33,971 research outputs found
Design of instrumentation for metabolic monitoring of the Adélie penguin : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Physics at Massey University
The motivating question for the work described in this thesis was "How does the Adélie penguin cope with cold?" It was reasoned that the time-scale of temperature changes in Antarctica precluded all but metabolic and physiological responses. To determine these, a system capable of measuring and recording these biological variables in the penguins natural environment, was designed. A device, based on the principles of near infrared spectroscopy, was developed that could measure the relative oxygen saturation of haemoglobin and the reduction state of cytochrome oxidase as well as heart rate and blood volume. The completed device was housed in a black, waterproof, plastic container, measuring 65mm x 92mm x 25mm and weighing 132.7g. Co-ordination of measurements was achieved with operating system-like control software implemented in Motorola HC11 assembly code. Synchronous detection was used for signal acquisition and a pulse algorithm, implemented in assembly code, allowed real time pulse measurement from the input signals. Programs were written in Matlab and C++ to investigate the characteristics and limits of these techniques. Preliminary testing of the device on human subjects successfully showed changes in metabolic state as a result of physical activity. The results of field testing on Adélie penguins were unable to answer the original question due to a number of physical factors. However, the success of human trials suggests that, with modification and improvement, the device has potential as a valuable research instrument, applicable to a variety of other species
Escalating The War On SPAM Through Practical POW Exchange
Proof-of-work (POW) schemes have been proposed in the past. One prominent
system is HASHCASH (Back, 2002) which uses cryptographic puzzles . However,
work by Laurie and Clayton (2004) has shown that for a uniform proof-of-work
scheme on email to have an impact on SPAM, it would also be onerous enough to
impact on senders of "legitimate" email. I suggest that a non-uniform
proof-of-work scheme on email may be a solution to this problem, and describe a
framework that has the potential to limit SPAM, without unduly penalising
legitimate senders, and is constructed using only current SPAM filter
technology, and a small change to the SMTP (Simple Mail Transfer Protocol).
Specifically, I argue that it is possible to make sending SPAM 1,000 times more
expensive than sending "legitimate" email (so called HAM). Also, unlike the
system proposed by Debin Liu and Jean Camp (2006), it does not require the
complications of maintaining a reputation system.Comment: To be presented at the IEEE Conference On Networking, Adelaide,
Australia, November 19-21, 200
A fast method for computing the output of rank order filters within arbitrarily shaped windows
Rank order filters are used in a multitude of image processing tasks. Their application can range from simple preprocessing tasks which aim to reduce/remove noise, to more complex problems where such filters can be used to detect and segment image features. There is, therefore, a need to develop fast algorithms to compute the output of this class of filter. A number of methods for efficiently computing the output of specific rank order filters have been proposed [1]. For example, numerous fast algorithms exist that can be used for calculating the output of the median filter. Fast algorithms for calculating morphological erosions and dilations - which are also a special case of the more general rank order filter - have also been proposed. In this paper we present an extension of a recently introduced method for computing fast morphological operators to the more general case of rank order filters. Using our method, we are able to efficiently compute any rank, using any arbitrarily shaped window, such that it is possible to quickly compute the output of any rank order filter. We demonstrate the usefulness and efficiency of our technique by implementing a fast method for computing a recent generalisation of the morphological Hit-or-Miss Transform which makes it more robust in the presence of noise. We also compare the speed and efficiency of this routine with similar techniques that have been proposed in the literature
Skimmers: Their Development and Use in Coastal Louisiana
The origin, development, and utilization of the skimmer net is reviewed along with other historical shrimp gears used in coastal Louisiana. The skimmer was developed to catch white shrimp, Penaeus setiferus, observed jumping over the cork line (headrope) of trawls being worked in shallow waters. A description of the gear is presented including basic components and various frame designs used by fishermen during its development. The advantages of skimmers over bottom trawls include: multiple use as both trawl and butterfly net (wing net), ease of deployment, increased maneuverability, reduction and greater survivability of bycatch, and ability to cover more area due to increased speed and continuous fishing capability. Disadvantages may include compromising vessel stability when stored upright on the deck, possible damage to water bottoms when improperly rigged, and limitation to a 12-foot (3.6 m) maximum depth due to size restrictions. The growing popularity of the skimmer net is evident by its introduction into North Carolina and inquiries from other southeastern Atlantic and Gulf coast states
An exploratory study on the impact of electoral participation upon a terrorist groupâs use of violence in a given year
Recent studies seeking to understand the determinants of terrorism tend to focus upon situational, rather than structural measures. Typically these studies examine the interaction of terrorist attacks and repressive state actions. However, we know very little about other situational measures that may impact upon a groupâs scale of violent activity within a particular year. This preliminary study analyses terrorist attacks committed by both the Provisional IRA (PIRA) and ETA and the electoral performances of the groupsâ political wings, Sinn Fein and Batasuna, from 1970 to 1998 and from 1978 to 2005 respectively. More specifically, this paper examines whether the nature and content of terrorist attacks differ in the build-up to that groupâs political-wing participating in elections. In other words, this article is a preliminary study of the influence of electoral participation on attack frequency and target selection. Results suggest that PIRA significantly decreased their attacks in an election year and this had a positive impact upon Sinn Feinâs electoral performance. On the other hand, ETA significantly increased its attacks in an election year and this had no significant impact upon Batasunaâs electoral performance
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Reducing Carbon emissions through transport taxation, GFC Briefing Paper 6
Road transport and aviation are, or are becoming, major sources of carbon emissions which will need to be reduced if the UKâs carbon dioxide (CO2) reduction targets are to be met. However, since 1980 the real costs of motoring have fallen while those of other transport modes have risen, and rising incomes have also increased transport demand, offsetting efficiency increases. Increased road transport taxation, which could be introduced as part of a green fiscal reform, will be essential if demand is to be managed and carbon emissions from road transport reduced.
