• Journal of the Korean Institute of Intelligent Systems
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• v.7 no.2
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• pp.34-42
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• 1997

This paper deals with the recognition of closed planar shape using a three dimensional spectral feature vector which is derived from the FFT(Fast Fourier Transform) spectrum of contour sequence and fuzzy ARTMAP neural network classifier. Contour sequences obtained from 2-D planar images represent the Euclidean distance between the centroid and all boundary pixels of the shape, and are related to the overall shape of the images. The Fourier transform of contour sequence and spectrum analyzer are used as a means of feature selection and data reduction. The three dimensional spectral feature vectors are extracted by spectrum analyzer from the FFT spectrum. These spectral feature vectors are invariant to shape translation, rotation and scale transformation. The fuzzy ARTMAP neural network which is combined with two fuzzy ART modules is trained and tested with these feature vectors. The experiments including 4 aircrafts and 4 industrial parts recognition process are presented to illustrate the high performance of this proposed method in the recognition problems of noisy shapes.

• Nuclear Engineering and Technology
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• v.11 no.1
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• pp.21-27
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• 1979

The relative reaction rates were measured in the TRIGA Mark II reactor core and analyzed to obtain the neutron spectrum parameters; relative neutron temperature T$^{n}$ and epithermal index (equation omitted) Measurements were made with the central thimble and the F2 position containing the light water. The relative neutron temperature was represented by the activation ratio of Lu-Mn, and the epithermal index was measured by Au-Mn foil activation. The multichannel analyzer was used to measure the relative ${\gamma}$-rays of the detector foils. The results were compared with the calculated values.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.1
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• pp.33-39
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• 2018

An additive noise reduction algorithm for a mass spectrum analyzer is proposed. From the measured ion signal, we first used an estimated threshold from the mode of the measured signal to eliminate background noises with the white Gaussian characteristics. Also, a signal block corresponding to each mass index is constructed to perform a second order curve fitting and a linear approximation to signal block. In this process, the effective signal block composed of only the ion signal can be reconstructed by removing the impulsive noises and the sample signals which are insufficient to be viewed as normal ion signals. By performing curve fitting on the effective signal block, the noise-free mass spectrum can be obtained. To evaluate the performance of the proposed method, a simulation was performed using the signals acquired from the development equipment. Simulation results show the validity of the threshold setting from the mode and the superiority of the proposed curve fitting and linear approximation based noise canceling algorithm.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.5
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• pp.165-171
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• 1996

A noncoherent full-digital PN(pseudo noise) code acquisition/tracking loop has been presetned and implemented in FPGA for the CDMA band-limited direct-sequence spread-spectrum (DS-SS) signals. It employs a simple decimator to control of local PN code phase to lower the hardware cost, and a second order loop to enable the more accurate tracking. The proposed acquisition/tracking loop has been designed in RTL-level VHDL, synthesized into logic gates using the design analyzer of synopsys software, implemented in an ALTERA FPGA chip, and tested. The number of logic gates used in the implemented FPGA chip is around 7000. The functionality has been verified using a PC interface circuitry and a logic analyzer.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.73-79
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• 2001

In this paper, shielding effectiveness(SE) of the shielding material of electromagnetic(EM) waves was investigated with actual experiments. The materials used in this study were made up of sputtering, film and powder of conductive materials - Cr, Al, Ag and Cu etc. Also, the polyester film was used as a base material. The experiment was carried out by using a shielding evaluator(Shielding box) TR17302 with an ADVANTEST spectrum analyzer, model R3361C. It was found from the experimental results that silver, copper, aluminum and chromium were good candidates as a shielding material against the EM waves with increasing the SE as the composite was laminated. The characteristics of the SE against the EM waves depended on a mode of preparation of specimen. The effects of density of particles on the SE were studied when the sputtering. The SE strongly depended on the electric resistance by density of sputtering and painting particles. SE increased as the density of particles was increasing.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.136-136
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• 2010

일반적인 플라즈마의 밀도측정에는 랑뮤어(Langmuir)탐침법이 보편적으로 사용되고 있다. 그러나 LCD(Liquid Crystal Display)나 PDP(Plasma Display Panel) 등 미세 방전 플라즈마는 이러한 방법으로는 측정이 너무 어려워서 잘 사용되지 않고 있다. 그래서 이러한 경우 간접측정 방법이 사용되고 있다. 본 연구에서는 알려진 간접 측정방법과는 다른 방식인 spectrum analyzer를 사용하여 측정해 보았다. LCD에서 사용되는 BLU(Back Light Unit)lamp와 PDP panel을 각각 측정하여 기존의 간접측정 방법의 결과와 비교해 보았다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.3
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• pp.224-238
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• 1987

In the proposed spectrum analyzer, open-loop VCO is replaced with PLL synthesizer incorporating digital frequency synthesizer using modulofunction for measuring precise frequencys. Three different frequency bands and channel spacings are realized by single loop synthesizer through the effective design of the system. The newly designed system with square detection has a good linearity of input range from 10mV to 8.5V, as a result the input sensitivity has been improved up to 500uV. The storage function enables us to analyze not only periodic but also nonperiodic wave-form and zoom-in function expands frequency resolution eight times for the dense spectra.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2450-2452
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• 1999

Presently, it is now developing the optical remote gas sensor system which can measure combustible gases such as $CH_4$ and $C_2H_2$ generating by partial discharges inside the cable and connection parts to detect thermal deterioration of Oil-Filled (OF) power cable at the appropriate time. It is the most important parameter to select central wavelength of laser diode (LD) by analyzing the absorption bend of measuring gases in the infrared region. In this research, we proposed the optical spectrum analyzer to absorption band of $CH_4$ and $C_2H_2$ for the preliminary research of optical fiber gas detecting system.

• Journal of IKEEE
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• v.19 no.2
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• pp.176-185
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• 2015

The study aims to a design hybrid frequency synthesizer in spectrum analyzer and to propose new techniques designed for evasion of in-band spurious. The study focuses on calculating the exact location of multiple phase locked loop of hybrid frequency synthesizer and spurious of direct digital synthesizer to evade in-band spurious outside of frequency range that the user wants to see and thereby simulating technique to improve input related spurious of spectrum analyzer for algorithm. The proposed technique is designed to calculate spurious evasion algorithm in central processing system when in-band spurious arises, and to move output frequency of DDS(direct digital synthesizer) into the place where no in-band spurious exists thereby improving performance of frequency synthesizer. The study used simulation and result representation to prove the effectiveness of the proposed technique.

• Proceedings of the Optical Society of Korea Conference
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• 2004.07a
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• pp.144-145
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• 2004