• 제목/요약/키워드: plastic rotation

검색결과 357건 처리시간 0.025초

편측성 완전구순열에서 Cronin 삼각피판법과 회전신전법에 의한 수복의 비교 (A COMPARATIVE STUDY ON CRONIN TRIANGULAR FLAP AND ROTATION-ADVANCEMENT REPAIR IN UNILATERAL COMPLETE CLEFT LIP)

  • 유선열;윤천주
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제23권5호
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    • pp.415-421
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    • 2001
  • 본 연구는 편측성 완전구순열에서 Cronin의 삼각피판법과 Millard의 회전신전법에 의한 수복시 술후 결과를 비교 하고자 시행되었다. 13명의 편측성 완전구순열 환자를 대상으로 삼각피판법과 회전신전법에 의해 구순성형술을 시행하고, 술전${\cdot}$술후 사진을 토대로 구순부에서는 수직 길이, 반흔, 적순, 입술의 볼록함(lip pout), 큐피드궁의 다섯항목에 대하여, 비부에서는 비익, 비주, 비공저, 비첨, 비중격의 다섯 항보겡 대하여 각 항복 당 $0{\sim}10$점씩 총 100점으로 평가하고 술후 결과를 분석하여 다음과 같은 결과를 얻었다. 총폄점은 Cronin의 삼각피판법을 시행한 경우에 $74.77{\pm}0.86$점으로 Millard의 회전신전법을 시행한 경우의 $66.50{\pm}1.14$점에 비해 유의하게 높았다. 반흔비대는 Millard의 회전신전법을 시행한 경우에 28.6%의 발생율을 나타냈으나 Cronin의 삼각피판법을 시행한 경우에는 발생되지 않았다. 구순 기엥 대한 객관적 평가 결과 평균 길이 비는 Millard의 회전신전법을 시행한 경우에 $0.73{\pm}0.10$으로 Cronin의 삼각피판법을 시행한 경우 $0.80{\pm}0.96$보다 짧았으나 통계학적으로 유의한 차이는 없었다. 이상의 결과는 편측성 오나전구순열에서 Cronin의 삼각피판법이 Millard의 회전신전법보다 더 좋은 결과를 나타냄을 시사한다.

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보-기둥 접합부를 가진 철근 콘크리트 모멘트 골조의 비탄성 회전 능력에 대한 평가 (Performance Evaluation of Inelastic Rotation Capacity of Special Moment Frame Connections)

  • 이기학
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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    • pp.688-691
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    • 2004
  • This study summarizes results of a research project aimed at investigating the inelastic rotation capacity of beam-column joints of reinforced concrete moment frames. A total of 28 specimens were classified as special moment frame connections based on the design and detailing requirements in the ACI 318-99 provisions. Then, the acceptance criteria, originally defined for steel moment frame connections in the AISC-97 Seismic Provisions, were used to evaluate the joint connections of concrete moment frames. Twenty seven out of 28 test specimens that satisfy the design requirements for special moment frame structures provided sufficient strength and are ductile up to a plastic rotation of $3\%$ without any major degradation in strength.

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평형부 내에서 회전 운동을 하는 스핀들의 운동 구속에 대한 연구 (A Study on Motion Constraint of Rotating Spindle in the Parallel Part at the Blocking Plate)

  • 임종현;한근조;심재준;한동섭;이성욱;김태형
    • 한국정밀공학회지
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    • 제22권8호
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    • pp.136-142
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    • 2005
  • The function of main starting valve for marine engine is to supply cylinder with the air to start marine engine. But, if the spindle, one of the main starting valve components, doesn't rotate accurately at the designated air pressure, the marine engine may have some trouble in starting. So, to resolve the problem due to spindle .elation in the main starting valve, the blocking device (blocking plate, limit switch, etc.) is installed in the upper part of spindle to constrain the rotation. So, in this paper we introduced the rotation constraining ability of blocking plate prevent the spindle from mis-working in the main starting value of the marine engine.

유한요소해석을 이용한 환봉 단조공정 최적화 (Optimization of Round Bar Forging Process by Using Finite Element Analysis)

  • 최성기;천명식;문영훈
    • 소성∙가공
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    • 제13권2호
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    • pp.142-147
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    • 2004
  • Three-dimensional rigid-plastic finite element analysis has been performed to optimize open die forging process to make round bar. In the round bar forging, it is difficult to optimize process parameters in the operational environments. Therefore in this study, finite element method is used to analyze the practice of open die forging, focusing on the effects of reduction, feeding pitch and rotation angle for optimal forging pass designs. The soundness of forging process has been estimated by the smoothness and roundness of the bar at various combination of feeding pitches and rotation angles. From the test result, process conditions to make round bar having precise dimensional accuracy have been proposed.

