• International Journal of Fuzzy Logic and Intelligent Systems
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• 제5권4호
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• pp.339-346
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• 2005

Artificial potential field (APF) is a widely used method for local path planning of autonomous mobile robot. So far, many different types of APF have been implemented. Once the artificial potential functions are selected, how to choose appropriate parameters of the functions is also an important work. In this paper, a detailed analysis is given on how to choose proper parameters of artificial functions to eliminate free path local minima and avoid collision between robots and obstacles. Two kinds of potential functions: Gaussian type and Quadratic type of potential functions are used to solve the above local minima problem respectively. To avoid local minima occurred in realistic situations such as 1) a case that the potential of the goal is affected excessively by potential of the obstacle, 2) a case that the potential of the obstacle is affected excessively by potential of the goal, the design guidelines for selecting appropriate parameters of potential functions are proposed.

• Bulletin of the Korean Chemical Society
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• 제21권7호
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• pp.727-733
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• 2000

Analytical potential energy surfaces have been constructed for the four-center elimination of HCI from 1,1-dichloroethylene.The potential functions are Morse-type functions which are modified by appropriate switching and attenuating functions with adjustable parameters. The parameters have been found by fitting the calculated vibrational frequencies, reaction endothermicity, equlibrium geometries of the reactant and products to those of experiments and ab initio calculations. The translational energy release obtained from classical trajectory calculations on this surface is in good agreement with the experiment.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.201-202
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• 2019

This paper aimed to identify potential opportunities of building information modeling (BIM) utilization for construction risk management. Construction risk factors and BIM functions were derived through conducting in-depth literature review. Nineteen construction risk factors could be resolved by various BIM functions. Phase planning, site analysis, design authoring, and 3D design coordination were identified as the most efficient BIM functions for construction risk management.

• 대한화학회지
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• 제56권6호
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• pp.669-672
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• 2012

Classical molecular dynamics (MD) simulations using a scaled OSS2 potential originally derived from ab initio calculations are used to study the radial distribution functions of water. The original OSS2 water potential is shown to represent a glassy or an ice at ambient temperature, but the diffusion coefficient increases on increasing the temperature of the system or decreasing the density. This suggests scaling the OSS2 potential. The O-O, O-H, and H-H radial distribution functions and the corresponding coordination numbers for the scaled OSS2 potential, obtained by MD simulation, are in good agreement with the experiment results and calculations for the SPC/E water potential over a range of temperatures.

• 제어로봇시스템학회논문지
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• 제19권4호
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• pp.349-356
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• 2013

This paper presents formation control based on potential functions for unicycle robots. The unicycle robots move to formation position which is made from a reference point and neighboring robots. In the framework, a local minimum case occurred by combination of potential repulsed from neighboring robots and potential attracted from a formation line is presented, in which the robot escapes from a local minimum using a virtual escape point after recognizing trapped situation. As well, in the paper, potential functions are designed to keep the same distance between neighboring robots on a formation line, i.e. the relative distance between neighboring robots on a formation line is controlled by a potential function parameter. The simulation results show that the proposed approach can effectively construct straight line, V, and polygon formation for multiple robots.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.1317-1322
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• 2001

What changes in the eigen values and eigen functions are produced if the boundary surface S is no longer rigid but has a specific acoustic admittance which may vary from point to point on S. In this paper, changes in eigen values and eigen functions are derived by using Kirchhoff-Helmholtz integral equation. And acoustic potential energy, which is representative measure describing the physical quantity in cavity, is defined. Acoustic potential energy can be divided into primary one and secondary one. Primary one is the acoustic potential energy through unchanged eigen functions, and secondary one is through changed eigen functions. Using these two term, we can find the eigenvalue problem, which gives the control performance when the boundary condition is changed.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.1204-1207
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• 2002

The fixed points of two known gradient flows defined on adjoint orbits of orthogonal groups are analyzed through the critical point analysis of the potential functions. The results show that some known properties of these gradient flows are shared with the gradient flows of the same potential functions with respect to other metrics.

• 한국세라믹학회지
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• 제23권5호
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• pp.47-54
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• 1986

The structures of crystalline vitreous and liquid $SiO_2$ were Monte carlo simulated employing the potential energy function comprising Lennard-Jones 2-body and Axilrod-Teller 3-body potentials. Although the Si-O-Si angular distribution functions obtained in the simulation appear to be higher than the experimental results the other simulation results including SiO, O-O and Si-Si radial distribution functions and O-Si-O anglular distribution functions agree well with experimental data within acceptable limits. Themost important outcome in this study is that various $SiO_2$forms were successfully reproduced with the same potential energy function.

• 한국항공우주학회지
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• 제36권5호
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• pp.448-454
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• 2008

본 논문에서는 포텐셜 함수와 슬라이딩 모드 제어기법을 이용한 행동양식 기반의 분산형 군집비행 제어구조를 제안하였다. 군집비행 행동양식을 위해 각 개체의 상호작용을 포텐셜 함수로 표현하였으며, 군집형태를 유지하며 기준궤적을 추종하기 위해 군집중심점 제어기법을 제안하였다. 시스템의 불확실성과 임무환경에 의한 포텐셜 함수 변화에 대해 강건한 성능을 유지하기 위해 슬라이딩 모드 제어기법을 적용하여 제어기를 구성하고 안정성을 평가하였다. 또한 예상하지 못한 장애물에 대한 군집 회피기동을 위해 비행경로 수정기법을 제시하였다. 수치 시뮬레이션을 통해 제안한 군집비행 제어기법의 성능을 평가하였다.

• Bulletin of the Korean Chemical Society
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• 제10권6호
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• pp.585-591
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• 1989

The effects of the charged metal on the overall electrostatic potential profiles and the capacitances of the electrical double layer are brought out. A model with a simplified jellium and a point-charged electrolyte is utilized in the present calculations. Electrons are assumed not to penetrate electrode surface due to a strong screening of electrolyte at the interface. Electron density functions and ion density functions are obtained, which are also based upon the Poisson equation and Boltzmann equation on either side of the interface. A complete potential profile starting from bulk electrode and ending at bulk electrolyte is obtained by connecting the two potential profiles (one inside the metal electrode, the other inside the electrolyte) with proper boundary conditions. In spite of the simplicity of the model, the present model reveals the importance of the effect of the charged metal on the electrostatic potential profile and the electrical double layer capacitances. The results are discussed and compared with the predictions by Gouy Chapman theory.