Search results for "CONSTRAINT"
showing 10 items of 361 documents
An approximate/exact objective based search technique for solving general scheduling problems
2018
Abstract In this paper, we analyze single machine scheduling problems under the following minimization objectives: the maximum completion time (makespan), the total completion time and the maximum lateness, including fundamental practical aspects, which often occur in industrial or manufacturing reality: release dates, due dates, setup times, precedence constraints, deterioration (aging) of machines, as well as maintenance activities. To solve the problems, we propose an efficient representation of a solution and a fast neighborhood search technique, which calculates an approximation of criterion values in a constant time per solution in a neighborhood. On this basis, a novel approximate/ex…
Theoretical and Practical Fundamentals
2014
Project managers carry out a project with several objectives in mind. They want to finish the project as soon as possible, with the minimum cost, the maximum quality, etc. This chapter studies project scheduling problems when several goals are sought, that is, multi-objective project scheduling problems (MOPSPs) and multi-objective resource-constrained project scheduling problems (MORCPSPs). We will discuss some of the most important issues that have to be taken into account when dealing with these problems. We will also prove some useful results that can help researchers create algorithms for some of these problems.
Overcoming acculturation: physical education recruits' experiences of an alternative pedagogical approach to games teaching
2015
Background: Physical education teacher education (PETE) programmes have been identified as a critical platform to encourage the exploration of alternative teaching approaches by pre-service teachers. However, the socio-cultural constraint of acculturation or past physical education and sporting experiences results in the maintenance of the status quo of a teacher-driven, reproductive paradigm. Previous studies have reported successfully overcoming the powerful influence of acculturation, resulting in a change in PETE students' custodial teaching beliefs and receptiveness to alternative teaching approaches. However, to date, limited information has been reported about how PETE students' accu…
Skilled workforce scheduling in Service Centres
2009
Abstract The Skilled Workforce Project Scheduling Problem (SWPSP) is a complex problem of task scheduling and resource assignment that comes up in the daily management of many company Service Centres (SC). The SWPSP considers many real characteristics faced daily by the SC: client-company service quality agreements that establish maximum dates for the beginning and the end of tasks with penalties for delays, criticality levels indicating the client-priority in processing each task, generalized precedence relationships that can produce cycle structures, time period and percentage time lags and variable task durations depending on the worker executing the task. Furthermore, the SC workforce i…
Bifurcations of Reachable Sets Near an Abnormal Direction and Consequences
2007
We describe precisely, under generic conditions, the contact and the bifurcations of the reachable set at time T along an abnormal direction, first for a single-input affine control system with constraint on the control, and then as an application for a sub-Riemannian system of rank 2. As a consequence we obtain in sub-Riemannian geometry a new splitting-up of the sphere near an abnormal minimizer γ into two sectors, bordered by the first Pontryagin’s cone along γ, called the L ∞-sector and the L 2-sector. Moreover we find again necessary and sufficient conditions of optimality of an abnormal trajectory for such systems, for any optimization problem.
The Impact of Climate, Resource Availability, Natural Disturbances and Human Subsistence Strategies on Sicilian Landscape Dynamics During the Holocene
2022
This paper presents a multidisciplinary summary of the most recent discoveries and hypotheses concerning factors driving the human subsistence economy and landscape shaping in Sicily during the Holocene. A number of scientific papers have recently pointed out the key role played by paleogeography, resource (water, food) availability and natural disturbances (volcanic eruptions, tsunamis) in local human activities. Modern anthropology and archaeology increasingly use biological remains (e.g. soils, bones, wood, plant macroremains, pollen) to better understand how human communities managed to survive and spread. Likewise, refined reconstructions of past human demographic fluxes and socio-econ…
STUDIO DI UNA FRIZIONE MAGNETOREOLOGICA PER AUTOVEICOLI
2013
Dopo un’accurata ricerca bibliografica sui fluidi magnetoreologici, il loro comportamento ed impiego, si è passati alla progettazione di una frizione magnetoreologica per autoveicoli. Considerando le caratteristiche di coppia trasmessa e potenza, il dispositivo è stato dimensionato tenendo presente i vincoli di ingombro del veicolo preso in esame. Sottoponendo il dispositivo ad analisi magnetostatica agli elementi finiti, si è determinato l’andamento delle linee di flusso del campo magnetico nel meato di fluido e nelle zone di maggior interesse, calcolando la coppia teoricamente trasmessa dall’innesto.È stato anche eseguito il confronto delle prestazionifra una frizione MR ed una frizione t…
Optimization study of acid-base flow battery stacks with monopolar and bipolar membranes
2021
The Acid-Base Flow Battery (AB-FB) is a novel technology for energy storage. It is based on reversible electrodialytic techniques with ion-exchange membranes. The kye elements are the bipolar membranes, which convert electrical energy in the form of pH gradients and vice versa. Despite the promising results of few experimental studies, the AB-FB potential has been poorly explored so far. This work presents an optimization study of the AB-FB. It was performed by a multi-scale process model previously developed (gPROMS Model Builder® environment) and experimentally validated. A two-objective optimization was conducted by maximizing the Net Round Trip Efficiency and the Net Power Density in th…
Three-dimensional matching based resource provisioning for the design of low-latency heterogeneous IoT networks
2019
Internet-of-Things (IoT) is a networking architecture where promising, intelligent services are designed via leveraging information from multiple heterogeneous sources of data within the network. However, the availability of such information in a timely manner requires processing and communication of raw data collected from these sources. Therefore, the economic feasibility of IoT-enabled networks relies on the efficient allocation of both computational and communication resources within the network. Since fog computing and 5G cellular networks approach this problem independently, there is a need for joint resource-provisioning of both communication and computational resources in the networ…
A data association approach to detect and organize people in personal photo collections
2011
In this paper we present a method to automatically segment a photo sequence in groups containing the same persons. Many methods in literature accom- plish to this task by adopting clustering techniques. We model the problem as the search for probable associations between faces detected in subsequent photos con- sidering the mutual exclusivity constraint: a person can not be in a photo two times, nor two faces in the same photo can be assigned to the same group. Associations have been found considering face and clothing descriptions. In particular, a two level architecture has been adopted: at the first level, associations are computed within meaningful temporal windows (situations); at the …