• Title/Summary/Keyword: Leeway

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A Study on the Techniques for Sailing Yacht Model Tests with Sailing Condition (항주자세를 고러한 세일링 요트의 선형기법 시험연구)

  • Sim, Sang-Mog;Kim, Dong-Joon;Kang, Byung-Yoon
    • Journal of the Society of Naval Architects of Korea
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    • v.43 no.1 s.145
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    • pp.32-42
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    • 2006
  • This study aims at establishing a technique for sailing yachts model tests with sailing condition. It is very important to estimate a ship's potential speed performance before building a real ship. Several methods are used to estimate a ship's potential speed performance such as using parent ship data, standard vessel chart and model test. Model test is the most precise among these options. In korea. model testing is widely used with general vessels but not with sailing yachts. Because sailing yachts are propelled with heeling and leeway. using the wind. another method is needed to estimate their speed. The new model test. which is different from tests for upright general vessels, is in a great demand. In this paper. we describe a test method for the sailing yacht model test. based on Masuyama's equation of motion. And we describe choosing scale ratio. production process and materials of the model. Also. various ways of measuring instruments. attaching jigs and adjusting calibration are described so that they can be utilized as useful data for model testing.

Prediction Model of Distressed Craft Drift (조난물체의 표류지점 추정 모델)

  • 강신영
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.6 no.1
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    • pp.111-120
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    • 2000
  • In this study the drift prediction models currently used in search and rescue(SAR) operations are introduced and the basic differences among them are analyzed by comparing the target classification, the treatment of environmental conditions, leeway equations and the determination of search area. In addition the new methods under development including AP98 of U.S. Coast Guard are compared and studied to improve the efficiency of SAR operation.

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A Study on the Improvement of SAR Capabilities in Korea - On the drifting characteristics of fishing vessel - (우리나라의 SAR 능력 향상에 관한 연구 - 어선의 표류 특성에 관하여 -)

  • 윤종휘;이문진;장하룡
    • Proceedings of KOSOMES biannual meeting
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    • 2001.05a
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    • pp.137-146
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    • 2001
  • To improve SAR capabilities in Korea, marine casualties during 5 years(1995-1999) were analyzed and drifting experiment of G/T 50 ton class vessel was carried out off Pusan harbor. As a result, it was found that the occurrence of casualty by fishing boat ranked highest and a considerable numbers of casualties took place more than 20 miles off the shore, and leeway was computed by two drifting experiments as 0.045U - 010 $^{\circ}$, 0.037U+ 021 $^{\circ}$ respectively.

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Clinical Implications of the Premature Loss of the Mandibular Primary Canine (하악 유견치 조기탈락은 무엇을 의미할까?)

  • Lee, Sang-Ho
    • Journal of the korean academy of Pediatric Dentistry
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    • v.42 no.1
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    • pp.87-101
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    • 2015
  • The premature loss of the mandibular primary canine is relatively frequent and a sign of the upcoming space problems in the transitional period. This situation is caused by the permanent lateral incisor resorbing the root of the primary canine during its eruption. Bilateral loss of primary canines in a crowded arch leads to the lingual tipping of the permanent incisors, with the consequent reduction in the arch perimeter and increase in overbite. When the loss of a primary canine is unilateral, tipping of the adjacent incisors occurs toward the space, resulting in midline deviation. In these situations, treatment possibilities, such as extraction of the antimeric tooth or placement of a passive lingual arch, can be applied; although there are some controversies concerning this. Most space problems with less than 4 mm can be resolved through preservation of the leeway space using sequential disking of the primary teeth and a passive lingual arch, regaining space or limited arch expansion in the late mixed dentition. In cases with 4~6 mm of space problems, arch expansion (A-P or transverse) can be applied. Space problems with more than 6 mm should be treated through diagnosis and treatment planning. Most of these cases will require extraction of permanent teeth including serial extraction (guidance of eruption).

Orthodontic Traction of Multiple Impacted upper Anterior Teeth: Case Report (상악 전치의 매복을 동반한 환자의 치험례)

  • Tark, Myung-Hyun;Cho, Jin-Woo;Chang, Na-Young;Cho, Jin-Hyoung
    • Journal of Dental Rehabilitation and Applied Science
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    • v.28 no.4
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    • pp.407-421
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    • 2012
  • Orthodontic problems of the oral maxillofacial area could be classified into skeletal and dental problems. Dental problems might cause various occlusal disharmony and among them congenital missing or eruption failure might cause not only functional problems but also esthetic problems. Additional psychological problems are also one of the reasons for patients seeking treatment. In cases showing eruption failure of many teeth in the maxilla, not only occlusal and esthetic problems but also difficulty in alveolar bone maintainment could occur. Therefore, successive approach is necessary when multiple teeth show eruption problems. In this case, a patient with eruption problems of #13, 12, 11, 23, 43 was successfully treated by surgical exposure and successive orthodontic extrusion resulting perfect occlusion. By additional periodontal treatment, gingival recession that occurred along with teeth eruption was solved. The impacted right mandibular canine was erupted successfully only by natural arch expansion and leeway space without any special surgical treatment.

