18 research outputs found

    A cloud-based, knowledge-enriched framework for increasing machining efficiency based on machine tool monitoring

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    The ever-increasing complexity in manufacturing systems caused by the fluctuating customer demands has highly affected the contemporary shop-floors. The selection of the appropriate cutting parameters is becoming more and more challenging due to the increasing complexity of products. Until now, the knowledge of the machine operators concerning the modification of the machining parameters and the monitoring information is not sufficiently exploited by the optimization systems. Web and Cloud technologies together with wireless sensor networks are required to capture the shop-floor data and enable the ubiquitous access from multiple IT tools. For addressing these challenges, this research work proposes a Cloud-based, knowledge-enriched framework for machining efficiency based on machine tool monitoring. More precisely, it focuses on the optimization of the machining parameters and moves through an event-driven optimization algorithm, utilizing the existing machining knowledge captured by the monitoring system. Based on the features of a new part, a similarity mechanism retrieves the cutting parameters of successfully executed past parts that have been machined. Afterwards, the optimization module, using event-driven function blocks, adapts these parameters to efficiently optimize the moves and the cutting parameters. The monitoring system uses a wireless sensor network and a human operator input via mobile devices. A case study from the mould-making industry is used for validating the proposed framework

    Ulcerated calcification of the interventricular septum causing Transient Ischemic Attacks: Case Report

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    Abstract Background Calcific deposits are frequently observed at sites of healed myocardial infarcts. Grossly visible calcification of myocardial infarcts and calcified intracavitary cardiac thrombi are less common but recently are becoming more frequent findings during surgical ventricular restoration procedures. Case Presentation A 64 years old male diabetic patient experienced two episodes of transient ischemic attacks during the last six months. During the diagnostic work up he was found to have triple vessel coronary artery disease with mild left ventricular dysfunction, akinesia of the anterior-apical wall and hypokinesia of the inferior wall. He was referred to our department for coronary artery bypass grafting. He underwent elective triple coronary artery bypass and a ventricular restoration procedure due to apical wall thinning. The inspection of the left ventricle revealed an ulcerated round shape calcification of the interventricular septum with a crater filled with clot. We resected the above lesion and covered the damaged area with the septal Dacron patch of the modified linear closure. The patient was discharged from the hospital on the 11th postoperative day and has been doing well 6 months later, with improvement in both ventricular function and clinical status. Conclusion The exploration of the left ventricular cavity reveals interesting phases of the post-infarction healing process. The suspicion of left ventricular thrombosis in patients with ventricular asynergy justifies a ventricular exploration during coronary artery bypass surgery.</p
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