Automated Flight Routing Using Stochastic Dynamic Programming

Airspace capacity reduction due to convective weather impedes air traffic flows and causes traffic congestion. This study presents an algorithm that reroutes flights in the presence of winds, enroute convective weather, and congested airspace based on stochastic dynamic programming. A stochastic disturbance model incorporates into the reroute design process the capacity uncertainty. A trajectory-based airspace demand model is employed for calculating current and future airspace demand. The optimal routes minimize the total expected traveling time, weather incursion, and induced congestion costs. They are compared to weather-avoidance routes calculated using deterministic dynamic programming. The stochastic reroutes have smaller deviation probability than the deterministic counterpart when both reroutes have similar total flight distance. The stochastic rerouting algorithm takes into account all convective weather fields with all severity levels while the deterministic algorithm only accounts for convective weather systems exceeding a specified level of severity. When the stochastic reroutes are compared to the actual flight routes, they have similar total flight time, and both have about 1% of travel time crossing congested enroute sectors on average. The actual flight routes induce slightly less traffic congestion than the stochastic reroutes but intercept more severe convective weather

The influence of school and teaching quality on children’s progress in primary school

This report investigates the way school and classroom processes affect the cognitive progress and social/behavioural development of children between the ages of 6 (Year 1) and 10 (Year 5) in primary schools in England. The research is part of the larger longitudinal study of Effective Pre-School and Primary Education (EPPE 3-11) funded by the Department for Children, Schools and Families (DCSF) that is following children’s cognitive and social/behavioural development from ages 3 to 11 years. The EPPE 3-11 study investigates both pre-school and primary school influences on children’s attainment, progress and social/behavioural development. This report describes the results of quantitative analyses based on a subsample of 1160 EPPE children across Year 1 to 5 of primary education. The research builds on the earlier analyses of children’s Reading and Mathematics attainments and social/behavioural outcomes in Year 5 for the full EPPE 3-11 sample (see Sammons, 2007a; 2007b), by investigating relationships between children’s outcomes and measures of classroom processes, collected through direct observation of Year 5 classes in 125 focal schools chosen from the larger EPPE 3-11 data set. The analyses also explore patterns of association between children’s outcomes and broader measures of overall school characteristics derived from teacher questionnaires and Ofsted inspection reports for this sub-sample of schools

Optimizing Aircraft Trajectories with Multiple Cruise Altitudes in the Presence of Winds

This study develops a trajectory optimization algorithm for approximately minimizing aircraft travel time and fuel burn by combining a method for computing minimum-time routes in winds on multiple horizontal planes, and an aircraft fuel burn model for generating fuel-optimal vertical profiles. It is applied to assess the potential benefits of flying user-preferred routes for commercial cargo flights operating between Anchorage, Alaska and major airports in Asia and the contiguous United States. Flying wind optimal trajectories with a fuel-optimal vertical profile reduces average fuel burn of international flights cruising at a single altitude by 1-3 percent. The potential fuel savings of performing en-route step climbs are not significant for many shorter domestic cargo flights that have only one step climb. Wind-optimal trajectories reduce fuel burn and travel time relative to the flight plan route by up to 3 percent for the domestic cargo flights. However, for trans-oceanic traffic, the fuel burn savings could be as much as 10 percent. The actual savings in operations will vary from the simulation results due to differences in the aircraft models and user defined cost indices. In general, the savings are proportional to trip length, and depend on the en-route wind conditions and aircraft types

Relationships between pupils’ self-perceptions, views of primary school and their development in Year 5

The Effective Pre-school and Primary Education Project 3-11 (EPPE 3-11) is a largescale longitudinal study of the impact of pre-school and primary school on children’s developmental outcomes, both cognitive and social/behavioural. The study has been following children from the start of pre-school (at age 3 years plus) through to the end of primary school. Previous reports have focused on the educational and social/behavioural outcomes of the EPPE 3-11 sample at the end of Year 5 (age 10) and progress from the end of Year 1 (age 6) to the end of Year 5 (age 10) in primary school (Sammons et al., 2007a; 2007b). The research also explored the predictive power of a wide variety of child, parent, and family characteristics on attainment and development, including the Early years home learning environment (HLE) during the years of preschool and aspects of the later HLE during Key stage 1 of primary school (Sammons et al., 2002; 2003; Sylva et al., 2004). This research builds on earlier reports (Sammons et al., 2007a; 2007b) by investigating relationships between children’s outcomes in Year 5 and aspects of pupils’ selfperceptions and their views of primary school, measured in Year 5 (age 10) and in Year 2 (age 7) of primary school, controlling for background characteristics. These measures have been derived from a self-report instrument completed by EPPE 3-11 children. The analyses explored associations between children’s progress and development over time and their self-perceptions and views of primary school

