Competition, Innovation and Increasing Returns

This paper concerns the operation of competition in the presence of a high rate of innovation and increasing returns. Given free competition there is likely to exist, in this case, a tendency towards what may be called ‘dynamic equilibrium’, a tendency, that is to say, for the rate of investment in product development to rise or fall towards the level at which this investment yields only a normal return. Thus, competition, increasing returns and innovation may co-exist.Innovation, increasing returns, competition

Reconfiguration based built-in self-test for analogue front-end circuits

Previous work has shown that it is feasible to implement a fully digital test evaluation function to realise partial self-test on an automatic gain control circuit (AGC). This paper extends the technique to INL, DNL, offset & gain error testing of analogue to digital converters (ADC's). It also shows how the same function can be used to test an AGC / ADC pair. An extension to full self-test is also proposed by the on-chip generation of input stimuli through reconfiguration of existing functions

Epidemiology and economic impact of Johne's disease in Irish dairy herds

End of project reportThis project addressed two aspects of an emerging infectious disease of Irish cattle; the epidemiology and the economic impacts of Johne’s disease (paratuberculosis). Though this disease has been present in Irish cattle herds for decades, only since the introduction of the Single European Market in 1992 has it become more widespread. In addition to this change in the epidemiology of the disease in Irish cattle, there is increasing evidence that the causative organism, Mycobacterium avium subsp. paratuberculosis (MAP) may be implicated in a human illness, Crohn’s disease, though proof of a zoonotic link is currently disputed (Tremblay, 2004). Against this background a collaborative research project was set up by Teagasc and funded by Irish dairy farmers

Economic Analysis, Public Policy and the Software Industry

This paper focuses on three related matters. It analyses the process of competition in the software industry, this being important both in itself and for the light it throws on competition within all industries characterised by low or zero marginal costs and a high rate of technical development. The software industry, operating under private enterprise, is dependent on copyright, and the issues raised by intellectual property protection are therefore also considered. Given the need for inter-operability between different software products, and between these and associated hardware, standardisation is important within the industry, and the processes by which standards may be established are evaluated. Consideration is given to the public policy issues that are raised by these three topics.Software, competition, innovation, standardisation, intellectual property protection

Conformal Field Theory and the Exact Solution of the BCS Hamiltonian

We propose a connection between conformal field theory (CFT) and the exact solution and integrability of the reduced BCS model of superconductivity. The relevant CFT is given by the $SU(2)_k$-WZW model in the singular limit when the level k goes to -2. This theory has to be perturbed by an operator proportional to the inverse of the BCS coupling constant. Using the free field realization of this perturbed Wess-Zumino-Witten model, we derive the exact Richardson's wave function and the integrals of motion of the reduced BCS model in the saddle point approximation. The construction is reminiscent of the CFT approach to the Fractional Quantum Hall effect.Comment: 10 pages, RevTe

Partitioning of carbon dioxide between the atmosphere and lithosphere on early Mars

It is pointed out that in addition to the 1 to 5 bar CO2 total inventory, a high level of global volcanism was needed to keep the CO2 from being drawn away permanently by weathering of igneous rocks; the volcanism would continually decompose the carbonate resulting in steady efficient recycling

An analytic model of plasma-neutral coupling in the heliosphere plasma

We have developed an analytic model to describe coupling of plasma and neutral fluids in the partially ionized heliosphere plasma medium. The sources employed in our analytic model are based on a $\kappa$-distribution as opposed to the Maxwellian distribution function. Our model uses the $\kappa$-distribution to analytically model the energetic neutral atoms that result in the heliosphere partially ionized plasma from charge exchange with the protons and subsequently produce a long tail which is otherwise not describable by the Maxwellian distribution. We present our analytic formulation and describe major differences in the sources emerging from these two distinct distributions.Comment: This paper has been accepted in Journal of Plasma Physics. It is in pres

A Comparison of Methodologies for Valuing Decreased Health Effects from Wildfire Smoke

Wildfire seasons are becoming longer and more intense throughout the world, making it increasingly important to monetize the full damages caused by wildfires when analyzing various fire management policies. We estimate the economic costs of the health effects associated with exposure to wildfire smoke using a simple cost of illness approach and for the first time to our knowledge we estimate willingness-to-pay (WTP) for a decrease in symptom days from wildfire smoke using the contingent valuation method and the averting behavior method. Comparing estimates across all three common approaches for estimating the economic cost of exposure to an air pollutant is an important contribution to the literature. This study uses data from the largest wildfire in Los Angeles County’s modern history, the Station Fire of 2009. Our results show that a simple cost of illness estimate is about $3 per day of symptoms, the averting behavior method results in a WTP value of$43 or $94 to avoid one day of wildfire-smoke induced symptom days, depending on the model used, and the contingent valuation method results in a WTP estimate of$74 - $98 to avoid one day of wildfire-smoke induced symptom days, depending on model specification.averting behavior method, contingent valuation method, cost of illness, wildfire smoke, health, morbidity, Environmental Economics and Policy, Health Economics and Policy, Q,

Arc Phenomena in low-voltage current limiting circuit breakers

Circuit breakers are an important safety feature in most electrical circuits, and they act to prevent excessive currents caused by short circuits, for example. Low-voltage current limiting circuit breakers are activated by a trip solenoid when a critical current is exceeded. The solenoid moves two contacts apart to break the circuit. However, as soon as the contacts are separated an electric arc forms between them, ionising the air in the gap, increasing the electrical conductivity of air to that of the hot plasma that forms, and current continues to flow. The currents involved may be as large as 80,000 amperes. Critical to the success of the circuit breaker is that it is designed to cause the arc to move away from the contacts, into a widening wedge-shaped region. This lengthens the arc, and then moves it onto a series of separator plates called an arc divider or splitter. The arc divider raises the voltage required to sustain the arcs across it, above the voltage that is provided across the breaker, so that the circuit is broken and the arcing dies away. This entire process occurs in milliseconds, and is usually associated with a sound like an explosion and a bright ash from the arc. Parts of the contacts and the arc divider may melt and/or vapourise. The question to be addressed by the Study Group was to mathematically model the arc motion and extinction, with the overall aim of an improved understanding that would help the design of a better circuit breaker. Further discussion indicated that two key mechanisms are believed to contribute to the movement of the arc away from the contacts, one being self-magnetism (where the magnetic field associated with the arc and surrounding circuitry acts to push it towards the arc divider), and the other being air flow (where expansion of air combined with the design of the chamber enclosing the arc causes gas flow towards the arc divider). Further discussion also indicated that a key aspect of circuit breaker design was that it is desirable to have as fast a quenching of the arc as possible, that is, the faster the circuit breaker can act to stop current flow, the better. The relative importance of magnetic and air pressure effects on quenching speed is of central interest to circuit design