• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.3
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• pp.284-290
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• 1991

A detection scheme wiich has based in rank statistic is obtained for detection of random signals in additive noise. It is shown that the detector has similarities to the locally optimum detector for random signals and that it is a generalization of the locally optimum rank detector for known signals. Performance of the detector is also considered together with that of other detectors.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1354-1357
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• 2002

In this paper, we propose a suboptimal receiver combining adaptive array antenna and orthogonal decision-feedback detector in DS/CDMA system. Adaptive array antenna can cancel out undesired signal using beamforming scheme. However, if there are interfering signals from undesired users with the same incident angle as that of a desired user, an adaptive array antenna cannot suppress them. The proposed receiver can cancel out remaining interference from users having nearly the same beam pattern. And we employ Orthogonal Decision-Feedback Detector (ODFD) as multiuser detection. The ODFD performs as good as the decorrelating decision -feedback detector (DDD) with much less complexity. Simulation results show that the proposed system provides a significantly enhanced performance.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.130-136
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• 1998

In the PANBOX 2 system an excore detector module simulating the excore signal responses during a short term transient is implemented in order to simulate the reaction of the flux detector and control system upon rapid power changes as it occurs e. g, in rod drop events. This module has been verified in the past by comparison calculations with the PANBOX 1 system. This report describes additional PANBOX 2 validation calculations which have bee compared with experiment data measured at german plant KKG, cycle 1, for a rod drop event. In general, the PANBOX 2 results are in very good agreement with the KKG experiments. Therefore it is concluded that the excore detector model of PANBOX 2 is successfully validated.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.5
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• pp.949-955
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• 1997

Detection of the existence of a desired user is considered in this paper. We assume that the signal to noise ratio is high enough for us to ignore the effects of noise compared with those of the interference by other users. The inter-user interference and user signals are modeled by the Nakagami model. An observation model for this situation is proposed, the locally optimum test statistic is derived under the model, and the asymptotic performance of the locally optimum detector is compared with of the envelope detector. We show that the locally optimum detector performs better than the conventional envelope detector.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.1
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• pp.96-102
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• 2004

In this paper, optical noise is reduced by a differential detector, which is composed of a beam splitter and two photodiodes whose spectral responses are different each other. In this configuration, the automatic gain control circuit is not required for noise cancellation because the noise intensities at the two photodiodes are kept equal by a beam splitter. The signal to noise ratio in a differential detector with a beam splitter was improved to be 14 ㏈ higher than in a single photodiode with optical filtering.

• Nuclear Engineering and Technology
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• v.55 no.5
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• pp.1533-1540
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• 2023

Self-Powered Neutron Detectors(SPNDs) are used to calculate core power distributions, an essential factor in the safe operation of nuclear power plants. Some detectors may fail during normal operation, and signals from failed detectors are isolated from intact signals. The calculated detailed power distribution accuracy depends on the number of available detector signals. Failed detectors decrease the operating margin by enlarging the power distribution measurement error. Therefore, a thorough reconstruction of the failed detector signals is critical. This note suggests a compressive sensing based methodology that rationally reconstructs the readings of failed detectors. The methodology significantly improves reconstruction accuracy by sorting signals and removing high-frequency components from conventional compressive sensing methodology.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.2C
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• pp.184-190
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• 2006

In this paper, we propose the blind multiuser detector which is robust against the effects of near-far and multiuser interference. The proposed detector is composed of the partial IC(interference canceller) and the blind MOE(minimum output energy) multiuser detector. The partial IC partially eliminates interference components from the received signal then the output of partial IC is fed into the input of multiuser detector. Simulation results show that the proposed detector has the robust property but the performance of conventional MOE multiuser detector is rapidly degraded in case of existing both near far and multiuser. Thus, the proposed partial IC BMUD(blind multiuser detection) technique has better performance than the conventional MOE.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.612-615
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• 2003

In this paper, a design of radiation detector for gamma column scanner is introduced. Distillation column is important unit in Petro-chemical industries, and its on-line diagnose is very important. To get density profile measured by the radiation transmitted through column is well method for on-line diagnose as gamma scanning. For this purpose radiation detection circuit, radiation source and mechanical system for moving source and detector are required. Conventional radiation detection circuit for this application is sensitive to electric noise because of interface between the radiation circuit and the controller for mechanical system. The radiation detection system introduced here is using loop coil instead of slip ring to remove contact noise. Radiation detection system designed here for gamma scanning consist of BGO detector, high voltage circuit, PHA circuit and FSK modem. The BGO detector is used as radiation sensor, high voltage circuit and peak height analysis circuit is essential to process the signal generated from BGO detector. Micro controller convert measured data into ASCII data. FSK modem transmit ASCII data. Transmitted ASCH data is picked up in antenna coil and processed for combined function with mechanical system. This method gives good result by isolating the controlling circuit of mechanical system from radiation detecting circuit which is sensitive to noise.

• Nuclear Engineering and Technology
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• v.56 no.5
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• pp.1733-1737
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• 2024

In order to specify the location of the scintillation pixel that interacted with gamma rays in the positron emission tomography (PET) detector, conventionally, after acquiring a flood image, the location of interaction between the scintillation pixel and gamma ray could be specified through a pixel-segmentation process. In this study, the experimentally acquired signal was specified as the location of the scintillation pixel directly, without any conversion process, through the simulation data and the deep learning algorithm. To evaluate the accuracy of the specification of the scintillation pixel location through deep learning, a comparative analysis with experimental data through pixel segmentation was performed. In the same way as in the experiment, a detector was configured on the simulation, a model was built using the acquired data through deep learning, and the location was specified by applying the experimental data to the built model. Accuracy was calculated through comparative analysis between the specified location and the location obtained through the segmentation process. As a result, it showed excellent accuracy of about 85 %. When this method is applied to a PET detector, the position of the scintillation pixel of the detector can be specified simply and conveniently, without additional work.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.45-48
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• 2003

This research presents an approach to simultaneously detect the faults and measure the length of the electric cables. This approach is easy to use and inexpensive. Moreover, it can be applied to any kinds and sizes of the electric cable. This paper uses 750V $4{\times}4$ Sq.mm. cables. The concept is to send the 2 kHz pulse into the electric cable. When the pulse bumps into the fault, it bounces back. Then, the total time the pulse travels back and forth and the shape of the pulse after bumping are inspected using the pulse detector and pulse converter. Next, the signal obtained is modulated with 10 MHz carrier pulse to segregate into several small pulses before sending to 8-bit counter. The length of the electric cable can be obtained using microcontroller and the location of the faults can be seen on the LCD screen. This approach can be used to inspect the electric cables with the length of at least 15 m.