Speech recognition

The authors have designed, successfully trained and tested an Arabic speech recognition system. This system was implemented using C++ programming language on Windows 95. It can be partitioned into five main modules. These modules are the front-end, feature extraction, training, pattern recognition and decision making and display. The front-end module functions as signal preparation and calibration. This includes: setting the signal sampling rate, removing the DC component from the signal, setting the scaling factor of the signal and detecting the endpoints of the utterance. The endpoint task removes the non-speech signal portions created by the speaker's pauses. This reduces the system computation time needed and the memory requirements. The feature extraction module is mainly a digital signal processor. The training module is the one that finds the best templates for every word or sound (phonemes) in the system's database. In short, this module needs to be executed only one time before users can utilize the system. The next module is the pattern recognition module. Its function is to compare the given utterance (test utterance) to all the stored templates (the reference module). The decision and display module functions as an interface between the user and the hidden system modules. In other words, after getting the recognition module results, this module displays the best candidate(s) and/or their likelihood percentage. The error rates are computed and displayed in this module     

Unstable Morse code recognition with adaptive variable-ratio threshold prediction for physically disabled persons.

With one or two switches, Morse code could provide an effective alternative communication channel for individuals with physical limitations. However, most of the physically disabled persons have difficulties in maintaining a stable typing of Morse code, and hence the automated recognition of unstable Morse code is becoming more on demand. In this study, an adaptive variable-ratio threshold prediction (AVRTP) algorithm is proposed to analyze the Morse code time series with variable unit time period and ratio. Two least-mean-square (LMS) predictors are applied to track the dot interval and the dot-dash difference concurrently, and then a predicted threshold based on a variable-ratio decision rule is used to distinguish between dots and dashes. The same method is also applied to identify character-spaces. By the adaptive prediction of variable-ratio threshold, AVRTP has successfully overcome the difficulty of analyzing severely unstable Morse code time series and outperformed the previously proposed adaptive unstable-speed prediction (AUSP) algorithm and LMS and matching (I,MS&M) algorithm. This study concludes with a computer simulation and a preliminary clinical evaluation that demonstrate AVRTP as an efficient and reliable method for unstable Morse code recognition.     

基于幅值滤波与分层特征融合策略的语音情感识别

针对语音情感识别在多语言联合数据集上识别准确率低的问题,提出了一种基于幅值滤波与分层特征融合策略的语 音情感识别方法。该方法首先对梅尔谱图内幅值分布规律进行幅值滤波,通过概率叠加扩大梅尔谱图内相近幅值之间的差 异,实现谱图内的高频强增益、低频弱增益;同时,通过概率相乘缩小梅尔谱图内相远幅值之间的差异,以显示谱图内中频的 细节部分。在此基础上,使用矩形卷积提取音频信号的时间动态特征,生成梅尔谱图动态特征图,并将其作为分层特征融合 策略的输入。分层特征融合策略通过压缩特征图来提取不同尺度的时间动态特征,并提取不同深度中的时间动态特征。在 多语言联合数据集 CER 上取得了84.44%的分类准确率。     

A robotic vehicle for disabled children

One of the most frequent effects of physical disability is reduced or impaired mobility. There are a number of technical aids for all the cases of physical impairment but none of the systems described in the literature address the particular problems of children affected by neuromotor disorders accompanied by mental retardation. The following addresses the development of the PALMA [(plataforma de apoyo ludico a la movilidad alternative) (assistive platform for alternative mobility)] system as a tool to assist the mobility of children affected by cerebral palsy. PALMA is specifically adapted to a personalized and early cognitive development of children affected by severe neuromotor problems. The rehabilitation process based on PALMA has an impact on the interaction between children and environment, on their motor dexterity, and on decision-making ability.     

Duration-Distribution-Based HMM for Speech Recognition

To overcome the defects of the duration modeling in the homogeneous Hidden Markov Model (HMM) for speech recognition, a duration-distribution-based HMM (DDBHMM) is proposed in this paper based on a formalized definition of a left-to-right inhomogeneous Markov model. It has been demonstrated that it can be identically defined by either the state duration or the state transition probability. The speaker-independent continuous speech recognition experiments show that by only modeling the state duration in DDBHMM, a significant improvement (17.8% error rate reduction) can be achieved compared with the classical HMM. The ideal properties of DDBHMM give promise to many aspects of speech modeling, such as the modeling of the state duration, speed variation, speech discontinuity, and interframe correlation. Translated from Acta Electronica Sinica, 2004, 32(1): 46–49 (in Chinese)     

The new design of an infrared-controlled human-computer interface for the disabled.

