ICT Use in the Developing World: An Analysis of Differences in Computer and Internet Penetration

Computer and Internet use, especially in developing countries, has expanded rapidly in recent years. Even in light of this expansion in technology adoption rates, penetration rates differ markedly between developed and developing countries and across developing countries. To identify the determinants of cross-country disparities in personal computer and Internet penetration, both currently and over time, we examine panel data for 161 countries over the 1999-2004 period. We explore the role of a comprehensive set of economic, demographic, infrastructure, institutional and financial factors in contributing to the global digital divide. We find evidence indicating that income, human capital, the youth dependency ratio, telephone density, legal quality and banking sector development are associated with technology penetration rates. Overall, the factors associated with computer and Internet penetration do not differ substantially between developed and developing countries. Estimates from Blinder-Oaxaca decompositions reveal that the main factors responsible for low rates of technology penetration rates in developing countries are disparities in income, telephone density, legal quality and human capital. In terms of dynamics, our results indicate fairly rapid reversion to long run equilibrium for Internet use, and somewhat slower reversion for computer use, particularly in developed economies. Financial development, either measured as bank lending or the value of stocks traded, is also important to the growth rate of Internet use.

The Determinants of the Global Digital Divide A Cross-Country Analysis of Computer and Internet Penetration

To identify the determinants of cross-country disparities in personal computer and Internet penetration, we examine a panel of 161 countries over the 1999-2001 period. Our candidate variables include economic variables (income per capita, years of schooling, illiteracy, trade openness), demographic variables (youth and aged dependency ratios, urbanization rate), infrastructure indicators (telephone density, electricity consumption), telecommunications pricing measures, and regulatory quality. With the exception of trade openness and the telecom pricing measures, these variables enter in as statistically significant in most specifications for computer use. A similar pattern holds true for Internet use, except that telephone density and aged dependency matter less. The global digital divide is mainly -– but by no means entirely -– accounted for by income differentials. For computers, telephone density and regulatory quality are of second and third importance, while for the Internet, this ordering is reversed. The region-specific explanations for large disparities in computer and Internet penetration are generally very similar. Our results suggest that public investment in human capital, telecommunications infrastructure, and the regulatory infrastructure can mitigate the gap in PC and Internet use.Computers, Internet, Digital Divide, Infrastructure, Pricing, Regulation

The Determinants of the Global Digital Divide: A Cross-Country Analysis of Computer and Internet Penetration

To identify the determinants of cross-country disparities in personal computer and Internet penetration, we examine a panel of 161 countries over the 1999-2001 period. Our candidate variables include economic variables (income per capita, years of schooling, illiteracy, trade openness), demographic variables (youth and aged dependency ratios, urbanization rate), infrastructure indicators (telephone density, electricity consumption), telecommunications pricing measures, and regulatory quality. With the exception of trade openness and the telecom pricing measures, these variables enter in as statistically significant in most specifications for computer use. A similar pattern holds true for Internet use, except that telephone density and aged dependency matter less. The global digital divide is mainly – but by no means entirely – accounted for by income differentials. For computers, telephone density and regulatory quality are of second and third importance, while for the Internet, this ordering is reversed. The regionspecific explanations for large disparities in computer and Internet penetration are generally very similar. Our results suggest that public investment in human capital, telecommunications infrastructure, and the regulatory infrastructure can mitigate the gap in PC and Internet use

The Role of Final State Interactions in Quasielastic 56^{56}Fe(e,e′)(e,e') Reactions at large ∣q⃗∣|\vec q|

A relativistic finite nucleus calculation using a Dirac optical potential is used to investigate the importance of final state interactions [FSI] at large momentum transfers in inclusive quasielastic electronuclear reactions. The optical potential is derived from first-order multiple scattering theory and then is used to calculate the FSI in a nonspectral Green's function doorway approach. At intermediate momentum transfers excellent predictions of the quasielastic $^{56}$Fe$(e,e')$ experimental data for the longitudinal response function are obtained. In comparisons with recent measurements at $|{\vec q|}=1.14$~GeV/c the theoretical calculations of $R_L$ give good agreement for the quasielastic peak shape and amplitude, but place the position of the peak at an energy transfer of about $40$~MeV higher than the data.Comment: 13 pages typeset using revtex 3.0 with 6 postscript figures in accompanying uuencoded file; submitted to Phys. Rev.

