• Title/Summary/Keyword: Motion study

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A Study on the Development of Residual Sway Motion Control System for the Container Crane (컨테이너 크레인의 흔들림 방지장치 개발에 관한 연구)

  • 손유식;김영복
    • Journal of Ocean Engineering and Technology
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    • v.14 no.4
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    • pp.35-42
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    • 2000
  • The sway control problem of the pendulum motion of a container hanging on the trolly, which transports containers from a container ship to trucks, is considered in the paper. In the container crane control problem, suppressing the residual swing motion of the container at the end of acceleration or the case of that the unexpected disturbance input exists is main issue. For this problem, in general, the trolley motion control strategy is introduced and applied. But in this paper, we introduce and synthesize a new type of swing motion control system. In this control system, a small auxiliary mass is installed on the spreader. And the actuator reacts against the auxiliary mass, applying intertial control forces to the container to reduce the swing motion in the desired manner. In this paper, we apply the LMI approach and simultaneous optimization design method to design the anti-swing motion control system for the controlled plant. And the simulation result shows that the proposed control strategy is shown to be robust to disturbances like winds and initial sway motion.

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Motion of Conductive Spherical Particle under Uniform Electric Field (평등전계에서 도전성 구형 입자의 운동)

  • Lim, Hun-Chan
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.8
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    • pp.39-47
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    • 2011
  • The motion of a conductive spherical particle under uniform electric field is investigated in order to find a suitable method for removing the conducting solid impurities contained in liquid plastic. When the positive dc voltage applied to the upper electrode, the vertical up-and-down motion of a charged particle by electrostatic force is observed by a charge-coupled device (CCD) camera or a high-speed video camera. The experimental data of the static threshold voltage by which the particle starts to move toward the counter electrode in air or silicone oil are in good agreement with theoretical value. When the applied voltage is larger than the static threshold voltage, the particle motion pattern in silicone oil consists of four stages: upward motion, stopping at the upper electrode, downward motion and stopping at the lower electrode. The stopping motion on the electrode is thought to be caused by the liquid flow accompanied by the particle motion. The particle charge calculated by integrating the pulse current, which is generated by the charge exchange between the electrode and the particle, is approximately 0.1~0.25 times of the theoretical value. This study is expected to help understand the electric properties of microparticles in oil circuit breaker (OCB) and oil transformer and improve their performance and longevity.

A Study on Feed Dog Motion of a Lock Stitch Sewing Machine (본봉용 재봉기의 톱니 운동에 관한 연구)

  • 전경진;송창섭;신대영
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.12
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    • pp.37-47
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    • 1998
  • This study discusses the feed dog feeding mechanism of an industrial lock stitch sewing machine, which is a good example to study a machine kinematics. The feed dog feeding mechanism makes the fabrics directly be fed by an elliptic motion of the feed dog that is moved by a rotation of the top shaft and controlled by the feeding control mechanism. This study makes mathematical expressions of machine's motion in the feed dog feeding mechanism. Thus, the motions of this mechanism are characterized, namely how an elliptic motion of the feed dog is affected by the feeding control mechanism. Therefore, the above mathematical expressions may be a basis for the new design of the feed dog feeding mechanism and may be adapted to analysis. Development of the similar feed dog feeding mechanism can be applied to other type sewing machine.

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Associative Motion Generation for Humanoid Robot Reflecting Human Body Movement

  • Wakabayashi, Akinori;Motomura, Satona;Kato, Shohei
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.12 no.2
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    • pp.121-130
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    • 2012
  • This paper proposes an intuitive real-time robot control system using human body movement. Recently, it has been developed that motion generation for humanoid robots with reflecting human body movement, which is measured by a motion capture. However, in the existing studies about robot control system by human body movement, the detailed structure information of a robot, for example, degrees of freedom, the range of motion and forms, must be examined in order to calculate inverse kinematics. In this study, we have proposed Associative Motion Generation as humanoid robot motion generation method which does not need the detailed structure information. The associative motion generation system is composed of two neural networks: nonlinear principal component analysis and Jordan recurrent neural network, and the associative motion is generated with the following three steps. First, the system learns the correspondence relationship between an indication and a motion using training data. Second, associative values are extracted for associating a new motion from an unfamiliar indication using nonlinear principal component analysis. Last, the robot generates a new motion through calculation by Jordan recurrent neural network using the associative values. In this paper, we propose a real-time humanoid robot control system based on Associative Motion Generation, that enables user to control motion intuitively by human body movement. Through the task processing and subjective evaluation experiments, we confirmed the effective usability and affective evaluations of the proposed system.

