Abstract: A variety of pulse compression methods are viewed as viable solutions to improve the signal to noise ratio (SNR) of received signal in air-coupled ultrasonic testing. However, the use of corresponding method to realistic inspection is faced with problem of optimal parameter selection to get better c...
Abstract: For a class of Lipschitz nonlinear system, the reconstruction problems of state estimation, unknown input and measurement noise were studied. Regarding the measurement noise as an extended state, the original system can be transformed into a descriptor system. For the descriptor system, first, a hig...
Abstract: Video capture, color space conversion and video data transmission were researched in order to improve video capture and pre-processing performance of airborne multi-mode video coding system. Taking into account the requirements of real-time multi-mode video capture, a robust video capture strategy b...
Abstract: In order to study the noise characteristic of wind turbine airfoils, the airfoil optimal design mathematic model was built based on airfoil functional integrated theory and noise calculated model. The new optimized objective function of maximizing lift/drag to noise was developed on the design angle...
Abstract: To describe the influence of performance degradation on storage life and reliability for solid propellant, a method of storage life and reliability assessment based on generalized linear model was proposed. According to the characteristic of solid propellant degradation data, the local scale model w...
Abstract: The index of distortion to evaluate the total quality of waveforms has special advantages and has been accepted widely by most people. Based on the analyses of the distortion definition of arbitrary waveform, a method using nonlinear-curve-fitting to evaluate the distortion of arbitrary waveform was...
Abstract: To solve the problem of temperature oscillation, even operation failure when loop heat pipe with single compensation chamber was subjected to acceleration force, the experimental setup was built for testing the performance of dual compensation champers loop heat pipe (DCCLHP) based on the centrifuga...
Abstract: The V-estimator (VE) for K-distribution shape parameter proposed by Oliver in 1993, bears the characteristics of without solving non-linear equations so it has a high estimating efficiency, but the estimating accuracy of it is lower than that of many other moment estimators, sometimes the VE even re...
Abstract: With electro-hydraulic servo system as the research object, the influence laws of nonlinear friction on system dynamic characteristics were explored. Based on the principle of the nonlinear dynamics, the nonlinear dynamical model of system was established. Then, a conclusion was put forward that the...
Abstract: The physical model of a variable-span variable-sweep morphing aircraft was simplified. Based on Kane's method, the morphing movements were assumed to be controllable known input, and the wings' movements were expressed by constraint equations. The six components of the translational velocity and the...
Abstract: For the effectiveness of the ant colony optimization algorithm for solving high-dimensional nonlinear search problem, a Bayesian maximum posteriori direction of arrival (DOA) estimation fast algorithm based on the ant colony optimization algorithm (ACO-Bayesian) was proposed. This algorithm adopts B...
Abstract: Compared with the low earth orbit synthetic aperture radar (SAR) system, the moon-borne SAR is distinct from its unique imaging geometry, so the Doppler parameters estimation method is different from conventional pickaback and satellite-borne SAR. Precise jet propulsion laboratory (JPL) ephemeris wa...
Abstract: In the field of maneuvering target tracking, the performance of Kalman filter(KF)and its variants is dependeds on the accuracy of the assumed process noise statistics. If the assumed process noise is not accurate, the performance of the KF and its improved algorithms will be degraded significantly. ...
Abstract: For the ultra-low altitude airdrop level off stage, many uncertain factors such as ground effect, sensor measurement errors and low altitude airflow interfere the precision of trajectory tracking, which exert serious threats on the aircraft safety and mission performance, a hybrid iteration sliding ...
Abstract: The layered and modularized design is always used in complex electronic equipment, where the maintenance level and test requirement are both characterized by hierarchy configuration. Therefore, a novel evaluation approach was presented based on hierarchical testability model. The multi-signal flow g...
Abstract: Fuzzy adaptive resonance theory (ART) with bounded side length was proposed to address the problem emerged while applying fuzzy ART to intelligent decision-making. Integrating the modified fuzzy ART and Q learning algorithm, bounded fuzzy ART-Q learning (FART-Q) intelligent decision-making network w...
Abstract: Force change problem during air combat course was studied. First of all, operation ability index of aircraft was converted to average combat level. Furthermore, in view of data link's influence on air combat and reinforcement force's joining to original force, differential equation model of every fo...
Abstract: A novel offline signature verification method based on the affine and scale invariant feature transform (ASIFT) was proposed by analyzing the existing local invariant features and the property of the disguised signature. The method consists of the following steps, the preprocessing including image g...
Abstract: With the development of computer technology and video, display technology, there are new requirements of video encryption algorithm. A video content associated key concept was proposed and used in the encryption of video after the research of current video encryption algorithm's defects in video cop...
Abstract: Electro-hydraulic load simulator is a typical case of the force (torque) servo system which is strongly coupled with a hydraulic position system. How to eliminate the extraneous torque from motion disturbances is the key difficulty in electro-hydraulic load simulators. Based on theoretical analysis ...
Abstract: Insects usually keep hovering or forward flight. Thus the dynamic stability of the two types of flight is significant to study the insect flight. The dynamic flight stability of a model dronefly in hovering and forward flight was studied. On the basis of an averaged model and the small disturbance t...
Abstract: The flow rate of a certain type onboard air separation unit to produce the nitrogen-rich air related with the flight height, inlet pressure, temperature and the nitrogen concentration was experimentally studied on a test apparatus. An empirical correlation to predict the flow rate of the nitrogen-ri...
Abstract: The propeller's revolving slipstream passing wing changes the drag/lift property of the wing. For the hyper long endurance unmanned flight vehicles design, the slipstream effect should be analyzed for the aeroelasticity of the very flexible wing. The Prandtl revised blade element-momentum theory was...
Abstract: Target's accelerations lead to spectrum shift and broadening of target's echo signal, resulting in the inaccuracy estimation of target's Doppler frequency with traditional pulse radar velocity measurement method. To overcome the effect of acceleration on pulse radar velocity measurement, an empirica...
Abstract: To solve high accuracy requirement in collaborative passive tracking of two aircrafts, according to the geometric situation of the two aircrafts to the target, the effect of the geometric situation to the passive detection accuracy was analyzed, the formula of position dilution of precision (PDOP) w...
Abstract: Coverage search of multi aircraft is a major task for unmanned aerial vehicle (UAV). After dividing the searching area, the problem turns into single UAV coverage search problem in each sub-area. This method will make the whole search problem simpler. The parallel searching strategy was analyzed in ...
Abstract: The spatial distribution of iGPS measurement uncertainty was studied to help rapid assessment and layout optimization of iGPS measurement. According to the measurement model of iGPS, a typical two-station model of measurement uncertainty was established. Furthermore, a universal analysis method of i...
Abstract: In order to reduce the radar cross section (RCS) of near space airship, the effect on the RCS of near space airship was studied, when its X-tail has different deformation angles. The RCS character effect of head, side and tail in the near space airship was simulated, when X-tail has different deform...
Founded: 1956 (
monthly
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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