• 제목/요약/키워드: Approach Angle

검색결과 977건 처리시간 0.026초

Computed Tomography (CT) Simulated Fluoroscopy-Guided Transdiscal Approach in Transcrural Celiac Plexus Block

  • Kong, Yu Gyeong;Shin, Jin Woo;Leem, Jeong Gill;Suh, Jeong Hun
    • The Korean Journal of Pain
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    • 제26권4호
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    • pp.396-400
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    • 2013
  • Conventional transcrural CPB via the "walking off" the vertebra technique may injure vital organs while attempting to proximally spread injectate around the celiac plexus. Therefore, we attempted the CT-simulated fluoroscopy-guided transdiscal approach to carry out transcrural CPB in a safer manner, spreading the injectate more completely and closely within the celiac plexus area. A 54-year-old male patient with pancreatic cancer suffered from severe epigastric pain. The conventional transcrural approach was simulated, but the needle pathway was impeded by the kidney on the right side and by the aorta on the left side. After simulating the transdiscal pathway through the T11-12 intervertebral disc, we predetermined the optimal insertion point (3.6 cm from the midline), insertion angle (18 degrees), and advancement plane, as well as the proper depth. With the transdiscal approach, we successfully performed transcrural CPB within a narrow angle, and the bilateral approach was not necessary as we were able to achieve the bilateral spread of the injectate with the single approach.

신경회로망과 Classifier를 이용한 부분방전패턴의 인식 (Recognition of Partial Discharge Patterns using Classifiers and the Neural Network)

  • 이준호;이진우
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 1999년도 학술대회논문집-국제 전기방전 및 플라즈마 심포지엄 Proceedings of 1999 KIIEE Annual Conference-International Symposium of Electrical Discharge and Plasma
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    • pp.132-135
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    • 1999
  • In this work, two approaches were proposed for the recognition of partial discharge patterns. The first approach was neural network with backpropagation algorithm, and the second approach was angle calculation between two operator vectors. PD signal were detected using three electrode systems; IEC(b), needle-plane and CIGRE method II electrode system. Both of neural network and angle comparison method showed good recognition performance for the patte군 similar to the trained patterns. And the number of operators to be used had a great influence on the recognition performance to the untrained patterns.

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대전차유도무기의 종말 받음각 및 입사각의 상관관계에 의한 표적 파괴율 분석 (Kill Probability Analysis Based on the Relation between Final Angle of Attack and Impact Angle of a Guided Anti-tank Missile)

  • 정동길
    • 한국군사과학기술학회지
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    • 제13권4호
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    • pp.520-527
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    • 2010
  • The kill probability of a missile depends on guidance error, warhead performance, and etc. In this paper, we analyzed the kill probability of anti-tank missile in a new approach. Under the condition that the missile hit the target, we studied the effect of angle of attack and impact angle. High impact angle increase the probability that the missile hits the upper armour which is relatively weaker, while high angle of attack at the impact instant decreases the effectiveness of the jet induced by the warhead. We proposed a way to increase the capability of penetration by analyzing the interrelation between impact angle and angle of attack.

최근접 각도를 이용한 복수 레이저 영상 추적 방법 연구 (A Study on the Multi-Laser Image Tracking Method using the Latest Approach Angle)

  • 조진표;고호정;김정호
    • 사물인터넷융복합논문지
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    • 제6권2호
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    • pp.37-43
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    • 2020
  • 본 논문은 스크린과 레이저 발사장치의 이격거리 변화에도 복수 개의 레이저 영상을 안정적으로 인식할 수 있는 최근접 각도 계산 방법을 제안하였다. 이 방법은 레이저 패턴 각도의 거리를 이용하여 사로를 인식하는 방법으로 레이저의 각도 추출은 레이블링 알고리즘을 이용하여 획득된 영상으로부터 레이저 영상을 검출하고, 허프 변환을 수행하여 직선의 각도를 추출한다. 유사성 척도 중 유클리드 거리를 이용하여 추출한 레이저 영상의 각도와 기준 각도의 거리를 계산하고, 계산된 거리 결과값을 이용하여 사로를 인식한다. 이격 거리를 "200cm~400cm"로 변경하면서 실험한 결과, 모든 이격 거리에서 개별 사로를 100% 인식했다. 실험을 통해 제안한 방법의 신뢰성을 확인하였다.

