Exploring Conditional Rewriting Logic Computations

[EN] Trace exploration is concerned with techniques that allow computation traces to be dynamically searched for specific contents. Depending on whether the exploration is carried backward or forward, trace exploration techniques allow provenance tracking or impact tracking to be done. The aim of provenance tracking is to show how (parts of) a program output depends on (parts of) its input and to help estimate which input data need to be modified to accomplish a change in the outcome. The aim of impact tracking is to identify the scope and potential consequences of changing the program input. Rewriting Logic (RWL) is a logic of change that supplements (an extension of) the equational logic by adding rewrite rules that are used to describe (nondeterministic) transitions between states. In this paper, we present a rich and highly dynamic, parameterized technique for the forward inspection of RWL computations that allows the nondeterministic execution of a given conditional rewrite theory to be followed up in different ways. With this technique, an analyst can browse, slice, filter, or search the traces as they come to life during the program execution. The navigation of the trace is driven by a user-defined, inspection criterion that specifies the required exploration mode. By selecting different inspection criteria, one can automatically derive a family of practical algorithms such as program steppers and more sophisticatedThis work has been partially supported by the EU (FEDER) and the Spanish MEC project Ref. TIN2010-21062-C02-02, the Spanish MICINN complementary action Ref. TIN2009-07495-E, and by Generalitat Valenciana Ref. PROMETEO2011/052. This work was carried out during the tenure of D. Ballis' ERCIM "Alain Bensoussan" Postdoctoral Fellowship. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement N. 246016. F. Frechina was supported by FPU-ME grant AP2010-5681, and J. Sapina was supported by FPI-UPV grant SP2013-0083.Alpuente Frasnedo, M.; Ballis, D.; Frechina Navarro, F.; Sapiña Sanchis, J. (2015). Exploring Conditional Rewriting Logic Computations. Journal of Symbolic Computation. 69:3-39. https://doi.org/10.1016/j.jsc.2014.09.028S3396

Translating between Alloy specifications and UML class diagrams annotated with OCL

Model-driven engineering (MDE) is a software engineering approach based on model transformations at different abstraction levels. It prescribes the development of software by successively transforming the models from abstract (specifications) to more concrete ones (code). Alloy is an increasingly popular lightweight formal specification language that supports automatic verification. Unfortunately, its widespread industrial adoption is hampered by the lack of an ecosystem of MDE tools, namely code generators. This paper presents a model transformation from Alloy to UML class diagrams annotated with OCL (UML+OCL) and shows how an existing transformation from UML+OCL to Alloy can be improved to handle dynamic issues. The proposed bidirectional transformation enables a smooth integration of Alloy in the current MDE contexts, by allowing UML+OCL specifications to be transformed to Alloy for validation and verification, to correct and possibly refine them inside Alloy, and to translate them back to UML+OCL for sharing with stakeholders or to reuse current model-driven architecture tools to refine them toward code.This work was funded by European Regional Development Fund (ERDF) through the COMPETE Programme (operational program for competitiveness) and by national funds through the FCT (Fundaaco para a Ciencia e a Tecnologia-portuguese Foundation for Science and Technology) within project FCOMP-01-0124-FEDER-020532. Part of the work was done while the first author was visiting the Software Design Group at CSAIL, MIT, USA, funded by FCT sabbatical grant SFRH/BSAB/1187/2011. The second author was also partially supported by QREN (the portuguese National Strategy Reference Chart) project 1621, while visiting the High-Assurance Software Laboratory at Universidade do Minho, Portugal. Finally, we would also like to thank all anonymous reviewers for the valuable comments and suggestions

Adhesión de las mujeres embarazadas a los ejercicios para fortalecer el suelo pélvico

Objective: To analyse the adherence of pregnant women to pelvic floor muscle exercises (PFME) during pregnancy. Methods: Prospective study, with 315 pregnant women; data collection was performed by phone and face-to-face; data analysis was descriptive and inferential with 5% significance level. Results: In the first half of pregnancy, the total adherence was 36.5%; when gathered total adherence and partial adherence, the percentage reached was 54%; during pregnancy, there was a gradual decrease (from 46% to 39.7%) of women who reported no adherence; there was no significant association between adherence and the sociodemographic, obstetric and clinics characteristics. Conclusion: The majority of pregnant women in all trimesters of pregnancy reported total or partial adherence to PFME; it was highly positive the proportion of women who reported performing PFME

Regression Models Analysis for the Degradation of Polystyrene Waste by Thermogravimetric Data

