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Optimized LDPC differential-encoded 16QAM scheme for high-speed transmission systems

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Journal of Systems Engineering and Electronics 2014年第5期25卷 728-734页

作者： Zhanji Wu xiang gao Zhiyu Xiao School of Information and Communication Engineering Beijing University of Posts and Telecommunications Huawei Technology Limited Corporation

The 16-ary quadrature amplitude modulation （16QAM） is a high spectral efficient scheme for high-speed transmission systems. To remove the phase ambiguity in the coherent detection system, differential-encoded 16QAM （DE-16QAM） is usually used, however, it will cause performance degradation about 3 dB as compared to the conventional 16QAM. To overcome the performance loss, a serial concatenated system with outer low density parity check （LDPC） codes and inner DE-16QAM is proposed. At the receiver, joint iterative differential demodulation and decoding （ID） is carried out to approach the maximum likelihood performance. Moreover, a genetic evolution algorithm based on the extrinsic information transfer chart is proposed to optimize the degree distribution of the outer LDPC codes. Both theoretical analyses and simulation results indicate that this algorithm not only compensates the performance loss, but also obtains a significant performance gain, which is up to 1 dB as compared to the conventional non-DE-16QAM.

关键词： quadrature amplitude modulation (QAM) low density parity check (LDPC) code genetic evolution (GE) algorithm iterative demodulation and decoding (ID) extrinsic information transfer (EXIT) chart.

Fuzzy Q learning algorithm for dual-aircraft path planning to cooperatively detect targets by passive radars

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Journal of Systems Engineering and Electronics 2013年第5期24卷 800-810页

作者： xiang gao Yangwang Fang Youli Wu School of Aeronautics and Astronautic Engineering Air Force Engineering University

The problem of passive detection discussed in this paper involves searching and locating an aerial emitter by dualaircraft using passive radars. In order to improve the detection probability and accuracy, a fuzzy Q learning algorithrn for dual-aircraft flight path planning is proposed. The passive detection task model of the dual-aircraft is set up based on the partition of the target active radar＇s radiation area. The problem is formulated as a Markov decision process （MDP） by using the fuzzy theory to make a generalization of the state space and defining the transition functions, action space and reward function properly. Details of the path planning algorithm are presented. Simulation results indicate that the algorithm can provide adaptive strategies for dual-aircraft to control their flight paths to detect a non-maneuvering or maneu- vering target.

关键词： Markov decision process (MDP) fuzzy Q learning dual-aircraft coordination path planning passive detection.

Coverage of communication-based sensor nodes deployed location and energy efficient clustering algorithm in WSN

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Journal of Systems Engineering and Electronics 2010年第4期21卷 698-704页

作者： xiang gao Yintang Yang Duan Zhou College of Microelectronics Xidian University Xi' an 710071 P. R. China College of Computer Science and Technology Xidian University Xi'an 710071 E R. China

An effective algorithm based on signal coverage of effective communication and local energy-consumption saving strategy is proposed for the application in wireless sensor *** algorithm consists of two *** is the multi-hop partition subspaces clustering algorithm for ensuring local energybalanced consumption ascribed to the deployment from another algorithm of distributed locating deployment based on efficient communication coverage probability（DLD-ECCP）.DLD-ECCP makes use of the characteristics of Markov chain and probabilistic optimization to obtain the optimum topology and number of sensor *** simulation,the relative data demonstrate the advantages of the proposed approaches on saving hardware resources and energy consumption of networks.

关键词： wireless sensor network probability distribution function Markov chain received signal strength indicator Gaussian distribution.

