A conservative, optimization-based semi-lagrangian spectral element method for passive tracer transport

We present a new optimization-based, conservative, and quasi-monotone method for passive tracer transport. The scheme combines high-order spectral element discretization in space with semi-Lagrangian time stepping. Solution of a singly linearly constrained quadratic program with simple bounds enforces conservation and physically motivated solution bounds. The scheme can handle efficiently a large number of passive tracers because the semi-Lagrangian time stepping only needs to evolve the grid points where the primitive variables are stored and allows for larger time steps than a conventional explicit spectral element method. Numerical examples show that the use of optimization to enforce physical properties does not affect significantly the spectral accuracy for smooth solutions. Performance studies reveal the benefits of high-order approximations, including for discontinuous solutions

Experimental verification of parameters in automobile crankshaft modelling for vibration analysis

In the interest of utilized more stable automobile components at high speed for reduction the vibration of mechanical system, dynamic characteristics analysis plays a vital role in complex mechanical parts. This paper introduces a clarified approach on statistical investigation and modal analysis methodology to study, predict and accurate crankshaft natural frequencies by using design of experiment (DOE). In this research, first, simulation had been done with MSC Nastran/ Patran to find out the natural frequencies in each mode shape of crankshaft as well as the verification with experiment was carried out. In order to less inaccuracy, numerous simplified crankshaft models were created by using these as input and DOE was established to acquire precise parameters of optimized crankshaft design as the second phase. This method can be further used for the optimizing the structural parameters and would provide some value basis to qualitative measure of parameters and determination of optimized structure. In Conclusion, modal verification accuracy between experimental and simulation has improved

The Unfulfilled Potential of Data-Driven Decision Making in Agile Software Development

With the general trend towards data-driven decision making (DDDM), organizations are looking for ways to use DDDM to improve their decisions. However, few studies have looked into the practitioners view of DDDM, in particular for agile organizations. In this paper we investigated the experiences of using DDDM, and how data can improve decision making. An emailed questionnaire was sent out to 124 industry practitioners in agile software developing companies, of which 84 answered. The results show that few practitioners indicated a widespread use of DDDM in their current decision making practices. The practitioners were more positive to its future use for higher-level and more general decision making, fairly positive to its use for requirements elicitation and prioritization decisions, while being less positive to its future use at the team level. The practitioners do see a lot of potential for DDDM in an agile context; however, currently unfulfilled

A Generic Tool for Tracing Executions Back to a DSML's Operational Semantics

International audienceThe increasing complexity of software development requires rigorously defined domain specific modeling languages (DSML). Model-driven engineering (\mde) allows users to define a DSML's syntax in terms of metamodels. The behaviour of a language can also be described, either operationally, or via transformations to other languages (e.g., by code generation). If the first approach requires to redefine analysis tools for each DSML (simulator, model-checker...), the second approach allows to reuse existing tools in the targeted language. However, the second approach (also called translational semantics) imply that the results (e.g., a program crash log, or a counterexample returned by a model checker) may not be straightforward to interpret by the users of a DSML. We propose in this paper a generic tool for formally tracing such analysis/execution results back to the original DSML's syntax and operational semantics, and we illustrate it on xSPEM, a timed process modeling language

Elevated arousal at time of decision-making is not the arbiter of risk avoidance in chickens

The somatic marker hypothesis proposes that humans recall previously experienced physiological responses to aid decision-making under uncertainty. However, little is known about the mechanisms used by non-human animals to integrate risk perception with predicted gains and losses. We monitored the behaviour and physiology of chickens when the choice between a high-gain (large food quantity), high-risk (1 in 4 probability of receiving an air-puff) option (HGRAP) or a low-gain (small food quantity), no-risk (of an air-puff) (LGNAP) option. We assessed when arousal increased by considering different stages of the decision-making process (baseline, viewing, anticipation, reward periods) and investigated whether autonomic responses influenced choice outcome both immediately and in the subsequent trial. Chickens were faster to choose and their heart-rate significantly increased between the viewing and anticipation (post-decision, pre-outcome) periods when selecting the HGRAP option. This suggests that they responded physiologically to the impending risk. Additionally, arousal was greater following a HGRAP choice that resulted in an air-puff, but this did not deter chickens from subsequently choosing HGRAP. In contrast to human studies, we did not find evidence that somatic markers were activated during the viewing period, suggesting that arousal is not a good measure of avoidance in non-human animals

