103 research outputs found
Water and the National Welfare—Programs in Search of a Policy
It is no secret to residents of the western states that water is a matter of primary public concern. Land and water policies are deeply imbedded in the region, and the imprint of federal water projects on the economic geography of the West is plain to see. It is increasingly clear, however, that no coherent national policy, past or present, has emerged from the massive federal effort in the field. There is no lack of interest, planning, and expenditure on the supply and quality of water, and much progress has been made in definition and measurement of the factors that determine an efficient water system. But sound principles are still honored as much in the breach as in the observance, and we still speak with a thousand voices on any water problem of real magnitude. The time is at hand when the plethora of overlapping and frequently quarrelsome federal agencies concerned with the development and allocation of water supplies and the protection of water quality must be subjected to the test of clearly formulated national objectives and of conceptually sound and consistent means of achieving them
Management of the North Pacific Fisheries: Economic Objectives and Issues
In this paper, we attempt to narrow the areas of conflict by specifying more precisely the objectives of fishery utilization (and, inferentially, of fisheries management) in the North Pacific, and by analysis of the extent to which the optimal combination of regulatory measures in a theoretical framework must be modified to accommodate the technological, administrative, and political complexities that beset an international fishery. The basic bioeconomic theory of an ocean fishery is modified to show its application to a typical case involving interdependent exploited species and international differences in market prices of both inputs and end products. The analysis is then cast in terms of the specific situation in the North Pacific. Alternative concepts of international regulation are examined from the standpoint of their economic repercussions, and recommendations are formulated for a longrun management program designed to yield continuing economic benefits as well as physical protection of the resources. Attention is centered on the Northeast Pacific, where the four major fishing powers are all actively engaged and in direct competition. The emphasis throughout is on what should be attempted rather than on what can be accomplished under present institutional and legal arrangements
Management of the North Pacific Fisheries: Economic Objectives and Issues
In this paper, we attempt to narrow the areas of conflict by specifying more precisely the objectives of fishery utilization (and, inferentially, of fisheries management) in the North Pacific, and by analysis of the extent to which the optimal combination of regulatory measures in a theoretical framework must be modified to accommodate the technological, administrative, and political complexities that beset an international fishery. The basic bioeconomic theory of an ocean fishery is modified to show its application to a typical case involving interdependent exploited species and international differences in market prices of both inputs and end products. The analysis is then cast in terms of the specific situation in the North Pacific. Alternative concepts of international regulation are examined from the standpoint of their economic repercussions, and recommendations are formulated for a longrun management program designed to yield continuing economic benefits as well as physical protection of the resources. Attention is centered on the Northeast Pacific, where the four major fishing powers are all actively engaged and in direct competition. The emphasis throughout is on what should be attempted rather than on what can be accomplished under present institutional and legal arrangements
Exact Synchronization for Finite-State Sources
We analyze how an observer synchronizes to the internal state of a
finite-state information source, using the epsilon-machine causal
representation. Here, we treat the case of exact synchronization, when it is
possible for the observer to synchronize completely after a finite number of
observations. The more difficult case of strictly asymptotic synchronization is
treated in a sequel. In both cases, we find that an observer, on average, will
synchronize to the source state exponentially fast and that, as a result, the
average accuracy in an observer's predictions of the source output approaches
its optimal level exponentially fast as well. Additionally, we show here how to
analytically calculate the synchronization rate for exact epsilon-machines and
provide an efficient polynomial-time algorithm to test epsilon-machines for
exactness.Comment: 9 pages, 6 figures; now includes analytical calculation of the
synchronization rate; updates and corrections adde
Reductions of Hidden Information Sources
In all but special circumstances, measurements of time-dependent processes
reflect internal structures and correlations only indirectly. Building
predictive models of such hidden information sources requires discovering, in
some way, the internal states and mechanisms. Unfortunately, there are often
many possible models that are observationally equivalent. Here we show that the
situation is not as arbitrary as one would think. We show that generators of
hidden stochastic processes can be reduced to a minimal form and compare this
reduced representation to that provided by computational mechanics--the
epsilon-machine. On the way to developing deeper, measure-theoretic foundations
for the latter, we introduce a new two-step reduction process. The first step
(internal-event reduction) produces the smallest observationally equivalent
sigma-algebra and the second (internal-state reduction) removes sigma-algebra
components that are redundant for optimal prediction. For several classes of
stochastic dynamical systems these reductions produce representations that are
equivalent to epsilon-machines.Comment: 12 pages, 4 figures; 30 citations; Updates at
http://www.santafe.edu/~cm
Spectral Simplicity of Apparent Complexity, Part II: Exact Complexities and Complexity Spectra
The meromorphic functional calculus developed in Part I overcomes the
nondiagonalizability of linear operators that arises often in the temporal
evolution of complex systems and is generic to the metadynamics of predicting
their behavior. Using the resulting spectral decomposition, we derive
closed-form expressions for correlation functions, finite-length Shannon
entropy-rate approximates, asymptotic entropy rate, excess entropy, transient
information, transient and asymptotic state uncertainty, and synchronization
information of stochastic processes generated by finite-state hidden Markov
models. This introduces analytical tractability to investigating information
processing in discrete-event stochastic processes, symbolic dynamics, and
chaotic dynamical systems. Comparisons reveal mathematical similarities between
complexity measures originally thought to capture distinct informational and
computational properties. We also introduce a new kind of spectral analysis via
coronal spectrograms and the frequency-dependent spectra of past-future mutual
information. We analyze a number of examples to illustrate the methods,
emphasizing processes with multivariate dependencies beyond pairwise
correlation. An appendix presents spectral decomposition calculations for one
example in full detail.Comment: 27 pages, 12 figures, 2 tables; most recent version at
http://csc.ucdavis.edu/~cmg/compmech/pubs/sdscpt2.ht
Structural Information in Two-Dimensional Patterns: Entropy Convergence and Excess Entropy
We develop information-theoretic measures of spatial structure and pattern in
more than one dimension. As is well known, the entropy density of a
two-dimensional configuration can be efficiently and accurately estimated via a
converging sequence of conditional entropies. We show that the manner in which
these conditional entropies converge to their asymptotic value serves as a
measure of global correlation and structure for spatial systems in any
dimension. We compare and contrast entropy-convergence with mutual-information
and structure-factor techniques for quantifying and detecting spatial
structure.Comment: 11 pages, 5 figures,
http://www.santafe.edu/projects/CompMech/papers/2dnnn.htm
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