Asymptotically Zero Energy Computing Using Split-Level Charge Recovery Logic

The dynamic power requirement of CMOS circuits is rapidly becoming a major concern in the design of personal information systems and large computers. In this work we present a number of new CMOS logic families, Charge Recovery Logic (CRL) as well as the much improved Split-Level Charge Recovery Logic (SCRL), within which the transfer of charge between the nodes occurs quasistatically. Operating quasistatically, these logic families have an energy dissipation that drops linearly with operating frequency, i.e., their power consumption drops quadratically with operating frequency as opposed to the linear drop of conventional CMOS. The circuit techniques in these new families rely on constructing an explicitly reversible pipelined logic gate, where the information necessary to recover the energy used to compute a value is provided by computing its logical inverse. Information necessary to uncompute the inverse is available from the subsequent inverse logic stage. We demonstrate the low energy operation of SCRL by presenting the results from the testing of the first fully quasistatic 8 x 8 multiplier chip (SCRL-1) employing SCRL circuit techniques.

Role of Low-level Mechanisms in Brightness Perception

Brightness judgments are a key part of the primate brain's visual analysis of the environment. There is general consensus that the perceived brightness of an image region is based not only on its actual luminance, but also on the photometric structure of its neighborhood. However, it is unclear precisely how a region's context influences its perceived brightness. Recent research has suggested that brightness estimation may be based on a sophisticated analysis of scene layout in terms of transparency, illumination and shadows. This work has called into question the role of low-level mechanisms, such as lateral inhibition, as explanations for brightness phenomena. Here we describe experiments with displays for which low-level and high-level analyses make qualitatively different predictions, and with which we can quantitatively assess the trade-offs between low-level and high-level factors. We find that brightness percepts in these displays are governed by low-level stimulus properties, even when these percepts are inconsistent with higher-level interpretations of scene layout. These results point to the important role of low-level mechanisms in determining brightness percepts.

Predicting random level and seasonality of hotel prices. A structural equation growth curve approach

This article examines the effect on price of different characteristics of holiday hotels in the sun-and-beach segment, under the hedonic function perspective. Monthly prices of the majority of hotels in the Spanish continental Mediterranean coast are gathered from May to October 1999 from the tour operator catalogues. Hedonic functions are specified as random-effect models and parametrized as structural equation models with two latent variables, a random peak season price and a random width of seasonal fluctuations. Characteristics of the hotel and the region where they are located are used as predictors of both latent variables. Besides hotel category, region, distance to the beach, availability of parking place and room equipment have an effect on peak price and also on seasonality. 3- star hotels have the highest seasonality and hotels located in the southern regions the lowest, which could be explained by a warmer climate in autumn

A Two-level Prediction Model for Deep Reactive Ion Etch (DRIE)

We contribute a quantitative and systematic model to capture etch non-uniformity in deep reactive ion etch of microelectromechanical systems (MEMS) devices. Deep reactive ion etch is commonly used in MEMS fabrication where high-aspect ratio features are to be produced in silicon. It is typical for many supposedly identical devices, perhaps of diameter 10 mm, to be etched simultaneously into one silicon wafer of diameter 150 mm. Etch non-uniformity depends on uneven distributions of ion and neutral species at the wafer level, and on local consumption of those species at the device, or die, level. An ion–neutral synergism model is constructed from data obtained from etching several layouts of differing pattern opening densities. Such a model is used to predict wafer-level variation with an r.m.s. error below 3%. This model is combined with a die-level model, which we have reported previously, on a MEMS layout. The two-level model is shown to enable prediction of both within-die and wafer-scale etch rate variation for arbitrary wafer loadings.

English social science units for primary : 3rd level.

El CEIP Manuel Pérez de Bollullos Par del Condado (Huelva) ha recibido el Primer Premio de Páginas Web Educativas de la Junta de Andalucía, y ha sido galardonado con la Medalla de Oro al Mérito Educativo

Structural invariance of multiple intelligences, based on the level of execution

Resumen tomado de la publicaci??n

A-level revision session collection

This collection contains some presentations which have been used to revise A-level chemistry content at the start of a lecture series.

A-level chemistry content

This document outlines the material covered by the main UK exam board specifications at A-level in chemistry. This is for the A-level taught up until and including June 2009 (i.e. relevant to undergraduates arriving at university in October 2009).

Review of A-level Chemistry content 2010

This document is a review of the content of the A-level Chemistry specifications from the main UK exam boards (Scottish highers not included - sorry!). These A-level specifications commenced teaching in September 2008. Students entering university in 2010 will have studied the new A-levels, and this document is intended to help academics to identify what students will have covered. The document also contains a summary of discussions which took place between teachers and academics at our annual Post-16 teachers' day in June 2010 regarding the nature of the 2010 intake and their capabilities in chemistry. Please inform us of any errors or typos that you spot and we'll update the document. LAST UPDATE at 13:15 on Aug 27th 2010.

Animal Biosafety Level 1 Training Video

This training video is intended to familiarise researchers and technicians working with Hazard Group 1 pathogens in Containment Level 1 animal facilities. It is in Flash video format which will require a free media player such as VLC Media Player (http://www.videolan.org/vlc/) to watch.

Animal Biosafety Level 3 Training Video

This training video is intended to familiarise researchers and technicians working with Hazard Group 3 pathogens in Containment Level 3 animal facilities. It is in Flash video format which will require a free media player such as VLC Media Player (http://www.videolan.org/vlc/) to watch.

Animal Biosafety Level 2 Training Video

This training video is intended to familiarise researchers and technicians working with Hazard Group 2 pathogens in Containment Level 2 animal facilities. It is in Flash video format which will require a free media player such as VLC Media Player (http://www.videolan.org/vlc/) to watch.

Powerpoint to promote chemistry to A-level students

This presentation has been modified by a B.Sc final year project student to promote chemistry as a degree and a career option for youngsters. The original presentation was produced by the Biological and Medicinal Chemistry Sector or the Royal Society of Chemistry. The project student has polished the slides to make them more appealing to today's A-level students. She has also evaluated the impact of her work. A summary of her report will be added in due course.

Physics video for AS/A Level Science & Art Competition

A video made by physics for the AS/A Level Science & Art Competition

AS/A Level Science & Art Competition: Particle Physics

A video made by physics for the AS/A Level Science & Art Competition