• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.6
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• pp.492-501
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• 2016

Three-Loop autopilot is generally used for the acceleration control of guided missiles. Because the acceleration command to the three-loop autopilot is given as values at the center of gravity, feedback information of IMU should be obtained at the same position. However, the position of IMU might not be located at the center of gravity due to the sub-system assignment. This paper presents the stability analysis of three-loop autopilot with respect to the arbitrary position of IMU and variation rate of center of gravity. Gain and phase margins are calculated for several trim points for general anti-tank missiles.

• Korean Journal of Applied Biomechanics
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• v.18 no.3
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• pp.71-82
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• 2008

W. S. CHAE, Ground Reaction Force Charateristics During Forward and Backward Walking Over 20 Degree Ramp. Korean Journal of Sport Biomechanics, Vol. 18, No. 3, pp. 71-82, 2008. The purpose of this study was to compare GRF characteristics during forward and backward walking over 20 degree ramp. Temporal parameters, GRFs, displacement of center of pressure (DCP), and loading and decay rates were determined for each trial. The results showed that the vertical GRF in BD during RTO was significantly greater than those found in FU. This reults indicated that GRF patterns may be changed by different walking conditions and altering position of ankle, knee, and center of mass throughout the walking cycle. The DCP during $RHC_2$-LHC in antero-posterior direction for downward was smaller than the corresponding value for upward condition. It' seems that the ankle and knee joints are locked in an awkward fashion at the toe contact to compensate for imbalance. Reducing the magnitude of loading rate can be achieved by walking in the backward direction. Accordingly, the results can be a benefit if one is suffering from an impact-type injury.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.635-640
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• 2003

본 논문에서는 일본 차량 번호판 인식에 적응적 탬플릿 마스킹 방법을 이용하여 번호판 문자, 숫자를 분할하고 패턴벡터기법을 이용하여 인식하는 방법을 제안하였다 주, 야간과 거리에 따른 일본 차량 번호판 영상을 입력받아 전처리 과정을 수행한 후 에지 정보와 명도값 변화의 빈도수를 이용하여 번호판 영역을 검출하였다 검출된 번호판 영역에서 각 문자 및 숫자의 위치정보와 적응적 탬플릿을 이용하여 분할하고 번호판의 지역문자를 무게중심 패턴으로 분류 한 다음 크기와 이동에 무관한 특실을 가지는 패턴 벡터를 적용하여 문자를 인식하였으며, 숫자는 Four Segment Pattern을 이용하여 인식하도록 하였다 본 논문에서 제안한 방법을 실제 일관 차량 번호판 인식에 적용한 결과 98.8％ 추출율과 96.6％의 인식율을 나타내었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1434-1439
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• 2012

Vehicle is a dynamic system combined with various parameters. Dynamic characteristics of a vehicle can vary with the change of these parameters. To investigate the effect of the design parameter on vehicle handling performance the sensitivity analysis is carried out by the numerical method. The vehicle model is described by equivalent cornering stiffness that considers parameters of suspension and steering system. As the analysis results show the effect on the static and dynamic characteristics of the vehicle system, the sensitivity analysis can be used for synthesis of the design parameters to improve the vehicle handling characteristics at the design stage as well as during the vehicle test under development.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1722-1729
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• 2005

In this paper, we used the quadruped walking robot Titan-VIII in order to carry out this simulation of sway compensation trajectory. The attitude angle ${\phi}_r$ and ${\phi}_p$ is obtained from 3-D motion sensor that is attached at the center of robot body and the attitude control carried out at every 10[ms] for stable gait of robot. Duty factor, that is fixed at 0.5. When we change period T into 1.5, 2.0, 3.0[sec] each and moving distance per period is changed into 0.2, 0.3(m), we sim띠ate several walking experiment of robot. and then we analyze the experiment results if there are any difference between the imaginary ZMP and actual ZMP of robot and the stable gait of robot is realized.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.5
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• pp.331-339
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• 2020