Taxes on vehicle purchase, ownership and use have different effects, and can be used to pursue different policy goals. For example, taxes on purchase and ownership can incentivise manufacturers to develop low carbon vehicles and people to buy them. Tax measures on vehicle use
are needed to reduce congestion and overall energy use.
This briefing discusses experience with road transport and aviation taxes in the UK and other European countries, and considers how they might develop to take account of increasingly stringent CO2 reduction targets and other issues such as the increasing diversity of road fuels, and the need to maintain government income. In particular, any shift to electric vehicles may require a parallel shift to road user charging if revenues from transport taxes, and incentives to reduce the damaging effects of road transport apart from emissions, are to be maintained.
Each tax introduced will affect some people more than others. Increasing fuel duty is progressive overall because most low-income households do not have a car, but there are concerns about the impact on low income motorists, particularly in rural areas, which can be at least partially addressed if the revenues are recycled in a progressive manner. Increasing taxation on air travel is even more progressive because most leisure flying is by the wealthiest 20 per cent of the population and those
on low incomes fly very little
United States Atlas of Optical Telescopes
This atlas shows the locations of and gives information about optical telescopes used for astronomical research in the United States as of late 1986. Those instruments with mirror or lens diameters of 3/4 m (approx. 30 inches) and larger are included. These telescopes are concentrated in the Southwest, on the West Coast and on the island of Hawaii
Atmospheric effects and spurious signals in GPS analyses
Improvements in the analyses of Global Positioning System (GPS) observations yield resolvable millimeter to submillimeter differences in coordinate estimates, thus providing sufficient resolution to distinguish subtle differences in analysis methodologies. Here we investigate the effects on site coordinates of using different approaches to modeling atmospheric loading deformation (ATML) and handling of tropospheric delays. The rigorous approach of using the time-varying Vienna Mapping Function 1 yields solutions with lower noise at a range of frequencies compared with solutions generated using empirical mapping functions. This is particularly evident when ATML is accounted for. Some improvement also arises from using improved a priori zenith hydrostatic delays (ZHD), with the combined effect being site-specific. Importantly, inadequacies in both mapping functions and a priori ZHDs not only introduce time-correlated noise but significant periodic terms at solar annual and semiannual periods. We find no significant difference between solutions where nontidal ATML is applied at the observation level rather than as a daily averaged value, but failing to model diurnal and semidiurnal tidal ATML at the observation level can introduce anomalous propagated signals with periods that closely match the GPS draconitic annual (âŒ351.4 days) and semiannual period (âŒ175.7 days). Exacerbated by not fixing ambiguities, these signals are evident in both stacked and single-site power spectra, with each tide contributing roughly equally to the dominant semiannual peak. The amplitude of the propagated signal reaches a maximum of 0.8 mm with a clear latitudinal dependence that is not correlated directly with locations of maximum tidal amplitude.Australian Research Councilâs Discovery Project
Taxes Versus Regulation: The Welfare Impacts of Policies for Containing Sprawl
Our central concern in this paper is to examine some alternative policies for physically containing the growth of urban areas. We undertake a microsimulation to provide a comparison between land use planning policies that enforce an urban growth boundary and policies that limit development at the periphery using taxes. We parameterise our microsimulation using the structure of demand and policy implemented in a rapidly growing city in the south of England. We make no judgment as to the optimality or otherwise of the existing degree of constraint: we take that as datum and analyse only the welfare costs, distributional impacts and effects on urban densities of alternative ways of achieving the currently observed degree of constraint. The methodology we deploy to address these issues could be turned to a wide range of other urban modeling purposes. It has the advantage of being clearly founded in microeconomic theory and applies observed behavioural relationships, estimated from the relevant economic data. We find that the use of a tax on land could produce the same limitation on growth as existing regulatory policies but provide higher equilibrium welfare levels. We find that the use of a tax on transport costs, however, while capable of producing a compact urban form, would not raise welfare when compared with regulatory approaches.Urban Sprawl, Property Tax, Land Use Regulation
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