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Posterior probability calculation procedure for recognition rate comparison

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Journal of Systems Engineering and Electronics 2016年第3期27卷 700-711页

作者： Jun He qiang fu Science and Technology on Automatic Target Recognition Laboratory College of Electronic Science and EngineeringNational University of Defense Technology

This paper focuses on the recognition rate comparison for competing recognition algorithms, which is a common problem of many pattern recognition research areas. The paper firstly reviews some traditional recognition rate comparison procedures and discusses their limitations. A new method, the posterior probability calculation（PPC） procedure is then proposed based on Bayesian technique. The paper analyzes the basic principle, process steps and computational complexity of the PPC procedure. In the Bayesian view, the posterior probability represents the credible degree（equal to confidence level） of the comparison results. The posterior probability of correctly selecting or sorting the competing recognition algorithms is derived, and the minimum sample size requirement is also pre-estimated and given out by the form of tables. To further illustrate how to use our method, the PPC procedure is used to prove the rationality of the experiential choice in one application and then to calculate the confidence level with the fixed-size datasets in another application. These applications reveal the superiority of the PPC procedure, and the discussions about the stopping rule further explain the underlying statistical causes. Finally we conclude that the PPC procedure achieves all the expected functions and be superior to the traditional methods.

关键词： pattern recognition performance evaluation algorithm uncertainty analysis

Theoretical dispersion curves for borehole real-valued wave modes in vertically transverse isotropic formations

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Petroleum Science 2022年第6期19卷 2649-2662页

作者： fu-qiang Zeng Chao Li Hubei Subsurface Multi-scale Imaging Key Laboratory Institute of Geophysics and GeomaticsChina University of GeosciencesWuhan430074HubeiChina State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of SciencesBeijing100190China Beijing Engineering and Technology Research Center for Deep Drilling Exploration and Measurement Beijing100190China

The dispersion curves of real-valued modes in a fluid-filled borehole are widely used in acoustic well *** accurate dispersion curves are the precondition of theoretical analysis and inversion ***,these curves can be obtained by solving the conventional dispersion equation for isotropic formations and most vertically transverse isotropy(VTI)***,if the real-valued solutions exist when the radial wavenumbers for the formation quasi-P and quasi-S equals to each other,the existed methods based on the conventional dispersion equation could lead to incorrect results for some VTI *** studies have focused on the influence of these real-valued solutions on dispersion curve *** remove these real-valued solutions,we have proposed a modified dispersion equation and its corresponding solving *** solving the dispersion equation,the Scholte wave velocity of VTI formation at high frequency is used as the initial *** two synthetic examples including fast and slow VTI formations validate that these real-valued solutions do not contribute to the wavefield,and the new dispersion curve extraction method is suitable for all kinds of VTI ***,the method can provide reliable dispersion curves for both theoretical analysis and anisotropic parameters inversion in VTI formations.

关键词： Dispersion equation Scholte wave velocity Acoustic properties Transverse isotropy Thomsen anisotropic parameters inversion

Mechanical properties of thermal aged HTPB composite solid propellant under confining pressure

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Defence Technology（防务技术） 2022年第4期18卷 618-625页

作者： Zhe-jun Wang Hong-fu qiang 206 Staff Room Xi’an Hi-Tech InstituteXi'an710025PR China

With the purpose of investigating the effects of confining pressure and aging on the mechanical properties of Hydroxyl-terminated polybutadiene(HTPB)based composite solid propellant,tensile tests of thermal accelerated aged propellant samples under room temperature and different confining pressure conditions were performed through the use of a self-made confining pressure device and conventional testing ***,the maximum tensile stressσmand the corresponding strainεm for the propellant under different test conditions were obtained and *** results indicate that confining pressure and aging can significantly affect the mechanical properties of HTPB propellant,and the coupled effects are very *** the one hand,the stressσmincreases as a whole when confining pressure becomes higher or thermal aging time ***,this stress is more sensitive to aging with increasing confining *** are almost three regions in the stress increments(σm P-σm0)/σm0and thermal aging time curves for HTPB *** maximum value of the stress increment(σm P-σm0)/σm0for the propellant is about 98%at 7.0 MPa and 170 *** the other hand,the strainεm decreases with increasing thermal aging time under the whole confining pressure ***,the variation of this strain with confining pressure is more complex at various thermal aging time,which is different from that of unaged solid propellant in previous *** addition,this strain is slightly less sensitive to aging as the confining pressure ***,there is also a critical confining pressure in this investigation,whose value is between 0.15 MPa and 4.0 *** this critical pressure,the trends of the stressσmand the corresponding strainεm all ***,there are some critical thermal aging time for the stress increment(σm P-σm0)/σm0and strain increment(εm P-εm0)/εm0of HTPB propellant in this investigation,which are about at 35,50 and 170 ***,based on the tw