Analysis of User Head Motion for Motion Classifier of Motion Headset (모션헤드셋의 동작분류기를 위한 사용자 머리동작 분석)

  • Shin, Choonsung;Lee, Youngho
    • Journal of Internet of Things and Convergence
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    • v.2 no.2
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    • pp.1-6
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    • 2016
  • Recently, various types of wearable computers have been studied. In this paper, we analyze the characteristics of head motion information for the operation of the motion classifier produced motion headset that the user can use while listening to music. The prototype receives music from smart phone over bluetooth communications, and transmits the motion information measured by the acceleration sensor to the smart phone. And the smartphone classifies the motion of the head through a motion classifier. we implemented a prototype for our experiment. The user's head motion "up", "down", "left" and "right" were classified using a Bayesian classifier. As a result, in case of the movement of the head "up" and "down", there are a large changes in the x, z-axis values. In future we have a plan to perform a user study to find suitable variables for creating motion classifier.

A Study on the Cyber motion sickness of VR Content -Focused on Content Environment- (VR 콘텐츠 사이버 멀미에 관한 연구 -콘텐츠 환경을 중심으로-)

  • Koo, Ja-yoon;Kim, Seung-In
    • Journal of the Korea Convergence Society
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    • v.10 no.3
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    • pp.135-140
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    • 2019
  • This study is aimed at analyzing cyber motion sickness factors focus on virtual environment-based VR and real-world VR. First literature study of cyber motion sickness, 3D animations and documentaries were conducted. As a measurement tool for the degree of motion sickness, the symptom values were measured in a standardized SSQ (Simulator Sickness Questnire) questionnaire. Following the measurement, an in-depth interview was conducted based on the SSQ questionnaire. The results are as follows, First, actual environment based VR caused bigger cyber motion sickness, second, values of strong saturation of VR contents cause cyber motion sickness. This study is expected to be used as design guidelines for configuring VR early contents and to be used for cyber motion sickness research.

The Effect of Motion Recognition Occupational Therapy on the Physical Self-efficacy, and Visual-motor Integration, Interactive Peer Play of Children with Neurodevelopmental Disorders (모션 인식 활용 작업치료가 신경발달장애 아동의 신체적 자기효능감 및 시각-운동통합 능력, 놀이기술에 미치는 영향)

  • Kim, Ko-Un;Oh, Hye-Won
    • Journal of The Korean Society of Integrative Medicine
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    • v.10 no.1
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    • pp.119-128
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    • 2022
  • Purpose : The purpose of this study was to examine the effects of applying occupational therapy that uses motion recognition on the physical self-efficacy, visual-motor integration ability, and play skills of children who have neurodevelopmental disorder before and after treatment. Methods : This The study chose 16 children with neurodevelopmental disorder as research subjects who were randomly and evenly allocated into an experimental group and a control group. The experiment followed a pretest-posttest design. As an intervention, the experimental group received motion recognition-based occupational therapy and a separate sensory integration program. The control group only participated in the separate sensory integration program. The eight-week experiment duration included 24 intervention sessions where the a 50-minute session was implemented three times a week for eight weeks. To compare the physical self-efficacy, visual-motor integration ability, and play skills before and after the intervention, measurement tools including the Physical self efficacy, Beery VMI-6, and Penn interactive peer play scale were used. All measured variables were analyzed and expressed as mean, standard deviation and percentage. Results : The motion recognition-based occupational therapy demonstrated a significant effect on improving the physical self-efficacy, visual-motor integration ability, and play skills of the experimental group. The intervention also caused a significant difference between the experimental group and control group in terms of the physical self-efficacy, visual-motor integration ability, and play skills. Conclusion : We confirmed the possibility motion recognition-based occupational therapy could be effective in improving the physical self-efficacy, visual-motor integration ability, and play skills for patients who have neurodevelopmental disorder. Based on the study result, further future studies are expected based on this study result that prove the application effect of the motion recognition-based occupational therapy using disabled and non- disabled children as subjects are expected in the future.

