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2020

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Full-Text Articles in Physical Sciences and Mathematics

Sybil Defense Using Efficient Resource Burning, Diksha Gupta Dec 2020

Sybil Defense Using Efficient Resource Burning, Diksha Gupta

Computer Science ETDs

In 1993, Dwork and Naor proposed using computational puzzles, a resource burning mechanism, to combat spam email. In the ensuing three decades, resource burning has broadened to include communication capacity, computer memory, and human effort. It has become a well-established tool in distributed security. Due to the cost attached to utilizing resource burning mechanism, these have not been popularized in domains apart from cryptocurrency.

In this dissertation, we design efficient resource burning based Sybil defense techniques for permissionless systems. As a first step, we identify existing resource burning mechanisms in literature in Chapter 2. Additionally, we enumerate numerous open problems …


Outdoor Air Pollution Exposure And Inter-Relation Of Global Cognitive Performance And Emotional Distress In Older Women, Andrew J. Petkus, Xinhui Wang, Daniel P. Beavers, Helena C. Chui, Mark A. Espeland, Margaret Gatz, Tara Gruenewald, Joel D. Kaufman, Joann E. Manson, Susan M. Resnick, James D. Stewart, Gregory A. Wellenius, Eric A. Whitsel, Keith Widaman, Diana Younan, Jiu-Chiuan Chen Dec 2020

Outdoor Air Pollution Exposure And Inter-Relation Of Global Cognitive Performance And Emotional Distress In Older Women, Andrew J. Petkus, Xinhui Wang, Daniel P. Beavers, Helena C. Chui, Mark A. Espeland, Margaret Gatz, Tara Gruenewald, Joel D. Kaufman, Joann E. Manson, Susan M. Resnick, James D. Stewart, Gregory A. Wellenius, Eric A. Whitsel, Keith Widaman, Diana Younan, Jiu-Chiuan Chen

Psychology Faculty Articles and Research

The interrelationships among long-term ambient air pollution exposure, emotional distress and cognitive decline in older adulthood remain unclear. Long-term exposure may impact cognitive performance and subsequently impact emotional health. Conversely, exposure may initially be associated with emotional distress followed by declines in cognitive performance. Here we tested the inter-relationship between global cognitive ability, emotional distress, and exposure to PM2.5 (particulate matter with aerodynamic diameter 2 (nitrogen dioxide) in 6118 older women (aged 70.6 ± 3.8 years) from the Women’s Health Initiative Memory Study. Annual exposure to PM2.5 (interquartile range [IQR] = 3.37 μg/m3) and NO2 (IQR …


Two New Finite Element Schemes And Their Analysis For Modeling Of Wave Propagation In Graphene, Jichun Li Dec 2020

Two New Finite Element Schemes And Their Analysis For Modeling Of Wave Propagation In Graphene, Jichun Li

Mathematical Sciences Faculty Research

© 2020 The Author(s) In this paper, we investigate a system of governing equations for modeling wave propagation in graphene. Compared to our previous work (Yang et al., 2020), here we re-investigate the governing equations by eliminating two auxiliary unknowns from the original model. A totally new stability for the model is established for the first time. Since the finite element scheme proposed in Yang et al. (2020) is only first order in time, here we propose two new schemes with second order convergence in time for the simplified modeling equations. Discrete stabilities inheriting exactly the same form as the …


Short Term Variations In The Leaf Area Index, Tiller Density And Botanical Composition Of The Grassland In Inner Mongolia As Affected By Light To Very Heavy Grazing Intensities, H. Wan, P. Schönbach, M. Gierus, Anne Schiborra, Y. Bai, Friedhelm Taube Dec 2020

Short Term Variations In The Leaf Area Index, Tiller Density And Botanical Composition Of The Grassland In Inner Mongolia As Affected By Light To Very Heavy Grazing Intensities, H. Wan, P. Schönbach, M. Gierus, Anne Schiborra, Y. Bai, Friedhelm Taube

IGC Proceedings (1993-2023)

No abstract provided.


