Physical Sciences and Mathematics Commons^™

Two Approximate Minkowski Sum Algorithms, Victor Milenkovic, Elisha P. Sacks

Department of Computer Science Faculty Publications

We present two approximate Minkowski sum algorithms for planar regions bounded by line and circle segments. Both algorithms form a convolution curve, construct its arrangement, and use winding numbers to identify sum cells. The first uses the kinetic convolution and the second uses our monotonic convolution. The asymptotic running times of the exact algorithms are increased by kmlogm with m the number of segments in the convolution and with k the number of segment triples that are in cyclic vertical order due to approximate segment intersection. The approximate Minkowski sum is close to the exact sum of perturbation regions that …

Transcriptome Sequencing Of The Blind Subterranean Mole Rat, Spalax Galili: Utility And Potential For The Discovery Of Novel Evolutionary Patterns, Assaf Malik, Abraham Korol, Sariel Hubner, Aaron Avivi, Alvaro Hernandez, Jyothi Thimmapuram, Shahjahan Ali, Mark Bond, Fabian Glaser, Arnon Paz

Cyber Center Publications

The blind subterranean mole rat (Spalax ehrenbergi superspecies) is a model animal for survival under extreme environments due to its ability to live in underground habitats under severe hypoxic stress and darkness. Here we report the transcriptome sequencing of Spalax galili, a chromosomal type of S. ehrenbergi. cDNA pools from muscle and brain tissues isolated from animals exposed to hypoxic and normoxic conditions were sequenced using Sanger, GS FLX, and GS FLX Titanium technologies. Assembly of the sequences yielded over 51,000 isotigs with homology to ~12,000 mouse, rat or human genes. Based on these results, it was …

Miniature Mass Spectrometry: Rf Amplitude Control System Design, Matthew Allen Kirleis

Purdue Polytechnic Masters Theses

This thesis covers the methods used to construct and characterize a custom digital RF amplitude control system. Many types of mass spectrometers exist, but few have been miniaturized as much as the Mini instruments developed at Purdue University. The goal of this research was to improve upon an earlier amplitude control system consisting of analog circuits first implemented in the Mini 11.5 mass spectrometer developed at Purdue University.

A custom set of control and data acquisition electronics were developed for testing the digital and analog control systems in a Mini 11.5 mass spectrometer chassis. A MATLAB Simulink simulation was done …

Solving The Mystery Of The Atacama Nitrate Deposits: The Use Of Stable Oxygen Isotope Analysis And Geochemistry, Ji-Hye Seo

The Journal of Purdue Undergraduate Research

The Atacama Desert, Chile, one of the oldest and driest deserts on Earth, is unique because it contains the largest known nitrate deposits in the world. The origin of these nitrate deposits has been a mystery since their discovery in the 1800s. There are two possible sources of natural nitrate: microbiological processes and photochemical reactions. The majority of material on Earth follows mass-dependent fractionation between stable oxygen isotopes with the abundance of ¹⁷Ο (denoted by δ) as half that of ¹⁸O. This relationship is quantified by Δ¹⁷O = δ¹⁷O – ½ δ¹⁸O, …

Do Wind Turbines Affect Weather Conditions?: A Case Study In Indiana, Meghan F. Henschen, Brittany Herrholtz, Lacey Rhudy, Kathryn Demchak, Brian Doogs, Joshua Holland, Erik Larson, Johnny Martin, Matthew Rudkin

The Journal of Purdue Undergraduate Research

Wind turbines are becoming increasingly widespread in the United States as the world looks for cleaner sources of energy. Scientists, policymakers, and citizens have strong opinions regarding the positive and negative effects of wind energy projects, and there is a great deal of misinformation about wind energy circulating on the Web and other media sources. The purpose of this study is to gain a better understanding of how the rotation of hundreds of turbines can influence local weather conditions within a wind farm and in the surrounding areas. This experiment measures temperature, atmospheric pressure, wind speed, wind direction, relative humidity, …

Comparison Of Turbine Engine Test Cell Airborne Nanoparticle Count Versus Ambient Background Particle Count, Ryne Larowe

