共查询到18条相似文献,搜索用时 78 毫秒
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本文讨论了一种基于Linux的MP3播放器的设计。系统基于Linux操作系统,利用GNU开发工具进行软件开发,使用C99标准的C语言编写,利用开源的高质量MPEG音频解码器MAD对MP3文件进行解码生成PCM数据,用ALSA中的PCM接口处理PCM数据,最后将数字信号转化为模拟信号,实现MP3音频的播放。 相似文献
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本文讨论了一种基于Linux的MP3播放器的设计.系统基于Linux操作系统,利用GNU开发工具进行软件开发,使用C99标准的C语言编写,利用开源的高质量MPEG音频解码器MAD对MP3文件进行解码生成PCM数据,用ALSA中的PCM接口处理PCM数据,最后将数字信号转化为模拟信号,实现MP3音频的播放. 相似文献
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随着大规模集成电路技术的飞速发展以及嵌入式系统在军事领域的应用也日趋广泛,对弹上遥测采编系统提出了新的要求;介绍了一种基于FPGA与ARM9嵌入式平台的弹上遥测采编系统设计;系统前端采用了智能传感器,并且引入了GPS技术;针对分包遥测比传统PCM遥测具有显著的优越,提出了基于分包遥测的遥测数据帧格式;基于FPGA和微处理器两种技术设计的采编系统具有可编程能力和灵活性. 相似文献
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USB VoIP终端是一种新型的计算机终端设备,通过它人们可以用普通电话机拨打网络电话服务商提供的VoIP电话.本文提出了USB VoIP终端硬件的设计方案,描述了各功能模块的实现,阐述了固件程序和上层控制程序,对PCM、SPI的实现部分进行了时间分析,提出了高效率的A-律到线性PCM转换算法思想. 相似文献
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基于CPLD的双音多频信号PCM编码的设计 总被引:1,自引:0,他引:1
本文介绍了可编程逻辑器件(PLD)在双音多频信号的PCM编码中的应用。从双音多频信号的PCM编码到PCM编码信号的输出,利用CPLD、硬件描述语言VHDL及MATLAB来实现整个功能,仿真结果正确,并给出了相应的开发应用系统。 相似文献
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本文简要介绍了遥测PCM数据分路技术的现状,提出了“先输入、后分路”的新思路,即先利用计算机通用串行总线(USB)把遥测PCM数据输入到计算机,然后用软件实现遥测PCM数据分路的新方法,并介绍了PCM-USB转换接口的硬件、驱动程序设计,软件分路中的帧、子帧同步策略和软件实现方法。 相似文献
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为检验采集模块输出的PCM码,设计基于FPGA的PCM码收发模块,通过设计模拟PCM码源、PCM码解码接收模块,自行判断输出和接收的正确性,收发模块逻辑功能由FPGA完成。解码接收后的数据经USB接口回传至上位机,通过上位机软件检验PCM码收发模块工作情况。 相似文献
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《Ergonomics》2012,55(5):716-723
Phase change material (PCM) absorbs or releases latent heat when it changes phases, making thermal-regulated clothing possible. The objective of this study was to quantify the relationships between PCM cooling rate and temperature gradient, mass and covering area on a thermal manikin in a climatic chamber. Three melting temperatures (24, 28, 32°C) of the PCMs, different mass, covering areas and two manikin temperatures (34 and 38°C) were used. The results showed that the cooling rate of the PCM vests tested is positively correlated with the temperature gradient between the thermal manikin and the melting temperature of the PCMs. The required temperature gradient is suggested to be greater than 6°C when PCM vests are used in hot climates. With the same temperature gradient, the cooling rate is mainly determined by the covering area. The duration of the cooling effect is dependent on PCM mass and the latent heat. Statement of Relevance: The study of factors affecting the cooling rate of personal cooling equipment incorporated with PCM helps to understand cooling mechanisms. The results suggest climatic conditions, the required temperature gradient, PCM mass and covering area should be taken into account when choosing personal PCM cooling equipment. 相似文献
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随着大数据分析应用时效性提升和“存储墙”问题日益突出,存储系统已成为当前计算机系统整体性能的瓶颈。以相变存储器(PCM)为代表的新型非易失性存储器(NVM)具有集成度高、功耗低、读写访问速度高、非易失、体积小和抗震等优良特性,已成为最具潜力的下一代存储设备。然而,写寿命有限是PCM实用化的一道障碍,如何通过减少写操作和磨损均衡以提升PCM使用寿命是当前的研究热点。
从减少PCM写操作、均匀写操作分布以及在混合内存中的页面迁移等三个方面介绍了当前PCM写寿命延长技术的研究现状以及优缺点,最后探讨未来进一步改进PCM寿命可能的研究方向。 相似文献
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An ultrawide band polarization conversion metasurface (PCM) is proposed to reduce the reflection of a slot antenna. The proposed PCM can convert a linearly polarized incident wave to the reflected wave with a 90° rotation. By arranging the PCM around the antenna symmetrically, an ideal phase cancelation is achieved. To verify the design, a metasurface‐slot antenna is simulated and measured to confirm the proposed PCM for a significant reduction of the reflection. Results show that the normal reflection of the proposed antenna at boresight is reduced more than 10 dB over an ultrawide band. In addition, 2 dB enhancement of the gain is achieved compared with a reference antenna which has the same dimensions. Meanwhile, the small influence is observed for the antenna radiation by introducing the PCM. 相似文献
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Phase change memory (PCM) is a promising candidate to replace DRAM as main memory, thanks to its better scalability and lower static power than DRAM. However, PCM also presents a few drawbacks, such as long write latency and high write power. Moreover, the write commands parallelism of PCM is restricted by instantaneous power constraints, which degrades write bandwidth and overall performance. The write power of PCM is asymmetric: writing a zero consumes more power than writing a one. In this paper, we propose a new scheduling policy, write power asymmetry scheduling (WPAS), that exploits the asymmetry of write power. WPAS improveswrite commands parallelism of PCM memory without violating power constraint. The evaluation results show that WPAS can improve performance by up to 35.5%, and 18.5% on average. The effective read latency can be reduced by up to 33.0%, and 17.1% on average. 相似文献
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Miquel De Cáceres Author Vitae Francesc Oliva Author Vitae Author Vitae 《Pattern recognition》2006,39(11):2010-2024
This paper initially describes the relational counterpart of possibilistic c-means (PCM) algorithm, called relational PCM (or RPCM). RPCM is then improved to better handle arbitrary dissimilarity data. First, a re-scaling of the PCM membership function is proposed in order to obtain zero membership values when the distance to prototype equals the maximum value allowed in bounded dissimilarity measures. Second, a heuristic method of reference distance initialisation is provided which diminishes the known PCM tendency of producing coincident clusters. Finally, RPCM improved with our initialisation strategy is tested on both synthetic and real data sets with satisfactory results. 相似文献
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相变存储器(PCM)由于其非易失性、高读取速度以及低静态功耗等优点,已成为主存研究领域的热点.然而,目前缺乏可用的PCM设备,这使得基于PCM的算法研究得不到有效验证.因此,本文提出了利用主存模拟器仿真并验证PCM算法的思路.本文首先介绍了现有主存模拟器的特点,并指出其并不能完全满足当前主存研究的实际需求,在此基础上提出并构建了一个基于DRAM和PCM的混合主存模拟器.与现有模拟器的实验比较结果表明,本文设计的混合主存模拟器能够有效地模拟DRAM和PCM混合存储架构,并能够支持不同形式的混合主存系统模拟,具有高可配置性.最后,论文通过一个使用示例说明了混合主存模拟器编程接口的易用性. 相似文献