Technical guidance and analytic services in support of SEASAT-A

The design of a high resolution radar for altimetry and ocean wave height estimation was studied. From basic principles, it is shown that a short pulse wide beam radar is the most appropriate and recommended technique for measuring both altitude and ocean wave height. To achieve a topographic resolution of + or - 10 cm RMS at 5.0 meter RMS wave heights, as required for SEASAT-A, it is recommended that the altimeter design include an onboard adaptive processor. The resulting design, which assumes a maximum likelihood estimation (MLE) processor, is shown to satisfy all performance requirements. A design summary is given for the recommended radar altimeter, which includes a full deramp STRETCH pulse compression technique followed by an analog filter bank to separate range returns as well as the assumed MLE processor. The feedback loop implementation of the MLE on a digital computer was examined in detail, and computer size, estimation accuracies, and bias due to range sidelobes are given for the MLE with typical SEASAT-A parameters. The standard deviation of the altitude estimate was developed and evaluated for several adaptive and nonadaptive split-gate trackers. Split-gate tracker biases due to range sidelobes and transmitter noise are examined. An approximate closed form solution for the altimeter power return is derived and evaluated. The feasibility of utilizing the basic radar altimeter design for the measurement of ocean wave spectra was examined

Internet and e-Commerce Use by Agribusiness Firms: 2004

In 2001, the dot.com bubble burst and U.S. e-commerce growth slowed. Slower e-commerce growth may signal changes in the use and perceptions of the Internet and e-commerce in agribusiness companies. Agribusiness firm managers were surveyed in 2004 to identify agribusiness use of the Internet and e-commerce and to solicit their perceptions about the Internet and e-commerce. The survey was developed from a similar survey conducted in 1999. In 2004, agribusiness firms were using e-commerce more with their suppliers than with their customers. Perceptions regarding Internet and e-commerce varied by the intensity of e-commerce use. Given the variety of opinions regarding the Internet and e-commerce, e-commerce capabilities in the agribusiness industry will remain highly diverse in the near term.agribusiness, e-commerce, Internet, Agribusiness, Research and Development/Tech Change/Emerging Technologies,

Study of radar pulse compression for high resolution satellite altimetry

Pulse compression techniques are studied which are applicable to a satellite altimeter having a topographic resolution of + 10 cm. A systematic design procedure is used to determine the system parameters. The performance of an optimum, maximum likelihood processor is analysed, which provides the basis for modifying the standard split-gate tracker to achieve improved performance. Bandwidth considerations lead to the recommendation of a full deramp STRETCH pulse compression technique followed by an analog filter bank to separate range returns. The implementation of the recommended technique is examined

Topical analgesia for acute otitis media

BACKGROUND: Acute otitis media (AOM) is a spontaneously remitting disease for which pain is the most distressing symptom. Antibiotics are now known to have less benefit than previously assumed.OBJECTIVES: To assess the effectiveness of topical analgesia for AOM.SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2006), MEDLINE (1966 to May Week 3 2006), EMBASE (1990 to December 2005) and LILACS (1982 to September 2005) without language restriction, and the reference lists of articles. We also contacted manufacturers and authors.SELECTION CRITERIA: Double-blind randomised or quasi-randomised controlled trials comparing an otic preparation with an analgesic effect (excluding antibiotics) versus placebo or an otic preparation with an analgesic effect (excluding antibiotics) versus any other otic preparation with an analgesic effect, in adults or children presenting at primary care settings with AOM without perforation.DATA COLLECTION AND ANALYSIS: Potential studies were screened independently and trial quality was assessed by three authors, and differences were resolved by discussion. Data was then independently extracted from the trials selected by two authors. We contacted the authors of three trials to acquire additional information not available in published articles.MAIN RESULTS: Our searches yielded 356 records; four trials met our criteria. One trial with 54 participants compared treatment with anaesthetic ear drops versus an olive oil placebo immediately at diagnosis. All patients were also given paracetamol. There was a statistically significant pain reduction of 25% in those receiving anaesthetic drops 30 minutes after instillation. Three trials (with one common co-author) compared anaesthetic ear drops with naturopathic herbal ear drops in 274 patients. One of these trials also used antibiotics in both groups. There were statistically significant differences at instillation of drops, or 15 or 30 minutes after the instillation (or both) on one to three days after diagnosis, always favouring the naturopathic group in each trial.AUTHORS' CONCLUSIONS: The evidence from these four randomised controlled trials, only one of which addresses the most relevant question of primary effectiveness, is insufficient to know whether ear drops are effective or not.</p

