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Vehicle to vulnerable road user (VRU) crashes occupy a large proportion of traffic crashes in China, and crash injury severity analysis can support traffic managers to understand the implicit rules behind the crashes. Therefore, 554 VRUs-involved crashes are collected from January, 2017, to February, 2021, in a city in northern China, including 322 vehicle-pedestrian crashes and 232 vehicle-bicycle crashes. First, a descriptive statistical analysis is conducted to investigate the characteristics of VRUs-involved crashes. Second, the extreme gradient boosting (XGBoost) model is introduced to identify the importance of risk factors (i.e., time of day, day of week, rushing hour, crash position, weather, and crash involvements) of VRUs-involved crashes. The statistical analysis demonstrates that the risk factors are closely related to VRUs-involved crash injury severity. Moreover, the results of XGBoost reveal that time of day has the greatest impact on VRUs-involved crashes, and crash position shows the minimum importance among these risk factors., Author(s): Shubo Wu [1]; Quan Yuan (corresponding author) [2]; Zhongwei Yan [1]; Qing Xu [2] 1. Introduction Crash injury severity analysis plays a crucial role in traffic crash analysis, which [...]

Drivers tend to have more range anxiety compared with driving traditional fuel vehicles if they are driving battery electric vehicle (BEV) with a long trip. Range anxiety could potentially have negative effect on driver's emotions and behaviors. In order to understand this behavior and improve the related safety issues, this paper will focus on BEV drivers' study in China. A survey on BEV drivers' actual range anxiety as well as the effect of range anxiety on drivers' behaviors is conducted in this research. Levels of feelings and attitudes of the interviewees are quantized with Likert scales using mathematical tools of the relationship. Safety buffer is defined as a measurement of the period given range anxiety starting to significantly intervene in driver's operation. The research reveals the proportional quotative relationship between BEV drivers' safety buffer and the mileage of trip. Factors, including driving experience, satisfactory level of recharge accessibility, and resistibility to emotions, are found to be significant contributing factors to influence the perceived range anxiety level of BEV drivers. This research will provide implications to the future study on the interface design of BEV., 1. Introduction Battery electric vehicle (BEV) drivers typically tend to have more range anxiety compared to traditional fuel vehicle drivers. High levels of range anxiety can potentially lead to negative [...]

This study sets out to investigate the effects of traffic composition on freeway crash frequency by injury severity. A crash dataset collected from Kaiyang Freeway, China, is adopted for the empirical analysis, where vehicles are divided into five categories and crashes are classified into no injury and injury levels. In consideration of correlated spatial effects between adjacent segments, a Bayesian multivariate conditional autoregressive model is proposed to link no-injury and injury crash frequencies to the risk factors, including the percentages of different vehicle categories, daily vehicle kilometers traveled (DVKT), and roadway geometry. The model estimation results show that, compared to Category 5 vehicles (e.g., heavy truck), larger percentages of Categories 1 (e.g., passenger car) and 3 (e.g., medium truck) vehicles would lead to less no-injury crashes and more injury crashes. DVKT, horizontal curvature, and vertical grade are also found to be associated with no-injury and/or injury crash frequencies. The significant heterogeneous and spatial effects for no-injury and injury crashes justify the applicability of the proposed model. The findings are helpful to understand the relationship between traffic composition and freeway safety and to provide suggestions for designing strategies of vehicle safety improvement., 1. Introduction As a primary component of roadway transportation system, the safety performance of freeways has attracted much attention in the field of traffic safety research in recent years [1-3]. [...]

