• 한국음향학회:학술대회논문집
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• 한국음향학회 1993년도 학술논문발표회 논문집 제12권 1호
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• pp.88-92
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• 1993

In speech signal processing, it is necessary to detect exactly the pitch. The algorithms of pitch extraction which have been proposed until now are difficult to detect pitches over wide range speech signals. Thus we propose a new algorithm which uses the G-peak extraction to do it. It is the method that finds the most MZI(maximum zero-crossing interval) at each frame and convolve it with speech signal ; this is the same with passing speech signals to variable LPF. Finally we obtained the pitch, improve the accuracy of pitch detection and extract it with the high speed.

• 한국정보처리학회논문지
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• 제6권2호
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• pp.522-533
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• 1999

본 논문에서는 피지 파라미터와 퍼지 추론을 포함한 화자 인식 알고리즘을 제안한다. 시간영역에서 검출 알고리즘의 장점인 잡음에 강인함을 가진 PVPF 법을 제안하여 피치를 검출한다. 또한 화자 인식에서 특징량들의 애매성을 표현하고 인식하는 방법으로 퍼지 이론을 도입하였다. PVPF는 음의 시간적인 특징을 이용하여 국부적으로 봉우리와 골을 이룬다는 것을 이용한 계산량이 적고 잡음에 강인한 피치 검출법이다.

• 한국통신학회논문지
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• 제16권12호
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• pp.1324-1335
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• 1991

본 논문은 음절을 음소로 분리하고 각각의 특징을 추출하여 음소를 판별할 수 있는 패턴을 설정하는 실험에 관한 연구이다. 음소분리는 피치검출, 각 성문피크펄스의 폭, 포락실, 진폭의 바이어스, 발성시간 등의 파라메타를 적용한다. 최초의 피치는 성문펄스의 폭, 에너지, 정규화와 성문피크의 가변바이어스 등의 변화에 따라 모음 포라선의 봉우리 부분에서 검출, 이를 기준으로 전체의 피치구간을 추적한다. 모음은 포만트 패턴의 유동을 감소시키는 방법과 제2포만트만으로 모음의 판별이 가능함을 제시하며, 피치 고저에 무관한 압축파형을 추정한다. 자음은 포락실, 스펙트럼, 압추파형, 분석방법 등을 발음방법과 음소 상호 영향에서 패턴을 추출한다. 실험결과 모음음소 90%, 초성자음80%, 종성자음 60% 판별된다.

• 한국어교육
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• 제28권3호
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• pp.25-51
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• 2017

This study aimed to identify the differences in pitch perception between tonal and non-tonal language listeners. A total of 60 Korean and Chinese listeners participated in the perception test. A two-syllable nonsense word /paba/ was manipulated in five steps. The pitch height or contour on the second syllable was raised or lowered. Both groups were asked to select which of the two syllables had the higher pitch. The findings showed that the majority of Korean listeners (GK) perceived decreased pitch as each peak of the syllable was lowered and perceived increased pitch as it was raised, which means the pitch height is a primary perceptual cue for GK. However, Chinese listeners (GC) perceived sensitive pitch movements as the pitch contour changed. GC's perception may presumably be affected by the L1's tone sandhi. We found it reasonable to assume that language experience has a significant effect on the cross-linguistic perceptual differences between tone and non-tonal language listeners.

• 대한전자공학회논문지
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• 제23권1호
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• pp.101-113
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• 1986

In this paper, a real-time pitch detector LPC vocoder as implemented on a high speed digital signal processor, NEC 7720, is described. The pitch detector was based mainly on the SIFT algorithm. The SIFT pitch detector consists primarily of a digital low pass filter, inverse filter, computation of autocorrelation, a peak picker, interpolation, V/UV defcision and a final pitch smoother. In our approach, modification, mainly on the V/UV decision and a final pitch smoother, was made to estimate more accurate pitches. An 16-bit fixed-point aithmatic was employed for all necessary computation and the simulated results were compared with the eye detected pitches obtained from real speech data. The pitch detector occupies 98.8% of the instruction ROM, 37% of the data ROM, and 94% of internal RAM and takes 15.2ms to estimate a pitch when an analysis frame is consisted of 128 sampled speech data. It is observed that the tested results were well agreed with the computer simulation results.

