• Title, Summary, Keyword: Frequency of Interaction

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Femto Slider Head/Disk Interaction Detection by Acoustic Emission and Natural Frequency Analysis

  • Hwang, Pyung;Galina Pan;Xuan Wu
    • KSTLE International Journal
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    • v.6 no.1
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    • pp.17-20
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    • 2005
  • The object of the present work is the natural lre%uency analysis of femto slider, HeaHdisk interaction during starustop and constant speed were detected by using the acoustic emission (AE) test system. The frequency spectrum analysis wasperformed using the AE signal obtained during the head/disk interaction. The FFT (Fast Fourier Transform) analysis of the AEsignals is used to understand the interaction between the AE signal and the state of contact. Natural frequency analysis wasperformed using the ANSYS program. The results indicate acceptable accordance of finite element calculation results with theexperimental results.

FREQUENCY SPECTRUM ANALYSIS OF ACOUSTIC EMISSION OF HARD DISK DRIVE HEAD/DISK INTERACTION

  • Chung, K.H.;Oh, J.K.;Moon, J.T.;Kim, D.E.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • pp.273-274
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    • 2002
  • In order to evaluate the flying characteristics of slider, the acoustic emission (AE) as well as friction signals are typically utilized. In this work the frequency spectrum analysis is performed using the AE signal obtained during the head/disk interaction such as load/unload mechanism using ramp, impact situation in the presence of a bump on disk surface and other contact phenomena including particle interaction. It was shown that the influence of impact can be characterized effectively in the AE frequency spectrum. As a result of this work, frequency spectrum analysis will be utilized with better understanding for studying the head/disk interface (HDI) characteristics and monitoring the particle interaction in HDI effectively.

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Natural Frequency Analysis of Sliders and Head/Disk Interaction Detection by Acoustic Emission

  • Hwang, Pyung;Pan, Galina;Khan, Polina
    • KSTLE International Journal
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    • v.5 no.1
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    • pp.28-31
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    • 2004
  • The object of the present work is the natural frequency analysis of subambient pressure tri-pad and pico sliders. Head/disk interaction during start/stop and constant speed were detected by using the acoustic emission (AE) test system. The frequency spectrum analysis is performed using the AE signal obtained during the head/disk interaction. The FFT (Fast Fourier Transform) analysis of the AE signals is used to understand the interaction between the AE signal and the state of contact. Natural frequency analysis was performed using the Ansys program. The results indicate acceptable accordance of finite element calculation results with the experimental results.

The Locus of the Word Frequency Effect in Speech Production (말소리 산출에서 단어빈도효과의 위치)

  • Koo, Min-Mo;Nam, Ki-Chun
    • Proceedings of the KSPS conference
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    • pp.99-108
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    • 2006
  • Three experiments were conducted to determine the exact locus of the frequency effect in speech production. In Experiment 1. a picture naming task was used to replicate whether the word frequency effect is due to the processes involved in lexical access or not. The robust word frequency effect of 31ms was obtained. The question to be addressed in Experiment 2 is whether the word frequency effect is originated from the level where a lemma is selected. To the end, using a picture-word interference task, the significance of interactions between the effects of target frequency, distractor frequency and semantic relatedness were tested. Interaction between the distractor frequency and semantic relatedness variables was significant. And interaction between the target and distractor frequency variables showed a significant tendency. In addition, the results of Experiment 2 suggest that the mechanism underlying the word frequency effect is encoded as different resting activation level of lemmas. Experiment 3 explored whether the word frequency effect is attributed to the lexeme level where phonological information of words is represented or not. A methodological logic applied to Experiment 3 was the same as to Experiment 2. Any interaction was not significant. In conclusion, the present study obtained the evidence supporting two assumptions: (a) the locus of the word frequency effect exists in the processes involved in lemma selection, (b) the mechanism for the word frequency effect is encoded as different resting activation level of lemmas. In order to explain the word frequency effect obtained in this study, the core assumptions of current production models need to be modified.

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The Analysis of Verbal Interaction on the Process of Elementary Students' Hypothesis Generation Learning

  • Park, Hee-Young;Lee, Il-Sun;Byeon, Jung-Ho;Kim, Won-Jung;Kwon, Yong-Ju
    • Journal of The Korean Association For Science Education
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    • v.32 no.8
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    • pp.1269-1280
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    • 2012
  • The purpose of this study is to analyze the verbal interaction during elementary students' hypothesis generation learning. For this study, 32 6th graders were selected and were assorted into heterogeneous small-groups by achievement levels. The topics of hypothesis generation learning were developed by analyzing the current elementary school curriculum. Each group's verbal interactions were audio/video taped and transcribed. After coding the protocol and having student retrospective interview, types and frequency of verbal interaction were analyzed. The frequency of verbal interaction during observation was highest and that of questioning situation identification was lowest. Regarding to the quality of verbal interactions, low level interactions were significantly frequent during observation. On the other hand, hypothetical explicans generation revealed high frequency of high level interactions. The results revealed that elementary students can make high level verbal interactions through hypothesis generation learning.

