• 제목/요약/키워드: Pitch angle

검색결과 698건 처리시간 0.028초

도시부 고가구조물에 의한 일조환경 영향분석 (Analysis on the Effects of Sunshine Environment by Overpass Structure in Urban Areas)

  • 금기정;김종보;최용길;김영준
    • 한국도로학회논문집
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    • 제11권4호
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    • pp.49-58
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    • 2009
  • 현행 우리나라의 일조규정은 공동주택 및 일반 건축물을 중심으로 되어있기 때문에 도로 및 고가 구조물의 특성을 충분히 반영하지 못하고 있다. 또한, 공동주택간의 인동간격 및 인동간격이 미치는 다양한 영향에 대한 연구는 많이 이루어지고 있으나, 도로 및 고가 구조물과 주거지역과의 이격거리 및 구조물에 의해 발생되는 일조장애들의 환경적인 요소와 그에 따른 인자에 관한 연구는 미비하다. 따라서 본 연구에서는 도로 및 고가 구조물 중 주거지역과 인접해 있는 고가구조물을 중심으로 일조환경을 검토하여, 현재 사용되는 이격거리의 적정성 여부를 검토해보고, 구조물의 방위각에 따른 방향별 특성을 분석하였다. 구조물의 특성에 따른 일영거리를 통해 높이에 따른 이격거리비율을 산정하여, 향후 건설시 발생되는 일조장애를 최소화 하기위하여 구조물에 관한 제도 정비의 필요성과 최소 이격거리산정에 필요한 기초자료를 제시하는데 주목적을 두었다.

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eVTOL 항공기 블레이드 피치 제어용 선형 구동기 기본설계 모델의 구조 안전성 평가 (Structural Safety Evaluation of Basic Design Model of Linear Actuator for Blade Pitch Control of eVTOL Aircraft)

  • 김영철;김동협;김상우;강정현;김도형
    • 항공우주시스템공학회지
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    • 제16권6호
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    • pp.106-113
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    • 2022
  • 본 연구에서는 eVTOL 개인항공기의 개별 블레이드 피치 제어용 선형 구동기 기본설계 모델에 대한 구조 안전성을 검토하였다. Stall 하중에 대한 정적 구조 안전성을 검토하기 위해 유한요소법을 이용한 응력해석을 수행하여 안전여유율을 계산하였다. 또한 선형 구동기의 운용조건에 대한 피로수명을 평가하기 위해 피로 해석을 수행하였다. 다물체 동역학 분석을 통해 블레이드 피치각에 따른 하중이력을 산출하였다. 또한 정하중 해석에 정격하중을 적용하여 응력 분포를 산출하고 피로 해석에 활용하였다. 해석 결과, 선형 구동기의 모든 부품은 0 이상의 안전여유율이 계산되었고, 107 cycles 이상의 피로수명이 산출되어 구조적으로 안전함이 확인되었다.

Effect of Taping Therapy and Inner Arch Support on Plantar Lower Body Alignment and Gait

  • Lee, Sojung;Jeong, Dawun;Kim, Dong-Eun;Yi, Kyungock
    • 한국운동역학회지
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    • 제27권3호
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    • pp.229-238
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    • 2017
  • Objective: The purpose of this study was to identify the effects of taping therapy and inner arch support on pes planus lower extremity alignment and gait. Method: The study was conducted on 13 women in their 20s who had pes planus and no gait problems. Independent variables were the condition of wearing basic socks (S1) and the condition of wearing socks with taping therapy and inner arch support (S2). The dependent variables were resting calcaneal stance position (RCSP), plantar pressure distribution during gait, and underlying and medial longitudinal arch angle measured using radiography. Statistical analysis was performed using the Wilcoxon test with SPSS 23.0 for comparison of S1 and S2. Results: In the RCSP measurement, the angle range of S2 changed to normal. Meary's angle appeared to be less than the angle of S1, indicating alleviation of the degree of pes planus. The calcaneal pitch angle increased at S2 from that at S1. The plantar pressure distribution was divided into four areas (toe, forefoot, midfoot, and hindfoot). At S2, the maximum pressure increased in the toe and midfoot. The maximum force increased significantly in the toe and midfoot but decreased significantly in the forefoot and hindfoot. In addition, the contact area increased overall especially at the midfoot and hindfoot. Contact time decreased in the toe and forefoot, but increased in the midfoot and hindfoot. Conclusion: Taping therapy and inner arch support showed structural improvement of the pes planus. In addition, the force and pressure applied to the foot during walking are distributed evenly in the area of the sole, thus positively affecting walking.

