http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
권기범 ( Ki Beom Kwon ),한희 ( Hee Han ),설아라 ( A Ra Seol ),정혜진 ( Hye Jean Chung ),정주상 ( Joo Sang Chung ) 한국산림과학회 2013 한국산림과학회지 Vol.102 No.4
This study was conducted to develop a simulation model for estimating the amount of such products as round wood, dimension lumber and the residual wood biomass produced by processing the individual trees of Larix kaempferi. In the model, the stem volume is assessed using the taper equations of the species to estimate the stem forms. Then, the model simulates the conversion processes of logs to round wood or lumber and assesses the maximum amount of the wood products by the lumber dimensions or round wood size. Also the model provides information on the amount of residuals for kerf and slabs produced on the conversion processes for sawn timber or round wood. According to the results of an application of the model to a L. kaempferi process, the trees greater than 12 cm of DBH can be converted to logs for lumber or round wood production. For the trees, of which DBH is available for log conversion, the maximum amount of final products by dimensions were analyzed. In this analysis, production of the bigger dimension lumber was assumed to be preferred to that of the smaller or round wood. This model can be used for assesment of forest economic value through estimation of merchantable volume for the trees, and assessment of mill residues which has the potential to provide significant amount of feedstock for bioenergy production as well.
거리독립 생장예측 시뮬레이션기법 적용에 의한 삼나무임분의 임분생장 및 탄소고정에 미치는 간벌시업 효과 분석
권기범 ( Ki Beom Kwon ),한희 ( Hee Han ),설아라 ( A Ra Seol ),정혜진 ( Hye Jean Chung ),정주상 ( Joo Sang Chung ) 한국임학회 2016 한국산림과학회지 Vol.105 No.1
본 연구에서는 거리독립 임분생장 예측 시뮬레이터 STEMS를 기반으로 제주도 한남시험림 삼나무 임분에 대한 잠재직경생장함수, 수정함수, 수관율 및 고사함수를 추정하고, 이를 토대로 간벌시업에 따른 임분의 생장패턴 및 탄소흡수량의 변화를 예측하였다. 시뮬레이터를 구성하는 주요 함수는 연구대상지의 13개 표본점으로부터 39본의 표준목을 선발하여 수간석해에 따른 분석결과를 토대로 추정하였다. 이 시뮬레이터를 적용하여 사례연구 대상 임분에 대한 간벌시업체계를 무간벌 및 1회 간벌에 간벌의 시기 및 강도를 달리하는 3개의 시나리오로 편성하여 간벌시업이 임분생장 및 탄소흡수 효과에 미치는 영향을 분석하였다. 분석결과 간벌시업과 지위지수에 따라 임분의 평균 수고 및 흉고직경, 경급별 임목본수나 임분재적에 따른 생장패턴이나 탄소고정에 미치는 효과가 유의미한 것으로 나타났다. The objectives of this study were to infer the parameters of forest stand growth functions of STEMS for Cryptomeria japonica stands of Jeju Hannam Experimental Forest, Korea Forest Research Institute, and to investigate the effects of thinning regimes on the patterns of stand growth and carbon absorption. The forest stand growth functions for the potential diameter growth, modifier, crown ratio and mortality are the major ones composing the independent-tree/distance-free forest stand growth simulator, STEMS. The parameters were inferred using the sets of growth data obtained from stem analyses of 39 trees, chosen from 13 sample plots of the forest stands. The effects of thinning regimes on the patterns of stand growth and carbon absorption were investigated by simulating the stand growth patterns of the case study stand with 3 different thinning regimes: no-thinning, early thinning with low intensity and late thinning with high intensity using the simulator. According to the results of the analyses, the different thinning regimes cause significant effects on the growth patterns of average DBH, average height, diameter distribution and stand volume as well as the amount of carbon absorptions.
권기범(Ki-Beom Kwon),신대영(Dea-Young Shin) 대한기계학회 2011 大韓機械學會論文集A Vol.35 No.6
본 연구에서는 미니로더의 유압시스템을 모델링 하였고, 시뮬레이션 결과와 실제 실험 결과의 비교를 통해 시뮬레이션의 타당성을 검증하였다. 그리고 미니로더의 유압시스템 해석을 통해 구성부품에 가해지는 하중을 구하였으며, 그 하중데이터를 바탕으로 구조해석을 진행하여 구조안전성을 평가하였다. 구조해석결과 강도 향상이 필요하다고 판단되는 main frame에 대해서는 실험계획법을 이용하여 중량은 유지하면서도 강도는 향상시킬 수 있는 최적 설계치수를 제안하였다. In this study, a hydraulic system of a mini-loader is modeled, and the model is validated by comparing the simulation results to the experimental results. A load force acting on the structure of the mini-loader is obtained from the simulation of the hydraulic system, and the structural analysis via finite element method is performed using the obtained load force to evaluate the structural safety of the loader. For the mainframe that requires additional strengthening according to the structural analysis, the optimum design parameters are proposed using the design of experiments to improve strength without additional mass.
모드중첩법과 최소자승법을 이용한 고충격 압저항 미소가속도계의 효율적인 출력젂압 과도해석
권기범(Ki Beom Kwon),권순재(Soon Jae Kwon),한정삼(Jeong Sam Han) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.10
The transient analysis for output voltage of a piezoresistive microaccelerometer takes a relatively high computation time because at least two iterations are required to calculate the coupled response at each time step. In this paper, the high computational cost for the transient voltages is tremendously reduced by integrating the mode superposition method and the least square method. The transient voltage is approximated from the displacement response which is cheaply calculated by the mode superposition method and the relation of voltage-displacement is determined through the second-order least square model. A high-impact microaccelerometer under several types of acceleration is adopted to represent the efficiency and accuracy of the suggested approach. In addition, the crosstalk of the sensor was also calculated using this method and compared with that from the full-order model.
유한요소 해석 기반 RK4 회전체 시스템의 이상상태 해석 및 검증
권기범(Ki Beom Kwon),정준하(Joonha Jung),한정삼(Jeong Sam Han) 한국소음진동공학회 2018 한국소음진동공학회 논문집 Vol.28 No.2
This paper represents the rotordynamic finite element (FE) analysis for a RK4 rotor kit system with abnormal conditions such as unbalance and shaft rubbing, which commonly occur in a rotating system, in comparison with experimental results. The rotordynamic FE model for the RK4 system is developed by using the commercial finite element analysis package ANSYS MAPLD. First, its modeling parameters such as material property, bearing stiffness, and the spring constant of the flexible coupling were tuned based on the step-by-step impact hammer test results on the RK4 system. For the unbalance analysis, the system is assumed to rotate with a constant rotating velocity of 3,600 RPM and be vibrated with excitation forces due to unbalance. The shaft rubbing is modeled using the node-to-node contact using the penalty method. Then, transient response analysis is performed for the initial few seconds and then the vibration signals are processed in both time and frequency domains. Results from simulation have a good agreement with those from the experiment in terms of the vibration signal, the orbit, and the FFT response. This method can be used as a substitute or complement when the test of the abnormal state for the rotating system is impossible and very limited.