• The Journal of the Acoustical Society of Korea
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• v.17 no.7
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• pp.50-56
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• 1998

본 논문은 자동 음소 분할기의 음소 경계 오류를 보상하기 위한 후처리 (Postprocessing)에 관한 연구이다. 이는 현재 음성 합성을 위한 음성/언어학적 연구, 운율 모델링, 합성단위 자동 생성 연구 등에 대량의 음소 단위 분절과 음소 레이블링된 데이터의 필요성에 따른 연구의 일환이다. 특히 수작업에 의한 분절 및 레이블링은 일관성의 유지가 어렵고 긴 시간이 소요되므로 자동 분절 기술이 더욱 중요시 되고 있다. 따라서, 본 논문은 자동 분절 경계의 오류 범위를 줄일 수 있는 후처리기를 제안하여 자동 분절 결과를 직접 합성 단위로 사용할 수 있고 대량의 합성용 운율 데이터 베이스 구축에 유용함을 기술한다. 제안된 후처리기는 수작업으로 조정된 데이터의 특징 벡터를 다층 신경회로망 (MLP:Multi-layer perceptron)을 통해 학습을 한 후, ETRI(Electronics and Telecommunication Research Institute)에서 개발된 음성 언어 번역 시스템을 이용한 자동 분절 결과와 후처리기인 MLP를 이용하여 새로운 음소 경계를 추출한다. 고립단어로 발성된 합성 데이터베이스에서 후처리기로 보정된 분절 결과는 음성 언어 번역 시스템의 분할율보 다 약 25%의 향상된 성능을 보였으며, 절대 오류(｜Hand label position-Auto label position ｜)는 약 39%가 향상되었다. 이는 MLP를 이용한 후처리기로 자동 분절 오류의 범위를 줄 일 수 있고, 대량의 합성용 운율 데이터 베이스 구축 및 합성 단위의 자동생성에 이용될 수 있음을 보이는 것이다.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06c
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• pp.342-345
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• 1994

본 논문에서는 무제한단어 음성합성 시스템인 한소리에 대해서 간략히 기술하고 청취실험을 통한 성능평가에 대해 논한다. 음성합성시스템의 음질을 결정하는 주요 요소들은 합성의 기본단위, 합성방법, 음운학적 전처리방법 및 운율조절방법이다. 한소리 합성시스템은 반음소를 음성합성의 기본단위로 하고, 형식형태소를 이용 음성학적 전처리를 실행하며, 개선된 한국어 운율조절방법이 적용되고, 음성단편조합방식을 합성방식을 사용한다. 청취실험결과 매우 한소리 합성시스템의 합성음이 자연스러움을 알 수 있다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.439-449
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• 2016

The methodology of synthetic unit hydrograph using geomorphic characteristics was suggested. Six geomorphic components over 19 watersheds were used to estimate synthetic unit hydrograph and the test watersheds were classified into two groups on the basis of the area of $200km^2$. The regression formulas between standardized geomorphic characteristics for each group and peak quantities of specific streamflow and time of representative unit hydrograph were suggested and the Nash and the Clark unit hydrographs were derived. For verifying the derived unit hydrographs, the resulting hydrographs were compared with the ones using the existing Clark unit hydrographs based on the empirical parameter estimation for the 145 storm events during 2010 to 2011 for the additional six watersheds. The results showed the relatively higher performance over the existing synthetic unit hydrograph methods, which could be a contribution to the hydrologic estimation in ungauged watersheds.

• Journal of Korea Water Resources Association
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• v.46 no.5
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• pp.547-558
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• 2013

Improved methodology of Synthetic Unit Hydrograph (SUH) utilized generally in hydrologic design work was suggested. In this study, regression analysis between peak hydrological data and geospatial data was applied to estimate specific peak flow and peak time for determining shape of SUH. Regression formulas for specific peak flow with respect to shape factors show higher coefficient of determination (0.73~0.81) than the ones with geospatial components only (0.52~0.69). The areal limitation of unit hydrograph application is regarded as 500~700 $km^2$. The validation through rainfall-runoff simulation shows encouraging results that relative error is 1.7~29.0%(Avg. 11.6%) for the case of using SUH developed in this study and 35.0~ 64.9% (Avg. 46.7%) for the SUH in the previous study except for the extraordinary cases.

• The Journal of the Acoustical Society of Korea
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• v.14 no.3
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• pp.49-60
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• 1995

This paper is a study on the design and implementation of the Korean Text-to-Speech system which is used for a small and simple system. In this paper, a parameter synthesis method is chosen for speech syntheiss method, we use PARCOR(PARtial autoCORrelation) coefficient which is one of the LPC analysis. And we use phoneme for synthesis unit which is the basic unit for speech synthesis. We use PARCOR, pitch, amplitude as synthesis parameter of voice, we use residual signal, PARCOR coefficients as synthesis parameter of unvoice. In this paper, we could obtain the 60% intelligibility by using the residual signal as excitation signal of unvoiced sound. The result of synthesis experiment, synthesis of a word unit is available. The controlling of phoneme duration is necessary for synthesizing of a sentence unit. For setting up the synthesis system, PC 486, a 70[Hz]-4.5[KHz] band pass filter for speech input/output, amplifier, and TMS320C30 DSP board was used.

