Abstract:According to simplified model of UCAV launching area, the attack trajectory decision-making for UCAV is introduced. A hierarchical trajectory-designing approach is proposed, and the problem is changed into optimization design. Firstly, the original trajectory is created by Voronoi diagram based on the known flight environment. Secondly, attack trajectory decision making model of UCAV is built based on attack trajectory constraint conditions, flight distance model and threaten model. And the discrete particle swarm optimization is presented to solve it. The simulation results show that DPSO algorithm is simple and can be used to effectively solve the problem of attack trajectory decision-making for UCAV.

Abstract:Plasma flow control has potential applications in shock wave control for improving aircraft/thruster performance obviously. Numerical simulation of plasma aerodynamic actuation reducing transonic drag of RAE2822 airfoil was presented. Based on phenomenological modeling viewpoint, the discharge plasma aerodynamic actuation was simplified as thermal energy injection into flow, which was initialized from experimental data and added in the flow N-S equation as thermal source term. The effect of plasma aerodynamic actuation on the airfoil drag characteristic was investigated under different conditions. The results show that plasma aerodynamic actuation can reduce airfoil transonic drag availability. The drag reduction depended on the freestream parameters, which was 13.58% at Ma=0.81. The drag reduction responded to source term temperature rarely, which was 11.77% at W=3 000 K. The drag reduction responded to the distance between the location of plasma actuation and shock wave, which was 13.17% at D=20 mm.

Abstract:Numerical simulations of oblique Shock-wave turbulent boundary-layer interaction on flat plate using GAO-YONG compressible turbulent model are presented. Convection terms and diffusion terms are calculated using AUSM scheme and CD (center difference) scheme in the present procedure, respectively. The Runge-Kutta time marching method is employed to solve space discrete control equations. This paper presents three cases with different incident shock angles, which induce attached and separation flows. Compressions between the computation and experiment are carried out including surface pressure distribution, mean velocity profiles, wall skin friction Cf and Stanton number. Good agreements between the calculations and experiment are obtained for the attached flow and incipient separation flow. Meanwhile, GAO-YONG turbulent model can predict distinct separation flow under the intensity interaction at high Mach number.

Abstract:The blast fence can generally be divided into integral fence and louver fence. Based on the purpose of analyzing blast fence's effect., the paper builts jet flow field model , simulated effect on jet flow field of different installation forms. Equation is scattered by standard format, and coupling of pressure and velocity use simple algorithm. The model applied Cartesian co-ordinates, and used structural grid. Simulation results indicate that blast fence's effect is obvious. And if the integral fence is too high or too steep, it can produce abundant airflow. The louver fence make airflow spread towards the back and above along the blade, and its air resistance is lower than the other one's.

Abstract:To meet the current demand for obstruction testing of airport clearance zone, the electronic theodolite, laser range finders and GPS capabilities are integrated, and an airport clearance intelligent monitoring instrument is developed. According to the electromagnetic wave's principleof measuring distance and the actual count rate, the precision of monitor's measuring distance is obtained.By specific analysis through error propagation of trigonometric leveling for obstacle in clearance zone and various errors, which includes side length error, observation error of the elevation angle, refractive error, such as error of the instrument height and sighting point height. etc., and in combination with the precision requirements of obstacle measurement by domestic and international civil aeronautics organization, the height precision requirements of monitor instrument is obtained through comprehensive analysis. Finally technical requirements for measuring distance accuracy ± 0.5 m and elevation accuracy ± 1 m are got by analysis and appraisal, which provide a theoretical basis for determining the main technical parameters of the airport clearance intelligent monitor and the selection of the appropriate instrument module from the market.

Abstract:Networked targeting (NT) is a new combat concept and technology with respect to satisfying the Network Central War. According to the character of the networked targeting, the air to air missile launch manner is analyzed and the method of calculating the missile launch acceptability region is given. The one-dimensional golden section is used to search the missile launch acceptability region based on the missile and target moving model. The air to air missile launch acceptability region is calculated in a simulation which combines six typical formations under NT. The launching areas of NT are compared with that of platform targeting, and the variation trend of missile launch acceptability region is summarized.

