Abstract:There are ungent requirements of large-scale messages transmission in the airborne networks with complex topologies. When the triditional Time-triggered Ethernet ( TTE ) scheduling methods are used to meet a requirement, the time complexity is very high. To solve this problem, we in this paper propose a new TTE message scheduling method based on the idea of load balancing. In this method, a set of candidate paths is firstly generated and then selected according to the message length and the data flow link load. Those paths with load balancing characteristics are choosen. Then the messages are scheduled based on static priority, sorted according to message length and cycle, and allocated by using the " back to back " rule. Finally, the method is compared to the triditional Satisfiablity Modulo Theory (SMT) method to illustrate its performance. Simulation results show that, while the method can reduce the computation time by more than 90% when the schedulable message frames are more than 6000, the computational efficiency is improved by 10~100 times on the basis of ensuring the real-time performance of the message. Therefore, the method is suitable for complex large-scale data scheduling table generation and can feasibly improve the message scheduling performance of airborne network.

Abstract:In this paper, an iterative algorithm is introduced for solving a class of optimal control problems constrained by time-periodic heat equation, where the optimization is concerned by searching a best source term of the heat equation to minimize the objective function. By applying the optimality condition, the problem is firstly transformed into two coupled time-period heat equations. Then iterative algorithm is applied to decouple the PDE system. Finally, the equations are separately solved in the Gauss-Seidel pattern. Numerical examples are presented to illustrate the robustness of convergence rate of the algorithm with respect to the discretization parameters.

Abstract:In this paper, based on the characteristics of a slender rigid block system, a method is introduced for computing the spectrum of Lyapunov exponent by combining the local map and the Poincare map. Then, by numerical simulation, the chaotic orbits generated by heteroclinic bifurcation under external periodic excitation are observed and the extended Lyapunov exponential spectrum method is applied to the rocking block system. Numerical results confirm the chaotic phenomenon does occur in the system.

Abstract:In this paper we investigate the crossing limit cycles of a 3D discontinuous piecewise-smooth system. In this system, the phase space is divided into two regions by a hypersurface and thus the system presents two different vector fields. Meanwhile, the system presents two-fold in which both vector fields are tangent to the hypersurface. We prove that the maximum number of crossing limit cycles is 2 and give necessary and sufficient conditions for one and two crossing limit cycles respectively. Furthermore, the crossing locations of crossing limit cycles are all determined as well as their periods.

Abstract:In this paper, by using the generalized Hua"s matrix inequality, the boundedness and compactness of a weighted composition operators on Bers-type space of the first Cartan-Hartogs domain are characterized.

Abstract:As the limited resources of the port, the optimal allocation of berths and quay cranes is conducive to improve the operation efficiency of the port and speed up the departure time of ships. Due to the limitation of geographical conditions, the berth lines of some ports are not linear, but show "L" or "F" shape, such as quay cranes can not free to move on these discontinuous berth, this kind of berth allocation problem cannot be optimized based on the continuous berth allocation problem, and the space of the berth line will be wasted based on the discrete berth allocation problem. For the irregular berths and quay crane integrated distribution problem, according to the relative location and time of arrived ships, a mixed linear programming mathematics models is established, three valid inequalities are extracted by analyzing the features and variable relationship, and CPLEX software is used to solve the model. With the increasing of the problem size, the solving time is increasing. Therefore, the improved particle swarm algorithm is proposed, a new velocity updating formula with random search strategy is used to avoid falling into local optimum. The experiment results show that the average solving time is reduced by 83.23% by adding the valid inequalities. The average result obtained by the improved particle swarm algorithm is reduced by 25.21% than that of the standard particle swarm algorithm. It is proved that the improved particle swarm optimization algorithm proposed in this paper is effective in solving the problem of irregular berth and quay crane allocation.

Abstract:Aiming at the disadvantage of traditional salt-and-pepper noise removal methods that the denoising performance is poor when the image noise density is high, a new adaptive median denoising model combined with cyclic iterative method is proposed, in order to improve the performance of denoising algorithm in high-density salt and pepper removal. The working mode of the proposed filter can be divided into three stages. First, the image is preprocessed, that is, the suspected noise points are obtained from the pixels to be processed using the extreme value judgment method. Secondly, the noise points are determined and replaced adaptively by the median or mean value in the neighborhood to complete the denoising. Finally, the suspected noise points are processed again, and whether the suspected noise points are noise points is further judged by the algorithm with built-in parameters and conditions. The noise mark point method is also induced, and the filtered image is obtained by finding the end of mark point denoising through iterative processing. The results of simulation experiments show that the proposed method has a certain improvement in denoising performance for both low-density noise images and high-density noise images, compared with several traditional salt-and-pepper noise removal filtering algorithms.

