• Title/Summary/Keyword: body position

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A New PSPM Modulation Scheme for Improving the Power Efficiency (전력 효율을 개선하는 새로운 PSPM 변조 방식)

  • Choe, Jae-Hun;Son, Jong-Won;Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.8A
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    • pp.752-759
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    • 2010
  • The low power consumption is the most important design factor for the In-Body communication system of WBAN. The conventional PSSK (Phase-Silence-Shift-keying) modulation technique can be regarded as an extension from PSK modulation. And this PSSK has better power efficiency than PSK modulation, and higher spectral efficiency than FSK modulation. PSSK modulation is to transmit two orthogonal symbols. The transmission power can be lowered because the symbol rate in signal period becomes half. BER performance is improved because transmission power is lower and the modulation symbol distance is widened. In addition, PSSK preserve the low-power and increase the data rate than FSK. In this paper, we analyzed existing PSSK and like to propose a new PSPM (Phase-Shift-Position-Modulation) modulation scheme. This PSPM is evaluated in terms of considered bandwidth efficiency and BER performance, compared with the PSSK. This PSPM modulation method transmits the information data by both PSK symbol data and symbol position data, so that we can significantly improve the power efficiency. New proposed PSPM method could be very useful for the In-body communication that requires the most power efficient system.

Development of Vertical Biomechanical Model for Evaluating Ride Quality (승차감 평가를 위한 수직 방향의 인체 진동 모델 개발)

  • 조영건;박세진;윤용산
    • Journal of KSNVE
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    • v.10 no.2
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    • pp.269-279
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    • 2000
  • This paper deals with the development of biomechanical model on a seat with backrest support in the vertical direction. Four kinds of biomechanical models are discussed to depict human motion. One DOF model mainly describes z-axis motion of hip, two and three DOF models describe z-axis of hip and head, and while nine DOF model suggested in this study represents more motion than the otehr model. Three kinds of experiments were executed to validate these models. The first one was to measure the acceleration of the floor and hip surface in z-axis, the back surface in x-axis, and the head in z-axis under exciter. From this measurement, the transmissiblities of each subject were obtained. The second one was the measurement of the joint position by the device having pointer and the measurement of contact position between the human body and the seat by body pressure distribution. The third one was the measurement of the seat and back cushion by dummy. The biomechanical model parameters were obtained by matching the simulated to the experimental transmissiblities at the hip, back, and head.

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Tolerance Analysis for Natural Frequencies of Multi-body Systems in Dynamic Equilibrium State (다물체계의 평형위치에서 고유진동수에 대한 공차해석)

  • Eom, Seung-Man;Choi, Dong-Hwan;Yoo, Hong-Hee
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.95-100
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    • 2006
  • Tolerance analysis method for natural frequencies of multi-body systems having a equilibrium position is suggested in this paper. To perform the tolerance analysis, the Monte-Carlo Method is conventionally employed. However, the Monte-Carlo Method has some weakness; spending too much time for analysis and having a low accuracy and hard to converge in the numerical unstable area. To resolve these problems, a tolerance analysis method is suggested in this paper. Sensitivity equations of natural frequencies are derived at the equilibrium position. By employing the sensitivity information of mass, damping and stiffness matrices, the sensitivity of natural frequencies can be calculated.

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A Study on the Fatigue Characteristics and the Behavior of Crack Propagation by Overload and Bending Moment in Car Body Structure (차체구조물에서 면내 굽힘모우멘트 및 과하중이 피로특성과 균열전파 거동에 미치는 영향에 관한 연구)

  • 성기찬;장경복;정진우;강성수
    • Journal of Welding and Joining
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    • v.19 no.6
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    • pp.652-657
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    • 2001
  • To analyze and predict crack initiation position and propagation directions on the spot welded area are very important for strength design of the automobile body structure. It is necessary to test by method considering random loads with variable amplitude for strength design of vehicle body structure, because driving cars are actually subjected to random loads with variable amplitude in the road. Although this condition, nearly all tests haute been performed under constant load conditions in the laboratory because it is impossible to replay like an actual conditions. In this study, using in-plane bending type specimens, the overload factor affecting on the fatigue strength, crack initiation and propagation directions of spot-welded specimens have been studied.

