Search results for " programmi"
showing 10 items of 1629 documents
Patient Specific Instrumentation for Total Knee Arthroplasty: a Literature Review
2014
During the past decade, total knee arthroplasty (TKA) has been markedly increased. Recently, patient-specific custom cutting guides have been commercially introduced in order to achieve an accurate component alignment during TKA. In fact, these cutting blocks are specific to a patient’s knee anatomy and should help the surgeons to perform bone cuts, reducing the complexity of conventional alignment and sizing tools. Nevertheless, there are critical arguments against patient-specific cutting guides for routine use, such as poor evidence and higher costs. Additionally, there are still no mild and long-term results available that describe the clinical outcomes following patient-specific instru…
Operator-Related Errors and Pitfalls in Dual Energy X-Ray Absorptiometry: How to Recognize and Avoid Them.
2020
Dual-energy X-ray absorptiometry (DXA) is the most common modality for quantitative measurements of bone mineral density. Nevertheless, errors related to this exam are still very common, and may significantly impact on the final diagnosis and therapy. Operator-related errors may occur during each DXA step and can be related to wrong patient positioning, error in the acquisition process or in the scan analysis. The aim of this review is to provide a practical guide on how to recognize such errors in spine and hip DXA scan and how to avoid them, also presenting some of the most common artifacts encountered in clinical practice.
Nesting Problems : Exact and Heuristic Algorithms
2013
Nesting problems are two-dimensional cutting and packing problems involving irregular shapes. This thesis is focused on real applications on Nesting problems such as the garment industry or the glass cutting. The aim is to study different mathematical methodologies to obtain good lower bounds by exact procedures and upper bounds by heuristic algorithms. The core of the thesis is a mathematical model, a Mixed Integer Programming model, which is adapted in each one of the parts of the thesis. This study has three main parts: first, an exact algorithm for Nesting problems when rotation for the pieces is not allowed; second, an Iterated Greedy algorithm to deal with more complex Nesting problem…
A Multi-Objective Design Approach for the c Chart Considering Taguchi Loss Function
2014
The present paper proposes a multi-objective design approach for the c chart, considering in the optimization process of the chart parameters both the statistical and the economic objectives. In particular, the minimization of the hourly total quality related costs is the considered objective to carry out the economic goal, whereas the statistical objective is reached by the minimization the out-of-control average run length of the chart. A mixed integer non-linear constrained mathematical model is formulated to solve the treated multi-objective optimization problem, whereas the Pareto optimal frontier is described by the «-constraint method. In order to show the employment of the proposed …
Continuous models combining slacks-based measures of efficiency and super-efficiency
2022
AbstractIn the framework of data envelopment analysis (DEA), Tone (Eur J Oper Res 130(3):498–509, 2001) introduced the slacks-based measure (SBM) of efficiency, which is a nonradial model that incorporates all the slacks of the evaluated decision-making units (DMUs) into their efficiency scores, unlike classical radial efficiency models. Next, Tone (Eur J Oper Res 143(1):32–41, 2002) developed the SBM super-efficiency model in order to differentiate and rank efficient DMUs, whose SBM efficiency scores are always 1. However, as pointed out by Chen (Eur J Oper Res 226(2):258–267, 2013), some interpretation problems arise when the so-called super-efficiency projections are weakly efficient, le…
Modeling epidemics through ladder operators
2020
Highlights • We propose an operatorial model to describe epidemics. • The model describes well the asymptotic numbers of the epidemics. • Ladder operators are used to model exchanges between the “actors” of the system.
Asymptotic Lipschitz regularity for tug-of-war games with varying probabilities
2018
We prove an asymptotic Lipschitz estimate for value functions of tug-of-war games with varying probabilities defined in $\Omega\subset \mathbb R^n$. The method of the proof is based on a game-theoretic idea to estimate the value of a related game defined in $\Omega\times \Omega$ via couplings.
Diverse partner selection with brood recombination in genetic programming
2018
The ultimate goal of learning algorithms is to find the best solution from a search space without testing each and every solution available in the search space. During the evolution process new solutions (children) are produced from existing solutions (parents), where new solutions are expected to be better than existing solutions. This paper presents a new parent selection method for the crossover operation in genetic programming. The idea is to promote crossover between two behaviourally (phenotype) diverse parents such that the probability of children being better than their parents increases. The relative phenotype strengths and weaknesses of pairs of parents are exploited to find out i…
Need for speed? Exploring the relative importance of patents and utility models among German firms
2017
Despite the wide use of two-tiered patent systems (patents and utility models (UMs)), there is little empirical evidence about how often UMs are actually used, what kind of firms use them to protect their intellectual property, and how firms rank them relative to patents. We offer such an analysis using data from Germany. We find that larger firms are more likely to use both protection methods. Moreover, a short life cycle of products and services is associated with an increased likelihood to use UMs. The features and functioning of the German UM system are of broader interest because it has been a benchmark for several second tier patent protection systems around the world. peerReviewed
Hard x-ray photoelectron spectroscopy: a snapshot of the state-of-the-art in 2020
2021
Journal of physics / Condensed matter 33(23), 233001 (1-44) (2021). doi:10.1088/1361-648X/abeacd