Navigation with Limited Prior Information Using Time Difference of Arrival Measurements from Signals of Opportunity

The Global Positioning System (GPS) provides world-wide availability to high-accuracy navigation and positioning information. However, the threats to GPS are increasing, and many limitations of GPS are being encountered. Simultaneously, systems previously considered as viable backups or supplements to GPS are being shut down. This creates the need for system alternatives. Navigation using signals of opportunity (SoOP) exploits any signal that is available in a given area, regardless of whether or not the original intent of the signal was for navigation. Common techniques to compute a position estimate using SoOP include received signal strength, angle of arrival, time of arrival, and time difference of arrival (TDOA). To estimate the position of a SoOP receiver, existing TDOA algorithms require one reference receiver and multiple transmitters, all with precisely known positions. This thesis considers modifications to an existing algorithm to produce a comparable position estimate without requiring precise a priori knowledge of the transmitters or reference receiver(s). Using Amplitude Modulation (AM) SoOP, the effect of erroneous a priori data on the existing algorithm are investigated. A proof-of-concept for three new estimation algorithms is presented in this research. Two of the estimators successfully demonstrate comparable performance to the existing algorithm. This is demonstrated in six different transmitter environments using four different receiver configurations

Does the Locally-Adaptive Model of Archaeological Potential (LAMAP) work for hunter-gatherer sites? A test using data from the Tanana Valley, Alaska

We report an assessment of the ability of the Locally-Adaptive Model of Archaeological Potential (LAMAP) to estimate archaeological potential in relation to hunter-gatherer sites. The sample comprised 182 known sites in the Tanana Valley, Alaska, which was occupied solely by hunter-gatherers for about 14,500 years. To estimate archaeological potential, we employed physiographic variables such as elevation and slope, rather than variables that are known to vary on short time scales, like vegetation cover. Two tests of LAMAP were carried out. In the first, we used the location of a random selection of 90 sites from all time periods to create a LAMAP model. We then evaluated the model with the remaining 92 sites. In the second test, we built a LAMAP model from 12 sites that pre-date 10,000 cal BP. This model was then tested with sites that post-date 10,000 cal BP. In both analyses, areas predicted to have higher archaeological potential contained higher frequencies of validation sites. The performance of LAMAP in the two tests was comparable to its performance in previous tests using archaeological sites occupied by agricultural societies. Thus, the study extends the use of LAMAP to the task of estimating archaeological potential of landscapes in relation to hunter-gatherer sites

The information systems environment of time-based competitors

Time-based competitors create product development and manufacturing practices that reduce response-time and enhance customization capabilities. These practices require an information-rich, internal environment capable of flexible resource deployment and direct and continuous feedback. These firms should have enhanced information systems planning capabilities, cross-functional involvement in information systems related activities, responsiveness to organizational computing demands, high levels of end-user development, and high levels of information systems performance. Data were collected from 265 manufacturers to develop measures for these information systems variables and to determine if there are relationships between the use of time-based practices and the levels of these variables. Results indicate that firms with high levels of time-based product development practices and time-based manufacturing practices have significantly higher scores across these information systems variables than firms with low levels of these time-based practices

Securing ZigBee Commercial Communications Using Constellation Based Distinct Native Attribute Fingerprinting

This work provides development of Constellation Based DNA (CB-DNA) Fingerprinting for use in systems employing quadrature modulations and includes network protection demonstrations for ZigBee offset quadrature phase shift keying modulation. Results are based on 120 unique networks comprised of seven authorized ZigBee RZSUBSTICK devices, with three additional like-model devices serving as unauthorized rogue devices. Authorized network device fingerprints are used to train a Multiple Discriminant Analysis (MDA) classifier and Rogue Rejection Rate (RRR) estimated for 2520 attacks involving rogue devices presenting themselves as authorized devices. With MDA training thresholds set to achieve a True Verification Rate (TVR) of TVR = 95% for authorized network devices, the collective rogue device detection results for SNR ≥ 12 dB include average burst-by-burst RRR ≈ 94% across all 2520 attack scenarios with individual rogue device attack performance spanning 83.32% \u3c RRR \u3c 99.81%

The accuracy of the palpation meter (PALM) for measuring scapular position in overhead athletes

