1,399 research outputs found

    NSSDC data listing

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    In a highly summarized way, data available from the National Space Science Data Center (NSSDC) is identified. Most data are offline data sets (on magnetic tape or as film/print products of various sizes) from individual instruments carried on spacecraft; these compose the Satellite Data Listing. Descriptive names, time spans, data form, and quantity of these data sets are identified in the listing, which is sorted alphabetically-first by spacecraft name and then by the principal investigator's or team leader's last name. Several data sets held at NSSDC, not associated with individual spaceflight instruments, are identified in separate listings following the Satellite Data Listing. These data sets make up the Supplementary Data Listings and include composite spacecraft data sets, ground-based data, models, and computer routines. The identifiers used in the Supplementary Data Listings were created by NSSDC and are explained in the pages preceding the listings. Data set form codes are listed. NSSDC offers primarily archival, retrieval, replication, and dissemination services associated with the data sets discussed in the two major listings identified above. NSSDC also provides documentation which enables the data recipient to use the data received. NSSDC is working toward expanding presently limited capabilities for data subsetting and for promotion of data files to online residence for user downloading. NSSDC data holdings span the range of scientific disciplines in which NASA is involved, and include astrophysics, lunar and planetary science, solar physics, space plasma physics, and Earth science. In addition to the functions mentioned above, NSSDC offers data via special services and systems in a number of areas, including Astronomical Data Center (ADC), Coordinated Data Analysis Workshops (CDAWs), NASA Climate Data System (NCDS), Pilot Land Data System (PLDS), and Crustal Dynamics Data Information System (CDDIS). Furthermore, NSSDC has a no-password account on its SPAN/Telenet-accessible VAX through which the NASA Master Directory and selected online data bases are accessible and through which any data described here may be ordered. Astrophysics data support by NSSDC is not limited to the ADC. Each of these special services/systems is described briefly

    Data catalog series for space science and applications flight missions. Volume 3B: Descriptions of data sets from low- and medium-altitude scientific spacecraft and investigations

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    The main purpose of the data catalog series is to provide descriptive references to data generated by space science flight missions. The data sets described include all of the actual holdings of the Space Science Data Center (NSSDC), all data sets for which direct contact information is available, and some data collections held and serviced by foreign investigators, NASA and other U.S. government agencies. This volume contains narrative descriptions of data sets from low and medium altitude scientific spacecraft and investigations. The following spacecraft series are included: Mariner, Pioneer, Pioneer Venus, Venera, Viking, Voyager, and Helios. Separate indexes to the planetary and interplanetary missions are also provided

    Measuring the price responsiveness of gasoline demand

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    This paper develops a new method for estimating the demand function for gasoline and the deadweight loss due to an increase in the gasoline tax. The method is also applicable to other goods. The method uses shape restrictions derived from economic theory to improve the precision of a nonparametric estimate of the demand function. Using data from the U.S. National Household Travel Survey, we show that the restrictions are consistent with the data on gasoline demand and remove the anomalous behavior of a standard nonparametric estimator. Our approach provides new insights about the price responsiveness of gasoline demand and the way responses vary across the income distribution. We reject constant elasticity models and find that price responses vary non-monotonically with income. In particular, we find that low- and high-income consumers are less responsive to changes in gasoline prices than are middle-income consumers.

    Measuring the price responsiveness of gasoline demand: economic shape restrictions and nonparametric demand estimation

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    This paper develops a new method for estimating a demand function and the welfare consequences of price changes. The method is applied to gasoline demand in the U.S. and is applicable to other goods. The method uses shape restrictions derived from economic theory to improve the precision of a nonparametric estimate of the demand function. Using data from the U.S. National Household Travel Survey, we show that the restrictions are consistent with the data on gasoline demand and remove the anomalous behavior of a standard nonparametric estimator. Our approach provides new insights about the price responsiveness of gasoline demand and the way responses vary across the income distribution. We find that price responses vary nonmonotonically with income. In particular, we find that low- and high-income consumers are less responsive to changes in gasoline prices than are middle-income consumers. We find similar results using comparable data from Canada.

    Data catalog series for space science and applications flight missions. Volume 6: Master index volume

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    The main purpose of the data catalog series is to provide descriptive references to data generated by space science flight missions. The data sets described include all of the actual holdings of the Space Science Data Center (NSSDC), all data sets for which direct contact information is available, and some data collections held and serviced by foreign investigators, NASA, and other U.S. government agencies. This volume contains the Master Index. The following spacecraft are included: Mariner, Pioneer, Pioneer Venus, Venera, Viking, Voyager, and Helios. Separate indexes to the planetary and interplanetary missions are also provided

    NSSDC data listing

    Get PDF
    The purpose here is to identify, in a highly summarized way, data available from the National Space Science Data Center (NSSDC). Most data are maintained as offline data sets gathered from individual instruments carried on spacecraft; these comprise the Satellite Data Listing. Descriptive names, time spans, data form, and quality of these data sets are identified in the listing, which is sorted alphabetically, first by spacecraft name and then by the principal investigator's or team leader's last name. Several data sets not associated with individual spaceflight instruments are identified in separate listings following the Satellite Data Listing. These include composite spacecraft data sets, ground based data, models, and computer routines. NSSDC also offers data via special services and systems in a number of areas, including the Astronomical Data Center, Coordinated Data Analysis Workshops, NASA Climate Data System, Pilot Land Data System, and Crustal Dynamics Data Information System

    Blood pressure responses in healthy older people to 50 g carbohydrate drinks with differing glycaemic effects

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    The aim of the present study was to determine the effects on blood pressure response of 50 g carbohydrate drinks with differing glycaemic effects in ten healthy elderly subjects (age >65 years; randomized crossover design). Systolic (SBP), diastolic (DBP) and mean arterial (MAP) blood pressure, heart rate and plasma glucose levels were determined following ingestion of equal volumes (379 ml) of water and 50 g carbohydrate drinks with differing reported glycaemic indices (GI) (surrogate marker for glycaemic effect): (1) low-GI: Apple & Cherry Juice; (2) intermediate-GI: Fanta Orange; (3) high-glucose. Glucose (SBP and DBP P,0·001; MAP P¼0·005) and Fanta Orange (SBP P¼0·005; DBP and MAP P,0·001) ingestion caused a significant decrease in BP whilst blood pressure increased (SBP P¼0·008; MAP P¼0·005) from baseline following Apple & Cherry Juice ingestion. Water had no significant effect on postprandial blood pressure. Fanta Orange and Apple & Cherry Juice caused similar (P¼0·679) glycaemic effects, which were significantly greater than water, but lower than glucose (P,0·001). There was no significant correlation between the glycaemic effect of the carbohydrate drinks and there was no change in blood pressure from baseline (SBP r 20·123, P¼0·509; DBP r 20·051, P¼0·784; MAP r 20·069, P¼0·712). Apple & Cherry Juice and Fanta Orange had similar glycaemic effects, but differing effects on blood pressure. Therefore, it is unlikely that the glycaemic effect of a drink can be used to predict the subsequent cardiovascular response.Renuka Visvanathan, Richard Chen, Michael Horowitz and Ian Chapma
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