Status of Chiral-Scale Perturbation Theory

Chiral-scale perturbation theory $\chi$PT$_\sigma$ has been proposed as an alternative to chiral $SU(3)_L\times SU(3)_R$ perturbation theory which explains the $\Delta I = 1/2$ rule for kaon decays. It is based on a low-energy expansion about an infrared fixed point in three-flavor QCD. In $\chi$PT$_\sigma$, quark condensation $\langle\bar q q \rangle_\mathrm{vac} \neq 0$ induces nine Nambu-Goldstone bosons: $\pi, K, \eta$ and a QCD dilaton $\sigma$ which we identify with the $f_0(500)$ resonance. Partial conservation of the dilatation and chiral currents constrains low-energy constants which enter the effective Lagrangian of $\chi$PT$_\sigma$. These constraints allow us to obtain new phenomenological bounds on the dilaton decay constant via the coupling of $\sigma/f_0$ to pions, whose value is known precisely from dispersive analyses of $\pi\pi$ scattering. Improved predictions for $\sigma \to \gamma \gamma$ and the $\sigma NN$ coupling are also noted. To test $\chi$PT$_\sigma$ for kaon decays, we revive a 1985 proposal for lattice methods to be applied to $K \to \pi$ on-shell.Comment: 10 pages, 1 figure. Presented at the 8th International Workshop on Chiral Dynamics, 29 June 2015 - 03 July 2015, Pisa, Italy. Revision: references and comment adde

Preformed stiffeners used to fabricate structural components for pressurized tanks

Process of fabricating stiffened section components of pressurized tanks for aerospace use was developed. A potential use of the fabrication process is the production of gore and quarter-panel sections of hydrogen and oxygen tanks for space vehicle boosters

Understanding the key drivers of and technology related issues associated with going multi-channel

A multi-channel retail strategy is viewed by many academics and practitioners to be the success model for most retailers. Yet, while there are many drivers of, and advantages related to, using multiple channels to sell products and services to customers likewise there are numerous technology-related issues. Despite this, the multi-channel retailing literature provides little empirical insight into these technology-related constraints. Moreover, there is a lack of multi-channel retailing research which explores the impetuses behind retailers adding new channels to go multi-channel, especially in the context of the UK retail sector. To contribute to gaps in the literature this study utilises a case study research strategy to examine the key motivations behind, and technology-related issues associated with, multi-channel retail strategic implementation, in the setting of the UK retail sector. Three UK based retailers (Boots, Screwfix and Bettys) are used which have different approaches to, and are at different stages of, adopting a multi-channel retail strategy. In addition, they have different backgrounds such as size, product range, sector and type. Consequently, the use of these three different retailers enables exploration of the drivers behind, and technological problems associated with, implementing a multi-channel retail strategy in the context of store and Internet/catalogue retailers. Case analysis reveals novel themes which are not identified, or not clearly recognised, in the literature. These include that key drivers behind retailers going multi-channel are to increase sales, and, meet the needs of the multi-channel shopper. Indeed, customers want to shop via multiple channels and therefore, these retailers have no choice but to go multi-channel if they are to meet customer needs. However, while at a strategic level these motivations were similar across the case study retailers, they also differed. For example, Screwfix added a store channel to enable customers to purchase products and receive them instantly. In contrast, Boots added an Internet channel to drive footfall in-store and increase store sales. Boots were also adding an Internet channel since it provided them with a marketing channel, which, going forward, was likely to replace other communications channels. The findings from this study also reveal that retailers encounter major technology-related issues when adding new, and using multiple, channels. These problems stem from the need to re-design existing logistics and IT infrastructure to offer a seamless, integrated offer to the customer. For instance, to leverage the brand and marketing mix consistently across all channels, and, to implement ‘click and collect’ (i.e. where customers purchase a product in one channel and collect it in another). Also, due to the need to use innovative marketing techniques, in particular, social media. Importantly, this study highlights that these technology-related multi-channel retailing constraints often have a ‘softer’ side. Technology-related problems are frequently intertwined with cultural, engagement and financial/staff resource related issues. This suggests a need for retailers to find entwined solutions to both technology and non- technology related issues to effectively implement a multi-channel retail strategy

Measuring attitude toward theistic faith : assessing the Astley-Francis Scale among Christian, Muslim and secular youth in England

