Identification of critical links under earthquake hazards for highway networks

Critical links are defined as easily damaged links with massive transport in highway networks, which also need intensive improvement. The total travel time increment caused by a link＇s failure reflects its importance and is taken as the measure of importance. Links are subdivided into segments according to their structure features and environments. Each segment＇s unreliability is the probability of its function failure that cannot be recovered within an expected time. The measure of criticality is defined as the expected total travel time increment and can be obtained from the product of importance and reliability. It reflects a links＇ importance and ability to provide continuous service for evacuation and rescues under earthquake situation. Critical links can then be identified from the sequence of their criticality. These measures are calculated in the highway network of earthquake-hit areas in Wenchuan. Results collected in geographic information system （GIS） visualization are consistent with the situation revealed in this earthquake, which indicates that the presented method can be used to identify critical links in advance and give guidance regarding refugee evacuation and facility protection from earthquakes.

The Analysis of Spatial-Temporal Evolution of City Accessibility Based on Highway Network in Henan Province in China

Accessibility is an important tool to evaluate the maturity of a regional traffic network structure which describes the traffic convenience in the traffic network. The paper defines a new accessibility index by using the resident population weighted average value of the sum of inverse of the traveling time distance and time threshold coming from ordinary traffic network, and then uses this accessibility index to analyze the spatial-temporal characteristics of Henan highway network, as well as its evolution patterns from 2005 to 2020. The results show that with the expansion and improvement of Henan highway network, city accessibility level has been significantly improved, spatial convergence is obvious, the cities in the north central are always High-High aggregation area, the cities in the south are always Low-Low aggregation area, gradually forming the characteristics of Northwest high and Southeast low, relative balance between East and West. There is some non-conforming phenomenon in highway mileage growth and improvement of the city accessibility levels, but this situation is being weakened, the highway network layout is gradually rationalized, the spatial distribution of city accessibility and that of population are beginning to converge.

Optimal Retrofit Scheme for Highway Network under Seismic Hazards

Many older highway bridges in the United States(US)are inadequate for seismic loads and could be severely damaged or collapsed in a relatively small earthquake.According to the most recentAmerican Society of Civil Engineers’infrastructure report card,one-third of the bridges in the US are rated as structurally deficient and many of these structurally deficient bridges are located in seismic zones.To improve this situation,at-risk bridges must be identified and evaluated and effective retrofitting programs should be in place to reduce their seismic vulnerabilities.In this study,a new retrofit strategy decision scheme for highway bridges under seismic hazards is developed and seamlessly integrate the scenario-based seismic analysis of bridges and the traffic network into the proposed optimization modeling framework.A full spectrum of bridge retrofit strategies is considered based on explicit structural assessment for each seismic damage state.As an empirical case study,the proposed retrofit strategy decision scheme is utilized to evaluate the bridge network in one of the active seismic zones in the US,Charleston,South Carolina.The developed modeling framework,on average,will help increase network throughput traffic capacity by 45%with a cost increase of only$15million for the Mw 5.5 event and increase the capacity fourfold with a cost of only$32m for the Mw 7.0 event.

Geohazards and risk assessment along highway in Sichuan Province, China

Geohazards along highways are the main natural hazards that could affect the safety and operation of highway systems.Understanding the risks faced by highways in areas affected by geohazards is an urgent problem to be solved.This study used historical geohazard events from Sichuan Province and highway network data to propose a geohazard risk index that reflects the risk geohazards along highways.Furthermore,this work applied the entropy method and expert scoring to calculate the weight of the index.The spatial distributions of landslides,debris flows,collapses,and unstable slopes along the highways were analysed based on ArcGIS spatial statistics,and the highway geohazard intensity index were obtained.The relationships between slope,rainfall,vegetation coverage,rock type,land use,and incision depth with geohazards were analysed,and the highway geohazard susceptibility index was calculated by the weighted information method.Based on the intensity and susceptibility index,we obtained a geohazard risk index which can better evaluate the risk of highways,and made a highway geohazard risk map to aid the prevention and mitigation of geohazards along highways and assist with highway network planning.

Economic Assessment of Planned Projects in Highway Network Planning

This paper presents a method of economic assessment for planned projects in the process of highway network planning. Economic assessment method is being done on the basis of cost benefit analysis, and the cost and benefit calculation methods are discussed respectively.

Towards better entity linking

As one of the most important components in knowledge graph construction,entity linking has been drawing more and more attention in the last decade.In this paper,we propose two improvements towards better entity linking.On one hand,we propose a simple but effective coarse-to-fine unsupervised knowledge base(KB)extraction approach to improve the quality of KB,through which we can conduct entity linking more efficiently.On the other hand,we propose a highway network framework to bridge key words and sequential information captured with a self-attention mechanism to better represent both local and global information.Detailed experimentation on six public entity linking datasets verifies the great effectiveness of both our approaches.

HAM:a deep collaborative ranking method incorporating textual information

The recommendation task with a textual corpus aims to model customer preferences from both user feedback and item textual descriptions.It is highly desirable to explore a very deep neural network to capture the complicated nonlinear preferences.However,training a deeper recommender is not as effortless as simply adding layers.A deeper recommender suffers from the gradient vanishing/exploding issue and cannot be easily trained by gradient-based methods.Moreover,textual descriptions probably contain noisy word sequences.Directly extracting feature vectors from them can harm the recommender’s performance.To overcome these difficulties,we propose a new recommendation method named the HighwAy reco Mmender(HAM).HAM explores a highway mechanism to make gradient-based training methods stable.A multi-head attention mechanism is devised to automatically denoise textual information.Moreover,a block coordinate descent method is devised to train a deep neural recommender.Empirical studies show that the proposed method outperforms state-of-the-art methods significantly in terms of accuracy.