Developing efficient web-based GIS applications

There is an increase in the number of web-based GIS applications over the recent years. This paper describes different mapping technologies, database standards, and web application development standards that are relevant to the development of web-based GIS applications. Different mapping technologies for displaying geo-referenced data are available and can be used in different situations. This paper also explains why Oracle is the system of choice for geospatial applications that need to handle large amounts of data. Wireframing and design patterns have been shown to be useful in making GIS web applications efficient, scalable and usable, and should be an important part of every web-based GIS application. A range of different development technologies are available, and their use in different operating environments has been discussed here in some detail

A statistical model for the intrinsically broad superconducting to normal transition in quasi-two-dimensional crystalline organic metals

Although quasi-two-dimensional organic superconductors such as $\kappa$-(BEDT-TTF)$_2$Cu(NCS)$_2$ seem to be very clean systems, with apparent quasiparticle mean-free paths of several thousand \AA, the superconducting transition is intrinsically broad (e.g $\sim 1$ K wide for $T_c \approx 10$ K). We propose that this is due to the extreme anisotropy of these materials, which greatly exacerbates the statistical effects of spatial variations in the potential experienced by the quasiparticles. Using a statistical model, we are able to account for the experimental observations. A parameter $\bar{x}$, which characterises the spatial potential variations, may be derived from Shubnikov-de Haas oscillation experiments. Using this value, we are able to predict a transition width which is in good agreement with that observed in MHz penetration-depth measurements on the same sample.Comment: 8 pages, 2 figures, submitted to J. Phys. Condens. Matte

Collaborative Mapping of London Using Google Maps: The LondonProfiler

This paper begins by reviewing the ways in which the innovation of Google Maps has transformed our ability to reference and view geographically referenced data. We describe the ways in which the GMap Creator tool developed under the ESRC National Centre for E Social Science programme enables users to ‘mashup’ thematic choropleth maps using the Google API. We illustrate the application of GMap Creator using the example of www.londonprofiler.org, which makes it possible to view a range of health, education and other socioeconomic datasets against a backcloth of Google Maps data. Our conclusions address the ways in which Google Map mashups developed using GMap Creator facilitate online exploratory cartographic visualisation in a range of areas of policy concern

Practice Factors which Influence Quality of Life for Chronically mentally Ill African Americans

The University Archives has determined that this item is of continuing value to OSU's history.Singleton, Sharron M., D.S.W., Howard University - "Practice Factors which Influence Quality of Life for Chronically Mentally Ill African Americans".The Ohio State University College of Social Wor

Neotectonics in San Diego, California: Paleoseismology, Slip Rate, and Offshore Structure of the Rose Canyon Fault

The Newport-Inglewood-Rose Canyon (NIRC) fault system is a major structural boundary that extends along coastal southern California from Los Angeles to San Diego. The material presented in this thesis provides new data that resolve uncertainties in fault behavior for the southern segment, the Rose Canyon fault (RCF). Stratigraphic evidence from newly opened paleoseismic trenches are used to interpret six surface-rupturing earthquakes on the RCF in the past 3,300 years. Paleoearthquake ages constrained by radiocarbon dating suggest a late-Holocene recurrence interval of ~700 years, with the most recent large-magnitude event occurring in the mid-1700s. When combined with previous paleoseismic studies, the new paleoearthquake ages show an apparent temporal correlation of earthquake occurrence between the southern and northern segments of the NIRC fault system, suggesting a possible northward-cascading sequence of earthquakes.The RCF includes a significant onshore segment, which provides an opportunity to use traditional geodetic techniques to resolve slip rate. Surface velocities from a combined campaign and continuous GPS network that spans the RCF are used to constrain elastic half-space models. The best-fitting model suggests a rate that is toward the higher end of geologic estimates, as well as a potential rheological contrast across the fault trace. The GPS surface velocities further suggest a more easterly trace for the RCF, and a possible connection with the San Miguel-Vallecitos fault system. South of downtown San Diego, the RCF splays out into a complex network of faults that accommodate the subsidence beneath San Diego Bay. Using legacy multi-channel seismic data and recently collected high-resolution chirp profiles, the fault structure and stratigraphic character beneath San Diego Bay is examined. Gridded surface horizons and fault maps show widespread down-to-the-east displacement. Fault orientations in the western portion of the San Diego Bay pull-apart basin are well described by a Rose Canyon–Descanso pull-apart basin, but faults in the eastern portion of the basin lie outside of this model and exhibit the wrong sense of displacement. A separate but related Rose Canyon–San Miguel-Vallecitos pull-apart basin may explain the faulting seen in the eastern portion of the basin

Analysis of dynamic stall using unsteady boundary-layer theory

The unsteady turbulent boundary layer and potential flow about a pitching airfoil are analyzed using numerical methods to determine the effect of pitch rate on the delay in forward movement of the rear flow reversal point. An explicit finite difference scheme is used to integrate the unsteady boundary layer equations, which are coupled at each instant of time to a fully unsteady and nonlinear potential flow analysis. A substantial delay in forward movement of the reversal point is demonstrated with increasing pitch rate, and it is shown that the delay results partly from the alleviation of the gradients in the potential flow, and partly from the effects of unsteadiness in the boundary layer itself. The predicted delay in flow-reversal onset, and its variation with pitch rate, are shown to be in reasonable agreement with experimental data relating to the delay in dynamic stall. From the comparisons it can be concluded (a) that the effects of time-dependence are sufficient to explain the failure of the boundary layer to separate during the dynamic overshoot, and (b) that there may be some link between forward movement of the reversal point and dynamic stall

Subtleties in the quasi-classical calculation of Hawking radiation

he quasi-classical method of deriving Hawking radiation is investigated. In order to recover the original Hawking temperature one must take into account a previously ignored contribution coming from the temporal part of the action. This contribution plus a contribution coming from the spatial part of the action gives the correct temperature.Comment: 6 pages revtex. Honorable Mention in 2008 GRF essay contest, typos fixed, sign errors corrected. To be published in Special Issue of IJMP

Hawking radiation, Unruh radiation and the equivalence principle

We compare the response function of an Unruh-DeWitt detector for different space-times and different vacua and show that there is a {\it detailed} violation of the equivalence principle. In particular comparing the response of an accelerating detector to a detector at rest in a Schwarzschild space-time we find that both detectors register thermal radiation, but for a given, equivalent acceleration the fixed detector in the Schwarzschild space-time measures a higher temperature. This allows one to locally distinguish the two cases. As one approaches the horizon the two temperatures have the same limit so that the equivalence principle is restored at the horizon.Comment: 9 pages. Added references and added discussion. To be published in PR

Opening of DNA double strands by helicases. Active versus passive opening

Helicase opening of double-stranded nucleic acids may be "active" (the helicase directly destabilizes the dsNA to promote opening) or "passive" (the helicase binds ssNA available due to a thermal fluctuation which opens part of the dsNA). We describe helicase opening of dsNA, based on helicases which bind single NA strands and move towards the double-stranded region, using a discrete ``hopping'' model. The interaction between the helicase and the junction where the double strand opens is characterized by an interaction potential. The form of the potential determines whether the opening is active or passive. We calculate the rate of passive opening for the helicase PcrA, and show that the rate increases when the opening is active. Finally, we examine how to choose the interaction potential to optimize the rate of strand separation. One important result is our finding that active opening can increase the unwinding rate by 7 fold compared to passive opening.Comment: 13 pages, 3 figure