Evidential grammars: A compositional approach for scene understanding. Application to multimodal street data

Automatic scene understanding from multimodal data is a key task in the design of fully autonomous vehicles. The theory of belief functions has proved effective for fusing information from several sensors at the superpixel level. Here, we propose a novel framework, called evidential grammars, which extends stochastic grammars by replacing probabilities by belief functions. This framework allows us to fuse local information with prior and contextual information, also modeled as belief functions. The use of belief functions in a compositional model is shown to allow for better representation of the uncertainty on the priors and for greater flexibility of the model. The relevance of our approach is demonstrated on multi-modal traffic scene data from the KITTI benchmark suite.     

Social and spatial equity effects of non-motorised accessibility to retail

The evaluation of social and spatial effects of how accessibility is distributed between individuals is key to studying equity issues in transportation. However, the establishment of minimum accessibility requirements and the identification of accessibility thresholds for population groups remain as key methodological barriers. This paper contributes to addressing these shortcomings by using Retail Mobility Environments as an analytical and geographical concept to identify advantageous and disadvantageous non-motorised accessibility to retail for different population groups. The city of Zaragoza, Spain provides the spatial laboratory for experimentation, and the study focuses on four target groups: the young employed, the young unemployed, seniors, and adults. The results reveal social and spatial inequalities in the distribution of non-motorised accessibility in Zaragoza, with marked negative effects on the young unemployed and adults. On the other hand, seniors and the young employed are the groups that benefit from the current setup. It is finally discussed on the capacity of the proposed methodology for exploring both social and spatial inequalities, for establishing minimum accessibility requirements, and for identifying accessibility thresholds according to different population groups. Furthermore, the convenience of linking equity issues to non-motorised accessibility is also highlighted.     

Cyber-harassment victimization in Portugal: Prevalence,fear and help-seeking among adolescents

Cyber-harassment is one of today's problems in adolescent health. This study aimed to determine the prevalence of cyber-victimization among Portuguese adolescents. It also explored its nature, patterns and victim's reactions of fear and help-seeking. A representative sample of 627 adolescents, aged 12–16, enrolled in schools from northern Portugal and Azores answered an online survey. Cyber-victimization was widely experienced by these adolescents, mainly among older adolescents. Results evidenced a high prevalence rate of adolescents (66.1%) double involved as both cyber-victim and cyber-aggressor. Although not all adolescents reported fear (37%) or sought help (45.9%), persistent victimization increased fear. In turn, fear increased help-seeking behaviors. Cyber-victims were more afraid encountering unknown cyber-aggressors (vs. acquainted) and when victimized by older males (vs. younger females cyber-aggressors). Younger girls reported more fear and more help-seeking behaviors while older boys were more often victim-aggressors. The subgroup of victim-aggressors was both the target of a higher diversity of cyber-victimization behaviors than the victim-only subgroup and also engaged in fewer help-seeking behaviors. Those adolescents who sought help considered it helpful. Implications for educational, social and political practices are discussed.     

Which Chinese cities are more inclusive and why?

China's household registration system allows local governments to control migration by limiting migrants' eligibility to local public services. Many cities exclude migrant residents from important social benefits, which reduces labor mobility and contributes to the socioeconomic gap between migrants and urban natives. This study measures the extent of China's local migration restriction from the perspective of inclusive provision of public services and explains cross-city disparities. We define urban inclusiveness as the extent to which migrants can access social benefits provided locally and construct an urban inclusiveness index using factor analysis. We find significant cross-city differences in urban inclusiveness toward migrants. Statistical analyses suggest that local fiscal capacity and labor demand, instead of cultural tradition, are the major determinants of urban inclusiveness. We further use the gap between the inclusiveness toward high- and low-skilled migrants to measure local skill-based migration selectivity. We find that more developed cities, i.e., cities with larger populations, higher levels of gross regional product per capita, and greater shares of industrial sector, are more selective based on migrants' skills, while cultural openness does not help bring down skill-based selectivity. Our research suggests an instrumental view of migrants in China's urban policy that contributes to social inequality and the lack of labor mobility, which can restrict China's development in the long term.     

