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Articles 181141 - 181170 of 295218
Full-Text Articles in Physical Sciences and Mathematics
Analysis Of Roms Estimated Posterior Error Utilizing 4dvar Data Assimilation, Joseph Patrick Horton
Analysis Of Roms Estimated Posterior Error Utilizing 4dvar Data Assimilation, Joseph Patrick Horton
Mathematics
The appropriateness of the approximate error calculated by the Regional Ocean Modeling System (ROMS) is analyzed using Four-Dimensional Data Assimilation (4DVAR) performed on a numerical model of the San Luis Obispo Bay. An effective method of sampling data to minimize the actual error associated with the assimilated numerical model is explored by using different data sampling methods. An idealized state of the SLO bay region ("Real Run") is created to be used as the real ocean, then a numerical model of this region is created approximating this Real Run; this is known as the "Simulated State". By taking samples from …
Creating An Environmental Education Program For Camp Fire Usa, Shannon Diaz
Creating An Environmental Education Program For Camp Fire Usa, Shannon Diaz
Natural Resources Management and Environmental Sciences
The topic area for this Senior Project is Environmental Education. There were four environmental hands-on lesson plans that were created for the non-profit organization Camp Fire USA, Central Coast Council. These lessons will be implemented at Camp Natoma, the resident camp the Central Coast Council owns in Paso Robles, California. The lesson plans take up hour-long increments and have been created for youth ages eight through fifteen. The topics covered in the lessons include: composting; reduce, reuse, and recycle; solar energy; and wetlands. These lesson plans will be implemented as a new “Nature Class” that campers can choose to take …
Camera Study For Mammalian Carnivore Presence Across Seasons In Montana De Oro State Park, San Luis Obispo County, Ca, Samuel R. Young
Camera Study For Mammalian Carnivore Presence Across Seasons In Montana De Oro State Park, San Luis Obispo County, Ca, Samuel R. Young
Natural Resources Management and Environmental Sciences
Montana de Oro (MDO) is one of the largest state parks in California. Little is known however about its wildlife or their habits. Large predators such as mountain lion (Puma concolor) and black bear (Ursus americanus), and non–native species such as red fox (Vulpes vulpes) and feral pig (Sus scropha) are of management concern because of their potentially dramatic ecological roles. Cameras were deployed at 5 sites along the Coon Creek hiking trail in spring (May 3–June 7), summer (July 15–August 19), and fall (October 10–November 23) sessions with the goal of …
An Extension Of Sic Predictions To The Wiener Coactive Model, Joseph W. Houpt, James T. Townsend
An Extension Of Sic Predictions To The Wiener Coactive Model, Joseph W. Houpt, James T. Townsend
Psychology Faculty Publications
The survivor interaction contrasts (SIC) is a powerful measure for distinguishing among candidate models of human information processing. One class of models to which SIC analysis can apply are the coactive, or channel summation, models of human information processing. In general, parametric forms of coactive models assume that responses are made based on the first passage time across a fixed threshold of a sum of stochastic processes. Previous work has shown that the SIC for a coactive model based on the sum of Poisson processes has a distinctive down--up--down form, with an early negative region that is smaller than the …
Remote Characterization Of Seafloor Adjacent To Shipwrecks Using Mosaicking And Analysis Of Backscatter Response, Giuseppe Masetti, Roberto Sacile, Andrea Trucco
Remote Characterization Of Seafloor Adjacent To Shipwrecks Using Mosaicking And Analysis Of Backscatter Response, Giuseppe Masetti, Roberto Sacile, Andrea Trucco
Center for Coastal and Ocean Mapping
The paper’s aim is to evaluate mosaicking and analysis of backscatter angular responses as adequate techniques to quickly characterize the seafloor adjacent to shipwrecks, extending the results of a limited number of grabs. Both techniques have been applied to the casestudy of the VLCC Haven shipwreck site, applying the approach known as Geocoder among the available methods. From these results, the development of the research activities will attempt to improve techniques and to generalize a methodological approach for the analysis of backscatter coming from an area of seafloor with the presence of one or more anthropic objects.
On The Sum Of Reciprocals Of Amicable Numbers, Jonathan Bayless, Dominic Klyve
On The Sum Of Reciprocals Of Amicable Numbers, Jonathan Bayless, Dominic Klyve
Mathematics Faculty Scholarship
Two numbers m and n are considered amicable if the sum of their proper divisors,
s(n) and s(m), satisfy s(n) = m and s(m) = n. In 1981, Pomerance showed that
the sum of the reciprocals of all such numbers, P, is a constant. We obtain both a
lower and an upper bound on the value of P.