The Use Of Concentrate Supplements To Overcome Seasonal Shortages Of Grazed Herbage In Beef Production Systems, Valéria P. B. Euclides, Kepler Euclides Filho, Fernando Paim Costa, Alexandre Scaff Raffia Dec 2020

The Use Of Concentrate Supplements To Overcome Seasonal Shortages Of Grazed Herbage In Beef Production Systems, Valéria P. B. Euclides, Kepler Euclides Filho, Fernando Paim Costa, Alexandre Scaff Raffia

IGC Proceedings (1993-2023)

No abstract provided.


Effects Of Novel Ryegrass Endophytes On Pasture Production And Milk Production From Dairy Cows In Northern New Zealand, Errol R. Thom, C. D. Waugh, E. M. K. Minneé, G. C. Waghorn, Alison J. Popay Dec 2020

Effects Of Novel Ryegrass Endophytes On Pasture Production And Milk Production From Dairy Cows In Northern New Zealand, Errol R. Thom, C. D. Waugh, E. M. K. Minneé, G. C. Waghorn, Alison J. Popay

IGC Proceedings (1993-2023)

No abstract provided.


The Cottonwood Ranch Riparian Management Case Study, Sherman Swanson, Kent Mcadoo, Agee Smith, Sandra Wyman Dec 2020

The Cottonwood Ranch Riparian Management Case Study, Sherman Swanson, Kent Mcadoo, Agee Smith, Sandra Wyman

IGC Proceedings (1993-2023)

No abstract provided.


Grazing Itineraries And Feed Intake Of Goats On Communal Pastures Of The Jabal Al Akhdar Mountain Range, Northern Oman, E. Schlecht, U. Dickhoefer, M. Predotova, Andreas Buerkert Dec 2020

Grazing Itineraries And Feed Intake Of Goats On Communal Pastures Of The Jabal Al Akhdar Mountain Range, Northern Oman, E. Schlecht, U. Dickhoefer, M. Predotova, Andreas Buerkert

IGC Proceedings (1993-2023)

No abstract provided.


Timing Of Grazing Affects Sandhills Grassland Productivity And Diet Quality, W. H. Schacht, J. D. Volesky, P. R. Schroeder Dec 2020

Timing Of Grazing Affects Sandhills Grassland Productivity And Diet Quality, W. H. Schacht, J. D. Volesky, P. R. Schroeder

IGC Proceedings (1993-2023)

No abstract provided.


Ever Graze‐More Livestock From Perennials, Geoffrey Saul, Angela Avery Dec 2020

Ever Graze‐More Livestock From Perennials, Geoffrey Saul, Angela Avery

IGC Proceedings (1993-2023)

No abstract provided.


Ever Graze‐Prime Lamb Production On Perennial Based Grasslands In Southwest Australia, Paul Sanford, J. Ryan, P. Jakobsson, E. Dobbe, E. Mccready Dec 2020

Ever Graze‐Prime Lamb Production On Perennial Based Grasslands In Southwest Australia, Paul Sanford, J. Ryan, P. Jakobsson, E. Dobbe, E. Mccready

IGC Proceedings (1993-2023)

No abstract provided.


Production Raigras According Topographic Position And Year In Natural Grasslands Buenos Aires, Argentina, Mónica B. Sacido, Ezequiel M. Latorre, Verónica Porello, Gerardo Divino, Alejandro Quiaquinta Dec 2020

Production Raigras According Topographic Position And Year In Natural Grasslands Buenos Aires, Argentina, Mónica B. Sacido, Ezequiel M. Latorre, Verónica Porello, Gerardo Divino, Alejandro Quiaquinta

IGC Proceedings (1993-2023)

No abstract provided.


