Momentum distributions and numerical methods for strongly interacting one-dimensional spinor gases

One-dimensional spinor gases with strong delta interaction fermionize and form a spin chain. The spatial degrees of freedom of this atom chain can be described by a mapping to spinless noninteracting fermions and the spin degrees of freedom are described by a spin-chain model with nearest-neighbor interactions. Here, we compute momentum and occupation-number distributions of up to 16 strongly interacting spinor fermions and bosons as a function of their spin imbalance, the strength of an externally applied magnetic field gradient, the length of their spin, and for different excited states of the multiplet. We show that the ground-state momentum distributions resemble those of the corresponding noninteracting systems, apart from flat background distributions, which extend to high momenta. Moreover, we show that the spin order of the spin chain---in particular antiferromagnetic spin order---may be deduced from the momentum and occupation-number distributions of the system. Finally, we present efficient numerical methods for the calculation of the single-particle densities and one-body density matrix elements and of the local exchange coefficients of the spin chain for large systems containing more than 20 strongly interacting particles in arbitrary confining potentials.Comment: See the ancillary files for the Mathematica notebook used to calculate the results of this paper, the derivation of the formula for the one-body density matrix elements, given by Eq. (22), and a table with the local exchange coefficients of up to 60 harmonically trapped particles. A less efficient method for calculating the exchange coefficients was given in the 2nd version of this manuscrip

Transforming a Business and Information Need Goals’ Ontology into a Formal Specification useful for a Strategy Pattern Recommender System

From a computer science point of view, ontologies are aimed at getting knowledge from a certain domain and providing a consensual understanding of it. In the conceptualization stage, ontologies can be represented by means of UML models. However, UML models are not semantically machine processable. Therefore, during the implementation stage, ontologies expressed as UML models should be translated into formal languages, which allow inferring the ontology. In this work, we present the ontology transformation made from an UML conceptual specification to an OWL formal specification for the quality evaluation domain. This ontology represents concepts and relationships related with goals (both business and information need goals) at different organizational levels in addition to projects, strategies and strategy patterns, which help to achieve specific evaluation goal purposes. The final aim of the transformation is to have a shared knowledge about evaluation goals and strategy patterns that permit to instantiate the suitable strategy to carry out goal purposes. This will allow us to develop a strategy pattern recommender system, which can be useful during the strategy selection process when implementing quality measurement and evaluation projects.Sociedad Argentina de Informática e Investigación Operativ

Transforming a Business and Information Need Goals’ Ontology into a Formal Specification useful for a Strategy Pattern Recommender System

From a computer science point of view, ontologies are aimed at getting knowledge from a certain domain and providing a consensual understanding of it. In the conceptualization stage, ontologies can be represented by means of UML models. However, UML models are not semantically machine processable. Therefore, during the implementation stage, ontologies expressed as UML models should be translated into formal languages, which allow inferring the ontology. In this work, we present the ontology transformation made from an UML conceptual specification to an OWL formal specification for the quality evaluation domain. This ontology represents concepts and relationships related with goals (both business and information need goals) at different organizational levels in addition to projects, strategies and strategy patterns, which help to achieve specific evaluation goal purposes. The final aim of the transformation is to have a shared knowledge about evaluation goals and strategy patterns that permit to instantiate the suitable strategy to carry out goal purposes. This will allow us to develop a strategy pattern recommender system, which can be useful during the strategy selection process when implementing quality measurement and evaluation projects.Sociedad Argentina de Informática e Investigación Operativ

Extending the Conceptual Base for a Holistic Quality Evaluation Approach

For software organizations often performing measurement, evaluation (ME), and even change/improvement (MEC) projects, a wellestablished quality evaluation approach can be useful. In this direction, we have developed a holistic quality evaluation approach whose architecture is based on two pillars, namely: a quality multi-view modeling framework, and ME/MEC integrated strategies. In this paper, we specify the conceptual base for the former pillar. Specifically, we specify an ontology of quality views documenting its main terms, properties and relationships. Quality views are paramount for selecting evaluation strategies and strategy patterns to be assigned as resources to ME/MEC projects. Also, we show how this ontology is semantically linked with the previously built ME domain ontology.Sociedad Argentina de Informática e Investigación Operativa (SADIO

