An Efficient Parallel Solver for SDD Linear Systems

We present the first parallel algorithm for solving systems of linear equations in symmetric, diagonally dominant (SDD) matrices that runs in polylogarithmic time and nearly-linear work. The heart of our algorithm is a construction of a sparse approximate inverse chain for the input matrix: a sequence of sparse matrices whose product approximates its inverse. Whereas other fast algorithms for solving systems of equations in SDD matrices exploit low-stretch spanning trees, our algorithm only requires spectral graph sparsifiers

Understanding Fatigue Within a Collegiate Aviation Program

Objective: The purpose of this study was fivefold: to investigate the symptoms that would prompt collegiate aviation pilots perceive they are fatigued; to investigate the time of the day they are most fatigued; to investigate their academic and personal schedules; to investigate the methods collegiate aviation pilots utilize to ensure they are fit to fly; and to investigate whether they have received any academic and/or flight fatigue identification and management training. Background: Fatigue is a pervasive safety hazard in aviation affecting several aspects of flight crew members’ ability to perform their job. Fatigue in aviation and its consequences has been researched across military and commercial operations, but until now Part 141 collegiate aviation pilots have been neglected. Method: Data were collected using an online survey questionnaire self-report questionnaire (N = 122) consisting of items investigating fatigue identification and management by Part 141 collegiate aviation pilots. Results: Sixty percent of the participants usually experience the mental and physical symptoms of fatigue during flight activities. A finding of concern was that 43% of the participants indicated they had not received any training in fatigue identification and management during ground and flight activities. Conclusion: The safety management of fatigue in a Part 141 collegiate aviation environment is a safety issue that warrants further research, and training and education

VIBRATION DOSAGE FOR HANDHELD POWER TOOLS BASED ON EXPOSURE-RESPONSE RELATIONSHIP FOR WHITE FINGER DISEASE

Power-tool vibrations can cause a variety of health disorders, ranging from inconsequential to disastrous. These vibrations may not be harmful when received in small doses but can cause vasospastic disorders, such as vibration-induced white finger disease (VWF), with frequent use or accumulated over time. Existing occupational guidance does not adequately describe the health risks associated with power-tool vibrations. In the current study, vibration levels for major brands of reciprocating saws and impact drivers were measured under typical use conditions, along with user comfort levels after different usage times. Results are provided in terms of acceleration and comfort levels as a function of usage time, varied grip-force conditions, and with or without use of gloves. Based on the VWF-incidence data from prior occupational studies, guidance on restrictions on usage of power tools is provided. It is found that existing ISO guidance for Europe overestimates allowable times, compared to those determined here

Fatigue In Collegiate Aviation

Flight training has received little attention in fatigue research. Only transfers of knowledge gained in commercial and military aviation have been applied to general aviation without bridging the gap to the training environment. The purpose of this study was to assess collegiate aviation students’ perceptions of lifestyle and mitigation strategies related to fatigue. Participants were recruited from a Midwestern university’s accredited Part 141 flight school and a partner fixed base operator (FBO). The researchers of this study used a survey questionnaire to gather quantitative and qualitative responses. The majority of participants (68%) had logged less than 250 flight hours and were under 25 years of age (93%). Many respondents (66%) reported fatigued stemming from sleep quantity or quality deficits. The primary fatigue contributing factors included an insufficient resting time and an inadequate work-free time balance. Daily free time activities conducive to healthy sleep patterns were frequently neglected. Furthermore, several other factors that affected participants’ lifestyles resulted from demands imposed by the college environment. A finding of concern was that half of the sample did not consider themselves to engage in fully adequate bodily exercise, nutritional habits, and workload or stress management. These areas, however, are prime considerations when working towards healthy sleep patterns. Lastly, the researchers presented recommendations for future research. Findings from this study can assist the general aviation community in gaining a greater understanding of how collegiate aviation students perceive, process, and manage the risk of fatigue in aviation

Fatigue Issues and Mitigation Strategies in Collegiate Aviation

The reduction of fatigue-related accidents has been in the NTSB most wanted list since 2016 (NSTB, 2019). Most research studies have focused on fatigue identification and management within the commercial and/or military aviation environments (Caldwell et al., 2009; Gawron, 2016; Sieberichs & Kluge, 2016). However, collegiate aviation may be the most challenging in terms of fatigue mitigation. Flight instructors and students often have schedules which may increase the risks for fatigue

Экономическая эффективность ранней диагностики и реабилитации при заболеваниях желчевыводящей системы у детей в Республике Беларусь

экономика медицинскаяжелчных путей болезниздравоохранение Республики Беларус

Measuring Fatigue and Sleepiness in Collegiate Aviation Pilots

The National Transportation Safety Board has communicated the need to reduce fatigue related accidents through the top ten most wanted list. Additionally, the International Civil Aviation Organization and Federal Aviation Administration have continuously promoted fatigue risk management. Most fatigue related research as well as safety standards in aviation involve air carrier and military operations. However, there has been a recent revival of fatigue related research in collegiate aviation. A recent study found that 85% of collegiate aviation pilots (n = 141) reported fatigue negatively impacted their flight training activities. Results of a qualitative study indicated poor knowledge and behaviors by Part 141 collegiate aviation students (n = 35) regarding quality and quantity of sleep, decision-making processes, and lifestyle choices. The current research study examines the sleepiness and fatigue of collegiate aviation pilots using self-reported scales. The Karolinska Sleepiness and the Samn-Perelli Scales measure the level of sleepiness and fatigue states, respectively. Thirty students (n = 30) were asked to track their fatigue and sleepiness levels four times a day, once a week, for four months, during the 2019 Fall academic semester. Researchers expect to gain a clearer understanding of how time of the day, day of the week, and month effect sleepiness and fatigue levels during flight operations in a collegiate aviation environment. Understanding these factors may help provide better safety promotion efforts such as training and education, fatigue awareness, and fatigue risk management standards. Findings of this study and opportunities for future research will be discussed

Fatigue in Collegiate Aviation

Flight training has received little attention in fatigue research. Only transfers of knowledge gained in commercial and military aviation have been applied to general aviation without bridging the gap to the training environment. The purpose of this study was to assess collegiate aviation students’ perceptions of lifestyle and mitigation strategies related to fatigue. Participants were recruited from a Midwestern university’s accredited Part 141 flight school and a partner fixed base operator (FBO). The researchers of this study used a survey questionnaire to gather quantitative and qualitative responses. The majority of participants (68%) had logged less than 250 flight hours and were under 25 years of age (93%). Many respondents (66%) reported fatigued stemming from sleep quantity or quality deficits. The primary fatigue contributing factors included an insufficient resting time and an inadequate work-free time balance. Daily free time activities conducive to healthy sleep patterns were frequently neglected. Furthermore, several other factors that affected participants’ lifestyles resulted from demands imposed by the college environment. A finding of concern was that half of the sample did not consider themselves to engage in fully adequate bodily exercise, nutritional habits, and workload or stress management. These areas, however, are prime considerations when working towards healthy sleep patterns. Lastly, the researchers presented recommendations for future research. Findings from this study can assist the general aviation community in gaining a greater understanding of how collegiate aviation students perceive, process, and manage the risk of fatigue in aviation. Abstract from Levin, E., Mendonca, F. C., Keller, J., & Teo, A. (2019). Fatigue In Collegiate Aviation. International Journal of Aviation, Aeronautics, and Aerospace, 6(4). https://doi.org/10.15394/ijaaa.2019.135