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Intense Microwave and Particle Beams iii 1992

The proceedings contain 64 papers. The topic discussed include: present and future developments of high-power relativistic klystron amplifiers;design and initial operation of a repetitively pulsed high-current relativistic klystron;fully self-consistent nonlinear theory of energy and current modulation in relativistic klystron amplifiers;critical reexamination of Pierce's space-charge factor (QC) in the conventional TWT theory;high-energy high-efficiency phase-locked HPM magnetron for an array;kinetic analysis of space-charge wave effects of a helical relativistic electron beam on the cyclotron maser instability;and coupling and scattering parameters of sinusoidal slow-wave structures that can be easily obtained from a state-variable analysis.

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Using moire method of measuring optical disks

Using moire method of measuring optical disks

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current developments in optical design and optical engineering II

作者： Cheng, Ter-Chin Jiang, Sheng-Nan Chang, Rong-Seng Natl. Central Univ. Chung-Li Taiwan

ISBN: (纸本)0819409251

A primary function of compact disk measuring systems is the measurement of various types of defects which represent either functional or cosmetic flaws and the measurement of the profile of the compact disk. Functional flaws can make a very bad interference with the reproduction of the recorded music. Cosmetic flaws are visual imperfections whose presence can cause the rejecting of the disc by the production line. A projection moire method is invented in which a light beam passes through a grating, and is projected onto the object by overlapping with the virtual grating in the computer software. The object's 3-dimensional profile will be reconstructed and the object's profile quality can be improved by our new method for moire image processing.

关键词： Compact disks

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New type of depolarizer of magnesium fluoride

New type of depolarizer of magnesium fluoride

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current developments in optical design and optical engineering II

作者： Xu, Fuyun Shandong Architectural Engineering Inst. Shandong Jinan China

ISBN: (纸本)0819409251

I have studied the transmission range of the existing depolarizer in this article and found we can depolarize visible light completely by using Calcite or Quartz depolarizer. But we can not depolarize near infrared and middle infrared light completely by using the existing depolarizer. According to this theory, I have invented a new type of monochromatic light magnesium fluoride double wedges depolarizer. Its structure is different from the quartz double wedges depolarizer. I have studied it by theoretical analysis and experiment measurement. I can depolarize the light completely whether the polarization plane of the incident light is known or frequently varies by using a new type of magnesium fluoride depolarizer. The polarization degree of the emerging light is below 1.0%. It can be used in the near ultraviolet, visible, near infrared and middle infrared light.

关键词： optical devices

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design AND INITIAL OPERATION OF A REPETITIVELY-PULSED HIGH-current RELATIVISTIC KLYSTRON 3

DESIGN AND INITIAL OPERATION OF A REPETITIVELY-PULSED HIGH-C...

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3RD ANNUAL CONF ON INTENSE MICROWAVE AND PARTICLE BEAMS

作者： LEVINE, JS COOKSEY, NJ HARTENECK, BD POMEROY, SR WILLEY, MJ FRIEDMAN, M SERLIN, V Physics International Co. (United States) Naval Research Lab. (United States)

ISBN: (纸本)0819407755

We have begun a program of repetitive operation of a high-current relativistic klystron on the CLIA facility at Physics International. Potential problems of beam formation have been investigated and found not to be a limitation at repetition rates as high as 200 Hz. We are presently beginning initial testing in repetitive mode of a 5 kA, 500 kV klystron, designed and tested in single shot mode at the Naval Research Laboratory. Initial results at 10 Hz do not indicate any problems that are inherently repetitive in nature.

关键词： Research laboratories

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DEVELOPMENT OF AN EFFICIENT TRANSDUCER design TOOL - COMPLETE FINITE-ELEMENT MODELING OF TRANSDUCER PERFORMANCE PARAMETERS ON A PC

DEVELOPMENT OF AN EFFICIENT TRANSDUCER DESIGN TOOL - COMPLET...

