Modeling, Analysis, and Simulation of Two Connected Intersections Using Discrete and Hybrid Petri Nets

Indiana University-Purdue University Indianapolis (IUPUI)In recent decades, Petri nets (PNs) have been used to model traffic networks for different purposes, such as signal phase control, routing, and traffic flow estimation, etc. Because of the complex nature of traffic networks where both discrete and continuous dynamics come into play, the Hybrid Petri net (HPN) model becomes an important tool for the modeling and analysis of traffic networks. In Chapter 1 a brief historical summery about traffic systems control and then related work is mentioned followed by the major contributions in this research. Chapter 2 provides a theoretical background on Petri nets. In Chapter 3, we develop a HPN model for a single signalized intersection first, then we extend this model to study a simple traffic network that consists of two successive intersections. Time delays between different points of network are also considered in order to make the model suitable for analysis and simulation. In addition to HPN models, we also consider discrete Petri nets where their modeling simplicity enables the characterization of the occurrences of all events in the system. This discrete PN is particularly useful to give a higher-level representation of the traffic network and study its event occurrences and correlations. In Chapter 4, we build a discrete PN model to represent a traffic network with two successive intersections. However, we find that the model leads to unbounded places which cannot accurately reflect the dynamics of the traffic in terms of event occurrences. Hence, we introduce the Modified Binary Petri nets (MBPN) to overcome the limitation and resolve the confliction problem when we design our controllers. This MBPN model is a powerful tool and can be useful for the modeling and analysis of many other applications in traffic networks. Chapter 5 gives a summary for each chapter, provides conclusion and discusses future work for both discrete and hybrid Petri nets

High prevalence of multi-drug resistant bacteria in selected poultry farms in Selangor, Malaysia.

Prevalence of multidrug resistant bacteria in apparently healthy chickens from 3 selected poultry farms in Selangor area of Malaysia was investigated. Conventional isolation techniques such as growth on selective media, gram staining and biochemical tests was utilised for the identification of the different bacterial isolates. Antimicrobial sensitivity test was monitored with the disc diffusion assay against 12 antimicrobial agents. A total of 96 Staphylococcus aureus, 48 E.coli, 7 Pasteurella sp. and 6 Salmonella sp. were isolated. All E. coli and Salmonella spp. isolates were multidrug resistant while 77.2% of Staphylococcus aureus and 71.5% of Pasteurella sp. isolates were multidrug resistant. The study further reveled highest resistance to tetracycline while cephatothin as the best drug of choice for treatment of infections caused by the isolates in the study area. Since not only chickens are at risk, this study recommends urgent intervention by regulatory agencies to limit the emergence and spread of these bacteria as well as prudent use of antibacterial agents among farmers in Malaysia

Islamic capitalism: an approaching truth or an expectant panorama for Islamic finance – a case of Pakistan and Malaysia

The investigation of future capitalism in the wake of Islam is rather complicated. The difference of interests and difference of opinions between secular scholars and fiqh scholars can stymie the progress of innovation. Nevertheless, a harmony between their intellectual views can prove to be a boon for encouraging Islamic financial elements. This paper scrutinizes an alternative capitalist structure as one of the basic and fundamental key elements for Islamic finance. In this study, interview-based multi case-study method is used, which is based on qualitative approach. This study concludes that Islam promotes the concept of risk sharing in trading and other financial activities, which may lead to lessen the burden on an individual. However, external factors are playing major roles in both of the countries as conventional system is very strong around the globe

Modeling, analysis, and simulation of two connected intersections using discrete and hybrid petri nets

