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Structural Vulnerability Of Coastal Bridges Under Extreme Hurricane Conditions, Arturo Montoya, Adolfo Matamoros, Firat Testik, Reza Nasouri, Adnan Shahriar, Arsalan Majlesi Aug 2019

Structural Vulnerability Of Coastal Bridges Under Extreme Hurricane Conditions, Arturo Montoya, Adolfo Matamoros, Firat Testik, Reza Nasouri, Adnan Shahriar, Arsalan Majlesi

Publications

This work presents the results of a numerical study evaluating the response of coastal bridges due to hurricane-induced waves. The analyses were conducted using the Coupled Eulerian-Lagrangian (CEL) approach, available on the commercial finite element software Abaqus, which allows modeling the interaction between water and the bridge. The work concentrated on (1) establishing an approach for modeling the desired wave characteristics (i.e., wave height, and frequency) within the CEL simulation, (2) conducting simulations using actual bridge dimensions of historically damaged bridges, (3) analyzing a range of foundation flexibilities to determine its effect on the uplift and shear forces acting on …

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Ice Spiral Patterns On The Ocean Surface, Andrei Ludu, Zhi Zong Jul 2019

Ice Spiral Patterns On The Ocean Surface, Andrei Ludu, Zhi Zong

Publications

We investigate a new two-dimensional compressible Navier-Stokes hydrodynamic model design to explain and study large scale ice swirls formation at the surface of the ocean. The linearized model generates a basis of Bessel solutions from where various types of spiral patterns can be generated and their evolution and stability in time analyzed. By restricting the nonlinear system of equations to its quadratic terms we obtain swirl solutions emphasizing logarithmic spiral geometry. The resulting solutions are analyzed and validated using three mathematical approaches: one predicting the formation of patterns as Townes solitary modes, another approach mapping the nonlinear system into a …

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Fine Sediment Modeling During Storm-Based Events In The River Bandon, Ireland, Juan T. Garcia, Joseph R. Harrington Jul 2019

Fine Sediment Modeling During Storm-Based Events In The River Bandon, Ireland, Juan T. Garcia, Joseph R. Harrington

Publications

The River Bandon located in County Cork (Ireland) has been time-continuously monitored by turbidity probes, as well as automatic and manual suspended sediment sampling. The current work evaluates three different models used to estimate the fine sediment concentration during storm-based events over a period of one year. The modeled suspended sediment concentration is compared with that measured at an event scale. Uncertainty indices are calculated and compared with those presented in the bibliography. An empirically-based model was used as a reference, as this model has been previously applied to evaluate sediment behavior over the same time period in the River …

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Design Of Personnel Big Data Management System Based On Blockchain, Houbing Song, Jian Chen, Zhihan Lv Jul 2019

Design Of Personnel Big Data Management System Based On Blockchain, Houbing Song, Jian Chen, Zhihan Lv

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With the continuous development of information technology, enterprises, universities and governments are constantly stepping up the construction of electronic personnel information management system. The information of hundreds of thousands or even millions of people’s information are collected and stored into the system. So much information provides the cornerstone for the development of big data, if such data is tampered with or leaked, it will cause irreparable serious damage. However, in recent years, electronic archives have exposed a series of problems such as information leakage, information tampering, and information loss, which has made the reform of personnel information management more and …

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Integrating Field Monitoring And Numerical Modeling To 3 Evaluate Performance Of A Levee Under 4 Climatic And Tidal Variations, Xavier A. Rivera-Hernandez, Ghada Ellithy, Farshid Vahedifard Jul 2019

Integrating Field Monitoring And Numerical Modeling To 3 Evaluate Performance Of A Levee Under 4 Climatic And Tidal Variations, Xavier A. Rivera-Hernandez, Ghada Ellithy, Farshid Vahedifard

