Physical Sciences and Mathematics Commons^™

Effects Of Seasonal Rest Grazing And Diet Selection Of Sheep On Pasture Composition In Bromus Inermis Improved Meadow Steppe, H. Zhang, Y. J. Zhang, N. Liu

IGC Proceedings (1977-2023)

To develop sustainable grazing management systems based on highly-productive dominant species, it is critical to maintain pasture growth and prevent land degradation on meadow steppe. A field study was performed to identify the impact of seasonal rest grazing on diet selection of sheep and pasture composition in Bromus inermis improved meadow steppe from 2015 to 2017 in Hulunbuir, Inner Mongolia, China. Three seasonal rest grazing strategies were conducted: R1 included a spring rest from June 15 to July 15, R2 a summer rest from July 15 to August 15 and R3 an autumn rest from August 15 to September 15. …

The Effect Of Hay Supplementation On Performance Of Grazing Alpaca In The Peruvian Andes, M. Enciso, C. Gómez, C. Osorio

IGC Proceedings (1977-2023)

Productivity of alpaca grazing rangelands in the Andes is often limited by the low availability and quality of those pastures during the dry season of the year. The use as supplements of forages cultivated during the rainy season in appropriate areas in the Andes may be a strategy to improve performance of alpacas. Therefore, the supplementation of oat-vetch pellets or oat hay was evaluated and compared with a control group without supplementation. Sixty three female alpacas (15 months of age, 34 ± 1.0 kg BW), divided in three groups, grazing range pastures (6.1% crude protein and 61.3% NDF) during dry …

Allodb: An R Package For Biomass Estimation At Globally Distributed Extratropical Forest Plots, Erika Gonzalez-Akre, Camille Piponiot, Mauro Lepore, Valentine Herrmann, James A. Lutz, Jennifer L. Baltzer, Christopher W. Dick, Gregory S. Gilbert, Fangliang He, Michael Heym, Alejandra I. Huerta, Patrick A. Jansen, Daniel J. Johnson, Nikolai Knapp, Kamil Král, Dunmei Lin, Yadvinder Malhi, Sean M. Mcmahon, Jonathan A. Myers, David Orwig, Diego I. Rodríguez-Hernández, Sabrina E. Russo, Jessica Shue, Xugao Wang, Amy Wolf, Tonghui Yang, Stuart J. Davies, Kristina J. Anderson-Teixeira

School of Natural Resources: Faculty Publications

Allometric equations for calculation of tree above-ground biomass (AGB) form the basis for estimates of forest carbon storage and exchange with the atmosphere. While standard models exist to calculate forest biomass across the tropics, we lack a standardized tool for computing AGB across boreal and temperate regions that comprise the global extratropics. Here we present an integrated R package, allodb, containing systematically selected published allometric equations and proposed functions to compute AGB. The data component of the package is based on 701 woody species identified at 24 large Forest Global Earth Observatory (ForestGEO) forest dynamics plots representing a wide diversity …

Determining If Active Galactic Nuclei (Agn) Jets Can Survive The Cold Fronts Of Merger Galaxies, Stephen Walker, Isabelle Wingate

Summer Community of Scholars (RCEU and HCR) Project Proposals

No abstract provided.

On Inclusions With Monotone-Type Mappings In Nonreflexive Banach Spaces, Vy Khoi Le

Mathematics and Statistics Faculty Research & Creative Works

We are concerned in this article with the existence of solutions to inclusions containing generalized pseudomonotone perturbations of maximal monotone mappings in general Banach spaces. Our approach is based on a truncation–regularization technique and an extension of the Moreau–Yosida–Brezis–Crandall–Pazy regularization for maximal monotone mappings in general Banach spaces. We also consider some applications to multivalued variational inequalities containing elliptic operators with rapidly growing coefficients in Orlicz–Sobolev spaces.

