0000000000778162
AUTHOR
V. Grasso
showing 6 related works from this author
Tool Failure in Sequential Cutting of two Different Materials
1985
In this paper the authors show that the premature tool breakage, characteristic of interrupted cutting, can be enhanced in sequential cutting of two materials having different mechanical and chemical properties. The results of experimental investigations carried out in turning pieces consisting of medium carbon steel and aluminium alloy show that the time to failure is significatively lower than that occurring in machining only one of the two materials; moreover the morphology of the damage depends by the cutting order. Working with the sequence steel-Al alloy welding phenomena caused by strong deoxidation due to the latter material are observed; these phenomena cause the early development …
Possibilistic Programming and Gas for Aggregate Production Planning under Vague Information
1999
In production planning activities, aggregate planning is surely the phase where the lack of information is more relevant. The reasons for that can be summarised in: a) the planning product is an aggregate one, very often not corresponding to actual products; b) the delay from the actual production is relevant so that information regarding actual production resources availability and performances are vague; c) the planning activity is often based on forecasts. On the other hand, all the subsequent production planning activities are based on the result of aggregate planning. In the paper a research going on at the Workgroup for Soft Computing Application in Manufacturing is presented. A Decis…
HEURISTIC PROCEDURES FOR GROUP SCHEDULING
1989
ABSTRACT The group scheduling problem is investigated, solving numerous small and large sized examples with eight sequencing algorithms. A new approach, basically consisting in the definition of real machines' idles for each group, utilizing allowed shifting of non critical activities, is proposed. Moreover the CDS multi-shot algorithm is extended to group scheduling.
Scheduling a cellular manufacturing system with GA
2002
The flexible manufacturing cell scheduling problem is considered with a multi-objective approach, pursuing together makespan minimisation and the in process job wait minimisation. The formulation of the scheduling problem is discussed, analysing how to generate well suited sequences, like generalised permutation sequences, and the proper construction of a JIT timing of activities. An evolutionary sequencing algorithm based on both classic genetic operators and hybrid operators is then proposed. The hybrid operators have been introduced to construct highly fit initial population, to perform periodically a local search on the population and to maintain enough genetical diversity in the actual…
An evolutionary approach to multi-objective scheduling of mixed model assembly lines
1999
In this paper a multi-objective genetic algorithm for the scheduling of a mixed model assembly line is proposed, pursuing the line stop time minimisation together with the component usage smoothing. Specific features of the developed GA are step by step random selection of diversified crossover and mutation operators, population control for the substitution of duplicate chromosomes, and in-process updating of GA control parameters. Three different formulation of the fitness function were been tested with some distinct line configurations.
Prophylaxis of venous thromboembolism in elderly patients with multimorbidity
2013
none 327 si Pharmacological thromboprophylaxis (TP) is known to reduce venous thromboembolism (VTE) in medical inpatients, but the criteria for risk-driven prescription, safety and impact on mortality are still debated. We analyze data on elderly patients with multimorbidities admitted in the year 2010 to the Italian internal medicine wards participating in the REPOSI registry to investigate the rate of TP during the hospital stay, and analyze the factors that are related to its prescription. Multivariate logistic regression, area under the ROC curve and CART analysis were performed to look for independent predictors of TP prescription. Association between TP and VTE, bleeding and death in …