On the Use of Various Oscillatory Air Flow Fields for Characterization of Biomimetic Hair Flow Sensors

To determine the characteristics of flow sensors, a suitable source for flow generation is required. We discuss three different sources for oscillating air flow, by considering their acoustic impedance, frequency range, velocity and ability to distinguish between flow and pressure. We discuss the impact of these sources on characterization of our biomimetic hair flow sensors, which operate at flow velocities from 1–100 mm/s within a frequency range from 10–1000 Hz

Listening to MEMS: An acoustic vibrometer

new way to characterize vibrating MEMS devices is presented. Using an acoustic particle velocity sensor the coupled sound field is measured, which is a measure for the movement of the MEMS device. We present several possible applications of this measurement method. It can be used as a read-out system for a mass flow sensor, and for characterization of in- and out-of-plane movements of MEMS devices. The method is an interesting alternative to laser scanning vibrometry due to its small size and low complexity; furthermore, it allows the user to `listen' directly to MEMS devices

Events not processes: Reassessing and Redating the Lower Fills of the South Stoa Wells at Corinth

Abstract from paper presented at: Pottery, Peoples and Places: the Late Hellenistic Period, c. 200-50 BC Between the Mediterranean and the Black Sea, International Conference at Sandbjerg Manor House, Aarhus, Denmark, November 2008. Available from: digitalcommons.butler.edu/facsch_papers/415

Corinth Excavations Archaeological Manual

“The publication of the Corinth Excavation Manual offers us a unique view into real-life archaeological practice on one of the most important Classical sites in the Mediterranean.” Adam Rabinowitz, Associate Professor and Assistant Director, Institute of Classical Archaeology, University of Texas, Austin The Corinth Excavations Archaeological Manual is the first major field manual published from an American excavation in Greece and among a very small number of manuals published from the Eastern Mediterranean in the last generation. The appearance of this book is timely, however, as there is a growing interest in field methods and the history of excavation practices throughout the discipline of archaeology. Moreover, Corinth Excavations has long held a special place in American archaeology in Greece as the primary training excavation for graduate students associated with the American School of Classical Studies at Athens. As a result, the field manual has had a particular influence among American excavators and projects in Greece, among Mediterranean archaeologists, and in archaeology classrooms. Published as a technical field manual, an archival document, and a key statement of practice from a major excavation, the Corinth Excavations Archaeological Manual presents a guide for daily procedures at the Corinth Excavations, a complete record of documentation forms used in the field, and a practical glimpse into the functioning of a complex, major, project. The manual is a landmark text appropriate for the university student, the scholar of methodology, and the working field archaeologist. “The Corinth manual has grown over the years into a comprehensive and authoritative guide to open-area, stratigraphic excavation, covering everything from excavation of pits, wells, and robbing trenches to the removal of deposits to inventorying objects in the museum. ” David Pettegrew, Associate Professor, Messiah College and author of The Isthmus of Corinth (2016). All of the authors have worked on the excavations at Corinth in various capacities. This manual was developed under the directorship of Dr. Guy Sanders by former field directors Alicia Carter Johnson and Dr. Sarah James. Additional contributions come from past and present Corinth staff including assistant director Dr. Ioulia Tzonou-Herbst, architect James Herbst, conservator Nicol Anastasatou, and archaeologist Katerina Ragkou. The authors would also like to recognize the contributions of the many students from the American School of Classical Studies at Athens who offered valuable feedback on earlier versions of this manual over the past 10 years.https://commons.und.edu/press-books/1005/thumbnail.jp

On the averaging principle for one-frequency systems. Seminorm estimates for the error

We extend some previous results of our work [1] on the error of the averaging method, in the one-frequency case. The new error estimates apply to any separating family of seminorms on the space of the actions; they generalize our previous estimates in terms of the Euclidean norm. For example, one can use the new approach to get separate error estimates for each action coordinate. An application to rigid body under damping is presented. In a companion paper [2], the same method will be applied to the motion of a satellite around an oblate planet.Comment: LaTeX, 23 pages, 4 figures. The final version published in Nonlinear Dynamic

USDA Forecasts Of Crop Ending Stocks: How Well Have They Performed?

