Singlet-triplet splitting, correlation and entanglement of two electrons in quantum dot molecules

Starting with an accurate pseudopotential description of the single-particle states, and following by configuration-interaction treatment of correlated electrons in vertically coupled, self-assembled InAs/GaAs quantum dot-molecules, we show how simpler, popularly-practiced approximations, depict the basic physical characteristics including the singlet-triplet splitting, degree of entanglement (DOE) and correlation. The mean-field-like single-configuration approaches such as Hartree-Fock and local spin density, lacking correlation, incorrectly identify the ground state symmetry and give inaccurate values for the singlet-triplet splitting and the DOE. The Hubbard model gives qualitatively correct results for the ground state symmetry and singlet-triplet splitting, but produces significant errors in the DOE because it ignores the fact that the strain is asymmetric even if the dots within a molecule are identical. Finally, the Heisenberg model gives qualitatively correct ground state symmetry and singlet-triplet splitting only for rather large inter-dot separations, but it greatly overestimates the DOE as a consequence of ignoring the electron double occupancy effect.Comment: 13 pages, 9 figures. To appear in Phys. Rev.

QoS Contract-Aware Reconfiguration of Component Architectures Using E-Graphs

International audienceIn this paper we focus on the formalization of component-based architecture self-reconfiguration as an action associated to quality-of-service (QoS) contracts violation. With this, we aim to develop on the vision of the component-based software engineering (CBSE) as a generator of software artifacts responsible for QoS contracts. This formalization, together with a definition of a QoS contract, forms the basis of the framework we propose to enable a system to preserve its QoS contracts. Our approach is built on a theory of extended graph (e-graph) rewriting as a formalism to represent QoS contracts, component-based architectural structures and architecture reconfiguration. We use a rule-based strategy for the extensible part of our framework. The reconfiguration rules are expressed as e-graph rewriting rules whose left and right hand sides can be used to encode design patterns for addressing QoS properties. These rules, given by a QoS property domain expert, are checked as safe, i.e., terminating and confluent, before its application by graph pattern-matching over the runtime representation of the system

A Framework for Evaluating Quality-Driven Self-Adaptive Software Systems

International audienceOver the past decade the dynamic capabilities of self-adaptive software-intensive systems have proliferated and improved significantly. To advance the field of self-adaptive and self-managing systems further and to leverage the benefits of self-adaptation, we need to develop methods and tools to assess and possibly certify adaptation properties of self-adaptive systems, not only at design time but also, and especially, at run-time. In this paper we propose a framework for evaluating quality-driven self-adaptive software systems. Our framework is based on a survey of self-adaptive system papers and a set of adaptation properties derived from control theory properties. We also establish a mapping between these properties and software quality attributes. Thus, corresponding software quality metrics can then be used to assess adaptation properties

DYNAMICO: A Reference Model for Governing Control Objectives and Context Relevance in Self-Adaptive Software Systems

International audienceDespite the valuable contributions on self-adaptation, most implemented approaches assume adaptation goals and monitoring infrastructures as non-mutable, thus constraining their applicability to systems whose context awareness is restricted to static monitors. Therefore, separation of concerns, dynamic monitoring, and runtime requirements variability are critical for satisfying system goals under highly changing environments. In this chapter we present DYNAMICO, a reference model for engineering adaptive software that helps guaranteeing the coherence of (i) adaptation mechanisms with respect to changes in adaptation goals; and (ii) monitoring mechanisms with respect to changes in both adaptation goals and adaptation mechanisms. DYNAMICO improves the engineering of self-adaptive systems by addressing (i) the management of adaptation properties and goals as control objectives; (ii) the separation of concerns among feedback loops required to address control objectives over time; and (iii) the management of dynamic context as an independent control function to preserve context-awareness in the adaptation mechanism

QPLEX: Realizing the Integration of Quantum Computing into Combinatorial Optimization Software

Quantum computing has the potential to surpass the capabilities of current classical computers when solving complex problems. Combinatorial optimization has emerged as one of the key target areas for quantum computers as problems found in this field play a critical role in many different industrial application sectors (e.g., enhancing manufacturing operations or improving decision processes). Currently, there are different types of high-performance optimization software (e.g., ILOG CPLEX and Gurobi) that support engineers and scientists in solving optimization problems using classical computers. In order to utilize quantum resources, users require domain-specific knowledge of quantum algorithms, SDKs and libraries, which can be a limiting factor for any practitioner who wants to integrate this technology into their workflows. Our goal is to add software infrastructure to a classical optimization package so that application developers can interface with quantum platforms readily when setting up their workflows. This paper presents a tool for the seamless utilization of quantum resources through a classical interface. Our approach consists of a Python library extension that provides a backend to facilitate access to multiple quantum providers. Our pipeline enables optimization software developers to experiment with quantum resources selectively and assess performance improvements of hybrid quantum-classical optimization solutions.Comment: Accepted for the IEEE International Conference on Quantum Computing and Engineering (QCE) 202

REFAS: A PLE Approach for Simulation of Self-Adaptive Systems Requirements

International audienceModel simulation has demonstrated its usefulness in evaluation and decision-making for improving preliminary versions of artefacts before production. Particularly, one of the main goals of simulation is to verify model properties based on data collected from its execution. In this paper, we present the simulation capabilities of our REFAS framework for specifying requirements models for dynamic software products lines and self-adaptive systems. The simulation is controlled by a feedback loop and a reasoning engine that operates on the functional and non-functional requirements. The paper contribution is threefold. First, REFAS allows developers to evaluate and improve requirements models through their simulation capabilities. Second, REFAS provides rich feedback in its interactive simulations for the human modeller to make informed decisions to improve her model. Third, REFAS automates the generation of simulation scenarios required to verify the model adequacy and correctness. We evaluate our contribution by comparing the application of REFAS to a case study used in other approaches

