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171.
一种用排队论指导的CAN总线语音通信系统设计 总被引:3,自引:0,他引:3
针对传统语音通信系统存在的地址编码繁杂、通信模式单一、难于维护的缺陷,设计了一款适用于工业现场的多功能语音通信系统。在排队论的基础上,对CAN总线语音通信系统进行了理论分析,重点介绍了CAN总线的软硬件设计。对系统的性能测试结果表明,系统的CAN帧丢失率<0.5‰,语音质量能通过主观试听和客观测试,整体系统工作良好。 相似文献
172.
173.
Klaus Schmeh 《Cryptologia》2013,37(1):14-45
Abstract “The Pathology of Cryptology” is the title of a chapter in David Kahn's book The Codebreakers. This chapter mainly deals with hidden messages, which amateur scientists claim to have discovered in the works of William Shakespeare and in other literary works. The present article picks up this subject and provides it with a theoretic framework under the name of “para-steganography.” Moreover, further case studies are added to those given by Kahn, including many examples that only became known after the publication of The Codebreakers. These considerations show that a hidden code can be found almost anywhere, provided that one looks for it in a suitable manner. 相似文献
174.
175.
Mária Gósy 《International Journal of Speech Technology》2001,4(1):75-85
Due to the various techniques used in experimental phonetics and the language inventories, more and more has been learned about the nature of stops of the world's languages. Stop consonants occur in all languages, with voiceless unaspirated stops being the most common. The differences in voice onset time (VOT) have been termed lead vs. short lag, where VOT itself is defined as the timing between the onset of phonation and the release of the occlusion of the vocal tract.For Hungarian, no systematic analysis of the stops has been carried out thus far. This paper aims to investigate the acoustic and perceptual properties of VOTs of the three Hungarian voiceless stops when they appear in isolation (in syllables and in words) but also when they occur in spontaneous speech.The results of the acoustic analysis show a clear difference between careful and spontaneous speech. Bilabials and velars are significantly shorter in fluent speech than in careful speech (18.51 msec and 35.31 msec respectively, as opposed to 24.64 msec and 50.17 msec) while dentals seem to be unchanged (23.3 msec as opposed to 26.59 msec). Therefore, the actual duration of VOT is characteristic of the place of the articulation of stops in spontaneous speech, and VOTs of bilabials and dentals do not differ from each other in careful speech. Vowels following the stops influence them more in careful than in spontaneous speech, which can also be explained by the experimentally confirmed phenomenon of the changing quality of the present-day Hungarian vowels into the neutral vowel. Voice onset time is a specific feature of the Hungarian unaspirated plosive consonants. A further experiment was carried out to define the actual function of the VOTs of the voiceless stops in the Hungarian listeners' perception. 相似文献
176.
According to the MPEG‐1/2 standard, full motion video can be compressed and stored in an information warehouse. Multiplexing with normal voice calls, it is retrieved and delivered to the customer's local BISDN central office via 155 Mb/s trunks. These voice calls have higher priority than video‐on‐demand (VOD) so that normal voice services will not be influenced by VOD transmission. The number of voice calls always fluctuates in real‐time. Thus, an efficient traffic control scheme is highly desired to guarantee a given level of performance and achieve as great as possible use of available bandwidth. Based on the fact that the number of real‐time voice calls is variable, and the use of available capacity is less than 100 per cent, this paper will present an efficient traffic control scheme for store‐and‐forward VOD services, and demonstrate the scheme by various simulation results. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
177.
VOIP与TDM的网络成本比较 总被引:1,自引:0,他引:1
本文从网络投资成本角度详细分析了这两种方案,给出了了一系列定量分析结果,并充分考虑了易变参数的影响。 相似文献
178.
汪洋 《数字社区&智能家居》2009,(15)
在日常工作中,我们经常要使用Excel录入大量的数据,如客户信息、学生成绩等。由于信息量大,在录入过程中,我们不可避免的会出现一些错误。如何快速、有效的检查、校验录入的信息是值得研究的。这里文章介绍两种轻松、高效的数据校验方法——公式审核法和语音校验法。 相似文献
179.
Stern Steven E.; Mullennix John W.; Wilson Stephen J. 《Canadian Metallurgical Quarterly》2002,87(2):411
Are perceptions of computer-synthesized speech altered by the belief that the person using this technology is disabled? In a 2x2 factorial design, participants completed an attitude pretest and were randomly assigned to watch an actor deliver a persuasive appeal under 1 of the following 4 conditions: disabled or nondisabled using normal speech and disabled or nondisabled using computer-synthesized speech. Participants then completed a posttest survey and a series of questionnaires assessing perceptions of voice, speaker, and message. Natural speech was perceived more favorably and was more persuasive than computer-synthesized speech. When the speaker was perceived to be speech-disabled, however, this difference diminished. This finding suggests that negatively viewed assistive technologies will be perceived more favorably when used by people with disabilities. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
180.
The design of a high speed, broadband packet switch with two priority levels for application in integrated voice/data networks is presented. The packet switch can efficiently cope with 128 byte packets converging on it from eight 140 Mbit/s dynamic time division multiplexed fibre optic links. The packet switch throughput varies with the load and traffic composition, and the delay experienced by voice and data packets is within 300 μs and 3 ms, respectively. The design is implemented by task-sharing in a multi-processor configuration. The design of the packet switch, including its subsystems, is detailed here. 相似文献