• Title/Summary/Keyword: 선 자세

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A Prediction on Running Attitude of High Speed Planing Craft (고속 활주선의 항주자세 추정)

  • Oh, Kwang-Ho;Yoo, Jae-Hoon
    • Journal of Korea Ship Safrty Technology Authority
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    • s.33
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    • pp.12-31
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    • 2012
  • 수치 계산으로 고속 활주선의 저항 성능을 평가하기 위해서는 활주 상태에서의 항주자세 예측이 무엇보다도 중요하다고 할 수 있다. 항주자세의 변화가 큰 고속 활주선의 경우에는 활주 자세에 따라 선저 바닥면에서 나타나는 압력 변화에 의한 동적 부양력 변화가 크므로 단순히 정지 중 흘수를 기준으로 계산되어진 유체력으로 항주자세를 예측하기 보다는 자세 변화에 따른 동적 부양력의 변화와 이에 의한 자세 변화를 반복 계산을 통해 수렴시키는 것이 요구되어진다. 본 연구에서는 선형화된 자유수면 조건의 포텐셜 수치 계산으로 유체 동압력인 부양력을 계산해내고 이를 유체 정역학적 힘으로 간주하여 부력과 선체중량과의 힘과 트림 모멘트 평형 관계를 만족시키는 방법으로 반복적인 계산을 통해 수렴된 활주 자세를 얻어내었다.

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Effects of the Modified Casual Shoes on Foot Pressure Distribution during Standing: Pilot study (기능성 신사화가 선자세의 족저압력 분포에 미치는 영향: 예비연구)

  • Lee, Namee;Bae, Young-Hyeon;Fee, Chae Yeol;Kim, Hyung-geun;Choe, Sangik;Kim, Sun-hyun
    • Proceedings of the Korea Contents Association Conference
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    • 2019.05a
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    • pp.341-342
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    • 2019
  • 본 연구는 기능성 신사화 착용이 즉각적인 선자세 족저압력 분포 변화에 미치는 영향을 확인하고자 하였다. 남성 물리치료사 8명을 대상으로 하루 간격을 두고 동일한 대상에게 일반적 신사화와 기능성 신사화를 착용하고 선 자세 동안 높은 족저압력의 발과 낮은 족저압력의 발간에 족저압력 분포를 비교하였다. 비교 분석 결과, 일반화를 착용한 선 자세에서 높은 족저압력의 발과 낮은 족저압력의 발간에 족저압력 비율이 유의한 차이를 보였지만 기능성 신사화에서 유의한 차이를 보이지 않았다. 그리고 높은 족저압력 분포 발에서 기능성 및 일반적 신사화간에 전족부와 후족부의 압력이 차이를 보였다. 선 자세에서 기능성 신사화가 일반적 신사화 보다 즉각적으로 정상 생리적 자세를 유도하는 것으로 보였다.

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Technical Improvement for Spine Radiography by Comparing Scoliotic and Lordotic Angle with Different Positioning Methods (촬영자세별 척추측만각과 척추전만각의 비교 분석에 따른 개선 방안)

  • Jung, Jae-Yeon;Son, Soon-Yong;Lee, Jong-Seok;Yoo, Beong-Gyu
    • Journal of radiological science and technology
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    • v.34 no.4
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    • pp.263-269
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    • 2011
  • Since the spine radiography were explained differently at every several hospitals and textbooks. the technique has not been accurately defined and interfered each other. We would like to define the most appropriate positioning for clinical cases, and reference books, by comparing scoliotic angle and lordotic angle. From Mar 2009 to Sep 2011, 85 patient cases were studied, who had not been undergone surgical treatment among spondylopathy patients. Scoliotic angle and lordotic angle were measured, using Cobb's method. We analyzed statistically using t-test(SPSS 18), and evaluated spine general radiography position. Moreover, we researched on the actual condition at 10 university hospitals in Seoul. The results of scoliotic angle measurement, the value at erect position showed 20.98% higher than supine position, and it has statistical significance (p<.01). In lordotic angle measurement, the value at neutral holding position represented 29.3% higher than supine position, and it also has statistical significance(p<.01). The results of clinical survey, supine posine(70.0%) took much higher possession than erect position(30.0%). In conclusion, compare to supine position, erect position shows increased scoliotic and lordotic angle. It was agreed with the importance of clinical erect position radiography, which gravity affects. So clinical radiologist must recognize the difference, and conduct an accurate study.

