93 research outputs found

    Degradation modeling applied to residual lifetime prediction using functional data analysis

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    Sensor-based degradation signals measure the accumulation of damage of an engineering system using sensor technology. Degradation signals can be used to estimate, for example, the distribution of the remaining life of partially degraded systems and/or their components. In this paper we present a nonparametric degradation modeling framework for making inference on the evolution of degradation signals that are observed sparsely or over short intervals of times. Furthermore, an empirical Bayes approach is used to update the stochastic parameters of the degradation model in real-time using training degradation signals for online monitoring of components operating in the field. The primary application of this Bayesian framework is updating the residual lifetime up to a degradation threshold of partially degraded components. We validate our degradation modeling approach using a real-world crack growth data set as well as a case study of simulated degradation signals.Comment: Published in at http://dx.doi.org/10.1214/10-AOAS448 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

    EVOLUTION OF WINTER WHEAT CROP UNDER THE INFLUENCE OF AGROTEHNICAL MEASURES AND CLIMATE CHANGES

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    In the context of climate change, crop technologies must be updated and adapted by identifying and implementing new technological links regarding: soil tillages, the fertilization system, the previous plant, which will contribute to significantly reducing the negative impact of climate change on production and quality for wheat crop. The relationship production - quality - technology highlighted the negative influence of excessive temperatures and deficient precipitation in important stages in the evolution of plants. Wheat yield and quality are affected by management practices, climate conditions and genetic characteristics. The research was carried out in the period 2019 – 2021, in the experimental field of NARDI Fundulea and the purpose of this study was to evaluate the effect of agrotechnical measures and climatic conditions on the yield and quality of wheat. The experiment involved three different soil works and four fertilized options. Yields and quality were maximized by associated factors. Soil conservation works associated with manure fertilization increase production values and final quality by 5-10%, depending on the variant

    NAVIGATING ETHICAL AND MORAL CHALLENGES LEADERS FACE IN STAKEHOLDER CAPITALISM

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    One can assume that the ethical business leader of the 21st century will need to become a leader of community in which they operate, answering to all stakeholders, guiding all stakeholders, mediating all stakeholders’ concerns. A virtuous position at first glance and one leader wants to aspire to in theory but frequently fail at in practice. The current paper strives to underline the need of ethical conduct at both leader and stakeholders’ level and proposes the introduction of a code of ethical principles to be followed and introduced by the leader and all stakeholders in an organization. Such a code should promote a set of well-established principles to be agreed and followed by the parties involved. A five criteria set is proposed for the development of further codes of conduct, that will lead to more appropriate judgements and findings

    Why leadership fails? Few causes for why good leaders do bad things:

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    The six factors considered for achieving success in leadership are clarity, role modeling, achievability, commitment, transparency and openness. The article analyzes the factors that generate a failure of leadership, even for the so-called widely renewed good leaders, precisely the behavior causes and developments that lead to failure and not their acquiring process. The chosen target population is represented by the leaders ruling large organizations, which need an integrated vision to produce effective leadership. The perspective will have a theoretical basis but also an empirical one. The quantitative part relies on a survey conducted among leaders for three different industries (pharmaceutical, IT and telecom). They were asked questions regarding the causes, which produce leadership failure and finally produce misconduct and breaches of the compliance rules and regulations. In addition, the survey asked the participants to develop their proposals for preventing leadership failure. It was established the importance of the tone from the top, leading by example, a clear mechanism for checking the health of the organization from a leadership perspective. The article will also show that the way to prevent leadership failure and avoid behaviors that lead to misconduct is a permanent journey

    Validation of a New Prognostic Score in Patients with Ovarian Adenocarcinoma

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    Background and Objectives: This study aimed to assess the impact of clinical prognostic factors and propose a prognostic score that aids the clinician’s decision in estimating the risk for patients in clinical practice. Materials and Methods: The study included 195 patients diagnosed with ovarian adenocarcinoma. The therapeutic strategy involved multidisciplinary decisions: surgery followed by adjuvant chemotherapy (80%), neoadjuvant chemotherapy followed by surgery (16.4%), and only chemotherapy in selected cases (3.6%). Results: After a median follow-up of 68 months, in terms of progression-free survival (PFS) and overall survival (OS), Eastern Cooperative Oncology Group (ECOG) performance status of 1 and 2 vs. 0 (hazard ratio—HR = 2.71, 95% confidence interval—CI, 1.96–3.73, p < 0.001 for PFS and HR = 3.19, 95%CI, 2.20–4.64, p < 0.001 for OS), menopausal vs. premenopausal status (HR = 2.02, 95%CI, 1.35–3,0 p < 0.001 and HR = 2.25, 95%CI = 1.41–3.59, p < 0.001), ascites (HR = 1.95, 95%CI 1.35–2.80, p = 0.03, HR = 2.31, 95%CI = 1.52–3.5, p < 0.007), residual disease (HR = 5.12, 95%CI 3.43–7.65, p < 0.0001 and HR = 4.07, 95%CI = 2.59–6.39, p < 0.0001), and thrombocytosis (HR = 2.48 95%CI = 1.72–3.58, p < 0.0001, HR = 3.33, 95%CI = 2.16–5.13, p < 0.0001) were associated with a poor prognosis. An original prognostic score including these characteristics was validated using receiver operating characteristic (ROC) curves (area under the curve—AUC = 0.799 for PFS and AUC = 0.726 for OS, p < 0.001). The median PFS for patients with none, one, two, three, or four (or more) prognostic factors was not reached, 70, 36, 20, and 12 months, respectively. The corresponding median overall survival (OS) was not reached, 108, 77, 60, and 34 months, respectively. Conclusions: Several negative prognostic factors were identified: ECOG performance status ≥ 1, the presence of ascites and residual disease after surgery, thrombocytosis, and menopausal status. These led to the development of an original prognostic score that can be helpful in clinical practice

    Improvement of acromegaly control with multimodal therapy in Romania

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    Introduction: In Romania, there is no acromegaly national register and there are no nationwide data available. However, some studies have reported the control rates in the country’s main referral centres. Our aim was to assess the overall control rate in our tertiary referral centre. Also, we assessed the control rate in the last three years, and we compared the results with our previous reports. Material and methods: We reviewed the charts of 186 patients with acromegaly assessed in our department between January 1st, 2012 and May 31st, 2019. We also compared the control rates for patients treated between April 1st, 2016 and May 31st, 2019 with historical controls (assessed between January 1st, 2012 and March 31st, 2016). Results: Primary analysis: There were 19 untreated and 167 treated patients, mean age 52.46 years, surgery being the most commonly used treatment. The surgical cure rate was 14.8%, and disease control with medical treatment was 35.3%. Secondary analysis: In the first group there were 45 patients, surgery also being the most commonly used treatment. The surgical cure rate was 26.9%, and disease control was 30.4%. In the second group (historical controls) there were 42 patients, surgery being the most commonly used treatment. The surgical cure rate was 9.7%, and disease control with medical treatment was 15.4%. Random GH and IGF-1 after surgery were lower in the first group (p &lt; 0.05) Conclusions: Changes in the Romanian protocol and highly specialised pituitary centres has improved the cure rate and disease control in patients with acromegaly.
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