Modular control-loop detection

This paper presents an efficient algorithm to detect control-loops in large finite-state systems. The proposed algorithm exploits the modular structure present in many models of practical relevance, and often successfully avoids the explicit synchronous composition of subsystems and thereby the state explosion problem. Experimental results show that the method can be used to verify industrial applications of considerable complexity

Incremental verification and synthesis of discrete-event systems guided by counter-examples

This article presents new approaches to system verification and synthesis based on subsystem verification and the novel combined use of counterexamples and heuristics to identify suitable subsystems incrementally. The scope of safety properties considered is limited to behavioral inclusion and controllability. The verification examples considered provide a comparison of the approaches presented with straightforward state exploration and an understanding of their applicability in an industrial context

Modular synthesis of discrete controllers

This paper presents supervisory control theory in a process-algebraic setting, and proposes a way of synthesising modular supervisors that guarantee nonblocking. The framework used includes the possibility of hiding actions which results in nondeterminism. As modularity crucially depends on the process equivalence used, the paper studies possible equivalences and points out that, in order to be consistent with respect to the nonblocking property and to supervisor synthesis, a conflict-preserving equivalence must be used. It applies the results to synthesise nonblocking modular supervisors for a manufacturing system

Risk Stratification in Post-MI Patients Based on Left Ventricular Ejection Fraction and Heart-Rate Turbulence

Objectives: Development of risk stratification criteria for predicting mortality in post-infarction patients taking into account LVEF and heart-rate turbulence (HRT). Methods: Based on previous results the two parameters LVEF (continuously) and turbulence slope (TS) as an indicator of the HRT were combined for risk stratification. The method has been applied within two independent data sets (the MPIP-trial and the EMIAT-study). Results: The criteria were defined in order to match the outcome of applying LVEF ( 30 % in sensitivity. In the MPIP trial the optimal criteria selected are TS normal and LVEF ( 21 % or TS abnormal and LVEF ( 40 %. Within the placebo group of the EMIAT-study the corresponding criteria are: TS normal and LVEF ( 23 % or TS abnormal and LVEF ( 40 %. Combining both studies the following criteria could be obtained: TS normal and LVEF ( 20 % or TS abnormal and LVEF ( 40 %. In the MPIP study 83 out of the 581 patients (= 14.3 %) are fulfilling these criteria. Within this group 30 patients have died during the follow-up. In the EMIAT-trial 218 out of the 591 patients (= 37.9 %) are classified as high risk patients with 53 deaths. Combining both studies the high risk group contains 301 patients with 83 deaths (ppv = 27.7 %). Using the MADIT-criterion as classification rule (LVEF ( 30 %) a sample of 375 patients with 85 deaths (ppv = 24 %) can be selected. Conclusions: The stratification rule based on LVEF and TS is able to select high risk patients suitable for implanting an ICD. The rule performs better than the classical one with LVEF alone. The high risk group applying the new criteria is smaller with about the same number of deaths and therefor with a higher positive predictive value. The classification criteria have been validated within a bootstrap study with 100 replications. In all samples the rule based on TS and LVEF (= NEW) was superior to LVEV alone, the high risk group has been smaller (( s: 301 ( 14.5 (NEW) vs. 375 ( 14.5 (LVEF)) and the positive predictive value was larger (( s: 27.2 ( 2.6 % (NEW) vs. 23.3 ( 2.2 % (LVEF)). The new criteria are less expensive due to a reduced number of high risk patients selected

Reflex and Tonic Autonomic Markers for Risk Stratification in Patients With Type 2 Diabetes Surviving Acute Myocardial Infarction

OBJECTIVE Diabetic postinfarction patients are at increased mortality risk compared with nondiabetic postinfarction patients. In a substantial number of these patients, diabetic cardiac neuropathy already preexists at the time of the infarction. In the current study we investigated if markers of autonomic dysfunction can further discriminate diabetic postinfarction patients into low- and high-risk groups. RESEARCH DESIGN AND METHODS We prospectively enrolled 481 patients with type 2 diabetes who survived acute myocardial infarction (MI), were aged ≤80 years, and presented in sinus rhythm. Primary end point was total mortality at 5 years of follow-up. Severe autonomic failure (SAF) was defined as coincidence of abnormal autonomic reflex function (assessed by means of heart rate turbulence) and of abnormal autonomic tonic activity (assessed by means of deceleration capacity of heart rate). Multivariable risk analyses considered SAF and standard risk predictors including history of previous MI, arrhythmia on Holter monitoring, insulin treatment, and impaired left ventricular ejection fraction (LVEF) ≤30%. RESULTS During follow-up, 83 of the 481 patients (17.3%) died. Of these, 24 deaths were sudden cardiac deaths and 21 nonsudden cardiac deaths. SAF identified a high-risk group of 58 patients with a 5-year mortality rate of 64.0% at a sensitivity level of 38.0%. Multivariately, SAF was the strongest predictor of mortality (hazard ratio 4.9 [95% CI 2.4–9.9]), followed by age ≥65 years (3.4 [1.9–5.8]), and LVEF ≤30% (2.6 [1.5–4.4]). CONCLUSIONS Combined abnormalities of autonomic reflex function and autonomic tonic activity identifies diabetic postinfarction patients with very poor prognoses