In this study, ways to reduce the edge pressure at the bottom plate of the caisson breakwater were considered. The water depth, freeboard, design wave height and period, and the location of the center of gravity on the super-structure of the breakwater were selected as key design variables that influence the edge pressure, and analyzed how the edge pressure changes according to the change of this key variables. The pressure distribution formulae suggested in the design standard was applied for the calculation of design wave forces. Based on the wave forces, the required effective self-weight of the super-structure and the minimum width of the caisson were determined to have a safety factor of 1.2 against sliding and overturning. From the results, it was found that the edge pressure rapidly increased as the water depth increased, and could exceed the allowable bearing capacity when it reached a certain water depth which is 20 m within the analysis conditions. It was also confirmed that the edge pressure gradually increased linearly as the freeboard increased, but decreased with the increase of the wave height and period. This edge pressure could be significantly reduced up to more than 20% by moving the center of gravity of the super-structure to the seaside, which is 5% of the caisson width. Based on the analysis results and the recently conducted research results, a method was proposed to reduce the edge pressure that can be used in the design.

• Journal of Sericultural and Entomological Science
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• v.50 no.2
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• pp.63-70
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• 2012

This study was conducted to investigated the distribution, ecological character and life cycle of Black Soldier Fly(BSF), Hermetia illucens, to determine effects of BSF on composing ability to the livestock feces. The distribution of BSF was defined in all parts of the country in Korea. Its main habitat was found to be areas near cattle sheds, feces sheds, living waste dump grounds, and food waste dump grounds. Excellent species of the bio-conversion using the livestock feces were selected out of two kinds of solider flies(Hermetia illucens and Ptecticus tenebrifer). And effects of BSF on composing ability to the livestock feces were pig feces 0.5 g, cattle feces 0.43 g and chicken feces 0.3 g per a larvae of BSF. In the examination of the ability of BSF to decompose food waste, volume of the livestock feces decreased by weight pig feces 77, cattle feces 83.62 and chicken feces 80%. Observed characteristics of BSF larvae and pupae stage were by developmental stage may be summarized as follows: size and length of larvae and pupae of BSF were higher than in pig feces and mixed sawdust treatments. In order to develop artificial indoor rearing techniques, The pupation and emergence rate were not visible the difference but important factor of the mating and egg-laying was a sun light. And it was visible the difference in mating ratio. Mating rate of H. illucens by seasonal change was the highest from May to July. Mating mostly occurred between 10 : 00 and 12 : 00 during which light intensity is high. As the egg-laying medium for artificial egg collection, calf feed and food waste were most effective. The ratio of egg-laying medium is waste food : sawdust(1 : 1) in volume. For egg-laying materials, flower foam and wood with holes were used; holes sized 3 ~ 5 mm in diameter, 7 ~ 10 mm in depth were most preferred for egg-laying.

• School Mathematics
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• v.5 no.4
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• pp.507-520
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• 2003

