55 research outputs found
A machine learning approach to enable bulk orders of critical spare-parts in the shipping industry
Purpose: The main purpose of this paper is to propose a methodological approach and a decision support tool, based on prescriptive analytics, to enable bulk ordering of spare parts for shipping companies operating fleets of vessels. The developed tool utilises Machine Learning (ML) and operations research algorithms, to forecast and optimize bulk spare parts orders needed to cover planned maintenance requirements on an annual basis and optimize the company’s purchasing decisions. Design/methodology/approach: The proposed approach consists of three discrete methodological steps, each one supported by a decision support tool based on clustering and Machine Learning (ML) algorithms. In the first step, clustering is applied in order to identify high interest items. Next, a forecasting tool is developed for estimating the expected needs of the fleet and to test whether the needed quantity is influenced by the source of purchase. Finally, the selected items are cost-effectively allocated to a group of vendors. The performance of the tool is assessed by running a simulation of a bulk order process on a mixed fleet totaling 75 vessels. Findings: The overall findings and approach are quite promising Indicatively, shifting demand planning focus to critical spares, via clustering, can reduce administrative workload. Furthermore, the proposed forecasting approach results in a Mean Absolute Percentage Error of 10% for specific components, with a potential for further reduction, as data availability increases. Finally, the cost optimizer can prescribe spare part acquisition scenarios that yield a 9% overall cost reduction over the span of two years. Originality/value: By adopting the proposed approach, shipping companies have the potential to produce meaningful results ranging from soft benefits, such as the rationalization of the workload of the purchasing department and its third party collaborators to hard, quantitative benefits, such as reducing the cost of the bulk ordering process, directly affecting a company’s bottom linePeer Reviewe
On the Radiative Corrections to the Pseudo-scalar Higgs Boson Mass
We reexamine the one-loop corrections to the mass of the pseudo-scalar Higgs boson, using the effective potential. In the absence of the chargino and neutralino contributions its mass exhibits a large scale dependence in the large regime, especially for values of . Thus, although of electroweak origin, the heaviness of the , in conjunction with the largeness of , makes these corrections very important for establishing a scale independent result and an unambiguous determination of the pseudo-scalar mass in this region of the parameter space
Acute myocardial infarction presumambly embolic, in a patient with a mechanical aortic valve: a rare cause of non atherosclerotic coronary arterial occlusion
AbstractWe present a case of an acute myocardial infarction with ST segment elevation in a patient with a mechanical aortic valve prosthesis who had discontinued anticoagulant therapy. We performed a primary coronary intervention procedure, including thrombus aspiration as well as plain balloon angioplasty (low atmospheres), in order to restore coronary flow in left anterior descending artery as soon as possible. Review of the literature suggests that in such cases the diagnosis of the embolic origin of the acute coronary syndrome is assumed and can never been proved definitely. Thrombus aspiration must be included in the therapeutic strategy of these patients.  
Δυνατότητες προπόνησης και συμμετοχής σε αγώνες των α.μ.ε.α. στο θαλάσσιο σκι και γουέηκμπορντ στην ελλάδα και σύγκριση με άλλα κράτη.
Η παρούσα μελέτη αναλύει τις δυνατότητες προπόνησης και συμμετοχής σε αγώνες των ΑΜΕΑ στο θαλάσσιο σκι και γουέηκμπορντ στην Ελλάδα ,σε σύγκριση με άλλα κράτη. Ως προς αυτό το σκοπό η μελέτη αναλύει τους όρους του θαλάσσιου σκι και γουέηκμπορντ, τα αγωνίσματα σε επίπεδο πρωταθλητισμού το σλάλομ το άλμα τις φιγούρες, τις ειδικές ανάγκες, τα εμπόδια που αντιμετωπίζουν τα ΑΜΕΑ στο θαλάσσιο σκι και το γουέηκμπορντ. Την εξέλιξη της τεχνολογίας των θαλάσσιων αθλημάτων και ανάλυση του εξοπλισμού για τα ΑμεΑ, την πρόσβαση τους στον αθλητισμό και τους κανονισμούς του κάθε αθλήματος των ΑΜΕΑ .