Abstract:This paper researches the deployment decision problem on terminal low altitude TBMD systems. Firstly, in view of the characters of terminal low altitude TBMD systems, the decision rules are discussed. Secondly, multiple attribute decision model of the weapon systems deployment is built, the basic deployment conditions and decision process are proposed, which include two important factors: decision parameter calculation and multiple attribute decision. Thirdly, according to the characters of the parameters and the deployment decision model, the System Dynamics (SD) calculating simulations model on decision parameters is built, which is useful for the calculation of two important decision parameters. Finally, the calculations of alternative deployment positions' decision parameters are performed by the SD model, and the deployment schemes order is acquired by the decision model. The case application shows that the decision model is effective.

Abstract:The application of Direction of arrival (DOA) estimation with antenna arrays in the scanning radar system can enhance the precision and differentiated ability, and is of some value. The unified frame of high-resolution parameter estimation algorithm for scanned radar is proposed based on the research on them. Various typical algorithms, such as MUSIC, MDMUSIC, ML, and WSF, can be consistent with the unified frame. The unified frame is the universal theoretical basis of high-resolution parameter estimation algorithm for scanned radar. Then, the Cramer-Rao Bound (CRB) of these algorithms is deduced. Finally, the performances of these algorithms are compared through simulation experiments.

Abstract:Subspace-based algorithms, which provide high spectrum resolution and is of less time-consuming, are the classical and commonly used methods. However, there are still problems when applying the algorithms to MIMO radar. To solve the problem of the DOA estimation of multiple targets for MIMO radar, a new method based on improved spatial smoothing is proposed. The concept of "equivalent sources" is introduced, based on it, the reason why several subspace-based algorithms would fail when the number of targets is more than the number of transmit antennas is analyzed. The mechanism of the proposed method to overcome the limitation of the number of transmit antennas in the condition of sufficient receive antennas is derived and expounded, which makes the MIMO radar estimate more targets in the case of fewer transmit antennas. The simulation results demonstrate that the proposed method has a better estimated performance than the TDS.

Abstract:With respect to error range of Anti Radiation Missile (ARM) under active decoy interference, the solutions to improve the performance of ARM under interference are put forward; To satisfy the requirement of angular resolution, set the model of 2D-DOA estimation based on UCA, and discuss the implement of the algorithm in Passive Radar Seeker (PRS); Computer simulation indicates that 2D-DOA estimation algorithm based on UCA can meet the need of angular resolution.

Abstract:The efficiency evaluation and tactics calculation of radar jamming is a puzzle that the troops of radar countermeasure have met and urgently need to solve but lack of system research. To solve this puzzle, the efficiency evaluation models of shooting degrees and kill probability against guidance radar under passive self-defensive jamming condition are established by analytical method, then, the tactics calculation methods of anti-radar reflector beam numbers, expending time interval and total wastage are also given. Finally, the effectiveness and feasibility of the models are illustrated with a numerical example and some valuable conclusions are reached, which can provide a reference for the operational efficiency evaluation and airborne weapon equipment.

Abstract:The research of adaptive command and control (C2) organization is one of the key technologies for the realization of NCW (Network Centric Warfare). Firstly, the concept and the main research content of adaptive C2 organization are depicted. Then the research advances of adaptive C2 organization is surveyed from two aspects, the methods of organization modeling and the methods of organization designing. The methods of organization modeling include computation and mathematic organization theory, Petri net, information theoretic criteria, agent and social network analytic methods. The methods of organization designing include three-phase organizational design method, the extended three-phase organizational design method, the organizational design method based on group technology and nested genetic algorithm and the organizational design method based on granular computing. Finally, the description of all kinds of modeling methods and designing methods are offered respectively, and the achievements and scarcities of these methods are analyzed.

Abstract:By building a virtual network topology named P2P overlay network on top of internet's physics topology layer based on P2P computing mode, a full-decentralized internet based self-organizing network routing model- Hierarchical Aggregation Self-organizing Network (HASN) is built effectively. The target and architecture of HASN routing model are described in this paper, as well as a detailed description of a P2P decentralized naming, route discovering and updating algorithm-HASN Scale. Simulation results testify the performance of HASN routing model.

