Dongwei Qiu

Application of virtual reality technology in bridge structure safety monitoring

Virtual reality technology is an immersive interactive technology which is based on computer technology and data processing technology. From virtual reality users can operate and apperceive all of the various objects in the virtual world and make access to the space and logical information implied among the virtual environment. Bridge approach slabs are designed to function as a transitional roadway to the bridge deck. Because of the stiffness difference and settlement deformation performance difference of bridge abutments and subgrade, it results in a differential settlement on the joint of bridge deck and road pavement which causes the steps or significant changes in lengthwise slope. The bumps and jumps will occur when the high-speed vehicles get across and it leads to the phenomenon of bridge bump. In this paper, the researched object is the bridge approach of Yushuguan Bridge in Beijing, China. Virtual reality technology is used to build the three-dimensional model of the bridge, and on this basis, the advanced safety monitoring of bridge is implemented. The establishment method of three-dimensional bridge scenery is introduced. The terrestrial laser scanning is applied to given precision panorama deformation monitoring of bridge approach. The 3D monitoring method is introduced here. Firstly, establish a high-precision horizontal control network with GPS. Secondly build elevation control network with the digital level. Thirdly achieve 3D model reconstruction of the bridge approach using three-dimensional laser scanner by collecting the point cloud data, registering the laser point cloud data, building triangulation model and generating solid models. Thus we can obtain the 3D image of the bridge approach deformation in a precision and stereo way effectively.

Vehicle routing optimization problem with time constraint using advanced PBIL algorithm

The intelligent optimization algorithm PBIL is applied to VRP. Faced to the concrete problem that the objective function is to minimize the cost and meet the time restriction. And the probability statistics for the road traffic status distributed in working hours is considered to decide the routing. The probability matrix of PBIL algorithm is modified with the quick velocity update strategy of particle swarm optimization algorithm. The modified PBIL algorithm is tested in a Beijing Stone Logistics Company. The good adaptability, validity and stability performance are fully shown by the results.

Three-dimensional virtual scenery construction of tunnel and its application in safety monitoring

Virtual reality technology is used to build the three-dimensional scenery model of the tunnel, and on this basis, the advanced safety monitoring of tunnel is implemented. The establishment method of three-dimensional scenery is introduced. First the tunnels three-dimensional scanning control network is built and then the integrated tunnel is scanned with Trimble VX Spatial scanners. Lastly we build the tunnels three-dimensional model using the obtained point cloud data. Based on the fitting calculation of various cross sections of the tunnel virtual scenery model, the integrated deformation of the tunnel is obtained.

Optimization of Urban Drain Layout Using GIS

The optimization of urban drain layout plays an important role to the protection of water ecosystem and urban environment. The paper puts forward a method to properly locate urban drain using population based incremental learning (PBIL) algorithm. The main factors such as regional containing sewage capacity, sewage disposal capacity quantity limit of drains within specific area are considered as constraint conditions. Analytic hierarchy process is used to obtain weight of single factor, and spatial analysis of environmental influencing factors is carried on based on GIS. The method is applied to actual engineering. The results have proved urban drain layout using GIS and PBIL algorithm excels traditional method and it can protect the urban environment efficiently and ensure the healthy development of water ecosystem successfully.

Landslide monitoring analysis of single-frequency BDS/GPS combined positioning with constraints on deformation characteristics

In order to optimise the selection of landslide monitoring points and save the cost of monitoring, a geological constitutive model was constructed by using 3D laser scanning and geological borehole data to simulate the relationship between rainfall and deformation. Thus, the main occurrence area and maximum deformation of the landslide were determined. Aiming at the deficiency of the single-epoch redundancy of the single-frequency GNSS receiver and the poor accuracy, this paper proposes a single-frequency BDS/GPS combined positioning and monitoring scheme with constraint of deformation features to restrict the search range of single-frequency ambiguity, obviously increase the ambiguity fixed success rate and then improve the BDS/GPS positioning accuracy. By contrast experiments, the landslide area obtained by numerical simulation basically matches with the on-site landslide area. The BDS/GPS combined positioning with constraint is consistent with the deep displacement changes, which can well reflect the displacement of the landslide body and make an early warning of disasters.

