• Title/Summary/Keyword: 매듭

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Sliding Knots and the Effect of Additional Half-Hitch Knots on Optimal Knot-Holding Capacity (체이동 매듭과 추가적인 반 매듭 증가에 따른 매듭의 장력 변화와 최적 유지력)

  • Hur, Chang-Yong;Kim, Seung-Ho;Kim, Byung-Kwan;Yoo, Jae-Chul
    • Journal of the Korean Arthroscopy Society
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    • v.8 no.1
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    • pp.37-44
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    • 2004
  • Purpose: To evaluate the optimal number of additional half hitches for achieving an optimal knot-holding capacity (KHC) of Lockable sliding knots. Methods: Four configurations of arthroscopic knots (Duncan loop, Field knot, Giant knot, and SMC knot) were tested for their knot-holding capacity. For each knot configuration, 6 sequential knots were made including the initial sliding knot and additional 5 knots by incrementing one half hitches at a time. Each added half-hitch were in reversing half-hitches with alternate posts (RHAPs) fashion. For each sequential knot configuration, 12 knots were made by No. 2 braided sutures. On the servo-hydraulic material testing system (Instron 8511, MTS, Minneapolis, MN), cyclic loading, load to clinical failure (3-mm displacement), load to ultimate failure, and mode of failure were measured. Results: Most of the initial loop without additional half-hitch showed dynamic failure with cyclic loading. The mean displacement after the end of cyclic loading decreased with each additional half-hitches. SMC and Giant knot reached plateau to 0.1 mm or less displacement after one additional half-hitch, shereas Field and Duncan loop needed 3 additional half-hitches. The SMC and Duncan knots needed 1 additional half-hitch to reach greater than 80N at clinical failure, whefeas the other 2 knots needed2 additional half-hitches. For the load exceeding 100N for clinical failure, the SMC knot required 3 additional half-hitches and the other three knots needed 4 additional half-hitches. As the number of additional half-hitches incremented, the mode of failure switched from pure loop failure (slippage) to material failure (breakage). Duncan loop showed poor loop security in that even with 5 additional half-hitches, some failed by slippage (17%). On the other hand, after 3 additional half-hitches, the 3 other knots showed greater than 75% of failure by material breakage mode (SMC and Field 92%, Giant 75%). Conclusion: Even with its own locking mechanism, lockable sliding knot alone does not withstand the initial dynamic cyclic load. For all tested variables, SMC knot requires a minimum of 2 additional half-hitches. Duncan knot may need more than 3 additional half-hitches for optimal security. All knots showed a mear plateau in knot security with 3 or more additional half-hitches.

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Seasonal Sedimentary Characteristics and Depositional Environments after the Construction of seawall on the Iwon Macrotidal Flat (방조제 건설 후 이원 대조차 조간대의 계절별 퇴적학적 특성 및 퇴적환경)

  • Kum, Byung-Cheol;Park, Eun-Young;Lee, Hi-Il;Oh, Jae-Kyung;Shin, Dong-Hyeok
    • Journal of the Korean earth science society
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    • v.25 no.7
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    • pp.615-628
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    • 2004
  • In order to elucidate seasonal sedimentary characteristics and depositional environment after construction of seawall on macrotidal flat, a seasonal observations of surface sediments (total 450) and sedimentation rates on 4 transects have been investigated for 2 years. The eastern area of Iwon tidal flat, has been changed from semi-closed coast to open coast by construction of seawall, shows general seasonal changes similar to characteristics of open coast type, which represented both fining and bad sorted distribution due to deposition of fine sediments under low energy condition in the summer, and relatively coarser and better sorted distribution because of erosion of fine sediments in the winter. In considering angles of transects, distribution patterns of surface sediments, the northern and southern parts of eastern tidal flat are dominantly influenced by wave and tidal effects, respectively. As time goes by, the eastern tidal flat shows coarsening-trend of surface sediments caused by direct effect of tidal current, were and typhoon. Meanwhile the western area of seawall, which has been re-formed by construction seawall, is sheltered from northwesterly seasonal wind. The seasonal change pattern of western area of seawall is slightly different from that of eastern tidal flat. Mean grain size and sorting of surface sediments during spring is finer and worse than those during summer. This seasonal change pattern maybe influenced by topographic effects caused from the construction of seawall. In consideration of all result, the transport of fine sediments in the study area, which is supplied to limited sediments, shows clockwise circulation pattern that fine sediments are transported from the eastern tidal flat to the western area of seawall because of blocking of seawall in the winter and are transported reversed direction the summer. As a result, many changes have been observed in the study area after construction of seawall; however, this change is still in progress and is expected to need continuous monitoring.

