• 전자공학회논문지T
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• 제36T권1호
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• pp.93-102
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• 1999

본 논문은 내용 기반 비디오 질의를 위한 데이터 모델과 검색 방법을 제안한다. 하나의 비디오를 같은 길이의 프레임(frame)들의 집합 즉 비디오-윈도우로 나눈 후에 각각의 비디오-윈도우를 다차원 공간의 한 점으로 사상시킨다. 인접한 비디오-윈도우를 연결하면 하나의 비디오는 다차원 공간에서의 하나의 궤적(trajectory)이된다. 두 비디오-윈도우의 유서성은 두 점의 유클리디안 거리로 정의되며, 비디오 단편(segment)의 유사성 비교는 궤적을 비교함으로써 검사한다. 여과(filtering), 정제(refinement)과정을 가지는 새로운 검색 방법을 개발한다. 새로운 검색 방법을 여과/정제 과정이 없는 질의 결과가 정확하고, 질의 처리 속도는 약 4.7배 향상되었다.

• 대한인간공학회지
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• 제16권3호
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• pp.1-10
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• 1997

This paper is concerned with the development and evaluation of the camera calibration method for a real-time head tracking system. Tracking of head movements is important in the design of an eye-controlled human/computer interface and the area of virtual environment. We proposed a video-based head tracking system. A camera was mounted on the subject's head and it took the front view containing eight 3-dimensional reference points(passive retr0-reflecting markers) fixed at the known position(computer monitor). The reference points were captured by image processing board. These points were used to calculate the position (3-dimensional) and orientation of the camera. A suitable camera calibration method for providing accurate extrinsic camera parameters was proposed. The method has three steps. In the first step, the image center was calibrated using the method of varying focal length. In the second step, the focal length and the scale factor were calibrated from the Direct Linear Transformation (DLT) matrix obtained from the known position and orientation of the camera. In the third step, the position and orientation of the camera was calculated from the DLT matrix, using the calibrated intrinsic camera parameters. Experimental results showed that the average error of camera positions (3- dimensional) is about $0.53^{\circ}C$, the angular errors of camera orientations are less than $0.55^{\circ}C$and the data aquisition rate is about 10Hz. The results of this study can be applied to the tracking of head movements related to the eye-controlled human/computer interface and the virtual environment.

• Journal of Computing Science and Engineering
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• 제8권1호
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• pp.1-10
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• 2014

The Bacterial Foraging Optimization Algorithm is a swarm intelligence optimization algorithm. This paper first analyzes the chemotaxis, as well as elimination and dispersal operation, based on the basic Bacterial Foraging Optimization Algorithm. The elimination and dispersal operation makes a bacterium which has found or nearly found an optimal position escape away from that position, which greatly affects the convergence speed of the algorithm. In order to avoid this escape, the sphere of action of the elimination and dispersal operation can be altered in accordance with the generations of evolution. Secondly, we put forward an algorithm of an adaptive adjustment of step length we called improved bacterial foraging optimization (IBFO) after making a detailed analysis of the impacts of the step length on the efficiency and accuracy of the algorithm, based on chemotaxis operation. The classic test functions show that the convergence speed and accuracy of the IBFO algorithm is much better than the original algorithm.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1169_1170
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• 2009

This paper introduces insulator pollutant accumulate pattern in the tunnel of korea railroad. To accomplish this goal, effective sample collecting method was proposed for the first step. Dust at the surface was collected directly. Distilled water and brush was used while collecting. Through this method dust is easily and accurately collected. The second step is pollutant analysis. Several analyze item is selected such as quantity, conductivity, contact angle, Optical Microscope(OM), IR, Equivalent Salt Deposit Density(ESDD), and ICP-AES. The third step, best represent tunnel was selected considering location, length and natural surroundings. Also to consider the difference at inside the tunnel, several bracket insulators were selected along to the location. To make the result precise, above procedure was repeated several times at the same target. Finally relation among type of train, numbers of movement, surroundings, length will be considered in combination with the pollution. With this result pollute map for KORAIL could be accomplished and inspect period will be optimized case by case.

• 대한물리의학회지
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• 제7권2호
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• pp.205-212
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• 2012

Purpose : The aim of this study was to investigate the relationship between weight-supporting asymmetry and gait symmetry in patients with stroke. Methods : Sixty two stroke patients with hemiplegia stood quietly with eye opens on a force platform to calculate weight-supporting asymmetry from vertical reaction force. The GAITRite was used to evaluate their gait parameters. The data were analyzed using Pearson correlation. Results : The results of this study was showed that the medio-lateral index (ML) was correlated with symmetry rate (SR), symmetry index (SI), and Gait asymmetry (GA) of step time and length but stronger correlation with spatial gait symmetry than temporal symmetry. In gait symmetry, step length has stronger correlation with weight-supporting asymmetry than step time. Conclusions : The results of this study shows weight-supporting asymmetry was correlated with more spatial gait symmetry than temporal symmetry.

