Une approche efficace pour l’étude de la diagnosticabilité et le diagnostic des SED modélisés par Réseaux de Petri labellisés : contextes atemporel et temporel

This PhD thesis deals with fault diagnosis of discrete event systems using Petri net models. Some on-the-fly and incremental techniques are developed to reduce the state explosion problem while analyzing diagnosability. In the untimed context, an algebraic representation for labeled Petri nets (LPNs) is developed for featuring system behavior. The diagnosability of LPN models is tackled by analyzing a series of K-diagnosability problems. Two models called respectively FM-graph and FM-set tree are developed and built on the fly to record the necessary information for diagnosability analysis. Finally, a diagnoser is derived from the FM-set tree for online diagnosis. In the timed context, time interval splitting techniques are developed in order to make it possible to generate a state representation of labeled time Petri net (LTPN) models, for which techniques from the untimed context can be used to analyze diagnosability. Based on this, necessary and sufficient conditions for the diagnosability of LTPN models are determined. Moreover, we provide the solution for the minimum delay ∆ that ensures diagnosability. From a practical point of view, diagnosability analysis is performed on the basis of on-the-fly building of a structure that we call ASG and which holds fault information about the LTPN states. Generally, using on-the-fly analysis and incremental technique makes it possible to build and investigate only a part of the state space, even in the case when the system is diagnosable. Simulation results obtained on some chosen benchmarks show the efficiency in terms of time and memory compared with the traditional approaches using state enumerationCette thèse s'intéresse à l'étude des problèmes de diagnostic des fautes sur les systèmes à événements discrets en utilisant les modèles réseau de Petri. Des techniques d'exploration incrémentale et à-la-volée sont développées pour combattre le problème de l'explosion de l'état lors de l'analyse de la diagnosticabilité. Dans le contexte atemporel, la diagnosticabilité de modèles RdP-L est abordée par l'analyse d'une série de problèmes K-diagnosticabilité. L'analyse de la diagnosticabilité est effectuée sur la base de deux modèles nommés respectivement FM-graph et FM-set tree qui sont développés à-la-volée. Un diagnostiqueur peut être dérivé à partir du FM-set tree pour le diagnostic en ligne. Dans le contexte temporel, les techniques de fractionnement des intervalles de temps sont élaborées pour développer représentation de l'espace d'état des RdP-LT pour laquelle des techniques d'analyse de la diagnosticabilité peuvent être utilisées. Sur cette base, les conditions nécessaires et suffisantes pour la diagnosticabilité de RdP-LT ont été déterminées. En pratique, l'analyse de la diagnosticabilité est effectuée sur la base de la construction à-la-volée d'une structure nommée ASG et qui contient des informations relatives à l'occurrence de fautes. D'une manière générale, l'analyse effectuée sur la base des techniques à-la-volée et incrémentale permet de construire et explorer seulement une partie de l'espace d'état, même lorsque le système est diagnosticable. Les résultats des simulations effectuées sur certains benchmarks montrent l'efficacité de ces techniques en termes de temps et de mémoire par rapport aux approches traditionnelles basées sur l'énumération des état

