• Title/Summary/Keyword: Pivot point

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The Trapezius Muscle Flap: A Viable Alternative for Posterior Scalp and Neck Reconstruction

  • Yang, Hee Jun;Lee, Dong Hun;Kim, Yang Woo;Lee, Sang Gu;Cheon, Young Woo
    • Archives of Plastic Surgery
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    • v.43 no.6
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    • pp.529-535
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    • 2016
  • Background The trapezius muscle flap is not usually the first reconstructive option for skin and soft tissue defects in the posterior neck and scalp due to surgeons' unfamiliarity with the surgical anatomy and developments in free tissue transfer techniques. The goals of this study were to describe the clinical use of trapezius flaps in posterior neck and scalp reconstruction, and to investigate the vascular anatomy of trapezius flaps in Asians in order to obtain information facilitating the safe design and elevation of flaps in which most of the muscle is preserved. Methods A retrospective chart review was performed of 10 patients who underwent trapezius muscle flap for posterior neck and scalp defects. We also performed an anatomical study of 16 flaps harvested from 8 preserved Asian adult cadavers and evaluated the main landmarks relevant for trapezius muscle flap. Results In the anatomical study, the mean vertical height from the inferior angle of the scapula to the point at which the superficial cervical artery penetrated the trapezius was $4.31{\pm}2.14cm$. The mean vertical height of the trapezius muscle flap pivot point was $9.53{\pm}2.08cm$ from the external occipital protuberance. Among the 10 flaps, partial necrosis on the overlaid skin graft occurred in 1 patient and postoperative seroma occurred in another patient. Conclusions Vascular variations in the trapezius muscle flap are uncommon in Asians, but when present, such variations appear to have little impact on harvesting the flap or on its circulation. The trapezius muscle flap is a viable alternative for posterior neck and scalp reconstruction.

The Maritime Strategy of Continental Powered Country and Maritime Powered Country based on Attack and Defense theory (공격과 방어의 관점에서 본 해양국가와 대륙국가의 해양전략 - 냉전 기 미·소간 해양전략 및 탈냉전 기 미·중간 해양전략 비교 -)

  • Jung, Gwang-Ho
    • Strategy21
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    • s.32
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    • pp.160-191
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    • 2013
  • This article is focused how the maritime strategy between continental powered country(the Soviet, the China) and maritime powered country(the U.S.) interact with attack and defense theory. We will know, what is the maritime strategy that the U.S. of military superiority has pursued with the point of view of attack, on the other hand, relatively what is the maritime strategy that the Soviet-Sino of military inferiority has pursued with the point of view of defense. In cold war, the Soviet has counteracted to 'blue belt defense' in active defense as to the U.S. 'sea strike' and in post cold war, the China counteract to 'A2/AD' as to the U.S. 'Air-Sea Battle'. The difference between the Soviet-Sino maritime strategy is that the China has emerged the second an economic power and their leadership has a strong's will to strengthen their navy's power. although the U.S. declare the pivot to Asia, the influence on Asia of the U.S. tend to decrease because of sequest. therefore, the China will seek to the more active defense beyond the first island chain. Meanwhile, the U.S. has reinforced of 'hub and spoke strategy' to solidify the U.S. formal allies to band together regional powers and to overcome the A2/AD challenge, the U.S. has been developed that the Air-Sea Battle concept meshes with Washington's 'rebalancing' policy toward the Asia-Pacific as its vital missions to safeguard core island or semi-island allies-namely, Korea and Japan-and crucial sea lanes of communication in the region are conducted mostly from or over the sea.

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Simplified Analytic Solution of Submerged Wave Board Motion and Its Application on the Design of Wave Generator (조파판 수중운동의 근사해석과 조파기 설계에 응용)

  • Kwon, Jongoh;Kim, Hyochul;Lew, Jae-Moon;Oh, Jungkeun
    • Journal of the Society of Naval Architects of Korea
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    • v.54 no.6
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    • pp.461-469
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    • 2017
  • A segment of the wave board has been expressed as a submerged line segment in the two dimensional wave flume. The lower end of the line segment could be extended to the bottom of the wave flume and the other opposite upper end of the board could be extended to the free surface. It is assumed that the motion of the wave board could be defined by the sinusoidal motion in horizontal direction on either end of the wave board. When the amplitude of sinusoidal motion of the wave board on lower and upper end are equal, the wave board motion could express the horizontally oscillating submerged segment of piston type wave generator. The submerged segment of flap type wave generator also could be expressed by taking the motion amplitude differently for the either end of the board. The pivot point of the segment motion could play a role of hinge point of the flap type wave generator. Simplified analytic solution of oscillating submerged wave board segment in water of finite depth has been derived through the first order perturbation method at two dimensional domain. The case study of the analytic solution has been carried out and it is found out that the solution could be utilized for the design of wave generator with arbitrary shape by linear superposition.