Operationalizing Niche Construction Theory With Stone Tools, Radu Lovita, David R. Braun, Matthew J. Douglass, Simon J. Holdaway, Sam C. Lin, Deborah I. Olsezewski, Zeljko Rezek Dec 2020

Operationalizing Niche Construction Theory With Stone Tools, Radu Lovita, David R. Braun, Matthew J. Douglass, Simon J. Holdaway, Sam C. Lin, Deborah I. Olsezewski, Zeljko Rezek

School of Natural Resources: Faculty Publications

One of the greatest difficulties with evolutionary approaches in the study of stone tools (lithics) has been finding a mechanism for tying culture and biology in a way that preserves human agency and operates at scales that are visible in the archaeological record. The concept of niche construction, whereby organisms actively construct their environments and change the conditions for selection, could provide a solution to this problem. In this review, we evaluate the utility of niche construction theory (NCT) for stone tool archaeology. We apply NCT to lithics both as part of the “extended phenotype” and as residuals or precipitates …


Nyc Communities Battle Flooding, But Not From Coastal Storms, Danielle C. Cruz Dec 2020

Nyc Communities Battle Flooding, But Not From Coastal Storms, Danielle C. Cruz

Capstones

A look at the impact high-tide flooding and inland flooding has on various communities in New York City. This article also looks into what city officials are doing and not doing to address the concerns of residents who have had to deal with recurring flooding in their community.

Link to Capstone: https://danielle-cruz.format.com/nyc-communities-battle-flooding


Adaptive Ensemble Of Classifiers With Regularization For Imbalanced Data Classification, Chen Wang, Chengyuan Deng, Zhoulu Yu, Dafeng Hui, Xiaofeng Gong, Ruisen Luo Dec 2020

Adaptive Ensemble Of Classifiers With Regularization For Imbalanced Data Classification, Chen Wang, Chengyuan Deng, Zhoulu Yu, Dafeng Hui, Xiaofeng Gong, Ruisen Luo

Biology Faculty Research

The dynamic ensemble selection of classifiers is an effective approach for processing label-imbalanced data classifications. However, such a technique is prone to overfitting, owing to the lack of regularization methods and the dependence on local geometry of data. In this study, focusing on binary imbalanced data classification, a novel dynamic ensemble method, namely adaptive ensemble of classifiers with regularization (AER), is proposed, to overcome the stated limitations. The method solves the overfitting problem through a new perspective of implicit regularization. Specifically, it leverages the properties of stochastic gradient descent to obtain the solution with the minimum norm, thereby achieving regularization; …


Coal Energy And Environmental Impacts: Introduction, Luis F. O. Silva, Amy L. Wolfe Dec 2020

Coal Energy And Environmental Impacts: Introduction, Luis F. O. Silva, Amy L. Wolfe

Faculty, Staff, and Affiliated Publications--KGS

No abstract provided.


Microstructural Constraints On The Nebular And Asteroidal Histories Of Calcium-Aluminum-Rich Inclusions From Cv3 Chondrites, Shaofan Che Dec 2020

Microstructural Constraints On The Nebular And Asteroidal Histories Of Calcium-Aluminum-Rich Inclusions From Cv3 Chondrites, Shaofan Che

Earth and Planetary Sciences ETDs

The petrology and mineralogy of calcium-aluminum-rich inclusions (CAIs) from CV3 carbonaceous chondrites have been investigated using transmission electron microscopy (TEM). The goal of this dissertation is twofold: (1) to gain new insights into the nebular processes, such as vapor-solid reactions, accretion, transport, that are responsible for the formation of non-igneous CAIs, and (2) to better understand the role of fluid in the secondary alteration of CAIs on the CV3 chondrite parent body. This work represents the first systematic microstructural study of CAIs from CV3 chondrites.

Chapter 2 presents the microstructural observations of primary mineralogies of fine-grained, spinel-rich inclusions (FGIs) from …


Paddock To Paddock Pasture Yield Variation On Dairy Farms In The Waikato Region Of New Zealand, Alvaro J. Romera, C. E. F. Clark Dec 2020

Paddock To Paddock Pasture Yield Variation On Dairy Farms In The Waikato Region Of New Zealand, Alvaro J. Romera, C. E. F. Clark

IGC Proceedings (1993-2023)

No abstract provided.


