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Generalized Odd-Even Mode Theory and Mode Synthesis Antenna Design Approach
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作者 Wen-Jun Lu 《Electromagnetic Science》 2024年第1期20-37,共18页
In this article,studies on the multimode excitation problem of waveguides and antennas,the balance/unbalance mech-anism and the balanced feeding techniques in dipole antenna systems are first briefly historically revi... In this article,studies on the multimode excitation problem of waveguides and antennas,the balance/unbalance mech-anism and the balanced feeding techniques in dipole antenna systems are first briefly historically reviewed.In this context,general-ized odd-even mode theory is advanced to quantitatively and approximately describe the mutual coupling effect between a feed line and an antenna.As is mathematically deduced and demonstrated,the modal parity mismatch between the feed line and the antenna should ultimately dominate the unbalance phenomenon in antenna systems.Thus,an elegant,closed-form formula is derived to ap-proximately calculate the“unbalance degree”of a straight dipole off-center fed by a symmetric twin-wire line.Design approaches for the simplest,linear,1-D multimode resonant antennas are introduced.Moreover,the“falling tone excitation”law gauged based on prototype dipoles is revealed and used to develop a mode synthesis design approach for microstrip patch antennas(MPAs)and 2-D sectorial electric dipole antennas.Design examples with distinctive radiation performance are presented and discussed.Finally,possible development trends of multimode resonant antennas are prospected. 展开更多
关键词 Generalized odd-even mode theory Modal parity mismatch Mode synthesis antenna design approach Multimode resonant antenna
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Research on predicting prosodic parameters for Chinese synthesis by data mining approach
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作者 WANG Wei CAI Lianhong(Department of Computer Science and Technology, Tsinghua University Beijing 100084) 《Chinese Journal of Acoustics》 2003年第2期184-192,共9页
Prosodic control is an important part of speech synthesis system. Prosodic parameters choice right or wrong influences the quality of synthetic speech directly. At present, text to speech system has less effective des... Prosodic control is an important part of speech synthesis system. Prosodic parameters choice right or wrong influences the quality of synthetic speech directly. At present, text to speech system has less effective describe to reflect data relationships in the corpus. A new research approach - data mining technology to discover those relationships by association rules modeling is presented. And a new algorithm for generating association rules of prosodic parameters including pitch parameters and duration parameters from corpus is developed. The output rules improve the correctness of syllable choice in text to speech system. 展开更多
关键词 by data is Research on predicting prosodic parameters for Chinese synthesis by data mining approach for into on
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A Knowledge-Based Approach to Program Synthesis from Examples
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作者 朱鸿 金凌紫 《Journal of Computer Science & Technology》 SCIE EI CSCD 1991年第1期47-58,共12页
This paper proposes an approach to synthesize functional programs of Backus' FP system from input/output instances.Based on a theory of orthogonal expansion of programs,the task of program synthesis is expressed i... This paper proposes an approach to synthesize functional programs of Backus' FP system from input/output instances.Based on a theory of orthogonal expansion of programs,the task of program synthesis is expressed in program equations,and fulfilled by solving them according to the knowledge about the equivalence between programs.Some general knowledge of solving program equations with a number of examples are given in the paper. 展开更多
关键词 A Knowledge-Based Approach to Program synthesis from Examples
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A microbially based approach for the asymmetric synthesis of both enantiomers of R-and S-fluoxetine
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作者 GU,Jian-Xin LI,Zu-Yi LIN,Guo-Qiang Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences,Shanghai 200032 《Chinese Journal of Chemistry》 SCIE CAS CSCD 1992年第4期355-358,共0页
Both enantiomers of fluoxetine were synthesized in five steps from ethyl benzoylacetate (1)using microbial-chemical approach with overall yields of 59% and 62% respectively.(S)-Enan- tiomer can be obtained in >99% ... Both enantiomers of fluoxetine were synthesized in five steps from ethyl benzoylacetate (1)using microbial-chemical approach with overall yields of 59% and 62% respectively.(S)-Enan- tiomer can be obtained in >99% e.e.by resting cell of baker's yeast and the R form was produced in 81 % e.e.by immobilized Geotrichum sp.G 38. 展开更多
关键词 A microbially based approach for the asymmetric synthesis of both enantiomers of R-and S-fluoxetine
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Fiber Materials for Electrocatalysis Applications 被引量:6
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作者 Fangzhou Zhang Jun Chen Jianping Yang 《Advanced Fiber Materials》 SCIE EI 2022年第4期720-735,共16页
Fiber materials are promising for electrocatalysis applications due to their structural features including high surface area,controllable chemical compositions,and abundant composite forms.In the past decade,considera... Fiber materials are promising for electrocatalysis applications due to their structural features including high surface area,controllable chemical compositions,and abundant composite forms.In the past decade,considerable research efforts have been devoted to construct advanced fiber materials possessing conductive network(to facilitate efficient electron transport)and large specific surface area(to support massive catalytically active sites)to boost electrocatalysis performance.Herein,we focused on recent advances in fiber-based electrocatalyst with enhanced electrocatalytic activity.Moreover,the synthesis,structure,and properties of fiber materials and their applications in hydrogen evolution reaction,oxygen evolution reaction,oxygen reduction reaction,carbon dioxide reduction reaction,and nitrogen reduction reaction are discussed.Finally,the research challenges and future prospects of fiber materials in electrocatalysis applications are proposed. 展开更多
关键词 Fiber electrocatalyst synthesis approach Structural feature Structural engineering Electrocatalytic performance
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State Observer Based Dynamic Fuzzy Logic System for a Class of SISO Nonlinear Systems
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作者 Mohamed Hamdy 《International Journal of Automation and computing》 EI CSCD 2013年第2期118-124,共7页
This paper presents an observer based dynamic fuzzy logic system (DFLS) scheme for a class of unknown single-input single-output (SISO) nonlinear dynamic systems with external disturbances. The proposed approach d... This paper presents an observer based dynamic fuzzy logic system (DFLS) scheme for a class of unknown single-input single-output (SISO) nonlinear dynamic systems with external disturbances. The proposed approach does not need the availability of the state variables. Within this scheme, the DFLS is employed to identify the unknown nonlinear dynamic system. The control law and parameter adaptation laws of the DFLS are derived based on Lyapunov synthesis approach. The control law is robustfied in H∞ sense to attenuate external disturbance, model uncertainties, and fuzzy approximation errors. It is shown that under appropriate assumptions, it guarantees the boundedness of all the signals in the closed-loop system and the asymptotic convergence to zero of tracking errors. The proposed method is applied to an inverted pendulum system to verify the effectiveness of the proposed algorithms. 展开更多
关键词 Single-input single-output (SISO) nonlinear system dynamic fuzzy logic system (DFLS) OBSERVER Lyapunov synthesis approach stability analysis.
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