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Tolerance Analysis for Natural Frequencies of Multi-body Systems in Dynamic Equilibrium State (다물체계의 평형위치에서 고유진동수에 대한 공차해석)

  • Eom, Seung-Man;Choi, Dong-Hwan;Yoo, Hong-Hee
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.1 s.118
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    • pp.65-71
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    • 2007
  • Tolerance analysis method for natural frequencies of multi-body systems having a equilibrium position is suggested in this paper. To perform the tolerance analysis, the Monte-Carlo Method is conventionally employed. However, the Monte-Carlo Method has some weakness; spending too much time for analysis and having a low accuracy and hard to converge in the dynamical unstable area. To resolve these problems, a tolerance analysis method is suggested in this paper. Sensitivity equations of natural frequencies are derived at the equilibrium position. By employing the sensitivity information of mass, damping and stiffness matrices, the sensitivity of natural frequencies can be calculated.

A Review on the Mechanism of Human Postural Control (인간의 자세조절 메커니즘에 대한 연구)

  • Lee, Dong-Woo
    • Korean Journal of Applied Biomechanics
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    • v.15 no.1
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    • pp.45-61
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    • 2005
  • Stance is defined as any state in which the total mass of the body is supported by the feet. In order to maintain stance, the sum of gravito-inertial forces acting on the body must be registered by equal and opposite forces at the region of contact between the organism and the support surface. Balance is controlled by applying forces to the surface of support so as to maintain the body's center of mass vertically above the feet. for a muIti-segment organism, there can be a variety of ways in which balance can be controlled, since movements of different body segments can have similar effects on the control of balance. In general, the organism tends to have a body configuration that is aligned with gravito-inertial force when there are no external forces acting on it. If any segments of the body are not aligned with gravito-inertial force vector, a torque on that segment would tend to move the body's center of mass. The maintenance of postural stability is accomplished in humans by a complex neural control system. This requires organizing integrating and acting upon visual, vestibular, and somatosensory input, providing orientation information to the postural control system. The information necessary to control and coordinate movement is provided by the visual sense of eye position with respect to the surrounding surface layout, the vestibular sense of head orientation in the gravito-inertial space, and the somatic sense of body segment position relative to one another and to the support surface. In this study, perception and action capability was examined from various points of view. The underlying assumption of the study was that the change of postural configuration could be effected by organism, environment and task goal.

A Study on Perspirations(汗出) in Daily Time Cycle (하루 중 시간변화(時間變化)에 따른 한출(汗出)의 기전(機轉)에 대한 연구(硏究))

  • Lyu, Jeong-Ah;Jeong, Chang-Hyun
    • Journal of Korean Medical classics
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    • v.22 no.3
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    • pp.271-289
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    • 2009
  • This thesis intend to help the eastern medical doctor to understand body condition from interpretation of perspirations(汗出) in daily time cycle. The conclusion is followed. 1. In most Eastern Medical classic and clinic literatures, the time of fever and perspirations are described as a result of disease's position at human body. Following this description, in daytime the perspirations must come from the Gi phase and night time the perspirations must come from the blood phase. Because in daytime the skin pores are opening and the defensive Gi is going out to the superficial portion of the body. In night time the skin pores are shutting and the defensive Gi is going in to the five solid organs. So a sweat in daytime comes out from the Gi phase and superficial portion of the body. And in night time comes out from the blood phase and five solid organs. But in recent real clinic cases, in daytime, there are so many perspirations from the five solid organs. Comparatively, the perspirations from the superficial portion of body are very little. And in same daytime perspirations, when the heat pathogens mixed with moist, the symptom revelation time delay to the afternoon. Therefore it can be concluded that the time of perspirations are combination of disease's Gi or blood phase and characteristics of pathogens. The position of disease at human body cannot simply judge the symptom revelation time. 2. The exchange of climate following time cycle of a day effect to the condition of human body. At same time it activates or not activates the pathogens in human body. So we can consider the kinds and characteristics of pathogens by distinguishing the symptom revelation time. In general differentiation of syndromes[辨證] pathogen's kinds and location are generally judged. By understanding the characteristics of pathogen, doctor can devise more correct and delicate prescription.