• 말소리와 음성과학
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• 제6권4호
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• pp.53-65
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• 2014

The current research examines whether pitch contour shapes in North Kyungsang pitch accent contrasts provide a phonetic dimension for phonological discreteness in a mimicry task. Two pitch accent continua resynthesized were created for HH vs. HL and HH vs. LH. To confirm a phonetic dimension for accounting for pitch accent categories in North Kyungsang Korean, the mimicries of speakers of two dialects (i.e., North Kyungsang & South Cholla) were compared. One of the findings showed that, for North Kyungsang speakers, the range of mean f0 peak times was a phonetic dimension undergoing a continuous shift within a stimulus continuum for both HH vs. HL and HH vs. LH. On the other hand, for South Cholla speakers, there were no apparent shifts around categorical boundaries for either HH vs. HL or HH vs. LH. Regarding individual mimicries on f0 peak timing, there are many variations. For HH vs. LH, three North Kyungsang speakers showed a discrete pattern reflecting a shift in phonological categories, but for HH vs. HL, there was no such distinction showing a categorical shift, though there were statistically significant differences for two speakers. Interestingly, one of the North Kyungsang speakers showed a continuous phonetic dimension for both HH vs. HL and HH vs. LH. Lastly, the f0 valley timing did not exhibit a discrete or gradient phonetic dimension for speakers of either dialect. On the basis of these results, what is interesting is that the tonal target such as high tone in North Kyungsang pitch accent categories within the autosegmental-metrical (AM) theory may be realized within individual cognitive systems for representing the interaction of perception and production.

• 대한전자공학회논문지
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• 제22권2호
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• pp.13-17
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• 1985

음성신호의 기본주파수를 구하는 새로운 방법인 area comparison method를 제안 하였다. 음성신호는 생성모델에 의한 한 pitch 구간에서 첫 봉우리의 면적이 강조 된다. 이 논문은 이러한 성질을 이용하여 pitch period를 구하는 것으로 기존의 방법에 비해 많은 장점을 갖는다. 시간 영역에서 취급하고 알고리즘이 간단하기 때문에 고속이다. 또한 sample의 개개가 아닌 면적을 적용하므로 impulse 성 잡음이나, 전처리 filtering이 필요없게 된다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(4)
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• pp.381-384
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• 2002

In speech signal processing, it Is very important to detect the pitch exactly in speech recognition, synthesis and analysis. but, it is very difficult to pitch detection from speech signal because of formant and transition amplitude affect. therefore, in this paper, we proposed a pitch detection using the spectrum flattening techniques. Spectrum flattening is to eliminate the formant and transition amplitude affect. In time domain, positive center clipping is process in order to emphasize pitch period with a glottal component of removed vocal tract characteristic. And rough formant envelope is computed through peak-fitting spectrum of original speech signal in frequency domain. As a results, well get the flattened harmonics waveform with the algebra difference between spectrum of original speech signal and smoothed formant envelope. After all, we obtain residual signal which is removed vocal tract element The performance was compared with LPC and Cepstrum, ACF 0wing to this algorithm, we have obtained the pitch information improved the accuracy of pitch detection and gross error rate is reduced in voice speech region and in transition region of changing the phoneme.

• The Korean Journal of Ecology
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• 제17권3호
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• pp.345-353
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• 1994

상수리나무림과 리기다소나무에서 낙엽 생산과 분해를 조사하였다. 낙엽 생산량은 litter trap을, 낙엽의 분해는 litterbag를 이용하여 정량적으로 조사하였다. 낙엽의 생산은 연중 계속 되었지만 가을에 최대치를 보였으며, 5월과 6월에는 생식기관이나 눈을 싸고 있던 비늘에 의해 두 번째의 peak가 나타났다. 연간 낙엽 생산량은 상수리나무림과 리가다소나무림에서 각각 567.1g/m2과 653.2g/m2이었다. 본 조사지역의 낙엽 생산량은 다른 지역의 결과에 비해 많았다. 낙엽의 영양염류 함량은 상수리나무가 리기다소나무에 비해 높았고, 칼슘을 제외하고 낙엽생산량이 최대인 가을에 그 값이 낮았다. 1년이 지난 후 낙엽의 잔존률은 상수리나무와 리기다소나무가 각각 43.6%, 58%이었고, 21개월 후에는 그 값이 각각 22.2%와 33.2% 이었다.

• 한국결정성장학회지
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• 제17권1호
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• pp.23-29
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• 2007

Pitch-coated anatase $TiO_2$ typed was prepared by $CCl_4$ solvent mixing method with different mixing ratios. Since the carbon layers derived from pitch on the $TiO_2$ particles were porous, the pitch-coated $TiO_2$ sample series showed a good adsorptivity and photo decomposition activity. The BET surface area for the carbon layer in the sample increases to increasing with pitch contents. The SEM results present to the characterization of porous texture on the pitch-coated $TiO_2$ sample and pitch distributions on the surfaces for all the materials used. From XRD data a weak and broad carbon peak of graphene with pristine anatase peaks were observed in the X-ray diffraction patterns for the pitch-coated $TiO_2$. The EDX spectra show the presence of C, O and S with strong Ti peaks. Most of these samples are richer in carbon and major Ti metal than any other elements. Finally, the excellent photocatalytic activity of pitch-coated $TiO_2$ with slope relationship between relative concentration of MB ($c/c_o$) and t could be attributed to the homogeneous coated pitch on the external surface by $CCl_4$ solvent method.