Intrinsically Universal Cellular Automata

This talk advocates intrinsic universality as a notion to identify simple cellular automata with complex computational behavior. After an historical introduction and proper definitions of intrinsic universality, which is discussed with respect to Turing and circuit universality, we discuss construction methods for small intrinsically universal cellular automata before discussing techniques for proving non universality

Structural Change in the Meat and Poultry Industry and the Pathogen Reduction Hazard Analysis Critical Control Point Rule

This paper uses plant-level micro-data covering the 1987-2002 and a translog cost function to estimate long-run costs in the meat and poultry industry in order to evaluate the impact of the Pathogen Reduction Hazard Analysis Critical Control Point Rule on cattle, hog and chicken slaughter and prepared pork products and sausage-making industries. Results suggest that costs rose in the cattle and hog slaughter and prepared pork products industries and the cost shares of meat declined and of labor and capital rose. There is little evidence that events over the period favored large or small plants.food safety, structural change, regulation, industrial organization, Agribusiness, Agricultural and Food Policy, Food Consumption/Nutrition/Food Safety, Industrial Organization,

The Cost of Food Safety Technologies in the Meat and Poultry Industries.

This paper uses plant-level micro-data from the 2002 Census of Manufactures, Food Safety Inspection Service, and the Economic Research Service in a translog cost function to examine the costs of effort devoted to the performance of sanitation and process control tasks and levels of food safety technology use. Results suggest that more effort devoted to performance of sanitation and process control tasks and greater use of food safety technologies modestly reduce long run costs.food safety, food safety technologies, translog cost function, long run costs, meat and poultry industry, Food Consumption/Nutrition/Food Safety, Industrial Organization, Production Economics,

THE IMPACT OF MARKET MECHANISMS AND HACCP REGULATION ON FOOD SAFETY QUALITY

Economists have long debated the relative effectiveness of markets and regulations in reaching socially desirable outcomes. This empirical study of meat and poultry food safety regulation suggests that market mechanisms and flexible regulatory instruments, e.g. HACCP systems, have a greater impact on food safety quality than less flexible regulatory instruments. Subject code: 9 (Food Safety and Nutrition).Food Consumption/Nutrition/Food Safety,

Combinatorial substitutions and sofic tilings

A combinatorial substitution is a map over tilings which allows to define sets of tilings with a strong hierarchical structure. In this paper, we show that such sets of tilings are sofic, that is, can be enforced by finitely many local constraints. This extends some similar previous results (Mozes'90, Goodman-Strauss'98) in a much shorter presentation.Comment: 17 pages, 16 figures. In proceedings of JAC 201

Intrinsic Simulations between Stochastic Cellular Automata

The paper proposes a simple formalism for dealing with deterministic, non-deterministic and stochastic cellular automata in a unifying and composable manner. Armed with this formalism, we extend the notion of intrinsic simulation between deterministic cellular automata, to the non-deterministic and stochastic settings. We then provide explicit tools to prove or disprove the existence of such a simulation between two stochastic cellular automata, even though the intrinsic simulation relation is shown to be undecidable in dimension two and higher. The key result behind this is the caracterization of equality of stochastic global maps by the existence of a coupling between the random sources. We then prove that there is a universal non-deterministic cellular automaton, but no universal stochastic cellular automaton. Yet we provide stochastic cellular automata achieving optimal partial universality.Comment: In Proceedings AUTOMATA&JAC 2012, arXiv:1208.249

EMPIRICAL EVIDENCE ON THE MOTIVES FOR MERGERS AND ACQUISITIONS IN EIGHT FOOD INDUSTRIES

This paper investigates the motives for mergers and acquisitions in eight U.S. food products industries from1977-92. Results show that acquired plants were highly productive before mergers and realized an increase in productivity growth in the post-merger period.Food product industries, mergers and acquisitions, labor productivity., Agribusiness,

AJAE Appendix: Mergers and Acquisitions and Productivity in the U.S. Meat Products Industries

The material contained herein is supplementary to the article named in the title and published in the American Journal of Agricultural Economics, Volume 88, Number 3, August 2006.Industrial Organization, Livestock Production/Industries,

The economic forces driving the costs of food safety regulation

The cost of compliance with the Pathogen Reduction Hazard Analysis Critical Control Program (PR/HACCP) rule of 1996 has been controversial from the time it was first proposed. Recent survey evidence indicates costs of about $0.01 per pound. These estimates may capture actual costs but do not indicate how different components of the rule itself, such as HACCP tasks, and indirect influences, such as plant size, affect costs differently. The purpose of this paper is to empirically examine these direct and indirect influences. Preliminary results suggest that plant size has a small, if any influence on costs. The most substantial direct cost is the cost of performing sanitation and tasks associated with a plant's HACCP process control plan.Food Consumption/Nutrition/Food Safety,

INNOVATION AND REGULATION IN THE PESTICIDE INDUSTRY

This paper examines the impact of pesticide regulation on the number of new pesticide registrations and pesticide toxicity. Results suggest that regulation adversely affects new pesticide introductions but encourages the development of pesticides with fewer toxic side effects. The estimated regression model implies that a 10% increase in regulatory costs (about $1.5 million per pesticide) causes a 5% reduction in the number of pesticides with higher toxicity.Agribusiness,