Essays in Econometrics and Dynamic Kidney Exchange

Thesis advisor: Stefan HoderleinThis dissertation is divided into two parts. Part I - Dynamic Kidney Exchange In recent years, kidney paired donation (KPD) has an emerged as an attractive alternative for end-stage renal disease patients with incompatible living donors. However, we argue that the matching algorithm currently used by organ clearinghouses is inefficient, in the sense that a larger number of patients may be reached if kidney transplant centers take into consideration how their pool of patients and donors will evolve over time. In our work Two Novel Algorithms for Dynamic Kidney Exchange, we explore this claim and propose new computational algorithms to increase the cardinality of matchings in a discrete-time dynamic kidney exchange model with Poisson entries and Geometric deaths. Our algorithms are classified into direct prediction methods and multi-armed bandit methods. In the direct prediction method, we use machine learning estimator to produce a probability that each patient-donor pair should be matched today, as op- posed to being left for a future matching. The estimators are trained on offline optimal solutions. In contrast, in multi-armed bandit methods, we use simulations to evaluate the desirability of different matchings. Since the amount of different matchings is enormous, multi-armed bandits (MAB) are employed to decrease order to decrease the computational burden. Our methods are evaluated using simulations in a variety of simulation configurations. We find that the performance of at least one of our methods, based on multi-armed bandit algorithms, is able to uniformly dominate the myopic method that is used by kidney transplants in practice. We restrict our experiments to pairwise kidney exchange, but the methods described here are easily extensible, computational constraints permitting. Part II - Econometrics In our econometric paper Heterogenous Production Functions, Panel Data, and Productivity, we present methods for identification of moments and nonparametric marginal distributions of endogenous random coefficient models in fixed-T linear panel data models. Our identification strategy is constructive, immediately leading to relatively simple estimators that can be shown to be consistent and asymptotically normal. Because our strategy makes use of special properties of “small” (measure-zero) subpopulations, our estimators are irregularly identified: they can be shown to be consistent and asymptotically Normal, but converge at rates slower than root-n. We provide an illustration of our methods by estimating first and second moments of random Cobb-Douglas coefficients in production functions, using Indian plant-level microdata.Thesis (PhD) — Boston College, 2018.Submitted to: Boston College. Graduate School of Arts and Sciences.Discipline: Economics

Oral History Conversation with Tyler Norris (SOULR)

This is an oral history interview with Tyler Norris conducted on March 28, 2017

Board Member Age Diversity and Financial Performance of Manufacturing Firms: A Developing Economy Perspective

This paper examines the relationship between board member age diversity and financial performance of manufacturing firms in Uganda. A cross section survey research design was employed using 78 manufacturing firms across the country. Data was analysed using descriptive statistics, chi-square analysis and point bi-serial correlation. The results showed that majority of the boards had members with an average age of 35-44years, followed by 25-34 years. In addition, boards comprising of majorly young board members registered low performance level, compared to the boards comprising of majorly older members. Further, the results indicated that board member age diversity is significantly associated with financial performance of manufacturing firms. Like any other research study, this study is limited in the following ways. Since only a single research methodological approach was employed, future research could undertake a mixed approach and triangulate to validate the current findings. Further, a longitudinal approach should be employed to study financial performance trends among manufacturing firms over years. Finally, board member age diversity was studied and by virtual of the results, there are other factors that explain the financial performance of the Uganda’s manufacturing sector that were not part of this study

Influência do letramento funcional em saúde na adesão ao tratamento com antidepressivos

Objetivo: Verificar a influência do nível de letramento funcional em saúde dos pacientes na adesão ao tratamento com antidepressivos.Método: Estudo transversal, realizado nas farmácias da Secretaria Municipal de Saúde de Marília-SP, em 2020/2021. O questionário de letramento funcional verificou as habilidades numéricas e de interpretação dos pacientes, diante de textos relacionados à área de saúde. A adesão ao tratamento foi verificada pela escala de adesão terapêutica de Morisky, e os dados foram analisados por Anova-one-way e teste de Kruskal-Wallis.Resultados: Participaram do estudo 150 pacientes, cuja maioria apresentou falhas na adesão e nível inadequado de letramento funcional em saúde, entretanto, não houve correlação entre letramento funcional em saúde e adesão ao tratamento.Conclusão: Embora não tenha sido encontrada correlação entre as variáveis, há a necessidade de maiores investimentos em relação à adesão ao tratamento, com estratégias que considerem o nível de letramento funcional em saúde, nestes pacientes. Palavras-chave: Letramento em saúde. Antidepressivos. Adesão à medicação

Metastatic lung cancer presenting as thoracic empyema: A Case report

Increased cancer risk in patients with inflammatory and infectious diseases has been reported in many studies and lung cancer\u2010associated empyema in <0.3% patients. We present a patient with empyema in whom the final diagnosis was metastatic lung adenocarcinoma. Purulent pleural fluid obtained by drainage or thoracentesis must always been examined because the association of malignant tumors and empyema should be taken into consideration

