Scene and crowd analysis using synthetic data generation with 3D quality improvements and deep network architectures

In this thesis, a scene analysis mainly focusing on vision-based techniques have been explored. The vision-based scene analysis techniques have a wide range of applications from surveillance, security to agriculture. A vision sensor can provide rich information about the environment such as colour, depth, shape, size and much more. This information can be further processed to have an in-depth knowledge of the scene such as type of environment, objects and distances. Hence, this thesis covers initially the background on human detection in particular pedestrian and crowd detection methods and introduces various vision-based techniques used in human detection. Followed by a detailed analysis of the use of synthetic data to improve the performance of state-of-the-art Deep Learning techniques and a multi-purpose synthetic data generation tool is proposed. The tool is a real-time graphics simulator which generates multiple types of synthetic data applicable for pedestrian detection, crowd density estimation, image segmentation, depth estimation, and 3D pose estimation. In the second part of the thesis, a novel technique has been proposed to improve the quality of the synthetic data. The inter-reflection also known as global illumination is a naturally occurring phenomena and is a major problem for 3D scene generation from an image. Thus, the proposed methods utilised a reverted ray-tracing technique to reduce the effect of inter-reflection problem and increased the quality of generated data. In addition, a method to improve the quality of the density map is discussed in the following chapter. The density map is the most commonly used technique to estimate crowds. However, the current procedure used to generate the map is not content-aware i.e., density map does not highlight the humans’ heads according to their size in the image. Thus, a novel method to generate a content-aware density map was proposed and demonstrated that the use of such maps can elevate the performance of an existing Deep Learning architecture. In the final part, a Deep Learning architecture has been proposed to estimate the crowd in the wild. The architecture tackled the challenging aspect such as perspective distortion by implementing several techniques like pyramid style inputs, scale aggregation method and self-attention mechanism to estimate a crowd density map and achieved state-of-the-art results at the time

Completeness of police reporting of traffic crashes in Nepal: Evaluation using a community crash recording system

Objective: Accurate road crash reporting is essential for evaluating road safety interventions and plans. Under-reporting of road traffic crashes, injuries, and fatalities in police records has been widely described. The aim of this study was to apply and evaluate a community crash recording system, and assess the quality of the data in comparison with traffic police data in Nepal. Methods: The crash data collection methodology involved recruiting Local Record Keepers working and living at locations known to be at a high risk of crashes. Six shopkeepers were recruited at three crash locations and trained to complete collision incident forms for crashes occurring over one year on the section of road visible from their premises. Manual traffic volume and pedestrian counts, and spot speed surveys were conducted. Data were compared with District police records for the same period and locations. Results: Over 12 months, 110 crashes were recorded by the Local Record Keepers. Of these, 70 resulted in 145 injuries (5 fatalities, 62 severe, and 78 minor injuries), while 40 resulted only in property damage. Comparable police data recorded 23 crashes, of which 18 crashes resulted in 27 injuries (8 fatalities, 13 serious, and 6 minor injuries), and 5 crashes in property damage only. The difference in recording of fatal and serious injuries was statistically significant (χ2(1) = 19.94, p < 0.001). The police reporting rate was highest for fatalities (62.5%) but only 11.6% and 7.1% for property damage cases and minor injuries respectively, and 3.8% for single-vehicle crashes. Compared to the Local Record Keeper data, the overall police crash reporting rate was 19.7%. Conclusions: Local Record Keepers’ recording of road traffic crashes and casualties is feasible and provides a more complete record than routinely collected police data. The low reporting rate in the police records of minor injury, property damage, and single-vehicle crashes suggest significant underestimation and bias in the reporting of the actual burden of road traffic crashes. Local Record Keeper recording is a viable method for validating police reports

Views of professional stakeholders on readiness for a safe road system in Nepal; an exploratory qualitative study

Road traffic injuries in Nepal are increasing despite being largely preventable. Little evidence exists regarding the barriers and facilitators to a safer road system. This study aimed to explore the perspectives of professionals whose jobs had the potential to influence road safety in Nepal regarding challenges and potential solutions. Semi-structured interviews with eight informants from diverse roles were analysed thematically. Three themes were identified: Modifying behaviours of road users; Road planning, construction and maintenance; and the Governance of roads and traffic. All participants considered the primary cause of crashes to be the negligent behavior of the road users, suggesting that improved knowledge would influence their decisions. Poor road design, building and maintenance, together with poor vehicle standards, and lack of investment and enforcement of existing road safety legislation, needed to be addressed through greater coordination of the agencies. The study identified a range of areas for future inquiry and action

Road safety and heavy goods vehicle driving in LMICs: Qualitative evidence from Nepal

