• The Journal of the Acoustical Society of Korea
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• v.26 no.4
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• pp.159-165
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• 2007

In this paper, we propose a new pre-selection of candidate units that is suitable for the unit selection based Japanese TTS system. General pre-selection method performed by calculating a context-dependent cost within IP (Intonation Phrase). Different from other languages, however. Japanese has an accent represented as the height of a relative pitch, and several words form a single accentual phrase. Also. the prosody in Japanese changes in accentual phrase units. By reflecting such prosodic change in pre-selection. the qualify of synthesized speech can be improved. Furthermore, by calculating a context-dependent cost within accentual phrase, synthesis speed can be improved than calculating within intonation phrase. The proposed method defines AP. analyzes AP in context and performs pre-selection using accentual phrase matching which calculates CCL (connected context length) of the Phoneme's candidates that should be synthesized in each accentual phrase. The baseline system used in the proposed method is VoiceText, which is a synthesizer of Voiceware. Evaluations were made on perceptual error (intonation error, concatenation mismatch error) and synthesis time. Experimental result showed that the proposed method improved the qualify of synthesized speech. as well as shortened the synthesis time.

• The Journal of the Acoustical Society of Korea
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• v.26 no.8
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• pp.403-408
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• 2007

In a large corpus-based speech synthesizer, a break, which is a parameter influencing the naturalness and intelligibility, is used as an important feature during a unit selection process. Japanese is a language having intonations, which ate indicated by the relative differences in pitch heights and the APs(Accentual Phrases) are placed according to the changes of the accents while a break occurs on a boundary of the APs. Although a break can be predicted by using J-ToBI(Japanese-Tones and Break Indices), which is a rule-based or statistical approach, it is very difficult to predict a break exactly due to the flexibility. Therefore, in this paper, a method is to conduct a unit search by dividing breaks into two types, such as a fixed break and a flexible break, in order to use the advantages of a large-scale corpus, which includes various types of prosodies. As a result of an experiment, the proposed unit selection method contributed itself to enhance the naturalness of synthesized speeches.

• Proceedings of the Korea Water Resources Association Conference
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• 1985.07a
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• pp.7-16
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• 1985

본 연구는 유역 추적에 자주 쓰이는 합성단위 유량도(synthetic unit hydrograph) 방법의 하나인 Snyder 방법에 있어서의 계수를 남한강수계에서 재조정하는 과정(procedure)을 제시하였다. 그 과정을 간략하게 설명하며, 이전에 구한 남한강 수계에서의 snyder 계수를 초기치로 하여 HEC-1 program을 이용하여 계수를 재조정한다. 이와 같은 과정을 통하여 재조정된 계수는 그 전의 계수에 의한 합성단위 유량도보다 지체시간($$)이 작아지고 첨두(peak)값이 커지는 특성을 가지고 있다.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.08a
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• pp.344-349
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• 1998

음성/언어학적 및 음성의 과학적 연구를 위해서는 대량의 음소 단위 분절 레이블링된 데이터베이스 구축이 필수적이다. 따라서, 본 논문은 음성 합성용 DB 의 구축 및 합성 단위 자동 생성 연구의 일환으로 자동 음소 분할기의 경계오류를 보상할 목적으로 MLP 기반 호처리기가 포함된 음소 분할 방식을 제안한다. 최근 자동 음소 분할기의 성능 향상으로 자동 분절 결과를 이용하여 음성 합성용 운율 DB를 작성하고 있으나, 여전히 경계오류를 수정하지 않고서는 합성 단위로 직접 사용하기 어렵다. 이로 인해 보다 개선된 자동 분절 기술이 요구된다. 따라서, 본 논문에서는 음성에 내제된 음향적 특징을 다층 신경회로망으로 학습하고, 자동 분절기 오류의 통계 특성을 이용하여 자동 분절 경계 수정에 용이한 방식을 제안한다. 고립단어로 발성된 합성 데이터베이스에서, 제안된 후처리기를 도입 후, 기존 자동 분절 시스템이 분할율에 비해 약 25% 의 향상된 성능을 보였으며, 절대 오류는 약 39%가 향상되었다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.11
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• pp.83-88
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• 2008

In this paper, a new scheduling method considering bit-level delays for high-level synthesis is proposed. Conventional bit-level delay calculation for high-level synthesis was usually limited for specific resources. However, we have developed an efficient bit-level delay calculation method which is applicable to various resources, in this research. This method is applied to scheduling. The scheduling algorithm is based on list scheduling and executes chaining considering bit-level delays. Furthermore, multi-cycle chaining can be allowed to improve performance under resource constraints. Experimental results on several well-known DSP examples show that our method improves the performance of the results by 14.7% on the average.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04b
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• pp.499-501
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• 2002

