• Title/Summary/Keyword: static and dynamic characteristic

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Three Dimensional Transient Analysis of Piezoelectric Beam Using Finite Element Method (유한요소법을 이용한 완전 세라믹의 3차원 과도해 해석)

  • Joo, Hyun-Woo;Lee, Chang-Hwan;Jung, Hyn-Kyo
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.608-610
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    • 2000
  • The static characteristic of a piezoelectric beam is for finding resonance frequency of the beam. In practice, it is required to analyze the beam with external command circuit including capacitors, inductors, and resistors for control. It means that the proper analysis of a piezoelectric beam with external command circuit is required by a dynamic analysis. We can also got transient and steady-state solution from the analysis. In this paper, the static and dynamic characteristic of the piezoelectric beam using FEM(Finite Element Method) are proposed.

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Dynamic Characteristic Analysis of LIM Using Coupled FEM and Control Algorithm (유한요소법(FEM)과 제어알고리즘이 결합된 기법을 이용한 선형 유도전동기(LIM)의 동특성 해석)

  • Jeon, Su-Jin;Park, Seong-June;Lee, Junn-Ho
    • Proceedings of the KIEE Conference
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    • 2005.07b
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    • pp.1086-1088
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    • 2005
  • It is necessary to modify the state-of-the-art of vector control theory, because of the phase asymmetry(static end effect) in the Linear Induction Motor(LIM). The dynamic characteristic analysis method of the vector controlled LIM using coupled FEM and control algorithm taking into account the movement is proposed. The focus of this paper is the analysis relative to phenomena of static end effect due to the motor structure. To prove the propriety of the proposed method, the Digital Signal Processor(DSP) installed experimental devices are equipped and the experiment is performed.

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Dynamic Characteristic Analysis of SSSC based on Multi-bridge PWM Inverter

  • Han Byung-Moon;Kim Hee-Joong;Baek Seung-Taek
    • Proceedings of the KIPE Conference
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    • 2001.10a
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    • pp.718-722
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    • 2001
  • This paper proposes an SSSC based on multi-bridge inverters in PWM scheme. The proposed system consists of 6 H-bridge inverter modules per phase. The dynamic characteristic of proposed system was analyzed by simulation with EMTP codes, assuming that the SSSC is inserted in the 154-kV transmission line of one-machine-infinite-bus power system. The feasibility of hardware implementation was verified through experimental works with a scaled-model. The proposed system can be directly inserted in the transmission line without coupling transformers, and has flexibility in expanding the operation voltage by increasing the number of H-bridges.

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A Study of Characteristics of Water Droplets on Various Nanoscale Structures Using Molecular Dynamics (분자동역학을 이용한 다양한 구조물 위의 수액적의 특성에 대한 연구)

  • Lee, Kwang Ho;Kwon, Tae Woo;Ha, Man Yeong
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.30 no.1
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    • pp.33-43
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    • 2018
  • This study numerically investigated statistic and dynamic behaviors of the water droplet on plate with or without various structured-pillars at nano-scale by molecular dynamics simulation. This study considered smooth plate, plate with the rectangular-structured pillar, and the plate with dual-structured pillar under various characteristic energy conditions. The static behavior of water droplet depending on the plate shape, plate surface energy, and the pillar characteristics were examined. After the water droplet reaches its steady state, this study investigated the dynamic behavior of the water droplet by applying a constant force. Finally, this study investigated the static and dynamic behaviors of the water droplet by measuring its contact angle and contact angle hysteresis. As a result, we found that the structure was more hydrophobic.

Probabilistic Structural Safety Assessment Considering the Initial Shape and Non-linearity of Steel Cable-Stayed Bridges (강사장교의 초기형상과 비선형성을 고려한 확률론적 구조안전성 평가)

  • Bang, Myung-Seok;Han, Sung-Ho;Lee, Woo-Sang;Lee, Chin-Ok
    • Journal of the Korean Society of Safety
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    • v.25 no.3
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    • pp.91-99
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    • 2010
  • In this study, the advanced numerical algorithm is developed which can performed the static and dynamic stochastic finite element analysis by considering the effect of uncertainties included in the member stiffness of steel cable-stayed bridges and seismic load. After conducting the linear and nonlinear initial shape analysis, the advanced numerical algorithm is the assessment tool which can performed structural the response analysis considering the static linearity and non-linearity of before or after induced intial tensile force, and examined the reliability assessment more efficiently. The verification of the developed numerical algorithm is evaluated by analyzing the regression analysis and coefficient of correlation using the direct monte carlo simulation. Also, the dynamic response characteristic and coefficient of variation of the steel cable-stayed bridge is calculated by considering the uncertainty of random variables using the developed numerical algorithm. In addition, the quantitative structural safety of the steel cable-stayed bridges is evaluated by conducting the reliability assessment based upon the dynamic stochastic finite element analysis result.

