• Title/Summary/Keyword: Windlass

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Biomechanical Analysis for the Development of Windlass Mechanism for Trail-walking Shoe (윈들라스 메커니즘을 적용한 트레일 워킹화 개발을 위한 생체역학적 분석)

  • Park, Jong-Jin;Park, Seung-Bum
    • Korean Journal of Applied Biomechanics
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    • v.25 no.4
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    • pp.489-498
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    • 2015
  • Objective : The purpose of this study was to analyze the effects of the windlass mechanism in trail-walking shoe prototypes that can effectively support arches. A study of these effects should help with the development of a first-rate trail-walking shoe development guide for the distribution of quality information to consumers. Methods : The subjects were ten adult males who volunteered to participate in the study. Shoes from three companies, which will be referred to as Company S (Type A), Company M (Type B), and Company P (Type C), were selected for the experiment. The subjects wore these shoes and walked at a speed of 4.2 km/h, and as they tested each shoe, the contact area, maximum pressure average, and surface force were all measured. Results : Shoe Type A showed a contact area of $148.78{\pm}4.31cm^2$, Type B showed an area of $145.74{\pm}4.1cm^2$, and Type C showed an area of $143.37{\pm}4.57cm^2$ (p<.01). Shoe Type A demonstrated a maximum average pressure of $80.80{\pm}9.92kPa$, Type B an average of $85.72{\pm}11.01kPa$, and Type C an average of $89.12{\pm}10.88bkPa$ (p<.05). Shoe Type A showed a ground reaction force of $1.13{\pm}0.06%BW$, Type B a force of $1.16{\pm}0.04%BW$, and Type C a force of $1.16{\pm}0.03%BW$ (p<.05). Conclusion : The Type A trail-walking shoe, which was designed with a wide arch from the center of the forefoot to the front of the rearfoot showed excellent performance, however, more development and analysis of the windlass mechanism for a variety of arch structures is still necessary.

Comparison of the Activity of the Abductor Hallucis Muscle during Short-foot Exercises using Foot Orthosis and the Windlass Effect in Sitting and One-leg Standing Positions (앉은 자세와 한발로 선 자세에서의 발 보조기와 권양기 효과를 이용한 짧은 발 운동 시 엄지 벌림근의 근 활성도 비교)

  • Kim, Do-Hyun;Jung, Do-Young
    • Journal of the Korean Society of Physical Medicine
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    • v.12 no.1
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    • pp.75-81
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    • 2017
  • PURPOSE: The purpose of this study was to compare the activity of the abductor hallucis (AbdH) muscle during short foot exercise (SFE) using foot orthosis (SFE-FO) and the windlass effect (SFO-WE) while sitting and in a one-leg standing position. METHODS: We recruited fourteen subjects with normal feet for this study. Surface electromyography (EMG) was used to measure the muscle activity of the AbdH muscle during SFE, SFE-FO, and SFE-WE while sitting and in a one-leg standing position. Three trials consisting of a 5 s hold for each of the three exercises were performed to measure the EMG activity of the AbdH muscle. Exercise type and position were randomly assigned. Two-way repeated-measures ANOVA was used to analyze the effects of exercise type (SFE vs. SFE-FO vs. SFE-WE) and position (sitting vs. one-leg standing position) on AbdH muscle activity. A statistical significance was set at ${\alpha}=.05$. RESULTS: The EMG activity of AbdH muscle in the SFE-WE exercise was significantly greater than that during SFE and SFE-FO in both exercise positions (p<.001). In addition, the EMG activity of the AbdH muscle in the one-leg standing position was significantly higher than that while sitting (p<.001) during all three exercises. CONCLUSION: These results suggest that SFE-WE is a more effective strengthening exercise than SFE or SFE-FO for activating the AbdH muscle.

Lightweight design for windlass base frame using optimal design technique (최적 설계 기법을 적용한 Windlass base frame의 경량화 설계)

  • Songr, Ju-Han;Pack, Min-Hyuk;Kang, Han-Bin;Pack, In-Seok;Lee, Dong-Wook;Lee, Gye-Gwang;Lee, Seok-Soon
    • Journal of Advanced Marine Engineering and Technology
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    • v.37 no.5
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    • pp.477-483
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    • 2013
  • The widlass base frame which is currently used is designed by lots of volume and costs so as to obtain high rigidity in spite of the greatly external load. The purpose of this research is to draw conceptual design of optimal design which can satisfy high rigidity existing windlass base frame has and lessening the body at the same time. Therefore, it progressed conceptual design by applying Topology optimization and Size optimization based on the finite-element analysis for the early model and indicated the result by comparing the early model with optimized model. As the result of Topology optimization, its stress was increased by about 6MPa and weight was decreased by about 560kg in comparison with the early model. In addition, in case of Size optimization, its stress was increased by about 7MPa and weight was decreased by about 1,560kg in comparison with the early model.

