358
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• 2003

This paper presents characteristics of vacuum preloaded porous air bearing. Pressure distribution of a porous pad and vacuum pocket are calculated. And load capacity and stiffness of the bearing are analyzed with various vacuum parameters, that is. clearance height. tube diameter, tube length. pumping speed of vacuum pump, vacuum pocket to porous pad area ratio. From the simulation results, optimum clearance for best performance can be selected adjusting these parameters, especially tube diameter which is the most dominant source.