bob手机在线登陆学报自然版

2017, 37(12): .

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2017, 37(12): .

Abstract(609) PDF(651)

Abstract:

Improved WENO Schemes for One-Dimensional Detonation Simulations

LI Peng, WANG Cheng

2017, 37(12): 1211-1216. doi:10.15918/j.tbit1001-0645.2017.12.001

Abstract(927) PDF(1213)

Abstract:
Based on three improved weighted essentially non-oscillatory (WENO) schemes, with WENO-Z scheme as the reference and using the different approach of nonlinear weight from the classical WENO scheme, the one-dimensional detonation systems under stable, slightly unstable and highly unstable cases were simulated; unlike the classical WENO scheme, these improved schemes overcame the problem of accuracy loss at critical points. The numerical results show that for the detonation systems in these three cases, the WENO-Z scheme, which is based on Lagrange polynomial reconstruct, is computationally stable and has the similar simulation results with the WENO-Z scheme, and is suitable for the simulation of detonation wave. For the stable and slightly unstable detonation systems, both the WENO-NS scheme and the WENO-P scheme have small oscillations, but they are computationally stable. However, for the highly unstable case, the WENO-NS scheme is computationally unstable, while its improved form, WENO-P scheme, is computationally stable.

Analysis of Dynamic Properties and Energy Dissipation of Sandstone and Granite

WANG De-rong, LIU Zhao-yan, LIU Jia-gui, SONG Chun-ming

2017, 37(12): 1217-1223. doi:10.15918/j.tbit1001-0645.2017.12.002

Abstract(962) PDF(996)

Abstract:
To compare the dynamic mechanical properties and destruction forms of sandstone and granite with the strain rate ranging from 49s^-1to 97s^-1, impact compression tests were conducted using the split Hopkinson pressure bar(SHPB) test device with a diameter of 100mm. The results show that the dynamic compressive strength of the two materials, the extent of damage and energy absorption increased with the increase of strain rate, but the energy dissipation rate of granite gradually decreased with the increase of strain rate, and all of them show strain rate correlation; the initial elastic modulus, peak strain and energy dissipation rate of sandstone under three types strain rates show little difference and a weak strain rate sensitivity.By analyzing the energy absorption and dissipation rate curves in the loading process, the dynamic failure modes were analyzed from the perspective of microstructure. Through the verification of the test validity, it is proved that the test meets the assumption of uniformity better.

Modelling and Simulation Method for Flexible Wing Aircraft

YU Yang, WANG Zheng-jie

2017, 37(12): 1224-1228. doi:10.15918/j.tbit1001-0645.2017.12.003

Abstract(976) PDF(907)

Abstract:
A new modelling and simulation method for flexible wing aircraft was presented to describe coupling effects between rigid-body movement and structure deflection. Rigid-body movements and structural deflections were calculated under independent inertial and non-inertial systems respectively. Aerodynamic forces and inertial forces were used to describe the rigid flexible coupling dynamic properties. The mathematical solution was to calculate forces, rigid-body movements and elastic deflections in a specific order inside a time-step, and a cyclic solving method was used between time-steps. Simulation results of aircraft's attitude dynamic response were used to check the reliability of this method. The results confirm that this modelling and simulation method is able to represent dynamic characters of flexible wing aircraft.

Gust Alleviation of Flexible Wing Aircraft with Multiple Control Surfaces

CHEN Yang, WANG Zheng-jie, GUO Shi-jun

2017, 37(12): 1229-1234,1240. doi:10.15918/j.tbit1001-0645.2017.12.004

Abstract(995) PDF(1385)

Abstract:
When small flexible wing aircraft encounter a strong gust, the attitude and the centroid acceleration will change drastically, and the elastic motion of the flexible wing will be induced, which may lead to instability. Flexible wing aircraft gust alleviation system should consider both the rigid and elastic degrees of freedom. The longitudinal state space equation of the flexible wing vehicle under the disturbance of continuous gust and continuous turbulence was deduced. A gust alleviation controller was designed by using the predictive control method,and the control allocation strategy of multiple control surfaces was proposed, which solved the problem of insufficient control ability of the independent control surface under strong gust disturbance. The simulation results show that the model predictive control can effectively reduce the structure load of the aircraft caused by discrete and continuous gust, stabilize the rigid body motion and elastic motion, and its control effect is better than that of LQG control.

