10,968 research outputs found
Visionless TRAC
This final report documents the activities during a sabbatical. Leo Monford was the principal NASA contact for this work. The work supported a flight experiment planned by the Space Research Consortium which investigated the potential of using a Targeting Reflective Alignment Concept (TRAC) sensor to automatically rendezvous satellites. Other work supported the Explorer flight experiment by providing TRAC reflectors for future rendezvous experiments. The third project initiated was a visionless TRAC sensing concept called the PSD concept
Study of LANDSAT-D thematic mapper performance as applied to hydrocarbon exploration
Improved delineation of known oil and gas fields in southern Ontario and a spectacularly high amount of structural information on the Owl Creek, Wyoming scene were obtained from analysis of TM data. The use of hue, saturation, and value image processing techniques on a Death Valley, California scene permitted direct comparison of TM processed imagery with existing 1:250,000 scale geological maps of the area and revealed small outcrops of Tertiary volcanic material overlying Paleozoic sections. Analysis of TM data over Lawton, Oklahoma suggests that the reducing chemical environment associated with hydrocarbon seepage change ferric iron to soluble ferrous iron, allowing it to be leached. Results of the band selection algorithm show a suprising consistency, with the 1,4,5 combination selected as optimal in most cases
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The Pennyland Project
This is the final report on the performance of 177 low-energy houses at Pennyland, Milton Keynes, monitored by the Open University Energy Research Group (ERG), for the Milton Keynes Development Corporation (MKDC), under contract to the Energy Technology Support Unit (ETSU) at Harwell.[The smaller file contains the Executive Summary; the larger file contains the main report, excluding the Executive Summary]
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Energy Projects in Milton Keynes: Energy Consultative Unit Progress Report 1976-1981
The Energy Consultative Unit was a joint Open University/MKDC body set up by Professor Jake Chapman, founder of the OU Energy Research Group. This report describes the work carried out on energy-related projects in Milton Keynes over the period 1976-1981, many of them involving the Open University. After a short explanation of how energy is used in the UK, the report introduces the Energy Consultative Unit projects and summarises the main conclusions drawn from the Unit's work. It then describes the projects on which the Unit has worked and summarises other energy projects under way in the new city. It does not go into the projects in detail, but there are a number of technical reports available for people who want to study them in more depth, and these are listed in the back of the report. The projects represent the work of a considerable number of people and a list of acknowledgements, indicating who should be contacted for further information, is also set out at the back of the report
Implications of information from LANDSAT-4 for private industry
The broader spectral coverage and higher resolution of LANDSAT-4 Thematic Mapper (TM) data open the door for identification from space of spectral phenomena associated with mineralization and microseepage of hydrocarbon. Digitally enhanced image products generated from TM data allow the mapping of many major and minor structural features that mark or influence emplacement of mineralization and accumulation of hydrocarbons. These improvements in capabilities over multispectral scanner data should accelerate the acceptance and integration of satellite data as a routinely used exploration tool that allows rapid examination of large areas in considerable detail. Imagery of Southern Ontario, Canada as well as of Cement, Oklahoma and Death Valley, California is discussed
TRAC based sensing for autonomous rendezvous
The Targeting Reflective Alignment Concept (TRAC) sensor is to be used in an effort to support an Autonomous Rendezvous and Docking (AR&D) flight experiment. The TRAC sensor uses a fixed-focus, fixed-iris CCD camera and a target that is a combination of active and passive components. The system experiment is anticipated to fly in 1994 using two Commercial Experiment Transporters (COMET's). The requirements for the sensor are: bearing error less than or equal to 0.075 deg; bearing error rate less than 0.3 deg/sec; attitude error less than 0.5 deg.; and attitude rate error less than 2.0 deg/sec. The range requirement depends on the range and the range rate of the vehicle. The active component of the target is several 'kilo-bright' LED's that can emit 2500 millicandela with 40 milliwatts of input power. Flashing the lights in a known pattern eliminates background illumination. The system should be able to rendezvous from 300 meters all the way to capture. A question that arose during the presentation: What is the life time of the LED's and their sensitivity to radiation? The LED's should be manufactured to Military Specifications, coated with silicon dioxide, and all other space qualified precautions should be taken. The LED's will not be on all the time so they should easily last the two-year mission
Evaluation of the suitability of Skylab data for the purpose of petroleum exploration
There are no author-identified significant results in this report
Blowing-Up the Four-Dimensional Z_3 Orientifold
We study the blowing-up of the four-dimensional Z_3 orientifold of
Angelantonj, Bianchi, Pradisi, Sagnotti and Stanev (ABPSS) by giving nonzero
vacuum expectation values (VEV's) to the twisted sector moduli blowing-up
modes. The blowing-up procedure induces a Fayet-Iliopoulos (FI) term for the
``anomalous'' U(1), whose magnitude depends linearly on the VEV's of the
blowing-up modes. To preserve the N=1 supersymmetry, non-Abelian matter fields
are forced to acquire nonzero VEV's, thus breaking (some of) the non-Abelian
gauge structure and decoupling some of the matter fields. We determine the form
of the FI term, construct explicit examples of (non-Abelian) D and F flat
directions, and determine the surviving gauge groups of the restabilized vacua.
We also determine the mass spectra, for which the restabilization reduces the
number of families.Comment: 19 pages, Late
Local sensory control of a dexterous end effector
A numerical scheme was developed to solve the inverse kinematics for a user-defined manipulator. The scheme was based on a nonlinear least-squares technique which determines the joint variables by minimizing the difference between the target end effector pose and the actual end effector pose. The scheme was adapted to a dexterous hand in which the joints are either prismatic or revolute and the fingers are considered open kinematic chains. Feasible solutions were obtained using a three-fingered dexterous hand. An algorithm to estimate the position and orientation of a pre-grasped object was also developed. The algorithm was based on triangulation using an ideal sensor and a spherical object model. By choosing the object to be a sphere, only the position of the object frame was important. Based on these simplifications, a minimum of three sensors are needed to find the position of a sphere. A two dimensional example to determine the position of a circle coordinate frame using a two-fingered dexterous hand was presented
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