• Spatial Information Research
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• v.16 no.1
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• pp.65-77
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• 2008

There have been many studies and technologies that define a current location of a moving vehicle with GPS(Global Positioning System). However, the navigation system with GPS has troubles to search an optimized route considering data such as realtime parking status and road conditions. Moreover, the GPS systems show malfunction in the downtown with very tall buildings, underground parking lot and the inside of buildings. On the contrary, the RFID systems are able to reflect real-time status of parking lots and roads in the downtown. This paper proposes a system of guiding path for parking lots to consider real-time constraints based on RFID. The results obtained from the implemented system show smooth guiding of a new route after immediately sensoring the change of the information of parking lots and roads: if a parking lot that a vehicle is heading to is fully occupied, the system re-searches a new route for a neighbor parking lot and immediately transfers it to customer's mobile, and if the designated route is under construction, the system guides a detour path. The proposed method will be useful for advanced integrated parking control system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.400-403
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• 2021

Algorithms for predicting the optimal route of vehicles are being actively sudied with the recent development of autonomous driving technology. Companies such as SK, Kakao, and Naver provide services that navigate the optimal route. They predicts the optimal path with information from the users in real time. However, they can predict the optimal route, but not optimal lane route. We proposes a system that navigates the optimal lane path with coordinates data from vehicles using Lidar sensor. The proposed method is a system that guides smooth lanes by acquiring time series coordinate data of a vehicle after performing the Lidar-based object detection method. we demonstrates the performance using actual acquired data from the experimental results.

• Journal of Korean Institute of Industrial Engineers
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• v.17 no.1
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• pp.37-49
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• 1991

This report describes an integrated approach to sculptured surface design and manufacture, and a software package for it on a multi-axis NC milling machine. The integrated software consists of four parts : (1) surface fitting procedure for generating the characteristic polyhedron from 3 dimensional CMM data, (2) surface description for generating the mathematical representation of sculptured surfaces. (3) tool path generation for approximating the surface representation into a sequence of linear cutter paths, and (4) tool control for generating the corresponding joint variable values. This integrated approach is generally applicable to sculptured surface manufacturing where multi-axis milling machines are necessary to produce smooth three-dimensional surfaces.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.5
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• pp.931-936
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• 2000

A novel CPFDTD algorithm for modeling the smooth curved surfaces is presented. This scheme subdivides electric fields on the distorted grid into the extended contour field, the non-distorted field, and the quasi-available field to avoid the collinear borrowing approximation. Several preceding methods are applied to the I-plane sectoral horn antenna to get far-field patterns. The accuracy of the presented method is demonstrated by comparison with measured values.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.462-466
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• 1989

This paper describes the methods of spline low-order polynomial trajectory planning using only a few limited look-ahead knots on the desired trajectory for the real-time computing. Specifically presented are the mixed joint trajectory planning methods which apply linear or LSPB method to initial and finial segments, overlapped cubic spline method to the other segments, where the displacements for initial and finial segments are chosen to be relatively smaller than the displacements for the other, equidistant segments. Experimental and simulation results of these methods show smooth motions and improved path tracking performances compared with any other interpolated joint trajectory planning methods.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.5
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• pp.65-73
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• 2001

In this paper, a mobile system using multi-wheel steering and driving mechanism is proposed to maximize maneuverability of the wheeled mobile system. Among various possible configurations, the two-wheel steering and driving systems, which is minimal in structural requirement, is proposed to reduce the complexity in actual design and difficulties in control. The system possesses three or four degrees of freedom depending on the orientations of two wheels, one or two for driving and two for steering, which implies that the system's mobility is always less than three DOF. The proposed system, nonetheless, can exactly emulate characteristics of the omnidirectional motion as long as the planned path is smooth i.e., the curvature changes continuously while velocity is not zero. Efficient kinematic and dynamic control algorithms are proposed for position and orientation control of the proposed wheeled mobile system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.4
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• pp.154-161
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• 2014

In this research we investigate motion controller performance for mobile robots according to changes in the control loop sampling time. As a result, we suggest a proper range of the sample time, which can minimize final posture errors while improving tracking capability of the controller. For controller implementation into real mobile robots, we use a smooth and continuous motion controller, which can respect robot's path curvature limitation. We examine motion control performance in experimental tests while changing the control loop sampling time. Toward this goal, we compare and analyze experimental results using two different mobile robot platforms; one with real-time control and powerful hardware capability and the other with non-real-time control and limited hardware capability.

• Journal of Ocean Engineering and Technology
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• v.14 no.1
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• pp.29-36
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• 2000

Surface micro-crack grows along intergranular or transgranular region of crystal grains. But if it meets the barrier such as sessile dislocation and precipitates it loses straightness and deflects. Investigators had many difficulties in estimating fatigue life of smooth specimen because of the random distribution growth and coalescence of surface micro-cracks. The path of surface micro-crack has irregularity due to nonhomogeneous microstructure. Euclidian geometry can't quantify the shape of surface micro-crack but fractal geometry can. Therefore in this paper fractal dimension is measured at various stage of cycle ratio and estimated cycle ratio in 2024-T3 aluminium, alloy.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4A
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• pp.241-249
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• 2005

ATM based MPLS(Multiprotocol Label Switching) is discussed for its provisioning QOS commitment capabilities, Traffic engineering and smooth migration for BcN in Korea. At this time, due to the comprehensive nature of ATM protocol, ATM has been adapted as the backbone system for carrying Internet traffic[1,2,3,4]. This paper presents preventive congestion control mechanisms for detecting HTR(Hard-To-Reach) LSP(Label Switched Path) in ATM based MPLS systems. In particular, we have introduced a HTR LSP detection method using network signaling information in an ATM layer. MPLS related studies can cover LSP failures in a physical layer fault, it can not impact network congestion status. Here we will present the research results for introducing HTR LSP detection methods and control mechanisms and this mechanism can be implementing as SOC for high speed processing a packet header. We concluded that it showed faster congestion avoidance abilities with a more reduced system load and maximized the efficiency of network resources by restricting ineffective machine attempts.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.10
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• pp.27-36
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• 1992

This paper proposes a numerical method of motion planning for manipulators using Foruier series. For a redundant manipulator, we predetermine the trajectories of redundant joints in terms of the Nth partial sum of the fourier series. then the optimal coefficients of the fourier series are searched by the Powell's method. For a nonredundant or redundant manipulator, CS02T-continuous smooth joint trajectory for a point-to-point task can be obtained while considering the frequency response. We apply the proposed method to the 3-link planar manipulator and the PUMA 560 manipulator. To show the validity of the proposed method, we analyze solutions by the Fast Fourier Transform (FFT). Also, several features are discussed to obtain an optimal solution.