On Diffusion of Ideas in the Academic World: the Case of Spatial Econometrics

Spatial econometrics is a fast-growing field in the series of quantitative disciplines, auxiliaries of economics and related social sciences. Space, friction, interdependence, spatiotemporal components, externalities and many other aspects interact and should be treated adequately in this field. The publication of the Paelinck and Klaassen book in the late 1970s generated virtually the field spatial econometrics This article studies the diffusion of spatial econometrics, through experienced history on the one hand, on the other through bibliometric methods. Although this field was an “Invisible College” up to 2006 (absence of any organization in form of association, conference, journal, etc.), the databases depict a fast diffusion in the past and strong prospects for the future.

The Tale of Two research Communities: The Diffusion of Research on Productive Efficiency

The field of theoretical and applied efficiency analysis is pursued both by economists and people from operational research and management science. Each group tends to cite a different paper as the seminal one. Recent availability of extensive electronically accessible databases of journal articles makes studies of the diffusion of papers through citations possible. Research strands inspired by the seminal paper within economics are identified and followed by citation analysis during the 20 year period before the operations research paper was published. The first decade of the operations research paper is studied in a similar way and emerging differences in diffusion patterns are pointed out. Main factors influencing citations apart from the quality of the research contribution are reputation of journal, reputation of author, number of close followers; colleagues, “cadres of protégés”, Ph.D. students, and extent of network (“invisible college”). Such factors are revealed by the citing papers. In spite of increasing cross contacts between economics and operations research the last decades co-citation analysis reveals a relative constant tendency to stick to “own camp” references.Farrell efficiency measures, data envelopment analysis, DEA, bibliometry

Image restoration using HOS and the Radon transform

The authors propose the use of higher-order statistics (HOS) to study the problem of image restoration. They consider images degraded by linear or zero phase blurring point spread functions (PSF) and additive Gaussian noise. The complexity associated with the combination of two-dimensional signal processing and higher-order statistics is reduced by means of the Radon transform. The projection at each angle is an one-dimensional signal that can be processed by any existing 1-D higher-order statistics-based method. They apply two methods that have proven to attain good one-dimensional signal reconstruction, especially in the presence of noise. After the ideal projections have been estimated, the inverse Radon transform gives the restored image. Simulation results are provided.Peer ReviewedPostprint (published version

Property, Unbundled Water Entitlements, and Anticommons Tragedies: A Cautionary Tale From Australia

As water becomes an increasingly scarce resource, a lack of clarity in relation to its use can produce both conflict among and inefficient use by users. In order to encourage markets in water and to ensure the viability and functionality of those markets, governments in many jurisdictions have moved away from commons property as a means of water allocation, and towards systems of private property in water. In doing so, one policy and legal option is “unbundling”, which seeks carefully to define both the entitlement to water and its separation into constituent parts. Advocates claim that unbundling makes water rights easier to value, monitor, and trade. But is unbundling the most efficient means of allocating water use rights? Or might such fragmentation produce what has come to be called an “anticommons tragedy”? To answer these questions, this article contains four parts. The Introduction provides the legal background to the modern means of allocating the use of water amongst competing, or rivalrous, users. Part I considers the theoretical nature of property, and the way in which such theory might be extended to water allocation through unbundling. Part II presents unbundling as it has been implemented in the Australian state of South Australia. This allows us to assess the extent to which the stated policy rationale for unbundling—certainty and transferability of entitlements—has been achieved and the extent to which this is a desirable outcome. Our analysis can be applied to any jurisdiction, most notably the arid and semi-arid southwestern United States, considering unbundling as a legal and policy option for the allocation of water use. The Conclusion reflects upon the potential for unbundling water entitlements in arid or semi-arid environments. The South Australian experience reveals a reluctance to embrace unbundling, both on the part of the state in terms of implementing, and on the part of market actors holding existing proprietary interests in water. This reluctance ought to be viewed by other jurisdictions as a warning about the effectiveness and efficiency of unbundling. We show that unbundling efforts may not only fail to provide efficiency gains, but also, and much more worryingly, may in fact drive anticommons tragedies that entirely inhibit any beneficial use. We propose that our anecdotal and theoretical analysis of South Australia requires empirical research both in Australia and in other jurisdictions climatologically, hydrologically, and in underlying legal framework, similar to Australia. Such empirical research will test our conclusions in relation to South Australia, both in respect to the operation of the water market and as to the behavior of market actors

