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排序方式: 共有274条查询结果,搜索用时 15 毫秒
1.
Kwok Wa Leung Hoi Kuen Ng 《Antennas and Propagation, IEEE Transactions on》2005,53(5):1762-1769
The aperture-coupled hemispherical dielectric resonator antenna (DRA) with a parasitic patch is studied rigorously. Using the Green's function approach, integral equations for the unknown patch and slot currents are formulated and solved using the method of moments. The theory is utilized to design a circularly polarized (CP) DRA and a wide-band linearly polarized (LP) DRA. In the former, the CP frequency and axial ratio (AR) can easily be controlled by the patch location and patch size, respectively, with the impedance matched by varying the slot length and microstrip stub length. It is important that the AR will not be affected when the input impedance is tuned, and the CP design is therefore greatly facilitated. For the wide-band LP antenna, a maximum bandwidth of 22% can be obtained, which is much wider than the previous bandwidth of 7.5% with no parasitic patches. Finally, the frequency-tuning characteristics of the proposed antenna are discussed. Since the parasitic patch can be applied to any DRAs, the method will find applications in practical DRA designs. 相似文献
2.
New temperature sensitive AB, ABA, and BAB amphiphilic block copolymers consisting of hydrophilic poly(ethylene oxide) and hydrophobic poly(ethyl glycidyl carbamate) blocks were synthesized by anionic polymerization followed by chemical modification reactions. The self-association of the block copolymers in aqueous media was studied by UV-vis spectroscopy and dynamic and static light scattering. The obtained block copolymers spontaneously form micelles in aqueous media. The critical micellization concentration varied from 0.5 to 4 g/L depending on the copolymer architecture and composition. The influence of the temperature upon the self-association of the block copolymers was investigated. The increase of temperature did not affect the value of the critical micellization concentration, but led to the formation of better defined micelles with narrow size distribution. 相似文献
3.
Hy Quy Nguyen Siu Wa Lee Xiaohai Tian Minghui Dong Eng Siong Chng 《Multimedia Tools and Applications》2016,75(9):5265-5285
Voice conversion methods have advanced rapidly over the last decade. Studies have shown that speaker characteristics are captured by spectral feature as well as various prosodic features. Most existing conversion methods focus on the spectral feature as it directly represents the timbre characteristics, while some conversion methods have focused only on the prosodic feature represented by the fundamental frequency. In this paper, a comprehensive framework using deep neural networks to convert both timbre and prosodic features is proposed. The timbre feature is represented by a high-resolution spectral feature. The prosodic features include F0, intensity and duration. It is well known that DNN is useful as a tool to model high-dimensional features. In this work, we show that DNN initialized by our proposed autoencoder pretraining yields good quality DNN conversion models. This pretraining is tailor-made for voice conversion and leverages on autoencoder to capture the generic spectral shape of source speech. Additionally, our framework uses segmental DNN models to capture the evolution of the prosodic features over time. To reconstruct the converted speech, the spectral feature produced by the DNN model is combined with the three prosodic features produced by the DNN segmental models. Our experimental results show that the application of both prosodic and high-resolution spectral features leads to quality converted speech as measured by objective evaluation and subjective listening tests. 相似文献
4.
5.
P. Golonka B. Kersevan T. Pierzcha?a Z. Wa?s M. Worek 《Computer Physics Communications》2006,174(10):818-835
We present the system for maintaining the versions of two packages: the TAUOLA of τ-lepton decay and PHOTOS for radiative corrections in decays. The following features can be chosen in an automatic or semi-automatic way: (1) format of the common block HEPEVT; (2) version of the physics input (for TAUOLA): as published, as initialized by the CLEO collaboration, as initialized by the ALEPH collaboration (it is suggested to use this version only with the help of the collaboration advice), new optional parametrization of matrix elements in 4π decay channels; (3) type of application: stand-alone, universal interface based on the information stored in the HEPEVT common block including longitudinal spin effects in the elementary Z/γ∗→τ+τ− process, extended version of the standard universal interface including full spin effects in the H/A→τ+τ− decay, interface for KKMC Monte Carlo, (4) random number generators; (5) compiler options. The last section of the paper contains documentation of the programs updates introduced over the last two years.