• 한국전문물리치료학회지
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• 제10권4호
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• pp.77-83
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• 2003

본 연구는 발가락 벌림 보조기(toe spreader)가 긴장성 발가락 굽힘 반사(Tonic Toe Flexion Reflex: TTFR)가 있는 양하지 뇌성마비 아동의 보행에 미치는 영향을 알아보고자 하였다. 12명의 TTFR이 있는 양하지 뇌성마비 아동을 대상으로 같은 날에 맨발과 발가락 벌림 보조기를 착용한 상태에서 보행분석을 실시하였다. 시간 거리 보행변수로 활보장(step length), 보장(step length), 보폭(step width), 발가락 외전각도(toe out angle), 활보시간(stride), 입각기(stance phase), 유각기(swing phase), 분속수(cadence), 보행속도(speed)를 측정하였다. 발가락 벌림 보조기 착용 시 시간 거리 보행변수는 통계적으로는 유의한 차이가 없었다(p>.05). 양하지 뇌성마비 아동에서 TTFR을 억제하기 위한 발가락 벌림 보조기의 즉시적인 효과는 유의하지 않다고 볼 수 있으며, 추후연구로 장기간 일상생활에서의 지속적인 착용을 통한 연구가 필요하다고 본다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1998년도 춘계 학술대회논문집
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• pp.168-173
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• 1998

A numerical analysis of axisymetric backward facing step main nozzle flow in air jet loom has been accomplished. To obtain basic design data for an optimum main nozzle for an air-jet loom and to predict the transonic/supersonic flow, a characteristic based upwind flux difference splitting compressible Navier-Stokes method has been used. The wall static pressure of the main nozzle and the flow velocity changes in the nozzle tube were analyzed by changing air tank pressures and acceleration tube lengths. The flow inside the nozzle experiences double choking one at the needle tip and the other at the acceleration tube exit at tank pressures over $4kg_f/cm^2$. The tank pressure $P_t$ leading to the critical condition depends on the acceleration tube length; i.e, $P_t$ is higher for longer acceleration tubes. The $P_t$ value required to bring the acceleration tube exit to the critical condition is nearly constant regardless of acceleration tube length. The round needle tip shape might lead to less total pressure loss when compared with step shape.

• 물과 미래
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• 제27권2호
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• pp.121-128
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• 1994

단락부에서의 모형실험을 통하여 표면 유속의 감소경향, 낙하리영역의 길이, 잠재핵(potential core)의 길이 등을 고찰하여 단구 전면에 대한 흐름을 규명하였다. 흐름속에 부류사가 혼재되어 있는 경우, 부유사가 낙하리영역 중에 퇴적하게 되어 단구의 진행 속도에 영향을 주게되므로 이를 규명하기 위하여 단락부에 있어서 부류사의 유입에 대한 실험을 실시하고, 이에 대한 식을 유도하여 실험 결과로부터 이들 식의 유효성을 증명하였다. 또한 단락부의 낙하리영역에서 사이폰에 의하여 채취되는 부류사량에 대한 실험 결과,$q_{s0}$ 를 규정하는 파라메타에 관한 검토를 실시하여 부류사의 퇴적 특성을 설명하였다.

• 한국운동역학회지
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• 제24권3호
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• pp.209-216
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• 2014

The purpose of this study was to explore the effect of 8 weeks after school classes of track sports on students' start motion through kinematic variables. 30 students in D National university of education participated for this study. These students divided into two groups, 17 students for experimental group and 13 students for control group. The two groups participated in general athletic class as common class, and the experimental group participated in after school class additionally. The general class taught track and jump skill for 3 hours a week, and the after school class taught only athletic running skill for 30 minutes a week. Pre and post test assessed to assess students' kinematic changes. Findings indicated that velocity and step rate were increased, and contact time, step length, displacement of center of mass were decreased in the experimental group. In the control group, early velocity, knee/hip angle velocity were increased, and contact time, step length, displacement of center of mass were decreased. In conclusion, the students who only participated in general class, could not maintain athletic skills obtained from the class. However, students who participated in both general and after school class accomplish athletic start skill. This is because Continuous learning effect helped students keep the skill and did not lose the skill. Thus, in order for students to learn specific sport skills, joining after school class with general class together is recommended.

• 한국조경학회지
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• 제23권2호
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• pp.157-166
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• 1995

To investigate walkability of ramps, walking patterns of 18 healthy adults,12 aged 20 to 26 and 6 aged 68 to 76,were studied at free,rhythm constrained walking up or down ramp using goniometer and footswitch Ramp inclinations were set 4,8,12,16,20 degrees. The results were as follows. 1)The step length of subjects were decreased significantly in12$^{\circ}C$′or 16′free downramp walking. With regard to step length, some subject groups walked abnormally in 16" or 20" ramp walking 2) The step width of subjects were increased significantly in 12" or 16" ramp walking. 3) The cadence duration of some subject groups were increased in 12" upramp walking. 4) The double stance duration and double stance ratio of some subject groups were increased significantly in 8",12", or 16"upramp walking. 5) The maximum knee flexion angle of stance phase were increased in 12" ramp walking. 6)Most temporal parameters and spatial parameters of gait were increased or decreassd greatly between 4" ramp and 8" ramp or between 8′ramp and 12′ramp. But statistics significancy were not recognized 7) The results suggest that ramp inclination less than 8′(14%) -12′(21%) is desirable for the normal gait the ramp inclination must not exceed 16" -20" in unavoidable circumstances.