A 16th century Iron Breech-Loading Swivel-Gun

Early in May 2000, the Mediterranean gave up another of its jealously kept treasures. While pleasure diving off Malta's southern coast, Michael Spiteri, a technical staff member of the Museums Department Archaeology Section discovered a rare and unusual gun. Lying there on the seabed was a sixteenth century, breechloading swivel-gun. Seafarers of various nations used small swivel-guns of this type extensively on ships, for many centuries. However, not that many have survived and at the time it was found, this was the first officially recorded discovery in Maltese waters of an early, breech-loading gun. Certainly not as sensational as the Riace Bronzes, this fascinating relic is nonetheless of considerable importance even by international standards.peer-reviewe

Bayesian modeling and forecasting of 24-hour high-frequency volatility: A case study of the financial crisis

This paper estimates models of high frequency index futures returns using `around the clock' 5-minute returns that incorporate the following key features: multiple persistent stochastic volatility factors, jumps in prices and volatilities, seasonal components capturing time of the day patterns, correlations between return and volatility shocks, and announcement effects. We develop an integrated MCMC approach to estimate interday and intraday parameters and states using high-frequency data without resorting to various aggregation measures like realized volatility. We provide a case study using financial crisis data from 2007 to 2009, and use particle filters to construct likelihood functions for model comparison and out-of-sample forecasting from 2009 to 2012. We show that our approach improves realized volatility forecasts by up to 50% over existing benchmarks.Comment: 48 pages, 7 figure

Service Enquiry Service in the 21st Century

The workshop set out to acknowledge and explore the potential of youth service as a strategy for social, economic and democratic development, to identify new work that needs to be undertaken, and to increase knowledge about youth

Why is it Difficult to Search for Two Colors at Once? How Eye Movements Can Reveal the Nature of Representations During Multi-target Visual Search

Visual search consists of locating a known target amongst a field of distractors. Often times, observers must search for more than one object at once. Eye movements were monitored in a series of visual search experiments examining search efficiency and how color is represented in order to guide search for multiple targets. The results demonstrated that observers were very color selective when searching for a single color. However, when searching for two colors at once, the degree of similarity between the two target colors had varying effects on fixation patterns. Search for two very similar colors was almost as efficient as search for a single color. As this similarity between the targets deceased, search efficiency suffered, resulting in more fixations on objects dissimilar to both targets. In terms of representation, the results suggest that the guiding template or templates prevailed throughout search, and were relatively unaffected by the objects encountered. Fixation patterns revealed that two similarly colored objects may be represented as a single, unitary range containing the target colors as well as the colors in between in color space. As the degree of similarity between the targets decreased, the two targets were more likely to be represented as discrete separate templates

Visual detection of blemishes in potatoes using minimalist boosted classifiers

This paper introduces novel methods for detecting blemishes in potatoes using machine vision. After segmentation of the potato from the background, a pixel-wise classifier is trained to detect blemishes using features extracted from the image. A very large set of candidate features, based on statistical information relating to the colour and texture of the region surrounding a given pixel, is first extracted. Then an adaptive boosting algorithm (AdaBoost) is used to automatically select the best features for discriminating between blemishes and non-blemishes. With this approach, different features can be selected for different potato varieties, while also handling the natural variation in fresh produce due to different seasons, lighting conditions, etc. The results show that the method is able to build ``minimalist'' classifiers that optimise detection performance at low computational cost. In experiments, blemish detectors were trained for both white and red potato varieties, achieving 89.6\% and 89.5\% accuracy, respectively

Young\u27s Double-Slit Interferometry within an Atom

An experiment is described which is an analog of Young\u27s double-slit interferometer using an atomic electron instead of light. Two phase-coherent laser pulses are used to excite a single electron into a state of the form of a pair of Rydberg wave packets that are initially on opposite sides of the orbit. The two wave packets propagate and spread until they completely overlap, then a third phase-coherent laser pulse probes the resulting fringe pattern. The relative phase of the two wave packets is varied so that the interference produces a single localized electron wave packet on one side of the orbit or the other

Young\u27s Double-Slit Interferometry within an Atom

An experiment is described which is an analog of Young\u27s double-slit interferometer using an atomic electron instead of light. Two phase-coherent laser pulses are used to excite a single electron into a state of the form of a pair of Rydberg wave packets that are initially on opposite sides of the orbit. The two wave packets propagate and spread until they completely overlap, then a third phase-coherent laser pulse probes the resulting fringe pattern. The relative phase of the two wave packets is varied so that the interference produces a single localized electron wave packet on one side of the orbit or the other

Excitation of an Atomic Electron to a Coherent Superposition of Macroscopically Distinct States

An atomic electron is prepared in a state closely analogous to Schrödinger’s coherent superposition of “live cat” and “dead cat.” The electronic state is a coherent superposition of two spatially localized wave packets separated by approximately 0.4 mm at the opposite extremes of a Kepler orbit. State-selective ionization is used to verify that only every other atomic level is populated in the “cat state,” and a Ramsey fringe measurement is used to verify the coherence of the superposition

Turning up the heat: assessing the impact of charring regime on the morphology and stable isotopic values of cereal grains

The stable isotopic values of charred crops are now frequently analysed in archaeology. While previous research has highlighted how grain morphology and stable carbon and nitrogen isotope values change with grain charring temperature, such research has been limited to temperature ranges under 260 °C and using predominately Mediterranean cereals and pulses. For the first time, this study provides experimental data on the impact of charring on two northern European cereals, rye and oat, both morphologically and isotopically. New experimental charring of rye, oat, bread wheat and hulled barley extends the charring window to 300 °C, providing an insight into the morphological changes to the grains as well as the difference between charred and uncharred isotopic values. This range of cereals and conditions opens up potential for stable isotopic investigation of medieval agricultural growing conditions and practices in Britain. The results indicate that isotopically, a 0.16‰ and a 0.32‰ offset should be applied to δ13C and δ15N values, respectively, of grains charred between 230 and 300 °C. Morphological and internal structural changes, as well as external distortion, are key attributes which vary with charring temperature and duration. Guidelines are provided to enable assessment of whether archaeological grains of bread wheat, hulled barley, rye and oat fall within the acceptable charring window for isotopic analysis