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Survival analysis of the gamma-ray burst data

Journal of the American Statistical Association 1994年第426期89卷 452-452页

作者： Efron, Bradley Petrosian, Vahé Professor/Chairman Statistics Department Stanford University CA 94305-4065 Professor of Health Research and Policy Department of Statistics Stanford University CA 94305-4065 Chairman of Astronomy Program and Professor of Physics and Applied Physics Departments Stanford University CA 94305-4065 We thank the SWiNE SMM and BATSE teams

Gamma-ray bursts are short but powerful pulses of electromagnetic radiation coming from space. Specially equipped satellites have observed the arrival of several hundred bursts during the past two decades. The origin of these bursts, whether from near the earth, across the galaxy, or out of the deep cosmos, has become a major question for astronomers. At the heart of this question lies a statistical puzzle relating to familiar issues in survival analysis Kaplan--Meier-type curves, data truncation, hazard rate analysis, Mantel--Haenszel statistics, and so on. Survival analysis is used here to critically examine two different models that have been proposed for the gamma-ray burst data. The analysis contradicts one of these models.

关键词： Bayesian statistics Climatic change Gaussian random fields

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SURFACE-EMITTING LASERS OF LOW-THRESHOLD 1.3-MU-M GAINASP/INP CIRCULAR PLANAR-BURIED HETEROSTRUCTURE

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ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS 1994年第2期77卷 29-38页

作者： BABA, T YOGO, Y SUZUKI, K KOYAMA, F IGA, K Precision and Intelligence Laboratory Tokyo Institute of Technology Yokohama Japan 227 Kasumasa Suzuki received his B.S. from Tokyo Institute of Technology where at present he is enrolled in the Master's program. He has been involved in research on surfaceemitting lasers. Member of the Japanese Applied Physics Society.

The GaInAsP/InP circular planar-buried hetero-structure is a promising structure to realize a low-threshold 1.3-mu m surface-emitting laser for continuous operation at room temperature. In the conventional regrowth process, pinholes which depend on the crystalline orientation of the circular active region tend to occur, resulting in the increase of nonradiative current, As a result, it has been difficult to achieve room temperature oscillation. To solve this problem, the planar-buried structure which could be formed by one liquid-phase epitaxial step without using a mask was adopted to fabricate mesa-type surface-emitting lasers. As a result, the reproducibility in forming the buried structure was improved and the nonradiative current decreased. The resultant devices showed stable electrical and optical characteristics. When the laser cavity was formed by using SiO2/Si dielectric multilayer mirrors, continuous oscillation was observed at 77 K and the threshold currents of 15 devices were lower than 15 mA. The lowest threshold current was 2.2 mA. In the room-temperature pulse operation, the threshold current was 34 mA, the lowest among the values ever reported. Pulse oscillation was observed at 45 degrees C and continuous operation was observed even at -57 degrees C. If reflecting mirrors with a high thermal conductivity are introduced, the temperature for continuous operation will increase and it will be possible to realize continuous operation at room temperature.

关键词： SEMICONDUCTOR LASER BURIED HETEROSTRUCTURE LASER SURFACE-EMITTING LASER VERTICAL CAVITY GAINASP/INP OPTICAL FIBER COMMUNICATION

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ACQUISITION REFORM AND BEST PRODUCT PROCUREMENT - AN ENGINEERING VIEW

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NAVAL ENGINEERS JOURNAL 1994年第6期106卷 41-57页

