Effects of asymmetry on the dynamic stability of aircraft

The oblique wing concept for transonic aircraft was proposed to reduce drag. The dynamic stability of the aircraft was investigated by analytically determining the stability derivatives at angles of skew ranging from 0 and 45 deg and using these stability derivatives in a linear analysis of the coupled aircraft behavior. The stability derivatives were obtained using a lifting line aerodynamic theory and found to give reasonable agreement with derivatives developed in a previous study for the same aircraft. In the dynamic analysis, no instability or large changes occurred in the root locations for skew angles varying from 0 to 45 deg with the exception of roll convergence. The damping in roll, however, decreased by an order of magnitude. Rolling was a prominent feature of all the oscillatory mode shapes at high skew angles

A Quantile Monte Carlo approach to measuring extreme credit risk

We apply a novel Quantile Monte Carlo (QMC) model to measure extreme risk of various European industrial sectors both prior to and during the Global Financial Crisis (GFC). The QMC model involves an application of Monte Carlo Simulation and Quantile Regression techniques to the Merton structural credit model. Two research questions are addressed in this study. The first question is whether there is a significant difference in distance to default (DD) between the 50% and 95% quantiles as measured by the QMC model. A substantial difference in DD between the two quantiles was found. The second research question is whether relative industry risk changes between the pre-GFC and GFC periods at the extreme quantile. Changes were found with the worst deterioration experienced by Energy, Utilities, Consumer Discretionary and Financials; and the strongest improvement shown by Telecommunication, IT and Consumer goods. Overall, we find a significant increase in credit risk for all sectors using this model as compared to the traditional Merton approach. These findings could be important to banks and regulators in measuring and providing for credit risk in extreme circumstances.Asset Selection, Factor Model, DEA, Quantile Regression

Review and appraisal - Cost-benefit analyses of earth resources survey satellite systems

Review and assessment of documents concerning cost and benefits of ERS satellites, and value of these studies in directing R and D activitie

Improved high temperature resistant matrix resins

The objective was to develop organic matrix resins suitable for service at temperatures up to 644 K (700 F) and at air pressures up to 0.4 MPa (60 psia) for time durations of a minimum of 100 hours. Matrix resins capable of withstanding these extreme oxidative environmental conditions would lead to increased use of polymer matrix composites in aircraft engines and provide significant weight and cost savings. Six linear condensation, aromatic/heterocyclic polymers containing fluorinated and/or diphenyl linkages were synthesized. The thermo-oxidative stability of the resins was determined at 644 K and compressed air pressures up to 0.4 MPa. Two formulations, both containing perfluoroisopropylidene linkages in the polymer backbone structure, exhibited potential for 644 K service to meet the program objectives. Two other formulations could not be fabricated into compression molded zero defect specimens

A phenomenological model of the superconducting state of the Bechgaard salts

We present a group theoretical analysis of the superconducting state of the Bechgaard salts, e.g., (TMTSF)_2PF_6 or (TMTSF)_2ClO_6. We show that there are eight symmetry distinct superconducting states. Of these only the (fully gapped, even frequency, p-wave, triplet) 'polar state' is consistent with the full range of the experiments on the Bechgaard salts. The gap of the polar state is d(k) (psi_uk,0,0), where psi_uk may be any odd parity function that is translationally invariant.Comment: 4 pages, no figure

Comparing Australian and US Corporate Default Risk using Quantile Regression

The severe bank stresses of the Global Financial Crisis (GFC) have underlined the importance of understanding and measuring extreme credit risk. The Australian economy is widely considered to have fared much better than the US and most other major world economies. This paper applies quantile regression and Monte Carlo simulation to the Merton structural credit model to investigate the impact of extreme asset value fluctuations on default probabilities of Australian companies in comparison to the USA. Quantile regression allows modelling of the extreme quantiles of a distribution which allows measurement of capital and PDs at the most extreme points of an economic downturn, when companies are most likely to fail. Daily asset value fluctuations of over 600 Australian and US investment and speculative entities are examined over a ten year period spanning pre-GFC and GFC. The events of the GFC also showed how the capital of global banks was eroded as defaults increased. This paper therefore also examines the impact of these fluctuating default probabilities on the capital adequacy of Australian and US banks. The paper finds highly significant variances in default probabilities and capital between quantiles in both Australia and the US, and shows how these variances can assist banks and regulators in calculating capital buffers to sustain banks through volatile times.Classification-JEL:Probability of default; Quantile regression; Australian banks; United States banks.

Tail Risk for Australian Emerging Market Entities

Whilst the Australian economy is widely considered to have fared better than many of its global counterparts during the Global Financial Crisis, there was nonetheless extreme volatility experienced in Australian financial markets. To understand the extent to which emerging Australia entities were impacted by these extreme events as compared to established entities, this paper compares entities comprising the Emerging Markets Index (EMCOX) to established entities comprising the S&P/ASX 200 Index using four risk metrics. The first two are Value at Risk (VaR) and Distance to Default (DD), which are traditional measures of market and credit risk. The other two focuses on extreme risk in the tail of the distribution and include Conditional Value at Risk (CVaR) and Conditional Distance to Default (CDD), the latter metric being unique to the authors, and which applies CVaR techniques to default measurement. We apply these measures both prior to and during the GFC, and find that Emerging Market shares show higher risk for all metrics used, the spread between the emerging and established portfolios narrows during the GFC period and that the default risk spread between the two portfolios is greatest in the tail of the distribution. This information can be important to both investors and lenders in determining share or loan portfolio mix in extreme economic circumstances. Classification-JEL:Conditional value at risk; Conditional distance to default; Australian emerging markets

Application of EREP imagery to fracture-related mine safety hazards in coal mining and mining-environmental problems in Indiana

The author has identified the following significant results. This investigation evaluated the applicability of a variety of sensor types, formats, and resolution capabilities to the study of both fuel and nonfuel mined lands. The image reinforcement provided by stereo viewing of the EREP images proved useful for identifying lineaments and for mined lands mapping. Skylab S190B color and color infrared transparencies were the most useful EREP imagery. New information on lineament and fracture patterns in the bedrock of Indiana and Illinois extracted from analysis of the Skylab imagery has contributed to furthering the geological understanding of this portion of the Illinois basin