• Title/Summary/Keyword: Frame type

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Somatometric Characteristics of Elementary School Boys at the Ages 7 to 8 and Classification Thereby (학령전기 남아의 상반신 체형 - 만 7 ~ 8세 남아를 대상으로 -)

  • 여혜린
    • Journal of the Korean Society of Costume
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    • v.52 no.2
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    • pp.115-124
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    • 2002
  • The purposes of this study were to classify somatotype was obtained from the factor scores of the upper half of bodies and analyze the Somatometric characteristics. The sample group (hereinafter referred to as "1st age group") was drawn from bays at the ages 7 to 8 living in Pusan and Kyungsangnam-do. Data from each boy comprised 36 anthropometric measurements and 7 photographic measurements. The study reached following conclusions. 1. According to the analysis to draw Somatometric factors by the 1st age group, seven indicative factors were obtained from measurements of the upper half of bodies. The most significant factor "sectional size" and the second most significant factor "longitudinal size" characterized most aspects of body shape of boys at the ages 7 to 8. 2. According to the analysis of Somatometric characteristics by the upper half of bodies, the 1st age group was categorized into three types : Boys in type 1 had highest stature, biggest frame, broadest shoulders, most protruded chest and shoulder blades and flattest belly : boys in type 2 had shortest stature, smallest frame, sloping shoulders and most protruded belly boys in type 3 had quite high stature and his other measurements were close to the averages of this age group.he averages of this age group.

Inserting the mass proportional damping (MPD) system in a concrete shear-type structure

  • Silvestri, Stefano;Trombetti, Tomaso;Ceccoli, Claudio
    • Structural Engineering and Mechanics
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    • v.16 no.2
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    • pp.177-193
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    • 2003
  • This paper presents an illustrative example of the advantages offered by inserting added viscous dampers into shear-type structures in accordance with a special scheme based upon the mass proportional damping (MPD) component of the Rayleigh viscous damping matrix. In previous works developed by the authors, it has been widely shown that, within the class of Rayleigh damped systems and under the "equal total cost" constraint, the MPD system provides best overall performance both in terms of minimising top-storey mean square response to a white noise stochastic input and maximising the weighted average of modal damping ratios. A numerical verification of the advantages offered by the application of MPD systems to a realistic structure is presented herein with reference to a 4-storey reinforced-concrete frame. The dynamic response of the frame subjected to both stochastic inputs and several recorded earthquake ground motions is here analysed in detail. The results confirm the good dissipative properties of MPD systems and indicate that this is achieved at the expense of relatively small damping forces.

A Novel Control Scheme for T-Type Three-Level SSG Converters Using Adaptive PR Controller with a Variable Frequency Resonant PLL

  • Lin, Zhenjun;Huang, Shenghua;Wan, Shanming
    • Journal of Power Electronics
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    • v.16 no.3
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    • pp.1176-1189
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    • 2016
  • In this paper, a novel quasi-direct power control (Q-DPC) scheme based on a resonant frequency adaptive proportional-resonant (PR) current controller with a variable frequency resonant phase locked loop (RPLL) is proposed, which can achieve a fast power response with a unity power factor. It can also adapt to variations of the generator frequency in T-type Three-level shaft synchronous generator (SSG) converters. The PR controller under the static α-β frame is designed to track ac signals and to avert the strong cross coupling under the rotating d-q frame. The fundamental frequency can be precisely acquired by a RPLL from the generator terminal voltage which is distorted by harmonics. Thus, the resonant frequency of the PR controller can be confirmed exactly with optimized performance. Based on an instantaneous power balance, the load power feed-forward is added to the power command to improve the anti-disturbance performance of the dc-link. Simulations based on MATLAB/Simulink and experimental results obtained from a 75kW prototype validate the correctness and effectiveness of the proposed control scheme.

