Imran Mahmood

Verifying Dynamic Semantic Composability of BOM-Based Composed Models Using Colored Petri Nets

Model reuse is a promising and appealing convention for effective development of simulation systems as it offers reduction in development cost and time. Various methodological advances in this area have given rise to the development of different component reusability frameworks such as BOM (Base Object Model). But lack of component matching and weak support for compos ability verification and validation, in these frameworks, makes it difficult to achieve effective and meaningful reuse. In this paper we focus on Compos ability verification and propose a process to verify BOM based composed model at dynamic semantic level. We suggest an extension to the BOM components, to capture behavior at a greater detail. Then we transform the extended BOM into our proposed Colored Petri Nets (CPN) based component model so that the components can be composed and executed at an abstract level. Subsequently we advocate to use CPN tools and analysis techniques to verify that the model satisfy given requirements. We classify the properties of a system among different groups and express the models requirements by selecting some of the properties from these groups to form requirement specification. Also we present an example of a Field Artillery model, in which we select a set of properties as requirement specification, and explain how CPN state-space analysis technique is used to verify the required properties. Our experience confirms that CPN tools provide strong support for verification of composed models.

Fairness Verification of BOM-Based Composed Models Using Petri Nets

Model reuse is a promising and appealing convention for effective development of simulation systems. However it poses daunting challenges to various issues in research such as Reusability and Composability in model integration. Various methodological advances in this area have given rise to the development of different component reusability frameworks such as BOM (Base Object Model). However, lack of component matching and support for composability verification and validation makes it difficult to achieve effective and meaningful reuse. For this reason there is a need for adequate methods to verify and validate composability of a BOM based composed model. A verified composed model ensures the satisfaction of desired system properties. Fairness, as defined in section II, is an important system property which ensures that no component in a composition is delayed indefinitely. Fairness in a composed model guarantees the participation of all components in order to achieve the desired objectives. In this paper we focus on verification and propose to transform a composed BOM into a Petri Nets model and use different analysis techniques to perform its verification. We propose an algorithm to verify fairness property and provide a case study of a manufacturing system to explain our approach.

An Agent-Based Environment for Simulation Model Composition

As Modelling and Simulation gains more popularity, the demand on reducing time and resource costs associated with development and validation of simulation models has also increased. Composing simulation models of reusable and validated simulation components is one approach for addressing the above demand. This approach requires a composition process that is able to support a modeller with discovery and identification of components as well as giving feedback on feasibility of a composition. Software agents are programs that can with some degree of autonomy perform tasks on behalf of a user or another program. In a Multi Agent System (MAS) autonomous agents interact and collaborate with each other in order to solve complex problems that are beyond the individual capabilities or knowledge of each agent, thus providing modularity and scalability. The objective of this work has been to develop a Multi Agent System for discovery and composition of BOM (Base Object Model) based simulation models, which provides the flexibility and adaptability to test and assess, amongst others different discovery and composition methods and techniques. The MAS that we developed is based on the JACKTM Intelligent Agents and executes a rule-based process for discovery and composition of BOMs. Our preliminary results indicate its feasibility, portability, adaptability and flexibility.

Smart Solutions for Smart Cities: Using Wireless Sensor Network for Smart Dumpster Management

Wireless sensor networks are being deployed in civil, military, environmental and health applications due to their versatility, low cost and rapid communication capabilities. Smart cities would be able to manage their services with the help of information and communication technologies relying to a great extent on wireless sensor networks. In this paper, we propose the use of wireless networking technologies to optimize the solid waste management through the use of smart dumpsters equipped with waste level sensors. These sensors can read the level of waste as being low, medium or high. The HC-SR04 ultrasonic sensors, selected for this study, yield the level sense results that can be used at the municipal authority server to deploy just the sufficient number of trucks and staff for waste collection. In addition, path planning and routing can be done to minimize the time and fuel needed. We have developed a simulation model and performed simulation for optimization of fuel and time.

Analyzing Emergency Evacuation Strategies for Mass Gatherings using Crowd Simulation And Analysis framework: Hajj Scenario

Hajj is one of the largest mass gatherings where Muslims from all over the world gather in Makah each year for pilgrimage. A mass assembly of such scale bears a huge risk of disaster either natural or man-made. In the past few years, thousands of casualties have occurred while performing different Hajj rituals, especially during the Circumambulation of Kaba (Tawaf) due to stampede or chaos. During such calamitous situations, an appropriate evacuation strategy can help resolve the problem and mitigate further risk of causalities. It is however a daunting research problem to identify an optimal course of action based on several constraints. Modeling and analyzing such a problem of real-time and spatially explicit complexity requires a microscale crowd simulation and analysis framework. Which not only allows the modeler to express the spatial dimensions and features of the environment in real scale, but also provides modalities to capture complex crowd behaviors. In this paper, we propose an Agent-based Crowd Simulation & Analysis framework that incorporates the use of Anylogic Pedestrian library and integrates/interoperate Anylogic Simulation environment with the external modules for optimization and analysis. Hence provides a runtime environment for analyzing complex situations, e.g., emergency evacuation strategies. The key features of the proposed framework include: (i) Ability to model large crowd in a spatially explicit environment at real-scale; (ii) Simulation of complex crowd behavior such as emergency evacuation; (iii) Interoperability of optimization and analysis modules with simulation runtime for evaluating evacuation strategies. We present a case study of Hajj scenario as a proof of concept and a test bed for identifying and evaluating optimal strategies for crowd evacuation

Composability Verification of Real Time System Models Using Colored Petri Nets

The discipline of component based modeling and simulation offers promising gains including reduction in development cost, time, and system complexity. It also promotes (re)use of modular components to build complex simulations. Many important issues in this area have been addressed, but composability verification is still considered a daunting challenge. In our observation most of the component based modeling frameworks possess weak built-in support for the composability verification, which is required to guarantee the correctness of the structural, behavioral and temporal aspects of the composition. In this paper we stage a practical approach to alleviate some of the challenges in composability verification and propose a process to verify composability of real-time system models. We emphasize on dynamic semantic level and present our approach using Colored Petri Nets and State Space analysis. We also present a Field Artillery model as an example of real-time system and explain how our approach verifies model composability.