• Journal of information and communication convergence engineering
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• 제9권2호
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• pp.201-206
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• 2011

FRUC (Frame Rate Up-Conversion) technique needs an effective frame interpolation algorithm using motion information between adjacent neighboring frames. In order to have good visual qualities in the interpolated frames, it is necessary to develop an effective detection and interpolation algorithms for occluded regions. For this aim, this paper proposes an effective occluded region detection algorithm through the adaptive forward and backward motion searches and also by introducing the minimum value of normalized cross-correlation coefficient (NCCC). That is, the proposed scheme looks for the location with the minimum sum of absolute differences (SAD) and this value is compared to that of the location with the maximum value of NCCC based on the statistics of those relations. And, these results are compared with the size of motion vector and then the proposed algorithm decides whether the given block is the occluded region or not. Furthermore, once the occluded regions are classified, then this paper proposes an adaptive interpolation algorithm for occluded regions, which still exist in the merged frame, by using the neighboring pixel information and the available data in the occluded block. Computer simulations show that the proposed algorithm can effectively classify the occluded region, compared to the conventional SAD-based method and the performance of the proposed interpolation algorithm has better PSNR than the conventional algorithms.

• 한국정밀공학회지
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• 제16권5호통권98호
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• pp.151-159
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• 1999

A self-propulsive polishing robot is proposed as a method which automates a floor polisher. The proposed robot with two rotary brushes does not require any mechanism such as wheels to obtain driving forces. When the robot polishes a floor with its two brushes rotating, friction forces occur between the two brushes and the floor. These friction forces are used to move the robot. Thus, the robot can move in any direction by controlling the two rotary brushes properly. In this paper, firstly a dynamics model of a brush is presented. It computes the friction force between the brush and the floor. Secondly, the dynamics of the proposed robot is presented by using the bush dynamics. Finally, the inverse dynamics is solved for the basic motions, such as the forward, backward, leftward, rightward motions and the pure rotaion. This paper will contribute to realize a self-propulsive polishing robot as proposed above, In addition, this paper will give basic ideas to automate the concrete floor finishing trowel, because its basic idea for motion is similar to that of the proposed robot.

• 전자공학회논문지SC
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• 제48권4호
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• pp.108-113
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• 2011

본 논문에서는 손목 부근에 장착한 근전도 및 가속도 센서를 통하여 기존 로봇의 차대 제어와 다른 새로운 방식의 제어 방법을 제안한다. 제안 하는 방법은 자동차를 운전하는 듯이 직관적인 팔의 움직임만으로 로봇을 원격 제어한다. 근전도 센서로부터 얻은 신호를 통하여 로봇 제어 여부를 결정하고 가속도 센서로부터 얻은 신호로부터 동작을 추론하여 추론된 동작에 해당되는 명령에 따라 전진, 후진, 좌회전, 우회전으로 제어한다. 4가지 동작에 대한 정확성은 99% 이상이며 실시간 지연 없이 자연스러운 제어가 가능하였다. 전체 시스템을 직접 구현하고 시현을 통하여 성능 및 유용성을 확인하였다

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권2호
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• pp.201-211
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• 2018

This paper illustrates recent advancements relative to a non-conventional propulsion system for boats and is based on two previous papers of the author presented at a conference (see Muscia, 2015a,b). The system does not consider propellers and utilizes the vibration generated by two or more pairs of counter rotating masses. The resultant of the centrifugal forces applies an alternate thrust to the hull that oscillates forward and backward along the longitudinal axis of the boat. The different hydrodynamic drag forces that oppose to the oscillation produce a prevalently forward motion of the vessel. The vibration that causes the motion can be suitably defined to maximize the forward displacement and the efficiency propulsion of the system. This result is obtained by using elliptical gears to rotate the counter rotating masses. The computation of the propulsion efficiency is based on a suitable physical mathematical model. Correlations between numerical experiments on models and possible full scale application are discussed. Some remarks in relation to practical applications and critical issues of the propulsive solution are illustrated. The results have been obtained with reference to a CAD model of a real boat already manufactured whose length is approximately equal to 13 m.

