The Large Area Crop Inventory Experiment (LACIE)

A Large Area Crop Inventory Experiment (LACIE) was undertaken to prove out an economically important application of remote sensing from space. The experiment focused upon determination of wheat acreages in the U.S. Great Plains and upon the development and testing of yield models. The results and conclusions are presented

Differences in opinions of occupational physicians on the required competencies by field of practice: results of an international Delphi study

Background: The activities and work demands of medical professionals, including occupational physicians (OPs), fall into three categories: clinical, academic, and administrative. Work demands of an OP consist of these three categories and additional specialty specific roles and competencies. Research on the core competencies and skills required for OPs have identified high levels of consensus amongst OPs internationally, however these opinions have not been examined between areas of practice specific groups. Furthermore, it has been identified that to a large extent academics are often the group who define the skills required of OPs. The aim of this study is to compare the opinions of OPs grouped by field of practice on the common core competencies required for occupational health (OH) practice using results from an international survey. Methods: An international modified Delphi study conducted among OPs, completed in two rounds (Rating-Round 1; Ranking-Round 2) using developed questionnaires based on the specialist training syllabus of a number of countries and expert discussions. Respondents were categorised as Physician, Manager/Physician, and Academic/Physician, based on self-reported job titles and place of work. Results: There was good agreement between the Physician and Manager/Physician groups, with the Academic/Physician group deviating the most. The top three and bottom three principle domains (PDs) were in good agreement across all groups. The top three were clinically based and would be considered core OH activities. The PDs with considerable intergroup variance were Environmental Issues Related to Work Practice and Communication Skills, categories which may reflect direct relevance and relative importance to the job tasks of respective groups. Conclusion: This study demonstrated general agreement between the three occupational groups. Academic/Physician opinions deviate the most, while good agreement is depicted between the Physician and Manager/Physician groups. The findings of this study can help identify potential gaps in training requirements for OPs and be used as a stepping stone to developing training programmes that are reflective of practice and tailored for those predominantly undertaking these specific roles

Angular Momentum Distribution Function of the Laughlin Droplet

We have evaluated the angular-momentum distribution functions for finite numbers of electrons in Laughlin states. For very small numbers of electrons the angular-momentum state occupation numbers have been evaluated exactly while for larger numbers of electrons they have been obtained from Monte-Carlo estimates of the one-particle density matrix. An exact relationship, valid for any number of electrons, has been derived for the ratio of the occupation numbers of the two outermost orbitals of the Laughlin droplet and is used to test the accuracy of the MC calculations. We compare the occupation numbers near the outer edges of the droplets with predictions based on the chiral Luttinger liquid picture of Laughlin state edges and discuss the surprisingly large oscillations in occupation numbers which occur for angular momenta far from the edge.Comment: 11 pages of RevTeX, 2 figures available on request. IUCM93-00

The large area crop inventory experiment: A major demonstration of space remote sensing

Strategies are presented in agricultural technology to increase the resistance of crops to a wider range of meteorological conditions in order to reduce year-to-year variations in crop production. Uncertainties in agricultral production, together with the consumer demands of an increasing world population, have greatly intensified the need for early and accurate annual global crop production forecasts. These forecasts must predict fluctuation with an accuracy, timeliness and known reliability sufficient to permit necessary social and economic adjustments, with as much advance warning as possible

On possible interactions between upper and lower atmosphere

Geomagnetic data was compared with data on tropospheric and stratospheric circulation characteristics; a statistically significant shrinking was found in areal extent of the stratospheric vortex from the third to the eighth day following a 'geomagnetic storm' The meridionality of the 30 640-m contour line at 10 millibars increases markedly from 5 to 8 days after the storm. During the contraction of the polar vortex edge, the mean height of the vortex central contour decreases only slightly. This indicates that a stratospheric warming event is associated with a steepening of the contour gradient rather than a warming over the entire area of the stratospheric polar vortex. The troposphere reacts to these weak, but significant, stratospheric warming events by a shrinkage of the area of the 500-millibar cold air pool. This shrinkage commences about 3 days after the stratospheric warming. The investigation indicates that the energy input into the stratosphere that is received in conjunction with the geomagnetic disturbance has to come at a propitious time, when the stratospheric-tropospheric circulation system is not already undergoing a major readjustment because of an inherent dynamic instability

In the soft-to-hard technical spectrum: Where is software engineering?

In the computer journals and tabloids, there have been a plethora of articles written about the software engineering field. But while advocates of the need for an engineering approach to software development, it is impressive how many authors have treated the subject of software engineering without adequately addressing the fundamentals of what engineering as a discipline consists of. A discussion is presented of the various related facets of this issue in a logical framework to advance the thesis that the software development process is necessarily an engineering process. The purpose is to examine more of the details of the issue of whether or not the design and development of software for digital computer processing systems should be both viewed and treated as a legitimate field of professional engineering. Also, the type of academic and professional level education programs that would be required to support a software engineering discipline is examined

Thematic mapper data quality and performance assessment in renewable resource/agricultural remote sensing

A "quick look" investigation of the initial LANDSAT-4, thematic mapper (TM) scene received from Goddard Space Flight Center was performed to gain early insight into the characteristics of TM data. The initial scene, containing only the first four bands of the seven bands recorded by the TM, was acquired over the Detroit, Michigan, area on July 20, 1982. It yielded abundant information for scientific investigation. A wide variety of studies were conducted to assess all aspects of TM data. They ranged from manual analyses of image products to detect obvious optical, electronic, or mechanical defects to detailed machine analyses of the digital data content for evaluation of spectral separability of vegetative/nonvegetative classes. These studies were applied to several segments extracted from the full scene. No attempt was made to perform end-to-end statistical evaluations. However, the output of these studies do identify a degree of positive performance from the TM and its potential for advancing state-of-the-art crop inventory and condition assessment technology

Existence Advertising, Price Competition, and Asymmetric Market Structure

We examine a two stage duopoly game in which firms advertise their existence to consumers in stage 1 and compete in prices in stage 2. Whenever the advertising technology generates positive overlap in customer bases the equilib- rium for the stage 1 game is asymmetric in that one firm chooses to remain small in comparison to its competitor. For a specific random advertising technology we show that one firm will always be half as large as the other. No equilibrium in pure price strategies exists in the stage 2 game and as long as there is some overlap in customer bases the mixed strategy equilibrium is far from the Bertrand equilibrium.Existence advertising; price dispersion; Bertrand paradox; information; duopoly