4,483 research outputs found

    SUPPLY RESPONSE TO RISK: THE CASE OF U.S. PINTO BEANS

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    A standard model of behavior under uncertainty is used to suggest price risk variables for use in a positive supply study. The suggested variables are intuitively appealing and empirically tested on Pinto bean data. Linearity is assumed and O.L.S. used. The empirical results show that the risk variables greatly improve the statistical fit of the supply equation, are quantitatively important and that a substantial bias occurs if they are neglected. Policy initiatives to reduce Pinto bean price fluctuations need to consider the risk reducing effects on the supply response.Crop Production/Industries, Risk and Uncertainty,

    Spectroscopic Constants and Vibrational Frequencies for l-C3H+ and Isotopologues from Highly-Accurate Quartic Force Fields: The Detection of l-C3H+ in the Horsehead Nebula PDR Questioned

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    Very recently, molecular rotational transitions observed in the photon-dominated region of the Horsehead nebula have been attributed to l-C3H+. In an effort to corroborate this finding, we employed state-of-the art and proven high-accuracy quantum chemical techniques to compute spectroscopic constants for this cation and its isotopologues. Even though the B rotational constant from the fit of the observed spectrum and our computations agree to within 20 MHz, a typical level of accuracy, the D rotational constant differs by more than 40%, while the H rotational constant differs by three orders of magnitude. With the likely errors in the rotational transition energies resulting from this difference in D on the order of 1 MHz for the lowest observed transition (J = 4 <- 3) and growing as J increases, the assignment of the observed rotational lines from the Horsehead nebula to l-C3H+ is questionable

    The Possible Interstellar Anion CH2CN-: Spectroscopic Constants, Vibrational Frequencies, and Other Considerations

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    It is hypothesized that the A ^1B_1 <- X ^1A' excitation into the dipole-bound state of the cyanomethyl anion (CH2CN-) is proposed as the carrier for one diffuse interstellar band. However, this particular molecular system has not been detected in the interstellar medium even though the related cyanomethyl radical and the isoelectronic ketenimine molecule have been found. In this study we are employing the use of proven quartic force fields and second-order vibrational perturbation theory to compute accurate spectroscopic constants and fundamental vibrational frequencies for ^1A' CH2CN- in order to assist in laboratory studies and astronomical observations

    The Failure of Correlation to Describe Out-of-Plane Carbon=Carbon Bending

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    Carbon-carbon multiply bonded systems are improperly described with standard correlation methods and basis sets. For computations of vibrational modes, the out-of- plane bends can be reported as imaginary at worst or simply too low at best. Utilizing the simplest of aromatic structures (cyclopropenylidene) and various levels of theory, this work diagnoses this known behavior for the first time. A combined 1-particle and n-particle basis set effect conspire to produce these non-physical results. When moving from sp2 to sp3 hybridization in the carbon atoms, the larger number of basis functions overcorrects the energy. This is exacerbated by correlation methods. These allow for occupation of the and orbitals in the expanded wave function that combine with the hydrogen s orbitals. As a result, the improperly described space can be further and non-physically stabilized by post-Hartree-Fock correlation. This represents a fundamental problem with at least Hartree-Fock based methods of all flavors in describing carbon. Beyond being a flaw in quantum chemical theory, other repercussions will be present in computations regarding spectroscopy as well as energy and environmental studies where highly-accurate hydrocabon vibrational transitions or thermochemical data are needed

    The financial stress index: identification of systemic risk conditions

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    This paper develops a financial stress index for the United States, the Cleveland Financial Stress Index (CFSI), which provides a continuous signal of financial stress and broad coverage of the areas that could indicate it. The index is based on daily public-market data collected from four sectors of the fi nancial markets—the credit, foreign exchange, equity, and interbank markets. A dynamic weighting method is employed to capture changes in the relative importance of these four sectors as they occur. In addition, the design of the index allows the origin of the stress to be identified. We compare the CFSI to alternative indexes, using a detailed benchmarking methodology, and show how the CFSI can be applied to systemic stress monitoring and early warning system design. To that end, we investigate alternative stress-signaling thresholds and frequency regimes and then establish optimal frequencies for filtering out market noise and idiosyncratic episodes. Finally, we quantify a powerful CFSI-based rating system that assigns a probability of systemic stress to ranges of CFSI outcomes.Systemic risk ; Risk assessment

    Maritime security:The uncharted politics of the global sea

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    In this introduction to a special section of the September 2019 issue of International Affairs, we revisit the main themes and arguments of our article ‘Beyond seablindness: a new agenda for maritime security studies’, published in this journal in November 2017. We reiterate our call for more scholarly attention to be paid to the maritime environment in international relations and security studies. We argue that the contemporary maritime security agenda should be understood as an interlinked set of challenges of growing global, regional and national significance, and comprising issues of national, environmental, economic and human security. We suggest that maritime security is characterized by four main characteristics, including its interconnected nature, its transnationality, its liminality—in the sense of implicating both land and sea—and its national and institutional cross-jurisdictionality. Each of the five articles in the special section explores aspects of the contemporary maritime security agenda, including themes of geopolitics, international law, interconnectivity, maritime security governance and the changing spatial order at sea

    Integrating the academic experience: An inter-disciplinary approach to the authentic marketing research experience

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    This paper describes the evolution of an innovative inter–disciplinary approach to teaching and learning in a University Faculty of Business. Further, it reviews the implementation of a series of unique, integrated and authentic assessments involving units based in the marketing, urban planning and business communication disciplines. The project has used the production of Revitalization Plans for the University‘s campuses as the basis for integrating student teaching and learning. It has championed an approach which moves away from the traditional ‗silo‘ methods of academic assessment to integrated, contextualised learning which develops both generic and discipline-specific skills such as client/consultation roles, business communications and knowledge in marketing, urban planning, and management. The paper concludes by reflecting on the issues involved with the introduction of the inter-disciplinary approach to teaching and learning with the University

    SAFE: An early warning system for systemic banking risk

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    This paper builds on existing microprudential and macroprudential early warning systems (EWSs) to develop a new, hybrid class of models for systemic risk, incorporating the structural characteristics of the fi nancial system and a feedback amplification mechanism. The models explain fi nancial stress using both public and proprietary supervisory data from systemically important institutions, regressing institutional imbalances using an optimal lag method. The Systemic Assessment of Financial Environment (SAFE) EWS monitors microprudential information from the largest bank holding companies to anticipate the buildup of macroeconomic stresses in the financial markets. To mitigate inherent uncertainty, SAFE develops a set of medium-term forecasting specifi cations that gives policymakers enough time to take ex-ante policy action and a set of short-term forecasting specifications for verification and adjustment of supervisory actions. This paper highlights the application of these models to stress testing, scenario analysis, and policy.Systemic risk ; Liquidity (Economics)
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