• Title/Summary/Keyword: Longitudinal wave

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Reciprocal Relations between Maternal Parenting Behavior and Preschoolers' Compliance/Noncompliance during Mother-child Interactions : A Short-term Longitudinal Study (모-자녀간 상호작용 시 어머니의 양육행동과 유아의 순응/불순응 행동 간의 상호적 관계 : 단기 종단 연구)

  • Shin, Nana;Park, Bokyung;Kim, Soyoung;Doh, Hyun-Sim
    • Korean Journal of Child Studies
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    • v.36 no.5
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    • pp.75-94
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    • 2015
  • This study examined short-term longitudinal reciprocal relationships between maternal parenting behavior and preschoolers' compliance/noncompliance, as well as stability in both maternal parenting behavior and preschoolers' compliance/noncompliance over time. The sample which was used for this study was taken from a two-wave (one year apart) longitudinal study of preschool-aged children and their mothers (N = 53 dyads). At both times, mothers and their children were invited to a laboratory and engaged in 25 minutes of play involving three episodes of mother-child interaction. Maternal parenting behavior and preschoolers' compliance/noncompliance during play were coded using the Dyadic Parent-Child Interaction Coding System-III (DPICS-III). Maternal codes included positive, neutral, and negative parenting behaviors and child codes were comprised of compliance and noncompliance. The results revealed that during the play session, maternal neutral and negative parenting behavior and preschoolers' compliance were stable over time. In addition, T1 maternal negative parenting behavior was significantly related to T2 child compliance/noncompliance. However, T1 child compliance/noncompliance were not significantly associated with T2 maternal parenting behavior. These findings suggest that during the preschool period, there are unidirectional effects from mothers to children.

The Longitudinal Reciprocal Relationship between Self-rated Health Status and Depression in the Elderly : Testing the Autoregressive Cross-lagged Model (노년기 주관적 건강상태와 우울 간의 종단적 상호인과관계: 자기회귀교차지연모형의 검증)

  • Sohn, Keunho;Kim, Kyoungho
    • The Journal of the Korea Contents Association
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    • v.22 no.9
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    • pp.473-484
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    • 2022
  • This study aimed to verify the reciprocal casual relationship between self-rated health status and depression in the elderly through longitudinal analysis. An autoregressive cross-lagged model was identified. This study analyzed 3,363 elderly people aged 65 or older using the 5th, 6th, and 7th wave data from Korean Longitudinal Study of Ageing(KLoSA). The results are as follows. First, self-rated health status had a positive(+) autoregressive effect. Second, depression had a positive(+) autoregressive effect. Third, self-rated health status had a negative(-) cross-lagged effect on depression, but depression was not a casual predictor of self-rated health status. Based on these findings, it was suggested that there is a need for systematic policies to improve basic fitness in the early stages of old age, as well as the need to expand health promotion programs and implement integrated depression management programs.

Suppression of leakage and crosstalk in millimeter-wave flip-chip packages (밀리미터파 플립 칩 실장구조에서의 누설파와 간섭효과 억제방법)

  • 이계안;이해영
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.35D no.4
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    • pp.40-46
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    • 1998
  • Leakage phenomena of flip-chip structures on common GaAs and alumina main substrates are characterized using the spectral domain approach to reduce the possible chip-to-chip crosstald and transmission resonance. We have found taht the longitudinal section magnetic mode is dominant for the coplanar waveguide leakage andthe leakage can be suppreassed by properly managing the gap height and the main substrate thickness in addition to the dielectric constant. These calculation results will be helpful for designing and flip-chip packagaing of high-frequency integrated circuits.

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Tunable Narrow-Bandwidth Optical Filter Based on Acoustically Modulated Fiber Bragg Grating (음파에 의한 광섬유 브래그 격자 변조를 이용한 좁은 선폭의 파장가변 광학필터)

  • 염동일;박희수;김병윤
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.07a
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    • pp.198-199
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    • 2003
  • 광섬유 브래그 격자(Fiber Bragg Grating, FBG)는 좁은 선폭과 적은 삽입손실 등의 뛰어난 스펙트럼 특성을 가지고 있어, 고밀도 파장분할 다중화 방식을 이용한 광통신 시스템과 여러 종류의 광섬유센서에 응용되고 있다. 브래그 격자의 광학적 스펙트럼을 능동적으로 조절하기 위하여, 광섬유에 열이나 스트레인을 인가하거나, 음파와 빛의 결합을 이용한 방법이 제안되었으며, 특히 음향 광학 브래그 격자 변조기(Acousto-Optic Superlattice Modulator)는 종 방향 음파(Longitudinal Acoustic Wave)를 이용하여 파장과 크기의 조절이 가능한 사이드 밴드(Side Band)를 생성해 내었다. (중략)

