Physical Sciences and Mathematics Commons^™

Augmented Measurement System Assessment, Nathaniel Stevens, R Browne, S H. Steiner, R J. Mackay

Mathematics

The standard plan for the assessment of the variation due to a measurement system involves a number of operators repeatedly measuring a number of parts in a balanced design. In this article, we consider the performance of two types of (unbalanced) assessment plans. In each type, we use a standard plan augmented with a second component. In type A augmentation, each operator measures a different set of parts once each. In type B augmentation, each operator measures the same set of parts once each. The goal of the paper is to identify good augmented plans for estimating the gauge repeatability …

Modeling And Analyzing Faults To Improve Election Process Robustness, B I. Simidchieva, Sophie J. Engle, M Clifford, A C. Jones, S Peisert, M Bishop, L A. Clarke, L J. Osterweil

Computer Science

This paper presents an approach for continuous process improvement and illustrates its application to improving the robustness of election processes. In this approach, the Little-JIL process definition language is used to create a precise and detailed model of an election process. Given this process model and a potential undesirable event, or hazard, a fault tree is automatically derived. Fault tree analysis is then used to automatically identify combinations of failures that might allow the selected potential hazard to occur. Once these combinations have been identified, we iteratively improve the process model to increase the robustness of the election process against …

Sampling The Conformation Of Protein Surface Residues For Flexible Protein Docking, Patricia Francis-Lyon, S Gu, J Hass, N Amenta, P Koehl

Nursing and Health Professions Faculty Research and Publications

Background: The problem of determining the physical conformation of a protein dimer, given the structures of the two interacting proteins in their unbound state, is a difficult one. The location of the docking interface is determined largely by geometric complementarity, but finding complementary geometry is complicated by the flexibility of the backbone and side-chains of both proteins. We seek to generate candidates for docking that approximate the bound state well, even in cases where there is backbone and/or side-chain difference from unbound to bound states.

Results: We divide the surfaces of each protein into local patches and describe the effect …

Ordway Weather And Water Data 2010, Macalester College

Ordway Weather Data

Contains daily readings for the year indicated. The values include: PAR umol/s/m2, avg wind dir degree, avg windspeed mph, Avg Max Windspeed mph, Avg airtemp C, Avg RH %, Avg BP mmHg, Avg DailyRain in, Avg Rain Duration sec, Avg RainIntensity in/h, Avg Water Temp F, Avg sp cond mS/cm, avg pH, Avg Turb NTU+, Avg ODOSat %, Avg ODO mg/L, Water station PAR umol/s/m2, Avg Water Level m. File format: CSV.

Spreadsheets Grow Up: Three Spreadsheet Engineering Methodologies For Large Financial Planning Models, Thomas A. Grossman Jr., O Ozluk

Business Analytics and Information Systems

Many large financial planning models are written in a spreadsheet programming language (usually Microsoft Excel) and deployed as a spreadsheet application. Three groups, FAST Alliance, Operis Group, and BPM Analytics (under the name “Spreadsheet Standards Review Board”) have independently promulgated standardized processes for efficiently building such models. These spreadsheet engineering methodologies provide detailed guidance on design, construction process, and quality control. We summarize and compare these methodologies. They share many design practices, and standardized, mechanistic procedures to construct spreadsheets. We learned that a written book or standards document is by itself insufficient to understand a methodology. These methodologies represent a …

Wildfire Promotes Dominance Of Invasive Giant Reed (Arundo Donax) In Riparian Ecosystems, Gretchen Coffman, R F. Ambrose, P W. Rundel

Environmental Science

Widespread invasion of riparian ecosystems by the large bamboo-like grass Arundo donax L. has altered community structure and ecological function of streams in California. This study evaluated the influence of wildfire on A. donax invasion by investigating its relative rate of reestablishment versus native riparian species after wildfire burned 300 ha of riparian woodlands along the Santa Clara River in southern California in October 2003. Post-fire A. donax growth rates and productivity were compared to those of native woody riparian species in plots established before and after the fire. Arundo donax resprouted within days after the fire and exhibited higher …

