5,517 research outputs found

    A characterization of visual feature recognition

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    technical reportNatural human interfaces are a key to realizing the dream of ubiquitous computing. This implies that embedded systems must be capable of sophisticated perception tasks. This paper analyzes the nature of a visual feature recognition workload. Visual feature recognition is a key component of a number of important applications, e.g. gesture based interfaces, lip tracking to augment speech recognition, smart cameras, automated surveillance systems, robotic vision, etc. Given the power sensitive nature of the embedded space and the natural conflict between low-power and high-performance implementations, a precise understanding of these algorithms is an important step developing efficient visual feature recognition applications for the embedded space. In particular, this work analyzes the performance characteristics of flesh toning, face detection and face recognition codes based on well known algorithms. We also show how the problem can be decomposed into a pipeline of filters that have efficient implementations as stream processors

    Effects of implementing school-wide positive behavioral intervention and supports in an alternative school setting

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    One correctional alternative to punitive consequences is School Wide Positive Behavioral Intervention and Supports. The program’s effects on behavior, achievement, and social behavior of students in a juvenile corrections facility were examined. There was a significant difference in the number of problem behavioral referrals between the pre (n = 130, M = 4.28) and post periods (n = 98, M = 3.23, p =.05, d=.27, small effect size). Themes from a focus group of school personnel (N=6): an improvement of classroom management skills by teachers, inconsistent application of positive behavioral supports, and a lack of administration support for the program

    Understanding the physics of hydrophobic solvation

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    Simulations of water near extended hydrophobic spherical solutes have revealed the presence of a region of depleted density and accompanying enhanced density fluctuations.The physical origin of both phenomena has remained somewhat obscure. We investigate these effects employing a mesoscopic binding potential analysis, classical density functional theory (DFT) calculations for a simple Lennard-Jones (LJ) solvent and Grand Canonical Monte Carlo (GCMC) simulations of a monatomic water (mw) model. We argue that the density depletion and enhanced fluctuations are near-critical phenomena. Specifically, we show that they can be viewed as remnants of the critical drying surface phase transition that occurs at bulk liquid-vapor coexistence in the macroscopic planar limit, i.e.~as the solute radius RsR_s\to\infty. Focusing on the radial density profile ρ(r)\rho(r) and a sensitive spatial measure of fluctuations, the local compressibility profile χ(r)\chi(r), our binding potential analysis provides explicit predictions for the manner in which the key features of ρ(r)\rho(r) and χ(r)\chi(r) scale with RsR_s, the strength of solute-water attraction εsf\varepsilon_{sf}, and the deviation from liquid-vapor coexistence of the chemical potential, δμ\delta\mu. These scaling predictions are confirmed by our DFT calculations and GCMC simulations. As such our theory provides a firm basis for understanding the physics of hydrophobic solvation.Comment: 18 page

    Density depletion and enhanced fluctuations in water near hydrophobic solutes: identifying the underlying physics

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    We investigate the origin of the density depletion and enhanced density fluctuations that occur in water in the vicinity of an extended hydrophobic solute. We argue that both phenomena are remnants of the critical drying surface phase transition that occurs at liquid-vapor coexistence in the macroscopic planar limit, ie. as the solute radius RsR_s\to\infty. Focusing on the density profile ρ(r)\rho(r) and a sensitive spatial measure of fluctuations, the local compressibility profile χ(r)\chi(r), we develop a scaling theory which expresses the extent of the density depletion and enhancement in compressibility in terms of RsR_s, the strength of solute-water attraction εs\varepsilon_s, and the deviation from liquid-vapor coexistence δμ\delta\mu. Testing the predictions against results of classical density functional theory for a simple solvent and Grand Canonical Monte Carlo simulations of a popular water model, we find that the theory provides a firm physical basis for understanding how water behaves at a hydrophobe.Comment: 5 pages, 4 figures. To appear in Phys. Rev. Let

    Role of σ\u3csup\u3eB\u3c/sup\u3e in Adaptation of \u3ci\u3eListeria monocytogenes\u3c/i\u3e to Growth at Low Temperature

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    The activity of σB in Listeria monocytogenes is stimulated by high osmolarity and is necessary for efficient uptake of osmoprotectants. Here we demonstrate that, during cold shock, σB contributes to adaptation in a growth phase-dependent manner and is necessary for efficient accumulation of betaine and carnitine as cryoprotectants

    Impact of Processing Conditions on Inter-tablet Coating Thickness Variations Measured by Terahertz In-Line Sensing.

