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According to the goal of improving the ability to in and out space, artificial intelligence technology innovative application in space transportation control has been explored. First, development need and basic principle of space transportation intelligent control have been described. Secondly, development status at home and abroad has been summarized. Finally, future development direction and research focus have been proposed for rocket intelligent control, reusable rocket intelligent control and intelligent control demonstration.

In order to improve the buffering performance of the data encrypted by CP-ABE (ciphertext policy attribute based encryption), this paper proposed a Markov prefetching model based on attribute classification. The prefetching model combines the access strategy of CP-ABE encrypted file, establishes the user relationship network according to the attribute value of the user, classifies the user by the modularity-based community partitioning algorithm, and establishes a Markov prefetching model based on attribute classification. In comparison with the traditional Markov prefetching model and the classification-based Markov prefetching model, the attribute-based Markov prefetching model is proposed in this paper has higher prefetch accuracy and coverage.

The putput section of the tube applied a 2-gap couple-output cavity techniques. The tube has a peak output power of 600kW, pulse-length of 200us, a instantaneous bandwith above of 220MHz, efficiency of 32%, gain of 43dB. The paper described the design issues, techniques features, computing simulation and test results.

Conventional protein docking methods use rigid docking algorithms but the results have been unsatisfactory, because protein structures are flexible in live environments. In this study, the side-chain flexibility is introduced into protein docking. First, the Morse theory is applied to curvature labelling and region-growing for segmenting the protein surface into smaller patches. The surface critical points are then extracted for each surface region which has been obtained in the segmentation, and a list of more precise and smaller surface patches can be obtained. Secondly, based on the segmented surface, we propose to describe the protein with an ensemble of conformations which incorporate the flexibility of interface side-chains by sampling their conformations using rotamers. We define a 3D rotation invariant shape descriptor based on the Spherical Harmonics Descriptor to deal with the flexible protein surface patches. The signature for each surface patch can be more accurately described and easily compared for the similarity between the signatures. The pairwise complementarity matching is needed only between the convex patches of the ligand with concave patches of the receptor and vice versa, thus the computational cost is greatly reduced. Finally, we are able to use the iterative closest point (ICP) algorithm, thanks to the advantage of our matching method that is able to pre-compute and store the transformation invariant, fast Fourier transform (FFT) docking correlation based representation of each flexible surface patch. Compared with the global geometric matching algorithm and other methods, our FlexDock system generates much less false positive docking candidates, it shows promising advantages in identification of the complementary candidates.

In order to solve several problems such as less automation, high labor intensity and inefficiency, which are brought by the traditional human inspection methods, we develop a machine vision system for film capacitor defect inspection in this paper. Specifically, we use high-definition CMOS industrial cameras, IPC board and STM32 controller to set up the hardware platform, and put forward suitable image processing algorithms for film capacitor appearance defect inspection, such as forward extraction, horizontal and vertical projection, shape detection and gradient detection. The proposed algorithms can well realize the detection of uneven appearance defect, glitch defect, red paint missing defect and protruding edge defect of film capacitors. The experimental results show that the proposed vision system has high accuracy and reliability, can meet the modern production requirements.

A moored and autonomous test has been taken in the South China Sea(SCS) with a turbulence measurement instrument that measures small-scale shear velocity using shear probes designed by OUC(Ocean University of China). The MTMI (Moored Turbulence Measuring Instrument) is embedded in a raindrop shape floating body, which is made of buoyancy material of glass microsphere. A accelerate senor is used for vibration measurement and removing the vibration noise. The data which contain velocity signals, vibration noise and attitude signals are sampled for 110 days. The pitch angle varies between −10°and +10°and does not changes in response to variations of current speed, showing that the instrument is stable. The measured velocity spectra are severely contaminated by eddyshedding from the mooring cable. With the consideration that y axes might not be rigidly perpendicular to the sensitivity beam of the shear probe, we develop double probe correction with two acceleration signals: y and z to eliminate the noise. As a result, the dissipation rates reduce two orders of the magnitude, being consistent with the scaling estimated from the SCS. The turbulent kinetic energy of dissipation rates calculated with data measured by MTMI are from 10−9 to 10−4 W/kg.

The blowout preventer valve is the last protective screen to prevent oil spilling in offshore drilling platform. To avoid the happen of the spilling and other disasters which is caused by the blowout preventer valve failure, a lifetime prognosis approach is employed to forecast the lifetime of blowout preventer valve based on Wiener process. Firstly, a performance degradation model is established according to degradation data of the blowout preventer valve. Secondly, parameters in the model are obtained in virtue of the maximum likelihood estimation method, and then the lifetime is prognosed. Finally, an example is given to verify its effectiveness and reliability.

Along with the development of computer and network, various universities basically have established the international trade course of the foreign trade practice simulation laboratory, this paper explains the SimTrade trade simulation software architecture model and content structure, analyzes its teaching practice in a realistic simulation environment, economic and trade professional training applied on the edge, and analyzed its disadvantages and application in the design of software of the problem.

An image processing software system framework for aerial remote sensing is designed and implemented in this paper. Different from commercial remote sensing processing software for satellite platforms, a serial of functions, including radiometric correction, geometric correction, image mosaic and fusion, are proposed referring to the feature of the aerial images. These functions can be freely composed to form a process pipeline with a friendly interactive user interface. Moreover, an automatic optimization method for processing pipeline is put forward based on the image quality evaluation. Besides, this system can yield valuable feedbacks to improve the imaging system. Its performance is verified by processing real aerial images. It is shown that the involved functional algorithms are robust against the instability of airborne platform, the variety of terrain, and other interfering factors resulting in imaging distortions.