Publications

Several short-duration and extreme hydraulic loadings impose time-dependent variably saturated seepage conditions on earthen 7 slopes and embankments. Difficulty assigning appropriate input parameters and lack of full-scale validation are among the main factors 8 introducing uncertainty and lack of confidence when performing numerical transient seepage analysis. This case study demonstrates how 9 to effectively use field-monitoring data to improve the numerical analysis of a levee under climatic and tidal variations. The case study 10 includes a silty sand setback levee located near Seattle. An array of tensiometers and soil moisture sensors installed within the levee’s embank11 ment and foundation, along …

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Adaboost‑Based Security Level Classifcation Of Mobile Intelligent Terminals, Feng Wang, Houbing Song, Dingde Jiang, Hong Wen Jul 2019

Adaboost‑Based Security Level Classifcation Of Mobile Intelligent Terminals, Feng Wang, Houbing Song, Dingde Jiang, Hong Wen

Publications

With the rapid development of Internet of Things, massive mobile intelligent terminals are ready to access edge servers for real-time data calculation and interaction. However, the risk of private data leakage follows simultaneously. As the administrator of all intelligent terminals in a region, the edge server needs to clarify the ability of the managed intelligent terminals to defend against malicious attacks. Therefore, the security level classification for mobile intelligent terminals before accessing the network is indispensable. In this paper, we firstly propose a safety assessment method to detect the weakness of mobile intelligent terminals. Secondly, we match the evaluation results …

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Preservation Of Our Astronomical Heritage: State Of The Profession White Paper For Astro2020, James Lattis, Wayne Osborn, Terry D. Oswalt, Jennifer Lynn Bartlett, Elizabeth Griffin, Thomas Hockey, Stephen Mccluskey, Alexei A. Pevtsov, Sara Schechner, Virginia Trimble Jul 2019

Preservation Of Our Astronomical Heritage: State Of The Profession White Paper For Astro2020, James Lattis, Wayne Osborn, Terry D. Oswalt, Jennifer Lynn Bartlett, Elizabeth Griffin, Thomas Hockey, Stephen Mccluskey, Alexei A. Pevtsov, Sara Schechner, Virginia Trimble

Publications

We argue that it is essential that the Astro2020 survey of the present state of American astronomy and the recommendations for the next decade address the issue of ensuring preservation of, and making more discoverable and accessible, the field’s rich legacy materials. These include both archived observations of scientific value and items of historical importance. Much of this heritage likely will be lost if action is not taken in the next decade. It is proposed that the decadal plan include recommendations on (1) compiling a list of historic sites and development of models for their preservation, (2) carrying out a …

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Range Of Motion Evaluation Of A Final Frontier Design Iva Spacesuit Using Motion Capture, Ryan L. Kobrick, Nicholas Lopac, Chase Covello, Benjamin Banner, Theodore Southern, Nikolay Moiseev Jul 2019

Range Of Motion Evaluation Of A Final Frontier Design Iva Spacesuit Using Motion Capture, Ryan L. Kobrick, Nicholas Lopac, Chase Covello, Benjamin Banner, Theodore Southern, Nikolay Moiseev

Publications

Embry-Riddle Aeronautical University’s Spacesuit Utilization of Innovative Technology Laboratory (S.U.I.T. Lab) is focused on improving human performance in spaceflight by concentrating on spacesuit research for intravehicular activities (IVA) and extravehicular activities (EVA). The design and execution of range of motion (ROM) protocols in an experimental setting will provide insight on the functions and restrictions of spacesuits, aiding in current and future designs or modification. The S.U.I.T. Lab worked with Final Frontier Design (FFD) to provide a quantitative analysis protocol for seated arm mobility of their NASA Flight Opportunities Program (FOP) IVA spacesuit. The lab used reflective tracking markers on three …

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Design Of Experiment Methods In High Speed Signal Via Transition In Printed Circuit Board, Amir A. Asif Jul 2019

Design Of Experiment Methods In High Speed Signal Via Transition In Printed Circuit Board, Amir A. Asif

