Abstract:Global stable region and stability of nonlinear axial compressor system are theoretically qualitatively analyzed in this paper, Criterion of stability of the system are presented by parameters . Based on the MG model of the nonlinear axial flow compressor systems and by applying the nonlinear dynamical theory, qualitative dynamical characters are analyzed for the limited singular point firstly. The stable conditions are achieved on the basis of the various matching of parameters . Simulation results prove that when [WTBX]γ=1.2,ψc0=1.5,β=0.67[WTBZ] singular point is center point; when γ=1.4,ψc0=1.75,β=1singular point is focus;when γ=1.2,ψc0=2.2,β=2singular point is node. Secondly, qualitative dynamical characters are analyzed for the unlimited singular point, the global stable region can be divided by the nonlinear axial flow compressor systems. In addition, the relation are researched between the stable conditions,global stable region and rotating stalls as well as surge. It has academic significance on achieving reliable active control of the nonlinear axial flow compressor and understanding the relations between the system's behaviors and the parameters.

Abstract:In order to overcome coupling effect of aero-engine's control loop, a general predictive decoupling controller based on coactive adaptive network-based fuzzy inference system (CANFIS) is designed for aero-engine distributed control system with long uncertain time-delay. The input and output data of engine nonlinear model are used as sample data to train CANFIS. The front parameters are fixed after training, and the latter parameters can be adjusted to make CANFIS approach actual system online. The network is taken as a predictive model, which can be used as a substitute for the feedback amending part of general predictive controller. The simulation results show that the control system has a fine performance of tracking and decoupling capability to different reference signals such as step and ramp, it can also follow the reference track stably when time-delay is changed, which proves that the controller is of insensibility to time-delay and of strong robustness.

Abstract:To fulfill the need of computer assistant decision-making and simulating battle drilling, based on the basic helicopter spot performance and a few of original data, the paper makes a model of the Algorithm of rotor's power. By analyzing the characteristics of dynamics and using the momentum theory and blade theory, a computational method of helicopter rotor power and available power is deduced. The rotor power will be respectively calculated as several parts. The pull's calculation model is established with the remnant power by using the linear outer insert method. Finally,a calculated example proves the feasibility of the simplified arithmetic model,thus the problems of flight performance assurance and dynamics simulation are solved.This algorithm is of applied importance.

Abstract:The study object in this article is a laminar aerofoil, which belongs to a high altitude long endurance UAV with big wing aspect ratio. With the help of advanced technology of computation fluid dynamics (CFD), genetic algorithms are combined with N-S equations for the aerofoil optimization design at the bound of low Reynolds number to perform the aerodynamic shape optimization design of aerofoil. The aerofoil is described by equations of linearity adding analytic Hicks-Henne shape function on the basis of original aerofoil. The individual is formatted by variables of the linearity adding analytic functions, by the program of selection, crossover and variance, the aerofoil is optimized with the purpose of rising lift-drag ratio. As a result, there is an increase of lift-drag ratio and life coefficient of the optimized aerofoil at low Reynolds number. The optimization results illustrate that the genetic algorithms are of an effective way for the optimization design of aerofoil.

Abstract:In order to accurately predict target intention prediction and help decision-making timely and reasonably, the D-S evidence theory is adopted in target intention prediction. First, the situation factors are extracted, and then the influence of each factor is analyzed, based on which, the mathematic modeling is created. With the D-S composition law, the influences of all factors are integrated, the probability evaluates of the likely propositions are calculated and the corresponding decision is made. Numerical examples of simulation show that the uncertain probability decreases greatly after fusion, the result of target intention prediction is reasonable, and the method can be extended to multi-formation.

Abstract:As a high performance -cost ratio equipment, IR screen is widely used in ground IR countermeasure field. But in air-to-air countermeasure aspect, it is difficult to interfere IR missile effectively with IR screen because of the impact of high speed airflow. The system including target war-craft, IR screen, IR missile is founded. The launching occasion, the original velocity, the orientation of IR screen and the target maneuver are combined together. According to the principle of relative movement, the accurate positioning of IR screen is realized and the launch method of the smoke bomb is obtained. By making full use of IR screen's shade effect, target's elusion trace is received, based which the target's control law is worked out, thereby target's elusion method is obtained. By this way, the influence of high speed airflow on IR screen is eliminated and a method of airborne IR screen interfering in IR missile is found. The simulation of the complex system including target, IR screen and missile shows that the interfering method is feasible, which offers a reference to the design of IR interfering system and the establishment of IR interfering tactic.

