Basim Zafar

Virtual Tawaf: A case study in simulating the behavior of dense, heterogeneous crowds

We present a system to simulate the movement of individual agents in large-scale crowds performing the Tawaf. The Tawaf serves as a unique test case. The crowd consists of a heterogeneous set of pilgrims, varying with respect to physical capacity as well as activity. Furthermore, the density of the crowd reaches very high levels. Our approach uses a finite state machine to specify the behavior of the agents at each time step in conjunction with a geometric, agent-based algorithm to specify how an agent interacts with its local neighbors to generate collision-free trajectories. The overall system can model agents with varying age, gender and behaviors, supporting the heterogeniety observed in the performance of the Tawaf, even at high densities.

Right of way

Pedestrian models typically represent interactions between agents in a symmetric fashion. In general, these symmetric relationships are valid for a large number of crowd simulation scenarios. However, there are many cases in which symmetric responses between agents are inappropriate, leading to unrealistic behavior or undesirable simulation artifacts. We present a novel formulation, called right of way, which provides a well-disciplined mechanism for modeling asymmetric relationships between pedestrians. Right of way is a general principle, which can be applied to different types of pedestrian models. We illustrate this by applying right of way to three different pedestrian models (two based on social forces and one based on velocity obstacles) and show its impact in multiple scenarios. Particularly, we show how it enables simulation of the complex relationships exhibited by pilgrims performing the Islamic religious ritual, the Tawaf.

Velocity-based modeling of physical interactions in dense crowds

We present an interactive algorithm to model physics-based interactions in dense crowds. Our approach is capable of modeling both physical forces and interactions between agents and obstacles, while also allowing the agents to anticipate and avoid upcoming collisions during local navigation. We combine velocity-based collision-avoidance algorithms with external physical forces. The overall formulation produces various effects of forces acting on agents and crowds, including balance recovery motion and force propagation through the crowd. We further extend our method to model more complex behaviors involving social and cultural rules. We use finite-state machines to specify a series of behaviors and demonstrate our approach on many complex scenarios. Our algorithm can simulate a few thousand agents at interactive rates and can generate many emergent behaviors.

Virtual Tawaf: A Velocity-Space-Based Solution for Simulating Heterogeneous Behavior in Dense Crowds

We present a system to simulate the movement of individual agents in large-scale crowds performing the Tawaf. The Tawaf serves as a unique test case; the large crowd consists of a heterogeneous set of pilgrims, varying in both physical capacity and activity. Furthermore, the density of the crowd reaches extremely high levels (up to 8 people/m2). This extreme density can place impractical constraints on simulation parameters. We use a velocity-space-based pedestrian model which exhibits consistent results even under extreme density: reciprocal velocity obstacles (RVO). Furthermore, we extend RVO to include priority and right of way—agents respond to potential collisions asymmetrically depending on context; one agent may yield, to varying degrees, to another. Our system uses a finite state machine to specify the behavior of the agents at each time step, to model the varied behaviors seen during the Tawaf. The finite-state machine, used in conjunction with RVO, generates collision-free trajectories for tens of thousands of agents in the performance of the Tawaf. The overall system can model agents with varying age, gender and behaviors, supporting the heterogeneity observed in the performance of the Tawaf, even at high densities.

ID-based secure real-time tracking system

This article focuses on the security issues involved in the transportation of valuable materials. It tries to build a secure smart real-time freight tracking system in which the valuable materials can be under inspection and control at all times during its transportation from the supplier to the end user. The real-time tracking system can be achieved by combining technologies from Real-Time Tracking Systems (RTTSs), such as GPS and RFID, while the system environment sensing can be achieved using Wireless Sensor Network (WSN) that can add sensing ability to the moving valuable materials. This paper not only proposes a novel Identity-Based Cryptosystem (IBC) for securing an E-Seal that can be used to secure the communication of the real-time tracking communication but also addresses IBC based with lightweight computation specification that can be used in low computation devices for locking and unlocking of the E-Seal.

Towards accelerated agent-based crowd simulation for Hajj and Umrah

There are many scientific applications ranging from weather prediction to oil and gas exploration that requires high-performance computing. It aids industries and researchers to enrich further their advancements. With the advent of general purpose computing over GPUs, most of the applications above are shifting towards High-Performance Computing (HPC). Agent-based crowd simulation is one of the candidates that requires high-performance computing. This type of application is used to predict crowd movement in highly congested areas. One of the most crucial scenarios in which this application can be used is to mimic the movement of the multi-cultural crowd performing Hajj and Umrah in Masjid Al-Haram, Makkah. Adequate performance for an agent-based crowd system is a common problem in computer science. While the existing event planning software, specifically for Hajj and Umrah, are unable to provide the required performance. The main reason is the increasing amount of autonomous pilgrims every year. In this paper, we propose a high performance agent-based crowd simulation that represents pilgrim movement during these rituals. The performance is achieved by parallelizing an open source steering library called OpenSteer using CUDA over GPU. By using our technique, event organizers will be able to simulate large crowds and will also be able to predict whether the developed event plan is viable or not. We have also discussed the architecture and implementation of this parallel Hajj simulation.