Abstract:To solve the problem of low accuracy of large pose face recognition in real scenes， a large pose face recognition algorithm framework is proposed based on the 3D-2D mapping focusing on the exploration of the key technologies of large pose face recognition from the perspective of data augmentation. Different from the current face recognition algorithm based on 3D point cloud data， the proposed method mainly uses 3D face data to enrich the posture information via the data expansion method by 3D-2D mapping. The specific posture face feature extraction models are trained and integrated into the unified large pose face recognition framework. The key of the proposed method is to use registered 3D face information to assist 2D face multi-pose recognition. It is easy to integrate existing 2D face recognition methods into the proposed framework. Experiments show that the method proposed in this paper can effectively improve the accuracy of large pose face recognition in unconstrained real scenes without increasing the significant computational load and provides a new idea for the current 3D information to solve the 2D face recognition problem.

Abstract:The temperature of the heat-sealing knife of the bagging machine is usually controlled by PID algorithm, but the control effect is not so good since the PID control parameters are mostly set by human experience. To solve this problem, an improved SA-WOA algorithm is proposed to realize the self-tuning of PID control parameters. First, the step response curve method is used to establish the transfer function model of the system, and then the advantages of the whale algorithm and the simulated annealing algorithm are considered, and the two are combined. On this basis, the algorithm is improved to improve the convergence speed and optimization effect of the algorithm. The improved algorithm is simulated and compared on the MATLAB R2017b platform. Finally, the control parameters obtained from the simulation are tested on the bagging machine. The simulation comparison results show that the parameter control effect obtained by the algorithm optimization in this paper is better compared with the relay feedback algorithm, the particle swarm algorithm and the improved particle swarm algorithm based on simulated annealing. The actual test results show that the parameter control effect obtained by the algorithm in this paper is good and can meet the actual demand.

Abstract:The relative position and attitude detection of space targets is the focus of research in the field of spacecraft docking, and the detection methods are mainly divided into two categories: telemetry and optical measurement methods. Among them, the latter has become the main method for close-range position and attitude detection relying on its advantages of high speed, high stability and large amount of information. The depth information of the characteristic light points on the spatially cooperative target can be calculated using the binocular vision model, and the target attitude can be obtained based on the known structure, size and other constraint information among the characteristic light points. The PSD has the advantages of having no image feature extraction process, responding fast and having high resolution for positions, compared with CCD and CMOS sensors, and the bionic structure of binocular stereo vision system can help directly obtain the depth information of the detection target. Therefore, this paper proposes a dual PSD vision model with joint modulation of luminance and order of feature light points to achieve the positional detection method of spatial cooperative targets. The experimental results show that the average measurement error of the system is 2.541° when the attitude of the cursor target is adjusted ±30°. The average deviation of the pitch angle and yaw angle are 0.923° and 0.563° when the attitude angle is less than 15°. The average deviation of the pitch angle and yaw angle increase to 4.566° and 4.106° when the attitude angle is larger than 15°, restricted by the divergent angle of the light source; the system can quickly and stably solve the spatial attitude of the cursor target.

Abstract:In order to improve the rationality of the mixed evacuation simulation of pedestrians and vehicles in complex human-vehicle interaction scenarios, reliable technical support is provided for safe design and efficient operation in such scenarios. Based on the cellular automata model, this paper constructs and develops a pedestrian-vehicle mixed-flow interaction model that takes into account factors such as pedestrians crossing obstacles, vehicles avoiding pedestrians, and vehicle parking on whether pedestrians pass the road or not. This method is used to simulate a typical commercial underground parking lot in Xi'an, and the relationship between the microscopic human-vehicle interaction behavior and evacuation time and safety accidents in the evacuation process in this scene is studied. The conclusion shows that the simulation method constructed in this paper sets independent behavior rules for pedestrians and vehicles and performs nonlinear coupling simulations， which is more in line with the real scene; the simulation results of the scene can be obtained, within the carrying capacity of the lane, the vehicle and the parking space in the lane The influence of interaction is the main factor that causes delays and dangerous situations in the process of mixed traffic between people and vehicles.

