IMPORT PRICES AND HARD CURRENCY CONSTRAINTS IN EASTERN EUROPE: IMPLICATIONS FOR COARSE GRAIN IMPORTS AND PRODUCTION OF MEAT

The objectives of this study were (a) to determine the degree to which hard currency earnings constrained overall imports and coarse grain imports in command economies; (b) to measure the importance of import prices on grain imports and to trace the link of grain availability to meat production; and (c) to determine how economic and political reforms in the selected countries may have affected the hard currency constraint, the importance of import prices, and grain imports and meat production. The results indicate that import demand was constrained by earnings of hard currency, but was not responsive to world prices, and meat production was affected by total grain availability, including imports.Coarse grain imports, Hard currency, Eastern Europe, Import prices, Meat production, Political reforms, International Relations/Trade,

Cash Settlement of Lean Hog Futures Contracts Reexamined

In 1997 the Chicago Mercantile Exchange replaced its live hog futures contract with a cash settlement mechanism based on a Lean Hog Index. Although cash settlement was expected to increase the use of the contract as a hedging tool, producers and packers are concerned that convergence between cash and futures prices is not occurring and that the volatility of the lean hog contract basis has increased in recent years. The purpose of the paper is to reexamine cash settlement of lean hog futures contracts as a hedging tool, focusing on basis behavior and management of basis risk. We also investigate alternative hedging instruments that take into account location differences between regional cash prices and the CME lean hog index. Our results indicate that basis has widened and its variability prior to expiration has increased in the cash settlement period. Nevertheless, there is no evidence that ex-ante basis risk has increased, suggesting that the ability to forecast basis prior to expiration has not decreased with cash settlement. Our findings indicate that a contract on a regional basis can reduce producer price risk and may increase market returns. The benefits of a regional basis appear to accrue from providing the producer with an opportunity to manage the variability in returns associated with both the price level and basis.basis behavior, cash settlement, ex-ante basis risk, lean hogs futures contract, regional basis, Agricultural Finance,

3D hp-Adaptive Finite Element Simulations of Bend, Step, and Magic-T Electromagnetic Waveguide Structures

Metallic rectangular waveguides are often the preferred choice on telecommunication systems and medical equipment working on the upper microwave and millimeter wave frequency bands due to the simplicity of its geometry, low losses, and the capacity to handle high powers. Waveguide translational symmetry is interrupted by the unavoidable presence of bends, transitions, and junctions, among others. This paper employs a 3D hp self-adaptive grid-refinement finite element strategy for the solution of these relevant electromagnetic waveguide problems. These structures often incorporate dielectrics, metallic screws, round corners, and so on, which may facilitate its construction or improve its design, but significantly difficult its modeling when employing semi-analytical techniques. The hp-adaptive finite element method enables accurate modeling of these structures even in the presence of complex materials and geometries. Numerical results demonstrate the suitability of the hp-adaptive method for modeling these waveguide structures, delivering errors below 0.5% with a limited number of unknowns. Solutions of waveguide problems obtained with the self-adaptive hp-FEM are of comparable accuracy to those obtained with semi-analytical techniques such as the Mode Matching method, for problems where the latest methods can be applied. At the same time, the hp-adaptive FEM enables accurate modeling of more complex waveguide structures.TEC2010-18175/TCM MTM2010-1651

Transition Design: Investigación y diseño colaborativo para procesos de emancipación ciudadanos