Image Algorithm of Ship Detection for Surface Vehicle

FANG Jing, FENG Shun-shan, FENG Yuan

2017, 37(12): 1235-1240. doi:10.15918/j.tbit1001-0645.2017.12.005

Abstract(1089) PDF(1055)

Abstract:
In order to solve the problem that the surface vehicle detecting ship targets in the nearshore waters was vulnerable to light, similar color background and wave reflection, ship detection algorithm based on improved visual attention model was proposed. First, low frequency and high frequency features of images were extracted by using wavelet transform theory. Then, the hue, saturation and value features of images were also extracted by converting the images of task waters from RGB color space to HSV color space. Finally, various features of images were merged in the application of image processing method of Gaussian Pyramid and normalization operator. The simulation results show that the proposed ship detection method can accurately detect the ship targets under complicated backgrounds and has satisfactory anti-interference capability.

C-OWL2: OWL2 Extension on the Cloud Model

LUO Li-ming, LIU Wang-ning, LIU Jie, ZHOU Jian-she, SHI Jin-sheng

2017, 37(12): 1241-1245,1252. doi:10.15918/j.tbit1001-0645.2017.12.006

Abstract(1073) PDF(891)

Abstract:
In order to describe uncertain knowledge in the objective world, including fuzziness and randomness, uncertain extension of OWL2 syntax was carried out by introducing cloud model, and an uncertain ontology language C-OWL2 was proposed. The method was proposed without changing the existing structure of OWL2, syntax extension was carried out by using the annotation property of OWL2, and the corresponding C-OWL2 description of concepts, roles, etc. was given. Finally, the specific methods of application were illustrated with examples. In this method, OWL2 ontology was divided into two parts, precise ontology and uncertain ontology. In addition, when ignoring the uncertain part, the expression and reasoning of precise knowledge is not affected. This method is an extension of the function of fuzzy description logic, and overcomes OWL2 language's limitation of dealing with the precise ontology only.

Intrusion Detection Model Based on Double Training Technique

LI Long-jie, YU Yang, BAI Shen-shen, HOU Yuan-wei, HAO Yong-le

2017, 37(12): 1246-1252. doi:10.15918/j.tbit1001-0645.2017.12.007

Abstract(841) PDF(887)

Abstract:
In this paper, a network intrusion detection model was proposed based on double training technique to improve the frequency detection performance and to advance the detection ability for the low-frequency and high serious attacks. Firstly, the important features were extracted from whole dataset according to PCA. Then, a network intrusion detection model was constructed based on the classifier trained with double training technique. In experiments, the decision tree, naive Bayes and KNN algorithms were used respectively to construct the intrusion detection models based on double training technique. The experimental results show that the models can enhance the performance of the intrusion detection, especially for the low-frequency attacks.

A Graphic Password Based Authentication Scheme and Applications in E-Commerce

ZHANG Zhen-jiang, LIU Kun, CHENG Jun-jun, LIU Qing

2017, 37(12): 1253-1258. doi:10.15918/j.tbit1001-0645.2017.12.008

Abstract(886) PDF(605)

Abstract:
In order to simplify the complexity of authentication and re-certification process in electronic commerce, a new authentication scheme based on graphical password was proposed. To overcome the problem of being easy attacked in text authentication, a graphical password was used along with text prompts for identifying and memory in the authentication process. And a random fuzzy graphics authentication scheme was used to resist educated guess attacks. Experiment results show that, the authentication scheme based on random fuzzy graphics is safe and easy to operate in re-certification and to resist guessing attacks in the electronic commerce websites. Results also demonstrate that the proposed scheme is superior to the traditional scheme in terms of the time of registration, the success rate of login, the authentication time and the number of attempts. Thus it is efficient, effective, and suitable in E-commerce applications.

A Method of the Security Problem Definition on the IC Card International Terminal Based on the Threat Modeling

WANG Yu-hang, GAO Jin-ping, SHI Hong-song, ZHANG Bao-feng

2017, 37(12): 1259-1264. doi:10.15918/j.tbit1001-0645.2017.12.009

Abstract(905) PDF(1032)

Abstract:
As the most important document, the validity of the security target is mostly dependent on the accuracy of security problem definition. However there is no necessary model and method in the security problem definition process. To reduce the subjectivity, taking IC card international terminal production applied in the online payment as the research object, a method of the threat definition was proposed based on the threat modeling method of the security development lifecycle (SDL) and threat tree analyzing. Furthermore, the definition method and considerations of other contents in security problem definition were illustrated. This paper will lay a foundation for the proposal of accurate security countermeasures in security target.