This study analyzes forecasts of U.S. ending stocks for corn, soybeans, and wheat issued by the USDA. The proposed efficiency tests focus on forecast revisions. Forecast errors are decomposed into monthly unforecastable shocks and idiosyncratic residuals. The error covariance matrix allows for heteroscedasticity and auto-correlations. Results suggest that the USDA forecasts are inefficient, providing strong evidence that the USDA is conservative in forecasting the ending stocks. Unforecastable shocks are heteroscedastic, and idiosyncratic residuals are small. Results are consistent across the three decades analyzed, but soybean forecasts are found to be considerably worse from 2005 to 2015

Online Makespan Minimization with Parallel Schedules

In online makespan minimization a sequence of jobs $\sigma = J_1,..., J_n$ has to be scheduled on $m$ identical parallel machines so as to minimize the maximum completion time of any job. We investigate the problem with an essentially new model of resource augmentation. Here, an online algorithm is allowed to build several schedules in parallel while processing $\sigma$. At the end of the scheduling process the best schedule is selected. This model can be viewed as providing an online algorithm with extra space, which is invested to maintain multiple solutions. The setting is of particular interest in parallel processing environments where each processor can maintain a single or a small set of solutions. We develop a (4/3+\eps)-competitive algorithm, for any 0<\eps\leq 1, that uses a number of 1/\eps^{O(\log (1/\eps))} schedules. We also give a (1+\eps)-competitive algorithm, for any 0<\eps\leq 1, that builds a polynomial number of (m/\eps)^{O(\log (1/\eps) / \eps)} schedules. This value depends on $m$ but is independent of the input $\sigma$. The performance guarantees are nearly best possible. We show that any algorithm that achieves a competitiveness smaller than 4/3 must construct $\Omega(m)$ schedules. Our algorithms make use of novel guessing schemes that (1) predict the optimum makespan of a job sequence $\sigma$ to within a factor of 1+\eps and (2) guess the job processing times and their frequencies in $\sigma$. In (2) we have to sparsify the universe of all guesses so as to reduce the number of schedules to a constant. The competitive ratios achieved using parallel schedules are considerably smaller than those in the standard problem without resource augmentation

Herbivorous turtle ants obtain essential nutrients from a conserved nitrogen-recycling gut microbiome.

Nitrogen acquisition is a major challenge for herbivorous animals, and the repeated origins of herbivory across the ants have raised expectations that nutritional symbionts have shaped their diversification. Direct evidence for N provisioning by internally housed symbionts is rare in animals; among the ants, it has been documented for just one lineage. In this study we dissect functional contributions by bacteria from a conserved, multi-partite gut symbiosis in herbivorous Cephalotes ants through in vivo experiments, metagenomics, and in vitro assays. Gut bacteria recycle urea, and likely uric acid, using recycled N to synthesize essential amino acids that are acquired by hosts in substantial quantities. Specialized core symbionts of 17 studied Cephalotes species encode the pathways directing these activities, and several recycle N in vitro. These findings point to a highly efficient N economy, and a nutritional mutualism preserved for millions of years through the derived behaviors and gut anatomy of Cephalotes ants

Predictors of care-giver stress in families of preschool-aged children with developmental disabilities

Background This study examined the predictors, mediators and moderators of parent stress in families of preschool-aged children with developmental disability. Method One hundred and five mothers of preschool-aged children with developmental disability completed assessment measures addressing the key variables. Results Analyses demonstrated that the difficulty parents experienced in completing specific caregiving tasks, behaviour problems during these caregiving tasks, and level of child disability, respectively, were significant predictors of level of parent stress. In addition, parents’ cognitive appraisal of care-giving responsibilities had a mediating effect on the relationship between the child’s level of disability and parent stress. Mothers’ level of social support had a moderating effect on the relationship between key independent variables and level of parent stress. Conclusions Difficulty of care-giving tasks, difficult child behaviour during care-giving tasks, and level of child disability are the primary factors which contribute to parent stress. Implications of these findings for future research and clinical practice are outlined

On the selection of AGN neutrino source candidates for a source stacking analysis with neutrino telescopes

The sensitivity of a search for sources of TeV neutrinos can be improved by grouping potential sources together into generic classes in a procedure that is known as source stacking. In this paper, we define catalogs of Active Galactic Nuclei (AGN) and use them to perform a source stacking analysis. The grouping of AGN into classes is done in two steps: first, AGN classes are defined, then, sources to be stacked are selected assuming that a potential neutrino flux is linearly correlated with the photon luminosity in a certain energy band (radio, IR, optical, keV, GeV, TeV). Lacking any secure detailed knowledge on neutrino production in AGN, this correlation is motivated by hadronic AGN models, as briefly reviewed in this paper. The source stacking search for neutrinos from generic AGN classes is illustrated using the data collected by the AMANDA-II high energy neutrino detector during the year 2000. No significant excess for any of the suggested groups was found.Comment: 43 pages, 12 figures, accepted by Astroparticle Physic