Pupils' self-perceptions and views of primary school in year 5

The Effective Pre-School and Primary Education 3-11 (EPPE 3-11) project investigates the impact of preschool, primary school and family on a range of outcomes for a national sample of approximately 2,800 children in England between the ages of 3 and 11 years. This Research Brief presents findings on pupils’ Self-perceptions (‘Enjoyment of school’, ‘Anxiety and Isolation’, ‘Academic self-image’ and ‘Behavioural self-image’) and their views of different features of primary school (‘Teachers’ support for pupils’ learning’, ‘Headteacher qualities’ and ‘Positive social environment’) in Year 5. The analyses involved two steps: first, differences in pupils’ Self-perceptions and Views of primary school measured at Year 5 were explored, in relation to child, family and Home Learning Environment (HLE) characteristics. Second, the relationships between pupils’ Self-perceptions and their Views of primary school and educational outcomes and progress, both cognitive (Reading and Mathematics) and social/behavioural (‘Self-regulation’, ‘Hyperactivity’, ‘Pro-social’ and ‘Anti-social’ behaviour) were investigated. The analyses also explored pupils’ Self-perceptions measured at a younger age (Year 2) and how they relate to children’s later cognitive and social/behavioural outcomes in Year 5 and progress from Year 1 to Year 5

A low-speed generator for energy conversion from marine currents-experimental validation of simulations

Abstract: A low-speed permanent magnet (PM) cable wound generator for electrical energy conversion from marine or tidal currents has been designed and constructed. A key feature of this variable speed direct drive generator is its capability to efficiently generate electricity from tidal currents with very low velocities, in the order of 1 m/s. In arriving at an appropriate design for the generator typical characteristics of tidal currents were considered. Using these characteristics as input, and accounting for the electromagnetic losses, detailed computer simulations using a finite-element method software were carried out to come up with the final design. Various parameters that can influence the generator design are presented. An experimental set-up has been constructed based on the above-mentioned design in order to study the electrical and mechanical performance of the generator through a variety of experiments. The power input for this set-up is a variable speed motor, capable of operating the generator at rotational speeds of 0-16 r/min, representing tidal currents with very low velocities. The generator presented in this paper may be beneficial for a better understanding of an appropriate design and layout of tidal energy conversion systems

Updated review on prognostic factors in mycosis fungoides and new skin lymphoma trials

Background Ten-year survival rates in mycosis fungoides (MF) broadly varies, however, there is no standardized prognostic index available. This is presumably due to low prevalence, heterogeneity, and diagnostic challenges in MF. Recent studies have focused on identifying objective prognostic indices by using different parameters for survival determinants. The Cutaneous Lymphoma International Prognostic Index (CLIPI) and the Prospective Cutaneous Lymphoma International Prognostic Index (PROCLIPI) represent prototypical studies that identify prognostic factors, seeking to improve management and outcomes in early-stage MF. Detecting these factors and stratifying MF patients according to their disease progression risk may help to manage these patients more efficiently. Aims Review the current literature to determine the risk factors determining prognosis in MF. Methodology A Comprehensive literature search was performed using electronic online databases "PubMed" and "Google Scholar" using key words ‘prognostic factor’, ‘prognostic indicator’, ‘mycosis fungoides’, ‘Sezary syndrome’, ‘Skin Lymphoma’, ‘Cutaneous Lymphoma’. Articles published in English language were considered for the review. Results The strongest prognostic factor in MF patients is the stage of the disease. T stage and the presence of extracutaneous disease are the most important factors for survival. Other factors that are associated with worse prognosis are male gender, age >60, presence of plaques, folliculotropism, eosinophilia and lymph node stage above N1/Nx. Elevated LDH was associated with later tumor stages and large cell phenotype at diagnosis had a better prognosis. KIR3DL2 was associated with malignant transformation. Conclusion The PROCLIPI study has assessed risk factors collected in MF patients from different countries and across different ethnicities following a rigorous clinicopathologic process. The findings presented here illustrated that disease prognosis in early stages depends on many contributing factors. Detection and stratification of such factors may allow a personalized approach to management of these patients

Laboratory Measurements of Fe XXIV Line Emission: 3→2 Transitions Near Excitation Threshold

Using the Electron Beam Ion Trap facility at Lawrence Livermore National Laboratory, we have measured relative cross sections for Fe XXIV line emission at electron energies between 0.7 and 3.0 keV. The measurements include line formation by direct electron impact excitation (DE), radiative cascades, resonant excitation (RE), and dielectronic recombination (DR) satellites with captured electrons in n≥5 levels. Good agreement with R-matrix and distorted wave calculations is found. In collisionally ionized plasmas, at temperatures near where the ion abundance peaks (kTe~1.7 keV), the RE contributions are found to be ≲5% of the line emission, while the DR satellites contribute ≲10%. While good agreement with state-of-the-art atomic physics calculations is found, there is less good agreement with existing spectral synthesis codes in common astrophysical use. For the Fe XXIV 3p3/2 → 2s1/2, 3p1/2 → 2s1/2, and 3d5/2 → 2p3/2 transitions, the synthesis code MEKAL underestimates the emissivity in coronal equilibrium by ~20% at temperatures near where the ion abundance peaks. In situations where the ionization balance is not solely determined by the electron temperature, RE and DR satellites may contribute a considerable fraction of the line emission

Semi-static hedging for certain Margrabe type options with barriers

It turns out that in the bivariate Black-Scholes economy Margrabe type options exhibit symmetry properties leading to semi-static hedges of rather general barrier options. Some of the results are extended to variants obtained by means of Brownian subordination. In order to increase the liquidity of the hedging instruments for certain currency options, the duality principle can be applied to set up hedges in a foreign market by using only European vanilla options sometimes along with a risk-less bond. Since the semi-static hedges in the Black-Scholes economy are exact, closed form valuation formulas for certain barrier options can be easily derived.Comment: 18 page