A Model‐Data Intercomparison Of Co2 Exchange Across North America: Results From The North American Carbon Program Site Synthesis, Christopher R. Schwalm, Christopher A. Williams, Kevin Schaefer, Ryan S. Anderson, M. Altaf Arain, Ian Baker, Alan Barr, T. Andrew Black, Guangsheng Chen, Jing Ming Chen, Philippe Ciais, Kenneth J. Davis, Ankur R. Desai, Michael Dietze, Danilo Dragoni, Marc L. Fischer, Lawrence B. Flanagan, Robert Grant, Lianhong Gu, David Hollinger, R. Cesar Izaurralde, Chris Kucharik, Peter Lafleur, Beverly E. Law, Longhui Li, Zhengpeng Li, Shuguang Liu, Erandathie Lokupitiya, Yiqi Luo, Siyan Ma, Hank Margolis, Roser Matamala, Harry Mccaughey, Russell K. Monson, Walter C. Oechel, Changhui Peng, Benjamin Poulter, David T. Price, Dan M. Riciutto, William Riley, Alok Kumar Sahoo, Michael Sprintsin, Jianfeng Sun, Hanqin Tian, Christian Tonitto, Hans Verbeeck, Shashi B. Verma

School of Natural Resources: Faculty Publications

Our current understanding of terrestrial carbon processes is represented in various models used to integrate and scale measurements of CO₂ exchange from remote sensing and other spatiotemporal data. Yet assessments are rarely conducted to determine how well models simulate carbon processes across vegetation types and environmental conditions. Using standardized data from the North American Carbon Program we compare observed and simulated monthly CO₂ exchange from 44 eddy covariance flux towers in North America and 22 terrestrial biosphere models. The analysis period spans ~220 site‐years, 10 biomes, and includes two large‐scale drought events, providing a natural experiment to evaluate …

Translocation To A Fragmented Landscape: Survival, Movement, And Site Fidelity Of Northern Bobwhites, Theron M. Terhune, D. Clay Sisson, William E. Palmer, Brant C. Faircloth, H. Lee Stribling, John P. Carroll

School of Natural Resources: Faculty Publications

Habitat fragmentation, degradation, and loss have taxed early-successional species including the Northern Bobwhite (Colinus virginianus) and numerous grassland obligate birds. Translocation is often applied to counteract the consequences of habitat fragmentation through the creation, reestablishment, or augmentation of wild populations for the purposes of conservation, biodiversity maintenance. However, the implementation of these techniques is often conducted without valid experimental designs and therefore lacks robust, empirical data needed to evaluate and advance the knowledge and application of translocation. Despite the increasing amount of habitat management applied to patches among fragmented landscapes, a paucity of source populations often limits natural …

Upwelling Couples Chemical And Biological Dynamics Across The Littoral And Pelagic Zones Of Lake Tanganyika, East Africa, Jessica R. Corman, P. B. Mcintyre, B. Kuboja, W. Mbemba, D. Fink, C. W. Wheeler, C. Gans, E. Michel, A. S. Flecker

School of Natural Resources: Faculty Publications

We studied the effects of upwelling on nutrient and phytoplankton dynamics in the pelagic and littoral zones of Lake Tanganyika near Kigoma, Tanzania. During the dry season of 2004, a rise in the thermocline and sudden drop in surface water temperatures indicated a substantial upwelling event. Increases in concentrations of nitrate, soluble reactive phosphorus, and silica in the surface waters occurred simultaneously after the temperature drop. Within days, chlorophyll a concentrations increased and remained elevated, while inorganic nutrient concentrations returned to preupwelling levels and organic nutrient concentrations peaked. We observed parallel temporal patterns of water temperature, nutrient concentrations, and phytoplankton …

Recursive Streamflow Forecasting: A State-Space Approach, Jozsef Szilagyi, Andras Szollosi-Nagy

School of Natural Resources: Faculty Publications

No abstract provided.

Testing The Intergenerational Differences In Mental Boundaries, John E. Barbuto Jr., Stephanie Bryant, Lisa Pennisi

School of Natural Resources: Faculty Publications

No abstract provided.

Locus Of Control, Sources Of Motivation, And Mental Boundaries As Antecedents Of Leader-Member Exchange Quality, John E. Barbuto Jr., Dayna Finch Weltmer, Lisa A. Pennisi

School of Natural Resources: Faculty Publications

No abstract provided.

Diurnal Fluctuations In Shallow Groundwater Levels And In Streamflow Rates And Their Interpretation: A Review, Zoltan Gribovszki, Jozsef Szilagyi, Peter Kalicz

School of Natural Resources: Faculty Publications

No abstract provided.

Complementary-Relationship-Based Evapotranspiration Mapping (Cremap) Technique For Hungary, Jozsef Szilagyi, Akos Kovacs

School of Natural Resources: Faculty Publications

No abstract provided.

