Abstract:Taking a suspension bridge with a streamlined girder of 1 660 m span as engineering background and using the methods of wind tunnel test and numerical simulation of CFD, this paper studies three main factors affecting the flutter stability of long-span suspension bridges, namely the main cable space form, aerodynamic shape of the girder section and height of central stabilizer, and then the mechanism of aerodynamic countermeasures is discussed. The results show that the influence of main cable layout on the flutter critical wind speed of bridge structures is mainly caused by the change of the torsional frequency of bridge structure according to the layout of main cables, which affects the critical wind speed of bridge structures. Appropriately increasing the ratio of width to height of the main girder section can effectively improve the flutter critical wind speed of bridge structures. Setting an appropriate height of central stabilizer can effectively improve the flutter critical wind speed of streamlined girder section with horizontal separation plates. The major effect of vortices generated near the central stabilizer is to generate the vertical aerodynamic force of streamlined main beam, leading to the increase of vertical movement degree of the main girder section and the suppression of torsional movement degree of the main girder section. Thus, the flutter stability of the streamlined girder section is improved.

Abstract:To investigate the flexural performance of precast UHPC joint beams with tooth block and bolted connection，flexural test was performed on six UHPC joint beams with tooth block and bolted connection（joint beams for short） and two UHPC beams without joints. The effects of bottom-longitudinal reinforcement, steel subplate, and epoxy glue setting on joint on the failure mode, flexural strength, mid-span deflection, top-bottom-side strain of connecting steel plate and joint top-bottom-side longitudinal relative displacement of these joint beams were discussed. The effect of UHPC creep under long-time compressive stress on the pre-tightening force of bolt was analyzed by finite element software ANSYS. The results show two failure modes of UHPC joint beams with different reinforcement ratio of bottom-longitudinal reinforcement, one of which is flexural rupture of UHPC section in the region where flexural rigidity is changed, and the other is joint failure caused by wedge-shaped failure of tooth block. The effect of joint-painted epoxy glue on the flexural behavior of joint beams is negligible, and steel subplate setting on the side of joint can not only increase the flexural strength of joint and flexural performance of connecting plate, but also reduce the mid-span deflection of joint beams and joint top-bottom-side longitudinal relative displacement. The UHPC creep under long-time compressive stress can reduce the pre-tightening force of bolt by 24.7%.

Abstract:In this study，the Dongting Lake Bridge II was chosen as engineering background to investigate the effects of the central buckle on the end displacement of suspension girder. Considering the geometric nonlinear effect，three finite element models of the suspension bridge were established. Based on the FE model and considering multiple driving conditions, the effect of central buckle on the dynamic characteristic of the suspension bridge and end displacement under vehicle excitation was investigated. It is shown that the central buckle can significantly increase the stiffness of the suspension bridge，and it seems to govern the longitude modal displacement at the end of the girder. Moreover, the transient analysis was performed to investigate the vehicle-induced dynamic response of the suspension bridge. Furthermore, the effects of the central buckle on the longitude modal displacement in the end of girder were evaluated. The results show that the central buckle can be designed to decrease the peak value of the dynamic response of the girder. However, it increases the cumulative displacement at the end of the girder.

Abstract:Based on the existing experimental results, the dynamic response of RC beams under impact loading is divided into local response stage and overall response stage. As RC beams are vulnerable to shear failure during the local response stage, this study investigates the transient response of the components in this stage. Thus, the effect of inertial force and reverse reaction on the internal force distribution at the local response stage is also discussed. Based on the basic principles of force equilibrium and parametric analysis results, a computing method for the internal force of RC beams is proposed. The results show that both the inertial force and negative reverse reaction affect the internal force distribution of beams during the local response stage, and the reverse reaction is approximately linear to the span-depth ratio and peak impact force. The assumption that the distribution of inertial force is linear can well reflect the actual force state of the beam.