• 대한전자공학회논문지SP
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• 제39권3호
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• pp.78-87
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• 2002

본 논문은 MPEG 비디오에서 나타나는 여러 예측 형태의 움직임 벡터를 프레임 타입에 관계없이 단일 예측방향만을 갖도록 새롭게 추정하여 비디오 영상물의 분석에 직접적으로 활용하는 방안에 대해 제시하고 있다. 또한 재추정된 각 프레임에서의 움직임 벡터를 이용한 비디오 시퀀스 내에서의 객체 추출 및 추적 기법 등에 대해서도 새롭게 제안하였다. 제안된 알고리즘은 압축 영상에 대한 전체적인 복원과정을 거치지 않고, 압축 비디오 영역으로부터 쉽게 추출될 수 있는 매크로 블록 영역 상에서 수행되었으며, 실험 결과는 제안된 방법의 높은 성능을 잘 나타내어 주고 있다.

• 대한물리의학회지
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• 제5권3호
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• pp.363-373
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• 2010

Purpose : The purpose of this study was to compare differences in thoracolumbar ranges of motions by comparing ratios among 4 type diagnosis for patient with chronic low back pain. Methods : The subjects were 58 chronic low back pain patients. A motion analysis program (Global Postural System) was used after photography for posture measurement. To analyze differences in mobility percentages and ratios of thoracolumbar ranges of motion, one-way ANOVA was used. Results : Regional difference spinal posture and movement were found to diagnosis patients with chronic low back pain. Comparison of thoracolumbar ranges of motion revealed significant differences in the thoracic region during forward-bending of the trunk (p<.05). In the upper thoracic region, the herniated intervertebral lumbar disc (HILD) group was significantly larger than the spinal stenosis/herniated intervertebral lumbar disc (SS/HILD) group (p<.05). In the lower thoracic region, chronic sprains (CS) were significantly greater than in the spinal stenosis (SS) group and in the (SS/HJLD) group (p<.05). Comparative analysis of thoracic/lumbar mobility ratio showed the CS group's ratio during forward bending was largest: 1.66, while the HILD group's ratio was smallest: 84 a significant difference between the two groups (p<.01). Diagnosis was not associated with difference in thoracolumbar backward-bending range of motion (p>.05). Conclusion : Theses results indicate the clinical efficacy of diagnosing for chronic low back pain by evaluating spinal mobility.

• 대한통합의학회지
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• 제11권2호
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• pp.207-219
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• 2023

Purpose : This study was conducted to investigate the changes in trunk movement and ground reaction during sit to stand motion using visual feedback. Methods : Fifteen adults (average age: 23.53±1.77 years) participated in this study. An infrared reflective marker was attached to the body each participant for motion analysis, and the participants performed sit to stand motion while wearing a hat attached with a laser pointer, which provided visual feedback. First, the sit to stand action was repeated thrice without obtaining any visual feedback, followed by a three minute break. Next, the laser pointers attached to hats were irradiated on a whiteboard, located at a distance of 5 m in front of the chairs, on which the participants sat; a baseline was set, and the participants performed stand up movements three times under this condition. A visual feedback was provided to the participants to prevent the laser pointers from crossing the set baseline. During each stand-up movement, the position of the reflective marker attached to the subject's body was recorded in real time using an infrared camera for motion analysis. The trunk movement and ground reaction force were extracted through recorded data and analyzed according to the presence or absence of visual feedback. Results : The results indicated that in the presence of a visual feedback during the sit-to-stand movements, the range of motion of the trunk and hip joints decreased, whereas that of the knee and ankle joints increased in the sagittal plane. The rotation angle of the trunk in the horizontal plane decreased. The left and right movement speed of the center of pressure increased, the pressing force decreased, and the forward and backward movement speed of the trunk decreased. Conclusion : The results suggest that the efficiency and stability of the stand up movement of a body increase when a visual feedback is provided.

