Philips

About: Philips is a company organization based out in Vantaa, Finland. It is known for research contribution in the topics: Signal & Layer (electronics). The organization has 68260 authors who have published 99663 publications receiving 1882329 citations. The organization is also known as: Koninklijke Philips Electronics N.V. & Royal Philips Electronics.

Spread spectrum radio transmission system

Abstract: A communications system wherein an intelligence signal modulates the spacing of relatively narrow pulses of a fixed rate pulse train, and these pulses key on a transmitter which employs a pair of series connected avalanche mode operated transistors. These are repetitively powered via a charged coaxial delay line, and the output, appearing across a resistive load, is fed directly, or through a shaping filter, to a discone transmitting antenna. At a receiving location, the received signal is amplified by a wide band amplifier and fed through a reverse contoured filter (of the transmitting filter, if one is employed). The signal is detected via synchronous detection which locks onto the received pulse train, after which the modulation evidence by the pulse train is recovered by a low pass filter.

Semiconductor Surface Reconstruction: The Structural Chemistry of Two-Dimensional Surface Compounds.

Abstract: The purpose of this article is to provide an overview of the surface structures of the clean surfaces of tetrahedrally coordinated semiconductors within the context of identifying the main features of their structural chemistry. We develop the point of view that the surface regions of these materials form twodimensional (2D) compounds whose bonding is constrained by the requirement of epitaxy with the substrate1 and that the coordination chemistry of these compounds differs from that of molecules or (three-dimensional) bulk solids in specific ways.2 Our coverage is confined to low-index faces. Specifically, our interest lies in the atomic geometries of ideal single-crystal regions of surfaces rather than in the morphology of surfaces with multiple domains, steps, or defects. Finally, although similar considerations have been applied to interpret oxide surface structures more generally,3 our attention herein is confined to tetrahedrally coordinated elemental and binary compound semiconductors. The traditional approach to constructing a review of this type is to consider each surface separately and to describe the structural studies4-11 or theoretical predictions of surface structure4-7,12,13 for each individual surface. This procedure offers an abundance of case histories, but little by way of guidance concerning how to make sense out of the wealth of Dr. Charles B. Duke is Senior Research Fellow at Xerox Corporation. Prior to holding this position, he was Deputy Director and Chief Scientist of the Pacific Northwest Division of the Battelle Memorial Institute and Affiliate Professor of Physics at the University of Washington. From 1972 to 1988 he held various technical and management positions at the Xerox Research Laboratories in Webster, NY and was an Adjunct Professor of Physics at the University of Rochester. During 1969−72, he was a Professor of Physics and member of the Materials Research Laboratory and Coordinated Science Laboratory at the University of Illinois in Urbana, IL, following six years as a staff member of the General Electric Corporate Research and Development Center in Schenectady, NY. He received his Ph.D. in physics from Princeton in 1963 following a B.S. Summa Cum Laude with distinction in mathematics from Duke University in 1959. He is a Fellow and an Honorary Member of the American Vacuum Society, a Fellow of the American Physical Society, a Fellow of the IEEE, and a life member of Sigma Xi. In 1977, Dr. Duke received the Medard W. Welch Award in Vacuum Science and Technology. In 1979 he served as President of the American Vacuum Society, and since 1979, as Treasurer of its Electronic Materials and Processing Division. He served on the Board of Directors of the American Vacuum Society for seven years. He was chairman of the 1977 Gordon Research Conference on the Chemistry and Physics of Solids and of the 1983 Gordon Research Conference on Organic Thin Films and Solid Surfaces. In 1981 he was named one of the ISI 1000 internationally most cited scientists. During 1985−86 he served as founding editor-in-chief of the Journal of Materials Research, the official journal of the Materials Research Society. From 1988 to 1992 and 1995 to 1997, he served (will be serving) on the council of the Materials Research Society, serving as Treasurer during 1991−2. In 1992 he was named editor of Surface Science. In 1993 he was elected to the National Academy of Engineering. He is serving on the Council of the American Physical Society during 1995−8. He was chairman of the Board of Editors of the Journal of Vacuum Science and Technology during 1976−82 and is currently a member of the editorial boards of Journal of Materials Research, Critical Reviews of Solid-State and Materials Sciences, Surface Science Reports, the Chemistry and Physics of Surfaces and Interfaces, and the Encyclopedia of Applied Physics. He served on the Governing Board of the American Institute of Physics from 1976 to 1987, being a member of the Board’s Executive Committee, Corporate Associates Committee, Educational Policy Committee, Journals Committee, and Committee on Public Education and Information. He has written over 350 papers on surface science, materials research, semiconductor physics, and the electronic structure of molecular solids, as well as a monograph on electron tunneling in solids. He is the editor of Surface Science: The First Thirty Years. 1237 Chem. Rev. 1996, 96, 1237−1259