제2 중족 족지 및 중족 설상 관절의 관절염에 대한 방사선학적 분석 (Radiological Analysis of Osteoarthritis of the Second Metatarsophlangeal and Tarsometatarsal Joint)

  • 김정래;김성윤;이우천
    • 대한족부족관절학회지
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    • 제16권2호
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    • pp.101-107
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    • 2012
  • Purpose: The aim of this study was to investigate the radiological characteristics of the osteoarthritis of the second metatarsophalangeal (MTP) and tarsometatarsal (TMT) joint. Materials and Methods: Between January 2002 and August 2010, 27 patients (33 feet) who had second metatarsal osteoarthritis (OA) were reviewed retrospectively. Group 1 was 14 patients (17 feet) with second MTP joint OA. Group 2 was 13 patients (16 feet) with second TMT joint OA. Group 3 was 24 patients (25 feet) had hallux valgus without second metatarsal (MT) OA as control. Weight bearing foot anteroposterior (AP) and lateral view were checked, and measured hallux valgus angle, metatarsus adductus angle (MAA), second MT functional length, first and second MT length by Hardy & Clapham method on AP view, angle of second MT with horizontal plane, calcaneal pitch, talo-first MT on lateral view. Results: On weight bearing foot AP view, second MT functional length of group 1, 2, 3 was 2.4 mm, -0.1 mm, 0.7 mm and MAA of group 1, 2, 3 was $17.7^{\circ}$, $17.7^{\circ}$, $14.5^{\circ}$. Second MT functional length of group 1 was longer than control group and it was statistically significant. MAA was significant different between group 1-3 and group 2-3. Angle of second MT with horizontal plane of group 2 was smaller than control group and it was statistically significant. Other radiographic parameters have no statistical significance. Conclusion: Group 1 has long functional length of second MT and group 2 has small angle of second MT with horizontal plane.

뒤꿈치 통증이 있는 족부의 방사선학적 분석 (A Radiographic Analysis of the Feet in Heel Pain)

  • 문형태;문정석;이우천
    • 대한족부족관절학회지
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    • 제9권1호
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    • pp.9-12
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    • 2005
  • Purpose: This study is to compare the medial longitudinal arch between heel pain group and normal painless group. Materials and Methods: Heel pain group 242 feet and normal group 140 feet were evaluated through the radiographic images of standing foot-ankle lateral view. Four radiographic indices, talo-1stmetatarsal angle (TMA), calcaneal-1st metatarsal angle (CMA), calcaneal pitch angle (CPA), and arch ratio (AR), were used as well as BMI. Results: There was no difference between heel pain group and normal group in the TMA, CMA, CPA, and AR. But in the BMI, heel pain group showed $1.7\;kg/m^2$ (p=0.0002) higher than normal group. To eliminate the sexual error, male and female were evaluated separately. Male heel pain group showed 2.9 degrees more dorsiflexion (p=0.001) in the TMA, 3.1 degrees greater (p=0.007) in the CMA, 0.01 lower (p=0.028) in the AR, and $1.0\;kg/m^2$ greater (p=0.033) in the BMI than normal male group. There were no difference in the CPA. Female heel pain group showed 3.6 degree greater (p=0.035) in the CMA, and $1.9\;kg/m^2$ greater (p=0.002) in the BMI than normal female group. But other indices demonstrated no differences. Conclusion: talo-$1^{st}$ metatarsal angle, calcaneal-$1^{st}$ metatarsal angle and arch ratio were radiographic indices related with heel pain.