作者： FISHER, DA SKOLNICK, A He has been involved with several weapon system developments. Among these were the Trident II fire control and navigation systems the BSY-I Anti-Submarine Warfare System and the Navy standard computers (UYK44 and EMSP). He served as manager of the Digital Circuits Engineering Branch and was then appointed as manager of the Automatic Test Equipment (ATE) Technology Division. As manager of the ATE Technology Division he was responsible for the SP-23 Fire Control System Support Project the SP-24 Navigation Project and the Fleet Progressive Maintenance Program (2M/ATE). This Division was responsible for selection and application of electronic product technology and for developing fleet test and repair techniques. He holds a B.S. in Electrical Engineering from the University of Evansville and is currently pursuing a Masters of Public Administration at Indiana University-Purdue University Indianapolis. Dr. Alfred Skolnick:retired from the Navy in 1983 with the rank of captain. He is president of System Science Consultants (SSC) specializing in strategic planning technical program definition technology assessment and engineering analyses on selected matters of national interest. Dr. Skolnick taught mathematics and management sciences at University of Virginia and Marymount University. He is adjunct faculty at Northern Virginia Community College. From 1985 to 1989 he was president of the American Society of Naval Engineers. In the Navy he served at Applied Physics Laboratory/The Johns Hopkins University then aboard USSBoston(CAG-1) and played leading roles in several weapon system developments inertial navigation (Polaris) deep submergence (DSRV) and advanced ship designs (SES). He later was director Combat System Integration Naval Sea Systems Command and head Combat Projects Naval Ship Engineering Center. In 1975 he became a major project manager and led the Navy's High Energy Lasers Program in 1981 he was assigned all Navy Directed Energy Weapons development efforts. He was vice president advanced tech

The military services are being moved in the direction of performance-based specifications and standards. They are being steered against dictating ''how to'' produce an item since such action forecloses on the ability to gain access to components or technology that may have a commercial equivalent. Why should the engineering community embrace the new approach? Aside from the obvious weight of it being approved policy, therefore currently mandated, it warrants examination because it is the correct approach at this time when applied to appropriate products. Military specifications and standards are to be displaced then, by acceptable alternative contractor design solutions. Industry bidders will be allowed to propose the particular design details, permitting procurement flexibility by contractually citing only system level or interface requirements, both physical and functional. Hopefully, this can broaden the industrial base and increase competition with reduced costs to follow. Conceptually, the approach appears both performance-sensible and cost-attractive (there are, of course, consequent risks) but how does implementation proceed? Is it possible to pursue the goals envisioned along paths that are not in themselves experimental? Can the American postulate, minimal loss of life and limb to U.S. military people, continue to be honored? Experience and track record elsewhere imply encouraging possibilities in select situations-useful prospects are identified and discussed in practical terms.

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THE CALLING(SM) NETWORK - A GLOBAL WIRELESS COMMUNICATION-SYSTEM

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INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS 1994年第1期12卷 45-61页

作者： TUCK, EF PATTERSON, DP STUART, JR LAWRENCE, MH Calling Communications Corporation. 1900 West Garvey Ave South. Suite 200 West Covina CA 91790 USA. Chairman of Calling Communications Corporation. He is also the Managing Director of Kinship Venture Management Inc. the general partner of Kinship Partners 11 and a General Partner of Boundary the general partner of The Boundary Fund. As a venture capitalist he has founded or participated in founding several telecommunications companies including Calling Communications Corporation Magellan Systems Corporation manufactures of Global Positioning System receivers Applied Digital Access manufacturer of DS-3 test access and network performance monitoring equipment Endgate Technology Corporation specialists in satellite phased array antennas and Poynting Systems Corporation. now a division of Reliance Corporation manufacturers of fibre optic transport equipment. He was a founder of Kebby Microwave Corporation where he invented the first solid-state. frequency-modulated commercial microwave link system. The company was acquired by ITT Corporation where he rose to the position of V.P. and Technical Director of ITT North America Telecommunications Inc. Subsequently he was V.P. of Marketing and Engineering at American Telecommunications Inc. (ATC). He was founding Director of American Telecom Inc. a joint venture between ATC and Fujitsu and has served on more than 20 boards of directors including those of three public companies. He has authored articles on microwave engineering and telephone signalling and was a contributor to Reference Data For Radio Engineers. He is a graduate of the University of Missouri at Rolla where he was later awarded an honorary Professional degree and serves on its Academy of Electrical Engineering. Mr Tuck is a Senior Member of the IEEE a Fellow of the Institution of Engineers (Australia) a Professional Member of the AIAA and a registered professional engineer in three states. More than 25 years of experience in the telecommunications industry where he has been responsibl