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CONF ON NEW developments IN ULTRASONIC TRANSDUCERS AND TRANSDUCER SYSTEMS

作者： LAN, J SIMONEAU, MJ BOUCHER, SG Airmar Technology Corp. (United States)

ISBN: (纸本)0819409065

The finite element method has been applied to the problem of predicting the eigenfrequencies, displacements, and stresses within an ultrasonic transducer. In the case of transducers suitable for ocean survey, fish detection, or air-ranging, these parameters are useful only as general predictors of transducer performance. In the current presentation, the finite element method has been extended to the prediction of parameters more directly useful to the designer. A finite element program has been written in Fortran to compile and run on a 33 MHz/386 PC. Eigenfrequencies, impedance, transmit and receive sensitivity, radiation pattern, displacement, and shear and principle stresses can be predicted for a transducer in its operating medium. Damping in acoustic isolation, backing, and matching layer materials are included in the model to provide an accurate and comprehensive design tool. Experimental results for different designs corroborating the predictions from the finite element models are presented. With several design iterations possible in an hour, new transducers have been designed in a day or so.

关键词： Transducers Finite element methods Acoustics Free space Chemical elements Dielectrics Resistance Foam Polyurethane Ultrasonics

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OPTIMIZED ERROR DIFFUSION BASED ON A HUMAN VISUAL MODEL 3

OPTIMIZED ERROR DIFFUSION BASED ON A HUMAN VISUAL MODEL

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CONF ON HUMAN VISION, VISUAL PROCESSING, AND DIGITAL DISPLAY 3

作者： KOLPATZIK, BW BOUMAN, CA Purdue Univ. (United States)

ISBN: (纸本)0819408204

Error diffusion is a powerful means to improve the subjective quality of a quantized image by shaping the spectrum of the display error. Considering an image in raster ordering, this is done by adding a weighted sum of previous quantization errors to the current pixel before quantization. These weights form an error diffusion filter. In this paper a method is proposed to find an optimized error diffusion filter for image display applications. The design is based on the lowpass characteristic of the contrast sensitivity of the human visual system. The filter is chosen so that a cascade of the quantization system and the observer's visual modulation transfer function yields a whitened spectrum of error. It is shown in this paper that the optimal error diffusion filter corresponds to a linear prediction filter of the human visual transfer function. A first order linear filter for an underlying non-separable vision model is examined. The resulting images contain mostly high frequency components of the display error, which are less noticeable for the viewer. This corresponds well to previously published results about the visibility of halftoning patterns. An informal comparison with other error diffusion algorithms shows less artificial contouring and increased image quality.

关键词： Diffusion Quantization Visual process modeling Visualization optical filters Image filtering Modulation transfer functions Linear filtering Error analysis Image processing

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OVERVIEW OF EUROPEAN developments IN DIGITAL PHOTOGRAMMETRIC WORKSTATIONS

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PHOTOGRAMMETRIC engineering AND REMOTE SENSING 1992年第1期58卷 51-56页

作者： DOWMAN, IJ EBNER, H HEIPKE, C TECH UNIV MUNICH CHAIR PHOTOGRAMMETRY & REMOTE SENSING W-8000 MUNICH 2 GERMANY

The current position of European Softcopy or Digital Photogrammetric Workstations (DPWS) in terms of operational systems as well as research and development activities is reviewed. European manufacturers (Leica, Matra, Galileo Siscam) have made significant strides in developing universal type DPWS for topographic applications. Operational close-range DPWS include the MAP VISION system and the Rolleimetric RS product line. European mapping organizations such as the Ordnance Survey (United Kingdom), the Institut Geographique National (France), the Institut Cartografic de Catalunya (Spain), the Landesvermessungsamt Nordrhein-Westfalen (Germany), and Eurosense (Belgium) have made first steps in using DPWS in the production environment, mainly for the automatic computation of digital terrain models and for orthoprojection. Within the universities there has been considerable research activity concerning design issues of DPWS, often focusing on specific applications. For example, work is in progress in Berlin, Glasgow, Hannover, and London on topographic applications, in Braunschweig and Zurich on close-range applications, and in Graz, London and Oberpfaffenhofen on radargrammetry. Similarly, a body of work on algorithmic aspects of DPWS has been carried out in Bonn, Darmstadt, Delft, Enschede, Karlsruhe, Lausanne, Munich, Stockholm, Stuttgart, and Zurich. These activities are reviewed and lead to a number of conclusions on the state-of-the-art and on future trends. The major ones are A DPWS is and will remain an interactive workstation, where the human operator handles less and less routine work, but stays responsible for verification and control. Digital orthoprojection is on the verge of becoming widely used in practice. Image matching techniques are applied in a number of DPWS for small-scale applications. The use of operational image understanding methods in DPWS has not yet been achieved. The incorporation of data from different sources, for example, optical and micr

关键词： Photogrammetry

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Mechanical design of 15- and 20-cm clear-aperture disk amplifiers for the OMEGA upgrade

Mechanical design of 15- and 20-cm clear-aperture disk ampli...

