The applications of neural network in mapping, modeling and change detection using remotely sensed data

Thesis (Ph.D.)--Boston UniversityAdvances in remote sensing and associated capabilities are expected to proceed in a number of ways in the era of the Earth Observing System (EOS). More complex multitemporal, multi-source data sets will become available, requiring more sophisticated analysis methods. This research explores the applications of artificial neural networks in land-cover mapping, forward and inverse canopy modeling and change detection. For land-cover mapping a multi-layer feed-forward neural network produced 89% classification accuracy using a single band of multi-angle data from the Advanced Solidstate Array Spectroradiometer (ASAS). The principal results include the following: directional radiance measurements contain much useful information for discrimination among land-cover classes; the combination of multi-angle and multi-spectral data improves the overall classification accuracy compared with a single multi-angle band; and neural networks can successfully learn class discrimination from directional data or multi-domain data. Forward canopy modeling shows that a multi-layer feed-forward neural network is able to predict the bidirectional reflectance distribution function (BRDF) of different canopy sites with 90% accuracy. Analysis of the signal captured by the network indicates that the canopy structural parameters, and illumination and viewing geometry, are essential for predicting the BRDF of vegetated surfaces. The inverse neural network model shows that the R2 between the network-predicted canopy parameters and the actual canopy parameters is 0.85 for canopy density and 0.75 for both the crown shape and the height parameters. [TRUNCATED

Modelling bidirectional radiance measurements collected by the advanced solid-state array spectroradiometer over Oregon transect conifer forests

Thesis (M.A.)--Boston UniversityThe primary objective of this research is to test and validate a geometric-optical bidirectional reflectance canopy model developed by Li and Strahler, with respect to actual forest canopy reflectance measurments. This model treats forest canopies as scenes of discrete, three dimensional objects that are illuminated and viewed from different positions in the hemisphere. The shapes of the objects, their count densities and patterns of placement are the driving variables, and they condition the mixture of sunlit and shaded objects and background that is observed from a particular viewing direction, given a direction of illumination. This mixture, in turn, controls the brightness apparent to an observer or a radiometric instrument. The Advanced Solid-State Array Spectroradiometer (ASAS) is chosen to be the sensor having the ability of collecting measurements at various look angles and its imaged reflectance was used to validate the model. The modelled BRF's were compared to actual ASAS measured BRF's in sites with different canopy structures and densities. The comparision revealed execellent match between the modelled and measured reflectance, and great ability of the model in predicting the shape and magnitude of the BRDF, in almost all the sites investigated. It is concluded that the geometric optics approach provided a good way to model the bidirectional reflectance distribution function of natural vegetation canopies, that captures the most important features exhibited by bidirectional measurements of such canopies. Further modifications have been suggested that will improve the predicted BRF's, and yield better results. [TRUNCATED

Self-aligned silicidation of surround gate vertical MOSFETs for low cost RF applications

We report for the first time a CMOS-compatible silicidation technology for surround-gate vertical MOSFETs. The technology uses a double spacer comprising a polysilicon spacer for the surround gate and a nitride spacer for silicidation and is successfully integrated with a Fillet Local OXidation (FILOX) process, which thereby delivers low overlap capacitance and high drive-current vertical devices. Silicided 80-nm vertical n-channel devices fabricated using 0.5-?m lithography are compared with nonsilicided devices. A source–drain (S/D) activation anneal of 30 s at 1100 ?C is shown to deliver a channel length of 80 nm, and the silicidation gives a 60% improvement in drive current in comparison with nonsilicided devices. The silicided devices exhibit a subthreshold slope (S) of 87 mV/dec and a drain-induced barrier lowering (DIBL) of 80 mV/V, compared with 86 mV/dec and 60 mV/V for nonsilicided devices. S-parameter measurements on the 80-nm vertical nMOS devices give an fT of 20 GHz, which is approximately two times higher than expected for comparable lateral MOSFETs fabricated using the same 0.5-?m lithography. Issues associated with silicidation down the pillar sidewall are investigated by reducing the activation anneal time to bring the silicided region closer to the p-n junction at the top of the pillar. In this situation, nonlinear transistor turn-on is observed in drain-on-top operation and dramatically degraded drive current in source-on-top operation. This behavior is interpreted using mixed-mode simulations, which show that a Schottky contact is formed around the perimeter of the pillar when the silicided contact penetrates too close to the top S/D junction down the side of the pillar

