• Title/Summary/Keyword: Frequency dependence

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Amplitude Dependent Dynamic Properties of Tall Building under the Strong Wind (풍응답계측시 RD법에 의한 고층건물의 동적특성의 진폭의존성)

  • Yoon, Sung-Won
    • Journal of Korean Association for Spatial Structures
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    • v.4 no.1 s.11
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    • pp.61-68
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    • 2004
  • The wind tracker and structural monitoring system recorded wind and dynamic response data. The measured building is located in the moutatin in Sokcho. The damping ratio and natural frequency were analysed in this paper to obtain amplitude dependence. Amplitude dependent damping was showed clearly in the increasing rate of 9%. The tendency of dynamic properties of building obtained here are useful for the validation of dynamic properties of buildings in the evaluation of serviceability.

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Raman Frequencies Calculated at Various Pressures in Phase I of Benzene

  • Tari, Ozlem;Yurtseven, Hamit
    • Journal of the Korean Chemical Society
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    • v.57 no.2
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    • pp.204-209
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    • 2013
  • We calculate in this study the pressure dependence of the frequencies for the Raman modes of A ($A_g$), B ($A_g$, $B_{2g}$) and C ($B_{1g}$, $B_{3g}$) at constant temperatures of 274 and 294K (room temperature) for the solid phase I of benzene. Using the mode Gr$\ddot{u}$neisen parameter of each lattice mode, which correlates the pressure dependence of the crystal volume and the frequency, the Raman frequencies of those modes are computed for phase I of benzene. Our results show that the Raman frequencies of the three lattice modes (A, B and C) increase as the pressure increases, as expected. The temperature effect on the Raman frequencies is not significant, which can be explained by the experimental measurements.

Operation Frequency Dependence of Output of Orthogonal Fluxgate Sensor Fabricated with Ferrite Core (페라이트 코어를 이용하여 제작한 직교형 플럭스게이트 센서의 감도에 미치는 구동주파수의 영향)

  • Shin, Kwang-Ho
    • Journal of the Korean Magnetics Society
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    • v.22 no.6
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    • pp.200-203
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    • 2012
  • In this study, we have investigated that the operation frequency dependences of the output properties of the orthogonal fluxgate sensor which was fabricated with a ferrite core. An orthogonal fluxgate sensor should be operated in as high as possible frequency to enhance its sensitivity in the case of small sized sensor, because sensitivity of the sensor is proportional to cross section area, winding number and operation frequency. In this study, we investigated the correspondence of the frequency dependence of output and the reactance (inductance and capacitance) of pickup coil and cable. Experimental results represented that we could obtain maximum output (= sensitivity) at optimal frequency which is near LC resonance frequency of the pickup coil and cable.

Temperature and Frequency Dependences of Ultrasonic Properties in Commercial MC Nylon Polymers (상용 MC Nylon계 고분자 재료에서 초음파 특성의 온도 및 주파수 의존성)

  • Kim, Myung Deok;Kim, Yong Tae;Lee, Kang Il
    • Journal of the Korean Society for Nondestructive Testing
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    • v.32 no.5
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    • pp.509-517
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    • 2012
  • In the present study, temperature and frequency dependences of ultrasonic properties such as attenuation coefficient and phase velocity was investigated for six kinds of commercial MC-Nylon polymer samples. The ultrasonic properties of the samples were measured by using a pulse transmission method in water over a broadband frequency range of 2 to 8 MHz. Water temperature was varied from 10 to $60^{\circ}C$ with the $10^{\circ}C$ interval. The attenuation coefficients of the samples increased with the frequency and the exponent n of frequency dependence ranged within 1.16 to 1.44, slightly deviating from the linear dependence (n=1). The phase velocities of the samples exhibited negative dispersion, i.e., decreasing velocity with increasing frequency, except for ivory sample at $60^{\circ}C$. The frequency-dependent phase velocities of the samples showed the decreasing tendency with increasing temperature.

Influencing Factors on Alexithymia of Patients with Alcohol Dependence (알콜 의존 환자의 감정표현불능증 영향 요인)

  • Ryu, Seuk-Hwan
    • Korean Journal of Psychosomatic Medicine
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    • v.12 no.1
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    • pp.47-55
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    • 2004
  • Objectives: The aim of this study was to investigate alexithymia, depressive symptoms, and stress response of patients with alcohol dependence. The results were taken as a basic data of ameliorating the quality of life. Methods: 94 patients with alcohol dependence completed stress response inventory, Korea depression scale, and toronto alexithymia scale successfully. Results: 55% of variance of alexithymia of patients with alcohol dependence were explained by the stress response and depressive symptoms and score of ADS, and the stress response had the most explanatory power. Conclusions: The alexithymia of patients with alcohol dependence may be influenced by depressive symptoms, education, frequency of drinking, and stress response. The specialists were identifying symptoms of depression and optimizing the management, therefore increasing the compliance and quality of life of patients with alcohol dependence.

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A study on the langevin type vibrators (란쥬반형진동자에 관한 연구)

  • 박정엽;한득영;박태곤
    • 전기의세계
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    • v.30 no.1
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    • pp.47-54
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    • 1981
  • The fabrication of Langevin type vibrators producing relatively high sonic and ultrasonic energy is described. The dependence of the acoustic output and the frequency characteristics on the thickness of the steel plates and the pressure at the ceramics are investigated. As results, the acoustic output of Langevin type vibrators are relatively high, and the resonant frequency is decreassed by thickening the steel plates and lowering the pressure at the ceramics. Using these results, sonic and ultrasonic vibrator whose resonant frequency is determined can be designed.

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The Study on Characteristics of High Frequency Glow Discharge in Organic Vapor (유기 가스중 고주파 글로우가전 특성에 관한 연구)

  • 이덕출;김은배;박상현;박종대
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.34 no.9
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    • pp.355-360
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    • 1985
  • In this paper, the discharge phenomena of high frequency glow discharge in organic vapor are basically investigted to establish the growth mechanism and preparation technique for organic thin film. According to the increasing of discharge frequency, the discharge firing voltage(Vs) of organic vapor decreases. The dependence of discharge voltage(Vd) on gas pressure is generally in accord with Paschen's Law and Vd decreases as gas flow rate become larger, but increases as dischange current density become higher. And the values of Vd in organic vapor are generally higher than those of inorganic gas.

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Electrical Transport Properties of Gd0.33Sr0.67FeO3 Ceramics (Gd0.33Sr0.67FeO3 세라믹스의 전기전도 특성)

  • Jung, Woo-Hwan
    • Journal of the Korean Ceramic Society
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    • v.43 no.2 s.285
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    • pp.131-135
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    • 2006
  • In this study, the dielectric, magnetic and transport properties of $Gd_{0.33}Sr_{0.67}FeO_3$ have been analyzed. The dielectric loss anomaly was found to be around 170 K. The activation energy corresponding to relaxation process of this dielectric anomaly was 0.17 eV. From the temperature dependence of the characteristic frequency, we concluded that the elementary process of the dielectric relaxation peak observed is correlated with polaron hopping between $Fe^{3+}\;and\;Fe^{4+}$ ions. The electrical resistivity displayed thermally activated temperature dependence above 200 K with an activation energy of 0.16 eV. In addition, the temperature dependence of thermoelectric power and resistivity suggests that the charge carrier responsible for conduction is strongly localized.