Abstract:Aimed at the whole military aircraft, the paper tries to solve the contradictory between keeping model effective and choosing the right expository variables. The basic modeling idea based on Effectiveness Indexes is analyzed and the form of models is established. According to the demand of cost modeling, the Effectiveness Indexes' constructing method is studied deeply. Finally, the cost modeling process based on Effectiveness Indexes is introduced through an example. In order to compare the effect of methods, some other models are established at the same time with the DAPCA model and PLSR. The comparison results explain that the models based on Effectiveness Indexes are better, because more parameters which impact the cost obviously are considered and the variables in the regression process are reduced, thus the models' validity is guaranteed.

Abstract:Judging air-raid attack targets is a complicated system project which includes a large amount of different dimension factors. The traditional manpower qualitative judging mode hasn′t applied to information-based air-defense operation any more. To solve the above-mentioned problem, in view of the demand of choosing important shelter targets during the commanding of aerial defense operation, the effect factors in choosing the air-raid attack by the air-raid side are analyzed based on the theory of modern air-raid attack target and from the view of aerial defense force. Then, applying the grey fixed weight clustering theory, an air raid targets range model is set up by the combination of the qualitative and quantitative analyses. This model can be used to compose the center of campaign, then the pivot and order of the air raid targets can be estimated. The model can be applied to managing fire power and can be a reference frame to the air-defense force.

Abstract:Configuration synthesis of structure element plays an important role in middleware design and function block diagram design of control strategies. In order to overcome the defect-the low efficiency of classical optimization algorithm when combination scale is large, an improved particle swarm optimization (PSO) algorithm is proposed. Firstly cyclic natural number coding method is employed to describe the position and velocity of every particle. Then greedy strategy is adopted to convert the problem into a unimodal function optimization. Sectional inertia parameter and guaranteed convergence algorithm are used to improve the global convergence ability. The multiple optimal solutions are obtained by means of recording multiple global optimal positions in each time of iteration. Finally an example of 378000 combinations is given to verify the effectiveness of the algorithm presented. The instance shows that the algorithm is simpler than Niching Technique in multiple optimal values searching and better than basic PSO in global convergence ability.

Abstract:Because of the influence of the complexity environment and noise jamming, target identification is uncertain in the flight-test examination. To enhance the preciseness rate in target identification, target characteristic information is extracted based on the measurement of the target by the sensor. The subjection degree relative to the reference target in the target storage is calculated via maximal subjection degree principle. The trusting degree of the sensor is gained via D-S theory. Fusion target identification result is calculated finally. Target character can be identified efficiently under the complex test flight environment via this method. The method is simple, credible and practical.

Abstract:The effectiveness evaluation of C4ISR system is an important link of the current research. Correctly and exactly evaluating the system effectiveness is an important means of decreasing cost and raising usage effectiveness of weapon equipment. In view of the complexity and changefulness of the diverse random events in deciding the competency matrix C and the fact that some criterions lack quantified representation in ADC method, an improvement on the method is proposed in this paper. Through the combination of qualitative and quantitative processes, ADC method, analytic hierarchical process and Delphi method are used jointly to implement the effectiveness evaluation of C4ISR systems. Firstly, the evaluation method employed in this paper, i.e. the improved ADC method, is determined based on the analysis of the advantages and disadvantages of the conventional ADC method. Secondly, the evaluation criteria and the primary evaluation process of C4ISR systems are established. Thirdly, availability vector A, dependability matrix D, competency matrix C and the computational models of their sub models are set up respectively. The process of establishing competency matrix C and its sub model is described emphatically, by applying the analytic hierarchy process and Delphi method synthetically, based on the ADC method. And finally the effectiveness and availability of the established model are verified through the calculation and analysis of examples.