Abstract:To study the seismic performance of high ductile concrete (HDC) short columns failed in shear-bond mode，seven HDC short columns and one RC short column were tested under pseudo static load. The effects of axial load ratio and stirrups ratio on the hysteresis behavior, shear capacity, deformation capacity and energy dissipation capacity of the HDC short columns were studied. The experimental results indicate that all the RC short column and HDC short columns were failed in shear-bond，the concrete cover of the RC short column was severely crushed after the bond cracks were fully developed. For the HDC short columns，the bond cracks were effectively confined by the fiber bridging effect and thus no crushing of HDC covers was observed，which indicated the HDC short columns were failed in shear-bond with ductility. Compared with the HDC short column，the deformation capacity and energy dissipation capacity of the HDC short columns were significantly improved. The increase of ultimate displacement was 43%~112% and the cumulative energy dissipation increase at the ultimate displacement was 39%~184%. In addition， the drift ratios of HDC short columns were larger than that of the RC column in different performance levels，which was good for achieving performance based seismic design.

Abstract:In this paper, a 10-story RC frame structure satisfying the current design codes was taken as a study example, and the structural response regulation under different site condition subjected to earthquake actions was simulated and calculated by SAP2000. Four kinds of cases namely considering the rigid foundation assumption without the influence of stiffness effects of the infill walls, soil-structure interaction without the influence of the stiffness effects of the infill walls, rigid foundation assumption together with the influence of the stiffness effects of the infill walls, and soil-structure interaction together with the influence of the stiffness effects of the infill walls, were examined in the dynamic time history analysis, respectively, and the seismic performance of this structure was studied comparatively. The comparison of the results showed that:（1）For the RC frame structure under rare earthquakes, considering the SSI effect with the stiffness of infill walls has negative influence on the structural response of the inter layer drift ratio. The structure with the rigid foundation assumption is not safe when the stiffness effect of the infill walls is not considered.（2）For structural collapse analysis, considering the stiffness effect of the infill walls with the SSI effect obviously generates the structural plastic deformation concentrated on the bottom story and decreases the peak values of the collapsed structure. The softer site soil results in the lower peak values of the collapse. It is suggested that designers should increase the ductility of columns to ensure the deformation demands under seismic action.

Abstract:The concrete core walls with steel plate bracings are simulated by finite element software ABAQUS, and the simulated results are in good agreement with the test results. The effects of loading process，aspect ratio, coupling beam steel ratio，corner column steel ratio，concealed column steel ratio and concealed bracing steel ratio for the shear lag are discussed, and the minimum effective flange width for various conditions is obtained. The results show that the effective flange width be reaches the minimum value when the core wall yields. The shear lag effect weakens as long as the aspect ratio increases, and thus the value of be increases. The reinforcement ratio and steel ratio have little impact on be，but be increases with the effect of span-depth ratio of the coupling beam. The axial load ratio is also helpful for the growth of be. Increasing the steel ratio of the corner column and concealed bracing increases be，but the effect of the concealed column steel ratio is not significant.

Abstract:The interface slip of simply-supported steel plate-concrete composite slabs under bending moment was analyzed by using the reduced stiffness method, the function of the interface shear with shear span was established, and then the calculation formula of deflection under single-point loading and two-point loading was deduced. Meanwhile，assuming the steel plate-concrete composite slab as a type of reinforced concrete with the steel bars anchored at the bottom，based on the stiffness formula of the reinforced concrete beams, the design method of flexural stiffness of composite slabs. was obtained and the mid-span deflection of the composite slab was derived by the material mechanic formula. The slip effect between the steel plate and concrete was considered by using the method of the modified width reduction of steel plate. These two methods were compared with the experimental results of 9 simply-supported composite slabs, which were in good agreement. Both the two methods can be used to calculate the deflection of composite slabs, the second method has some safety reservation, and the second method is convenient to the design and application of the practice engineering.

Abstract:A novel type of steel buckling-restrained braces (BRBs) is proposed, in which the core plate is perforated, termed as PBRB. PBRB is composed of a perforated core plate, 2 filling plates and restraining plates, which are assembled by bolts. Quasi-static cyclic tests and the corresponding numerical analyses were carried out on 3 specimens with different configurations of holes, the effect of which on the seismic performance was investigated emphatically. It was showed that PBRBs had stable hysteretic properties, high ductility and energy dissipation capacity. The compressive deformation of perforated core plates was found to be composed of compression, shear and flexural deformation. The slenderness ratio of "stub columns" is a critical parameter that affects seismic performance of PBRBs. An oversized slenderness ratio can lead to relatively poor seismic performance. A conservative design limit for the slenderness ratio was proposed based on the experimental results. A method with good accuracy has been proposed to evaluate initial stiffness of PBRBs.

