Locking device for turbine rotor blades Patent

Locking device for retaining turbine rotor blades on turbine whee

Erastus, Quaestor of Corinth: The Administrative Rank of ὁ οἰκονόμος τής πόλεως (Rom 16.23) in an Achaean Colony

Erastus (Rom 16.23) has featured prominently in the ongoing debate over the social and economic make-up of the early Pauline communities, since how one renders his title (ὁ οἰκονόμος τῆς πόλεως) dramatically affects the range of economic stratification represented in the Corinthian church. Relying chiefly on epigraphy, including an important new inscription from the Achaean colony of Patras, this article engages the scholarly dialogue about the Latin equivalent of Erastus’ title, rebutting the arguments in favour of arcarius and aedilis, and contends that he served as quaestor, a high-ranking municipal position exclusively occupied by the economic elite

Improved Combinatorial Group Testing Algorithms for Real-World Problem Sizes

We study practically efficient methods for performing combinatorial group testing. We present efficient non-adaptive and two-stage combinatorial group testing algorithms, which identify the at most d items out of a given set of n items that are defective, using fewer tests for all practical set sizes. For example, our two-stage algorithm matches the information theoretic lower bound for the number of tests in a combinatorial group testing regimen.Comment: 18 pages; an abbreviated version of this paper is to appear at the 9th Worksh. Algorithms and Data Structure

Analysis of the Precipitation Detection Algorithm for the GEONOR T-200B Precipitation Gauge to Improve Accuracy

In an effort to improve the precipitation detection algorithm for the Geonor All Weather Precipitation Gauge, an automated truth algorithm has been created to detect errors in the original algorithm. The original algorithm detects precipitation in real time and uses the rate of precipitation to indicate an event. The automated truth does not detect in real time, and focuses on precipitation accumulation to indicate an event. Since the automated truth is delayed, it is able to consider the data collected before and after the point it is analyzing. The automated truth is already more accurate than the original algorithm but the accuracy can be improved further. The goal of this study was to develop ways to improve the automated truth algorithm’s accuracy in order to compare it to the original algorithm to detect errors. Ultimately, this will be used to detect errors in the original algorithm for years of data. In order to improve the truth algorithm, we created a human truth output using data collected over a four month time period by four Geonor gauges located at NCAR’s Marshall Test Field in Boulder, CO. The human truth was created by two individuals who observed the Geonor accumulation data and indicated when an event occurred. Because humans are able to process and analyze images more precisely than computers, this human truth is considered the most accurate output. It was completed using a web based plotting tool to create graphs that can be further analyzed. The human truth output will be compared to the automated truth output in order to detect errors in the algorithm so that scientists will be able to correct these errors and improve the automated truth algorithm

More is Less: Perfectly Secure Oblivious Algorithms in the Multi-Server Setting

The problem of Oblivious RAM (ORAM) has traditionally been studied in a single-server setting, but more recently the multi-server setting has also been considered. Yet it is still unclear whether the multi-server setting has any inherent advantages, e.g., whether the multi-server setting can be used to achieve stronger security goals or provably better efficiency than is possible in the single-server case. In this work, we construct a perfectly secure 3-server ORAM scheme that outperforms the best known single-server scheme by a logarithmic factor. In the process, we also show, for the first time, that there exist specific algorithms for which multiple servers can overcome known lower bounds in the single-server setting.Comment: 36 pages, Accepted in Asiacrypt 201

Environmental change network diatom analysis and archiving project

This report provides details of work performed on the Environmental Change Network (ECN) contract to ENSIS Ltd. involving the preparation of historic (March 2007 – March 2012) ECN diatom samples and the analysis of diatom time-series from three river sites; the River Eden, Cumbria, the River Wye and the River Frome

