HIGH PRICE VOLATILITY AND SPILLOVER EFFECTS IN ENERGY MARKETS

Replaced with revised version of paper 07/22/11.Asymmetric shocks, energy markets, oil, spillover effects, volatility, Marketing, Resource /Energy Economics and Policy, GARCH,

The effect of adding inhaled corticosteroids to tiotropium and long-acting beta(2)-agonists for chronic obstructive pulmonary disease (Review)

BackgroundLong-acting bronchodilators comprising long-acting beta(2)-agonists and the anticholinergic agent tiotropiumare commonly used, either on their own or in combination, for managing persistent symptoms of chronic obstructive pulmonary disease. Patients with severe chronic obstructive pulmonary disease who are symptomatic and who suffer repeated exacerbations are recommended to add inhaled corticosteroids to their bronchodilator treatment. However, the benefits and risks of adding inhaled corticosteroid to tiotropium and long-acting beta2-agonists for the treatment of chronic obstructive pulmonary disease are unclear.ObjectivesTo assess the relative effects of adding inhaled corticosteroids to tiotropium and long-acting beta2-agonists treatment in patients with chronic obstructive pulmonary disease.Search strategyWe searched the Cochrane Airways Group Specialised Register of trials (February 2011) and reference lists of articles.Selection criteriaWe included parallel group, randomised controlled trials of three months or longer comparing inhaled corticosteroid and long-acting beta(2)-agonist combination therapy in addition to inhaled tiotropium against tiotropium and long-acting beta2-agonist treatment for patients with chronic obstructive pulmonary disease (COPD).Data collection and analysisTwo review authors independently assessed trials for inclusion and then extracted data on trial quality and the outcome results. We contacted study authors for additional information. We collected information on adverse effects from the trials.Main resultsOne trial (293 patients) was identified comparing tiotropium in addition to inhaled corticosteroid and long-acting beta(2)-agonist combination therapy to tiotropium plus long-acting beta2-agonist. The study was of good methodological quality, however it suffered from high and uneven withdrawal rates between the treatment arms. There is currently insufficient evidence to know how much difference the addition of inhaled corticosteroids makes to people who are taking tiotropium and a long-acting beta(2)-agonist for COPD.Authors' conclusionsThe relative efficacy and safety of adding inhaled corticosteroid to tiotropium and a long-acting beta(2)-agonist for chronic obstructive pulmonary disease patients remains uncertain and additional trials are required to answer this question

Second Line of Defense Virtual Private Network Guidance for Deployed and New CAS Systems

This paper discusses the importance of remote access via virtual private network (VPN) for the Second Line of Defense (SLD) Central Alarm System (CAS) sites, the requirements for maintaining secure channels while using VPN and implementation requirements for current and future sites

Sediment Graphs Based on Entropy Theory

Using the entropy theory, this paper derives an instantaneous unit sediment graph (IUSG or USG) to determine sediment discharge and the relation between sediment yield and runoff volume. The derivation of IUSG requires an expression of the effective sediment erosion intensity whose relation with rainfall is revisited. The entropy theory provides an efficient way to estimate the parameters involved in the derivations. Sediment discharge is also computed using the instantaneous unit hydrograph (IUH), which can also be derived using the entropy theory. This method works as well as the IUSG method, especially when the peak sediment discharge and peak runoff occur at the same time. The entropy theory yields the probability distribution of sediment yield and of sediment discharge, which can then be used to estimate uncertainty in sediment yield prediction

Periodic Optical Variability of Radio Detected Ultracool Dwarfs

A fraction of very low mass stars and brown dwarfs are known to be radio active, in some cases producing periodic pulses. Extensive studies of two such objects have also revealed optical periodic variability and the nature of this variability remains unclear. Here we report on multi-epoch optical photometric monitoring of six radio detected dwarfs, spanning the $\sim$M8 - L3.5 spectral range, conducted to investigate the ubiquity of periodic optical variability in radio detected ultracool dwarfs. This survey is the most sensitive ground-based study carried out to date in search of periodic optical variability from late-type dwarfs, where we obtained 250 hours of monitoring, delivering photometric precision as low as $\sim$0.15%. Five of the six targets exhibit clear periodicity, in all cases likely associated with the rotation period of the dwarf, with a marginal detection found for the sixth. Our data points to a likely association between radio and optical periodic variability in late-M/early-L dwarfs, although the underlying physical cause of this correlation remains unclear. In one case, we have multiple epochs of monitoring of the archetype of pulsing radio dwarfs, the M9 TVLM 513-46546, spanning a period of 5 years, which is sufficiently stable in phase to allow us to establish a period of 1.95958 $\pm$ 0.00005 hours. This phase stability may be associated with a large-scale stable magnetic field, further strengthening the correlation between radio activity and periodic optical variability. Finally, we find a tentative spin-orbit alignment of one component of the very low mass binary LP 349-25.Comment: Accepted to The Astrophysical Journal; 22 pages; 12 figure

An Experimental and Modeling Study on the Response to Varying Pore Pressure and Reservoir Fluids in the Morrow A Sandstone

In mature oil fields undergoing enhanced oil recovery methods, such as CO2 injection, monitoring the reservoir changes becomes important. To understand how reservoir changes influence compressional wave (P) and shear wave (S) velocities, we conducted laboratory core experiments on five core samples taken from the Morrow A sandstone at Postle Field, Oklahoma. The laboratory experiments measured P- and S-wave velocities as a function of confining pressure, pore pressure, and fluid type (which included CO2 in the gas and supercritical phase). P-wave velocity shows a response that is sensitive to both pore pressure and fluid saturation. However, S-wave velocity is primarily sensitive to changes in pore pressure. We use the fluid and pore pressure response measured from the core samples to modify velocity well logs through a log facies model correlation. The modified well logs simulate the brine- and CO2-saturated cases at minimum and maximum reservoir pressure and are inputs for full waveform seismic modeling. Modeling shows how P- and S-waves have a different time-lapse amplitude response with offset. The results from the laboratory experiments and modeling show the advantages of combining P- and S-wave attributes in recognizing the mechanism responsible for time-lapse changes due to CO2 injection

Revisiting Maximum Entropy Inverse Reinforcement Learning: New Perspectives and Algorithms

We provide new perspectives and inference algorithms for Maximum Entropy (MaxEnt) Inverse Reinforcement Learning (IRL), which provides a principled method to find a most non-committal reward function consistent with given expert demonstrations, among many consistent reward functions. We first present a generalized MaxEnt formulation based on minimizing a KL-divergence instead of maximizing an entropy. This improves the previous heuristic derivation of the MaxEnt IRL model (for stochastic MDPs), allows a unified view of MaxEnt IRL and Relative Entropy IRL, and leads to a model-free learning algorithm for the MaxEnt IRL model. Second, a careful review of existing inference algorithms and implementations showed that they approximately compute the marginals required for learning the model. We provide examples to illustrate this, and present an efficient and exact inference algorithm. Our algorithm can handle variable length demonstrations; in addition, while a basic version takes time quadratic in the maximum demonstration length L, an improved version of this algorithm reduces this to linear using a padding trick. Experiments show that our exact algorithm improves reward learning as compared to the approximate ones. Furthermore, our algorithm scales up to a large, real-world dataset involving driver behaviour forecasting. We provide an optimized implementation compatible with the OpenAI Gym interface. Our new insight and algorithms could possibly lead to further interest and exploration of the original MaxEnt IRL model.Comment: Published as a conference paper at the 2020 IEEE Symposium Series on Computational Intelligence (SSCI