A graphical user interface for stand-alone and mixed-type modelling of reinforced concrete structures

  • Sadeghian, Vahid;Vecchio, Frank
    • Computers and Concrete
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    • v.16 no.2
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    • pp.287-309
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    • 2015
  • FormWorks-Plus is a generalized public domain user-friendly preprocessor developed to facilitate the process of creating finite element models for structural analysis programs. The lack of a graphical user interface in most academic analysis programs forces users to input the structural model information into the standard text files, which is a time-consuming and error-prone process. FormWorks-Plus enables engineers to conveniently set up the finite element model in a graphical environment, eliminating the problems associated with conventional input text files and improving the user's perception of the application. In this paper, a brief overview of the FormWorks-Plus structure is presented, followed by a detailed explanation of the main features of the program. In addition, demonstration is made of the application of FormWorks-Plus in combination with VecTor programs, advanced nonlinear analysis tools for reinforced concrete structures. Finally, aspects relating to the modelling and analysis of three case studies are discussed: a reinforced concrete beam-column joint, a steel-concrete composite shear wall, and a SFRC shear panel. The unique mixed-type frame-membrane modelling procedure implemented in FormWorks-Plus can address the limitations associated with most frame type analyses.

Seismic Performance of an Inverted V-type Eccentrically Braced Steel Frames with Slit Dampers Using Shape Memory Alloy (형상기억합금을 이용한 슬릿댐퍼 적용 역V형 편심가새골조의 내진 성능)

  • Jang, Han Ryul;Kim, Joo-Woo
    • Journal of Korean Association for Spatial Structures
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    • v.22 no.4
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    • pp.39-48
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    • 2022
  • The energy dissipation of inverted V-type eccentric steel braced frames can be achieved through the yielding of a slit link, through yielding of a number of strips between slits when the frame is subjected to inelastic cyclic deformation. On the other hand, the development of seismic resistance system without residual deformation is obtained by applying the superelasdtic shape memory alloy (SMA) material into the brace and link elements. This paper presents results from a systematic three-dimensional nonlinear finite element analysis on the structural behavior of the eccentric bracing systems subjected to cyclic loadings. A wide scope of structural behaviors explains the horizontal stiffness, hysteretic behaviors, and failure modes of the recentering eccentric bracing system. The accurate results presented here serve as benchmark data for comparison with results obtained using modern experimental testing and alternative theoretical approaches.

The Mechanical Modeling and design of saw frame in band sawing machine (띠톱기계 톱대의 역학적 모델링 및 설계)

  • LUO, luPing;DING, zelin;DING, shengxia;JIANG, Ping;FAN, li;XIAO, leihua;PAN, bosong;An, Boyoung;No, Joonkkyu;Li, Wenqi;Han, Changsoo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.12
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    • pp.390-397
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    • 2019
  • A mechanical model of band sawing saw frame was established according to an analysis of a commonly used saw-frame structure diagram to overcome the problems of low service life, substandard cutting precision and efficiency, and high manufacturing cost caused by the unreasonable design of saw frame. Taking a particular type of sawing machine as an example, stress cycle analysis of the saw blade was carried out according to the mechanical model of the saw frame, and the fatigue analysis model of the most dangerous cross-section point that was most prone to fatigue failure of the saw blade was then established. The fatigue analysis result was used as the basis for the improved design of the saw frame, and the improved detailed saw-frame design parameters were obtained. The results suggested that the saw frame system is much more compact and the saw blade force met the fatigue strength requirements through the improved design. In addition, the service life of the saw blade and the cutting precision were increased. The established mechanical model of the saw frame in this paper is used widely and has high practical application values.