Method for creating multiplanar ultrasonic images of a three dimensional object

Abstract: A method for creating multiple planar images of a volumetric region of an object without acquiring data from the entire volumetric region. The method includes sweeping a transducer across the volumetric region. At sampling positions during the sweep, ultrasonic beams from the transducer are transmitted into the volumetric region, which intersect one or more of a plurality of surfaces to be scanned. The number of transmitted beams during the sweep is fewer than the number of beams that would be transmitted to scan the entire volumetric region. Echoes from the volumetric region are received at the transducer in response to the transmitted beams. From the received echoes, planar images corresponding to the plurality of surfaces are formed. In a variation, the method includes receiving at the transducer fewer echoes from the volumetric region than the echoes that would be received from scanning the entire volumetric region. This enables the creation of planar images corresponding to buried surfaces within the volumetric region. Because only a finite plurality of surfaces of the region is being scanned rather than the entire volumetric region, planar images of high image quality and a broad field of view can be created and displayed in real-time. The method can also be performed by scanning the transducer. The method is carryied out by ultrasonic apparatus.

Intracranial arterial wall imaging using three-dimensional high isotropic resolution black blood MRI at 3.0 Tesla.

Abstract: Purpose: To develop a high isotropic-resolution sequence to evaluate intracranial vessels at 3.0 Tesla (T). Materials and Methods: Thirteen healthy volunteers and 4 patients with intracranial stenosis were imaged at 3.0T using 0.5-mm isotropic-resolution three-dimensional (3D) Volumetric ISotropic TSE Acquisition (VISTA; TSE, turbo spin echo), with conventional 2D-TSE for comparison. VISTA was repeated for 6 volunteers and 4 patients at 0.4-mm isotropic-resolution to explore the trade-off between SNR and voxel volume. Wall signal-to-noise-ratio (SNRwall), wall-lumen contrast-to-noise-ratio (CNRwall-lumen), lumen area (LA), wall area (WA), mean wall thickness (MWT), and maximum wall thickness (maxWT) were compared between 3D-VISTA and 2D-TSE sequences, as well as 3D images acquired at both resolutions. Reliability was assessed by intraclass correlations (ICC). Results: Compared with 2D-TSE measurements, 3D-VISTA provided 58% and 74% improvement in SNRwall and CNRwall-lumen, respectively. LA, WA, MWT and maxWT from 3D and 2D techniques highly correlated (ICCs of 0.96, 0.95, 0.96, and 0.91, respectively). CNRwall-lumen using 0.4-mm resolution VISTA decreased by 27%, compared with 0.5-mm VISTA but with reduced partial-volume-based overestimation of wall thickness. Reliability for 3D measurements was good to excellent. Conclusion: The 3D-VISTA provides SNR-efficient, highly reliable measurements of intracranial vessels at high isotropic-resolution, enabling broad coverage in a clinically acceptable time. J. Magn. Reson. Imaging 2011;. © 2011 Wiley-Liss, Inc.

The algebraic basis of mathematical morphology

Abstract: For pt.I see ibid., vol.50, p.245-295, 1990. In (Part I) the authors introduced and investigated an abstract algebraic framework for mathematical morphology. The main assumption is that the object space is a complete lattice. Of interest are all (increasing) operators which are invariant under a given abelian group of automorphisms on the lattice. In Part I the authors were mainly concerned with the basic operations dilation and erosion. In this paper they concentrate on openings and closings, which are very special classes of idempotent operators. Much attention is given to specific methods for building openings and closings in an economical way; in particular they study annular openings and inf-overfilters. They also consider the possibility of generating new openings by iteration of anti-extensive operators. Some examples illustrate the abstract theory.