Pattern-based analysis of automated production systems

As formal verification tools gain popularity, the problem arises of making them more accessible to engineers. A correct understanding of the logics in which properties are expressed is needed in order to guarantee that properties correctly encode the intent of the verification process. Writing appropriate properties, in a logic suitable for verification, is a skilful process. Errors in this step of the process can create serious problems since a false sense of security if gained with the analysis. However, when compared to the effort put into developing and applying modelling languages, little attention has been devoted to the process of writing properties that accurately capture verification requirements. This paper illustrates how a collection of property patterns, and its tool support, can help in simplifying the process of generating logical formulae from informally expressed requirements.(undefined

Supporting requirements formulation in software formal verification

Formal verification tools such as model checkers have reached a stage were their applicability in the development process of dependable and safety critical systems has become viable. While the formal verification step in tools such as model checkers is fully automated, writing appropriate models and properties is a skillful process. In particular, a correct understanding of the logics used to express properties is needed to guarantee that properties correctly encode the original requirements. In this paper we illustrate how a patterns-based tool can help in simplifying the process of generating logical formulae from informally expressed requirements

Partial plant models in formal verification of industrial automation discrete systems

The use of a plant model for formal verification of Industrial Automation systems controllers must be used in order to improve the obtained results. However, if there are some cases where the use of a plant model makes the formal verification results more realistic and robust, there are other cases where this does not always happen. The discussion presented in this paper is related with the need of using a Plant Model considering, not all of the Plant Model, but Partial Plant models in order to facilitate formal verification tasks of Industrial Automation Discrete Event Systems

Temperature-independent quantum logic for molecular spectroscopy

We propose a fast and non-destructive spectroscopic method for single molecular ions that implements quantum logic schemes between an atomic ion and the molecular ion of interest. Our proposal relies on a hybrid coherent manipulation of the two-ion system, using optical or magnetic forces depending on the types of molecular levels to be addressed (Zeeman, rotational, vibrational or electronic degrees of freedom). The method is especially suited for the non-destructive precision spectroscopy of single molecular ions, and sets a starting point for new hybrid quantum computation schemes that combine molecular and atomic ions, covering the measurement and entangling steps.Comment: v3. Substantially enlarged manuscript with details of derivations and calculations in two appendices. To appear in PR

Property patterns for the formal verification of automated production systems

In recent years, several approaches to the analysis of automation systems dependability through the application of formal verification techniques have been proposed. Much of the research has been concerned with the modelling languages used, and how best to express the automation systems, so that automated verification might be possible. Less attention, however, has been devoted to the process of writing properties that accurately capture the requirements that need verification. This is however a crucial aspect of the verification process. Writing appropriate properties, in a logic suitable for verification, is a skilful process, and indeed there have been reports of properties being wrongly expressed. In this paper we put forward a tool and a collection of property patterns that aim at providing help in this area

Análisis cinemático de la trayectoria de la barra en la Arrancada y su relación con el rendimiento

El objetivo de este estudio está centrado en la descripción de la trayectoria de la barra en la Arrancada, así como analizar las diferencias entre levantadores de diferente nivel de rendimiento en términos relativos, incorporando como elemento de análisis el desplazamiento de los pies. La muestra está formada por 31 levantadores de categoría masculina de diferentes categorías de peso. Para el estudio comparativo se conforman dos grupos de levantadores en función de la carga relativa, esto es, la carga  máxima levantada en función del peso corporal. Se utiliza la metodología Fotogrametría 3D. Los resultados revelan que los levantadores que consiguen una mayor carga relativa desplazan la barra siguiendo una trayectoria más vertical. Estas diferencias se concretan en un menor desplazamiento horizontal de la barra en el instante en que la barra alcanza la máxima elevación y en el instante del encaje (p: 0,030 y p: 0,005, respectivamente) y en un menor desplazamiento atrás de los pies (p: 0,012). No se han encontrado diferencias en el recorrido vertical de la barra. Estos hallazgos podrían ser tenidos en cuenta en el entrenamiento individualizado de los levantadores, especialmente de los más jóvenes