Publications

With increase in data transfer speeds between integrated circuits, memories and connectors, the interconnects in printed circuit boards require careful design and optimization. A critical part of an interconnect is via transition. To meet the design goals and maintain signal integrity, every part of the interconnect needs to be carefully designed. Designing via involves variation of several parameters and it is extremely important to understand their contribution to find the usable parameters yielding best possible performance. Out of these numerous combinations of parameters, Design of Experiments (DOE) can offer much needed understanding, suggest possible values and speed up the design …

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Carbon Nanotube And Cellulose Nanocrystal Hybrid Films, Mingzhe Jiang, Robert Seney, Paul Charles Bayliss, Christopher L. Kitchens Jul 2019

Carbon Nanotube And Cellulose Nanocrystal Hybrid Films, Mingzhe Jiang, Robert Seney, Paul Charles Bayliss, Christopher L. Kitchens

Publications

The use of cellulose nanocrystals (CNC) in high performance coatings is attractive for micro-scale structures or device fabrication due to the anisotropic geometry, however CNC are insulating materials. Carbon nanotubes (CNT) are also rod-shaped nanomaterials that display high mechanical strength and electrical conductivity. The hydrophobic regions of surface-modified CNC can interact with hydrophobic CNT and aid in association between the two anisotropic nanomaterials. The long-range electrostatic repulsion of CNC plays a role in forming a stable CNT and CNC mixture dispersion in water, which is integral to forming a uniform hybrid film. At concentrations favorable for film formation, the multiwalled …

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Cost-Effective Methods To Retrofit Metal Culverts Using Composites, Mahmoud Reda Taha, Susan Bogus Halter Jul 2019

Cost-Effective Methods To Retrofit Metal Culverts Using Composites, Mahmoud Reda Taha, Susan Bogus Halter

Publications

One of the current pressing problems for all DOTs is the corrosion-oriented deterioration of existing metal culverts. These metal culverts typically are designed for a life of 50 years. However, corrosion is making them last no longer than 30 years. A Glass Fiber Reinforced Polymers (GFRP) pipe section has been evaluated as a fit-in GFRP profile liner for complete repair and rehabilitation of the corroded metal culvert with an expected life of 75 years. This is mainly because of the corrosion free nature of the GFRP material. A comprehensive rehabilitation methodology and laboratory scale three-point bending test was conducted to …

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Meshless Modeling Of Flow Dispersion And Progressive Piping In Poroelastic Levees, Anthony Khoury, Eduardo Divo, Alain J. Kassab, Sai Kakuturu, Lakshmi Reddi Jun 2019

Meshless Modeling Of Flow Dispersion And Progressive Piping In Poroelastic Levees, Anthony Khoury, Eduardo Divo, Alain J. Kassab, Sai Kakuturu, Lakshmi Reddi

Publications

Performance data on earth dams and levees continue to indicate that piping is one of the major causes of failure. Current criteria for prevention of piping in earth dams and levees have remained largely empirical. This paper aims at developing a mechanistic understanding of the conditions necessary to prevent piping and to enhance the likelihood of self-healing of cracks in levees subjected to hydrodynamic loading from astronomical and meteorological (including hurricane storm surge-induced) forces. Systematic experimental investigations are performed to evaluate erosion in finite-length cracks as a result of transient hydrodynamic loading. Here, a novel application of the localized collocation …

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Seismic Vulnerability Assessment Of Anchored Block Type Contents Due To Sliding And Overturning, Sereen Majdalaweyh, Weichiang Pang, Amir Safiey, Ershad Ziaei, Keivan Rokneddin, Mohammad Javanbarg, Saurabh Prabhu Jun 2019

Seismic Vulnerability Assessment Of Anchored Block Type Contents Due To Sliding And Overturning, Sereen Majdalaweyh, Weichiang Pang, Amir Safiey, Ershad Ziaei, Keivan Rokneddin, Mohammad Javanbarg, Saurabh Prabhu