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Solid State Lasers iii

作者： Shoup iii, Milton J. Kelly, John H. Tedrow, Melissa T. Rister, Frederick A. Thorp, Keith A. Univ. of Rochester Hilton NY USA

ISBN: (纸本)0819407739

Although a number of papers exist on the optimization of large-aperture disk amplifiers for use in fusion-laser systems, there is a relative paucity of information on the detailed mechanical design of these devices. In particular, there is little information on their reliability, maintainability, and producibility (RMP). This paper describes two recent designs developed and built by the University of Rochester's Laboratory for Laser Energetics. These 15- 20-cm clear-aperture Nd:glass amplifiers use longitudinal and transverse lamps, respectively, which are water cooled. We describe the design rationale and potential pitfalls. In particular, the disk sizing for a prescribed clear aperture is described. The various laser disk mounting techniques are described and the advantages and disadvantages are compared. Consequences for disk distortion, cladding expansion, cladding survivability, disk stability, and cleanliness are enumerated. The driving requirements for the amplifier frame, which is similar for both devices, are describe. The consequences for cleanliness, stability, and ease of assembly are also described. Finally, the modules containing the flash-lamp arrays are described. These presented the particularly interesting challenge to deliver high voltage and current, cooling water, not degrade pumping efficiency, to be readily serviceable in the event of a lamp failure, and to be cost effective. A working compromise among all of these conflicting requirements was achieved. The module designs, materials used, and the actual performance are described.

关键词： Solid state lasers

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Layered approach to workstation design for medical image viewing

Layered approach to workstation design for medical image vie...

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Medical Imaging VI: PACS design and Evaluation

作者： Haynor, David R.M.D. Zick, Gregory L. Heritage, Marcus B. Kim, Yongmin Univ. of Washington Seattle WA USA

ISBN: (纸本)0819408069

Software engineering principles suggest that complex software systems are best constructed from independent, self-contained modules, thereby maximizing the portability, maintainability and modifiability of the produced code. This principal is important in the design of medical imaging workstations, where further developments in technology (CPU, memory, interface devices, displays, network connections) are required for clinically acceptable workstations, and it is desirable to provide different hardware platforms with the 'same look and feel' for the user. In addition, the set of desired functions is relatively well understood, but the optimal user interface for delivering these functions on a clinically acceptable workstation is still different depending on department, specialty, or individual preference. At the University of Washington, we are developing a viewing station based on the IBM RISC/6000 computer and on new technologies that are just becoming commercially available. These include advanced voice recognition systems and an ultra-high-speed network. We are developing a set of specifications and a conceptual design for the workstation, and will be producing a prototype. This paper presents our current concepts concerning the architecture and software system design of the future prototype. Our conceptual design specifies requirements for a Database Application Programming Interface (DBAPI) and for a User API (UAPI). The DBAPI consists of a set of subroutine calls that define the admissible transactions between the workstation and an image archive. The UAPI describes the requests a user interface program can make of the workstation. It incorporates basic display and image processing functions, yet is specifically designed to allow extensions to the basic set at the application level. We will discuss the fundamental elements of the two API's and illustrate their application to workstation design.

关键词： Computer workstations

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optical signal acquisition and processing in future accelerator diagnostics

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AIP Conference Proceedings 1992年第1期279卷 821-833页

作者： Gerald P. Jackson Alizon Elliott Fermi National Accelerator Laboratory MS 341 P.O. Box 500 Batavia IL 60510 Univeristy of Illinois at Chicago Dept. of Electrical Engineering Chicago IL 60607

Beam detectors such as striplines and wall current monitors rely on matched electrical networks to transmit and process beam information. Frequency bandwidth, noise immunity, reflections, and signals to noise ratio are considerations that require compromises limiting the quality of the measurement. Recent advances in fiber optics related technologies have made it possible to acquire and process beam signals in the optical domain. This paper describes recent developments in the application of these technologies to accelerator beam diagnostics. The design and construction of an optical notch filter used for a stochastic cooling system is used as an example. Conceptual ideas for future beam detectors are also presented.

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