• Title/Summary/Keyword: 십자인대

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Design of 3-Dimensional Cross-Lattice Signal Constellations with Increased Compactness (조밀도가 증가된 3차원 십자격자형 신호성상도의 설계)

  • Li, Shuang;Kang, Seog Geun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.4
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    • pp.715-720
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    • 2016
  • In this paper, a method to design 3-dimensional (3-D) cross-lattice signal constellations with increased compactness is presented and analyzed. Here, the symbols located at the outermost sides in the conventional lattice constellation are moved symmetrically to fill in empty sides and sunken corners. While the minimum Euclidean distance (MED) among adjacent symbols remains unchanged, the presented cross-lattice constellations have 3~5% reduced average power and upto 25% reduced total volume as compared with the conventional ones. Due to the increase compactness, average power of the new 3-D constellations is lower than that of the conventional ones. As a result, computer simulation verifies that the presented cross-lattice constellations can improve symbol error performance of a digital transmission system about 0.4 [dB]. Hence, the proposed 3-D cross-lattice constellations are appropriate for low-power and high-quality digital communication systems.

Anterior Cruciate Ligament Reconstruction Using Hamstring Tendon Autograft : Advantage, Disadvantage, Hamstring Regeneration (자가 슬건을 이용한 재건술: 장점, 단점, 슬건의 재생)

  • Kim, Jin-Goo;Choi, Jeong-Yoon
    • Journal of the Korean Arthroscopy Society
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    • v.14 no.2
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    • pp.92-101
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    • 2010
  • The Hamstring autograft and the bone patellar bone tendon autograft have been widely used for anterior cruciate ligament reconstruction. In recent years, use of hamstring autograft for ACL reconstrution has been increased. The reason seems to be the advantages of the hamstring tendon such as high ultimate tensile load, low donor site morbidity and development of graft fixation method. These theoretical advantages have been increased as studies have shown that hamstring tendons actually regenerate after harvesting for ACL reconstruction. However, the concerns have arisen regarding the disadvantages of hamstring harvest, which were weakness of tibial internal rotation, the loss of flexion strength. The flexion strength loss has been controversial, therefore it needs to study whether restoration of flexion strength after hamstring regeneration is or not. In this study, we reviewed the current research of concerns on the advantage and disadvantage of hamstring tendon autograft and the hamstring regeneration. Furthermore, we compared the earlier studies and experiences regarding Hamstring regeneration with our research.

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Immediate Full Weight Bearing in Extension Brace Following Arthroscopic Primary Repair or Reconstruction of ACL (관절경하 전방십자인대 일차수복술 및 재건술후 신전보조기를 착용한 조기 완전체중부하)

  • Kim Jung Man;Chang Cheong Ho;Cho Woo-Shin
    • Journal of the Korean Arthroscopy Society
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    • v.1 no.1
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    • pp.128-131
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    • 1997
  • 전방십자인대의 일차수복술이나 재건술후에 장기간의 비체중부하가 필요한지를 결정하기 위해서 일차수복술을 시행한 96례와 재건술을 시행한 82례등 총 178례를 대상으로 술후 체중부하시기에따라 두군으로 나누어 비교분석 하였다. 모든 례에서 술후 보조기를 착용하였고 120례에서는 술후 첫6주간 점차적으로 관절운동범위를 증가를 시키고 다음 6주간은 완전운동범위 회복상태에서 유지후 술후 12주에 체중부하를 허용하였으며 나머지 58례에서 술후 완전신전상태에서 즉시 체중부하를 시켜서 정기적으로 Lachman검사, KT 2000을 이용하여 불안정성여부를 관찰하였다. 평균 추시기간은 4.2년(2년$\~$6년)이었고 불안정성에 대한 평가는 AMA 분류에 따랐다. 최종추시상 모든환자에서 1+이상의 불안정성은 발견되지 않았으며 술후 12주에 체중부하를 한군에서 1a+가 104례$(86.7\%)$, 1b+군이 16례$(13.3\%)$로 관찰되고 즉시 체중부하를 한 군에서 1a+가 51례$(87.9\%)$, 1b+가 7례$(12.1\%)$에서 보였으나 통계적으로 의미있는 차이는 없었다(P>0.05). 본연구의 결과로 전방십자인대 일차수복술이나 재건술후 신전보조기를 착용시키고 즉시 보행을 시키는 것이 술후 슬관절의 불안정성에 영향을 주지 않으며 안전한 재활방법으로 생각된다.