DIMENSIONS OF ATACTIC POLY(α-METHYLSTYRENE)CHAINS WITH SIDE GROUPS

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Chinese Journal of Polymer Science 2006年第1期24卷 87-93页

作者： Hai-zhu Ma gao-xiang Ye Department of Physics Zhejiang University Hangzhou 310027 China Department of Physics Zhejiang Education Institute Hangzhou 310012 China

An improved configurational-confomational statistical method is developed and the mean-square radius of gyration for atactic poly（α-methylstyrene）（PαMS） chains is studied, in which the effect of large side groups is considered. The deduced formulas, based on the rotational isomer state theory, are used to investigate the configuration-dependent properties of the atactic polymer chain, and the statistical correlation of the unperturbed polymer chain dimension and structure parameters are calculated. For the fraction of meso dyads Wm= 0.4, the dependence of the radius of gyration Rg and the intrinsic viscosity [η] on the molecule mass M are Rg = 2.63×10^-2 M^0.50 nm and [η] = 7.36 × 10^-2 M^0.497, respectively, which are in agreement with the previous experimental data for the PαMS samples. A small hump is detected in the curve of the characteristic ratio of the unperturbed mean-square radius of gyration versus the chain length for short PαMS chains. The Rg increases linearly with the temperature T, and the effects of the chain length and the tacticity on the temperature coefficient are remarkable. These are quite different from the results for PαMS chains not considering side groups or for the monosubstituted polystyrene chain.

关键词： Side groups Rotational isomeric state Radius of gyration Poly(α-methylstyrene) chain.

Unperturbed dimensions of atactic poly(dibenzyl itaconate)s

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第7期8卷 991-998页

作者： MA Hai-zhu YE gao-xiang Department of Physics Zhejiang University Hangzhou 310027 China School of Science and Technology Zhejiang Education Institute Hangzhou 310012 China

The unperturbed dimension and temperature character of poly(dibenzyl itaconate)s (PDBzI) are studied by a revised rotational isomeric state (RIS) method. The improved formulas of the mean-square radius of gyration, deduced by the pseudo-stereochemical equilibrium approach, may be used to investigate the configurational-conformational properties of atactic polymers with large side groups [poly(itaconates) for instance]. The calculated results showed that poly(itaconates) have larger dimension of the molecule than other vinyl polymers. Comparison of the dimension between considering and without considering side groups showed that the effect of large side groups on the unperturbed dimension for short-chain polymers is more obvious than that of long-chain polymers and, if the dimension of side groups increases, the effect also increases. The dimension differences of PDBzI between short-chain and long-chain polymers are investigated by the relation of characteristic ratios and temperature coefficients with temperature. Moreover, the dependence between the temperature coefficients and the tacticity of chains shows that the temperature characters of the isotactic, syndiotactic and atactic PDBzI chains have remarkable difference.

关键词： Poly(dibenzyl itaconate)s Mean-square radius of gyration Temperature coefficient Tacticity

Potential role of hippocampal neurogenesis in spinal cord injury induced post-trauma depression

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Neural Regeneration Research 2024年第10期19卷 2144-2156页

作者： Ying Ma Yue Qiao xiang gao Spinal Cord and Brain Injury Research Group Stark Neuroscience Research InstituteIndianapolisINUSA Department of Neurological Surgery Indiana University School of MedicineIndianapolisINUSA Department of Neurology Shengjing Hospital of China Medical UniversityShenyangLiaoning ProvinceChina

It has been reported both in clinic and rodent models that beyond spinal cord injury directly induced symptoms, such as paralysis, neuropathic pain, bladder/bowel dysfunction, and loss of sexual function, there are a variety of secondary complications, including memory loss, cognitive decline, depression, and Alzheimer's disease. The largescale longitudinal population-based studies indicate that post-trauma depression is highly prevalent in spinal cord injury patients. Yet, few basic studies have been conducted to address the potential molecular mechanisms. One of possible factors underlying the depression is the reduction of adult hippocampal neurogenesis which may come from less physical activity, social isolation, chronic pain, and elevated neuroinflammation after spinal cord injury. However, there is no clear consensus yet. In this review, we will first summarize the alteration of hippocampal neurogenesis post-spinal cord injury. Then, we will discuss possible mechanisms underlie this important spinal cord injury consequence. Finally, we will outline the potential therapeutic options aimed at enhancing hippocampal neurogenesis to ameliorate depression.