This paper reports on the development of an eyeglass- type infrared (IR)-controlled computer interface for the disabled. This system may serve to assist those who suffer from spinal cord injuries or other handicaps to operate a computer. This system is comprised of three major components: 1) an infrared transmitting module, 2) an infrared receiving/signal-processing module, and 3) a main controller, the Intel-8951 microprocessor. The infrared transmitting module utilizes tongue-touch circuitry which is converted to an infrared beam and a low power laser (<0.1 mW) beam. The infrared receiving/signal-processing module, receives the infrared beam and fine tunes the unstable infrared beam into standard pulses which are used as control signals. The main controller is responsible for detecting the input signals from the infrared receiving/signal-processing module and verifying these signals with the mapping table in its memory. After the signal is verified, it is released to control the keys of the computer keyboard and mouse interface. This design concept was mainly based on the idea that the use of an infrared remote module fastened to the eyeglasses could allow the convenient control of the input motion on the keys of a computer keyboard and mouse which are all modified with infrared receiving/signal-processing modules. The system is designed for individuals with spinal cord injuries and disabled in which the subjects' movement are severely restricted. The infrared transmitting module can be easily mounted on eyeglasses or artificial limbs.     

在电力高技能人才培训工作会议上的讲话

电力高技能人才培训项目是国家高技能人才培训工程的重要组成部分。为了具体落实电力高技能人才培训项目 ,2 0 0 4年 4月 2 1日中国电力企业联合会在北京召开了电力高技能人才培训工作会议 ,并在此次会议上成立了电力高技能人才培训项目推动工作委员会。本期的“本刊特稿”栏目将摘要刊发劳动和社会保障部张小建副部长的《在电力高技能人才培训工作会议上的讲话》、中电联孙玉才副理事长的《同心协力 ,联合推动电力高技能人才培训项目的实施》和中电联教培中心薛静副主任的《创新求实 ,规划落实好电力高技能人才培训项目》等 3篇讲话 ,以飨读者     

Morse code application for wireless environmental control systems for severely disabled individuals

Some physically-disabled people with neuromuscular diseases such as amyotrophic lateral sclerosis, multiple sclerosis, muscular dystrophy, or other conditions that hinder their ability to write, type, and speak, require an assistive tool for purposes of augmentative and alternative communication in their daily lives. In this paper, we designed and implemented a wireless environmental control system using Morse code as an adapted access communication tool. The proposed system includes four parts: input-control module; recognition module; wireless-control module; and electronic-equipment-control module. The signals are transmitted using adopted radio frequencies, which permits long distance transmission without space limitation. Experimental results revealed that three participants with physical handicaps were able to gain access to electronic facilities after two months' practice with the new system.     

锌银贮备电池贮存失效模式与失效机理探讨

在对锌银贮备电池的结构、贮存失效模式与失效机理进行分析的基础上,进行了两种锌银贮备电池的干态检测、干态解剖和电池组放电,通过分析和电池组实效贮存试验结果,得到锌银贮备电池贮存失效的主要原因是电性能下降,主要体现在电压下降和容量损失的初步结论。而电性能下降的主要原因是正极板AgO含量的降低和Ag2O含量的增加、负极板Zn含量的降低和ZnO含量的增加及隔膜性能的降低。     

在电力施工企业资质工作会议上的讲话

各位代表、同志们 :首先我代表国家电力公司电网建设部对应邀出席本次会议的国家建设部有关领导、专家表示感谢 ,对来自全国的电力施工企业和有关单位的代表表示欢迎 !建设部今年颁布了《建筑业企业资质管理规定》和《建筑业企业资质等级标准》 ,这是国务院建设行政主管部门为了加强监督 ,规范建筑市场秩序 ,保证建设工程质量而采取的一项重大举措。这次会议的主要目的就是学习和理解建设部的 2个文件 ,研讨施工企业在资质就位工作中存在的问题 ,请建设部的有关专家就疑难问题给予指导和帮助。这次会议也标志着国家电力公司系统施工企业资质…     

Speech processing and synthesis for assessing vocal disorders

Techniques for the quantitative assessment and classification of vocal disorders are described. Models for vocal disorders using speech synthesis are examined. Methods for characterizing the electroglottography (EGG) waveform and the assessment of vocal quality using acoustic and EGG signal features are discussed.     

