Digital Commons Network^™

Spatio-Temporal Soil Moisture Measurement With Wireless Underground Sensor Networks, Xin Dong, Mehmet C. Vuran

School of Computing: Conference and Workshop Papers

In this paper, the estimation distortion of distributed soil moisture measurement using Wireless Underground Sensor Networks (WUSNs) is investigated. The main focus of this paper is to analyze the impact of the environment and network parameters on the estimation distortion of the soil moisture.More specifically, the effects of rainfall, soil porosity, and vegetation root zone are investigated by exploiting a rainfall model, in addition to the effects of sampling rate, network topology, and measurement signal noise ratio. Spatio-temporal correlation is characterized to develop a measurement distortion model with respect to these factors. The evaluations reveal that with porous soil and …

Face Needs, Intragroup Status, And Women’S Reactions To Socially Aggressive Face Threats, Erin K. Willer, Jordan Soliz

Department of Communication Studies: Faculty Publications

Given the potential negative consequences of being a recipient of such behavior, the role of positive face needs, intragroup status, and the face-threatening nature of social aggression in predicting cor-relates of negative affect experienced as a result of being a target of SAFTs, including the face threat of the response, forgiveness, and well-being was investigated. On the basis of the survey responses from 199 college-aged women, findings indicated that targets’ positive face needs and intragroup status are directly and indirectly associated with forgiveness and overall well-being. Implications for these findings in relation to theorizing about face and intragroup identity as …

A Partial Taxonomy Of Substitutability And Interchangeability, Shant Karakashian, Robert J. Woodward, Berthe Y. Choueiry, Steven D. Prestwich, Eugene C. Freuder

School of Computing: Conference and Workshop Papers

Substitutability, interchangeability and related concepts in Constraint Programming were introduced approximately twenty years ago and have given rise to considerable subsequent research. We survey this work, classify, and relate the different concepts, and indicate directions for future work, in particular with respect to making connections with research into symmetry breaking. This paper is a condensed version of a larger work in progress.

Survivor Buddy And Scigirls: Affect, Outreach, And Questions, Robin R. Murphy, Vasant Srinivasan, Negar Rashidi, Brittany Duncan, Aaron Rice, Zachary Henkel, Marco Garza, Cliff Nass, Victoria Groom, Takis Zourntos, Roozbeh Daneshwar, Sharath Prasad

School of Computing: Conference and Workshop Papers

This paper describes the Survivor Buddy human-robot interaction project and how it was used by four middle-school girls to illustrate the scientific process for an episode of “SciGirls”, a Public Broadcast System science reality show. Survivor Buddy is a four degree of freedom robot head, with the face being a MIMO 740 multi-media touch screen monitor. It is being used to explore consistency and trust in the use of robots as social mediums, where robots serve as intermediaries between dependents (e.g., trapped survivors) and the outside world (doctors, rescuers, family members). While the SciGirl experimentation was neither statistically significant nor …

Quantitative Evaluation Of The Bim-Assisted Construction Detailed Cost Estimates, Zhigang Shen, Raja R. A. Issa

Department of Construction Engineering and Management: Faculty Publications

The increased interest in using Building Information Modeling (BIM) in detailed construction cost estimates calls for methodologies to evaluate the effectiveness of BIM-Assisted Detailed Estimating (BADE) tools in generating detailed construction cost estimates. The focus of this study is on developing a quantified evaluation method to measure the impact of these BADE tools. Further, in order to understand the cognitive details of the estimator, this study also tested and evaluated the impact of the visualization factor and the compound impact of the visualization factor and aggregated calculation factor on the construction cost-estimating process. Two types of BADE tools were tested …

Refugees As People: The Portrayal Of Refugees In American Human Interest Stories, Sarah Steimel

Department of Communication Studies: Faculty Publications

This study combines discourse analysis and narrative analysis (Yin 2007) to examine top US newspapers’ coverage of refugees in American human interest stories. I find that the refugees are presented (a) as prior victims; (b) as in search of the American Dream; and (c) as unable to achieve the American Dream. As human-interest features, the stories provide a largely positive portrayal of individual refugees and their families. However, the human interest stories also depict refugees as current victims of the American economic crisis; deeply frustrated by their inability to achieve the American Dream. Together these discourses represent a narrative of …

A Novel Weighted-Graph-Based Grouping Algorithm For Metadata Prefetching, Peng Gu, Jun Wang, Yifeng Zhu, Hong Jiang, Pengju Shang

