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A NEW LIKELIHOOD-BASED MODULATION CLASSIFICATION ALGORITHM USING MCMC

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Journal of Electronics(china) 2012年第Z1期 17-22页

作者： Jin xiaoyan Zhou xiyuan (National key laboratory of integrated services networks,xidian university,xi’an 71.071.china) (The No.54 Research Institute of CETC,Shijiazhuang 050081,china)

In this paper,a new likelihood-based method for classifying phase-amplitude-modulated signals in Additive White Gaussian Noise (AWGN) is *** method introduces a new Markov Chain Monte Carlo (MCMC) algorithm,called the Adaptive Metropolis (AM) algorithm,to directly generate the samples of the target posterior distribution and implement the multidimensional integrals of likelihood *** classification is achieved along with joint estimation of unknown parameters by running an ergodic Markov *** results show that the proposed method has the advantages of high accuracy and robustness to phase and frequency offset.

关键词： Modulation classification Markov Chain Monte Carlo (MCMC) Adaptive Metropolis (AM) Maximum Likelihood (ML) test

Responses of growth performance,antioxidant function,small intestinal morphology and mRNA expression of jejunal tight junction protein to dietary iron in yellow-feathered broilers

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Journal of Integrative Agriculture 2024年第4期23卷 1329-1337页

作者： Kaiwen Lei Hao Wu Jerry W Spears xi Lin xi Wang Xue Bai Yanling Huang key laboratory of Animal Science of state Ethnic Affairs Commission Southwest Minzu UniversityChengdu 610041China key laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization Southwest Minzu UniversityChengdu 610041China Department of Animal Science North Carolina State UniversityRaleighNC 27695-7621USA

This study aimed to investigate the dose-effect of iron on growth performance,antioxidant *** morphology,and mRNA expression of jejunal tight junction protein in 1-to21-d-old yellow-feathered broilers.A total of 7201-d-old yellow-feathered maleb roilers were allocated to 9 treatments with 8 replicate cages of 10 birds per *** dietary treatments were consisted of a basal diet(contained 79.6 mg Fe kg^(-1))supplemented with 0,20,40,60,80,160,320,640,and 1,280 mg Fe kg^(-1)in the form of FeSO_(4)·7H_(2)*** with the birds in the control group,birds supplemented with 20mg Fe kg^(-1)had higher average daily gain(ADG)(P280 mg Fe kg^(-1)significantly decreased ADG(P20mg Fe kg^(-1).Malondialdehyde(MDA)concentration in plasma and duodenum increased linearly(P20 mg Fe kg^(-1),the supplementation of640 mg Fe kg^(-1)or higher increased(P?0.05)MDA concentrations in plasma,duodenum,and jejunum,decreased VH in the duodenum and jejunum,and the addition of 1,280 mg Fe kg^(-1)reduced(P?0.05)the jejunal tight junction protein(claudin-1,ZO-1,occludin)mRNA *** summary,640 mg of supplemental Fe kg^(-1)or greater was associated with decreased growth performance,increased oxidative stress,disrupted intestinal morphology,and reduced mRNA expression of jejunal tight junction protein.

关键词： iron yellow-feathered broiler antioxidant function intestinal morphology tight junction protein

Oxidation Protective C/SiC/Si-SiC Multilayer Coating for Carbon/Carbon Composites Applying at 1873 K

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Journal of Materials Science & Technology 2010年第12期26卷 1139-1142页

作者： Yulei Zhang,Hejun Li,xinfa Qiang and Kezhi Li C/C Composites Research Center,state key laboratory of Solidification Processing,Northwestern Polytechnical university,xi an 710072,china [a] C/C Composites Research Center state key laboratory of Solidification Processing Northwestern Polytechnical university xi(an 710072 china

A C/SiC/Si-SiC multilayer coating for protecting carbon/carbon （C/C） composites against oxidation was prepared by slurry and pack cementation. X-ray diffraction （XRD） and energy dispersive spectroscopy （EDS） analysis showed that the inner coating obtained from the slurry and pack cementation was a C/SiC gradient layer acting as bonding layer, and the exterior coating formed in the second pack cementation was a Si-SiC double phase coating. Oxidation tests at 1873 K in air showed that the coating exhibited excellent oxidation protective ability and thermal shock resistance. The coating could effectively protect C/C composites from oxidation at 1873 K in air for 170 h and undergo the thermal cycling between 1873 K and room temperature for 8 cycles. The weight loss of the coated C/C composites is due to the formation of cracks and holes in the coating and the volatilization of SiO2 glass at high temperature.

