• The Journal of the Acoustical Society of Korea
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• v.22 no.2
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• pp.135-144
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• 2003

A method for the automatic segmentation of speech signals is described. The method is dedicated to the construction of a large database for a Text-To-Speech (TTS) synthesis system. The main issue of the work involves the refinement of an initial estimation of phone boundaries which are provided by an alignment, based on a Hidden Market Model(HMM). Multi-layer perceptron (MLP) was used as a phone boundary detector. To increase the performance of segmentation, a technique which individually trains an MLP according to phonetic transition is proposed. The optimum partitioning of the entire phonetic transition space is constructed from the standpoint of minimizing the overall deviation from hand labelling positions. With single speaker stimuli, the experimental results showed that more than 95% of all phone boundaries have a boundary deviation from the reference position smaller than 20 ms, and the refinement of the boundaries reduces the root mean square error by about 25%.

• IEIE Transactions on Smart Processing and Computing
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• v.6 no.1
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• pp.66-70
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• 2017

Radioactive materials are used in medicine, non-destructive testing, and nuclear plants. Source localization is especially important during nuclear decommissioning and decontamination because the actual location of the radioactive source within nuclear waste is often unknown. The coded-aperture imaging technique started with space exploration and moved into X-ray and gamma ray imaging, which have imaging process characteristics similar to each other. In this study, we simulated $21{\times}21$ and $37{\times}37$ coded aperture collimators based on a modified uniformly redundant array (MURA) pattern to make a gamma imaging system that can localize a gamma-ray source. We designed a $21{\times}21$ coded aperture collimator that matches our gamma imaging detector and did feasibility experiments with the coded aperture imaging system. We evaluated the performance of each collimator, from 2 mm to 10 mm thicknesses (at 2 mm intervals) using root mean square error (RMSE) and sensitivity in a simulation. In experimental results, the full width half maximum (FWHM) of the point source was $5.09^{\circ}$ at the center and $4.82^{\circ}$ at the location of the source was $9^{\circ}$. We will continue to improve the decoding algorithm and optimize the collimator for high-energy gamma rays emitted from a nuclear power plant.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.7
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• pp.666-676
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• 1992

In this paper, algorithm and testable circuit to find all PSF(Pattern Sensitive Fault ) occured in RAM were proposed. Conventional test circuit and algorithm took much time in testing because consecutive test for RAM cells or f-dimensional memory struciure was not employed. In this paper, methodology for parallel RAM-testing was proposed by compensating additional circuit for test to conventional RAM circuit. Additional circuits are parallel comparator, error detector, group selector circuit and a modified decoder used for parallel testing. And also, the constructive method of Eulerian path to obtain efficient test pattern was performed. Consequently, If algorithm proposed in this paper Is used, the same operations as 32sxwor4 lines will be needed to test b x w=n matrix RAM. Circuit simulation was performerd, and 10 bits x :If words testable RAM was designed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.11
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• pp.1635-1644
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• 1993

In this paper, we examine the statistical characteristics of edge enhancing filters and their efficacy as preprocessing operator before edge detection. In particular, edge enhancing filters called the Comparison and Selection(CS), Hachimura-kuwahara(HK), and Selective Average(SA) filters are considered. These filters can reduce noise while producing step-type edges, thus seem to be effective for preprocessing noisy images prior to applying edge detecors. The ability of edge enhancing filters to suppress white Gaussian noise and the error probabilities occured during the edge detection following SA prefiltering are evaluated statistically through numerical analysis. The effect of prefiltering on edge detection is assessed by applying the edge enhancing fitters to a noise image degraded by additive white noise prior to applying the Sobel operator and the Laplacian of Gaussian( LoG ) operator, respectively. It is shown that the edge enhancing filters tend to produce ideal step-type edges while reducing the noise reasonably well, and the use of edge enhancing filters prior to edge detection can improve the performance of subsequent edge detector.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.12A
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• pp.1279-1284
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• 2004

