Search results for "Scheduling"
showing 10 items of 275 documents
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…
A Population-Based Approach to the Resource-Constrained Project Scheduling Problem
2004
We present a population-based approach to the RCPSP. The procedure has two phases. The first phase handles the initial construction of a population of schedules and these are then evolved until high quality solutions are obtained. The evolution of the population is driven by the alternative application of an efficient improving procedure for locally improving the use of resources, and a mechanism for combining schedules that blends scatter search and path relinking characteristics. The objective of the second phase is to explore in depth those vicinities near the high quality schedules. Computational experiments on the standard j120 set, generated using ProGen, show that our algorithm produ…
Critical Path Analysis with Imprecise Activities Times
2018
The aim of the paper is to present the conceptual framework related to critical path analysis with imprecise activity duration times. This article is motivated by the fact that most approaches to project planning are deterministic. In reality, the problem is accompanied by uncertainty and risk associated with dealing with imprecise data. Taking this uncertainty into account when performing analyses and calculations not only helps to better project planning, but also to expand the applicability of project scheduling methods under real-life or uncertain conditions. The major contribution of this paper is the development of a novel approach to critical path analysis in the presence of uncertai…
Theoretical Game Approach for Mobile Users Resource Management in a Vehicular Fog Computing Environment
2018
Vehicular Cloud Computing (VCC) is envisioned as a promising approach to increase computation capabilities of vehicle devices for emerging resource-hungry mobile applications. In this paper, we introduce the new concept of Vehicular Fog Computing (VFC). The Fog Computing (FC) paradigm evolved and is employed to enhance the quality of cloud computing services by extending it to the edge of the network using one or more collaborative end-user clients or near-user edge devices. The VFC is similar to the VCC concept but uses vehicles resources located at the edge of the network in order to serve only local on-demand mobile applications. The aim of this paper is to resolve the problem of admissi…
Latency-Oblivious Distributed Task Scheduling for Mobile Edge Computing
2018
Mobile Edge Computing (MEC) is emerging as one of the effective platforms for offloading the resource- and latency-constrained computational services of modern mobile applications. For latency- and resource-constrained mobile devices, the important issues include: 1) minimize end-to-end service latency; 2) minimize service completion time; 3) high quality-of-service (QoS) requirement to offload the complex computational services. To address the above issues, a latencyoblivious distributed task scheduling scheme is designed in this work to maximize the QoS performance and goodput for the MEC services. Unlike most of the existing works, we consider the latency-oblivious property of different …
Analysis and Performance Evaluation of the IEEE 802.16 ARQ Mechanism
2008
The IEEE 802.16 standard defines the ARQ mechanismas a part of the MAC layer. The functioning of the ARQmechanism depends on a number of parameters. The IEEE802.16 specification defines them but it does not provide concrete values and solutions. This paper studies the key features and parameters of the 802.16 ARQ mechanism. In particular, we consider a choice for the ARQ feedback type, an algorithm to build block sequences, the ARQ feedback intensity, a scheduling of the ARQ feedbacks and retransmissions, the ARQ block rearrangement, ARQ transmission window and the ARQ block size. We ran simulation scenarios to study these parameters and how they impact the performance of application protoc…
Impact of COVID-19 on hand surgery in Italy: A comparison between the Northern and the Southern regions
2021
The aims of this study were to evaluate the impact of the COVID-19 pandemic on emergency and elective hand surgery in four Italian regions that had either a high (Lombardy and Piemonte) or a low (Sicilia and Puglia) COVID-19 case load to discuss problems and to elaborate strategies to improve treatment pathways. A panel of hand surgeons from these different regions compared and discussed data from the centers they work in. The COVID-19 pandemic had an enormous impact on both elective and emergency surgery in Italy, not only in highly affected regions but also – and paradoxically even at a higher extent – in regions with a low COVID-19 case load. A durable and flexible redesign of hand surge…
Blood Pressure Monitoring in Cardiovascular Disease
2017
While the practice of taking blood pressure readings at the physician’s office continues to be valid, home blood pressure monitoring is being increasingly used to enhance diagnostic accuracy and ensure a more personalized follow-up of patients. In the case of white coat hypertension and resistant arterial hypertension, ambulatory blood pressure monitoring is indispensable. Recent studies attach great importance to nocturnal blood pressure patterns, with a reduction in these becoming a treatment goal, a strategy known as chronotherapy. Home blood pressure monitoring is useful for both diagnosis and follow-up of arterial hypertension. Its use, particularly if combined with other patient-suppo…
Enhancing the performance of HSDPA communication with multipoint transmission techniques
2015
The evolution of mobile phones, tablets and other mobile communication devices has led to a significant increase in the amount of data delivered over mobile networks. In order to satisfy the climbing data rate demands of customers, existing mobile broadband networks are being expanded with new features that allow ubiquitous and consistent networking experience. This research presents three multipoint transmission techniques for Wideband Code Division Multiple Access (WCDMA) based High-Speed Downlink Packet Access (HSDPA) communication protocol. Multiflow, High-Speed Single-Frequency Network (HS-SFN) and Multipoint-to-Point Single-Frequency Network (M2P-SFN) enable transmission of user-dedicat…
Scheduling under the network of temporo-spatial proximity relationships
2017
We discuss and introduce to the schedulingeld a novel, qualitative optimization model - scheduling under the network of temporo-spatial proximity relationships.We introduce a half perimeter proximity measure as an objective of scheduling.We present and evaluate an incremental Sequence Pair neighborhood evaluation algorithm, applicable to both scheduling and rectangle packing problems in VLSI industry. In this paper, we discuss and introduce to the scheduling field a novel optimization objective - half perimeter proximity measure in scheduling under the network of temporo-spatial proximity relationships. The presented approach enables to qualitatively express various reasons of scheduling ce…