Abstract:In order to accurately calculate the three-dimensional dose distribution in a lung phantom photon under a small fied, photon characteristic line hybrid pencil beam model has been proposed. The model is based on the photon characteristic line algorithm to obtain the depth dose for lung phantoms in the reference field. On this basis, the pencil beam kernel of lung phantom is processed by heterogeneous correction, including equivalent depth correction and weighted density correction. Finally, the pencil beam kernel for lung phantom is calculated for obtaining the dose at each point on the central axis for the 6 MV photon beam. The results show that the central axis percentage depth dose obtained by this algorithm is basically consistent with the Monte Carlo simulation results, and the relative error is less than 3% in most cases. Especially in the middle and posterior portion of lung, the average relative error is less than 1%. However, the dose difference between the two methods is obvious at media interfaces and lung anterior portion, and the relative errors decrease with the increase of field size and lung density, with the maximum relative error ranging from 7.8% to 36.9%. Nevertheless, the model can accurately describe the dose distribution in small fields for lung radiotherapy.

Abstract:The signal-to-noise ratio and mean first passage time of asymmetric bistable stochastic resonance (ABSR) system driven by Gaussian colored noise are studied. Based on the unified color noise approximation and two-state model theory, the formulas of mean first passage time and signal-to-noise ratio are derived. The influence of various parameters on signal-to-noise ratio and mean first passage time are discussed, and the parameters are optimized. It is found that stochastic resonance is a non-monotonic function of noise intensity and potential well asymmetry, and the same parameter has different effects on the mean first passage time in two different directions. Simulation and experiment prove that ABSR system has obvious advantages in bearing fault diagnosis.

Abstract:A three-dimensional chaotic map is created with global coupling by substituting the mean field with standard 1-D Logistic map. The complex dynamics and hidden dynamics of coupled system are analyzed and identified by coordinate rotation transformation. The attractors and the bifurcation structure together with the coexistent attraction domain of the coupled system, are shown in respective diagram before and after utilizing the coordinate rotation transformation. The comparison among them shows that the projection of the attractors and the coexisting basin of attraction of the original coupled system on the rotated plane are of triangular symmetry. Co-dimension 1 and 2 bifurcation lines are superimposed on the two-parameter steady-state diagrams. It provides a way to recognize possible coexisting attractors in parameter domains. Both two-parameter steady state distribution diagram and bifurcation lines are independent of coordinate rotation transformation. However, their computation speed would be greatly accelerated with the help of orthogonal transformation.

Abstract:The ground state structures, stabilities, electronic configurations and magnetic properties of Bn X clusters(n=1~11; X=B, Be, Mn) have been systematically investigated by density functional theory. The results show that the X atoms are all located with high coordination number in BnX clusters (n=5-11; X=Be, Mn) , The lowest energy structures of BnBe are low spin multiplicity states with multiplicities of 1 or 2. The average binding energies of BnX clusters are increasing with increased size. When n is the same, the cluster Bn+1 has the highest average binding energy. The energy gaps of BnX clusters indicate that the stability of Bn+1 is increased by X-doping (X=Be, Mn). The Be atom is the acceptor of charges in BnBe clusters. The orbital electrons of Mn atoms in BnMn clusters exhibit significant spd hybridization. The magnetic moments of BnX clusters (X = B, Be) with open-shell structures are mainly contributed by 2p orbitals. The electronic structures of BnMn clusters are all Open shell , and the magnetic moment are mainly contributed by Mn3d orbitals. The coordination number of Mn atoms and the average bond lengths of B-Mn increased with size increasing. Accordingly the magnetic moment of BnMn clusters decreased by the reduction of Mn3d orbital magnetic moment.

