Book reviews

Electronic Finance Law Chris Reed, 1993 Hemel Hempstead: Woodhead‐Faulkner. 450 pp. £50.00

Introduction to Computer Law, 2nd Edn David I. Bainbridge, 1993 London: Pitman £18.99

Deontic Logic in Computer Science: normative system specification John‐Jules CH. Meyer & Roel J. Wieringa, 1993 London: John Wiley £34.95, xiv + 317pp.     

Book reviews

Abstract

Industrial robots often operate at high speed, with unpredictable motion patterns and erratic idle times. Serious injuries and deaths have occurred due to operator misperception of these robot design and performance characteristics. The main objective of the research project was to study human perceptual aspects of hazardous robotics workstations. Two laboratory experiments were designed to investigate workers' perceptions of two industrial robots with different physical configurations and performance capabilities. Twenty-four subjects participated in the study. All subjects were chosen from local industries, and had had considerable exposure to robots and other automated equipment in their working experience. Experiment 1 investigated the maximum speed of robot arm motions that workers, who were experienced with operation of industrial robots, judged to be ‘safe’ for monitoring tasks. It was found that the selection of safe speed depends on the size of the robot and the speed with which the robot begins its operation. Speeds of less than 51 cm/s and 63cm/s for large and small robots, respectively, were perceived as safe, i.e., ones that did not result in workers feeling uneasy or endangered when working in close proximity to the robot and monitoring its actions. Experiment 2 investigated the minimum value of robot idle time (inactivity) perceived by industrial workers as system malfunction, and an indication of the ‘safe-to-approach’ condition. It was found that idle times of 41 s and 28 s or less for the small and large robots, respectively, were perceived by workers to be a result of system malfunction. About 20% of the workers waited only 10 s or less before deciding that the robot had stopped because of system malfunction. The idle times were affected by the subjects' prior exposure to a simulated robot accident. Further interpretations of the results and suggestions for operational limitations of robot systems are discussed.     

Book reviews

THE BRAIN AND BEHAVIORAL SCIENCES (ISSN 0140-525x).Published quarterly by Cambridge University Press (£35.00).

COMPUTATIONAL PROBABILITY AND SIMULATION by Sidney J.Yakowitz pub. Addison-Wesley Pub. Co. Inc., 1977, pp. 240, £10.00 paperbound £18.00 hardnbound.

THE WORLD FERTILITY SURVEY JAN-DEC 1977-ANNUAL REPORT.

COMPSTAT LECTURES I. LECTURES IN COMPUTATIONAL STATISTICS, Ed. by Horst Skarabis and Peter Sint 1978. 132 pages. Bound, pub. Physica-Verlag, Wurzburg, Germany (DM30).

COMPSTAT 1978. PROCEEDINGS OF 3RD SYMPOSIUM IN COMPUTATIONAL STATISTICS LEIDEN 1978, Ed. by L. C. A.

Corsten and J. Hermans, 1978, 538 pages, Bound, pub. Physica-Verlag, Germany (DM59).     

Book reviews

Proximal and remote sensing measurements were used to calculate different vegetation indices that were applied as predictors of gross primary production (GPP), total ecosystem respiration (TER), net ecosystem production (NEP) and leaf area index (LAI). Reflectance data and carbon fluxes were collected during the 2005 growing season at a mountain grassland site in the Italian Alps. Significant relationships were found between GPP, TER, NEP, LAI and the most commonly used spectral vegetation indices, the Normalized Difference Vegetation Index (NDVI) and Green‐NDVI. Saturation of the spectral indices was evident in the estimation of both biophysical and ecophysiological parameters. Among the different indices, Green‐NDVI was less affected by saturation on both a spatial and a temporal basis. Therefore, the use of an additional green‐band sensor for spectral measurements at eddy covariance grassland sites is recommended. Concerning the bandwidth for the calculation of the indices, the highest predictive capacities among the sensor simulations included in the analysis were those of the Moderate Resolution Imaging Spectroradiometer (MODIS) and the high‐resolution hyperspectral instrument Hyperion, indicating the advantage of narrow bands for the prediction of plant parameters. Further analyses are, however, required to investigate the relationships between NEP, GPP and vegetation indices retrieved from satellite platforms, using the bands available on MODIS and Hyperion sensors.