Automated Auction Mechanism Design With Competing Markets, Jinzhong Niu
Automated Auction Mechanism Design With Competing Markets, Jinzhong Niu
Publications and Research
Resource allocation is a major issue in multiple areas of computer science. Despite the wide range of resource types across these areas, for example real commodities in e-commerce and computing resources in distributed computing, auctions are commonly used in solving the optimization problems involved in these areas, since well designed auctions achieve desirable economic outcomes.
Auctions are markets with strict regulations governing the information available to traders in the market and the possible actions they can take. Auction mechanism design aims to manipulate the rules of an auction in order to achieve specific goals. Economists traditionally use mathematical methods, mainly …
A Hybrid Background Error Covariance Model For Assimilating Glider Data Into A Coastal Ocean Model, Max Yaremchuk, Dmitri A. Nechaev, Chudong Pan
A Hybrid Background Error Covariance Model For Assimilating Glider Data Into A Coastal Ocean Model, Max Yaremchuk, Dmitri A. Nechaev, Chudong Pan
Faculty Publications
A hybrid background error covariance (BEC) model for three-dimensional variational data assimilation of glider data into the Navy Coastal Ocean Model (NCOM) is introduced. Similar to existing atmospheric hybrid BEC models, the proposed model combines low-rank ensemble covariances B(m) with the heuristic Gaussian-shaped covariances B(0) to estimate forecast error statistics. The distinctive features of the proposed BEC model are the following: (i) formulation in terms of inverse error covariances, (ii) adaptive determination of the rank m of B(m) with information criterion based on the innovation error statistics, (iii) restriction of the heuristic covariance operator B(0) to the null space of …
Local Closed-World Reasoning With Description Logics Under The Well-Founded Semantics, Matthias Knorr, Jose Julio Alferes, Pascal Hitzler
Local Closed-World Reasoning With Description Logics Under The Well-Founded Semantics, Matthias Knorr, Jose Julio Alferes, Pascal Hitzler
Computer Science and Engineering Faculty Publications
An important question for the upcoming Semantic Web is how to best combine open world ontology languages, such as the OWL-based ones, with closed world rule-based languages. One of the most mature proposals for this combination is known as hybrid MKNF knowledge bases (Motik and Rosati, 2010 [52]), and it is based on an adaptation of the Stable Model Semantics to knowledge bases consisting of ontology axioms and rules. In this paper we propose a well-founded semantics for nondisjunctive hybrid MKNF knowledge bases that promises to provide better efficiency of reasoning, and that is compatible with both the OWL-based …
Constraint Qualifications And Optimality Conditions For Nonconvex Semi-Infinite And Infinite Programs, Boris S. Mordukhovich, T T. A. Nghia
Constraint Qualifications And Optimality Conditions For Nonconvex Semi-Infinite And Infinite Programs, Boris S. Mordukhovich, T T. A. Nghia
Mathematics Research Reports
The paper concerns the study of new classes of nonlinear and nonconvex optimization problems of the so-called infinite programming that are generally defined on infinite-dimensional spaces of decision variables and contain infinitely many of equality and inequality constraints with arbitrary (may not be compact) index sets. These problems reduce to semi-infinite programs in the case of finite-dimensional spaces of decision variables. We extend the classical Mangasarian-Fromovitz and Farkas-Minkowski constraint qualifications to such infinite and semi-infinite programs. The new qualification conditions are used for efficient computing the appropriate normal cones to sets of feasible solutions for these programs by employing advanced …
Numerical Modeling Of The Cn Spectral Emission Of The Stardust Re-Entry Vehicle, Alexandre Martin, Erin D. Farbar, Iain D. Boyd
Numerical Modeling Of The Cn Spectral Emission Of The Stardust Re-Entry Vehicle, Alexandre Martin, Erin D. Farbar, Iain D. Boyd
Mechanical Engineering Faculty Publications