유한회전과 접합부 특성을 고려한 공간프레임의 대변형 탄소성 해석 (Large Deformational Elasto-Plastic Analysis of Space Frames Considering Finite Rotations and Joint Connection Properties)

  • ;한상을
    • 한국강구조학회 논문집
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    • 제21권6호
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    • pp.597-608
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    • 2009
  • 본 연구에서는 접합부 특성이 고려된 공간프레임의 대변형 탄소성해석법에 관한 내용을 기술한다. 이 해석법은 유한변형을 고려한 대변형 탄성해석법에 기초한 것으로 부재의 재료적 탄소성, 접합부 반강접 특성을 추가적으로 고려하였다. 절점의 유한변형은 오일러의 개념으로 부터 유도되었으며, 부재좌표계에서 계산된 부재변형은 보-기둥식에 대입하여 부재력을 계산하였다. 부재변형은 부재축변형과 휨에 의한 축변형효과를 함께 고려하여 계산하였으며, 부재축력의 휨강성, 비틀림강성에 대한 효과를 고려하여 항복함수를 계산하였다. 재료는 완전 탄소성으로 가정하였고, 항복은 부재 양단부에서 집중하여 발생하는 소성힌지의 개념을 사용하였다. 부재 접합부 반강접 특성은 지수모델이나 선형모델을 적용하였고, 접합부 특성이 고려된 탄소성 후좌굴해석을 수행하기 위해 호장법을 사용하였다. 본 연구내용의 정확성 및 효율성을 검증하기 위해 공간프레임에 대한 해석을 수행하였다.

반복재하 실물대 실험에 의한 컬럼-트리(Column-Tree) 형식 철골 모멘트 접합부의 내진거동 연구 (Cyclic Seismic Testing of Full-Scale Column-Tree Type Steel Moment Connections)

  • 이철호;박종원
    • 한국강구조학회 논문집
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    • 제10권4호통권37호
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    • pp.629-639
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    • 1998
  • 본 연구에서는 반복재하 실물대 실험에 의해 철골 모멘트접합부(column-tree 형식)의 내진거동을 평가하였다. 시험체는 $H-600{\times}200$ (보) 및 $H-400{\times}400$ (기둥) 계열의 SS41 (SS400) 압연형강으로 제작되었으며 보에 대한 패널존의 상대강도를 실험의 주요변수로 고려하였다. 본 실험결과에 의할 때 패널존의 강도가 클수록 열등한 내진성능을 보였다. 시험체의 모멘트 접합부에서 접합부의 파괴 이전까지 발휘된 총소성회전각은 1.8 (% rad)에서 3 (% rad) 범위에 있었다. 시험체의 접합부는 보플랜지 열영향부의 파단 또는 기둥플랜지 두께방향의 뽑힘으로 인하여 파괴되었다. 비록 제한된 실험자료이긴 하나 본 연구의 결과는 보에만 항복을 유발하는 것 보다는 패널존의 항복도 허용하는 것이 접합부의 전체적 소성변형능력을 높이는데 유리할 것임을 시사한다. 이러한 실험결과를 역학적으로 설명할 수 있는 모델도 제시하고자 하였다.

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Personal technique for definite repair of complete unilateral cleft lip: modified Millard technique

  • Han, Kihwan;Park, Jeongseob;Lee, Seongwon;Jeong, Woonhyeok
    • 대한두개안면성형외과학회지
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    • 제19권1호
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    • pp.3-12
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    • 2018
  • Background: Millard's rotation-advancement repair, which is used by many surgeons, can make a natural philtral column, but most surgeons use a modification of the rotation-advancement flap. The purpose of this article is to introduce a modification utilized by the authors and to provide detailed surgical procedure. Methods: We retrospectively reviewed 82 patients' medical records and presented surgical technique and outcomes. The main features of the authors' strategy are emphasizing horizontal length of the lip, orbicularis oris muscle duplication for improving the definition of the philtral column, overcorrection of domal portion than the non-cleft side in order to compensate for the recurrence during growth. Two judges rated two times the appearance of the patients' nose and lip using Asher-McDade aesthetic index. Intra- and interobserver reliabilities were determined using Cohen's kappa statistics. Results: All patients recovered eventually after surgery; however, two patients have a minor complications (wound infection in one patient, wound disruption due to trauma in the other patient). The improvement of the aesthetic results can be achieved with this modified Millard technique. Total mean scores of the Asher-McDade index was 2.08, fair to good appearance. The intraobserver reliabilities were substantial to almost perfect agreement and the interobserver reliabilities were moderate to almost perfect agreement. Conclusion: We modified Millard method for repair of complete unilateral cleft lip. The surgical outcomes were favorable in long-term follow-up. We hope our technique will serve as a guide for those new to the procedure.