Abstract:In both the analysis and appraisal of existing spatial structures，structures should be modeled in accordance with the actual geometric shapes. A function of correlation coefficient was recommended to model the correlated deviation of nodal positions according to the geometric characteristics of the existing spatial structures, and the approach to calculating model parameters was given. Based on the correlation analysis of nodal positional deviations，a new method of reckoning the structural geometric shapes by sampling nodal positions was proposed. In the proposed method, the deviation distributions of unmeasured nodal positions can be inferred from sampling data where expectations should be calculated by conditional distributions and variances would be estimated as upper limits of the confidence intervals from the cross validation. Then, using the calculated deviation distributions, uncertain geometric models can be established to analyze and assess the existing spatial structures. Through calculating the shell shape by sampling the nodes and analyzing its overall stability, it concludes that the method based on nodal positions correlation analysis meets the actual case. The proposed method was applied to reckoning the geometric shape of a reticulated shell structure，and the nonlinear static stability analysis was carried out. It is shown that the proposed method can give reliable results and apply to the appraisal of existing spatial structures.

Abstract:Wind turbines vibrate under the excitation of environmental loads and rotor movement in normal operating conditions, and vibrations of the tower affect the service life of such system. In order to analyze the vibration and dynamic characteristics of the wind turbine during startup and shutdown process, vibration of a 1.5 MW turbine tower was monitored for a long term. First-order natural frequencies and damping ratios of the wind turbine were identified utilizing a data-driven stochastic subspace identification method. Monitoring data revealed that the wind turbine usually operated near the rotation speed of grid connection. In addition, obvious resonance at the turbine startup was noted as it surpassed the rotation speed of grid connection, but was not apparent at the turbine shutdown. Modal identification results revealed that the first-order natural frequencies varied slightly under different operating conditions, while the damping ratios were found to be smaller when the wind turbine started up, and its rotation speed surpassed that of grid connection, which were found to be greater at turbine shutdown. In addition, the characteristics of different vibration phenomena in the turbine during startup and shutdown processes were explained with the Sommerfeld effect. Our findings contribute to the field of vibration analysis and allow for more efficient optimization of dynamic parameters in wind turbines of similar design.

Abstract:Mountainous areas are the regions where downburst often occurs. In order to study the wind field characteristics of continuous mountains under the downburst, the influence of height, distance and other geomorphic elements on the wind field of the characteristic position was analyzed by Large Eddy Simulation (LES). The results show that when the height of the mountain was greater than 50 m, the radial extreme wind speed at the foot of the mountain and the crest gradually reduced as the height of the mountain increasesd. The speed-up effect at the crest was significantly affected by mountain height，and the acceleration factor was larger near the ground，while the acceleration effect was larger in the upper space at the foot of mountain. For the two mountains, the rear mountain had less effect on the turbulence intensity of the front mountain, but the turbulence of the rear mountain ranges increased firstly and then decreased with the augment of the mountain distance and augmented gradually with the height increases of the front mountain.

Abstract:The three-dimensional packing problem has been widely used in many fields.At present，the research on three-dimensional packing for offline rectangular objects is extensive.The research on online 3D packing outside the rectangular body is relatively simple.This paper proposes a three-dimensional packing problem of online constrained variable size spheres.And gives a solution to the problem，Make the cells into cells by loading them into the appropriate rhombohedral dodecahs and then loading them；Furthermore，according to the weighting method，the competition ratio in the bounded environment can be obtained.It solves the problem of packing on the assembly line with different weights of the same type of goods.

