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Zhang H.,Chinese Research Institute of Highway | Zhang T.,Qingdao Urban Planning and Design Research Institute
Wuhan Ligong Daxue Xuebao (Jiaotong Kexue Yu Gongcheng Ban)/Journal of Wuhan University of Technology (Transportation Science and Engineering) | Year: 2013

To better organize the subway transportation and deal with the emergency situations for the planning and operation managers, basic characteristics of subway network should be analyzed and obtained. Based on complex network theory, subway networks are analyzes in terms of cascading failure through matlab simulation methods. The results indicate that deliberate attack has a faster transmission speed than random attack in the diffusion of cascading failure in the urban subway networks, but presents a similar trend in the relationship in the scale of failure and the perturbation amplitude, the effect of deliberate attack is not obvious; multi-target random attack speed up the process of the diffusion of cascading failure in subway networks, but has little effect on the scale of failure. Source

Zhao J.-W.,Shandong University of Science and Technology | Peng F.-L.,Tongji University | Wang T.-Q.,Qingdao Urban Planning and Design Research Institute | Zhang X.-Y.,Shenyang Urban Planning and Design Institute | Jiang B.-N.,Jiangsu Institute of Urban Planning and Design
Tunnelling and Underground Space Technology | Year: 2015

Following economic growth and urban development in China in the past two decades, rapid urbanization have incurred many pronounced problems to many Chinese cities. Since 2000, key areas in many Chinese cities, drawing on valuable urban development experience from America and European countries, flock to conduct master planning of urban underground space (UUS) development. The compiling practice is conducive to the orderly development of urban space and alleviation of increasing human-land conflicts. Through selecting and analyzing the master planning UUS in Qingdao, this paper first investigates the current problems of UUS development and utilization in China, and then analyzes the planning methods and general thoughts of overall underground space layout. In general, the paper presents some current advanced research findings in the master planning of UUS development in China. © 2015 Elsevier Ltd. Source

Li Q.,Qingdao Urban Planning and Design Research Institute | Jiang G.,Ningbo University
Harbin Gongcheng Daxue Xuebao/Journal of Harbin Engineering University | Year: 2013

In order to solve the problem of ineffective incident detection due to the severe shortage of traffic sensors for expressways in China, on the basis of analyzing toll data characteristics, an automatic incident detection algorithm using toll collection data was designed. The algorithm was based on standard normal deviation algorithm. First, in order to reduce the false alarms caused by traffic fluctuations, this paper proposed a traffic data synthetic method based on rolling time series. On the basis of the first step, in order to reduce the false alarms caused by recurring congestion, this paper proposed a modification by comprehensively considering the horizontal time series and the longitudinal time series of traffic parameter data. Furthermore, in order to reduce the false alarms caused by detection logic of the algorithm itself, this paper proposed an improved scheme based on the standard deviation value of traffic parameters and the current traffic flow minus the mean in the data analyzing time window. The proposed algorithm was tested with field data collected from the Hu-Hang-Yong Expressway in China. The test and comparison analysis results indicate that at the same false alarm rate level, the detection rate of the proposed algorithm is significantly better than the standard normal deviation algorithm, the mean time of detection is basically equivalent to that of the standard normal deviation algorithm. Moreover, the proposed algorithm has very strong robustness. Source

Fu Q.,Tsinghua University | Song J.,Ocean University of China | Song J.,Qingdao Urban Planning and Design Research Institute | Mao F.,Tsinghua University | And 3 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2012