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Comparison of Brand-name School Uniform Patterns for Middle School Girls and Development of School Uniform Patterns by Students' Body Shape, Using 3D Virtual Clothing Simulation (3D virtual clothing simulation을 활용한 여자 중학생의 브랜드교복 패턴비교 및 체형별 교복 패턴개발)

  • Shin, Jang-Hee
    • Journal of the Korea Fashion and Costume Design Association
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    • v.24 no.2
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    • pp.117-129
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    • 2022
  • In terms of junior high school girls' growth patterns during early adolescence, unlike childhood when relatively balanced growth patterns are found and high school years in which the normal adult body type is almost reached, junior high school girls display imbalanced and rapid growth. In fact, diverse size changes by body part occur with a significant difference among individuals. Therefore, it has been difficult for junior high school students to select their exact size when buying a school uniform. This study attempted to develop winter blouse and skirt patterns reflecting the latest comfortable and active school uniform trends, using middle school girl avatars of various body shapes. Skirt and blouse pattern-drawing methods and margins differed. Based on such results, research prototypes were prepared. Then, virtual wear prospective drawings, clothing pressure, and appearance were assessed by body shape. Skirts were assessed with 22 factors while blouses were analyzed with 25 factors. Then, correlations between skirts and blouses were analyzed. According to the analysis, the reason why the dart & pleats position and margin were rated low was confirmed. In a virtual wear assessment on skirt patterns by body shape, a significant difference was found in all categories except for position of the hip circumference, margin of the hips, width of the skirt, and appropriateness of waist line position. The virtual wear assessment on the blouse patterns by body shape also revealed a significant difference in all categories but fit and shape pf the back part. In blouses, a significant difference was observed around shoulders and waist in type 1 and around the belly in type 2. On the contrary, for skirts, a significant difference was found around the hips and waists in type 1 and type 2. Therefore, these factors should be considered in making blouses and skirts. The above results suggested that skirt and blouse patterns should vary by body shape. It is anticipated that there should be further studies comparing brand-name school uniforms for high school girls and school uniforms by body shape.

The Effect of Visual Cue Deprivation for the Head Alignment on Unilateral Neglect Patient: Case Report (편측 무시 환자에서 시각 정보 차단이 머리 위치 정렬에 미치는 영향: 사례 연구)

  • Chang, Jong-Sung;Park, Jung-Mi;Lee, Mi-Young
    • Journal of the Korean Society of Physical Medicine
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    • v.8 no.3
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    • pp.337-342
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    • 2013
  • PURPOSE: The Unilateral neglect is characterized by difficulty shifting attention to the side of space opposite the brain lesion and frequently reducing use of contralesional extremities. This study was to identify whether the visual deprivation was responsible for head position on unilateral neglect patient after stroke. METHODS: A patient with left middle cerebral artery infarction participated in the study. We assessed neglect using line bisection and star cancellation test. Patient was instructed to maintain correct alignment of trunk and head in a sit position. We evaluated degree of head lateral tilting and rotation. Then, patient was blocked visual input. Also, we evaluated head position in the same way. RESULTS: He scored 3 points in the line bisection test and 9 points star cancellation test. In postural evaluation, he had deviated posture such as lateral head tilting and rotation. After visual cue deprivation, patient showed different head position which was decreased degree of head tilting and rotation. CONCLUSION: For vertical body orientation, it was used multiple sensory references including the vestibular, somatosensory, and visual system. This finding suggested that abnormal posture of neglect patient could be related to the visual input. It has important clinical implications in terms of understanding the neglect.

The Effect of Pelvic Tilt Exercise with Changing the Body Position on Foot Contact Pattern in Hemiplegic Patients (자세에 따른 골반경사운동이 편마비 환자의 발 접촉양상에 미치는 효과)

  • Jang, Sang-Hun;Park, Soo-Jin;Kim, Min-Hee;Kim, Joong-Hwi;Kim, Jin-Sang
    • Journal of the Korean Society of Physical Medicine
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    • v.5 no.3
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    • pp.445-453
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    • 2010
  • Purpose : The purpose of this study was to investigate the effect of pelvic tilt exercise with changing the body position on foot contact pattern in the hemiplegic patients. Methods : Thirty seven hemiplegic patients were randomly divided 3 groups; control group (CG), sitting exercise group (SIEG) and standing exercise group (STEG). F-mat system and F-scan system were used for the measurement of foot contact pattern of hemiplegic side in walking. Data were analyzed statistically using paired t-test and one-way ANOVA. Results : The results were as follows : 1) Contact area of CG and SIEG were not significant difference in walking. Contact area of STEG was significant increased in walking. 2) Anteroposterior distance of COP of SIEG and STEG were significant increased in walking. Conclusion : These results suggest that pelvic tilt exercise in sitting and standing position are effective in the improvement of Anteroposterior distance of COP and gait stability are increased in only standing position.