Empirical research within the social scientific study of religion in general and within the psychology of religion in particular remains very conscious of the complex nature of its subject matter. Empirical research in this field needs to take cognisance of the many forms in which religion is expressed (say, Buddhism, Christianity, Hinduism, Islam, Judaism, and Sikhism) and the many facets within the forms (say, beliefs, behaviours and affiliation). Working in the 1970s, Francis (1978a; 1978b) advanced the view that the attitudinal dimension of religion offered a particularly fruitful basis for coordinating empirical enquiry into the correlates, antecedents and consequences of religiosity across the life span

Is One Hyperparameter Optimizer Enough?

Hyperparameter tuning is the black art of automatically finding a good combination of control parameters for a data miner. While widely applied in empirical Software Engineering, there has not been much discussion on which hyperparameter tuner is best for software analytics. To address this gap in the literature, this paper applied a range of hyperparameter optimizers (grid search, random search, differential evolution, and Bayesian optimization) to defect prediction problem. Surprisingly, no hyperparameter optimizer was observed to be `best' and, for one of the two evaluation measures studied here (F-measure), hyperparameter optimization, in 50\% cases, was no better than using default configurations. We conclude that hyperparameter optimization is more nuanced than previously believed. While such optimization can certainly lead to large improvements in the performance of classifiers used in software analytics, it remains to be seen which specific optimizers should be applied to a new dataset.Comment: 7 pages, 2 columns, accepted for SWAN1

Sustained load crack growth design data for Ti-6Al-4V titanium alloy tanks containing hydrazine

Sustained load crack growth data for Ti-6Al-4V titanium alloy in hydrazine per MIL-P-26536 and refined hydrazine are presented. Fracture mechanics data on crack growth thresholds for heat-treated forgings, aged and unaged welds, and aged and unaged heat-affected zones are reported. Fracture mechanics design curves of crack growth threshold stress intensity versus temperature are generated from 40 to 71 C

CF6 jet engine performance deterioration results

The use of the performance baseline from the flight planning manual as a reference to measure changes in cruise fuel flow rates was discussed. For the CF6-6D engine, the introduction of design changes for performance and durability reasons was seen to introduce an average increment relative to this baseline of 3.2% WFM increase at Nl, 2.5% Fn increase at Nl, 0.8% specific fuel consumption (SFC) increase at Fn, and 7 C EGT increase at Nl, while maintaining sufficient SFC margin of the delivered airplane. The effect of revenue service deterioration and performance restoration relative to the reference was shown to be an adder on top of these design effects. A schematic of typical CF6-6D performance through revenue service and airline maintenance is presented in terms of percent cruise SFC relative to an airline datum point (average level upon entering revenue service). The typical changes in SFC margin are shown for airline revenue service through for installations and refurbishments

Modelling temperature-dependent larval development and\ud subsequent demographic Allee effects in adult populations of the alpine butterfly Parnassius smintheus

Climate change has been attributed as a driver of changes to ecological systems worldwide and understanding the effects of climate change at individual, population, community, and ecosystem levels has become a primary concern of ecology. One avenue toward understanding the impacts of climate change on an ecosystem is through the study of environmentally sensitive species. Butterflies are sensitive to climatic changes due to their reliance on environmental cues such as temperature and photoperiod, which regulate the completion of life history stages. As such, the population dynamics of butterflies may offer insight into the impacts of climate change on the health of an ecosystem. In this paper we study the effects of rearing temperature on the alpine butterfly Parnassius smintheus (Rocky Mountain Apollo), both directly through individual phenological changes and indirectly through adult reproductive success at the population level. Our approach is to formulate a mathematical model of individual development parameterized by experimental data and link larval development to adult reproductive success. A Bernoulli process model describes temperature-dependent larval phenology, and a system of ordinary differential equations is used to study impacts on reproductive success. The phenological model takes field temperature data as its input and predicts a temporal distribution of adult emergence, which in turn controls the dynamics of the reproductive success model. We find that warmer spring and summer temperatures increase reproductive success, while cooler temperatures exacerbate a demographic Allee effect, suggesting that observed yearly fluctuations in P. smintheus population size may be driven by inter-annual temperature variability. Model predictions are validated against mark-recapture field data from 2001 and 2003 − 2009