Archaean and Proterozoic diamond growth from contrasting styles of large-scale magmatism

Precise dating of diamond growth is required to understand the interior workings of the early Earth and the deep carbon cycle. Here we report Sm-Nd isotope data from 26 individual garnet inclusions from 26 harzburgitic diamonds from Venetia, South Africa. Garnet inclusions and host diamonds comprise two compositional suites formed under markedly different conditions and define two isochrons, one Archaean (2.95 Ga) and one Proterozoic (1.15 Ga). The Archaean diamond suite formed from relatively cool fluid-dominated metasomatism during rifting of the southern shelf of the Zimbabwe Craton. The 1.8 billion years younger Proterozoic diamond suite formed by melt-dominated metasomatism related to the 1.1 Ga Umkondo Large Igneous Province. The results demonstrate that resolving the time of diamond growth events requires dating of individual inclusions, and that there was a major change in the magmatic processes responsible for harzburgitic diamond formation beneath Venetia from the Archaean to the Proterozoic

Conservation and biology of the rediscovered nationally endangered Canterbury knobbled weevil, Hadramphus tuberculatus

Three areas near Burkes Pass Scenic Reserve were surveyed for the presence of Hadramphus tuberculatus, a recently rediscovered endangered weevil. The reserve itself was resurveyed to expand on a 2005/2006 survey. Non-lethal pitfall traps and mark and recapture methods were used. Six H. tuberculatus were caught in pitfall traps over 800 trap nights. Day and night searching of Aciphylla aurea was conducted. Four specimens were observed on Aciphylla flowers between 9 am and 1.30 pm within the reserve. No specimens were found outside of the reserve by either method. Other possible locations where H. tuberculatus may be found were identified and some visited. At most locations Aciphylla had already finished flowering, no H. tuberculatus were found. Presence of H. tuberculatus at other sites would be best determined by searching of Aciphylla flowers during the morning from late October onwards

Full-Folding Optical Potentials for Elastic Nucleon-Nucleus Scattering based on Realistic Densities

Optical model potentials for elastic nucleon nucleus scattering are calculated for a number of target nuclides from a full-folding integral of two different realistic target density matrices together with full off-shell nucleon-nucleon t-matrices derived from two different Bonn meson exchange models. Elastic proton and neutron scattering observables calculated from these full-folding optical potentials are compared to those obtained from `optimum factorized' approximations in the energy regime between 65 and 400 MeV projectile energy. The optimum factorized form is found to provide a good approximation to elastic scattering observables obtained from the full-folding optical potentials, although the potentials differ somewhat in the structure of their nonlocality.Comment: 21 pages, LaTeX, 17 postscript figure

How do UK-based foreign exchange dealers think their market operates?

This paper summarises the results of a survey of UK based foreign exchange dealers conducted in 1998. It addresses topics in three main areas: The microeconomic operation of the foreign exchange market; the beliefs of dealers regarding the importance, or otherwise, of macroeconomic fundamental factors in affecting exchange rates; microstructure factors in FX. We find that heterogeneity of traders’ beliefs is evident from the results but that it is not possible to explain such disagreements in terms of institutional detail, rank or trading technique (e.g. technical analysts versus fundamentalists). As expected, nonfundamental factors are thought to dominate short horizon changes in exchange rates, but fundamentals are deemed important over much shorter horizons that the mainstream empirical literature would suggest. Finally, market ‘norms’ and behavioural phenomena are very strong in the FX market and appear to be key determinants of the bid-ask spread

Ultra-broadband wavelength-swept Tm-doped fiber laser using wavelength-combined gain stages

A wavelength-swept thulium-doped fiber laser system employing two parallel cavities with two different fiber gain stages is reported. The fiber gain stages were tailored to provide emission in complementary bands with external wavelength-dependent feedback cavities sharing a common rotating polygon mirror for wavelength scanning. The wavelength-swept laser outputs from the fiber gain elements were spectrally combined by means of a dichroic mirror and yielded over 500 mW of output with a scanning range from ~1740 nm to ~2070 nm for a scanning frequency of ~340 Hz

Irrigation demand model

Presented at the 2002 USCID/EWRI conference, Energy, climate, environment and water - issues and opportunities for irrigation and drainage on July 9-12 in San Luis Obispo, California.Includes bibliographical references.Like many jurisdictions in North America, the irrigation industry in Alberta, Canada has found it necessary to intensively examine its future state of development, in view of substantially increased competition for a finite supply of available water. In order to do so, it was recognized that available technical science and assessment tools needed to be up-dated and expanded. Specifically, the opportunity and ability to utilize state-of-the-art computer modelling techniques could allow much more detailed and varied analyses to be carried out. As part of a broad scope basin water management planning review, the development of a complex irrigation demand model was undertaken. After several years of detailed and intensive software development, a suite of data input, irrigation simulation and analysis tools has been derived. The application of the irrigation demand model component provides for very detailed projections of daily water requirements, consumptive use, conveyance and application losses, as well as return flows. Annual and multi-year irrigation demands can be determined in conjunction with water supply conditions that reflect both the interrelationship with the vagaries of climate as well as varying scenarios of development within the industry. In particular, output from the application of the whole suite of tools indicates both the projected level of water supply deficits as well as the potential impacts of those shortages