Structural Design of a Cathode-ray Tube (CRT) to Improve its Mechanical Shockproof Character

  • Park, Sang-Hu;Kim, Won-Jin
    • Journal of Mechanical Science and Technology
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    • v.20 no.9
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    • pp.1361-1370
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    • 2006
  • An electronic beam mis-landing phenomenon on the RGB (red/green/blue) -fluorescent surface has been considered as one of serious problems to be solved in cathode-ray tube (CRT), which is generally caused by mechanical shock and vibration. In this work, structural design concepts on the major parts of the CRT, such as a frame, a shadow mask, and a spring, are studied to improve the mechanical shockproof character of a CRT by FEM-analyses and experimental approaches ; a frame is newly designed to have strength employing the double-corner-beads which reduces considerably the distortion of the frame and the shadow mask : the edge-bead of a shadow-mask is redesigned to maintain the wide curved surface of a shadow-mask after mechanical shock : finally, a spring supporting the frame and the shadow-mask is designed to have enough flexibility along drop-direction. As an example, a conventional type of a 15inch CRT was utilized to demonstrate the feasibility and usefulness of this work. Overall, some favorable information on the structural design of the CRT is achieved, and the mechanical shockproof character of a 15-inch CRT is improved in the degree of 3G $(1G=9.81m/s^2)$ as an average-value.

Load Test Method of Vehicle Body and Bogie Frame for Urban Maglev Vehicle (도시형 자기부상열차의 차체 및 대차프레임 하중시험방법)

  • Han, Jeong-Woo;Kim, Jae-Dong;Huh, Young-Cheol;Han, Sung-Wook;Kim, Beom-Soo
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.924-930
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    • 2011
  • Maglev vehicle has two parts a vehicle body and a series of bogies. The vehicle body is connected through a pneumatic suspension on the bogie frame operating loads, vehicle weight and passengers, repeatedly during the service life. The bogie frame plays an important role in sustaining the weight of the vehicle body and controlling the magnets in the correct alignment to meet requirements of stable running on railway. It is also subjected to the levitation and guidance force and propulsion force generated by electromagnets and linear induction motor (LIM) respectively. To guarantee a vehicle system, it is necessary to identify a load test method with proper loads that the vehicle is expected to experience while in service. In this paper, a test method was proposed to verify the structural safety of vehicle body and bogie frame that are applied to an EMS(electromagnetic suspension)-type urban Maglev vehicle considering in case of not only running on the ground but also levitated running.

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Analytical study on the influence of distributed beam vertical loading on seismic response of frame structures

  • Mergos, P.E.;Kappos, A.J.
    • Earthquakes and Structures
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    • v.5 no.2
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    • pp.239-259
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    • 2013
  • Typically, beams that form part of structural systems are subjected to vertical distributed loading along their length. Distributed loading affects moment and shear distribution, and consequently spread of inelasticity, along the beam length. However, the finite element models developed so far for seismic analysis of frame structures either ignore the effect of vertical distributed loading on spread of inelasticity or consider it in an approximate manner. In this paper, a beam-type finite element is developed, which is capable of considering accurately the effect of uniform distributed loading on spreading of inelastic deformations along the beam length. The proposed model consists of two gradual spread inelasticity sub-elements accounting explicitly for inelastic flexural and shear response. Following this approach, the effect of distributed loading on spreading of inelastic flexural and shear deformations is properly taken into account. The finite element is implemented in the seismic analysis of plane frame structures with beam members controlled either by flexure or shear. It is shown that to obtain accurate results the influence of distributed beam loading on spreading of inelastic deformations should be taken into account in the inelastic seismic analysis of frame structures.

Stereoscopic Conversion based on Key Frames (키 프레임 기반 스테레오스코픽 변환 방법)

  • 김만배;박상훈
    • Journal of Broadcast Engineering
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    • v.7 no.3
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    • pp.219-228
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    • 2002
  • In this paper, we propose a new method of converting 2D video into 3D stereoscopic video, called stereoscopic conversion. In general, stereoscopic images are produced using the motion informations. However unreliable motion informations obtained especially from block-based motion estimation cause the wrong generation of stereoscopic images. To solve for this problem, we propose a stereoscopic conversion method based upon the utilization of key frame that has the better accuracy of estimated motion informations. As well, as generation scheme of stereoscopic images associated with the motion type of each key frame is proposed. For the performance evaluation of our proposed method, we apply it to five test images and measure the accuracy of key frame-based stereoscopic conversion. Experimental results show that our proposed method has the accuracy more than about 90 percent in terms of the detection ratio of key frames.