基于多任务学习的多语言语音情感识别方法

由于人类情感的表达受文化和社会的影响,不同语言语音情感的特征差异较大,导致单一语言语音情感识别模型泛化能力不足。针对该问题,提出了一种基于多任务注意力的多语言语音情感识别方法。通过引入语言种类识别辅助任务,模型在学习不同语言共享情感特征的同时也能学习各语言独有的情感特性,从而提升多语言情感识别模型的多语言情感泛化能力。在两种语言的维度情感语料库上的实验表明,所提方法相比于基准方法在Valence和Arousal任务上的相对UAR均值分别提升了3.66%~5.58%和1.27%~6.51%;在四种语言的离散情感语料库上的实验表明,所提方法的相对UAR均值相比于基准方法提升了13.43%~15.75%。因此,提出的方法可以有效地抽取语言相关的情感特征并提升多语言情感识别的性能。     

基于音节时间长度高斯拟合的汉语音节切分方法

研究汉语自然语音音节切分方法具有明显现实意义,比较准确的自然语音切分方法可以代替人工对一些拥有参照文本的语音进行标注。然而至今为止并没有完全准确的汉语语音音节切分方法。依据相同发音环境下汉语语音音节时间长度服从某种高斯分布和相邻语音音节之间存在短时能量波谷两个假设,提出了基于音节时间长度高斯拟合的汉语音节切分方法。对算法进行分析,根据初步切分短时能量波谷分散到各分语音段的特性,提出了简化算法,有效降低了该音节切分方法的时间复杂度。实验结果表明,音节切分准确度(与人工标注切分时间距离平方的均值)达到小数点后3位,在台式机Matlab环境下运算时间均不超过1 s,可以达到应用要求。     

融合多策略的维吾尔语词干提取方法

维吾尔语是形态变化复杂的黏着性语言,维吾尔语词干词缀切分对维吾尔语信息处理具有非常重要的意义,但到目前为止,维吾尔语词干提取的性能仍存在较大的改进空间。该文以N-gram模型为基本框架,根据维吾尔语的构词约束条件,提出了融合词性特征和上下文词干信息的维吾尔语词干提取模型。实验结果表明,词性特征和上下文词干信息可以显著提高维吾尔语词干提取的准确率,与基准系统比较,融入了词性特征和上下文词干信息的实验准确率分别达到了95.19%和96.60%。
     

基于Multigram语言模型的主动学习中文分词

分词是中文处理中的重要基础问题。为了克服Web文本分析中传统方法在适应繁杂的专业领域和多变的语言现象时存在的困难,本文以无督导分词方法为基本框架,使用EM算法建立n元multigram语言模型,提出了一种基于置信度的主动学习分词算法,使得系统在主要利用大量未标注数据的同时,还能够主动选择少量最有价值的数据提交人工标注。实验结果表明算法性能优于相关的几种无督导分词算法。     

利用投票选择机制进行语音分割的新方法

针对在噪声背景下连续语音信号的语音分割性能会明显下降的问题,提出了一种针对连续语音信号分割的新方法。该方法不再采用单一的端点检测方法,而是将基于分形维数的端点检测方法,基于倒谱特征的端点检测方法,基于HMM的端点检测方法等多种不同方法下得到的端点检测结果,通过投票选择的方式,得到最终的端点检测结果,从而达到对连续语音信号进行分割的目的。实验结果表明,该方法较明显地提高了语音分割的准确性。     

Automatic segmentation and identification of mixed-language speech using delta-BIC and LSA-based GMMs

This paper proposes an approach to segmenting and identifying mixed-language speech. A delta Bayesian information criterion (delta-BIC) is firstly applied to segment the input speech utterance into a sequence of language-dependent segments using acoustic features. A VQ-based bi-gram model is used to characterize the acoustic-phonetic dynamics of two consecutive codewords in a language. Accordingly the language-specific acoustic-phonetic property of sequence of phones was integrated in the identification process. A Gaussian mixture model (GMM) is used to model codeword occurrence vectors orthonormally transformed using latent semantic analysis (LSA) for each language-dependent segment. A filtering method is used to smooth the hypothesized language sequence and thus eliminate noise-like components of the detected language sequence generated by the maximum likelihood estimation. Finally, a dynamic programming method is used to determine globally the language boundaries. Experimental results show that for Mandarin, English, and Taiwanese, a recall rate of 0.87 for language boundary segmentation was obtained. Based on this recall rate, the proposed approach achieved language identification accuracies of 92.1% and 74.9% for single-language and mixed-language speech, respectively.     

