• Current Optics and Photonics
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• 제2권5호
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• pp.400-406
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• 2018

The Semiconductor Optical Amplifier (SOA)-based Mach-Zehnder interferometer is a major contributor in all-optical digital processing and optical computation. Optical tree architecture provides one of the new, alternative schemes for integrated all-optical arithmetic and logical operations. In this paper, we propose an all-optical 3-bit integrated parity generator and checker using SOA-MZI-based optical tree architecture. The proposed scheme, able to process input signals at a desired operating wavelength, has been characterized using RZ-modulated signals at 10 Gbps. The maximum extinction ratios achieved at the output of the parity generator and checker are 10 dB and 8 dB respectively.

• Journal of Forest and Environmental Science
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• 제31권3호
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• pp.235-240
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• 2015

Zelkova serrata is an important hardwood species for the timber industry in Japan. Tree breeding programs for this species have mainly focused on growth characteristics such as stem diameter (D), tree height (TH), stem form, and branching. In order to fulfill timber industry needs, wood quality improvement should be included in the tree breeding program of this species. In the present study, growth characteristics, such as D and TH, and the stress-wave velocity (SWV), which is highly correlated with Young's modulus of wood, were measured for 20-year-old Z. serrata from eight half-sib families planted in a progeny test site with three different initial spacings. Significant differences in all the measured characteristics were found among the eight half-sib families. The variance components of the half-sib families for D, TH, and SWV were 27.2%, 47.3%, and 33.5%, respectively. These results indicate that all the measured characteristics of this species could be improved by tree breeding programs. In addition, only low correlation coefficients were obtained between the growth characteristics and SWV, indicating that extensive selection on SWV in tree breeding programs may not always lead to a reduction in yield volume.

• 산업경영시스템학회지
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• 제35권4호
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• pp.73-82
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• 2012

Currently, R&D investment of government is increased dramatically. However, the budget of the government is different depending on the size of ministry and priorities, and then it is difficult to obtain consensus on the budget. They did not establish decision support systems to evaluate and execute R&D budget. In this paper, we analyze factors affecting research funds by linear regression and decision tree analysis in order to increase investment efficiency in national research project. Moreover, we suggested strategies that budget is estimated reasonably.

• 대한기계학회논문집A
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• 제27권9호
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• pp.1546-1554
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• 2003

Efficient layout in a fixed work volume reduces build time when multiple parts are built at once in stereolithography systems. An efficient algorithm is developed for 3D layout planning. And it reduces build time and increases efficiency of SLA system. Genetic algorithm is implemented to locate as many parts as possible in the fixed work volume. A 3D collision detection algorithm, k-DOPs Tree, is implemented for the fast evaluation of a layout plan.

• Journal of Ecology and Environment
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• 제41권3호
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• pp.85-92
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• 2017

Unmanned aerial vehicles (UAVs) are a new and yet constantly developing part of forest inventory studies and vegetation-monitoring fields. Covering large areas, their extensive usage has saved time and money for researchers and conservationists to survey vegetation for various data analyses. Post-processing imaging software has improved the effectiveness of UAVs further by providing 3D models for accurate visualization of the data. We focus on determining the coniferous tree coverage to show the current advantages and disadvantages of the orthorectified 2D and 3D models obtained from the image photogrammetry software, Pix4Dmapper Pro-Non-Commercial. We also examine the methodology used for mapping the study site, additionally investigating the spread of coniferous trees. The collected images were transformed into 2D black and white binary pixel images to calculate the coverage area of coniferous trees in the study site using MATLAB. The research was able to conclude that the 3D model was effective in perceiving the tree composition in the designated site, while the orthorectified 2D map is appropriate for the clear differentiation of coniferous and deciduous trees. In its conclusion, the paper will also be able to show how UAVs could be improved for future usability.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.345-348
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• 2007

This research aimed at developing a technique for estimating the tree height using BRF (Bi-directional Reflectance Factor) through the clarification of the relation between shape of the tree crown and the tree height and the relations between the shape of the tree crown and BRF. This paper, reports the results of analyses of data acquired by field measurements done to clarify relation between crown shape and tree height.

