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Luo C.,Shenzhen University | Luo C.,National University of Singapore | Hong H.,National University of Singapore | Cheng L.,VirginiaTech | And 3 more authors.
Journal of Network and Computer Applications | Year: 2016

Fingerprint-based indoor localization has attracted extensive research efforts due to its potential for deployment without extensive infrastructure support. However, the accuracies of these different systems vary and it is difficult to compare and evaluate these systems systematically. In this work, we propose a Gaussian process based approach that takes the radio map and the localization algorithm as an input, and outputs the expected accuracy of the localization system. With an efficient error estimation algorithm, many applications such as landmark detection, localization algorithm selection and access point subset selection can be performed. Our evaluations show that our approach provides sufficient accuracy and can serve as a useful tool for system evaluation and performance tuning when developing fingerprint-based indoor localization systems. © 2016 Elsevier Ltd. All rights reserved.


Westman E.C.,VirginiaTech. | Luxbacher K.D.,VirginiaTech. | Schafrik S.J.,VirginiaTech. | Swanson P.I.,Spokane Research Laboratory | Zhang H.,Anhui University of Science and Technology
46th US Rock Mechanics / Geomechanics Symposium 2012 | Year: 2012

Bumps in underground coal mines are violent events that result from a buildup of stress, usually in mines underlain and overlain by massive strata. Seismic velocity tomography can be implemented to infer stress distribution at mines and determine when a dangerous situation is developing. Three different methods were employed to compare time-lapse passive seismic tomograms at a longwall coal mine. The dataset is well sampled with a dense receiver array. Parameterization and results were compared using GeoTom, TomoDD, and SIMULPS. TomoDD and SIMULPS both allow for variable gridding and relocation of microseismic events while GeoTOM does not. All three methods produced consistent results for the data set showing clear high velocity zones in areas where abutment stress is expected and low velocity zones corresponding with gob. TomoDD proved to be the most suitable method for generating tomograms from mining-induced microseismic events because it resulted in the most consistent images and the calculated velocity distribution matched prior stress distribution measurements at the site. Copyright 2012 ARMA, American Rock Mechanics Association.


PubMed | VirginiaTech, Oecd Nuclear Energy Agency and University of Toronto
Type: Journal Article | Journal: Ergonomics | Year: 2016

We introduce Process Overview, a situation awareness characterisation of the knowledge derived from monitoring process plants. Process Overview is based on observational studies of process control work in the literature. The characterisation is applied to develop a query-based measure called the Process Overview Measure. The goal of the measure is to improve coupling between situation and awareness according to process plant properties and operator cognitive work. A companion article presents the empirical evaluation of the Process Overview Measure in a realistic process control setting. The Process Overview Measure demonstrated sensitivity and validity by revealing significant effects of experimental manipulations that corroborated with other empirical results. The measure also demonstrated adequate inter-rater reliability and practicality for measuring SA based on data collected by process experts. Practitioner Summary: The Process Overview Measure is a query-based measure for assessing operator situation awareness from monitoring process plants in representative settings.


Gao W.,Purdue University | Zhang Y.,Purdue University | Ramanujan D.,Purdue University | Ramani K.,Purdue University | And 6 more authors.
CAD Computer Aided Design | Year: 2015

Additive manufacturing (AM) is poised to bring about a revolution in the way products are designed, manufactured, and distributed to end users. This technology has gained significant academic as well as industry interest due to its ability to create complex geometries with customizable material properties. AM has also inspired the development of the maker movement by democratizing design and manufacturing. Due to the rapid proliferation of a wide variety of technologies associated with AM, there is a lack of a comprehensive set of design principles, manufacturing guidelines, and standardization of best practices. These challenges are compounded by the fact that advancements in multiple technologies (for example materials processing, topology optimization) generate a "positive feedback loop" effect in advancing AM. In order to advance research interest and investment in AM technologies, some fundamental questions and trends about the dependencies existing in these avenues need highlighting. The goal of our review paper is to organize this body of knowledge surrounding AM, and present current barriers, findings, and future trends significantly to the researchers. We also discuss fundamental attributes of AM processes, evolution of the AM industry, and the affordances enabled by the emergence of AM in a variety of areas such as geometry processing, material design, and education. We conclude our paper by pointing out future directions such as the "print-it-all" paradigm, that have the potential to re-imagine current research and spawn completely new avenues for exploration. © 2015 Elsevier Ltd.


