A Study of the Effects of Repeated 36-Hour Simulated Missions on B-1B Aircrew Members

1994 ◽  
Vol 38 (1) ◽  
pp. 51-55 ◽  
Author(s):  
Kelly J. Neville ◽  
Roger U. Bisson ◽  
Jonathan French ◽  
Johnnie Martinez ◽  
William F. Storm
Keyword(s):  
Cognitive Performance ◽  
Long Range ◽  
Research Effort ◽  
Early Morning ◽  
Multiple Data ◽  
Long Duration ◽  
Global Power ◽  
Sleep Management ◽  
Expert Ratings ◽  
The Military

The military goal of Global Reach - Global Power entails an unprecedented dependence on immediate and sustained long range bombing campaigns. This research effort was initiated to evaluate the feasibility of this type of long range operation by studying the effects of multiple long duration missions on bomber aircrews. Measures of cognitive performance, mood, fatigue, and sleep management suggest that crews learned to adapt to the missions. However, cognitive performance deteriorated during the early morning hours of each mission and expert ratings of flight deck performance suggest that some components of performance may have been negatively impacted by the repeated missions. This research contributes to the base of information that may be used to make operational risk decisions and suggests ways to reduce schedule-related risks. It also explores the effects of sustained operations on complex tasks, as well as on simple tasks, and explores the use of multiple data collection techniques in a non-laboratory setting.

Effects of Fatigue on Cognitive Performance in Long-Duration Simulated Flight Missions

2020 ◽  
Vol 10 (2) ◽  
pp. 82-93
Author(s):  
Eduardo Rosa ◽  
Ola Eiken ◽  
Mikael Grönkvist ◽  
Roger Kölegård ◽  
Nicklas Dahlström ◽  
...  
Keyword(s):  
Executive Functions ◽  
Task Performance ◽  
Cognitive Performance ◽  
Cognitive Tasks ◽  
Fatigue Index ◽  
Fighter Aircraft ◽  
Long Duration ◽  
Metacognitive Accuracy

Abstract. Fighter pilots may be exposed to extended flight missions. Consequently, there is increasing concern about fatigue. We investigated the effects of fatigue and cognitive performance in a simulated 11-hr mission in the 39 Gripen fighter aircraft. Five cognitive tasks were used to assess cognitive performance. Fatigue was measured with the Samn–Perelli Fatigue Index. Results showed that performance in the non-executive task degraded after approximately 7 hr. Fatigue ratings showed a matching trend to the performance in this task. Performance in tasks taxing executive functions did not decline. We interpreted that fatigue can be overridden by increased attentional effort for executive tasks but not for non-executive components of cognition. Participants underestimated their performance and metacognitive accuracy was not influenced by fatigue.

LONG DURATION ECHOES FROM AURORA, METEORS, AND IONOSPHERIC BACK-SCATTER

1953 ◽  
Vol 31 (2) ◽  
pp. 171-181 ◽  
Author(s):  
D. W. R. McKinley ◽  
Peter M. Millman
Keyword(s):  
Long Range ◽  
High Frequency ◽  
The Other ◽  
Very High Frequency ◽  
Long Duration ◽  
E Region ◽  
Very High ◽  
Visual Observations

In the course of the Ottawa meteor program some unusual echoes have been detected on 33 Mc. Echoes from the aurora are discussed and correlated with visual observations. Two mechanisms of radio reflections from the aurora have been proposed but the data here presented are insufficient to favor one over the other. On Aug. 4, 1948, six extremely long duration meteor echoes were observed which may have been due to abnormal ionospheric conditions. From time to time since August, 1948, a weak semipermanent echo has been recorded, usually appearing at a range of about 80 km., and enduring up to an hour. It is suggested that this echo is due to back-scatter from the same sources in the lower E-region that are presumed to be responsible for long-range very high frequency propagation.

scholarly journals Seasonal Variation of the Diurnal Cycle of Rainfall in Southern Contiguous China

