• 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.

• 조명전기설비학회논문지
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• 제16권4호
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• pp.117-123
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• 2002

접지저항의 측정은 접지계통의 접지성능이 적정한가를 평가하기 위한 가장 기본적이고 중요한 작업이라고 할 수 있다. 그러나 실제 현장에서, 특히 접지극의 크기가 큰 경우일수록 접지저항을 정확히 측정하기란 쉽지 않은데, 이는 정확한 접지전위 측정을 위한 기준전위 점을 찾기가 힘들기 때문이다. 본 논문에서는 접지극 주변에서 측정한 지표면전위를 분석하여 기준전위 점의 위치를 정확히 식별하는 방법과 그 정당성을 제시하였다.

• Korean Journal of Geomatics
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• 제1권1호
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• pp.43-49
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• 2001

Although many kinds of stereo matching method have been developed in the field of computer vision and photogrammetry, wrong matches are not easy to avoid. This paper presents a new method to reduce wrong matches after matching, and experimental results are reported. The main idea is to analyze the histogram of the image attribute differences between each pair of image patches matched. Typical image attributes of image patch are the mean and the standard deviation of gray value for each image patch, but there could be other kinds of image attributes. Another idea is to check relative position among potential matches. This paper proposes to use Gaussian blunder filter to detect the suspicious pair of candidate match in relative position among neighboring candidate matches. If the suspicious candidate matches in image attribute difference or relative position are suppressed, then many wrong matches are removed, but minimizing the suppression of good matches. The proposed method is easy to implement, and also has potential to be applied as post processing after image matching for many kinds of matching methods such as area based matching, feature matching, relaxation matching, dynamic programming, and multi-channel image matching. Results show that the proposed method produces fewer wrong matches than before.

• 한국생물환경조절학회:학술대회논문집
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• 한국생물환경조절학회 2001년도 봄 학술발표논문집
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• pp.79-80
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• 2001

This study was conducted to estimate rooting and shooting in single-node cuttings (SNC) of roses 'Rote Rose' and 'Teresa' to several conditions: growth stage, node position, and leaf area of cutting, so that single-stemmed roses (SSR) could be used in rose factory system. There was no effects of growth stage of flowering shoots far cutting on the rooting and shooting of SNC in both of the two cultivars. However, the node position and leaf area of cuttings significantly affected the rooting and shooting of SNC: the speed was accelerated with larger leaf area and upper node cuttings, but the rate showed little difference as above 95%. Based on above results, rooting and shooting in SNC was forced by leaf area mainly, followed by node positions. On the other hand, flowering rate of shoots from SNC was improved mainly with larger leaf area in cuttings. Shoots of 45cm-longer, qualified for rose factory system, increased with lower node and larger leaf area significantly. Therefore, it could be said that the potential growth of shoots from SNC would be influenced mainly by leaf area, followed by node position on cutting.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제29회 KOSCI SYMPOSIUM 논문집
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• pp.161-166
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• 2004

A study of argon droplet vaporization is conducted using molecular dynamics. Instead of using traditional method such as the Navier-Stokes equation. Molecular dynamics uses Lagrangian frame to describe molecular behavior in a system and uses only momentum and position data of all molecules in the system. So every property is not a hypothetical input but a statistical result calculated from the momentum and position data. This work performed a simulation of the first-order stability for phase transition of a three dementional submicron argon droplet within quiescent environment. Lennard-Jones 12-6 potential function is used as a intermolecular potential function. The molecular configuration is examined while an initially non-sperical droplet is changed into the spherical shape and droplet evaporates or condensates.

• 대한기계학회논문집A
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• 제24권4호
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• pp.874-880
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• 2000

In this paper, a DC potential drop measurement system was used to find the position of the flaw on a simple thin plate. Four-point probe test was evaluated and used for this study. In the four-point probe test, the more distance between current pins provides the more measurable scope, the less voltage difference, and the more voltage difference rate. In the other hand, the more distance between voltage pins provides the less voltage difference and the less voltage difference rate. An optimized four-point probe was applied to measure the relation between voltage and the relative position of flaw to the probe. The Maxwell 21) simulator was used to analyze the electromagnetic field, and it showed that the analytical result was similar to the experimental result within 11.4% maximum error.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.121-126
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• 2003

A study of argon droplet vaporization is conducted using molecular dynamics, instead of using traditional methods such as the Navier-Stokes equation. Molecular dynamics uses Lagrangian frame to describe molecular behavior in a system and uses only momentum and position data of all molecules in the system. So every property is not a hypothetical input but a statistical result calculated from the momentum and position data. This work performed a simulation of the complete vaporization of a three dimensional submicron argon droplet within quiescent environment. Lennard-Jones 12-6 potential function is used as a intermolecular potential function. The molecular configuration is examined while an initially non-spherical droplet is changed into the spherical shape and droplet evaporates. And the droplet radius versus time is calculated with temperature and pressure profile.

• 약학회지
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• 제33권2호
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• pp.87-100
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• 1989

Salicylic acids as anti-inflammatory agents were analyzed by ab initio, quantum chemical methods to study the possible modes of binding to the receptor. As the result of multiple regression analysis of reactivity indices and interpretation of normalized frontier orbital charges of drugs, potency seems to be related to energy of HOMO and LUMO at the 5 position of benzene ring, and in the 5-phenyl substituted case, the para position of substituting ring is important. The binding occurs first at the positive site of its receptor. The charge density exhibited by the frontier orbitals suggests that charge moves from receptor site to carboxyl group. The electrostatic orientation effect makes an important contribution to the binding of the active molecules to their receptors. Also the electrostatic potential model may be able to rationalize the source of activity or inactivity of the drugs under investigation.

• 제어로봇시스템학회논문지
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• 제21권6호
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• pp.497-502
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• 2015

One of the goals in the field of mobile robotics is the development of personal service robots for the elderly which behave in populated environments. In this paper, we describe a security robot system and ongoing research results that minimize the risk of the elderly and the infirm to access an area to enter restricted areas with high potential for falls, such as stairs, steps, and wet floors. The proposed robot system surveys a potential falling area with an equipped laser scanner sensor. When it detects walking in elderly or infirm patients who in restricted areas, the robot calculates the velocity vector, plans its own path to forestall the patient in order to prevent them from heading to the restricted area and starts to move along the estimated trajectory. The walking human is assumed to be a point-object and projected onto a scanning plane to form a geometrical constraint equation that provides position data of the human based on the kinematics of the mobile robot. While moving, the robot continues these processes in order to adapt to the changing situation. After arriving at an opposite position to the human's walking direction, the robot advises them to change course. The simulation and experimental results of estimating and tracking of the human in the wrong direction with the mobile robot are presented.

• 전기학회논문지P
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• 제59권2호
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• pp.222-231
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• 2010

This paper presents numerical analysis of measurement errors of ground electrode using the fall-of-potential method. In order to analyze ground resistance error according to the positions of auxiliary probes, firstly, national and international standards were researched. Secondly, numerical ground resistance error of hemispheric electrode was analyzed according to the locations of auxiliary probes and the angle between probes. Then, error-reduced positions of auxiliary probes were shown according to the distance to auxiliary current probe versus ground electrode size. Finally, error compensation method was presented. The results presented in this paper provide useful information regarding ground resistance error of alternative positions of auxiliary probes in case that the auxiliary probes could not be located at the proper position in such cases as there are buildings, roadblock or underground metallic pipe at that position.