• 제목/요약/키워드: Concentrated Force

검색결과 355건 처리시간 0.025초

Protective System from Medical Needle-sticks. Part I: Background and System Development

  • Turner, LaDawnya C.;Seyam, Abdelfattah M.;Banks-Lee, Pamela
    • Fibers and Polymers
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    • 제4권2호
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    • pp.54-58
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    • 2003
  • Previous research on healthcare workers’ protection has concentrated on liquid barrier protection by providing impermeable personal articles such as latex gloves. This property is of high importance but since most blood-borne pathogen transmissions in the healthcare industry are caused by needle-stick injuries, protection from sharp invasive instruments should also be of high concern. And since latex and alike provide no protection against needle-stick injuries, new protective systems need to be developed and evaluated. This part of the study provides a review regarding the current practice of protection and the serious problems that arise from needle-flick injuries. Additionally, the development of new protective system is described. In part II of the study, evaluation of the new system will be provided.

이승만 대통령의 전쟁지도 (President Syngman Rhee and the Conduct of the Korean War)

  • 김행복
    • 안보군사학연구
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    • 통권1호
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    • pp.35-70
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    • 2003
  • President Lee, Syngman was ROK supreme commander at the Korean war. But, it is doubt that he executed his authority and responsibility by the ROK constitution and law. At the phase of the Korean War conduct, his role may be divided into 'military operation execution one' and 'political-diplomacy one'. He appointed unqualified person to the important position of the national defence, didn't make war execution system, and was not make to meet the war. And, after transferring the ROK force operation commanding authority to the Commander in Chief, UN Command, his role was extremely trivial at the military operation execution phase. Any way, he intended to recover the inferior national strength and military capacity with USA aid, and concentrated his effort toward diplomacy with USA. At last, he succeeded in making a mutual defence treaty and gained a big result to harden Korea national security after war. In sum, president Lee was shrewd politician and diplomat than military leader. And, it can be evaluated that he supplemented the lost part of military affairs side with diplomat one.

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돌핀방호공의 선박충돌해석 (The ship collision analysis of dolphin protection system)

  • 이계희;이성로;고재용;유원진
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
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    • pp.143-150
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    • 2005
  • In this study, to evaluate the collision behaviors of the navigating vessel and the dolphin protective system protecting the substructures of bridges, the numerical simulation was performed. The analysis model of vessel bow that the plastic deformations are concentrated was composed by shell elements, and the main body of vessel was modeled by beam elements to represent the mass distribution and the change of potential energy. The material model reflecting the confining condition was used for the modeling of the filling soil of dolphin system. The surrounding soil of the dolphin system was modeled as nonlinear springs. As results, it is verified that the dolphin system can adequately dissipate the kinematic energy of the collision vessel. The surrounding soil of the dolphin system is able to resist the collision force of the vessel. And the major energy dissipation mechanism of collision energy is the plastic deformation of the vessel bow and the dolphin system.

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Numerical analysis of dynamic response of jacket structures subject to slamming forces by breaking waves

  • Woo, Chanjo;Chun, Insik;Navaratnam, Christy Ushanth;Shim, Jaeseol
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제9권4호
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    • pp.404-417
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    • 2017
  • The present study numerically analyzed the dynamic behavior of 3D framed structures subject to impulsive slamming forces by violent breaking waves. The structures were modeled using multiple lumped masses for the vertical projections of each member, and the slamming forces from the breaking waves were concentrated on these lumped masses. A numerical algorithm was developed to properly incorporate the slamming forces into a dynamic analysis to numerically determine the structural responses. Then, the validity of the numerical analysis was verified using the results of an existing hydraulic experiment. The numerical and experimental results for various model structures were generally in good agreement. The uncertainties concerning the properties of the breaking waves used in the verification are also discussed here.

과도 수파중의 복합실린더에 작용하는 쇄파력에 관한 연구 (Wave Force Acting on Cylinders in Transient Waves)

  • 조효제;구자삼;이상길
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2001년도 추계학술대회 논문집
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    • pp.220-226
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    • 2001
  • It is important to estimate exactly wave forces acting on various types of offshore structures under the severe environmental conditions in the ocean site. This paper presents an easy experimental method which deals with transient waves. The proposed scheme made it possible to generate breaking waves at any position in the wave tank by changing the maximum slope of the component waves. The theoretical and experimental methods were investigated by generating concentrated waves which acted on a single and multiple cylinders. The waves forces increased rapidly when the models encountered breaking waves. The theoretical results underestimates the forces due to breaking waves. Therefore, the effects due to breaking waves should be considered carefully in the design process of a structure under the influence of breaking waves.

