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Data fusion of target characteristic in multistatic passive radar

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Journal of Systems Engineering and Electronics 2021年第4期32卷 811-821页

作者： CAO Xiaomao yi Jianxin GONG Ziping RAO Yunhua wan Xianrong School of Electronic Information Wuhan UniversityWuhan 430072China Shenzhen Research Institute Wuhan UniversityShenzhen 518057China

Radar cross section(RCS)is an important attribute of radar targets and has been widely used in automatic target recognition(ATR).In a passive radar,only the RCS multiplied by a coefficient is available due to the unknown transmitting *** different transmitter-receiver(bistatic)pairs,the coefficients are ***,the recovered RCS in different transmitter-receiver(bistatic)pairs cannot be fused for further *** this paper,we propose a quantity named quasi-echo-power(QEP)as well as a method for eliminating differences of this quantity among different transmitter-receiver(bistatic)*** QEP is defined as the target echo power after being compensated for distance and pattern propagation *** proposed method estimates the station difference coefficients(SDCs)of transmitter-receiver(bistatic)pairs relative to the reference transmitter-receiver(bistatic)pair ***,it compensates the QEP and gets the compensated *** compensated QEP possesses a linear relationship with the target *** analyses on the simulated and real-life QEP data show that the proposed method can effectively estimate the SDC between different stations,and the compensated QEP from different receiving stations has the same distribution characteristics for the same target.

关键词： data fusion multistatic passive radar radar cross section(RCS) target characteristic

Improved flame resistance properties of unsaturated polyester resin with TiO2-MXOY solid superacid

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Chinese Journal of Chemical Engineering 2020年第9期28卷 2474-2482页

作者： Xuexi Chen Mei wan Ming Gao Yanxia wang Deqi yi School of Safety Engineering North China Institute of Science and TechnologyBeijing 101601China School of Environmental Engineering North China Institute of Science and TechnologyBeijing 101601China National Laboratory of Flame Retardant Materials School of Materials Science and EngineeringBeijingInstitute of TechnologyBeijing 100081China

Five SO4^2-/TiO2-MXOY solid super acids(SSA:Cu@Ti:SSA,Zr@Ti:SSA,Fe@Ti:SSA,Mn@Ti:SSA,Mo@Ti:SSA)were successfully prepared by sol-gel method,and its chemical structure and element content were characterized by X-ray diffraction(XRD)analysis,Fourier transform infrared spectroscopy(FHIR)and energy dispersive spectroscopy(EDS).Then,a compound flame retardant system containing SSA and ammonium polyphosphate/montmorillonite(AM)were was introduced into an unsaturated polyester resin(UPR)to enhance the flame *** effect of SSA on the flammability and thermal stability of the UPR was evaluated by the limiting oxygen index(LOI),cone calorimeter te st(CCT)and thermogravimetric analysis(TGA).The LOI results showed that the flame retardance of the UPR composites was significantly improved with the addition of ***,their heat release rate(HRR),total heat release(THR),the smoke production rate(SPR)and CO and CO2 yield were much *** addition,the initial decomposition temperature of UPR/AM/S SA was delayed,indicating that their thermal stability was increased,and the residual char of UPR/AM/SSA was also increa sed due to strong catalytic of SSA ability for esterification and ***,the microstructure of the residual char after combustion of the UPR composites was studied by the scanning electron microscopy(SEM),and it was found that the char layer structure was more continuous and dense after the addition of the *** sum up,the synergistic effect between SSA and AM was the main factor for the great improvement of flame retardant of UPR composites.

关键词： Flame retardance Unsaturated polyester resin(UPR) Solid super acid Cone calorimeter

A robust symbol timing strategy for cellular systems

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Digital Communications and Networks 2023年第3期9卷 757-768页

作者： Yangpeng Dan Jianxin yi Xianrong wan Yunhua Rao Yan Liu School of Electronic and Information Wuhan UniversityWuhan430072China Shenzhen Research Institute of Wuhan University Shenzhen518000China

In cellular systems,establishing the initial symbol timing of potential preambles is the first step of a cell *** envelope fluctuation of the downlink signal hinders the successful timing of conventional symbol timing *** solve this problem,a hybrid timing strategy is proposed with two novel detectors,namely the normalized replica-based detector and normalized differential *** strategy first detects all potential preambles via the normalized replica-based detector and then employs the normalized differential detector to verify the target preamble,which comes from the target cell and has the highest *** strategy is unaffected by envelope fluctuation and has computational complexity comparable to that of conventional ***-lations and real-data tests show that the hybrid timing strategy is robust and practical for initial symbol timing.

