• Title/Summary/Keyword: frequency problem

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Understanding and Physical therapy of Functional Disability Factors according to Disease (질환에 따른 기능장애 요소의 이해와 물리치료)

  • Park, Seung-Kyu;Kim, Sang-Yeob
    • Journal of Korean Physical Therapy Science
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    • v.6 no.3
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    • pp.83-89
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    • 1999
  • We are approaches various painful diseases in clinic. Although same disease, it is different to acute, subacute and chronic stage of disease. Therefore, to understanding of tissue anatomy, pathology and physiology is necessary to under-standing pattern of diseases. It is duty work that choice of hot or ice, electrotherapy, choice of adaptable frequency and mathod of exercise therapy etc. During treatment it is important method to choose to treat the client. As treating the client by exercising or treating when the client is resting and seeing if anything else is a problem etc. So what I have approached some of the treatment that a physical therapist could miss during treatment.

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A Comparative Study on Measuring Methods of Absorption Characteristics for Electromagnetic Wave Using Standing Wave Measurement Method and Time Domain Method. (정재파측정법과 Time Domain법에 의한 전파흡수능측정법의 비교 연구)

  • 김동일;김상태;박지용;정세모
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 1994.10a
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    • pp.79-90
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    • 1994
  • The goal of this research is to get a measuring system for absorption characteristics of electromagnetic wave absorbers in ferrite type which are lat grid-type special type etc. It is however very difficult to measure the absorption characteristics as in low frequency as in 30 MHz, To solve the problem therefore we propose a standing wave method and a measurement method in time domain using parallel striplines construct the measuring system and measure the characteristics of ferrite microwave absorbers in grid type using the proposed measuring system.

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A Study on Estimating the Contingency Cost of Small Construct Project (소규모 건설 프로젝트에서의 공사예비비 산정방법에 관한 연구)

  • 송진우;표영민;박성호;이상범
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2004.05a
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    • pp.113-117
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    • 2004
  • We need the contingency cost in order to deal with the uncertainty to be accompanied inevitably at the construction and an every kind risk not to forecast in advance. And also the contingency colt needed for the change order and we need it for reduction of the delay and reduce the trouble between owner and constructor. This study, through checking and analyzing the risk factor, in the step of domestic construction, suggests optimal management reserve to specific business about the contract type and the scale. The main results of this research are summarized as follow. First, I investigated the recognition about the contingency cost, grasped the risk to be happened at the construction step and found out the frequency occurrence, through making up question to engineer are carrying out their job in the domestic construction. Second, I computed optimal contingency cost rate by the statistics investigation, and proposed an improvement plan and problem when compute a contingency cost.

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Performance Uncertainty Estimation of a Nonlinear Vibration System Based on a Sampling Method (샘플 추출방법에 근거한 비선형 진동계의 성능 불확실성 예측)

  • Choi, Chan-Kyu;Yoo, Hong-Hee
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2009.10a
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    • pp.113-118
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    • 2009
  • A designer regards the vibration system as a linear system. However, in real world, nonlinearity of a vibration system should exist caused by various factors like manufacturing conditions or uncertain material properties. So, properties of a spring and a damper which are consisting the vibration system have statistical distribution. Therefore, a designer needs to analyze the statistical nonlinearity in a vibration system. In this paper, $1^{st}$ Taylor series expansion method and univariate dimension reduction method apply to a performance measure of nonlinear vibration system, and compare each result. And then, merits and demerits of each method are discussed. For apply more actual problem, a performance measure population is estimated based on design variable samples like properties of spring or damper.

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DETECTING OF SCUFFING USING ACOUSTIC EMISSION

  • Kim, J.H.;Kim, T.W.;Cho, Y.J.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2002.10b
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    • pp.191-192
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    • 2002
  • The scuffing failure is a critical problem in modern machine components, especially for the requirement of high efficiency and small size. In this study. scuffing experiments are conducted using Acoustic Emission(AE) measurement by an indirect sensing approach to detect scuffing failure. Using AE signals we con get and indication about the state of the friction processes, about the quality of solid and liquid layers on the contacting surface in real time. The FFT(Fast Fourier Transform)analyses of the AE signal are used to understand the interfacial interaction and the relationship between the AE signal and the state of contact is presented.