2008 ◽  
Vol 21 (22) ◽  
pp. 6036-6043 ◽  
Author(s):  
Jian Li ◽  
Rucong Yu ◽  
Tianjun Zhou
Keyword(s):  
Seasonal Variation ◽  
Diurnal Cycle ◽  
Radiative Forcing ◽  
Early Morning ◽  
Rain Gauge ◽  
Rainfall Events ◽  
Late Afternoon ◽  
Long Duration ◽  
China Region ◽  
Afternoon Peak

Abstract Hourly station rain gauge data are employed to study the seasonal variation of the diurnal cycle of rainfall in southern contiguous China. The results show a robust seasonal variation of the rainfall diurnal cycle, which is dependent both on region and duration. Difference in the diurnal cycle of rainfall is found in the following two neighboring regions: southwestern China (region A) and southeastern contiguous China (region B). The diurnal cycle of annual mean precipitation in region A tends to reach the maximum in either midnight or early morning, while precipitation in region B has a late-afternoon peak. In contrast with the weak seasonal variation of the diurnal phases of precipitation in region A, the rainfall peak in region B shifts sharply from late afternoon in warm seasons to early morning in cold seasons. Rainfall events in south China are classified into short- (1–3 h) and long-duration (more than 6 h) events. Short-duration precipitation in both regions reaches the maximum in late afternoon in warm seasons and peaks in either midnight or early morning in cold seasons, but the late-afternoon peak in region B exists during February–October, while that in region A only exists during May–September. More distinct differences between regions A and B are found in the long-duration rainfall events. The long-duration events in region A show dominant midnight or early morning peaks in all seasons. But in region B, the late-afternoon peak exists during July–September. Possible reasons for the difference in the diurnal cycle of rainfall between the two regions are discussed. The different cloud radiative forcing over regions A and B might contribute to this difference.

scholarly journals First simultaneous measurements of peroxyacetyl nitrate (PAN) and ozone at Nam Co in the central Tibetan Plateau: impacts from the PBL evolution and transport processes

2017 ◽  
Author(s):  
Xiaobin Xu ◽  
Hualong Zhang ◽  
Weili Lin ◽  
Ying Wang ◽  
Shihui Jia
Keyword(s):  
Long Range ◽  
Early Morning ◽  
Diurnal Variations ◽  
Long Range Transport ◽  
Nam Co ◽  
Monsoon Period ◽  
Air Masses ◽  
Upper Troposphere ◽  
Central Tibetan Plateau ◽  
Range Transport

Abstract. Both peroxyacetyl nitrate (PAN) and ozone (O3) are key photochemical products in the atmosphere. Most of the previous in-situ observations of both gases have been made in polluted regions and at low altitude sites. Here we present first simultaneous measurements of PAN and O3 at Nam Co (NMC, 90°57′ E, 30°46′ N, 4745 m  a.s.l.), a remote site in the central Tibetan Plateau (TP). The observations were made during summer periods in 2011 and 2012. The PAN concentrations averaged 0.36 ppb (range: 0.11–0.76 ppb) and 0.44 ppb (range: 0.21–0.99 ppb) during 16–25 August 2011 and 15 May to 13 July 2012, respectively. The O3 concentration varied from 27.9 ppb to 96.4 ppb, with an average of 60.0 ppb. Profound diurnal cycles of PAN and O3 were observed, with minimum values around 05:00 LT, steep rises in the early morning, and broader platforms of high values during 09:00–20:00 LT. We find that the evolution of planetary boundary layer (PBL) played a key role in shaping the diurnal patterns of both gases, particularly the rapid increases of PAN and O3 in the early morning. Air entrainment from the free troposphere into the PBL seemed to cause the early morning increase and be a key factor of sustaining the daytime high concentrations of both gases. The days with higher daytime PBL (about 3 km) showed stronger diurnal variations of both gases and were mainly distributed in the drier pre-monsoon period, while those with shallower daytime PBL (about 2 km) showed minor diurnal variations of both gases and were mainly distributed in the humid monsoon period. Episodes of higher PAN levels were observed occasionally at NMC. These PAN episodes were caused either by rapid downward transport of air masses from the middle/upper troposphere or by long-range transport of PAN plumes from North India. The PAN level in the downward transport cases ranged from 0.5 ppb to 0.7 ppb and may indicate the PAN abundance in the middle/upper troposphere. In the long-range transport case, the PAN level varied in the range of 0.6–1.0 ppb. This long-range transport process influenced most of the western and central TP region for about a week in early June 2012. Our results suggest that polluted air masses from South Asia can significantly enhance the PAN level over the TP. As PAN act as a reservoir of NOx, the impacts of pollution transport from South Asia on tropospheric photochemistry over the TP region deserve further studies.

