• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.4
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• pp.386-394
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• 2011

This paper is concerned with the application of the vision control scheme for robot's point placement task in discontinuous trajectory caused by obstacle. The proposed vision control scheme consists of four models, which are the robot's kinematic model, vision system model, 6-parameters estimation model, and robot's joint angles estimation model. For this study, the discontinuous trajectory by obstacle is divided into two obstacle regions. Each obstacle region consists of 3 cases, according to the variation of number of cameras that can not acquire the vision data. Then, the effects of number of cameras on the proposed robot's vision control scheme are investigated in each obstacle region. Finally, the practicality of the proposed robot's vision control scheme is demonstrated experimentally by performing the robot's point placement task in discontinuous trajectory by obstacle.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.9
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• pp.1-11
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• 2002

The optimal AP placement for wireless LAN is important factor for improving service quality and reducing cost. Decision of AP placement is depend on radio signal strength, environment factor and logical area property, which is user's frequently posed place. This paper proposes optimal multiple AP placement method based on radio prediction tool. The proposed method can get flexibility in multiple AP placement using user defined parameter and the optimization design uses Hopfield network algorithm. And path-loss model is used for one of radion prediction model. The result of simulation shows that it is efficiently reduces the process to find optimal AP placement. And the proposed optimization design of multiple AP placement can improve service quality for wireless LAN.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.156-161
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• 1991

It is difficult to realize precise control by a fuzzy control scheme alone because control signals are derived from fuzzy inferences. On the other hand, pole-placement control can offer a precise control to a known system. In this paper, a VSC(variable structure control)scheme is proposed, which is an attempt to take merits of pole-placement control and fuzzy control. On the vicinity of the reference point the pole-placement control scheme takes over the role of the fuzzy controller to improve the set point response.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.371-374
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• 2002

The optimal AP placement for wireless LAN is important factor for improving service quality and reducing cost. Logical area property, which is user's frequently posed place, must be considerated for flexible design. This paper proposes optimal multiple AP placement method based on path loss model which is one of radio prediction tool. The proposed method can got flexibility in multiple AP placement using user's defined parameter and tile optimization design uses Hopfield network algorithm The result of simulation shows that the proposed optimization design of multiple AP placement can improve service quality for wireless LAN.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.107-108
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• 2011

• Journal of the Korean Society for Precision Engineering
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• v.29 no.9
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• pp.986-994
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• 2012

This paper is concerned with the application of the vision control algorithm with weighting matrix in robot point placement task. The proposed vision control algorithm involves four models, which are the robot kinematic model, vision system model, the parameter estimation scheme and robot joint angle estimation scheme. This proposed algorithm is to make the robot move actively, even if relative position between camera and robot, and camera's focal length are unknown. The parameter estimation scheme and joint angle estimation scheme in this proposed algorithm have form of nonlinear equation. In particular, the joint angle estimation model includes several restrictive conditions. For this study, the weighting matrix which gave various weighting near the target was applied to the parameter estimation scheme. Then, this study is to investigate how this change of the weighting matrix will affect the presented vision control algorithm. Finally, the effect of the weighting matrix of robot vision control algorithm is demonstrated experimentally by performing the robot point placement.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.342-344
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• 2002

This paper presents a new strategy to find starting points for placing optimally Phasor Measurement Units(PMUs). The performance of the starting point, initial placement set of PMUs, affect critically the computational burden and/or time, because the Optimal PMU Placement (OPP) problem is formulated the combinatorial optimization. By analyzing the properties of OPP solutions on IEEE sample systems in detail, a new strategy for initial PMU placement, in this paper, is proposed. To verify the performance of the suggested strategy, the comparison with the existing strategy and the new one, on IEEE sample systems. is performed. By using the new strategy, the numbers of search spaces to solve the OPP problem is drastically decreased.

• Journal of Multimedia Information System
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• v.8 no.1
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• pp.23-30
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• 2021

Palmprint has become a popular biometric modality; however, palmprint recognition has not been conducted in video media. Video palmprint recognition (VPR) has some advantages that are absent in image palmprint recognition. In VPR, the registration and recognition can be automatically implemented without users' manual manipulation. A good-quality image can be selected from the video frames or generated from the fusion of multiple video frames. VPR in contactless mode overcomes several problems caused by contact mode; however, contactless mode, especially mobile mode, encounters with several revere challenges. Double-line-single-point (DLSP) assisted placement technique can overcome the challenges as well as effectively reduce the localization error and computation complexity. This paper modifies DLSP technique to reduce the invalid area in the frames. In addition, the valid frames, in which users place their hands correctly, are selected according to finger gap judgement, and then some key frames, which have good quality, are selected from the valid frames as the gallery samples that are matched with the query samples for authentication decision. The VPR algorithm is conducted on the system designed and developed on mobile device.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.8
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• pp.175-183
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• 1996

This paper presents three-dimensional robot task using the vision control method. A minimum of two cameras is required to place points on end dffectors of n degree-of-freedom manipulators relative to other bodies. This is accomplished using a sequential estimation scheme that permits placement of these points in each of the two-dimensional image planes of monitoring cameras. Estimation model is developed based on a model that generalizes known three-axis manipulator kinematics to accommodate unknown relative camera position and orientation, etc. This model uses six uncertainty-of-view parameters estimated by the iteration method.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.1
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• pp.43-48
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• 2011

Introduction: This study examined the anatomical morphology of the medial surface of the posterior mandible using 3-dimensional cone-beam computed tomography (CT) images to reduce the number of complications related to dental implant placement. Materials and Methods: Fifty patients were enrolled in this study with an average age (${\pm}$standard deviation) of 44.28 (${\pm}13.05$). On the coronal views cone-beam CT of the first molars, the distance between the top of the canal and alveolar crest vertical distance (VD), the distance between the upper-most point of the canal and the point perpendicular to the lingual cortical margin of the mandible lingual distance (LD), the location of the starting point of VD for reducing from the vertical reference line (VD point), and the inclination of the mandibular medial surface (lingual inclination) were measured, and a statistical evaluation was performed using SPSS for Windows version 15.0. Results: The mean VD0 was $16.91{\pm}2.47\;mm$ and VDx decreased with increasing x value. The mean LD was $5.27{\pm}1.36\;mm$. The VD began to decrease at the mean location of $6.12{\pm}0.96\;mm$ from the vertical reference line. The mean lingual inclination was $1.52{\pm}0.72^{\circ}$. Conclusion: These results will assist in the accurate placement of dental implants and the reduction of complications, particularly in the case of preoperative implant planning using only 2-dimensional imaging methods. (ex. panoramic radiography)