1,815 research outputs found

    Structural Change in the U.S. Food Manufacturing Sector

    Get PDF
    This study examines the market structure-conduct-performance relationship for 48 four-digit SIC Food and Tobacco Processing Industries during the 1970s, 1980s and 1990s. The simultaneous-equation analyses are used to explore the relationship among price-cost margin (PCM), market concentration, advertising outlay, and various control variables. With an intertemporal setting, our findings provide evidence of structural changes over time in the U.S. food manufacturing sector and support some of the conventional SCP wisdoms, but challenge others.Agribusiness,

    A principled approach to the measurement of situation awareness in commercial aviation

    Get PDF
    The issue of how to support situation awareness among crews of modern commercial aircraft is becoming especially important with the introduction of automation in the form of sophisticated flight management computers and expert systems designed to assist the crew. In this paper, cognitive theories are discussed that have relevance for the definition and measurement of situation awareness. These theories suggest that comprehension of the flow of events is an active process that is limited by the modularity of attention and memory constraints, but can be enhanced by expert knowledge and strategies. Three implications of this perspective for assessing and improving situation awareness are considered: (1) Scenario variations are proposed that tax awareness by placing demands on attention; (2) Experimental tasks and probes are described for assessing the cognitive processes that underlie situation awareness; and (3) The use of computer-based human performance models to augment the measures of situation awareness derived from performance data is explored. Finally, two potential example applications of the proposed assessment techniques are described, one concerning spatial awareness using wide field of view displays and the other emphasizing fault management in aircraft systems

    Pilot opinions on high level flight deck automation issues: Toward the development of a design philosophy

    Get PDF
    There has been much concern in recent years about the rapid increase in automation on commercial flight decks. The survey was composed of three major sections. The first section asked pilots to rate different automation components that exist on the latest commercial aircraft regarding their obtrusiveness and the attention and effort required in using them. The second section addressed general 'automation philosophy' issues. The third section focused on issues related to levels and amount of automation. The results indicate that pilots of advanced aircraft like their automation, use it, and would welcome more automation. However, they also believe that automation has many disadvantages, especially fully autonomous automation. They want their automation to be simple and reliable and to produce predictable results. The biggest needs for higher levels of automation were in pre-flight, communication, systems management, and task management functions, planning as well as response tasks, and high workload situations. There is an irony and a challenge in the implications of these findings. On the one hand pilots would like new automation to be simple and reliable, but they need it to support the most complex part of the job--managing and planning tasks in high workload situations

    Alaska's Population and Economy

    Get PDF
    State of AlaskaYe
    corecore