Τα εμπόδια που αντιμετωπίζουν αυτά τόσο εν γένει όσο και στον αθλητισμό. Η μελέτη εν συνεχεία διεξάγει μία ποιοτική ανάλυση με τη χρήση συνεντεύξεων διαφόρων ομοσπονδιών – συλλόγων, αθλητών και προπονητών της Ελλάδας και του εξωτερικού θαλάσσιου σκι και γουέηκμπορντ. Έπειτα, γίνεται μία σύγκριση των συνεντεύξεων μεταξύ της Ελλάδος και των υπόλοιπων χωρών του εξωτερικού και διαφαίνεται ότι η Ελλάδα δυσκολεύεται στην παροχή δυνατοτήτων προπόνησης στα ΑΜΕΑ, οι υποδομές απουσιάζουν, οι αθλητές που ασχολούνται είναι πολύ λίγοι. Οι δυνατότητες συμμετοχής σε αγώνες δεν υπάρχουν καθώς δεν έχουν διεξαχθεί αρκετοί αγώνες για ΑΜΕΑ στην Ελλάδα. Η Ελληνική ομοσπονδία δεν είχε και δεν έχει επιτροπή για ΑΜΕΑ. Δεν υπάρχει προγραμματισμός προσέγγισης των ΑΜΕΑ για ενασχόληση με το άθλημα. Δεν υπάρχει καταγραφή ούτε γνώση για την ερασιτεχνική ενασχόληση των ΑΜΕΑ. Αντίθετα στο εξωτερικό η ζήτηση του αθλήματος είναι μεγαλύτερη, ασχολούνται αρκετοί αθλητές με το καθιστό θαλάσσιο σκι – γουεηκμπορντ. Οι υποδομές υπάρχουν για εύκολη πρόσβαση στο νερό, διεξάγονται και αγώνες για ΑΜΕΑ μαζί με τις υπόλοιπες κατηγορίες. Επομένως καταλήγουμε στο συμπέρασμα ότι η Ελλάδα υστερεί σε σχέση με τις υπόλοιπες χώρες.οχ
Carotid artery endarterectomy vs. stenting: are there any relevant morphological and hemodynamic implications?
Groin surgical site infection incidence in vascular surgery with intradermal suture versus metallic stapling skin closure. A study protocol for a pragmatic open-label parallel-group randomized clinical trial (VASC-INF trial)
Background: Surgical site infection is 1 of the most frightening complications in vascular surgery due to its high morbimortality. The use of intradermal sutures for skin closure might be associated with a reduction in infections incidence. However, the data available in the literature is scarce and primarily built on low-evidence studies. To our knowledge, no multicenter clinical trial has been published to assess if the intradermal suture is associated with a lower surgical site infection incidence than metallic staples in patients who will undergo revascularization surgery requiring a femoral approach. Methods: VASC-INF is a pragmatic, multicenter, multistate (Spain, Italy, and Greece), randomized, open-label, clinical trial assessing the surgical site infection incidence in patients undergoing revascularization surgery requiring a femoral approach. Patients will be randomized on a 1:1 ratio to intradermal suture closure (experimental group) or to metallic staples closure (control group).The primary outcome is the number (percentage) of patients with surgical site infection (superficial and/or deep) associated with a femoral approach up to 28 (±2) days after surgery. Among the secondary outcomes are the number (percentage) of patients with other surgical wound complications; the number (percentage) of patients with surgical site infections who develop sepsis; type of antibiotic therapy used; type of microorganisms' species isolated and to describe the surgical site infection risk factors. Discussion: Intradermal suture closure may be beneficial in patients undergoing revascularization surgery requiring a femoral approach. Our working hypothesis is that intradermal suture closure reduces the incidence of surgical site infection respect to metallic staples closure
Inmate cancer patients – highlighting the importance of a holistic approach to oncological care
Purpose: Inmate oncologic patients' rates increased drastically worldwide. Elderly, limited exercise, unhealthy diet, hepatitis, HIV+ status, tobacco and alcohol use, constitute the main cancer risk factors. We present an outline of practical oncological management and ethical thinking, in the specific environment of a detention facility. Methods: PubMed, Cochrane Database of Controlled Trials, SCOPUS and grey literature were extensively searched upto October 2021. Ιncarcerated oncologic patients experiencevarious everyday challenges:their confinement in high securityfacilities, the lack of access to critical care and related ethicaldilemmas inherent to the context of a correctional facility. Results: The detention facilities may be inadequate in providing early cancer diagnosis and appropriate care mainlydue to a lack of specialized personnel, b) in-house or in external specialized cancer hospitals, care variability (e.g. admissions in small local or regional hospitals), c) delays inproviding access and d) gatekeeper systems. There is a paucity of administration of a) systemic therapy(chemotherapy, targeted drug therapy etc), b) radiotherapy, c)palliative care, and d) enrollment in clinical trials. Conclusions: Correctional facilities must encourage teamwork between healthcare and correctional professionals inorder to improve the provided anticancer care
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