• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.718-720
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• 1999

This paper describes a charge pump PLL architecture which achieves high frequency operation and fast acquisition. This architecture employs multi-phase frequency detector comprised of precharge type phase frequency detector and conventional phase frequency detector. Operation frequency is increased by using precharge type phase frequency detector when the phase difference is small and acquisition time is shortened by using conventional phase frequency detector and increased charge pump current when the phase difference is large. By virtue of this multi-phase frequency detector structure, the maximum operating frequency of 694MHz at 3.0V and faster acquisition were achieved by simulation.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.106-109
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• 1998

Wireless communication systems, in particular, must operate in a crowded electro-magnetic environmnet where in-band undesired signals are treated as noise by the receiver. These interfering signals are often random but not Gaussian Due to nongaussian noise, the distribution of the observables cannot be specified by a finite set of parameters; instead r-dimensioal sample space (pure noise samples) is equiprobably partitioned into a finite number of disjointed regions using quantiles and a vector quantizer based on training samples. If we assume that the detected symbols are correct, then we can observe the pure noise samples during the training and transmitting mode. The algorithm proposed is based on a piecewise approximation to a regression function based on quantities and conditional partition moments which are estimated by a RMSA (Robbins-Monro Stochastic Approximation) algorithm. In this paper, we develop a diversity combiner with modified detector, called Non-Linear Detector, and the receiver has a differential phase detector in each diversity branch and at the combiner each detector output is proportional to the second power of the envelope of branches. Monte-Carlo simulations were used as means of generating the system performance.

• Journal of Sensor Science and Technology
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• v.13 no.2
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• pp.133-138
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• 2004

Today, the obstacle detection system has massive size and restrictive detection range. To solve these problems, this paper proposes the capacitance variation detector using the variated capacitance value as a result of the obstacle approaching. If obstacle approaches, the capacitance value of capacitance sensor is increased and the operating frequency of oscillator is decreased. Then this changed frequency appears to the output of the mixer that operate down conversion. The capacitance variation detector is produced by Hynix$0.35{\mu}$ CMOS process. In experiment result, the frequency of final output is 6.81 MHz at no obstacle and 31.45 MHz at approaching obstacle. In conclusion, proposed capacitance variation detector has small size, low power consumption and easiness to set up anywhere. So it is expected to substitute the obstacle detector.

• 한국데이터정보과학회:학술대회논문집
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• 2004.04a
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• pp.197-201
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• 2004

We describe a new edge detector based on the robust rank-order (RRO) test which is a useful alternative to Wilcoxon test, using $r{\times}r$ window for detecting edges of all possible orientations in noisy images. Some experiments of statistical edge detectors based on the Wilcoxon test and T test with our RRO detector are carried out on synthetic and real images corrupted by both Gaussian and impulse noise. We also implement these edge detectors using Java on the Web.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.389-393
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• 2003

This paper describes the design of enhanced TSSI RF Power Detector which has wide dynamic range using switch and Log amp. This Power Detector consists of low and high gain loops, and they adaptively switched by output DC voltage which is proportioned to input power level. Because Power Detector needs to separate the channel, so architecture is heterodyne system having 70MHz intermediate frequency. This proposed RF Power Detector is settle to the satisfaction of Closed loop power control system for W-CDMA optic repeater, and the obtained dynamic range cover the higher than 50dB.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.9
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• pp.707-712
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• 2017

In this paper, the performance characteristic of 3 dimensional pulse detector using SMA connector is analyzed. Modeling of 3D pulse detectors is done in a commercial simulator. When a pulse is incident on the detector, we analyze the performance characteristics of the detector and verify the feasibility of the pulse detector.

• Journal of information and communication convergence engineering
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• v.18 no.1
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• pp.33-38
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• 2020

Elasticsearch is an open source search and analytics engine that can search petabytes of data in near real time. It is designed as a distributed system horizontally scalable and highly available. It provides RESTful APIs, thereby making it programming-language agnostic. Full text search of multilingual text requires language-specific analyzers and field mappings appropriate for indexing and searching multilingual text. Additionally, a language detector can be used in conjunction with the analyzers to improve the multilingual text search. Elasticsearch provides more than 40 language analysis plugins that can process text and extract language-specific tokens and language detector plugins that can determine the language of the given text. This study investigates three different approaches to index and search Chinese, Japanese, and Korean (CJK) text (single analyzer, multi-fields, and language detector-based), and identifies the advantages of the language detector-based approach compared to the other two.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.4
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• pp.53-60
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• 2008

Electron detectors used in scanning electron microscope accept electrons emitted from the specimen and convert them to an electrical signal that, after amplification, is used to modulate the gray-level intensities on a cathode ray tube, producing an image of the specimen. Electron detector is one of the key components dominating the performance of scanning electron microscope so that the development of electron detectors having high performance is indispensable to acquire high quality images using scanning electron microscope. In this paper, we designed and manufactured an electron detector and conducted a couple of image capture experiments using it. In particular, scintillator which generates light photons when it is struck by high-energy electrons was manufactured and experimental studies on the optimization of manufacturing condition was carried out. From experiments to evaluate the performance of our detector, it was verified that the performance of our detector is equivalent to or better than that of the conventional one.

• Fire Science and Engineering
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• v.17 no.3
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• pp.26-30
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• 2003

This paper presents a study on the analysis for false alarm of heat detector using HRR(Heat Release Rate). And it is represented to threshold value and domain of false alarm. The HRR threshold value of false alarm is calculated to use parameters obtained by small scale fire-experiment. The experiment is conducted to measure detector activation time and flame spread of wood cribs fire, etc. The results show that HRR threshold value of Fixed type detector is 20.24 kW and rate of rise type detector is 13.59 kW, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.4
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• pp.796-804
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• 1998

Multiplicative noise is known to be useful in modeling multipath propagation, which is crucial in mobile communication systems analysis. In this paper, nonparametric detection of weak random signals in multiplicative noise is considered. The locally optimum detector based on signs and ranks of observations isderived for good weak-signal detection performance under any noise probability density function. the detector has similarities to the locally optimum detector for random signals in multiplicative noise. It is shown that the nonparametric detector asymptotically hs almost the same performance as the locally optimum detector.