Test Automation for Android Applications Based on Particle Swarm Optimization Algorithm

MA Rui, REN Shuai-min, MA Ke, HU Chang-zhen, XUE Jing-feng

2017, 37(12): 1265-1270. doi:10.15918/j.tbit1001-0645.2017.12.010

Abstract(1040) PDF(837)

Abstract:
Test automation is an important factor for the quality of Android applications. In order to improve the efficiency of automation, test case generation and the ability of abnormity discovering in traditional automated testing of Android application, an automatic test method for Android application was proposed based on particle swarm optimization algorithm, named particle swarm optimization for Android (PSOA). The PSOA method was arranged with three functions, including information collecting of control units, test process modularizing, test case generating and test data optimizing with the particle swarm algorithm. Experimental comparing with traditional automated test, the proposed method can successfully improve the ability of abnormity discovering, the efficiency of test case generation and the rate of automation.

Intrusion Detection Algorithm Based on Convolutional Neural Network

JIA Fan, KONG Ling-zhi

2017, 37(12): 1271-1275. doi:10.15918/j.tbit1001-0645.2017.12.011

Abstract(1287) PDF(2856)

Abstract:
As an effective algorithm of deep learning, deep convolutional nets have brought about breakthroughs in processing images, video, speech and audio, etc. In this paper, a convolutional neural network (CNN) modeling approach was used for intrusion detection, the convolution kernel was selected and convoluted with the data to extract local correlation, to improve the validity and efficiency of feature extraction. Through multiple "convolution-downsampling" layer, collected feature was used to represent the normal and abnormal user behavior deeply. Finally, the multi-layer perception was used to classify these features. The experiment results on the KDD 99 data set show that, compared with the classical intrusion detection algorithms, the new model can improve the classification accuracy in the intrusion detection and recognition tasks.

An Android Software Protection Scheme Based on Anti-Debugging and Online Encryption Verification

LI Ke-qiu, SHI Xiao-long, XU Jun-feng

2017, 37(12): 1276-1281. doi:10.15918/j.tbit1001-0645.2017.12.012

Abstract(962) PDF(1174)

Abstract:
In order to enhance the resistance of Android software to reverse analysis and malicious crack, the existing technology was improved by means of analyzing anti-debugging technology in Android security, and an Android reinforcement scheme based on online key was designed and implemented with comprehensive utilization of anti-debugging, software encryption, reflection and dynamic loading techniques. The feasibility of the scheme, the effectiveness of anti-debugging and anti-shell cracking were experimentally verified. Experimental results show that the proposed scheme can effectively prevent Android software from being reverse analysis, increase the difficulty of cracking Android software and enhance the security of Android software.

Real-Time Sprung Mass Estimation for Off-Road Vehicles

ZHENG Shu-hua, CAO Xin-lei, WANG Xiang-zhou

2017, 37(12): 1282-1286. doi:10.15918/j.tbit1001-0645.2017.12.013

Abstract(857) PDF(1217)

Abstract:
In order to estimate the sprung mass for the off-road vehicle in real time, an estimation method was proposed based on measuring the air pressure of the hydro-pneumatic air chamber and vehicle attitude. Based on the established seven-degree of freedom nonlinear full vehicle model with single tube hydro-pneumatic spring, the simulation was carried out by using the recursive least square estimation method with forgetting factor on the D-level road excitation. The influence of vehicle speed, filtering parameter and recursive least squares forgetting factor on the estimation performance was investigated. And the simulation results show that, the proposed method can provide the estimation with high accuracy and short response time.

Heading Deviation Correction and Stability Augmentation Control for Small UAV Taxiing

GUO Jie, LI Zhen, CHEN Tian-yue, LIU Zhen-chang, TANG Sheng-jing

2017, 37(12): 1287-1294. doi:10.15918/j.tbit1001-0645.2017.12.014

Abstract(1047) PDF(995)

Abstract:
To solve the taxiing rollover problem which is likely to happen during deviation correction for small UAV, a mathematical model of UAV taxiing was established to analyze the cause of rollover.A fuzzy logic controller was designed for correcting the heading deviation, which provided synergetic controlling of nose wheel, elevator and aileronto improve the taxiing stability of UAV.The fuzzy-PID control system based on ACO (ant colony algorithm) was designed to optimize PID parameters offline and adjust PID parameters online.The simulation and experiments results show that the control system can correct the heading deviation effectively, and increase the taxiing stability of small UAV.

