67 research outputs found

    A cost modelling methodology based on machine learning for engineered-to-order products

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    Recent scientific studies are targeted at applying and assessing the effectiveness of Machine Learning (ML) approaches for cost estimation during the preliminary design phases. To train ML prediction models, comprehensive and structured datasets of historical data are required. This solution is inapplicable when such information is unavailable or sparse due to the lack of structured datasets. For engineered-to-order products, the number of historical records is often limited and strongly influenced by different purchasing or manufacturing strategies, thus requiring complex normalisation of such data. This method overcomes the above limitations by presenting an ML-based cost modelling methodology for the conceptual design that is applicable even when historical data are insufficient to train the prediction algorithms. The training dataset is generated through an analytical and automatic software tool for manufacturing cost estimation. Such a tool, starting from a 3D model of a product, can quickly and autonomously assess the related cost in different scenarios. An extensive and structured training dataset can be easily generated. The proposed methodology was based on CRISP-DM (Cross Industry Standard Process for Data Mining). Cost engineers of an Oil & Gas company used the method to develop parametric cost models for discs and spacers of an axial compressor. The solution guarantees lower error (7% vs 9%) and significant time-saving (minutes instead of hours) than estimations based on other approaches. Cost models are more comprehensive (capable of analysing different scenarios), explainable (not conceived as a black box), and self-learning (can be updated by extending the training dataset)

    cost estimation method for gas turbine in conceptual design phase

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    Abstract Introduction of new gas turbine machines on market is a complex project that requires optimization of different performance parameters such as power, efficiency, maintenance plan, product cost and life. The ability to control cost and impact on performances and life strongly decreases from conceptual to detailed design phase. Actually, 80 % of product's cost and performances are committed based on decisions made in conceptual design. This Paper describes a systematic procedure to estimate the cost of multiple design alternatives during conceptual design phase, comparing different cross sections for gas turbine solutions. Examples of parametric costing tool for part family will be described, to show the approach that allows to estimate costs in conceptual design phase, when detailed design has not been developed and lack of information is a daily topic. The idea is to be able to read design information of each part from an enhanced cross section and enter parametric costing tool to have a preliminary cost estimation in conceptual phase. Doing that for each part or module present, it will be possible to estimate total cost of the product. The scope is to create an internal database where the whole know-how and best practices are stored. This database can be examined in early program stages, to reduce time to market and avoid pursuing solutions that would not be viable or convenient, in a sort of digital twin approach. Another positive aspect pursued and presented, is the positive impact on engineering productivity, that directly reflects on program development cost

    CT and MRI radiomics of bone and soft-tissue sarcomas: a systematic review of reproducibility and validation strategies

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    Feature reproducibility and model validation are two main challenges of radiomics. This study aims to systematically review radiomic feature reproducibility and predictive model validation strategies in studies dealing with CT and MRI radiomics of bone and soft-tissue sarcomas. The ultimate goal is to promote achieving a consensus on these aspects in radiomic workflows and facilitate clinical transferability

    Petroclival clinoidal folds and arachnoidal membranes of the anteromedial incisural space: clinical anatomy for neuro critical care

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    A systematic and narrative literature review was performed, focusing attention on the anatomy of the area located at the junction of the sphenoid and the basal portion of the temporal bone (petrous bone, petrous apex, upper petro-clival region) encircled by the free edge of the tentorium, the insertion of the tentorium itself to the petrous apex and the anterior and posterior clinoid processes that give rise to three distinct dural folds or ligaments: the anterior petroclinoid ligament, the posterior petroclinoid ligament and the interclinoid ligament. These dural folds constitute the posterior portion of the roof of the cavernous sinus denominated "the oculomotor triangle". The main purpose of this review study was to describe this anatomical region, particularly in the light of the relationships between the anterior margin of the free edge of the tentorium and the above-mentioned components of the sphenoid and petrous bone

    Different Molecular Signatures in Magnetic Resonance Imaging-Staged Facioscapulohumeral Muscular Dystrophy Muscles

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    Facioscapulohumeral muscular dystrophy (FSHD) is one of the most common muscular dystrophies and is characterized by a non-conventional genetic mechanism activated by pathogenic D4Z4 repeat contractions. By muscle Magnetic Resonance Imaging (MRI) we observed that T2-short tau inversion recovery (T2-STIR) sequences identify two different conditions in which each muscle can be found before the irreversible dystrophic alteration, marked as T1-weighted sequence hyperintensity, takes place. We studied these conditions in order to obtain further information on the molecular mechanisms involved in the selective wasting of single muscles or muscle groups in this disease

