280 research outputs found
Decision Problems for Petri Nets with Names
We prove several decidability and undecidability results for nu-PN, an
extension of P/T nets with pure name creation and name management. We give a
simple proof of undecidability of reachability, by reducing reachability in
nets with inhibitor arcs to it. Thus, the expressive power of nu-PN strictly
surpasses that of P/T nets. We prove that nu-PN are Well Structured Transition
Systems. In particular, we obtain decidability of coverability and termination,
so that the expressive power of Turing machines is not reached. Moreover, they
are strictly Well Structured, so that the boundedness problem is also
decidable. We consider two properties, width-boundedness and depth-boundedness,
that factorize boundedness. Width-boundedness has already been proven to be
decidable. We prove here undecidability of depth-boundedness. Finally, we
obtain Ackermann-hardness results for all our decidable decision problems.Comment: 20 pages, 7 figure
Adaptive Multi-Pattern Fast Block-Matching Algorithm Based on Motion Classification Techniques
Motion estimation is the most time-consuming subsystem in a video codec. Thus, more efficient methods of motion estimation should be investigated. Real video sequences usually exhibit a wide-range of motion content as well as different degrees of detail, which become particularly difficult to manage by typical block-matching algorithms. Recent developments in the area of motion estimation have focused on the adaptation to video contents. Adaptive thresholds and multi-pattern search algorithms have shown to achieve good performance when they success to adjust to motion characteristics. This paper proposes an adaptive algorithm, called MCS, that makes use of an especially tailored classifier that detects some motion cues and chooses the search pattern that best fits to them. Specifically, a hierarchical structure of binary linear classifiers is proposed. Our experimental results show that MCS notably reduces the computational cost with respect to an state-of-the-art method while maintaining the qualityPublicad
Static Analysis of Usefulness States in Transition P systems
Transition P Systems are a parallel and distributed computational model based on the notion of the cellular membrane structure. Each membrane determines a region that encloses a multiset of objects and evolution rules. Transition P Systems evolve through transitions between two consecutive configurations that are determined by the membrane structure and multisets present inside membranes. Moreover, transitions between two consecutive configurations are provided by an exhaustive non-deterministic and parallel application of evolution rules. But, to establish the rules to be applied, it is required the previous calculation of useful, applicable and active rules. Hence, computation of useful evolution rules is critical for the whole evolution process efficiency, because it is performed in parallel inside each membrane in every evolution step. This work defines usefulness states through an exhaustive analysis of the P system for every membrane and for every possible configuration of the membrane structure during the computation. Moreover, this analysis can be done in a static way; therefore membranes only have to check their usefulness states to obtain their set of useful rules during execution
Denotational semantics for timed testing
In this paper we present a denotational semantics for a timed process algebra, which is fully abstract with respect to the must testing semantics previously developed [Lla96,LdFN96]. The domain of semantic processes is made up of consistent sets of barbs, which generalize the notion of acceptance sets, in such a way that the actions that are offered but not taken in each state are also recorded. the main difficulty when defining this denotational semantics has been that the natural ordering between semantic processes cannot be proved to be complete. So an alternative stronger complete ordering has to be considered, which is proved to be consistent with the original one, in the sense that lubs of chains with respect to the new ordering are also lubs with respect to the original one
Natural History of MYH7-Related Dilated Cardiomyopathy.
Background
Variants in myosin heavy chain 7 (MYH7) are responsible for disease in 1% to 5% of patients with dilated cardiomyopathy (DCM); however, the clinical characteristics and natural history of MYH7-related DCM are poorly described.
Objectives
We sought to determine the phenotype and prognosis of MYH7-related DCM. We also evaluated the influence of variant location on phenotypic expression.
Methods
We studied clinical data from 147 individuals with DCM-causing MYH7 variants (47.6% female; 35.6 ± 19.2 years) recruited from 29 international centers.
Results
At initial evaluation, 106 (72.1%) patients had DCM (left ventricular ejection fraction: 34.5% ± 11.7%). Median follow-up was 4.5 years (IQR: 1.7-8.0 years), and 23.7% of carriers who were initially phenotype-negative developed DCM. Phenotypic expression by 40 and 60 years was 46% and 88%, respectively, with 18 patients (16%) first diagnosed at <18 years of age. Thirty-six percent of patients with DCM met imaging criteria for LV noncompaction. During follow-up, 28% showed left ventricular reverse remodeling. Incidence of adverse cardiac events among patients with DCM at 5 years was 11.6%, with 5 (4.6%) deaths caused by end-stage heart failure (ESHF) and 5 patients (4.6%) requiring heart transplantation. The major ventricular arrhythmia rate was low (1.0% and 2.1% at 5 years in patients with DCM and in those with LVEF of â€35%, respectively). ESHF and major ventricular arrhythmia were significantly lower compared with LMNA-related DCM and similar to DCM caused by TTN truncating variants.
