Principles of procedural support in man-machine systems

Two alternative ways of embedding human performance models into man-machine systems exist, namely embedding them directly into the man-machine interface or into the technical system proper as a decision support. The boundary between these two solutions is rather fuzzy and their simultaneous application could also be reasonable and effective

Convergence of eigenvalues for a highly non-self-adjoint differential operator

In this paper we study a family of operators dependent on a small parameter $\epsilon > 0$, which arise in a problem in fluid mechanics. We show that the spectra of these operators converge to N as $\epsilon \to 0$, even though, for fixed $\epsilon > 0$, the eigenvalue asymptotics are quadratic.Comment: 16 page

Empirical source noise prediction method with application to subsonic coaxial jet mixing noise

A general empirical method, developed for source noise predictions, uses tensor splines to represent the dependence of the acoustic field on frequency and direction and Taylor's series to represent the dependence on source state parameters. The method is applied to prediction of mixing noise from subsonic circular and coaxial jets. A noise data base of 1/3-octave-band sound pressure levels (SPL's) from 540 tests was gathered from three countries: United States, United Kingdom, and France. The SPL's depend on seven variables: frequency, polar direction angle, and five source state parameters: inner and outer nozzle pressure ratios, inner and outer stream total temperatures, and nozzle area ratio. A least-squares seven-dimensional curve fit defines a table of constants which is used for the prediction method. The resulting prediction has a mean error of 0 dB and a standard deviation of 1.2 dB. The prediction method is used to search for a coaxial jet which has the greatest coaxial noise benefit as compared with an equivalent single jet. It is found that benefits of about 6 dB are possible

Fish, Family, and Profit

The frightening increase in piracy off the coast of Somalia since the turn of the present century demonstrates just how fast this kind of threat can emerge and how severe the difficulties involved in understanding and subduing it can be. Since 1992, in fact, there have been 3,583 piratical attacks worldwide. According to the United Kingdom’s House of Commons Transport Committee: “This represents an increase from 1993 to 2005 of 168%. In the same period, 340 crew members and passengers died at the hands of pirates, and 464 received injuries

The Search for an American Submarine Strategy and Design

A devastating comparison of the latest American submarines with some captured German U-boats after World War I caused a design and strategy debate in the U.S. Navy which led eventually to a complete redefinition of the American submarine\u27s place in war

Assessing Baseline and Post-Discharge Risk Factors in Subjects with and without Sleep Apnea Undergoing Endoscopy with Deep Sedation

ABSTRACT ASSESSING BASELINE AND POST-DISCHARGE RISK FACTORS IN SUBJECTS WITH AND WITHOUT SLEEP APNEA UNDERGOING ENDOSCOPY WITH DEEP SEDATION Background: Outpatient procedures encompass over 60% of all surgeries in the United States, and the prevalence of obstructive sleep apnea (OSA) remains high among adult surgical ambulatory patients. Ambulatory surgery poses problems for patients with OSA because narcotics and anesthetics used during surgery can complicate the negative effects of OSA, leading to cardiac events, brain hypoxia, and even death. This study was designed to evaluate the prevalence of cardiopulmonary risk factors among post endoscopic patients with diagnosed and undiagnosed sleep apnea. Methods: The study involved a prospective, descriptive cross-sectional design and incorporated a pre-test or post-test data collection approach, using Actigraphy, pulse oximetry and 24-hour ECG monitoring via Bluetooth technology to monitor outpatients undergoing endoscopy with deep Propofol sedation. Patients were recruited pre-procedure to obtain a resting baseline ECG, and pre-procedure values were then monitored post procedure continuously for 24 hours. A p-value less than 0.05 was considered to be statistically significant. A target sample included 50 adult outpatients from a Florida suburban endoscopy center. Results: Pulse oximetry and Actigraph scores revealed no difference based on OSA. The ANOVA for oxygen desaturation events and sleep quality indices reflected no differences across groups. Sleep quality had no measurable influence on adverse events and was similar across groups; participants diagnosed with OSA slept longer than those in the untreated or no OSA group. Regressions for sleep quality indices reflected no differences among groups. Conclusions: There remains a lack of literature on cardiopulmonary and ECG indicators of cardiac risks in patients with OSA in the 24 hours following discharge from ambulatory surgery. This dissertation characterized the ECG at baseline and post-discharge among post-endoscopy outpatients with OSA and without OSA. Further research is recommended

Surviving the Peace: The Advent of American Naval Oceanography, 1914-1924

Throughout the history of the United States, surviving the peace has proved as difficult as winning the war. At the conclusion of the worldwide carnage of 1914-1918, most Americans turned their backs on the prospect of armed conflict and foreign entanglements

THE LEADERSHIP EXPERIENCES OF FEMALE SPECIAL EDUCATION ADMINISTRATORS

When Ella Young Flagg, the first female superintendent of the Chicago Public Schools, proposed that educational leadership was a woman’s “natural field” she could not have predicted that one hundred years later women would have neither a majority of school leadership positions, nor would they be proportionally represented when compared with female teachers (Grogan & Shakeshaft, 2011). Unlike the school leadership positions of the principal and superintendent that have been traditionally dominated by men, female leaders have achieved greater parity in special education administration (Keefe & Parmley, 2003). Although female special education administrators represent an exception to this phenomenon of underrepresentation in school leadership, limited research has been done on this specific population. The purpose of this qualitative study with phenomenological interviewing was to understand the leadership experiences of female special education administrators. The central research question asked: How do female administrators in special education understand their leadership experiences? Eight female special education administrators shared how their personal history and their current leadership experiences influenced their leadership behaviors. For the female special education administrators, their leadership experiences were understood as (1) collaborative-relational, (2) instructional, (3) activism, (4) political, and (5) balanced. Parallels between women’s leadership and the foundations of special education offer an explanation for the success of women leaders in the field. A model of the ways female administrators of special education lead is included. The model demonstrates how collaborative-relational leadership is central to female leadership in special education. Recommendations for future research are included

MECHANISMS OF DISEASE Acute Oxygen-Sensing Mechanisms

JOSEPH PRIESTLEY, ONE OF THE THREE SCIENTISTS CREDITED WITH THE discovery of oxygen, described the death of mice that were deprived of oxygen. However, he was also well aware of the toxicity of too much oxygen, stating, “For as a candle burns much faster in dephlogisticated [oxygen enriched] than in common air, so we might live out too fast, and the animal powers be too soon exhausted in this pure kind of air. A moralist, at least, may say, that the air which nature has provided for us is as good as we deserve.”1 In this review we examine the remarkable mechanisms by which different organs detect and respond to acute changes in oxygen tension. Specialized tissues that sense the local oxygen tension include glomus cells of the carotid body, neuroepithelial bodies in the lungs, chromaffin cells of the fetal adrenal medulla, and smooth-muscle cells of the resistance pulmonary arteries, fetoplacental arteries, systemic arteries, and the ductus arteriosus. Together, they constitute a specialized homeostatic oxygen-sensing system. Although all tissues are sensitive to severe hypoxia, these specialized tissues respond rapidly to moderate changes in oxygen tension within the physiologic range (roughly 40 to 100 mm Hg in an adult and 20 to 40 mm Hg in a fetus)Junta de Andalucí