Water quality management is important in cage culture of the Asian swamp eel (Monopterus albus). However, it is difficult to manage water quality after a large number of eels have died within the cages. The present study seeks to solve this problem by establishing a method to judge and maintain water quality. To this end, the effect of temperature and eel body weight on the water quality and microorganisms after the death of Asian swamp eels have been examined in the laboratory. The results showed that the changes in water quality parameters were similar at different temperatures and different eel weights. For example, at 26°C, the water quality started deteriorating at 5–7 days after death, which corresponded to the oxygen consumption stage. This was followed by the anaerobic decomposition stage at 11 days after death, at which point the self‐purification process of the water body was initiated. Under a lower temperature of 18°C, the oxygen consumption stage and, therefore, the overall decomposition process were extended. Proteobacteria, Bacteroidetes and Verrucomicrobia were the dominant phyla detected during the decomposition process, but the relative proportions of the dominant families differed across the stages. Based on these findings, we have provided innovative suggestions for water quality detection and management in Asian swamp eel production: (i) at a water temperature of 16–23°C, the following measures should be taken to deal with dead eels 15 days after the introduction of seedlings: (a) at an ammonia nitrogen level higher than 2 mg/L, the bodies present at the bottom of the cage need to be fished out with a net. However, when the ammonia nitrogen level is not higher than 2 mg/L, the whole cage should be sprayed with detoxifying substrate improver or Bacillus powder, according to the instructions, to improve water quality. (ii) At a water temperature of 23–30°C, the above measures should be taken on the 6th day after the seedlings are released, provided the critical value of ammonia nitrogen is 1.57 mg/L. An important limitation of this study is that water exchange was not possible under the laboratory experimental conditions, and the deterioration of water quality caused by eel death may have been alleviated due to water exchange between the inside and outside of the cage. [ABSTRACT FROM AUTHOR]

With the dramatic development of social network applications, such as the Facebook, Twitter, and MySpace, privacy-preserving problem is getting increasingly concerned. Apart from node information, researchers have found that structure information can also leak data providers' privacy, especially in weighted social networks. However, most of the existing private-preserving schemes focus on a single aspect. The comprehensive consideration introduces two challenges. On one hand, the different anonymity demands of node and structure information lead to the collision of different design criteria, which is called as consistency matching problem. On the other hand, the simple combination of existing schemes may introduce large amounts of unnecessary changes, which makes the published information meaningless. Thus, we must find the balance between anonymity demands and changes, which is called as optimization trade-off problem. In this paper, we propose a γ-Strawman privacy-preserving scheme in weighted social networks to solve these challenges. To address consistency matching problem, we propose a greedy algorithm based on a user trade-off metric. For optimization tradeoff problem, a closeness edge-editing technology is considered, which can change the private information slightly. Finally, we evaluate our scheme on real-world datasets, the experimental results show that the γ-Strawman scheme is efficient. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

User's security and privacy are core issues of network applications. This paper proposes a privacy protection model to evaluate property risk of users, which takes into account both sensitivity of the property and requester's level of assurance. Furthermore, the sensitivity of the property is evaluated by problem of expectation-maximization algorithm. Experiments show that the optimal size of samples for EM is relatively small, which indicates the high efficiency of the algorithm. The proposed privacy protection model cannot only assist users to do correct authorization, but also benefit the privacy reservation of users in online service. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This article presents the design and implementation of a single‐layer wideband millimeter‐wave circularly polarized (CP) monopulse cavity‐backed antenna based on substrate integrated waveguide (SIW) technology. The antenna consists of a 2×8 array of CP cavity‐backed antenna elements, a 90° 3‐dB coupler, power dividers, and phase shifters. In order to enhance the operating bandwidths, the sequential rotation feeding technology is adopted in the design of the monopulse antenna. To validate the proposed concept, a prototype operating at 42 GHz was fabricated and measured. The measured 3‐dB axial ratio (AR) bandwidth for the sum beam can cover a frequency range from 37 to 46 GHz. The measured gain for the sum beam at the center frequency of 42 GHz is 17.5 dBiC, while the null‐depth of the difference beam is measured to be −36.8 dB. The proposed monopulse antenna has advantages of low‐cost, easy‐fabrication, and easy integration with planar circuits. [ABSTRACT FROM AUTHOR]