Re-entry vehicles designed for space exploration are usually equipped with thermal protection systems made of ablative material. In order to properly model and predict the aerothermal environment of the vehicle, it is imperative to account for the gases produced by ablation processes. In the case of charring ablators, where an inner resin is pyrolyzed at a relatively low temperature, the composition of the gas expelled into the boundary layer is complex and may lead to thermal chemical reactions that cannot be captured with simple ow chemistry models. In order to obtain better predictions, an appropriate gas ow chemistry model needs …
From Sink To Resurgence: The Buffering Capacity Of A Cave System In The Tongass National Forest, Usa, Chris Groves, Melissa Hendrikson
From Sink To Resurgence: The Buffering Capacity Of A Cave System In The Tongass National Forest, Usa, Chris Groves, Melissa Hendrikson
Earth, Environmental, and Atmospheric Sciences Faculty Publications
The Tongass National Forest of Southeast Alaska, USA, provides a unique environment for monitoring the impact of the cave system on water quality and biological productivity. The accretionary terrane setting of the area has developed into a complex and heterogeneous geologic landscape which includes numerous blocks of limestone with intense karstification. During the Wisconsian glaciation, there were areas of compacted glacial sediments and silts deposited over the bedrock. Muskeg peatlands developed over these poorly drained areas. The dominant plants of the muskeg ecosystem are Sphagnum mosses, whose decomposition leads to highly acidic waters with pH as low as 2.4. These …
The Mass Of The Black Hole In Arp 151 From Bayesian Modeling Of Reverberation Mapping Data, Brendon J. Brewer, Tommaso Treu, Anna Pancoast, Aaron J. Barth, Vardha N. Bennert, Misty C. Bentz, Alexei V. Filippenko, Jenney E. Greene, Matthew A. Malkan, Jong-Hak Woo
The Mass Of The Black Hole In Arp 151 From Bayesian Modeling Of Reverberation Mapping Data, Brendon J. Brewer, Tommaso Treu, Anna Pancoast, Aaron J. Barth, Vardha N. Bennert, Misty C. Bentz, Alexei V. Filippenko, Jenney E. Greene, Matthew A. Malkan, Jong-Hak Woo
Physics
Supermassive black holes are believed to be ubiquitous at the centers of galaxies. Measuring their masses is extremely challenging yet essential for understanding their role in the formation and evolution of cosmic structure. We present a direct measurement of the mass of a black hole in an active galactic nucleus (Arp 151) based on the motion of the gas responsible for the broad emission lines. By analyzing and modeling spectroscopic and photometric time series, we find that the gas is well described by a disk or torus with an average radius of 3.99 ± 1.25 light days and an opening …
Megamaser Detection And Nuclear Obscuration In Seyfert Galaxies, M. Ramolla, M. Hass, V. N. Bennert, R. Chini
Megamaser Detection And Nuclear Obscuration In Seyfert Galaxies, M. Ramolla, M. Hass, V. N. Bennert, R. Chini
Physics
We revisit the relation between H2O maser detection rate and nuclear obscuration for a sample of 114 Seyfert galaxies drawn from the CfA, 12 μm, and IRAS F25/F60 catalogs. These sources have mid-infrared spectra from the Spitzer Space Telescope and we search for accompanying X-ray and [O III] 5007 Å fluxes from the literature. We use the strength of the [O IV] 25.9 μm emission line as a tracer of the intrinsic AGN strength. After the normalization by [O IV], the observed X-ray flux provides information about X-ray absorption. The distribution of X-ray/[O IV] flux ratios …
130Te Neutrinoless Double-Beta Decay With Cuoricino, E. Andreotti, C. Arnaboldi, F.T. Avignone Iii, M. Balata, I. Bandac, M. Barucci, J.W. Beeman, F. Bellini, C. Brofferio, A. Bryant, C. Bucci, L. Canonica, S. Capelli, L. Carbone, M. Carrettoni, M. Clemenza, O. Cremonesi, R.J. Creswick, D. Di Domizio, M.J. Dolinski, L. Ejzak, R. Faccini, H. A. Farach, E. Ferri, E. Fiorini, L. Foggetta, A. Giachero, L. Gironi, A. Giuliani, P. Gorla, E. Guardincerri, Thomas D. Gutierrez, E. E. Haller, K. Kazkaz, S. Kraft, L. Kogler, C. Maiano, R. H. Maruyama, C. Martinez, M. Martinez, S. Newman, S. Nisi, C. Nones, E. B. Norman, A. Nucciotti, F. Orio, M. Pallavicini, V. Palmieri, L. Pattavina, M. Pavan, M. Pedretti, G. Pessina, S. Pirro, E. Previtali, L. Risegari, C. Rosenfeld, C. Rusconi, C. Salvioni, S. Sangiorgio, D. Schaeffer, N. D. Scielzo, M. Sisti, A. R. Smith, C. Tomei, G. Ventura, M. Vignati