Abstract:In order to estimate the LCC of new pattern ground radar equipment more logically, exactly and effectively, a right method should be chosen in estimation. In allusion to that there are many difficulties in common methods of estimating the LCC of the ground radar equipment, such as the heavy estimation workload, the estimation precision with quite stronger subjectivity and uncertainty, and the existence of great limitations in the process of the model and emulation, and from BP nerving network, a method is proposed based on BP nerving network in estimating the LCC. By using this method, the full use of the computer software resources is done and a nerving network model of estimating the LCC of the ground radar equipment is set up. In this paper, the Matlab software is adopted to build up an implement function of typical network. Firstly, the author uses the expenditure data similar to the former one of the ground radar equipment as a sample.Then trains the data and modulates the coefficient.Finally, the author estimates the factual expenditure based on the corresponding data. With the estimating and analyzing example, and through comparing with the common estimation method, the result shows that the model can be applied to estimating the LCC of new pattern ground radar equipment and has a higher precision in estimation.

Abstract:A lot of research result indicate optimization design of backoff mechanism and contention window can improve performance of IEEE802.11 DCF MAC. Based on the formation of small UAVs, the information flying satellites and IEEE802.11, an optimized MAC mechanism was proposed: DCF/CCW.A station estimated the number of competing terminals through monitoring the channel, and used constant contention window. This mechanism is of topology, the system contention code obtained from monitoring channel changes with network configuration. Thereby it can adjust optimal constant contention window dynamically. The analysis results indicate when network scale is definited, system throughput have more effect on contention window, and less effect on system access delay. The optimized mechanism can develop and improve the communication performances of the cooperative network.

Abstract:Integrating several kinds of navigation systems together is an effective way to increase the performance cost ratio of the navigation system. With the development of information fusion technology, the federated filtering becomes more and more attractive in navigation field, since the federated Kalman filter can be flexibly used in designing the integrated navigation system with high precision or best fault-tolerance capability. Based on the study and analysis of the algorithm and the characteristic in structure of the federated Kalman filter, a project of GPS/INS/TAN integration navigation system is presented, in this project the good fault-tolerance can be guaranteed, simultaneously the high precision and the operation tempo can also be taken into consideration. In this paper the mathematic model of GPS/INS/TAN integration navigation system is established, simulated and analyzed. The result indicates that this project is an effective way to improve the precision of navigation.

Abstract:In this paper, a new fast sub-carrier and bit allocation algorithm in multi-user OFDM systems is proposed. Under the BER and each user's rate requests, according to the information of channel state of all users, first the sub-carriers are pre-allocated, then, bit allocation is performed to every sub-carrier.Based on the above,After this, we exchange the pre-allocated subcarriers using the method intruduced in this paper and optimize iterativly to achieve the final allocate to realize the minimize the transmiting power. At the same time, this paper analyses the tradition static subcarrier-allocation method and several adaptive subcarrier and bit allocation method. According to comparing the method of different algorithms, compare the merit and defect of them. The simulation results show that the proposed algorithm performances better than the tradition static subcarrier-allocation method and convergences quickly, the performance being close to the Lagrange algorithm, while the complexity is low.

Abstract:In the antiaircraft missile weapon system based on network operation, the netting intelligence process is the basis for sharing information and cooperative operation, and the performance evaluation is beneficial to ameliorating shortage of the existing system and to developing a better new system. The performance evaluation is a complex problem which involves many factors including that some information about specification is incomplete and vague. By thoroughly analyzing the factors those have influence on the performance of antiaircraft netting intelligence in processing, a comprehensive index system is built up. A first-run comparison method based on key indexes is put forward when many systems are evaluated. The evaluating model and algorithm based on multi-hierarchical gray relation analysis（GRA） are given, and the index weight is calculated by entropy weight method. Using this method can availably reduce the influence of humankind. Finally, a practical example is given. The research result has been applied to the evaluation practice, which demonstrates the validity and practicability of the method.

