4,978 research outputs found
Characterization of 60 GHz Shadowing by Human Bodies and Simple Phantoms
The 60 GHz band is very prominsing for high data rate (>1 Gb/s) wireless systems operating at short ranges. However, due to the short wavelengths in this frequency band, the shadowing effects cuased by human bodies and furniture are severe and needs to be modeled properly. In this paper, we present an experimental, measurementbased characterization of the reflection and shadowing effects in the 60 GHz band caused by human bodies and various phantoms, in order to find simple phantoms suitable for use in human shadowing measurements. It is shown that a water-filled human phantom serves as a good choice for this purpose
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TUGS â The tactile user guidance system
The Electronic System and Information Technology Research Group at Brunel University has designed a multifaceted navigation system for blind and visually impaired pedestrians. The primary operation of the system mimics the advantages of an informed sighted guide by using Global Positioning Systems and remote (sighted on the user) video cameras as navigational sensors. The information generated is streamed to a central control centre. This allows the system to operate in a fully automatic or operator assisted mode dependent on the users requirements. Initially the system used an audio link to transfer information to the user, however this has proved problematic. Clear unimpeded access to ambient sound is vital for visually impaired and blind pedestrians, both for efficient wayfinding and safety. Any system which has a continuing dialogue with the user, for example, navigational instructions received through an audio link, interferes with the users ability to process ambient sounds. To solve this problem a novel Tactile User Guidance System (TUGS) with vibrating actuators, has been designed and experimentally tested.
In this paper we present the design and experimental verification of TUGS with both visually impaired and sighted users. Although we have taken the visually impaired user as the âworst case scenarioâ a practical ability to transfer information through the tactile sense has considerable value to other groups who may find themselves in restricted or overloaded visual or audio situations. These groups include; front line responders in the emergency services, railroad workers, pilots and remote vehicle operators
New shield for gamma-ray spectrometry
Gamma-ray shield that can be evacuated, refilled with a clean gas, and pressurized for exclusion of airborne radioactive contaminants effectively lowers background noise. Under working conditions, repeated evacuation and filling procedures have not adversely affected the sensitivity and resolution of the crystal detector
ECONOMIC FEASIBILITY OF BIODIESEL PRODUCTION IN NORTH DAKOTA
The U. S. biodiesel industry is rapidly expanding due to energy production concerns, environmental concerns, and recent legislation. The most common type of biodiesel in the United States is derived from soybean oil. Soybeans are a major crop in North Dakota and could easily supply a 5 million gallon per year biodiesel facility. Potential market segments of a biodiesel facility in North Dakota include agriculture, construction, and state fleet sectors based on current diesel use. However, with existing technology and no subsidy, biodiesel operation and investment costs for a North Dakota facility are not competitive with petroleum diesel. Using soybean oil prices of 17 cents to 25 cents per pound, the per gallon cost of producing diesel in southeastern North Dakota ranges between 2.64, while the wholesale price for regular diesel is $0.91. The cost of producing biodiesel is highly dependent on the price and availability of soybean oil. While biodiesel production technology is feasible and fairly simple, producing biodiesel in North Dakota is not economically feasible at least in the foreseeable future.biodiesel, soybeans, economic feasibility, Resource /Energy Economics and Policy,
ECONOMIC FEASIBILITY OF BIODIESEL PRODUCTION IN NORTH DAKOTA
The U. S. biodiesel industry is rapidly expanding due to energy production concerns, environmental concerns, and recent legislation. The most common type of biodiesel in the United States is derived from soybean oil. Soybeans are a major crop in North Dakota and could easily supply a 5 million gallon per year biodiesel facility. Potential market segments of a biodiesel facility in North Dakota include agriculture, construction, and state fleet sectors based on current diesel use. However, with existing technology and no subsidy, biodiesel operation and investment costs for a North Dakota facility are not competitive with petroleum diesel. Using soybean oil prices of 17 cents to 25 cents per pound, the per gallon cost of producing diesel in southeastern North Dakota ranges between 2.64, while the wholesale price for regular diesel is $0.91. The cost of producing biodiesel is highly dependent on the price and availability of soybean oil. While biodiesel production technology is feasible and fairly simple, producing biodiesel in North Dakota is not economically feasible at least in the foreseeable future.biodiesel, soybeans, economic feasibility, Resource /Energy Economics and Policy,
Financial Benchmarks of North Dakota Farm Operators: 1992 Update
Agricultural Finance, Farm Management,
Color separate singlets in annihilation
We use the method of color effective Hamiltonian to study the properties of
states in which a gluonic subsystem forms a color singlet, and we will study
the possibility that such a subsystem hadronizes as a separate unit. A parton
system can normally be subdivided into singlet subsystems in many different
ways, and one problem arises from the fact that the corresponding states are
not orthogonal. We show that if only contributions of order are
included, the problem is greatly simplified. Only a very limited number of
states are possible, and we present an orthogonalization procedure for these
states. The result is simple and intuitive and could give an estimate of the
possibility to produce color separated gluonic subsystems, if no dynamical
effects are important. We also study with a simple MC the possibility that
configurations which correspond to "short strings" are dynamically favored. The
advantage of our approach over more elaborate models is its simplicity, which
makes it easier to estimate color reconnection effects in reactions which are
more complicated than the relatively simple annihilation.Comment: Revtex, 24 pages, 7 figures; Compared to the previous version, 1 new
figure is added and Monte-Carlo results are re-analyzed, as suggested by the
referee; To appear in Phys. Rev.
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