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Synthetic Strategy and Optical Property Characterization of Complex Nanorods: Plasmon Wave Guide and Solar Cell

  • Park, Sung-Ho
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.111-111
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    • 2012
  • In this talk, we represent a novel approach to investigating intra-nanorod surface plasmon coupling with control over block compositions. The multi-component rod-like nanostructures, which consist of optically active components (Au and Ag) and optically less active component (for example, Ni) in UV-vis-NIR spectral window, showed interesting optical response depending on each block length and the total length of the structure. By controlling the composition and relative lengths of the blocks that comprise these structures, we can tailor the overall optical properties. Depending on the relative fraction of Au and Ag blocks, the intensity of the transverse modes varied without noticeable peak shifts. However, the strong intraparticle surface plasmon coupling resulted in the collective appearance of longitudinal LSP modes, including higher-order modes. The experimental observations were confirmed by theoretical calculation, using a discrete dipole approximation method. In addition, we will briefly discuss how single nanorod solar cells can be synthesized by using by using electrochemical deposition and AAO hard templates.

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Development of sensors with mode-selective measuring capability of ultrasonic waves traveling on a cylindrical shaft (축을 따라 전파되는 초음파 모드의 선택적 측정이 가능한 센서 개발)

  • Lee, Ho-Cheol
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.336-339
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    • 2007
  • A sensor having capability to measure two different kinds of ultrasonic waves selectively is described. Under the same bias field configuration, this magnetostrictive type sensor can selectively measure longitudinal waves and flexural ones. Since the switching operation of mode selection is made only by changing the polarity of the permanent magnets used to configure the bias field, it will be very useful after the permanent magnet are interchanged with electromagnets. In order to find the optimal operating bias field, finite elements analysis is used and the condition for flexural wave measurements to meet is found. The linearity of the sensor is verified by experiments and the requirements for linearity also are proposed.

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Scanning Tomographic Acoustic Microscope System by Using Transverse waves

  • Daesik Ko
    • The Journal of the Acoustical Society of Korea
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    • v.16 no.2E
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    • pp.21-26
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    • 1997
  • We propose to use transverse waves instead of longitudinal waves in a scanning tomographic acoustic microscope (STAM) and new type of multiple-transducer with the functions of muliple-angle and multiple-frequency tomography. Proposed multiple-transducer scheme has three insonification angles and three resonance frequencies in order to operate in the transverse wave mode and multiple-angle and multiple frequency tomography for the STAM. In order to evaluate the performance of proposed transducer scheme we have simulated tomographic reconstruction with back-and-forth propagation(BFP) algorithm. Simulation results showed proposed multiple-transducer scheme is capable of obtaining good resolution with transverse wave mode and multiple-frequency tomography. It is also showed that proposed scheme is an efficient rotation scheme by proportion to the number of projections.

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Experimental study of performance characteristics of various fin types for fin-tube heat exchanger (휜-관 열교환기에 있어서 각종 휜 형상의 성능 특성에 관한 실험적 연구)

  • Yoon, Baek;Kim, Young-Saeng;Park, Hwan-Young;Park, Hyun-Yeon
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.11 no.4
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    • pp.484-491
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    • 1999
  • Air side heat transfer and pressure drop for ø9.52 fin-tube heat exchanger with various types of slit and louver fins were measured, and compared with wave-slit fin. Longitudinal and transverse tube spacings of the heat exchangers are 21.65mm and 25mm respectively. Actual heat exchanger was tested using water, and the tests were performed for 2 row heat exchangers with 3 different fin spacings, 1.3, 1.5 and 1.7mm. The overall performance of the enhanced fins was evaluated by comparing heat transfer coefficient with respect to fan power.

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A Note on Vertical Motions of a Ship in Shallow Water (천수중(淺水中)에서의 파랑강제력(波浪强制力)과 선체응답(船體應答)에 관하여)

  • J.H.,Hwang;K.P.,Rhee;J.M.,Yoo
    • Bulletin of the Society of Naval Architects of Korea
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    • v.17 no.3
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    • pp.1-4
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    • 1980
  • It is well known that discrepancies between measured and predicted ship motions are significant in the range of low frequencies. In this paper, the vertical ship motions in regular longitudinal waves in a shallow water are briefly discussed. The investigation is focussed on the role of wave exciting forces and moments to the motion responses in these low frequencies. It is confirmed that diffraction forces are in general small in a shallow water as one may expect. Furthermore the wave exciting forces and moments on a displacement-type ship will be larger practicularly in low frequencies, when the contribution of the diffraction effect is neglected. As a result of this fact theoretically predicted responses for the pitch motion becomes closer to the experimental one. The discrepancies for the heave motion, however, are still apparent.

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