School of Computing: Faculty Publications

Although data prefetching algorithms have been extensively studied for years, there is no counterpart research done for metadata access performance. Existing data prefetching algorithms, either lack of emphasis on group prefetching, or bearing a high level of computational complexity, do not work well with metadata prefetching cases. Therefore, an efficient, accurate, and distributed metadata-oriented prefetching scheme is critical to leverage the overall performance in large distributed storage systems. In this paper, we present a novel weighted-graph-based prefetching technique, built on both direct and indirect successor relationship, to reap performance benefit from prefetching specifically for clustered metadata servers, an arrangement envisioned …

Xlp: A Cross-Layer Protocol For Efficient Communication In Wireless Sensor Networks, Mehmet C. Vuran, Ian F. Akyildiz

School of Computing: Faculty Publications

Severe energy constraints of battery-powered sensor nodes necessitate energy-efficient communication in Wireless Sensor Networks (WSNs). However, the vast majority of the existing solutions is based on classical layered protocols approach, which leads to significant overhead. It is much more efficient to have a unified scheme which blends common protocol layer functionalities into a cross-layer module. In this paper, a cross layer protocol (XLP) is introduced, which achieves congestion control, routing, and medium access control in a cross-layer fashion. The design principle of XLP is based on the cross-layer concept of initiative determination, which enables receiver-based contention, initiative-based forwarding, local …

Nebraska Statewide Groundwater-Level Monitoring Report 2010, J. T. Korus, M. E. Burbach, L. M. Howard, R. M. Joeckel

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Polishing Esthetic Restorative Materiai, Caren M. Barnes

College of Dentistry: Faculty Publications

When esthetic dental restorations are encountered during charting, they should be included in the treatment plan for the specific polishing procedures that are required. If the brand and type of esthetic restoration are known through the patient chart, the polishing procedures and products used should be those recommended by the manufacturer. If not possible, alternative polishing procedures should be used. A cleaning agent containing feldspar and rubber polishing cup can be used on all esthetic restorative materials with no chance of damage to the surface characterization.

The principles for polishing esthetic restorations are the same as for natural teeth. If …

Isomer Identification And Resolution In Small Gold Clusters, Wei Huang, Rhitankar Pal, Lei-Ming Wang, Xiao Cheng Zeng, Lai-Sheng Wang

Xiao Cheng Zeng Publications

A variety of experimental techniques are used to resolve energetically close isomers of Au_{7 ⁻} and Au_{8 ⁻} by combining photoelectron spectroscopy and ab initio calculations. Two structurally distinct isomers are confirmed to exist in the cluster beam for both clusters. Populations of the different isomers in the cluster beam are tuned using Ar-tagging, O₂-titration, and isoelectronic atom substitution by Cu and Ag. A new isomer structure is found for Au_{7 ⁻}, which consists of a triangular Au₆ unit with a dangling Au atom. Isomer-specific photoelectron spectra of Au_{8 ⁻} are obtained …

What Can Be Done About School Bullying? Linking Research To Educational Practice, Susan M. Swearer Napolitano, Dorothy L. Espelage, Tracy Vaillancourt, Shelley Hymel

Department of Educational Psychology: Faculty Publications

In this article, the authors review research on individual, peer, and school contributions that may be critical factors for enhancing efforts to address bullying among students. Methodological challenges are delineated,with an emphasis on how bullying is defined and assessed and the subsequent implications for bullying prevention and intervention program evaluation. The impact of school-based anti-bullying programs and the challenges currently facing educators and researchers in this area are discussed. The article concludes with a proposal for a broader, ecologically based model of school bullying based on the emerging literature.

Childhood Depression, Kelly Brey Love, Susan M. Swearer Napolitano

Department of Educational Psychology: Faculty Publications

It has only been within the past two decades that the majority ofclinicians and researchers reached agreement that children can experience a depressive disorder. Initially, researchers believed children’s lack of psychosexual development prohibited development of depression in childhood.