A new plant modelling approach for formal verification purposes

This paper presents a new approach in plant modeling for the formal verification of real time systems. A system composed by two tanks is used, where all its components are modeled by simple modules and all the interdependences of the system?s modular models are presented. As innovating parameters in the plant modeling, having as purpose its use on formal verification tasks, the plant is modeled using Dymola software and Modelica programming language. The results obtained in simulation are used to define the plant models that are used for the formal verification tasks, using the model-checker UPPAAL. The paper presents, in a more detailed way, the part of this work that is related to formal verification, being pointing out the used plant modeling approach.SCAPS Project supported by FCT, the Portuguese Foundation for Science and Technology, and FEDER, the European regional development fund, under contract POCI/EME/61425/2004 that deals with safety control of automated production syste

How does easing liquidity constraints affect aggregate employment?

We measure the impact of removing liquidity constraints on aggregate employment by focusing on a sudden and unexpected large liquidity injection to Spanish firms in early 2012, when the Spanish central government paid all invoices of firms to regional and municipal governments that were in arrears. We identify the effect on employment from the cross-sectional variation in the size of the liquidity injection received by Spanish municipalities. Our preliminary finding sindicate that labor market responses can be detected both in the municipality where the liquidity injection occurs and in the municipality where firms are headquartered. We find evidence that the effect on unemployment is stronger where the liquidity injection originates whereas the effect on employment is stronger where the firms are located

Testing for alpha-1 antitrypsin in COPD in outpatient respiratory clinics in Spain: A multilevel, cross-sectional analysis of the EPOCONSUL study

Background Alpha-1 antitrypsin deficiency (AATD) is the most common hereditary disorder in adults, but is under-recognized. In Spain, the number of patients diagnosed with AATD is much lower than expected according to epidemiologic studies. The objectives of this study were to assess the frequency and determinants of testing serum α1-antitrypsin (AAT) levels in COPD patients, and to describe factors associated with testing. Methods EPOCONSUL is a cross-sectional clinical audit, recruiting consecutive COPD cases over one year. The study evaluated serum AAT level determination in COPD patients and associations between individual, disease-related, and hospital characteristics. Results A total of 4,405 clinical records for COPD patients from 57 Spanish hospitals were evaluated. Only 995 (22.5%) patients had serum AAT tested on some occasion. A number of patient characteristics (being male [OR 0.5, p < 0.001], ≤55 years old [OR 2.38, p<0.001], BMI≤21 kg/m2 [OR 1.71, p<0.001], FEV1(%)<50% [OR 1.35, p<0.001], chronic bronchitis [OR 0.79, p < 0.001], Charlson index ≥ 3 [OR 0.66, p < 0.001], or history or symptoms of asthma [OR 1.32, p<0.001]), and management at a specialized COPD outpatient clinic [OR 2.73,p<0.001] were identified as factors independently associated with ever testing COPD patients for AATD. Overall, 114 COPD patients (11.5% of those tested) had AATD. Of them, 26 (22.8%) patients had severe deficiency. Patients with AATD were younger, with a low pack-year index, and were more likely to have emphysema (p<0.05). Conclusion Testing of AAT blood levels in COPD patients treated at outpatient respiratory clinics in Spain is infrequent. However, when tested, AATD (based on the serum AAT levels ≤100 mg/dL) is detected in one in five COPD patients. Efforts to optimize AATD case detection in COPD are needed.SEPA

An infrastructure for experience centered agile prototyping of ambient intelligence

Ubiquitous computing poses new usability challenges that cut across design and development. We are particularly interested in "spaces" enhanced with sensors, public displays and personal devices. How can prototypes be used to explore the user's mobility and interaction, both explicitly and implicitly, to access services within these environments? Because of the potential cost of development and design failure, the characteristics of such systems must be explored using early versions of the system that could disrupt if used in the target environment. Being able to evaluate these systems early in the process is crucial to their successful development. This paper reports on an effort to develop a framework for the rapid prototyping and analysis of ambient intelligence systems