Search results for "Turing"
showing 10 items of 2644 documents
A Decision Making Tool in FMS Design
1995
In FMS design one of the initial fundamental decision concerns the flexibility level of the workstations to be implemented. New machining centers offer the possibility to carry out several operations on the workpieces to be processed, thus reducing the workload both of the material handling system and of the resources used to control the part flow in the FMS. In spite of advantages related to the use of the machining centers with high flexibility, the better typology of each workstation must be evaluated taking into account its influence on the tools fleet and on the workload of the handling and tool room subsystems.
Incremental forming of friction stir welded taylored sheets
2006
In the last decade sheet metal forming market has undergone substantial mutations since the development of more efficient strategies in terms of flexibility and cost reduction is strictly due. Such requirements are not consistent with traditional metal stamping processes which are characterized by complex equipment, capital and tooling costs; thus the industrial application of such processes is economically convenient just for large scale productions. For this reason most of the research work developed in the last years has been focused on the development of new sheet forming processes able to achieve the above discussed goals. Contemporary, with particular reference to the automotive indus…
Principles of scatter search
2006
Scatter search is an evolutionary method that has been successfully applied to hard optimization problems. The fundamental concepts and principles of the method were first proposed in the 1970s, based on formulations dating back to the 1960s for combining decision rules and problem constraints. In contrast to other evolutionary methods like genetic algorithms, scatter search is founded on the premise that systematic designs and methods for creating new solutions afford significant benefits beyond those derived from recourse to randomization. It uses strategies for search diversification and intensification that have proved effective in a variety of optimization problems. This paper provides…
Semiparametric stochastic frontier models: A generalized additive model approach
2017
Abstract The choice of the functional form of the frontier into a stochastic frontier model is typically neglected in applications and canonical functions are usually considered. This paper introduces a semiparametric approach for stochastic frontier estimation that extends previous works based on pseudo-likelihood estimators allowing flexibility in model selection and capability of imposing monotonicity and concavity constraints. For these purposes the present work introduces a generalized additive framework that moreover permits to model the influence of contextual/environmental factors to the hypothesized production process by the relative extension given by generalized additive models f…
Real-Time Routing Selection in Flexible Manufacturing Systems
1993
Routing flexibility is one of the main peculiarities of Flexible Manufacturing Systems. This paper proposes three methods for real-time routing selection. The first one makes decisions comparing the current workload of machines in each alternative path. The second method considers the current workloads at the bottleneck machines in each allowed route. The third approach makes real-time decisions minimizing a merit index that represents a measure of the still required resource amount. The index is computed by short discrete-event simulation runs. Some case studies evaluate and compare the proposed approaches.
Manufacturing Strategy: Production Problem Analysis for Assessing Focused Flexibility
2008
The objective of this chapter is to define an operationalization pattern which supports decision makers and managers in determining the level of manufacturing flexibility competences, given the business strategy and the manufacturing structure of the firm. This should drive the production system design and configuration activity. Specifically, this chapter presents an innovative approach to develop a manufacturing strategy, which is based on the idea that information on potential production problems that the manufacturing system could face throughout a given long-term planning horizon should be used as a starting point to determine the level of flexibility that the system should possess.
A review of emerging trends in membrane science and technology for sustainable water treatment
2020
Abstract Access to clean or potable water will continue to be a global challenge in as much as sustainable solutions are far-fetched. It has become imperative to improve the efficiency of conventional membrane science and technologies for water treatment in order to reduce their deleterious impact on the environment. Some sustainability solutions have been proposed and studied in recent years. Therefore, a critical and comprehensive review of emerging trends in sustainable membrane-based desalination and wastewater treatment is presented in this paper. Some of the emerging trends in membrane science and technology for sustainable water treatment include the reuse of membranes, reuse of wast…
Perfluorinated Compounds in Food: A Global Perspective
2011
Perfluorinated compounds (PFCs) are resistant to breakdown and are turning up in unexpected places around the world, becoming emerging food contaminants. Although these chemicals have been used in countless products since the 1950s, they have been subject to little control until now. There is still an insufficient knowledge of their sources, occurrence, and hazards for food safety decision making. This article provides a comprehensive review of the food contamination levels and dietary intake risks posed by PFCs, as well as the specific methods developed for their determination. It is based on the evaluation of the published literature between 2004 and the beginning of 2010, with special em…
Micro-machining
2008
This chapter provides comprehensive knowledge regarding the fabrication of micro-products and element of micro-electromechanical systems using various techniques and processes. Both well-established techniques such as micro-machining and new trends in improving micro-processes taking into account EDM, laser, FIB, LIGA and DRIE processes are overviewed. The background of micro-machining processes, including typical machining operations such as turning, milling and drilling and different construction materials, is outlined. Moreover, a special focus was made on new constructions, control systems and effective applications of micro-machining techniques. In addition, the focus was directed towa…
Mathematical models for assessment of vehicle crashworthiness: a review
2021
This article reviews approaches to mathematical modeling of a vehicle crash. The growing focus on vehicle and occupant safety in car crashes has triggered the need to study vehicle crashworthiness in the initial stages of vehicle development. The major motivation for this work is to support vehicle crashworthiness design during the product development process.The article is divided into two parts; the first one overviews existing mathematical models used to solve engineering problems. The second part describes modeling strategies applied for replicating non-linear vehicle crash event and occupant kinematics in an occupant protection loadcase. We also highlight alternative modeling strategie…