130Te Neutrinoless Double-Beta Decay With Cuoricino, E. Andreotti, C. Arnaboldi, F.T. Avignone Iii, M. Balata, I. Bandac, M. Barucci, J.W. Beeman, F. Bellini, C. Brofferio, A. Bryant, C. Bucci, L. Canonica, S. Capelli, L. Carbone, M. Carrettoni, M. Clemenza, O. Cremonesi, R.J. Creswick, D. Di Domizio, M.J. Dolinski, L. Ejzak, R. Faccini, H. A. Farach, E. Ferri, E. Fiorini, L. Foggetta, A. Giachero, L. Gironi, A. Giuliani, P. Gorla, E. Guardincerri, Thomas D. Gutierrez, E. E. Haller, K. Kazkaz, S. Kraft, L. Kogler, C. Maiano, R. H. Maruyama, C. Martinez, M. Martinez, S. Newman, S. Nisi, C. Nones, E. B. Norman, A. Nucciotti, F. Orio, M. Pallavicini, V. Palmieri, L. Pattavina, M. Pavan, M. Pedretti, G. Pessina, S. Pirro, E. Previtali, L. Risegari, C. Rosenfeld, C. Rusconi, C. Salvioni, S. Sangiorgio, D. Schaeffer, N. D. Scielzo, M. Sisti, A. R. Smith, C. Tomei, G. Ventura, M. Vignati
Physics
We report the final result of the CUORICINO experiment. Operated between 2003 and 2008, with a total exposure of 19.75 kg · y of 130Te, CUORICINO was able to set a lower bound on the 130Te 0vββ half-life of 2.8 x 1024 years at 90% C.L. The limit here reported includes the effects of systematic uncertainties that are examined in detail in the paper. The corresponding upper bound on the neutrino Majorana mass is in the range 300–710 meV, depending on the adopted nuclear matrix element evaluation.
Best Linear Unbiased Estimate Using Buys-Ballot Procedure When Trend-Cycle Component Is Linear, Ifeanyi S. Wueze, Nwogu C. Eleazar, Jude C. Ajaraogu
Best Linear Unbiased Estimate Using Buys-Ballot Procedure When Trend-Cycle Component Is Linear, Ifeanyi S. Wueze, Nwogu C. Eleazar, Jude C. Ajaraogu
CBN Journal of Applied Statistics (JAS)
The Best linear unbiased estimate (BLUE) of Buys-Ballot estimates when trend-cycle component is linear are discussed in this paper. The estimates are those proposed by Iwueze and Nwogu (2004). Discussed are the Chain Based Estimation (CBE) method and the Fixed Based Estimation (FBE) method. The variates for the CBE method were found to have constant mean and variance but are correlated with only one significant autocorrelation coefficient at lag one. The variates for the FBE method were found to have constant mean, non-constant variance but with constant autocorrelation coefficient at all lags . Because the CBE variates exhibit stationarity, Best …
Stock Market Reaction To Selected Macroeconomic Variables In The Nigerian Economy, Abraham Williams Terfa
Stock Market Reaction To Selected Macroeconomic Variables In The Nigerian Economy, Abraham Williams Terfa
CBN Journal of Applied Statistics (JAS)
This study examines the relationship between the stock market and selected macroeconomic variables in Nigeria. The all share index was used as a proxy for the stock market while inflation, interest and exchange rates were the macroeconomic variables selected. Employing error correction model, it was found that a significant negative short run relationship exists between the stock market and the minimum rediscounting rate (MRR) implying that, a decrease in the MRR, would improve the performance of the Nigerian stock market. It was also found that exchange rate stability in the long run, improves the performance of the stock market. Though …
On Fractionally Integrated Logistic Smooth Transitions In Time Series, Olanrewaju I. Shittu, Yaya S. Olaolua
On Fractionally Integrated Logistic Smooth Transitions In Time Series, Olanrewaju I. Shittu, Yaya S. Olaolua
CBN Journal of Applied Statistics (JAS)
Long memory and nonlinearity are two key features of some macroeconomic time series which are characterized by persistent shocks that seem to rise faster during recession than it falls during expansion. A variant of nonlinear time series model together with long memory are used to examine these features in inflation series for three economies. The results which compares favourably with that of van Dijk et al. (2002) elicit some interesting attributes of inflation in the developed and developing economies.