Software System Developing of Original Data Packets Quick Display for Meteorological Satellite Payloads

WANG Shao-lin, CHENG Jing, ZHANG Li-guo, MA Wen-jia, YANG Chun-yan, CAI Xian-jun, ZHANG Bo

2017, 37(12): 1295-1299. doi:10.15918/j.tbit1001-0645.2017.12.015

Abstract(846) PDF(1161)

Abstract:
A convenient method is very important to test original data packets of payloads during whole satellite verification test before launching. Firstly, the basic requirements and methods about original data packet test of meteorological satellite payload were introduced. And the advantages were analyzed about developing a quick display software for low bit rate payload based on Matlab. Then, the software developing strategy and process were presented, and many programming methods and codes were introduced based on Matlab about TCP/IP communication, finding packet headers in data, data visualizing and dealing. Finally, some programming skills about elevating program running rate were introduced. The actual running results show that Matlab GUI is very suitable for developing all kinds of data quick display software of payload in satellite engineering.

Analog Circuit for Self-Destruction of Fuze Based on Energy Balance

HE Guang-lin, ZHANG Zhan

2017, 37(12): 1300-1304. doi:10.15918/j.tbit1001-0645.2017.12.016

Abstract(839) PDF(1127)

Abstract:
To rescue the low voltage failure of self-destruction circuit of fuze, an improved analog circuit using discrete components was proposed, which was based on energy balance. By strictly limiting input terminals' voltage of the comparator, full charge of the capacitor used for detonating was achieved in a low charging voltage; energy consumption modeling was completed and the time of self-destruction was designed accurately; using the Monte Carlo method, the influence of components tolerance on the characteristics of the circuit was analyzed. The simulation shows that detonating threshold can be reduced to 4.5V, relative deviation of self-destruction time is under 1% and the circuit is reliable under the voltage range of 5.5V to 15.0V.

Impact of Temperature and Pressure on The Ti-Si Self-Propagating Reaction

CUI Nai-fu, CHEN Peng-wan

2017, 37(12): 1305-1309. doi:10.15918/j.tbit1001-0645.2017.12.017

Abstract(742) PDF(859)

Abstract:
The impact of temperature and pressure on the activity of Ti-Si powder's self-propagating reaction under the condition of shock was investigated in this paper. On the one hand, the samples of different compactness were loaded by the same intensity plane shock to study the effect of temperature on self-propagating reaction. On the other hand, the samples of identical compactness were loaded by the different intensity cylindrical shock to study the effect of pressure on self-propagating reaction; XRD and SEM tests were used to further determine the degree of self-propagating reaction of Ti-Si reactive powder. Experimental results show that:under the condition of plane shock, the sample of low compactness starts self-propagating reaction entirely, in other words, higher shock temperature is beneficial to reaction; under the condition of cylindrical shock, the sample of higher compactness starts self-propagating reaction entirely, in other words, high shock pressure is beneficial to reaction.

Theoretical Study on Formulation Optimization for Multi-Index Solid Propellant

YU Zhen-fei, YAO Wei-shang, FU Xiao-long, YU Hong-jian, QIN Guang-ming, TAN Hui-min, CUI Guo-liang

2017, 37(12): 1310-1314. doi:10.15918/j.tbit1001-0645.2017.12.018

Abstract(946) PDF(894)

Abstract:
In order to meet the requirements of novel solid propellant for insensitivity, high energy and low signature, theoretical optimal formulations were calculated. Firstly, a uniform design table was used to get testing formulations, insuring a complex formulation with lesser test times. Then, energetic parameters and combustion product composition of the formulations were calculated with a Matlab software. The relationship between formulation and impact sensitivity was established with impact sensitivity factor. Finally, comprehensive optimization was carried out by using partial least squaresregression analysis for different energetic parameters, combustion product composition and impact sensitivity factors, getting a solid propellant formulation with optimal insensitivity, high energy and low signature. The calculated result is close to the data reported in literature, showing the reliability of the method and the software.

Algorithm of Networked Ammunition Attack Decision-Making Based on AHP-TOPSIS

LI Ming, LUO Guo-hua, JIANG Chun-lan, HAO Yuan

2017, 37(12): 1315-1320. doi:10.15918/j.tbit1001-0645.2017.12.019

Abstract(942) PDF(721)

Abstract:
Aiming at the problem of networked ammunition attack decision-making, an algorithm of networked ammunition attack decision-making based on AHP-TOPSIS was presented. The key attributes affecting the networked ammunition attack decision-making were analyzed. The AHP algorithm was used to construct the hierarchical structure, the judgment matrix was constructed and the weights of the attributes were determined. Then, the improved TOPSIS algorithm was used to get the ranking result of the decision scheme. The simulation results show that the algorithm has the advantages of low computational complexity and high real-time performance. The proposed algorithm can effectively solve the multi-node attack decision-making problem, and effectively restrain the algorithm from reverse order, and has certain robustness and practicability.

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