Transforming a Business and Information Need Goals’ Ontology into a Formal Specification useful for a Strategy Pattern Recommender System

From a computer science point of view, ontologies are aimed at getting knowledge from a certain domain and providing a consensual understanding of it. In the conceptualization stage, ontologies can be represented by means of UML models. However, UML models are not semantically machine processable. Therefore, during the implementation stage, ontologies expressed as UML models should be translated into formal languages, which allow inferring the ontology. In this work, we present the ontology transformation made from an UML conceptual specification to an OWL formal specification for the quality evaluation domain. This ontology represents concepts and relationships related with goals (both business and information need goals) at different organizational levels in addition to projects, strategies and strategy patterns, which help to achieve specific evaluation goal purposes. The final aim of the transformation is to have a shared knowledge about evaluation goals and strategy patterns that permit to instantiate the suitable strategy to carry out goal purposes. This will allow us to develop a strategy pattern recommender system, which can be useful during the strategy selection process when implementing quality measurement and evaluation projects.Sociedad Argentina de Informática e Investigación Operativ

Decentralization effects in ecological fiscal transfers - the case of Portugal

Portugal has a unitary system in which the central government transfers funds to lower government levels for their public functions. In 2007, Portugal introduced Ecological Fiscal Transfers (EFT), where municipalities receive transfers for hosting Protected Areas (PA). We study whether introducing EFT in Portugal incentivized municipalities to designate PA and has led to a decentralization of conservation decisions. We employ a Bayesian structural time series approach to estimate the effect of introducing EFT in comparison to a simulated counterfactual time series. Quantitative results show a significant increase in the ratio of municipal and national PA designations following Portugal’s EFT introduction. The analysis furthermore places emphasis on the importance of relevant municipal conservation competencies and the role of local decision makers’ motivations for PA designations. Results have important implications for conservation policy-making in terms of allocating budgets and competencies in multi-level governments

C2C value creation : social anxiety and retail environment

Purpose – Most customers want to interact, whether on social networks or on company websites. This study aims to examine the relationship between customer-to-customer (C2C) interaction and value, considering the roles of social anxiety and the retail environment. Design/methodology/approach – This paper presents three written-scenario experimental studies, where C2C interaction and the retail environment are manipulated, and social anxiety levels are measured. The settings and the measures are changed across the experiments to increase the results’ validity. Findings – A three-way interaction among C2C interaction, social anxiety and retail environment has impacts on experience value and other value-related variables (satisfaction and positive mood). In the offline retail environment, as social anxiety levels increase, the effects of C2C interaction on these variables become weaker. In the online retail environment, as social anxiety levels increase, these effects become stronger. Research limitations/implications – This paper contributes to the literature in three ways. First, it investigates the downside of positive C2C interactions when considering social anxiety and the retail environment where they occur. Second, this paper amplifies the literature about value by extending it to other consumers who can affect the service experience. Finally, this study explores online C2C interaction in a retail environment, an aspect that has been neglected in the research about online interactions. Practical implications – This paper suggests strategies to manage C2C interaction for customers of varying levels of social anxiety in offline and online retail environments to maximise value for them. Originality/value – This paper challenges the widespread idea that a positive C2C interaction always leads to value. By considering social anxiety and the retail environment in C2C literature, this paper explains why and when it is a false notion

Quantum magnetism without lattices in strongly interacting one-dimensional spinor gases

