• Journal of the Korea Society of Computer and Information
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• v.21 no.12
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• pp.131-137
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• 2016

In this paper, the peak finding algorithms corresponding to the Autocorrelation Function (ACF), which are widely exploited for detecting the pitch of voiced signal, are proposed. According to various researchers, it is well known fact that the estimation of fundamental frequency (F0) in speech signal is not only very important task but quite difficult mission. The proposed algorithms, presented in this paper, are implemented by using many characteristics - such as monotonic increasing function - of ACF function. Thus, the proposed algorithms may be able to estimate both reliable and correct the fundamental frequency as long as the autocorrelation function of speech signal is accurate. Since the proposed algorithms may reduce the computational complexity it can be applied to the real-time processing. The speech data, is composed of Korean emotion expressed words, is used for evaluation of their performance. The pitches are measured to compare the performance of proposed algorithms.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.7
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• pp.898-902
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• 2018

A novel heart beat interval estimation algorithm is presented based on parabola approximation method. This paper presented a two-step processing scheme; a first stage is finding R-peak in the Electrocardiogram (ECG) by Shannon energy envelope estimator and a secondary stage is computing the interpolated peak location by parabola approximation. Experimental results show that the proposed algorithm performs better than with the previous method using low sampled ECG signals.

• ETRI Journal
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• v.42 no.2
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• pp.247-257
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• 2020

Spatial experiences in route finding, such as the ability of finding low-traffic routes, exert a significant influence on travel time in big cities; therefore, the spatial experiences of seasoned individuals such as taxi drivers in route finding can be useful for improving route-finding algorithms and preventing using routes having considerable traffic. In this regard, a spatial experience-based route-finding algorithm is introduced through ontology in this paper. To this end, different methods of modeling experiences are investigated. Then, a modeling method is chosen for modeling the experiences of drivers for route finding depending on the advantages of ontology, and an ontology based on the taxi drivers' experiences is proposed. This ontology is employed to create an ontology-based route-finding algorithm. The results are compared with those of Google maps in terms of route length and travel time at peak traffic time. According to the results, although the route lengths of route-finding method based on the ontology of drivers' experiences in three cases (from nine cases) are greater than that based on Google maps, the travel times are shorter in most cases, and in some routes, the difference in travel time reaches only 10 minutes.

• Korean Journal of Optics and Photonics
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• v.11 no.6
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• pp.395-399
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• 2000

In white light interferometry, fast and accurate localization of the fringe visibility is the most essential part in application of the principle. So much attention has been concentrated on speeding up the process, we in this study decided to investigate the results of the various peak-finding algorithms. Of the many approaches, two most simplistic algorithms were selected for their straightforwardness and robustness. Both were equally accurate in measuring the step height of a sample, but the method based on the weighted average technique proved to be truer to the surface topography. A model explaining the shortcomings of the correlation technique is presented. ented.

• Journal of the Korean Wood Science and Technology
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• v.41 no.5
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• pp.399-405
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• 2013

This study demonstrates the utilization of light microscopy and Fast Fourier Transform-Peak Finding (FPF) method for microfibril angle (MFA) measurement from unstained sections of red pine (Pinus densiflora). To obtain an image with optimal contrast and resolution for MFA measurement, effects of numerical aperture (NA) of condenser lens and color filters were investigated. About 60% of NA of the maximum condenser NA produced an image with optimal contrast, but a color filter with short wavelength range (DAPI) created images with improved resolution. Manual angle measurement and the FPF method were applied to the image with optimal contrast for MFA measurement. The experimental results from the FPF method were considered to be more repeatable and less subjective than those from the manual angle measurement.