MEMS Gyro North Finding 방법을 이용한 실내 이동로봇의 전방향 탐지 (Indoor Mobile Robot Heading Detection Using MEMS Gyro North Finding Approach)

  • 위원룡;이민철;김지언
    • 로봇학회논문지
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    • 제6권4호
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    • pp.334-343
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    • 2011
  • This paper presents a new approach for mobile robot heading detection using MEMS Gyro north finding method in the indoor environment. Based on this, the robot heading angle measurement scheme is proposed; improved north finding theory and algorithm are also explained. Several approaches are applied to confirm system's precision and effectiveness. In order to find out the heading angle, a single axis MEMS gyroscope to sense the angle between the robot heading direction and the north is used. To reach enough estimation accuracy and reduce detection time, the least square method (LSM) for the signal fitting and parameter estimation is applied. Through a turn-table, we setup a carouseling system to decrease the substantial bias effect on gyroscope's heading angle. For the evaluation of the proposed method, this system is implemented to the Pioneer robot platform. The performance and heading error are analyzed after the test. From the simulation and experimental results, system's accuracy, usefulness and adaptability are shown.

섬유강화 복합재료 내 탄성파 반사현상의 제3임계각 (The Third Critical Angle in Reflection of Elastic Waves in Fiber-reinforced Composites)

  • 임현준;백은솔
    • Composites Research
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    • 제20권1호
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    • pp.15-22
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    • 2007
  • 이 논문에서는 섬유강화 복합재료에서의 초음파의 거동에 대해 파동의 모드, 방향, 자유표면에서의 반사파의 반사계수 등을 예측하는 해석적인 방법을 소개한다. 이 논문은 또한 복합재료의 자유표면에서 반사가 일어날 때의 특이한 현상을 새로이 고찰하였는데, 이는 완도면(slowness surface)만을 고려하면 존재할 것으로 예상되지만 실제로는 존재하지 않는 반사파에 대한 것이다. 이는 입사파가 유사횡파일 경우, 입사각이 이 논문에서 새로 정의된 제3임계각을 넘어설 경우 나타나는 현상이다. 본 논문의 내용은 초음파검사와 같은 해당 분야에 종사하는 연구자들에게 유용한 가이드라인을 제시할 것으로 기대된다.

2011 대구 세계육상선수권대회 여자 장대높이뛰기경기 기술의 운동학적 분석 (Kinematic Analyses of Women's Pole Vault in IAAF World Championships, Daegu 2011)

  • 최규정;이경옥;김남희;강지은;김혜림
    • 한국운동역학회지
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    • 제21권5호
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    • pp.561-571
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    • 2011
  • The purpose of this study was to perform the kinematic analyses of the women's pole vault skills in IAAF World Championships Daegu 2011. Subjects were the 1st through 8th place finishers in the pole vault. The kinematic analyses were divided into four phases: two dimensional run up analysis, and three dimensional analyses for the remaining plant, swing up, and extension phases. Run-up variables consisted of run up distance, number of steps, average step length, ratio of step length to height, average velocity at the final 5~10 m, approach position. Three variables were analyzed during plant: pole angle, center of gravity (COG) velocity, and COG takeoff angle. Swing up phase variables included: pole flection angle, COG velocity (horizontal, vertical, resultant), COG trajectory and bar approach angle of COG. Compared to the 2009 World Championships in Berlin, the average vault height increased, while run up velocity and approach position were almost unchanged. However, horizontal velocity during the last two steps of the final approach decreased noticeably compared to speeds from 1990. These results reflect the change in both technique and physical fitness in pole vaulters. During extension, the peak height of COG surpassed the clearance height by an average of 0.11m. These specific results can help coaches and athletes modify training and improve performance.

