11,560 research outputs found
Advanced Launch System (ALS): Electrical actuation and power systems improve operability and cost picture
To obtain the Advanced Launch System (ALS) primary goals of reduced costs and improved operability, there must be significant reductions in the launch operations and servicing requirements relative to current vehicle designs and practices. One of the primary methods for achieving these goals is by using vehicle electrical power system and controls for all actuation and avionics requirements. A brief status review of the ALS and its associated Advanced Development Program is presented to demonstrate maturation of those technologies that will help meet the overall operability and cost goals. The electric power and actuation systems are highlighted as a specific technology ready not only to meet the stringent ALS goals (cryogenic field valves and thrust vector controls with peak power demands to 75 hp), but also those of other launch vehicles, military and civilian aircraft, lunar/Martian vehicles, and a multitude of commercial applications
Applications of ISES for vegetation and land use
Remote sensing relative to applications involving vegetation cover and land use is reviewed to consider the potential benefits to the Earth Observing System (Eos) of a proposed Information Sciences Experiment System (ISES). The ISES concept has been proposed as an onboard experiment and computational resource to support advanced experiments and demonstrations in the information and earth sciences. Embedded in the concept is potential for relieving the data glut problem, enhancing capabilities to meet real-time needs of data users and in-situ researchers, and introducing emerging technology to Eos as the technology matures. These potential benefits are examined in the context of state-of-the-art research activities in image/data processing and management
Civil air transport: A fresh look at power-by-wire and fly-by-light
Power-by-wire (PBW) is a key element under subsonic transport flight systems technology with potential savings of over 10 percent in gross take-off-weight and in fuel consumption compared to today's transport aircraft. The PBW technology substitutes electrical actuation in place of centralized hydraulics, uses internal starter-motor/generators and eliminates the need for variable engine bleed air to supply cabin comfort. The application of advanced fiber optics to the electrical power system controls, to built-in-test (BITE) equipment, and to fly-by-light (FBL) flight controls provides additional benefits in lightning and high energy radio frequency (HERF) immunity over existing mechanical or even fly-by-wire controls. The program plan is reviewed and a snapshot is given of the key technologies and their benefits to all future aircraft, both civil and military
Consistency and heterogeneity of individual behavior under uncertainty
By using graphical representations of simple portfolio choice problems,
we generate a very rich data set to study behavior under uncertainty
at the level of the individual subject. We test the data for
consistency with the maximization hypothesis, and we estimate preferences
using a two-parameter utility function based on Faruk Gul
(1991). This specification provides a good interpretation of the data
at the individual level and can account for the highly heterogeneous
behaviors observed in the laboratory. The parameter estimates jointly
describe attitudes toward risk and allow us to characterize the distribution
of risk preferences in the population
Competition Policy Reform in Agriculture: A Comparison of the BRICs Countries
This paper forms part of a project titled ‘Facilitating Efficient Agricultural Markets in India: An Assessment of Competition and Regulatory Reform Requirements funded by the Australian Centre for International Agricultural Research (ACIAR). The project follows from previous research which found that India’s border reforms need to be complemented by ‘behind-the-border’ domestic reforms if government policy objectives of improved productivity, higher rural employment and incomes and enhanced food security are to be met. The project is being undertaken by Indian and Australian collaborators with expertise in agricultural policy development. Stage 1 of the project is designed to develop a common understanding among those collaborators of contemporary market based policy development principles and the extent to which they have been adopted in other developing countries. The BRICs economies of Brazil, Russia, India and China, as well as South Africa, were chosen for this purpose. A comparative overview of agricultural policy developments in these economies is underway drawing observations about policy reform impacts on agricultural production and the extent to which policy reforms have been consistent with competition policy and microeconomic reform principles applied in developed economies, such as Australia. The extent to which trade practices law has emerged in developing economies as an alternative to direct regulation is also considered. Preliminary findings are reported to facilitate broader discussion and encourage input from interested parties. Stage 2 of the project, commencing later in 2009, will involve the application of competition policy principles to the marketing regulations of a selection of agricultural industries in India. Consideration will be given to clarifying regulatory objectives, assessing their consistency with accepted forms of ‘market failure’ and assessing whether regulatory measures address those policy objectives in a manner least restrictive on competition. As well as facilitating efficient policy reform within India’s agricultural sector, the project aims to enhance the development of market based agricultural policy frameworks and the policy development skills of Indian and Australian policy makers.
Global and Feature Based Gender Classification of Faces: A Comparison of Human Performance and Computational Models
Original paper can be found at: http://eproceedings.worldscinet.com/9789812701886/9789812701886_0036.html Copyright World Scientific Publishing Company. http://dx.doi.org/10.1142/9789812701886_0036Most computational models for gender classification use global information (the full face image) giving equal weight to the whole face area irrespective of the importance of the internal features. Here, we use a global and feature based representation of face images that includes both global and featural information. We use dimensionality reduction techniques and a support vector machine classifier and show that this method performs better than either global or feature based representations alone.Peer reviewe
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Replication of mixing achieved in large co-rotating screw extruder using a novel laboratory 10-100g minimixer
YesWhen compounding polymers with additives to develop materials at specifications (colouring plastics is the simplest example), the difficulties is in getting the formulation right the first time. Also, when developing completely new materials such as in nanotechnology applications, there is a need to do the initial trials safely and with as small quantities as possible to enable a wide range of experimentation. Wiith traditional applications, often the initial compounding formulation is done using small single or twin screw extruders but with machines that have a fair output to instruct the large scale operation. This step is costly in material wastage and time but more importantly it often does not provide the right formulation which in turn results in bigger wastage cost at the industrial scale before the right formulation is eventually obtained. With the very new material formulations, any reduction in cost of development is always essential. With these aims in mind, we have developed a new minimixer capable of handling tiny quantities of order 10-100g but the minimixer is capable of reproducing the very high mixing conditions experienced in large machines. This invention provides a new opportunity to develop new products quickly, safely and cheaply. The application is not restricted to polymers and can be extended to other soft materials. It has also other spin-offs as a research tool for studying mixing and developing new, more efficient, mixing flows. In this paper we explain the principle of operation we have engineered to produce such intense mixing. Basically, the device is based on combining two opposing flows: a single screw extruder circulation flow with a twin screw extruder mixing flow. The mixing is carried out as a batch but on its completion, the single screw extruder flow is reversed and becomes co-current with the twin extruder flow to enable the discharging of the batch through a die. In the paper we present mixing data obtained with various polymer-additive combinations tested in the minimixer under various conditions of screw speeds, mixing times and temperatures and at the larger scale to underpin the operation of this novel mixer. The quality of mixing of the extrudate was measured using a variety of methods depending on applications: using image analysis of microtome sections of the extrudate or of blown film samples produced from the formulations or measuring electrical properties
A neural network model of visual object recognition impairment after brain damage
Dysfunction of the visual object recognition system in humans is briefly discussed and a basic connectionist model of visual object recognition is introduced. Experimentation in which two variants of this model are lesioned is undertaken. The results suggest that the well documented phenomenon of superordinate preservation is model independent. Differential category specific recognition deficits are also observed in this model, however these are sensitive to each particular variant
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