There is a very large demand for basic telephone service in developing nations, and remote parts of industrialized nations, which cannot be met by conventional wireline and cellular systems. This is the world's largest unserved market. We describe a system which uses recent advances in active phased arrays, fast-packet switching technology, adaptive routeing, and light spacecraft technology, in part based on the work of the Jet Propulsion Laboratory and on recently-declassified work done on the Strategic Defense Initiative, to make it possible to address this market with a global telephone network based on a large low-Earth-orbit constellation of identical satellites. A telephone utility can use such a network to provide the same modern basic and enhanced telephone services offered by telephone utilities in the urban centres of fully-industrialized nations. Economies of scale permit capital and operating costs per subscriber low enough to provide a service to all subscribers, regardless of location, at prices comparable to the same services in urban areas of industrialized nations, while generating operating profits great enough to attract the capital needed for its construction. The bandwidth needed to support the capacity needed to gain these economies of scale requires that the system use K(alpha)-band frequencies. This choice of frequencies places unusual constraints on the network design, and in particular forces the use of a large number of satellites. Global demand for basic and enhanced telephone service is great enough to support at least three networks of the size described herein. The volume of advanced components, and services such as launch services, required to construct and replace these networks is sufficient to propel certain industries to market leadership positions in the early 21st Century.

关键词： LOW EARTH ORBIT SATELLITE COMMUNICATIONS FAST PACKET SWITCHING EARTH FIXED CELLS ADAPTIVE ROUTEING LIGHT SPACECRAFT K(A) BAND PHASED-ARRAY ANTENNAS

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Development of a Gas-Generation Model for the Waste Isolation Pilot Plant

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MRS Online Proceedings Library 1993年第1期333卷 241-246页

作者： H. Brush J. W. Garner L. J. Storz WIPP Gas Generation Program Department 6348 Sandia National Laboratories Albuquerque USA Applied Physics Inc. Albuquerque USA

Design-basis transuranic (TRU) waste to be emplaced in the Waste. Isolation Pilot Plant (WIPP) in southeastern New Mexico may generate significant quantities of gas, which may affect theperformance of the WIPP with respect to regulations for radioactive and/or chemically hazardous waste constituents. We are developing a model topredict gas generation in WIPP disposal rooms during and after filling and sealing. Currently, the model includes: (1) oxic and anoxic corrosion of steels and other Fe-base alloys, includingpassivation and depassivation; (2) microbial degradation of cellulosics with O2, NO3-, FeO(OH), SO42-, or CO2 as the electron acceptor; (3) α radiolysis of brine; (4) consumption of CO2 and,perhaps, H2S by Ca(OH)2 (in cementitious materials) and CaO (apotential backfill additive). The code simulates theseprocesses and interactions among them by converting reactants (steels, cellulosics, etc.) to gases and otherproducts at experimentally observed or estimated rates andplotting temporal reactionpaths in three-dimensionalphase diagrams for solids in the Fe-H2O-CO2-H2-H2S system.

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Benchmark Tests of Principal Fissile Nuclide Data in JENDL-3 with Simple Fast Critical Assemblies

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Journal of Nuclear Science and Technology 1993年第11期30卷 1087页

作者： TIAN, Dongfeng HASEGAWA, Akira NAKAGAWA, Tsuneo KIKUCHI, Yasuyuki Nuclear Data Center Department of PhysicsTokai Research EstablishmentJapan Atomic Energy Research Institute A visiting scientist through STA Scientist Exchange Program from Institute of Applied Physics and Computational Mathematics

