The design method of a sentence set for a speech-synthesis database strongly influences the quality of the synthesized speech. To minimize the costs associated with making the speech recordings and constructing the speech database, the number of the sentence set should be limited. However, if a sentence set does not include sufficient data, the quality of the synthesized speech can be inadequate. In this paper, we propose a method for generating a sentence set from templates. When applied to the templates in the "Weather Report" radio program, the proposed method reduced the number of the sentence set to less than several percent of that required by a comparison method. In addition, the mean opinion score of speech samples synthesized using the proposed method was 4.32 on a five-point scale.

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We propose and analyze a novel optics method that combines cylindrical lenses and embedded striped patterns to reduce vergence-accommodation conflict in stereoscopic vision. The proposed method enables the viewer see an image that includes high frequency striped patterns through a cylindrical lens. When viewers are shown such a pattern the depth at which their eyes focus depends on the inclination angle of the stripes, for the cylindrical lens works as a lens with different focal length depending on the orientation of lines. To control the status of accommodation correctly, we obtained the correspondence between the inclination angle of stripes and the focusing distance based on optical calculation. Optometric experiments demonstrated that using a refractometer with the proposed method can induce the desired focal accommodation of the viewers as expected. In addition, psychological experiments demonstrated that the proposed method can improve the precision of viewers' depth perception.

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