• 제목/요약/키워드: CENTER OF BODY

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고고도 모사용 Center Body Diffuser에서의 Center Body의 위치에 따른 시동 특성에 관한 연구 (A Study on Starting Characteristics of Center Body Diffuser with Various The Location of Center Body for High Altitude Simulation)

  • 박진;이명원;이성훈;김홍집
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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    • pp.1148-1152
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    • 2017
  • 고고도용 로켓은 지상에서의 대기압에 비하여 매우 낮은 압력조건에서 작동한다. 따라서 고고도용 로켓 실험을 지상에서 구현하기 위해서는 충분히 낮은 압력환경을 조성해 주어야 한다. 이를 위한 고고도 모사용 실험설비 중 하나인 Center Body diffuser를 작동함에 있어서 Center Body의 위치가 진공도와 시동압력에 미치는 영향을 연구하기 위하여 ANSYS FLUENT를 통하여 수치해석을 진행하였다. 본 연구의 결과는 향후 고고도 모사용 Center Body Diffuser를 운용하는데 있어서 실질적인 Data Base로써 가치가 있다고 판단된다.

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Center-body 디퓨져 형상설계를 위한 수치적연구 (Numerical Study for Design of Center-body Diffuser)

  • 김종록;김재수
    • 한국추진공학회지
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    • 제18권3호
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    • pp.34-39
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    • 2014
  • center-body디퓨져에 대한 형상 설계 요소를 분석하고 수치적 기법을 통한 설계형상 변수를 구성하였다. 수치기법으로는 Center-body 디퓨져의 내부유동해석을 위하여 2차원 축대칭 Navier-Stokes equation와 $k-{\epsilon}$ 난류모델을 사용하였다. 또한 center-body디퓨져의 시동압력과 진공도 및 형상설계변수에 대해서 2차목 디퓨져와 비교하였다. 냉각시스템의 성능향상 방안으로 CBD의 원추선단에 역류제트를 활용한 TPS시스템의 개념을 제시하였다.

Center-body 디퓨져 형상설계를 위한 수치적연구 (Numerical Study for Design of Center-body Diffuser)

  • 김종록
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2009년도 제33회 추계학술대회논문집
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    • pp.487-491
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    • 2009
  • center-body디퓨져에 대한 형상 설계 요소를 분석하고 수치적 기법을 통한 설계형상 변수를 구성하였다. 수치기법으로는 Center-body 디퓨져의 내부유동해석을 위하여 2차원 축대칭 Navier-Stokes equation와 $k-{\omega}$난류모델을 사용하였다. 또한 center-body디퓨져의 시동압력과 진공도 및 형상설계변수에 대해서 2차목 디퓨져와 비교하였다.

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Center Body 위치와 Cone 각도에 따른 Center Body Diffuser의 유동특성 및 시동에 대한 수치적 연구 (A Numerical Study of the Flow Characteristics and Starting Pressure of a Center Body Diffuser According to the Center Body Position and Cone Angle)

  • 이성훈;박진;김홍집
    • 한국추진공학회지
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    • 제23권5호
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    • pp.10-18
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    • 2019
  • Center Body Diffuser (CBD)의 Center Body (CB) 형상에 의한 유동 특성 및 시동압력을 해석하였다. CB 위치와 Cone 각도의 변경을 통해 초음속 유동 특성 및 시동압력을 비교하였다. CB 위치를 변수로 하여 Diffuser 해석한 결과, 유동의 모멘텀의 형성에 따라 강한 경사충격파의 발생위치가 달라지는 것을 확인하였다. 또한 경사충격파가 발생할 경우, 초음속 유동의 방향이 디퓨저 벽면으로 유도되는 것을 확인하였다. Cone 각도 변화에 따른 경사충격파의 각도 차이로 인하여, CBD의 시동압력이 영향을 받는 것을 확인하였다.

카이로프락틱 골반 교정이 경추증후군의 신체균형에 미치는 영향 (The Effect of Body Balance on the Cervical Syndrome by Pelvis Adjustment of Chiropractic)

  • 이한춘;오평일;홍승희;이태영;장부규
    • 한국임상보건과학회지
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    • 제1권2호
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    • pp.21-29
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    • 2013
  • Purpose. This study was to investigate that the adjustment of Chiropractic pelvis method have effect on body balance and improvement people who has some problem in their daily life. Methods. With 20 students of experiment group and 20 students of compare group who has cervical syndrome, experiment group has adjustment of chiropractic pelvis 2 times a week for 4 weeks, the other group who didn't take any action. Results. As a result, center of body of experiment group wasn't improved relations between left and right statistically. But the relations between front and back of center of body increased statistically, cross analysis relations between short leg and center of body increased statistically. Conclusions. As a conclusion, experiment group with the front of center of body was improved 12.88% average of center of body. Experiment group with back of center of body was improved 13.84% average of center of body. This result come to the conclusion that chiropractic pelvis adjustment help the front and back of body balance.