• Journal of Electrical Engineering and Technology
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• 제10권6호
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• pp.2413-2419
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• 2015

Core spinal muscles are related to trunk stability and assume the main role of stabilizing the spine during daily activities; strengthening of core muscles around the spine can therefore reduce the chance of back pain. The objective of the study was to investigate the effect of core muscle strengthening in the spine during spine stabilization exercise using a whole body tilt device. To achieve this, a validated musculoskeletal (MS) model of the whole body was used to replicate the input motion from the whole body tilting exercise. An inverse dynamics analysis was executed to estimate spine loads and muscle forces depending on the tilting angles of the exercise device. The activation of long and superficial back muscles such as the erector spinae (iliocostalis and longissimus) were mainly affected by the forward direction (-40°) of the tilt, while the front muscles (psoas major, quadratus lumborum, and external and internal obliques) were mainly affected by the backward tilting direction (40°). Deep muscles such as the multifidi and short muscles were activated in most directions of the rotation and tilt. The backward directions of the tilt using this device could be carefully applied for the elderly and for rehabilitation patients who are expected to have less muscle strength. In this study, it was shown that the spine stabilization exercise device can provide considerable muscle exercise effect.

• 한국컴퓨터정보학회논문지
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• 제7권2호
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• pp.95-100
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• 2002

피드백 채널을 이용한 디코더는 인코더로 전송에러에 의한 오염된 매크로 블록들의 주소를 알려준다. NACK 메시지의 수신으로 인코더는 전송에러가 발생된 프레임의 GOB와 MB를 기준으로 forward dependency를 적용으로 확산된 에러전파영역을 지닌 다음순서의 프레임을 만들어낸다. 이 프레임으로 현재 인코딩 하려는 프레임의 각 MB안에 4-corner에 존재하는 픽셀들에 대한 backward dependency를 적용함으로써 오염된 MB을 찾아낼 수가 있다. 이들 오염된 MB들에 대한 INTRA코딩을 적용함으로써 에러확산을 완전히 중단시킬 수 있다. 이와 같이 빠른 알고리즘의 적용으로 보다 적은 연산량과 보다 적은 양의 메모리 요구를 얻을 수 있다 또한 이러한 장점은 실시간 비디오 전송에 특히 적합하다.

• 한국과학교육학회지
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• 제8권1호
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• pp.43-55
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• 1988

This study intended to find the differences between expert's and novice's thinking processes when they solve physics problems. Five physics professors and twenty sophomore students in a physics department were participated in the study. The researcher investigated their thinking processes in solving three physics problems on NEWTON's law of motion. The researcher accepted so called "Thinking Aloud" method. The thinking processes were recorded and transfered into protocols. The protocols were analysised by problem solving process coding system which was developed by the researcher on the basis of Larkin's problem solving process model. The results were as follows: (1) There was no difference of time required in solving physics problem of low difficulty between expert and novices; but, it takes 1.5 times longer for novices than experts in solving physics problems which difficulties are high and average. (2) Novices used working forward strategy and working backward strategy at the similiar rate in solving physics problems which difficulties were average and low. while Novices mo mostly used working backward strategy in solving physic problems which difficulty was high. Experts mostly used working forward strategy in solving physics problems whose difficulties was average and low, however experts used working forward strategy and working backward strategy at the similiar rate in solving physics problem which difficulty was high. (3) Novices usually wrote only a few information on the diagram of figure they drawn, on the other hand experts usually wrote almost all the information which are necessary for solving the problems. (4) Experts spent much time in understand the problem and evaluation stage than novices did, however experts spent less time in plan stage than novices did. (5) Physics problems are solved in sequence of understanding the problem, plan, carrying out the plan, and evaluation steps regardless of problem difficulty.