1,989 research outputs found

    Trace checking of Metric Temporal Logic with Aggregating Modalities using MapReduce

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    Modern complex software systems produce a large amount of execution data, often stored in logs. These logs can be analyzed using trace checking techniques to check whether the system complies with its requirements specifications. Often these specifications express quantitative properties of the system, which include timing constraints as well as higher-level constraints on the occurrences of significant events, expressed using aggregate operators. In this paper we present an algorithm that exploits the MapReduce programming model to check specifications expressed in a metric temporal logic with aggregating modalities, over large execution traces. The algorithm exploits the structure of the formula to parallelize the evaluation, with a significant gain in time. We report on the assessment of the implementation - based on the Hadoop framework - of the proposed algorithm and comment on its scalability.Comment: 16 pages, 6 figures, Extended version of the SEFM 2014 pape

    Colored Non-Crossing Euclidean Steiner Forest

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    Given a set of kk-colored points in the plane, we consider the problem of finding kk trees such that each tree connects all points of one color class, no two trees cross, and the total edge length of the trees is minimized. For k=1k=1, this is the well-known Euclidean Steiner tree problem. For general kk, a kρk\rho-approximation algorithm is known, where ρ1.21\rho \le 1.21 is the Steiner ratio. We present a PTAS for k=2k=2, a (5/3+ε)(5/3+\varepsilon)-approximation algorithm for k=3k=3, and two approximation algorithms for general~kk, with ratios O(nlogk)O(\sqrt n \log k) and k+εk+\varepsilon

    The Association between Primary Endometrioid Carcinoma of the Ovary and Synchronous Malignancy of the Endometrium

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    Objective. Ovarian and endometrial cancers coincide rather frequently in the same patient. Few data are available on the involvement of the specific morphological subtypes. To identify histological pathways in the synchronous occurrence, a population-based study was performed in The Netherlands. Methods. Using the national pathology database (PALGA) information of ovarian cancers and of earlier or later cancer in the endometrium was obtained. 5366 Patients were identified with primary malignant epithelial or borderline malignancy. Results. In 157 cases (2.9%) a new primary malignancy in the endometrium was diagnosed (146 within 1 year). The ratio of observed versus expected number of synchronous malignancy in the endometrium was estimated at 3.6 (95% CI: 2.7–4.7). Among 460 ovarian endometrioid carcinoma patients 53 cases showed a second primary endometrial cancer; 40 out of these 53 cases (75.5%) showed at both organ sites an endometrioid adenocarcinoma. Conclusion. These findings suggest an important role for the endometrioid subtype and prompt to mechanism-based studies incorporating molecular techniques

    Understanding Barriers to the Realization of Human Rights Among Older Women With Mental Health Conditions

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    There is increasing emphasis in research and at the level of international human rights bodies such as the United Nations on the gendered contours of age-based disadvantage and discrimination, and the cumulative effects of gender inequalities over the life-course on outcomes in later life. However, to date, the role of mental health in shaping the age/gender nexus in the realization of human rights has received little attention. In response, this paper aims to 1) elucidate the economic, social and cultural disadvantages and discrimination faced by older women living with mental health conditions; and 2) identify opportunities to protect their human rights. It concludes that older women face inequalities and disadvantages at the intersections of age, gender, and mental health and wellbeing that compromise their capacity to age well, illuminating the urgent need for a UN Convention on the Human Rights of Older Persons that considers the role of mental health in shaping the realization of human rights among older people. (Am J Geriatr Psychiatry 2021; 29:1009-1014

    Can cohort data be treated as genuine panel data?

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    If repeated observations on the same individuals are not available it is not possible to capture unobserved individual characteristics in a linear model by using the standard fixed effects estimator. If large numbers of observations are available in each period one can use cohorts of individuals with common characteristics to achieve the same goal, as shown by Deaton (1985). It is tempting to analyze the observations on cohort averages as if they are observations on individuals which are observed in consecutive time periods. In this paper we analyze under which conditions this is a valid approach. Moreover, we consider the impact of the construction of the cohorts on the bias in the standard fixed effects estimator. Our results show that the effects of ignoring the fact that only a synthetic panel is available will be small if the cohort sizes are sufficiently large (100, 200 individuals) and if the true means within each cohort exhibit sufficient time variation

    A quantitative analysis of faulty EPCs in the SAP reference model

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    The SAP reference model contains more than 600 non-trivial process models expressed in terms of Event-driven Process Chains (EPCs). We have automatically translated these EPCs into YAWL models and analyzed these models usingWofYAWL, a veri¯cation tool based on Petri nets. We discovered that at least 34 of these EPCs contain errors (i.e., at least 5.6% is °awed). We analyzed which parts of the SAP reference model contain most errors. Moreover, based on 15 characteristics (e.g., the size of the model), we used logistic regression to ¯nd possible pre- dictors for these errors. This systematic analysis of the SAP reference model illustrates the need for veri¯cation tools such as WofYAWL

    Severity of Diverticulitis Does Not Influence Abdominal Complaints during Long-Term Follow-Up

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    Background: Diverticulitis can lead to localized or generalized peritonitis and consequently induce abdominal adhesion formation. If adhesions would lead to abdominal complaints, it might be expected that these would be more prominent after operation for perforated diverticulitis with peritonitis than after elective sigmoid resection. Aims: The primary outcome of the study was the incidence of abdominal complaints in the long-term after acute and elective surgery for diverticulitis. Methods: During the period 2003 through 2009, 269 patients were opera

    Engineering Good: How Engineering Metaphors Help us to Understand the Moral Life and Change Society

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    Engineering can learn from ethics, but ethics can also learn from engineering. In this paper, I discuss what engineering metaphors can teach us about practical philosophy. Using metaphors such as calculation, performance, and open source, I articulate two opposing views of morality and politics: one that relies on images related to engineering as science and one that draws on images of engineering practice. I argue that the latter view and its metaphors provide a more adequate way to understand and guide the moral life. Responding to two problems of alienation and taking into account developments such as Fab Lab I then further explore the implications of this view for engineering and society
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