• Title/Summary/Keyword: Wave focusing

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The Effect of Sex Role Stereotypes on Juvenile Delinquency Mediated by Stigma : Focusing on Gender Difference (청소년의 성역할고정관념이 낙인을 매개로 비행에 미치는 영향 : 성별차이를 중심으로)

  • Yang, Eun Byeor;Jin, Mi Seon;Oh, Su Kyung;Park, Si Ha;Chung, Ick Joong
    • Korean Journal of Child Studies
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    • v.35 no.5
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    • pp.99-111
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    • 2014
  • The purpose of this study was to investigate the relationship between sex role stereotypes and delinquency, and determine if it is mediated by stigma. The data was taken from the fourth wave of the 2010 Korea Youth Panel Survey(KYPS), which was administered by the Korea Youth Policy Institute. The major findings are as follows: First, sex role stereotypes were found to increase stigma and delinquency. Second, the relationship between sex role stereotypes and delinquency is mediated by stigma. Third, the results revealed that there was a significant gender difference in mediating models. As for the female participants, stigma had a mediating effect in the relationship between sex role stereotyping and delinquency. In contrast, for the male participants, the mediating effect of stigma was found to be insignificant. Based on these results, this research suggested that delinquency prevention programs need improvement considering gender difference and sex role stereotypes.

Bandgap capability of hybrid Kirigami inspired cellular structures

  • Del Broccolo, S.;Ouisse, M.;Foltete, E.;Scarpa, F.
    • Advances in aircraft and spacecraft science
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    • v.6 no.6
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    • pp.479-495
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    • 2019
  • Periodic cellular core structures included in sandwich panels possess good stiffness while saving weight and only lately their potential to act as passive vibration filters is increasingly being studied. Classical homogeneous honeycombs show poor vibracoustic performance and only by varying certain geometrical features, a shift and/or variation in bandgap frequency range occurs. This work aims to investigate the vibration filtering properties of the AUXHEX "hybrid" core, which is a cellular structure containing cells of different shapes. Numerical simulations are carried out using two different approaches. The first technique used is the harmonic analysis with commercially available software, and the second one, which has been proved to be computationally more efficient, consists in the Wave Finite Element Method (WFEM), which still makes use of finite elements (FEM) packages, but instead of working with large models, it exploits the periodicity of the structure by analysing only the unit cell, thanks to the Floquet-Bloch theorem. Both techniques allow to produce graphs such as frequency response plots (FRF's) and dispersion curves, which are powerful tools used to identify the spectral bandgap signature of the considered structure. The hybrid cellular core pattern AUXHEX is analysed and results are discussed, focusing the investigation on the possible spectral bandgap signature heritage that a hybrid core experiences from their "parents" homogeneous cell cores.

The Determinants of Corporate Training in Korea - Market Failure and State Intervention - (한국 기업의 교육훈련 결정요인 - 시장실패와 정부 개입을 중심으로 -)

  • Kim, Ahn-Kook
    • Journal of Labour Economics
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    • v.31 no.1
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    • pp.105-133
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    • 2008
  • Focusing market failure and state intervention, this article analyzes the determinants of corporate training in Korea. Analysing the first wave of HCCP(Human Capital Corporate Panel) data produced by KRIVET(Korea Research Institute for Vocational Education and Training), this article finds that even though the skills attainead in corporate in Korea are mostly general(industry-specific), but the market failure in training appears rather small and is confined to the manufacturing industry. And the state intervention in corporate training works only at manufacturing industry, it does not work at new service industry. The results mean that in new service industry, it is difficult to find out the existence of market failure in training due to the positive externalities. Therefore Korea government should look thoroughly into the state intervention in training in new service industry.

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The design and characteristics of disk-type ultrasonic motor (디스크타입 초음파모터의 제작 및 특성평가)

  • Yun, Yong-Jin;Park, Sung-Hee;Kang, Sung-Hwa;Lim, Ki-Joe
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.11a
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    • pp.232-233
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    • 2005
  • In this paper, disk-type ultrasonic motor using a combination of radial and bending vibration modes is newly designed and fabricated. The characteristics of the test motor are also measured. By means of travelingelastic wave induced at the surface of circumference of the elastic disk, a steel bar in contact with the surface of circumference of elastic disk bonded onto the piezoelectric ceramic disks is driven inboth directions by changing the sine and cosine voltage inputs. The stator of the motor is composed of two sheets of piezoelectric ceramic disk to bond onto both surfaces of a elastic disk, respectively. As the results, the diameter of elastic body is increased, the resonant frequency is decreased. The resonant frequency of the stator is about 92 kHz, which is composed with piezoelectric ceramic disks of 28 mm in diameter and 2 mm in thickness, and an elastic body of 32 mm in diameter and 2 mm in thickness. A driving voltage of 20 Vpp produces 200 rpm with a torque of 1Nm and an efficiency of about 10 %.

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Nonlinear guided-wave properties in planar waveguides with two nonlinear bounding thin films (비선형 박막으로 둘러싸인 평면 광도파로에서의 비선형 도파광 특성)

  • 정종술;송석호;이일항
    • Korean Journal of Optics and Photonics
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    • v.7 no.2
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    • pp.136-141
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    • 1996
  • We present a novel description of TE nonlinear guided waves in planar waveguides with two nonlinear bounding thin films. The nonlinear dispersion relations of the nonlinear waveguides are obtained by adopting the nonlinear transfer matrix. The optical properties obtained from these equations include: the power dependence of mode indices, the transition of the field maximum location, and the power distribution. The planar waveguide with self-focusing nonlinear layers shows the optical bistability of power-dependent mode indices, and the critical powers for the optical bistability increase with decreasing thickness of the nonlinear layers. The power distributions display the optical bistabilities, similar to those of nonlinear Fabry-Perot etalon.