최근의 합성음성단위 연결을 통한 음성합성 방법의 잘 알려진 문제점은 연결 부분에서 불연속이 발생한다는 것이다. 본 논문에서는 음성을 합성할 때 나타나는 스펙트럼의 불연속을 제거하기 위하여 개선된 스펙트럼 스무딩 방법을 제안한다. 그리고 보다 좋은 스무딩의 결과를 얻기 위하여 음성합성의 단위로는 문맥에 민감한 클러스터링된 다이폰을 사용한다. 스무딩 방법에서는 연결 구간에서의 다이폰 바운더리에서의 양쪽 스펙트럼의 분포를 고려하여 시간에 따라 가중치를 다르게 주어 스무딩을 수행한다. 또한 가중치를 결정할 때 비선형 함수인 B-Spline함수를 사용하여 스무딩을 수행하여 보다 자연스러운 스펙트럼을 생성 할 수 있었다.

• The Mathematical Education
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• v.62 no.1
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• pp.1-21
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• 2023

The purpose of this study is to explore how the student, who interiorized three levels of units, constructed fractions as multipliers by analyzing her ways of conceiving improper fractions with three levels of units and coordinating two three-levels-of-units structures. Among the data collected from our teaching experiment with two 4th grade students meeting 13 times for three months, we focus on how Seyeon, one of the participating students, wrote numerical expressions in the form of "× fraction" for the given situations using her splitting operation for composite units. Given the importance of splitting operation for composite units for the construction of fractions as multipliers, implications for further research are discussed.

• The Journal of the Acoustical Society of Korea
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• v.20 no.3
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• pp.24-33
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• 2001

this paper describes a baseline for an implementation of a corpus-based Korean TTS system. The conventional TTS systems using small-sized speech still generate machine-like synthetic speech. To overcome this problem we introduce the corpus-based TTS system which enables to generate natural synthetic speech without prosodic modifications. The corpus should be composed of a natural prosody of source speech and multiple instances of synthesis units. To make a phone level synthesis unit, we train a speech recognizer with the target speech, and then perform an automatic phoneme segmentation. We also detect the fine pitch period using Laryngo graph signals, which is used for prosodic feature extraction. For break strength allocation, 4 levels of break indices are decided as pause length and also attached to phones to reflect prosodic variations in phrase boundaries. To predict the break strength on texts, we utilize the statistical information of POS (Part-of-Speech) sequences. The best triphone sequences are selected by Viterbi search considering the minimization of accumulative Euclidean distance of concatenating distortion. To get high quality synthesis speech applicable to commercial purpose, we introduce a domain specific database. By adding domain specific database to general domain database, we can greatly improve the quality of synthetic speech on specific domain. From the subjective evaluation, the new Korean corpus-based TTS system shows better naturalness than the conventional demisyllable-based one.

• KSBB Journal
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• v.22 no.4
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• pp.179-184
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• 2007

This study introduces the characteristics and some applications of repetitive polypeptides, especially to the biomaterial, tissue engineering scaffolds, drug delivery system, and DNA separation systems. Since some fibrous proteins, which consist of repeating peptide monomers, have been reported that their physical properties are changed dramatically by means of temperature alteration or pH shifting. For that reason, fibrous protein-mimetic polypeptides, which are produced by the recombinant technology, can be applied to the diverse biological fields. Repetitive polypeptides can also be used in the bioseparation area such as DNA sequencing, because they make DNA separation possible in free-solution electrophoresis by conjugating DNA fragments to them. Moreover, artificial synthesis of repetitive polypeptides helps to demonstrate the correlations between mechanical properties and structures of natural protein polymer, which have been proven that repetitive domains are affected by the sequence of the repeating domains and the number of repeating subunits. Repetitive polypeptides can be biologically synthesized using some special cloning methods, which are represented here. Recursive directional ligation (RDL) and controlled cloning method (CCM) have been proposed as excellent cloning methods in that we can control the number of repetition in the multimerization of polypeptides and the components of repetitive polypeptides by either method.

• The Journal of the Acoustical Society of Korea
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• v.12 no.2
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• pp.14-27
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• 1993

본 논문은 매 40ms 정도의 음성파형으로부터 추출된 6내지 9ms 정도의 1피치주기 파형을 합성단위로 사용하여 합성시킨 시간영역에서의합성방식을 한국어 문어 변환 시스템내에서의 음성합성기에 적용시킨 연구결과이다. 시험 결과, 4가지 유형의 한국어 음절 합성이 가능하고, 장단강약과 같은 운율요소의 제어가 용이하고, 또한 합성 알고리즘이 간단하여 실시간 처리가 가능하였으나, 문장 단위의 음성을 합성하기 위하여는 문장내에서의 다양한 피치 패턴에 대한 연구와 이의 효율적인 제어에 관한 연구가 이루어져야 할 것이다. 합성음에 대한 평가방법으로는 원음과 합성음에 대한 시간영역에서의 파형비교, 주파수 영역에서의 스펙트럼 포락선 유사성 비교 및 합성음에 대한 청취도 실험을 행하였다.