Marginal Proportional Hazards Models For Clustered Interval-Censored Data With Time-Dependent Covariates, Kaitlyn Cook, Wenbin Lu, Rui Wang

Harvard University Biostatistics Working Paper Series

The Botswana Combination Prevention Project was a cluster-randomized HIV prevention trial whose follow-up period coincided with Botswana’s national adoption of a universal test-and-treat strategy for HIV management. Of interest is whether, and to what extent, this change in policy (i) modified the observed preventative effects of the study intervention and (ii) was associated with a reduction in the population-level incidence of HIV in Botswana. To address these questions, we propose a stratified proportional hazards model for clustered interval-censored data with time-dependent covariates and develop a composite expectation maximization algorithm that facilitates estimation of model parameters without placing parametric assumptions on …

Sustainability Obligations And Liabilities For The Company Director, Richard Allen, Michael Tang, Jan Tan, Gautam Mukharya

Perspectives@SMU

SGX now requires its listees to issue a sustainability report. Why is this happening? And what do directors need to know?

A Multigrid Multilevel Monte Carlo Method For Stokes–Darcy Model With Random Hydraulic Conductivity And Beavers–Joseph Condition, Zhipeng Yang, Ju Ming, Changxin Qiu, Maojun Li, Xiaoming He

Mathematics and Statistics Faculty Research & Creative Works

A multigrid multilevel Monte Carlo (MGMLMC) method is developed for the stochastic Stokes–Darcy interface model with random hydraulic conductivity both in the porous media domain and on the interface. Three interface conditions with randomness are considered on the interface between Stokes and Darcy equations, especially the Beavers–Joesph interface condition with random hydraulic conductivity. Because the randomness through the interface affects the flow in the Stokes domain, we investigate the coupled stochastic Stokes–Darcy model to improve the fidelity. Under suitable assumptions on the random coefficient, we prove the existence and uniqueness of the weak solution of the variational form. To construct …

Global And Regional Sea Level Rise Scenarios For The United States, National Oceanic And Atmospheric Administration (Noaa)

State & Federal Reports and Publications

This report and accompanying datasets from the U.S. Sea Level Rise and Coastal Flood Hazard Scenarios and Tools Interagency Task Force provide 1) sea level rise scenarios to 2150 by decade that include estimates of vertical land motion and 2) a set of extreme water level probabilities for various heights along the U.S. coastline. These data are available at 1-degree grids along the U.S. coastline and downscaled specifically at NOAA tide-gauge locations. Estimates of flood exposure are assessed using contemporary U.S. coastal flood-severity thresholds for current conditions (e.g., sea levels and infrastructure footprint) and for the next 30 years (out …

Corrected Tilt Calculation For Atmospheric Pressure-Induced Seismic Noise, Richard Raspet, Craig J. Hickey, Bipin Koirala

Faculty and Student Publications

In a literature search on the coupling of wind-generated pressure fluctuations into seismic noise, it was noticed that the expression for the angular tilt induced by pressure fluctuations in the seminal paper “A preliminary investigation into the relationship between long-period seismic noise and local fluctuations in the atmospheric pressure” by G. G. Sorrells was only valid at the surface. A search of the literature which cites the Sorrells paper was performed to see if any subsequent research corrected this error, and what effect the error might have on the research. A recent paper by Tanimoto and Wang notes the correct …

Probability Models With Discrete And Continuous Parts, James E. Marengo, David L. Farnsworth

Articles

In mathematical statistics courses, students learn that the quadratic function E ((X – x )-squared) is minimized when x is the mean of the random variable X, and that the graphs of this function for any two distributions of X are simply translates of each other. We focus on the problem of minimizing the function defined by y ( x) = E ( IX – xI-squared ) in the context of mixtures of probability distributions of the discrete, absolutely continuous, and singular continuous types. This problem is important, for example, in Bayesian statistics, when one attempts to compute the decision …

2022 Gray Wolf Questions And Answers, United States Fish And Wildlife Service

United States Fish and Wildlife Service: Publications

2022 Gray Wolf Questions and Answers

What does the February 10, 2022, ruling mean?

How does this ruling affect wolves in the Northern Rocky Mountains?

When does the court decision to vacate the delisting rule go into effect?

What is the legal status of gray wolves as of this ruling?

Is the Service continuing its status review of wolves in the western United States?

Is emergency listing an option for the Northern Rocky Mountain population?

Are wolf hunts going to stop as a result of the court decision?

How does this ruling affect wolves in Yellowstone National Park?