Estimation Vehicular Waiting Time at Traffic Build-Up Queues

Due to the high growth of social economic activities and the increased need for mobility in recent days, transportation problems like congestion, accidents, and pollution have been increased. However, improving the reliability of delay estimates and real-time dissemination of information remains a challenge. An advanced border-crossing system corresponding to the changes of cross-border circumstances becomes an urgent matter. An automated system for queue end monitoring has been proposed using image processing based transformed domain and empirical mode decomposition (EMD) feature extraction systems. The performance of feedforward backpropagation algorithm artificial neural networks (ANNs) was evaluated and tested, based on a selected set of features. The experimental results showed that the use of discrete wavelet transform (DWT) based Daubechies with decomposition of level 2 has accomplished the target with a processing time 2 sec and 3 epochs of training network only with best validation performance of (2.1053e-007) for vehicle recognition. Also the use of EMD as a feature extractor has accomplished the target of vehicle recognition with a best validation performance of (about 3.42e-09) and a processing time of 1 sec at epoch 3 of training network only with a minimal percentage of error for the recognition of each vehicle in the appropriate queue with the aid of the new concept of road side unit (RSU).

A New Lightweight Mutual Authentication Protocol to Secure Real Time Tracking of Radioactive Sources

Radioactive applications are employed in many aspects of our life, such as industry, medicine and agriculture. One of the most important issues that need to be addressed is the security of the movement of radioactive sources. There are many threats that may occur during the transportation of the radioactive sources from one place to another. This paper investigates the security issues in the transportation of the radioactive sources. Thus, it is an attempt to build a secure, real time freight tracking system in which the radioactive source can be under inspection and control at all times during transportation from the shipment provider to the end user. Thus, we proposed a novel lightweight mutual authentication protocol to be used for securing the transportation of radioactive materials. Also, the security requirements for the proposed protocol were verified using the Scyther tool.

Estimation of Density Levels in the Holy Mosque from a Network of Cameras

In this work we developed a system for estimating the density levels in the holy mosque of Makkah using video cameras installed in the mosque. This set-up relies on dividing the image into smaller segments and counting the number of people in each segment to infer the density. This algorithm used texture and SIFT interest point features to get an accurate count of the number of people at each segment using support vector regression. Having segments at different sizes helped to account for objects with different size in the image. In addition, the use of overlapping segment smooth the estimated density maps as each pixel receive a contribution from different patches. Our methodology has been tested extensively with different cameras during the Fasting season of 2015 with images from very crowded areas in the mosque.

Adjustment of cross-track dependence of TRMM Precipitation Radar observation

The Tropical Rainfall Measuring Mission (TRMM) is NASAs first mission dedicated to observing and understanding tropical rainfall and its effects on global climate. The Precipitation Radar in TRMM is the first spaceborne instrument designed to obtain three-dimensional maps of precipitation reflectivity. Such measurements yield information on the intensity and distribution of rain, rain type and storm depth. An advantage of space radar is that the scattering volume has similar size at any location. However, it has been a challenge to compare data to the one that is collected from the Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) for varying scan angles. Intercomparisons between ground radar and spaceborne radar on a point-by-point basis can be a difficult task. Errors result from the mismatch between ground radar and spaceborne radar resolution volume, spatial alignment, and operating frequencies as well as the limited number of the data set collected instantaneously by both instruments. Differences in viewing aspects and resolution that result from the measurement of return signals from different volumes of the precipitation medium contribute to the intercomparison error. A study of the characteristics of the region of the bright band from TRMM-PR vertical profile measurements on a global scale indicates that while bright band height varies widely, the distribution of bright band structure does not vary around the globe. The results show that the average profile of the bright band vertical profile using bright band height as a reference point around the globe has unique profile and do not changes around the globe for large data set. This unique profile can be used to adjust the radar observation error due to different parameters. The TRMM-PR vertical resolution becomes poorer with increasing distance of the TRMM-PR samples from the nadir. Studying the model profile at the nadir profile and other profiles that are off-nadir ray can be used to build the statistical model that can be used to adjust the effect of the scanning cross-track at angle far from the nadir-ray, and the results are presented.