In recent decades, Petri nets (PNs) have been used to model traffic networks for different purposes, such as signal phase control, routing, and traffic flow estimation, etc. Because of the complex nature of traffic networks where both discrete and continuous dynamics come into play, the Hybrid Petri net (HPN) model becomes an important tool for the modeling and analysis of traffic networks. In Chapter 1 a brief historical summery about traffic systems control and then related work is mentioned followed by the major contributions in this research. Chapter 2 provides a theoretical background on Petri nets. In Chapter 3, we develop a HPN model for a single signalized intersection first, then we extend this model to study a simple traffic network that consists of two successive intersections. Time delays between different points of network are also considered in order to make the model suitable for analysis and simulation. In addition to HPN models, we also consider discrete Petri nets where their modeling simplicity enables the characterization of the occurrences of all events in the system. This discrete PN is particularly useful to give a higher-level representation of the traffic network and study its event occurrences and correlations. In Chapter 4, we build a discrete PN model to represent a traffic network with two successive intersections. However, we find that the model leads to unbounded places which cannot accurately reflect the dynamics of the traffic in terms of event occurrences. Hence, we introduce the Modified Binary Petri nets (MBPN) to overcome the limitation and resolve the confliction problem when we design our controllers. This MBPN model is a powerful tool and can be useful for the modeling and analysis of many other applications in traffic networks. Chapter 5 gives a summary for each chapter, provides conclusion and discusses future work for both discrete and hybrid Petri nets

Investigation of Circular Hollow Concrete Columns Reinforced with GFRP Bars and Spirals

Glass fiber-reinforced polymer (GFRP) reinforcements are useful alternatives to traditional steel bars in concrete structures, particularly in vertical structural elements such as columns, as they are less prone to corrosion, and impart increasing strength and endurance of buildings. There is limited research on the finite element analysis (FEA) of the structural behavior of hollow glass fiber-reinforced polymer reinforced concrete (GFRPRC) columns. The hollow portion can be used for the service duct and for reducing the self-weight of the members. Numerical analysis of the compressive response of circular hollow concrete columns reinforced with GFRP bars and spirals is performed in this study. This article aims to investigate the axial behavior of hollow GFRP concrete columns and compare it with that of solid steel reinforced concrete (RC) columns as well as hollow steel RC columns. The Abaqus software is used to construct finite element models. After calibration of modeling using an experimental test result as a control model, a parametric study is conducted. The columns with the same geometry, loading, and boundary conditions are analyzed in the parametric study. It is resulted that the hollow GFRP concrete columns provide a greater confinement effect than the solid steel RC columns. The average variation in the ultimate axial load-carrying capacities of the experimental results, from that of the FEA values, is noted to be only 3.87%, while the average difference in the corresponding deformations is 7.08%. Moreover, the hollow GFRP concrete columns possess greater axial load and deformation capacities compared with the solid steel RC columns

Methane and Carbon Dioxide Hydrate Formation in the Presence of Metal-Based Fluid

Hydrate-based technology has yet to find its way to commercial applications due to several issues, including formation conditions and slow kinetics. Several solid particles were introduced to speed up hydrate formation. However, these solid compounds have given contradictory results. This study investigated the effect of high thermal conductive metallic nanofluids of silver (Ag) and copper (Cu) on CH4 and CO2 hydrates. The solid particles were suspended in a 0.03 wt% SDS aqueous solution, and the results were compared with the 0.03 wt% SDS and deionized water samples. A stirred tank batch reactor was used to conduct the thermodynamic and kinetic experiments. The thermodynamic study revealed that 0.1 wt% of solid particles do not shift the equilibrium curve significantly. The kinetic evaluation, including induction time, the initial rate of gas consumption, half-completion time, t50 and semi-completion time, t95, gas uptake, and storage capacity, have been studied. The results show that the Ag and Cu promote CH4 hydrates while they inhibit or do not significantly influence the CO2 hydrates formation. A predictive correlation was introduced to get the apparent rate constant of hydrate formation in the presence of metal-based fluid at the concentrations range of 0.005–0.1 wt%

Customers' relationship with their grocery store: Direct and moderating effects from store format and loyalty programs

This paper aims: (i) to characterize the priorities designed and implemented by grocery retailers concerning relationship marketing with customers; (ii) to analyse customers’ relationship with their grocery store and to evaluate store format and loyalty programs as key determinants of this relationship. Exploratory interviews were conducted with grocery store managers. Two independent samples of Portuguese customers answered a questionnaire and collected data were analysed using Structural Equation Modelling. Main results suggest that supermarkets lead to higher levels of customers’ trust (directly) and customers’ loyalty (indirectly). Furthermore, the positive effect of customers’ satisfaction on customers’ loyalty is higher for members of grocery store loyalty programs.publishe