36,657 research outputs found
The NASA/Baltimore Applications Project (BAP). Computer aided dispatch and communications system for the Baltimore Fire Department: A case study of urban technology application
An engineer and a computer expert from Goddard Space Flight Center were assigned to provide technical assistance in the design and installation of a computer assisted system for dispatching and communicating with fire department personnel and equipment in Baltimore City. Primary contributions were in decision making and management processes. The project is analyzed from four perspectives: (1) fire service; (2) technology transfer; (3) public administration; and (5) innovation. The city benefitted substantially from the approach and competence of the NASA personnel. Given the proper conditions, there are distinct advantages in having a nearby Federal laboratory provide assistance to a city on a continuing basis, as is done in the Baltimore Applications Project
Capillary wave dynamics on supported viscoelastic films: Single and double layers
We study the capillary wave dynamics of a single viscoelastic supported film
and of a double layer of immiscible viscoelastic supported films. Using both
simple scaling arguments and a continuum hydrodynamic theory, we investigate
the effects of viscoelasticity and interfacial slip on the relaxation dynamics
of these capillary waves. Our results account for the recent observation of a
wavelength-independent decay rate for capillary waves in a supported
polystyrene/brominated polystyrene double layer [X. Hu {\em et al.}, Phys. Rev.
E {\bf 74}, 010602 (R) (2006)].Comment: 14 pages, 9 figure
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Lessons learned from an application of static concurrency analysis
Horizon Report 2009
El informe anual Horizon investiga, identifica y clasifica las tecnologÃas emergentes que los expertos que lo elaboran prevén tendrán un impacto en la enseñanza aprendizaje, la investigación y la producción creativa en el contexto educativo de la enseñanza superior. También estudia las tendencias clave que permiten prever el uso que se hará de las mismas y los retos que ellos suponen para las aulas. Cada edición identifica seis tecnologÃas o prácticas. Dos cuyo uso se prevé emergerá en un futuro inmediato (un año o menos) dos que emergerán a medio plazo (en dos o tres años) y dos previstas a más largo plazo (5 años)
A survey of manufacturers of solar thermal energy systems
Sixty-seven firms that had received funding for development of solar thermal energy systems (STES) were surveyed. The effect of the solar thermal technology systems program in accelerating (STES) were assessed. The 54 firms still developing STES were grouped into a production typology comparing the three major technologies with three basic functions. It was discovered that large and small firms were developing primarily central receiver systems, but also typically worked on more than one technology. Most medium-sized firms worked only on distributed systems. Federal support of STES was perceived as necessary to allow producers to take otherwise unacceptable risks. Approximately half of the respondents would drop out of STES if support were terminated, including a disproportionate number of medium-sized firms. A differentiated view of the technology, taking into account differing firm sizes and the various stages of technology development, was suggested for policy and planning purposes
Internationalization and the Evolution of Corporate Valuation
By documenting the evolution of Tobin's "q" before, during, and after firms internationalize, this paper provides evidence on the bonding, segmentation, and market timing theories of internationalization. Using new data on 9,096 firms across 74 countries over the period 1989-2000, we find that Tobin's "q" does not rise after internationalization, even relative to firms that do not internationalize. Instead, "q" rises significantly one year before internationalization and during the internationalization year. But, then "q" falls sharply in the year after internationalization, relinquishing the increases of the previous two years. To account for these dynamics, we show that market capitalization rises one year before internationalization and remains high, while corporate assets increase during internationalization. The evidence supports models stressing that internationalization facilitates corporate expansion, but challenges models stressing that internationalization produces an enduring effect on "q" by bonding firms to a better corporate governance system.
Migration, spillovers, and trade diversion : the impact of internationalization on stock market liquidity
What is the impact of firms that cross-list, issue depositary receipts, or raise capital in international stock markets on the liquidity of remaining firms in domestic markets? Using a panel of over 3,200 firms from 55 countries during 1989-2000, Levine and Schmukler find that internationalization reduces the liquidity of domestic firms through two channels. First, the trading of international firms migrates from domestic to international markets and the reduction in domestic liquidity of international firms has negative spillover effects on domestic firm liquidity. Second, there is trade diversion within domestic markets as liquidity shifts out of domestic firms and into international firms.Small and Medium Size Enterprises,Payment Systems&Infrastructure,Microfinance,Economic Theory&Research,Small Scale Enterprise,Economic Theory&Research,Financial Intermediation,Microfinance,Private Participation in Infrastructure,Small Scale Enterprise
The influence of ground conductivity on the structure of RF radiation from return strokes
The combination of the finite conductivity of the Earth plus the propagation of the return stroke current up the channel which results in an apparent time delay between the fast field changes and RF radiation for distant observers is shown. The time delay predicted from model return strokes is on the order of 20 micro and the received signal has the characteristics of the data observed in Virginia and Florida. A piecewise linear model for the return stroke channel and a transmission line model for current propagation on each segment was used. Radiation from each segment is calculated over a flat Earth with finite conductivity using asymptotics approximations for the Sommerfeld integrals. The radiation at the observer is processed by a model AM radio receiver. The output voltage was calculated for several frequencies between HF-UHF assuming a system bandwidth (300 kHz) characteristic of the system used to collect data in Florida and Virginia. Comparison with the theoretical fast field changes indicates a time delay of 20 microns
<a comparative study of the evolution of enzymes and nucleic acids< semi-annual status report, nov. 1, 1964 - apr. 30, 1965
Lactic dehydrogenases and protein immunochemicals in vertebrate evolution - irradiation of nucleic acid
Feeding IC 342: The nuclear spiral of a starburst galaxy
IC 342 is a large nearby (1.8 Mpc, Turner and Hurt, 1991, hereafter T&H) spiral galaxy undergoing a moderate nuclear starburst. T&H have previously mapped the inner arcminute in CO-13(1-0) using the Owens Valley Millimeter Interferometer and found evidence that the nuclear molecular gas takes the form of spiral arms in a density wave pattern. They suggest that radial streaming along the arms may channel gas from the exterior of the galaxy into the nucleus, feeding the starburst. We have mapped the CO-12(1-0) emission of the inner 2 kpc of IC 342 at 2.8 inch resolution using the Owens Valley Radio Observatory (OVRO) Millimeter Interferometer. The greater sensitivity of CO-12 observations has allowed us to trace the spiral pattern out to a total extent of greater than 1 kpc. The CO-12 observations extend considerably the structure observed at CO-13 and offer further evidence that a spiral density wave may extend from the disk into the nucleus of IC 342
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