We show that strongly interacting multicomponent gases in one dimension realize an effective spin chain, offering an alternative simple scenario for the study of one-dimensional (1D) quantum magnetism in cold gases in the absence of an optical lattice. The spin-chain model allows for an intuitive understanding of recent experiments and for a simple calculation of relevant observables. We analyze the adiabatic preparation of antiferromagnetic and ferromagnetic ground states, and show that many-body spin states may be efficiently probed in tunneling experiments. The spin-chain model is valid for more than two components, opening the possibility of realizing SU(N) quantum magnetism in strongly interacting 1D alkaline-earth-metal or ytterbium Fermi gases. © 2014 American Physical Society.DFG/EXC/QUESTGerman-Israeli foundationSwiss SNFNCCR Quantum Science and TechnologySwedish Research CouncilLund Universit

Enhancing the Process Specification for Systematic Literature Reviews

SLR (Systematic Literature Review) is a research methodology intended to obtain evidence from scientific articles stored in digital repositories. It must be systematic, repeatable and auditable to formulate research questions about a thematic area or phenomenon of interest and to search, select, analyze and communicate all basic or applied research relevant findings in order to answer those questions. SLR can be carried out on primary or secondary studies. In both cases, well-established processes and methods are required. Although there are guides to the SLR process in Software Engineering, which indicate the steps to be followed in the three phases of the process proposed by Kitchenham, we considered that would be a contribution for the research community the strengthening of its current process specification. For this goal, we document the SLR process specification using mainly the SPEM (Software & Systems Process Engineering Metamodel) language and process modeling perspectives. As long as we develop the present work, we exemplify process aspects using a pilot SLR on software testing ontologies already performed.Sociedad Argentina de Informática e Investigación Operativ

Aplicando una estrategia de mejora que incluye conceptos de requisitos funcionales y no funcionales

Organizations should set and reach business goals for varied purposes using the suitable strategies. Basically, a strategy specifies the activities, methods and another related resources that should be considered in order to achieve a given goal purpose. Goal purposes and their associated strategies can aim at evaluating, testing, developing, or maintaining some entity. Some concrete evaluation purposes such as to understand or monitor can be achieved by strategies embracing non-functional requirements definition, measurement, evaluation and analysis activities. Other specific evaluation purposes such as to improve or control also imply changing the target entity; therefore, strategies should embrace functional requirements definition activities as well. Moreover, specific development and maintenance purposes always involve functional requirements. In this work, we relate business and information need goals with functional and nonfunctional requirements concepts, which are paramount for well-defined strategies. Therefore, we specify vocabularies for them, and illustrate the applicability of an improving strategy –which embeds these concepts- in the context of a running example. Having well-structured vocabularies serving as common ground for diverse strategies may promote a more effective operationalization of projects dealing with evaluation, testing, development and maintenance goal purposes.Las organizaciones deben establecer y alcanzar metas de negocio para diferentes propósitos utilizando las estrategias adecuadas. Básicamente, una estrategia especifica las actividades, los métodos y los recursos relacionados que deben considerarse para lograr un determinado propósito. Los propósitos de las metas y sus estrategias asociadas pueden apuntar a la evaluación, prueba, desarrollo o mantenimiento de alguna entidad. Algunos propósitos específicos de evaluación, como comprender o monitorear, pueden lograrse mediante estrategias que abarcan actividades de definición de requisitos no funcionales, medición, evaluación y análisis. Otros propósitos de evaluación, como mejorar o controlar, implican además cambiar la entidad o su contexto; por lo tanto, las estrategias también deben incluir actividades de definición de requisitos funcionales. En cuanto a los propósitos específicos de desarrollo y mantenimiento, estos siempre implican requisitos funcionales. Este trabajo relaciona las metas de negocio y de necesidad de información con conceptos de requisitos funcionales y no funcionales, que son fundamentales para estrategias bien definidas. Por lo tanto, especificamos sus vocabularios e ilustramos la aplicabilidad de una estrategia de mejora –la cual embebe estos conceptos- mediante un ejemplo que desarrollamos a lo largo de las secciones. Tener vocabularios bien estructurados que sirvan de base común para diversas estrategias puede promover una operacionalización más efectiva de los proyectos que tienen que ver con propósitos de metas de evaluación, prueba, desarrollo y mantenimiento.Facultad de Informátic