    Urogynecological prolapse and enterocele are predictive of poor functional outcome after failed or complicated STARR procedures

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    Stapled anorectal procedures have been widely practiced worldwide over the last 20 years. This is largely due to the fact that these procedures are advertised as less painful and associated with a faster return to work compared to con- ventional surgical techniques. Stapled transanal rectal resection (STARR) quickly came to be considered safe and effective despite only weak evidence , and it has rapidly gained wide acceptance in clinical practice worldwide. However, several reports have questioned the role of STARR in treating obstructed def- ecation syndrome (ODS) because of high recurrence rates and unusual and severe complications including deat

    Painful ejaculation: a review

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    BACKGROUND. Pain at ejaculation/orgasm perceived in perineum, urethra and/or urethral meatus, has a profound impact on the quality of life of the affected man. Although underestimated, this condition is reported to have a 1-9.7% prevalence over the general population. METHODS. Structured review of the relevant available literature. RESULTS. Among the main causes of pain experienced at ejaculation/orgasm are: prostatevesicular causes (LUTS/BPH, prostatitis, ejaculatory duct obstruction, vesicular stone), postsurgical causes (radical prostatectomy, inguinal hernioplasty), pharmacologic causes (antidepressants), psychogenic causes (psychosexual conflicts, sexual abuse), rare causes. For these pathologies, diagnostic and therapeutic strategies have been proposed. CONCLUSIONS. Ejaculatory pain is associated with a high level of personal distress, and represents a possible request for help within the andrologic/urologic area. Each field specialist should be competent in correctly interpreting every single case, in order to manage it appropriately

    Diagnosing erectile dysfunction: instruments for the study of smooth muscle relaxation

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    Complete cavernosal smooth muscle relaxation is the pre-requisite for the reliability of every evaluation of the integrity of the corporal veno-occlusive system. Such evaluation is needed whenever reaching a diagnostic conclusion on the haemodynamic status of a given patient is clinically relevant. Clinical challenges that a laboratory evaluation of veno-occlusive integrity face comprise both the induction of complete smooth muscle relaxation, and the possibility to monitor it. This article will review the relevant aspects of normal range values of veno-occlusive function, existing strategies aimed to promote complete smooth muscle relaxation, and available techniques to monitor the cavernosal smooth muscle status

    Carbon-coated microbeads anal injection in outpatient treatment of minor fecal incontinence

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    Abstract PURPOSE: Anal bulking agents are injected to pose a stronger obstacle to the involuntary passage of feces and gas. This prospective, multicenter study was designed to evaluate the safety and efficacy of Durasphere anal injection for the treatment of fecal incontinence. PATIENTS AND METHODS: Thirty-three unselected patients with incontinence (24 females; mean age, 61.5 +/- 14 (range, 22-83) years) underwent anal bulking agent submucosal injection with carbon-coated microbeads (Durasphere) in the outpatient regimen. The causes of incontinence were obstetric lesions in 18.2 percent, iatrogenic in 36.4 percent, rectal surgery in 12.1 percent, and idiopathic in 33.3 percent. Previous unsuccessful treatments for fecal incontinence included diet and drugs in 16 patients, biofeedback training in 7 patients, sacral nerve modulation in 6 patients, sphincteroplasty in 2 patients, artificial bowel sphincter in 1 patient, and PTQ macroplastique bulking agent in 1 patient. Under local anesthesia and antibiotic prophylaxis, a mean of 8.8 (range, 2-19) ml of Durasphere were injected into the submucosa by using a 1.5-inch, angled, 18-gauge needle. RESULTS: After a median follow-up of 20.8 (range, 10-22) months, the median Cleveland Clinic continence score decreased significantly from 12 to 8 (P < 0.001) and the median American Medical System score from 89 to 73 (P = 0.0074), but the Fecal Incontinence Quality of Life did not change significantly (74 to 76, P = not significant). Anal manometry significantly improved (resting pressure increasing from 34 to 42 mmHg; P = 0.008) and squeezing pressure from 66 to 79 mmHg (P = 0.04). Two patients complained of moderate anal pain for a few days after the implant, one patient had asymptomatic leakage of the injected material through a mucosa perforation, and two had distal migration of the Durasphere along the dentate line. CONCLUSIONS: Anal bulking agent injection is a safe treatment and can mitigate the severity of fecal incontinence by increasing anal pressure but does not significantly improve the quality of lif
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