Transport Canada

Real-world testing, whether through naturalistic or test-track driving, cannot generate the test coverage required to prove the safety of autonomous vehicles with acceptable statistical significance. Virtual Testing Environments (VTEs) offer a complementary solution by enabling the creation of challenging safety-critical test scenarios that are difficult to replicate in real-world conditions. To ensure that a VTE is a sufficient representation of the real-world, our previous work proposed the development of a VTE using a digital twin of an actual roadway environment. This VTE can generate synthetic LiDAR scans, which can then be compared to real-world scans used to create the digital twin. We employed chamfer distance and density-aware chamfer distance as the metrics for this comparison. In this study, we implemented this approach on a variety of roadway scenes to investigate how different scene compositions affect the comparison metrics. Our findings reveal that factors such as road surface smoothness, vegetation presence, and the LiDAR’s point of view (elevation) significantly influence the comparison results.

Abstract BACKGROUNDCobalt is a valuable metal whose total annual supply from recycling is projected to be 34 000 t by 2030, primarily from batteries. Supported liquid membrane (SLM) technology is emerging as a promising technology alternative to conventional hydrometallurgy for cobalt recovery.RESULTSThis work featured the development of a novel physics‐based computational fluid dynamics simulation for cobalt extraction from acetate‐buffered synthetic Co–Ni solution in a hollow‐fiber SLM system. The system involved cobalt and nickel, both at 0.167 mol L−1 initial concentration, sodium acetate buffer at 0.5 mol L−1 and pH adjusted to 5.85 with KOH or H2SO4. The process module had 57 m2 active surface area with a single fiber modeled as a cylindrical tube of 200 μm in diameter and 0.85 m in length in the Poiseuille flow regime with a total flow rate of 5.5 L min−1. At the fiber wall, an acidic organophosphorus SLM was present, where ion exchange between Co2+ and H+ occurred. Using experimental cobalt mass transfer rates dependent on Co2+concentration and the acetate pKa, simulation results within 5% of operational data were obtained for outlet Co2+concentration and pH. Parametric effects of feed flow rate and buffer concentration were explored to enhance system design and performance.CONCLUSIONSThe simulation was validated with good fidelity against measurements from an industrial‐scale module. The results show near‐optimal cobalt recovery possible at the test flow rate, even with sodium acetate buffer at 100 mol m−3, about 20% of the trial‐run level. The model is sufficiently general and fundamental, thus readily adaptable to other SLM systems. © 2025 His Majesty the King in Right of Canada. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI). Reproduced with the permission of the Minister of Innovation, Science, and Economic Development.

The navigation system for such a vehicle may use hardware solutions that differ in price, functionality, user-friendliness and problems associated with their operation. The navigation of such an off-road vehicle may be based on: GPS, LoRa wireless communication, and IMU inertial units. However, as the first half of 2024 has shown, this system is experiencing significant disruptions. In extreme situations, it may even be disabled (e.g. because of warfare). Where special-purpose off-road vehicles for PWSN are operated in mountainous terrain, especially on rocky ground with various structures, IMUs are particularly susceptible to errors building up during travel. This article addresses the research on the LoRa technology envisaged for implementation in a navigation system intended for this type of vehicle. Given the foregoing premises, it is crucial to determine the possibility of effective exchange of information in the transmitter-receiver system using the LoRa protocol for purposes of communication in difficult mountainous terrain, in the presence of obstacles, and often under harsh weather conditions. The pilot studies discussed in this article were conducted with the above problems in mind. This article formulates assumptions for a navigation system based on the LoRa standard. Based on the studies conducted by the authors, both the implementation validity as well as the advantages and disadvantages of the solution proposed have been described. The research results imply that the solution in question can be treated as an alternative if the GPS signal is either unavailable or significantly disturbed, and its additional features provide significant support for PWSN using off-road vehicles.

In the Czech Republic, floating car data currently serve as a supplementary source of information on traffic conditions. This data source may become advantageous in the future, particularly due to its availability and independence from fixed infrastructure. Although this data includes several parameters related to congestion, its validity has not been sufficiently documented. This article focuses on analyzing the relationship between vehicle speed, travel time, and congestion detection to verify the quality and reliability of this data. Through statistical analyses, consistent correlations between speed parameters and travel time were identified, confirming their suitability for further traffic modeling. On the other hand, parameters related to congestion detection exhibit significant variability, indicating the need for more in-depth analysis and the application of more sophisticated modeling methods.