Publications

Damage to contents and nonstructural components is often the main driver of property losses against smaller earthquakes as evidenced by empirical evidence from past events. In the 2014 South Napa earthquake in California, for example, 56% of the affected buildings reported content damage. The primary modes of content damage include sliding, rocking, and overturning. The FEMA P-58 document provides seismic fragility functions for sliding and overturning of unanchored block content types, but no data is provided for anchored components. The ASCE/SEI 7-16 provides stability guidelines for different types of nonstructural components, but falls short of providing recommendations for the contents …

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Using More Frequent And Formative Assessment When Replicating The Wright State Model For Engineering Mathematics Education, Leroy Long Iii, Claudia Morello Jun 2019

Using More Frequent And Formative Assessment When Replicating The Wright State Model For Engineering Mathematics Education, Leroy Long Iii, Claudia Morello

Publications

A mid-sized private university in the Southeast has created an experimental first-year engineering course based on the Wright State Model for Engineering Mathematics Education. The course aims to increase student retention, motivation and success in engineering through an application-oriented, hands-on introduction to engineering mathematics. When compared to the traditional Wright State Model for Engineering Mathematics Education, the new course also focused on student communication (written, oral), teamwork, self-regulated learning and professionalism. The new experimental course also uses more frequent and formative assessment techniques. Faculty used Wright State’s sample homework assignments to provide students’ with formative feedback and Wright State’s sample …

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Propulsion System Testing For A Long-Endurance Solar-Powered Unmanned Aircraft, D. Dantsker, Robert Deters, Marco Caccamo Jun 2019

Propulsion System Testing For A Long-Endurance Solar-Powered Unmanned Aircraft, D. Dantsker, Robert Deters, Marco Caccamo

Publications

The increase in popularity of unmanned aerial vehicles (UAVs) has been driven by their use in civilian, education, government, and military applications. However, limited on-board energy storage significantly limits flight time and ultimately usability. The propulsion system plays a critical part in the overall energy consumption of the UAV; therefore, it is necessary to determine the most optimal combination of possible propulsion system components for a given mission profile, i.e. propellers, motors, and electronic speed controllers (ESC). Hundreds of options are available for the different components with little performance specifications available for most of them. In order to determine the …

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Parameterizing Wave‐Driven Vertical Constituent Transport In The Upper Atmosphere, Alan Z. Liu, Chester S. Gardner, Yafang Guo Jun 2019

Parameterizing Wave‐Driven Vertical Constituent Transport In The Upper Atmosphere, Alan Z. Liu, Chester S. Gardner, Yafang Guo

Publications

Dissipating waves contribute to vertical mixing of the atmosphere, alter molecular and eddy diffusion, and induce chemical transport of reactive species. These processes induce strong vertical transport of atmospheric constituents in regions where wave dissipation is significant. The effective wave diffusivity is proportional to the Stokes drift velocity imparted by the spectrum of vertically propagating waves, which is related to the vertical heat and wave energy fluxes. Because the heat flux cannot be derived from wave parameterization schemes employed in most atmospheric models, wave‐driven constituent transport has not been fully incorporated. However, we show in this paper that wave diffusivity …

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History Of St. Peter Claver Church, Kelli Johnson Jun 2019

History Of St. Peter Claver Church, Kelli Johnson

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History of St. Peter Claver Church, written by Sandra Clements

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Seismic Performance Of Mid-Rise Code-Conforming X-Braced Steel Frames, Mokhtar Ansari, Hosein Gholi Pour, Amir Safiey Jun 2019

Seismic Performance Of Mid-Rise Code-Conforming X-Braced Steel Frames, Mokhtar Ansari, Hosein Gholi Pour, Amir Safiey

Publications

Prolixity and complexities inherent in the nonlinear dynamic analysis (NDA) impel engineers to lean towards nonlinear static analysis (NSA) in practice. This paper partly explores differences and similarities in responses obtained from these two simulation techniques. The scope of the study is narrowed down to ubiquitous regular code-conforming mid-rise steel X-braced frames. Different common lateral load patterns are coupled with NSA to study their interactive effects on responses. The modal nonlinear static analysis is also carried out, where deemed necessary. NDA using three different earthquake records are conducted as well, to validate NSA results. Results of nonlinear analyses are undertaken …