Global Financial Meltdown And The Reforms In The Nigerian Banking Sector, Sanusi L. Sanusi
Global Financial Meltdown And The Reforms In The Nigerian Banking Sector, Sanusi L. Sanusi
CBN Journal of Applied Statistics (JAS)
The paper examined the global financial meltdown and the reforms in the Nigerian banking sector. It was a public speech by the formal Governor of the Central Bank of Nigeria that observed the extent and severity of the crisis that began with the bursting of the housing bubble in the United States in August 2007 reflects the confluence of myriad of factors some of which are familiar from previous crises, while others are new. As in previous times of financial turmoil, the pre-crisis period was characterized by (i) surging asset prices that proved unsustainable; (ii) a prolonged credit expansion leading …
Effects Of Global Climate Change On Nigerian Agriculture: An Empirical Analysis, Apata T. .G
Effects Of Global Climate Change On Nigerian Agriculture: An Empirical Analysis, Apata T. .G
CBN Journal of Applied Statistics (JAS)
This paper presents an empirical analysis of the effects of global warming on Nigerian agriculture and estimation of the determinants of adaptation to climate change. Data used for this study are from both secondary and primary sources. The set of secondary sources of data helped to examine the coverage of the three scenarios (1971-1980; 1981-1990 and 1991-2000). The primary data set consists of 900 respondents’ but only 850 cases were useful. This study analyzed determinants of farm-level climate adaptation measures using a Multinomial choice and stochastic-simulation model to investigate the effects of rapid climatic change on grain production and the …
Statistical Reanalysis Of Jewish Priests’ And Non-Priests’ Haplotypes Using Exact Methods, Shlomo S. Sawilowsky
Statistical Reanalysis Of Jewish Priests’ And Non-Priests’ Haplotypes Using Exact Methods, Shlomo S. Sawilowsky
Theoretical and Behavioral Foundations of Education Faculty Publications
Researchers in an article appearing in Nature used asymptotic (i.e., large sample) chi-square tests in analyzing haplotypes of Y chromosomes using the polymerase chain reaction applied to genomic DNA from male Israeli, North American, and British Jews. The use of classical methods for analyzing extremely sparse contingency tables is frequently done, but with the advent of statistical software capable of conducting exact tests, researchers should certainly cease relying on outdated methods for small sample analyses. A reanalysis was conducted using modern statistical methods. Results and implications for using exact tests are discussed.
Quantum Mechanics, Quantum Computation, And The Density Operator In Sympy, Addison Cugini
Quantum Mechanics, Quantum Computation, And The Density Operator In Sympy, Addison Cugini
Physics
Because aspects of quantum mechanics are both difficult to understand and difficult algebraically, there is a need for software which symbolically simulates quantum mechanical phenomena. To accomplish this goal, code has been added to an open-source computer algebra system, called SymPy, which models the abstraction of Dirac notation and the density operator. Additionally, a quantum computer simulation has been built using this abstraction. This paper shall discuss the code that has been added as well as any relevant physics important to understanding the code. In particular, we shall focus on the density operator of statistical quantum mechanics using SymPy's density …
Laser-Induced Breakdown Spectroscopy, Connor Drake
Laser-Induced Breakdown Spectroscopy, Connor Drake
Physics
The goal of this work is to use a Neodymium-Doped Yttrium Aluminum Garnet (Nd:YAG) Laser, spectrometer, and computer to create a Laser Induced Breakdown Spectroscopy (LIBS) system. LIBS utilizes a focused, high-powered, pulsed laser whose peak electric field ionizes materials at the beam focal point, creating localized plasma. The plasma state includes broken molecular bonds, atom/electron-ionization, and excited electrons, which on the macroscopic level is a loud “snap” and a bright spark. In this project, a fiber optic cable is used to capture light emitted from the spark, and direct it into a spectrometer which tallies the number of photons …
Symbolic Quantum Circuit Simplification In Sympy, Matthew Curry
Symbolic Quantum Circuit Simplification In Sympy, Matthew Curry
Physics
In the field of quantum information science, one can design a series of quantum logic operations known as a circuit. Circuits are the basis for quantum computations in quantum computing. As circuits will most likely be designed from a logical standpoint, there could exist mathematical redundancies which will lead to a larger circuit than necessary. These redundancies are computationally expensive, and there is a need for them to be found and eliminated to simplify the circuit. We present our research on finding the rules for simplifying circuits and its implementation in SymPy.
