• Title/Summary/Keyword: Free movement

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Effective Methods Reducing Joint Vibration and Elongation in High speed Rail Bridge (고속철도교 신축부의 진동 및 신축의 효율적인 저감 방안)

  • Min, Kyung-Ju;Kang, Tae-Ku;Lim, Nam-Hyoung
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.800-806
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    • 2011
  • Thermal expansion which occurs at the high speed rail joint is proportional to the free length from the point of fixity. This thermal expansion behaves similar to free expansion because the girder longitudinal stiffness is much larger than longitudinal resistance of rail pads. But the longitudinal displacement in the long rail is nominal because the longitudinal support condition of the girder is normally MFM(movable-fix-movable) system. Due to these girder expansion characteristics, there is longitudinal relative displacement at the rail pad and rail fastener spring which connects rail and girder. If the relative displacement between rail and girder is beyond the elastic limit for the rail pad, rail fastener system shall be applied using sliding fastener to prevent rail pad damage and fastener separation resulting from slip. On the other hand, train vertical vibration and tilting can occur due to the lack of fastener vertical force if the sliding fastener is applied at the girder joint. In the high speed rail bridge, vibration can occur due to the spring stiffness of the elastomeric bearing, also both vertical downward and upward displacement can occur. The elastomeric bearing vertical movement can cause rail displacement and finally the stability of the ballast is reduced because the gravel movement is induced.

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Compensation Ability in Speech Motor Control in Children with and without Articulation Disorders (조음장애아동과 비장애아동의 말운동통제 보상능력 비교)

  • Song, Yun-Kyung;Sim, Hyun-Sub
    • Speech Sciences
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    • v.15 no.3
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    • pp.183-201
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    • 2008
  • This study attempted to reveal the physiologic etiology or related factors associated with speech processing by comparing the compensation ability in speech motor control in children with and without articulation disorders. Subjects were 35 children with articulation disorder and 35 children without articulation disorder whose age ranged from 5 to 6 years. They were asked to rapidly repeat /$p^ha$/, /$t^ha$/, /$k^ha$/, /$p^hat^hak^ha$/ diadochokinetic movement while mandible was free and mandible was stabilized with bite block. The results showed that children with articulation disorder revealed significantly greater difference in elapsed time for diadochokinetic movement between mandible free and stabilized state compared to the without articulation disorder group. But the correlation between the percentage of consonants correct and the compensation ability in speech motor control in the articulation disorder group was irrelevant. These results point out to the fact that children with articulation disorder have poor compensation ability in speech motor control compared to the children without articulation disorder. On the other hand, the poor ability does not have any relation with the severity of articulation disorder. These results suggest either general or individual characteristics of children with articulation disorder.

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A Plan for Cooperation in Fisheries between South and North Korea for Unification in the 21st Century (21세기(世紀) 통일기반(統一基盤) 구축(構築)을 위한 수산협력(水産協力) 방안(方案) - 수산물교역을 중심으로 -)

  • Pak, Myong-Sop
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.14
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    • pp.323-348
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    • 2000
  • Facing the current difficulties of fisheries industry nationally and internationally, economic cooperations between South and North Korea are needed urgently. Applying the process of economic integration to fisheries sector of separated nation, cooperation processes are divided as follows; (1) indirect and direct fisheries trade, (2) reciprocal use of fishing grounds, (3) joint venture in fisheries sector, (4) free movement of production factors and common fisheries policy. Here, fisheries trade falls under economic interchange stage. Reciprocal use of fishing ground and fisheries joint venture come in economic cooperation stage. Finally. free factor movement and common fisheries policy are related with economic integration stage. This paper investigates the schemes for fisheries cooperation between South and North Korea in preparation for a unified Korea, focusing on fisheries trade. The paper is composed of 5 chapters. Chapter 2 discusses structure and characteristics of North Korea trade, and trade situation between South and North Korea. Then, the present condition of North Korea fisheries industry and fisheries trade trend between South and North Korea are presented in chapter 3. Next, chapter 4 tackles the most common problems encountered in fisheries trade between South and North Korea, and the devices and schemes to raise fisheries trade between South and North Korea. Finally, chapter 5 summarizes and concludes the research results.

