The PIDS-NEDA Annual Macroeconometric Model, Version 1989: A Summary

The development of PIDS-NEDA Macroeconometric Model is a joint effort by both institutions to come up with a model that government economic planners could use in arriving at annual and medium-term economic forecasts or targets. This paper is a summary of the complete version of the macroeconometric model and the dynamic simulation results.policy analysis, planning tools and monitoring systems, econometric modeling

On the Emergence of Nonextensivity at the Edge of Quantum Chaos

We explore the border between regular and chaotic quantum dynamics, characterized by a power law decrease in the overlap between a state evolved under chaotic dynamics and the same state evolved under a slightly perturbed dynamics. This region corresponds to the edge of chaos for the classical map from which the quantum chaotic dynamics is derived and can be characterized via nonextensive entropy concepts.Comment: Invited paper to appear in "Decoherence and Entropy in Complex Systems", ed. H.T. Elze, Lecture Notes in Physics (Springer, Heidelberg), in press. 13 pages including 6 figures and 1 tabl

An evaluation of biotic ligand models predicting acute copper toxicity to Daphnia magna in wastewater effluent

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2010 SETAC.The toxicity of Cu to Daphnia magna was investigated in a series of 48-h immobilization assays in effluents from four wastewater treatment works. The assay results were compared with median effective concentration (EC50) forecasts produced by the HydroQual biotic ligand model (BLM), the refined D. magna BLM, and a modified BLM that was constructed by integrating the refined D. magna biotic ligand characterization with the Windermere humic aqueous model (WHAM) VI geochemical speciation model, which also accommodated additional effluent characteristics as model inputs. The results demonstrated that all the BLMs were capable of predicting toxicity by within a factor of two, and that the modified BLM produced the most accurate toxicity forecasts. The refined D. magna BLM offered the most robust assessment of toxicity in that it was not reliant on the inclusion of effluent characteristics or optimization of the dissolved organic carbon active fraction to produce forecasts that were accurate by within a factor of two. The results also suggested that the biotic ligand stability constant for Na may be a poor approximation of the mechanisms governing the influence of Na where concentrations exceed the range within which the biotic ligand stability constant value had been determined. These findings support the use of BLMs for the establishment of site-specific water quality standards in waters that contain a substantial amount of wastewater effluent, but reinforces the need for regulators to scrutinize the composition of models, their thermodynamic and biotic ligand parameters, and the limitations of those parameters.EPSRC and Severn Trent Water

Beyond the Veil

The philosophy behind my work is accented by this process in the sense of its micro-complexity. The idea of reshaping a flat surface to mimic complex topography coincides with the question I’ve been asking myself throughout making this work: What is outside of our structured and contrived reality and what does that look like? The complexity of depth within the process and the constant re-evaluation of the surface of the print is a parallel attempt to answer this fundamental question. To answer this, the fear of the unknown will always be present, but we must not let its complexity distract from the beauty and love between us. One must appreciate the beauty of our existence to rise up from our fears for the better of our society. This complex technique approaches Intaglio plates as sculptural surfaces. By applying inks of different viscosity with brayers that have different densities, the ink interacts at varying levels of the plate and expresses the variations and intensities of the image. The process is quite complex, and the expressiveness of imagery is outstanding. In this process, I render digital drawings onto my plate using screen printing, which allows for a solid base of extreme highlights and harsh lines. This image transfer process helps me plan the areas I want to have sitting on the top layer and which areas need to fall back into space. Using a rotary drill tool, I can emboss the highlighted top layer by cutting it into the plate, creating valleys and plateaus to interact with the ink. The variation of mark-making and careful planning of color layering allows for a dynamic sense of space and vibrancy at a micro-level. Developing my work with this method made my practice reach levels I never imagined. I recently graduated from the University of North Florida with a degree in painting, drawing and printmaking. The content of my work questions the unknown of our reality and represents the constant struggle of good and evil. By questioning our fundamental purpose, I hope to encourage the viewer to ponder our existential purpose as beings and radiate the light of love within us

Noise, Synchrony and Correlations at the Edge of Chaos

We study the effect of a weak random additive noise in a linear chain of N locally-coupled logistic maps at the edge of chaos. Maps tend to synchronize for a strong enough coupling, but if a weak noise is added, very intermittent fluctuations in the returns time series are observed. This intermittency tends to disappear when noise is increased. Considering the pdfs of the returns, we observe the emergence of fat tails which can be satisfactorily reproduced by $q$-Gaussians curves typical of nonextensive statistical mechanics. Interoccurrence times of these extreme events are also studied in detail. Similarities with recent analysis of financial data are also discussed.Comment: 6 pages, 8 figures, new figure added - Version accepted for publication in Physical Review