• Title/Summary/Keyword: potential function

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Electro-elastic analysis of a sandwich thick plate considering FG core and composite piezoelectric layers on Pasternak foundation using TSDT

  • Mohammadimehr, Mehdi;Rostami, Rasoul;Arefi, Mohammad
    • Steel and Composite Structures
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    • v.20 no.3
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    • pp.513-543
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    • 2016
  • Third order shear deformation theory is used to evaluate electro-elastic solution of a sandwich plate with considering functionally graded (FG) core and composite face sheets made of piezoelectric layers. The plate is resting on the Pasternak foundation and subjected to normal pressure. Short circuited condition is applied on the top and bottom of piezoelectric layers. The governing differential equations of the system can be derived using Hamilton's principle and Maxwell's equation. The Navier's type solution for a sandwich rectangular thick plate with all edges simply supported is used. The numerical results are presented in terms of varying the parameters of the problem such as two elastic foundation parameters, thickness ratio ($h_p/2h$), and power law index on the dimensionless deflection, critical buckling load, electric potential function, and the natural frequency of sandwich rectangular thick plate. The results show that the dimensionless natural frequency and critical buckling load diminish with an increase in the power law index, and vice versa for dimensionless deflection and electrical potential function, because of the sandwich thick plate with considering FG core becomes more flexible; while these results are reverse for thickness ratio.

Navigation Technique of Unmanned Vehicle Using Potential Field Method (포텐셜 필드 기법을 이용한 무인차량의 자율항법 개발)

  • Lee, Sang-Won;Moon, Young-Geun;Kim, Sung-Hyun;Lee, Min-Cheol
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.4
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    • pp.8-15
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    • 2011
  • This paper proposes a real-time navigation algorithm which integrates the artificial potential field (APF) for an unmanned vehicle in the unknown environment. This approach uses repulsive potential function around the obstacles to force the vehicle away and an attractive potential function around the goal to attract the vehicle. In this research, laser range finder is used as range sensor. An obstacle detected by the sensor creates repulsive vector. Differential global positioning system (DGPS) and digital compass are used to measure the current vehicle position and orientation. The measured vehicle position is also used to create attractive vector. This paper proposes a new concept of potential field based navigation which controls unmanned vehicle's speed and steering. The magnitude of repulsive force based on the proposed algorithm is designed not to be over the magnitude of attractive force while the magnitude is increased linearly as being closer to obstacle. Consequently, the vehicle experiences a generalized force toward the negative gradient of the total potential. This force drives the vehicle downhill towards its goal configuration until the vehicle reaches minimum potential and it stops. The effectiveness of the proposed APF for unmanned vehicle is verified through simulation and experiment.

Reduced Mass Effects on the Ring Inversion Vibration of 1,3-Cyclohexadiene (1,3-Cyclohexadiene의 고리반전 진동운동에 미치는 환산질량 효과)

  • Choo, Jae Bum;Han, Seong Jun
    • Journal of the Korean Chemical Society
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    • v.41 no.3
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    • pp.123-129
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    • 1997
  • In order to consider the reduced mass effects on the out-of-plane ring inversion vibration of 1,3-CHD, the vector-based computer program has been written and the kinetic energy expansion function for the large amplitude ring inversion vibration has been calculated using this program. The structural parameters for the calculations have been determined from the ab initio HF/6-31G** calculation. The potential energy function for the out-of-plane ring inversion vibration of 1,3-CHD has been determined from the kinetic energy expansion function and previously reported low-frequency Raman data. The vibrational Hamiltonian calculation including kinetic energy expansion function made it possible to determine the more reliable out-of-plane potential energy function for the ring inversion of 1,3-CHD.

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Channel Function of TRPML1 Prompts Lipolysis in Mature Adipocytes

  • Kim, Mi Seong;Kim, Min Seuk
    • International Journal of Oral Biology
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    • v.43 no.1
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    • pp.23-27
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    • 2018
  • Increased intracellular levels of $Ca^{2+}$ are generally thought to negatively regulate lipolysis in mature adipocytes, whereas store-operated $Ca^{2+}$ entry was recently reported to facilitate lipolysis and attenuate lipotoxicity by inducing lipophagy. Transient receptor potential mucolipin1 (TRPML1), a $Ca^{2+}$-permeable non-selective cation channel, is mainly expressed on the lysosomal membrane and plays key roles in lysosomal homeostasis and membrane trafficking. However, the roles of TRPML1 in lipolysis remains unclear. In this study, we examined whether the channel function of TRPML1 induces lipolysis in mature adipocytes. We found that treatment of mature adipocytes with ML-SA1, a specific agonist of TRPML1, solely upregulated extracellular glycerol release, but not to the same extent as isoproterenol. In addition, knockdown of TRPML1 in mature adipocytes significantly reduced autophagic flux, regardless of ML-SA1 treatment. Our findings demonstrate that the channel function of TRPML1 partially contributes to lipid metabolism and autophagic membrane trafficking, suggesting that TRPML1, particularly the channel function of TRPML1, is as therapeutic target molecule for treating obesity.