Meiksins P.,Cleveland State University | Beddoes K.,Oregon State University | Layne P.,VirginiaTech | McCusker M.,VirginiaTech | And 2 more authors.
SWE Magazine | Year: 2015

SWE's assessment of the most significant research found in the past year's social science literature on women engineers and women in STEM disciplines. © 2015, Society of Women Engineers. All rights reserved.


Gao W.,Purdue University | Zhang Y.,Purdue University | Ramanujan D.,Purdue University | Ramani K.,Purdue University | And 6 more authors.
CAD Computer Aided Design | Year: 2015

Additive manufacturing (AM) is poised to bring about a revolution in the way products are designed, manufactured, and distributed to end users. This technology has gained significant academic as well as industry interest due to its ability to create complex geometries with customizable material properties. AM has also inspired the development of the maker movement by democratizing design and manufacturing. Due to the rapid proliferation of a wide variety of technologies associated with AM, there is a lack of a comprehensive set of design principles, manufacturing guidelines, and standardization of best practices. These challenges are compounded by the fact that advancements in multiple technologies (for example materials processing, topology optimization) generate a "positive feedback loop" effect in advancing AM. In order to advance research interest and investment in AM technologies, some fundamental questions and trends about the dependencies existing in these avenues need highlighting. The goal of our review paper is to organize this body of knowledge surrounding AM, and present current barriers, findings, and future trends significantly to the researchers. We also discuss fundamental attributes of AM processes, evolution of the AM industry, and the affordances enabled by the emergence of AM in a variety of areas such as geometry processing, material design, and education. We conclude our paper by pointing out future directions such as the "print-it-all" paradigm, that have the potential to re-imagine current research and spawn completely new avenues for exploration. © 2015 Elsevier Ltd.


McDonald W.M.,Virginia Polytechnic Institute and State University | Brogan D.S.,VirginiaTech | Lohani V.K.,VirginiaTech | Dymond R.L.,Virginia Polytechnic Institute and State University | Clark R.L.,Roanoke College
International Journal of Engineering Education | Year: 2015

The Learning Enhanced Watershed Assessment System (LEWAS) is a high-frequency, real-time environmental monitoring lab on the Virginia Tech campus that supports watershed research and education. Student-centered modules that incorporate hands-on activities and LEWAS data have been implemented into a senior level hydrology course at VT (30 students) and several freshman level introductory engineering courses at Virginia Western Community College (73 students). A multi-loop assessment plan demonstrates how researchers at a large public university can collaborate with community college faculty to improve assessment methods and classroom module development. Assessment results show student learning gains through active and collaborative LEWAS-based learning modules. A pilot test of a LEWAS-based interactive online educational tool called the Online Watershed Learning System (OWLS), which allows students to access real-time data, virtually explore the LEWAS watershed, and examine case studies, has also produced results that indicate that student learning improves through virtual access to real-time and historical watershed data. © 2015 TEMPUS Publications.


Layne P.,VirginiaTech
Leadership and Management in Engineering | Year: 2010

Despite tremendous gains over the past 30 years, women are still severely underrepresented in engineering and engineering education. The advancement of women into leadership roles in engineering education has the potential to make engineering as a career more attractive to young women and to encourage women currently pursuing careers in engineering education to aspire to leadership positions themselves. This article reports on a series of structured interviews in which women deans of engineering were asked to describe their role and accomplishments as dean, their career paths, and their perspective on the impact of gender on their leadership style. The interviews provide insights into how these women saw themselves as leaders and how they were leading their institutions in creating engineers for the 21st century. © 2010 ASCE.


Cai J.,VirginiaTech | Moen C.D.,VirginiaTech
Thin-Walled Structures | Year: 2016

This paper presents a method to perform generalized beam theory buckling analysis on thin-walled structural members with holes. Generalized beam theory (GBT) is an ideal tool for analyzing thin-walled structures because it can directly compute buckling mode participation in an eigen-buckling analysis. The GBT extension to members with holes is made by treating a thin-walled structural member as an assembly of prismatic sub-members, and compatibility constraints on the GBT modal amplitudes are introduced to connect these sub-members. GBT shear modes with nonlinear warping deformation are included in both first order and buckling analyses to account for the nonlinear normal stress distribution in the vicinity of a hole. GBT buckling mode shapes are verified with shell finite element analysis (SFEA) in three examples that highlight the potential for quantitatively documenting buckling modes initiated by the presence of holes. © 2016 Elsevier Ltd

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