Purdue Polytechnic Directed Projects

With the establishment of the National Test Facility for Aerospace Fuels and Propulsion at Purdue University in October of 2009, new equipment has been acquired to measure and classify exhaust emissions. This facility utilizes the Honeywell F109 turbofan and Pratt & Whitney PT-6 turboprop engine test cells to analyze the emissions and engine operation of new alternative aviation fuels. This observational study investigates what, if any difference there is in the amount of ambient residual Particulate Matter (PM) in the turbofan engine test cell when compared to ambient particle count associated with the Purdue University Airport (KLAF) property. The project …

Comparison Of Clustered Rdf Data Stores, Venkata Patchigolla

Purdue Polytechnic Masters Theses

Storing data in RDF format helps in simpler data interchange among different researchers compared to present approaches. There has been tremendous increase in the applications that use RDF data. The nature of RDF data is such that it tends to increase explosively. This makes it necessary to consider the time for retrieval and scalability of data while selecting a suitable RDF data store for developing applications. The research concentrates on comparing BigOWLIM. Bigdata, 4store and Virtuoso RDF stores on basis of their scalability and performance of storing and retrieving cancer proteomics and mass spectrometry data using SPARQL queries. In this …

The Use Of Large-Scale Climate Data To Predict Drought, River Flows, And Vegetation Over Central-Southwest Asia, Matthew Barlow

2011 Symposium on Data-Driven Approaches to Droughts

Central-Southwest Asia is a semi-arid, economically stressed region where droughts have severe societal impacts in terms of agriculture, farming, access to fresh water for drinking, and sanitation. There are two sources of drought predictability for this area: the influence of predictable modes of large-scale climate variability at both seasonal and intraseasonal timescales, and the importance of the snow pack to warm season river flows and vegetation. Local data scarcity is a critical problem for the region, both for historical analysis and for real-time monitoring. However, analysis shows that satellite data can be used to provide a considerable amount of high-resolution …

Building An Enhanced Drought Early Warning System (Dews): Tools And Services For Decision Support, Mark Svoboda

2011 Symposium on Data-Driven Approaches to Droughts

Perhaps no other hazard lends itself as well to the need for a diligent early warning system (DEWS) than drought. Droughts typically evolve slowly, but have the potential to cover very large areas compared to hazards like hurricanes, tornadoes and floods, which have a much smaller geographic footprint. The U.S. took first steps in 2006 toward developing coordinated and integrated DEWS through the creation of the National Integrated Drought Information System, or NIDIS. More recently, the National Drought Mitigation Center (http://drought.unl.edu) has been working with NIDIS and other international parties (WMO, GEO, United Nations, etc.) with a goal of developing …

Analyzing Past And Predicting Future Drought With Comprehensive Drought Indices For Arkansas-Red River Basin, Lu Liu, Yang Hong, James E. Hocker

2011 Symposium on Data-Driven Approaches to Droughts

This study is intended to examine the past drought and predict future drought scenarios for Arkansas-Red River Basin with comprehensive drought indices ranging from meteorology, hydro-meteorology to hydrology. In this proceeding, we present some early results and analysis with the Standardized Precipitation Index (SPI) and the Palmer Drought Severity Index (PDSI). Historical climate data within the 1900-2009 timeframe were archived to derive the drought indices calculations. The projected A2, A1B climate data modules from 16 statistically downscaled Global Climate Models (GCM) were applied in drought occurrence frequency and affected area prediction. The results from the SPI and PDSI show that …

Climatic Characterization And Response Of Water Resources To Climate Change In Limestone Areas: Some Considerations On The Importance Of Geological Setting, Di Matteo Lucio, Valigi Daniela, Cambi Costanza

2011 Symposium on Data-Driven Approaches to Droughts

It is worldwide recognized and accepted that, in Southern Europe and the Mediterranean area in the last hundred years, the atmospheric temperature has risen by about 1°C, accompanied by a general decrease in precipitation. The trends detected in historical thermo-pluviometric series recorded in South/Central Italy show a general decrease in precipitation on an annual scale and a concentration of negative trends in the months from October to March. Analysis of the Standard Precipitation Index for the period 1951-2008 indicates higher frequency and duration of droughts in the last two decades: four prolonged dry periods (each lasting for up to three …

