• 제목/요약/키워드: surface relaxation

검색결과 314건 처리시간 0.024초

인지질 유기박막의 유전특성에 관한 연구 (A Study on the Dielectric Properties of Phospholipid Organic Thin Films)

  • 송진원;이경섭
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 D
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    • pp.1983-1985
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    • 1999
  • The dielectric constant of a monolayer on a material surface was calculated with consideration of the local field acting on polar molecules with a permanent dipole moment, and the interaction working between the molecules and a material. It is revealed that the dielectric relaxation time r of monolayers in the isotropic polar orientational phase is determined using a linear relationship between the monolayers compression speed a and the molecular area. The dielectric relaxation time of phospholipid monolayers was examined on the basis of analysis developed here.

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Self-Relaxation for Multilayer Perceptron

  • Liou, Cheng-Yuan;Chen, Hwann-Txong
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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    • pp.113-117
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    • 1998
  • We propose a way to show the inherent learning complexity for the multilayer perceptron. We display the solution space and the error surfaces on the input space of a single neuron with two inputs. The evolution of its weights will follow one of the two error surfaces. We observe that when we use the back-propagation(BP) learning algorithm (1), the wight cam not jump to the lower error surface due to the implicit continuity constraint on the changes of weight. The self-relaxation approach is to explicity find out the best combination of all neurons' two error surfaces. The time complexity of training a multilayer perceptron by self-relaxationis exponential to the number of neurons.

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Photo-thermo-elastic interaction in a semiconductor material with two relaxation times by a focused laser beam

  • Jahangir, A.;Tanvir, F.;Zenkour, A.M.
    • Advances in aircraft and spacecraft science
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    • 제7권1호
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    • pp.41-52
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    • 2020
  • The effect of relaxation times is studied on plane waves propagating through semiconductor half-space medium by using the eigen value approach. The bounding surface of the half-space is subjected to a heat flux with an exponentially decaying pulse and taken to be traction free. Solution of the field variables are obtained in the form of series for a general semiconductor medium. For numerical values, Silicon is considered as a semiconducting material. The results are represented graphically to assess the influences of the thermal relaxations times on the plasma, thermal, and elastic waves.

내압을 받는 Y 배관의 크리프 수명 평가를 위한 3차원 응력해석 (3-Dimensional Stress Analysis for Creep Life Assessment of Y-Piece Under Inner Pressure)

  • 신규인;이진상;윤기봉
    • 한국안전학회지
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    • 제22권2호
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    • pp.22-27
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    • 2007
  • To assess a creep life of elevated temperature plant components, inspections and analysis are usually focused on the critical locations. In this study, stress analysis of a weld region in branch part of Y-piece was conducted by using a three-dimensional finite element analysis. The stresses at the inner and outer surface in the weld part were estimated by using elastic and elastic-creep analysis. For the elastic-creep analysis two kinds of elastic-creep analysis was conducted. The one was assumed that base and weld material properties were same and the other was that material properties were different between base and weld metal. The material properties of base and weld metal were used from reference data. The results showed the stress relaxation level and its location. The result stresses are also compared with elastic stresses.

p-n 접합에 있어서의 비등방성 응력효과 (Anisotropic stress Effects in p-n junction)

  • 손병기;이건일
    • 대한전자공학회논문지
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    • 제11권3호
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    • pp.22-26
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    • 1974
  • The effects of anisotropic mechanical stress applied normal to the surface of p-n junctions have been investigated. As the stress increased, the breakdown voltage was decreased and the breakdown mode became softer. Within a certain limitation in the applied stress, the above phenomena werw reversibbe, though relaxation and hysteresis phenomena were observed. The time constant of relaxation depended upon the shape of the stressing tip, but for the given tip and device a unique time constant was obtained. The stress.dependence of breakdown voltage showed a good linearity up to about 3.0${\times}10^4$ kgw/$\textrm{cm}^2$, when the flat tip of radius 15$\mu$ was used, and the temperatere-dependence of breakdown voltage under the stress also showed a good linearity in the temperature range of 100 to $300^{\circ}K$.