A series of benchmark tests was made to check the neutron nuclear data of main fissile nuclides (239Pu, 236U and 233U) of JENDL-3 for fast reactors. A total of nine critical assemblies were analyzed. They are assemblies of single material, high enrichment and simple geometry with small volume and therefore suitable for nuclear data testing. Criticality calculation was made by ANISN with S16P5 using the VITAMIN-J 175-energy-group. Discussions are made on ken, spectral indices at core center and leakage spectra. From the study, a problem was pointed out relating to the interpolation of secondary-neutron energy distributions for threshold reactions near the threshold energy point adopted in the original JENDL-3 and its remedy was proposed. By the benchmark tests of thus revised JENDL-3 (JENDL-3.1), it was shown that integral experiments for 239Pu and 235U cores were reproduced quite satisfactorily. On the contrary, it was revealed that large deviations for 233U cores from the experiment were due to uncertainties of the fission spectrum and the inelastic scattering cross sections, In the present work, sensitivity of "a" parameter (level density parameter) of Madland-Nix's fission spectrum formula to the integral data was extensively studied. Some recommendations are made to improve JENDL-3.1.

关键词： JENDL-3 fast reactors benchmarks neutrons nuclear data cross section plutonium-239 uranium-235 uranium-233 Madland-Nix's fission spectra k eff spectral index leakage spectra accuracy

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Theory of The Active Nonlinear Coupler Laser

Theory of The Active Nonlinear Coupler Laser

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Nonlinear Guided-Wave Phenomena, NLGW 1993

作者： Walton, Donnell T. Winful, Herbert G. Applied Physics Program University of Michigan 1301 Beal Ave. Rm 1214 Ann ArborMI48109 United States Department of Electrical and Computer Engineering University of Michigan 1301 Beal Ave. Ann ArborMI48109 United States

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Stochastic Treatment of Adsorbate Local-Potential Effects on Surface-Ion Neutralization

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Physical Review Letters 1993年第24期71卷 4075-4075页

作者： Zoran L. Mišković Sydney G. Davison Frank O. Goodman Department of Applied Mathematics University of Waterloo Waterloo Ont. N2L 3G1 Canada Institute of Nuclear Sciences-Vinča Belgrade Department of Physics University of Waterloo Guelph-Waterloo Program for Graduate Work in Physics

The influence of a laterally inhomogeneous electrostatic potential of an adsorbate-covered surface on the resonant charge transfer in ion-surface scattering is investigated by means of the time-dependent Anderson-Newns Hamiltonian. The adsorbate-induced random modulation of the projectile orbital energy level is treated as a stochastic process, and its role in the charge transfer is evaluated analytically, in the Gaussian-process approximation, for low projectile speeds and low surface coverage by alkali atoms.

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CIRCULAR OVERMODED WAVE-GUIDE FOR SHIPBOARD USE

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NAVAL ENGINEERS JOURNAL 1993年第2期105卷 39-52页

作者： HUTING, WA WARREN, JW GARNER, PN KRILL, JA William A. Huting:received the B.S.E. degree in electrical engineering from Duke University in 1981 the M.S.E.E. degree from the Georgia Institute of Technology in 1982 and the Ph.D. degree in electrical engineering (electrophysics) from the University of Maryland in 1989. From September 1981 to December 1983 he was a graduate teaching assistant with Georgia Tech. Since January 1984 he has been with The Johns Hopkins University Applied Physics Laboratory where he has principally been involved with the development of circular overmoded waveguides and tapered waveguide transitions for use in naval radar systems. Dr. Huting is a member of the Institute of Electrical and Electronics Engineers. Jeffery W. Warren:received a B.S. degree in 1982 and an M.S. degree in 1984 both in electrical engineering from the University of South Carolina. His thesis research evaluated electro-optical measurements of surface charging of insulators in low-frequency fields. He joined The Johns Hopkins University Applied Physics Laboratory in 1984. Mr. Warren's activities include development and testing of electro-optical systems and the development of high-power low-loss overmoded waveguides. Mr. Warren is a member of the Institute of Electrical and Electronics Engineers. Paul N. Garner: Jr. received the B.S. degree in mathematics and the B.S. degree in mechanical engineering from the University of Maryland in 1973 and 1980 respectively and the M.B.A. degree from the Florida Institute of Technology in 1984. Since 1987 he has been involved with the Cooperative Engagement Capability Program as the lead mechanical engineer and since 1990 he has been with The Johns Hopkins University Applied Physics Laboratory where he is now a member of the Senior Professional Staff. Jerry A. Krill:received the B.S.E.E. and M.S.E.E. degrees from Michigan State University in 1973 and 1974 respectively and a Ph.D. in electrical engineering (electrophysics) from the University of Maryland in 1978. From 1973 to the present he has been with The Johns

