• International Journal of Fuzzy Logic and Intelligent Systems
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• v.4 no.1
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• pp.23-28
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• 2004

This paper proposes a sensor-fusion technique where the data sets for the previous moments are properly transformed and fused into the current data sets to enable accurate measurement, such as, distance to an obstacle and location of the service robot itself. In the conventional fusion schemes, the measurement is dependent on the current data sets. As the results, more of sensors are required to measure a certain physical parameter or to improve the accuracy of the measurement. However, in this approach, instead of adding more sensors to the system, the temporal sequence of the data sets are stored and utilized for the measurement improvement. Theoretical basis is illustrated by examples and the effectiveness is proved through the simulations. Finally, the new space and time sensor fusion(STSF) scheme is applied to the control of a mobile robot in an unstructured environment as well as structured environment.

• International Journal of Aeronautical and Space Sciences
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• v.11 no.3
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• pp.234-239
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• 2010

The utilization of micro-electro-mechanical system (MEMS) gyros and accelerometers in low-level inertial measurement unit (IMU) influences cost effectiveness in a positive way under the condition that device error characteristics are fully calibrated. The conventional calibration process utilizes a rate table; however, this paper proposes a new method for achieving reference calibration data from the natural motion of pendulum to which the IMU undergoing calibration is attached. This concept was validated with experimental data. The pendulum angle measurements correlate extremely well with the solutions acquired from the pendulum equation of motion. The calibration data were computed using the regression method. The whole process was validated by comparing the measurement from the 6 sensor components with the measurements reconstructed using the identified calibration data.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.408-410
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• 2009

We present an efficient and robust measurement model for visual tracking. This approach builds on and extends work on subspace representations of measurement model. Subspace-based tracking algorithms have been introduced to visual tracking literature for a decade and show considerable tracking performance due to its robustness in matching. However the measures used in their measurement models are often restricted to few approaches. We propose a novel measure of object matching using Angle In Feature Space, which aims to improve the discriminability of matching in subspace. Therefore, our tracking algorithm can distinguish target from similar background clutters which often cause erroneous drift by conventional Distance From Feature Space measure. Experiments demonstrate the effectiveness of the proposed tracking algorithm under severe cluttered background.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.164-165
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• 2005

As MSOA(organism activity measurement system) is a system that measure organism's activities using the 455[kHz] supersonic transducer, it's composed to MCM(main control module), LDM(loop design module) and CMM(control and monitoring module). The purpose of this research is to confirm the effectiveness of supersonic measurement in organism activity as comparison with organism's respiration measurement using oxygen meter.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.2
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• pp.56-63
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• 2001

The objective of this research is to develop a measurement error compensation method for On-Machine Measurement (OMM) process based on a closed-loop configuration. Geometric errors of vertical machining center are measured using ball-bar system, and probing errors are measured using master ball. The errors are represented using homogeneous trans-formation matrices and the closed-loop configuration method is applied to calculate 3-dimensional errors. To verify the effectiveness of the method proposed in this research, compensated results are compared to the data using CMM process, and the results are analyzed. The results show the proposed method can be applied in OMM process to make the measured data more reliable.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.97-103
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• 2006

A modified one-sided measurement technique is proposed for Rayleigh wave (R-wave) velocity measurement in concrete. The scattering from heterogeneity may affect the waveforms of R-waves in concrete, which may make the R-waves dispersive. Conventional one-sided techniques do not consider the scattering dispersion of R-waves in concrete. In this study, the maximum energy arrival concept is adopted to determine the wave velocity by employing its continuous wavelet transform. Experimental study was performed to show the effectiveness of the proposed method. The present method is applied to monitor the strength development of early-age concrete. A series of experiments were performed on early-age concrete specimens with various curing conditions. Results reveal that the proposed method can be effectively used to measure the R-wave velocity in concrete structures and to monitor the strength development of early-age concrete.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.12
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• pp.1133-1139
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• 2014

This paper proposes a simple method to improve a sensitivity of a straightness measurement system for a linear stage, which is applied to a system based on a geometric optic method. An optical system for this method is composed of a corner-cube retro-reflector, a ball-lens and a twodimensional position sensitive detector (2D PSD). The effectiveness of the proposed method was examined theoretically, and verified experimentally using a prototype measurement system. The results show that the measuring sensitivity was dependent on the size of the ball-lens and the setup position of PSD from the ball-lens, and that the proposed method is efficient method to improve the measuring sensitivity.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.6
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• pp.76-81
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• 2006

In this paper, profile error measurement method of a turbine blade using 3D-scanner is developed. The method begins with scanning the upper and lower sides of the blade on which three small balls are attached, and constructs a solid measurement model by registering the two scanned surfaces. Airfoils are derived from the model at each interval by intersecting it with a plane, and arranged with design airfoils. The $2^2$ factorial design search method is engaged in arranging the two airfoils, from which the main blade parameters including the edge radius are computed. The developed measurement technique is applied to practical blade manufacturing and validates its effectiveness.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.1
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• pp.131-142
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• 1996

Most industrial robots cannot be off-line programmed to carry out a task accurately, unless their kinematic model is suitably corrected through a calibration procedure. However, normal calibration is an expensive and time-consumming precedure due to the highly accurate measurement equipment required and due to the significant amount of data that must be collected. This paper presents a simple and economic procedure to improve the efficiency of robot calibration especially for arc welding application. To simplify the measurement process, an automotic data measurement algorithm as well as a simple measurement device are developed. Also, a calibration algorithm which can automatically identify the independent model parameters to be estimated is presented. To demonstrated the simplicity and the effectiveness of the procedure, experimental studies and computer simulations are performed and their results are discussed.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.713-720
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• 2009

The development goals of the next generation EMU are to improve the system maintainability, transportation capacity, reliability, passenger service and energy efficiency. In this paper, we propose a measurement scheme for the development goals of the next generation Electric Multiple Unit(EMU). To achieve that, we drew meaningful characteristics for each development goal, which mainly affect effectiveness and performance of vehicle system. Finally, the measurement scheme for the development is obtained by using the characteristics, which could be a numerical values such as maximum velocity, acceleration of the vehicle and so on or subjective values such as a results of surveys from passengers and so on. We expect the proposed measurement scheme will be used to measure the development goals of other similar system as well as the next generation EMU.