Looking for trouble: A multilevel analysis of disagreeable contacts in online social networks

Identifying characteristics of troublemakers in online social networks, those contacts who violate norms via disagreeable or unsociable behaviour, is vital for supporting preventative strategies for undesirable, psychologically damaging online interactions. To date characterising troublemakers has relied on self-reports focused on the network holder, largely overlooking the role of network friends. In the present study, information was obtained on 5113 network contacts from 52 UK-based Facebook users (age range 13–45; 75% female) using digitally derived data and in-depth network surveys. Participants rated their contacts in terms of online disagreement, relational closeness and interaction patterns. Characteristics of online troublemakers were explored using binary logistic multilevel analysis. Instances of online disagreement were most apparent in the networks of emerging adults (19–21 years). Contacts were more likely to be identified as online troublemakers if they were well connected within the network. Rates of offline and Facebook exchanges interacted such that contacts known well offline but with low rates of Facebook communication were more likely to be identified as troublemakers. This may indicate that users were harbouring known troublemakers in a bid to preserve offline relationships and reputational status. Implications are discussed in terms of an individual's susceptibility to undesirable encounters online.     

Anxiety about internet hacking: Results from a community sample

Electronic data breaches and internet “hacking” are common threats to individuals' security, frequently reported in news media. Our aim was to determine the anxiety and stress associated with possible internet hacking. We utilized an online survey, sampling 304 adult participants. We assessed resting anxiety – that is, “worry, anxiety, or stress” reported at the beginning of the survey. We also assessed anxiety related to possible data breaches. Internet hacking (or “Data breach”) anxiety was rated with somewhat greater severity than resting anxiety. Higher resting anxiety was not related to data breach-related anxiety, indicating that data breach anxiety is specific. Demographic characteristics and secure online practices were not associated with internet hacking anxiety. Anxiety related to data breaches is important to study. However, behaviors intended to protect internet security are rare; education and intervention is needed to reduce anxiety and increase internet security.     

Low-complexity high-quality adaptive deblocking filter for H.264/AVC system

Blocking artifacts always appear on the reconstructed image, particularly in a low bit-rate video coding system. This paper presents an adaptive offset method to improve image quality for H.264 decoding. First, the histogram statistic is used to analyze the correlation between the offset and the filtering performance. The best filtering performance can mostly be found at the position of three offsets. Second, the best offset can be searched for with the minimum SAE (Summation of Absolute Error) among the three candidates. This algorithm can not only keep low computations, but it can also obtain good filtering quality. The average performance can be improved about 0.25 to 0.45 dB (decibels) higher than the original H.264 deblocking filter. The blocky effect on the decoding image can be smoothed in vision.     

Newspaper coverage of artificial intelligence: A perspective of emerging technologies

The focus of the study is on how newspapers have covered artificial intelligence (AI) over the past decades. Analyzing 1776 news articles culled from four mainstream newspapers (i.e., the New York Times, Washington Post, the Guardian, and USA Today), the study examined the general landscape of media coverage as well as media framing of the topic through a mixed methodology (i.e., automatic content analysis and manual coding). Fourteen major topics (e.g., regulation & policy, risk & weapon) emerged from the accumulated articles. Furthermore, the study found that journalists have used different framing devices, including lexical compounds and argumentation patterns, to frame AI as a sophisticated, powerful, and value-laden issue. Also, different actors (e.g., research communities, governments, business sectors) combined to constitute a complex network in the media discourses.     

The politics of “Unfriending”: User filtration in response to political disagreement on social media

This article examines exposure to political disagreement on social media and user filtration in response to it. Popular arguments suggest that social media sites prevent exposure to political disagreement either through algorithmic filtration or selective affiliation. Another popular argument says that when users are exposed to political disagreement on social media, they filter it from their feeds by “unfriending”/“unfollowing” or “hiding” the author. We put these narratives to the test by examining (a) the relationship between social media use and exposure to political disagreement and (b) the factors that predict user filtration in response to political disagreement. Results from analysis based on a nationally representative sample of Colombian adults in urban areas show that (a) engagement with news and public affairs content on social media is positively associated with exposure to political disagreement and (b) the amount of disagreement users are exposed to is not related to user filtration in response.     

Cross-cultural and gender associations with anxiety about electronic data hacking

We investigated the impact of data hacking on clinical anxiety and worry. 389 American and 216 Korean college students were recruited, surveyed using the Generalized Anxiety Disorder-7 (GAD-7) questionnaire, and adapted GAD-7 specifically assessing data hacking anxiety. Using confirmatory factor analysis with measurement invariance testing, Koreans scored higher on severity of hacking anxiety items, and differently on factor loadings. Controlling for other variables such as age and prior hacking victimization, cultural group status remained a robust predictor for hacking anxiety. Hacking anxiety in both cultural groups was higher in women than men. Results are placed into the context of theory on information privacy concerns and cross-cultural differences on such concerns.