Depth calibration method of SWASH vessel using its position and ultrasonic sensor (SWASH형 시험선의 자세 및 초음파센서를 이용한 심도 보정 방법)

  • Hwang, Heesung;Cha, Jeongmin;You, Youngjoon
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.1140-1141
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    • 2017
  • Depth of SWASH(Small Waterplane Area Single Hull) vessel which is an input value of its control system is measured by ultrasonic sensor. Distance to the its center of gravity can be simply calculated through ultrasonic sensor attached to the front of the vessel from the known values. However, it is to be calibrated with respect to its position for the accurate depth because it has geometric relation between the measurement value of ultrasonic sensor and the depth. In this research, depth calibration method of SWASH vessel using its position and ultrasonic sensor is introduced.

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Zigbee와 초음파를 이용한 자세결정

  • Park, Chan-Sik;Gang, Dong-Yeon;Yun, Hui-Hak;Kim, Seung-Beom;Cha, Eun-Jong;Lee, Sang-Jeong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.2
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    • pp.551-556
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    • 2006
  • 위치 정보를 얻기 위해 GPS를 이용하며 다수의 GPS 안테나를 이용하면 자세까지 구할 수 있다. 그러나 실내에서는 GPS 신호 세기가 너무 약해 동작하지 않는 단점이 있다. 본 논문에서는 GPS 대신 Zigbee와 초음파를 이용하여 실내에서도 위치와 자세를 구하는 기법을 제시하였다. Zigbee 신호와 초음파 신호의 도착 시간차로부터 송신기와 수신기간의 거리를 구할 수 있으며 이로부터 위치를 구할 수 있다. 여기에 추가의 발신기를 장착하면 두 발신기의 위치 차이로 정의되는 기저선 벡터를 구할 수 있으며 이로부터 자세를 구할 수 있다. 본 논문에서는 다수의 발신기를 이용하여 효과적으로 기저선 벡터를 구하는 기법과, 이로부터 자세를 구하는 시스템을 구축하였다. 추가로 오차해석을 통하여 구해진 자세의 정확도를 예측하였다. 실제 실험을 통하여 20cm 간격의 두 발신기를 이용하여 1도 이하의 오차를 갖는 방위각과 앙각을 연속적으로 구할 수 있음을 확인하였다.

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비행선 자세각에 따른 부력중심 이동 및 종적 정안정성

  • Lee, Yung-Gyo;Kim, Dong-Min;Lee, Jin-Woo
    • Aerospace Engineering and Technology
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    • v.2 no.2
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    • pp.18-24
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    • 2003
  • Center of buoyancy moves along with pitch attitude variation, which causes Helium gas inclination. In this paper, movement of center of buoyancy and corresponding variation of longitudinal static stability were observed. The effect of separating wall, which is placed in the envelop to minimize movement of center of buoyancy was also investigated. Installation of separating wall was proved to be essential for current design, because movement of center of buoyancy aggravates longitudinal static stability. Investigation of longitudinal static stability for various speeds reveals a 50m airship is statically stable only in a low speed regime.

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Fitness Measurement system using deep learning-based pose recognition (딥러닝 기반 포즈인식을 이용한 체력측정 시스템)

  • Kim, Hyeong-gyun;Hong, Ho-Pyo;Kim, Yong-ho
    • Journal of Digital Convergence
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    • v.18 no.12
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    • pp.97-103
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    • 2020
  • The proposed system is composed of two parts, an AI physical fitness measurement part and an AI physical fitness management part. In the AI fitness measurement part, a guide to physical fitness measurement and accurate calculation of the measured value are performed through deep learning-based pose recognition. Based on these measurements, the AI fitness management part designs personalized exercise programs and provides them to dedicated smart applications. To guide the measurement posture, the posture of the subject to be measured is photographed through a webcam and the skeleton line is extracted. Next, the skeletal line of the learned preparation posture is compared with the extracted skeletal line to determine whether or not it is normal, and voice guidance is provided to maintain the normal posture.