W-POS语言模型及其选择与匹配算法

n-grams语言模型旨在利用多个词的组合形式生成文本特征,以此训练分类器对文本进行分类。然而n-grams自身存在冗余词,并且在与训练集匹配量化的过程中会产生大量稀疏数据,严重影响分类准确率,限制了其使用范围。对此,基于n-grams语言模型,提出一种改进的n-grams语言模型--W-POS。将分词后文本中出现概率较小的词和冗余词用词性代替,得到由词和词性的不规则排列组成的W-POS语言模型,并提出该语言模型的选择规则、选择算法以及与测试集的匹配算法。在复旦大学中文语料库和英文语料库20Newsgroups中的实验结果表明,W-POS语言模型既继承了n-grams语言模型减少特征数量、携带部分语义和提高精度的优点,又克服了n-grams语言模型产生大量稀疏数据、含有冗余词的缺陷,并验证了选择和匹配算法的有效性。     

Syllable Segmentation of Tamil Speech Signals Using Vowel Onset Point and Spectral Transition Measure

Segmentation plays vital role in speech recognition systems. An automatic segmentation of Tamil speech into syllable has been carried out using Vowel Onset Point (VOP) and Spectral Transition Measure (STM). VOP is a phonetic event used to identify the beginning point of the vowel in speech signals. Spectral Transition Measure is performed to find the significant spectral changes in speech utterances. The performance of the proposed syllable segmentation method is measured corresponding to manual segmentation and compared with the exiting syllable method using VOP and Vowel Offset Point (VOF). The result of the experiments shows the effectiveness of the proposed system.     

采用改进DeepLab网络的遥感图像分割

基于深度学习的语义分割方法具有较好的应用前景,但针对海量的遥感数据,深度学习算法在训练速度上仍有较大提升空间。在前人研究基础上,提出一种改进的全卷积网络,改进的网络以DeepLab为网络前端,结合Inception结构,在不降低特征提取能力的前提下,通过减少网络参数数量,降低网络运算复杂度,有效提升了网络的训练速度。基于INRIA Aerial Image Dataset高分辨率航空遥感数据集开展语义分割对比实验,实验结果显示改进的网络在训练速度和精度上均较DeepLab网络有所提升。所提出的改进DeepLab网络对为处理数据量庞大的遥感影像提供了可参考的解决方案。     

自由表述口语语音评测后验概率估计改进方法

该文研究了两种用于改善深度神经网络声学建模框架下自由表述口语语音评测任务后验概率估计的方法: 1)使用RNN语言模型对一遍解码N-best候选做语言模型得分重估计来获得更准确的识别结果以重新估计后验概率;2)借鉴多语种神经网络训练框架,提出将方言数据聚类状态加入解码神经网络输出节点,在后验概率估计中引入方言似然度得分以评估方言程度的新方法。实验表明,这两种方法估计出的后验概率与人工分相关度分别绝对提升了3.5%和1.0%,两种方法融合后相关度绝对提升4.9%;对于一个真实的评测任务,结合该文改进的后验概率评分特征,总体评分相关度绝对提升2.2%。     

Cascaded model adaptation for dialog act segmentation and tagging

There are many speech and language processing problems which require cascaded classification tasks. While model adaptation has been shown to be useful in isolated speech and language processing tasks, it is not clear what constitutes system adaptation for such complex systems. This paper studies the following questions: In cases where a sequence of classification tasks is employed, how important is to adapt the earlier or latter systems? Is the performance improvement obtained in the earlier stages via adaptation carried on to later stages in cases where the later stages perform adaptation using similar data and/or methods? In this study, as part of a larger scale multiparty meeting understanding system, we analyze various methods for adapting dialog act segmentation and tagging models trained on conversational telephone speech (CTS) to meeting style conversations. We investigate the effect of using adapted and unadapted models for dialog act segmentation with those of tagging, showing the effect of model adaptation for cascaded classification tasks. Our results indicate that we can achieve significantly better dialog act segmentation and tagging by adapting the out-of-domain models, especially when the amount of in-domain data is limited. Experimental results show that it is more effective to adapt the models in the latter classification tasks, in our case dialog act tagging, when dealing with a sequence of cascaded classification tasks.     

