• Phonetics and Speech Sciences
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• v.9 no.1
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• pp.41-47
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• 2017

The main advantage of the statistical parametric speech synthesis is its flexibility in changing voice characteristics. A personalized text-to-speech(TTS) system can be implemented by combining a speech synthesis system and a voice transformation system, and it is widely used in many application areas. It is known that the fundamental frequency and the spectral envelope of speech signal can be independently modified to convert the voice characteristics. Also it is important to maintain naturalness of the transformed speech. In this paper, a speech synthesis system based on Hidden Markov Model(HMM-based speech synthesis, HTS) using the STRAIGHT vocoder is constructed and voice transformation is conducted by modifying the fundamental frequency and spectral envelope. The fundamental frequency is transformed in a scaling method, and the spectral envelope is transformed through frequency warping method to control the speaker's vocal tract length. In particular, this study proposes a voice transformation method using the correlation between fundamental frequency and vocal tract length. Subjective evaluations were conducted to assess preference and mean opinion scores(MOS) for naturalness of synthetic speech. Experimental results showed that the proposed voice transformation method achieved higher preference than baseline systems while maintaining the naturalness of the speech quality.

• Journal of Information Science Theory and Practice
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• v.11 no.1
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• pp.31-48
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• 2023

Digital service transformation study is a part of research in the field of digital transformation, which is devoted to exploring the transformations that occur in digital service products, which have been intensely explored in recent years to address digital disruption. Several concepts and definitions of digital service transformation have emerged as a result of an approach from the point of view of digital transformation and digital services concepts. This paper is organized to provide a foundational understanding of digital service transformation terminology. This paper uses the systematic literature review method to compile 52 qualified articles from previous studies. We conduct an analysis and synthesis of articles to answer research questions. The results of this study are a descriptive summary of research in the digital service transformation field, determining digital service transformation terminology and components, and also a proposed digital service transformation model to explain the position of transformation in digital service products in the overall transformation process. We construct this model using the findings of previously determined components synthesis.

• Journal of the Korean Ceramic Society
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• v.30 no.1
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• pp.41-45
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• 1993

synthesis of artificial kaolinite and the transformation of domestic halloysite have been attempted by means of the hydrothermal treatment. The hydrothermal reaction of the mixtures of gibbsite and amorphous silica was conducted for the synthesis of kaolinite under the pressure of 125MPa at 30$0^{\circ}C$ and especially the seed of kaolinite was added so as to facilitate the synthesis reaction. Domestic pink kaolin of B-grade was hydrothermally treated, in a similar way, for the transformation of crystalline form of it. Boehmite and the artificial kaolinite less than 0.4${\mu}{\textrm}{m}$ could be obtained through the hydrothermal reaction. It could also be found that the majority of hyalloysite was transformed into the plate-type kaolinite through the recrystallization by treating hydrothermally for a long time.

• Archives of Pharmacal Research
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• v.13 no.1
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• pp.97-100
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• 1990

A convenient route is reported for the synthesis of fused pyrrolo [2, 3-d][1, 3]-oxazine and pyrrolo [2, 3-d]-pyrimidine derivatives from 2-amino-1-benzyl-3-t-butoxy-carbonyl-4, 5-dimethylpyrrole.

• YAKHAK HOEJI
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• v.29 no.2
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• pp.107-109
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• 1985

A novel synthesis of 7-membered 1,3,5-benzotriazepine (IV) from 1,3-Dimethyl-5-azauracil in one step by s-Triazine ring transformation is reported.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.34C no.6
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• pp.1-10
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• 1997

By considering low power design at higher levels of abstraction rather than at lower levels of abstraction, we can apply various transformation techniques to a system design with wider view and obtain much more effective power reduction with less cost and effort. In this paper, a transformation technique, called power - conscious loop folding is proposed for high level synthesis of a low power system.Our work is focused on reducing the power consumed by functional units in adata path dominated circuit through the decrease of switching activity. Te transformation algorithm has been implemented and integrated into HYPER, a high level synthesis system for experiments. In our experiments, we could achieve a pwoer reduction of up to 50% for data path dominated circuits.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.2
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• pp.182-187
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• 2014

We propose nonlinear GMM-based transformation functions in an attempt to deal with the over-smoothing effects of linear transformation for voice processing. The proposed methods adopt RBF networks as a local transformation function to overcome the drawbacks of global nonlinear transformation functions. In order to obtain high-quality modifications of speech signals, our voice conversion is implemented using the Harmonic plus Noise Model analysis/synthesis framework. Experimental results are reported on the English corpus, MOCHA-TIMIT.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.3
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• pp.186-193
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• 2009

In this article, the effect of silica addition on the phase transformation characteristics of $TiO_2$ nanoparticles synthesized by using an $O_2$-enriched coflow, hydrogen, diffusion flame was investigated. TTIP(titanium tetra-isopropoxide) and TEOS(tetraethyl-orthosilicate) were used as precursors for $TiO_2$ and $SiO_2$ nanoparticles, respectively. Based on the results from TEM and XRD analysis, it is believed that the silica addition on the flame synthesis of $TiO_2$ nanoparticles reduces the particle size distribution and raises the temperature of the phase transition from anatase to rutile. But the reduced sizes of the synthesized particles due to the silica addition made the sintering and phase transformation of particles more easily.

• YAKHAK HOEJI
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• v.28 no.2
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• pp.97-100
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• 1984

We have investigated the feasibility of using cyclic ambident nucleophiles in s-triazine ring transformation reaction and found that they can replace the $N_{1}-C_{2-N_{3}$ fragment of s-triazine directly in basic conditions, yielding the corresponding bicyclic products. In this paper, we described the reaction and mechanistic aspects of s-triazine to pyrimidopyrimidine transformation by 6-aminouracil derivatives. This type of ring transformation is supposed to be first attempt that deals with the successful s-triazine to bicyclic heterocycle transformation.

• Bulletin of the Korean Chemical Society
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• v.30 no.3
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• pp.695-699
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• 2009

A short and efficient synthesis of (2S,3S)-safingol from commercially available D-ribo-(2S,3S,4R)-phytosphingosine is described. The highlights of the synthesis are a stereoselective one-pot transformation of a diol into an epoxide under phase transfer catalytic conditions and a regioselective epoxide-opening reduction with a hydride reagent.