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A New Type of Nonthermal Plasma Reactor

  • Geum, Sang-Taek;Moon, Jae-Duk;Jun, Sun-Gon
    • The Korean Journal of Ceramics
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    • 제5권3호
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    • pp.245-249
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    • 1999
  • A new type of nonthermal plasma reactor utilizing ferroelectric pellets is proposed to generate nonthermal plasma efficiently, which is used for simultaneous control of various pollutant gases. Electric charges stored on ferroelctric pellets by corona discharge between a corona tip and a mesh electrode provide partial electrical discharges among ferroelectric pellets. These partial electrical discharges can enhance partial discharges around the surface of ferroelectric pellets. This method utilizes wide reacting area of ferroelectric pellets and partial discharge. Positive and negative dc voltage are applied to the corona tip to generate partial discharges, and corona currents are estimated to investigate charge storage on ferroelectric pellets as function of time and charge relaxation time constants of ferroelectric pellects. As a result, charge relaxationtime, dielectric constants of ferroelectric pellets, polarity of applied voltage and applied time influence partial discharges among ferroelectric pellect.

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Multi-cracking modelling in concrete solved by a modified DR method

  • Yu, Rena C.;Ruiz, Gonzalo
    • Computers and Concrete
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    • 제1권4호
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    • pp.371-388
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    • 2004
  • Our objective is to model static multi-cracking processes in concrete. The explicit dynamic relaxation (DR) method, which gives the solutions of non-linear static problems on the basis of the steady-state conditions of a critically damped explicit transient solution, is chosen to deal with the high geometric and material non-linearities stemming from such a complex fracture problem. One of the common difficulties of the DR method is its slow convergence rate when non-monotonic spectral response is involved. A modified concept that is distinct from the standard DR method is introduced to tackle this problem. The methodology is validated against the stable three point bending test on notched concrete beams of different sizes. The simulations accurately predict the experimental load-displacement curves. The size effect is caught naturally as a result of the calculation. Micro-cracking and non-uniform crack propagation across the fracture surface also come out directly from the 3D simulations.

자유냉각된 폴리카보네이트 평판에서의 열에 의한 복굴절 (Thermally-Induced Birefringence in Freely Quenched Plates of Polycarbonate)

  • 이호상
    • 소성∙가공
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    • 제16권3호
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    • pp.193-200
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    • 2007
  • Simulations of the thermally-induced residual stresses and birefringence in freely quenched plates of polycarbonate were performed by using the linear viscoelastic and photoviscoelastic constitutive equations for the mechanical and optical properties, respectively, and the first order rate equation for volume relaxation. The predictions for the birefringence showed good agreement with experimental measurements. However, for initial temperature close to the glass transition temperature, some differences existed around the surface layer. Based on the simulation, the influences of various cooling conditions on the residual stress and birefringence in plates were investigated. The residual stress and birefringence increased with increasing initial temperature, decreasing coolant temperature and increasing heat transfer coefficient of coolants.

위증(療證)으로 진단한 하지마비 환자의 치험 1례 (Clinical Observation on 1 Case of Both Leg Paralysis Patient Diagnosed Wei Symptom)

  • 위통순
    • 동의생리병리학회지
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    • 제20권3호
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    • pp.748-752
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    • 2006
  • Wei symptom(?證) is symptom that reveals muscle relaxation without contraction and muscle relaxation occurs in the lower or upper limb, in severe case, leads to death. This is the clinical report about the Wei symptom(?證)-patient doubt as Transverse Myelitis and Conversion Disorder. The patient was treated by acupuncture, moxibustion, herb medication(十全大補湯), electriccal stimulation theraphy, Bee Venom acupuncture, and had significant improvement in Wei symptom(?證). these results suggest the surface temperature differ remarkably from before being treated. The temperature is measured by using Digital Infrared Thermal Imaging(DITI). The results suggest that oriental medicare is an effective treatment for Wei symptom. We expected that therapeutic value of treatment of both leg Paralysis in the oriental medicine will be higher if more clinical studies and researches are accomplished.