VariaMos: an extensible tool for engineering (dynamic) product lines

International audienceThis paper presents the new release of VariaMos, a Java-based tool for defining variability modeling languages, modeling (dynamic) product lines and cyber-physical self-adaptive systems, and supporting automated verification, analysis, configuration and simulation of these models. In particular, we describe the characteristics of this new version regarding its first release: (1) the capability to create languages for modeling systems with variability, even with different views; (2) the capability to use the created language to model (dynamic) product lines; (3) the capability to analyze and configure these models according to the changing context and requirements; and (4) the capability to execute them over several simulation scenarios. Finally, we show how to use VariaMos with an example, and we compare it with other tools found in the literature

Aspectos claves en la definición y adopción de estándares de interoperabilidad electrónica de datos : El caso de HL7 en el área de la salud

This article presents the results of the analysis that the DRISO research group has conducted about some as­pects which have been found as criti­cal in the process of definition and adoption of standards for exchange of electronic data, in the context of the HL7 standard for interoperability in health. For each considered aspect, its potential contribution to a stan­dard for semantic interoperability is identified, as well as how it is used in the modeling of the objects to ex­change, and in the modeling of the exchange process itself. The analysis of the critical aspects of standards is done following the line of the evolu­tion of HL7 standard, identifying and distinguishing their structural and dynamic aspects. Finally, as a matter of conclusion, a reflection about the applicability of this analysis to the Colombian Ministry of Communica­tions GEL-XML project, for electronic data exchange of basic data in all sectors of the economy.A partir de la revisión de distintos estándares de interoperabilidad electrónica de datos que ha realizado el grupo de investigación DRISO de la Facultad de Ingeniería de la Universidad Icesi, en un esfuerzo conjunto con la Fundación HL7 Colombia, se presenta en este artículo un análisis de algunos aspectos que se han identificado como claves en el proceso de definición y adopción de estándares para el intercambio de información electrónica, previstos en el contexto del estándar de interoperabilidad en salud, HL7. Para cada aspecto considerado, se identifica su contribución potencial a un estándar de interoperabilidad semántica, y cómo se utiliza en el modelamiento, tanto de los objetos a intercambiar, como del proceso de intercambio. Este análisis, además se contextualiza sobre la evolución que ha seguido HL7 en sus distintas versiones, identificando los aspectos estructurales y dinámicos en el estándar.Finalmente, a manera de conclusión, se hace una reflexión de la aplicabilidad del análisis realizado, a proyectos de definición de estándares de interoperabilidad como el proyecto GEL-XML (Gobierno en Línea – XML) del Ministerio de Comunicaciones, que pretende definir un estándar de interoperabilidad para los datos básicos de todos los sectores de la economía colombiana

Visible camera cryostat design and performance for the SuMIRe Prime Focus Spectrograph (PFS)

We describe the design and performance of the SuMIRe Prime Focus Spectrograph (PFS) visible camera cryostats. SuMIRe PFS is a massively multi-plexed ground-based spectrograph consisting of four identical spectrograph modules, each receiving roughly 600 fibers from a 2394 fiber robotic positioner at the prime focus. Each spectrograph module has three channels covering wavelength ranges 380~nm -- 640~nm, 640~nm -- 955~nm, and 955~nm -- 1.26~um, with the dispersed light being imaged in each channel by a f/1.07 vacuum Schmidt camera. The cameras are very large, having a clear aperture of 300~mm at the entrance window, and a mass of $\sim$280~kg. In this paper we describe the design of the visible camera cryostats and discuss various aspects of cryostat performance

Methodological Aspects of the hl7v3 Adoption in Colombia: The Experience of the Clinical Laboratory Tests Technical Committee

El Comité Técnico de Caso de Uso (CTCU) de Órdenes y Resultados de Laboratorio Clínico fue el primer Comité Técnico que inició actividades en la Fundación HL7 Colombia y el primero en proponer estándares HL7 adaptados para Colombia. El trabajo colaborativo entre sus miembros ha sido la base para la definición de las guías de implementación de los casos de uso de Resultados y de Órdenes de Laboratorio. Adicionalmente, como CTCU pionero en el país, realizó una propuesta de guía de guías, es decir, un estándar para la definición de guías de implementación que se basen en CDA (Clinical Document Architecture). Este artículo presenta un recuento de la evolución de los sistemas de información de salud en Colombia y de los primeros pasos que se han dado en la adopción del estándar internacional HL7; se describe la metodología empleada para el desarrollo y la adaptación de las primeras guías de implementación HL7.The clinical laboratory orders and results was the first Use Case Technical Committee (UCTC) which began operations in Colombia and the first one in proposing HL7 adapted standards for Colombia. The collaborative work among its members has been the basis for defining implementation guides for the clinical laboratory orders and results use cases. Additionally, as a pioneer UCTC in Colombia, it developed a guide-for guides proposal, i.e. a standard for defining implementation guides in any domain within the CDA scope. This article presents an overview of the evolution of health information systems in Colombia and the first steps that have been taken for the adoption of the HL7 international standard in the country. It also describes the methodology for the development and adaptation of the first HL7 implementation guides