Several future Navy combat systems under development require efficient delivery of high power microwave energy from remote transmitters to array antennas. To achieve this requirement, a family of microwave components has been developed and tested. Progress is described in the design and testing of an overmoded circular TE01 mode waveguide applicable to special shipboard needs. Because such a waveguide had originally been developed for low power millimeter band trunkline communications between cities, new theoretical, design, and fabrication techniques had to be developed to meet our specific performance requirements. Moreover, in order to fulfill the combat system requirements, the waveguide would have to withstand harsh military requirements. Over several years the obstacles to the application of overmoded technology to Navy combat systems have been systematically eliminated. The effort has resulted in the invention of several new components, the development and validation of a new computer aided design package, and the implementation of new microwave measurement techniques. The first application of an overmoded waveguide to a combat system element was recently achieved in the successful demonstration of the prototype Cooperative Engagement Capability, and steps toward a production military version of the waveguide have been initiated.

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TOMAHAWK NITROGEN PRESSURIZATION MAINTENANCE - WHY

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NAVAL ENGINEERS JOURNAL 1993年第2期105卷 66-68页

作者： CIARULA, TA NERADKA, VF Cdr. Thomas A. Ciarula: USN was born in Pottstown Pa. He attended Northrop University in Inglewood Calif. where he earned a bachelor of science degree in aircraft maintenance engineering in September 1971. He was selected for Officer Candidate School where he was commissioned an ensign (Aeronautical Maintenance Duty) in August 1972. Cdr. Ciarula has been assigned to VA-37 The AIMD at NAF Kadena Okinawa Japan VXE-6 and the USS Forrestal. He was the wing maintenance for training officer for Air Wing Three at NAS Chase Field in Beeville Tex. and the AIMD officer at NAS Key West Fla. In 1988 Cdr. Ciarula was assigned to the Cruise Missiles Project (PEO-CU) where he was the TASM class desk officer and the director of logistics. While at the Cruise Missiles Project he was awarded his master of science in general administration from Central Michigan University. He is currently assigned to PMA-205 in the Naval Air Systems Command. Vincent F. Neradka:received B.S. and M.S. degrees from the University of Maryland in aerospace engineering in 1964 and 1969 and an MS in technical management from the Johns Hopkins University in 1986. He joined the Johns Hopkins University Applied Physics Laboratory in 1979 working on the Vertical Launching System of the Aegis cruisers. Since that time he has participated in activities on the Phalanx program the SPS-48E radar and long term involvement with the Cruise Missile Program. On the Cruise Missile Program Mr. Neradka has focused on the specification of and testing related to environments. Simulation activities have included modeling of pneumatic systems and NASTRAN dynamic modeling. Mr. Neradka is a registered professional engineer.

This paper discusses the data that were recorded during a three-month accelerated humidity test of two Tomahawk all-up rounds (AURs), one pressurized with dry nitrogen in accordance with the current practice, and the other left unpressurized. Temperature and humidity were recorded inside the canisters and missiles. Data analysis consisted of psychrometric calculations to determine the moisture intrusion into these missiles during the test. The work was carried out in support of a technical effort directed at changing the storage and stowage environmental protection of the Tomahawk missile.

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