Abstract: The flow field and performance of a helicopter in common forward flight and forward flight near the ground were analyzed using CFD (computational fluid dynamics) technique. The general governing equations of turbulent flow were set up, and were directly solved by finite volume method and SIMPLER (se...
Abstract: At a given time the altitude and azimuth of celestial bodies measured by star sensor and other celestial body measure devices contain the information of lunar rover’s position and pose. So the position and pose of lunar rovers can be determined using this kind of information. A new autonomous positi...
Abstract: The locally stationary parametric model was established to analyze the nonstationary random vibration environment of aircraft during lift-off. The computation of a time-varying spectrum was decomposed into two separate operations, one to define the time-varying mean square value of the signal, and t...
Abstract: A new algorithm of solving for ranges during the final translation phase of spacecraft rendezvous and docking using computer vision system was presented to determine relative attitude and position between target and chase spacecraft by Quaternion Estimation. In this algorithm for ranges, a weighted ...
Abstract: The performance of gyroscope decides the accuracy of inertial reference system. In order to diminish the error of the gyroscope and to improve its precision, the gyroscope′s error model was accurately founded. Methods of PSD(power spectrum density), ARMA, and Allan variance were federally used to st...
Abstract: The concept of stellar horizon atmospheric refraction is considered to be one of the most promising concepts for satellite autonomous navigation. However, the precision of the method is limited due to the uncertainty of the stellar horizon atmospheric refraction model. According to the rule that atm...
Abstract: The numerical detailed model and compact model were created for plastic quad flat package(PQFP), and the accuracy of two models was verified by the measurement values. The steady thermal performance of PQFP was studied under harsh environment, and factors effecting on the inner and outer thermal res...
Abstract: The application of local approach for fault detection in stochastic dynamic systems was presented. It was demonstrated that the selection of samples numbers plays an important role in improving the performance of the local approach. And it was pointed out that by enlarging the number of samples, the...
Abstract: Double-Layered satellite networks consisting of LEO(low earth orbit) and MEO(medium earth orbit) satellites have advantages on networking and communication performances. Based on the advantages of MEO and LEO satellites in long-distance and short-distance communications respectively, a hierarchical ...
Abstract: A robust human-imitating intelligent control was proposed for nonlinear systems. Firstly, a human-imitating qualitative control law was developed through the analyses of the physical model of the plant. The qualitative control law was quantified by some method of parameter-optimization based on the ...
Abstract: A GPS(global positioning system) GRIMS(ground-based regional integrity monitoring system) was established by considering the particularities of Chinese terrain and the distribution of air traffic flow. A ground-based monitoring network composed of 7 monitoring stations gathered data of all GPS satel...
Abstract: To reduce the ripple current of standard two-level pulse width modulation (PWM) switching power amplifier for magnetically suspended flywheel system, a novel three-level PWM switching power amplifier was proposed. The ripple current of the switching power amplifier using two different PWM techniques...
Abstract: INSAR (interferometric synthetic aperture radar) signal simulation methods were investigated deeply, and the fundamental principle of the INSAR simulation was presented. Various noise interference factors in INSAR images were analyzed. The simulation model of the INSAR system was discussed in detail...
Abstract: With the technique of software radio in digital interpolation, digital filtering, A/D(analog/digital) converter, a mathematic model for signal processing of digital IF(intermediate frequency) in the GPS satellite signal simulator was established, and the approaches achieving the practical hardware d...
Abstract: A fully 3-D image-reconstruction algorithm that quasi-monostatic mode is used and the transmitting antenna works in step frequency was developed.The algorithm is not restricted by far field as the traditional imaging algorithm. Through synthetic aperture processing for radar data, the resolutions of...
Abstract: Teleoperation testing system for Stewart platform was developed to study Stewart platform teleoperation stability under condition of large time delay. Ethernet was used to simulate the telecommunication channel, which linked two Stewart platforms control systems. DirectX technology was used to build...
Abstract: An aqueous organic silicone hydrophobic agent which was based on the matrix of a commercially available silicone emulsion and was prepared in the presence of a metal salt catalyst and a water soluble corrosion inhibitor of alcoholamine modified phytic acid was applied to treat A3 steel specimen. Fac...
Abstract: A new finite element solid model was established based on the unit cell model of 4-step rectangular three-dimensional braided composites and the assumption of the yarns with the hexagonal cross-section. The surface of model is parallel to the surface of perform, which coincides with the actual confi...
Abstract: A numerical analysis modeling was created about the case shell on aeroengine combustion chamber, which is one of the crucial parts of the aeroengine, during the process of laser welding. Welding deformation due to circumferential welds at the joint between the two cylindrical shells was studied usin...
Abstract: A new method named interval analysis method, which solves the free vibration of composite laminated beams with uncertain parameters, was presented. Based on interval mathematics and Taylor series expansion, uncertain parameters were described by interval numbers. Instead of conventional probabilisti...
Abstract: It is insufficient to describe maintenance process and relevant resources with existing modeling technique, and existing methods are deficient to combine the expression of maintenance task and maintenance action simulation. Therefore, MTN (maintenance task net) was proposed in order to solve the int...
Abstract: Constricted capillary tubes were used in order to study bubble mobility condition in composite material during cure processing. The effects of bubble length, radius of capillary tube and the variety of liquid on the drive critical condition of a single bubble traversing through a joint of flow chann...
Abstract: The assembly configurations of a kind of non-planar nine-link Barranov truss were analyzed by using Dixon's resultants. Four equations were established for the four loops of the mechanism by using vector method and they were changed into complex exponent numbers form. Dixon method was adopted to con...
Abstract: Orientation space of parallel mechanisms was analyzed. Physical constraints and singular constraints are the two main reasons which restrict the orientation ability of parallel mechanisms. The corresponding solutions from the two aspects were presented. New joints and redundant active UPS(universal ...
Abstract: Several multi-objective optimization methods in common use were concluded. In two examples of bi-objective optimization for cantilever beam and rocket engine, linear weighted method and gradual easy constraint method and neighborhood cultivation genetic algorithm(NCGA) method were used to obtain Par...
Abstract: A content-based film video retrieval system named SupEye using MPEG-7(multimedia content description interface) was designed, which consisted of three parts: feature extraction, data storage and feature retrieval. The part of feature extraction took charge of the extraction of video features and vid...
Abstract: In order to realize secure and efficient mobile node authentication in mobile ad hoc networks (MANET) which have no traditional public key infrastructure (PKI), a scheme consisting of identity-based cryptograph, distributed secrete sharing algorithm and elliptic curves encryption was proposed. Ident...
Abstract: Manage users and access rights are a complex and challengeable job in enterprise portal. Importing the role concept may simplify the access control, but its implementation is usually constrained by the single system and application. A new model,TRBAC(token role-based access control), was proposed fo...
Founded: 1956 (
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Sponsor: Ministry of Industry and Information Technology of the People's Republic of China
Sponsored by: Beijing University of Aeronautics and Astronautics