Background: Heavy goods vehicle drivers are an influential driving population in Nepal, with over 90% of goods in the country are transported by road. Due to the time spent on the road, drivers have long periods of exposure to the risk of crash involvement. The study explores the perceptions and experiences of heavy goods vehicle drivers and representatives from their professional association regarding road danger. Methods: We conducted semi-structured interviews with fifteen heavy goods vehicle drivers regularly driving on the East-West highway of Makwanpur District, Nepal. A focus group was conducted with eleven members from a major transportation entrepreneur's association in Nepal. The focus group and interviews were audio-recorded, transcribed, translated, and analyzed using thematic analysis. Results: Four themes were developed- assumptions of blame; perceptions of safety culture in the trucking industry; influence of road infrastructure; and behaviours of road users. The road and traffic environment, enforcement, and the safety culture in the heavy vehicle industry not only influenced the attitudes of the road users towards traffic safety but also legitimized and encouraged behaviours that affect safety. General and industry-related road safety improvements suggested by participants included: making provision for heavy good vehicles parking areas, separating the highway with a median strip, improving crash investigation capacity, conducting road safety awareness and training programs, strictly enforcing the speed limit and laws about driving under the influence of alcohol/drugs, and formulating strategies to create a safe, supportive working environment in the heavy vehicle industry. Conclusion: Heavy goods vehicle drivers and members of the professional association can provide rich information regarding the barriers and facilitators of road risk in Nepal. Their perceptions and opinions can contribute to devising interventions at individual, societal, organizational, and governmental levels, and inform efforts to develop a positive safety culture within the heavy vehicle transport industry

Experience of living near a highway in Nepal: Community perceptions of road dangers in Makwanpur district

Introduction: Road traffic injuries are a major but neglected global challenge. There are high and rising rates of road traffic injuries in Nepal. Most of the studies reporting these injuries in Nepal have used quantitative methods to describe the injury burden. Little qualitative research has been conducted to describe the contexts and social processes surrounding crashes, or public perceptions of risks and potential solutions. The aim of this study was to explore the perceptions of road dangers from communities living alongside a major highway in Nepal. Methods: In this qualitative study we recruited members of neighbourhood development committees and a mother's group to take part in focus groups exploring their views. Data were audio-recorded, transcribed, translated and analysed thematically. Results: Four focus groups were conducted involving 34 participants aged 24-65. Our study findings highlight the challenges faced by people living near a major highway and their fear of getting injured on the road. Five themes that emerged were: risky behaviours of road users, infrastructure for safer behaviour, poor condition and maintenance of roads and vehicles, limited adherence and enforcement of traffic laws, and the need for road safety awareness programmes. Conclusion: The community groups expressed multiple concerns regarding the safety of members of their communities and lived-in fear of death and injury on the road where they lived. There is an urgent need for government agencies to understand these concerns and to take action in relating to infrastructure provision, regulation and behavioural change programmes

Middle mountains forests of Nepal

Publication no. 3201

High mountains and high Himal forests of Nepal

Publication no. 4201

Novel molecular, structural and evolutionary characteristics of the phosphoketolases from bifidobacteria and Coriobacteriales.

Members from the order Bifidobacteriales, which include many species exhibiting health promoting effects, differ from all other organisms in using a unique pathway for carbohydrate metabolism, known as the "bifid shunt", which utilizes the enzyme phosphoketolase (PK) to carry out the phosphorolysis of both fructose-6-phosphate (F6P) and xylulose-5-phosphate (X5P). In contrast to bifidobacteria, the PKs found in other organisms (referred to XPK) are able to metabolize primarily X5P and show very little activity towards F6P. Presently, very little is known about the molecular or biochemical basis of the differences in the two forms of PKs. Comparative analyses of PK sequences from different organisms reported here have identified multiple high-specific sequence features in the forms of conserved signature inserts and deletions (CSIs) in the PK sequences that clearly distinguish the X5P/F6P phosphoketolases (XFPK) of bifidobacteria from the XPK homologs found in most other organisms. Interestingly, most of the molecular signatures that are specific for the XFPK from bifidobacteria are also shared by the PK homologs from the Coriobacteriales order of Actinobacteria. Similarly to the Bifidobacteriales, the order Coriobacteriales is also made up of commensal organisms, that are saccharolytic and able to metabolize wide variety of carbohydrates, producing lactate and other metabolites. Phylogenetic studies provide evidence that the XFPK from bifidobacteria are specifically related to those found in the Coriobacteriales and suggest that the gene for PK (XFPK) was horizontally transferred between these two groups. A number of the identified CSIs in the XFPK sequence, which serve to distinguish the XFPK homologs from XPK homologs, are located at the subunit interface in the structure of the XFPK dimer protein. The results of protein modelling and subunit docking studies indicate that these CSIs are involved in the formation/stabilization of the protein dimer. The significance of these observations regarding the differences in the activities of the XFPK and XPK homologs are discussed. Additionally, this work also discusses the significance of the XFPK-like homologs, similar to those found in bifidobacteria, in the order Coriobacteriales