959 research outputs found
Computational Approach to Function Minimization and Optimization with Constraints
This research conducted analyzes function minimization and optimization in the MATLAB programming environment. Different methods are examined and an assessment is made on which tool to utilize given an arbitrary function. This function can be of many types such as quadratic, linear, least squares, smooth nonlinear differential equation, or non-smooth differential equation. The constraints can be of many types as well such as bound, linear, general smooth, and discrete. It is important to note that optimization can also be done on functions which are not bound by constraints. Optimization methods are assessed under two categories, accuracy and computation time, in an attempt to determine the best optimizer to be used given a set type of function. In addition, this research focuses on the function minimization process of typical optimization testing functions. With system optimization becoming a growing field, this research has impactful implications on its computational approach and improving efficiencies of such processes
L.A.S.E.R. (Light Aircraft Solar Extended Range)
With the aviation sector becoming a notable contributor to atmospheric pollution, there is a quantum-shift in the technology of air travel. A radical re-think is occurring in not only how aircrafts are designed but also what they are actually made of. L.A.S.E.R. (Light Aircraft Solar Extended Range) is a team of multi-disciplinary undergraduate students focused on designing, building, and testing a UAV (Unmanned aerial vehicle) which employs non-fossil fuel sources of energy to accomplish various missions. The goals of this research are to claim the record for the farthest distance travelled in a straight line by a solar-powered UAV (F5-SOL Category, FAI), to design and fly an aircraft that uses both hydrogen fuel cells and solar technology as a means to power onboard propulsion and electronic systems, and to continue to design and test eco-friendly UAVs that can accomplish a variety of missions. The team is currently constructing L.A.S.E.R. 5, a fully composite sailplane design, and testing circuit designs which safely charge the onboard battery using two power source systems, hydrogen fuel cells and a solar array. This project advances the state-of-the-science and demonstrates the practicality and feasibility of alternative sources of energy for aircraft to address varied missions
Investigation into Unmanned Aircraft System Incidents in the National Airspace System
With the promulgation of Federal Aviation Regulations for small unmanned aircraft systems, the volume of unmanned flight operations is expected to increase, which demands an analysis of potential hazards to the National Airspace System. Descriptive statistics were used to investigate reports archived in the Aviation Safety Information and Analysis and Sharing system involving unmanned aircraft systems, as well as the FAA UAS Sightings Reports database. The frequency of reports involving airspace violations, and Near Mid-air Collisions by unmanned aircraft systems as well as an analysis of the location, sponsor category, phase of flight, altitude, and airspace type in which the incident occurred were investigated. An upward trend was observed in the number of events with 2015 showing the highest frequency. Most events took place in California and New York and often transpired in Class B Airspaces. The cruise and approach to landing portions of the flight envelope account for the highest number of UAS-related events. A majority of reported events took place between 1000 feet and 2000 feet above the ground and were academic institution sponsored activity. Additionally, the majority of events involved conflicts with commercial manned aircraft transporting passengers
Effect of Social Media on College Students Academic Performance
Social media act as an online communications channels dedicated to community-based input, interaction, content-sharing and teamwork. Social media is becoming an essential part of life online as social websites and applications proliferate. The new and easy ways to of getting the knowledge have emerged using social networks in both formal and informal method. Now days demand of social media increasing everyday people love to share their ideas, views, information. The purpose of this research paper is to understand the effect of social media on academic performance of college students. Taken this into consideration 166 students were randomly taken from different colleges who were using social media as means of education tools. The study was conducted an 8-item questionnaire with Likert Scale (Disagree-1 and 5 for Agree). Various aspects of behavior & Social Networking pattern were taken into consideration. The analysis was done based on Mean & t-test, the result shows that Social Media put positive impact on behavior of the students but has not changed the academic performance of the students in terms of improved grades. It was also found that Female students are using more social media than the male students. Keywords Social media, communications channels, performance DOI: 10.7176/EJBM/11-9-20 Publication date:March 31st 201
DispersioNET: Joint Inversion of Rayleigh-Wave Multimode Phase Velocity Dispersion Curves using Convolutional Neural Networks
Rayleigh wave dispersion curves have been widely used in near-surface
studies, and are primarily inverted for the shear wave (S-wave) velocity
profiles. However, the inverse problem is ill-posed, non-unique and nonlinear.
