5,428 research outputs found
A STOCHASTIC SIMULATION-BASED HYBRID INTERVAL FUZZY PROGRAMMING APPROACH FOR OPTIMIZING THE TREATMENT OF RECOVERED OILY WATER
In this paper, a stochastic simulation-based hybrid interval fuzzy programming (SHIFP) approach
is developed to aid the decision-making process by solving fuzzy linear optimization problems.
Fuzzy set theory, probability theory, and interval analysis are integrated to take into account the
effect of imprecise information, subjective judgment, and variable environmental conditions. A
case study related to oily water treatment during offshore oil spill clean-up operations is conducted
to demonstrate the applicability of the proposed approach. The results suggest that producing a
random sequence of triangular fuzzy numbers in a given interval is equivalent to a normal
distribution when using the centroid defuzzification method. It also shows that the defuzzified
optimal solutions follow the normal distribution and range from 3,000-3,700 tons, given the
budget constraint (CAD 110,000-150,000). The normality seems to be able to propagate
throughout the optimization process, yet this interesting finding deserves more in-depth study
and needs more rigorous mathematical proof to validate its applicability and feasibility. In
addition, the optimal decision variables can be categorized into several groups with different
probability such that decision makers can wisely allocate limited resources with higher
confidence in a short period of time. This study is expected to advise the industries and
authorities on how to distribute resources and maximize the treatment efficiency of oily
water in a short period of time, particularly in the context of harsh environments
Quadratic and nonlinear programming problems solving and analysis in fully fuzzy environment
AbstractThis paper presents a comprehensive methodology for solving and analyzing quadratic and nonlinear programming problems in fully fuzzy environment. The solution approach is based on the Arithmetic Fuzzy Logic-based Representations, previously founded on normalized fuzzy matrices. The suggested approach is generalized for the fully fuzzy case of the general forms of quadratic and nonlinear modeling and optimization problems of both the unconstrained and constrained fuzzy optimization problems. The constrained problems are extended by incorporating the suggested fuzzy logic-based representations assuming complete fuzziness of all the optimization formulation parameters. The robustness of the optimal fuzzy solutions is then analyzed using the recently newly developed system consolidity index. Four examples of quadratic and nonlinear programming optimization problems are investigated to illustrate the efficacy of the developed formulations. Moreover, consolidity patterns for the illustrative examples are sketched to show the ability of the optimal solution to withstand any system and input parameters changes effects. It is demonstrated that the geometric analysis of the consolidity charts of each region can be carried out based on specifying the type of consolidity region shape (such as elliptical or circular), slope or angle in degrees of the centerline of the geometric, the location of the centroid of the geometric shape, area of the geometric shape, lengths of principals diagonals of the shape, and the diversity ratio of consolidity points. The overall results demonstrate the consistency and effectiveness of the developed approach for incorporation and implementation for fuzzy quadratic and nonlinear optimization problems. Finally, it is concluded that the presented concept could provide a comprehensive methodology for various quadratic and nonlinear systems’ modeling and optimization in fully fuzzy environments
Solving P - Norm Intuitionistic Fuzzy Programming Problem
In this paper, notion of p - norm generalized trapezoidal intuitionistic
fuzzy numbers is introduced. A new ranking method is introduced for p - norm
generalized trapezoidal intuitionistic fuzzy numbers. Also we consider linear
programming problem in intuitionistic fuzzy environment. In this problem, all
the coefficients and variables are represented by p - norm generalized
trapezoidal intuitionistic fuzzy numbers. To overcome the limitations of the
existing methods, a new method is proposed to compute the intuitionistic fuzzy
optimal solution for intuitionistic fuzzy linear programming problem. An
illustrative numerical example is solved to demonstrate the efficiency of the
proposed approach.Comment: some erro
Automated software quality visualisation using fuzzy logic techniques
In the past decade there has been a concerted effort by the software industry to improve the quality of its products. This has led to the inception of various techniques with which to control and measure the process involved in software development. Methods like the Capability Maturity Model have introduced processes and strategies that require measurement in the form of software metrics. With the ever increasing number of software metrics being introduced by capability based processes, software development organisations are finding it more difficult to understand and interpret metric scores. This is particularly problematic for senior management and project managers where analysis of the actual data is not feasible. This paper proposes a method with which to visually represent metric scores so that managers can easily see how their organisation is performing relative to quality goals set for each type of metric. Acting primarily as a proof of concept and prototype, we suggest ways in which real customer needs can be translated into a feasible technical solution. The solution itself visualises metric scores in the form of a tree structure and utilises Fuzzy Logic techniques, XGMML, Web Services and the .NET Framework. Future work is proposed to extend the system from the prototype stage and to overcome a problem with the masking of poor scores
BigFCM: Fast, Precise and Scalable FCM on Hadoop
Clustering plays an important role in mining big data both as a modeling
technique and a preprocessing step in many data mining process implementations.
Fuzzy clustering provides more flexibility than non-fuzzy methods by allowing
each data record to belong to more than one cluster to some degree. However, a
serious challenge in fuzzy clustering is the lack of scalability. Massive
datasets in emerging fields such as geosciences, biology and networking do
require parallel and distributed computations with high performance to solve
real-world problems. Although some clustering methods are already improved to
execute on big data platforms, but their execution time is highly increased for
large datasets. In this paper, a scalable Fuzzy C-Means (FCM) clustering named
BigFCM is proposed and designed for the Hadoop distributed data platform. Based
on the map-reduce programming model, it exploits several mechanisms including
an efficient caching design to achieve several orders of magnitude reduction in
execution time. Extensive evaluation over multi-gigabyte datasets shows that
BigFCM is scalable while it preserves the quality of clustering
Evolutionary Computation Methods for Fuzzy Decision Making on Load Dispatch Problems
This chapter introduces basic concepts relating to a day-ahead market in a power system. A load dispatch model considers a ramp rate and valve-point-loading effects. An environment/economic load dispatch model is presented to handle uncertainty factors. The model provides theoretical foundations for the research on operations and decision making in the electric power market. To solve load dispatch problems from day-ahead markets in power systems, a hybrid evolutionary computation method with a quasi-simplex technique, a weight point method for multi-objective programming, and a fuzzy-number-ranking-based optimization method for fuzzy multi-objective non-linear programming are developed
Dominance Measuring Method Performance under Incomplete Information about Weights.
In multi-attribute utility theory, it is often not easy to elicit precise values for the scaling weights representing the relative importance of criteria. A very widespread approach is to gather incomplete information. A recent approach for dealing with such situations is to use information about each alternative?s intensity of dominance, known as dominance measuring methods. Different dominancemeasuring methods have been proposed, and simulation studies have been carried out to compare these methods with each other and with other approaches but only when ordinal information about weights is available. In this paper, we useMonte Carlo simulation techniques to analyse the performance of and adapt such methods to deal with weight intervals, weights fitting independent normal probability distributions orweights represented by fuzzy numbers.Moreover, dominance measuringmethod performance is also compared with a widely used methodology dealing with incomplete information on weights, the stochastic multicriteria acceptability analysis (SMAA). SMAA is based on exploring the weight space to describe the evaluations that would make each alternative the preferred one
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