접근 각도 개념을 이용한 과소 작동기 무인 잠수정의 경로 추적 제어기 설계 (Design of Path Tracking Controller for Underactuated Autonomous Underwater Vehicle Using Approach Angle Concept)

  • 김경주;최윤호;박진배
    • 한국지능시스템학회논문지
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    • 제22권2호
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    • pp.225-231
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    • 2012
  • 본 논문에서는 접근 각도 개념을 이용하여 과소작동기 형태의 무인 수중 잠수정의 경로 추적 제어기 설계 방법을 제안한 다. 과소 작동기 형태를 가지는 무인 수중 잠수정은 종 방향 추진력과 회전력에 의해 속도와 방향을 조절하나, 횡 방향 추 진기가 없기 때문에 횡 방향에 대한 움직임을 제어 할 수 없다. 이러한 무인 수중 잠수정의 과소 작동기 문제를 해결하기 위하여 본 논문에서는 기준 경로에 대한 접근 각도 개념을 제안하고, 제안한 접근 각도를 이용하여 경로 추적 제어기를 설 계한다. 이를 위해 동체 고정 좌표계에서 새로운 오차 방정식을 구하고, 리아푸노프 방법을 기반으로 경로 추적 제어기를 설계한다. 본 논문에서는 컴퓨터 시뮬레이션 통해 제안한 방법에 의해 설계된 제어기의 성능을 검증한다.

Transbuccal versus transoral approach for management of mandibular angle fractures: a prospective, clinical and radiographic study

  • Khandeparker, Purva Vijay Sinai;Dhupar, Vikas;Khandeparker, Rakshit Vijay Sinai;Jain, Hunny;Savant, Kiran;Berwal, Vikas
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제42권3호
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    • pp.144-150
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    • 2016
  • Objectives: We compared the transbuccal and transoral approaches in the management of mandibular angle fractures. Materials and Methods: Sixty patients with mandibular angle fractures were randomly divided into two equal groups (A, transoral approach; group B, transbuccal approach) who received fracture reduction using a single 2.5 mm 4 holed miniplate with a bar using either of the two approaches. Intraoperatively, the surgical time and the ease of surgical assess for fixation were noted. Patients were followed at 1 week, 3 months, and 6 months postoperatively and evaluated clinically for post-surgical complications like scarring, infection, postoperative occlusal discrepancy, malunion, and non-union. Radiographically, the interpretation of fracture reduction was also performed by studying the fracture gap following reduction using orthopantomogram tracing. The data was tabulated and subjected to statistical analysis. A P -value less than 0.05 was considered significant. Results: No significant difference was seen between the two groups for variables like surgical time and ease of fixation. Radiographic interpretation of fracture reduction revealed statistical significance for group B from points B to D as compared to group A. No cases of malunion/non-union were noted. A single case of hypertrophic scar formation was noted in group B at 6 months postsurgery. Infection was noted in 2 patients in group B compared to 6 patients in group A. There was significantly more occlusal discrepancy in group A compared to group B at 1 week postoperatively, but no long standing discrepancy was noted in either group at the 6 months follow-up. Conclusion: The transbuccal approach was superior to the transoral approach with regard to radiographic reduction of the fracture gap, inconspicuous external scarring, and fewer postoperative complications. We preferred the transbuccal approach due to ease of use, minimal requirement for plate bending, and facilitation of plate placement in the neutral mid-point area of the mandible.

Determination of inclination of strut and shear strength using variable angle truss model for shear-critical RC beams

  • Li, Bing;Tran, Cao Thanh Ngoc
    • Structural Engineering and Mechanics
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    • 제41권4호
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    • pp.459-477
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    • 2012
  • This paper attempts to determine the inclination of the compression strut within variable angle truss models for RC beams loaded in shear-flexure through a proposed semi-analytical approach. A truss unit is used to analyze a reinforced concrete beam, by the principle of virtual work under the truss analogy. The inclination of the compression strut is then theoretically derived. The concrete contribution is addressed by utilizing the compatibility condition within each truss unit. Comparisons are made between the predicted and published experimental results of the seventy one RC beams with respect to the shear strength and the inclined angle of the compression strut at this state to investigate the adequacy of the proposed semi-analytical approach.