142 research outputs found

    The Grace of Directing the Exercises

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    Subscriber churn in the Australian ISP market

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    Rapid growth in Internet use, combined with easy market entry by Internet service providers (ISPs), has resulted in a highly competitive supply of Internet services. Australian ISPs range in size from a few large national operators to niche ISPs focused on specialised service. With many ISPs currently not profitable, subscriber retention is an important aspect of survival. This study develops a model which relates the probability of subscriber churn to various service attributes and subscriber characteristics. Estimation results show that churn probability is positively associated with monthly ISP expenditure, but inversely related to household income. Pricing also matters with subscribers preferring ISPs which offer flat-rate pricing arrangements.

    Subscriber churn in the Australian ISP market

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    Rapid growth in Internet use, combined with easy market entry by Internet service providers (ISPs), has resulted in a highly competitive supply of Internet services. Australian ISPs range in size from a few large national operators to niche ISPs focused on specialised service. With many ISPs currently not profitable, subscriber retention is an important aspect of survival. This study develops a model which relates the probability of subscriber churn to various service attributes and subscriber characteristics. Estimation results show that churn probability is positively associated with monthly ISP expenditure, but inversely related to household income. Pricing also matters with subscribers preferring ISPs which offer flat-rate pricing arrangements.Internet; customer churn; pricing

    Advanced communications policy and adoption in rural Western Australia

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    Recent moves toward contestable universal service markets for rural areas raises issues of measuring the net cost of service provision. Measurement of net cost requires estimates of latent demand for advanced communications. This paper seeks for the first time to provide quantitative estimates of the magnitude of latent income pools available to carriers in rural WA. Estimates of latent expenditure on broadband services in rural WA are obtained using a combination of stated-preference and survey data. These expenditures increase with computer ownership, community isolation and information need. Further, the statistical model supports the commonly held belief that more distant populations have stronger information demands and are willing to pay for services. This finding suggests that carrier aversion to providing services to rural regions may not be justified on commercial grounds.Advanced communications; broadband service; internet rural access; universal service obligations

    NASA/USRA high altitude research aircraft. Gryphon: Soar like an eagle with the roar of a lion

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    At the equator, the ozone layer ranges from 65,000 to 130,000+ feet. This is beyond the capabilities of the ER-2, which is NASA's current high altitude reconnaissance aircraft. The Universities Space Research Association, in cooperation with NASA, is sponsoring an undergraduate program which is geared to designing an aircraft that can study the ozoned layer at the equator. This aircraft must be able to satisfy four mission profiles. Mission one is a polar mission which ranges from Chile to the South Pole and back to Chile, a total range of 6000 n. mi. at 100,000 feet with a 2500 lb. payload. The second mission is also a polar mission with a decreased altitude of 70,000 feet and an increased payload of 4000 lb. For the third mission, the aircraft will take-off at NASA Ames, cruise at 100,000 feet carrying a 2500 lb. payload, and land in Puerto Montt, Chile. The final mission requires the aircraft to take-off at NASA Ames, cruise at 100,000 feet with a 1000 lb. payload, make an excursion to 120,000 feet, and land at Howard AFB, Panama. All three missions require that a subsonic Mach number be maintained due to constraints imposed by the air sampling equipment. The aircraft need not be manned for all four missions. Three aircraft configurations were determined to be the most suitable for meeting the above requirements. The performance of each configuration is analyzed to investigate the feasibility of the project requirements. In the event that a requirement can not be obtained within the given constraints, recommendations for proposal modifications are given

    Subscriber churn in the Australian ISP market

    Get PDF
    Rapid growth in Internet use, combined with easy market entry by Internet service providers (ISPs), has resulted in a highly competitive supply of Internet services. Australian ISPs range in size from a few large national operators to niche ISPs focused on specialised service. With many ISPs currently not profitable, subscriber retention is an important aspect of survival. This study develops a model which relates the probability of subscriber churn to various service attributes and subscriber characteristics. Estimation results show that churn probability is positively associated with monthly ISP expenditure, but inversely related to household income. Pricing also matters with subscribers preferring ISPs which offer flat-rate pricing arrangements

    Subscriber churn in the Australian ISP market

    Get PDF
    Rapid growth in Internet use, combined with easy market entry by Internet service providers (ISPs), has resulted in a highly competitive supply of Internet services. Australian ISPs range in size from a few large national operators to niche ISPs focused on specialised service. With many ISPs currently not profitable, subscriber retention is an important aspect of survival. This study develops a model which relates the probability of subscriber churn to various service attributes and subscriber characteristics. Estimation results show that churn probability is positively associated with monthly ISP expenditure, but inversely related to household income. Pricing also matters with subscribers preferring ISPs which offer flat-rate pricing arrangements

    Advanced communications policy and adoption in rural Western Australia

    Get PDF
    Recent moves toward contestable universal service markets for rural areas raises issues of measuring the net cost of service provision. Measurement of net cost requires estimates of latent demand for advanced communications. This paper seeks for the first time to provide quantitative estimates of the magnitude of latent income pools available to carriers in rural WA. Estimates of latent expenditure on broadband services in rural WA are obtained using a combination of stated-preference and survey data. These expenditures increase with computer ownership, community isolation and information need. Further, the statistical model supports the commonly held belief that more distant populations have stronger information demands and are willing to pay for services. This finding suggests that carrier aversion to providing services to rural regions may not be justified on commercial grounds

    Observations of the Cosmic Microwave Background and Implications for Cosmology and Large Scale Structure

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    Observations of the Cosmic Microwave Background (CMB) are discussed, with particular emphasis on current ground-based experiments and on future satellite, balloon and interferometer experiments. Observational techniques and the effects of contaminating foregrounds are highlighted. Recent CMB data is used with large scale structure (LSS) data to constrain cosmological parameters and the complementary nature of CMB, LSS and supernova distance data is emphasized.Comment: 23 pages, 10 figures. Phil. Trans. R. Soc. Lond. A., 1998, in pres

    The phylogeny of the four pan-American MtDNA haplogroups: Implications for evolutionary and disease studies

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    Only a limited number of complete mitochondrial genome sequences belonging to Native American haplogroups were available until recently, which left America as the continent with the least of information about sequence variation of entire mitochondrial DNAs. In this study, a comprehensive overview of all available complete mitochondrial DNA (mtDNA) genomes of the four pan-American haplogroups A2, B2, C1, and D1 is provided by revising the information scattered throughout GenBank and the literature, and adding 14 novel mtDNA sequences. The phylogenies of haplogroups A2, B2, C1, and D1 reveal a large number of sub haplogroups but suggest that the ancestral Beringian population(s) contributed only six (successful) founder haplotypes to these haplogroups. The derived are overall starlike with coalescence times ranging from 18,000 to 21,000 years (with one exception) using the conventional calibration. The average of about 19,000 years somewhat contrast with the corresponding lower age of about 13,500 years that was recently proposed by employing a different calibration and estimation approach. Our estimate indicates a human entry and spread of the pan-American haplogroups into the Americas right after the peak of the Last Glacial Maximum and comfortably agrees with the undisputed ages of the earliest Paleoindians in South America. In addition, the phylogenetic approach also indicates that the pathogenic status proposed for various mtDNA mutations, which actually define branches of Native American haplogroups, was based on insufficient grounds.Instituto Multidisciplinario de Biología CelularFacultad de Ciencias Naturales y Muse
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