Ferrofluids, James Patt
Ferrofluids, James Patt
Physics
Ferrofluids are truly fascinating. Technologically savvy artists have been able to capture the human imagination with little but a judicious application of a magnetic field. The substance seems to defy gravity, flowing and shaping itself seemingly like magic (see Figure 1). The true magic, however, is the vast range of properties that this intrinsically simple substance can exhibit. It can vary its viscosity given the strength of the magnetic field. It can draw heat away from an over worked mechanical component. It can even split a beam of light in two. It’s hard to imagine what kind of strange and …
Experimental Observation Of Ion Beams In The Madison Helicon Experiment, Matt Wiebold, Yung-Ta Sung, John E. Scharer
Experimental Observation Of Ion Beams In The Madison Helicon Experiment, Matt Wiebold, Yung-Ta Sung, John E. Scharer
Physics Faculty Publications
Argon ion beams up to Eb=165 eV at Prf=500 W are observed in the Madison Helicon eXperiment (MadHeX) helicon source with a magnetic nozzle. A two-grid retarding potential analyzer (RPA) is used to measure the ion energy distribution, and emissive and rf-filtered Langmuir probes measure the plasma potential, electron density, and temperature. The supersonic ion beam (M=vi/cs up to 5) forms over tens of Debye lengths and extends spatially for a few ion-neutral charge-exchange mean free paths. The parametric variation of the ion beam energy is explored, including flow rate, rf power, and …
Coffee_Shop: Investigations Into Modern Word Processors., Nathaniel Welch
Coffee_Shop: Investigations Into Modern Word Processors., Nathaniel Welch
Computer Science and Software Engineering
My senior project was spent building a desktop application similar to WriteRoom and OmmWriter. These two applications are both word processors for the Macintosh OS X operating system. Both of these applications are designed to be a reset on word processing software, bringing their interfaces back to the days of Microsoft Word 3.0 and Word Perfect. They do this by spending more time on focusing on the design of the software interface, and focusing on keeping it minimalistic, instead of filling the product with new obscure features, which is a common complaint against the current iterations of Microsoft Word.
The …
The Graph Distance Game, Wayne Goddard, Anne Sinko, Peter J. Slater, Honghai Xu
The Graph Distance Game, Wayne Goddard, Anne Sinko, Peter J. Slater, Honghai Xu
Mathematics Faculty Publications
In the graph distance game, two players alternate in constructing a maximal path. The objective function is the distance between the two endpoints of the path, which one player tries to maximize and the other tries to minimize. In this note, we examine the distance game for various graphs, and provide general bounds, exact results for special graphs, and an algorithm for trees. Computer calculations suggest interesting conjectures for grids.
Approach To Typicality In Quantum Systems, Shawn Dubey
Approach To Typicality In Quantum Systems, Shawn Dubey
Applied Physics Masters Theses Collection
The study of quantum mechanics has greatly broadened since its inception in the early twentieth century. Recent research has focused on the emergence of thermalization in quantum many-body systems. In this thesis I will demonstrate the approach to typicality--the notion that for specific sets of objects, most of the objects share a common property--in a single, many-body spins chain of spin half particles. This notion of typicality is new. But it serves as a good explanation for the emergence of thermalization.
Detecting Spatiotemporal Changes Of Corn Developmental Stages In The U.S. Corn Belt Using Modis Wdrvi Data, Toshihiro Sakamoto, Brian D. Wardlow, Anatoly A. Gitelson
Detecting Spatiotemporal Changes Of Corn Developmental Stages In The U.S. Corn Belt Using Modis Wdrvi Data, Toshihiro Sakamoto, Brian D. Wardlow, Anatoly A. Gitelson
School of Natural Resources: Faculty Publications
The dates of crop developmental stages are important variables for many applications including assessment of the impact of abnormal weather on crop yield. Time-series 250-m vegetation-index (VI) data acquired from the Moderate Resolution Imaging Spectroradiometer (MODIS) provide valuable information for monitoring the spatiotemporal changes of corn growth across large geographic areas. The goal of this study is to evaluate the performance of a new crop phenology detection method, namely, two-step filtering (TSF), for revealing the spatiotemporal pattern of specific corn developmental stages (early vegetative: V2.5; silking: R1; dent: R5; mature: R6) over an eight-year period (2001–2008) across Iowa, Illinois, and …