An accelerated first-order method for solving SOS relaxations of unconstrained polynomial optimization problems

Our interest lies in solving sum of squares (SOS) relaxations of large-scale unconstrained polynomial optimization problems. Because interior-point methods for solving these problems are severely limited by the large-scale, we are motivated to explore efficient implementations of an accelerated first-order method to solve this class of problems. By exploiting special structural properties of this problem class, we greatly reduce the computational cost of the first-order method at each iteration. We report promising computational results as well as a curious observation about the behaviour of the first-order method for the SOS relaxations of the unconstrained polynomial optimization problem.     

Changes in the sensitivity to appetitive and aversive arousal across adulthood.

In 2 cross-sectional studies, the authors examined age-related differences in the evaluation of emotional stimuli in 2 community samples, with participants ranging in age from young to older adulthood (18–81 years old). Pictures of the International Affective Picture System were used in Study 1, and written verbs were used in Study 2. Participants rated these stimuli along the 2 major affective dimensions of hedonic valence and emotional arousal, thus yielding a 2-dimensional affective space for each participant. Young adults showed the expected pattern of 2 distinct clusters of stimuli in this space, representing increasing pleasantness (appetitive activation) and unpleasantness (aversive activation) with increasing emotional arousal. In contrast, for older adults, emotional valence and arousal ratings were linearly related: Low-arousing stimuli were rated as most pleasant, and high-arousing stimuli were rated as most unpleasant. When regressed on age, these changes revealed a gradual decrease of appetitive activation (i.e., the relationship between pleasure and arousal) across adulthood and a linear increase in aversive activation (i.e., the relationship between displeasure and arousal). These results extend previous work on emotional development, adding information as to the role of emotional intensity for affective experience in different age groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Improved calculation of Si sputter yield via first principles derived interatomic potential

Silicon sputter yield under medium energy Ar+ ion bombardment is calculated via molecular dynamics, using a highly accurate interatomic potential for Ar-Si interactions derived from first-principles calculations. Unlike the widely used universal repulsive potentials such as the Moliere or ZBL parameterizations, this new potential, referred to as DFT-ArSi, is developed via localized basis density functional theory. Sputter yields for Si obtained with the DFT-ArSi potential at 500 eV and 1 keV incident energies are found to be within 6% and 2% of experimental results, respectively, while errors using existing potentials are typically on the order of 11%. The DFT-ArSi potential differs from existing empirical potentials in the ∼1 Å interatomic separation range which is shown to be the most important range for modeling low-to-medium energy ion bombardment.     

BRE low-energy-house laboratories—examples of the use of heat Pumps

The low-energy-house laboratories at the Building Research Station incorporate various techniques for reducing energy consumption for space and water heating. They have been built to high standards of insulation, but the main experimental features concern the eight heat pumps. most of which have been purpose designed for their particular applications. In this paper the houses and their heating systems are described briefly and. whilst these are only experiments, it is expected that some may indicate cost-effective ways in which heat pumps may be employed in both new and existing construction in the future.     

Application of β-Sitosterol + γ-Oryzanol-Structured Organogel as Migration Barrier in Filled Chocolate Products

Oil migration in filled pralines is a phenomenon that is highly correlated with the occurrence of chocolate bloom. In this study the potential to suppress or prevent oil migration by incorporation of sterol/sterolster-structured organogels was evaluated. Different quantities, 2.5 or 14% (w/w), of gel with structurant levels of either 10 or 25% (w/w) were studied in a layered model system. The gel was either a part of the nougat or of the chocolate phase, or as a separate layer. Samples were monitored regularly for a period of 24 weeks at storage temperatures of 10, 18 and 28 °C. The amount of migrated oil was determined via DSC analysis of a surface sample. The results indicate that, despite the additional oil brought into the system via the oleogel, the level of oil found in the chocolate layer is reduced through the presence of the gel. In particular, the three-layer system and gelled chocolate appear to be promising routes to either suppress oil migration or improve nutritional profiles by incorporation of liquid oils.