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Analysis of Lattice Temperature in Super Junction Trench Gate Power MOSFET as Changing Degree of Trench Etching

  • Lee, Byeong-Il;Geum, Jong Min;Jung, Eun Sik;Kang, Ey Goo;Kim, Yong-Tae;Sung, Man Young
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제14권3호
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    • pp.263-267
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    • 2014
  • Super junction trench gate power MOSFETs have been receiving attention in terms of the trade-off between breakdown voltage and on-resistance. The vertical structure of super junction trench gate power MOSFETs allows the on-resistance to be reduced compared with conventional Trench Gate Power MOSFETs. The heat release of devices is also decreased with the reduction of on-resistance. In this paper, Lattice Temperature of two devices, Trench Gate Power MOSFET and Super junction trench gate power MOSFET, are compared in several temperature circumstance with the same Breakdown Voltage and Cell-pitch. The devices were designed by 100V Breakdown voltage and measured from 250K Lattice Temperature. We have tried to investigate how much temperature rise in the same condition. According as temperature gap between top of devices and bottom of devices, Super junction trench gate power MOSFET has a tendency to generate lower heat release than Trench Gate Power MOSFET. This means that Super junction trench gate power MOSFET is superior for wide-temperature range operation. When trench etching process is applied for making P-pillar region, trench angle factor is also important component. Depending on trench angle, characteristics of Super junction device are changed. In this paper, we focus temperature characteristic as changing trench angle factor. Consequently, Trench angle factor don't have a great effect on temperature change.

간접평판형 검출기에서 변조전달함수 측정 시 Edge 각도에 따른 비교 연구 (Comparison of Modulation Transfer Function in Measurements by Using Edge Device angle in Indirect Digital Radiography)

  • 민정환;정회원
    • 대한방사선기술학회지:방사선기술과학
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    • 제42권4호
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    • pp.259-263
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    • 2019
  • This study was purpose to compare image quality of Indirect digital radiography (IDR) system by using the International electro-technical commission standard(IEC 62220-1) which were applied to IEC in medical imaging. To evaluation the analysis of Modulation transfer function(MTF) measurements edge device each angle by using edge method. In this study, Aero (Konica, Japan) which is Indirect flat panel detector(FPD) was used, the size of image receptor matrix $1994{\times}2430$ which performed 12bit processing and pixel pitch is $175{\mu}m$. In IEC standard method were applied to each angle were compared. The results of shown as LSF at $2.0^{\circ}$ and $3.0^{\circ}$ angeles. Shape is constant and shows smooth shape. The amount of data seemed reasonable and 2.19 cycles/mm and 2.01 cycles/mm at a spatial frequency of $2.0^{\circ}$ and $3.0^{\circ}$ at an MTF value of 0.1. At an MTF value of 0.5, the spatial frequencies were $2.0^{\circ}$ and 1.11 cycles/mm and 0.93 cycles/mm at an angle of $3.0^{\circ}$. This study were to evaluate MTF by setting the each $2{\sim}3^{\circ}$ each angle and to suggest the quantitative methods of measuring by using IEC.

영상학적 및 관절경적 소견으로 평가한 족근동 증후군의 다양한 병적 상태 (Various Pathologic Conditions of Sinus Tarsi Syndrome Assessed by Imaging and Arthroscopic Findings)

  • 박정진;조승재;조성현;박철현
    • 대한족부족관절학회지
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    • 제28권2호
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    • pp.60-67
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    • 2024
  • Purpose: Sinus tarsi syndrome (STS) is caused by various pathologies. However, the exact etiology of STS remains controversial. This study evaluated the imaging and arthroscopic findings of patients who underwent surgical treatment after conservative treatment for STS failed. Materials and Methods: Between December 2014 and August 2018, 20 patients (21 cases) who underwent surgical treatment for STS were included in the study. The clinical results were analyzed using the visual analog scale (VAS) and the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot functional scale. The radiographic results were analyzed using Meary's angle, calcaneal pitch angle, and hindfoot alignment angle. The pathologic conditions of sinus tarsi were confirmed by magnetic resonance imaging (MRI) and subtalar arthroscopy. Synovitis, bone edema, and accessory anterolateral talar facet (AALTF) were evaluated on MRI. Synovial thickening, cartilage damage, interosseous talocalcaneal ligament (ITCL) and cervical ligament rupture, soft tissue impingement, AALTF, and accessory talar facet impingement (ATFI) were evaluated by subtalar arthroscopy. Results: The mean duration of symptoms was 28.7 months (4~120). All patients showed significant improvement in the VAS and AOFAS ankle-hindfoot scale. Significant improvements in hindfoot alignment angle and Meary's angle postoperatively were noted in patients who underwent medial displacement calcaneal osteotomy. MRI confirmed synovitis in all patients, AALTF in 19 cases (90.5%), and ATFI with bone edema in seven cases (33.3%). In subtalar arthroscopy, pathologic conditions were observed in the following order: synovitis in 21 cases (100%), AALTF in 20 cases (95.2%), ITCL partial rupture in nine cases (42.9%), and soft tissue impingement in seven cases (33.3%). All cases had two or more pathological conditions, and 15 (71.4%) had three or more. Conclusion: In cases of STS that do not respond to conservative treatment, a comprehensive examination of the lesions of the tarsal sinus and lesions around the subtalar joint is essential.