Establishing the Structural Criteria to install Scaffolding-Use Brackets (비계지지브라켓 유형별 구조기준 설정에 관한 실험적 연구)

  • Son, Ki-Sang;Kal, Won-Mo
    • Journal of the Korean Society of Safety
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    • v.10 no.4
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    • pp.87-96
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    • 1995
  • It is only three(3) years since we applied brackets for scaffolding in the construction area. Unfortunately, there is no structural criteria on how to install those in the site so far, despite the fact that those brackets have been applied into the site by the firms already. It is shown that resistant capacity of each bracket type has been investigated, analyzed from this experimental study. Accident-concerning data on construction site analyzed by the Ministry of Labor, show temporary structure involves 18.6% of the total industrial accident, which the accidents from scafold-supporting brackets have rate of 42.5% of the ones occurred from the temporary structures. There are two main aspects to be observed : one is how much resistant capacity the brackets have themselves, the other is how exactly to install those without eccentricity. But practically, nobody does check of this bolt-installing conditions in the site and no check of tightening level of nut because there is no available tool to check torque amount for this kind of nut. We just have to rely on scaffolders experience of this tightening. This experiment involves just this variable of tightness at site. Eventually this insufficient tightness causes to collapse those scaffolding structures. The bracket might have less the one than its original capacity due to this insufficient tightness. Three(3) times of PIVOT tests show that fractured condition of two(2) row brackets has occurred mostly at lower bolt due to shear force. Therefore, tightness of bracket-installing bolt, tensile strength of the bolt, shear strength of the bolt, loading condition with equal two point or inequal two point loads, are mainly investigated as variables in this study.

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Optimum Design of Radial Gate (회전식 수문의 최적 설계)

  • 권영두;권순범;박창규;윤영중
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.14 no.3
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    • pp.267-276
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    • 2001
  • On the basis of structural analysis of the radial gate(that is, Tainter gate), this paper focuses on the optimization of the moment distribution according to the location of the arm of the radial gate. In spite of its importance from economical view point, we could hardly find the study on the optimum design of radial gate. Accordingly, the present study identifies the optimum section modulus for a radial arm along with the optimum position for 2 of 3 radial arms with a convex cylindrical skin plate relative to a given radius of the skin plate curvature, pivot point, water depth, ice pressure, etc. These optimum measurements are then compared with previously constructed radial gates. The results indicate that the optimum section modulus vague for a radial arm was appreciably smaller than the previously constructed examples.

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The Relationship between Bone Bruise in MR-Imaging and the Degrees of Acute Anterior Cruciate Ligament Injury (급성 전방십자인대 손상 시 자기공명영상에서 나타나는 골멍과 전방십자인대 손상 정도의 관계)

  • Jeong, Hwa-Jae;Shin, Hun-Kyu;Ko, Chun-Suk;Kim, Jang-Hwan
    • Journal of the Korean Arthroscopy Society
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    • v.16 no.1
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    • pp.17-25
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    • 2012
  • Purpose: The aim of this retrospective study was to evaluate the relationship between appearance and size of bone bruise and severity of anterior cruciate ligament (ACL) injury with magnetic resonance imaging (MRI), furthermore, to identify the mechanism of ACL injury by analyzing the footprint of bone bruise. Materials and Methods: Sixty-five subjects who was taken an MRI within 6 weeks after acute ACL injury were studied. All MRI showed ACL injury and associated bone bruises. Bone bruises were analyzed using Costa-Paz classification based on appearance and location and also scored using Kornaat bone bruise grading system based on size and location. The severity of the ACL injury was graded using a 4-point system (ie, grade 0-3) with oblique coronal MRI. Results: There was statistically significant correlation between Costa-Paz classification of bone bruises in lateral femoral condyle and grade of ACL injury. There were more type 2 lesions in partial tear group (grade 1, 2), however, type 3 lesions of Costa-Paz classification in complete tear group (P=0.037). Significant positive correlations were observed between Kornaat total bone bruise score and grade of ACL injury (P=0.014). Most common ACL injury mechanism was pivot shift injury. Other mechanisms were clip valgus injury, phantom foot injury, and hyperextension injury. Conclusion: It is highly suggested that appearance and size of bone bruise is related to severity of ACL injury after acute ACL injury. The foot print of bone bruise provides valuable clues to identify ACL injury mechanism.

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Diatally-Based Medial Crural Adipofascial Flap for Coverage of Medial Foot and Ankle

  • Kim, Min Bom;Lee, Young Ho;Choi, Ho Sung;Kim, Dong Hwan;Lee, Jung Hyun;Baek, Goo Hyun
    • Archives of Reconstructive Microsurgery
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    • v.24 no.2
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    • pp.56-61
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    • 2015
  • Purpose: We report on the clinical result after coverage of a soft tissue defect on the medial foot and ankle with an adipofascial flap based on the perforator from the posterior tibia artery. Materials and Methods: Nine patients with soft tissue defects on the medial foot and ankle area from March 2009 to May 2014 underwent the procedure. Average age was 54 years old (range, 8~82 years). There were five male patients and four female patients. The causes of the defect were trauma (4), tumor (3), and infection (2). The pivot point of transposition of this flap is the lower perforator originating from the posterior tibia artery. The fatty tissue side of this flap could be used to resurface the defect. The donor site was closed primarily with the preserved skin, and a small caliber drain tube was used. The split-thickness skin graft was grafted to the flap and the wound. If the wound was still infected, this skin graft could be performed at a later date. Results: All flaps survived and normal soft tissue coverage was obtained for the medial foot and ankle of all patients after the skin graft. Normal footwear was possible for all cases because of thin coverage. There was an extension contracture on the medial ray of the foot, which was resolved by contracture release and skin graft. Conclusion: For the medial foot and ankle soft tissue defect, the medial crural adipofascial flap based on a perforator branch of the posterior tibia artery could be a good option to cover it.