scholarly journals The GRINDER CONSTRUCTION DESIGN OF A BALL MILL MACHINE FOR THE PROCESS OF HOMOGENIZING BLACK POWDER USING AN AUTOMATIC SYSTEM

2021 ◽  
Vol 2 (Oktober) ◽  
pp. 22-28
Author(s):  
Arif Setiawan ◽  
Dedy Pradigdo ◽  
Farid Hendro Wibowo
Keyword(s):  
Long Range ◽  
Manufacturing Process ◽  
Ball Mill ◽  
Automatic System ◽  
Quantitative Method ◽  
Rapid Development ◽  
Black Powder ◽  
Construction Design ◽  
Steel Balls ◽  
The Military

Combat technology in the military world has undergone a very rapid development in both close combat and long-range combat. Long-range combat is identical to a rocket weapon where the rocket works because of the presence of an igniter that serves to burn the propellant so that when the propellant burns it will produce pressure that will push the rocket hurtling towards a predetermined target. Igniter is very important in the launch of rockets where the filling of the igniter is black powder that has been difficult to obtain because of the difficult manufacturing process and risk of explosion. This research aims to design a tool that can produce black powder with a large enough capacity and good quality and reduce the risk of explosions to support the manufacture of igniters for rocket launches, especially those owned by Indonesian Army. This research used pure experimental quantitative method with empirical calculations to obtain tools with the desired specifications. The results obtained after the calculation are the volume of octagonal prism tubes 2942.5 cm3, the total volume of steel balls with two size variations is 979.5 cm3, the maximum lendutan that occurs on the shaft of the player is 0.108 mm, so it is said to be safe.

Cognitive Performance During Long-Duration Vibration

1982 ◽  
Author(s):  
Richard W. Shoenberger ◽  
C. S. Harris
Keyword(s):  
Cognitive Performance ◽  
Long Duration

Military Budget, War Against Boko Haram Insurgency, and Its Impact on Nigerian Politics and Economy

2018 ◽  
pp. 427-447 ◽  
Author(s):  
Moses Metumara Duruji ◽  
Sunday Idowu ◽  
Okachukwu Dibia ◽  
Favour U. Duruji-Moses
Keyword(s):  
Civil Society ◽  
Poor Performance ◽  
Defense Spending ◽  
Boko Haram ◽  
Northeast Region ◽  
Long Duration ◽  
Religious Sect ◽  
The Military ◽  
The Relationship ◽  
Military Budget

This chapter examines the relationship between the components of defense spending, the fight against insurgency in Nigeria, particularly Boko Haram in the Northeast, and its impact on the politics and economics of the country for the period 2009-2017. The long duration of military rule in Nigeria contributed significantly to under-developing the military, a strategy by the military men in power to secure their hold on power. Added to this was the general poor performance of the military administrations in Nigeria that suppressed civil society in the country. Consequently, the widening of political space when the country transited to democracy in 1999 opened up the space for bottled-up agitations that gave rise to ethnic and religious sect militias propagating diverse agendas. One of such is the Boko Haram which waged an insurgency against Nigeria in the northeast region of the country. To tackle the challenge, the budget for the military was increased. The chapter also discusses the military budget as a result of the counter insurgency, its management in the prosecution of the war against Boko Haram, and its impact on the Nigerian economy.