Abstract:The geometric active contour（GAC） model can avoids reparameterization based on the geometry characteristics， but it has the poorly ability in dividing a fuzzy boundary. In contrast， by maximizing the grayscale difference between the target and the background， the Chan-Vese（CV） model can effectively differentiate the fuzzy boundary. Based on the aforementioned consideration， the GAC-CV hybrid model is proposed， where the edge of the image and the region information are merged into the same "energy" function， and the various segmentation strategies are adopted for different segmentation targets to improve the capture ability of the concave edge.The segmentation results about thewater-repellent images of seven grade of the insulators show that the hybrid model has superior segmentation performance， and the detection rate of water bead highlights is as high as 95%.

Abstract:Considering the issue of reasonably selecting the strength index in different construction procedures of high-speed railway cut slope, borehole shear test (BST) was carried out on silty soil. The influence of loading addition way on in situ strength characteristics of silty soil was studied by adding different normal stress levels and unloading to a certain stress after adding a higher normal stress (herein called preloading), taking Hajia high speed railway as engineering background. The results show that in-situ stress-strain curves of silty soil generally present the variation characteristic of weak hardening. Preloading greatly contributes to the shear strength, mainly in cohesion. With the increase of preloading from 0 kPa to 400 kPa, cohesion increases distinctly in the increment of 18.7~51.8 kPa, while internal friction angle rarely varies. Both cohesion and its increment after the preloading are nearly negatively linear to the water content of silty soil, but a critical preloading may occur when water content reaches to a certain value. The cohesion is positively linear to preloading, which should be fully used to back calculate the required preloading according to the safety factor that the project should satisfy. It provides a reference to engineering design and construction.

Abstract:In order to realize automatic recognition of the jewelry，a set of jewelry recognition system based on machine vision is designed，and the corresponding algorithm is proposed. In this study，8 different kinds of jewels are used as experimental samples.The color threshold segmentation method is used by the componentsofG+R. Binary image is filtered with a template of 27×27 pixel. A method of edge extraction is proposedbased on values of pixels combined with the threshold by the 2×2pixel window.The features of areaand the distancefrom image centroid to edgeare extracted.The values of area are judgedwithin the limits of given values，and the cross-correlation algorithm is applied to the values of distance feature. The experimental results show that the precision rate of the method is 100% and average recognition time for each is about 3 seconds，which meets the requirements of practical application.

Abstract:A 2D DEM-FDM coupled numerical modelling scheme was proposed to simulate a single stone column in soft clay. The discrete granular materials which firm the stone column can be better simulated by the DEM model, which is beyond the capability of continuum approaches. In the proposed numerical model, the stone column was represented by discrete rigid blocks based on the Voronoi tessellation, the surrounding clay was represented by the continuum Mohr-coulomb material. The settlement，bugling deformation，failure process and the involved complicated interactions between the stone column and surrounding soil were well captured by the proposed numerical model. The accuracy of the proposed model was verified using experimental model test results. The consistency between the numerical simulation and model test results shows a good potential for the proposed modelling scheme to further study the load-deformation and failure behavior of soft soils reinforced by stone columns. The limitations of the proposed model were also discussed in this study.

Abstract:In the OCT image of coronary artery，the catheter imaging at different locations largely impacts the detection results of other objects inner the vessel. To decrease the effects of catheter and obtain an efficient and accurate image information，an automatic method of rapid detection and identification of catheter regions is proposed. Circle center coordinate transforming area is firstly defined and circumferential intensity detection model was built under polar coordinate. Then，the feature data describing the current detection circle are constructed，and the obtained feature data are statistically analyzed. To deal with the distortion problem of catheter imaging，dynamically transforming the center coordinate and radius of the detection circle is proposed. The method is applied to the detection of catheters in 4 groups of OCT images （about 300 per group）. The accuracy was 97.35% with the situation of containing a small amount of residual blood，and the processing time was about 0.7 seconds.

Abstract:With the development of cloud storage technology，the cloud storage platforms meets the storage and management requirements of big data. However，when the amount of data and the number of users are further expanded，the system performance requirements of cloud storage are gradually improved，and the data storage management technology in the current cloud storage environment needs to be deeply researched and improved. Considering that the application of the actual cloud storage cluster for optimization research is very vulnerable to the platform environment，this paper implements a hierarchical cloud storage simulation model named TCSS in CloudSim，while implements a three-level hierarchical organization structure of storage devices，then the functional structure such as data I/O service processing and data storage management has been established. In this paper，all the extended function modules have been integrated into the CloudSim layer of the CloudSim simulation tool. Based on the given TCSSmodel，Users can complete the modeling and testing of the cloud storage optimization strategy proposed by themselves.