Introduction To The Basic Drivers Of Climate, Alison P. Stevens

School of Natural Resources: Faculty Publications

Climates on Earth vary from the warm, wet tropics to the cold, dry Arctic and Antarctic. What drives this variation?

Every day, we note the weather: temperature, rain, cloud cover, wind and humidity. Climate is the long-term prevailing weather in an area and is largely determined by temperature and precipitation. The climate in a desert is hot and dry. The climate in the tropics is warm and wet. The climate of a particular area is the largest determinant to the life found there. Climate is a key focus in ecology. Variations in climate include daily and seasonal cycles. Climatic variation …

Toward A Whole-Landscape Approach For Sustainable Land Use In The Tropics, R. Defries, C. Rosenzweig

United States National Aeronautics and Space Administration: Publications

Increasing food production and mitigating climate change are two primary but seemingly contradictory objectives for tropical landscapes. This special feature examines synergies and trade-offs among these objectives. Four themes emerge from the papers: the important roles of both forest and agriculture sectors for climate mitigation in tropical countries; the minor contribution from deforestation-related agricultural expansion to overall food production at global and continental scales; the opportunities for synergies between improved food production and reductions in greenhouse gas emissions through diversion of agricultural expansion to already-cleared lands, improved soil, crop, and livestock management, and agroforestry; and the need for targeted policy …

Toward Establishing A Realistic Benchmark For Airframe Noise Research: Issues And Challenges, Mehdi R. Khorrami

United States National Aeronautics and Space Administration: Publications

The availability of realistic benchmark configurations is essential to enable the validation of current Computational Aeroacoustic (CAA) methodologies and to further the development of new ideas and concepts that will foster the technologies of the next generation of CAA tools. The selection of a real-world configuration, the subsequent design and fabrication of an appropriate model for testing, and the acquisition of the necessarily comprehensive aeroacoustic data base are critical steps that demand great care and attention. In this paper, a brief account of the nose landing-gear configuration, being proposed jointly by NASA and the Gulfstream Aerospace Company as an airframe …

Remote Sensing Of Phytoplankton Pigment Distribution In The United States Northeast Coast, Xiaoju Pan, Antonio Mannino, Mary E. Russ, Stanford B. Hooker, Lawrence Harding

United States National Aeronautics and Space Administration: Publications

Phytoplankton pigments constitute many more compounds than chlorophyll a that can be applied to study phytoplankton diversity, populations, and primary production. In this study, field measurements were applied to develop ocean color satellite algorithms of phytoplankton pigments from in-water radiometry measurements. The match-up comparisons showed that the satellite-derived pigments from our algorithms agree reasonably well (e.g. 30–55% of uncertainty for SeaWiFS and 37–50% for MODIS-Aqua) to field data, with better agreement (e.g. 30–38% of uncertainty for SeaWiFS and 39–44% for MODIS-Aqua) for pigments abundant in diatoms. The seasonal and spatial variations of satellite-derived phytoplankton biomarker pigments, such as fucoxanthin, which …

The Carbon Budget Of California, Christopher Potter

United States National Aeronautics and Space Administration: Publications

The carbon budget of a region can be defined as the sum of annual fluxes of carbon dioxide (CO₂₎ and methane (CH₄) greenhouse gases (GHGs) into and out of the regional surface coverage area. According to the state government’s recent inventory, California’s carbon budget is presently dominated by 115 MMTCE per year in fossil fuel emissions of CO₂ (>85% of total annual GHG emissions) to meet energy and transportation requirements. Other notable (non-ecosystem) sources of carbon GHG emissions in 2004 were from cement- and lime-making industries (7%), livestock-based agriculture (5%), and waste treatment activities (2%). …

Thermal Expansion Of Vacuum Plasma Sprayed Coatings, S.V. Raj, A. Palczer

United States National Aeronautics and Space Administration: Publications

Metallic Cu–8%Cr, Cu–26%Cr, Cu–8%Cr–1%Al, NiAl and NiCrAlY monolithic coatings were fabricated by

vacuum plasma spray deposition processes for thermal expansion property measurements between 293

and 1223 K. The corrected thermal expansion, (∆L/L₀)_thermal, varies with the absolute temperature, T, as