Performance Predictions for Sailing Yacht by Towing Tests and VPP Calculation (예인수조 시험 및 VPP 계산에 의한 세일링 요트의 성능 추정)

  • Yoo Jae-Hoon;Ahn Hae-Seong
    • Journal of Advanced Marine Engineering and Technology
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    • v.30 no.1
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    • pp.116-124
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    • 2006
  • A model test was carried out, in order to verify the hydrodynamic performances of public 30 feet class sailing yacht. In the initial design stage, the performances and the running attitude of sail yacht including the hull form and sail plan, appendages were estimated by VPP, from which made the representative test conditions. A new experiment system such as captive model device was composed because the running attitude could be changed by wind conditions. The test results show that the minimum resistance is generated in the heeling 20 degree. which was expected in the initial design stage. It is thought to be the useful informations that the keel has an effects on hydrodynamic forces and resistance differences between the upwind and the downwind condition. Also this paper is associated with the state-of-the-art of calculating sailing yacht performance as this is performed in velocity Prediction program (VPP) The VPP results shows a typical shape of a sailing yacht and the designed yacht has the best performance at 120 degree angle of true wind with 20 knots.

Awareness and Attitudes Toward Advance Directives among Korean Adults (사전의료지시(서)에 대한 성인의 인식과 태도)

  • Kim, Su-Hyun
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.17 no.4
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    • pp.450-459
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    • 2010
  • Purpose: The purposes of this study were to identify awareness and attitudes toward advance directives (ADs) among Korean adults and to examine various opinions in the utilization of ADs among young, middle-aged, and older adults. Methods: Data were collected using a structured questionnaire from 384 adults selected by a quota sampling method on the basis of age. Results: The majority of participants preferred that they themselves would be the primary decision maker. Most of them were unaware of the option of ADs but supported the utilization of ADs. Most of the participants preferred detailed descriptions on end-of-life decisions in ADs but wanted to allow some leeway in following it. Significant differences were found among age groups in terms of the preferences regarding the utilization of ADs. Conclusion: It is suggested that nurses make efforts to educate the general public about ADs and facilitate advance care planning, which focuses on the process of communication on end-of-life preferences within the social network of relationships.

Performance Predictions for Sailing Yacht (세일링 요트의 성능 추정에 관한 연구)

  • Yoo, Jae-Hoon;Ahn, Hae-Seong
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2005.06a
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    • pp.824-831
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    • 2005
  • A model test was carried out, in order to verify the hydrodynamic performances of public 30 feet class sailing yacht. In the initial design stage, the performances and the running attitude of sail yacht including the hull form and sail plan, appendages were estimated by VPP, from which made the representative test conditions. A new experiment system such as captive model device was composed because the running attitude could be changed by wind conditions. The test results show that the minimum resistance is generated in the heeling 20 degree, which was expected in the initial design stage. It is thought to be the useful informations that the keel has an effects on hydrodynamic forces and resistance differences between the upwind and the downwind condition. Also this paper is associated with the state-of-the-art of calculating sailing yacht performance as this is performed in velocity prediction program (VPP). The VPP results shows a typical shape of a sailing yacht and the designed yacht has the best performance at 120 degree angle of true wind with 20 knots.

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Experimental Study on the Hydrodynamic Forces of 30 Feet Sailing Yacht (30피트급 요트의 유체력에 대한 실험적 연구)

  • Yoo, Jae-Hoon;Ahn, Hae-Seong
    • Journal of the Society of Naval Architects of Korea
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    • v.42 no.3
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    • pp.233-240
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    • 2005
  • A model test was carried out, in order to verify the hydrodynamic performances of public 30 feet class sailing yacht. In the initial design stage, the performances and the running attitude of sail yacht including the hull form and sail plan, appendages were estimated by VPP, from which made the representative test conditions. A new experiment system such as captive model device was composed because the running attitude could be changed by wind conditions. The test results show that the minimum resistance is generated in the heeling 20 degree, which was expected in the initial design stage. It is thought to be the useful informations that the keel has au effects on hydrodynamic forces and resistance differences between the upwind and the downwind condition.

Promoting a Shared Representation of Workers' Activities to Improve Integrated Prevention of Work-Related Musculoskeletal Disorders

  • Roquelaure, Yves
    • Safety and Health at Work
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    • v.7 no.2
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    • pp.171-174
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    • 2016
  • Effective and sustainable prevention of work-related musculoskeletal disorders (WR-MSDs) remains a challenge for preventers and policy makers. Coordination of stakeholders involved in the prevention of WR-MSDs is a key factor that requires greater reflection on common knowledge and shared representation of workers' activities among stakeholders. Information on workers' strategies and operational leeway should be the core of common representations, because it places workers at the center of the "work situation system" considered by the intervention models. Participatory ergonomics permitting debates among stakeholders about workers' activity and strategies to cope with the work constraints in practice could help them to share representations of the "work situation system" and cooperate. Sharing representation therefore represents a useful tool for prevention, and preventers should provide sufficient space and time for dialogue and discussion of workers' activities among stakeholders during the conception, implementation, and management of integrated prevention programs.