Applying SMT Solvers to the Test Template Framework

The Test Template Framework (TTF) is a model-based testing method for the Z notation. In the TTF, test cases are generated from test specifications, which are predicates written in Z. In turn, the Z notation is based on first-order logic with equality and Zermelo-Fraenkel set theory. In this way, a test case is a witness satisfying a formula in that theory. Satisfiability Modulo Theory (SMT) solvers are software tools that decide the satisfiability of arbitrary formulas in a large number of built-in logical theories and their combination. In this paper, we present the first results of applying two SMT solvers, Yices and CVC3, as the engines to find test cases from TTF's test specifications. In doing so, shallow embeddings of a significant portion of the Z notation into the input languages of Yices and CVC3 are provided, given that they do not directly support Zermelo-Fraenkel set theory as defined in Z. Finally, the results of applying these embeddings to a number of test specifications of eight cases studies are analysed.Comment: In Proceedings MBT 2012, arXiv:1202.582

EXPERIENCE OF PSYCHIATRY TEACHING AT MEDICAL SCHOOL INFLUENCES CROATIAN MEDICAL STUDENTS’ ATTITUDES TOWARDS CHOOSING PSYCHIATRY AS A CAREER

Background: Reports indicate that the number of students interested in choosing psychiatry as their future profession is constantly decreasing in the last decades. Our aim was to determine the proportion of medical students intending to pursue a career in psychiatry and to define undergraduate education-related factors influencing that choice. Subjects and methods: We report the preliminary findings of a cross sectional quantitative survey of final year Croatian medical students as part of the International Survey Of Student Career Choice In Psychiatry (ISOSCCIP). We surveyed medical students attending their final year at Zagreb School of Medicine in the academic year 2009/2010, using a structured questionnaire examining demographics, students\u27 preferences on future career choice and their evaluations of undergraduate psychiatry teaching. Results: The overall student evaluation of the compulsory psychiatry curriculum was “average”. Significantly higher ratings were reported by students who felt more involved in the teaching of the subject. The possibility of psychiatry as a career choice correlated significantly with better evaluation grades of psychiatry lectures. Furthermore, poor evaluation grades predicted a higher likelihood that medical students completely ruled out choosing a career in psychiatry. Conclusion: This is the first survey of this kind in Croatia. Student ratings of medical school psychiatric education and perceived involvement in teaching appears to influence the likelihood of a stated career in psychiatry. Addressing these issues may increase the number of students motivated to pursue psychiatry as their future career choice

Age- and Sex-Specific Analyses of Diet Quality and 4-Year Weight Change in Nonobese Adults Show Stronger Associations in Young Adulthood

Background: Although the general importance of diet quality in the prevention of unintentional weight gain is known, it is unknown whether its influence is age or sex dependent. Objective: The aim of this study was to investigate whether the strength of the association between diet quality and 4-y weight change was modified by age and sex. Methods: From the Dutch population-based Lifelines Cohort, 85,618 nonobese adult participants (age 18-93 y), recruited between 2006 and 2013, were included in the study. At baseline, diet was assessed with a 110-item food-frequency questionnaire. The Lifelines Diet Score, based on international evidence for diet-disease relations at the food group level, was calculated to assess diet quality. For analyses, the score was divided in quintiles (Qs). Body weight was objectively measured at baseline and after a median follow-up of 44 mo (25th-75th percentile: 35-51 mo). In between, body weight was self-reported twice. Linear mixed models were used to investigate the association between diet quality and weight change by sex and in 6 age categories (18-29, 30-39, 40-49, 50-59, 60-69, and ≥70 y). Results: Mean 4-y weight change decreased over age categories. Confounder-adjusted linear mixed models showed that the association between diet quality and weight change was modified by sex (P-interaction = 0.001). In women, the association was also modified by age (P-interaction = 0.001). Poor diet quality was most strongly associated with weight gain in the youngest men [Q1 compared with Q5: +0.33 kg/y (95% CI: 0.10, 0.56)] and women [+0.22 kg/y (95% CI: 0.07, 0.37)]. In contrast, in women aged ≥70 y, poor diet quality was associated with greater weight loss [-0.44 kg/y (95% CI: -0.84, -0.05)]. Conclusions: Poor diet quality was related to higher weight gain, especially in young adults. Oppositely, among women aged ≥70 y, poor diet quality was related to higher weight loss. Therefore, a healthful diet is a promising target for undesirable weight changes in both directions

Evaluation der Experimentierklausel nach § 6c SGB II - Vergleichende Evaluation des arbeitsmarktpolitischen Erfolgs der Modelle der Aufgabenwahrnehmung "Optierende Kommune" und "Arbeitsgemeinschaft"; Untersuchungsfeld 2: Implementations- und Governanceanalyse; Zwischenbericht Mai 2007 an das BMAS

Zwischenbericht 2007 der FH Frankfurt, Institut für Stadt- und Regionalentwicklung, und des Instituts für angewandte Sozialwissenschaft (infas) zur Implementations- und Governanceanalyse im Rahmen der Evalouation der Experimentierklausel nach § 6c SGB II. Die Implementations- und Governanceanalyse untersucht die Umsetzung der durch das SGB II definierten Leistungsprozesse anhand einer Stichprobe von 154 regionalen Einheiten aus allen Arbeitsgemeinschaften (ARGEn), zugelassenen kommunalen Trägern und Fällen getrennter Aufgabenwahrnehmung. Der Bericht analysiert im ersten Teil überregionale Governance-Strukturen (z. B. rechtliche und finanzielle Vorgaben, Zielvereinbarungen), die Auswirkungen auf die Leistungserbringung der SGB II-Einheiten haben. Im zweiten Teil werden die lokalen Steuerungs- und Organisationsstrukturen in den Formen der Aufgabenwahrnehmung untersucht und wird eine Typologie der Organisation des Leistungsprozesses entwickelt. Der dritte Teil beschäftigt sich mit der Ausgestaltung der Schnittstellen zwischen SGB II, SGB III und SGB VIII, insbesondere im Hinblick auf Eingliederungsleistungen für Jugendliche und junge Erwachsene sowie die Organisation der Arbeitsvermittlung