( ∆L ) = A(T-293)³ + B(T-293)² + C(T -293) + D

(L₀)_thermal

where A, B, C and D are regression constants. Excellent reproducibility was observed for all of the

coatings except for data obtained on the Cu–8%Cr and Cu–26%Cr coatings in the first heat-up …

Test Method Variability In Slow Crack Growth Properties Of Sealing Glasses, J. Salem, R. Tandon

United States National Aeronautics and Space Administration: Publications

The crack growth properties of several sealing glasses were measured by using constant stress rate testing in ~2% and 95% RH (relative humidity). Crack growth parameters measured in high humidity are systematically smaller (n and B) than those measured in low humidity, and crack velocities for dry environments are ~100 x lower than for wet environments. The crack velocity is very sensitivity to small changes in RH at low RH. Biaxial and uniaxial stress states produced similar parameters. Confidence intervals on crack growth parameters that were estimated from propagation of errors solutions were comparable to those from Monte …

Albedo Estimates For Land Surface Models And Support For A New Paradigm Based On Foliage Nitrogen Concentration, David Y. Hollinger, S. V. Ollinger, A. D. Richardson, T. P. Meyers, D. B. Dail, M. E. Martin, N. A. Scott, T. J. Arkebauer, D. D. Baldocchi, K. L. Clark, P. S. Curtis, K. J. Davis, A. R. Desai, D. Dragoni, M. L. Goulden, L. Gu, G. G. Katul, S. G. Pallardy, K. T. Pawu, H. P. Schmid, P. C. Stoy, Andrew E. Suyker, Shashi Verma

School of Natural Resources: Faculty Publications

Vegetation albedo is a critical component of the Earth’s climate system, yet efforts to evaluate and improve albedo parameterizations in climate models have lagged relative to other aspects of model development. Here, we calculated growing season albedos for deciduous and evergreen forests, crops, and grasslands based on over 40 site-years of data from the AmeriFlux network and compared them with estimates presently used in the land surface formulations of a variety of climate models. Generally, the albedo estimates used in land surface models agreed well with this data compilation. However, a variety of models using fixed seasonal estimates of albedo …

A Black Hills-Madison Aquifer Origin For Dakota Aquifer Groundwater In Northeastern Nebraska, Randy Stotler, F. Edwin Harvey, David C. Gosselin

School of Natural Resources: Faculty Publications

Previous studies of the Dakota Aquifer in South Dakota attributed elevated groundwater sulfate concentrations to Madison Aquifer recharge in the Black Hills with subsequent chemical evolution prior to upward migra¬tion into the Dakota Aquifer. This study examines the plausibility of a Madison Aquifer origin for groundwater in northeastern Nebraska. Dakota Aquifer water samples were collected for major ion chemistry and isotopic analysis (¹⁸O, ²H, ³H, ¹⁴C, ¹³C, ³⁴S, ¹⁸O-SO₄, ⁸⁷Sr, ³⁷Cl). Results show that groundwater beneath the eastern, un¬confined portion of the study area is distinctly different from …

Measuring Economic Impacts Of Drought: A Review And Discussion, Ya Ding, Michael J. Hayes, Melissa Widhalm

School of Natural Resources: Faculty Publications

A comprehensive assessment of drought economic impacts provides critical information to rational decisions supporting drought mitigation policies and programs. The objective of this paper is to increase the understanding of the full scope of drought economic impacts and the associated quantitative assessment methodologies. To accomplish this, the paper reviews the literature of drought economic impact studies in both agricultural and non-agricultural sectors, summarizes the methods and data employed, compares the various results, and investigates the problems and limitations of previous studies. The paper concludes with a discussion of the challenges and directions of future improvement on drought economic impact assessment.

Modeling Whole-Tree Carbon Assimilation Rate Using Observed Transpiration Rates And Needle Sugar Carbon Isotope Ratios, Jia Hu, David J. P. Moore, Diego Andrés Riveros-Iregui, Sean P. Burns, Russell K. Monson

School of Natural Resources: Faculty Publications

• Understanding controls over plant–atmosphere CO₂ exchange is important for quantifying carbon budgets across a range of spatial and temporal scales. In this study, we used a simple approach to estimate whole-tree CO₂ assimilation rate (A_Tree) in a subalpine forest ecosystem.
• We analysed the carbon isotope ratio (δ¹³C) of extracted needle sugars and combined it with the daytime leaf-to-air vapor pressure deficit to estimate tree water-use efficiency (WUE). The estimated WUE was then combined with observations of tree transpiration rate (E) using sap flow techniques to estimate A_Tree. …