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Expert Suggestions for the Implementation of Science and Engineering Integrated Lesson in Middle Science Classrooms (과학·공학 융합 수업의 중학교 현장적용을 위한 전문가 제안)

  • Yi, Hyojin;Nam, Younkyeong
    • Journal of Engineering Education Research
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    • v.23 no.3
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    • pp.20-31
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    • 2020
  • The purpose of this study is to suggest a meaningful way of implementing science and engineering integrated lessons in school science settings. To this end, two types of science and engineering integrated lesson units (focusing on the physic concepts of light and wave) were developed based on the core elements of science and engineering integrated lesson; object, context, engineering design, and connection with science. These two units were implemented in free semester program in a middle school in a metropolitan city. Throughout the process of program implementation, instructor's reflection and focus group interview with participant students were collected to reveal problems arising from the field implementation. In addition, engineering education experts were interviewed to discuss the potential problems and possible solutions for the problems. As results of the study, five main problems of implementing escience and engineering integrated lessons in a school science setting were revealed and practical solutions for the problems were suggested by the experts.

Thermal instability during the melting process in an isothermally heated horizontal cylinder (등온가열 수평원관내 융해과정동안의 열적 불안정성)

  • Jeong, Jae-Dong;Yu, Ho-Seon;Lee, Jun-Sik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.6
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    • pp.2046-2056
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    • 1996
  • The constrained melting inside an isothermally heated horizontal cylinder has been repeatedly investigated in many studies only for the moderate Rayleigh numbers. This study extends the range of Rayleigh numbers to systematically investigate the transition during melting processes, especially focusing on the complex multi-cellular flow pattern and thermal instability. The enthalpy-porosity formulation, with appropriate source terms to account for the phase change, is employed. For low Rayleigh numbers, initially developed single-cell base flow keeps the flow stable. For moderate Rayleigh numbers, even small disturbances in balance between thermal buoyance force and viscous force result in branched flow structure. For high Rayleight numbers, Benard type convection is found to develop within a narrow gap between thee wall and the unmelted solid. The marginal Rayleigh number and the corresponding wave number are in excellent agreement with those from linear stability theory.

Diffraction-Limited High-Power Single-Cycle Terahertz Pulse Generation in Prism-Cut LiNbO3 for Precise Terahertz Applications

  • Baek, In Hyung;Kang, Bong Joo;Jeong, Young Uk;Rotermund, Fabian
    • Journal of the Optical Society of Korea
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    • v.18 no.1
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    • pp.60-64
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    • 2014
  • We report the generation of 3.3-mW single-cycle terahertz (THz) pulses at 1-kHz repetition rate via optical rectification in MgO-doped prism-cut stoichiometric LiNbO3. Efficient pulse-front tilting of 800-nm pulses was realized by an optimized single-lens focusing scheme for radially-symmetric propagation of THz beams. In this geometry, nearly-diffraction-limited THz Gaussian beams with electric field strength as high as 350 kV/cm were generated. The pump-to-THz energy conversion efficiency of $1.36{\times}10^{-3}$ and the extremely high signal-to-noise ratio of ~1:15000 achieved are among the best results for 1-kHz single-cycle terahertz pulse generation ever demonstrated in room temperature operation.

3D Simulation of Earthquake Ground Motion Using Locally Variable Time-Step Finite-Difference Method

  • Kang, Tae-Seob;Baag, Chang-Eob
    • Proceedings of the International Union of Geodesy And Geophysics Korea Journal of Geophysical Research Conference
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    • 2003.05a
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    • pp.18-18
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    • 2003
  • Three-dimensional finite-difference simulation of earthquake ground motion is performed using a locally variable time-step (LVTS) scheme matching with discontinuous grids. Discontinuous grids in three directions and extension of the discontinuous grids' boundary to the free-surface in the LVTS scheme minimize the cost of both the computational memory and the CPU time for models like the localized sedimentary basin. A simplified model of sedimentary basin is dealt to show the feasibility and efficiency of the LVTS scheme. The basin parameters are examined to understand the main characteristics on ground-motion response in the basin. The results show that the seismic energy is concentrated on a marginal area of the basin far from the source. This focusing effect is mainly due to the constructive interference of the direct S-wave with the basin-edge induced surface waves. The ground-motion amplification over the deepest part of the basin is relatively lower than that above the shallow basin edge. Therefore the ground-motion amplification may be more related to the source azimuth or the direction of the incident waves into the basin rather than the depth of it.

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Study on the Editorial Fashion Styling of Korean Image - Focusing on Vogue Korea - (한국적 이미지에 관한 에디토리얼 패션 스타일링 연구 - 보그 코리아를 중심으로 -)

  • Jung, Seung-Yean;Lee, In-Seong
    • Journal of the Korea Fashion and Costume Design Association
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    • v.16 no.4
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    • pp.37-47
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    • 2014
  • Recently, the Korean wave has caused many foreign nations to pay attention to various fields including Korean culture, arts, fashion and beauty. Korean images so far were mainly discussed in terms of aesthetics, and there is lack of efforts to visually shape Korean images. On the contrary, Oriental images focused around Japan and China have greater global influence and better globalized fashion styles compared to Korea. Therefore, it is necessary to suggest a globalized proposal of Korean fashion styling which reflects original and unique aesthetic characteristics of Korea that can be accepted by the global market. In this study, the concept and types of fashion styling and stylists were examined, as well as the definition of Korean image and types and characteristics of Korean images shown on fashion magazines. Also, after collecting photographs having Korean images that were included in the editorial fashion styling of Vogue Korea, their characteristics were analyzed. The results of interviews with professional fashion stylists were summarized to propose an editorial fashion styling with Korean image for overseas consumers who long for and wish to imitate Korean fashion styling.

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