Data modeling and handling for analysis and visualization in a collaborative setting

This paper discusses the development of a data modeling and handling methodology to display results from a large-scale Finite Element Analysis in real-time from any geographic location in the world to aid in complex decision-making. The developed methodology enables real-time collaboration before, during, and after a complex engineering analysis. The collaborative capabilities include a three dimensional, interactive representation of the analysis data available through the Internet on any computing platform without the need of installed software or specialized hardware. A scientist has the ability to change data resolutions on-the-fly as well as view animated representations of the analysis results. In this paper, the developed methodology was applied to a geophysical situation. However, the benefits could be realized in a range of application areas from mechanical design to biomedical imaging. The details of the development are presented in this paper. The full paper will present additional descriptions as well as example problems

Diversity and frame invariance characteristics in Particle Swarm Optimization with and without digital pheromones

Academic problems for testing optimization methods are widely criticized for not being a good representative of real world problems. Due to the unavailability of publishable proprietary information from industries they collaborate with, researchers tend to simulate complex problems by using ‘n-dimensional’ multimodal and/or multi-objective academic test problems for evaluating optimization methods developed. Most of these benchmarking test problems can be decomposed and solved as ‘n’ 1-dimensional optimization problems, rendering them as ineffective representation of real-world problems. However, studies show that coordinate rotation of test problems through an arbitrary angle makes design variables dependent on each other and cannot easily be decomposed into simpler problem chunks. Test problems formulated with coordinate rotation therefore will represent a realistic test bed for evaluating the performance of an optimization routine. However with coordinate rotation, the complexity of the problems potentially increases from O(nn) to O(exp(n ln n)) imposing performance loss on the optimization method that solves the problem. In this paper, the authors attempted to investigate whether coordinate rotation affects the performance characteristics of the digital pheromone implementation of Particle Swarm Optimization (PSO). In particular, two characteristics - swarm diversity with different random number schemes for the velocity vector, and frame invariance with rotational problems are studied and reported. In other words, the authors intended to evaluate whether PSO with digital pheromones is truly capable of solving complex problems

A parallel implementation of particle swarm optimization using digital pheromones

A parallel implementation of Particle Swarm Optimization (PSO) using digital pheromones to coordinate the movements of the swarm within an n-dimensional design space is presented in this paper. Digital pheromones are models simulating real pheromones emitted by insects for communication to indicate a source of food or a nesting location. This principle of communication and organization between each insect in a swarm offers substantial improvement when integrated into a Particle Swarm Optimization algorithm. Digital swarms are used to search a design space with digital pheromones aiding communication within the swarm to improve search efficiency. With statistical analysis, the pheromone strength in a region of the design space is determined. The swarm then reacts accordingly based on the probability that this region may contain an optimum. When implemented in a parallel computing architecture, significant performance increases were observed. This paper presents the method development and results from several test cases

Particle Swarm Optimization Based Source Seeking

Signal source seeking using autonomous vehicles is a complex problem. The complexity increases manifold when signal intensities captured by physical sensors onboard are noisy and unreliable. Added to the fact that signal strength decays with distance, noisy environments make it extremely difficult to describe and model a decay function. This paper addresses our work with seeking maximum signal strength in a continuous electromagnetic signal source with mobile robots, using Particle Swarm Optimization (PSO). A one to one correspondence with swarm members in a PSO and physical Mobile robots is established and the positions of the robots are iteratively updated as the PSO algorithm proceeds forward. Since physical robots are responsive to swarm position updates, modifications were required to implement the interaction between real robots and the PSO algorithm. The development of modifications necessary to implement PSO on mobile robots, and strategies to adapt to real life environments such as obstacles and collision objects are presented in this paper. Our findings are also validated using experimental testbeds.Comment: 13 pages, 12 figure

Real-time visualization of magnetic flux densities for transcranial magnetic stimulation on commodity and fully immersive VR systems

Transcranial Magnetic Stimulation (TMS) is a non-invasive procedure that uses time varying short pulses of magnetic fields to stimulate nerve cells in the brain. In this method, a magnetic field generator (“TMS coil”) produces small electric fields in the region of the brain via electromagnetic induction. This technique can be used to excite or inhibit firing of neurons, which can then be used for treatment of various neurological disorders such as Parkinson’s disease, stroke, migraine, and depression. It is however challenging to focus the induced electric field from TMS coils to smaller regions of the brain. Since electric and magnetic fields are governed by laws of electromagnetism, it is possible to numerically simulate and visualize these fields to accurately determine the site of maximum stimulation and also to develop TMS coils that can focus the fields on the targeted regions. However, current software to compute and visualize these fields are not real-time and can work for only one position/orientation of TMS coil, severely limiting their usage. This paper describes the development of an application that computes magnetic flux densities (h-fields) and visualizes their distribution for different TMS coil position/orientations in real-time using GPU shaders. The application is developed for desktop, commodity VR (HTC Vive), and fully immersive VR CAVETM systems, for use by researchers, scientists, and medical professionals to quickly and effectively view the distribution of h-fields from MRI brain scans

