• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.367-372
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• 2000

Accuracy of a machined component is determined by the relative motion between the cutting tool and the workpiece. One of the important factors which affects the accuracy of this relative motion is the geometric error of machine tools. In this study, geometric error is modeled using form shaping motion of machine tool, where a form shaping function is derived from the homogeneous transformation matrix. Geometric errors are measured by laser interferometer. After that, the local positioning error can be estimated from the form shaping model and geometric error data base. From this information, we can remodel the part by shifting the design surface to the amount of positional error. By generating tool path to the redesigned surface, we can reduce the machining error.

• The Journal of Korea Robotics Society
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• v.5 no.3
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• pp.216-223
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• 2010

Most lamp units at ceilings, walls, and streets are static and no automatic motion capabilities are available at all to adjust lamp tilting angles and its zooming position. This paper proposes a new robotic lamp that creates three degrees of freedom (DOF) motion by using a spherical-type parallel mechanism with a unique forward kinematic position. In the robotic lamp, three motors are placed at the base frame to control two tilting angles and one zoom in-and-out motion for a localized light. The kinematic model of this device is derived and the proto type has been developed. The performance of this device was verified through experiment.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.631-632
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• 2006

In this paper, acquiring the more desirable to adopt design SoC for the fast hierarchical motion estimation, we exploit foreground and background search algorithm (FBSA) base on the dual arithmetic processor element(DAPE). It is possible to estimate the large search area motion displacement using a half of number PE in general operation methods. And the proposed architecture of MHME improve the VLSI design hardware through the proposed FBSA structure with DAPE to remove the local memory. The proposed FBSA which use bit array processing in search area can improve structure as like multiple processor array unit(MPAU).

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.3
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• pp.161-172
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• 2007

This article suggests an inverse kinematics analysis of a two degree of freedom spatial parallel motion simulator and design methodology of the robust PID controller. The parallel motion simulator consists of a fixed base and a moving frame connected by two serial chains, with each serial chain containing one revolute joint and two passive spherical joint. First, an inverse kinematics problems are solved in order to find the joint variable necessary to bring the end effector to track the desired trajectory. Second, an inverse optimal PID controller is proposed to track trajectories in the face of uncertainty. And the $H_{\infty}$ optimality and robust stability of the closed-loop system is acquired through the PID controller. Finally numerical results show the effectiveness of the PID controller that is designed by square/linear tuning laws.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.331-332
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• 2012

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.399-402
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• 1999

This study is about seismic performance of the EDF(Electricite De France) system, that is among various base isolator. We get solutions of equation of motion of this system for displacement, velocity, acceleration and compared with solutions using finite element program. And, through shaking table tests we will prove seismic performance

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.975-976
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• 2009

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.110-113
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• 2003

Most traffic accidents are caused by drivers' carelessness and lack of information on the surrounding objects. In this paper we proposed a model of human intention recognition through case-base learning and to build up an experiment system. The system can help us recognize object's intention (e.g. turn left, turn right or straight) by using detected data about human's motion, speed of the car and the distance between the car and the intersection. Furthermore, we included an example using case-base learning in this paper to improve the precision of recognition as well as an example to explain the use of the system. PC can be used to predict the driving reaction beforehand and send a warning signal to the driver in time if there is any danger.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.04b
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• pp.257-261
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• 1993

This paper presents a design method of turning device for robotic assembly based on the verification of a instability for a base assembly. To derive the instability, first we inference collision free assembly directions by extracting separable directions for the part, and calculate the separability which gives informations as to how the part can be dasily separated. Using the result, we determine the instability evaluated by summing the all separabilites of each component part in base assembly. The proposed method gives a design guidance of turning device by evaluating a degree of the motion istability for the base assembly in flexible manufacturing application. An example is given to illustrate the concepts and procedure of the proposed scheme.

• Earthquakes and Structures
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• v.4 no.5
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• pp.527-555
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• 2013

This paper proposes probabilistic models for estimating the seismic demands on reinforced concrete (RC) bridges with base isolation. The models consider the shear and deformation demands on the bridge columns and the deformation demand on the isolation devices. An experimental design is used to generate a population of bridges based on the AASHTO LRFD Bridge Design Specifications (AASHTO 2007) and the Caltrans' Seismic Design Criteria (Caltrans 1999). Ground motion records are used for time history analysis of each bridge to develop probabilistic models that are practical and are able to account for the uncertainties and biases in the current, common deterministic model. As application of the developed probabilistic models, a simple method is provided to determine the fragility of bridges. This work facilitates the reliability-based design for this type of bridges and contributes to the transition from limit state design to performance-based design.