关键词： Thermal accelerated aging Confining pressure Hydroxyl-terminated polybutadiene propellant Mechanical properties Strength criterion

Distribution of Miss Distance for Pursuit-Evasion Problem

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IEEE/CAA Journal of Automatica Sinica 2020年第4期7卷 1161-1168页

作者： Shengwen Xiang Hongqi Fan qiang fu the National Key Laboratory of Science and Technology on ATR National University of Defense TechnologyChangsha 410073China

Miss distance is a critical parameter of assessing the performance for highly maneuvering targets interception(HMTI). In a realistic terminal guidance system, the control of pursuer depends on the estimate of unknown state, thus the miss distance becomes a random variable with a prior unknown distribution. Currently, such a distribution is mainly evaluated by the method of Monte Carlo simulation. In this paper, by integrating the estimation error model of zero-effort miss distance(ZEM) obtained by our previous work, an analytic method for solving the distribution of miss distance is proposed, in which the system is presumed to use a bang-bang control strategy. By comparing with the results of Monte Carlo simulations under four different types of disturbances(maneuvers), the correctness of the proposed method is validated. Results of this paper provide a powerful tool for the design, analysis and performance evaluation of guidance system.

关键词： Analytical method bang-bang strategy miss distance distribution pursuit-evasion problem

A Generative Adversarial Nets Method for Monitoring Data Generation on Aircraft Engines

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Transactions of Nanjing University of Aeronautics and Astronautics 2019年第4期36卷 609-616页

作者： fu qiang WANG Huawei College of Civil Aviation Nanjing University of Aeronautics and AstronauticsNanjing 211106P.R.China

A sufficient sample size of monitoring data becomes a key factor for describing aircraft engines *** adversarial nets(GAN)can be used to expand the sample size based on the existing state monitoring *** the paper,a GAN model is introduced to design an algorithm for generating the monitoring data of aircraft *** feasibility of the method is illustrated by an *** experimental results demonstrate that the probability density distribution of generated data after a large number of network training iterations is consistent with the probability density distribution of monitoring *** proposed method also effectively demonstrates the generated monitoring data of aircraft engine are in a reasonable *** method can effectively solve the problem of inaccurate performance degradation evaluation caused by the small amount of aero?engine condition monitoring data.

关键词： generative adversarial nets(GAN) aircraft engine condition monitoring monitoring data

Bernoulli Filter for Extended Target in Clutter Using Poisson Models

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Chinese Journal of Electronics 2015年第2期24卷 326-331页

作者： CAI Fei FAN Hongqi fu qiang ATR Key Laboratory National University of Defense Technology

This paper presents a joint detection and tracking filter for a single extended target in the presence of clutter measurements and missed detections. The filter is obtained by adapting the Poisson extended target model into the Bernoulli filter proposed by Mahler. The resulted filter is an optimal extended target joint detection and tracking filter. Predictor and corrector are derived follows the random set filtering framework. A particle filter implementation is presented, in which simplification methods are used to make it easy to be realized. Simulation results show that the proposed filter is effective at detection and tracking of extended target in dense clutter backgrounds.