• The Journal of the Acoustical Society of Korea
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• v.18 no.7
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• pp.10-16
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• 1999

In this paper, we propose a concatenation-based speech synthesizer using CVC(consonant-vowel-consonant) speech segments extracted from an undesigned continuous speech corpus. Natural synthetic speech can be generated by a proper modelling of coarticulation effects between phonemes and the use of natural prosodic variations. In general, CVC synthesis unit shows smaller acoustic degradation of speech quality since concatenation points are located in the consonant region and it can properly model the coarticulation of vowels that are effected by surrounding consonants. In this paper, we analyze the characteristics and the number of required synthesis units of 4 types of speech synthesis methods that use CVC synthesis units. Furthermore, we compare the speech quality of the 4 types and propose a new synthesis method based on the most promising type in terms of speech quality and implementability. Then we implement the method using the speech corpus and synthesize various examples. The CVC speech segments that are not in the speech corpus are substituted by demonstrate speech segments. Experiments demonstrate that CVC speech segments extracted from about 100 Mbytes continuous speech corpus can produce high quality synthetic speech.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.1B
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• pp.47-55
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• 2011

This study suggests new synthetic unit hydrograph method considering hydrodynamic characteristic on the basin. The suggested method based on width function GIUH, and the procedure is summarized as follows; 1) Draw up a travel distance distribution map (width function) which is raster of length between from center of individual cells to the outlet by GIS. 2) Calculation of travel time distribution map (rescaled width function) by hydrodynamic parameters and travel distance distribution map. 3) Derivation of IUH and Duration UH from rescaled width function. 4) Comparison of shape of UH between suggested method and existing synthetic unit hydrograph methods. The target basins are selected Ipyeong and Tanbu subwatershed in the Bocheong Basin. The target basins are similar scale (watershed area), but different drainage structure (drainage density et al.). Therefore we anticipate that there are different hydrologic response functions because different hydrodynamic characteristics. As a result of derivation of UH, existing synthetic unit hydrograph methods are similar shape of UHs about Ipyeong and Tanbu watersheds, but the suggested method is different shape of ones. As a result of application to observed data, the peak discharge by suggested method is similar to existing synthetic unit hydrograph methods, but the peak time is well correspondence between those. Henceforth, if the suggested method combines with the rational velocity estimation method, it is useful method for synthetic of UH in ungauged watershed.

• Journal of Korea Water Resources Association
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• v.34 no.6
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• pp.627-640
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• 2001

Generally, the synthetic unit hydrograph method is presented to estimate the design flood in the ungaged watershed. However, due to the lack of rainfall-runoff data, the models developed in other countries such as U.S.A. and Japan have been widely used in Korea. Therefore, it may be essential to develope the rainfall-runoff model suitable for the hydrological char-acteristics in Korea. In this study, the representative unit hydrographs are derived from rainfall-runoff data at 19 basins in Selma-Cheon and 3-IHP experimental watersheds using ridge-regression method and Nash model. And a new synthetic unit hydrograph for Korea is suggested by integrating the described results and previous studies on unit hydrograph. The newly developed method is represented as two regression forms with three independent variables of watershed area, channel length, and channel slope by multiple regression analysis is carried out for each watershed, the coefficients of determination are not improved in all cases compared out for each watershed, the coefficients of determination are not improved n all cased the synthetic unit hydrograph for each watershed. Therefore, when the new method is applied to some watersheds, the result analyzed for all data has to be used.

• Proceedings of the Acoustical Society of Korea Conference
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• 1992.06a
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• pp.81-84
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• 1992

포만트형 합성기에 사용될 반음절 데이터 베이스의 구성과 필요한 파라미터의 추출 과정에 대하여 논한다. 포만트 합성기는 많은 구동 파라미터를 필요로 하기 때문에 저장 장소를 절약하기 위해서 적절한 합성단위의 선택과 합성단위의 효율적인 표현이 필요하다. 본 연구에서는 포만트 합성기에 있어서 합성음의 음질에 큰 영향을 미치는 포만트궤적의 추출과 데이터베이스의 구성에 대하여 기술한다.

• Water for future
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• v.19 no.2
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• pp.157-166
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• 1986

The objective of this study was to determine the best representative synthetic unit hydrograph that is applicable to ungaged small watershed. A typical unit hydrograph was established with the actual data from a small watershed. Four currently well-known methods for analyzing ungaged small watershed, including Snyder's, Clark's S.C.S. and Nash methods, were evaluated with the data from the same small watershed. The following observations were noted from the analysis of four methods. The Snyder's method yielded the similar peak discharge value as the typical unit hydrograph. With co-ordinates of three discharge values, i.e. 25%, 50% and 75% of peak discharge, were not adequate for deriving a typical unit hydrograph in ungaged small watershed. With Clark's method there shall be some way of obtaining the exact base length of time area diagram and isochrone of each reach of the stream. With Nash method peak discharge and base flow time are affected by the storage constant and gamma function argument; therefore, for deriving a more reliable and workable unit hydrograph one needs to select for the better estimation of storage constant and gamma function argument. In S.C.S. method peak discharge is directly related to the watershed area and inversely related to the time of peak diacharge. Therefore area with faster peak discharge yielded the higer peak discharge value. Although the peak discharge value obtained frome the S.C.S. method higher than the value obtained from the unit hydrograph developed from the actual data, this method contains a number of advantageous factors. The peak discharge value and the time of peak discharge can be claculated easity from the morphological characteristics of the watershed, and in S.C.S method co-ordinates of the unit hydrograph can be calculated easily from that of the dimensionless unit hydrograph. When the four currently used methods were evaluated with a typical unit hydrograph obtained from the actual data, the S.C.S method was show to be the best method in deriving a synthetic unit hydrograph for ungaged small watershed.