A Study on the Roles of Daheojang and Maedeupjang in the Joseon Dynasty (조선시대 다회장과 매듭장의 역할 규명)

  • SEOL, Jihee
    • Korean Journal of Heritage: History & Science
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    • v.54 no.3
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    • pp.52-67
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    • 2021
  • This study is an attempt to explore the roles of and the collaborative relationship between Daheojang and Maedeupjang. Daheojang and Maedeupjang share a similar manufacturing process. However, in modern times, Daheojang totally disappeared, and Maedeupjang was designated as an intangible cultural property. The present study will investigate the role of Daheojang and Maedeupjang based on the literature of the Joseon dynasty. Daheojang were craftsmen who made bands and strings of woven or twisted silk strands. They made mangsu and tassels or made knots to produce magnificent artifacts. Maedeupjang complete all steps of the process, from refining, dyeing, combining threads, daheo, maedeup, to the tassel. Daheojang in the Joseon dynasty was the center of this process. Daheojang belonged to almost all Uigwe because it used items ranging from large uso to cushion straps. Dahoe is a craft with various items and techniques. It has been widely used to produce majestic items like formal dresses, ritual ceremony pieces, and mountings, as well as daily items like jodae, pocket straps, and norigae. Based on the records of Uigwe in the late Joseon dynasty, the study explored the collaborative relationship between Daheojang and Maedeupjang. Sambang, the room where both Daheojang and Maedeupjang belong, was the room to produce the royal chair. The royal chair essentially includes large uso. The large uso is an artifact that ties a knot in a thick circle more than two meters long. While Daheojang made rounded daheo, Maedeupjang made delicate and balanced knots. Also, they produced royal inscriptions together with a royal seal with decorative mangsu and a seal of thick rounded daheo. In order to learn about traditional technology, it is necessary to study the system of the times and social trends. Therefore, the study focused on Daheojang, who were common master craftsmen during the Joseon dynasty but now are not familiar to most people.

Studies on Strength of Netting (2) The Knot Strength of Knotted Notting with Meshes Opened (그물감의 강도에 관한 연구(2) 주름을 준 매듭 그물감의 매듭의 강도)

  • KIM Dai An
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.9 no.1
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    • pp.13-18
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    • 1976
  • 1) The variation of the reef knot strength $T_r$ and the trawler knot strength $T_\varrho$ with the angle $\varphi$ between the adjacent bars are given by $$T_r=T_{ro}-k_{r\varphi}$$ and $$T_\varrho=T_{{\varrho}o}+k_{\varrho\varphi}$$ where $T_{ro}$ and $T_{{\varrho}o}$ are values of $T_r$ and $T_\varrho$ at $\varphi=0^{\circ}$ respectively, and $k_r$ and $k_\varrho$ constants decided by the fibre materials of netting twines ($\varphi\;is\;0^{\circ}$ when the knot is pulled lengthwise). 2) The variation of the reef knot strength $T_r'$ and the trawler knot strength $T_\varrho'$ with the angle $\varphi'$ between any one bar and the plane made by the other three bars may be expressed by $$T_r'=T_{ro}{'}\varrho^{-c\varphi'}$$ and $$T_\varrho'=T_{{\varrho}o}{'}\varrho^{-c\varphi'}$$ where $T_{ro}{'}$ and $T_{\varrho}o{'}$ are values of $T_r{'}$ and $T_\varrho{'}$ at $\varphi'=0^{\circ}\;{(\varphi=45^{\circ})}$ respectively, and o is the coefficient of attenuation. 3) Knot strength of knotted netting may be expressed by the expression derived in the preyious paper, disregarding its shape and the direction of tensile loads acting on it.

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Studies on Strength of Netting (1) The Decrease in Strength of Netting Twines by Knotting (그물감의 강도에 관한 연구 (1) 그물실의 강도가 매듭에서 감소하는 기구)

  • KIM Dai An
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.9 no.1
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    • pp.1-7
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    • 1976
  • 1) The decrease in strength of netting twines at the knot may be regarded to be due mainly to the frictional force acting on the tip of the knot. The knot strength T may be given by $$T=\frac{T_0}{1+{\mu}\frac{s}{\rho}\varrho^{\mu\theta}$$ were $T_0$ is the tensile strength of unknotted netting twines, $\mu$ the coefficient of friction beween two netting twines forming a knot, s the contact length between the tip and the netting twine compressing it, $\rho$ the radius of curvature of the compressing, and $\theta$ the angle at which the compressing rubs with another one in the vicinity of the opposite tip. 2) Knots are arranged in order of strength as follows : the reef knot pulled lengthwise $\risingdotseq$ the trawler knot pulled breadtwise the reef knot pulled breadthwise.