In‐Herd Diversity Of Lifetime Performances: A Key For The Sustainability Of Livestock Farming System Based On Grassland, Laurence Puillet, D. Sauvant, M. Tichit Dec 2020

In‐Herd Diversity Of Lifetime Performances: A Key For The Sustainability Of Livestock Farming System Based On Grassland, Laurence Puillet, D. Sauvant, M. Tichit

IGC Proceedings (1993-2023)

No abstract provided.


The Feeding Scheme Of Extensive Animal Production Systems In Montado, José Mira Potes Dec 2020

The Feeding Scheme Of Extensive Animal Production Systems In Montado, José Mira Potes

IGC Proceedings (1993-2023)

No abstract provided.


Rheological Effect During Swelling Of Polymer Membranes In Aqueous Solutions With Different Dithyremic Content, Yulchi T. Juraev, Leonard M. Sabirov, Nikolay F. Bunkin, Valeriy A. Kozlov Dec 2020

Rheological Effect During Swelling Of Polymer Membranes In Aqueous Solutions With Different Dithyremic Content, Yulchi T. Juraev, Leonard M. Sabirov, Nikolay F. Bunkin, Valeriy A. Kozlov

Scientific Journal of Samarkand University

It was shown that the swelling of the initially hydrophobic Nafion plate in ordinary water (157 ppm deuterium content) and in deuterium-depleted water (1 ppm deuterium content) in a limited volume cell occurs differently. It turned out that small changes in the deuterium content in water lead to significant differences in the dynamics of swelling of the polymer membrane. For a 175-micron thick Nafion plate, this effect is most pronounced when the distance between the windows is L = 200 microns.


A Criterion For The Solvability Of The Cauchy Problem For The System Of Thermoelasticity Equations, Iqbol Niyozov, Olimjan Maxmudov Dec 2020

A Criterion For The Solvability Of The Cauchy Problem For The System Of Thermoelasticity Equations, Iqbol Niyozov, Olimjan Maxmudov

Scientific Journal of Samarkand University

In this paper, we considered the problem of analytical continuation of the solution of the system equations of the thermoelasticity in bounded domain from its values and values of its strains on part of the boundary of this domain, i.e., the Cauchy’s problem and we give a criterion for the solvability of the Cauchy problem.


Raman Scattering Spectra Of Α-Alanine Molecular Complexes, Hakim Hushvaktov Dec 2020

Raman Scattering Spectra Of Α-Alanine Molecular Complexes, Hakim Hushvaktov

Scientific Journal of Samarkand University

The article presents the results of studying the complexity of the Raman spectra of a-alanine in the crystalline state. It has been shown by ab initio calculations that the change in the Raman spectra is explained by the formation of several types of hydrogen bonds. In Raman spectra, the presence of a hydrogen bond between molecules is manifested in the form of asymmetry and splitting of vibrational bands.


On Properties Of Some Singular Surfaces, Salim Usmanov Dec 2020

On Properties Of Some Singular Surfaces, Salim Usmanov

Scientific Journal of Samarkand University

В данной статье рассматриваются некоторые особые поверхности, задаваемые параметрическими уравнениями. Доказано, что хотя бы одна из главных кривизн не обращается в нуль в каждой регулярной точке этих поверхностей.


A Logical Method For Finding Maximum Compatible Subsystems Of Systems Of Boolean Equations, Anvar Kabulov, Erkin Urunbaev, Mansur Berdimurodov Dec 2020

A Logical Method For Finding Maximum Compatible Subsystems Of Systems Of Boolean Equations, Anvar Kabulov, Erkin Urunbaev, Mansur Berdimurodov

Scientific Journal of Samarkand University

The problem of finding the maximum joint subsystem of Boolean equation systems is solved. An algorithm for finding the maximum upper zero of a monotone Boolean function is proposed. An efficient procedure for calculating the values of monotone functions on sets of a - dimensional cube is investigated and developed. An algorithm for solving systems of Boolean equations based on the search for the maximum upper zero of monotone functions of the logic algebra is developed.