Abstract:In order to combine the theory study and material object research together properly, this paper designs and implements a NC-OFDM system of CR based on USRP2, and presents the flow path of both software and hardware in detail, meanwhile, it also presents the solution to the key problems. The paper introduces a fast and effective self-adaption algorithm based on traditional algorithm and Pruning algorithm. The software and hardware simulation results show that this system is available to implement the wireless communication based on the USRP2. And the proposed algorithm not only can reduce the time of dealing with data effectively, but also can improve the robust of data transmitting and enhance the performance of the whole system.

Abstract:In realistic graphics, how to reflect realistic shadow effect is an important aspect to enhance the sense of reality of the model. The shadow should meet the real physical situation as far as possible, meanwhile, a smooth edge is necessary. However, rectangular array of pixels will easily cause jagged aliasing phenomenon at the edges. How to deal with the aliasing problems effectively has been a hot topic in the field of graphics. When solving aliasing of the shadow boundary in real-time rendering, the conventional Percentage Closer Filter (PCF) is not only inefficient, but also the smoothing effect of the boundary is limited. This paper improves the PCF algorithm, the improvement makes the algorithm more efficient in implementation. This new algorithm is based on conventional Shadow Mapping and uses higher accuracy of the filter template to deal with aliasing adaptively, especially to the area which has impact on visual effects, .thus increasing the overall computational efficiency substantially. The experiment results show that this algorithm is obviously improved in efficiency compared with the conventional PCF.

Abstract:The micro-Doppler (m-D) features and extracting method based on the FMCW-ISAR is mainly studied in the paper. The target's continuous moving in pulse repetition interval (PRI) will induce the main lobe widening and deviation of the range profile in FMCW-ISAR system. The induced error will influence the processing of the extraction of m-D features and imaging. The accurate micro motion features cannot be obtained by immediately utilizing existing method of extracting m-D features. To solve this problem, the detailed manifestation and characteristics of target's m-D in FMCW-ISAR is analysed firstly. And then, combining with the extended Hough transform, an extracting method of m-D features parameters in FMCW-ISAR based on Polynomial Phase Transform is proposed in the paper. Finally, some results are given for validating the theoretical derivation and the effectiveness of the proposed method

Abstract:The location algorithm having the distributed and anchor-free features is always one of the important developing directions in the node location techniques of sensor network. On the basis of analyzing a great many anchor-free location algorithm, the article finds out a distributed anchor-free location algorithm with which the location obtained is quite accurate. In order to further improve its location accuracy, the article establishes an error model of the algorithm and then proposes a method of reducing the target node positioning error by analyzing this error model. And to measure the accuracy of the estimated location of node, the article puts forward two targets, positioning level and credibility. According to the conclusion from error analysis, the article designs an optimization mechanism with the usage of the targets proposed on the basis of the original algorithm, which can filter out high-precision neighbor nodes from the neighbor table of a target node, and thereby the positioning accuracy of the target node is improved. The computer simulation shows that the availability and reliability of estimated location which are calculated by the optimized algorithm are higher than those calculated by the original algorithm, thus the feasibility of this optimization is verified.

Abstract:Ensemble learning is an important research direction in machine learning, in recent years, support vector machine (SVM) ensemble has attracted the attentions of researchers in the field of machine learning and statistical learning, and has become an active research hotspot. The research and application of SVM ensemble in recent years are surveyed in this paper and the fundamental problems in SVM ensemble are discussed. Methods of constructing SVM base classifiers with higher diversity, effective ways for combining base classifiers, and the typical applications of SVM ensemble are discussed and analyzed. The problems those exist in the research and application of SVM ensemble are pointed out and the important research directions are given.

Abstract:Based on the seven conventional aero-metals fatigue test data, the relationship between cyclic stress-fatigue life and the S-N curve are obtained by the Least Squares Support Vector Machine(LSSVM) firstly. The S-N curves got by LSSVM and by the power function and the three-parameter equation are compared. It is found that the LSSVM not only can be used to describing the relationship between the cyclic stress-fatigue life, but also is the best method compared with the power function and the three-parameter equation. Using the S-N curve got by LSSVM, the fatigue life under the cyclic stress can be precisely obtained, and the fatigue limit can be obtained too. So, the security can be ensured for the structure design and using.