본 연구는 실질적인 의미에서 학생들로 하여금 수학을 더 잘 이해할 수 있도록 돕기 위해 테크놀로지를 학교 교실에서 직접 활용하는 방안에 대한 연구이다. 특히 여기서는 수학을 가르치고 배우는 과정에서 가상학습체계가 주요한 도구로서 적용되었다. 내용은 무게중심을 택했고 12명의 중학생을 대상으로 현직교사가 직접 지도하였다. 학생들은 수업초기에 교사에 의해 소개되는 학생중심 학습활동에 강한 관심과 호기심을 보였고 집중력이 아주 강했다. 전통적인 수업방식과는 달리 학생들이 참여하였고 테크놀로지를 이용하여 전통적인 방식의 교실에서 할 수 없었던 수업의 시작은 학생들의 호기심을 자극하는데 충분하였다. 전반적으로 테크놀로지 환경에서의 수업을 선호하였지만 아직 전통적인 방식인 칠판과 분필을 이용한 수업을 선호한 학생들도 있었다. 새로운 변화도 좋지만 새로운 환경에 친화적이지 않거나 테크놀로지를 이용한 수업의 빠른 진행이 학생을 오히려 혼란하게 만들기도 하였다. 마지막으로 교사는 가상학습체계를 교실에서 활용함에 있어서 현 교육과정과 교과서를 크게 개혁하지 않아도 잘 준비되고 계획된 테크놀로지의 활용에 대한 잠재력을 확인할 수 있었다. 우리는 현재 테크놀로지의 보급에 비해 그 활용도가 낮다는 것을 잘 알고 있고 기타 입학시험이라는 현실이 교육과정과 학습방법의 개혁을 현실적으로 추진하는 것이 어려운 일임을 잘 알고 있다. 그래서 현 상황에서 테크놀로지의 사용을 가능하게 할 수 있는 방법을 모색하였다. 이미 보급된 테크놀로지와 교사와 학생의 테크놀로지에 대한 이해가 앞으로 그 잠재력을 갖고 있다고 확인하였다.보다 낮은 일반세균수 값을 보여주었다. 봄철 시료에 있어서 소규모 도계장은 본 냉각 후 도계과정을 제외하곤 모든 도계공정 단계에서 대규모 도계장보다 높은 일반 세균수의 측정값을 보여주었다. 봄철 시료의 냉각말기의 냉각수 일반세균수는 소규모 도계장이 대규모 도계장보다 높은 측정값을 보여주었다.주었다.다.㏖/s/$m^2$에서는 이앙후 각각 18일로 두 품종 모두 늦어, 약광은 유묘기에 분화되었던 분얼아를 휴면으로 유도할 수 있음을 시사하였다. 4. 유효경비율은 1220~220 $\mu$㏖/s/$m^2$에서 다산벼는 47~55%, 화성벼는 100~72%로 다산벼가 화성벼보다 낮았다. 이것은 다산벼는 무효분얼이 많다는 것을 시사하는 것으로 품종 육성시 유효경비율을 높여야 할 것이다.타났고, \circled2 회복상태에서, 10 lu$\chi$인 경우 서간에 1.26 $\mu\textrm{V}$, 야간에 1.59 $\mu\textrm{V}$였고, 100 lu$\chi$인 경우 서간에 2.63 $\mu\textrm{V}$ 야간에 3.65 $\mu\textrm{V}$였으며, 400 lu$\chi$인 경우 서간에 2.52 $\mu\textrm{V}$, 야간에 3.67 $\mu\textrm{V}$로 나타났다.히, 흉선, F냥, 비장 등의 림프구에 초기 세포용해성 감염을 일으키는데, B

• Journal of Korea Entertainment Industry Association
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• v.13 no.1
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• pp.207-215
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• 2019

This study examines the effect of the height of cane that hemiplegic patients due to stroke use on their plantar pressure in standing position, gait speed. The study suggests a new standard for appropriate cane height that considers the change of average height of population. Research subjects included 12 patients hospitalized in S Medical Care Hospital located in Gwangju Metropolitan City in South Korea who were diagnosed with stroke. Group A uses a cane of the height of the greater trochanter of femur, group B uses a cane of 5cm above the height of the greater trochanter of femur, and group C is a cane of 10cm above the height of the greater trochanter of femur. In the study result, non-affected side plantar pressure and affected side plantar pressure showed a significant difference among the cases where the cane height was the same as the A group, B group, C group. In the post-hoc analysis result, a significant difference was observed between the case of A group and C group. Gait speed showed no significant difference among the case of the A group, B group, C group. The asymmetry of the stroke affects not only the posture but also the walking that is related to daily life. Changes in the height of the cane did not affect walking speed. The change in the height of the cane showed a change in the weight support ratio, which is thought to have a positive effect on the asymmetry. In future clinical setting, this study result will be able to provide fundamental data regarding the cane height in the standing or walking therapy for hemiplegic patients due to stroke with cane application.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.423-429
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• 2018

Objective: This study was conducted to investigate the effects of WBVE on biomechanical factor analysis of drop landing jumps before and after a four week training program. Methods: Participants were divided into two group: VEG (n=5, age: $25.7{\pm}2.3yrs$, height: $170{\pm}7.6cm$, weight: $69.3{\pm}8.3kg$) and OEG (n=5, age: $24.6{\pm}3.4yrs$, height: $164{\pm}4.9cm$, weight: $58.8{\pm}9.2kg$). Ten infrared cameras (Vicon, UK) with a sampling rate of 100 Hz were used in two GRF measurement systems (AMTI, USA). Results: The variability of the center of mass was largest at the falling phase, and there was a great risk of injury when landing after the jump. Second, the jumping heights of the VEG (vibration exercise group) were higher than those of the OEG (only exercise group), regardless of training period. Third, there were significant differences in the hip joint P1 (flexion) and knee joint P2 (extension) between the exercise groups after 4 weeks of training. However, there were no significant differences among training periods or phases. Conclusion: regardless of training periods, the VEG showed increased jump height compared with the OEG, but the consistency between the jump height and the lower joint power could not be determined.