Abstract:To elucidate the mechanism of selective growth of Ag nanowires in capping agents, we investigated and the interaction between polyvinylpyrrolidone (PVP) molecules and various Ag crystal surfaces by first-principles calculations. The results show that PVP molecules severely affect the stability of Ag surfaces. Only Ag (200) and Ag (111) facets well maintain their structures upon the absorption of PVP molecules, suggesting their preferential growth in this capping agent. With the increase of PVP concentration, the binding of PVP molecules to the Ag (200) facet becomes stronger than that of Ag (111), which may facilitate the formation of Ag (200) nanostructure. The regulation mechanism of long-chain PVP molecules on Ag (200) nanostructures is mainly governed by the van der Waals force as well as the chemical bonding between ketone oxygen and Ag atoms.

Abstract:In order to overcome the disadvantage of low content of epoxy group and solid in current waterborne epoxy (WEP) emulsion, polyethylene glycol 400 (PEG400) was used as soft section to prepare non-ionec WEP emulsion firstly. Then, the modified non-ionic waterborne epoxy (YWEP) emulsion was synthesized with the side hydrophilic chain extender (Ymer N120). The effects of the dosage of Ymer N120 on the properties of YWEP emulsion and paint film were studied. The results showed that the epoxy group content (represented by epoxy value) of the WEP emulsion could be increased as high as 0.36, and the solid content pof YWEP emulsion increased by 73.3% from 30% to 52% while maintaining the high expoxy value. After curing, the tensile strength of the film increases from 57.3 MPa to 64.8 MPa. The corrosion current density decreased from7.97E-8 mA*cm-2 to 9.99E-9 mA*cm-2. In conclusion, the transfer of hydrophilic groups from the main chain to the side group can effectively improve the properties of waterborne epoxy emulsions, coatings and coatings.

Abstract:In this work, the relationship between solid content and viscosity for light curing slurry was studied. The preparation and printing of high solid content slurry (45 vol%) were realized by regulating rheological priperties of the dispersant. It is found that the processes of degreasing and sintering are key factors and cracks, which directly affect the quality of ceramics. Thus, the degreasing curve was adjusted according to the type of organic matter in the prepared alumina ceramic slurry. In addition, the two-step degreasing methods of pyrolysis in vacuum and carbon removal in air can fully remove the organic mater, which is not easy to peroduce pores. Finally, the alumina ceramic material with the dense structure was obtained. In all, the effects of dispersant type, concentration and alumina solid content on slurry viscosity were systematically analyzed and the degreasing process was optimized. We hope our work can provied an experimental basis for the light curing molding and the perormance optimization of complex structural ceramic materials.

Abstract:In this work, a silver ion coordination polymer material ([Ag2(BPBP)3PW12O40]), based on phosphotungstic heteropolyacid (H3PW12O40) was synthsised by hydrothermal method. Single crystal X-ray diffraction analysis showed that silver ion was connected with organic ligands to form a one-dimensional chain, while Ag-O bonds linked POMs which located on one side of the chain. The chains form to final three-dimensional structure through supramolecular interactions such as hydrogen bonds. We used carbon electrode (GCE) as the working electrode, and investigated the electrochemical properties of the material. Meanwhile, we studied the thermal stability of the material.

Abstract:In order to explore the potential function of the TPS gene family in perfume plant, a comprehensive investigation of the TPS gene family was conducted in the well-known perfume plant Zanthoxylum armatum, and the basic physical and chemical properties, gene duplication type, subcellular localization, evolutionary relationship, chromosome localization and collinear analysis, gene structure and gene expression pattern were analyzed. A total of 53 ZaTPS genes were identified in the whole genome of Z. armatum. The amino acid length of their proteins ranges from 173 to 859 aa, and the molecular weight ranges from 20.21 to 98.44 kDa. The isoelectric point ranges from 4.87 to 9.10, and the subcellular localizations are mainly in the cytoplasm and chloroplast. Phylogenetic analysis showed that ZaTPSs could be divided into six subfamilies, and the members of TPS-a and TPS-b subfamilies were the majority ones. There are 48 ZaTPSs containing motif1 that are conserved in the TPS proteins. Chromosomal localization and collinear analysis showed that 53 ZaTPSs were unevenly distributed on 11 chromosomes, and there were four pairs of tandem repeats, and the collinear analysis revealed that TPS genes in Z. armatum and Citrus sinensis from the same family have closer evolutionary relationships. The gene differential expression analysis based on transcriptome datasets showed that ZaTPSs had tissuespecific expression patterns, with the highest expression level was found in young flowers, followed by husks. These results indicate that ZaTPSs played an important role in the synthesis of husks volatile oil and defense.

