• 한국정보통신학회논문지
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• 제10권1호
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• pp.23-28
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• 2006

피치 주기는 음성 인식, 화자 식별, 음성 분석 및 합성 등과 같은 음성 신호 처리 분야에 있어서 중요한 요소이며, 이러한 피치 주기 검출에 관련된 다양한 알고리즘이 지금까지 연구되고 있다. 피치 검출에 사용되는 알고리즘의 하나인 AMDF(average magnitude difference function)는 각 계곡점의 거리를 피치 주기로 계산한다. 이때, 피치 주기 검출을 위한 계곡점 선정에 있어서 알고리즘이 복잡해지는 문제점이 발생한다. 따라서 본 논문에서는 AMDF의 회전변환을 이용하여 전체 최소 계곡점을 음성 신호의 피치 주기로 검출하는 간단한 알고리즘을 제안하였으며, 시뮬레이션을 통해 기존의 방법들과 비교하였다.

• 한국세라믹학회지
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• 제34권9호
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• pp.963-968
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• 1997

Coal tar pitch was used to study the effect of the pyrolysis conditions to produce mesophase pitch used as a matrix precursor for carbon/carbon composites. The pyrolysis conditions were presented in all cases that the total pressure was 1 atm and the first stage temperature was changed from 25$0^{\circ}C$ to 34$0^{\circ}C$ to remove the low molecular weight compounds in the pitch, and then, heated to 40$0^{\circ}C$ to form anisotropic mesophase as the second stage temperature. The first stage temperature was very affected to form resulting anisotropic mesophase pitch. The resulting mesophase pitches show a significantly increased anisotropic contents upto 30$0^{\circ}C$. However, the contents of mesophase were decreased above 30$0^{\circ}C$. It was the reason that the first stage temperature had been control the number of free radicals to react the aromatic compounds in the pitch to form high molecular weight compound. Therefore, the two stage pyrolysis method could be very effectively used to control various contents of anisotropic polyaromatic mesophase compared to continuous to continuous heating method.

• 말소리와 음성과학
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• 제8권4호
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• pp.71-78
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• 2016

The purpose of this study is to investigate the effect of Japanese(L1) on the production of Korean accentual phrases(L2). Korean and Japanese have a similar prosodic structure. But different from Korean, Japanese is a pitch accent language. So each word has its own pitch accent. And pitch accents are maintained in the sentence intonation. This difference will have a negative influence on the production of Korean sentence intonation. For this study 4 Korean natives speakers and 10 advanced Japanese learners of Korean participated in the production test. The material analysed constituted 11 Korean sentences, six of which contain formally identical Sino-Korean and Sino-Japanese words. The results show that the initial pitch pattern of Korean accentual phrases was affected by Japanese pitch accent types and this interference was greater for formally identical Sino-Korean and Sino-Japanese words. But besides initial tones of accentual phrase, some positive interference was observed in the internal tonal pattern of accentual phrase. In the phonetic realization, the internal pitch range and initial pitch rising of accentual phrases was greater for Japanese learners of Korean than native speakers of Korean.

• Journal of Preventive Medicine and Public Health
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• 제30권1호
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• pp.145-155
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• 1997

Interview survey and dermatological examination have been performed to investigate the health problems of workers continuously exposed to coal-tar pitch. The phototoxicity of coal-tar pitch was confirmed by the photopatch tests for six healthy adults. The main results are followings; 1. There was no special history of allergic diseases in both the exposed and non-exposed group. 2. The frequency of the phototoxic dermatosis and the coal-tar acne in the exposed group was significantly greate.(p<0.05) than that of the control group. In the exposed group, the phototoxic dermatosis and the coal-tar acne were observed in nine workers(90%) and seven workers(70%), respectively. However, those, disease were not observed in the control group. 3. Five results(83%) were positive to the photopatch test for coal-ta. pitch 48 hours after UVA irradiation. But the lesion was subsiding 72 hours after UVA irradiation. 4. Malignant cancers were not reported among workers ever exposed to coal-tar pitch. In conclusion, it appears that workers exposed to coal-tar pitch have high risks of phototoxic dermatosis and coal-tar acne. A health policy should be provided to prevent phototoxic dermatosis among coal-tar pitch workers. More studies are required to determine malignancy.

• 말소리와 음성과학
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• 제3권2호
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• pp.11-22
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• 2011

The purpose of this study is to find the influence of Chinese falling-rising tone on the pitch pattern of corresponding Sino-Korean words delivered by Chinese learners of Korean and to examine how the falling-rising tone of corresponding Chinese words affect the pitch patterns of Sino-Korean words. The scope of this research is limited to Chinese learners of Korean, especially when they pronounce same-form-same-meaning Sino-Korean words. In this study, Chinese learners pronounced both Chinese words and corresponding Sino-Korean words. Learners' pitch patterns were recorded and analyzed using software and compared with the tone of corresponding Chinese words. Experimental results showed that Sino-Korean words were affected by Chinese 'falling-rising tone - high and level tone' when they started with lenis sounds. On the other hand, when Sino-Korean words started with aspirated sounds they were affected by Chinese 'falling-rising tone - high and level tone', 'falling-rising tone - falling-rising tone', and 'falling-rising tone - falling tone'. In conclusion, the Chinese learners' pitch patterns of Sino-Korean words are affected by Chinese falling-rising tone, especially when Sino-Korean words start with aspirated sounds.