Where can …

Ordered Weighted Averaging (Owa), Decision Making Under Uncertainty, And Deep Learning: How Is This All Related?, Vladik Kreinovich

Departmental Technical Reports (CS)

Among many research areas to which Ron Yager contributed are decision making under uncertainty (in particular, under interval and fuzzy uncertainty) and aggregation -- where he proposed, analyzed, and utilized ordered weighted averaging (OWA). The OWA algorithm itself provides only a specific type of data aggregation. However, it turns out that if we allow several OWA stages, one after another, we obtain a scheme with a universal approximation property -- moreover, a scheme which is perfectly equivalent to modern ReLU-based deep neural networks. In this sense, Ron Yager can be viewed as a (grand)father of ReLU-based deep learning. We also …

Motivations Do Not Decrease Procrastination, So What Can We Do?, Olga Kosheleva, Vladik Kreinovich, Christian Servin

Departmental Technical Reports (CS)

Students often start working on their assignments late and, as a result, turn them in late. This procrastination makes grading more difficult. It also delays posting correct solutions that could help students understand their mistakes – and this hinders the students’ progress in studying following topics. At first glance, motivation seems to be a solution to all pedagogical problems: a motivated student eagerly collaborates with the instructor to learn more. Motivation indeed increases students’ knowledge, but, unfortunately, it does not decrease procrastination. So what can we do? We can institute heavy penalties for late submissions, but this would unfairly punish …

Unexpected Economic Consequence Of Cloud Computing: A Boost To Algorithmic Creativity, Francisco Zapata, Eric Smith, Vladik Kreinovich

Departmental Technical Reports (CS)

While theoreticians have been designing more and more efficient algorithms, in the past, practitioners were not very interested in this activity: if a company already owns computers that provide computations in required time, there is nothing to gain by using faster algorithms. We show the situation has drastically changed with the transition to cloud computing: many companies have not yet realized this, but with the transition to cloud computing, any algorithmic speed up leads to immediate financial gain. This also has serious consequences for the whole computing profession: there is a need for professionals better trained in subtle aspects of …

Unreachable Statements Are Inevitable In Software Testing: Theoretical Explanation, Francisco Zapata, Eric Smith, Vladik Kreinovich

Departmental Technical Reports (CS)

Business gurus recommend that an organization should have, in addition to clearly described realistic goals, also additional aspirational goals -- goals for which we may not have resources and which most probably will not be reached at all. At first glance, adding such a vague goal cannot lead to a drastic change in how the company operates, but surprisingly, for many companies, the mere presence of such aspirational goals boosts the company's performance. In this paper, we show that a simple geometric model of this situation can explain the unexpected success of aspirational goals.

A Natural Causality-Motivated Description Of Learning, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

Teaching is not easy. One of the main reasons why it is not easy is that the existing descriptions of the teaching process are not very precise -- and thus, we cannot use the usual optimization techniques, techniques which require a precise model of the corresponding phenomenon. It is therefore desirable to come up with a precise description of the learning process. To come up with such a description, we notice that on the set of all possible states of learning, there is a natural order s ≤ s' meaning that we can bring the student from the state s …

Why Gaussian Copulas Are Ubiquitous In Economics: Fuzzy-Related Explanation, Chon Van Le, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

In many real-life situations, deviations are caused by a large number of independent factors. It is known that in such situations, the distribution of the resulting deviations is close to Gaussian, and thus, that the copulas -- that describe the multi-D distributions as a function of 1-D (marginal) ones -- are also Gaussian. In the past, these conclusions were also applied to economic phenomena, until the 2008 crisis showed that in economics, Gaussian models can lead to disastrous consequences. At present, all economists agree that the economic distributions are not Gaussian -- however, surprisingly, Gaussian copulas still often provide an …

Video Or Text? Bullets Or No Bullets? Why Not Both?, Olga Kosheleva, Vladik Kreinovich, Christian Servin

Departmental Technical Reports (CS)

Some students – which are, in terms of pop-psychology – more left-brain – prefer linear exposition, others – more right-brain ones – prefer 2-D images and texts with visual emphasis (e.g., with bullets). At present, instructors try to find a middle grounds between these two audiences, but why not prepare each material in two ways, aimed at both audiences?