여섯 손가락증의 수술적 교정: 새로운 수술 방법의 고안과 적용 (Surgical Correction of Hexadactyly: Innovation of new technique and its application)

  • 탁관철;이명철
    • Archives of Plastic Surgery
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    • 제36권5호
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    • pp.642-648
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    • 2009
  • Purpose: Hexadactyly without thumb is a rare congenital anomaly of the hand where six triphalangeal digits are symmetrically distributed without thumb. Contrary to mirror hands, triphalangeal six digits are symmetrically distributed on each side at the midline with well - differentiated carpal bones, extensor tendons, one ulnar and one radius. The authors developed a new surgical technique based on a three - dimensional concept to correct the hexadactyly and applied to 2 cases of hexadactyly with good functional and aesthetic results. Here we document the surgical technique and its result. Methods: A 16 month old male patient visited our clinic with chief complaints of bilateral hexadactyly deformity. On physical examination most radial first and second digits showed no opposition and adduction motion on both side hands. Radiography showed 6 triphalangeal digits with normal development of carpal, radial and ulnar bone. Right side abnormality was corrected by removal of most radial side extra - digit, rotation and migration of 2nd ray to thumb position and creation of 1st web by transposing a mid - palm based rectangular palmar flap as in Snow & Littler procedure which has been being applied for correction of 1st web syndactyly in cleft hand deformity. Seven months later, left side abnormality was also corrected with the same procedure. Results: Postoperative appearances of the both hands were satisfactory. Flexion, extension, opposition and grasping were possible with the pollicized 2nd ray. Pinching power was 3.0 kg 15 months after surgery and 2.5 kg 22 months after in right hand respectively. Conclusion: In correction of hexadactyly deformity, satisfactory aesthetic and relevant functional results can be expected with authors' newly developed technique: removal of most radial digit, rotation and migration of 2nd digit to thumb position as well as creation of the 1st web space by transposition of mid - palm based rectangular flap.

Optimal harvest and efficient use of septal cartilage in rhinoplasty

  • Yoon, Sung Ho;Kim, Cha Soo;Oh, Jae Wook;Lee, Keun Cheol
    • 대한두개안면성형외과학회지
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    • 제22권1호
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    • pp.11-16
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    • 2021
  • Background: Nasal septal cartilage is used to obtain favorable aesthetic and functional outcomes in rhinoplasty, but is often difficult to harvest or the harvested amount is insufficient. Therefore, the objective of this study is to introduce how to harvest septal cartilage optimally without losing and use harvested cartilage efficiently. Methods: From March 2015 to January 2020, we tried to harvest as much septal cartilage as possible while maintaining the L-strut in 30 patients. A spreader flap and septal rotation suture were used instead of a spreader graft. Also in patients who needed a spreader graft and septal extension graft, a spreader graft was used on one side and a one-piece spreader graft combined with a septal extension graft was performed on the other side. For tip plasty, a columella septal suture was performed first. Postoperative patient satisfaction was assessed using the Rhinoplasty Outcome Examination questionnaire. Results: No serious complications were observed. The patient satisfaction score was 50% or above in 27 patients (90%) and less than 50% in only three patients (10%). The average score was 81.5 points. Conclusion: For septal cartilage deficiency, a spreader flap, the septal rotation suture, or onepiece spreader graft combined with a septal extension graft was used. The nasal tip was sufficiently rotated using the columellar septal suture technique first. These techniques made it possible to obtain good aesthetic outcomes using only septal cartilage, without harvesting other cartilage.

Improvement of Shoulder Motion in Two-Stage Dual-Plane Implant-Based Breast Reconstruction followed by Radiation Therapy through Delayed Prepectoral Conversion

  • Jin Sol Park;Ung Sik Jin
    • Archives of Plastic Surgery
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    • 제51권1호
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    • pp.52-61
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    • 2024
  • Background Although prepectoral implant-based breast reconstruction has recently gained popularity, dual-plane reconstruction is still a better option for patients with poor-quality mastectomy skin flaps. However, shoulder morbidity is aggravated by subpectoral reconstruction, especially in irradiated patients. This study aimed to demonstrate shoulder exercise improvement in subpectoral reconstruction by delayed prepectoral conversion with an acellular dermal matrix (ADM) inlay graft technique at the time of expander-to-implant exchange after irradiation. Methods Patients with breast cancer treated for expander-to-implant exchange after subpectoral expander insertion and subsequent radiotherapy between January 2021 and June 2022 were enrolled. An ADM inlay graft was inserted between the pectoralis major muscle and the previously inserted ADM. The ADM was sutured partially overlapping the pectoralis muscle from the medial side with the transition part, to the muscle border at the lateral side. Perioperative shoulder joint active range-of-motion (ROM) for forward flexion, abduction, and external rotation was also evaluated. Results A total of 35 patients were enrolled in the study. Active shoulder ROM significantly improved from 163 degrees preoperatively to 176 degrees postoperatively in forward flexion, 153 to 175 degrees in abduction, and 69 to 84 degrees in external rotation. There was no difference in patient satisfaction regarding the final outcome between the conventional prepectoral reconstruction group and the study group. Conclusion Shoulder exercises in irradiated patients who underwent subpectoral reconstruction were improved by delayed prepectoral conversion using an ADM inlay graft. It is recommended that subpectoral reconstruction not be ruled out due to concerns regarding muscle contracture and shoulder morbidity in radiation-planned patients with poor mastectomy skin flaps.