Single pilot IFR program overview and status

The history of the General Aviation Single Pilot IFR research program at NASA LaRC was discussed in general terms. The program objective, justification, and technical approach were given. The facilities used to conduct the research were discussed briefly. A general overview of recent accomplishments, present activities and near term plans were given

Single pilot IFR operating problems determined from accidental data analysis

The accident reports examined were restricted to instrument rated pilots flying in IFR weather. A brief examination was made of accidents which occurred during all phases of flight and which were due to all causes. A detailed examination was made of those accidents which involved a single pilot which occurred during the landing phases of flight, and were due to pilot error. Problem areas found include: (1) landing phase operations especially final approach, (2) pilot weather briefings, (3) night approaches in low IFR weather, (4) below minimum approaches, (5) aircraft icing, (6) imprecise navigation, (7) descending below minimum IFR altitudes, (8) fuel mismanagement, (9) pilot overconfidence, and (10) high pilot workload especially in twins. Some suggested areas of research included: (1) low cost deicing systems, (2) standardized navigation displays, (3) low cost low-altitude warning systems, (4) improved fuel management systems, (5) improved ATC communications, (6) more effective pilot training and experience acquisition methods, and (7) better weather data dissemination techniques

Helicopter sling load accident/incident survey: 1968 - 1974

During the period considered a mean of eleven accidents per year occurred and a mean of eleven persons were killed or seriously injured per year. Forty-one percent of the accidents occurred during hover, and 63 percent of the accidents had pilot error listed as a cause/factor. Many accidents involved pilots losing control of the helicopter or allowing a collision with obstructions to occur. There was a mean of 58 incidents each year and 51 percent of these occurred during cruise

Adaptation of time line analysis program to single pilot instrument flight research

A data base was developed for SPIFR operation and the program was run. The outputs indicated that further work was necessary on the workload models. In particular, the workload model for the cognitive channel should be modified as the output workload appears to be too small. Included in the needed refinements are models to show the workload when in turbulence, when overshooting a radial or glideslope, and when copying air traffic control clearances

Singlet Higgs Phenomenology and the Electroweak Phase Transition

We study the phenomenology of gauge singlet extensions of the Standard Model scalar sector and their implications for the electroweak phase transition. We determine the conditions on the scalar potential parameters that lead to a strong first order phase transition as needed to produce the observed baryon asymmetry of the universe. We analyze the constraints on the potential parameters derived from Higgs boson searches at LEP and electroweak precision observables. For models that satisfy these constraints and that produce a strong first order phase transition, we discuss the prospective signatures in future Higgs studies at the Large Hadron Collider and a Linear Collider. We argue that such studies will provide powerful probes of phase transition dynamics in models with an extended scalar sector.Comment: 36 pages, 13 figures, matches published version; Version with higher resolution figures available at http://www.its.caltech.edu/~profumo/higgs/EWPT.pd

Recommendations about the Big Ideas in Statistics Education: A Retrospective from Curriculum and Research

Five decades of research and curriculum development on the teaching and learning of statistics have produced many recommendations from both researchers and national organizations on the statistical education of our students. Within the last ten years work by both statisticians and statistics educators has focused on a collection of big ideas that are the most important concepts and processes to develop the statistical thinking of our students, our work force, and the lifelong statistical literacy of our citizens. In this paper I look back at the roots of big ideas in statistics education and identify what I believe are the two most important overarching ideas for the statistical education of our students as they progress from the elementary years into tertiary. The paper discusses research on student thinking about big ideas in statistics and presents recommendations for the future of teaching and research in statistics education

