System locates randomly placed remote objects

System to locate objects submerged underwater uses active/passive sonar techniques in which a transmitter is attached to the object to be recovered and a receiver is used for search. The system is rugged, has a long term operating life, and furnishes a precise bearing on the object

The relevance of information systems (IS) research publications to IS practitioners\u27 key concerns

The primary aim of the research was to determine if, and if so how, the topics published in information systems (IS) journal articles were related to the key issues reported to be of concern to IS managers. The secondary aim was to determine what proportions of the journal articles were investigating closely-related and distantly-related information, , - technology (IT) phenomena. The research covered 1376 -articles published in nine highly rated journals for the seven-year period 1995-2001. The journals chosen for the research included five US-academic journals, two European academic journals, and two practitioner journals. -\u27The\u27 primary data source for the managers\u27 key issue data was the ‘Top IS Management Issues\u27 survey responses presented in the Computer Sciences Corporation Surveys over the period 1995 to 2001. An IS topic classification scheme (taxonomy) was developed and each article abstract• was examined and allocated between one and three topic classification codes. An analysis of the level of coverage the journal articles provided for the taxonomy topics was then produced. The three most frequently occurring topics were group decision support system\u27(GDSS) research, MIS research methods and approaches, and systems evaluation. Over 20% of all the articles covered one of these three topics. The analysis also identified a number of specific taxonomy topics that had not been covered or only _very poorly covered. These included IT Strategy Formulation ,& Building a Responsive . , IT Infrastructure, Component-based Development (CBD)\u27,Systems Security, System Maintenance & Migration Processes, and Wireless & Mobile Computing. An \u27IT-relatedness\u27 classification ,scheme (the \u27IS conceptual net\u27) was then developed. The analysis of the journal articles\u27 coverage of the components of the net revealed that only about a quarter of the articles addressed topics that were directly related to an IT artefact or its first-order antecedents/effects. The taxonomy nodes and journal articles were then mapped to their related management issues. The subsequent analysis revealed that just over half of the journal articles were related to one or more of the (twenty-five) management issues. Some issues were, very well covered by the journal articles and some were very poorly, covered. The two best covered issues were each covered by more than 10% of the articles whereas the eight .\u27. , worst covered issues were each covered by less than 1%. Less than half of the US - academic journal articles were issue-related whereas over two thirds of the European and three-quarters of the practitioner journal articles were issue-related. An analysis of the relationships between the annual rank orders of the management issues and the issue-related article coverage levels was carried out. The analysis revealed that the management issue rankings could not generally be used as direct (Dr lead) indicators of the number of IS research articles (to be) published on related topics. Similarly, there was evidence that IS research publications were general lead indicators of management issues. However, three, out of the twenty-five issues, did appear to show some evidence of a direct relationship. Included in the final chapter is a discussion on the significance of the research and an outline of some of the scope limitations of the research. The final chapter also identifies three groups of further research questions that arise from these scope limitations

WFPC2 Observations of Star Clusters in the Magellanic Clouds: I. The LMC Globular Cluster Hodge 11

We present our analysis of Hubble Space Telescope Wide Field Planetary Camera 2 observations in F555W (broadband V) and F450W (broadband B) of the globular cluster Hodge 11 in the Large Magellanic Cloud galaxy. The resulting V vs. (B-V) color-magnitude diagram reaches 2.4 mag below the main-sequence turnoff (which is at V_TO = 22.65 +- 0.10 mag or M_V^TO = 4.00 +- 0.16 mag). Comparing the fiducial sequence of Hodge 11 with that of the Galactic globular cluster M92, we conclude that, within the accuracy of our photometry, the age of Hodge 11 is identical to that of M92 with a relative age-difference uncertainty ranging from 10% to 21%. Provided that Hodge 11 has always been a part of the Large Magellanic Cloud and was not stripped from the halo of the Milky Way or absorbed from a cannibalized dwarf spheroidal galaxy, then the oldest stars in the Large Magellanic Clouds and the Milky Way appear to have the same age.Comment: 14 pages (LaTeX+aaspp4.sty), 3 tables and 4 figures (Postscript, gzipped tar file). Postscript version of paper, tables, and full-resolution figures available at http://www.astro.columbia.edu/~mighell/hodge11.html To appear in the Astronomical Journa

Disruption of Star Clusters in the Interacting Antennae Galaxies

We reexamine the age distribution of star clusters in the Antennae in the context of N-body+hydrodynamical simulations of these interacting galaxies. All of the simulations that account for the observed morphology and other properties of the Antennae have star formation rates that vary relatively slowly with time, by factors of only 1.3 - 2.5 in the past 10^8 yr. In contrast, the observed age distribution of the clusters declines approximately as a power law, dN/dt \propto t^{gamma} with gamma = -1.0, for ages 10^6 yr \la t \la 10^9 yr. These two facts can only be reconciled if the clusters are disrupted progressively for at least 10^8 yr and possibly 10^9 yr. When we combine the simulated formation rates with a power-law model, f_surv \propto t^{delta}, for the fraction of clusters that survive to each age t, we match the observed age distribution with exponents in the range -0.9 \la delta \la -0.6 (with a slightly different delta for each simulation). The similarity between delta and gamma indicates that dN/dt is shaped mainly by the disruption of clusters rather than variations in their formation rate. Thus, the situation in the interacting Antennae resembles that in relatively quiescent galaxies such as the Milky Way and the Magellanic Clouds.Comment: 9 pages, 5 figures, 1 table, accepted for publication in the Astrophysical Journal, including revisions after referee repor

Yield stress and shear-banding in granular suspensions

We study the emergence of a yield stress in dense suspensions of non-Brownian particles, by combining local velocity and concentration measurements using Magnetic Resonance Imaging with macroscopic rheometric experiments. We show that the competition between gravity and viscous stresses is at the origin of the development of a yield stress in these systems at relatively low volume fractions. Moreover, it is accompanied by a shear banding phenomenon that is the signature of this competition. However, if the system is carefully density matched, no yield stress is encountered until a volume fraction of 62.7 0.3%

Risk of prostate cancer in a population-based cohort of men with coeliac disease

Background: Prostate cancer (PC) is a leading cause of fatal cancer in men in developed countries. Coeliac disease (CD) has previously been linked to a raised cancer risk, and changes in some exposures following a CD diagnosis might hypothetically raise PC risk. Methods: We identified 10 995 patients with CD who had undergone a small intestinal biopsy in 1969–2007. Statistics Sweden then identified 54 233 age-matched male reference individuals from the general population. PC data were obtained from the Swedish Cancer Register. Hazard ratios (HRs) for PC were estimated using Cox regression analysis. Results: During follow-up, 185 individuals with CD (expected n=200) had an incident diagnosis of PC. This corresponds to a HR of 0.92 (0.79–1.08) (with 95% confidence interval) and an absolute risk reduction of 15/100 000 person-years among those with CD. An increased risk was not observed even when identification of PC began 5 years after biopsy. Conclusion: Our conclusion is that a CD diagnosis does not represent an increased risk for PC