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초경공구를 사용한 Ti-6A1-4V 타이타늄 합금이 절삭가공시 공구마멸과 절삭특성에 관한 연구 (A Study on the Tool Wear and Cutting Characteristics in the Machining of Ti-6Al-4V Using Tungsten Carbide Tool)

  • 김남용;고준빈;이동주
    • 한국공작기계학회논문집
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    • 제11권2호
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    • pp.9-16
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    • 2002
  • The machinability of Ti-6Al-4V titanium alloy and tool wear behavior in machining of Ti-6Al-4V titanium alloy was studied to understand the machining characteristics. This material is one of the strong candidate materials in present and future aerospace or medical applications. Recently, their usage has already been broaden to everybody's commercial applications such as golf heads, finger rings and many decorative items. To anticipate the general use of this material and development of the titanium alloys in domestic facilities, the review and the study of the machining parameters for those alloys are necessary. This study is concentrated to the machining parameters of the Ti-6A1-4V alloy due to their dominant position in the production of titanium alloys.

과도 수파중의 복합실린더에 작용하는 쇄과력에 관한 연구 (Wave Force Acting on Cylinders in Transient Waves)

  • 조효제;구자삼;이상길
    • 한국해양공학회지
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    • 제15권4호
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    • pp.8-13
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    • 2001
  • It is important to estimate exactly wave forces acting on various types of offshore structures under the severe environmental conditions in the ocean site. This paper presents an easy experimental method which deals with transient waves. The proposed scheme made it possible to generate breaking waves at any position in the wave tank by changing the maximum slope of the component waves. The theoretical and experimental methods were investigated by generating concentrated waves which acted on a single and multiple cylinders. The waves forces increased rapidly when the models encountered breaking waves. The theoretical results underestimates the forces due to breaking waves. Therefore, the effects due to breaking waves should be considered carefully in the design process of a structure under the influence of breaking waves.

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Inelastic lateral-distortional buckling of continuously restrained continuous beams

  • Lee, Dong-Sik
    • Steel and Composite Structures
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    • 제5권4호
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    • pp.305-326
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    • 2005
  • The inelastic buckling behaviour of continuously restrained two and three-span continuous beams subjected to concentrated loads and uniformly distributed loads are studied in this paper. The restraint type considered in this paper is fully restrained against translation and elastic twist applied at the top flange. These types of restraints are most likely experienced in industrial structures, for example steel-concrete composite beams and half through girders. The buckling analysis of continuous beam consists of two parts, firstly the moment and shear distribution along the member are determined by employing force method and the information is then used for an out-of-plane buckling analysis. The finite element method is incorporated with so-called simplified and the polynomial pattern of residual stress. Owing to the inelastic response of the steel, both the in-plane and out-of-plane analysis, which is treated as being uncoupled, extend into the nonlinear range. This paper presents the results of inelastic lateral-torsional and lateral-distortional buckling load and finally conclusions are drawn regarding the web distortion.

The bending-shear-torsion performance of prestressed composite box beam

  • Wei, Hu S.;Yu, Zhao K.;Jie, Wei C.
    • Structural Engineering and Mechanics
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    • 제62권5호
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    • pp.577-585
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    • 2017
  • To study the mechanical performances of prestressed steel-concrete composite box beam under combination of bending-shear-torsion, nine composite beams with different ratio of torsion to bending were designed. Torsion was applied to the free end of the beam with jacks controlled accurately with peripherals, as well as concentrated force on the mid-span with jacks. Based on experimental data and relative theories, mechanical properties of composite beams were analyzed, including torsional angle, deformation and failure patterns. The results showed that under certain ratio of torsion to bending, cracking and ultimate torsion increased and reached to its maximum at the ratio of 2. Three phases of process is also discussed, as well as the conditions of each failure mode.

폴리머 기반 슬림형 촉각센서의 최적 설계 및 새로운 공정 방법 (Polymer Based Slim Tactile Sensor: Optimal Design and New Fabrication Method)

  • 이정일;사토 카즈오
    • 제어로봇시스템학회논문지
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    • 제17권2호
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    • pp.131-134
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    • 2011
  • In this study, we propose an optimal design and new fabrication method for a slim tactile sensor. Slim tactile sensor can detect 3-axial forces and has suitable flexibility for intelligent robot fingers. To amplify the contact signal, a unique table-shaped structure was attempted. A new layer-by-layer fabrication process for polymer micromachining that can make a 3D structure by using a sacrificial layer was proposed. A table-shaped epoxy sensing plate with four legs was built on top of a flexible polymer substrate. The plate can convert an applied force to a concentrated stress. Normal and shear forces can be detected by combining responses from metal strain gauges embedded in the polymer substrate. The optimal positions of the strain gauges are determined using the strain distribution obtained from finite element analysis.