A flight investigation of a terminal area navigation and guidance concept for STOL aircraft

A digital avionics system referred to as STOLAND has been test-flown in the NASA CV-340 to obtain performance data for time-controlled guidance in the manual flight director mode. The advanced system components installed in the cockpit included an electronic attitude director indicator and an electronic multifunction display. Navigation guidance and control computations were all performed in the digital computer. Approach paths were flown which included a narrow 180-deg turn and a 1-min, 5-deg straight-in approach to the 30-m altitude go-around point. Results are presented for 20 approaches: (1) blended radio/inertial navigation using TACAN and a microwave scanning beam landing guidance system (MODILS) permitted a smooth transition from area navigation (TACAN) to precision terminal navigation (MODILS), (2) guidance system (flight director) performance measured at an altitude of 30.5 m was within that prescribed for category II CTOL operations on a standard runway, and (3) time of arrival at a point about 2 mi from touchdown was about 4 sec plus or minus sec later than the computed nominal arrival time

A flight investigation of a terminal area navigation and guidance concept for STOL aircraft

A digital avionics system was installed in the CV-340 transport aircraft. Flight tests were made to obtain preliminary performance data in the manual flight director mode using time controlled guidance. These tests provide a basis for selection of terminal area guidance, navigation, and control system concepts for short haul aircraft and for investigating operational procedures

Study of the single body yawed-wing aircraft concept

Areas relating to the development and improvement of the single-fuselage, yawed-wing transonic transport concept were investigated. These included: (1) developing an alternate configuration with a simplified engine installation;(2) determining a structural design speed placard that would allow the engine-airframe match for optimum airplane performance; and (3) conducting an aeroelastic stability and control analysis of the yawed-wing configuration with a flexible wing. A two-engine, single-fuselage, yawed-wing configuration was developed that achieved the Mach 1.2 design mission at 5560 km (3000 nmi) and payload of 18,140 kg (40,000 lb) with a gross weight of 217,700 kg (480,000 lb). This airplane was slightly heavier than the aft-integrated four-engine configuration that had been developed in a previous study. A modified structural design speed placard, which was determined, resulted in a 6% to 8% reduction in the gross weight of the yawed-wing configurations. The dynamic stability characteristics of the single-fuselage yawed-wing configuration were found to be very dependent on the magnitude of the pitch/roll coupling, the static longitudinal stability, and the dihedral effect

Mixed-state twin observables

Twin observables, i.e. opposite subsystem observables A+ and A- that are indistinguishable in measurement in a given mixed or pure state W, are investigated in detail algebraicly and geometrically. It is shown that there is a far-reaching correspondence between the detectable (in W) spectral entities of the two operators. Twin observables are state-dependently quantum-logically equivalent, and direct subsystem measurement of one of them ipso facto gives rise to the indirect (i.e. distant) measurement of the other. Existence of nontrivial twins requires singularity of W. Systems in thermodynamic equilibrium do not admit subsystem twins. These observables may enable one to simplify the matrix representing W.Comment: 13 page

Education and older adults at the University of the Third Age

This article reports a critical analysis of older adult education in Malta. In educational gerontology, a critical perspective demands the exposure of how relations of power and inequality, in their myriad forms, combinations, and complexities, are manifest in late-life learning initiatives. Fieldwork conducted at the University of the Third Age (UTA) in Malta uncovered the political nature of elder-learning, especially with respect to three intersecting lines of inequality - namely, positive aging, elitism, and gender. A cautionary note is, therefore, warranted at the dominant positive interpretations of UTAs since late-life learning, as any other education activity, is not politically neutral.peer-reviewe

Residents\u27 perceptions of smart energy metres

Smart metres are a form of expert system with performance features beyond energy‐consumption record keeping, to include monitoring, analysing, and estimating metre readings. Although smart metres have great capabilities, this technology is still in its infancy in many developing countries, and little is known about the kinds of risks associated with smart metres from residents\u27 perspectives. This research therefore aims to fill this gap by examining the influence of four different types of perceived risk on residents\u27 intentions to use smart metres in Jordan. By following a quantitative approach, 242 survey responses were tested by using structural equation modelling–partial least squares. The statistical results indicated that perceived security and technical risks have a significant and negative impact on residents\u27 intentions to use smart metres. However, perceived privacy and health risks, surprisingly, were found to have no significant negative influence on intention to use. Theoretical and practical implications are indicated, and directions of future research are subsequently specified

Iatrogenic encephalocele: a rare complication of vacuum extraction delivery

Vacuum extraction is a frequently used form of assisted vaginal delivery. Here we describe a child who was born by vacuum extraction delivery. Days after the birth, a frontal swelling, which was thought to be a caput succedaneum, enlarged. Imaging revealed an iatrogenic encephalocele with a large subcutaneous CSF collection. Surgical reconstruction was performed. A parasagittal dura defect was closed. There was no involvement of the superior sagittal sinus. To our knowledge, encephalocele is an infrequent complication of vacuum extraction delivery, rarely described in literature. The child had a good recovery after the operation, without neurologic deficits

The structure of iterative methods for symmetric linear discrete ill-posed problems

The iterative solution of large linear discrete ill-posed problems with an error contaminated data vector requires the use of specially designed methods in order to avoid severe error propagation. Range restricted minimal residual methods have been found to be well suited for the solution of many such problems. This paper discusses the structure of matrices that arise in a range restricted minimal residual method for the solution of large linear discrete ill-posed problems with a symmetric matrix. The exploitation of the structure results in a method that is competitive with respect to computer storage, number of iterations, and accuracy.Acknowledgments We would like to thank the referees for comments. The work of F. M. was supported by Dirección General de Investigación Científica y Técnica, Ministerio de Economía y Competitividad of Spain under grant MTM2012-36732-C03-01. Work of L. R. was supported by Universidad Carlos III de Madrid in the Department of Mathematics during the academic year 2010-2011 within the framework of the Chair of Excellence Program and by NSF grant DMS-1115385

Decadal changes in summertime reactive oxidized nitrogen and surface ozone over the Southeast United States

Widespread efforts to abate ozone (O3) smog have significantly reduced emissions of nitrogen oxides (NOx) over the past 2 decades in the Southeast US, a place heavily influenced by both anthropogenic and biogenic emissions. How reactive nitrogen speciation responds to the reduction in NOx emissions in this region remains to be elucidated. Here we exploit aircraft measurements from ICARTT (July–August 2004), SENEX (June–July 2013), and SEAC4RS (August–September 2013) and long-term ground measurement networks alongside a global chemistry–climate model to examine decadal changes in summertime reactive oxidized nitrogen (RON) and ozone over the Southeast US. We show that our model can reproduce the mean vertical profiles of major RON species and the total (NOy) in both 2004 and 2013. Among the major RON species, nitric acid (HNO3) is dominant (∼ 42–45%), followed by NOx (31%), total peroxy nitrates (ΣPNs; 14%), and total alkyl nitrates (ΣANs; 9–12%) on a regional scale. We find that most RON species, including NOx, ΣPNs, and HNO3, decline proportionally with decreasing NOx emissions in this region, leading to a similar decline in NOy. This linear response might be in part due to the nearly constant summertime supply of biogenic VOC emissions in this region. Our model captures the observed relative change in RON and surface ozone from 2004 to 2013. Model sensitivity tests indicate that further reductions of NOxemissions will lead to a continued decline in surface ozone and less frequent high-ozone events