A Behavior Analysis of HSR concrete slab track under Variety of Rail pad stiffness on fatigue effect (피로효과를 고려한 레일패드 스프링계수 변화에 따른 콘크리트 슬래브 궤도의 거동분석)

  • Eom, Mac;Choi, Jung-Youl;Chun, Dae-Sung;Park, Yong-Gul
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.340-350
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    • 2007
  • The major objective of this study is to investigate the fatigue effects of rail pad on High Speed Railway with concrete slab track system. It analyzed the mechanical behaviors of HSR concrete slab track with applying rail pad stiffness based on fatigue effect(hardening and increasing stiffness) on the 3-dimensional FE analysis and laboratory test for static & dynamic characteristics. As a result, the hardening of rail pad due to fatigue loading condition are negative effect for the static & dynamic response of concrete slab track which is before act on fatigue effect. The analytical and experimental study are carried out to investigate rail pad on fatigue effected increase vertical acceleration and stress and decrease suitable deflection on slab track. And rail pad based on fatigue effect induced dynamic maximum stresses, the increase of damage of slab track is predicted by adopting fatigue effected rail pad. after due consideration The servicing HSR concrete slab track with resilient track system has need of the reasonable determination after due consideration fatigue effect of rail pad stiffness which could be reducing the effect of static and dynamic behavior that degradation phenomenon of structure by an unusual response characteristic and a drop durability.

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A Study Vibration Characteristic of Railway Freight Car's End Beam for Taebaek Line (태백선을 주행하는 화차 엔드빔의 진동특성에 관한 연구)

  • 함영삼;문경호;홍재성;이동형;서정원
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.378-383
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    • 2004
  • Bogie is the connection device between carbody and wheel. It is the core part that exert a important effect on the passenger safety and running safety. Bogie largely consist of bogie frame, suspension, brake, wheel set. Static and Dynamic load have acted on it complexly. So when the bogie is designed, finite element method, static load test, fatigue test running test should be considered. Some bogie frame of high speed railway freight car have the problem. It's end beam was cracked. The crack of the end beam have a bad effect on brake system. ROTEM co. made an improved end beam and applied one set to freight car. this report showed the vibration characteristic which was compared conventional bogie to improved bogie for running safety.

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Design and Dynamic Analysis of LDM by using FE Analysis (부하를 고려한 LDM의 동특성 해석에 관한 연구)

  • Kang, Gyu-Hong;Yeom, Sang-Bu;Hong, Jung-Pyo;Kim, Gyu-Tak;Jung, Joong-Gi;Ha, Kyeun-Su
    • Proceedings of the KIEE Conference
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    • 1999.07a
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    • pp.164-166
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    • 1999
  • In this study, dynamic analysis of Linear DC motor has been performed. Dynamic characteristic is carried out from coupling the electrical circuit equation and mechanical kinetic equation. Trust constant and circuit parameters are obtained by FE analysis and static characteristic experiment. From the previous results, dynamic analysis is performed and the appropriateness of analysed result is verified by comparing with experimental result.

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Measurements of Elastic Moduli of Rock Cores Using Free-Free Resonance Tests (자유단 공진시험을 이용한 암석의 탄성계수 측정)

  • 목영진
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1998.10a
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    • pp.353-360
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    • 1998
  • Dynamic measurements are used rather sparingly to determine the elastic moduli of rock cores and modulus values are not much utilized in design practice. The reason seems to result from the general perception that values obtained by dynamic measurement are much higher (about 10 times) than those determined statically. This paper presents results from dynamic and static tests on rock cores. The findings are : 1) elastic moduli can be consistently determined by laboratory seismic testing. 2) nonlear deformation characteristic of rock cores was tentatively proposed with variation in elastic modulus with strain.

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The Effects of Elastic Ankle Taping on Static and Dynamic Postural Control in Individuals With Chronic Ankle Instability

  • Lim, Jin-seok;Kim, Seo-hyun;Moon, Il-young;Yi, Chung-hwi
    • Physical Therapy Korea
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    • v.28 no.3
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    • pp.200-207
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    • 2021
  • Background: Postural control deficit is a major characteristic in patients with chronic ankle instability (CAI). Elastic ankle tapings are commonly used to facilitate postural control in patients with CAI as well as prevent relapse of a lateral ankle sprain. However, equivocal evidence exists concerning the effect of elastic ankle taping on postural control. Objects: This study aimed to evaluate the effects of elastic ankle tapings using kinesio taping (KT) and dynamic taping (DT) on static and dynamic postural control in patients with CAI. Methods: Fifteen subjects with CAI were participated in this study. The participants performed tests under three conditions (barefoot, KT, and DT). Static postural control was evaluated using the one-leg standing test (OLST) and dynamic postural control using the modified Star Excursion Balance Test (mSEBT). One-way repeated-measures analysis of variance was used to compare center of pressure (CoP) data and normalized mSEBT reach distances among the three conditions (with α = 0.05). Results: The CoP parameters (path length, ellipse area, and mean velocity) of the OLST significantly decreased on applying KT and DT compared with those when barefoot. The normalized reach distances in the anteromedial (AM), medial (M), and posteromedial (PM) directions of the mSEBT significantly increased with DT compared to that in the control condition. Further, the higher reach distances with KT compared with those in the control condition were obtained in the M and PM directions of the mSEBT. No significant differences were identified in any of the OLST and SEBT parameters between the two different taping applications. Conclusion: KT and DT improved static postural control during the OLST compared with the control condition. Moreover, these tapes improved dynamic postural control during the mSEBT compared to the control. Therefore, elastic ankle tapings are useful prophylactic devices for the prevention and treatment of ankle sprain in people with CAI.