检索结果-内蒙古大学图书馆

International Conference on Signal Processing Proceedings (ICSP)

作者： Yongfeng Huang Yang Juan Sifa Zhang Jiangling Zhang National Storage System Laboratory School of Computer Huazhong University of Science and Technology Wuhan China

This paper describes how to implement the G.723.1 recommendation in the IP telephony gateway and studies in detail the programming of the TMS320C6201 DSP and optimization methods for reducing the speech processing delay of the G.723.1 codec. As a result of adopting these optimization and programming methods, we have implemented a high-speed speech codec which can process concurrently 18 voice channels with a single TMS320C6201 chip in the IP telephony gateway. Finally, the paper summarizes the performance of the resulting ITU-T G.723.1 speech codec.

关键词： Speech codecs Digital signal processing Internet telephony Filters Linear predictive coding Decoding Optimization methods Speech processing Delay effects Speech coding

来源：评论

学校读者我要写书评

暂无评论

Sift algorithm to improve performance of Chinese character classifier using linear decision function

Sift algorithm to improve performance of Chinese character c...

引用

World Congress on Intelligent Control and Automation (WCICA)

作者： Jin Yijiang Zhang Min Ma Shaoping State Key Laboratory of Intelligent Technology and System Department of Computer Science & Technology Tsinghua University Beijing China Tsinghua University Beijing Beijing CN

Presents a method to improve the performance of a Chinese character classifier. The method examines the candidates of an existing classifier using a linear decision function to select the most probable one. The algorithm together with a complete scheme has been proposed. The possible improvement of the performance has been estimated based on the experimental inspection of the separability of Chinese characters. The result shows that recognition accuracy can be increased dramatically. This means that the algorithm is practical.

关键词： Laboratories Intelligent systems computer science Inspection

来源：评论

学校读者我要写书评

暂无评论

Micromachined picosecond optical near-field probe for pulse-coupling measurement of interconnection lines

Micromachined picosecond optical near-field probe for pulse-...

引用

IEEE Topical Meeting on Electrical Performance of Electronic Packaging (EPEPS)

作者： Jongjoo Lee Heeseok Lee Seungyong Baek Yuchul Jung Joungho Kim Department of Electrical Engineering & Computer Science KAlST Terahertz Media and System Laboratory Daejeon South Korea Korea Advanced Institute of Science and Technology Daejeon Daejeon KR

We have successfully developed a novel picosecond optical near-field probe for the high-frequency field mapping of interconnection lines. The transverse tangential electric field distribution of the microstrip coupled... 详细信息

关键词： Pulse measurements Optical interconnections Probes Optical pulses Integrated circuit interconnections High speed optical techniques Optical films Spatial resolution Optical switches Optical pulse generation

来源：评论

学校读者我要写书评

暂无评论

Evaluation and analysis of a dynamic allocation scheme on a C++-based parallel programming library

Evaluation and analysis of a dynamic allocation scheme on a ...

引用

International Conference on High Performance Computing in the Asia-Pacific Region

作者： T. Tezuka B.O. Apduhan T. Sueyoshi I. Arita Kyushu Multimedia System Research Laboratory Matsushita Elecrric Indusrrial Company Limited Japan Department of Artificial Intelligence Kyushu Institute of Technology Japan Department of Computer Science Kumamoto University Japan

We are currently studying the implementation of a C++-based parallel programming library to simplify parallel programming and efficiently execute parallel programs on a locally distributed computers with nonuniform performances. The class library employs dynamic allocation scheme of Light-Weight Processes (LWPs) and efficient execution of parallel applications. In this paper, we describe the dynamic allocation scheme implemented in the class library, discuss the experimental evaluation with parallel applications, and provide comparison with static allocation. The experiments results show that with dynamic allocation implemented in the class library, there is a significant performance advantage on a cluster environment with machines having nonuniform performances. Furthermore, this study provides insights on the trade-offs between task or process allocation and memory-access costs.

关键词： Dynamic programming Parallel programming Libraries Concurrent computing Distributed computing Workstations Parallel processing Electronic mail Application software Personal communication networks

来源：评论

学校读者我要写书评

暂无评论

Fully complex backpropagation for constant envelope signal processing

Fully complex backpropagation for constant envelope signal p...