Computing The Range Of A Function-Of-Few-Linear-Combinations Under Linear Constraints: A Feasible Algorithm, Salvador Robles, Martine Ceberio, Vladik Kreinovich

Departmental Technical Reports (CS)

In many practical situations, we need to find the range of a given function under interval uncertainty. For nonlinear functions -- even for quadratic ones -- this problem is, in general, NP-hard; however, feasible algorithms exist for many specific cases. In particular, recently a feasible algorithm was developed for computing the range of the absolute value of a Fourier coefficient under uncertainty. In this paper, we generalize this algorithm to the case when we have a function of a few linear combinations of inputs. The resulting algorithm also handles the case when, in addition to intervals containing each input, we …

Flexible Dye-Sensitized Solar Cells Assisted With Lead-Free Perovskite Halide, Judy Fan

Physics Faculty Research

Dye-sensitized solar cells (DSSCs) have shown promising alternative to Si-based counterparts due to low-cost, abundant raw materials, and non-vacuum processing. Here, we report a solution-based process to create flexible DSSCs on aluminum foils. Mesoporous TiO₂ electrode was directly deposited on Al foil through spin casting. After post-thermal annealing, the resultant samples render optical smooth, crack-free, and large nanocrystalline thin films. The as-prepared double-layer porous TiO₂ thin film was incorporated with a porphyrin dye followed by a perovskite halide salt Cs₂SnI₆, as the hole transport material, replacing liquid electrolyte. A transparent conducting plastic sheet was …

An Equity-First Approach To Climate Adaptation, San Diego Regional Climate Collaborative, San Diego Association Of Governments

San Diego Regional Climate Collaborative

The Equity-First Approach to Climate Adaptation guidance document (Equity Guidance; document) serves as a general framework for local agency planners and transportation planning professionals. The Equity Guidance’s overall goal is to provide best practices for designing, planning, and implementing a climate adaptation process that supports equitable outcomes. This document identifies trends, assumptions, emerging practices, indicators, metrics, and implementation opportunities, that support and operationalize an equitable climate adaptation planning process.

Supertranslations At Timelike Infinity, Sumanta Chakraborty, Debodirna Ghosh, Sk Jahanur Hoque, Aniket Khairnar, Amitabh Virmani

Faculty and Student Publications

We propose a definition of asymptotic flatness at timelike infinity in four spacetime dimensions. We present a detailed study of the asymptotic equations of motion and the action of supertranslations on asymptotic fields. We show that the Lee-Wald symplectic form Ω(g, δ1g, δ2g) does not get contributions from future timelike infinity with our boundary conditions. As a result, the “future charges” can be computed on any two-dimensional surface surrounding the sources at timelike infinity. We present expressions for supertranslation and Lorentz charges.

Tess Giants Transiting Giants. I.: A Noninflated Hot Jupiter Orbiting A Massive Subgiant, N. Saunders, S. K. Grunblatt, D. Huber, K. A. Collins, Eric L.N. Jensen, A. Vanderburg, R. Brahm, A. Jordán, N. Espinoza, T. Henning, M. J. Hobson, S. N. Quinn, G. Zhou, R. P. Butler, L. Crause, R. B. Kuhn, K. M. Mogotsi, C. Hellier, R. Angus, S. Hattori, A. Chontos, G. R. Ricker, J. M. Jenkins, P. Tenenbaum, D. W. Latham, S. Seager, R. K. Vanderspek, J. N. Winn, C. Stockdale, R. Cloutier

Physics & Astronomy Faculty Works

While the population of confirmed exoplanets continues to grow, the sample of confirmed transiting planets around evolved stars is still limited. We present the discovery and confirmation of a hot Jupiter orbiting TOI-2184 (TIC 176956893), a massive evolved subgiant (M_⋆ = 1.53 ± 0.12 M_⊙, R_⋆ = 2.90 ± 0.14 R_⊙) in the Transiting Exoplanet Survey Satellite (TESS) Southern Continuous Viewing Zone. The planet was flagged as a false positive by the TESS Quick-Look Pipeline due to periodic systematics introducing a spurious depth difference between even and odd transits. Using a new pipeline …

Toi-1842b: A Transiting Warm Saturn Undergoing Reinflation Around An Evolving Subgiant, R. A. Wittenmyer, J. T. Clark, T. Trifonov, B. C. Addison, D. J. Wright, K. G. Stassun, J. Horner, N. Lowson, J. Kielkopf, S. R. Kane, P. Plavchan, A. Shporer, H. Zhang, B. P. Bowler, M. W. Mengel, J. Okumura, M. Rabus, M. C. Johnson, D. Harbeck, R. Tronsgaard, L. A. Buchhave, K. A. Collins, K. I. Collins, T. Gan, Eric L.N. Jensen, S. B. Howell, E. Furlan, C. L. Gnilka, K. V. Lester, R. A. Matson, N. J. Scott, G. R. Ricker, R. Vanderspek, D. W. Latham, S. Seager, J. N. Winn, J. M. Jenkins, A. Rudat, E. V. Quintana, D. R. Rodriguez, D. A. Caldwell, S. N. Quinn, Z. Essack, L. G. Bouma