Abstract:The purpose of this study was to understand the prevalence, distribution and serotypes of Salmonella from yak sources in Tibet. By collecting yak diarrhea feces in seven districts of Tibet, the bacteria in the samples were isolated and identified by using bacterial culture, biochemical characteristics, and molecular biology methods, and then the isolated strains were serotyped according to serum specific agglutination, and finally, animal infection and HE staining of animal tissue were used to understand the pathogenicity of strains. The results showed that a total of 50 Salmonella strains were isolated from the whole region of Tibet, with a detection rate of 25.13% (50/199). Among them, the separation rate of Lhasa, Qamdo, and Shannan was higher than the other four, and the Ngari area is the lowest; the serotyping results show that 4 serogroups including B group, C1 group, C2 group and D group were isolated. The serogroup includes 18 serotypes including Salmonella Dublin, Salmonella Typhi, and Salmonella Aboni. According to serogroup statistics, among the 4 serogroups, group D accounts for the most serogroups and is a common serogroup; 50 Salmonella strains were dominated by Salmonella, accounting for 20.00% (10/50 ) of all strains; The typing results of Salmonella in various regions show that the number of serogroups and serotypes in each region are different. The results of the pathogenicity test showed that the LD50 of KM mice infected with yak-derived S.dublin was 0.368×108CFU/mL, which was a highly lethal strain. The results of tissue HE staining showed that yak-derived S.dublin could cause systemic damage to the host. Among them, the spleen, lung, intestine and stomach have more severe lesions. The results of this experiment suggest that Salmonella does exist in Tibetan Yak sources, and has a certain trend of prevalence. At the same time, the common serogroups, dominant serotypes and dominant serotypes of Salmonella dublin from yak sources in Tibet have been identified, and the pathogenicity of the dominant serotype was also identified.

Abstract:In order to understand the potential functions of actin in the growth and development of Charophytes, bioinformatics methods were used to analyze the actin gene family in Chara braunii. A total of 16 actin genes were identified in Chara braunii, and they were renamed as CbACT1~CbACT16 according to their order on scaffolds with 361 to 1182 amino acids, and the relative molecular masses ranged form 39 886.71 to 117 256.72 Da, and protein isoelectric point was range from 4.68 to 8.93. Subcellular localization prediction indicated that 15 actin genes were located in the cytoplasm; and only one in the chloroplast. The secondary structure of the actin gene was mainly composed of random coils and α-helices. Only one pair of paralogous genes derived from segmental duplication was found in the collinearity analysis. The phylogenetic results divided actin genes into two subfamilies with the same subfamily tend to have similar exon distribution and more common motifs. Promoter cis-element analysis indicated that 16 actin genes were involved in many biological activities including biotic and abiotic stresses, hormone regulation and light response. Further tissue expression analysis suggested that 16 genes were differentially expressed in four different tissues, indicating that they have different functions in the growth and development of different tissues. Therefore, the actin gene family may be involved in the development of different tissues and response to biotic and abiotic stresses of Charophytes.

Abstract:Jatropha curcas ribosome-inactivating proteins Curcin and Curcin C have N-glycosidase activity, but their in vitro translation inhibition ability is significantly different, which implies that there are also differences in the N-glycosidase activity of the two proteins. In order to explore the structural basis for this difference, this study used trRosetta to predict the tertiary structure of the two proteins, and evaluates the quality of the predicted tertiary structure model through PROCHECK and Qmean.The structure of adenine and adenosine was optimized by Chem3D, and the amino acid composition of Curcin and Curcin C active site was predicted by UCSF Chimera.Finally, AutoDock was used for molecular docking to predict the interaction of two protein model with adenine and adenosine. The docking results showed that the interaction modes between the two proteins and adenine were similar, but the key amino acid Arg of Curcin did not participate in the interaction with the ligand. In addition, the binding energy of Curcin C to adenine and adenosine is lower than that of Curcin, and the difference between the binding energy of Curcin C to adenosine and adenine is also higher than that of Curcin.This result implies that the difference in activity between Curcin and Curcin C is related to the structural features at the active site, and the key amino acid Arg in Curcin C is closer to the binding sites of adenine and adenosine.This will lead to lower binding energy between Curcin C and the substrate, which is more conducive to the catalytic reaction.