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Effect of Blast Cleaning on Fatigue Behavior of Non-load-carrying Fillet Welded Cruciform Joints (블라스트 표면처리가 하중비전달형 십자필렛 용접이음의 피로거동에 미치는 영향)

  • Kim, In Tae;Jung, Young Soo;Kim, Kwang Jin;Lee, Dong Uk
    • Journal of Korean Society of Steel Construction
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    • v.21 no.1
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    • pp.55-62
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    • 2009
  • Blast cleaning has been applied in steel bridges for cleaning forged surface and increasing adhesive property of applied coating systems. Blasting is the operation of cleaning or preparing a surface by forcible propelling a stream of abrasive metals against it. Blast cleaning may improve surface geometry and induce compressive residual stress, and eventually may increase fatigue life of weld joints. In this paper, fatigue tests were carried out on three types of non-load-carrying fillet welded cruciform joints, as-welded joints, blast-treated joints, and stress-relieved joints after blasting, in order to investigate effect of blast cleaning on fatigue behavior of the weld joints. By Blast cleaning, the weld toe radius was increased by 29% and compressive residual stress was induced near weld toes. Blast cleaning increased fatigue life and fatigue endurance limit of the weld joints. When the applied stress ranges decreased, the increment in fatigue life became larger. About a 150% increase in fatigue limit could be realized by using blast cleaning.

A Tenosynovial Giant Cell Tumor Arising from Posterior Cruciate Ligament of Knee Joint: A Case Report (슬관절 후방 십자 인대에서 기원한 건막 거대 세포종: 1예 보고)

  • Kim, Hong Kyun;Choi, Chang Hyun;Chung, Kook Jin;Lee, Young Min;Shin, Mi Kyung;Hwang, Ji Hyo
    • The Journal of the Korean bone and joint tumor society
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    • v.20 no.2
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    • pp.85-88
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    • 2014
  • Localized forms of giant cell tumor are known to arise commonly in the synovial membrane of the finger joints. Multinucleated giant cells are its characteristic pathology finding, giant cell tumor shows a low rate of recurrence after complete excision. When occurring at the knee joints, giant cell tumor manifests a wide form of symptoms, from no symptom at all, to intermittent locking. Complete excision is possible by arthroscopy, but if done incompletely, it is reported to recur in 45% of cases. We present here a case of giant cell tumor that has arisen from the anterior portion of the posterior cruciate ligament, excised by arthroscopy and followed by pathologic confirmation.

Localized Pigmented Villonodular Synovitis Developed on the Posterior Cruciate Ligament of the Knee: Treatment Using Posterior Trans-septal Portal - A Case Report - (후방 십자 인대에 발생한 국소형 색소 융모 결절성 활액막염 : 관절경하 후방 경격막 삽입구를 이용한 치료 - 증례 보고 -)

  • Lee, Gyu-Yeong;Lee, Hwa-Sung;Chang, Dong-Gune
    • Journal of the Korean Arthroscopy Society
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    • v.13 no.3
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    • pp.264-267
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    • 2009
  • Pigmented villonodular synovitis (PVNS) is a benign proliferative disorder of the synovium of joints. It occurs most commonly in the knee joint. The disease is composed of 2 different forms: diffuse and localized. The localized form is less frequent than the diffuse one. Most cases of localized PVNS involve the anterior compartment of the knee and can be usually easily diagnosed and treated with arthroscopy. We experienced a patient of localized PVNS developed on the posterior cruciate ligament, whose main symptom was persistent pain after trauma. This case occurs rarely and complete removal of the lesion was performed arthroscopically, using posterior trans-septal portal. We report this case with review of literatures.

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