• 말소리와 음성과학
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• 제6권4호
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• pp.79-90
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• 2014

An intonation curve stylization was used for an acoustical analysis of English speech. For the analysis, acoustical feature values were extracted from 1,848 utterances produced with normal and fast speech rate by 28 (12 women and 16 men) native speakers of English. Men are found to speak faster than women at normal speech rate but no difference is found between genders at fast speech rate. Analysis of pitch point features has it that fast speech has greater Pt (pitch point movement time), Pr (pitch point pitch range), and Pd (pitch point distance) but smaller Ps (pitch point slope) than normal speech. Men show greater Pt, Pr, and Pd than women. Analysis of sentence level features reveals that fast speech has smaller Sr (sentence level pitch range), Sd (sentence duration), and Max (maximum pitch) but greater Ss (sentence slope) than normal speech. Women show greater Sr, Ss, Sp (pitch difference between the first pitch point and the last), Sd, MaxNr (normalized Max), and MinNr (normalized Min) than men. As speech rate increases, women speak with greater Ss and Sr than men.

• 대한전자공학회논문지
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• 제17권4호
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• pp.38-44
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• 1980

본 논문에서는 peak 검출과 average magnitude difference function (AMDF)방법을 이용해서 음성의 주기를 고속도로 추출하는 방법이 연구되었다. 먼저 입력 음성을 800Hz로 대역폭을 줄인다음 Pitch peak가 될 만한 몇개의 Peak을 검출한다. 그 다음 이들 peak들의 값을 갖고 AMDF를 계산해서 이들 값들 중에서 최소의 AMDF치를 갖는 peak를 원하는 음성주기로 결정을 한다. 이 방법을 사용하여 음성의 주기를 검출하면 타 음성주기 추출방법 보다 훨씬 적은 계산 시간이 소요될 분만 아니라 비교적 정확한 결과를 얻을 수 있다.

• 음성과학
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• 제12권2호
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• pp.121-128
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• 2005

This study was an attempt to determine acoustic characteristics in myna bird's notes. Two myna birds' sounds imitating a normal male voice in his late 20's were sampled and analyzed. The analyses included the mean values of F1, F2, F3 and pitch contours. The results were as follows; First, there was a significan difference in the mean values of F1, F2, and F3 in isolatd vowel /a/ and /i/ between the myna birds' sounds and the human voice. However, there was no apparent difference in pitch contour of their formants. Second, there was a difference in pitch contour of their formants in their sentence ('hn-nyung-ha-se-yo?' meaning 'How are you?') production. Namely, the myna birds' pitch contour was located higher than that of the human's.

• 한국방사선학회논문지
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• 제14권7호
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• pp.981-989
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• 2020

본 연구는 Pitch의 변화에 따른 CT 감약계수(CT Number)와 잡음(Noise)의 변화를 정량적으로 측정하고자 자체 제작한 맞춤형 팬텀(Customized Phantom)을 사용하였다. 팬텀을 이용한 영상의 획득을 위해 팬텀 내부는 멸균증류수로 가득 채웠다. 유리관 내부에는 생리식염수와 조영제의 비율을 각각 생리식염수 100%, 400:1, 200:1, 100:1, 50:1로 희석한 용액을 담은 후 영상화하였고, 이때 용액의 희석비율별로 pitch를 0, 0.35, 0.7, 1.05, 1.4의 단계로 나누어 각각 영상화하였다. 희석비율별로 모든 ROI에서 측정한 CT number와 noise 값의 평균이 pitch의 변화에 따라 유의한 차이를 보이는지 검증하고자 일원 배치 분산분석(One-way ANOVA Analysis)과 사후검정을 시행하였다. 실험 결과 각 희석비율별 pitch의 변화에 대한 CT number의 변화는 통계적으로 유의한 차이가 없었지만, noise 값은 pitch의 증가에 따라 증가하는 경향을 보였으며, 통계적으로도 유의한 차이를 보이는 것으로 나타났다. 나선형 영상획득 방식은 pitch에 따라 noise가 유의한 수준으로 달라질 수 있다. 따라서 나선형 영상획득 방식을 적용한 CT 영상의 화질평가 항목과 기준을 설정할 필요가 있을 것이다.

• 반도체디스플레이기술학회지
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• 제23권1호
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• pp.97-103
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• 2024

In this paper, the difference between the S-parameter and the characteristic impedance according to the structural change of the fine pitch coaxial socket was analyzed. A pitch of the probe pin was applied to 0.20mm, and ground pins of different conditions were placed on each of the five signal pins. Insertion loss and reflection loss were analyzed for the coaxial socket of normal structure and the two sockets of the proposed structure. In addition, the difference in characteristic impedance was analyzed using time domain reflectometry. Through the analysis, it was confirmed that the characteristic impedance was improved applying the new structures of the socket at the same pitch

• 대한원격탐사학회지
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• 제35권4호
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• pp.545-560
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• 2019