Study on Dynamic Stability of Cylindrical Structure in Waves (파랑 중 실린더형 구조물의 동적 안정성에 대한 연구)

  • Jang, Min-Suk;Jo, Hyo-Jae;Hwang, Jae-Hyuk;Kim, Jae-Heui;Lee, Byeong-Seong;Park, Chung-Hwan
    • Journal of Ocean Engineering and Technology
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    • v.31 no.3
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    • pp.196-201
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    • 2017
  • A cylindrical structure has a very long period of heave and pitch motion response in ocean waves. To obtain the dynamic stability of a cylindrical structure, it is necessary to obtain the suitable metacentric height (GM). However, in a structure with sufficient metacentric height, Mathieu instability can occur if the natural frequency of the heave motion is double the natural frequency of the roll and pitch motion. This study carried out numerical calculations and experiments for vertical-axis wind turbines with cylindrical floaters, which had three different centers of gravity. In the regular wave experiment, the divergence of the structure motion without yaw was observed when the natural frequency of the heave motion was double the natural frequency of the roll and pitch motion. In the irregular wave experiment, the motion spectra of the structures with the different centers of gravity were compared, and one was very high when the natural frequency of the heave motion was double the natural frequency of the roll and pitch motion.

Impact of Firefighters' Protective Clothing and Equipment on Upper Body Range of Motion (소방용 방화복 및 방화 장비에 따른 상반신 관절 각도의 동작 범위 연구)

  • Kim, Seonyoung;Park, Huiju
    • Fashion & Textile Research Journal
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    • v.17 no.4
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    • pp.635-645
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    • 2015
  • This study analyzed the range of motion of upper body in different configurations of firefighters' protective clothing and equipment. The purpose of this study was to understand the influence of firefighters' protective clothing and equipment over upper body motion in order to improve design of firefighters' protective clothing and equipment. 12 firefighters' upper body range of motion was analyzed while performing standing and walking trials in five different garment configurations including turnout ensemble, fire boots and the self-contained breathing apparatus. Analysis of upper body range of motion included spinal joints of L5S1, L4L3, T1C7, and C1Head. During standing trials, garment configurations caused a significant difference in range of motions at joints of L5S1, L4L3, T1C7, and C1Head. Analysis on the mean of range of motions at L5S1 and L4L3, showed that firefighters' waist bent forward significantly to a greater extent while they wore a self-contained breathing apparatus. A significantly increased range of motion was found for T1C7 and C1Head while carrying a self-contained breathing apparatus, which indicated an increase in the extension of the trunk and neck backward to stand upright and look squarely. A significant difference in range of motion was also found for L5S1 and L4L3 during walking trials.

The Motion Evaluation of Arthritis Patients' Dressing and Undressing Corresponding to their Joint Range of Motion (관절염질환자의 관절가동범위에 대응한 착탈의 동작평가)

  • Han, Seung-Hee;Choi, Mi-Sung
    • Journal of the Korea Fashion and Costume Design Association
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    • v.14 no.2
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    • pp.75-87
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    • 2012
  • This study aims at measuring and comparing the joint range of motion(ROM) of the elderly, quantitatively understanding the joint ROM and duration for their dressing and undressing of pants with 3D motion analysis equipment, and thereby providing basic data necessary for the future development of clothes carrying functional designs. The findings are as follows. As for the study method, the 9-item joint ROM measurements were conducted with goniometer, and the questionnaire analyses were carried out for t-test, ANOVA, and regression analysis with spss12.0 program. The 3D motion analyses were handled with 3D Motion Analysis Package Version 3.1 Program. The findings are as follows. First, the ROM was shown to be significantly low, as the arthritis-pain consciousness level was felt higher by the subject than the average one. Seven ROM variables, such as hip flexion, hip adduction, hip internal rotation, hip external rotation, knee flexion, ankle dorsiflexion, and ankle plantar flexion, were shown to significantly affect the discomfort level experienced at the time of dressing or undressing. Second, in the motion of inserting the remaining leg into the pant crotch part(3e), the difference of angles in the hip joint and knee joint was the largest between the women in their 20s and the elderly women with arthritis. Third.

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