TRANSITION DESIGN is an emerging practice within design that aims to create alternatives lifestyles beneficial for the economy, society and the planet. With this goal in mind, this design practice is developed in domains such as system of stakeholders, public polices or interactions between organisations. Carnegie Mellon University School of Design is offering doctoral studies in TRANSITION DESIGN, and interdisciplinary organisations such as Reos Partners or Forum for the Future develop projects that can be considered of reference. TRANSITION DESIGN is yet in a process of practical experimentation and critical investigation that can also be understood as a creative process in transition. The design led transitions to sustainability advocated are achieved through the creation of visions and organisational structures that create conditions for sustainable lifestyles, rather than ‘repairing’ inefficiencies in the existing material environment. Those creative transformations are collaborative, interdisciplinary practices with users, communities, where the designers’ role becomes that of an expert designer participating in a collective design agency. Cooperatives, as modes of organisation promoting alternative socio-economic models and stronger sociality apear as a fertile ground where TRANSITION DESIGN practice emerge. A case study presented here is La Borda, a housing cooperative of shared ownership born as a satellite project of the neighbour platform Can Batlló. In this context, TRANSITION DESIGN can be understood as a design practice contributing to collective emancipatory processes. Research Group Design Processes: Innovative Practices in Art & Design. EINA, centro Universitario de diseño y arte adscrito a la Universidad Autónoma de Barcelona – Research Project MINECO Generating Knowledge in Artistic Research: TowardEl TRANSITION DESIGN es una práctica emergente dentro del ámbito del diseño que trabaja para crear estilos de vida alternativos beneficiosos para la economía, la sociedad y el planeta. Con este objetivo prioritario, el TRANSITION DESIGN se desarrolla a nivel de sistema, diseño de políticas públicas o de nuevas relaciones entre organizaciones. La universidad Carnegie Mellon Design ofrece el doctorado en Transition Design y grupos de trabajo interdisciplinares, como Reos Partners o Forum for the Future, realizan proyectos bajo la misma denominación. Aun así, el TRANSITION DESIGN todavía es un ámbito en proceso de experimentación práctica e investigación crítica que también puede entenderse como un proceso creativo en transición. El objetivo de sostenibilidad del TRANSITION DESIGN se consigue a través de la creación de nuevos escenarios y estructuras organizativas que posibiliten modificar estilos de vida, en lugar de “reparar” las ineficiencias del entorno material existente. Los procesos de trabajo adecuados a tales expectativas son prácticas colaborativas, interdisciplinares y co-creativas junto a los usuarios, con lo que el rol de diseñador se aproxima más al de diseñador experto dentro de un proceso colectivo donde todos diseñan.  La asociación cooperativa, en tanto que modelo socioeconómico alternativo y en tanto que desarrollo de las iniciativas ciudadanas, aparece como terreno fértil donde pueden emerger prácticas de TRANSITION DESIGN. Un caso de estudio cercano es La Borda, la cooperativa de viviendas en cesión de uso nacida al amparo de la plataforma vecinal Can Batlló. Al respecto, puede entenderse el TRANSITION DESIGN como una metodología de trabajo que ayuda a desarrollar procesos de emancipación colectivos. Grupo de Investigación Design Processes: Innovative Practices in Art & Design. EINA, centro Universitario de diseño y arte adscrito a la Universidad Autónoma de Barcelona - Proyecto de Investigación MINECO Generating Knowledge in Artistic Research: Towar

Correlation and regression analysis between residual gradation and uncorrected visual acuity one year after refractive surgery with LASIK, FS-LASIK, PRK, PRK Xtra techniques and the implantation of ICL® posterior chamber phakic lens in myopic correction

Purpose To analyze the influence of the final spherical equivalent (SE) in LogMAR uncorrected distance visual acuity (UDVA) one year after refractive surgery. We analysed refractive results, their predictability and efficacy, and the safety results of the different methods as secondary outcomes. Setting Refractive Surgery Unit of the Institut Català de Retina (ICR) in Barcelona, Spain. Design Retrospective, analytical observational study. Methods Retrospective and observational study of 654 eyes of 327 patients who underwent refractive surgery to treat their myopia or myopic astigmatism using LASIK, FS-LASIK, PRK, PRK Xtra or ICL-type lens implantation surgery were included. Results The correlation between the SE in absolute value was statistically significant in all techniques utilized, reaching higher values in the FS-LASIK and LASIK techniques, 0.774 and0.706 respectively, and lesser values in PRK (0.480) and PRK Xtra (0.482). A significant adjustment via a univariate linear regression model could be implemented in all techniques, albeit the R2 coefficient of determination values were higher than those for the FS-LASIK (0.599) and LASIK (0.494) techniques. Conclusions There is a positive correlation between post-surgical SE value and post-operative LogMAR UDVA. These regression models can be adjusted to predict the final UDVA according to the final SE. The techniques that are most influenced by the final SE in terms of their visual results are FS-LASIK and LASIK