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    A novel in-line technique utilising pulsed terahertz radiation for direct measurement of the film coating thickness of individual tablets during the coating process was previously developed and demonstrated on a production-scale coater. Here, we use this technique to monitor the evolution of tablet film coating thickness and its inter-tablet variability during the coating process under a number of different process conditions that have been purposefully induced in the production-scale coating process. The changes that were introduced to the coating process include removing the baffles from the coater, adding uncoated tablets to the running process, halting the drum, blockage of spray guns and changes to the spray rate. The terahertz sensor was able to pick up the resulting changes in average coating thickness in the coating drum and we report the impact of these process changes on the resulting coating quality.This work was conducted with financial support from the UK Technology Strategy Board (AB293H). H.L. And J.A.Z. would like to acknowledge the Engineering and Physical Sciences Research Council (EP/L019922/1) and the Newton Trust Cambridge for research funding. J.A.Z. would like to thank Gonville & Caius College, Cambridge for a research fellowship. The authors acknowledge Colorcon Ltd. and Meggle AG for providing the excipients used in this study, Provel Ltd. (Bolton, UK) for the kind loan of the mixing equipment to disperse the coating polymer and Staffan Folestad (AstraZeneca) for useful discussions. Additional data related to this publication is available as a supplementary data to this publication as well as at the University of Cambridge data repository (https://www.repository.cam.ac.uk).This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/jps.2450

    Deepwater circulation on Blake Outer Ridge (western North Atlantic) during the Holocene, Younger Dryas, and Last Glacial Maximum

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    Three depth transects containing a total of 33 sediment cores were investigated along the Blake Outer Ridge in the western subtropical North Atlantic. Sortable silt mean () grain size and stable isotope records were used to assess the position and relative intensity of the Western Boundary Undercurrent (WBUC) during the Holocene, the Last Glacial Maximum (LGM), and the Younger Dryas (YD) intervals. The Holocene reconstruction is consistent with modern physical and chemical hydrographic measurements in the area, suggesting a deep position for the fast flowing core of the WBUC (3000–4000 m, deepening to ∼4500 m water depth on the ridge flanks) and a water column dominated by North Atlantic Deep Water (NADW). The LGM and YD reconstructions show that a comparable hydrographic regime was present during both these intervals, suggesting a similar mode of circulation that was appreciably different from the Holocene reconstruction. The WBUC's zone of maximum flow speed during these intervals is suggested to have shifted above 2500 m water depth, consistent with nutrient depleted Glacial North Atlantic Intermediate Water formation with an increasing influence of Southern Source Water (SSW) beneath. Below 4000 m water depth, results hint at increased SSW flow vigor during both the LGM and YD with higher flow speeds than during the Holocene. This study provides a framework for aiding the interpretation of time series records of paleocurrent flow speed changes in the region of the WBUC

    Summer Distribution of Bowhead Whales, Balaena mysticetus, Relative to Oil Industry Activities in the Canadian Beaufort Sea, 1980-84

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    Aerial surveys in 1980-84 showed that summer distribution of bowheads in the Beaufort Sea varied markedly between years. Distribution varied both outside and within the "main industrial area" (MIA), the area of island construction, drilling and intensive ship and helicopter traffic. Numbers of bowheads in the MIA were high in 1980, lower in 1981, near zero in 1982 and very low in 1983-84. The few whales in the MIA in 1983-84 were mainly near its edges, contrary to 1980-81. These data, plus limited evidence from 1976-79, indicate that bowheads were numerous in the centre of the MIA in 3 of 5 years from 1976-80 (1976-77, 1980) vs. 0 of 4 years from 1981-84. One hypothesis is that progressively increasing industrial activities affected bowhead distribution after 1980. However, bowheads probably also react to variations in their zooplankton prey, which may be affected by year-to-year changes in oceanography and weather. Influences of natural factors on zooplankton and bowheads need to be better understood in order to assess whether oil exploration caused any of the observed changes in bowhead distribution.Key words: bowhead whale, Balaena mysticetus, Beaufort Sea, oil exploration, seismic exploration, aerial surveysDes relevés aériens effectués entre 1980 et 1984 ont montré que la répartition estivale des baleines franches dans la mer de Beaufort varie nettement d’année en année. Elle varie à fois à l’extérieure et à l’intérieur de la “zone industrielle principale” (ZIP), qui est la zone de construction de l’île, de forage et de circulation intense de bateaux et d’hélicoptères. Le nombre de baleines franches dans la ZIP était élevé en 1980, plus bas en 1981, près de zéro en 1982, et très bas en 1983 et 1984. Les quelques baleines présentes dans la ZIP en 1983 et 1984 étaient principalement à la périphérie, contrairement à 1980 et 1981. Ces données, jointes à des évidences plus limitées de 1976 à 1979, indiquent que les baleines franches étaient nombreuses au centre de la ZIP pendant 3 années sur 5, allant de 1976 à 1980 (1976, 1977 et 1980), par rapport à aucune année sur les quatre allant de 1981 à 1984. On avance l’hypothèse que les activités industrielles progressivement croissantes ont affecté la répartition des baleines franches après 1980. Cependant, les baleines franches ont probablement réagi aussi aux variations de zooplancton qui constitue leur nourriture et qui peut être affecté par les changements qui ont lieu d’année en année dans l’océanographie et le climat. I1 est nécessaire de mieux comprendre l’influence des facteurs naturels sur le zooplancton et les baleines franches afin d’évaluer si l’exploration pétrolière a provoqué l’un quelconque des changements observés dans la répartition de ces baleines.Mots clés: baleine franche, Balaena mysticetus, mer de Beaufort, exploration pétrolière, exploration sismique, relevés aérien
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