Program summary
Title of program:tauola-photos-F, release IICatalogue identifier:ADXO_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADXO_v1_0Programs obtainable from: CPC Program Library, Queen's University of Belfast, N. IrelandComputer: PC running GNU/Linux operating systemProgramming languages and tools used:CPP: standard C-language preprocessor, GNU Make builder tool, also FORTRAN compilerNo. of lines in distributed program, including test data, etc.: 194 118No. of bytes in distributed program, including test data, etc.:2 481 234Distribution format: tar.gzCatalogue identifier:ADXO_v2_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADXO_v2_0No. of lines in distributed program, including test data, etc.:308 235No. of bytes in distributed program, including test data, etc.:2 988 363Distribution format:tar.gzDoes the new version supersede the previous version:YesNature of the physical problem: The code of Monte Carlo generators often has to be tuned to the needs of large HEP Collaborations and experiments. Usually, these modifications do not introduce important changes in the algorithm, but rather modify the initialization and form of the hadronic current in τ decays. The format of the event record (HEPEVT common block) used to exchange information between building blocks of Monte Carlo systems often needs modification. Thus, there is a need to maintain various, slightly modified versions of the same code. The package presented here allows the production of ready-to-compile versions of TAUOLA [S. Jadach, Z. Wa?s, R. Decker, J.H. Kühn, Comput. Phys. Comm. 76 (1993) 361; A.E. Bondar, et al., Comput. Phys. Comm. 146 (2002) 139] and PHOTOS [E. Barberio, Z. Wa?s, Comput. Phys. Comm. 79 (1994) 291] Monte Carlo generators with appropriate demonstration programs. The new algorithm, universal interface of TAUOLA to work with the HEPEVT common block, is also documented here. Finally, minor technical improvements of TAUOLA and PHOTOS are also listed.Method of solution: The standard UNIX tool: the C-language preprocessor is used to produce a ready-to-distribute version of TAUOLA and PHOTOS code. The final FORTRAN code is produced from the library of ‘pre-code’ that is included in the package.Reasons for new version: The functionality of the version of TAUOLA and PHOTOS changed over the last two years. The changes, and their reasons, are documented in Section 9, and our new papers cited in this section.Additional comments: The updated version includes new features described in Section 9 of the paper. PHOTOS and TAUOLA were first submitted to the library as separate programs. Summary details of these previous programs are obtainable from the CPC Program Library.Typical running time: Depends on the speed of the computer used and the demonstration program chosen. Typically a few seconds. 相似文献6.
维吾尔语广播新闻连续语音敏感词检索系统 总被引:1,自引:0,他引:1
首先介绍语音信号来源于新疆人民广播电台维吾尔语新闻的敏感词语音语料库的建设。然后用该语料库进行基于HMM的模型训练。模型训练中详细介绍识别基元端点检测、特征提取、矢量量化、码本构建、HMM模型训练过程和结果。最后用该语料库和HMM训练模型对维吾尔语广播新闻连续语音信号进行敏感词检索,并对检索结果进行分析。 相似文献
7.
中国古典园林在世界园林史上独树一帜,与中国文人画及田园诗词艺术所抒发的审美情趣是一致的,纵观其发展,与传统文化有着紧密的联系.本文试从园林、意境及与儒道佛及诗词艺术的相互渗透入手,阐述中国古典园林的传统特质. 相似文献
8.
Hye-Jin Kim You-Jung Lee Wa Gao Chung-Han Chung Jin-Woo Lee 《Korean Journal of Chemical Engineering》2012,29(3):384-391
The concentration of four mineral salts in the medium for the production of carboxymethylcellulase (CMCase) by Psychrobacter aquimaris LBH-10 were optimized using orthogonal array method (OAM) and response surface method (RSM) and their results from two statistical
methods were compared. The analysis of variance (ANOVA) of data from central composite design (CCD) based on OAM indicated
that potassium phosphate gave the highest percentage participation for cell growth as well as production of CMCase. However,
their relative participations of four salts for cell growth were different from those for production of CMCase. The ANOVA
of results from RSM indicated that highly significant factors (“probe>F” less than 0.0001) for cell growth were K2HPO4 and (NH4)2SO4, whereas those for production of CMCase were K2HPO4, NaCl, and MgSO4·7H2O. The optimal concentration of K2HPO4, NaCl, MgSO4·7H2O, and (NH4)2SO4 for cell growth extracted by Design Expert Software based on RSM were 7.10, 0.84, 0.24, and 0.33 g/L, respectively, whereas
those for production of CMCase were 3.00, 0.52, 0.34, and 0.45 g/L. The optimal concentrations of salts for cell growth and
production of CMCase using RSM basically coincided with those using OAM as well as those from ‘one-factor-at-a-time’ method.
The production of CMCase by P. aquimaris LBH-10 with optimized concentrations of salts was 273.0 U/mL, which was enhanced by 1.27 times higher than the previous report. 相似文献
9.
Abstract Among the parameters that affect photolithography, the most important are exposure and development time which affect the coating photoresist characteristics. This study further researches the relationship between the exposure and development time using a high speed image inspection system, and the relationship between the development time and photoresist depth using a Scanning Probe Microscope (SPM). A partial scan CCD camera and high speed frame capture card were used to obtain the photoresist development processing parameters. The experimental results verified that this imaging system provides an economical and effective method for producing a micro‐photo‐etched product. It is expected that these experiments can also offer some good references useful in the micro electro mechanical industrial field. 相似文献
10.
王兴礼 《电信工程技术与标准化》2007,20(7):29-30
1 问题的提出 工作中偶而涉及铜的电阻率,查阅《建筑电工手册》,第659页表12.1-1竟然和第660页的表12.1-3相差100倍,哪个数值对呢? 相似文献