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SIMULATION OF FREE SURFACE FLOW OVER TRAPEZOIDAL OBSTACLE WITH LATTICE BOLTZMANN METHOD (격자볼츠만법을 이용한 장애물 월반 자유수면 시뮬레이션)

  • Korkmaz, Emrah;Jung, Rho-Taek
    • Journal of computational fluids engineering
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    • v.19 no.2
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    • pp.79-85
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    • 2014
  • An air-water free surface flow simulation by using the Lattice Boltzmann Method(LBM) has not been studied a lot compared with the done by the Navier-Stoke equation. This paper shows the LBM is as one of the application tools for the free surface movement over an obstacle. The Mezo scaled application tool has been developed with two dimensional and nine discretized velocity direction using conventional lattice Bhatnagar-Gross-Krook model. Boundary conditions of a halfway-based for solid wall and a kinematic-based for interface are adopted. A validation case with a trapezoidal shape bump to make a comparison between freesurface movements from computational results and experimental ones was described with grid size dependency.

A STUDY ON THE MANDIBULAR MOVEMENT OF MANDIBULAR PROGNATHIC PATIENTS (하악전돌증 환자의 하악운동에 관한 연구)

  • Kim Ki-Sook;Kim Kwang-Nam;Chang Ik-Tae
    • The Journal of Korean Academy of Prosthodontics
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    • v.29 no.3
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    • pp.43-53
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    • 1991
  • It is important to harmonize the occlusion with TMJ and neuromuscular system. However, clinically, how to harmonize is very difficult. The mandibular movement is the motion in which all component part of stomatognathic system participate. This study was performed to compare mandibular movement of mandibular prognathic patients group with that of normal group, to ascertain which components of mandibular movement have differences between two groups, and to use for occlusal treatment of mandibular movement. Thirteen adult who have physiologically normal occlusion and are free of TMJ dysfunction were selected as a control group(Group 1). Eight adult who are mandibular prognathic patient and have more than four anterior teeth crossbite, therefore have not anterior guidance function and have posterior interference at protrusion were selected as a experimental group(Group 2). Electronic pantograph, Denar Pantronic (Denar Corp., U.SA.), was used to record mandibular movement. Pantronic survey was performed by using an arbitrary hinge axis according to manufacturer's direction. Of the Pantronic recordings, immediate side shift (ISS), progressive side shift (PSS), orbiting condylar path (ORB), protrusive condylar path (PRO) between two groups were compared and analysed. The results were as follows: 1. The average protrusive and orbiting condylar inclination of mandibular prognathic patient$(28.44^{\circ},\;36.94^{\circ})$ was significantly lower than those of normal group$(40.15^{\circ},\;48.00^{\circ})$ (P<0.01). 2. There was no statistically significant difference between .the average immediate and progressive side shift of mandibular prognathic patient $(0.37mm,\;6.19^{\circ})$ and those of normal group$(0.52mm.\;5.96^{\circ})$ (P>0.01). 3. The significant correlation was found between orbiting condylar inclination and protrusive condylar inclination.

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Numerical Analysis of the Movement of an Initially Hemispherical Droplet on Hydrophilic/Hydrophobic Surfaces (친수성/소수성 표면상에서 초기 반구형 액적의 움직임에 관한 수치해석)

  • Myong, Hyon Kook;Kwon, Young Hoo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.39 no.5
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    • pp.405-414
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    • 2015
  • Fluid transport is a key issue in the development of microfluidic systems. Recently, Myong (2014) has proposed a new concept for droplet transport without external power sources and numerically validated the results for a hypothetical 2D, initially having a hemicylindrical droplet. In this paper, the movement of an actual water droplet, initially having a 3D hemispherical shape, on horizontal hydrophilic/hydrophobic surfaces is simulated using a commercial computational fluid dynamics (CFD) package, Fluent, with VOF (volume of fluid) method. The results are compared with the 2D analysis of Myong (2014), and the transport mechanism for the actual water droplet is examined based on the numerical results of the time evolution of the droplet shape, as well as the total kinetic, gravitational, surface free and pressure energies inside the droplet.

Fabrication of functionally customized fixed prosthesis in a hemimandibulectomy patient with fibular graft using double scan technique: A case report (비골이식을 받은 하악골절제술 환자에서 스캔중첩법을 이용한 기능적 고정성 보철물 제작: 증례 보고)

  • Win, Thaw Thaw;Lee, Du-Hyeong
    • The Journal of Korean Academy of Prosthodontics
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    • v.60 no.2
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    • pp.195-201
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    • 2022
  • Hemimandibulectomy and free fibular flap (FFF) in patients with squamous cell carcinoma could disturb the functional movement of the mandible. The muscular function in the sectioned side was compromised because of the incompetency of the muscle attachment to the mandible, leading to the unstable occlusal contact in the centric and eccentric occlusion. In this report, we present a case of a 63-year-old male who underwent cancer surgery and reconstruction with fibular graft, and he needed a fixed dental prosthesis to restore tooth loss in the anterior region. Occlusal contact change and instability were found according to the bite force in the centric relation and eccentric movement. This case report aimed to present the prosthetic procedure for fabricating the functionally optimized fixed prosthesis wherein the functionally generated path (FGP) technique and digital imaging method were applied to replicate mandibular movement and vertical dimension of the patient.

