2 research outputs found

    Sustainable Conflict Resolution: Modelling, Analysis, and Strategic Insights

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    New methodological contributions for modelling and analyzing conflicts evolving over time are developed to provide strategic insights into the sustainability of equilibria. More specifically, key characteristics of evolving conflicts are identified in order to recognize a long-term conflict. A unique procedure for assessing robustness of equilibria is introduced to measure the possibility of deviation from these potential resolutions. By considering partial achievement of an option or course of action, attempts for a decision maker to improve an equilibrium situation can be formally taken into account. As a consequence of these advancements, certain challenges found in an ongoing Canadian energy conflict can be formally investigated, better understood, and eventually resolved. There have been many successes in the modelling and analysis of strategic conflicts using the Graph Model for Conflict Resolution. But, as illustrated by the re-occuring Great Canadian Hydroelectric Power conflict, many important obstacles remain. This conflict, between the Canadian province of Newfoundland and Labrador (NL) and the province of Quebec (QC), continued for over half a century, passing through several distinct stages and raising questions that are difficult to answer using the standard graph model approach. These questions are addressed in this thesis, and the new models and techniques developed are then demonstrated using the NL-QC conflict. A framework for conflict characterization is suggested to help analysts understand the different stages of a conflict that evolves over time. Particularly problematic are instances when a conflict reaches an equilibrium, maintains it for some time, and then re-starts and shifts to another equilibrium. Traditional conflict resolution models, which analyze only a single round of a conflict during a specific period of time, cannot explain such observations. The conflict characterization is specifically designed to provide input parameters for models of conflicts that evolve over time. A new representation, the enhanced preference graph model, includes decision makers' preferences, allowing for an expeditious and intuitive interpretation of some stability questions. One major issue is the sustainability of equilibrium. In a conflict that continues for half a century, it is possible for an equilibrium to be reached, maintained for a few decades, but then to fall apart. Can the resolution of strategic conflicts be made sustainable? The concept of Level of Freedom is introduced to provide a measure of equilibrium robustness that facilitates the ranking of equilibria based on their relative robustness and offers insight into this form of long-term stability. In a graph model, a decision maker's strategy is a selection of his or her options. Hence, an option is either taken or not selected within a given state. To make a graph model easier to link to reality, a modelling structure is proposed that allows binary (two-level) options to be replaced by options with more than two levels. This new structure facilitates the representation of preference in the modelling stage and the understanding of conflict evolution within the analysis stage. Combined with concepts relating to the robustness of equilibria, the utilization of multi-level options makes a graph model more expressive of reality and easier to understand

    Tunnel air quality modeling: a case study of the Souk Sagheer traffic tunnel, Makkah, Saudi Arabia

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    Traffic tunnels have become increasingly popular in modern cities as a way to ease traffic congestion and overcome natural barriers. However, traffic tunnels present significant environmental and health issues due to the elevated levels of pollutants inside the tunnels, poor visibility, and smoke caused by accidents. In this research, a critical review of the recent literature on air pollution modeling in traffic tunnels and on the ventilation systems used in tunnels is presented. In addition, an air quality modeling concept that has been applied to the Souk Sagheer Traffic Tunnel in Makkah, Saudi Arabia, is also presented. This tunnel is bidirectional and has a forced ventilation system. The level of air pollution inside the tunnel, especially the carbon monoxide (CO) concentration, has been reported to exceed the permissible limits. The tunnel is particularly congested with traffic during the pilgrimage season and has different modes of operation at different times of the year. In the present work, the current status of the tunnel is simulated using a one-dimensional model that takes into consideration the effects of the forced ventilation and the piston action of vehicles. The developed model that validated with measured data, and the Mann-Whitney test shows that the means values of measured and predicted results are equal at a 7% significance level. The measured results show that during peak traffic times, high concentrations of CO, nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and fine particulate matter often exceed the regulatory limits. SO₂ has the highest ratio of measured to recommended concentration of all of the pollutants considered. In this study, several solution scenarios are simulated, such as improving the current longitudinal ventilation, utilizing a transverse ventilation system, or building a wall to separate the tunnel into two smaller tubes. The simulation results show that building a separation wall between the two directions of traffic will significantly reduce the pollution inside the tunnel. For example, the mean value of CO inside the tunnel is reduced from 43.8 mg/m³ to 12.1 mg/m³ when a wall barrier is introduced. A wall barrier will increase the wind speed and enhance the piston action, thus improving the longitudinal ventilation. Finally, a risk assessment chapter calculates the ratio of exposure and maximum allowable limits by World Health Organization. The ratios are calculated for short exposure level. -- This study is important because it shows that bidirectional tunnels are inefficient to ventilate. Moreover, it shows that for the case of the Souk Sagheer Tunnel, additional rows of jet fan does not seem to solve the air quality problem inside the tunnel. Finally, this paper highlights the necessity to investigate SOx emissions because they seem to be the most polluting inside the tunnel
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