• Korean Journal of Computational Design and Engineering
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• v.21 no.3
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• pp.341-352
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• 2016

Manual 3D pipeline modeling from LiDAR scanned point cloud data is laborious and time-consuming process. This paper presents a method to extract the pipe, elbow and branch information which is essential to the automatic modeling of the pipeline connection. The pipe geometry is estimated from the point cloud data through the Hough transform and the elbow position is calculated by the medial axis intersection for assembling the nearest pair of pipes. The branch is also created for a pair of pipe segments by estimating the virtual points on one pipe segment and checking for any feasible intersection with the other pipe's endpoint within the pre-defined range of distance. As a result of the automatic modeling, a complete 3D pipeline model is generated by connecting the extracted information of pipes, elbows and branches.

• Journal of Power Electronics
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• v.6 no.3
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• pp.226-234
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• 2006

Photovoltaic (PV) generators have nonlinear V-I characteristics and maximum power points which vary with illumination level and temperature. Using a maximum power point tracker (MPPT) with an intermediate converter can increase the system efficiency by matching the PV systems to the load. This paper presents a maximum power point tracker based on fuzzy logic and a control scheme for a single-phase inverter connected to the utility grid. The fuzzy logic controller (FLC) provides an adaptive nature for system performance. Also the FLC provides excellent features such as fast response, good performance and the ability to change the fuzzy parameters to improve the control system. A single-phase AC-DC inverter is used to connect the PV system to the grid utility and local loads. While a control scheme is implemented to inject the PV output power to the utility grid at unity power factor and reduced harmonic level. The simulation results have shown the effectiveness of the proposed scheme.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.4
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• pp.125-132
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• 2015

PCI Express is high-speed point-to-point serial protocol, the system is designed by analysing loss and jitter through Eye Diagram. It is necessarily analyzing high speed serial signals when the PCI Express Gen3 which has 8Gbps physical signal speed is designed especially. This paper deals with topology extraction, channel analysis, extraction of s-parameters and system signal integrity simulation within transceiver buffer models through PCI Express Gen3 server connecting switch system design. Optimal parameters of transmitter buffer equalizer are found through solution space simulation of de-emphasis and preshoot parameters to compensate channel loss.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.12
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• pp.1992-2007
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• 1997

A new algorithm for planning a collision-free path is developed based on linear prametric curve. In this paper robot is assumed to a point, and two linear parametric curve is used to construct a path connecting start and goal point, in which single intermediate connection point between start and goal point is considered. The intermediate connection point is set in polar coordinate(${\theta}{\delta}$) , and the interference between path and obstacle is mapped into CPS(connection point space), which is defined a CWS GM(circular work space geometry mapping). GM of all obstacles in workspace creates overlapping images of obstacle in CPS(Connection Point Space). The GM for all obstacles produces overlapping images of obstacle in CPS. The empty area of CPS that is not occupied by obstacle images represents collision-free paths in Euclidian Space. A GM based on connection point in elliptic coordinate(${\theta}{\delta}$) is also developed in that the total length of path is depend only on the variable .delta.. Hence in EWS GM(elliptic work space geometry mapping), increasing .delta. and finding the value of .delta. for collision-free path, the shortest path can be searched without carring out whole GM. The GM of obstacles expersses all possible collision-free path as empty spaces in CPS. If there is no empty space available in CPS, it indicates that path planning is not possible with given number of connection points, i.e. path planning is failed, and it is necessary to increase the number of connection point. A general case collision-free path planning is possible by appling GM to configuration space obstacles. Simulation of GM of obstacles in Euclidian space is carried out to measure performance of algorithm and the resulting obstacle images are reported.

• The Journal of the Korean dental association
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• v.17 no.7 s.122
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• pp.521-524
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• 1979

The Author measured the position of the mandibular foramen with oblique cephalography in 41 8-aged, and 45 12-aged Korean children. The results of the studies were as follows; 1) The distance from the posterior occlusal plane to the mandibular foramen was 1.85±1.23mm. in age 8 and 1.85±1.21mm. in age 12 to the below. 2) The meeting point of the occlusal plane and anterior of the ramus to the mandibular foramen was 16.68±1.68mm. in age 8 and 16.84±2.09mm. in age 12. 3) the angulation between the occlusal plane and the line connecting the mandibular foramen and the meeting point of anterior of the ramus with occlusal plane was 8.15±1.87˚ in age 8 and 7.11±1.89˚ in age 12 to the below. 4) % depth was 53.98 ±3.40% in age 8 and 53.81±4.05% in age 12.

• Journal of applied mathematics & informatics
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• v.30 no.3_4
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• pp.635-646
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• 2012

This paper is concerned with an SIRS epidemic model with spatial diffusion and time delay representing the length of the immunity period. By using a new cross iteration scheme and Schauder's fixed point theorem, we reduce the existence of traveling wave solutions to the existence of a pair of upper-lower solutions. By constructing a newfashioned pair of upper-lower solutions, we derive the existence of a traveling wave solution connecting the uninfected steady state and the infected steady state.

• International Journal of Ocean System Engineering
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• v.2 no.3
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• pp.139-150
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• 2012

This paper presents an improved guidance algorithm for autonomous underwater vehicles (AUV) in 3D space for generating smoother vehicle turn during the course change at the way-points. The way-point guidance by the line-of-sight (LOS) method has been modified for correcting the reference angles to achieve minimal calculation and smoother transition at the way-points. The algorithm has two phases in which the first phase brings the vehicle to converge to a distance threshold point on the line segment connecting the first two way-points and the next phase generates an angular path with smoother transition at the way-points. Then the desired angles are calculated from the reference and correction angles. The path points are regularly parameterized in the spherical coordinates and mapped to the Cartesian coordinates. The proposed algorithm is found to be simple and can be used for real time implementation. The details of the algorithm and simulation results are presented.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.9 no.5
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• pp.64-70
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• 1995

This paper presents a practical approach to evaluate the reliability indices of electric distribution systems. The use of reliability evaluation is placed with framework of distribution system planning and operation. In this paper, the reliability model is based on an analytical method, connecting component failure to load point outage in each section. Five cases are reported in the paper to study the effect of varying failure rates and repair times on real distribution systems. Simulations are preformed by the developed reliability evaluation program.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.2
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• pp.129-134
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• 2017

The process of producing a fish trap frame is very complicated and manual, so it is expensive, the quality of the product is unstable, the quality is not guaranteed, the durability is weak, and it cannot be used for a long time. Therefore, we made a fish trap frame-making machine to reduce the manpower and costs and to make robust products. This machine cuts the wire of mild steel to a certain size and then makes the connecting parts into a trapezoid shape by spot welding. In this study, the weld point shear strength between manual and automatic operation was compared and analyzed.

• Journal of The Korean Digital Architecture Interior Association
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• v.11 no.3
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• pp.99-107
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• 2011

The prime purpose of this study is to view traditional residential space not only as visual and figurative but also experiencing space from the perspective of aesthetics. This study points out that traditional residential space should be perceived as "true space" of connecting people, life and experience. Although it was not clearly defined as a visual entity, the value, phenomenon and experience of space materialized through conjecture and expectation are interpreted as the arena of aesthetics and philosophy. This study aims at drawing a conclusion that the characteristics of traditional residential space, which is perceived as experiencing space centered on objective and subjective human behaviors, makes a linkage to aesthetic elements.