In this research, the effect of using waste glass powder (WGP) as a partial replacement for cement on the flexural behavior of reinforced-concrete-beams (R-C-Bs) was investigated. For this aim, a total of 9 specimens were produced, and investigational experimentations were conducted to evaluate the flexural performances of R-C-Bs. Subsequently, the cement was partially replaced with WGP with weight percentages of 0%, 10%, 20% and 30%. Furthermore, the influence of stirrup spacing (SS) in the longitudinal reinforcement on productivity was also examined. The results presented indicate that the efficient WGP percentage might be considered as 10% of the partial replacement of cement. Increasing the WGP percentage within the cement by more than 10% may considerably reduce the ability of the R-C-Bs, noticeably when the lengthwise reinforcement proportion is high. Additionally, the experimental shear strengths of R-C-Bs attained from the flexural tests were compared with the shear capacities estimated using Eurocode 2 and ACI 318 − 19 regulations. It was concluded that the shear capacities calculated with ACI318-19 are much lower than the values calculated with EC2. Furthermore, it may be observed that ACI318-19 calculates the shear capacities of R-C-Bs to be 15–51% higher than those of the experimental results. Furthermore, the Digital Image Correlation (DIC) was used to study the flexural cracks/micro-cracks in R-C-Bs. Comparisons indicate that DIC has similar deformations and fracture properties for the R-C-Bs as the experimental tests. Finally, it was considered that the optimum consumption quantities determined by the results of the present research would be a guide for future investigation.

Abstract A growing and increasingly globalised human population, requiring the movement of goods and commodities, is placing increasing demands on the maritime industry, resulting in a concurrent increase in global shipping activities. This has consequences for the marine environment, particularly for species vulnerable to the impacts of vessel traffic. For example, vessel collisions can result in sub‐lethal or fatal injuries for marine mammals, whilst vessel noise can cause acoustic masking that effectively reduces an animal's listening space, potentially impacting their communication, navigation and foraging capacity. While a number of parallel approaches to mapping collision risk to large whales have arisen, these methods vary in their focus, usually on either co‐occurrence, collision probability, or probability of mortality. However, little attention has been given to the implications of methodological choice and data selection on subsequent risk predictions. To assess differences between these approaches, we used a standardised input dataset comprised of telemetry‐point data from tagged bowhead whales, and satellite‐based Automated Identification System (AIS) data of spatial vessel movements covering the Davis‐Baffin Arctic Marine Area. We applied this data to eight different, previously published analyses for deriving areas of vessel risk. We found that the choice of risk mapping approach affected the location, and total area, identified as ‘high risk’, and that more computationally complex approaches did not necessarily equate to different predictions. There was considerable variation in the total area of ‘high risk’ predicted within each map (range = 20–42,246 km2). Synthesis and Applications. The results underscore the importance of methodological transparency, informed data selection and careful interpretation when predicting collision risk. We provide practical recommendations for enhancing transparency when predicting risk, and discuss choice of approach suitable for different situations or management applications. It is critical that managers and policy makers are aware of the implications of applying different approaches when interpreting risk evaluation outputs.

Agent-based modeling and simulation is a method well suited for studying individual behavior and interactions among members of a population connected by social networks. Although the development of such simulation models can be relatively complex, it is even more challenging to develop models that are empirically valid. In the case of reverse logistics, the sophisticated and difficult-to-predict behavior of consumers must be modeled. In this paper, an agent-based simulation model of consumer behavior and interactions was configured to conduct a case study of the voluntary deposit collection program for wine bottles in the Val-Saint-François region of Quebec. As this collection program was officially launched in 2019, two empirical samples were obtained to test the validity of the model and study how social interactions such as word of mouth contributes to the success of the collection program. The first sample represents the amount of glass collected during the last 26 weeks of 2019, while the second sample covers the first 13 weeks of 2020. Having observed an increase in collection rates between 2019 and 2020, word of mouth was introduced into the model to explain this phenomenon. Statistical tests show that the model is indeed valid with the inclusion of diffusion of awareness, as the simulation results are significantly consistent with the empirical data. The validation of the model demonstrates the viability of using multiple heterogeneous data-sources to configure a simulation model based on the Theory of Planned Behavior without using Structural Equation Modeling.