A Two Components Approach for Long Range Remote Raman and Laser-Induced Breakdown (LIBS) Spectroscopy Using Low Laser Pulse Energy

2018 ◽  
Vol 73 (3) ◽  
pp. 320-328 ◽  
Author(s):  
Anupam K. Misra ◽  
Tayro E. Acosta-Maeda ◽  
John N. Porter ◽  
Genesis Berlanga ◽  
Dalton Muchow ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Long Range ◽  
Raman Spectra ◽  
Homeland Security ◽  
Pulse Energy ◽  
Laser Energy ◽  
Research Effort ◽  
Research Work ◽  
High Signal ◽  
Laser Induced Breakdown

The remote detection of chemicals using remote Raman spectroscopy and laser-induced breakdown spectroscopy (LIBS) is highly desirable for homeland security and NASA planetary exploration programs. We recently demonstrated Raman spectra with high signal-to-noise ratio of various materials from a 430 m distance during daylight with detection times of 1–10 s, utilizing a 203 mm diameter telescopic remote Raman system and 100 mJ/pulse laser energy at 532 nm for excitation. In this research effort, we describe a simple two-components approach that helps to obtain remote Raman and LIBS spectra of targets at distance of 246 m with 3 mJ/pulse in daytime. The two components of the method are: (1) a small spectroscopy system utilizing 76 mm diameter collection optics; and (2) a small remote lens near the target. Remote Raman spectra of various chemicals are presented here with detection time of 1 s. Remote LIBS spectra of minerals using single laser pulse of 3 mJ/pulse energy from a distance of 246 m are also presented. This research work demonstrates a simple approach that significantly improves remote Raman and LIBS capabilities for long range chemical detection with compact low laser power Raman and LIBS systems.

scholarly journals Simple And Complex Cognitive Functions Under Exertional Heat Stress

2015 ◽  
Vol 16 (1) ◽  
pp. 21-25
Author(s):  
Jelena Maric ◽  
Milan Marjanovic ◽  
Dalibor Jovanovic ◽  
Filip Stojanovic ◽  
Djordje Vukmirovic ◽  
...  
Keyword(s):  
Heat Stress ◽  
Reaction Time ◽  
Cognitive Performance ◽  
Cognitive Functions ◽  
Stress Tests ◽  
Physical Strain ◽  
Spatial Part ◽  
Hot Environments ◽  
The Military ◽  
Exertional Heat Stress

ABSTRACTHeat stress is a significant problem in the military services. This study investigated the effects of exertional heat stress on cognitive performance.Forty unacclimated male soldiers performed exertional heat stress tests in cool (20 °C) and hot environments (40 °C). Cognitive performance was assessed using a computerized battery before and immediately after tests. Physical strain in cool conditions induced mild but significant deficits in accuracy in complex tests. The number of correct answers in the Matching to Sample Visual Search was reduced (92,18% correct answers before vs. 88,64 after; p<0,05) and also in the spatial part of the Pattern and Spatial Recognition Memory Test (85,25 vs. 8,75%; p<0,05). These decreases were more pronounced in hot conditions (92,38 vs. 84,31% in before and 84,21 vs. 73,42% in the latter test; ps<0,01 and <0,001, respectively). Exertional heat stress also impaired more simple cognitive functions. A significant decrease in accuracy (95,74 vs. 93,89%) and an increase in reaction time (300,32 vs. 315,00 ms) was observed in the Reaction Time test.Strenuous physical activity in a hot environment induces mild cognitive deficits, especially in more complex tasks.

Long-range Navigation Techniques for the Supersonic Transport

1968 ◽  
Vol 21 (2) ◽  
pp. 226-233 ◽  
Author(s):  
R. H. Waldman
Keyword(s):  
Long Range ◽  
Navigation System ◽  
Point Of View ◽  
Navigation Systems ◽  
Flight Crew ◽  
Supersonic Transport ◽  
Practical Guidelines ◽  
System Verification ◽  
The Military ◽  
Flight Deck

In this paper, presented by the International Air Navigators Council, and written by its Executive Vice Chairman, the navigation of the S.S.T. is considered from the practising navigator's point of view. Extrapolating from present procedures the conclusion is drawn that navigation system verification should continue to be the responsibility of flight-deck management, that self-contained D.R. systems should be monitored by an externally referenced aid, that raw navigational data should continue to be available to the flight crew and finally that simplicity and reliability in navigation systems should be preferred to finite accuracy.Consideration of an environment in which operational data and experience are limited to the military is a difficult assignment at the best of times. In order to discuss, with some degree of intelligence, the long-range navigation system considered desirable in the supersonic environment, we have relied mainly on the process of extrapolation using existing data and operational ‘know how’ to formulate practical guidelines.

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