2,991 research outputs found

    Engineering analysis of ERTS data for southeast Asian agriculture

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    The present program focuses on rice because of its importance world-wide as a food. Specifically, the focus is on rice fields in the Philippines. Two primary program objectives are: (1) to establish the feasibility of extracting from ERTS imagery the areas where rice is grown, and (2) to determine those measurements on the imagery which enable the assessment of crop condition. Achieving these objectives with procedures which can be cost-effective can lead the way toward yield prediction, irrigation system management, and similar functions which are known to be important needs in Southeast Asia

    Modelling heterogeneity in response behaviour towards a sequence of discrete choice questions: a latent class approach

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    There is a growing body of evidence in the non-market valuation literature suggesting that responses to a sequence of discrete choice questions tend to violate the assumptions typically made by analysts regarding independence of responses and stability of preferences. Heuristics such as value learning and strategic misrepresentation have been offered as explanations for these results. While a few studies have tested these heuristics as competing hypotheses, none have investigated the possibility that each explains the response behaviour of a subgroup of the population. In this paper, we make a contribution towards addressing this research gap by presenting an equality-constrained latent class model designed to estimate the proportion of respondents employing each of the proposed heuristics. We demonstrate the model on binary and multinomial choice data sources and find three distinct types of response behaviour. The results suggest that accounting for heterogeneity in response behaviour may be a better way forward than attempting to identify a single heuristic to explain the behaviour of all respondents

    Households’ Willingness to Pay for Undergrounding Electricity and Telecommunications Wires

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    Underground telecommunications and low-voltage electricity networks have several advantages over overhead networks including reliability of supply, safety and improved visual amenity. The economic viability of replacing existing overhead networks with new underground networks depends on the value of these benefits to households, but no complete value estimates are available in the literature. This paper represents a contribution towards addressing this research gap. A stated choice survey is used to estimate willingness-to-pay for undergrounding in established residential areas in Canberra. Average willingness-to-pay is at least $6,838 per household and there is significant variation in preferences over the population. The results suggest that benefits would be highest in areas with higher household income and older residents where visual amenity, safety, tree trimming or restrictions on the use of yard space are of concern.Stated preference; willingness-to-pay; undergrounding; supply reliability

    Cornell University remote sensing program

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    There are no author-identified significant results in this report

    Characterization of physio-chemical properties of polymeric and electrochemical materials for aerospace flight

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    Sealed nickel cadmium cells having undergone a large number of cycles were discharged using the Hg/HgO reference electrode. The negative electrode exhibited the second plateau. SEM of negative plates of such cells show clusters of large crystals of cadmium hydroxide. These large crystals on the negative plates disappear after continuous overcharging in flooded cells. Atomic Absorption Spectroscopy and standard wet chemical methods are being used to determine the cell materials viz: nickel, cadmium, cobalt, potassum and carbonate. The anodes and cathodes are analyzed after careful examination and the condition of the separator material is evaluated

    Cornell University remote sensing program

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    Aircraft and satellite remote sensing technology were applied in the following areas: (1) evaluation of proposed fly ash disposal sites; (2) development of priorities for drainage improvements; (3) state park analysis for rehabilitation and development; (4) watershed study for water quality planning; and (5) assistance project-landfill site selection. Results are briefly summarized. Other projects conducted include: (1) assessment of vineyard-related problems; (2) LANDSAT analysis for pheasant range management; (3) photo-historic evaluation of Revolutionary War sites; and (4) thermal analysis of building insulation. The objectives, expected benefits and actions, and status of these projects are described

    A New Look at the Wealth Adequacy of Older U.S. Households

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    We examine the current wealth adequacy of older U.S. households using the 1998-2006 waves of the Health and Retirement Study (HRS). We find that the median older U.S. household is reasonably well situated, with a ratio of comprehensive net wealth to present value poverty- line wealth of about 3.9 in 2006. About 18 percent of households, however, have less wealth than would be needed to generate 150 percent of poverty-line income over their expected future lifetimes. We see similar patterns of wealth adequacy when we examine ratios of annualized comprehensive wealth to pre-retirement earnings. Comparing the leading edge of the baby boomers in 2006 to households of the same age in 1998, we find that the baby boomers show slightly less wealth, in real terms, than their elders did, but still have appear to have adequate resources at the median. Moreover, we find a rising age profile of annualized wealth, even within households over time and after controlling for other factors, suggesting that older households are not spending their wealth as quickly as their survival probabilities are falling.

    Modelling heterogeneity in response behaviour towards a sequence of discrete choice questions: a latent class approach

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    There is a growing body of evidence in the non-market valuation literature suggesting that responses to a sequence of discrete choice questions tend to violate the assumptions typically made by analysts regarding independence of responses and stability of preferences. Heuristics such as value learning and strategic misrepresentation have been offered as explanations for these results. While a few studies have tested these heuristics as competing hypotheses, none have investigated the possibility that each explains the response behaviour of a subgroup of the population. In this paper, we make a contribution towards addressing this research gap by presenting an equality-constrained latent class model designed to estimate the proportion of respondents employing each of the proposed heuristics. We demonstrate the model on binary and multinomial choice data sources and find three distinct types of response behaviour. The results suggest that accounting for heterogeneity in response behaviour may be a better way forward than attempting to identify a single heuristic to explain the behaviour of all respondents.Choice experiment; latent class; ordering effects; strategic response; willingness-to-pay

    A comparison of responses to single and repeated discrete choice questions

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    According to neoclassical economic theory, a stated preference elicitation format comprising a single binary choice between the status quo and one alternative is incentive compatible under certain conditions. Formats typically used in choice experiments comprising a sequence of discrete choice questions do not hold this property. In this paper, the effect on stated preferences of expanding the number of binary choice tasks per respondent from one to four is tested using a split sample treatment in an attribute-based survey relating to the undergrounding of overhead electricity and telecommunications wires. We find evidence to suggest that presenting multiple choice tasks per respondent decreases estimates of expected willingness to pay. Preferences stated in the first of a sequence of choice tasks are not significantly different from those stated in the incentive compatible single binary choice task, but, in subsequent choice tasks, responses are influenced by cost levels observed in past questions. Three behavioural explanations can be advanced – weak strategic misrepresentation, reference point revision and cost-driven value learning. The evidence is contrary to the standard assumption of truthful response with stable preferences.Choice experiment; willingness-to-pay; incentive compatibility; order effects; undergrounding

    Cornell University remote sensing program

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    The major activities of the program staff from December 1, 1973 to May 31, 1974 are reported and include: (1) communication and instruction; (2) data and facilities; (3) research completed; (4) research in progress; (5) selected correspondence; (6) grant sponsored travel; and (7) seminars and newsletters. Detailed information and maps are given for the following selected projects: (1) ERTS mapping of waterways in the Tug Hill region of New York State; (2) photo-archeological investigation of Great Gully, New York; and (3) evaluation of selected highway impacts using aerial photography
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