• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 춘계학술대회 논문집
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• pp.5-5
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• 2010

The depth of the object pointed by the laser beam is computed depending on the pixel position on the CCD There involved several number of internal and external parameters such as inter-pixel distance, focal length, position and orientation of the system components in the depth measurement error. In this paper, it is shown through the error sensitivity analysis of the parameters that the most important parameters in the sense of error sources are the angle of the laser beam and the inter pixel distance. Also, the calibration technique to minimize their effect for the depth computation is proposed.

• 제어로봇시스템학회논문지
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• 제19권11호
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• pp.955-959
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• 2013

It is possible to obtain an omnidirectional stereo image via a single camera by using a catadioptric approach with a convex mirror and concave lens. In order to measure three-dimensional distance using the imaging system, the optical parameters of the system are required. In this paper, a calibration procedure to extract the parameters of the imaging system is described. Based on the parameters, experiments are carried out to verify the performance of the three-dimensional distance measurement of a single camera omnidirectional stereo imaging system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.84-84
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• 2000

This paper proposes a new impedance control scheme based on a variable stiffness matrix for a bilateraL teleoperation. In this scheme, stiffness matrix of the impedance model in the slave is modulated based on the distance, measured by an ultrasonic sensor, between the slave and environment. At the same time, the stiffness matrix of the master is also changed accordingly in order for the impedance parameters of the combined system to remain constant The proposed scheme is implemented on a 1-dof master/slave system to perform a simple task. In the experiments, the teleoperator with the impedance parameter modulation shows better performance than one with fixed impedance parameters, especially in reducing task execution time and in avoiding excessive external forces.

• 한국표면공학회지
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• 제37권3호
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• pp.158-163
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• 2004

ITO thin film was deposited on the glass by RF magnetron sputtering. Dependance of the process parameters such as thickness, target-to-substrate distance, substrate temperature and oxygen partial pressure on the transmittance and electrical resistance of ITO film were investigated. The deposition conditions for getting better optical and electrical ITO characteristics were the 1800-$2300\AA$ thickness, 65mm substrate-to-target distance, $350^{\circ}C$ substrate temperature and 8% oxygen partial pressure. At these conditions, the transmittance and sheet resistance of the ITO film were 83.3% and 77.86Ω/$\square$, respectively.

• 한국염색가공학회지
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• 제25권3호
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• pp.232-239
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• 2013

In this study, 25gsm melt-blown polypropylene nonwoven for dust-proof/medical masks was finished by the corona discharging treatment. The influence of corona discharging parameters on the filtration efficiency was investigated. Several parameters such as discharging voltage, discharging speed, distance to discharging wire and configuration of discharging system had an effect on filtration efficiency, while the parameters had no effect on breathing resistance. Optimum corona discharging conditions are as follows: Wires were installed on the upper part of the nonwoven and paper pipe was installed on the lower part of the nonwoven having a distance of 5cm. The sequence of wire voltages was +60 kV, +60 kV, 0, -60 kV, and -60 kV. The discharging voltage and speed were 60 kV and 30m/min respectively. The nonwoven treated by corona discharging at the optimum condition showed a filtration efficiency of 80% or more, which is suitable for dust-proof/medical masks.

• 한국항해항만학회지
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• 제32권4호
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• pp.271-277
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• 2008

When performing steering by an autopilot (automatic steering gear), a sensitivity adjustment is mainly determined by P value and D value. These values differ in the optimal combination by model of ship and external forces. This research was carried out simulation case studies and examined movement of Pure Car Carrier, which easily received ship by wind pressure influence in low speed We investigated the relation of horizontal migration(transfer) of ship's body and P-D value. Based on it, four parameters of P-D at approaching berth could be suggested Hence there were suggestions of parameters; Distance to maximum lee point, Time to maximum lee point, Time to return to original course and Time to 300th second. The correlation of these parameters and P-D value were also considered. As a result, we think that this index, like formulated P-D, leads to an easy and safe navigation by utilizing these indices.

• 한국정밀공학회지
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• 제12권8호
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• pp.73-85
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• 1995

The sensor system to measure the distance precisely from the center of the sensor system to the obstacle is needed to recognize the surrounding environments, and the sensor system is to be calibrated thoroughly to get the range information exactly. This study covers the calibration of the active range sensor which consists of camera and laser slit emitting device, and provides the equations to get the 3D range data. This can be possible by obtaining the extrinsic parameters of laser slit emitting device through image processing the slits measured during the constant distance intervals and the intrinsic parameters from the calibration of camera. The 3D range data equation derived from the simple geometric assumptions is proved to be applicable to the general cases using the calibration parameters. Also the exact 3D range data were obtained to the object from the real experiment.

• Journal of Welding and Joining
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• 제24권4호
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• pp.27-31
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• 2006

Optimization of process parameters for laser-arc hybrid welding process is intrinsically sophisticated because the process has three kinds of parameters-arc, laser and hybrid welding parameters. In this paper, the relationship between weldability and several process parameters such as laser beam-arc distance, electrode height, welding current and welding speed, were investigated by the full factorial experimental design. Weld quality was evaluated by using weight of spatters which is related with the pore area. It was found that the weld quality was increased with the increases in laser beam-arc distance and welding current, and decreased with the increases in electrode height and welding speed.

• Fisheries and Aquatic Sciences
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• 제9권4호
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• pp.167-174
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• 2006

Two typical responses have been documented for flatfish when they encounter the ground gear of bottom trawls: herding response and falling back response. These two responses were analyzed from video recordings of fish and were characterized by time sequences for four parameters: swimming speed, angular velocity, acceleration, and distance between the fish and the ground gear. When flatfish displayed the falling-back response, absolute values of the three swimming parameters and their deviations were significantly higher than those during the herding response. However, the swimming parameters were not dependent on the distance between the flatfish and the ground gear, regardless of which response occurred. The dominant periods for most of the movement parameters ranged from 2.0 to 3.7 s, except that no periodicity was observed for swimming speed or angular velocity during the falling-back response. However, variations in the four parameters during the falling -back response revealed greater irregularity in periodicity and higher amplitudes. This complex behavior is best described as a chaos phenomenon' and is discussed as the building block for a model predicting the responses of flatfish to ground gear as part of the general understanding of the fish capture process.

• 제어로봇시스템학회논문지
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• 제5권7호
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• pp.814-820
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• 1999

We propose a target identification algorithm for visual tracking. Target identification is realized by finding out corresponding line segments to the hypothesized model segments of the target. The key idea is the combination of the Mahalanobis distance with the geometrical relationship between model segments and extracted line segments.