343 research outputs found

    Texas-Oklahoma Producer Cotton Market Summary: 2003/2004

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    The analysis of the West Texas and East Texas/Oklahoma spot market using the Daily Price Estimation System (DPES) indicated an overall increase in quality in the 2003/04 marketing year. The results also indicated an overall price increase compared to the last four years, averaging 63.68 cents a pound. The combined total bales and total sales between the two regions were lower in 2003/04, with most of the decrease due to lower sales in West Texas. Total sales in East Texas/Oklahoma did not change much and total bales were 15 percent higher than their 2002/03 level. For the 2003/04 marketing year, the results indicated lower premiums for low leaf grade and higher premiums for higher staple length, color grade, and higher level of strength. However, premium levels for better than base quality first digit color grade appear to be minimal. Price discounts in 2003/04 for staple length, first and second digit color grade, strength, and uniformity either remained unchanged or decreased, while discounts for leaf, micronaire, and bark increased compared to the 2002/03 levels.Crop Production/Industries,

    2006 Global Cotton Outlook

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    Agricultural and Food Policy,

    Structured mesh generation and numerical analysis of a scroll expander in an open-source environment

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    The spread of the organic rankine cycle applications has driven researchers and companies to focus on the improvement of their performance. In small to medium-sized plants, cyanthe expander is the component that has typically attracted the most attention. One of the most used types of machine in this scenario is the scroll. Among the other methods, numerical analyses have been increasingly exploited for the investigation of the machine's behaviour. Nonetheless, there are major challenges for the successful application of computational fluid dynamics cyan(CFD) to scrolls. Specifically, the dynamic mesh treatment required to capture the movement of working chambers and the nature of the expanding fluids require special care. In this work, a mesh generator for scroll machines is presented. Given few inputs, the software described provides the mesh and the nodal positions required for the evolution of the motion in a predefined mesh motion approach. The mesh generator is developed ad hoc for the coupling with the open-source CFD suite OpenFOAM. A full analysis is then carried out on a reverse-engineered commercial machine, including the refrigerant properties calculations via CoolProp. It is demonstrated that the proposed methodology allows for a fast simulation and achieves a good agreement with respect to former analyses

    Understanding Acre for Cotton

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    The Food, Conservation, and Energy Act of 2008 was passed into law on May 22, 2008 with veto override votes in the House of Representatives and the Senate (House 2008). A difference between the 2002 and the 2008 bills is the newly instituted revenue-based counter-cyclical program called the Average Crop Revenue Election (ACRE) program available beginning crop year 2009. The ACRE program is offered as an alternative to the counter-cyclical payment (CCP) program that was in place during the 2002-2008 period. Beginning with the 2009 crop year, producers will have the option to enroll their farm in either the CCP program or the ACRE program. If ACRE is elected, producers cannot change program participation for the duration of the 2008 farm bill (ERS 2008). This is a very complex decision due to the number of variables that must be considered and depends on the individual farm situation. It requires that farms, rather than crops or commodities, enter the program, so that the decision relies on the impacts of program choice on farm income. That aside, understanding commodity situations is a first step toward understanding and making decisions on individual farm situations. The purpose of this briefing paper is to provide assistance in understanding the differences between the ACRE and CCP programs for one crop, cotton, in one state, Texas. The briefing paper will also show the results of a comparison between CCP and ACRE payments using a sample of actual farm data.Agricultural and Food Policy,

    CFD Simulations of Single- and Twin-Screw Machines with OpenFOAM

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    Over the last decade, Computational Fluid Dynamics (CFD) has been increasingly applied for the design and analysis of positive displacement machines employed in vapor compression and power generation applications. Particularly, single-screw and twin-screw machines have received attention from the researchers, leading to the development and application of increasingly efficient techniques for their numerical simulation. Modeling the operation of such machines including the dynamics of the compression (or expansion) process and the deforming working chambers is particularly challenging. The relative motion of the rotors and the variation of the gaps during machine operation are a few of the major numerical challenges towards the implementation of reliable CFD models. Moreover, evaluating the thermophysical properties of real gases represents an additional challenge to be addressed. Special care must be given to defining equation of states or generating tables and computing the thermodynamic properties. Among several CFD suite available, the open-source OpenFOAM tool OpenFOAM, is regarded as a reliable and accurate software for carrying out CFD analyses. In this paper, the dynamic meshing techniques available within the software as well as new libraries implemented for expanding the functionalities of the software are presented. The simulation of both a single-screw and a twin-screw machine is described and results are discussed. Specifically, for the single-screw expander case, the geometry will be released as open-access for the entire community. Besides, the real gas modeling possibilities implemented in the software will be described and the CoolProp thermophysical library integration will be presented