Algorithms For Remote Estimation Of Chlorophyll-Α In Coastal And Inland Waters Using Red And Near Infrared Bands, Alexander A. Gilerson, Anatoly A. Gitelson, Jing Zhou, Daniela Gurlin, Wesley Moses, Ioannis Ioannou, Samir A. Ahmed

School of Natural Resources: Faculty Publications

Remote sensing algorithms that use red and NIR bands for the estimation of chlorophyll-α concentration [Chl] can be more effective in inland and coastal waters than algorithms that use blue and green bands. We tested such two-band and three-band red-NIR algorithms using comprehensive synthetic data sets of reflectance spectra and inherent optical properties related to various water parameters and a very consistent in situ data set from several lakes in Nebraska, USA. The two-band algorithms tested with MERIS bands were R_rs(708)/R_rs(665) and R_rs(753)/Rrs(665). The three-band algorithm with MERIS bands was in the form R3 …

Non-Destructive Estimation Pigment Content Ripening Quality And Damage In Apple Fruit With Spectral Reflectance In The Visible Range, Alexei E. Solovchenko, Olga B. Chivkunova, Anatoly A. Gitelson, Mark N. Merzlyak

School of Natural Resources: Faculty Publications

Modern non-destructive optical-reflectance-based techniques for estimation of pigment (chlorophyll, carotenoid, anthocyanin, and flavonol) contents, the rate of on- and off-tree ripening as well as for detection of common physiological disorders, such as sunscald, superficial scald, and water core, and other damages to apple fruit are an emphasis on the methods developed by the authors. The basic spectral features of fruit reflectance in the visible and near infra-red are briefly considered together with their implications for the development of algorithms for non-destructive pigment content assessment. The use of reflectance spectroscopy for estimating chlorophyll and carotenoid content as well as carotenoid/chlorophyll ratio …

Algorithms For Remote Estimation Of Chlorophyll-A In Coastal And Inland Waters Using Red And Near Infrared Bands, Alexander A. Gilerson, Anatoly A. Gitelson, Jing Zhou, Daniela Gurlin, Wesley Moses, Ioannis Ioannou, Samir A. Ahmed

School of Natural Resources: Faculty Publications

Remote sensing algorithms that use red and NIR bands for the estimation of chlorophyll-a concentration [Chl] can be more effective in inland and coastal waters than algorithms that use blue and green bands. We tested such two-band and three-band red-NIR algorithms using comprehensive synthetic data sets of reflectance spectra and inherent optical properties related to various water parameters and a very consistent in situ data set from several lakes in Nebraska, USA. The two-band algorithms tested with MERIS bands were R_rs(708)/R_rs(665) and R_rs(753)/R_rs(665). The three-band algorithm with MERIS bands was in the …

Long-Term Response Of Groundwater Nitrate Concentrations To Management Regulations In Nebraska’S Central Platte Valley, Mary Exner Spalding, Hugo Perea-Estrada, Roy F. Spalding

School of Natural Resources: Faculty Publications

The impact of 16 years (1988–2003) of management practices on high groundwater nitrate concentrations in Nebraska’s central Platte River valley was assessed in a 58,812-ha (145,215-ac) groundwater quality management area intensively cropped to irrigated corn (Zea mays L.). Crop production and groundwater nitrate data were obtained from ~23,800 producer reports. The terrace, comprising ~56% of the study area, is much more intensively cropped to irrigated corn than the bottomland. From 1987 to 2003, average groundwater nitrate concentrations in the primary aquifer beneath the bottomland remained static at ~8 mg N/l. During the same period, average groundwater nitrate concentrations in the …

Finding The Smoothest Path To Success: Model Complexity And The Consideration Of Nonlinear Patterns In Nest-Survival Data, Max Post Van Der Burg, Larkin A. Powell, Andrew J. Tyre

School of Natural Resources: Faculty Publications

Quantifying patterns of nest survival is a first step toward understanding why birds decide when and where to breed. Most studies of nest survival have relied on generalized linear models (GLM) to explore these patterns. However, GLMs require assumptions about the models’ structure that might preclude finding nonlinear patterns in survival data. Generalized additive models (GAM) provide a flexible alternative to GLMs for estimating linear and nonlinear patterns in data. Here we present a comparison of GLMs and GAMs for explaining variation in nest-survival data. We used two different model-selection criteria, the Bayes (BIC) and Akaike (AIC) information criteria, to …