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  • 1
    Electronic Resource
    Electronic Resource
    O(3,3)-like symmetries of coupled harmonic oscillators (1995)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 36 (1995), S. 3940-3954 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: In classical mechanics, the system of two coupled harmonic oscillators is shown to possess the symmetry of the Lorentz group O(3,3) or SL(4,r) in the four-dimensional phase space. In quantum mechanics, the symmetry is reduced to that of O(3,2) or Sp(4), which is a subgroup of O(3,3) or SL(4,r), respectively. It is shown that among the six Sp(4)-like subgroups, only one possesses the symmetry which can be translated into the group of unitary transformations in quantum mechanics. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.530940
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  • 2
    Electronic Resource
    Electronic Resource
    Symmetries of two-mode squeezed states (1993)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 34 (1993), S. 5493-5508 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: It is known that the symmetry of two-mode squeezed states is governed by the group Sp(4) which is locally isomorphic to the O(3,2) de Sitter group. It is shown that this complicated ten-parameter group can be regarded as a product of two three-parameter Sp(2) groups. It is shown also that two coupled harmonic oscillators serve as a physical basis for the symmetry decomposition. It is shown further that the concept of entropy is needed when one of the two modes is not observed. The entropy is zero when the system is uncoupled. The system reaches thermal equilibrium when the entropy becomes maximal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.530318
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  • 3
    Electronic Resource
    Electronic Resource
    Lorentz deformation and the jet phenomenon (1979)
    Springer
    Foundations of physics 9 (1979), S. 947-954 
    Details
    ISSN: 1572-9516
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract It is shown that the Lorentz-deformation property discussed in previous papers is consistent with the hadronic jet phenomenon in high-energy production processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00708703
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  • 4
    Electronic Resource
    Electronic Resource
    Physical basis for minimal time-energy uncertainty relation (1979)
    Springer
    Foundations of physics 9 (1979), S. 375-387 
    Details
    ISSN: 1572-9516
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A physical basis for the minimal time-energy uncertainty relation is formulated from basic high-energy hadronic properties such as the resonance mass spectrum, the form factor behavior, and the peculiarities of Feynman's parton picture. It is shown that the covariant oscillator formalism combines covariantly this time-energy uncertainty relation with Heisenberg's space-momentum uncertainty relation. A pictorial method is developed to describe the spacetime distribution of the localized probability density.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00708529
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  • 5
    Electronic Resource
    Electronic Resource
    Lorentz deformation and the jet phenomenon. II. Explanation of the nearly constant average jet transverse momentum (1980)
    Springer
    Foundations of physics 10 (1980), S. 635-639 
    Details
    ISSN: 1572-9516
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract It is shown that the jet mechanism derivable from the Lorentz deformation picture leads to a nearly constant average jet transverse momentum. It is pointed out that this is consistent with the high-energy experimental data. It is pointed out further that this result strengthens the physical basis for the minimal time-energy uncertainty combined covariantly with Heisenberg's space-momentum uncertainty relation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00715044
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  • 6
    Electronic Resource
    Electronic Resource
    Physical principles in quantum field theory and in covariant harmonic oscillator formalism (1981)
    Springer
    Foundations of physics 11 (1981), S. 895-905 
    Details
    ISSN: 1572-9516
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract It is shown that both covariant harmonic oscillator formalism and quantum field theory are based on common physical principles which include Poincaré covariance, Heisenberg's space-momentum uncertainty relation, and Dirac's “C-number” time-energy uncertainty relation. It is shown in particular that the oscillator wave functions are derivable from the physical principles which are used in the derivation of the Klein-Nishina formula.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00727106
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  • 7
    Electronic Resource
    Electronic Resource
    Design and construction of a microdensitometer computer interface (1978)
    Springer
    Journal of medical systems 2 (1978), S. 315-326 
    Details
    ISSN: 1573-689X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This project consisted in modifying the output of a scanning microdensitometer so that a computer could accept and process the (optical) density versus position information gathered from radiographic film. The system functions were separated into two parts: the actual datagathering process, which required real-time response, and the calculation associated with the data. Separation of functions allowed a less expensive system overall while still preserving flexibility. For the real-time control computer, a relatively slow microprocessor-based system (Motorola MC6800) was chosen. The microdensitometer was modified to allow computer control of the scan. The density versus position information was digitized using optical shaft encoders. Cassette tape was used as a mass-storage medium for complete scans. Using an acoustic coupler, the microprocessor was cofigured to transmit accumulated data to a timeshare system for analysis. The results were retransmitted and displayed on a TV screen or printed on a line printer or teletype. The total cost of the microprocessor system was a little less than $5,000. The time required to produce the software was 50 to 100 hrs (approximately 1 week).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02221897
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    Paper (German National Licenses)
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  • 8
    Electronic Resource
    Electronic Resource
    A modular computer system for the Nuclear Medicine/ultrasound laboratory: A multidisciplinary proposal (1977)
    Springer
    Journal of medical systems 1 (1977), S. 251-261 
    Details
    ISSN: 1573-689X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In many Nuclear Medicine studies computer-controlled graphic displays are an absolute necessity for obtaining meaningful results. Design criteria developed by an interdisciplinary scientific panel are presented to achieve a display system based on television technology; an instrument interface employing list mode using bubble-memory storage technology, thus having a low information-loss rate; and flexible modular software easily tailored to the specific needs of both clinicians and technicians. The panel considers a minicomputer system with broad, flexible applications to be a valuable tool, particularly in doing those function studies that only can be done via nuclear medicine techniques. The final specifications ultimately allow the selection of a vendor and hospital installation, even though all criteria are not currently achievable.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02222587
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  • 9
    Electronic Resource
    Electronic Resource
    Standardizing the raster display for medical images using a fixed set of frame buffer primitives (1986)
    Springer
    Journal of medical systems 10 (1986), S. 209-228 
    Details
    ISSN: 1573-689X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Two major difficulties associated with medical image processing are the diverse image formats that must be dealt with because of the differences in image sources and the number of incompatible display systems available for viewing images both before and after processing. We describe a very small set of primitives that need to be defined to utilize any raster display. When these primitives have been implemented for a particular device, then a standard set of image display programs can be compiled and images and the results of image processing can be displayed. The main purpose of this paper is to describe what a raster display looks like from the point of view of the programmer and to define the specific hardware and software data about the raster display that must be known in order to implement the small set of primitives.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00992817
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    Paper (German National Licenses)
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  • 10
    Electronic Resource
    Electronic Resource
    Graphical 3D Medical Image Registration and Quantification (1997)
    Springer
    Journal of medical systems 21 (1997), S. 155-172 
    Details
    ISSN: 1573-689X
    Keywords: image registration ; image fusion ; 3-D visualization ; 3-D measurement ; cancer diagnosis and treatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We present a graphical three-dimensional method that facilitates image registration and fusion, and provides quantitative geometric and volume information. In particular it enhances the use of functional (radiopharmaceutical) imaging (SPECT, PET) which, though a powerful clinical tool, has the disadvantage of low spatial resolution and ill-defined boundaries. Registration between functional images and structural images (MRI, CT) can augment the anatomical context of these functional images.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022860206127
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