Predicting effects of interactive stresses on human performance during long-duration space operations

Author(s):  
P. HANCOCK ◽  
J. CAIRD ◽  
R. PARASURAMAN
Author(s):  
Richard J. Hornick ◽  
Norman M. Lefritz

This article describes a study conducted to determine the effects of long duration, random vibration—characteristic of low-altitude high-speed (LAHS) flight aircraft—on human performance, physiological, biodynamic, and tolerance responses. Ten subjects experienced 0.10, 0.15, and 0.20 RMS g with a shaped power spectral density from 1 to 12 cps while engaging in LAHS control tasks. Simulation runs were of 5 hours duration, with the centermost 4 hours under dynamic conditions. Results of this experiment are related to those of other studies which had the same general objectives in order to provide a brief review and summary about what is known regarding human capabilities for LAHS flight.


1983 ◽  
Vol 27 (6) ◽  
pp. 472-472
Author(s):  
John C. Guignard ◽  
Alvah C. Bittner ◽  
Mary M. Harbeson

Oscillatory ship motion and vibration effects on crews in modern naval air and sea systems can be the limiting factor in mission performance. The mechanisms of these effects, however, have not yet been clearly delineated; nor have a practical taxonomy and standard methodology for distinguishing and evaluating the deleterious action of whole-body vibratory motion on human performance been established. Some effects of vibration on performance appear to be directly attributable to immediate mechanical disruption of input and /or output (i.e., interference at the points of contact—displays or controls—between operator and task). Far more meager is clear evidence for time-dependent disruptive or degrading effects of vibration on central cognitive processes: these of course may also be affected indirectly by changes in the physiological state (including motion sickness and fatigue) induced by the motion or vibration. The distinction between direct and indirect mechanisms of performance decrement in the motion environment has important implications for both protective measures and the focus of future research. This report considers published work on the performance effects of vibration in relation to the etiology of performance change and those implications. A critical review of the methodology of performance studies in motion and vibration environments is under way at the Naval Biodynamics Laboratory; and a series of experiments (some previously published) on whole-body vibration effects on performance is also in progress. While the duality of the mechanisms of action of oscillatory motion on performance remains an open question, the evidence so far adduced for other than direct mechanical effects is sparse, at least in the frequency range of major body resonance phenomena. Further experimentation, including long-duration studies, is needed to resolve this question. Implications both for future research directions and for current national and international standardization efforts in this area are discussed.


1986 ◽  
Vol 30 (4) ◽  
pp. 365-369
Author(s):  
David M. Regal

Space provides a unique living and working environment. Humans in space are, in many respects, different creatures than their Earth-bound counterparts (e.g., they float). If we want to design an environment that makes our astronauts as efficient and productive as possible we must design for their capabilities as they exist in space. In this paper I first describe some of the ways in which human capabilities in space are different from those on Earth. I then discuss psychological and social factors that can affect crew performance on long-duration space missions.


1994 ◽  
Vol 144 ◽  
pp. 279-282
Author(s):  
A. Antalová

AbstractThe occurrence of LDE-type flares in the last three cycles has been investigated. The Fourier analysis spectrum was calculated for the time series of the LDE-type flare occurrence during the 20-th, the 21-st and the rising part of the 22-nd cycle. LDE-type flares (Long Duration Events in SXR) are associated with the interplanetary protons (SEP and STIP as well), energized coronal archs and radio type IV emission. Generally, in all the cycles considered, LDE-type flares mainly originated during a 6-year interval of the respective cycle (2 years before and 4 years after the sunspot cycle maximum). The following significant periodicities were found:• in the 20-th cycle: 1.4, 2.1, 2.9, 4.0, 10.7 and 54.2 of month,• in the 21-st cycle: 1.2, 1.6, 2.8, 4.9, 7.8 and 44.5 of month,• in the 22-nd cycle, till March 1992: 1.4, 1.8, 2.4, 7.2, 8.7, 11.8 and 29.1 of month,• in all interval (1969-1992):a)the longer periodicities: 232.1, 121.1 (the dominant at 10.1 of year), 80.7, 61.9 and 25.6 of month,b)the shorter periodicities: 4.7, 5.0, 6.8, 7.9, 9.1, 15.8 and 20.4 of month.Fourier analysis of the LDE-type flare index (FI) yields significant peaks at 2.3 - 2.9 months and 4.2 - 4.9 months. These short periodicities correspond remarkably in the all three last solar cycles. The larger periodicities are different in respective cycles.


2008 ◽  
Vol 44 ◽  
pp. 11-26 ◽  
Author(s):  
Ralph Beneke ◽  
Dieter Böning

Human performance, defined by mechanical resistance and distance per time, includes human, task and environmental factors, all interrelated. It requires metabolic energy provided by anaerobic and aerobic metabolic energy sources. These sources have specific limitations in the capacity and rate to provide re-phosphorylation energy, which determines individual ratios of aerobic and anaerobic metabolic power and their sustainability. In healthy athletes, limits to provide and utilize metabolic energy are multifactorial, carefully matched and include a safety margin imposed in order to protect the integrity of the human organism under maximal effort. Perception of afferent input associated with effort leads to conscious or unconscious decisions to modulate or terminate performance; however, the underlying mechanisms of cerebral control are not fully understood. The idea to move borders of performance with the help of biochemicals is two millennia old. Biochemical findings resulted in highly effective substances widely used to increase performance in daily life, during preparation for sport events and during competition, but many of them must be considered as doping and therefore illegal. Supplements and food have ergogenic potential; however, numerous concepts are controversially discussed with respect to legality and particularly evidence in terms of usefulness and risks. The effect of evidence-based nutritional strategies on adaptations in terms of gene and protein expression that occur in skeletal muscle during and after exercise training sessions is widely unknown. Biochemical research is essential for better understanding of the basic mechanisms causing fatigue and the regulation of the dynamic adaptation to physical and mental training.


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