Effects of early mobilization on the incidence of postoperative complications in patients undergoing thoracoscopy: a randomized controlled trial

BACKGROUND: mobilization is crucial for reducing postoperative complications. In literature no precise inidications exist regarding mobilization timing and posture after thoracoscopy. This study aims to compare the effects of early Fowler’s position (first 6 hours after surgery) with bedrest in supine position for the first 24 hours. METHODS: open-label clinical trial, on 28 patients undergoing thoracoscopy. The subjects were randomly allocated to be mobilized in Fowler's position within 45min after surgery up to 6h (study group) or to maintain recumbent position until the first postoperative day. Forced vital expiration (FEV1) was measured after 6 and 24 hours from surgery. Chest X-ray was performed immediately after surgery and on the first postoperative day. RESULTS: the cases of atelectasis in the study group decreased from 53.3% to 20.0% (control group: from 69.2% to 46.2%). FEV1 showed statistically significant improvement in the study group both after 6 and 24 hours from surgery (p<.001). CONCLUSIONS: early mobilization in Fowler's position improves respiratory outcomes by reducing the episodes of atelectasis. It also results in clinically relevant improvement in FEV1 if compared to recumbent position.INTRODUZIONE: la mobilizzazione è fondamentale per ridurre le complicanze postoperatorie. In letteratura non esistono criteri precisi per quanto riguarda i tempi di mobilizzazione e la postura dopo la toracoscopia. Questo studio mira a confrontare gli effetti della mobilizzazione precoce (entro le prime 6 ore dopo l'intervento chirurgico) in posizione di Fowler  e la posizione supina per le prime 24 ore. METODI: studio sperimentale a due bracci, in aperto con arruolamento di 28 pazienti sottoposti a toracoscopia. I soggetti sono stati assegnati in modo casuale alla mobilizzazione in posizione di Fowler entro 45 minuti dopo l'intervento chirurgico fino a 6 ore (gruppo di studio) o per mantenere la posizione supina fino al primo giorno postoperatorio. La variabile dipendente studiata era il volume espiratorio massimo nel 1° secondo (FEV1) dopo 6 e 24 ore dall'intervento chirurgico. La radiografia del torace è stata eseguita subito dopo l'intervento chirurgico e il primo giorno postoperatorio. RISULTATI: i casi di atelettasia nel gruppo di studio sono diminuiti dal 53.3% al 20.0% (gruppo di controllo: dal 69.2% al 46.2%). Il FEV1 ha mostrato un miglioramento statisticamente significativo nel gruppo di studio sia dopo 6 che dopo 24 ore dall'intervento chirurgico (p<.001). CONCLUSIONI: la mobilizzazione precoce nella posizione di Fowler sembra migliorare i risultati respiratori riducendo gli episodi di atelettasia; si traduce anche in un miglioramento clinicamente rilevante del FEV1 rispetto alla posizione supina. I risultati attuali devono essere confermati su campioni ampi e stratificati

Unexpected thymoma in a challenging case of hyperparathyroidism

We report the case of a woman with primary hyperparathyroidism suspected of mediastinal ectopic parathyroid adenoma revealed to be a thymoma. Our aim was to focus on some possible criticisms in distinguishing between ectopic parathyroid and thymus

Pneumomediastinum after a swimming race and dental extraction

A 16-year-old male competitive swimmer presented with dyspnea, chest pain, and right neck crepitus after a race. He had undergone an uncomplicated lower right third molar tooth extraction 2 days earlier. He had no known allergies. On examination, he was alert, well-perfused, and afebrile. The peritoneal signs were negative. A chest radiograph showed subcutaneous emphysema with pneumomediastinum. Computed tomography showed submandibular, neck, and mediastinal emphysema (Figure 1). Conservative therapy based on observation and prophylactic parenteral administration of antibiotics (clindamycin 450\u2009mg every 6\u2009h and ceftriaxone 2\u2009g daily for 10 days) was successfully adopted, and he was discharged after 3 days