Physics & Astronomy Faculty Works

The imminent launch of space telescopes designed to probe the atmospheres of exoplanets has prompted new efforts to prioritize the thousands of transiting planet candidates for follow-up characterization. We report the detection and confirmation of TOI-1842b, a warm Saturn identified by TESS and confirmed with ground-based observations from Minerva-Australis, NRES, and the Las Cumbres Observatory Global Telescope. This planet has a radius of 1.04 (+0.06)/(-0.05) R_J, a mass of 0.214 (+0.040)/(-0.038) M_J, an orbital period of 9.5739 (+0.0002)/(-0.0001) days, and an extremely low density (ρ = 0.252 ± 0.091 g cm⁻³). TOI-1842b has among the …

Disturbance Reduces Fungal White-Rot Litter Mat Cover In A Wet Subtropical Forest, D. Jean Lodge, Ashley E. Van Beusekom, Grizelle González, Mareli Sánchez-Julia, Sarah Stankavich

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Fungi that bind leaf litter into mats and produce white-rot via degradation of lignin and other aromatic compounds influence forest nutrient cycling and soil fertility. Extent of white-rot litter mats formed by basidiomycete fungi in Puerto Rico decreased in response to disturbances—a simulated hurricane treatment executed by canopy trimming and debris addition in 2014, a drought in 2015, a treefall, and two hurricanes 10 days apart in September 2017. Percent fungal litter mat cover ranged from 0.4% after Hurricanes Irma and Maria to a high of 53% in forest with undisturbed canopy prior to the 2017 hurricanes, with means mostly …

New Formulations Of The Union-Closed Sets Conjecture, Sudipta Mallik

Mathematics Faculty Research

The union-closed sets conjecture states that if a finite set A of finite sets is union-closed and A ≠ {∅}, then there exists an element in ∪ _{A ∈ A} A that belongs to at least half of the sets in A. We present three new formulations of the union-closed conjecture in terms of matrices, graphs, and hypergraphs.

Commonsense-Continuous Dynamical Systems -- Stationary States, Prediction, And Reconstruction Of The Past: Fuzzy-Based Analysis, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

Traditional analysis of dynamical systems usually assumes that the mapping is continuous -- in precise mathematical sense. However, as many formal definitions, the mathematical definition of continuity does not always adequately capture the commonsense notion of continuity: that small changes in the input should lead to small changes in the output. In this paper, we provide a natural fuzzy-based formalization of this intuitive notion, and analyze how the requirement of commonsense continuity affects the properties of dynamical systems. Specifically, we show that for such systems, the set of fixed points is closed and convex, and that the only such systems …

Need For Techniques Intermediate Between Interval And Probabilistic Ones, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

In high performance computing, when we process a large amount of data, we do not have much information about the dependence between measurement errors corresponding to different inputs. To gauge the uncertainty of the result of data processing, the two usual approaches are: the interval approach, when we consider the worst-case scenario in which all measurement errors are strongly correlated, and the probabilistic approach, when we assume that all these errors are independent. The problem is that usually, the interval approach leads to too pessimistic, too large uncertainty estimates, while the probabilistic approach often underestimates the resulting uncertainty. To get …

Fuzzy Or Neural, Type-1 Or Type-2 -- When Each Is Better: First-Approximation Analysis, Vladik Kreinovich, Olga Kosheleva

Departmental Technical Reports (CS)

In many practical situations, we need to determine the dependence between different quantities based on the empirical data. Several methods exist for solving this problem, including neural techniques and different versions of fuzzy techniques: type-1, type-2, etc. In some cases, some of these techniques work better, in other cases, other methods work better. Usually, practitioners try several techniques and select the one that works best for their problem. This trying often requires a lot of efforts. It would be more efficient if we could have a priori recommendations about which technique is better. In this paper, we use the first-approximation …