3 research outputs found

    Fuzzy clustering with balance constraint

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    We study equality in fuzzy clustering algorithms where an equality constraint is added to the existing model. Equality is being used in various areas, such as districting (either zonal or political), industries (distribution companies). We focus on wireless sensor networks problem. Existing protocols do not pay too much attention to the cluster head selection step and equality of workload of the clusters. These two issues have significant e ect on the consumption of energy in a network where increasing lifetime of network is critical. A solution approach based on the Lagrangean relaxation is developed. The proposed algorithm is compared with the popular LEACH protocol. Results show that in the same simulated environment, our algorithm works better

    Fuzzy zoning: a lagrangean relaxation approach

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    This research arises from the need of equality in real life problems. Clustering algorithms are being used in many applications where equality is an interest, such as districting (either zonal or political) and industry (distribution companies). One of the well known clustering algorithms is Fuzzy clustering. We add an equality constraint to the existing model. We call the new problem ”Zoning” problem. One of the application where equality can play a critical role is Wireless Sensor Network. A Lagrangean relaxation based approach is developed to solve Zonnig problem. The proposed algorithm is simulated and the results show robust performance regarding the equality of the clusters

    A heuristic approach to solve the preventive health care problem with budget and congestion constraints

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    This document is the Accepted Manuscript version of the following article: Soheil Davari, Kemal Kilic, and Siamak Naderi, ‘A heuristic approach to solve the preventive health care problem with budget and congestion constraints’, Applied Mathematics and Computation, Vol. 276, pp. 442-453, March 2016, doi: https://doi.org/10.1016/j.amc.2015.11.073. This manuscript version is made available under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License CC BY NC-ND 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way.Preventive health care is of utmost importance to governments since they can make massive savings on health care expenditure and promote the well-being of the society. Preventive care includes many services such as cancer screenings, vaccinations, hepatitis screenings, and smoking cessation programs. Despite the benefits of these services, their uptake is not satisfactory in many countries in the world. This can be attributed to financial barriers, social issues., and other factors. One of the most important barriers for preventive care is accessibility to proper services, which is a function of various qualitative and quantitative factors such as the distance to travel, waiting time, vicinity of facilities to other attractive facilities (such as shopping malls), and even the cleanliness of the facilities. Statistics show that even a small improvement in people’s participation can save massive amounts of money for any government and improve the well-being of the people in a society. This paper addresses the problem of designing a preventive health care network considering impatient clients, and budget constraints. The objective is to maximize the accessibility of services to people. We model the problem as a mixed-integer programming problem with budget constraints, and congestion considerations. An efficient variable neighborhood search procedure is proposed and computational experiments are performed on a large set of instances.Peer reviewedFinal Accepted Versio
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