In this paper, we propose a novel and simple optical technique for the detection of subcarrier-multiplexed(SCM) labels using optical interleavers. Optical-baseband packet signals with suppressed subcarriers appear at the through-pass port of the optical interleaver and SCM labels with suppressed optical carrier exit from the optical SCM extraction port. Since it does not require optical circulators, this structure shows less insertion loss than the previously proposed optical label detectors. The periodic nature of the interleaver transfer function makes it possible to detect multiple SCM channels simultaneously from an incoming wavelength-multiplexed signal stream. Detection of a 155-Mb/s ASK modulated 9.79-GHz subcarrier using a 10-GHz SCM optical label detector has been performed successfully and verified through optical spectra and bi t-error-rate measurements.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.6A
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• pp.500-505
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• 2009

In this paper, We present a low complexity candidate list generation scheme in iterative MIMO receiver. Since QAM modulation can be decomposed into HP symbols and LP symbol and HP symbol is robust in error capability, we generate HP symbol list with simple ZF detector output and its corresponding neighbor HP symbols, Then, based on HP symbol list, the LP symbol list is generated by using the sphere decoder. From the second iteration, since apriori value from channel decoder is available, the candidate list is updated based on demodulated apriori value. Through the simulation, we observe that at the first iteration, the BER performance is worse than LSD. However, as the number of iteration is increased, the proposed scheme has almost same performance as LSD. Moreover, the proposed one has reduced candidate list generation time and lower number of candidate list compared with LSD.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.7
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• pp.646-652
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• 2016

This paper presents a tumor detection for breast cancer that utilizes two-dimensional(2D) image reconstruction with microwave tomographic imaging. The breast cancer detection system under development consists of 16 transmit/receive antennas, and the microwave tomography system operates at 1,700 MHz. The four types of breast(ED-, HD-, SC-, and FT-type) are used for image reconstruction. To solve a 2D inverse scattering problem, the method of moments(MoM) is employed for forward problem solving, and the simplex method employed as an optimization algorithm. The results of the reconstructed image show that the ED- and HD-types of breasts are well reconstructed, but SC- and FT-type breasts are not well because of the error including.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.5
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• pp.71-76
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• 2000

A TC-16ADPSK scheme for transmitting different kinds of information simultaneously is proposed in this paper. The scheme is designed for simultaneously transmitting two kinds of Information on one channel. In signal mapping, a data of two kinds of information is used to phase modulation on Star-16APSK constellation and the other to amplitude modulation. In detection, each data independently recovers from mixing signal on each detector Therefore, we can transmit two kinds of Information on one channel can be transmitted efficiently. BER performance of the proposed scheme is analyzed on AWGN channel and Rayleigh fading channels on a computer with Matlab communication toolbox. On same SNR, the Gray code mapping has more 0.5-1.5dB coding gains than Ungerboeck's code mapping gains.

• Journal of Korea Multimedia Society
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• v.12 no.3
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• pp.329-334
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• 2009

When an optical disc is being played. the pick-up converts light to analog signal at first. The analog signal is equalized for removing the inter-symbol interference and then the equalized analog signal is converted into the digital signal for extracting the synchronized data and clock signals. There are a lot of algorithms that minimize the BER in extracting the synchronized data and clock when high. density optical disc like BD is being played in low speed. But if the high-density optical disc is played in high speed, it is difficult to adopt the same extraction algorithm to data PLL and PRML architecture used in low speed application. It is because the signal with more than 800MHz should be processed in those architectures. Generally, in the 0.13-${\mu}m$ CMOS technology, it is necessary to have the high speed analog cores and lots of efforts to layout. In this paper, the parallel data PLL and PRML architecture, which enable to process in BD 8x speed of the maximum speed of the high-density optical disc as the extracting data and clock circuit, is proposed. Test results show that the proposed architecture is well operated without processing error at BD 8x speed.

• Analytical Science and Technology
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• v.15 no.5
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• pp.399-409
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• 2002

A system software on-line spectral analysis of atomic emission spectrometer. The system program consisted of a control part for the optical instruments and the spectrum analysis part the artificial intelligence method to reduce nonlinear error of the wavelengths. McPHERSON 207 Monochromator controlled GPIB communication protocol, and the detector signal was measured from PMT by using A/D Amplifier that was made by Photon_Tek. co.. HNN(Hybrid Neural Network) of artificial intelligence technique was applied to the qualitative analysis of P, Cu, Fe, Cr, and that was accurately applied to the quantitative analysis of Cd with 10 ppb level better than the conventional methods.