基于语音编码技术多通道语音通信记录

传统的多通道语音通信记录设备基于模拟或数字磁带机构成，结构庞大复杂且价格高昂。随着语音压缩编码技术的发展，以PC机和大容量硬盘为载体，用软件控制的全数字多通道语音通信记录设备应运而生。文中介绍多通道语音记录卡的软硬件构成和实验结果。     

初中英语教师与后进生的课堂言语行为策略

教师是学校教育的执行者,是课堂的组织者,其言行对学生尤其是对后进生有着重要的影响.本文以言语行为理论为指导,在分析后进生和初中英语教师课堂言语行为特点的基础上,提出了英语教师应当施行的课堂言语行为策略,以促进后进生的全面发展.     

Reliable method for driving events recognition

Motor vehicles greatly influence human life but are also a major cause of death and road congestion, which is an obstacle to future economic development. We believe that by learning driving patterns, useful navigation support can be provided for drivers. In this paper, we present a simple and reliable method for the recognition of driving events using hidden Markov models (HMMs), popular stochastic tools for studying time series data. A data acquisition system was used to collect longitudinal and lateral acceleration and speed data from a real vehicle in a normal driving environment. Data were filtered, normalized, segmented, and quantified to obtain the symbolic representation necessary for use with discrete HMMs. Observation sequences for training and evaluation were manually selected and classified as events of a particular type. An appropriate model size was selected, and the model was trained for each type of driving events. Observation sequences from the training set were evaluated by multiple models, and the highest probability decides what kind of driving event this sequence represents. The recognition results showed that HMMs could recognize driving events very accurately and reliably.     

Tachycardia recognition algorithms for implantable systems

The detection algorithm of current antitachycardia pacing systems incorporates derivatives of heart rate as the only objective parameter used for recognition. Present pacing systems use one or more rate-related parameters: (1) rate cutoff, (2) sudden onset, (3) rate stability, and (4) sustained high rate. Recently, the development of antitachycardia systems has focused on combining the four detection criteria to form multiple recognition algorithms. Nevertheless, inability to differentiate between supraventricular and ventricular tachycardias at compatible rates remains a limitation. Incorporating atrial sensing capability, in addition to ventricular sensing capability, an alternative strategy that potentially could enhance diagnostic accuracy, is discussed. The incorporation of time and frequency analysis, arterial pressure, and stroke volume are also examined.     

边界判别投影在人脸识别上的应用

针对最大边界准则和边界Fisher分析在人脸特征提取过程中的不足,提出一种边界判别投影降维算法,利用类样本均值与其同类边界样本定义类内离散度,利用类样本均值与其异类边界样本定义类间离散度。同时结合最大边界准则解决类内离散度矩阵奇异的问题。与经典的最大边界准则和边界Fisher分析算法相比,可以同时考虑样本的全局结构和局部结构,避免小样本问题。在人脸数据集上的实验表明,边界判别投影是一种有效的特征提取算法,提高了人脸识别准确率。     

Speech coding with wavelets

Speech is a very basic way for humans to convey information to one another. From a communications standpoint, information can be sent efficiently by sending it as just text. However, with a bandwidth of only 4 kHz, speech can convey information with the emotion of a human voice. People want to be able to hear someone's voice from anywhere in the world-as if the person was in the same room. As a result, new, efficient speech coding techniques have impacted areas such as cellular telephony, mobile radios and voice mail systems     

具有语音功能的超声波测距仪

介绍一种基于单片机AT89C52的超声波测距系统,它带有ISD2590语音芯片,能实时读出所测距离,采用一线串行温度传感器DS18B20修正声波传播速度.并介绍了该系统的硬件电路及软件设计,实验表明该系统测量精度高,抗干扰能力强,并具有微型化数字显示和语音播报等功能.