Abstract:When evidences combine and fusion, because the unknown new propositions appear in system and the sensor gathered evidences are uncertain, the D-S combination rules are inapplicable for conflict evidence combination. In order to manage the conflict evidence effectively, a modified conflict evidence reasoning method based on non-closed frame of discernment is proposed. First, an aggregate denoting unknown new proposition is added in closed frame of discernment, then the closed frame of discernment is expanded to non-closed frame of discernment, and the evaluate method of new proposition basic probability assignment is given, the focal element combination method in non-closed frame of discernment is given based on the relations between the new proposition and the known evidence. With this as the foundation, the local conflicts are distributed, on the basis of the basic probability assignment and the reliability of evidence among the conflict focal elements. Finally the distribution method of conflicts is verified through an example. The result shows that this proposed approach, compared with the result of with Dempster combination rules in non-closed frame of discernment, is effective in identifying the new propositions. By the modified evidence reasoning method and closed frame of discernment, two kinds of conflicts of new proposition between known evidences and between known evidences can be distributed locally by non-closed frame. By managing the two reasons of conflict evidence in a comprehensive way, the final evidence reasoning result focus on the reasonable direction.

Abstract:Application of the high impedance surface EBG structures for cylindrical conformal microstrip antenna is studied. Through modeling and numerical simulation, the effects of EBG structures on antenna resonance frequency and pattern as well as effect of curvature on antenna performance with EBG structures are obtained. The results demonstrate that the resonance frequency of antenna shifts higher frequency, the antenna pattern is improved obviously, the forward gain increases, the back lobe decrease,3 dB beam width gets narrower. The comparison research shows that the effect of curvature on cylindrical conformal microstrip antenna gain is decreased remarkably after EBG structures are applied to antenna.

Abstract:The paper introduces a principle and application of power supply that gets energy from high tension line for electronic current transformers (ECT). Some problems of designing the new type of active ECT with self-excitation power supply and the relevant techniques and methods are fully studied. The ECT with self-excitation power supply has successfully created and put into practical. The wake-up current of the new ECT is only 0.588 A and Wake-up time is less than 20 ms.The original restricting electrical current "funnel structure"（a special restricting current component）is used to have solved key technology problems of impacting system by saturation large current. With some other special technical measures，self-excitation power supply can make sampling and transmitting circuit work in the purifying power and ensure measurement accuracy. The whole technology of creating the ECT with self-excitation power supply not only has simplified the structure of the ECT and also has achieved a major breakthrough in optical isolation ECT technology of china，that greatly lift the integrated automation level of power system. The new type of ECT has been approbated durable products and has entered the electric power market.

Abstract:Quantum error-correcting codes protect quantum information against undesirable noise in quantum computation and quantum communication. It is one of important problems that constructing very good quantum codes. There are two methods that use binary codes to construct quantum codes,one is CSS construction, another is Steane construction. These two methods are all based on the construction of binary self-orthogonal codes. Combinational construction of binary self-orthogonal codes is investigated in this paper. From known codes chains of binary self-orthogonal codes and their dual codes chains with given dual distance, new binary self-orthogonal codes of dual distance three, four, five and six are constructed. Based on these results, for each satisfying , S-chains with parameters and are constructed. According to Steane's construction, many very good quantum codes of distance five and six are constructed by the obtained S-chains, some of these quantum codes are new and some of these quantum codes have improved parameters than previously known codes.

Abstract:First of all an error in Reference is pointed out. It is also pointed out that in the results of the intuitionistic fuzzy set being decomposed itself appears in the decomposition as a constructive team and a great deal of teams in the decomposition are repeated. A standpoint is put forward that a decomposition theorem of a (intuitionistic) fuzzy set expresses the (intuitionistic) fuzzy set as a union or an intersection of a family of other (intuitionistic) fuzzy sets which are related to the (intuitionistic) fuzzy set and have some common characteristic. And then on the basis of introducing concepts of -cut products (strong -cut products) and -cut sums (strong -cut sums) of fuzzy sets and intuitionistic fuzzy sets, a fundamental theorem of intuitionistic fuzzy sets is given which shows that all the -cut products and -cut sums (go without saying, strong -cut products and strong -cut sums) of any intuitionistic fuzzy set are still intuitionistic fuzzy sets. It also proves that any fuzzy set or intuitionistic fuzzy set is equal to the union of all the -cut products (all the strong -cut products) as well as equal to the intersection of all the -cut sums (all the strong -cut sums) of it, these results are respectively called the decomposition theorems of fuzzy sets and intuitionistic fuzzy sets.