ADOPTION OF E-COMMERCE STRATEGIES FOR AGRIBUSINESS FIRMS

This paper analyzes the factors guiding Internet and e-commerce implementation by agribusiness firms. The relationship between Internet/e-commerce strategies and manager perceptions on the barriers and factors to e-commerce adoption are analyzed in a supply-chain management framework. Using factor analysis and an ordered Probit model, results indicate that the implementation of Internet/e-commerce strategies is more likely to be adopted in larger firms with a global scope. Also, manager perceptions regarding supply-chain functions influencing transaction costs are more strongly associated with Internet/e-commerce adoption than other functions influencing production costs.e-commerce, supply-chain, transaction costs, factor analysis, order Probit, Agribusiness, Marketing,

Optimization of satellite altimeter and wave height measurements

Two techniques for simultaneously estimating altitude, ocean wave height, and signal-to-noise ratio from the GEOS-C satellite altimeter data are described. One technique was based on maximum likelihood estimation, MLE, and the other on minimum mean square error estimation, MMSE. Performance was determined by comparing the variance and bias of each technique with the variance and bias of the smoothed output from the Geos altimeter tracker. Ocean wave height tracking performance for the MLE and MMSE algorithms was measured by comparing the variance and bias of the wave height estimates with that of the expression for the return waveform obtained by a fit to the average output of the 16 waveform sampling gates

First Long-Term Application of Squeezed States of Light in a Gravitational-Wave Observatory

We report on the first long-term application of squeezed vacuum states of light to improve the shot-noise-limited sensitivity of a gravitational-wave observatory. In particular, squeezed vacuum was applied to the German/British detector GEO600 during a period of three months from June to August 2011, when GEO600 was performing an observational run together with the French/Italian Virgo detector. In a second period squeezing application continued for about 11 months from November 2011 to October 2012. During this time, squeezed vacuum was applied for 90.2% (205.2 days total) of the time that science-quality data was acquired with GEO600. Sensitivity increase from squeezed vacuum application was observed broad-band above 400Hz. The time average of gain in sensitivity was 26% (2.0dB), determined in the frequency band from 3.7kHz to 4.0kHz. This corresponds to a factor of two increase in observed volume of the universe, for sources in the kHz region (e.g. supernovae, magnetars). We introduce three new techniques to enable stable long-term application of squeezed light, and show that the glitch-rate of the detector did not increase from squeezing application. Squeezed vacuum states of light have arrived as a permanent application, capable of increasing the astrophysical reach of gravitational-wave detectors.Comment: 4 pages, 4 figure

Adoption of Internet Strategies by Agribusiness Firms

This paper explores the factors guiding Internet adoption by agribusiness firms. The relationship between Internet strategies and manager perceptions on the barriers to and catalysts for Internet adoption are analyzed in a supply-chain management framework. Using factor analysis and an ordered Probit model, results indicate that Internet strategies are more likely to be adopted in larger firms with a global scope. Also, manager perceptions regarding the impact of Internet adoption on transaction costs are just as likely to influence adoption as the perceived impacts on more traditional production costs.Internet, E-commerce, Supply-chain, Transaction costs, Ordered Probit, Agribusiness, Research and Development/Tech Change/Emerging Technologies,

E-Business and Distribution Channel Strategies in Agribusiness Industries

The explosion of e-business activity presents many challenges to manufacturers, distributors, and dealers as they select a distribution channel for the delivery of products, services, and information. The expected growth in Internet sales by agribusiness firms is analyzed to provide insight into the selection of an e-business distribution channel. Agribusiness firm managers were surveyed regarding the application and perceived impacts of e-business activity on their firm's operations. Firm characteristics and manager perceptions regarding the impact of e-business activity were analyzed descriptively and in regression analysis to understand the drivers of expected Internet sales growth. Expected Internet sales growth was found to vary by the firm's position in the distribution channel. Yet, firms with greater levels of existing e-communication with either customers or suppliers and with managers perceiving greater ability of e-business activity to improve inventory management and logistics issues have higher levels of expected Internet sales.Agribusiness,

HOG PRODUCER INVESTMENT IN VALUE-ADDED AGRIBUSINESS: RISK AND RETURN IMPLICATIONS

Although producers have been enticed into investment in value-added agribusiness the risk and return impacts have not been quantified. A spreadsheet simulation model is used to evaluate how investments by hog farmers in slaughter plants and other alternatives affect returns and risk. Results suggest that hog producer investment in value-added agribusiness is efficient.Value-Added, Producer Investment, Financial Economics, Livestock Production/Industries,