关键词： Symbol timing Synchronization Preamble Cell search Cellular system Envelope fluctuation

DOA estimation based on multi-frequency joint sparse Bayesian learning for passive radar

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Journal of Systems Engineering and Electronics 2022年第5期33卷 1052-1063页

作者： WEN Jinfang yi Jianxin wan Xianrong GONG Ziping SHEN Ji School of Electronic Information Wuhan UniversityWuhan 430072China

This paper considers multi-frequency passive radar and develops a multi-frequency joint direction of arrival(DOA)estimation algorithm to improve estimation accuracy and *** developed algorithm exploits the sparsity of targets in the spatial ***,we first extract the required frequency channel data and acquire the snapshot data through a series of preprocessing such as clutter suppression,coherent integration,beamforming,and constant false alarm rate(CFAR)***,based on the framework of sparse Bayesian learning,the target’s DOA is estimated by jointly extracting the multi-frequency data via evidence *** results show that the developed algorithm has better estimation accuracy and resolution than other existing multi-frequency DOA estimation algorithms,especially under the scenarios of low signalto-noise ratio(SNR)and small ***,the effectiveness is verified by the field experimental data of a multi-frequency FM-based passive radar.

关键词： multi-frequency passive radar DOA estimation sparse Bayesian learning small snapshot low signal-to-noise ratio(SNR)

A mass and energy estimation for the hydrogen utilization in the iron-making process

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Science China(Technological Sciences) 2011年第7期54卷 1655-1660页

作者： wan Ho kim Dong Joon MIN Department of Materials Science and Engineering YONSEI University

The possibility of using hydrogen to lower CO 2 emissions in the iron-making process was confirmed by the heat and mass balances in the blast furnace operation. The mass and heat balances for hydrogen utilization in the blast furnace were estimated by using the basic concept of RIST operating diagram. In this study, the RIST operating diagram was modified to be suitable for representing the operation with respect to hydrogen, where the RIST operating diagram is a graphical representation of heat and mass balance in blast furnace operation. RIST operating diagram was applied here to some individual parameters of interest such as H 2 injection in blast furnace process to reduce coke (carbon consumption). It was observed that the point W moved to the right in the RIST operating diagram under the condition of increasing hydrogen injection at tuyere, which originates from the contribution of gas composition (O/H 2 ) equilibrated with Fe/FeO at a certain temperature. Point P also moved downward due to heat requirement with respect to hydrogen utilization, by which the new RIST operating diagram for hydrogen utilization was able to be constructed. Under the condition of hydrogen injection, the expected overall carbon consumption in the blast furnace decreased due to the contribution of hydrogen.

关键词： hydrogen carbon consumption (CO2 emission) mass and heat balances RIST operating diagram blast furnace

Canonical Foliations of Certain Classes of Almost Contact Metric Structures

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Acta Mathematica Sinica,English Series 2005年第4期21卷 841-846页

作者： Tae wan kim Hong Kyung PAK Department of Mathematics Education Silla UniversityPusan617-736.Korea Department of Computer and Information Security Daegu Haany University

The purpose of this paper is to study the canonical foliations of an almost cosymplectic or almost Kenmotsu manifold M in a unified way. We prove that the canonical foliation F defined by the contact distribution is Riemannian and tangentially almost Kahler of codimension 1 and that F is tangentially Kahler if the manifold M is normal. Furthermore, we show that a semi-invariant submanifold N of such a manifold M admits a canonical foliation FN which is defined by the antiinvariant distribution and a canonical cohomology class c（N） generated by a transversal volume form for FN. In addition, we investigate the conditions when the even-dimensional cohomology classes of N are non-trivial. Finally, we compute the Godbillon Vey class for FN.

