Search results for "Fuzzy number"
showing 10 items of 86 documents
Cyclic Dynamic Evaluation of Logistics Services Stakeholders Based on System with OFN Model
2021
The challenge for enterprises and supply chains is to deliver successful logistics services in compliance with their aims. Logistics services are affected by many stakeholders. Recognizing their impact on the undertaken services is important for the planning and execution of a sufficiently rigorous stakeholder management process. The aim of the paper is to present a new approach to the analysis of stakeholders - cyclic dynamic evaluation, which could be used in service management, such as in logistics services. We present a novel fuzzy inference system based on the mathematical apparatus of Ordered Fuzzy Numbers (OFNs). The evaluation of stakeholders consists in assessing key factors as - f…
Solving type-2 assembly line balancing problem with fuzzy binary linear programming
2013
This paper deals with the use of fuzzy set theory as a viable alternative method for modelling and solving the stochastic assembly line balancing problem. This paper presents a fuzzy extension of the simple assembly line balancing problem of type 2 SALBP-2 with fuzzy job processing times since uncertainty, variability, and imprecision are often occurred in real-world production systems. The job processing times are formulated by triangular fuzzy membership functions using their statistical distributions. This study proposes to solve a Fuzzy Binary Linear Problem FBLP with fuzzy coefficients in the objective function and in a constraint. Finally, the effect of the unbalancing of a station in…
Fuzzy logic and meteorological variables: a case study of solar irradiance
2002
Solar irradiance is an extreme case of an uncertain variable when measured on an hourly, or shorter time interval. In this paper solar irradiance has been considered as a case study for physical fuzzy modelling of a climate variable. The uncertainty of the solar irradiance is treated as a fuzzy uncertainty whilst other variables are considered crisp. The approach is robust as it does not rely on statistical assumptions, and it is a possible alternative to modelling complex systems. To our knowledge, this is the first time that a physical model of a meteorological variable based on fuzzy numbers has been proposed. Previous rule-based fuzzy meteorological models are only descriptive, and cann…
F.A.L.C.A.D.E.: a fuzzy software for the energy and environmental balances of products
2004
Abstract It is generally well known that the reliability of Life Cycle Analysis (LCA) studies depends upon exact, complete and sharp input data that, unfortunately, are not always available. Furthermore, when available, the input data are affected by uncertainty whose importance is not always adequately taken into consideration. This paper describes the software F.A.L.C.A.D.E. (Fuzzy Approach to Life Cycle Analysis and Decision Environment): a tool designed for the calculation of the eco-profile of products, based on a fuzzy logic approach. The originality of the method already treated in other papers is to use the fuzzy representation to manage the complex relationships that arise in compi…
deaR-Shiny: An Interactive Web App for Data Envelopment Analysis
2021
In this paper, we describe an interactive web application (deaR-shiny) to measure efficiency and productivity using data envelopment analysis (DEA). deaR-shiny aims to fill the gap that currently exists in the availability of online DEA software offering practitioners and researchers free access to a very wide variety of DEA models (both conventional and fuzzy models). We illustrate how to use the web app by replicating the main results obtained by Carlucci, Cirà and Coccorese in 2018, who investigate the efficiency and economic sustainability of Italian regional airport by using two conventional DEA models, and the results given by Kao and Liu in their papers published in 2000 and 2003, wh…
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…
A fuzzy-based tool for modelization and analysis of the vulnerability of aquifers: a case study
2005
Abstract A fuzzy-based tool, called FUZZY-SRA (Fuzzy Spatial Reliability Analysis), is used for realizing a more “reliable” study of the values of the final parameters concerning the vulnerability of aquifers located in the territory of Cava de' Tirreni, city in the district of Salerno (Italy). The SINTACS method is adopted for evaluating the involved parameters and these evaluations are modelled from attributes represented from triangular fuzzy numbers which supply the overall final information if combined with suitable algebraic operations. The tool FUZZY-SRA is implemented inside a GIS (Geographical Information Systems) software.
Multi-objective human resources allocation in R&D projects planning
2009
In a R&D department, several projects may have to be implemented simultaneously within a certain period of time by a limited number of human resources with diverse skills. This paper proposes an optimisation model for the allocation of multi-skilled human resources to R&D projects, considering individual workers as entities having different knowledge, experience and ability. The model focuses on three fundamental aspects of human resources: the different skill levels, the learning process and the social relationships existing in working teams. The resolution approach for the multi-objective problem consists of two steps: firstly, a set of non-dominated solutions is obtained by exploring the…
Assessing the profitability of investment projects using ordered fuzzy numbers
2019
Background: This article is motivated by the fact that most approaches to capital budgeting are deterministic. In reality, the capital budgeting problem is accompanied by the uncertainty and risk associated with dealing with imprecise data. Taking this uncertainty into account when performing analyses and calculations not only helps to better measure the profitability of investment projects, but also to expand the applicability of capital budgeting methods under real-life or uncertain conditions. The major contribution of this paper is the development of a novel approach to assessing the profitability of an investment project in the presence of uncertainty. Methods: We present a novel appro…
Szacowanie czasu realizacji projektu przy nieprecyzyjnych zmiennych
2017
The paper presents the essence and significance of the project time estimation under uncertainty and risk using ordered fuzzy numbers. The proposed approach is based on a fuzzy model of uncertainty using ordered fuzzy numbers as imprecise data – duration times. The presented extended critical path method is a new approach that has not been presented so far in the literature of the subject. The authors present the implementation of the approach on an example. The advantages of the proposed approach have been outlined in the paper. The proposed approach can find practical applications in decision-making problems under conditions of risk and uncertainty, supporting decision-makers in the plann…