Standard Particle Swarm Optimization on Source Seeking Using Mobile Robots

In this paper, we explore the implementation of standard particle swarm optimization (SPSO) on a swarm of physical mobile robots conducting a source seeking task. The signal source is electromagnetic, whose strength is non-differentiable at many points making most gradient based source seeking strategies ineffective in this scenario. We analyze the physical limitations of the robots and modify SPSO accordingly to make them compatible with each other. We also compare different SPSO topology models to determine the one best suited for our problem. Finally, we incorporate obstacle avoidance strategies into PSO, and compare the performance of original PSO, SPSO 2006 and SPSO 2011 in a complex environment with obstacles. Simulation results demonstrate the efficacy of implementing SPSO to robot source seeking problem. Moreover, it is shown that SPSO 2011 is not only superior as an optimization method, but also provides better performance in robotic implementation compared to SPSO 2006 and original PSO

Comparison of a Virtual Game-Day Experience on Varying Devices

Collegiate athletics, particularly football, provide tremendous value to schools through branding, revenue, and publicity. As a result, extensive effort is put into recruiting talented students. When recruiting, home games are exceptional tools used to show a school\u27s unique game-day atmosphere. However, this is not a viable option during the offseason or for off-site visits. This paper explores a solution to these challenges by using virtual reality (VR) to recreate the game-day experience. The Virtual Reality Application Center in conjunction with Iowa State University (ISU) athletics, created a VR application mimicking the game-day experience at ISU. This application was displayed using the world\u27s highest resolution six-sided CAVETM, an Oculus Rift DK2 computer-driven head mounted display (HMD) and a Merge VR smart phone-driven HMD. A between-subjects user study compared presence between the different systems and a video control. In total, 82 students participated, indicating their presence using the Witmer and Singer questionnaire. Results revealed that while the CAVETM scored the highest in presence, the Oculus and Merge only experienced a slight drop compared to the CAVETM. This result suggests that the mobile ultra-low-cost Merge is a viable alternative to the CAVE TM and Oculus for delivering the game-day experience to ISU recruits

An Application of Conceptual Design and Multidisciplinary Analysis Transitioning to Detailed Design Stages

This paper presents conceptual design and feasibility analysis for oversized grain harvesting combine headers with dynamic topology. To meet customer harvesting productivity requirements, the harvesting header must increase in width from 40 to 60 feet, yet be usable on current generation combine harvesters. While designing concepts for an oversized harvester head is a complex problem by itself, it also presents a latent challenge with packaging and transporting. Transporting a 60ft harvester header using traditional methods will violate road transport regulations imposed by US state and federal governments. This warrants innovations in both designing an oversized header concepts and viable means to package it for domestic and international shipping. The Advanced Systems Design Suite (ASDS) was used to design, visualize and perform quick assessment of the proposed concept designs. Three preliminary design concepts were generated based on customer requirements and manufacturer’s guidelines, of which one design was chosen for transitioning into detailed design stages. Static engineering analysis showed that the combine harvester’s feederhouse mount can support the additional mass of the larger header. Articulation mechanisms were represented by primitive shapes created in ASDS to visualize the preliminary design solution for packaging the header for transportation. Finite Element Analyses (FEA) was performed to determine the required size, shape, and position of the articulation mechanisms. Harvest productivity analyses were performed to assess business feasibility on the oversized header design. Header performance requirements identified potential time and monetary savings of an articulated header compared to a non articulated head of the same size. Reducing the time required to perform “non-harvesting activities” with currently available combines enables the manufacturer to generate a more feasible detailed design addressing this difficult design challenge. The ASDS, along with supplementary analyses tools can be used to generate viable design concepts and the work presented in this paper shows that the oversized combine header design is feasible and is worthy of transitioning into detailed design stages

Game-day football visualization experience on dissimilar virtual reality platforms

College football recruiting is a competitive process. Athletic administrations attempt to gain an edge by bringing recruits to a home game, highlighting the atmosphere unique to campus. This is however not always possible since most recruiting efforts happen off-season. So, they relate the football game experience through video recordings and visits to football facilities. While these substitutes provide a general idea of a game, they cannot capture the feeling of playing while cheered on by a crowd of 55,000 people. To address this challenge and improve the recruitment process, the Iowa State University (ISU) athletic department and the Virtual Reality Applications Center (VRAC) teamed up to build an alternative to the game-day experience using the world’s highest resolution six-sided virtual reality (VR) environment - the C6, and a portable low-cost head-mounted display (HMD) system. This paper presents techniques used in the development of the immersive and portable VR environments followed by validation of the work through quantifying immersion and presence through a formal user study. Results from the user study indicate that both the HMD and C6 are an improvement over the standard practice of showing videos to convey the atmosphere of an ISU Cyclone football game. In addition, both the C6 and HMD were scored similar in immersion and presence categories. This indicates that the low-cost portable HMD version of the application produces minimal trade off in experience for a fraction of the cost