Urban socio-economic development and spatial urban expansion has led to the loss and fragmentation of habitat. Global climate change adds to the gravity of these effects. An ecological network describes a network of habitats and connecting corridors that is mapped using habitat suitability and land use/ land cover data. Connectivity within a habitat network ensures a flow of material, energy and information among the various patches, and allows species-movement from inappropriate to appropriate areas. This ensures the abundance of species reaches a dynamic equilibrium at the network level and also means that the disappearance of species from any particular patch does not change the function of the regional ecosystem network. Thus, management of ecological network is an effective measure to counter the loss of biodiversity caused by reductions in habitat quality and area, as well as habitat fragmentation, in the context of rapid urbanization and climate change. The least cost path method is a way to construct and analyze ecological networks based on landscape spatial structure and dynamic biological processes. Based on the understanding that the characteristic of the matrix is one of the important factors determining the movement of species between patches, the least cost path method gives different cost values to different landscape types, and generates a cost surface to substitute the Euclidean space. Therefore, the dispersal paths generated by the least cost method are similar to those of actual species movement. Qingdao city is located in the eastern coastal region of China where the economy is relatively well-developed. The region is also where marine and terrestrial ecosystems meet. In this paper, we propose a wetland ecological network in the Qingdao district based on remote sensing and geographic information systems technology. We evaluate the overall structure of the network and the importance of individual patches using the correlation length index and betweenness centrality index, and use the findings to identify optimal strategies and make recommendations. In this paper, we discuss the following five questions: (1) How to classify landscapes? (2) How to determine the cost value of each landscape type? (3) How to evaluate the importance of each core patch? (4) How to evaluate the importance of stepping stones? (5) What is optimal management strategy for the wetland systems in the study area? The result shows that the network connectivities are very different in terms of threshold levels of path cost. Core patches in Jiao Zhou bay wetlands and Da Gu river have a relatively high degree of importance. Stepping stone patches with a high degree of importance are found in two zones: one comprising Jiao Zhou bay, Jiao Lai river and Wei He river estuary, and the other comprising Jiao Zhou bay and Ding Zi bay. In this paper, we propose a wetland management plan based on an ecological network including one core area, two axes and a ring in Qingdao and its surrounding area, to provide a scientific and quantitative basis for the selection of urban development sites within Qingdao City that simultaneously achieves wetland ecosystem protection. These network construction and evaluation methods can be used for other ecological network analysis. Source

Fu Q.,Tsinghua University | Mao F.,Tsinghua University | Wang T.,Qingdao Urban Planning and Design Research Institute | Yang B.,Tsinghua University | And 2 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2012

Urban socio-economic development and urban spatial expansion has led to the loss and fragmentation of habitat. Global climate change adds to the gravity of these effects. The survival of wildlife species is subjected to enormous pressure due to natural environmental changes and human activities. Agent-based models (ABMs) are computer simulation models analyzing and simulating human or animal behavior through the integration of learning, adaptation, evolution and logical analysis. ABMs study the overall system characteristics by analyzing internal elements of the system (such as the interaction among individual agents, and agents with the environment) with a bottom-up approach. The agents in ABMs can complete given objectives, perceive and respond to changes of the external environment through the default logic control, and respond to stimuli from other agents and the external environment through learning and adaptation functions. This paper designed an agent-based evaluation model of an ecological pattern, which was used to analyze the impact of different woodland patterns on species survival and dispersal. The model focused on the logic control of survival and dispersal of agents, and used the dispersal strategy integrating CRW and LW models, which combines the advantages of these two models. The survival of the agent is control by the age-specified U-shaped survival curve and determination function considering their own energy and environmental risks. The model was developed on the GIS platform, realizing the seamless integration of the agent model and GIS, which could then be applied to real geographical environment simulation. Qingdao is a city located in the eastern coastal region of China where the economy is relatively well-developed. The region is also where marine and terrestrial ecosystems meet. Woodland is mainly distributed in the Laoshan Mountains in the east, the Daze Mountains in the north, and the Dazhu, Xiaozhu and Tiejue Mountains in the south. In the study area, the ecological environment is deteriorating, and various wildlife species are being impacted, with some species being endangered or facing extinction. This paper selected the woodlands in the Qingdao district as the study object, analyzing the effect of different spatial patterns on the survival and spread of woodland species. Simulation results showed that, compared with the original state, species populations and migration have improved significantly under different levels of ecological network framework, and the higher the level of ecological network framework, the more obvious the improvement. The distance between patches had a large influence on the dispersal of simulated species because they were not able to arrive at patches that were far away from the original patch. Therefore, this paper makes the suggestion that an approach integrating wetland and woodland systems could strengthen woodland system functional contact in the study area. It is suggested that the region around Jiaozhou Bay and the mainstream of Dagu River be used to increase the spatial distribution of woodland. Based on the simulation results, suggestions for the woodland ecological pattern construction are given below: (1) ensure that the large woodland can not be destroyed; (2) the wetland system district in the middle of Qingdao is an ideal place for a new woodland construction; (3) the ecological network framework can be used as a spatial reference for an ecological barrier to prevent the spread of urban land into woodland. Source

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