The fixed pattern noise (FPN) of the infrared focal plane array severely limits the system performance, and the non-uniformity correction algorithm is a key technique of thermal imaging system. The scene-based non-uniformity correction algorithm does not require a shutter to block the field of view, but utilizes the scene information of image sequences to calculate the infrared focal plane array non-uniformity parameters. This paper introduces an improved neural network non-uniformity correction algorithm, which speeds up the convergence rate of the conventional neural network algorithm. The improved algorithm employs the edge detection method to overcome the ghosting artifacts generated by the conventional algorithm. In the test of infrared image sequences, the algorithm introduced in this paper is proved to be reasonable and effective‥

Sn-Zn based lead free solder is one type of promising candidate to replace Sn-Pb eutectic solder due to its low cost and melt temperature which near to Sn-Pb eutectic solder. The Sn-Zn-Cu lead free solder was developed by alloying Sn with Zn and Cu in this paper. The effect of Zn and Cu content on the wettability of solder to Cu substrate has been investigated by spread test. The microstructure and composition at interface between solder and Cu substrate were analyzed through optical microscope (OM) and electron probe microanalysis (EPMA). Results show that Sn-4Zn solder has best wettability among Sn-Zn solders. Adding Cu to Sn-4Zn solder can improve the wettability of Sn-4Zn solder for Cu can combine with Zn to produce Cu-Zn alloy and prevent Zn riched phase from existing in the surface of solder. Prior to Sn, Zn combined with Cu dissolved from substrate to produce Cu-Zn intermetallic compounds at the interface of solder and substrate. The formation of continuous Cu-Zn intermetallic compounds layer at the interface between solder and Cu substrate has depressed the forming of Sn-Cu inter metallic compounds layer.

With the exposure of serious problems in a series of enterprise groups such as Lantian Group, Yinguangxia Group, Delong and Nanhai huaguang Group, the credit risks stand out for those commercial banks, which provide loans to these enterprise groups. Enterprise groups have complicated of organizational structure and concealed internal transactions, which mean that enterprise groups are grey systems. However, commercial banks matching credit evaluation and credit management at their developing stages lack of a whole objective technology that is suitable for management regulations and credit rating system. Based on investigation and research on persons, this paper proposes specially credit evaluation index system of group enterprises, including quantitative and qualitative indexes. It processes these indexes by principal component analysis method and entropy method based on grey relational analysis model of the credit score values of enterprises. Finally, it evaluates grey relational grade of credit risk between parent corporation and its subsidiary about Group “QiaQia”. The results of this analysis are consistent with practice.

As for why to carry out public utility reform, generally, efficiency hypothesis is mainly adopted as its analysis premises. However, this Article holds that there exists serious one-sidedness in efficiency hypothesis. Public utility reform is a compelled choice under the condition that local governments are short of financial power to continue to provide astronomical particular investment demanded by operation of public utility. This perspective can provide new thread of thinking for the public utility reform.

Most existing cross-realm client-to-client (C2C) key exchange protocols are based on password authentication, which are vulnerable to password guessing attacks. Sun et al. and Lee et al. have proposed three-party key exchange protocols respectively, which achieve higher security through verifier authentication instead of password authentication. However, their key exchange protocols can only be used in single-server C2C setting. In this paper, we propose a new cross-realm C2C-PAKE protocol, which is based on verifier authentication, and enable two clients to agree on a common session key with assistance of two servers in different realms. The protocol is shown to be resistant against various attacks including password guessing attacks and server compromise attack.

A 500 kW C-band klystron with broad bandwidth has been developed. The klystron is successfully built and met design specification and applied for microwave amplifier.

In this paper, the mathematical differential equations of a cylindrical permanent magnet are established. Based on simulation and analysis of the magnetic field of the permanent magnet and its magnetic dipole, a location tract method with magnetoresistive sensors for the wireless capsule endoscope is studied. The experiment results indicate the location tract method is feasible.

With the development of superconductivity technology, the current source multi-level inverter (CSI) will be paid more and more attention, appearing some new topology, but the corresponding controller has not appeared, for example split-phase control current source multi-level inverter. In view of this situation, a solution based on FPGA is proposed. Using the FPGA technology, all logical function will be integrated to a chip, reduced the system cubage greatly, enhanced the system performance, moreover triple-harmonic filling is conveniently, through fill the triple-harmonic, the efficiency of the inverter will be enhanced 1.15 times .The entire design is validated on a five level experiment system.

This paper presents a novel single-chip IC (integrated circuit) realization of the 3-sinusoidal PWM (SPWM) controller. The controller's outputs, such as fundamental voltage, frequency, dead time and so on, are controlled by several input clocks' frequency. With an EDA (electronic design automation) methodology, the control IC is implemented using only one single advanced FPGA from Altera, Inc. The output fundamental frequency can be adjusted from 0.094 to 2 kHz or more, and it can be real-time display. The SPWM switching frequency can be set 50 kHz. The dead time for the IGBT is arbitrarily adjustable. The designed SPWM IC can be incorporated with a digital signal processor (DSP) to provide a simple and effective solution for high-performance AC drivers. Further more, the design can be converted into a soft IP (intellectual property) core for other purposes. Simulation and experimental results are given to verify the constructed controller.