Abstract:In order to solve the problem of soil resistance reduction caused by the existence of slopes, this paper carried out a comparison test of the horizontal loading model on the foundation piles in the flat soil and different slope conditions of the clay soil. The test results show that the load deformation curve and internal force variation of the laterally loaded piles under two conditions are basically the same, but the bearing capacity of the piles located on the slope body is obviously reduced. However, the reduction effect is closely related to the slope angle and pile location in the slope. The influencing factors of the soil resistance reduction effect are further quantitatively analyzed, and the quantitative relationship between the reduction effect and the position and slope angle of the pile in the slope is proposed. On this basis, the p-y curve formula of lateral loaded piles that can consider the soil resistance reduction effect at the slope is established by reasonably correcting the ultimate soil resistance and initial stiffness of the slope. The comparison between the theoretically calculated value and the existing experimental results shows that these two agree well with each other.

Abstract:The BLSTM-CRF neural network model is built to improve the performance of Chinese domain named entity recognition in the absence of feature engineering.First，the CBOW model was used to carry out recursion training of negative sampling on the corpus of People's Daily from January to June in 1998 to generate a low-dimensional dense word vector table for the query needs；then，based on Boson entity corpus，the word vector was formed by querying the word vector table，and the information feature vector of the words in the corpus was obtained by using the Jieba participle；finally，the combined word vector and word information feature vector are input into BLSTM-CRF deep neural network.Experimental results show that the model can be well identified for the Chinese domain named entities，and the F1 value is up to 91.86%.

Abstract:There are many kinds of sensors in coal mine，especially gas，air volume，roof pressure and other sensors，which play an important role in safety warning. In order to make the software of sensors easy to maintain，this paper puts forward an upgrade system of underground sensors based on STM32. The principle of scattered loading of target code by MCU and other key technologies such as breakpoint continuation are mainly used. Practice has proved that the system can solve the problem of updating and replacing the downhole sensor software without losing safety.

Abstract:In order to study the torsional behavior of longitudinal special-shaped piles, a longitudinal cross-section pile torsion elasto-plastic analysis model was built in homogeneous soil ground. The model considers variable cross-section of the special-shaped pile, and the pile-soil system along the depth direction is divided into finite segments. Based on the T-φ curve at traditional circular pile top and the torque-angle distribution curves along the pile shaft, the corresponding formula was obtained. The calculation program was run through MATLAB software. The torsional behaviors of longitudinal special-shaped piles and uniform circular piles were comparatively analyzed. The optimum design parameters for tapered pile were analyzed. The results show that the torsional performance is influenced by the top pile diameter obviously. The torsional performances of longitudinal cross-section special-shaped pile are relatively better than those of uniform circular pile with the same concrete usage. The torsional bearing capacity of tapered pile increases with the increase of the shear modulus, diameter, and taper angle, and the torsional bearing capacity is improved to 3~5 times under two times diameter.

Abstract:With the rapid increase of the number of non-motor vehicles，the problem of theft is becoming more and more prominent，and the traditional anti-theft measures are insufficient. The paper designs a non-motor vehicle anti-theft system based on RFID technology，which essentially avoids non-motorized vehicles. Anti-theft problem. The intelligent detection algorithm in the system has higher accuracy and performance，and has lower misrecognition rate and rejection rate based on RFID technology. In practical applications，the platform also has automatic and long-distance recognition capabilities，and when it detects stolen non-motor vehicles，it will trigger a linkage alarm to protect the property security of the people.