Characterizing Dust-Radiation Feedback and Refining the Horizontal Resolution of the MarsWRF Model Down to 0.5 Degree

Acknowledgments Once again, our warmest thanks go to the PlanetWRF development team for providing the MarsWRF model free of charge to us and their proactive attitude in general. We would also like to thank two anonymous reviewers and the Associate Editor Dr Claire Newman for their several detailed and insightful comments and suggestions that helped to significantly improve the quality of the paper. We would like to acknowl- edge the support of this work by funding from the United Arab Emirates University (UAE University). Also, we are deeply grateful to High-Performance Computing, Division of Information Technology, UAE University, for the valuable access to the computational resources required for this work. We thank IT engineers Asma AlNeyadi, Anil Thomas, and Nithin Damodaran for their professional assistance and support in technical questions. M.-P. Z. has been partially funded by the AEI (MDM-2017-0737, Unity of Excellence “María de Maeztu” - Centro de Astro- biología (CSIC-INTA)) and the Spanish Ministry of Science and Innovation (PID2019-104205GB-C219). Finally, we declare that there are no real or perceived conflicts of interests for any author.Peer reviewedPublisher PD

Fully Interactive and Refined Resolution Simulations of the Martian Dust Cycle by the MarsWRF Model

Acknowledgments: First of all, our warmest thanks go to the PlanetWRF development team for providing the MarsWRF model free of charge to us and their proactive attitude in general. We thank Andy Heaps, National Centre for Atmospheric Science (NCAS), Department of Meteorology, University of Reading, UK, for his helpful advice regarding the data visualization using cf‐Python. We would also like to thank Michael Mischna, Alexandre Kling, and the Associate Editor Claire Newman for their several detailed and insightful comments and suggestions that helped to significantly improve the quality of the paper. M. P. Z. acknowledges the partial support by the Spanish State Research Agency (AEI) project MDM‐2017‐0737 Centro de Astrobiología (CSIC‐INTA), Unidad de Excelencia María de Maeztu. Internally, we would like to express our greatest thanks to the High‐Performance Computing, Division of Information Technology, United Arab Emirates University. Our particular thanks go to Asma AlNeyadi, Anil Thomas, and Nithin Damodaran for their intensive and continuous support in technically demanding questions. Also, we would like to thank the Digitization Unit, UAEU Libraries, for the digitization of auxiliary data on the observational record of the atmospheric T15 temperature and vertical weighting functions of Viking/IRTM. In addition, we thank UAEU Libraries for their assistance in making supporting data of this article available online. In particular, we are grateful to Digitization Technician Shireen M. Wolied, Fadl M. Musa/Digital Library Service, and Student Muhammad Abdul Rahim Sami Ullah. Funding Information: United Arab Emirates University (UAEU). Grant Number: 21R033‐NSS Center 7‐2017 Spanish State Research Agency (AEI). Grant Number: MDM‐2017‐0737Peer reviewedPublisher PD

Bottom ash utilization: a review on engineering applications and environmental aspects

Bottom ash produced from coal-fired power plants has been utilized in engineering applications for the purpose of recycling and solving disposal issue of bottom ash. This study reviews various applications of bottom ash in engineering fields. The engineering properties exhibited by bottom ash in terms of free draining, granular, lightweight and interlocking nanostructures allow them to be used for different functions. The bottom ash used is not limited to its raw state, but can be mixed and modified for advanced applications without neglecting the impacts on the environmental. The presence of metals in bottom ash are well known and being discussed whether they are harmful to the environment. Many countries have their own threshold limit of maximum contaminants, hence TCLP result will determine the hazardous status of bottom ash. This review helps in promoting the solution and potential usage of bottom ash, since coal is one of the dominant source of energy in power generation sector