关键词： Almost α-cosymplectic manifold Almost cosymplectic manifold Almost Kenmotsu manifold Semi-invariant submanifold

Compensation of image noise induced by difference in optical characteristics of array-LED chips of LED print head

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Science China(Technological Sciences) 2017年第12期60卷 1819-1830页

作者： kim wan-Chin PARK Yong-Shik kim Sung-Dae LIM Jiseok Department of Automotive Engineering Honam University Gwansan-gu Gwangju 62399 Korea Mangoslab Co. Ltd. Startupeampus 20 Pangyo-ro 289beon-gil Bundang-gu Seongnam-si Gyeonggi-do 13488 Korea S-Printing Solution Co. Ltd. (Samsung Electronics Ltd) Suwon Gyeonggi-do 443-742 Korea School of Mechanical Engineering Yeungnam University Gyeongsan Gyeongbuk 38541 Korea

There are various applied electro-optical devices, which utilize light emitting didoe(LED) chip array for applications to displays and opto-electronic sensors. In those devices, it is the one of the critical technical issues to minimize uncertain fluctuations including optical power and optical density. Due to variation in operating environment of a device, those are not corrected precisely by controlling parameters based on simple relation between parameters and resultant abovementioned ***, there is essential need to correct outputs in real-time based on correction function generated from the consideration on various operation condition. In this article, we introduce an output correction method through reporting real-time image noise reduction in the application to electro-photography with LED print head. In the technology of LED print head, as differences in optical characteristics between each LED cause vertical image noise, it should be corrected in order to obtain images that are comparable or better in quality compared to those produced by the conventional laser scanning method. Even though it seems that the method used to obtain uniform light power from each LED can solve this problem, it does not work well for high-resolution printing. Therefore, a scan method involving correction by a printed and scanned pattern is introduced through this work. The scan method is composed of correction patterns to minimize printing noise by its shape, the correction algorithm to calculate the optimized value and the printing algorithm to control gray levels in real-time precisely. We believe that the developed correction method upgrades the printing quality of the LPH printer better than commercial printers. The developed correction method can also be applied to various application areas that use an array-type light source such as display systems and lighting systems.

关键词： real-time image correction LED print head(LPH) vertical image noise electro-photography temporal correction spatial correction

A Smoothing Method for Solving Bilevel Multiobjective Programming Problems

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Journal of the Operations Research Society of China 2014年第4期2卷 511-525页

作者： yi-Bing Lü Zhong-Ping wan School of Information and Mathematics Yangtze UniversityJingzhou 434023HubeiChina School of Mathematics and Statistics Wuhan UniversityWuhan 430072China

In this paper,a bilevel multiobjective programming problem,where the lower level is a convex parameter multiobjective program,is *** the KKT optimality conditions of the lower level problem,this kind of problem is transformed into an equivalent one-level nonsmooth multiobjective optimization ***,a sequence of smooth multiobjective problems that progressively approximate the nonsmooth multiobjective problem is *** is shown that the Pareto optimal solutions(stationary points)of the approximate problems converge to a Pareto optimal solution(stationary point)of the original bilevel multiobjective programming *** results showing the viability of the smoothing approach are reported.

关键词： Bilevel multiobjective programming Stationary point Constraint qualification Smoothing method

Performance analysis of optical multicast in a new switching structure

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The Journal of China Universities of Posts and Telecommunications 2007年第3期14卷 43-47页

作者： JIA Peng ZHANG Jie GU wan-yi Key Laboratory of Optical Communication and Lightwave Technologies Ministry of Education Beijing University of Posts and TelecommunicationsBeijing 100876 China

The emergence of new services demands multicast function in optical network. Because of the high cost and complex architecture of multicast capable （MC） node, splitter- sharing switch structure is introduced in which the light splitters are shared by all input signals. To accommodate to this situation, by extending resource ReSerVation protocol-traffic engineering （RSVP-TE） and open shortest path first-traffic engineering （OSPF-TE）, a new optical multicast mechanism is provided and the signaling flow and its finite state machine model are given. At the same time, a multicast routing algorithm in splitter-sharing optical network and a changing link weight policy to balance network traffic are proposed. Simulations in NSFNET show no matter with or without wavelength converters, when the number of splitters is 25% of that demanded by traditional MC nodes, the multicast performance has been close to the ideal circumstance. Wavelength converters and changing link weight help much in improving the traffic performance when the number of splitters is adequate.

关键词： splitter-sharing optical multicast optical network wavelength converter