Exploring The Link Between Droughts And Atmospheric Aerosol Loading, Umarporn Charusombat, Dev Niyogi

2011 Symposium on Data-Driven Approaches to Droughts

Are higher atmospheric aerosol levels and droughts related? To address this question, we explore the relation between atmospheric aerosol loading and droughts using insitu and satellite observations over different urban/rural settings and heterogeneous drought conditions. A related objective was to report on the relationship and the variability between aerosol optical depth (AOD) retrieved from the Moderate Resolution Imaging Spectroradiometer (MODIS) and insitu particular matter (PM2.5 and PM10) over different land use. Daily measurement of PM2.5 and PM10 data were retrieved from seven EPA air quality monitoring stations in Indiana: Virgo, Lake and Clark County in urban area, Marion, Know and …

Monitoring Drought In The Midwest, Steve Hilberg

2011 Symposium on Data-Driven Approaches to Droughts

Climate monitoring is one component of the mission of the Regional Climate Centers, and the Midwestern Regional Climate Center (MRCC) has created web pages to provide near real-time monitoring of the weather and climate of the Midwest. A dedicated drought monitoring page was developed by the MRCC to provide a snapshot of current moisture conditions in the region using a number of specialized maps and products. Users are able to drill down to state and local conditions and impacts through links to the respective state climate offices and water resources agencies.

Monitoring Drought Across Many Scales, Chris Funk

2011 Symposium on Data-Driven Approaches to Droughts

Monitoring drought across many scales Chris Funk As gas and food prices increase while per capita harvested area decreases, drought and disruptions in food availability exert more and more pressure on the political and economic stability of ‘frailed’ states. Improved drought monitoring across many spatial and temporal time scales has therefore become increasingly important. As this need mounts, so have our capacities to observe and understand the earth’s climate. Relatively new satellite systems, such as the Moderate Resolution Imaging Spectrometer, allow us to watch the earth at scales of ~100 meters. Improved rainfall retrievals give us more timely and accurate …

An Update On Noaa’S National Integrated Drought Information System, Doug Kluck

2011 Symposium on Data-Driven Approaches to Droughts

NOAA through the National Integrated Drought Information System (NIDIS) supports planning and early warning preparedness amongst communities and states. Since the inception of NIDIS in 2006 there have been a series of regional drought projects across the United States that have begun to help different groups renew or begin to plan for drought. This presentation will briefly touch upon some of the successes those pilot projects have achieved and where they are headed. In addition and overview of NIDIS and the drought portal will be included.

Probabilistic Assessment Of Drought Characteristics Using A Hidden Markov Model, Ganeshchandra Mallya, Shivam Tripathi, Sergey Kirshner, Rao S. Govindaraju

2011 Symposium on Data-Driven Approaches to Droughts

Droughts are evaluated using drought indices that measure the departure of meteorological and hydrological variables such as precipitation and stream flow from their long-term averages. While there are many drought indices proposed in the literature, most of them use pre-defined thresholds for identifying drought classes ignoring the inherent uncertainties in characterizing droughts. In this study, a hidden Markov model (HMM) [1] is developed for probabilistic classification of drought states. The HMM captures space and time dependence in the data. The proposed model is applied to assess drought characteristics in Indiana using monthly precipitation and stream flow data. The comparison of …

A Modified Standardized Precipitation Index For Drought Monitoring, Brent Mcroberts, John Nielsen-Gammon

2011 Symposium on Data-Driven Approaches to Droughts

The SPI Blend is a modified Standardized Precipitation Index (SPI) created for use in a newly developed, high-resolution drought monitoring tool, assessing drought using precipitation data on multiple time scales. Unlike the traditional SPI, the SPI Blend uses a linear weighting system that places a higher importance on recent precipitation within a time period. At each time scale, the MPE precipitation data are divided into several periods and the precipitation total from the most recent period is given the highest weight, with a linear decrease in the weights for succeeding periods. The high-resolution (4 km) precipitation data are obtained daily …

Quantifying Multiple Types Of Damping Acting On Bronze-Wound Guitar Strings, Jonathan Christian

