• 제목/요약/키워드: reciprocity principle

검색결과 32건 처리시간 0.03초

가역성 원리를 이용한 반무한보의 진동 인텐시티 측정 (Measurement of Vibration Intensity of a Semi-Infinite Beam Using the Principle of Reciprocity)

  • 양귀봉;길현권;홍석윤
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 추계학술대회논문집 II
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    • pp.1073-1077
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    • 2001
  • The objective of this paper is to apply an experimental method based on the principle of reciprocity to measuring the structural intensity. Since only one accelerometer is used in this method it has the advantages of shortening measurement time. reducing accelerometer phase error. overcoming the limitation that the situation should be stationary during the experiment. It has been used to measure the vibration intensity of an infinite beam (beam with damped ends) and a semi-infinite beam (beam with simply supported and damped ends). Results showed that the experiment method based on the principle of reciprocity can be effectively used to measure the structural intensity.

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효규범에 대한 사적인 고찰 -호혜성 및 공정성을 중심으로- (Historical Review on Filial Piety Norm -focus on Reciprocity and Fairness-)

  • 성미애
    • 대한가정학회지
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    • 제35권3호
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    • pp.245-257
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    • 1997
  • The purpose of this study is to interpretate filial piety norm based on reciprocity and fairness. For this goal, we reviewed literature related to social, economical, and cultural situations, centered on the middle of the seventeenth century. The major results can be summerized as follow: The interaction between the parent generation and the married adult children generation changed according to the context of particular social, economical, and cultural conditions, so filial piety norm must also change paced along with social change. Therefore, the concepts of reciprocity and fairness has been an important one which maintains the quality of the relationship between the parent generation and the married adult children generation. So in general, we think it is reasonable to draw the conclusion that there are reciprocity and fairness principle between the parent generation and the married adult children generation.

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Numerical Solutions of Multi-Dimensional Solidification/Melting Problems by the Dual Reciprocity Boundary Element Method

  • Jo, Jong-Chull;Shin, Won-Ky
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 1997년도 추계학술발표회논문집(1)
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    • pp.617-624
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    • 1997
  • This Paper Presents an effective and simple procedure for the simulation of the motion of the solid-liquid interfacial boundary and the transient temperature field during phase change process. To accomplish this purpose, an iterative implicit solution algorithm has been developed by employing the dual reciprocity boundary element method. The dual reciprocity boundary element approach provided in this paper is much simpler than the usual boundary element method applying a reciprocity principle and an available technique for dealing with domain integral of boundary element formulation simultaneously. The effectiveness of the present analysis method have been illustrated through comparisons of the calculation results of an example with its semi-analytical or other numerical solutions where available.

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구조가진과 음향 가진의 결합에 의한 차량의 구조-음향 전달 함수 측정 (Measurement of Mechanical-acoustic Transfer Functions of Vehicles by Combination of Mechanical and Acoustic Excitations)

  • 고강호;이장무
    • 한국자동차공학회논문집
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    • 제7권9호
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    • pp.158-164
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    • 1999
  • In this paper a simple measurement technique for mechanical-acoustic transfer functions is proposed . The mechanical-acoustic transfer functions, generally , are measured through mechanical excitations ; impact hammers or shakers. Recently , by virtue of vibro-acoustical reciprocity principle, they are measured through acoustic excitations : loudspeakers. This kind of test needs to measure the volume velocity , the radiation characteristics of a sound source. Because the volume velocity of the sound source is changed by driving signal , it is difficult to measure it. However , the new method in this paper needs not to measure the volume velocity of a sound source by combination of mechanical and acoustic excitations. Moreover, this method has the methodological advantages, such as usage of a general loudspeaker for the reciprocal excitation, no sptatial limitations for measurements of mechanical-acoustic transfer functions.

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초음파 변환기의 감도 교정 시스템 구성 (Design of the Calibration System for Determining the Sensitivity of Ultrasonic Transducer)

  • 사공성대;조문재;최봉열
    • 제어로봇시스템학회논문지
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    • 제5권2호
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    • pp.200-207
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    • 1999
  • In this paper, a precise sensitivity measurement system of ultrasonic transducer in the frequency range from 1 MHz to 15 MHz, which can implement the reciprocity principle is constructed. All of the elements of this system such as the ultrasonic preamplifier, ultrasonic absorber, water tank, water degassing system, and four-axes translator and reflector are constructed. For the performance evaluation of the calibration system, a standard hydrophone precisely calibrated from PTB(Physikalisch Technische Bundesanstalt) in Germany are used. And the system parameters which affected the evaluation of the measurement accuracy and the reproducibility in various measuring conditions are considered. The measurement uncertainty of the calibration system is estimated within $\pm$ 2.0㏈.

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가역성 원리를 이용한 보강 원통형 셸에서의 탄성파 전파에 대한 실험적 해석 (Experimental Analysis of Elastic Wave Propagation m a Ribbed Cylindrical Shell Using the Principle of Reciprocity)

  • 길현권;양귀봉;김창렬;홍석윤
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 추계학술대회논문집 II
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    • pp.1089-1092
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    • 2001
  • In order to measure the vibration of a ribbed clindrical shell, the principle of reciprocity has been implemented. An accelerometer was fixed at the position defined as the excitation point. An impact hammer was used to tap at the response array points (64 points) located along the circumference of the shell. The frequency response function was reciprocally measured at each point in turn. The response data was processed to obtain the frequency/wavenumber spectrum. From the spectrum the characteristics of wave propagation on the ribbed cylindrical shell have been observed.