강제진동 기법을 이용한 무미익 비행체의 동안정 미계수 측정 (Measurement of Dynamic Stability Derivatives of Tailless Lamda-shape UAV using Forced Oscillation Method)

  • 양광진;정형석;조동현;안은혜;고준수;홍진성;김용덕;이명섭;허기봉
    • 한국항공우주학회지
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    • 제44권7호
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    • pp.552-561
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    • 2016
  • 본 연구에서는 강제진동 기법을 이용하여 람다형상을 갖는 무미익 무인기의 동안정 미계수를 측정하였다. 강제진동 기법은 시험모델을 일정한 크기의 각 변위로 진동시키면서 항공기에 작용하는 공력의 시간이력(time history) 데이터를 측정하고, 입력진동 대비 공력데이터의 위상차와 진폭을 추출함으로써 비행체의 동안정 미계수를 계산하는 방법이다. 본 연구에서는 롤, 피치, 요 방향으로 각각 진동시킬 수 있는 실험 장치를 설계, 제작하여 국내 최초로 무미익 항공기의 동안정 미계수 측정 시험을 수행하였다. 롤 댐핑 동안정 미계수 측정 결과, 진동 주파수와 진동의 크기가 증가하여도 동안정 미계수의 경향성은 동일하게 나타나며, 전반적으로 측정 받음각 구간에서 안정한 특성을 보였다. 피치 댐핑 동안정 미계수의 경우 작은 진동 주파수에서 동적으로 더 안정해지며, 받음각 $15^{\circ}$ 이상에서는 동적으로 불안정해지는 경향성을 보였다. 각 시험데이터들은 반복성 시험을 통해 데이터의 신뢰성을 검증하였으며, 본 연구에 적용된 강제진동 기법이 무미익 항공기의 동안정 미계수를 성공적으로 측정할 수 있음을 확인하였다.

다족형 로봇의 자세 제어 시스템 설계 및 구현에 관한 연구 (A Study On Design & Implementation of An Attitude Control System of a Lot of Legs Robots)

  • 남상엽;홍성호;김석중
    • 전자공학회논문지 IE
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    • 제45권4호
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    • pp.11-18
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    • 2008
  • 본 연구는 다족 로봇용 자세제어장치(ACS - Attitude Control System)인 관성측정 시스템(IMU) 의 H/W 설계와 자세제어 알고리즘 S/W을 설계하여 다관절용 로봇의 IMU 통합시스템을 구현 후 이 시스템의 동작성능을 검증하기 위해 Mtx와 MTx와의 성능을 비교 검증을 하고자 한다. ACS는 자이로와 가속도계 그리고 지자기 센서를 이용하여 항체의 롤, 피치각 자세를 제어하는 시스템이다. 일반적인 저가형 MEMS 관성센서로는 오차가 심하게 발생하여 항체의 정확한 위치를 계산하기 힘들다. 본 연구에서는 ACS 개발하기 위하여 상용의 MEMS 가속도계 및 자이고 센서, 추가적으로 지자기 센서를 사용하여 관성측정 시스템(IMU)을 표현한다. 구현된 IMU 시스템에 자세계산 프로그램을 내장하여 일정 성능을 보장하는 롤, 피치, 요 자세각 알고리즘을 설계하여 시스템에 포팅한다. 본 연구에서는 자이로와 가속도계 출력을 혼합하여 롤, 피치각을 보상함으로써 지속적으로 일정 수준이상의 성능을 보장하는 ACS를 구현하기위해 목표 플랫폼에 적재하여 실시간으로 구동하여 포팅하고 검증하였다.