45,847 research outputs found

    The application of remote sensing techniques: Technical and methodological issues

    Get PDF
    Capabilities and limitations of modern imaging electromagnetic sensor systems are outlined, and the products of such systems are compared with those of the traditional aerial photographic system. Focus is given to the interface between the rapidly developing remote sensing technology and the information needs of operational agencies, and communication gaps are shown to retard early adoption of the technology by these agencies. An assessment is made of the current status of imaging remote sensors and their potential for the future. Public sources of remote sensor data and several cost comparisons are included

    A Skylab program for the International Hydrological Decade (IHD)

    Get PDF
    There are no author-identified significant results in this report

    Simple Max-Min Ant Systems and the Optimization of Linear Pseudo-Boolean Functions

    Full text link
    With this paper, we contribute to the understanding of ant colony optimization (ACO) algorithms by formally analyzing their runtime behavior. We study simple MAX-MIN ant systems on the class of linear pseudo-Boolean functions defined on binary strings of length 'n'. Our investigations point out how the progress according to function values is stored in pheromone. We provide a general upper bound of O((n^3 \log n)/ \rho) for two ACO variants on all linear functions, where (\rho) determines the pheromone update strength. Furthermore, we show improved bounds for two well-known linear pseudo-Boolean functions called OneMax and BinVal and give additional insights using an experimental study.Comment: 19 pages, 2 figure

    An ERTS-1 investigation for Lake Ontario and its basin

    Get PDF
    The author has identified the following significant results. Methods of manual, semi-automatic, and automatic (computer) data processing were evaluated, as were the requirements for spatial physiographic and limnological information. The coupling of specially processed ERTS data with simulation models of the watershed precipitation/runoff process provides potential for water resources management. Optimal and full use of the data requires a mix of data processing and analysis techniques, including single band editing, two band ratios, and multiband combinations. A combination of maximum likelihood ratio and near-IR/red band ratio processing was found to be particularly useful

    Integrated Motion Measurement for Flexible Structures

    Get PDF
    Integrated navigation, as an example of integrated motion measurement systems, is typically based on inertial sensors (accelerometers, gyros) and GPS and is commonly used for vehicle guidance. Traditionally, the vehicle of integrated navigation systems is assumed to be a rigid body. However, extending these integrated systems to elastic structures is possible. The considered continuum, in particular a flexible beam, is an attempt to obtain motion measurements of an aerofoil of a flying aircraft with large structural dimensions. Integrated systems considered here in general are fusing different measuring methods by using their benefits and blinding out their disadvantages. For instance, gyros and accelerometers are used to obtain reliable signals with a good time resolution. On the other hand, aiding sensors like radar units and strain gauges are known to be long-term accurate. The kernel of the integrated systems presented in this article consists, however, of an continuous-discrete extended Kalman filter estimating the motion state of the structure. Besides the sensor signals to be amalgamated, the filter requires a kinematical model of the vehicle motion considered, which has to be developed individually. This kinematical model describes the standardised dynamics of the vehicle by means of specific forces, i.e. accelerations, and of rotational velocities. Thus, there are no dynamometers or mass and stiffness properties needed in this approach. Diverse kinematical models of the beam were developed and evaluated, using model reduction in regard of the naturalmodes. Based on simulation the paper shows this approach, appropriate sensor sets, and estimated motion results of a flexible beam

    MAGIC observations of Mkn 421 in 2008, and related optical/X-ray/TeV MWL study

    Full text link
    The HBL-type blazar Markarian 421 is one of the brightest TeV gamma-ray sources of the Northern sky. From December 2007 until June 2008 it was intensively observed in the VHE (E>100 GeV) band by the MAGIC gamma-ray telescope. The source showed intense and prolonged activity during the whole period. In some nights the integral flux rose up to 3.6 Crab units (E>200 GeV). Intra-night rapid flux variations were observed. We compared the optical (KVA) and X-ray (RXTE-ASM, Swift-XRT) data with the MAGIC VHE data, investigating the correlations between different energy bands.Comment: 4 pages,4figures, Contribution to the 31st ICRC, Lodz, Poland, July 200

    Anomalous diffusion profiles of Ag in CdTe due to chemical self-diffusion

    Get PDF

    Progress of the Felsenkeller shallow-underground accelerator for nuclear astrophysics

    Full text link
    Low-background experiments with stable ion beams are an important tool for putting the model of stellar hydrogen, helium, and carbon burning on a solid experimental foundation. The pioneering work in this regard has been done by the LUNA collaboration at Gran Sasso, using a 0.4 MV accelerator. In the present contribution, the status of the project for a higher-energy underground accelerator is reviewed. Two tunnels of the Felsenkeller underground site in Dresden, Germany, are currently being refurbished for the installation of a 5 MV high-current Pelletron accelerator. Construction work is on schedule and expected to complete in August 2017. The accelerator will provide intense, 50 uA, beams of 1H+, 4He+, and 12C+ ions, enabling research on astrophysically relevant nuclear reactions with unprecedented sensitivity.Comment: Submitted to the Proceedings of Nuclei in the Cosmos XIV, 19-24 June 2016, Niigata/Japa
    corecore