Relativistic Mean Field calculations of nuclear properties in early stages of stellar collapse

We use the Relativistic Mean Field (RMF) method to calculate properties of neutron rich, usually deformed nuclei, important for equation of state calculations and which have significant abundance in the early stages of stellar collapse. We compare the results of our microscopic calculations with existing cold nuclear equations of state based on macroscopic liquid drop model and the FRLDM model.Comment: 4 pages , Latex, 4 figures, uses espcrc1.sty. To appear in Nucl. Phys. A, proceedings of "Nuclei in the Cosmos 1996" 4th International Symposium on Nuclear Astrophysics. e-mail contact: [email protected]

The determinants of new firm formation dynamics

Explaining uneven economic growth and development within a country or a state or even within a metropolitan area has drawn attention of many scholars as well as public officials around the world. Most of the theories proposed so far have not been able to explain clearly the processes that underlie economic development and growth, making them unsuitable for policy actions. Regional planners and government officials are more interested in identifying factors that drive economic growth and development at the local or regional level. This paper explores regional factors as determinants of new firm formations (hereafter, NF2) that are central to the phenomenon of economic growth and development. Specifically, it explores regional factors as determinants of NF2 for the Texas manufacturing sector for the 1976-91 period. All twenty-seven (27) Texas metropolitan areas have been used to account for the variation in NF2 over time and space. The results are of practical importance to policy makers, economists, and would be entrepreneurs alike. In the absence of specific theories of new firm formations, this study draws on neoclassical theory as well as ideas of Adam Smith, Alfred Marshall, and Joseph Schumpeter. A historical evaluation of entrepreneurs and associated entrepreneurial innovations is carried out to better understand the role of entrepreneurship in influencing economic development and growth in the present context. Empirical studies of new firm formations, though mostly from European countries, have been reviewed to get a first hand look at current status of research in the area. The problem of appropriate data with which one can measure the key processes undergirding economic dynamism and change is explained in detail. In this context, relative superiority of the data set used in this study to the data sets used in most of the previous empirical studies is explained in greater depth. Using Hicks' micro-level data on establishment entries and exits, this study develops pooled time-series data on entries and exits of firms collected over a period of 16 years (1976-91) using sales tax files for the manufacturing sector. The issues of: (1) the treatment of missing data, (2) the selection of referents for regional and time dummy variables, and (3) violations and remedies of OLS assumptions (heteroscedasticity, multicollinearity, and serial correlation) are addressed to maximize the reliability of regression models developed for further analysis. Fixed-effects regression models with region and time as dummy variables have been formulated to control for region-specific and time-specific influences, respectively. The fixed-effects models are estimated using two different regression estimation techniques, robust regression and estimated weighted least squares. Time-series analyses is employed to test for ten hypotheses proposed, one for each variable included in the model. All regression results are found to be consistent with their respective hypothesis. Robust regression model results indicated a positive and independent influence of mean establishment size, entry rate, exit rate, and per capita bank deposits on NF2; whereas change in unemployment rate indicated a negative influence on NF2. The empirical findings provide strong support for the role of deep churning - turnover and replacement in a business base - in understanding the forces shaping economic development and growth. Moreover, the findings provide a counterpoint to neoclassical theory by suggesting a symbiotic, rather than an adversarial, relationship between small and large firms.

X-ray and radio prompt emission from a hypernova SN 2002ap

Here we report on combined X-ray and radio observations of SN 2002ap with XMM-Newton ToO observation and GMRT observations aided with VLA published results. In deriving the X-ray flux of SN 2002ap we account for the contribution of a nearby source, found to be present in the pre-SN explosion images obtained with Chandra observatory. We also derive upper limits on mass loss rate from X-ray and radio data. We suggest that the prompt X-ray emission is non-thermal in nature and its is due to the repeated compton boosting of optical photons. We also compare SN's early radiospheric properties with two other SNe at the same epoch.Comment: 4 pages, 5 figures. Uses espcrc2.sty. To appear in proceedings of symposium on X-ray astronomy "The Restless High-Energy Universe", May 2003, Amsterdam, The Netherlands, eds. E.P.J. van den Heuvel, J.J.M. in 't Zand, and R.A.M.J. Wijer

Classifying malicious windows executables using anomaly based detection

A malicious executable is broadly defined as any program or piece of code designed to cause damage to a system or the information it contains, or to prevent the system from being used in a normal manner. A generic term used to describe any kind of malicious software is Maiware, which includes Viruses, Worms, Trojans, Backdoors, Root-kits, Spyware and Exploits. Anomaly detection is technique which builds a statistical profile of the normal and malicious data and classifies unseen data based on these two profiles. A detection system is presented here which is anomaly based and focuses on the Windows® platform. Several file infection techniques were studied to understand what particular features in the executable binary are more susceptible to being used for the malicious code propagation. A framework is presented for collecting data for both static (non-execution based) as well as dynamic (execution based) analysis of the malicious executables. Two specific features are extracted using static analysis, Windows API (from the Import Address Table of the Portable Executable Header) and the hex byte frequency count (collected using Hexdump utility) which have been explained in detail. Dynamic analysis features which were extracted are briefly mentioned and the major challenges faced using this data is explained. Classification results using Support Vector Machines for anomaly detection is shown for the two static analysis features. Experimental results have provided classification results with up to 94% accuracy for new, previously unseen executables

“Safe and Sound” – An Accelerated Bridge Improvement Program in Missouri – A Case Study

Predicted increases in the number of trucks and axle loads on the roads will continue to degrade the roads more rapidly. Deterioration of the bridges is expected, but it can be monitored and controlled through properly funded maintenance, rehabilitation, and replacement activities. Proper funding and a continued focus on bridges, such as the Missouri Department of Transportation’s (MoDOT) Safe and Sound Bridge Improvement Program, is necessary to decrease the number of structurally deficient and functionally obsolete bridges in the country. The innovative approach developed by KTU Constructors, a joint venture of Kiewit Western (a subsidiary of Kiewit Corporation), Traylor Brothers and United Contractors, along with HNTB Corporation and The LPA Group as design consultants provided MoDOT with a way to replace 554 of Missouri’s ailing bridges at an accelerated pace. The complexity resulted from 554 scattered bridge sites in ten different MoDOT districts (then existing) with distinct hydraulic, geotechnical and environmental characteristics required advanced planning, streamlined design and plan production process and strategic construction timelines. An average of 45 days is allotted per bridge for reconstruction including demolition of the existing bridge. In order to meet this aggressive design and construction schedule, the project team developed the following approach: - Early evaluation of all 554 bridges - Standardization of proposed bridge spans, widths and skews - Incorporation of various designs and details used by other State Department of Transportation that would help accelerate design and construction process - Minimization of construction duration through the utilization of concrete precast components for superstructure and pile bents for substructure - Standardization of the superstructure and substructure design and detailing processes - Development and utilization of standard plan sheets. As the first successful program of its kind in the United States, the Safe and Sound Bridge Improvement Program now serves as a model for alternative project delivery. Many states are watching the outcome of the program and considering its applicability in their own states. MoDOT has proven with this unique design-build program that it is possible to accomplish a statewide logistics project under extreme budget limitations and time constraints