    Affordances in Psychology, Neuroscience, and Robotics: A Survey

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    The concept of affordances appeared in psychology during the late 60s as an alternative perspective on the visual perception of the environment. It was revolutionary in the intuition that the way living beings perceive the world is deeply influenced by the actions they are able to perform. Then, across the last 40 years, it has influenced many applied fields, e.g., design, human-computer interaction, computer vision, and robotics. In this paper, we offer a multidisciplinary perspective on the notion of affordances. We first discuss the main definitions and formalizations of the affordance theory, then we report the most significant evidence in psychology and neuroscience that support it, and finally we review the most relevant applications of this concept in robotics

    Explicit action perception shares resources with music syntax: A controlled behavioral study

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    Given evidence that neural resources monitoring language syntax also underlie the perception of music syntax (Koelsch, 2005) and recently a proposed ‘syntax’ in sequential action (Fazio et al., 2009), a previous EEG study investigated whether neural resources may be shared between implicit perception of music and action (Sammler et al., 2010). Results yielded a syntactic-like ERP pattern elicited by the errors in sequential action, but no interaction of resources across the music and action domains. The present follow-up study sought behavioral signs of resource-overlap when perception is instead explicit. Five chords accompanied five reach-to-grasp images in a 2x2 factorial interference paradigm (target: regular/irregular cadence paired with correct/incorrect grasp). Results indeed revealed an interaction of resources which monitored the action and music sequences, manifested in task accuracy. A control experiment with accompanying pure tones instead of chords (standard/deviant final tone) did not, however, show the same interaction. Crucially, the null-result control study speaks to a neural resource involved in action perception that is shared only with syntactically organized sound, not a simple auditory distraction. This promising behavioral data warrants follow-up neuropsychological experimentation with explicit-task paradigms

    Integration of Action and Language Knowledge: A Roadmap for Developmental Robotics

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    “This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder." “Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.”This position paper proposes that the study of embodied cognitive agents, such as humanoid robots, can advance our understanding of the cognitive development of complex sensorimotor, linguistic, and social learning skills. This in turn will benefit the design of cognitive robots capable of learning to handle and manipulate objects and tools autonomously, to cooperate and communicate with other robots and humans, and to adapt their abilities to changing internal, environmental, and social conditions. Four key areas of research challenges are discussed, specifically for the issues related to the understanding of: 1) how agents learn and represent compositional actions; 2) how agents learn and represent compositional lexica; 3) the dynamics of social interaction and learning; and 4) how compositional action and language representations are integrated to bootstrap the cognitive system. The review of specific issues and progress in these areas is then translated into a practical roadmap based on a series of milestones. These milestones provide a possible set of cognitive robotics goals and test scenarios, thus acting as a research roadmap for future work on cognitive developmental robotics.Peer reviewe

    Bimanual non-congruent actions in motor neglect syndrome: A combined behavioral/fMRI study

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    In Motor Neglect (MN) syndrome, a specific impairment in non-congruent bimanual movements has been described. In the present case-control study, we investigated the neuro-functional correlates of this behavioral deficit. Two right-brain-damaged (RBD) patients, one with (MN+) and one without (MN−) MN, were evaluated by means of functional Magnetic Resonance Imaging (fMRI) in a bimanual Circles-Lines (CL) paradigm. Patients were requested to perform right-hand movements (lines-drawing) and, simultaneously, congruent (lines-drawing) or non-congruent (circles-drawing) left-hand movements. In the behavioral task, MN− patient showed a bimanual-coupling-effect, while MN+ patient did not. The fMRI study showed that in MN−, a fronto-parietal network, mainly involving the pre-supplementary motor area (pre-SMA) and the posterior parietal cortex (PPC), was significantly more active in non-congruent than in congruent conditions, as previously shown in healthy subjects. On the contrary, MN+ patient showed an opposite pattern of activation both in pre-SMA and in PPC. Within this fronto-parietal network, the pre-SMA is supposed to exert an inhibitory influence on the default coupling of homologous muscles, thus allowing the execution of non-congruent movements. In MN syndrome, the described abnormal pre-SMA activity supports the hypothesis that a failure to inhibit ipsilesional motor programs might determine a specific impairment of non-congruent movements
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