Ontario Ministry of Transportation

About: Ontario Ministry of Transportation is a government organization based out in Toronto, Ontario, Canada. It is known for research contribution in the topics: Poison control & Asphalt. The organization has 4652 authors who have published 3882 publications receiving 59011 citations.

Numerical simulations of tidally cued vertical migrations of flatfish larvae in the North Sea

Abstract: A coupled Eulerian–Lagrangian Hybrid Ecological Model was applied to model the transport of flatfish larvae at different scenarios of tidally cued activity. Hydrodynamic data were supplied by a two-dimensional hydrodynamic model of the southern North Sea and were used as input in a Lagrangian particle model in which the flatfish larvae were represented by particles, which responded differently to tidal cues—in this case, hydrostatic pressure. It was used to investigate the interference of vertical migration, in phase with the tidal rhythm, with the specific circulation pattern of the North Sea, by comparison with passive particle advection and diffusion. Instead of what was anticipated after tests in a simple one-dimensional tidal flow, the horizontal advection was not increased, which would allow a greater distance between spawning ground and nursery area. Rather, tidally cued vertical migration turns the direction of transport towards the nearest coast in the North Sea. This is caused by the phase difference between the onshore component of the water velocity and the along-shore component in this area. Tidally cued vertical migration would also be a very efficient mechanism to enter the Wadden Sea through a tidal inlet. The application of the present model looks promising but needs fine-tuning and calibration with real larval distributions and behaviour during the transport phase.

Effect of Inclination Angle on the Heat Transfer Performance of a Two-Phase Closed Thermosyphon under Low-Temperature Conditions

Abstract: In this study, a series of laboratory investigations were performed to examine the heat transfer performance of a two-phase closed thermosyphon (TPCT) with different inclination angles under low-temperature conditions. A stainless steel TPCT with ammonia as the working fluid was tested with inclination angles ranging from 0 to 90° from the horizontal. In order to simulate low-temperature conditions, the temperature in the jacket of evaporator section was controlled at −0.5°C, and the temperature in the jacket of the condenser section was changed from −0.7 to −15.0°C. The experimental results show that inclination angle has a significant impact on the heat transfer performance of a TPCT under the experimental conditions, but the inclination angle does not control the startup temperature difference for the TPCT when the inclination angle is more than 0°. A horizontal TPCT has a good heat transfer performance and a small startup temperature difference; however, the thermal semiconduction effect disap...

A Space-Time Network-Based Modeling Framework for Dynamic Unmanned Aerial Vehicle Routing in Traffic Incident Monitoring Applications

Abstract: It is essential for transportation management centers to equip and manage a network of fixed and mobile sensors in order to quickly detect traffic incidents and further monitor the related impact areas, especially for high-impact accidents with dramatic traffic congestion propagation. As emerging small Unmanned Aerial Vehicles (UAVs) start to have a more flexible regulation environment, it is critically important to fully explore the potential for of using UAVs for monitoring recurring and non-recurring traffic conditions and special events on transportation networks. This paper presents a space-time network- based modeling framework for integrated fixed and mobile sensor networks, in order to provide a rapid and systematic road traffic monitoring mechanism. By constructing a discretized space-time network to characterize not only the speed for UAVs but also the time-sensitive impact areas of traffic congestion, we formulate the problem as a linear integer programming model to minimize the detection delay cost and operational cost, subject to feasible flying route constraints. A Lagrangian relaxation solution framework is developed to decompose the original complex problem into a series of computationally efficient time-dependent and least cost path finding sub-problems. Several examples are used to demonstrate the results of proposed models in UAVs’ route planning for small and medium-scale networks.

Application of Complex Network Theory and Genetic Algorithm in Airline Route Networks

Abstract: To cope with increasing customer demand and market changes, airline companies need to organize and manage their route networks in a more cost-efficient way. In addition, the robustness of flight operations against unpredictable accidents such as terrorist attacks and natural disasters has become more important to airlines. In this study, the concepts and techniques from complex network theory are used to model airline route networks, and then an effective and efficient genetic algorithm is developed to optimize airline route networks in terms of network properties that may have crucial roles to play in improving the cost-effectiveness and reliability of airspace systems. The simulation results illustrate that the work reported in this study has a good potential to improve the topology of airline route networks in terms of given network properties such as operating costs and network robustness.