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인체 중심과 분절 중심에 대한 연구 (Study of the Center of Gravity in the Human Body and each Segment)

  • 정형국;배성수
    • The Journal of Korean Physical Therapy
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    • 제5권1호
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    • pp.61-69
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    • 1993
  • It was performed to encourage for Physical Therapist to apply the theory of center of the human body and segments in clinical situations. This study was investigated literarily on center of the human body and segments. Methods which search for the center-2 types, that is, method using reaction broad and segmental method-was suggested. The center location difference of gravity in human body depends on individual character. Generally, the center location is in kent of 2nd sacrum, that is, at $55\%$ of height from foot. The center of each segment is on 'link'. In the first place we must how the weight of segment we can search for the center easily. Mean segment coater location of extremities is at $42.33\%$ from each proximal end, and mean center of head and trunk lies at $45\%$.

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The Morphological Study of Wild and Farmed Olive Flounder (Paralichthys olivaceus): The Role of Indirect Selection within and between Populations

  • Park, Jong-Won;Lee, Young-Mee;Noh, Jae-Koo;Kim, Hyun-Chul;Park, Choul-Ji;Hwang, In-Joon;Kim, Sung-Yeon;Lee, Jeong-Ho
    • 한국발생생물학회지:발생과생식
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    • 제16권4호
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    • pp.309-314
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    • 2012
  • This study was conducted to analyze the difference of body types within and between wild and farmed populations of olive flounder Paralichthys olivaceus using measured records of morphological traits. The results showed that surveyed traits and standard deviation were $1,355{\pm}742g$ of body weight, $48.01{\pm}7.79cm$ of total length, and $40.96{\pm}6.80cm$ of body length. Also body height, body shape index and condition factor were $17.19{\pm}3.43cm$, $9.99{\pm}0.74$ and $11.16{\pm}1.54$, respectively. As result of least squares mean and standard error for each trait assumed in this study, those of farmed population showed significantly higher than those of wild population in all traits, exclusively in total length and body length (p<0.01). Particularly, the values of the body height and the body weight of the farmed population were higher than those of the wild population in the same total length. And the phenotypic correlation coefficients of the body weight, the total length, the body length and the body height showed strong positive correlation in all populations. These result suggested that morphological differences exist in farmed and wild flounder. Therefore, introduction of wild flounder is essential for the future production to improve the body type of farmed flounder, and parental fish should be chosen by considering selection of commercially important traits in the production process.

Unusual Plastic-Metal Foreign Body in the Mandible

  • Kwon, Yong-Dae;Lee, Jung-Kyo;Lee, Baek-Soo;Kim, Yeo-Gab
    • Journal of Korean Dental Science
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    • 제2권2호
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    • pp.53-55
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    • 2009
  • A foreign body may present diagnostic difficulties. If the foreign body has been in existence for a long time, the diagnosis may be even more complex. This report shows an unusual foreign body that turned out to be the cap of a ball point pen.

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4족 보행 로봇의 걸음새 안정화를 위한 몸체 임피던스 제어 (Body Impedance Control for Walking Stabilization of a Quadrupedal Robot)

  • 이수영;홍예선
    • 대한전기학회논문지:시스템및제어부문D
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    • 제49권5호
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    • pp.257-263
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    • 2000
  • One of the basic assumptions in the static gait design for a walking robot is that the weight of leg should be negligible compared to that of body, so that the total gravity center is not affected by swing of a leg. Based on the ideal assumption of zero leg-weight, conventional static gait has been simply designed for the gravity center of body to be inside the support polygon, consisting of each support leg's tip position. In case that the weight of leg is relatively heavy, however, while the gravity center of body is kept inside the support polygon, the total gravity center of walking robot can be out of the polygon due to weight of a swinging leg, which causes instability in walking. Thus, it is necessary in the static gait design of a real robot a compensation scheme for the fluctuation in the gravity center. In this paper, a body impedance control is proposed to obtain the total gravity center based on foot forces measured from load cells of a real walking robot and to adjust its position to track the pre-designed trajectory of the corresponding ideal robot's body center. Therefore, the walking stability is secured even in case that the weight of leg has serious influence on the total gravity center of robot.

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Qualitative Study on Body Image and Appearance Behaviors in the Diet Center

  • Lee, Seung-Hee
    • 패션비즈니스
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    • 제8권6호
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    • pp.113-122
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    • 2004
  • The purpose of this study was to examine and understand body image, appearance behaviors, and eating disturbances among females in the Diet Center. Subjects for this research were 40 females enrolled at the Diet Center in Seoul. They were interviewed for this study using an interview schedule at September in 2004. As a result, most of the subjects (87%) were dissatisfied with their bodies, especially their lower body such as hip, thighs, legs, stomach. Subjects tended to use dieting and fasting (46.3%) as the most common appearance management behaviors in relation to the body parts. Make-up (32.9%) was also used as routine appearance behaviors, while 37.5% of subjects have had cosmetic surgery on eyes, nose and liposuction. Sixty percent of subjects had participated in Diet center programs more than twice. This may mean that society pressures women to have a slim body, which then will result in more self-confidence. Subjects tend to engage in unhealthy eating behaviors, such as 'fasting', 'inducing vomit', 'using diet pills or laxatives', and 'after chewing, spit out'. Based on these results, socio-cultural body image regarding ideal beauty would be discussed.