• Title/Summary/Keyword: energy direction

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Analysis of Sea Surface Wind over the Complex Coastal Area Using SAR images (SAR영상에 의한 복잡해안지역 해상풍 분석)

  • Hwang, Hyo-Jung;Kim, Hyun-Goo
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.482-483
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    • 2009
  • This paper is foundation paper about national wind map verification using remote sensing, based on analysis of comparison between numerical simulation and remote sensing on complex coastal area of regional coast. As a result analysis using NCAR/NCEP, wind direction of numerical simulation and remote sensing is same. but, wind direction of some case is showed different. Such as this result, if it would be used without verification of analyzed data, present ability of occurring lots of error, and it will be verified based on using survey data or atmospheric data.

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A Study on dynamic Fracturing Behavior of Anisotropic Granite by SHPB Test (스플릿 흡킨슨 바(SHPB)를 이용한 이방성 화강암의 동적파괴거동 연구)

  • Choi, Mi-Jin;Cho, Sang-Ho;Yang, Hyung-Sik
    • Tunnel and Underground Space
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    • v.18 no.3
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    • pp.214-218
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    • 2008
  • Dynamic fracturing of anisotropic granite was investigated by SHPB (Split Hopkinson Pressure Bar). Energy absorption during the test and maximum stress were increased as strain rate increased. Maximum stresses in every direction were dependent on the strain rate but not so sensitive to anisotropy. Elastic wave velocity was decreased as strain rate increased and dependent on strain rate in every direction. Especially, elastic wave velocity decreased more rapidly in a strong rock.

Possibility of Wind Power Generation by a Vehicle-Induced Wind at the Median Strip on Hightway (주행차량에 의한 중앙분리대 유도풍의 풍력발전 활용 가능성)

  • Woo, Sang-Woo;Kim, Hyun-Goo;Jang, Moon-Seok;Shin, Hyung-Ki
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.10a
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    • pp.315-317
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    • 2008
  • The purpose of this study is to confirm the possibility of wind power generation by a vehicle-induced at the median strip on highway. In order to find out wind field information, a CFD method was used. According to the simulation results, the x, y, z-component of the wind velocity around a median strip are rapidly changed at near before and behind a moving vehicle. The x-component of the wind velocity appears high within the range of the length of the passing vehicle, and the wind direction appeared in the opposite direction at the behind of a vehicle. However, x and y-components of the wind velocity at the behind of vehicle are shown constantly. We confirmed possibility of wind power generation using a vehicle-induced wind at the median strip.

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EFFECT OF POROSITY ON THE TRANSIENT MHD GENERALIZED COUETTE FLOW WITH HEAT TRANSFER IN THE PRESENCE OF HEAT SOURCE AND UNIFORM SUCTION AND INJECTION

  • Attia, Hazem Ali;Ewis, Karem Mahmoud;Awad-Allah, Nabil Ahmed
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.16 no.2
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    • pp.125-135
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    • 2012
  • The transient magnetohydrodynamic (MHD) generalized Couette flow with heat transfer through a porous medium of an electrically conducting, viscous, incompressible fluid bounded by two parallel insulating porous plates is studied in the presence of uniform suction and injection and a heat source considering the Hall effect. A uniform and constant pressure gradient is imposed in the axial direction and an externally applied uniform magnetic field as well as a uniform suction and injection are applied in the direction perpendicular to the plates. The two plates are kept at different but constant temperatures while the Joule and viscous dissipations are included in the energy equation. The effect of the Hall current, the porosity of the medium and the uniform suction and injection on both the velocity and temperature distributions is investigated.

Multidirectional Liquid Crystal Orientation by Using Ion Beam Irradiation

  • Ahn, Han-Jin;Kim, Kyung-Chan;Kim, Jong-Bok;Hwang, Byung-Har;Baik, Hong-Koo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.543-546
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    • 2005
  • We have investigated the alignment ability of multi-domains by using ion beam irradiation on diamond-like carbon (DLC) thin film layers. The DLC thin films were deposited by plasma enhanced chemical vapor deposition (PECVD) system and the low energy ion beam is irradiated from Kaufman type ion gun. The direction of liquid crystal alignment is varied by the direction of Ar ion beam irradiation.

