• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.2
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• pp.240-246
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• 2006

This paper proposes the intelligent immigration control system that authorizes the traveler through immigration and detects forged passports by using automatic recognition of passport codes, the passport photo and face verification. The proposed system extracts and deskewes the areas of passport codes from the passport image. This paper proposes the novel ART algorithm creating the adaptive clusters to the variations of input patterns and it is applied to the extracted code areas for the code recognition. After compensating heuristically the recognition result, the detection of forged passports is achieved by using the picture and face verification between the passport photo extracted from the passport image and the picture retrieved from the database based on the recognized codes. Due to the proposed ART algorithm and the heuristic refinement, the proposed system relatively shows better performance.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.34 no.7
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• pp.289-296
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• 1985

The Townsend primary ionization coefficient a was measured by the luminous-flux method using the fact that the intensity of radiant light is proportional to electron density in the townsend discharge domain. The ranges of measurements were 15for He gas and 10

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.365-367
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• 2006

광용적맥파를 이용하여 일상생활에서 심장 박동을 관찰하고 심장 박동의 이상을 경고할 수 있는 저렴하면서도 간단한 심박 측정 장치를 구성하고 심장박동을 검출하였다. 심장박동의 검출을 위해 Ring형 광용적맥파 센서를 635nm의 적색 LD와 Si Photodiode로 제작하였다. 제작된 Ring형 광용적맥파 센서는 잡음 및 오차로 작용하는 외부 광원을 차단하였으며, 동(動)잡음의 영향을 최소화하기 위해 측정부위에 밀착하도록 하였다, 측정결과 제작된 센서는 심장박동 신호를 외부 영향 없이 안정적인 검출이 가능함을 알 수 있었다.

• Journal of the Optical Society of Korea
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• v.17 no.1
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• pp.73-80
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• 2013

In the process of lithography using ultra violet light sources for semiconductor devices, most of defects are made by sub-micrometer pollutants generated at photochemical reactions. We proposed and developed a novel vibration-insensitive on-axis interferometer with a sub-micrometer lateral resolution by using the interference between two beams: one scattered from defects and the other reflected from a reference area without defects. The proposed system was successfully demonstrated to detect a small Al defect of 0.5 ${\mu}m$ diameter within the inspection time of less than 30 minutes over the area of the photo-mask which is 6 inch by 6 inch square.

• Particle and aerosol research
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• v.13 no.1
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• pp.25-31
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• 2017

This paper offer the characteristics for the detection and classification of biological and non-biological aerosol particles in the air by using laser-induced-fluorescence (LIF) based Bio-aerosol Detection System (BDS). The BDS is mainly consist of an optical chamber, in-outlet nozzle system, 405 nm diode laser, an avalanche photo detector (APD) for scattering signal and photomultiplier tubes (PMT) for fluorescence signals in two different wavelength range ; F1, 510-600 nm and F2, 435-470 nm. The detection characteristics, especially ratio of fluorescence signal intensity were examined using well-known components : polystylene latex (PSL), fluorescence PSL, $2{\mu}m$ of SiO2 micro sphere, dried yeast, NADH, ovalbumin, fungicide powder and standard dust. The results indicated that the 405 nm diode laser-based LIF instrument can be a useful bio-aerosol detection system for unexpected biological threaten alter in real-time to apply for dual-use technology in military and civilian fields.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.10
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• pp.2189-2196
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• 2009

Theoretical analysis is presented for expending of the usable frequency range of optoelectronic mixing detection in the radio over fiber network system. We define the normalized gain to evaluate the performance of the optical mixing detection, and conform the possibilities of detection for the high frequency signals beyond the cutoff frequency of a photodiode. Optical mixing detection mechanism is analyzed by solving the continuity equation for the carriers of a photodiode. The normalized gain is independent on the signal frequency and the frequency difference between the optical signal and the local signal. Also, the amplitude of the local signal and the bias voltage are needed to be optimized at the same time in order to maximize the normalized gain.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.7
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• pp.1386-1392
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• 2009

An analysis is presented for super-high-speed optical demodulation by an avalanche photodiode(APD) with electric mixing. A normalized gain is defined to evaluate the performance of the optical mixing detection. Unlike previous work, we include the effect of the nonlinear variation of the APD capacitance with bias voltage as well as the effect of parasitic and amplifier input capacitance. As a results, the normalized gain is dependent on the signal frequency and the frequency difference between the signal and the local oscillator frequency. However, the current through the equivalent resistance of the APD is almost independent of signal frequency. The mixing output is mainly attributed to the nonlinearity of the multiplication factor. We show also that there is an optimal local oscillator voltage at which the normalized gain is maximized for a given avalanche photodiode.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.378-379
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• 2011

PV system's islanding occurs when the uitilty grid is removed but local sources continue to operate and provide power to local loads. Islanding is one of the serious problems in an electric power system connected with dispersed power sources. Also, this can present safety hazards and the possibility of damage to other electric equipments. If the real and reactive power of RLC load and PV system are closely matched, islanding detection by passive methods becomes difficult. Novel islanding detection method is proposed for grid-connected PV system.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.2
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• pp.303-308
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• 2012

One dimensional line edge detection sensor was investigated for the application to detect line or edge of wide sheet winding to cylindrical roller. Line edge detection sensor was realized using align-free 1:1 optical system having 1 convex lens and by processing sum or difference of signals from two photo-diodes in a bi-cell photodetector. Line width up to 0.1mm on object having various materials and colors was detectable, and the deviation of wound sheet was found to be under 0.2mm.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.540-540
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• 2012

Selective detection of single nucleotide polymorphism (SNP) of Cytochrome P450 2C19 (CYP2C19) was carried out by the PNA chips which were electrically-interfaced with interdigitated nanogap electrodes (INEs). The INEs whose average gap distance and effective gap length were about ~70 nm and ${\sim}140{\mu}m$, respectively, were prepared by the combination of the photo lithography and the surface-catalyzed chemical deposition, without using the e-beam lithography which is almost inevitable in the conventional lab-scale fabrication of the INEs. Four different types of target DNAs were successfully detected and discriminated by the INE-based PNA chips.