Rapid Radiological Analysis Of Building Materials, Askar Safarov, Joseph Sharonov, Ali Mukhamedov, Askarali Azimov, Akmal Safarov, Mukhammad Salimov, B Radzhabboev Dec 2020

Rapid Radiological Analysis Of Building Materials, Askar Safarov, Joseph Sharonov, Ali Mukhamedov, Askarali Azimov, Akmal Safarov, Mukhammad Salimov, B Radzhabboev

Scientific Journal of Samarkand University

Measurements of the dose-forming radionuclide concentrations such as Rа-226, Тh-232 and К-40 were carried out in samples of building materials with different ageing times. The radium equivalent activities of the samples were determined. Possible values of the correcting coefficients to the activity of Ra-226 that take into account the radioactive equilibrium were calculated. This, in turn, allows to perform rapid radiological analysis of building materials.


A Survey On Subsurface Signal Propagation, Usman Raza, Abdul Salam Dec 2020

A Survey On Subsurface Signal Propagation, Usman Raza, Abdul Salam

Faculty Publications

Wireless Underground Communication (WUC) is an emerging field that is being developed continuously. It provides secure mechanism of deploying nodes underground which shields them from any outside temperament or harsh weather conditions. This paper works towards introducing WUC and give a detail overview of WUC. It discusses system architecture of WUC along with the anatomy of the underground sensor motes deployed in WUC systems. It also compares Over-the-Air and Underground and highlights the major differences between the both type of channels. Since, UG communication is an evolving field, this paper also presents the evolution of the field along with the …


Carbon Fixation Trends In Eleven Of The World’S Largest Lakes: 2003–2018, Michael Sayers, Karl Bosse, Gary L. Fahnenstiel, Robert Shuchman Dec 2020

Carbon Fixation Trends In Eleven Of The World’S Largest Lakes: 2003–2018, Michael Sayers, Karl Bosse, Gary L. Fahnenstiel, Robert Shuchman

Michigan Tech Publications

Large freshwater lakes provide immense value to the surrounding populations, yet there is limited understanding of how these lakes will respond to climate change and other factors. This study uses satellite remote sensing to estimate annual, lake-wide primary production in 11 of the world’s largest lakes from 2003–2018. These lakes include the five Laurentian Great Lakes, the three African Great Lakes, Lake Baikal, and Great Bear and Great Slave Lakes. Mean annual production in these lakes ranged from under 200 mgC/m2/day to over 1100 mgC/m2/day, and the lakes were placed into one of three distinct groups …


Monitoring The Low Frequency Radio Transient Sky With The Long Wavelength Array, Savin Shynu Varghese Dec 2020

Monitoring The Low Frequency Radio Transient Sky With The Long Wavelength Array, Savin Shynu Varghese

Physics & Astronomy ETDs

Transient searches in radio astronomy have discovered some of the most extreme astrophysical phenomena in our universe. This has enabled us to study the physics of these explosive and dynamic sources. Most of the transient searches over the past 70 years have been at frequencies higher than 100 MHz leaving the transient sky below 100 MHz unexplored. The Long Wavelength Array (LWA) telescope offers an excellent opportunity to study the transient sky below 100 MHz with its wide field of view, high sensitivity and fast imaging at shorter timescales. This dissertation presents the transient searches carried out using the all-sky …


Finding All ∈-Good Arms In Stochastic Bandits, Blake Mason, Lalit Jain, Ardhendu S. Tripathy, Robert Nowak Dec 2020

Finding All ∈-Good Arms In Stochastic Bandits, Blake Mason, Lalit Jain, Ardhendu S. Tripathy, Robert Nowak

Computer Science Faculty Research & Creative Works

The pure-exploration problem in stochastic multi-armed bandits aims to find one or more arms with the largest (or near largest) means. Examples include finding an ∈-good arm, best-arm identification, top-k arm identification, and finding all arms with means above a specified threshold. However, the problem of finding all ∈-good arms has been overlooked in past work, although arguably this may be the most natural objective in many applications. For example, a virologist may conduct preliminary laboratory experiments on a large candidate set of treatments and move all ∈-good treatments into more expensive clinical trials. Since the ultimate clinical efficacy is …