A Study of Radiation Incidence Angle in Cervical Vertebra Anteroposterior(AP) Examination by Position (자세에 따른 목뼈 정면 입사각에 대한 연구)

  • Kwak, Jonghyeok
    • Journal of the Korean Society of Radiology
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    • v.9 no.2
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    • pp.101-107
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    • 2015
  • In anteroposterior radiation test for cervical vertebra, it is general that the incidence angle of X-ray is $15^{\circ}$ to $20^{\circ}$ degrees to head regardless of position. So this study suggests appropriate incidence angle of cervical vertebra depended on the position. From 1 January 2013 to 31 December 2013, cervical spine radiographys and magnetic resonance imaging was performed in 107 people who visited P Hospital located in Pusan. Among them, 39 people(men 24, women 15) were below 80 above 20 years old(average age 54 years) with normal cervical lordosis(normal $40^{\circ}{\pm}5^{\circ}$). In erect position, the incidence angle of cervical vertebra is measured from lateral radiographic images. And in supine position, it measured from MRI sagittal images. Results based on gender, the incidence angle of cervical vertebra in erect position was $25.9^{\circ}$ for men, women was $23.1^{\circ}$, showed statistically significant (p<0.05). And the angle in supine was $11.6^{\circ}$ for men, women was $12.6^{\circ}$, showed not statistically significant (p>0.05) An analysis of age group shows, the incidence angle of cervical vertebra in erect position was $24.6^{\circ}$ under 50, and $25.0^{\circ}$ over 50. The angle in supine was $12.0^{\circ}$ under 50, and $11.9^{\circ}$ over 50. And all of them showed not statistically significant (p>0.05). At all ages, the average of incidence angles in erect position were $24.8^{\circ}$, and the angle in supine was $12.0^{\circ}$, showed statistically significant (p<0.05). The cervical vertebra incidence angle for X-ray was $15^{\circ}$ to $20^{\circ}$ degrees to head in general. But, through the results, it is recommended that the angle is $24.8^{\circ}$ in erect and $12.0^{\circ}$ in supine position. It could be shown true anteroposterior(AP) view of cervical vertebra and accurate intervertebral fusion fixing devices.

Radiation Dose and Image Evaluation for Position Change in Low Extremity Teleography (하지전신계측검사에 자세의 변화에 따른 방사선량 및 영상평가)

  • Kim, Yeongcheon;Song, Jongnam;Choi, Namgil;Han, Jaebok
    • Proceedings of the Korea Contents Association Conference
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    • 2014.11a
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    • pp.233-234
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    • 2014
  • 하지전신계측검사(low extremity teleography)에서 자세 변화에 따른 중요장기의 방사선량을 측정하고 영상을 비교 분석하여 검사방법에 따른 유용성을 알아보고자 하였다. 대상은 하지전신계측검사를 시행한 성인남자 10명을 대상하였고 촬영조건은 관전압 73 kVp, 관전류량 32 mAs, SID 180 cm로 설정하였다. 방사선량 측정은 란도 팬텀을 이용하여 수정체, 갑상선, 생식선 부위에 유리선량계(ion chamber)를 부착한 후 전후방향자세와 후전방향자세를 각각 5번씩 시행하여 부위별로 방사선량을 측정한 후 Paired T-test로 비교 분석 하였다. 영상평가는 전후방향자세와 후전방향자세를 시행한 영상을 blind test를 실시하여 5점 척도로 평가하였다. 결과적으로 전후방향자세검사에 비해 후전방향자세검사가 수정체 약 6%, 갑상선 약 6%, 생식선에 미치는 방사선량을 약 27% 감소시킬 수 있으며 영상평가에서도 두 그룹 간에 큰 차이가 없어, 하지전신계측검사에서 전후방향자세검사보다 후전방향자세검사가 유용할 것으로 사료된다.

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Development of a Static Prosthesis-Alignment Device Using a Force Plate and a Laser Light (힘측정판과 레이저 광을 이용한 정적 의족정렬장치의 개발)

  • 이기원;김기완;김영호
    • Journal of Biomedical Engineering Research
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    • v.21 no.4
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    • pp.385-390
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    • 2000
  • The alignment of the prosthetics is very important in an amputee's gait. In the present study. a static prosthesis-alignment device was developed. It consisted of a force plate with four load cells, a laser beam controlled by a step motor, and a control part programmed by PCBASIC. Using the static prosthesis-alignment device, we measured the distance between the load line and various joints of 24 normal volunteers in three standing postures. such as neutral, forward leaning, and backward leaning. Only neutral postures were evaluated on four trans-tibial amputees. The load line for the normal person's neutral position located anterior to the ankle, the knee, and the greater trochanter, but posterior to the shoulder joint. Forward and backward leaning of the normal person resulted in a significant anterior and posterior movements of the load line, respectively. The load line for the amputated side of the trans-tibial amputee also located anterior to the ankle, the extremity prostheses, providing a good relative locations of the load line with respect to various joints.

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