引用

IEEE Workshop on Neural Networks for Signal Processing

作者： Taehwan Kim T. Adali Information Technology Laboratory Department of Computer Science and Electrical Engineering University of Maryland Baltimore County Baltimore MD USA Center for Advanced Aviation System Development MITRE Corporation McLean VA USA

One of the challenges in designing a neural network to process complex-valued signals is finding a suitable nonlinear complex activation function. The main reason for this difficulty is the conflict between the boundedness and the differentiability of complex functions in the entire complex plane, stated by Louiville's theorem. To avoid this difficulty, splitting, i.e., using two separate real nonlinear activation functions for the real and imaginary signal components has been the traditional approach. We introduce a feedforward neural network (FNN) architecture employing hyperbolic tangent tanh(z) function defined in the entire complex domain, and compare its performance with the FNN that uses a split complex structure. Since tanh(z) is analytic and bounded almost everywhere in the complex plane, when trained by backpropagation, it can easily outperform the non-analytic split complex activation function in convergence speed and achievable minimum squared error when the domain is bounded around the unit circle. We demonstrate this property by an equalization example, equalization of multi-phase shift keying (MPSK) signals corrupted by a multipath channel. The properties of tanh(z) and future directions to combat nonlinear distortions in complex transmission schemes are discussed.

关键词： Backpropagation Signal processing Neural networks Signal analysis Phase modulation Wireless communication Information technology Laboratories computer science Signal design

来源：评论

学校读者我要写书评

暂无评论

A 1.1 V SOI CMOS frequency divider using body-inputting SCL circuit technology

A 1.1 V SOI CMOS frequency divider using body-inputting SCL ...

引用

IEEE SOI-3D-Subthreshold Microelectronics technology Unified Conference (S3S)

作者： T. Fuse M. Tokumasu S. Kawanaka H. Fujii A. Kameyama M. Yoshimi S. Watanabe Computer & Network Systems Laboratory Corporate Research & Development Center Toshiba Corporation Japan Advanced CMOS Technology Development Group System LSI Development Center Semiconductor Company Toshiba Corporation Yokohama Japan Computer & Network Systems Laboratory Corporate Research & Development Center Toshiba Corporation Saiwai Japan

SOI CMOS technology is one of the most effective candidates for realization of low power and high performance digital/RF circuits, with demand for single-chip LSI in portable communications equipment. By optimizing the threshold voltage, the CMOS logic in digital circuits can operate at less than 1 V (Fujii et al, 1999; Fuse et al, 1997). In the series gating ECL (emitter coupled logic) or SCL (source coupled logic) which is often used in RF circuits, on the other hand, the minimum operating voltage is raised to 1.8-2.6 V, due to the stacked configuration where plural transistors are connected in series (Yamashina et al., 1992). In this paper, we propose a body-inputting SCL circuit, which decreases the minimum operating voltage to around 1 V, by applying the input signal to the body of SOI devices. The fabricated 1/128 frequency divider realized 1.1 V operation with a maximum clock frequency of 450 MHz and each current source of 35 /spl mu/A.

关键词： Frequency conversion CMOS logic circuits CMOS digital integrated circuits CMOS technology Radio frequency Coupling circuits Logic circuits Voltage Large scale integration Communication equipment

来源：评论

学校读者我要写书评

暂无评论

Polycrystalline and amorphous sol-gel derived WO/sub 3/ thin films and their gas sensing properties

Polycrystalline and amorphous sol-gel derived WO/sub 3/ thin...

引用

Conference on Optoelectronic and Microelectronic Materials and Devices

作者： Y.X. Li K. Galatsis W. Wlodarski J. Cole S. Russo J. Gorman N. Rockelmann C. Cantalini School of Electrical and Computer System Engineering Department of Applied Physics RMIT University Australia Laboratory of Functional Inorganic Materials Chinese Academy and Sciences Shanghai China School of Electrical and Computer System Engineering Department of Applied Physics RMIT University Melbourne Australia Department of Chemistry and Materials University di L''Aquila Italy Manufacturing Science and Technology CSIRO Italy

ISBN: (纸本)0780366980

Amorphous and polycrystalline tungsten trioxide (WO/sub 3/) thin films were prepared using the sol-gel process. Tungsten ethoxide was used as precursor material. The WO/sub 3/ thin films were spun onto the sapphire and silicon substrates at 2500 rpm for 30 s. The X-ray diffraction (XRD) results revealed that the films annealed at low temperature of 420/spl deg/C for 1 hr. are amorphous while those annealed at as high as 500/spl deg/C are polycrystalline. The scanning electronic microscope (SEM) images revealed that the film annealed at 360/spl deg/C was amorphous and the surface was smooth. The film showed good responses to 100 ppm, 1000 ppm and 1% O/sub 2/ at an operating temperature of 170/spl deg/C. At high operating temperatures the films showed unsaturated and sluggish responses to oxygen gas. The amorphous WO/sub 3/ thin films showed no response to ozone. The crystallized thin films showed very stable response to oxygen.