Energy transfer and gas diffusion at gas-liquid interfaces

The interactions of gasses and liquids play an important role in many systems in chemistry. Gas-liquid surface scattering techniques are a useful tool towards the investigation of energy transfer resulting from gas-liquid collisions. We use molecular dynamics to simulate surface scattering in order to investigate the effects of incident energy, incidence angle, and surface temperature on energy transfer of a CO2 molecule scattering from a liquid indium surface modeled as a simple Lennard-Jones liquid. We focus our investigation on the two-channel theory of gas-liquid scattering with a primary focus on the trapping-desorption scattering channel. We use a novel technique to investigate the average trajectory of the scattering gas species to determine the effects of energy transfer on this channel. We find species scattering via this channel are unaffected by incident energy and incidence angle in agreement with experimental trends. We find our gas species scattered by the trapping desorption channel emerge with four degrees of freedom thermalized to the surface temperature, with substantial variance in the translational degree of freedom in the surface normal direction which we attribute to both the enthalpy of desorption and interactions with vapor-phase indium atoms. We observe a substantial increase in interactions with vapor-phase indium with increasing temperature. Our second simulation uses molecular dynamics to examine the diffusion of various gas species through a room temperature ionic liquid at standard pressure conditions. We were able to replicate the bulk properties of the bmim PF6 ionic liquid with reasonable accuracy compared with other experimental and theoretical work. We varied the gas species mass, the gas species dipole moment, and the ionic liquid temperature to examine the effects of each variable on gas diffusivity. We find a general trend of increased diffusivity with increasing temperature; however, we are unable to discern a definite trend relating to gas species mass or dipole moment. We observe significant short-time trapping effects on our diffusing gas species, particularly at low temperatures, that make examining the diffusivity of our gases problematic

A system for spacecraft attitude control and energy storage

A conceptual design for a double-gimbal reaction-wheel energy-wheel device which has three-axis attitude control and electrical energy storage capability is given. A mathematical model for the three-axis gyroscope (TAG) was developed, and a system of multiple units is proposed for attitude control and energy storage for a class of spacecraft. Control laws were derived to provide the required attitude-control torques and energy transfer while minimizing functions of TAG gimbal angles, gimbal rates, reaction-wheel speeds, and energy-wheel speed differences. A control law is also presented for a magnetic torquer desaturation system. A computer simulation of a three-TAG system for an orbiting telescope was used to evaluate the concept. The results of the study indicate that all control and power requirements can be satisfied by using the TAG concept

Bayesian estimation of the spatial Durbin error model with an application to voter turnout in the 2004 presidential election

The potential for spatial dependence in models of voter turnout, although plausible from a theoretical perspective, has not been adequately addressed in the literature. Using recent advances in Bayesian computation, we formulate and estimate the previously unutilized spatial Durbin error model and apply this model to the question of whether spillovers and unobserved spatial dependence in voter turnout matters from an empirical perspective. Formal Bayesian model comparison techniques are employed to compare the normal linear model, the spatially lagged X model (SLX), the spatial Durbin model, and the spatial Durbin error model. The results overwhelmingly support the spatial Durbin error model as the appropriate empirical model

Have We Observed the Higgs (Imposter)?

We interpret the new particle at the Large Hadron Collider as a CP-even scalar and investigate its electroweak quantum number. Assuming an unbroken custodial invariance as suggested by precision electroweak measurements, only four possibilities are allowed if the scalar decays to pairs of gauge bosons, as exemplified by a dilaton/radion, a non-dilatonic electroweak singlet scalar, an electroweak doublet scalar, and electroweak triplet scalars. We show that current LHC data already strongly disfavor both the dilatonic and non-dilatonic singlet imposters. On the other hand, a generic Higgs doublet give excellent fits to the measured event rates of the newly observed scalar resonance, while the Standard Model Higgs boson gives a slightly worse overall fit due to the lack signal in the tau tau channel. The triplet imposter exhibits some tension with the data. The global fit indicates the enhancement in the diphoton channel could be attributed to an enhanced partial decay width, while the production rates are consistent with the Standard Model expectations. We emphasize that more precise measurements of the ratio of event rates in the WW over ZZ channels, as well as the event rates in b bbar and tau tau channels, are needed to further distinguish the Higgs doublet from the triplet imposter.Comment: 20 pages, 4 figures; v2: updated with most recent public data as of August 7. A generic Higgs doublet now gives the best fit to data, while the triplet imposter exhibits some tensio