Here, we introduce DispersioNET, a deep learning model based on convolution
neural networks (CNN) to perform the joint inversion of Rayleigh wave
fundamental and higher order mode phase velocity dispersion curves.
DispersioNET is trained and tested on both noise-free and noisy dispersion
curve datasets and predicts S-wave velocity profiles that match closely with
the true velocities. The architecture is agnostic to variations in S-wave
velocity profiles such as increasing velocity with depth and intermediate
low-velocity layers, while also ensuring that the output remains independent of
the number of layers.Comment: Preprint of the paper submitted to the 2nd Indian Near Surface
Geophysics Conference & Exhibition by AF Academy and the European Association
of Geoscientists & Engineers (EAGE
Guidelines for coverage-based comparisons of non-adequate test suites
A fundamental question in software testing research is how to compare test suites, often as a means for comparing test-generation techniques that produce those test suites. Researchers frequently compare test suites by measuring their coverage. A coverage criterion C provides a set of test requirements and measures how many requirements a given suite satisfies. A suite that satisfies 100% of the (feasible) requirements is called C-adequate. Previous rigorous evaluations of coverage criteria mostly focused on such adequate test suites: given two criteria C and C′, are C-adequate suites (on average) more effective than C′-adequate suites? However, in many realistic cases, producing adequate suites is impractical or even impossible.
This thesis presents the first extensive study that evaluates coverage criteria for the com- mon case of non-adequate test suites: given two criteria C and C′, which one is better to use to compare test suites? Namely, if suites T1, T2,...,Tn have coverage values c1,c2,...,cn for C and c′1,c2,...,c′n for C′, is it better to compare suites based on c1,c2,...,cn or based on c′1,c2,...,c′n? This thesis evaluates a large set of plausible criteria, including basic criteria such as statement and branch coverage, as well as stronger criteria used in recent studies, including criteria based on program paths, equivalence classes of covered statements, and predicate states. The criteria are evaluated on a set of Java and C programs with both manually written and automatically generated test suites. The evaluation uses three correlation measures. Based on these experiments, two criteria perform best: branch coverage and an intra-procedural acyclic path coverage. We provide guidelines for testing researchers aiming to evaluate test suites using coverage criteria as well as for other researchers evaluating coverage criteria for research use
Native fauna interact differently with native and alien trees in a tropical megacity
The negative effects of invasive alien plant species on natural ecosystems are well known. However, in rapidly growing cities, alien plants can provide native fauna with resources otherwise lost due to the biotic homogenization, which is common to urban ecosystems. Interactions of native fauna with alien flora have thus far focused largely on invertebrate pollinators in temperate cities in the northern hemisphere. Cities in tropical areas, however, are larger and are growing more rapidly, and host a variety of vertebrate pollinators. Understanding how birds and mammals interact with native and alien flora in these megacities could improve management of urban ecosystems in highly biodiverse regions while limiting invasion potential. Therefore, here we investigate whether native diurnal birds and mammals interact differ-ently with native versus alien trees in Bengaluru, India where historical planting has led to an abundance of alien tree species. We find that tree origin alone was not an important predictor for bird species richness and abundance, but taller native trees with large floral display sizes were more species rich than alien trees of similar floral displays. As expected from their shared evolutionary history, nectarivorous birds fed from native trees more often in a manner that could facilitate pollination, but engaged in nectar theft more often with alien trees. Squirrels (the mammal ob-served most frequently to interact with flowers) were more likely, however, to depredate flowers of native trees. Our results suggest alien trees can be an important resource for fauna in expanding urban areas, and that nectar theft by birds could reduce the seed set of alien trees.Peer reviewe
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