The Study for Improve the braking power of Mooring winch brake (무어링 윈치 브레이크의 제동력 향상을 위한 연구)

  • Ha, Jeong-Min;Han, Dong-Seop;Han, Geun-Jo
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.512-517
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    • 2008
  • The brake system is very important part of the machine working. If the machine can't be stopped, it would be serious accident. It is the same as the ship. The mooring winch brake hold the ship in harbor. But sometimes it appeared the excessive stress and brake lining would be broken. So it is necessary to change the shape of brake system with improve the braking power. This study carried out research on optimum design like as moved the position of link pin or modified the thickness of brake band and lining.

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Upward Migration of a Peritoneal Catheter Following Ventriculoperitoneal Shunt

  • Cho, Kyung Rae;Yeon, Je Young;Shin, Hyung Jin
    • Journal of Korean Neurosurgical Society
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    • v.53 no.6
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    • pp.383-385
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    • 2013
  • We present an unusual case of peritoneal catheter migration following a ventriculoperitoneal shunt operation. A 7-month-old infant, who had suffered from intraventricular hemorrhage at birth, was shunted for progressive hydrocephalus. The peritoneal catheter, connected to an 'ultra small, low pressure valve system' (Strata$^{(R)}$; PS Medical,Gola, CA, USA) at the subgaleal space, was placed into the peritoneal cavity about 30 cm in length. The patient returned to our hospital due to scalp swelling 21 days after the surgery. Simple X-ray images revealed total upward migration and coiling of the peritoneal catheter around the valve. Possible mechanisms leading to proximal upward migration of a peritoneal catheter are discussed.

Introduction of Optimized Design of Anchoring System through Design Modification of Pocket and Chain Compressor (설계 개선을 통한 선박의 계류 시스템 최적화 사례 소개)

  • Lee, Jae-Hoon
    • Special Issue of the Society of Naval Architects of Korea
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    • 2011.09a
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    • pp.55-62
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    • 2011
  • Although the performance of the commercial vessel has been dramatically improved through innovations, there has been no big changes on the traditional anchoring method of commercial vessels, both on design and operation until now. In this paper, two cases of design modifications were introduced for optimized design of pocket type anchor handling, which resulted in improved performance of the vessel's anchoring. From the first time fully balanced type anchors were applied on vessels in Korean shipyard, main design problem on this application was that the anchor doesn't normally slide into the pocket when the anchor fluke is not in line with pocket, as the anchor freely rotates by the swivel on forerunner. In order to prevent the problem, swivel has been deleted on the forerunner to prevent anchor rotation until now, but this solution caused problems such as twist lock of anchor chain, restriction of windlass direction, etc. On this paper, one of the solution is introduced to overcome the design problem by tilting the hawse pipe to some extent, which makes anchor turned at the time anchor ring touches the pocket skirt and that it properly slides into the pocket. Secondly, one of the solution is introduced to overcome misalignment problem between anchor chain cable and roller of chain compressor, which has been frequently occurred, by modification of roller design.

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The Strength Analysis of Mooring winch according to the division angle (무어링 윈치의 분할각도에 따른 강도해석)

  • Han, Jeong-Min;Han, Dong-Seop;Han, Geun-Jo
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2009.06a
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    • pp.181-182
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    • 2009
  • In the machinery, the brake system is as important part as machine's working. If the machine doesn't stopped, would be big occident. For the ships, it is important too. Use the windlass winch to stop the voyage and use mooring winch to keep the stop in the port. In this study, improve the braking power divided the brake band and search the optimize portion.

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A Study on Repair Process Analysis of Ship Hul Part (선박 선체에 대한 수리작업 공정분석에 관한 연구)

  • Chang-Su Jeon
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.6_3
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    • pp.1305-1314
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    • 2023
  • The global ship repair and modification market is expected to grow up to approximately $ 30 billion by 2025. Korea's shipbuilding industry is leading the world grounded on its international competitiveness in design and production technology. The reality, however, is that the ship repair and modification industry is centered on Gyeongnam, and there are only two to three ship repair workplaces that can repair large ships. Therefore, domestic ship repair companies target small and medium-sized ships mainly. This is because there are few workplaces equipped with a large dock in which large ships like LNG ships can be inspected regularly or repaired, complaints are severe for environmental problems, and related environmental regulations are so strict that it is very hard to obtain government approval for the extension of ship repair and modification workplaces or the opening of new shipbuilding sites. Besides, on account of the workers' high wages, few experts related, and higher ship repair price compared to that of Southeast Asia, most of the volume of repairing large ships including domestic LNG ships is being lost to Southeast Asian or Chinese markets. In this study, the work process and pre-work preparation process for ship hull (winch, windlass, hatch cover, ramp door, cargo gear, anchor chain) repair were analyzed and presented to foster domestic ship repair experts and revitalize related industries.