Evaluation of coal bottom ash properties and its applicability as engineering material

Coal ash is obtained in the combustion of coal for electricity production in coal based power stations. The non-combustible by-product including bottom ash and fly ash are discarded as a landfill. Consequently, the hazardous elements contained in the ashes can adulterate the ground and surface water. This study was carried out to emphasize the engineering properties of bottom ash collected at Tanjung Bin power station. An experimental study was carried out for particle size analysis, specific gravity, shear strength, compaction and relative density. The results depict that bottom ash possess particle size distribution nearly identical to sand, low specific gravity and dry density as compared to natural soil and having higher internal friction angle closer to granular materials. Based on the results, bottom ash can be employed in roadways, embankments and filling material for retaining walls by virtue of its low specific gravity, easy to compact and good frictional characteristics

Improving influenza vaccination rate among primary healthcareworkers in Qatar

The purpose of this study was to improve influenza vaccination, and determine factors influencing vaccine declination among health care workers (HCW) in Qatar. We launched an influenza vaccination campaign to vaccinate around 4700 HCW in 22 Primary Health Care Corporation (PHCC) centers in Qatar between 1st and 15th of November, 2015. Our target was to vaccinate 60% of all HCW. Vaccine was offered free of charge at all centers, and information about the campaign and the importance of influenza vaccination was provided to employees through direct communication, emails, and social media networks. Staff were reported as vaccinated or non-vaccinated using a declination form that included their occupation, place of work and reasons for declining the vaccine. Survey responses were summarized as proportional outcomes. We exceeded our goal, and vaccinated 77% of the target population. Only 9% declined to take the vaccine, and the remaining 14% were either on leave or had already been vaccinated. Vaccine uptake was highest among aides (98.1%), followed by technicians (95.2%), and was lowest amongst pharmacists (73.2%), preceded by physicians (84%). Of those that declined the vaccine, 34% provided no reason, 18% declined it due to behavioral issues, and 21% declined it due to medical reasons. Uptake of influenza vaccine significantly increased during the 2015 immunization campaign. This is attributed to good planning, preparation, a high level of communication, and providing awareness and training to HCW with proper supervision and monitoring. 1 2017 by the authors. Licensee MDPI, Basel, Switzerland.Acknowledgments: We would like to thank all staff for participation in the 2015 influenza vaccination campaign at the PHCC. Members of the Health protection at MoPH and PHCC communicable disease control team are highly acknowledged for assistance with implementation. This Study was funded by the Ministry of Public Health.Scopu

Performance of Layer-by-Layer-Modified Multibore® Ultrafiltration Capillary Membranes for Salt Retention and Removal of Antibiotic Resistance Genes

Polyether sulfone Multibore® ultrafiltration membranes were modified using polyelectrolyte multilayers via the layer-by-layer (LbL) technique in order to increase their rejection capabilities towards salts and antibiotic resistance genes. The modified capillary membranes were characterized to exhibit a molecular weight cut-off (at 90% rejection) of 384 Da. The zeta-potential at pH 7 was −40 mV. Laboratory tests using single-fiber modified membrane modules were performed to evaluate the removal of antibiotic resistance genes; the LbL-coated membranes were able to completely retain DNA fragments from 90 to 1500 nt in length. Furthermore, the pure water permeability and the retention of single inorganic salts, MgSO$_{4}$, CaCl$_{2}$ and NaCl, were measured using a mini-plant testing unit. The modified membranes had a retention of 80% toward MgSO$_{4}$ and CaCl$_{2}$ salts, and 23% in case of NaCl. The modified membranes were also found to be stable against mechanical backwashing (up to 80 LMH) and chemical regeneration (in acidic conditions and basic/oxidizing conditions)