• The Korean Journal of Ecology
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• 제26권3호
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• pp.123-127
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• 2003

Cubic-meter volumes estimated from two proxy taper functions were compared to observed volumes of Japanese red cedar trees (Cryptomeria japonica D. Don) to evaluate accuracy and precision in the centroid method. Centroid volume estimates were also compared to volume estimates from existing whole-tree volume equations developed for another geographic region. This study found that one proxy function produced unbiased volume estimates while the other was biased. Volume estimates from the whole-tree equations were also biased. However, the volume estimates from the whole-tree equations were more precise than those from the centroid method. These results support previous studies that the centroid method can produce reliable volumes of trees when no other reliable volume equations exist.

• 한국산림과학회지
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• 제90권6호
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• pp.742-746
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• 2001

본 연구의 목적은 1920년대부터 우리나라 남부지방에 대단위로 조림된 삼나무(Cryptomeria japonica D. Don)조림지를 대상으로 하여 최적의 간재적추정식을 개발코자 하였다. 남부지방의 대표적인 삼나무조림지인 6개 지역을 조사하였으며, 이들 지역에서 대표적인 31개의 표준목을 선발하여 수간석해를 실시하였다. 이 중 이용 가능한 29개체목에 대한 수간석해 자료를 이용하여 개발한 최적의 삼나무 재적추정식은 $V=-0.002908+0.000125D^{1.907114}H^{0.645131}$이 제시되었다. 이 식을 이용하여 간재적 실측치와 추정치를 사용한 동시 F-검정(절편=0와 기울기=1)을 실시한 결과, 통계적으로 유의성을 나타내지 않았다(p=0.1936). 따라서 본 연구에서 제시된 간재적 추정식은 남부지방에 조림된 삼나무의 입목 간재적표조제와 경영에 필요한 기초적 자료를 제공해 줄 것으로 판단된다.

• 정보처리학회논문지D
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• 제8D권4호
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• pp.305-312
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• 2001

최근 고차원 색인 구조들이 멀티미디어 데이터베이스, 데이터 웨어하우징과 같은 데이터베이스 응용에서 유사성 검색을 위해 요구된다. 본 논문에서는 고차원 특징벡터에 대한 효율적인 저장과 검색을 지원하는 셀-기반 시그니쳐 트리(CS-트리)를 제안한다. 제안하는 CS-트리는 고차원 특징 벡터 공간을 셀로써 분할하여 하나의 특징 벡터를 그에 해당되는 셀의 시그니쳐로 표현한다. 특징 벡터 대신 셀의 시그니쳐를 사용함으로써 트리의 깊이를 줄이고, 그 결과 효율적인 검색 성능을 달성한다. 또한 셀에 기반하여 탐색 공간을 효율적으로 줄이는 유사성 검색 알고리즘을 제시한다. 마지막으로 우수한 고차원 색인 기법으로 알려져 있는 X-트리와 삽입시간, k-최근접 질의에 대한 검색 시간 그리고 부가저장 공간 측면에서 성능 비교를 수행한다. 성능비교 결과 CS-트리가 검색 성능에서 우수함을 보인다.

• 생물환경조절학회지
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• 제17권4호
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• pp.306-311
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• 2008

본 연구는 2001년부터 2003년까지 '후지'/M.9가 재식된 밀식사과원에서 적정 수세와 적정 착과량을 조사하였다. 엽과비는 평균 과중(y=1.715x+205.02, $R^2=0.66^{**}$)과 수량(y=-35.156x+5963.7, $R^2=0.44^{**}$)에서 고도로 유의한 상관이 있는 것으로 나타났고, 주당엽수와 평균 과중 또한 상관이 있었다. 그러나 착과량에 따른 수체생육, 과실품질 요인중 당도 및 착색도에서는 처리간 차이가 없었다. 격년결실이 발생하지 않으면서 300g 이상의 과실을 생산하는 기준은 엽과비는 55 수준에서 착과량이 주당 약 $55{\sim}64$개의 수준이 적합하였다. '후지'/M.9 밀식재배시 성목기의 안정된 수세 기준은 평균 신초장이 $20{\sim}25cm$, 신초 정지율이 95% 이상수준을 보여야 되는 것으로 판단되며, 보다 세부적으로는 2차 생장이 거의 발생되지 않으며 과대지 비율은 적어도 $20{\sim}30%$ 정도 되어야 할 것으로 판단되었다.