Large-Scale Agile Transformation: A Case Study of Transforming Business, Development and Operations

Today, product development organizations are adopting agile methods in units outside the software development unit, such as in sales, market, legal, operations working with the customer. This broader adoption of agile methods has been labeled large-scale agile transformation and is considered a particular type of organizational change, originating in the software development units. So far, there is little research-based advice on conducting such transformations. Aiming to contribute towards providing relevant research advice on large-scale agile transformation, we apply a research-based framework for evaluating organizational agility on a product development program in a maritime service provider organization. We found that doing a large-scale agile transformation involves many significant challenges, such as having a shared understanding of the problem, getting access to users, and getting commitment to change that needs to be done. In order to overcome such challenges, we discuss the need for a holistic and integrated approach to agile transformation involving all the units linked to software development.publishedVersio

A New Class of Majoron-Emitting Double-Beta Decays

Motivated by the excess events that have recently been found near the endpoints of the double beta decay spectra of several elements, we re-examine models in which double beta decay can proceed through the neutrinoless emission of massless Nambu-Goldstone bosons (majorons). Noting that models proposed to date for this process must fine-tune either a scalar mass or a VEV to be less than 10 keV, we introduce a new kind of majoron which avoids this difficulty by carrying lepton number $L=-2$. We analyze in detail the requirements that models of both the conventional and our new type must satisfy if they are to account for the observed excess events. We find: (1) the electron sum-energy spectrum can be used to distinguish the two classes of models from one another; (2) the decay rate for the new models depends on different nuclear matrix elements than for ordinary majorons; and (3) all models require a (pseudo) Dirac neutrino, having a mass of a several hundred MeV, which mixes with $\nu_e$.Comment: 43 pages, 10 figures (included), [figure captions are now included

Deactivation of Li by vacancy clusters in ion-implanted and flash-annealed ZnO

Li is present in hydrothermally grown ZnO at high concentrations and is known to compensate both n- and p-type doping due to its amphoteric nature. However, Li can be manipulated by annealing and ion implantation in ZnO. Fast, 20 ms flash anneals in the 900–1400°C range result in vacancy cluster formation and, simultaneously, a low-resistive layer in the implanted part of the He- and Li-implanted ZnO. The vacancy clusters, involving 3-4 Zn vacancies, trap and deactivate Li, leaving other in-grown donors to determine the electrical properties. Such clusters are not present in sufficient concentrations after longer (1h) anneals because of a relatively low dissociation barrier ∼2.6 ± 0.3 eV, so ZnO remains compensated until Li diffuses out after 1250°C anneals.Peer reviewe

A three-day forest-bathing retreat enhances positive affect, vitality, optimism, and gratitude: An option for green-care tourism in Italy?

Forest-bathing experiences can be seen as guided recreational activities led by non-clinical trained practitioners in the context of green, slow, and mindful tourism. Notwithstanding its growing practice, there is a lack of research on the psychological benefits which can help support nature-based tourism destination managers in unlocking the potential of this emerging tourism demand. This study will fill in this gap by testing the hypothesis that a three-day forest-bathing retreat, which fits with the most common type of holidays in Europe, will enhance positive affect, vitality, optimism, and gratitude as indicators of hedonic and eudaimonic well-being. Forty-four adults were involved in the residential program and filled-in self-report questionnaires before and after the experience to assess the well-being dimensions considered. Results showed a significant increase for all the assessed variables. We conclude that forest bathing as a mindful tourism practice carried out in natural settings dominated by forests can favor hedonic and eudaimonic well-being, thus becoming a potential source of attractiveness for nature-based touristic destinations, but more transdisciplinary efforts are needed to exploit this potential. In particular, research gaps still exist in Europe on cause-effect relations between forest features and psychological benefits, how forests could be managed to guarantee these benefits to the advantage of a tourism destination, and how tourism and forest management sectors could collaborate in this direction