Scale-invariant cellular automata and self-similar Petri nets

Two novel computing models based on an infinite tessellation of space-time are introduced. They consist of recursively coupled primitive building blocks. The first model is a scale-invariant generalization of cellular automata, whereas the second one utilizes self-similar Petri nets. Both models are capable of hypercomputations and can, for instance, "solve" the halting problem for Turing machines. These two models are closely related, as they exhibit a step-by-step equivalence for finite computations. On the other hand, they differ greatly for computations that involve an infinite number of building blocks: the first one shows indeterministic behavior whereas the second one halts. Both models are capable of challenging our understanding of computability, causality, and space-time.Comment: 35 pages, 5 figure

Retail Rate Impacts of Distributed Solar: Focus on New England

The Lawrence Berkeley National Laboratory (LBNL) recently issued a study entitled “Putting the Potential Rate Impacts of Distributed Solar into Context,” authored by Galen Barbose. The LBNL study estimates the potential rate impact of distributed solar on national average retail electricity prices, and importantly, compares that impact to the potential impact of other rate drivers such as natural gas prices, renewable portfolio standards, and utility capital expenditures.1 This brief applies a similar style analysis as used by LBNL to regional and state level data to estimate more granular impacts for New England. We estimate rate impacts for various penetration rates of net metered distributed solar and compare them to the potential rate impacts of future natural gas prices, energy efficiency gains, RPS costs, RGGI costs, and utility capital expenditures. Like LBNL, we attempt to isolate the impact of these rate drivers as well as represent uncertainty around future policy choices, commodity costs, and technology costs

Electronic coordination in oligopolistic markets: Impact on transport costs and product differentiation

Electronic coordination links markets at different locations that have initially been (partially) separated by transport costs. Rising competitive pressure should in turn affect incentives to differentiate products. In this paper investment decisions concerning transport cost reduction and product differentiation are analyzed in a heterogenous product duopoly where firms compete in two spatially separated markets. We show that firms always have nonnegative incentives to invest in transport cost reduction, while there exist parameter ranges where product differentiation will actually be reduced after an exogenous reduction of transport cost. We also compare social and privat investment incentives for both price strategies (most likely with digital products) and quantity competition (capacity decisions for physical products). Based on these results we discuss in detail how investment decisions are likely to differ from the efficient solution for each of the two kind of products. -- Durch elektronische Koordination wachsen räumlich getrennte Märkte zusammen, die bislang nur unvollständig ökonomisch integriert waren. Der daraus resultierende verstärkte Wettbewerbsdruck sollte die Anreize der Unternehmen zur Produktdifferenzierung eigentlich erhöhen. Wir analysieren die Interaktion der Investitionsentscheidungen in transportkostensenkende elektronische Koordination und in verstärkte Produktdifferenzierung in einem Duopol mit räumlich getrennten Märkten. Wir zeigen, dass immer ein zumindest schwach positiver Anreiz zur Investition in Transportkostensenkung besteht, während Parameterbereiche existieren in denen die Unternehmen nach einer exogenen Senkung der Transportkosten die Produktdifferenzierung verringern. Des Weiteren vergleichen wir soziale und private Investitionsanreize sowohl bei Preisstrategien (plausibel bei digitalen Gütern) als auch bei Mengenwettbewerb (realistisch als Kapazitätsentscheidung bei physischen Produkten) und diskutieren im Detail, welche Abweichung von der effizienten Entscheidung bei jeder der beiden Produkttypen zu erwarten ist.Electronic markets,Strategic investments,Transport costs,Product differentiation,Elektronische Märkte,Strategische Investition,Transportkosten,Produktdifferentierung

Health as a driving economic force

This chapter illustrates the contribution which could be made to realising the Lisbon Strategy of the European Union for growth and jobs by innovative healthcare policy favouring a preventive orientation of healthcare. The prevention and control of risk factors for chronic diseases, as well as their potential impact on the quality of human capital as a union of health and education, are discussed. Human capital refers to health and education both of the individual, and of the population as a whole… --

The Evolution of Extortion in Iterated Prisoner's Dilemma Games

Iterated games are a fundamental component of economic and evolutionary game theory. They describe situations where two players interact repeatedly and have the possibility to use conditional strategies that depend on the outcome of previous interactions. In the context of evolution of cooperation, repeated games represent the mechanism of reciprocation. Recently a new class of strategies has been proposed, so called 'zero determinant strategies'. These strategies enforce a fixed linear relationship between one's own payoff and that of the other player. A subset of those strategies are 'extortioners' which ensure that any increase in the own payoff exceeds that of the other player by a fixed percentage. Here we analyze the evolutionary performance of this new class of strategies. We show that in reasonably large populations they can act as catalysts for the evolution of cooperation, similar to tit-for-tat, but they are not the stable outcome of natural selection. In very small populations, however, relative payoff differences between two players in a contest matter, and extortioners hold their ground. Extortion strategies do particularly well in co-evolutionary arms races between two distinct populations: significantly, they benefit the population which evolves at the slower rate - an instance of the so-called Red King effect. This may affect the evolution of interactions between host species and their endosymbionts.Comment: contains 4 figure

Analysis of unconstrained nonlinear MPC schemes with time varying control horizon

For discrete time nonlinear systems satisfying an exponential or finite time controllability assumption, we present an analytical formula for a suboptimality estimate for model predictive control schemes without stabilizing terminal constraints. Based on our formula, we perform a detailed analysis of the impact of the optimization horizon and the possibly time varying control horizon on stability and performance of the closed loop

No evidence for oncogenic mutations in guanine nucleotide-binding proteins of human adrenocortical neoplasms

G-Proteins are membrane-bound heterotrimeric polypeptides that couple receptor signals to second messenger systems such as cAMP. Recently, point mutations at 2 codons of the highly preserved alpha-chain of Gs, the adenyl cyclase-stimulating G-protein, were found in GH-secreting pituitary tumors. These mutations resulted in constitutively activated Gs alpha and high intracellular cAMP levels. In addition, point mutations at similar codons of a different G-protein, G(i) alpha 2, were reported in adrenocortical neoplasms, suggesting a potential role of this isoform in the genesis of these tumors. We reevaluated the frequency of constitutively activating point mutations in the alpha- chain of the stimulatory (Gs alpha) and inhibitory (G(i) alpha 2) G- proteins in human adrenocortical tumors. Seven adrenocortical carcinomas, 2 human adrenocortical tumor cell lines, and 11 adrenocortical adenomas were studied. Genomic DNA was purified from either frozen tumor tissue or paraffin-embedded sections. Using specific primers and the polymerase chain reaction, DNA fragments surrounding codons 201 and 227 (Gs alpha) and 179 and 205 (G(i) alpha 2) were amplified and visualized on a 2% agarose gel. In a second asymmetric polymerase chain reaction, using nested primers, single stranded DNA was generated using 1-10 microL of the initial amplification mixture and directly sequenced using the dideoxy chain termination method of Sanger. We found no mutations at codons 201, 227 and 179, 205 of Gs alpha and G(i) alpha 2, respectively, in the tumors studied. We conclude that previously identified oncogenic point mutations in the stimulatory and inhibitory alpha-chain of G-proteins do not appear to be present at high frequency in adrenal neoplasms. Thus, the mechanism(s) of tumorigenesis in these tumors is different from that in GH-secreting adenomas and may involve oncogenic mutations of other cell constituents