An English-to-Korean Transliteration Model based on Grapheme and Phoneme (자소 및 음소 정보를 이용한 영어-한국어 음차표기 모델)

  • Oh Jong-Hoon;Choi Key-Sun
    • Journal of KIISE:Software and Applications
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    • v.32 no.4
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    • pp.312-326
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    • 2005
  • There has been increasing interest in English-to-Korean transliteration recently. Previous ,works are related to a direct method like $\rightarrow$Korean graphemes> and a pivot method like $\rightarrow$English phoneme$\rightarrow$Korean graphemes>. Though most of the previous works focus on the direct method, transliteration, however, is a phonetic process rather than an orthographic one. In this point of view, we present an English-Korean transliteration model using grapheme and phoneme information. Unlike the previous works, our method uses phonetic information such as phonemes and their context. Moreover, we also use graphemes corresponding to phonemes. Our method shows about $60\%$ word accuracy.

Combining Two Scales to Assess Risk Factors of Falling in Community-Dwelling Elderly Persons: A Preliminary Study (노인의 낙상에 영향을 주는 요인을 평가하기 위한 ABC-BBS의 적용: 사전연구)

  • Park, So-Yeon
    • Physical Therapy Korea
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    • v.15 no.2
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    • pp.44-53
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    • 2008
  • The purpose of this preliminary study was to develop a measurement for assessing risk factors for falling in community-dwelling elderly persons. Rasch analysis and principal component analysis were performed to examine whether items on the Activities-Specific Balance Confidence (ABC), assessing self-efficacy, and items on the Berg Balance Scale (BBS), assessing balance function, contribute jointly to a unidimensional construct in the elderly. A total of 35 elderly persons (4 men, 31 women) participated. In this study, each item of ABC (16 items) and BBS (14 items) was scored on a 5-point ordinal rating scale from 0 to 4. The initial Rasch and principal component analysis indicated that 3 of the ABC items and 2 of the BBS items were misfit for this study. These 5 items were excluded from further study. After combining ABC and BBS, Rasch and principal component analyses were examined and finally 23 items selected; 12 items from ABC, 11 items from BBS. The 23 combined ABC-BBC items were arranged in order of difficulty. The hardest item was 'walk outside on icy sidewalks' and the easiest item was 'pivot transfer'. Although structural calibration of each 5 rating scale categories was not ordered, the other three essential criteria of Linacre's optimal rating scale were satisfied. Overall, the ABC-BBS showed sound item psychometric properties. Each of the 5 rating scale categories appeared to distinctly identify subjects at different ability levels. The findings of this study support that the new ABC-BBS scale measure balance function and self-efficacy. It will be a clinically useful assessment of risk factors for falling in the elderly. However, the number of subjects was too small to generalize our results. Further study is needed to develop a new assessment considering more risk factors of falling in elderly.

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Reconstruction of the Soft Tissue Defect of the Lower Leg by Distally Based Superficial Sural Artery Fasciocutaneous Island Flap Using Supercharged Vein (원위기저 도서형 천비복동맥 근막피판으로 하지 재건 시 과급정맥문합의 이용)

  • Ha, Young In;Choi, Hwan Jun;Choi, Chang Yong;Kim, Yong Bae
    • Archives of Plastic Surgery
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    • v.35 no.2
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    • pp.208-213
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    • 2008
  • Purpose: Distally based superficial sural artery island flap has some disadvantages such as postoperative flap edema, congestion, and partial necrosis of the flap margin. Venous congestion is an area of considerable concern in distally based superficial sural artery fasciocutaneous flap and is one of the main reasons for failure, particularly when a large flap is needed. However, we could decrease these disadvantages by means of venous superdrainage. Methods: From June of 2006 to June of 2007, a total of two patients with soft tissue defects of lower one third of the leg underwent venous supercharging distally based superficial sural artery island flap transfer. The distal pivot point of this flap was designed at septocutaneous perforator from the peroneal artery of the posterolateral septum, which was 5 cm above the tip of the lateral malleolus. Briefly, this technique is performed by anastomosing the proximal end of the lesser saphenous vein and collateral vein to any vein in the area of the recipient defect site. Results: No venous congestion was noted in any of the two cases. No other recipient or donor-site complications were observed, except for minor wound dehiscence in one case. In 3 to 6 months follow-up, patients had minor complaints about lack of sensation in the lateral dorsal foot. Conclusion: The peroneal artery perforator is predictable and reliable for the design of a distally based superficial sural artery island flap. Elevation of the venous supercharging flap is safe, easy, and less time consuming. In conclusion, the venous supercharging distally based superficial sural artery island flap offers an alterative to free tissue transfer for reconstruction of the lower extremity.