关键词： Extended target Target detection Target tracking Random set

Direct self-assembly of CTAB-capped Au nanotriangles

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Nano Research 2016年第11期9卷 3247-3256页

作者： qiang fu Guangjun Ran Weilin Xu State Key Laboratory of Electroanalytical Chemistry and Jilin Province Key Laboratory of Low Carbon Chemical Power Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China College of Chemistry and Environmental Engineering Shenzhen University Shenzhen 518060 China University of Chinese Academy of Sciences Beijing 100049 China

Densely packed and ordered ＂suprastructures＂ are new types of nanomaterials exhibiting broad applications. The direct self-assembly of cetyltrimethylammonium bromide （CTAB）-capped gold nanotriangles to form ＂suprastructures＂ was systematically investigated by varying the temperature and tilt angle of the silicon wafer used in the assembly process. Under optimal conditions, nanotriangles form into regular patterns, maintain their integrity, and form edge-to-edge, point-to-point, and face-to-face connections to form ordered ＂suprastructures＂ within an area of hundreds of square microns, achieving a high level of regularity. The formation of the ＂suprastructures＂ under optimal conditions could be mainly attributed to the complex balance between multiple temperature-dependent factors, including the atom diffusion rate, solvent evaporation rate, self-assembly rate, and the time for which the nanoparticle stays in the wet medium.

关键词： suprastructure Au nanotriangles self-assembly cetyltrimethylammonium bromide (CTAB)

fuzzy-based indoor scene modeling with differentiated examples

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Computational Visual Media 2023年第4期9卷 717-732页

作者： qiang fu Shuhan He Hongbo fu Xueming Li Zhigang Deng School of Digital Media and Design Arts Beijing University of Posts and TelecommunicationsBeijingChina School of Creative Media City University of Hong KongHong KongChina Department of Computer Science University of HoustonTXUSA

Well-designed indoor scenes incorporate interior design knowledge,which has been an essential prior for most indoor scene modeling ***,the layout qualities of indoor scene datasets are often uneven,and most existing data-driven methods do not differentiate indoor scene examples in terms of *** this work,we aim to explore an approach that leverages datasets with differentiated indoor scene examples for indoor scene *** solution conducts subjective evaluations on lightweight datasets having various room configurations and furniture layouts,via pairwise comparisons based on fuzzy set *** also develop a system to use such examples to guide indoor scene modeling using user-specified ***,we focus on object groups associated with certain human activities,and define room features to encode the relations between the position and direction of an object group and the room *** perform indoor scene modeling,given an empty room,our system first assesses it in terms of the user-specified object groups,and then places associated objects in the room guided by the assessment results.A series of experimental results and comparisons to state-of-the-art indoor scene synthesis methods are presented to validate the usefulness and effectiveness of our approach.

关键词： indoor scene modeling modeling by example fuzzy sets

Preparation of Self-limiting Heating Cables with Excellent Processability, Mechanical Properties and PTC Effect via Thermal and Electrical Treatments

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Chinese Journal of Polymer Science 2024年第4期42卷 511-520页

作者： Tian-Hao Yang Tong Wu qiang fu State Key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China State Key Laboratory of Polymer Materials Engineering Polymer Research Institute of Sichuan UniversityChengdu610065China

Polymer/conductive filler composites have been widely used for the preparation of self-limiting heating cables with the positive temperature coefficient (PTC) effect. The control of conductive filler distribution and network in polymer matrix is the most critical for performance of PTC materials. In order to compensate for the destruction of the filler network structure caused by strong shearing during processing, an excessive conductive filler content is usually added into the polymer matrix, which in turn sacrifices its processability and mechanical properties. In this work, a facile post-treatment of the as-extruded cable, including thermal and electrical treatment to produce high-density polyethylene (HDPE)/carbon black (CB) cable with excellent PTC effect, is developed. It is found for the as-extruded sample, the strong shearing makes the CB particles disperse uniformly in HDPE matrix, and 25 wt% CB is needed for the formation of conductive paths. For the thermal-treated sample, a gradually aggregated CB filler structure is observed, which leads to the improvement of PTC effect and the notable reduction of CB content to 20 wt%. It is very interesting to see that for the sample with combined thermal and electrical treatment, CB particles are agglomerated and oriented along the electric field direction to create substantial conductive paths, which leads to a further decrease of CB content down to 15 wt%. In this way, self-limiting heating cables with excellent processability, mechanical properties and PTC effect have simultaneously been achieved.

关键词： Self-limiting heating cables Positive temperature coefficient Thermal treatment Electrical treatment