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Magnetization Curves Measurement for Fundamental Characteristics Analysis of Disk-type Single Phase SRM (Disk형 단상 SRM의 기본 특성 해석을 위한 자화곡선 측정)

  • Lee, Chung-Won;Lee, Jong-Han;Lee, Eun-Woong;Oh, Young-Woong
    • Proceedings of the KIEE Conference
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    • 2003.04a
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    • pp.91-93
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    • 2003
  • Disk type Single Phase SRM(Switched Reluctance Motor) can be used axial direction magnetic flux and radial direction magnetic flux. In this paper, the flux linkage was measured according as rotor positions of disk-tyre single phase SRM, which is designed and manufactured in previous research. From the measured data, we got the magnetization curves, inductance profile and Co-energy.

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The Effect of Phenoxymethyl Side Groups on the Liquid Crystal Alignment Behavior of Polystyrene Derivatives

  • Kang, Hyo;Lee, Jong-Chan;Kang, Dae-Seung
    • Macromolecular Research
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    • v.17 no.7
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    • pp.506-515
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    • 2009
  • We synthesized a series of polystyrene derivatives containing various side chain terminal moieties, such as phenoxymethyl, 4-methoxyphenoxymethyl, 4-fluorophenoxymethyl, 4-methylphenoxymethyl, and 4-trifluoromethoxyphenoxymethyl groups, using polymer analogous reactions, in order to investigate the effect of the side group on their liquid crystal (LC) alignment behaviors. The polymers containing 4-fluorophenoxymethyl, 4-methylphenoxymethyl, or 4-trifluoromethoxyphenoxymethyl side groups had lower surface energy values and the LC cells fabricated using the unrubbed films of these polymers showed homeotropic LC alignment behavior. The LC cells fabricated using the rubbed films of the polymers containing phenoxymethyl or 4-fluorophenoxymethyl groups showed homogeneous planar LC alignment behavior in which the LCs were aligned perpendicular to the rubbing direction. This homogeneous planar and perpendicular alignment behavior was ascribed to the favorable anisotropic interactions between the LC molecules and the side groups preferentially oriented perpendicular to the rubbing direction.

Study on Present Status and Future Direction of Korean Offshore Wind Power (한국의 해상풍력 현황과 발전방향에 관한 연구)

  • Sung, Jin Ki;Lee, Tae Jin
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.3
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    • pp.312-321
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    • 2013
  • In this study, we review the status of Southwest sea 2.5GW offshore wind project and expected various problems. And we suggest government policies for offshore wind industrialization. Especially, we would like to mention the necessity of offshore wind development in order to diversify power sources and guarantee energy security in Korea. And we would like to mention necessity and direction to make offshore wind into growth engine industry thorough fusion between industries and energization for the existing industry such as civil, shipbuilding, steel, etc. that was headed into downturn.

Magnetic Properties of Ordered L12 FePt3: A First Principles Study

  • Kim, Dong-Yoo;Hong, Ji-Sang
    • Journal of Magnetics
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    • v.16 no.3
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    • pp.197-200
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    • 2011
  • Using the full potential linearized augmented plane wave (FLAPW) method, the influences of uniform and tetragonal strains on the magnetic state have been explored for chemically ordered bulk $L1_2$ $FePt_3$. The ordered state displays antiferromagnetic $Q_1$ (AFM-$Q_1$) state but it transitions into antiferromagnetic $Q_2$ (AFM-$Q_2$) state at about 10% uniform strain. The ferromagnetic (FM) state is observed at 11% uniform strain. For tetragonal strain, it is also seen that the transition from AFM-$Q_1$ to AFM-$Q_2$ depends on the strength and direction of the applied strain. The FM state does not appear in this case. Magnetocrystalline anisotropy (MCA) calculations for tetragonal distortion reveal that the spin reorientation transition occurs. In addition, we find that the direction of magnetization and the magnitude of magnetic anisotropy energy strongly depend on the c/a ratio.

An Experimental Study on Heat Transfer Characteristics of Thermal Diode Type Enclosure Cavity (熱다이오식 밀폐공간의 熱傳達 特性에 關한 實驗的 硏究)

  • 장영근;김석현
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.12
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    • pp.1073-1080
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    • 2000
  • Thermal diode is a device which allows heat to be transferred in one direction by convection due to density difference of fluid ,and blocks heat flow in the opposite direction. It is simple in construction and low in cost. And so, it is used as heat collection system of solar energy. In order to acquire a basic design data, thermal diode heat collection system has been studied experimentally for flux Rayleigh numbers from $2\times10^8\;to\;8\times10^8$. The heat transfer rate of this system is shown 10~47% higher than that of other earlier research results. He correlation obtained in this study is Nu=0.0037(Ra^*)^{0.429}(d^*)^{0.05}\frac{(Lr)}{H}^{0.415}$.

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