There has also been disagreement regarding which symptomatology comprises childhood depression, and how it differs from depression in adults. Many clinicians and researchers shared the belief that depression in children was “masked” by other symptoms (e.g., aggression, enuresis, anxiety, among others). More recent research has identified and emphasized the similarities between depressive symptoms experienced by adults and children. Cohort data suggest that …

Estimating Dilemma Zone Hazard Function At High Speed Isolated Intersection, Anuj Sharma, Darcy Bullock, Srinivas Peeta

Anuj Sharma Publications

The traditional surrogate measures of safety (like number of vehicles in dilemma zone) fail to quantify the risk of crash. Traffic conflict has been proposed as an improved surrogate measure of safety for operations at isolated intersections to quantify the risk. This paper develops a dilemma zone hazard function estimating procedure to obtain the probability of traffic conflict occurring. This approach is an extension of the current approach of dilemma zone boundaries to determine the risk of traffic conflict for an individual vehicle in the case of a dilemma zone incursion. Field data collected from the intersection of SR37 and …

Energy Consumption And Latency Analysis For Wireless Multimedia Sensor Networks, Alvaro Pinto, Zhe Zhang, Xin Dong, Senem Velipasalar, Mehmet C. Vuran, M. Cenk Gursoy

School of Computing: Conference and Workshop Papers

Energy and bandwidth are limited resources in wireless sensor networks, and communication consumes significant amount of energy. When wireless vision sensors are used to capture and transfer image and video data, the problems of limited energy and bandwidth become even more pronounced. Thus, message traffic should be decreased to reduce the communication cost. In many applications, the interest is to detect composite and semantically higher-level events based on information from multiple sensors. Rather than sending all the information to the sinks and performing composite event detection at the sinks or control-center, it is much more efficient to push the detection …

Categorizing The Resistance Of Soybean Genotypes To The Soybean Aphid (Hemiptera: Aphididae), L. M. Pierson, Tiffany M. Heng-Moss, Thomas E. Hunt, J. C. Reese

Department of Entomology: Faculty Publications

We evaluated selected soybean, Glycine max (L.) Merr., genotypes during their reproductive stages for resistance to the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), under greenhouse conditions and documented the categories of aphid-resistant soybean. Two screening studies were performed to assess the level of resistance to the soybean aphid on six soybean genotypes during the reproductive stages of development. Significant differences in aphid damage ratings were detected among the soybean evaluated in the screening studies. Three genotypes (KS4202, K-1639-2, and K1621) were considered moderately resistant based on the assessed damage ratings. Two of these genotypes (K-1639-2 and KS4202), along with …

Centennial Eolian Cyclicity In The Great Plains, Usa: A Dominant Climate Pattern Of Wind Transport Over The Past 4000 Years?, Antje Schwalb, Walter E. Dean, Sherilyn C. Fritz, Christoph E. Geiss, Bernd Kromer

Department of Earth and Atmospheric Sciences: Faculty Publications

Proxy evidence at decadal resolution from Late Holocene sediments from Pickerel Lake, northeastern South Dakota, shows distinct centennial cycles (400-700 years) in magnetic susceptibility; contents of carbonate, organic carbon, and major elements; abundance in ostracodes; and δ¹⁸O and δ¹³C values in calcite. Proxies indicate cyclic changes in eolian input, productivity, and temperature. Maxima in magnetic susceptibility are accompanied by maxima in aluminum and iron mass accumulation rates (MARs), and in abundances of the ostracode Fabaeformiscandona rawsoni. This indicates variable windy, and dry conditions with westerly wind dominance, including during the Medieval Climate Anomaly. Maxima in …

Millennial-Scale Climate Variability During The Last Glacial Period In The Tropical Andes, Sherilyn C. Fritz, P. A. Baker, E. Ekdahl, G. O. Seltzer, L. R. Stevens

Department of Earth and Atmospheric Sciences: Faculty Publications

Millennial-scale climate variation during the Last Glacial period is evident in many locations worldwide, but it is unclear if such variation occurred in the interior of tropical South America, and, if so, how the low-latitude variation was related to its high-latitude counterpart. A high-resolution record, derived from the deep drilling of sediments on the floor of Lake Titicaca in the southern tropical Andes, is presented that shows clear evidence of millennial-scale climate variation between ~60 and 20 ka BP. This variation is manifested by alternations of two interbedded sedimentary units. The two units have distinctive sedimentary, geochemical, and paleobiotic properties …

Groundwater Recharge In Natural Dune Systems And Agricultural Ecosystems In The Thar Desert Region, Rajasthan, India, Bridget Scanlon, Abhijit Mukherjee, John B. Gates, Robert C. Reedy, Amarendra K. Sinha