Analysis of Performance on Asymmetric LED Lens Design Using Three-Dimensional Free-Form Surface Expression (3차원 자유곡면식을 이용한 LED 비대칭 렌즈 설계 및 성능 비교 분석)

  • Lee, Chang Soo;Lee, Soo Young;Hyun, Dong Hoon
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.26 no.3
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    • pp.328-336
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    • 2017
  • The exit surface of a lens is designed using a three-dimensional free-form expression in order to easily modify a curved surface. This enables the design of numerical values and mathematical things using three-dimensional free-form expression, and enhances precision because it can be fine-tuned via numerical control. The standard of "Classification of Luminaire Light Distribution" for outdoor lighting fixtures by IESNA is adopted in order to examine the correlation between three-dimensional free-form surface expression and lighting performance. The variation of light distribution type and range is analyzed using the values of maximum light intensity and 50% light intensity. The actual tolerance occurs owing to parameters such as the thickness of the lens, the distance between LEDs, and the movement of the center of the incident surface; the effects of changes in these parameters on the performance are compared and analyzed.

Development of Atomization Spraying System for Solvent-free Paints(II) - Structural Analysis of Hydraulic Actuator - (무용제 도료용 무화 분사시스템 개발(II) - 유압 엑츄에이터의 구조해석 -)

  • Kim, Dong-Keon;Kim, Bong-Hwan;Shin, Sun-Bin
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.10 no.2
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    • pp.67-72
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    • 2011
  • Solvent-free paint is sprayed from higher-pressure conditions, because the viscosity is large. The hydraulic actuator which can be operated under higher-pressure condition is required to spray solvent-free paints in painting process for the environmental protection. The purpose of this paper is to develop the hydraulic actuator under higher-pressure conditions for solvent-free paint spraying system. The hydraulic actuator consists of inner spool, outer spool and ball. The analysis of a structural stability was conducted by using ANSYS V11 under the design condition of upward and downward movement of spool. As a result, the maximum von-Mises stress applied on spool under 4mm displacement showed a value of 106MPa which was greater than the allowable stress of the spool with a value of 250MPa and a value of safety factor 3. This result suggested that the spool system be unstable under the design condition so that it was necessary for the spool system to be reinforced to secure the structural stability.

Consideration of Urgent Facing Strategies for the Designation of Customs Free Zone of Incheon City (인천항 관세자유지역 지정시 당면과제 고찰)

  • 박창호;이기철;노흥승;여기태
    • Journal of Korea Port Economic Association
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    • v.17 no.2
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    • pp.183-204
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    • 2001
  • This study is intended for the development of urgent facing strategies for the designation of a CFZ(Customs Free Zone) in Incheon city. First, it analyzes the current status of the Incheon CFZ. Next, it suggests several strategies for successfully growing the CFZ of Incheon City. Finally, it develops and proposes a method for establishing an integrated management system for the effective management of the CFZ. The key findings of this study are as follows: First, the CFZ should provide state-of-the-art movement of port logistics, create new added value caused by the movement of logistics, and provide other public support. The Incheon CFZ should be developed in three stages: an inducement stage in 2002-2005, a growth stage in 2005-2008, and an implementation stage in 2008-2011. Second, The parties responsible for the management of the CFZ would be as follows: for the port area, the Ministry of Maritime and Fisheries; for the back space of CFZ, Incheon City; and for port management, port management companies. However, a committee for CFZ management is strongly suggested for the improved efficiency and effectiveness of CFZ management. Furthermore, additional regulations ensuring the role of local government will likely be necessary for the sucessful designation and sustainable management of the CFZ. Third, For the creation of additional revenue, reformation of the current laws of the CFZ are recommended in the area of business administration. Fourth, A strategic marketing plan that supports the successful management of the companies of the CFZ will be a key component in the success of the CFZ. Thus, the new marketing plan should be developed in the near future based on case studies of other CFZs. Fifth A method for an integrated CFZ management system was developed and suggested for the comprehensive and transparent management of port logistics.

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