TIP-LAS:一个开源的藏文分词词性标注系统

TIP-LAS是一个开源的藏文分词词性标注系统,提供藏文分词、词性标注功能。该系统基于条件随机场模型实现基于音节标注的藏文分词系统,采用最大熵模型,并融合音节特征,实现藏文词性标注系统。经过试验及对比分析,藏文分词系统和词性标注系统取得了较好的实验效果,系统的源代码可以从网上获取。希望该研究可以推动藏文分词、词性标注等基础工作的发展,提供一个可以比较、共享的研究平台。
     

Conversational natural language understanding interfacing city event information

The article describes aspects of the development of a conversational natural language understanding (NLU) system done during the first year of the European research project CATCH-2004 (Converse in AThens Cologne and Helsinki) [http://www.catch2004.org]. The project is co-funded by the European Union in the scope of the IST programme (IST 1999-11103).

Its objectives focus on multi-modal, multi-lingual conversational natural language access to information systems. The paper emphasises on architecture, and telephony-based speech and NLU components as well as aspects of the implementation of a city event information (CEI) system in English, Finnish, German and Greek. The CEI system accesses two different databases in Athens and Helsinki using a common retrieval interface. Furthermore the paper singles out methodologies involved for acoustic and language model of the speech recognition component, parsing techniques and dialog modelling for the conversational natural language subsystem. For the implementation it outlines an incremental system refinement methodology necessary to adapt the system components to real-life data. It addresses the implementation of language specific characteristics and a common dialog design for all four languages, but also deals with aspects towards a multilingual conversational system. Finally, it presents prospects for further developments of the project.     

Topic tracking language model for speech recognition

In a real environment, acoustic and language features often vary depending on the speakers, speaking styles and topic changes. To accommodate these changes, speech recognition approaches that include the incremental tracking of changing environments have attracted attention. This paper proposes a topic tracking language model that can adaptively track changes in topics based on current text information and previously estimated topic models in an on-line manner. The proposed model is applied to language model adaptation in speech recognition. We use the MIT OpenCourseWare corpus and Corpus of Spontaneous Japanese in speech recognition experiments, and show the effectiveness of the proposed method.     

一种新的基于主题的语言模型自适应方法

基于主题的语言模型自适应方法应尽可能提高语言模型权重系数的更新速度并降低语言模型的调用量以满足语音识别实时性要求。本文采用基于聚类的方法实现连续相邻二元词对的量化表示并以此刻画语音识别预测历史和各个文本主题中心,依据语音识别历史矢量和各个文本主题中心矢量的相似度更新语言模型权重系数并摒弃全局语言模型。同传统的基于EM算法的自适应方法相比,实验表明该方法明显提高了语音识别性能和实时性,识别错误率相对下降5.1% ,说明该方法可比较准确地判断测试内容所属文本主题。     

自适应正则化活动轮廓模型

针对Chan-Vese模型含有许多参数,分割时需要人为调整参数,耗费大量的人力和时间的问题,提出了一个自适应正则化活动轮廓模型。首先,对Chan-Vese模型的数据项进行简化;其次,使用改进的边界加权H¹正则化代替长度项;最后,形成了一个新的不含任何参数的活动轮廓模型。在分割实验中,该模型对初始轮廓的大小、位置不敏感,具有较强的抗噪性,分割6幅图像的平均时间和迭代次数分别为1.5834 s、19次。实验结果表明,所提模型无需人工调整参数,能够分割强噪声图像和灰度不均图像,并且具有较快的分割速度。