Browsing by Author "Lin, Cheng-Hsien"

Now showing 1 - 4 of 4

Hierarchical prosody modeling for Mandarin spontaneous speech
(2019-04-01)
Lin, Cheng-Hsien
;
You, Chung-Long
;
Chiang, Chen-Yu
;
Wang, Yih-Ru
;
Chen, Sin-Horng
In this paper, a hierarchical prosody model (HPM)-based method for Mandarin spontaneous speech is proposed. First, an HPM is designed for describing relations among acoustic features of utterances, linguistic features of texts, and prosodic tags representing the underlying hierarchical prosodic structures of utterances. Subsequently, a sequential optimization algorithm is employed to train the HPM based on a large conversational speech corpus, the Mandarin Conversational Dialogue Corpus (MCDC), which features orthographic transcriptions and prosodic event annotations. In this unsupervised training method, all utterances of the MCDC are labeled with two types of prosodic tags, namely, break and prosodic states, automatically and simultaneously. After training, the HPM parameters are examined to identify critical prosodic properties of Mandarin spontaneous speech, which are then compared with their counterparts in the read-speech HPM. The prosodic tags on the studied utterances enable mapping of various prosodic events onto the hierarchical prosodic structures of the utterances. Prosodic analyses of some disfluent events are conducted using the prosodic tags affixed to the MCDC. Finally, an application of the HPM to assist in Mandarin spontaneous-speech recognition is discussed. Significant relative error rate reductions of 9.0%, 9.2%, 15.6%, and 7.3% are obtained for base-syllable, character, tone, and word recognition, respectively. (C) 2019 Acoustical Society of America.
Integration of Spatial Reuse and Allocation for Downlink Broadcast in LTE-Advanced and WiMAX Relay Networks
(2015-11-01)
Lin, Cheng-Hsien
;
Hwang, Ren-Hung
;
Wu, Jang-Jiin
;
Lee, Jeng-Farn
;
Lin, Ying-Dar
Downlink broadcast in LTE-Advanced-(LTE-A) and WiMAX-based relay networks is a crucial service for multimedia delivery. Currently, most research effort goes into devising efficient resource allocation mechanisms to achieve more efficient resource utilization. However, spatial reuse, which is an important technique in improving transmission capacity, has received little attention in the literature. Thus, in this work, we investigate ways of achieving more efficient resource allocation in wireless relay networks via spatial reuse. We first formulate a joint spatial reuse and resource allocation problem as an integer linear programming (ILP) model. We then consider a grouping mechanism in which relay stations (RSs) are grouped together if they do not interfere with each other\'s transmission signal. RSs in the same group can thus utilize spatial reuse by using the same set of resources to broadcast data. Because of the high computational complexity of the ILP model, we propose a two-phase heuristic solution. In the first phase, the enhanced-resource diminishing principle approach is employed to determine the number of resources required by the base station and a set of selected RSs. In the second phase, a max-coloring algorithm is employed to organize the selected RSs into broadcast groups and then assign the required resources to each group by exploring the maximum advantage of spatial reuse. The simulation results show that the proposed solution improves system performance up to 61%, as compared with two existing mechanisms.
Rich Prosodic Information Exploration on Spontaneous Mandarin Speech
(2016-01-01)
Lin, Cheng-Hsien
;
You, Chung-Long
;
Chiang, Chen-Yu
;
Wang, Yih-Ru
;
Chen, Sin-Horng
In this paper, rich prosodic information of spontaneous Mandarin speech is explored. The joint prosody labeling and modeling algorithm proposed previously for read speech is extended to spontaneous-speech prosody modeling by additionally considering the modeling of disfluency speech parts. It trains a hierarchical prosodic model and performs prosody labeling from a large speech corpus automatically. Rich prosodic information is then explored via analyzing model parameters and labeling results. By comparing the resulting prosodic model with that of read speech, we find that most affecting patterns, such as F0 contour patterns of 4 tones, have similar shapes or same trends but with much less dynamic ranges. Besides, the prosodic characteristics of various disfluency events, including repetition, restart, repair, contraction, and hesitation, are intensively investigated based on the labeling results. The information explored increases our knowledge about the phonology of spontaneous speech, and should be useful for assisting in ASR.
Single-crystalline mesoporous ZnO nanosheets prepared with a green antisolvent method exhibiting excellent photocatalytic efficiencies
(2012)
Dong, Ji-Yao
;
Lin, Cheng-Hsien
;
Hsu, Yung-Jung
;
Lu, Shih-Yuan
;
Wong, David Shan-Hill
Single-crystalline mesoporous ZnO nanosheets were prepared with a green, deep eutectic solvent based antisolvent process followed by calcination at 300 degrees C. The antisolvent procedure led to formation of nanosheets of a mixed composition of zinc carbonate hydroxide and ZnO, calcination of which generated the product. The product nanosheets were ultrathin with a thickness of around 10 nm and pore sizes increasing from less than 10 nm to several tens nanometers with increasing calcination time and temperature. These nanosheets exhibited excellent photocatalytic efficiencies as good as that of a commercial photocatalyst, P-25 TiO2 in terms of photocatalytic degradation of a model pollutant, methylene blue. The success is attributable to the structural advantages of the nanosheets of being ultrathin, mesoporous, and single-crystalline.