Analysis of Subthreshold Current Deviation for Gate Oxide Thickness of Double Gate MOSFET (게이트 산화막 두께에 따른 이중게이트 MOSFET의 문턱전압이하 전류 변화 분석)

  • Jung, Hakkee;Jeong, Dongsoo;Lee, Jong-In;Kwon, Oshin
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.05a
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    • pp.762-765
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    • 2013
  • This paper analyzed the change of subthreshold current for gate oxide thickness of double gate(DG) MOSFET. Poisson's equation had been used to analyze the potential distribution in channel, and Gaussian function had been used as carrier distribution. The potential distribution was obtained as the analytical function of channel dimension, using the boundary condition. The subthreshold current had been analyzed for gate oxide thickness, and projected range and standard projected deviation of Gaussian function. Since this analytical potential model was verified in the previous papers, we used this model to analyze the subthreshold current. Resultly, we know the subthreshold current was influenced on parameters of Gaussian function and gate oxide thickness for DGMOSFET.

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Analysis of Subthreshold Current Deviation for Gate Oxide Thickness of Double Gate MOSFET (채널도핑농도에 따른 이중게이트 MOSFET의 문턱전압이하 전류 변화 분석)

  • Jung, Hakkee
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.05a
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    • pp.768-771
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    • 2013
  • This paper analyzed the change of subthreshold current for channel doping concentration of double gate(DG) MOSFET. Poisson's equation had been used to analyze the potential distribution in channel, and Gaussian function had been used as carrier distribution. The potential distribution was obtained as the analytical function of channel dimension, using the boundary condition. The subthreshold current had been analyzed for channel doping concentration, and projected range and standard projected deviation of Gaussian function. Since this analytical potential model was verified in the previous papers, we used this model to analyze the subthreshold current. As a result, we know the subthreshold current was influenced on parameters of Gaussian function and channel doping concentration for DGMOSFET.

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Gate Oxide Dependent Subthreshold Current of Double Gate MOSFET (이중게이트 MOSFET의 문턱전압이하 전류에 대한 게이트 산화막 의존성)

  • Jung, Hakkee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.2
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    • pp.425-430
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    • 2014
  • This paper analyzed the change of subthreshold current for gate oxide thickness of double gate(DG) MOSFET. Poisson's equation had been used to analyze the potential distribution in channel, and Gaussian function had been used as carrier distribution. The potential distribution was obtained as the analytical function of channel dimension, using the boundary condition. The subthreshold current had been analyzed for gate oxide thickness, and projected range and standard projected deviation of Gaussian function. Since this analytical potential model was verified in the previous papers, we used this model to analyze the subthreshold current. Resultly, analytical model showed that subthreshold current was influenced by parameters of Gaussian function and gate oxide thickness of DGMOSFET.

Calculation of Stress Intensity Factors Using Single-Layer Potential and Weight Function (Single-Layer 포텐셜과 가중함수를 이용한 응력강도계수의 계산)

  • 이형연;홍창선
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.4
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    • pp.981-989
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    • 1995
  • A new weight function approach to determine SIF(stress intensity factor) using single-layer potential has been presented. The crack surface displacement field was represented by one boundary integral term whose kernel was modified from Kelvin's fundamental solution. The proposed method enables the calculation of SIF using only one SIF solution without any modification for the crack geometries symmetric in two-dimensional plane such as a center crack in a plate with or without an internal hole, double edge cracks, circumferential crack or radial cracks in a pipe. The application procedure to those crack problems is very simple and straightforward with only one SIF solution. The necessary information in the analysis is two reference SIFs. The analysis results using present closed-form solution were in good agreement with those of the literature.

L2 HARMONIC FORMS ON GRADIENT SHRINKING RICCI SOLITONS

  • Yun, Gabjin
    • Journal of the Korean Mathematical Society
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    • v.54 no.4
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    • pp.1189-1208
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    • 2017
  • In this paper, we study vanishing properties for $L^2$ harmonic 1-forms on a gradient shrinking Ricci soliton. We prove that if (M, g, f) is a complete oriented noncompact gradient shrinking Ricci soliton with potential function f, then there are no non-trivial $L^2$ harmonic 1-forms which are orthogonal to df. Second, we show that if the scalar curvature of the metric g is greater than or equal to (n - 2)/2, then there are no non-trivial $L^2$ harmonic 1-forms on (M, g). We also show that any multiplication of the total differential df by a function cannot be an $L^2$ harmonic 1-form unless it is trivial. Finally, we derive various integral properties involving the potential function f and $L^2$ harmonic 1-forms, and handle their applications.

A Far Field Solution of the Slowly Varying Drift Force on the Offshore Structure in Bichromatic Waves-Three Dimensional Problems

  • Lee, Sang-Moo
    • Journal of Ocean Engineering and Technology
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    • v.24 no.6
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    • pp.1-6
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    • 2010
  • A far field approximate solution of the slowly varying force on a 3 dimensional offshore structure in gravity ocean waves is presented. The first order potential, or at least the far field form of the Kochin function, of each frequency wave is assumed to be known. The momentum flux of the fluid domain is formulated to find the time variant force acting on the floating body in bichromatic waves. The second order difference frequency force is identified and extracted from the time variant force. The final solution is expressed as the circular integration of the product of Kochin functions. The limiting form of the slowly varying force is identical to the mean drift force. It shows that the slowly varying force components caused by the body disturbance potential can be evaluated at the far field.