1,728 research outputs found

    Time Series Analysis, Cointegration, and Applications

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    The two prize winners in Economics this year would describe themselves as "Econometricians," so I thought that I should start by explaining that term. One can begin with the ancient subject of Mathematics which is largely concerned with the discovery of relationships between deterministic variables using a rigorous argument. (A deterministic variable is one whose value is known with certainty.) However, by the middle of the last millennium it became clear that some objects were not deterministic, they had to be described with the use of probabilities, so that Mathematics grew a substantial sub-field known as "Statistics." This later became involved with the analysis of data and a number of methods have been developed for data having what may be called "standard properties."time series; cointegration

    Modeling Amazon Deforestation for Policy Purposes

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    Brazil has long ago removed most of the perverse government incentives that stimulated massive deforestation in the Amazon in the 70s and 80s, but one highly controversial policy remains: Road building. While data is now abundantly available due to the constant satellite surveillance of the Amazon, the analytical methods typically used to analyze the impact of roads on natural vegetation cover are methodologically weak and not very helpful to guide public policy. This paper discusses the respective weaknesses of typical GIS analysis and typical municipality level regression analysis, and shows what would be needed to construct an ideal model of deforestation processes. It also presents an alternative approach that is much less demanding in terms of modeling and estimation and more useful for policy makers as well.Deforestation, Amazon, Brazil, econometric modeling

    Improved efficiency of nutrient and water use for high quality field vegetable production using fertigation

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    Drip-based fertigation may improve the application efficiency of water and nutrients while maintaining or improving marketable yield and quality at harvest and post-harvest. Two plantings of lettuce (Lactuca sativa) were grown in the UK, with six N treatments and two methods of irrigation and N application. The conventional overhead irrigated treatments had all N applied in the base dressing with irrigation scheduled from SMD calculations. The closed loop treatments had nitrogen and irrigation delivered via drip automatically controlled by a sensor and logger system. The work established that water content in the root zone can be monitored in real time using horizontally oriented soil moisture sensors linked to data logging and telemetry, and that these data can be used to automatically trigger drip irrigation for commercially grown field vegetables. When the closed loop irrigation control was combined with fertigation treatments, lettuce crops were grown with savings of up to 60% and 75% of water and nitrogen respectively, compared to standard UK production systems. However, excess supply of N through fertigation rather than solid fertiliser was more detrimental to marketable yield and post harvest quality highlighting that care is needed when selecting N rates for fertigation

    Advances in Supply Chain Management: Potential to Improve Forecasting Accuracy

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    Forecasting is a necessity almost in any operation. However, the tools of forecasting are still primitive in view of the great strides made by research and the increasing abundance of data made possible by automatic identification technologies, such as, radio frequency identification (RFID). The relationship of various parameters that may change and impact decisions are so abundant that any credible attempt to drive meaningful associations are in demand to deliver the value from acquired data. This paper proposes some modifications to adapt an advanced forecasting technique (GARCH) with the aim to develop it as a decision support tool applicable to a wide variety of operations including supply chain management. We have made an attempt to coalesce a few different ideas toward a “solutions” approach aimed to model volatility and in the process, perhaps, better manage risk. It is possible that industry, governments, corporations, businesses, security organizations, consulting firms and academics with deep knowledge in one or more fields, may spend the next few decades striving to synthesize one or more models of effective modus operandi to combine these ideas with other emerging concepts, tools, technologies and standards to collectively better understand, analyze and respond to uncertainty. However, the inclination to reject deep rooted ideas based on inconclusive results from pilot projects is a detrimental trend and begs to ask the question whether one can aspire to build an elephant using mouse as a model

    Impact of Communication on Depressive Vulnerability in Deaf Individuals

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    Mode of communication and perceived communication with mother deserve attention within the mother-deaf child relationship. This study explored the impact of both factors on each other and on the vulnerability of young deaf college students for depressive symptoms using measures revised to meet the language needs of this population. Depression was negatively associated with perceived communication with mother. Mode of communication significantly related to perceived communication with mother, with oral subjects scoring highest. They were also least depressed. Further analysis revealed that subjects communicating with their mothers through signs only and vice versa scored as high for perceived maternal communication as did oral subjects. This suggests that a good match between mother and child in mode of communication positively impacts on the young deaf adult\u27s emotional health

    Errata Idaho\u27s Memo in Support for Mtn SJ

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    An errata to the State\u27s Memorandum in Support of Motion for Summary Judgment, substituting a paragraph that begins at the bottom of page 49 and continues to the top of page 50

    Errata Idaho\u27s Memo in Support for Mtn SJ

    Get PDF
    An errata to the State\u27s Memorandum in Support of Motion for Summary Judgment, substituting a paragraph that begins at the bottom of page 49 and continues to the top of page 50
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