Purdue Polytechnic Masters Theses

The goal of this study was to quantify the contributions of multiple damping types acting on guitar strings for each mode over a wide frequency range so that design variables could be identified to one day create frequency based damping in guitar strings. Structural dynamic testing was used to obtain the time-response of a vibrating string in open air and in a vacuum. From this signal, each harmonic was filtered and the decay envelope was curve-fitted with a function that was a linear summation of decay functions. From the curve-fits, the damping coefficients for aerodynamic, friction, and material damping were …

How Much Do U.S. University Students Know, And Want To Know, About Sustainability And Green Building? The Findings Of A Survey, And Possible Implications For General Elective Curricula., Jeremy R. Farner

Purdue Polytechnic Masters Theses

Using the survey approach, this investigation examined the attitudes and interest of college students at two universities in different geographic locations within the United States. Approximately 24,000 students from all disciplines and majors at Weber State University (WSU) in Utah, and 4,000 at Purdue University in Indiana, were invited to participate in a study to determine current knowledge, familiarity, and interest in topics within the sustainability and Green Building educational arena. The goal of this study was to determine what students already know, would like to know, and how much interest there would be in developing …

How Much Do U.S. University Students Know, And Want To Know, About Sustainability And Green Building? The Findings Of A Survey, And Possible Implications For General Elective Curriculum., Jeremy R. Farner

Purdue Polytechnic Masters Theses

Using the survey approach, this investigation examined the attitudes and interest of college students at two universities in different geographic locations within the United States. Approximately 24,000 students from all disciplines and majors at Weber State University (WSU) in Utah, and 4,000 at Purdue University in Indiana, were invited to participate in a study to determine current knowledge, familiarity, and interest in topics within the sustainability and Green Building educational arena. The goal of this study was to determine what students already know, would like to know, and how much interest there would be in developing …

Stereoscopic Visualization As A Tool For Learning Astronomy Concepts, Norman M. Joseph

Department of Computer Graphics Technology Degree Theses

Three-dimensional (3D) visualization is becoming an extensively used educational tool. 3D visualization tends to be most useful when demonstrating concepts involving the very large – such as astronomy, or the very small – such as nanotechnology. Stereo visualization allows students to familiarize and immerse themselves in worlds which are difficult or impossible to experience in real life. This study will evaluate the educational benefit of teaching lessons involving a highly spatially-oriented topic (astronomy) using stereoscopic visualization technology.

We have used a stereoscopic visualization system, installed in a classroom, to deploy 3D simulation packages for use in classroom instruction. This educational …

A Cost-Benefit Analysis Of A Campus Computing Grid, Preston M. Smith

Purdue Polytechnic Masters Theses

Any major research institution has a substantial number of computer systems on its campus, often in the scale of tens of thousands. Given that a large amount of scientific computing is appropriate for execution in an opportunistic environment, a campus grid is an inexpensive way to build a powerful computational resource. What is missing, though, is a model for making an informed decision on the cost-effectives of a campus grid. In this thesis, the author describes a model for measuring the costs and benefits of building a campus computing resource based on the institution’s existing investment in computing hardware.

For …

Orchardgrass (Dactylis Glomerata L.) Est And Ssr Marker Development, Annotation, And Transferability., B.S. Bushman, S.R. Larson, M Tuna, M.S. West, A.G. Hernandez, D Vullaganti, G Gong, J.G. Robbins, K. B. Jensen, Jyothi Thimmapuram

Cyber Center Publications

Orchardgrass, or cocksfoot [Dactylis glomerata (L.)], has been naturalized on nearly every continent and is a commonly used species for forage and hay production. All major cultivated varieties of orchardgrass are autotetraploid, and few tools or information are available for functional and comparative genetic analyses and improvement of the species. To improve the genetic resources for orchardgrass, we have developed an EST library and SSR markers from salt, drought, and cold stressed tissues. The ESTs were bi-directionally sequenced from clones and combined into 17,373 unigenes. Unigenes were annotated based on putative orthology to genes from rice, Triticeae grasses, other Poaceae, …