Department of Earth and Atmospheric Sciences: Faculty Publications

Water and nutrient availability for crop production are critical issues in (semi)arid regions. Unsaturated-zone Cl tracer data and nutrient (NO₃ and PO₄) concentrations were used to quantify recharge rates using the Cl mass balance approach and nutrient availability in the Thar Desert, Rajasthan, India. Soil cores were collected in dune/interdune settings in the arid Thar Desert (near Jaisalmer) and in rain-fed (nonirrigated) and irrigated cropland in the semiarid desert margin (near Jaipur). Recharge rates were also simulated using unsaturated zone modeling. Recharge rates in sparsely vegetated dune/interdune settings in the Jaisalmer study area are 2.7-5.6 mm/year (2-3% …

Estimation Of Cellular Manufacturing Cost Components Using Simulation And Activity-Based Costing, Paul Savory, Robert Williams

Department of Industrial and Management Systems Engineering: Faculty Publications

It can be difficult estimating all of the cost components that are attributed to a machined part. This problem is more pronounced when a factory uses group technology manufacturing cells as opposed to a functional or process layout of a job shop. This paper describes how activity-based costing (ABC) concepts can be integrated into a discrete-event simulation model of a U-shaped manufacturing cell producing a part family with four members. The simulation model generates detailed Bills of Activity for each part type and includes specific information about the cost drivers and cost pools. The enhanced model output can be used …

Tetrapod Fauna Of The Lowermost Usili Formation (Songea Group, Ruhuhu Basin) Of Southern Tanzania, With A New Burnetiid Record, Christian A. Sidor, Kenneth D. Angielczyk, D. Marie Weide, Roger M. H. Smith, Sterling J. Nesbitt, Linda A. Tsuji

Department of Earth and Atmospheric Sciences: Faculty Publications

Vertebrate fossils from the Ruhuhu Basin of southern Tanzania have been known for over 75 years, but the details of their stratigraphic distribution remain imperfectly understood. Recent fieldwork in the Upper Permian Usili Formation (Songea Group) has led to the discovery of a tetrapod assemblage in a conglomeratic unit at its base. The fossils are concentrated in matrix-supported intraformational clay pebble conglomerates interpreted as mass flow deposits in wide, shallow channels in the distal reaches of an alluvial fan. Included in this new collection are fossils representing the first record of a burnetiid therapsid from Tanzania. The anatomy of the …

Improved Algorithm For Modis Satellite Retrievals Of Aerosol Optical Thickness Over Land In Dusty Atmosphere: Implications For Air Quality Monitoring In China, Jun Wang, Xiaoguang Xu, R. Spurr, Yuxuang Wang, Easan Drury

Department of Earth and Atmospheric Sciences: Faculty Publications

A new algorithm, using the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite reflectance and aerosol single scattering properties simulated from a chemistry transport model (GEOS-Chem), is developed to retrieve aerosol optical thickness (AOT) over land in China during the spring dust season. The algorithmfirst uses a “dynamic lower envelope” approach to sample theMODIS dark-pixel reflectance data in lowAOT conditions, to derive the local surface visible (0.65 μm)/near infrared (NIR, 2.1 μm) reflectance ratio. Joint retrievals of AOT at 0.65 μm and surface reflectance at 2.1 μm are then performed, based on the time, location, and spectraldependent single scattering properties of the …

The Endogeneity Problem In Cost-Benefit Analysis, Gregory S. Crespi

Faculty Journal Articles and Book Chapters

Cost-benefit analysis, an important technique in American public sector decision-making, is used to assess policies through aggregating the estimated willingness to pay of the affected persons to enjoy the benefits or avoid the burdens of those policies. Such analyses are generally based on the implicit simplifying assumptions that both the preferences of existing persons and the genetic identities of the persons who will comprise future generations are exogenous with respect to that policy. If, however, some persons’ preferences are endogenous in that they are altered by a policy, which is often the case, then this exogenous preferences assumption will introduce …

A Critical Legal Rhetoric Approach To In Re African-American Slave Descendants Litigation, Lolita Buckner Inniss

Faculty Journal Articles and Book Chapters

No abstract provided.

