Seasonal soybean crop reflectance

Data are presented from field measurements of 1980 including 5 acquisitions of handheld radiometer reflectance measurements, 7 complete sets of parameters for implementing the Suits mode, and other biophysical parameters to characterize the soybean canopy. LANDSAT calculations on the simulated Brazilian soybean reflectance are included along with data collected during the summer and fall on 1981 on soybean single leaf optical parameters for three irrigation treatments. Tests of the Suits vegetative canopy reflectance model for the full hemisphere of observer directions as well as the nadir direction show moderate agreement for the visible channels of the MSS and poor agreement in the near infrared channel. Temporal changes in the spectral characteristics of the single leaves were seen to occur as a function of maturity which demonstrates that the absorptance of a soybean single leaf is more a function of thetransmittancee characteristics than the seasonally consistent single leaf reflectance

A plant canopy light absorption model with application to wheat

From the light absorption model the absorption of light in the photosynthetically active region of the spectrum was calculated for a Penjamo wheat crop for several situations including: (1) the percent absorption of the incident radiation by a canopy having a four layer structure; (2) the percent absorption of light by the individual layers within a four layer canopy and by the underlying soil; (3) the percent absorption of light by each vegetative canopy layer for variable sun angle; and (4) the cumulative solar energy absorbed by the developing wheat canopy as it progresses from a single layer through its growth stages to a three layer canopy. This calculation was also presented as a function of the leaf area index

Using Channel Output Feedback to Increase Throughput in Hybrid-ARQ

Hybrid-ARQ protocols have become common in many packet transmission systems due to their incorporation in various standards. Hybrid-ARQ combines the normal automatic repeat request (ARQ) method with error correction codes to increase reliability and throughput. In this paper, we look at improving upon this performance using feedback information from the receiver, in particular, using a powerful forward error correction (FEC) code in conjunction with a proposed linear feedback code for the Rayleigh block fading channels. The new hybrid-ARQ scheme is initially developed for full received packet feedback in a point-to-point link. It is then extended to various different multiple-antenna scenarios (MISO/MIMO) with varying amounts of packet feedback information. Simulations illustrate gains in throughput.Comment: 30 page

The worship of Astarte in Palestine during the Old Testament period

This item was digitized by the Internet Archive. Thesis (M.A.)--Boston Universityhttps://archive.org/details/theworshipofasta00cha

Air mass factor formulation for spectroscopic measurements from satellites: Application to formaldehyde retrievals from the Global Ozone Monitoring Experiment

Abstract. We present a new formulation for the air mass factor (AMF) to convert slant column measurements of optically thin atmospheric species from space into total vertical columns. Because of atmospheric scattering, the AMF depends on the vertical distribution of the species. We formulate the AMF as the integral of the relative vertical distribution (shape factor) of the species over the depth of the atmosphere, weighted by altitudedependent coefficients (scattering weights) computed independently from a radiative transfer model. The scattering weights are readily tabulated, and one can then obtain the AMF for any observation scene by using shape factors from a three dimensional (3-D) atmospheric chemistry model for the period of observation. This approach subsequently allows objective evaluation of the 3-D model with the observed vertical columns, since the shape factor and the vertical column in the model represent two independent pieces of information. We demonstrate the AMF method by using slant column measurements of formaldehyde at 346 nm from the Global Ozone Monitoring Experiment satellite instrument over North America during July 1996. Shape factors are computed with the Global Earth Observing System CHEMistry (GEOS-CHEM) global 3-D model and are checked for consistency with the few available aircraft measurements. Scattering weights increase by an order of magnitude from the surface to the upper troposphere. The AMFs are typically 20-40 % less over continents than over the oceans and are approximately half the values calculated in the absence of scattering. Model-induced errors in the AMF are estimated to be • 10%. The GEOS-CHEM model captures 50 % and 60 % of the variances in the observed slant and vertical columns, respectively. Comparison of the simulated and observed vertical columns allows assessment of model bias. 1

Opportunities and barriers faced by early-career civil engineers enacting global responsibility

The term ‘global responsibility’ projects a holistic sense of ethics, sustainability, and obligation. To achieve the long-term viability of human life on Earth, civil engineering must be conducted in increasingly responsible ways, and civil engineers must value and enact global responsibility in their work. Interviews conducted with nine civil engineers in London provide insight regarding engineers’ familiarity with the term, how they learned about it, what opportunities and barriers they face, and what might be done by professional and educational institutions to help them practice more responsibly. Results indicate: the term itself is novel but underlying concepts are not; continuing professional development has played a crucial role in their understanding; material selection and Health & Safety represent primary avenues for contributing responsibly at work. This paper provides advice to professional institutions regarding transparencies, procedures, and metrics to enhance the UK workplace and ideas for educational institutions preparing engineering students for practice