Evaluation and Analysis of Dam Operating Status Using One Clock-Synchronized Dual-Antenna Receiver

Higher monitoring cost is the main limiting factor in the application of geodetic receivers in dam deformation monitoring, as the number of receivers applied in one dam is always too large. In this paper, an improved GNSS monitoring scheme is proposed. Firstly, three-dimensional finite element model is built to simulate the main deformation part of the dam, and only one clock-synchronized dual-antenna receiver is used to set the reference and monitoring stations; then, the dam displacement warning standard is determined based on the relationship between the corresponding surface displacement and safety factor of the different mechanical parameter combination; finally, through BDS/GPS dam deformation monitoring system for Lijiaxia in China, the operating status of dam is evaluated. Through comparative analysis, it is found that the scheme is feasible.

An Improved Particle Filter Algorithm for Geomagnetic Indoor Positioning

Geomagnetic indoor positioning is an attractive indoor positioning technology due to its infrastructure-free feature. In the matching algorithm for geomagnetic indoor localization, the particle filter has been the most widely used. The algorithm however often suffers filtering divergence when there is continuous variation of the indoor magnetic distribution. The resampling step in the process of implementation would make the situation even worse, which directly lead to the loss of indoor positioning solution. Aiming at this problem, we have proposed an improved particle filter algorithm based on initial positioning error constraint, inspired by the Hausdorff distance measurement point set matching theory. Since the operating range of the particle filter cannot exceed the magnitude of the initial positioning error, it avoids the adverse effect of sampling particles with the same magnetic intensity but away from the target during the iteration process on the positioning system. The effectiveness and reliability of the improved algorithm are verified by experiments.

Adjacency List Based Multicast QoS Routing Problem Optimization with Advanced Immune Algorithm

QoS problem of multicast with uncertain parameters constrained is a challenging problem for the prevalent multimedia communications in Internet. In this paper the advanced bionic immune algorithm is used to solve the problem. Every node’s priority based adjacency list is designed which guarantees the higher performance path has greater probability to be chosen. Immune algorithm’s personal characteristic such as antibody and antigen considered it has ability to seek some information features or knowledge to optimize the process and restrain the compute evolutionary degradation. The solutions’ fitness is obtained by the concentration mechanism and affinity function of immune algorithm. The immune operator and immune adjust strategy is helpful to the solution evolutionary process. With test on simulation multiple constraints QoS routing problem the advanced algorithm is proved to have high performance and efficiency.

Large Building Overhead Installation Control Surveying

In the process of urbanization, along with a high degree of integration of the intensification of land use and urban architecture function, many large-scale large buildings have appeared which have enormous architectural space and the structure is complex. They are the citys landmarks and are the import integration of urban functions and landscape. During the construction of complex steel structure the high altitude installation need high demand to control surveying. It requires not only the surveying accuracy, precision, but also high surveying techniques on the spatial structure of three-dimensional positioning, docking, and assembly. Conventional planar and high level processing surveying mode cannot meet the construction needs. In this paper the arched surface steel roof truss high altitude installation project of China Tianjin West Railway Station is researched which has north-south length of 394 meters and east to west span 126 meters. The research aims to establish an accuracy of high three-dimensional surveying control network. This paper presents a specific implementation method of control surveying. And though data processing, accuracy evaluation and the analysis of engineering applications results, we verify the correctness of the method. This method support spatial location and geometric characteristics for arched surface of steel roof truss high attitude installation. It ensures the project successfully implemented.

Research on Algorithms Performance about JSP Scheduling

Three typical intelligent evolutionary algorithms are applied on Job Shop scheduling problem which are Quantum algorithm, Genetic Algorithm and Population Based Incremental Learning algorithm. They three algorithms have some common features in computation, encoding strategy and probability application, but with the different problems and different scale sizes of the same problem they show different performance. In this paper we take JSP as example to test their performance difference and analyze their applicability. Two benchmark Job Shop problems are used to fulfill the comparison. The results denote that Quantum algorithm is good in a great quantity of solution individual, GA is excellent in stability and PBIL had good performance in accuracy. The research also makes a reliable instruction on the application or combination of the three algorithms.