The Heavily Polluted Atmosphere Of The Daz White Dwarf Galex J193156.8+011745, Stephane Vennes, Adéla Kawka, Péter Németh

Aerospace, Physics, and Space Science Faculty Publications

We report on the discovery of a new heavily polluted white dwarf. The DAZ white dwarf GALEX J193156.8+011745 was identified in a joint Galaxy Evolution Explorer (GALEX)/GSC survey of ultraviolet-excess objects. Optical spectra obtained at ESO New Technology Telescope show strong absorption lines of magnesium and silicon, and a detailed abundance analysis based on Very Large Telescope-Kueyen UVES spectra reveal super-solar abundances of silicon and magnesium and near-solar abundances of oxygen, calcium and iron. The overall abundance pattern bears the signature of on-going accretion on to the white dwarf atmosphere. The infrared spectral energy distribution shows an excess in the …

Chandra Observations Of The Radio Galaxy 3c 445 And The Hot Spot X-Ray Emission Mechanism, Eric S. Perlman, Markos Georganopoulos, Emily M. May, Deosthenes Kazanas

Aerospace, Physics, and Space Science Faculty Publications

We present new Chandra observations of the radio galaxy 3C 445, centered on its southern radio hot spot. Our observations detect X-ray emission displaced upstream and to the west of the radio-optical hot spot. Attempting to reproduce both the observed spectral energy distribution and the displacement excludes all one-zone models. Modeling of the radio-optical hot spot spectrum suggests that the electron distribution has a low-energy cutoff or break approximately at the proton rest mass energy. The X-rays could be due to external Compton scattering of the cosmic microwave background coming from the fast (Lorentz factor Γ ≈ 4) part of …

Chandra Observations Of The Radio Galaxy 3c 445 And The Hot Spot X-Ray Emission Mechanism, Eric S. Perlman, Markos Georganopoulos, Emily M. May, Demosthenes Kazanas

Aerospace, Physics, and Space Science Faculty Publications

We present new Chandra observations of the radio galaxy 3C 445, centered on its southern radio hot spot. Our observations detect X-ray emission displaced upstream and to the west of the radio-optical hot spot. Attempting to reproduce both the observed spectral energy distribution and the displacement excludes all one-zone models. Modeling of the radio-optical hot spot spectrum suggests that the electron distribution has a low-energy cutoff or break approximately at the proton rest mass energy. The X-rays could be due to external Compton scattering of the cosmic microwave background coming from the fast (Lorentz factor Γ ≈ 4) part of …

A Multi-Wavelength Spectral And Polarimetric Study Of The Jet Of 3c 264, Eric S. Perlman

Aerospace, Physics, and Space Science Faculty Publications

We present a comprehensive multi-band spectral and polarimetric study of the jet of 3C 264 (NGC 3862). Included in this study are three Hubble Space Telescope (HST) optical and ultraviolet polarimetry data sets, along with new and archival Very Large Array radio imaging and polarimetry, a re-analysis of numerous HST broadband data sets from the near infrared to the far ultraviolet, and a Chandra ACIS-S observation. We investigate similarities and differences between optical and radio polarimetry, in both degree of polarization and projected magnetic field direction. We also examine the broadband spectral energy distribution of both the nucleus and jet …

Acceleration Of Suprathermal Particles By Compressional Plasma Wave Trains In The Solar Wind, Ming Zhang

Aerospace, Physics, and Space Science Faculty Publications

This paper presents a calculation of particle acceleration by an idealized compressional plasma wave train. In this model, suprathermal particles, such as pickup ions, are continuously injected into a wave train consisting of a series of compression or rarefaction regions. The momentum distribution of particles will become broader and broader as they go through the wave train, which is very similar to diffusion in momentum space. The acceleration process is very fast: it does not take too many wave cycles even with a small compression amplitude to reach an asymptotic steady state momentum distribution. In the absence of large-scale adiabatic …

Diffusion Of Relativistic Runaway Electrons And Implications For Lightning Initiation, Joseph R. Dwyer

Aerospace, Physics, and Space Science Faculty Publications

Using detailed Monte Carlo simulations, the diffusion coefficients for relativistic runaway electron avalanches in air are found for the range of electric field strengths applicable to thunderclouds. Diffusion causes runaway electron avalanches to spread perpendicular to and parallel to the avalanche direction, resulting in much smaller peak conductivities than would be inferred otherwise. The idea that runaway electron avalanches seeded by extensive cosmic ray air showers may initiate lightning has gained considerable popularity in recent years. However, using the diffusion coefficients calculated in this paper along with the avalanche multiplication limit from X-ray and positron feedback, it is found that …