Article
http://dspace.library.iitb.ac.in/jspui/handle/100/13681
2016-06-28T22:21:42ZVehicle Actuated Control for Heterogeneous Traffic Using Stop Line Detection
http://dspace.library.iitb.ac.in/jspui/handle/100/18424
Vehicle Actuated Control for Heterogeneous Traffic Using Stop Line Detection
NULI, S; MATHEW, TV
Increasing road traffic congestion in major cities significantly undermines the mobility of urban areas around the globe. Since the space is constraint for construction of new roads for such urban areas, many efforts towards congestion relief are focused on better utilization of existing transportation facilities through the use of electronics and communication technologies. Advanced Transportation Management Systems (ATMS), a key component of the Intelligent Transportation Systems deals with such problems of urban traffic control. Traditional methods of signal control such as pre-timed or signal coordination works well when there is no fluctuations in the traffic i.e., saturated or over-saturated conditions. However, vehicle actuated (VA) controllers offer better signal time management especially when the traffic has fluctuations. VA controllers were implemented using upstream detectors in most of the developed countries, however their implementations in heterogeneous traffic poses greater challenges. These heterogeneous vehicles have diverse static and dynamic characteristics such as dimensions, acceleration and decelerations respectively. In addition, suchtraffic is characterized by heavy pedestrian movements, no lane discipline, and occasional violation of signals Modelling such traffic, present in several developing countries, is quite a difficult task. Therefore, developing a vehicle actuated control model to handle highly heterogeneous traffic is a challenging task. The challenge arises because of the difficulty in estimating the demand associated with each turning movement for computing signal timings. Such complex situations can be addressed by placing a detector at stop line rather than in-advance as in homogeneous traffic conditions. Therefore, the objective of this paper is to implement and evaluate proposed vehicle actuated control algorithm using stop line detector. To test the performance of the model atypical four-way four phase intersection with variable flow is simulated using a traffic simulator (VISSIM) and interfaced with the proposed model. The performance is compared with a traditional pre-timed control. The results using this approach shows significant improvement over traditional control, for both medium and high traffic.
2015-01-01T00:00:00ZA Statistical Analysis of Pedestrian Behaviour at Signalized Intersections
http://dspace.library.iitb.ac.in/jspui/handle/100/18423
A Statistical Analysis of Pedestrian Behaviour at Signalized Intersections
MARISAMYNATHAN, S; VEDAGIRI, P
In India pedestrian crashes mostly occurs when pedestrians cross the road, especially at signalized intersections. This study examines various factors affecting pedestrian crossing behaviours at signalized intersections under mixed traffic conditions. The pedestrian crossing movements were captured throughvideographic survey conducted at selected 8 signalized intersections in Mumbai, India The captured data consisting of around 2476 pedestrians and observed that the rate of pedestrian compliance with traffic signal was 53%. This study is oriented towards various levels of pedestrian crossing behaviour such as pedestrian arrival pattern, crossing speed, compliance behaviour and pedestrian-vehicular interaction at signalized intersections. In first level, the pedestrian arrival pattern was analysed to find best fit. In second level, the factors affecting pedestrian crossing speed were identified by suitable statistical test with respect to pedestrian and traffic characteristics. The third level involves the analysis of pedestrian compliance behaviour with respect to pedestrian gender, age, platoon, crossing type, crosswalk marking, crossing direction and crossing speed based on various statistical tests. The fourth level comprises of pedestrian-vehicular interactions in detail,based on conducted statistical test. The pedestrian-vehicular interaction was modelled by using binary logit model. Study results indicate that approaching vehicle direction and gap sizewere the highly influencing factors for interactions. Findings from this study will help to understand the pedestrian crossing behaviour at signalized intersections where the pedestrians noncompliance are predominant and recommends for adequate facilities to be provided to all pedestrians to cross the street with utmost safe, comfort and convenience.
2015-01-01T00:00:00ZWreath product action on generalized Boolean algebras
http://dspace.library.iitb.ac.in/jspui/handle/100/18422
Wreath product action on generalized Boolean algebras
MISHRA, A; SRINIVASAN, MK
Let G be a finite group acting on the finite set X such that the corresponding (complex) permutation representation is multiplicity free. There is a natural rank and order preserving action of the wreath product G similar to S-n on the generalized Boolean algebra B-X (n). We explicitly block diagonalize the commutant of this action.
2015-01-01T00:00:00ZOn graph parameters guaranteeing fast sandpile diffusion
http://dspace.library.iitb.ac.in/jspui/handle/100/18421
On graph parameters guaranteeing fast sandpile diffusion
CHOURE, A; VISHWANATHAN, S
The Abelian Sandpile Model (Dhar 1990) is a discrete diffusion process, defined on graphs, which serves as the standard model of selporganized criticality. One is allowed to add sand particles on the nodes of the graph such that each node can stably hold at most some bounded number of particles. The particles flow through the graph as a consequence of surpassing the node capacities, until they reach a special sink node possessing infinite capacity. These simple dynamics give rise to a very interesting Markovian system. The transience class of a sandpile is defined as the maximum number of particles that can be added without making the system recurrent. We identify a small set of key graph properties that guarantee polynomial bounds on transience classes of the sandpile families satisfying them. These properties governing the speed of sandpile diffusion process are volume growth parameters, boundary regularity type properties and non-empty interior type constraints. This generalizes a previous result by Babai arid Gorodezky (2007) in which they establish polynomial bounds on the n x n grid. Indeed the properties we show are based on ideas extracted from their proof as well as the continuous analogs in the theory of harmonic functions.
2015-01-01T00:00:00Z