关键词： Carbon/carbon composites Oxidation Coating

ERASED-CHASE DECODING FOR RS-CODED MPSK SIGNALING OVER A RAYLEIGH FADING CHANNEL

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Journal of Electronics(china) 2007年第3期24卷 296-300页

作者： Xu Chaojun Sun Yue Wang xinmei state key Lab. of integrated Service networks Xidian University Xi＇an 710071 China

In this paper,a novel dual-metric,the maximum and minimum Squared Euclidean Distance Increment (SEDI) brought by changing the hard decision symbol,is introduced to measure the reli-ability of the received M-ary Phase Shift keying (MPSK) symbols over a Rayleigh fading channel. Based on the dual-metric,a Chase-type soft decoding algorithm,which is called erased-Chase algorithm,is developed for Reed-Solomon (RS) coded MPSK schemes. The proposed algorithm treats the unre-liable symbols with small maximum SEDI as erasures,and tests the non-erased unreliable symbols with small minimum SEDI as the Chase-2 algorithm does. By introducing optimality test into the decoding procedure,much more reduction in the decoding complexity can be achieved. Simulation results of the RS(63,42,22)-coded 8-PSK scheme over a Rayleigh fading channel show that the proposed algorithm provides a very efficient tradeoff between the decoding complexity and the error performance. Finally,an adaptive scheme for the number of erasures is introduced into the decoding algorithm.

关键词： Reed-Solomon (RS) codes Coded M-ary Phase Shift keying (MPSK) Rayleigh fading Dual-metric Chase decoding

A NEW EFFICIENT ID-BASED PROXY BLIND SIGNATURE SCHEME

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Journal of Electronics(china) 2008年第2期25卷 226-231页

作者： Ming Yang Wang Yumin state key Lab of integrated Service Network Xidian University Xi＇an 710071 China

In a proxy blind signature scheme,the proxy signer is allowed to generate a blind signature on behalf of the original signer. The proxy blind signature scheme is useful in several applications such as e-voting,e-payment,etc. Recently,Zheng,et al. presented an IDentity(ID) -based proxy blind sig-nature. In this paper,a new efficient ID-based proxy blind signature scheme from bilinear pairings is proposed,which can satisfy the security properties of both the proxy signatures and the blind signature schemes. Analysis of the scheme efficiency shows that the new scheme is more efficient than Zheng,et al.'s scheme. The proposed scheme is more practical in the real world.

关键词： Blind signature Proxy signature Bilinear pairing

Numerical Investigation of Developing Turbulent Flow in a Helical Square Ductwith Large Curvature

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Journal of Thermal Science 2001年第1期10卷 1-6页

作者： Gao Hui,Guo Liejin (state key laboratory of Multiphase Flow in Power Engineering, xi’an Jiaotong university, xi’an 710049, china ) state key laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an China

A fully elliptic numerical study has been carried out to investigate the three-dimensional turbulent developing flow in a helical square duct with large curvature. A two-layer zonal model is proposed and used, in which the whole region is divided into a viscosity-affected near wall layer and a fully turbulent region. A DSM closure is applied in the former, and a one-equation model is solved in the latter. The results presented in this paper cover a Reynolds number range of (l- 10) x 104. The development of flow is found to be dominated by radial pressure gradient and Dean-type secondary motion. The distribution of Reynolds stresses in fully developed flow exhibit a complex pattern of turbulence anisotropy The development of peripherally averaged friction factor and the distribution of local friction factor in fully developed flow are given and discussed.

关键词： curved pipe developing flow turbulence model numerical simulation.