• 펄프종이기술
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• 제42권3호
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• pp.1-6
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• 2010

A new testing method named pitch deposit tester (PDT) was developed by KRICT in order to evaluate the deposit potential of micro-stickies. The new method involves depositing the potential pitch particles on the air bubble covered plastic film set in the pitch deposit tester (PDT) and analysing the deposited area by an image analyzer. In this study, the effect of fixing agents on potential pitch deposition was elucidated. The effects of some fixing agents (polyamine and polyethyleneimine) on pitch control were investigated by the PDT test of 100% recycled newsprint stock. The study suggested that proper use of the PEI can lead to better pitch control than that of polyamine. The efficiency of novel screening method using the PDT and retention and drainage analyser (RDA) for fixing agents in terms of retention and deposit contamination could be confirmed by above mentioned results.

• Structural Engineering and Mechanics
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• 제49권3호
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• pp.311-327
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• 2014

The safety relating to leakage of water and pitch instability of ship chambers of the full balanced hoist vertical shiplifts has been the focus of adoption of the type of vertical shiplifts. This paper aims to remove the doubts through theoretical and engineering researches. The leakage and pitch stability of ship chambers of full balanced hoist vertical ship lifts are investigated on the basis of theoretical analysis and exploration of engineering measures. Regarding the issue of leakage of ship chambers, a mathematical model on leaking process is built and corresponding formula and coping measures are obtained which can be applied in control program of ship lifts by linking with monitoring. The concept of safety grade is put forward to seek the best technical and economic index and the corresponding technical measures are for different grades of ship lift is suggested. For the issue of pitch instability, a methodology of combining theoretical deduction and summary of achievements of design and operation of the type of the full balanced hoist shiplifts is adopted, and the formula for design about pitch stability of ship chambers is derived.

• 음성과학
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• 제8권2호
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• pp.133-148
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• 2001

Focus and information structure are closely related with the distribution of pitch accents. A focused word conveys new information and bears a pitch accent. A content word can usually get a pitch accent, but it can be deaccented if it is mentioned earlier in the discourse. In this paper, we test how English native speakers and Korean learners of English realize pitch accents according to focus and information structure of a sentence. The production experiment shows that English native speakers give a pitch accent to narrow-focused items, deaccenting all the other items of the sentence. For VP broad focus, native speakers give a pitch accent either to both the verb and its complement or to the complement only. On the other hand, it is found that Koreans give pitch accents to most content words regardless of focus and information structure. Moreover, the perception experiment confirms that Koreans' intonation patterns, which are not appropriate in terms of focus and information structure, may jeopardize listeners' comprehension. This paper shows that Korean speakers have little knowledge about focus and information structure for intonational realization, and that such notions should be applied to teaching of English intonation.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.264-267
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• 2003

Pitch measurements of 150 nm pitch one-dimensional grating standards were carried out using an contact mode atomic force microscopy(C-AFM) with a high resolution three-axis laser interferometer. It was called as 'Nano-metrological AFM' In Nano-metrological AFM, Three laser interferometers were aligned well to the end of AFM tip. Laser sources of the three-axis laser interferometer in the nano-metrological AFM were calibrated with an I$_2$-stablilzed He-Ne laser at a wavelength of 633 nm. So, the Abbe error was minimized and the result of the pitch measurement using the nano-metrological AFM has a traceability to the length standard directly. The uncertainty in the pitch measurement was estimated in accordance with the Guide to the Expression of Uncertainty in Measurement(GUM). The Primary source of uncertainty in the pitch-measurements was derived from repeatability of pitch-measurement, and its value was approx 0.186 nm. Expanded uncertainty(k=2) of less than 5.23 nm was obtained. It is suggested that the metrological AFM is a useful tool for the nano-metrological standard calibration.

• 한국음향학회지
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• 제15권5호
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• pp.5-12
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• 1996

본 연구에서는 음성 및 EGG 신호를 2-채널 피치검출 알고리즘을 제안하였다. 성대의 떨림에 관한 정확한 정보를 얻을 수 있는 EGG 신호를 이용함으로써 음성신호로부터 피치를 검출하고자 할 때 수반되는 문제점들을 최소화 할 수 있으며, EGG 신호의 왜곡 및 불규칙한 변화는 음성신호의 분석을 통해 보완해 줌으로써 시간영역에서 음성신호에 동기된 정확한 피치 marker를 검출하였다. 2-채널 피치검출 알고리즘은 음성신호만을 이용한 일반적인 피치검출 알고리즘에 비해 보다 정확하고 개선된 피치궤적을 얻을 수 있음을 실험을 통해 보였으며, 따라서 새로이 개발되는 피치검출 알고리즘의 객관적인 비교 및 평가에 이용될 수 있다.