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EMI Analysis of Soft Switching Inverter on High Power AC Motor Drive (대전력 교류전동기 구동용 소프트 스위칭 인버터의 EMI 해석)

  • 권순걸
    • Journal of the Institute of Convergence Signal Processing
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    • v.3 no.3
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    • pp.76-81
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    • 2002
  • In high power motor drive system, the hard-switching topology produces severs switching losses and EMI noises. Also the inverter switching frequency is thus limited because of excessive loss and thermal handling problem. The primary purpose of the proposed works on the induction motor drive system is to develop an advanced soft-switching inverter topology that is most suitable for high power induction motor drive applications. To make the optimal selection EMI comparison of the switching losses presented. To verify the proposed design procedure, detailed simulation analysis with theoretical and experimental approaches have been done using laboratory prototype.

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Dynamic Characteristics Analysis on the Power Factor Correction (PFC) System for Propulsion System of KTX High Speed Train (KTX 고속전철 추진제어시스템의 역률제어장치(PFC) 동작특성 분석)

  • Lee, Eul-Jae;Lee, Eun-Gyu;Yoon, Cha-Jung
    • Proceedings of the KSR Conference
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    • 2011.05a
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    • pp.82-92
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    • 2011
  • This paper presents a PFC(Power Factor Correction) system to control the power factor of input current of the converter system which is working in the propulsion system of KTX high speed train. In the KTX train system, initially introduced from ALSTOM, the thyristor converter with phase controlling technique is adopted in the current fed type powering system. The input current induces harmonic losses highly because the waveform becomes rectangular shapes according to the filter inductor current increased as the train speed increasing gradually. Especially the interference with the signalling systems is severe concerned due to high current harmonics on the catenary line. To protect this problem, a frequency trap filter(notch filter) is operating with the input converter system. In this paper, an analysis work and PC simulation have been done on the PFC system to upgrade its performance and maintenance efficiency.

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PAR reduction using Adaptive Block Coding in the OFDM system (OFDM시스템에서 블록코딩을 이용한 PAR감소에 대한 연구)

  • Kim, Tae-Han;Kim, Young-Soo
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.2745-2754
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    • 2011
  • In this paper, we propose a Peak to Average power Ratio(PAR) reduction algorithm by using the Adaptive Block Coding(ABC). The problem of a PAR due to each sub-carrier overlap phenomenon in the OFDM (Orthogonal Frequency Division Multiplexing) system causes the an increasing in the complexity of the A/D converter in the transmitter and a reduction in the efficiency of the amplifier. The proposed ABC algorithm selects the block coding which provides the lowest PAR value based on the various check bit position. It is shown that a PAR of the ABC algorithm can be reduced from 8.35dB to 6.02dB in 16 sub-carriers compared to theconventional block coding scheme. We also extended the ABC algorithm to a larger number of sub-carriers and estimated their PAR values.

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A new Capturing Application for EPCIS (EPC 정보 시스템을 위한 새로운 Capturing Application)

  • Jia, Fengjuan;Hong, Bong-Hee;Kwon, Joon-Ho
    • Proceedings of the Korean Information Science Society Conference
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    • 2012.06a
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    • pp.316-318
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    • 2012
  • Radio Frequency Identification(RFID) technology has been widely used to identify and keep track of physical objects. The EPC Network Architecture, which is proposed by EPCglobal to promote EPC and RFID technologies, consists of several layers to deal with the captured data. Many studies concentrated on dealing with RFID tag data (ECReports) from ALE. However, there is no well-known work on specifying how to generate high level EPCIS events. For the incoming ECReports, Capturing Application cannot decide to generate which event types and how to get the semantic fields. In this paper, we propose the new Capturing Application (NCA) to solve the problem. NCA can generate EPCIS events correctly and automatically.

The Homotopy Perturbation Method for free vibration analysis of beam on elastic foundation

  • Ozturk, Baki;Coskun, Safa Bozkurt
    • Structural Engineering and Mechanics
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    • v.37 no.4
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    • pp.415-425
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    • 2011
  • In this study, the homotopy perturbation method (HPM) is applied to free vibration analysis of beam on elastic foundation. This numerical method is applied on three different axially loaded cases, namely: 1) one end fixed, the other end simply supported; 2) both ends fixed and 3) both ends simply supported cases. Analytical solutions and frequency factors are evaluated for different ratios of axial load N acting on the beam to Euler buckling load, $N_r$. The application of HPM for the particular problem in this study gives results which are in excellent agreement with both analytical solutions and the variational iteration method (VIM) solutions for all the cases considered in this study and the differential transform method (DTM) results available in the literature for the fixed-pinned case.