Plastics are known for their beneficial properties, such as lightness, strength, and low cost, and they are used in different applications such as construction, electronics, and packaging. However, plastics do not degrade naturally, accumulating in soils and affecting the environment. Recycling techniques have been developed to minimize plastic waste; chemical recycling through pyrolysis has been cataloged as an effective method for transforming plastic waste into high-value products in the chemical and petrochemical industry. Previous studies of feedstock degradation through thermogravimetry analysis (TGA) have been essential to estimate the optimal temperature ranges to evaluate the pyrolysis process. The present work aims to study regression models to estimate the temperature degradation of polystyrene (PS) through thermogravimetry data, which can be applied before the pyrolysis process. In addition, this work compares linear and polynomial regression models to estimate the best-fitting model and to determine the maximum temperature of degradation of PS by different heating rates. Relative errors were calculated by comparing them with experimental values from the literature not included in the models. As a result, a polynomial model of a fourth-order obtained a better fit with an r2=70.45 % compared to the linear models, where the best fit was obtained with r2= 69.71 %. However, a higher relative error was obtained, with the polynomial models being the lowest, 7.35 and 0.50 % for 15 and 60 °C min-1; for the linear models, 7.05 and 0.39 % were obtained for heating rates of 15 and 60 °C min-1, respectively

Liquid flow-focused by a gas: jetting, dripping and recirculation

The liquid cone-jet mode can be produced upon stimulation by a co-flowing gas sheath. Most applications deal with the jet breakup, leading to either of two droplet generation regimes: jetting and dripping. The cone-jet flow pattern is explored by direct axisymmetric VOF numerical simulation; its evolution is studied as the liquid flow-rate is increased around the jetting-dripping transition. As observed in other focused flows such as electrospraying cones upon steady thread emission, the flow displays a strong recirculating pattern within the conical meniscus; it is shown to play a role on the stability of the system, being a precursor to the onset of dripping. Close to the minimum liquid flow rate for steady jetting, the recirculation cell penetrates into the feed tube. Both the jet diameter and the size of the cell are accurately estimated by a simple theoretical model. In addition, the transition from jetting to dripping is numerically analyzed in detail in some illustrative cases, and compared, to good agreement, with a set of experiments.Comment: Submitted to the Physical Review E on December 8th, 200

La Informática como materia fundamental en un sistema educativo del siglo XXI

Es innegable la importancia que ha alcanzado la informática en la sociedad, y ya es imprescindible para entender y tener éxito en el mundo actual. Sin embargo, en el currículo educativo de primaria y secundaria esta importancia no se ve reflejada, y la informática aparece como asignatura complementaria orientada a usuarios. Creemos que ha llegado el momento de que, al igual que en otros países avanzados, la informática dé el paso a materia troncal. Con la reciente reforma de la LOMCE se ha perdido una buena oportunidad para esto. Sin embargo, esto puede paliarse mediante la definición de una asignatura con estructura y contenidos concretos orientada al pensamiento computacional y a la formación de creadores.The importance of computing in our society is undeniable. It is essential to understand and be successful in the current world. However, the educational curricula for primary and secondary school does not reflect this, and computing appears just as a useroriented, complementary subject. We believe that the time has come for computing to be a core area, as it is in other advanced countries. The recent reformation of the education law in Spain (LOMCE) was a missed opportunity to achieve this. Nevertheless, it can be somehow remedied by defining a subject with a structure and concrete contents, oriented towards the computational thinking and the developing of creators

Planet-star interactions with precise transit timing. III. Entering the regime of dynamical tides

Hot Jupiters on extremely short-period orbits are expected to be unstable to tidal dissipation and spiral toward their host stars. That is because they transfer the angular momentum of the orbital motion through tidal dissipation into the stellar interior. Although the magnitude of this phenomenon is related to the physical properties of a specific star-planet system, statistical studies show that tidal dissipation might shape the architecture of hot Jupiter systems during the stellar lifetime on the main sequence. The efficiency of tidal dissipation remains poorly constrained in star-planet systems. Stellar interior models show that the dissipation of dynamical tides in radiation zones could be the dominant mechanism driving planetary orbital decay. These theoretical predictions can be verified with the transit timing method. We acquired new precise transit mid-times for five planets. They were previously identified as the best candidates for which orbital decay might be detected. Analysis of the timing data allowed us to place tighter constraints on the orbital decay rate. No statistically significant changes in their orbital periods were detected for all five hot Jupiters in systems HAT-P-23, KELT-1, KELT-16, WASP-18, and WASP-103. For planets HAT-P-23 b, WASP-18 b, and WASP-103 b, observations show that the mechanism of the dynamical tides dissipation probably does not operate in their host stars, preventing them from rapid orbital decay. This finding aligns with the models of stellar interiors of F-type stars, in which dynamical tides are not fully damped due to convective cores. For KELT-16 b, the span of transit timing data was not long enough to verify the theoretical predictions. KELT-1 b was identified as a potential laboratory for studying the dissipative tidal interactions of inertial waves in a convective layer.Comment: Accepted for publication in A&