Conclusions
MYH7-related DCM is characterized by early age of onset, high phenotypic expression, low left ventricular reverse remodeling, and frequent progression to ESHF. Heart failure complications predominate over ventricular arrhythmias, which are rare.pre-print1333 K
Indoor Environmental Quality and Consumption Patterns before and during the COVID-19 Lockdown in Twelve Social Dwellings in Madrid, Spain
This article analyses the situation that prevailed in 12 dwellings located on the outskirts of Madrid during Spainâs state of emergency. How did 24/7 occupation affect the quality of indoor air and power consumption patterns? The mixed method used (surveys and instrumental monitoring) pragmatically detected the variation in consumption, comfort and indoor air quality patterns before and during the COVID-19 pandemic. The characteristics initially in place and household predisposition had a conclusive effect on such variations. The starting conditions, including household composition, habits and the way daily activities were performed, differed widely, logically affecting power consumption: 8/12 case studies increase occupancy density by more than 25 percent; 11/12 improve thermal comfort; 10/12 improve air quality but not necessarily translate in a sufficient ventilation practices; air quality was lower in the bedrooms on the whole; only 4/12 case studies use the potential of passive measures; only one household adopted energy savings strategies; 10/12 case studies increase electric power consumption but none of the dwellings was fitted with a renewable power generation system. The conclusion drawn is that, despite starting conditions differing widely, household composition, habits (including performance of daily activities performance) and power consumption also played an active role in the end result. This approach allowed to integrate qualitative and quantitative findings on indoor environmental quality (IEQ), energy use and householdsâ behavior. The objective data on the energy situation of the case studies not only is useful for the study, but also for potential enrollment in energy rehabilitation programs, such as the European Regional Development Fund (ERDF).This study was funded by the Spanish Ministry of the Economyâs National Programme for R&D + I Geared to Societal Challenges under the project BIA2017-83231-C2-1-R âNueva herramienta integrada de evaluaciĂłn para ĂĄreas urbanas vulnerables. Hacia la autosuficiencia energĂ©tica y a favor de un modelo de habitabilidad biosaludableâ and âHabita_RES-(2018â2021)â.S
Phenotype and clinical outcomes of Glu89Lys hereditary transthyretin amyloidosis: a new endemic variant in Spain.
Background
The p.Glu109Lys variant (Glu89Lys) is a rare cause of hereditary transthyretin amyloidosis (ATTRv) for which clinical spectrum remains unresolved. We sought to describe the clinical characteristics and outcomes of ATTR Glu89Lys amyloidosis and assess a potential founder effect in Spain.
Methods
Patients with the p.Glu109Lys ATTRv variant from 14 families were recruited at 7 centres. Demographics, complementary tests and clinical course were analysed. Haplotype analysis was performed in 7 unrelated individuals.
Results
Thirty-eight individuals (13 probands, mean age 40.4â±â13.1âyears) were studied. After median follow-up of 5.1âyears (IQR 1.7â9.6), 7 patients died and 7 required heart transplantation (median age at transplantation 50.5âyears). Onset of cardiac and neurological manifestations occurred at a mean age of 48.4 and 46.8âyears, respectively. Median survival from birth was 61.6âyears and no individual survived beyond 65âyears. Patients treated with disease-modifying therapies exhibited better prognosis (pâ<â0.001). Haplotype analysis revealed a common origin from an ancestor who lived âŒ500âyears ago in southeast Spain.
Conclusions
Glu89Lys ATTRv is a TTR variant with a founder effect in Spain. It is associated with near complete penetrance, early onset and mixed cardiac and neurologic phenotype. Patients have poor prognosis, particularly if not treated with disease-modifying therapies.post-print2555 K
Self-criticisms toward a socially responsible science in the field of management
Management scholarship should be placed in a unique position to develop relevant scientific knowledge because business
and management organizations are deeply involved in most global challenges. However, different critical voices have
recently been raised in essays and editorials, and reports have questioned research in the management field, identifying
multiple deficiencies that can limit the growth of a relatively young field. Based on an analysis of published criticisms
of management research, we would like to shed light on the current state of management research and identify some
limitations that should be considered and should guide the growth of this field of knowledge. This work offers guidance
on the main problems of the discipline that should be addressed to encourage the transformation of management
research to meet both scientific rigor and social relevance. The article ends with a discussion and a call to action for
directing research toward the possibility and necessity of reinforcing âresponsible researchâ in the management field.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study has benefited from financing from the Research Project ECO2014-56580-R of the Spanish Ministry of Economy and Competitively, and the Research Projects P12-SEJ-1810 and P12-SEJ-1618 from the Andalusia Government (Spain) and PR2016-018 (Research Projects University of Cadiz)
Mobile Synchronizing Petri Nets: A Choreographic Approach for Coordination in Ubiquitous Systems
AbstractThe term Ubiquitous Computing was coined by Mark Weiser almost two decades ago. Despite all the time that has passed since Weiser's vision, ubiquitous computing still has a long way ahead to become a pervasive reality. One of the reasons for this may be the lack of widely accepted formal models capable of capturing and analyzing the complexity of the new paradigm. We propose a simple Petri Net based model to study some of its main characteristics. We model both devices and software components as a special kind of coloured Petri Nets, located in locations, that can move to other locations and synchronize with other co-located nets, offering and requesting services. We obtain an amenable model for ubiquitous computing, due to its graphical representation. We present our proposal in a progressive way, first presenting a basic model where coordination is formalized by the synchronized firing of pairs of compatible transitions that offer and request a specific service, and ad hoc networks are modeled by constraining mobility by the dynamic acquisition of locality names. Next, we introduce a mechanism for the treatment of robust security properties, namely the generation of fresh private names, to be used for authentication properties
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