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진동-음향 상반 원리에 이용되는 음원의 유효 면적 측정 (The Application of Equivalent Area to the Volume Velocity for Using the Vibro-acoustical Reciprocity)

  • 고강호
    • 소음진동
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    • 제9권5호
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    • pp.943-948
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    • 1999
  • This paper proposes a feasible and effective method for measuring the mechanical-acoustic transfer function by the application of equivalent area and velocity transfer function, a manifestation of the vibro-acoustical reciprocity principle. On the contrary to the volume velocity used in traditional method, the equivalent area is a peculiar raidation characteristics of sound sources and not influenced by any input signal for driving sound source. This invariant property of equivalent area can get rid of boresome works to measure the volume velocity of a sound source every time the driving signal is changed. Moreover, this method has a remarkable advantage to use a general loudspeaker as an accoustic exciter without the assumption of point source and can be applied to all kinds of sound sources even if they are not omni-directional sources.

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NEW TECHNIQUE IN THE USE OF VIBRO-ACOUSTICAL RECIPROCITY WITH APPLICATION TO THE NOISE TRANSFER FUNCTION MEASUREMENT

  • Ko, K.H.;Kook, H.S.;Heo, S.J.
    • International Journal of Automotive Technology
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    • 제7권2호
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    • pp.173-177
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    • 2006
  • A noise transfer function(NTF) is the frequency response function between an input force applied to an exterior point of a vehicle body and the resultant interior sound pressure usually measured at the driver's ear position. It represents the measure of noise sensitivity for the output force transmitted to the joints between the body and chassis. The principle of vibro-acoustic reciprocity is often utilized in the measurement of NTF. One difficulty in using the volume source is that most of the previously proposed methods require the knowledge of the volume velocity of the acoustic source in advance. A new method proposed in the present work does not require any calculation related with the volume velocity of the acoustic source, but still yields even more accurate results both in the amplitude and phase of the NTF. In the present work, the new method is applied to obtain NTF data for a midsize sedan.

영국의 근로복지(Workfare) 개혁에 관한 연구 : 노동당의 이념적 변화를 중심으로 (A Study of the Workfare Reform in Britain : with Special References to the Ideological Change of Labour Party)

  • 문진영
    • 한국사회복지학
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    • 제56권1호
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    • pp.45-70
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    • 2004
  • 본 논문은 영국 블레어 정부의 근로복지 개혁이 유럽대륙 국가의 개혁과는 다른 한편으로, 미국식 신자유주의적 재편과도 다른 성격을 가지고 발전하게 된 배경을 살펴보고 그 원인을 규명할 목적을 가지고 작성되었다. 이러한 목적을 달성하기 위해서, 근로복지형 제도의 도입과정을 영국 노동당의 이념적 변화, 특히 당헌 제4조의 개정을 둘러싸고 나타난 당내(黨內) 좌 우파간의 갈등과 타협을 통해서 신노동당 프로젝트가 성립되는 과정에 초점을 맞추어 설명하고자 한다. 따라서 제2장에서는 영국 노동당의 제3의 길과 신노동당 프로젝트를 중심으로 노동당의 이념적 변화를 살펴보고, 이러한 변화의 핵심이라고 할 수 있는 '권리와 의무의 상호주의 원칙'을 추출한다. 그리고 제3장에서는 이러한 상호주의 원칙이 1997년 집권 이후 전개되고 있는 영국의 근로복지 개혁에 어떻게 반영되어 나타나는 가를 살펴본다. 그리고 제4장에서는 영국의 근로복지 개혁이 유럽대륙 국가와 다른 한편으로, 미국식 근로복지 개혁과도 다르게 전개되는 배경과 그 원인을 영국의 독특한 정치질서에서 찾고, 특히 노동당의 이념적 체질변화 과정에서 확립된 상호주의 원칙이 근로복지 개혁을 지도하였기 때문이라는 결론을 도출한다.

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흥인지문의 진동특성 및 상반성 분석 (Investigation on Vibration Characteristics and Structural Reciprocity of Heunginjimun)

  • 최재성;이성경;민경원;윤원규;김덕문
    • 한국소음진동공학회논문집
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    • 제20권4호
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    • pp.338-347
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    • 2010
  • Heunginjimun designated as a Treasure No.1 is a two-story wooden structure with 5 bay and 2 bay in its front and side views, respectively. This paper presents an investigation on vibration characteristics of Heunginjimun through both ambient vibration and impact hammer tests. Ambient vibration test was performed to identify the natural frequency of Heunginjimun from the spectrum analysis of time history. Impact hammer test was undertaken to find the frequency of Heunginjimun which is affected by the surrounding traffics and to verify the reciprocal principle for the wooden structural system. Ambient vibration test results of Heunginjimun showed that the natural frequencies in two principal axes 1.5 Hz and 1.1 Hz, respectively. It was confirmed from impact hammer tests for a ground that the frequency of 4.2 Hz is caused by the traffics surrounding Heunginjimun. It was also observed that from the impact hammer test results between two locations in Heunginjimun that the transfer functions measured from two corresponding locations coincided well with each other. This result shows that the wooden structural system is globally linear, and the reciprocal principle is established.