Location and product bundling in the provision of WiFi networks

WiFi promises to revolutionise how and where we access the internet. As WiFi networks are rolled out around the globe, access to the internet will no longer be through fixed networks or unsatisfactory mobile phone connections. Instead access will be through low cost wireless networks at speeds of up to 11Mbps. It is hard not to be impressed by the enthusiasm with which WiFi has been embraced. GREEN, ROSENBUSH, CROKETT and HOLMES (2003) assert that WiFi is a disruptive technology akin to telephones in the 1920s and network computers in the 1990s. WiFi is seen as both an opportunity in its own right, as well as an enabler of opportunities for others. Computer manufacturers are hoping that WiFi will increases sales of their laptops, whilst Microsoft feels that WiFi will result in users upgrading their operating systems to Windows XP. This paper seeks to understand why three companies have sought to provide WiFi

The impact of mobile telephony on developing country micro-enterprises: a Nigerian case study

Informational challenges-absence, uncertainty, asymmetry-shape the working of markets and commerce in many developing countries. For developing country micro-enterprises, which form the bulk of all enterprises worldwide, these challenges shape the characteristics of their supply chains. They reduce the chances that business and trade will emerge. They keep supply chains localised and intermediated. They make trade within those supply chains slow, costly, and risky. Mobile telephony may provide an opportunity to address the informational challenges and, hence, to alter the characteristics of trade within micro-enterprise supply chains. However, mobile telephony has only recently penetrated. This paper, therefore, presents one of the first case studies of the impact of mobile telephony on the numerically-dominant form of enterprise, based around a case study of the cloth-weaving sector in Nigeria. It finds that there are ways in which costs and risks are being reduced and time is saved, often by substitution of journeys. But it also finds a continuing need for journeys and physical meetings due to issues of trust, design intensity, physical inspection and exchange, and interaction complexity. As a result, there are few signs of the de-localisation or disintermediation predicted by some commentators. An economising effect of mobile phones on supply chain processes may therefore co-exist with the entrenchment of supply chain structures and a growing 'competitive divide' between those with and without access to telephony

Static and Dynamic Resource Allocation Effects of Corporate and PersonalTax Integration in the U.S.: A General Equilibrium Approach(Rev)

This paper presents estimates of static and dynamic general equilibrium resource allocation effects for four alternative plans for corporate and personal income tax integration in the U.S. A medium—scale numerical general equilibrium model is used which integrates the U.S. tax system with consumer demand behavior by household and producer behavior by industry. Results indicate that total integration of personal and corporate taxes would yield an annual static efficiency gain of around $4 billion (1973 dollars). Partial integration plans yield less. Dynamic effects are larger, and our analysis indicates that full integration may yield gains whose present value is as large as$400 billion or 0.8% of the discounted present value of the GNP stream to the U.S. economy after correction for population growth. Plans differ in their distributional impacts, although these findings depend on the nature of replacement taxes used to preserve government revenues. The size of dynamic resource allocation effects are sensitive to the choice of the replacement tax, while static gains are reasonably robust.

Development of the PsAQoL: a quality of life instrument specific to psoriatic arthritis

Background: Patient reported outcome measures used in studies of psoriatic arthritis (PsA) have been found to be inadequate for determining the impact of the disease from the patient’s perspective. Objective: To produce the PsAQoL, a PsA-specific quality of life (QoL) instrument, employing the needs based model of QoL that would be relevant and acceptable to respondents, valid, and reliable. Methods: Content was derived from qualitative interviews conducted with patients with PsA. Face and content validity were assessed by field test interviews with a new sample of patients with PsA. A postal survey was conducted to improve the scaling properties of the new measure. Finally, a test-retest postal survey was used to identify the final measure and to test its scaling properties, reliability, internal consistency, and validity. Results: Analysis of the qualitative interview transcripts identified a 51 item questionnaire. Field test interviews confirmed the acceptability and relevance of the measure. Analysis of data from the first postal survey (n = 94) reduced the questionnaire to 35 items. Rasch analysis of data from the test-retest survey (n = 286) identified a 20 item version of the PsAQoL with good item fit. This version had excellent internal consistency (a = 0.91), test-retest reliability (0.89), and validity. Conclusions: The PsAQoL is a valuable tool for assessing the impact of interventions for PsA in clinical studies and trials. It is well accepted by patients, taking about three minutes to complete, is easy to administer, and has excellent scaling and psychometric properties

Correction to "Wasserstein distance estimates for the distributions of numerical approximations to ergodic stochastic differential equations"

A method for analyzing non-asymptotic guarantees of numerical discretizations of ergodic SDEs in Wasserstein-2 distance is presented by Sanz-Serna and Zygalakis in ``Wasserstein distance estimates for the distributions of numerical approximations to ergodic stochastic differential equations". They analyze the UBU integrator which is strong order two and only requires one gradient evaluation per step, resulting in desirable non-asymptotic guarantees, in particular $\mathcal{O}(d^{1/4}\epsilon^{-1/2})$ steps to reach a distance of $\epsilon > 0$ in Wasserstein-2 distance away from the target distribution. However, there is a mistake in the local error estimates in Sanz-Serna and Zygalakis (2021), in particular, a stronger assumption is needed to achieve these complexity estimates. This note reconciles the theory with the dimension dependence observed in practice in many applications of interest.Comment: 8 page

Paraoxonase gene polymorphisms and haplotype analysis in a stroke population

Peer reviewedPublisher PD

Scaffolding, the Zone of Proximal Development, and Novice Programmers

The work, which is part of a doctoral research project, reported here aims to explore the learning strategies that novice computer programmers adopt when writing code, the ways in which they integrate knowledge, and the processes they employ when applying their knowledge and skills in different contexts. Here we present an analysis of the data obtained using think‐aloud retrospective interviews of two novice programmers attempting to solve a set of programming tasks. Our findings, based on a narrative analysis of these interviews, indicate that scaffolding can influence progression in learning and can extend a student’s zone of proximal development

Domestication of the Australian Perennial Native Grass, Microlaena stipoides

Microlaena stipoides (Labill.) R.Br. is a year-long green perennial grass which is common throughout eastern and southern Australia. This species is a valuable component of pastures in parts of the New South Wales Tablelands because of its tolerance of acid soils and its ability to survive recent droughts

HepForge: A lightweight development environment for HEP software

Setting up the infrastructure to manage a software project can become a task as significant writing the software itself. A variety of useful open source tools are available, such as Web-based viewers for version control systems, "wikis" for collaborative discussions and bug-tracking systems, but their use in high-energy physics, outside large collaborations, is insubstantial. Understandably, physicists would rather do physics than configure project management tools. We introduce the CEDAR HepForge system, which provides a lightweight development environment for HEP software. Services available as part of HepForge include the above-mentioned tools as well as mailing lists, shell accounts, archiving of releases and low-maintenance Web space. HepForge also exists to promote best-practice software development methods and to provide a central repository for re-usable HEP software and phenomenology codes.Comment: 3 pages, 0 figures. To be published in proceedings of CHEP06. Refers to the HepForge facility at http://hepforge.cedar.ac.u

New Analysis of a Model of Time to Build

We solve a model of time to build, in closed form, for the special case where the only option is commencing investment. The ratio of the optimal to the NPV investment threshold is as in the standard analysis of irreversible investment. We then report numerical solutions for the general case where there is also an option to suspend investment, investigating variation in the time to build, the uncertainty of payoff and the opportunity cost of foregone cashflows. The two options have opposite effects on the optimal investment decision and NPV calculation is sometimes an appropriate guide to investment.Irreversible investment, time to build, numerical solution of partial differential equations.