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Social Shaping Of Mobile Geomedia Services: An Analysis Of Yelp And Foursquare, Jordan Frith, Rowan Wilken Jun 2019

Social Shaping Of Mobile Geomedia Services: An Analysis Of Yelp And Foursquare, Jordan Frith, Rowan Wilken

Publications

In their book, Location-Based Social Media: Space, Time and Identity, Leighton Evans and Michael Saker remark on the apparent ‘death’ of location-based social networks, suggesting that location-based social networks can now be understood as ‘a form of “zombie-media” that animates and haunts other media platforms’. In this article, we use this perspective as a point of departure for a social shaping of technology-informed analysis of two key geomedia platforms: Yelp and Foursquare. With Yelp approaching its 15th year of service and Foursquare approaching its 10th anniversary, this article provides a timely opportunity to (re-)examine the significance of Yelp and …

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Development And Evaluation Of Recurrent Neural Network-Based Models For Hourly Traffic Volume And Annual Average Daily Traffic Prediction, Zadid Khan, Sakib Mahmud Khan, Kakan Dey, Mashrur Chowdhury Jun 2019

Development And Evaluation Of Recurrent Neural Network-Based Models For Hourly Traffic Volume And Annual Average Daily Traffic Prediction, Zadid Khan, Sakib Mahmud Khan, Kakan Dey, Mashrur Chowdhury

Publications

The prediction of high-resolution hourly traffic volumes of a given roadway is essential for transportation planning. Traditionally, automatic traffic recorders (ATR) are used to collect these hourly volume data. These large datasets are time-series data characterized by long-term temporal dependencies and missing values. Regarding the temporal dependencies, all roadways are characterized by seasonal variations that can be weekly, monthly or yearly, depending on the cause of the variation. Traditional time-series forecasting models perform poorly when they encounter missing data in the dataset. To address this limitation, robust, recurrent neural network (RNN)-based, multi-step-ahead forecasting models are developed for time-series in this …

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Poster: Life After Sports: Black Males Pursuing Engineering And Related Stem Fields, Leroy L. Long Iii, Robert A. Bennett Iii, Morris R. Council Iii, Mckenna James Jun 2019

Poster: Life After Sports: Black Males Pursuing Engineering And Related Stem Fields, Leroy L. Long Iii, Robert A. Bennett Iii, Morris R. Council Iii, Mckenna James

Publications

This poster summarizes findings and offers recommendations from a research study involving Black males who majored in engineering or a related STEM field and played a collegiate sport. Specifically, the poster highlights ways in which the research participants were able to transition from playing sports to pursuing an engineering or related STEM career. For this particular poster, the presenters focused on the experiences of four Black men. Two of the Black men played college football at historically Black colleges and universities (HBCUs) in the Southeast. Two other Black men ran track at Division 2 (D2) predominantly White institutions (PWIs) in …

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Impact Of Oxygen Plasma Treatment On Carrier Transport And Molecular Adsorption In Graphene, Hongmei Li, Austin Singh, Ferhat Bayram, Anthony S. Childress, Apparao Rao, Goutam Koley May 2019

Impact Of Oxygen Plasma Treatment On Carrier Transport And Molecular Adsorption In Graphene, Hongmei Li, Austin Singh, Ferhat Bayram, Anthony S. Childress, Apparao Rao, Goutam Koley

Publications

Impact of plasma treatment on graphene's transport properties and interaction with gas molecules has been investigated with Raman, X-ray photoelectron spectroscopy, and Hall measurements. Experimental results indicate the formation of nanocrystalline domains and the enhanced fraction of adsorbed oxygen following oxygen plasma treatment, which correlates with a significant reduction in carrier mobility and an increase in carrier density. The oxygen plasma treated graphene was found to exhibit much stronger sensitivity toward NH3 molecules both in terms of magnitude and response rate, attributable to increased domain edges and oxygen adsorption related enhancement in p-type doping. The carrier mobility in plasma exposed …