Determining F-factor using ground-based Doppler radar: Validation and results

Using a two-dimensional linear least-squares method applied to Doppler radar data, we test the viability of determining F-factor remotely. The ultimate application of such an algorithm will be supplying real-time F-factor maps, derived from ground-based Doppler radars to air traffic control personnel and pilots. Data from NASA deployments to the MIT/Lincoln Lab TDWR testbed radar in Orlando in 1991 and 1992 along with NASA deployments to the NCAR TDWR testbed radar in Denver are examined. Preliminary analyses show that the two-dimensional method correlates reasonably well with in situ measurements. Several effects, independent of the method used, act to reduce the correlation to less than one. These include time differences between radar and aircraft data, vertical misalignment between the aircraft and the radar beam, different spatial resolution scales between aircraft and radar data, inhomogeneous radar beam filling, noise in radar data that eludes filtering, and phase lag between time and space due to low pass filtering of the aircraft data. In the final assessment, it appears that a shear-based F-factor algorithm is preferable to the currently implemented TDWR algorithms which lack any local shear estimates

Progress in Turbulence Detection via GNSS Occultation Data

The increased availability of radio occultation (RO) data offers the ability to detect and study turbulence in the Earth's atmosphere. An analysis of how RO data can be used to determine the strength and location of turbulent regions is presented. This includes the derivation of a model for the power spectrum of the log-amplitude and phase fluctuations of the permittivity (or index of refraction) field. The bulk of the paper is then concerned with the estimation of the model parameters. Parameter estimators are introduced and some of their statistical properties are studied. These estimators are then applied to simulated log-amplitude RO signals. This includes the analysis of global statistics derived from a large number of realizations, as well as case studies that illustrate various specific aspects of the problem. Improvements to the basic estimation methods are discussed, and their beneficial properties are illustrated. The estimation techniques are then applied to real occultation data. Only two cases are presented, but they illustrate some of the salient features inherent in real data

Planting the Seeds of College and Career Readiness in Preschool

Many jobs require some type of post-secondary degree or specialized training beyond high school, therefore addressing college and career readiness concepts at an early age may influence young children’s future success. This mixed-methods authentic case study explores the implementation and challenges of introducing a structured framework to enhance the culture of universal achievement at one non-profit preschool in a rural hub city. The research site is non-profit preschool accredited by the National Association for the Education of Young Children (NAEYC) which serves predominantly low-income families. The purpose of the study was to discover how the core beliefs of the No Excuses University (NEU) program have influenced awareness of post-secondary opportunities and prospects for educational achievement. Participants included 18 preschool faculty/staff members, 37 parents of preschool students, and 31 preschool students. Adult participants answered online survey questions, while preschool students responded to face-to-face interview questions. Analysis of the collected data revealed that fostering a culture of universal achievement in a preschool setting can enhance young students’ and their families’ awareness of future educational opportunities, increase communication regarding long-term post-secondary goals, and support the development of a positive future story. Conclusions drawn from this study indicate that implementing a structured framework that addresses a variety of educational opportunities can positively influence the child, their parents, members of the school faculty, and the local community. Strategies and effective approaches executed by the preschool include the use of powerful symbolism and multi-faceted collaboration. Some untold challenges to program implementation are discussed. The implications from this research study on early exposure to college and career readiness concepts are applicable to many fields of study

Lights, Camera, Action! Exploring Effects of Visual Distractions on Completion of Security Tasks

Human errors in performing security-critical tasks are typically blamed on the complexity of those tasks. However, such errors can also occur because of (possibly unexpected) sensory distractions. A sensory distraction that produces negative effects can be abused by the adversary that controls the environment. Meanwhile, a distraction with positive effects can be artificially introduced to improve user performance. The goal of this work is to explore the effects of visual stimuli on the performance of security-critical tasks. To this end, we experimented with a large number of subjects who were exposed to a range of unexpected visual stimuli while attempting to perform Bluetooth Pairing. Our results clearly demonstrate substantially increased task completion times and markedly lower task success rates. These negative effects are noteworthy, especially, when contrasted with prior results on audio distractions which had positive effects on performance of similar tasks. Experiments were conducted in a novel (fully automated and completely unattended) experimental environment. This yielded more uniform experiments, better scalability and significantly lower financial and logistical burdens. We discuss this experience, including benefits and limitations of the unattended automated experiment paradigm