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Clinical Results of Arthroscopic Bankart Repair with Absorbable Knot-tying and Absorbable Knotless Suture Anchors (견관절 전방 불안정증에서 관절경적 방카트르 봉합술 시 흡수성 매듭 봉합 나사못과 흡수성 비 매듭 봉합 나사못을 이용한 임상적 치료결과 비교)

  • Kim, Seong-Jun;Lu, Yao-Jia;Oh, Kyung-Soo;Bahng, Seung-Chul;Park, Jin-Young
    • Journal of the Korean Arthroscopy Society
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    • v.17 no.1
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    • pp.50-55
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    • 2013
  • Purpose: The purpose of this study was to compare the clinical results of absorbable knot-tying and absorbable knotless suture anchors in arthroscopic Bankart repair. Materials and Methods: This study compared the patients who underwent arthroscopic Bankart repairs using absorbable knottying suture anchors (59 patients: KT Group), and absorbable knotless suture anchors (52 patients: KL Group). Preoperative and postoperative evaluations were performed by Rowe scores, patient satisfaction score, visual analogue scale (VAS), American shoulder and elbow surgeons (ASES) score, range of motion (ROM), and re-dislocation rate. Results: Postoperative VAS, Rowe scores, ASES score were significantly not different between the 2 groups (VAS: p=0.250, Rowe score: p=0.412, ASES: p=0.052). Mean postoperative VAS was 0.5 in KT Group and 0.8 in KL Group (p=0.250), and limited ROM was noted only in one patient in KL Group. Mean Rowe score was 94.3 in KT Group and 96.3 in KL Group (p=0.412), and mean ASES score was 97.3 in KT Group and 94.0 in KL Group (p=0.052). Re-dislocation rate were no different between the 2 groups. Conclusion: There were no differences in clinical outcomes and re-dislocation rate between Knot-Tying and Knotless repairs.

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Numerical Analysis on the Tow Point of Gaori Kite (가오리연의 매듭에 대한 수치해석 연구)

  • Sah, Jong-Youb
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.3
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    • pp.195-202
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    • 2016
  • There is two popular kites, Bangpae and Gaori. While the Bangpae kite is being widely loved by experts, the Gaori kite is popular for kids and beginners. Three types of Gaori kite product have been survayed on the tow point. The aerodynamic force on Gaori kite is numerically calculated by using Fluent. Through flight simulations at the tow point of each kite type, the new tow point, at which the required minimum velocity is lower than those of existing tow points, has been proposed as a standard. The required minimum velocity is the threshold wind velocity at which the kite begins to fly.

중학교 진학을 앞둔 청소년들의 책읽기

  • Kim, Byeong-Gyu
    • The Korean Publising Journal, Monthly
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    • s.98
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    • pp.8-9
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    • 1992
  • 예비중학생의 시절은 독서의 한 매듭을 맺는 계절이다. 이 매듭은 대나무의 마디와 같다. 마디는 또다른 자람의 디디미돌이 되고 더 큰 자람으로 이어진다. 중학교 지니학을 앞둔 어린이들에게 독서의 도약을 이룰 수 있도록, 감명 깊었던 책 다시 읽기, 못 읽은 필독도서 마저 읽기, 어려운 책 한번 읽어보기를 권하고 싶다.

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Usefulness of Ultrasonographic Diagnosis for Knot Impingement Syndrom: 3 Cases Report (매듭 충돌 징후에 대한 초음파 진단의 유용성: 증례보고 3례)

  • Chae, Seung Bum;Choi, Chang Hyuk;Kim, Min Su
    • The Journal of Korean Orthopaedic Ultrasound Society
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    • v.6 no.2
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    • pp.70-75
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    • 2013
  • We experienced three cases with chronic shoulder pain due to a knot impingement after arthroscopic rotator cuff tear repair and treated with arthroscopic revision surgery. Ultrasonography is commonly used for an imaging scan and an useful diagnostic tool to follow up after rotator cuff repair recently. We also could diagnose three cases with the knot impingement using ultrasonography obviously. And we report these cases with a review of current literature.

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Surgical Removal of Knotted Pulmonary Artery Catheter -A case report- (매듭지어진 폐동맥도관의 외과적 적출 -1례 보고-)

  • Kim, Byung-Il;Kim, Hyuk;Sohn, Sang-Tae;Jeong, Tae-Yeol;Chung, Won-Sang;Kim, Young-Hak;Kang, Jeong-Ho;Jee, Heng-Ok
    • Journal of Chest Surgery
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    • v.32 no.3
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    • pp.315-317
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    • 1999
  • The complications associated with the use of pulmonary artery catheter include dysrhythmias, heart block, pulmonary artery rupture, pulmonary infarction, endocardial damage, balloon rupture, arterial puncture, thromboembolism, air embolism, infection, pneumothorax, and knotting of the catheter. Knotting of the catheter is a rare complication and it should be anticipated if there is an excessive advancement of the pulmonary artery catheter beyond the normally expected distance. We report a successful surgical removal of knotted pulmonary artery catheter by sternotomy and cardiopulmonary bypass.

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