• Journal of Environmental Science International
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• v.11 no.10
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• pp.1081-1087
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• 2002

This study was performed to research the characteristics of suspended particulate for Yellow Sand of January, 1999 in Busan. Yellow Sand frequency during 13 years(1988~2000) in Busan showed maximum in April(57%), next to March(21%), May(16%). According to result of 850hPa weather map and backward isentropic trajectory, this event originated from the Gobi Desert and the Loess Plateau of China. And three mode was found in time series of TSP and PM10 concentration, primary peak showed the maximum hourly concentration at ali station. Gamjeondong as industrial site showed the highest TSP concentration and also had the longest high concentration($geq700\mu\textrm{g}/m^3$). In PM10, concentration of primary peak showed maximum value at Yeonsandong, maximum concentration of secondary and third peak was Deokcheondong. Lasted time from primary peak to secondary peak was about 30 hours, between secondary peak and third peak was 18 hours in Busan, The traveling time between occurrence of Yellow Sand the finding of it was 8~9 hours in Busan and 4~5 hours in central area.

• Phonetics and Speech Sciences
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• v.4 no.3
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• pp.43-49
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• 2012

This paper describes the categorical effects of pitch accent contrasts in a mimicry task. It focuses, specifically, on examining how fundamental frequency (f0) variation reflects phonological contrasts from speakers of two distinct varieties of Korean (i.e., North Kyungsang and South Cholla). The results showed that, in a mimicry task using synthetic speech continua, there was a categorical effect in f0 peak timing for North Kyungsang speakers, but the timing of f0 peaks and valleys in the responses of South Cholla speakers was more variable, presenting a gradient or non-categorical effect. Evidence of categorical effects was represented as the shift of f0 peak times along an acoustic continuum for North Kyungsang speakers. The range for the shift of f0 valley times was much narrower, compared to that of f0 peak times. The degree of a shift near the middle of the continuum showed variability across individual mimicry responses. However, the categorical structure in mimicry responses regarding the clustering of f0 peak points was more significant for North Kyungsang speakers than for South Cholla speakers. Additionally, the finding of the current study implies that the location of f0 peak times depends on individuals' imitative (or cognitive) abilities.

• The Journal of the Acoustical Society of Korea
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• v.13 no.5
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• pp.77-82
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• 1994

In speech signal processing, it is very important to detect the pitch exactly. Although various methods for detecting the pitch of speech signals have been developed, it is difficult to exactly extract the pitch for wide range of speakers and various utterances. Thus we propose a new pitch detection algorithm which takes advantage of the G-peak extraction. It is a method to detect the pitch period of the voiced signals by finding MZCI (maximum zero-crossing interval) of the G-peak which is defined as cut-off bandwidth rate of LPF (low pass filter). This algorithm performs robustly with a gross error rate of 3.63% even in 0 dB SNR environement. The gross error rate for clean speech is only 0.18%. Also it is able to process all courses with high speed.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.825-826
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• 2006

In this paper, we propose an algorithm that applies Rolle's theorem to automatically detect and label peak III and V of the normal, suprathreshold auditory brainstem response (ABR). ABR waveform were recorded from 55 normal-hearing ears at screening levels varying from 30 to 60 dBnHL. For each ABR waveform, the peak-finding algorithm proceeded in fourth steps: (1) Select maximum and minimum values of the target ABR waveform, (2) divide this range into n equal parts, (3) effective candidate peaks in the ABR waveform are identified using Rolle's theorem (4) peak III and V are identified from these candidate peaks based on their latency and morphology. As a result, proposed auto dectection method showed high correlation and accuracy with manual detection method performed by clinician. By using proposed algorithm, clinician can detect and label peak III and V faster and more efficient than manual detection method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.2C
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• pp.174-180
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• 2007

In the tone reservation (TR) scheme, it is known that the set of randomly selected peak reduction tones (PRT's) performs better than the contiguous PRT set and the interleaved PRT set in the PAPR reduction of orthogonal frequency division multiplexing (OFDM). It is also known that finding the optimal PRT set corresponds to the secondary peak minimization problem in the TR scheme. However, the problem cannot be solved for the practical number of tones since it is NP-hard. In this paper, a new search algorithm for the near optimal PRT set is proposed based on the fact that the secondary peak value of the PRT set statistically tends to decrease asthe variance of the PRT set decreases.