Natural Resources Dynamics: Another Look

In this paper we study the problem of exhaustible resources and renewable resources in a theoretical endogenous growth framework, under various assumptions. In particular, we consider the hypotheses that those two inputs are or are not technologically perfect substitutes of each other. Moreover, we develop the starting model accounting for the negative externality of waste accumulation. Finally, a comparative analysis is made between Pigouvian tax and waste recycling as an environmental policy to internalize the negative externality represented by refuse accumulation.Economic growth, Endogenous technological progress, Exhaustible resources, Pigouvian taxes, Renewable natural inputs, Technological substitutability

Robust and Irreversible Development in Cell Society as a General Consequence of Intra-Inter Dynamics

A dynamical systems scenario for developmental cell biology is proposed, based on numerical studies of a system with interacting units with internal dynamics and reproduction. Diversification, formation of discrete and recursive types, and rules for differentiation are found as a natural consequence of such a system. "Stem cells" that either proliferate or differentiate to different types stochastically are found to appear when intra-cellular dynamics are chaotic. Robustness of the developmental process against microscopic and macroscopic perturbations is shown to be a natural consequence of such intra-inter dynamics, while irreversibility in developmental process is discussed in terms of the gain of stability, loss of diversity and chaotic instability.Comment: 17 pages with 3 ps figures. submitted to Physica A as a proceeding paperfor Paladin Memorial Con

Natural flow patterns and structured people dynamics: a constructal view

Constructal theory that has been successfully applied to planetary circulations and climate and to river basin morphology is shown to provide a useful framework for describing flows of people. We showed here, with simple examples, that intuitive rules of traffic organization can be anticipated based on principle, i.e., based on the Constructal Law. In addition, and similarly to the case of flows of inanimate matter, in the case of flows of people, flow patterns emerge as a necessary consequence of reduction of global flow resistances. These flow patterns point to decreasing resistivity to flows of people and commodities. Pathway length varies inversely with resistivity while pathway number increases with resistivity

Active Learning and Best-Response Dynamics

We examine an important setting for engineered systems in which low-power distributed sensors are each making highly noisy measurements of some unknown target function. A center wants to accurately learn this function by querying a small number of sensors, which ordinarily would be impossible due to the high noise rate. The question we address is whether local communication among sensors, together with natural best-response dynamics in an appropriately-defined game, can denoise the system without destroying the true signal and allow the center to succeed from only a small number of active queries. By using techniques from game theory and empirical processes, we prove positive (and negative) results on the denoising power of several natural dynamics. We then show experimentally that when combined with recent agnostic active learning algorithms, this process can achieve low error from very few queries, performing substantially better than active or passive learning without these denoising dynamics as well as passive learning with denoising