Unlike other critical forest diseases, pine pitch canker in Korea has shown rather mild symptoms of partial loss of crown foliage and leaf discoloration. This study used high-resolution satellite images to detect and monitor canopy decline by pine pitch canker. To enhance the subtle change of canopy reflectance in pitch canker damaged tree crowns, multi-temporal analysis was applied to two KOMPSAT multispectral images obtained in 2011 and 2015. To assure the spectral consistency between the two images, radiometric corrections of atmospheric and shadow effects were applied prior to multi-temporal analysis. The normalized difference vegetation index (NDVI) of each image and the NDVI difference (${\Delta}NDVI=NDVI_{2015}-NDVI_{2011}$) between two images were derived. All negative ΔNDVI values were initially considered any pine stands, including both pitch canker damaged trees and other trees, that showed the decrease of crown foliage from 2011 to 2015. Next, $NDVI_{2015}$ was used to exclude the canopy decline unrelated to the pitch canker damage. Field survey data were used to find the spectral characteristics of the damaged canopy and to evaluate the detection accuracy from further analysis.Although the detection accuracy as assessed by limited number of field survey on 21 sites was 71%, there were also many false alarms that were spectrally very similar to the damaged canopy. The false alarms were mostly found at the mixed stands of pine and young deciduous trees, which might invade these sites after the pine canopy had already opened by any crown damages. Using both ${\Delta}NDVI$ and $NDVI_{2015}$ could be an effective way to narrow down the potential area of the pitch canker damage in Korea.

• 말소리와 음성과학
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• 제6권3호
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• pp.131-138
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• 2014

A close-copy stylization of intonation curve was used for an acoustical analysis of emotional speech. For the analysis, 408 utterances of five emotions (happiness, anger, fear, neutral and sadness) were processed to extract acoustical feature values. The results show that certain pitch point features (pitch point movement time and pitch point distance within a sentence) and sentence level features (pitch range of a final pitch point, pitch range of a sentence and pitch slope of a sentence) are affected by emotions. Pitch point movement time, pitch point distance within a sentence and pitch slope of a sentence show no significant difference between male and female participants. The emotions with high arousal (happiness and anger) are consistently distinguished from the emotion with low arousal (sadness) in terms of these acoustical features. Emotions with higher arousal show steeper pitch slope of a sentence. They have steeper pitch slope at the end of a sentence. They also show wider pitch range of a sentence. The acoustical analysis in this study implies the possibility that the measurement of these acoustical features can be used to cluster and identify emotions of speech.

• 음성과학
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• 제11권3호
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• pp.157-164
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• 2004

Human has average pitch-level when speak naturally. That is 'Habitual pitch level'. However, if noise added at speech, the pitch-wave is changed irregularly. We can estimate noise level of speech by using this point. This paper calculates energy level of the input speech, pitch period from of above limited energy level by NAMDF (Normalized Average Magnitude Difference Function) method, after cut each frame by pitch period unit, and propose a method that estimate noise level through closed pitch of input speech.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 추계종합학술대회
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• pp.1019-1022
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• 2005

최근 정보 통신 기술의 급속한 발전에 의해 음성 신호 처리에 관련된 많은 연구가 진행됨에 따라 피치 주기는 음성 인식, 화자 식별, 음성 분석 및 합성 등과 같은 많은 응용분야에서 중요한 요소로써 적용되고 있다. 이러한 피치 주기 검출에 관련된 시간 영역과 주파수 영역에서의 많은 알고리즘이 제안되었으며, 시간 영역의 피치 검출 알고리즘의 하나인 AMDF(average magnitude difference function)는 각 valley점의 거리를 피치 주기로 계산한다. 그러나 피치 주기 검출을 위한 valley점 선정에 있어서 알고리즘이 복잡해지는 문제점이 발생한다. 따라서 본 논문에서는 AMDF의 회전변환을 이용하여 전체 최소 valley점을 음성 신호의 피치 주기로 인식하는 간단한 알고리즘을 제안하였으며, 음성의 시작구간에 대해 경계값을 설정하여 피치 주기 선정에 대한 판단기준으로 사용하였다. 그리고 제안한 알고리즘을 시뮬레이션을 통해 기존의 방법들과 비교하였다.

• 말소리와 음성과학
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• 제2권3호
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• pp.75-80
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• 2010

The present research investigated the characteristics of voice between genders and nationalities by measuring the acoustic parameter values of Korean and Chinese students. Sound Forge was used to collect voice samples and Praat was used to measure and analyze jitter, shimmer, NHR, $sF_0$, and pitch range. The results of this research are a follows. First, during prolongation of the vowels, there was no significant difference in $F_0$ between Korean and Chinese males and Korean and Chinese females. Korean males and females had higher $F_0$ values than Chinese males and females. Secondly, during sentence reading, there was no significant difference between Korean and Chinese males in $sF_0$. But between female groups, there was a significant difference in $sF_0$. Thirdly, during sentence reading, the pitch range in Korean males was found to be narrower compared to Korean and Chinese females who had wider pitch range, showing a significant difference. Fourthly, jitter in the five vowels /a, i, u, e, o/ was found to be higher in Chinese than Korean subjects. In the vowels /a, e, u/ females were higher than males showing a significant difference. Fifthly, shimmer in the vowels /a, e, u/ was found to be higher in Chinese than Korean subjects showing a significant difference. Finally, NHR in the vowels /a, u, o/ was found to be higher in Chinese than Korean subjects showing a significant difference.