• Title/Summary/Keyword: Focusing wave

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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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The Effect of Parenting Styles on Private Educational Expenditure and Academic Performance of Children: Focusing on Mediation Effect of Private Educational Expenditure (부모의 양육유형이 사교육비지출과 자녀의 학업성적에 미치는 영향: 사교육비지출의 매개효과를 중심으로)

  • Lee, Seonglim
    • Human Ecology Research
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    • v.56 no.5
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    • pp.461-472
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    • 2018
  • Using a sample of third grade middle school students from the forth wave of Children and Youth Panel Survey in 2012, the mediation effects of private educational expenditure between parenting styles and children's academic performance were investigated by applying factor, cluster, tobit, and two stage regression analysis. The major results were as follows. First, four types of parenting style were identified. The most frequent parenting style was ambivalent parenting (tiger parenting) which was followed by authoritative parenting. Second, compared to permissive parenting style, ambivalent, authoritative, and authoritarian parenting styles were significantly associated with more private educational expenditures. Third, more private educational expenditures were significantly associated with higher academic performance of children. I found both a full mediation effect of private educational expenditure for ambivalent and authoritarian parenting styles, and a partial mediation effect for authoritative parents. Authoritative parenting style has a negative moderating effect on the relationship between household income and private educational expenditure, along with a positive direct effect on the academic performance of children. The results suggested that an authoritative parenting style was related with higher academic performance of children with less private educational expenditures compared to other parenting styles. The results also implied that the public policies to enhance authoritative parenting style among parents would be effective to reduce household's private educational expenditures.

A Study on the Interactive space of Contemporary City - focused on interactive space of citize - (현대도시에서 나타나는 상호작용 공간에 대한 연구 - 시민과 상호작용하는 공간을 중심으로 -)

  • Koh, Gwi-Han;Kim, Jung-Gon
    • Korean Institute of Interior Design Journal
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    • v.21 no.5
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    • pp.57-64
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    • 2012
  • The ideologie of modern society as per something to phenomenology problem is to show various different looks. The community space is spring from Greek and Roman of community place by agora and forum is make a active communicate to interpersonally. Subject to centrically In the context, this paper is study on the Sustainable development for community space about interactive space. and focusing is Response to human of interact in each other intelligent space. And this paper suggestion is composition method of community space in technology advanced, Interactive interface form for human, sustainable to community space direction elements. First, I'll rearrange the distinctive features of modern society through references of various scholars. This is to understand how interactivity affects the whole society and what is the importance of this interactive wave. Second, I'll analyze several trends of modern community space and figure the change of methodology of design based on the advancement of design technology. This is to understand the interactive relation of the subjects. Third, I'll seek how community space design has changed in modern society and under which process design is made. This is to clarify the fact that the portion of interaction will increase in future design according to the intervention of equipment, which is one of the objects of interaction space.

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