Controlled Linear Perturbation, Elisha P. Sacks, Victor Milenkovic, Min-Ho Kyung

Department of Computer Science Faculty Publications

We present an algorithmic solution to the robustness problem in computational geometry, called controlled linear perturbation, and demonstrate it on Minkowski sums of polyhedra. The robustness problem is how to implement real RAM algorithms accurately and efficiently using computer arithmetic. Approximate computation in floating point arithmetic is efficient but can assign incorrect signs to geometric predicates, which can cause combinatorial errors in the algorithm output. We make approximate computation accurate by performing small input perturbations, which we compute using differential calculus. This strategy supports fast, accurate Minkowski sum computation. The only prior robust implementation uses a less efficient algorithm, requires …

Visual Learning Styles Among Digital Natives, Eric Palmer

Department of Computer Graphics Technology Degree Theses

This study explored the concept of digital nativity and its educational implications, including application of the learning styles hypothesis. The concept of digital natives, first put forth by Marc Prensky, introduced the notion that individuals raised in a technological environment have developed in such a way as to utilize information differently than the non-native generations before them. This study examined the possibility that these differences may include an increased efficiency in the utilization of narrative imagery versus textual information. The potential benefit of utilizing narrative imagery as an instructional tool is discussed. An experimental test application was developed for the …

Crustal Structure Across The Central Alaska Range: Anatomy Of A Mesozoic Collisional Zone, P.R.K. Brennan, H. Gilbert, K. D. Ridgway

Department of Earth, Atmospheric, and Planetary Sciences Faculty Publications

A first-order process in the growth of continents is the collision and accretion of terranes against continental margins. Collision leads to the formation of a suture zone between the accreted terrane and the former continental margin. New insights on the suturing process are observed from two receiver function transects across the Mesozoic Alaska Range suture zone. Three distinct crustal sections are identified from observations of crustal thickness, intracrustal discontinuities, and Vp/Vs: a northern section with ∼27 km thick crust of felsic to intermediate composition, a central section that is ∼37 km thick that exhibits intracrustal discontinuities and has felsic to …

Identification And Analysis Of Common Bean (Phaseolus Vulgaris L.) Transcriptomes By Massively Parallel Pyrosequencing, Venu Kalavacharla, Zhanji Liu, Blake C. Meyers, Jyothi Thimmapuram, Kalpalatha Melmaiee

Cyber Center Publications

Common bean (Phaseolus vulgaris) is the most important food legume in the world. Although this crop is very important to both the developed and developing world as a means of dietary protein supply, resources available in common bean are limited. Global transcriptome analysis is important to better understand gene expression, genetic variation, and gene structure annotation in addition to other important features. However, the number and description of common bean sequences are very limited, which greatly inhibits genome and transcriptome research. Here we used 454 pyrosequencing to obtain a substantial transcriptome dataset for common bean.

Privacy-Preserving Assessment Of Location Data Trustworthiness, Chenyun Dai, Fang-Yu Rao, Gabriel Ghinita, Elisa Bertino

Cyber Center Publications

Assessing the trustworthiness of location data corresponding to individuals is essential in several applications, such as forensic science and epidemic control. To obtain accurate and trustworthy location data, analysts must often gather and correlate information from several independent sources, e.g., physical observation, witness testimony, surveillance footage, etc. However, such information may be fraudulent, its accuracy may be low, and its vol-
ume may be insufficient to ensure highly trustworthy data. On the other hand, recent advancements in mobile computing and positioning systems, e.g., GPS-enabled cell phones, highway sensors, etc., bring new and effective technological means to track the location of …

Prox-Rbac: A Proximity-Based Spatially Aware Rbac, Michael Kirkpatrick, Maria Luisa Damiani, Elisa Bertino

Cyber Center Publications

As mobile computing devices are becoming increasingly dominant in enterprise and government organizations, the need for fine-grained access control in these environments continues to grow. Specifically, advanced forms of access control can be deployed to ensure authorized users can access sensitive resources only when in trusted locations. One technique that has been proposed is to augment role-based access control (RBAC) with spatial constraints. In such a system, an authorized user must be in a designated location in order to exercise the privileges associated with a role. In this work, we extend spatially aware RBAC systems by defining the notion of …