• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.540-542
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• 1998

The Position Sensitive Detector(PSD) is an useful device which can be used to measure the position of an incidence light in accuracy and in real-time. In this paper, 2-D PSD sensor is used to measure the 2-D position of moving object with light source. To get the position of light source from PSD sensor exactly, we propose two position computation methods ; the parameter calibration and neural network. Experimental data is presented that offer the comparision between two methods and demonstrates the effectiveness of proposed approach.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.536-539
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• 2003

This paper presents a study of position tracing system for Underwater Vehicle Robots(UVR) that is inspecting an atomic furnace. This system development is the basic research for the purpose of position estimation of UVR and preventing that UVR crash into the wall of an atomic furnace. For this purpose, Pan/Tilt Unit that is attached Laser is pointing PSD(Position Sensitive Detector) Sensor which is stuck to the upper side of UVR. Through this action, we can find the Position of UVR. In this paper, we construct the system for aiming the laser pointer at PSD Sensor using pan/tilt and study the optimum algorithm for finding the optional position that is located at the space which is pointable area by Laser device.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.660-665
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• 1993

Neural networks are used in the framework of sensorbased tracking control of robot manipulators. They learn by practice movements the relationship between PSD ( an analog Position Sensitive Detector) sensor readings for target positions and the joint commands to reach them. Using this configuration, the system can track or follow a moving or stationary object in real time. Furthermore, an efficient neural network architecture has been developed for real time learning. This network uses multiple sets of simple backpropagation networks one of which is selected according to which division (corresponding to a cluster of the self-organizing feature map) in data space the current input data belongs to. This lends itself to a very fast training and processing implementation required for real time control.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.415-419
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• 2000

Multi-degree-of-freedom (MDOF) displacement measurement Is needed In many application fields: precision machine control, precision assembly, vibration analysis, and so on. This paper presents a new MDOF displacement measurement method using a laser diode (LD), two position-sensitive detectors (PSDs), and a conventional diffraction grating. It utilizes typical features of a diffraction grating to obtain the information of MDOF displacement. MDOF displacement is calculated from the independent coordinate values of the diffracted ray spots on the PSDs. Forward and inverse kinematic problems were solved to compute the MDOF displacement of a rigid body. Experimental results show maximum absolute errors of less than ${\pm}10$ micrometers in translation and ${\pm}30$ arcsecs in rotation.

• Nuclear Engineering and Technology
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• v.54 no.3
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• pp.1030-1036
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• 2022

A high detection efficiency thermal neutron detector based on the ⁶LiF/ZnS(Ag) scintillation screens, wavelength-shifting fibers (WLSF) and Silicon photomultiplier (SiPM) readout is under development at China Spallation Neutron Source (CSNS) for the Engineering Material Diffractometer (EMD).A prototype with a sensitive volume of 180mm×192mm has been built. Signals from SiPMs are processed by the self-design Application Specific Integrated Circuit (ASIC). The performances of this detector prototype are as follows: neutron detection efficiency could reach 50.5% at 1 Å, position resolution of 3, the dark count rate <0.1Hz, the maximum count rate >200KHz. Such detector prototype could be an elementary unit for applications in the EMD detector arrays.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.35-37
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• 2002

Conceptual design of the next generation PET with both high sensitivity and high spatial resolution has been performed. A detector unit using a depth encoding scheme was designed and constructed for trial. The unit consists of four Gd$_2$SiO$\sub$5/:Ce crystal blocks in a 2x2x4 array coupled to a position-sensitive photomultiplier tube having metal channel dynodes and 4x4 multi-anodes. Our proposed detector is a very reliable and simple solution suitable for volume PET devices since the proposed depth encoding scheme does not need additional photo-detectors.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.583-585
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• 2004

In this paper we will deal with a calibration method for low cost motion capture system using psd(position sensitive detection) optical sensor. To measure the incident direction of the light from LED emitted marker, the PSD is used the output current ratio on the electrode of PSD is proportional with the incident position of the light focused by lens. In order to defect the direction of the light, the current output is converted into digital voltage value by opamp circuits peak detector and AD converter with the digital value the incident position is measured. Unfortunately, due to the non-linearly problem of the circuit poor position accuracy is shown. To overcome such problems, we compensated the non-linearly by using least-square fitting method. After compensated the non-linearly in the circuit, the system showed more enhanced position accuracy.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2665-2667
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• 2004

This paper presents a study of a position finding system for a reactor inspection robot. The position of PSD(Position Sensitive Detector) sensor is calculated by the degree of pan-tilt and the difference in height between pan-tilt and PSD. For that, the DSP which control pan-tilt is used for precise operation and the PIC microcontroller process PSD sensor data that indicate light incident position. A user using computer can acquire the conditions of pan-tilt and PSD.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.293-296
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• 1999

In conventional automatic container-terminal, the gantry cranes are operated manually or semi-automatically. But UGC is an unmanned-operated gantry crane and the positioning information for UGC is supplied only by position-measuring devices. In order to enhance the operation efficiency of UGC, it is required that the position-measuring devices have long maintenance period and are not sensitive to the weather and environment condition. And in order to be used practically in container terminal, the cost of position-measuring devices is not higher than currently used measuring devices. In the study, it is discussed the requirements for position-measuring devices in UGC, And it is studied on the measuring devices suitable to UGC. From this study, it is expected that the combination of a rotary encoder and a ferrous metal detector is useful for position-measuring devices in UGC.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1845-1847
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• 2013

The lateral photovoltaic effect (LPE) can be observed in semiconductors by irradiating a light spot position between electrodes on sample's surface. Because lateral photovoltaic voltage (LPV) is sensitively changed by light spot position, a LPE device has been tried as a position-sensitive detector. This study discusses the correlation between LPV and conductivity in p-type silicon and nano-structured Au deposited p-type silicon (nano-Au silicon), respectively. Conductivity measurement of the sample was carried out using the four-wire method to eliminate contact resistance, and conductivity dependence on LPV was simultaneously measured by changing the light irradiation position. The result showed a strong correlation between conductivity and LPV in the p-type silicon sample. The correlation coefficient was 0.87. The correlation coefficient between LPV and conductivity for the nano-Au silicon sample was 0.41.