Vertical Vibration Analysis of Single Pile-Soil Interaction System Considering the Interface Spring (접합면 스프링요소를 고려한 단말뚝-지반 상호작용계의 수직진동해석)

  • 김민규;김문겸;이종세
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • pp.106-113
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    • 2002
  • In this study, a numerical analysis method for soil-pile interaction in frequency domain problem is presented. The total soil-pile interaction system is divided into two parts so called near field and far field. In the near field, beam elements are used for a pile and plain strain finite elements for soil. In the far field, dynamic fundamental solution for multi-layered half planes based on boundary element formulation is adopted for soil. These two fields are coupled using FE-BE coupling technique In order to verify the proposed soil-pile interaction analysis, the dynamic responses of pile on multi-layered half planes are simulated and the results are compared with the experimental results. Also, the dynamic response analyses of interface spring elements are performed. As a result, less spring stiffness makes the natural frequency decrease and the resonant amplitude increase.

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Analysis on the Measured Natural Frequencies Due to the Structure-Exciter Interaction (구조물-가진기 상호작용에 의한 공진주파수 변동에 대한 해석)

  • Han, Sang-Bo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.7
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    • pp.2108-2117
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    • 1996
  • The purpose of this paper is to investigate the influence of the exciter attached for the measurement of natural frequencies when extracting the frequency response functions of the test structure in experimental modal analysis. The procedure is first to model the attached exciter as an additional degree of freedom system and next to verify the suggested model by experimentally extracting the natural frequencies of the test structure with various values of exciter mass, stinger stiffness and attachment position of the exciter on the test structure. It is concluded that as additional degree of freedom system which includes the natural frequency of the exciter itself and axial stiffness of stinger should be considered to quantatively define the coupling effects of structure-exciter interaction on the measured natural frequencies. It is not the mass of the exciter itself but the coupling effect of the additional degree of freedom mass-spring system consisting of exciter body and armature coil that characterizes the natural frequency deviation. Therefore, when the natural frequency of this additional mass-spring system is outside of the test frequency range, the coupling effect of structure-exciter interaction can be minimized.

Coupled foot-shoe-ground interaction model to assess landing impact transfer characteristics to ground condition

  • Kim, S.H.;Cho, J.R.;Choi, J.H.;Ryu, S.H.;Jeong, W.B.
    • Interaction and multiscale mechanics
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    • v.5 no.1
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    • pp.75-90
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    • 2012
  • This paper investigates the effects of sports ground materials on the transfer characteristics of the landing impact force using a coupled foot-shoe-ground interaction model. The impact force resulting from the collision between the sports shoe and the ground is partially dissipated, but the remaining portion transfers to the human body via the lower extremity. However, since the landing impact force is strongly influenced by the sports ground material we consider four different sports grounds, asphalt, urethane, clay and wood. We use a fully coupled 3-D foot-shoe-ground interaction model and we construct the multi-layered composite ground models. Through the numerical simulation, the landing impact characteristics such as the ground reaction force (GRF), the acceleration transfer and the frequency response characteristics are investigated for four different sports grounds. It was found that the risk of injury, associated with the landing impact, was reduced as the ground material changes from asphalt to wood, from the fact that both the peak vertical acceleration and the central frequency monotonically decrease from asphalt to wood. As well, it was found that most of the impact acceleration and frequency was dissipated at the heel, then not much changed from the ankle to the knee.

Time domain earthquake response analysis method for 2-D soil-structure interaction systems

  • Kim, Doo-Kie;Yun, Chung-Bang
    • Structural Engineering and Mechanics
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    • v.15 no.6
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    • pp.717-733
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    • 2003
  • A time domain method is presented for soil-structure interaction analysis under seismic excitations. It is based on the finite element formulation incorporating infinite elements for the far field soil region. Equivalent earthquake input forces are calculated based on the free field responses along the interface between the near and far field soil regions utilizing the fixed exterior boundary method in the frequency domain. Then, the input forces are transformed into the time domain by using inverse Fourier transform. The dynamic stiffness matrices of the far field soil region formulated using the analytical frequency-dependent infinite elements in the frequency domain can be easily transformed into the corresponding matrices in the time domain. Hence, the response can be analytically computed in the time domain. A recursive procedure is proposed to compute the interaction forces along the interface and the responses of the soil-structure system in the time domain. Earthquake response analyses have been carried out on a multi-layered half-space and a tunnel embedded in a layered half-space with the assumption of the linearity of the near and far field soil region, and results are compared with those obtained by the conventional method in the frequency domain.

Consumer Competencies of Urban Wives and Related Variables (도시주부의 소비자능력과 관련요인)

  • 황덕순;김미라
    • Korean Journal of Human Ecology
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    • v.1 no.2
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    • pp.23-36
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    • 1998
  • The purpose of this study was to investigate consumer competencies of urban wives an variables on it. The framework of this study was consumer socialization theory. The results were as follows; 1. There were significant differences in competencies of urban wives according to employment status, interaction with family members, interaction with peers and frequency of media exposure. 2. Employment status, interaction with family members and frequency of media exposure were independent influencing factors on consumer competencies of urban wives. 3. Reviewing a causal model, the results were as follows. Employment status, interaction with family members and frequency of media exposure had an effect on consumer competencies of urban wives directly. (Korean J Human Ecology 1(2):23~30, 1998)

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