关键词： antidepressants chronic pain depression exercise hippocampal neurogenesis inflammation inhibition neuroinflammation physical activity deficits social isolation spinal cord injury

Trade Destruction and Trade Deflection:A Quasi-Natural Experiment Based on the US Additional Tariffs

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Journal of Systems Science & Complexity 2023年第6期36卷 2467-2496页

作者： ZHANG Yu gao xiang XU Ran YANG Cuihong Yangtze Industrial Economic Institute Nanjing UniversityNanjing210093China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing100190China School of Management Engineering Qingdao University of TechnologyQingdao266520China

This paper adopts the DID approach to investigate the trade destruction effects and trade deflection effects of the US additional *** authors find that the US additional tariffs significantly reduce China's exports of tariffed products to the US(i.e.,trade destruction effect),especially intermediate and labor-intensive *** the other hand,they significantly increase China's exports of tariffed products to the third market(i.e.,trade deflection effect).For the$50 billion list,both the trade destruction effect and trade deflection effect are concentrated on processing exports,and the US additional tariffs significantly increase China's exports of tariffed products to ASEAN,Japan and *** the$200 billion list,the US additional tariffs boost China's exports of chemicals,textiles,wood,metal products,furniture and other products to the EU,Australia,Japan,South Africa and Hong Kong,***,most trade deflections are not realized by lowering export prices,indicating that the trade deflections could compensate for the profit losses caused by the US additional tariffs to a certain *** proposed results suggest that searching for substitutions of export markets and a more open trade policy is an important way to avoid profit losses and reduce risks for enterprises and economies suffering from trade frictions.

关键词： DID approach trade deflection trade destruction US additional tariffs

The Pathway Toward Carbon Neutrality:Challenges and Countermeasures

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Engineering 2022年第7期8卷 1-2页

作者： Xiaoye Zhang xiang gao State Key Laboratory of Severe Weather&Key Laboratory of Atmospheric Chemistry of the China Meteorological Administration Chinese Academy of Meteorological SciencesBeijing 100081China State Key Laboratory of Clean Energy Utilization State Environmental Protection Engineering Center for Coal-Fired Air Pollution ControlZhejiang UniversityHangzhou 310027China

China’s solemn commitment to the world to strive for carbon neutrality by 2060 demonstrates the nation’s determination to take a new development route,different from its impressive achievements during the more than 40 years since *** a green,low-carbon,and high-quality development path is also a strong manifestation of China’s determination to follow its consis-tent development belief of“conformity with morality,”with its emphasis on multilateral mechanisms and a willingness to make the best possible contribution to global concerns such as adaption to and mitigation of climate change.

关键词： Countermeasures neutral morality

A novel signal feature extraction technology based on empirical wavelet transform and reverse dispersion entropy

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Defence Technology（防务技术） 2021年第5期17卷 1625-1635页

作者： Yu-xing Li Shang-bin Jiao xiang gao School of Automation and Information Engineering Xi’an University of TechnologyXi’an710048China School of Electrical Engineering Xi’an University of TechnologyXi’an710048China

Feature extraction is an important part of signal processing,which is significant for signal detection,classification,and *** nonlinear dynamic analysis method can extract the nonlinear characteristics of signals and is widely used in different *** dispersion entropy(RDE)proposed by us recently,as a nonlinear dynamic analysis method,has the advantages of fast computing speed and strong anti-noise ability,which is more suitable for measuring the complexity of signal than traditional permutation entropy(PE)and dispersion entropy(DE).Empirical wavelet transform(EWT),based on the theory of wavelet analysis,can decompose a complex non-stationary signal into a number of empirical wavelet functions(EWFs)with compact support set spectrum,which has better decomposition performance than empirical mode decomposition(EMD)and its improved *** the advantages of RDE and EWT,on the one hand,we introduce EWT into the field of underwater acoustic signal processing and fault diagnosis to improve the signal decomposition accuracy;on the other hand,we use RDE as the features of EWFs to improve the signal separability and ***,we propose a novel signal feature extraction technology based on EWT and RDE in this *** results show that the proposed feature extraction technology can effectively extract the complexity features of actual ***,it also has higher distinguishing ability for different types of signals than five latest feature extraction technologies.

关键词： Feature extraction Empirical mode decomposition Empirical wavelet transform Permutation entropy Reverse dispersion entropy