The purpose of this study was to determine the validity, reliability and precision of the Palpation Meter while measuring scapular position in overhead athletes and to establish differences in scapular position with dominant shoulders versus non-dominant shoulders in overhead. A correlation analyses was used to determine if there was a relationship between laboratory and clinical measures of scapular position in twenty-nine Division I or recreational college-age overhead athletes. Intra Class Correlation and SEM values were used to determine the intratester reliability and precision of the Palpation Meter. Lastly, a paired t-test was used to determine the differences in scapular position at rest and 90° of abduction in dominant shoulder versus non-dominant. The Palpation Meter was found to be valid, reliable and precise when measuring scapular position at rest. The dominant scapular position of an overhead athlete was significant upwardly rotated, scapular upward/downward rotation, anterior/posterior tipping, and pectoralis minor length

Dynamics that Influence Current Student Retention of Students Who Have Transferred

Capstone Project Presented in Partial Fulfillment of the Requirements for the Master of Education Degree in the College of Education and Human Service Professions by Heather M Rondeau, University of Minnesota Duluth, June 2017. Advisor: Dr. Lynn Brice. 1 computer file (PDF); vi, 86 pages, appendices I-III. This item has been modified from the original to redact the signatures present.The purpose of this study was to describe the experiences of current students who have transferred from a community college over a two-year period of time. Three students were interviewed one-on-one for sixty minutes at a four-year, medium sized, regional, comprehensive, public university in the upper Mid-west region of the United States. Four themes emerged across the three participants' experiences at the four-year university which were: support, both academically and socially; financial aid which includes FAFSA and scholarships; transfer credits and the transfer credit policies that influence how credits transfer; and connections to faculty, students, and staff on the four-year university campus. The present study found that although Tinto's (1993, 2012) theories on student retention have similarities, there are differences between the experiences of first-year students at a university and students who have transferred. To ensure the retention of students who have transferred, different methods and techniques should be considered by practitioners and administrators when creating retention plans.University of Minnesota, Duluth. College of Education and Human Service Professions

Biological inventory and conservation recommendations for the Great Sand Dunes and San Luis Lakes, Colorado, A

Prepared for: the Nature Conservancy, San Luis Valley Program, Saguache Colorado.March 1999.Includes bibliographical references

Desorption/Ionization on self-Assembled Monolayer Surface (DIAMS) Evaluation of a New Matrix-Free Laser Desorption/Ionization method

Date du colloque&nbsp;: 06/2008</p

The biosynthesis of the cannabinoids

Cannabis has been integral to Eurasian civilization for millennia, but a century of prohibition has limited investigation. With spreading legalization, science is pivoting to study the pharmacopeia of the cannabinoids, and a thorough understanding of their biosynthesis is required to engineer strains with specific cannabinoid profiles. This review surveys the biosynthesis and biochemistry of cannabinoids. The pathways and the enzymes’ mechanisms of action are discussed as is the non-enzymatic decarboxylation of the cannabinoic acids. There are still many gaps in our knowledge about the biosynthesis of the cannabinoids, especially for the minor components, and this review highlights the tools and approaches that will be applied to generate an improved understanding and consequent access to these potentially biomedically-relevant materials

Extending Critical Infrastructure Element Longevity using Constellation-based ID Verification

This work supports a technical cradle-to-grave protection strategy aimed at extending the useful lifespan of Critical Infrastructure (CI) elements. This is done by improving mid-life operational protection measures through integration of reliable physical (PHY) layer security mechanisms. The goal is to improve existing protection that is heavily reliant on higher-layer mechanisms that are commonly targeted by cyberattack. Relative to prior device ID discrimination works, results herein reinforce the exploitability of constellation-based PHY layer features and the ability for those features to be practically implemented to enhance CI security. Prior work is extended by formalizing a device ID verification process that enables rogue device detection demonstration under physical access attack conditions that include unauthorized devices mimicking bit-level credentials of authorized network devices. The work transitions from distance-based to probability-based measures of similarity derived from empirical Multivariate Normal Probability Density Function (MVNPDF) statistics of multiple discriminant analysis radio frequency fingerprint projections. Demonstration results for Constellation-Based Distinct Native Attribute (CB-DNA) fingerprinting of WirelessHART adapters from two manufacturers includes 1) average cross-class percent correct classification of %C \u3e 90% across 28 different networks comprised of six authorized devices, and 2) average rogue rejection rate of 83.4% ≤ RRR ≤ 99.9% based on two held-out devices serving as attacking rogue devices for each network (a total of 120 individual rogue attacks). Using the MVNPDF measure proved most effective and yielded nearly 12% RRR improvement over a Euclidean distance measure