Browsing by Author "AbouRizk, Simaan"

Now showing 1 - 4 of 4
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    A Combined Discrete-Continuous Simulation Model for Analyzing Train-Pedestrian Interactions
    (IEEE., 2016) Ekyalimpa, Ronald; Werner, Michael; Hague, Stephen; AbouRizk, Simaan
    Computer simulation has defined itself as a reliable method for the analysis of stochastic and dynamic complex systems in both academic and practical applications. This is largely attributed to the advent and evolution of several simulation taxonomies, such as, Discrete Event Simulation, Continuous Simulation, System Dynamics, Agent-Based Modeling, and hybrid approaches, e.g., combined discrete-continuous simulation, etc. Each of these simulation methods works best for certain types of problems. In this paper, a discrete-continuous simulation approach is described for studying train and pedestrian traffic interactions for purposes of decision support. A practical operations problem related to commodity train operation within two small towns in Alberta, Canada, is then used to demonstrate the implementation of the approach within the Simphony.NET simulation system. Simulation results generated are presented.
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    A Prototype for Simulating the Kinematics of Crane Rigging Oscillatory Motion using Simphony.Net
    (IEEE., 2016) Ekyalimpa, Ronald; Chiteri, Martin Akolo; AbouRizk, Simaan
    Crane hoisting operations represent a significant portion of the work scope on construction sites, especially those that have adopted a modularized approach to construction. Creating metrics that can be used in the automation of these processes can result in higher jobsite efficiencies from a safety and productivity perspective. This study created a virtual simulation environment prototype that can be experimented with to generate the required metrics for crane hoisting automation. The equation of motion for this oscillatory motion was first defined. Thereafter numeric solutions to this equation were explored from a continuous simulation perspective using Simphony.NET. Then prototyping of simple pendulum motion was implemented using the continuous simulation services in Simphony.NET and verification done using Mathematica.
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    Simulation of Mobile Falsework Utilization Methods in Bridge Construction
    (IEEE., 2012) Liu, He-Xu; Siu, Ming-Fung Francis; Ekyalimpa, Ronald; Lu, Ming; AbouRizk, Simaan
    Scaffolds and shoring systems are generally referred to as the falsework in bridge construction, serving as temporary structures to support bridge span construction. The falsework cost usually accounts for 50-70% of the total project concrete budget. Falsework installation and advancing methods can greatly impact the completion time and actual cost. Thus, simulation can be instrumental in planning bridge construction operations and analyzing various options by evaluating postulated “what-if” scenarios. This study uses a previously constructed bridge in Sweden as a case study to test three feasible construction sequence alternatives. One of these alternatives was implemented on the actual construction of this bridge. Modeling was performed in Simphony, which captures the unique construction sequence requirements and constraints, resulting in project durations for each alternative. Results from simulation experiments were corroborated by the construction engineer who had worked on the bridge project in terms of the advantages that each alternative method possesses.
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    Updating Geological Conditions using Bayes Theorem and Markov Chain
    (IEEE., 2015) Zhang, Limao; Ekyalimpa, Ronald; Hague, Stephen; Werner, Michael; AbouRizk, Simaan
    Due to cost constraints, geological conditions are investigated using boreholes. However, this means conditions are never known exactly, particularly for deep and long tunnels, because uncertainties exist between neighboring boreholes. Simulation can deal with underlying uncertainty, and offers benefits to project planners in the development of better alternatives and optimization. This research developed a simulation model using Bayes theorem and Markov chain, aiming to continuously update geological conditions of one-meter sections for tunnel construction, given the geological condition of the previous one-meter section is observed as construction progresses. An actual tunneling project is used as a case study to demonstrate the applicability of the developed methodology. The impacts are analyzed and discussed in detail. The simulation results show that continuous updates during construction can significantly improve prediction of project performance by eliminating uncertainty in the original assumption. The model can be expanded to predict results of future geologic exploration programs.