A new positive time-frequency distribution

This article studies the formulation of new members of the Cohen-Posch (1985) class of positive time-frequency energy distributions. Members of this class are always positive functionals and satisfy the marginal constraints. Therefore, they can be properly interpreted as distributions. We considered the minimization of cross-entropy measures with respect to different priors orPeer ReviewedPostprint (published version

Coccidioidomycosis: Medical and Spatio-Temporal Perspectives

Coccidioidomycosis (CM) is a disease of major public health importance due to the challenges in its diagnosis and treatment. To understand CM requires the attributes of a multidisciplinary network analysis to appreciate the complexity of the medical, the environmental and the social issues involved: public health, public policy, geology, atmospheric science, agronomy, social sciences and finally humanities, all which provide insight into this population transformation.In section 1 of this paper, we describe the CM-epidemiology, the clinical features, the diagnosis and finally the treatment.In section 2, we highlight the most important contributions and controversies in the history of the CM-research by using scientometric or bibliometric evaluations of research that are based on Garfield’s work (Garfield.library.upenn.edu) on the propagation of scientific thinking

Migration, Environment and Public Health: Theory and Interdisciplinary Research from a Regional Science Perspective

As regional climate evolves into new climatic states in different parts of the world, humanity will be facing increasing issues associated with migration environment and health concerns. Challenges of major hazards and impacts on human societies, involving water resources, agriculture, economy and energy issues are central issues. This paper examines the generalization of Tiebout’s model in our understanding of the forced environmental migration of the Great Planes farmers to California during the Dust Bowl period in 1931-1939. The paper considers the issues of public health that arose from this migration after the arrival and settlement of the Okies in California. Settlement of the migrants in California was more bitter than the migration itself, prompting John Steinbeck to write his award winning novel of the journey in the “Grapes of Wrath.” Among many health risks in their new environment a relatively unappreciated and unpublicized airborne fungus causing Valley fever when inhaled emerged. Valley fever was, and is today, highly endemic in California’s San Joaquin Valley where many of the Okies remained, staying for employment in agriculture and working the fertile soil that harbored the fungus. The vast majority of migrants into the San Joaquin Valley had been infected, but we know today that most who were, did not report it. A very high percentage of migrants did become infected when a few statistics emerged, such as 25% of the population of one migrant camp were diagnosed with the disease. Many migrants fought the disease only to die later in the 1940s and 1950s. The destiny of the migrants was not exposed in books or mass media until the early 1960s. Many migrants escaped infection when they left the fields for employment in the factories and manufacturing supporting the World War II effort. Other reasons for this historical silence were the Great Depression, those who went to war, the Cold War era, and the Californian farmers themselves who kept the infection secret. The second generation migrants or the “survivors” from Valley fever infection exposed the destiny of their parents in the Californian farms in the mass media in the early 1960s and later on Internet webpages and blogs in the 1980s. We examine the general implications and lessons learned from these historical cases

Parametric Approach to Blind Deconvolution of Nonlinear Channels

A parametric procedure for the blind inversion of nonlinear channels is proposed, based on a recent method of blind source separation in nonlinear mixtures. Experiments show that the proposed algorithms perform efficiently, even in the presence of hard distortion. The method, based on the minimization of the output mutual information, needs the knowledge of log-derivative of input distribution (the so-called score function). Each algorithm consists of three adaptive blocks: one devoted to adaptive estimation of the score function, and two other blocks estimating the inverses of the linear and nonlinear parts of the channel, (quasi-)optimally adapted using the estimated score functions. This paper is mainly concerned by the nonlinear part, for which we propose two parametric models, the first based on a polynomial model and the second on a neural network, while [14, 15] proposed non-parametric approaches

Can Classical Noise Enhance Quantum Transmission?

A modified quantum teleportation protocol broadens the scope of the classical forbidden-interval theorems for stochastic resonance. The fidelity measures performance of quantum communication. The sender encodes the two classical bits for quantum teleportation as weak bipolar subthreshold signals and sends them over a noisy classical channel. Two forbidden-interval theorems provide a necessary and sufficient condition for the occurrence of the nonmonotone stochastic resonance effect in the fidelity of quantum teleportation. The condition is that the noise mean must fall outside a forbidden interval related to the detection threshold and signal value. An optimal amount of classical noise benefits quantum communication when the sender transmits weak signals, the receiver detects with a high threshold, and the noise mean lies outside the forbidden interval. Theorems and simulations demonstrate that both finite-variance and infinite-variance noise benefit the fidelity of quantum teleportation.Comment: 11 pages, 3 figures, replaced with published version that includes new section on imperfect entanglement and references to J. J. Ting's earlier wor