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Formative Assessment Techniques For Online Learning, Emily Faulconer, Beverly Wood May 2019

Formative Assessment Techniques For Online Learning, Emily Faulconer, Beverly Wood

Publications

While most faculty think of assessments as used to measure learning after the fact, formative assessment classroom techniques (FACTs) give an instructor a snapshot of where students are in their learning so as to address any gaps in their understanding. Online instructors have a variety of tools at their disposal to incorporate engaging FACTs into their courses that will improve learning outcomes.

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Guiding Students Through Choppy Creative Waters: Collaborative Pedagogy To Empower Ethical Creators, Kelsey Sheaffer, Jessica Kohout-Tailor May 2019

Guiding Students Through Choppy Creative Waters: Collaborative Pedagogy To Empower Ethical Creators, Kelsey Sheaffer, Jessica Kohout-Tailor

Publications

With the rise of ‘multimodality’, students are increasingly creating digital projects that require an understanding of copyright that includes Creative Commons, to both search for and appropriately remix the original work of others. In this session, learn how two librarians collaboratively developed their student-centered pedagogy to apply active-learning strategies in the classroom for these special creative copyright sessions. In their approach, the librarians engaged the student-as-producer to make creative copyright more accessible and applicable to their projects. These instructional interventions build on the traditional lecture-style session on Copyright Law to support non-traditional projects.

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A State-Of-The-Art Review Of Bending And Shear Behaviors Of Corrosion-Damaged Reinforced Concrete Beams, Mahmoodreza Soltani, Amir Safiey, Almarie Brennan May 2019

A State-Of-The-Art Review Of Bending And Shear Behaviors Of Corrosion-Damaged Reinforced Concrete Beams, Mahmoodreza Soltani, Amir Safiey, Almarie Brennan

Publications

Steel corrosion is mainly at fault for the trend of deterioration among U.S. infrastructure—namely, bridges, pipelines, and wharves. Reinforced concrete (RC) is used as the primary construction material worldwide. Reinforcement corrosion can significantly impair mechanical properties of RC members, including shear and bending capacities. In the past decades, several attempts have been made to investigate the impacts of corrosion on the mechanical behavior of RC members. It can be observed that the number of research programs conducted on this topic has rapidly increased in recent years. Therefore, there is a need in the body of knowledge to encapsulate the relevant …

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Multimodal Emotion Classification, Anurag Illendula, Amit Sheth May 2019

Multimodal Emotion Classification, Anurag Illendula, Amit Sheth

Publications

Most NLP and Computer Vision tasks are limited to scarcity of labelled data. In social media emotion classification and other related tasks, hashtags have been used as indicators to label data. With the rapid increase in emoji usage of social media, emojis are used as an additional feature for major social NLP tasks. However, this is less explored in case of multimedia posts on social media where posts are composed of both image and text. At the same time, w.e have seen a surge in the interest to incorporate domain knowledge to improve machine understanding of text. In this paper, …

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Knowledge-Aware Assessment Of Severity Of Suicide Risk For Early Intervention, Manas Gaur, Amanuel Alambo, Joy Prakash Sain, Ugur Kursuncu, Krishnaprasad Thirunarayan, Ramakanth Kavuluru, Amit Sheth, Randon S. Welton, Jyotishman Pathak May 2019

Knowledge-Aware Assessment Of Severity Of Suicide Risk For Early Intervention, Manas Gaur, Amanuel Alambo, Joy Prakash Sain, Ugur Kursuncu, Krishnaprasad Thirunarayan, Ramakanth Kavuluru, Amit Sheth, Randon S. Welton, Jyotishman Pathak