关键词： Amorphous materials Transistors Annealing Temperature Tungsten Scanning electron microscopy Semiconductor thin films Silicon Substrates X-ray imaging

来源：评论

学校读者我要写书评

暂无评论

Texture features for land cover change detection at 250 m resolution-an application of machine learning feature subset selection

Texture features for land cover change detection at 250 m re...

引用

IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： J.C.-W. Chan R.S. DeFries Xiwu Zhan Chengquan Huang J.R.G. Townshend Laboratory for Global Remote Sensing Studies Department of Geography University of Maryland College Park USA Department of Geography and Earth System Interdisciplinary Science Center University of Maryland College Park USA USGSIEROS Data Center Raytheon Information Technology and Scientific Services USA Department of Geography and Institute for Advanced Computer Studies University of Maryland College Park USA

Texture measures have been widely studied in addition to spectral features to characterize land cover type. Texture measures can be used to update land cover maps and enhance classification accuracy. Most previous studies have focussed only on fine resolution data such as Landsat, SPOT and Synthetic Aperture Radar imagery. Texture analysis at coarser resolution (250 m) has not been investigated because data are only beginning to become available with the launch of MODIS (Moderate Resolution Imaging Spectroradiometer). To meet the need of global change research, the MODIS instrument is planned to provide global coverage at 250 m resolution in the red and infrared bands. Early warning of human-induced land cover changes, such as urbanization and deforestation, is expected from MODIS. This paper examines whether texture analysis at this scale would be useful for detecting changes. There are at least two issues in using texture analysis: 1) which texture measures should be used, and 2) what window size is most appropriate for capturing textures. In this study we test a large number of texture measures and window sizes on MODIS data simulated from Landsat data using the data mining technique of feature selection.

关键词： MODIS Image resolution Satellites Remote sensing Image texture analysis Size measurement Synthetic aperture radar Image analysis Instruments Testing

来源：评论

学校读者我要写书评

暂无评论

Electromagnetic field characteristics of radial line slot antennas for surface wave coupled plasma production

Electromagnetic field characteristics of radial line slot an...

引用

Antennas and Propagation Society International Symposium

作者： T. Yamamoto M. Ono M. Ando N. Goto N. Ishii Y. Yasaka Department of Electrical Engineering and Computer Sci. Faculty of Eng Yamagata University Yonezawa Yamagata Japan Department of Electrical and Electronic Engineering Faculty of Eng Tokyo Institute of Technology Meguro Tokyo Japan Department of Electronics and System Faculty of Engineering Takushoku University Hachioji Tokyo Japan Corporate R&D Central Research Laboratory Tokyo Electron Limited Nirasaki Yamanashi Japan

In plasma processing systems for large sized wafer, quick evacuation of reaction gas by making the process space gap narrow is required to realize higher productivity and better quality of microelectronic devices. The wafer must be placed closely to the antenna aperture in this case. A radial line slot antenna (RLSA) for surface wave coupled plasma (SWP) is a promising candidate to this end. A novel slot arrangement in the aperture, which consists of densely arrayed transverse slots, was fabricated and tested. A uniform, high electron density of 3/spl times/10/sup 11/ cm/sup -3/ and large-area plasma under the condition of low electron temperature has already been realized by experiments. It dispenses with DC magnetic fields required in ECR systems. For further development of slot design as well as the mechanism extraction of plasma generation, this paper evaluates the electromagnetic near fields of SWP RLSAs. As the first step, antennas in free space without the plasma as well as the glass vacuum window, is analyzed using the periodic array model. The predicted near field distribution is compared with the experiments and reasonable agreement is reported.

关键词： Electromagnetic fields Slot antennas Plasma temperature Plasma devices Apertures Plasma density Plasma waves Electrons Plasma properties Plasma materials processing

来源：评论

学校读者我要写书评

暂无评论

Asynchronous Heterogeneous Mechanism for Hyper-Distributed Hyper-Parallel Al Processing

引用

Journal of computer Science & technology 1999年第3期14卷 234-241页

作者：帅典勋 Department of Computer Science East-China University of Science and Technology Shanghai P.R. China State Key Laboratory of Intelligence and System Tsinghua University Beijing P.R. China

This paper proposes an asynchronous heterogeneous propagation approach of concurrent competitive waves for hyper-distributed hyper-parallel heuris tic problem-solving. This approach is much more powerful than the synchronous homogeneous mechanisms and the asynchronous superimposition algorithms, and has universal validity and availability. The basic conception, concurrent algorithm and its properties are discussed. The theory and conclusions drawn in this paper are of essential importance for the hardware implementation of hyper-distributed hyper-parallel processing based on chaotic cellular networks.

关键词： asynchronous heterogeneous competitive waves hyper-distributed hyper-parallel processing concurrent algorithm heuristic search implicit AND/OR graph

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：