Latent ancestral graph of structure vector autoregressive models

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Journal of Systems Engineering and Electronics 2010年第2期21卷 233-238页

作者： Wei Gao1,2and Zheng Tian2,3 1.School of Statistics,xi’an university of Finance&Economics,xi’an 710061,P.R.china 2.Department of Applied Mathematics,Northwestern Polytechnical university,xi’an 710072,P.R.china 3.state key laboratory of Remote Sensing Science,Institute of Remote Sensing Applications,Chinese Academy of Sciences,Beijing 100101,P.R.china School of Statistics Xi'an University of Finance & EconomicsXi'an 710061P.R.China Department of Applied Mathematics Northwestern Polytechnical UniversityXi'an 710072P.R.China Department of Applied Mathematics Northwestern Polytechnical UniversityXi'an 710072P.R.China state key laboratory of Remote Sensing Science Institute of Remote Sensing ApplicationsChinese Academy of SciencesBeijing 100101P.R.China

A class of latent ancestral graph for modelling the dependence structure of structural vector autoregressive （VAR） model affected by latent variables is proposed. The graphs are mixed graphs with possibly two kind of edges, namely directed and bidirected edges. The vertex set denotes random variables at dif- ferent times. In Gaussian case, the latent ancestral graph leads to a simple parameterization model. A modified iterative conditional fitting algorithm is presented to obtain maximum likelihood esti- mation of the parameters. Furthermore, a log-likelihood criterion is used to select the most appropriate models. Simulations are performed using illustrative examples and results are provided to demonstrate the validity of the methods.

关键词： multivariate time series latent ancestral graph itera- tive conditional fitting.

Reliability-aware automatic composition approach for web services

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Science china(Information Sciences) 2012年第4期55卷 921-937页

作者： LI Mu 1,2,LI Bo 1,2 & HUAI JinPeng 1,2 1 state key laboratory of Software Development Environment,Beihang university,Beijing 100191,china 2 School of Computer Science and Engineering,Beihang university,Beijing 100191,china 1. state key laboratory of Software Development Environment Beihang University Beijing 100191 China2. School of Computer Science and Engineering Beihang University Beijing 100191 China

In this paper,we study the reliability-aware synthesis problem for composing available services automatically and guaranteeing that the composed result satisfies the specification,such as temporal constraints of functionality and reliability,centered on a synthesis model for mediator of web services composition (CSM).This approach focuses on handling attributes and state relations,and permitting users and services to operate over them,i.e.,read /write their data values and compare them according to a dense state *** show that the reliability-aware synthesis problem for the specification is EXPTIME-complete and we give an exponential-time algorithm (CSM-NSA) which for a given formula ψ and a synthesis model,synthesizes available services in the library satisfying ψ over the synthesis model (if they exist) or responds with "not satisfiable" (otherwise).The specification ψ is a fragment of PCTL (probabilistic computation tree logic),obtained from "ordinary" CTL (computation tree logic) by replacing the EX,AX,EU and AU operation with their quantitative counterparts X >p,X =1,U >p,and U =1,*** opposed to NSA,we provide a more effective algorithm to replace the NSA algorithm called CSM-HSA (heuristic synthesis algorithm).Though HSA is an incomplete algorithm,the answer is *** experiments show that the HSA algorithm solves the problem of reliability-aware service synthesis effectively and efficiently.

关键词： reliability web services synthesis problem synthesis model heuristic algorithm

A tetrahedral data model for unstructured data management

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Science china(Information Sciences) 2010年第8期53卷 1497-1510页

作者： LI Wei & LANG Bo state key laboratory of Software Development Environment, Beihang university, Beijing 100191, china 1. state key laboratory of Software Development Environment Beihang University Beijing 100191 China

This paper proposes a tetrahedral data model for unstructured data management. The model defines the four components of unstructured data including: basic attributes, semantic characteristics, low-level features and raw data on its four facets, and the relations between these components. The internal implementation structure of the model and the data query language are designed and briefly introduced. This model provides a unified, integrated and associated description for different kinds of unstructured data, and supports intelligent data services such as associated retrieval and data mining. An example is given to demonstrate how to use the model for describing and manipulating data from a sample video base.

关键词： unstructured data data model query language associated retrieval intelligent services