Abstract:To determine the impact of climate data and material parameter on building envelope simulation results，and to investigate the difference between coupled heat and moisture transfer model （HM model） and the widely used Glaser model，15 groups of exterior walls were constructed in WUFI Plus with 20 representative cities of the North America typical climate zones as external conditions，and simulated for the annual HVAC demand，indoor hygrothermal environment and the exterior walls hygrothermal performance. Correlation analyses between the simulation results and the climate parameters showed that the exterior air temperature，solar radiation，relative humidity and drying rain affected the related simulation results to varying degrees. Comparison among the 2 HM and 3 Glaser model groups distinguished with specific material parameters，showed that liquid water dependent parameters，variation of moisture content dependent heat and moisture transport properties had significant influence on the simulation results. The HM model simulation in North America typical climate zones could contribute implications to the studies on climate data，material parameters and evaluation methods for the heat and moisture process in building envelope.

Abstract:Reliable and applicable communication network is an important part of smart home. A typical home communication network can be composed of terminal，main gateway，server and client.The terminal adopts the ZigBee protocol microprocessor CC2530 launched by TI company，and forms the ZigBee LAN，including nodes，routers and coordinators.The main gateway adopts mediatech 7688 hardware +OpenWrt system，and USES the open platform of China mobile Internet of things as the server background to realize data interaction.The feasibility of the intelligent home communication network architecture is verified through the test of temperature and humidity status display and remote operation of platoon and plug.

Abstract:At present，China's investment in the construction of smart cities is increasing，and various kinds of platform software emerge in an endless stream，but a variety of problems also emerge. How to completely eliminate the information isolated island and form a real information interconnection and interoperability still needs further study.Against this background，this paper analyses the current situation of smart city construction，introduces the concept of micro-service design，gives the implementation method of micro-service application in software platform construction，and finally discusses the advantages and disadvantages of micro-service.

Abstract:Due to the collection and identification of application layer information， more accurate performance analysis and intrusion detection can be realized， which is of great significance for improving network security and performance. For this reason， the identification of application protocol under SSH tunnel is studied. First， analyze the SSH protocol to determine what information can be obtained from the connection establishment phase. Then， based on the extended functions created by the traffic monitoring infrastructure， the acquired information is analyzed， and information related to the application layer protocol included in the SSH data is obtained. Finally， the SSH connection is monitored on the real network and the monitoring results are analyzed. The research results show that through the analysis of SSH traffic data， application layer protocols including port and client software can be identified to improve the detection of security vulnerabilities such as brute force password attacks.

Abstract:This paper takes snort as the core and builds the defense system of APT attack-based intrusion detection module based on hierarchical distributed network， and proposes a new OTN dynamic matching algorithm. Firstly， the characteristics of APT attacks are introduced. Then a set of snort-based defense detection model for APT attacks is proposed. Based on the original three-step dynamic adjustment algorithm of snort， a new dynamic matching algorithm is proposed. Finally， a new dynamic matching algorithm is proposed. Using the original dynamic matching algorithm and the new dynamic matching algorithm to do the contrast experiment， the final result is compared and analyzed. and the conclusion is that the distributed network detection model using the new dynamic matching algorithm can better meet the needs of network security protection.

Abstract:As for the adversarial data samples which indeed exist in real-world datasets，on the one hand，they can mislead data classifiers into correct predictions which results in poor classification. On the other hand，appropriate applications of the adversarial data samples can distinctly improve the generalization of data classifiers. However，most of existing classification methods do not take the adversarial data samples into account to build corresponding classification models. An adversarial classification algorithm （ACA） based on attacks on the labels of data samples which aims to obtain outperformed classification performance by learning the adversarial data samples is proposed. In a given dataset，a certain percentage of data samples are chosen as adversarial data samples，namely the labels of these chosen data samples are substituted by the other labels which are different from the original labels of the chosen data samples. A SVM model can be generated by using the support vector machine（SVM） algorithm to training the given dataset which contains the adversarial data samples. And the first-order gradient information on the output error of the generated SVM with respect to the input samples can be computed. The input samples can be updated by embedding the first-order gradient information into the original input samples. Consequently，adversarial SVM （A-SVM） can be generated by using the SVM alg-orithm again to train the updated input samples. In terms of theoretical analysis and experimental results on UCI real-world datasets，the mathematically computed first-order gradient information not only provided a positive relation between the outputs and the inputs of a classifier，but also indeed can improve the actual classification performance of A-SVM.