New Set Of Actions Research Articles

Distribution functions for resonantly trapped orbits in the Galactic disc

The present-day response of a Galactic disc stellar population to a non-axisymmetric perturbation of the potential has previously been computed through perturbation theory within the phase-space coordinates of the unperturbed axisymmetric system. Such an Eulerian linearized treatment however leads to singularities at resonances, which prevent quantitative comparisons with data. Here, we manage to capture the behaviour of the distribution function (DF) at a resonance in a Lagrangian approach, by averaging the Hamiltonian over fast angle variables and re-expressing the DF in terms of a new set of canonical actions and angles variables valid in the resonant region. We then follow the prescription of Binney (2016), assigning to the resonant DF the time average along the orbits of the axisymmetric DF expressed in the new set of actions and angles. This boils down to phase-mixing the DF in terms of the new angles, such that the DF for trapped orbits only depends on the new set of actions. This opens the way to quantitatively fitting the effects of the bar and spirals to Gaia data in terms of distribution functions in action space.

Distribution functions for resonantly trapped orbits in our Galaxy

AbstractWe show how to capture the behaviour of the phase-space distribution function (DF) of a Galactic disc stellar population at a resonance. This is done by averaging the Hamiltonian over fast angle variables and re-expressing the DF in terms of a new set of canonical actions and angles variables valid in the resonant region. We then assign to the resonant DF the time average along the orbits of the axisymmetric DF expressed in the new set of actions and angles. This boils down to phase-mixing the DF in terms of the new angles, such that the DF for trapped orbits only depends on the new set of actions. This opens the way to quantitatively fitting the effects of the bar and spirals to Gaia data in terms of distribution functions in action space.

Distribution functions for Galactic disc stellar populations in the presence of non-axisymmetric perturbations

AbstractThe present-day response of a Galactic disc stellar population to a non-axisymmetric perturbation of the potential, in the form of a bar or spiral arms, can be treated, away from the main resonances, through perturbation theory within the action-angle coordinates of the unperturbed axisymmetric system. The first order moments of such a perturbed distribution function (DF) in the presence of spiral arms give rise to non-zero radial and vertical mean stellar velocities, called breathing modes. Such an Eulerian linearized treatment however diverges at resonances. The Lagrangian approach to the impact of non-axisymmetries at resonances avoids this problem. It is based on the construction of new orbital tori in the resonant trapping region, which come complete with a new system of angle-action variables. These new tori can be populated by phase-averaging the unperturbed DF over the new tori. This boils down to phase-mixing the DF in terms of the new angles, such that the DF for trapped orbits only depends on the new set of actions. This opens the way to quantitatively fitting the effects of the bar and spirals to Gaia data with an action-based DF.

A new sustainability model: engaging the entire firm

Purpose – The sustainable activity model re-envisions Porter's value chain to reflect the emerging impact of sustainability on firm strategy. The model helps to convert high level sustainability vision statements into a new set of actions that can create value from emerging issues like climate change, resource constraints, and a smaller, more connected world. Design/methodology/approach – The emergence and growth of sustainability, provides an opportunity to rethink traditional business models to better reflect current and emerging market conditions. Porter's value chain was adapted to reflect that: the value of a firm is based on more than just the profit margin and includes reputation, brand value and license to operate; sustainability can generate value by improving both internal and external engagement and collaboration; and the impact that the firm has on the outside world need to be included in firm strategy and decision making. Findings – The sustainable activity model is useful for focusing strategy on the material impacts of the firm rather than focusing on the issues that are most prevalent in the media or where managers have a particular interest. The model allows the firm to clearly set out new actions and new behaviors that change how the firm interacts with the world and how value is created. Originality/value – The sustainable activity model adapts the traditional value chain model to better fit the business issues that have emerged over the last 25 years and to prepare for a future that will continue to change at an ever increasing rate. Applying the model to strategy and business decisions will encourage new ways of thinking about value and generate new activities for creating value and enhancing the resilience of the firm against future changes as the sustainability trend continues to evolve.

Multicriteria decision support using rules that represent rough-graded preference relations

The approach described in this paper aims to support multicriteria choice and ranking of actions when the input preference information acquired from the decision maker is a graded comprehensive pairwise comparison (or ranking) of reference actions. It is based on decision-rule preference model induced from a rough approximation of the graded comprehensive preference relation among the reference actions. The set of decision rules applied to a new set of actions provides a graded fuzzy preference relation, which can be exploited by weighted-fuzzy net flow score or lexicographic-fuzzy net flow score procedure to obtain a final recommendation in terms of the best choice or of the ranking.

Implications of design deficiency on building maintenance at post-occupational stage

The repercussions from design failures have been the subject of much study. With every passing moment the implications of design deficiency presents a new set of actions and reactions. In this contemporary technological/scientific era, this field of study acts as a ‘Testing Lab’ of designers’ ideas. Any part of the globe can serve as a testing field for such studies if there is building design. These studies can help both the designer to improve their skills and industry to develop new materials. Despite current technological advancement, the prevention of unplanned building maintenance is still not being achieved. This research paper highlights examples of design that were not finished within the required parameters and thus resulted in faults. The study also highlights the effect of faulty design on building maintenance.

Analysis in indexing: document and domain centered approaches

The paper discusses the notion of steps in indexing and reveals that the document-centered approach to indexing is prevalent and argues that the document-centered approach is problematic because it blocks out context-dependent factors in the indexing process. A domain-centered approach to indexing is presented as an alternative and the paper discusses how this approach includes a broader range of analyses and how it requires a new set of actions from using this approach; analysis of the domain, users and indexers. The paper concludes that the two-step procedure to indexing is insufficient to explain the indexing process and suggests that the domain-centered approach offers a guide for indexers that can help them manage the complexity of indexing.

Parent actions, dualities and new Weyl-invariant actions of bosonicp-branes

By using the systematic approach of parent action method, we derive one Weyl-noninvariant and two Weyl-invariant actions of bosonic $p$-branes ($p\geq 2$) starting from the Nambu-Goto action, and establish the duality symmetries in this set of four actions. Moreover, we discover a new bosonic $p$-brane action (including the string theory) and deduce two corresponding Weyl-invariant formulations by proposing a new special parent action. We find that the same duality symmetries as those mentioned above exist in this new set of actions. The new $p$-brane actions are also briefly analyzed.

Internal adaptations to effects of changes in financial accounting standards

Managers of organizations may be expected to select actions which will lead to favorable performance evaluations. Evaluations which are based upon accounting measures may be affected by changes in financial accounting standards. These effects on performance evaluations may motivate managers to change selctions of actions in order to maintain favorable evaluations even though the new set of actions may not be in the best interests of the organization. A survey of current research reveals that these effects have been misclassified in assessing the effects of changes in accounting standards. This paper develops a conceptual framework for testing the proposition that firms which have failed to effectively adapt internally for the effects of changes in financial accounting standards may experience unintended side effects as a result of changed management actions. The major points of the paper are illustrated in a hypothetical case study involving Research and Development activity.