Publications

Mental health illness such as depression is a significant risk factor for suicide ideation, behaviors, and attempts. A report by Substance Abuse and Mental Health Services Administration (SAMHSA) shows that 80% of the patients suffering from Borderline Personality Disorder (BPD) have suicidal behavior, 5-10% of whom commit suicide. While multiple initiatives have been developed and implemented for suicide prevention, a key challenge has been the social stigma associated with mental disorders, which deters patients from seeking help or sharing their experiences directly with others including clinicians. This is particularly true for teenagers and younger adults where suicide is the second …

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On The Long Lasting “C‐Type” Structures In The Sodium Lidargram: The Lifetime Of Kelvin‐Helmholtz Billows In The Mesosphere And Lower Thermosphere Region, S. Mondal, S. Sarkhel, Jay Agarwal, D. Chakrabarty, R. Sekar, Tao Yuan, Alan Z. Liu, Et Al. Apr 2019

On The Long Lasting “C‐Type” Structures In The Sodium Lidargram: The Lifetime Of Kelvin‐Helmholtz Billows In The Mesosphere And Lower Thermosphere Region, S. Mondal, S. Sarkhel, Jay Agarwal, D. Chakrabarty, R. Sekar, Tao Yuan, Alan Z. Liu, Et Al.

Publications

In order to understand the characteristics of long‐lasting “C‐type” structure in the Sodium (Na) lidargram, six cases from different observational locations have been analyzed. The Na lidargram, collected from low‐, middle‐, and high‐latitude sites, show long lifetime of the C‐type structures which is believed to be the manifestation of Kelvin‐Helmholtz (KH) billows in the Mesosphere and Lower Thermosphere (MLT) region. In order to explore the characteristics of the long‐lasting C‐type structures, the altitude profile of square of Brunt‐Väisälä frequency in the MLT region has been derived using the temperature profile collected from the Na lidar instruments and the SABER instrument …

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Influences Of Catchment And River Channel Characteristics On The Magnitude And Dynamics Of Storage And Re-Suspension Of Fine Sediments In River Beds, Jungsu Park, Ramon J. Batalla, François Bírgand, Michel Esteves, Francesco Gentile, Joseph R. Harrington, Oldrich Navratil, José Andres López-Tarazón, Damiá Vericant Apr 2019

Influences Of Catchment And River Channel Characteristics On The Magnitude And Dynamics Of Storage And Re-Suspension Of Fine Sediments In River Beds, Jungsu Park, Ramon J. Batalla, François Bírgand, Michel Esteves, Francesco Gentile, Joseph R. Harrington, Oldrich Navratil, José Andres López-Tarazón, Damiá Vericant

Publications

Fine particles or sediments are one of the important variables that should be considered for the proper management of water quality and aquatic ecosystems. In the present study, the effect of catchment characteristics on the performance of an already developed model for the estimation of fine sediments dynamics between the water column and sediment bed was tested, using 13 catchments distributed worldwide. The model was calibrated to determine two optimal model parameters. The first is the filtration parameter, which represents the filtration of fine sediments through pores of the stream bed during the recession period of a flood event. The …

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Gravity Wave Ducting Observed In The Mesosphere Over Jicamarca, Peru, Gerald A. Lehmacher, Christopher J. Heale, Jonathan B. Snively, Erhan Kudeki, Pablo M. Reyes, Kiwook Lee Apr 2019

Gravity Wave Ducting Observed In The Mesosphere Over Jicamarca, Peru, Gerald A. Lehmacher, Christopher J. Heale, Jonathan B. Snively, Erhan Kudeki, Pablo M. Reyes, Kiwook Lee

Publications

Short-period gravity waves are ubiquitous in the mesosphere, but the vertical structures of their perturbations are difficult to observe. The Jicamarca 50-MHz very high frequency radar allows observations of winds and turbulent scatter with high temporal and vertical resolution. We present a case of a quasi-monochromatic gravity wave with period 520 (±40) s that is likely ducted below a southward wind jet between 68 and 74 km. Above this layer of evanescence, a northward wind enables it to emerge into a more stable layer, where it is refracted to a short vertical wavelength of 2.2 (±0.2) km; data show evidence …

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