Eunice Oliveira

A multi-objective simulated annealing approach to reactive power compensation

Reactive power compensation is an important problem in electrical distribution systems, involving the sizing and location of capacitors (sources of reactive power). The installation of capacitors also contributes to releasing system capacity and improving voltage level. A multi-objective simulated annealing approach to provide decision support in this problem is presented. This approach is able to compute a set of well-distributed and diversified solutions underlying distinct trade-offs, even for a challenging network. The characterization of the non-dominated front is relevant information for aiding planning engineers to select satisfactory compromise solutions (compensation schemes) to improve the network operation conditions.

A comparative study of different approaches using an outranking relation in a multi-objective evolutionary algorithm

This paper presents a comparative analysis of three versions of an evolutionary algorithm in which the decision makers preferences are incorporated using an outranking relation and preference parameters associated with the ELECTRE TRI method. The aim is using the preference information supplied by the decision maker to guide the search process to the regions where solutions more in accordance with his/her preferences are located, thus narrowing the scope of the search and reducing the computational effort. An example dealing with a pertinent problem in electrical distribution network is used to compare the different versions of the algorithm and illustrate how meaningful information can be elicited from a decision maker and used in the operational framework of an evolutionary algorithm to provide decision support in real-world problems.

Direct Load Control in the Perspective of an Electricity Retailer – A Multi-Objective Evolutionary Approach

The judicious use of end-use electric loads in the framework of demand-side management programs as valuable resources to increase the global efficiency of power systems as far as economical, technical and quality of service aspects are concerned, is a relevant issue in face of the changes underway in the power systems industry. This paper presents the results of a multi-objective optimization model, in the perspective of an electricity retailer, which is aimed at designing load control actions to be applied to groups of electric loads. An evolutionary algorithm is used to compute solutions to this problem.

Incorporation of Preferences in an Evolutionary Algorithm Using an Outranking Relation: The EvABOR Approach

The incorporation of preferences into Evolutionary Algorithms (EA) presents some relevant advantages, namely to deal with complex real-world problems. It enables focus on the search thus avoiding the computation of irrelevant solutions from the point of view of the practical exploitation of results (thus minimizing the computational effort), and it facilitates the integration of the DM’s expertise into the solution search process (thus minimizing the cognitive effort). These issues are particularly important whenever the number of conflicting objective functions and/or the number of non-dominated solutions in the population is large. In EvABOR (Evolutionary Algorithm Based on an Outranking Relation) approaches preferences are elicited from a decision maker (DM) with the aim of guiding the evolutionary process to the regions of the space more in accordance with the DM’s preferences. The preferences are captured and made operational by using the technical parameters of the ELECTRE TRI method. This approach is presented and analyzed using some illustrative results of a case study of electrical networks.

An Evolutionary Algorithm based on an outranking relation for sorting problems

A new approach for using the preferences elicited from a Decision Maker (DM) into the operational framework of an Evolutionary Algorithm (EA) is presented. The preference representation is achieved using the parameters and principles of the ELECTRE TRI method devoted to the sorting problem. The outranking relation is used to replace the non-dominance relation in the usual operators in the EA (crossover, mutation and selection operator). The aim of this approach is to focus the search on the region of interest defined by the DMs preferences and consequently restrict the number of solutions in the Pareto-optimal front to be subject to further screening. This aspect is particularly important when dealing with problems that lead to a large number of non-dominated solutions.

Sustainability Based on Biomimetic Design Models

Ecodesign is an approach to designing products with special consideration for the environmental impacts of the product’s life cycle. In a lifecycle assessment, the life cycle of a product is usually divided into procurement, manufacture, use, and disposal. Ecodesign is a growing responsibility and understanding of our ecological footprint on the planet. It is imperative to search for new productive solutions that are environmentally friendly and lead to a reduction in the consumption of materials and energy while maintaining the desired performance of the products. Bearing this in mind, additive manufacturing has the capability of producing components with the lowest amount of raw material needed and the highest geometrical complexity. This work aims to present novel bioinspired design methodologies for the production of additive manufacturing products with lower amounts of material and higher performance. The bioinspired design considers natural cellular-based concepts for the definition of novel product definitions.

An evolutionary algorithm guided by preferences elicited according to the ELECTRE TRI method principles

The resolution of a multi-objective optimization problem involves not just a search and computation phase, capable of providing a representative sample of the Pareto-optimal front, but also a decision support process to aid the Decision Maker (DM) to progress in the learning of the trade-offs at stake in different regions of the search space. This is accomplished by integrating in the search process the DMs preferences to guide the search and limit both the cognitive effort, in assessing Pareto-optimal solutions with distinct characteristics, and the computational effort, by reducing the scope of the search according to the preferences expressed by the DM. The introduction of meaningful preference expression parameters used in the ELECTRE TRI method for sorting problems in the framework of an evolutionary algorithm is proposed. Illustrative results in an operational planning problem in electricity networks are reported.

Anthropometrics and Ergonomics in Pregnant Women

Pregnancy is a women life event that impacts her own and offspring’s life; surprisingly, few systematic and scientific maternal information is available in the literature for anthropometric and ergonomic purposes. Regarding ergonomics, some authors state that guidelines should be design for pregnant women. These guidelines may consider anthropometric issues such as changes in weight and distribution of mass, which influence mobility, home and labour performance, mood and cognition. Anthropometrics allows the body measurement, but in pregnancy women are sparingly characterized, besides Body Mass Index and few other parameters. Ergonomics not only aids in the design process of work or home layouts, but also contains several evaluation tools to determine the level of risk of musculoskeletal disorders of daily or labour tasks. Some of these tools are very specific and others have certain conditions that should be met before using them. The purpose of this study is to present an overview of guidelines and discuss which anthropometric and ergonomic evaluation tools may be used, and under which conditions can be implemented in pregnant women.

Potential defaults of anthropometric assessment parameters during pregnancy

Pregnancy is one of the most common life events, surprisingly little systematic and scientific information is available in the literature when considering anthropometrics. Studies regarding the pregnant’s body size variation, namely for the design of clothes during gestation are quit common. But anthropometrics is a lot more, it is also a science that aids in characterizing the body morphology and composition of humans. There are standard data of anthropometric parameters for specific populations, however, it doesn’t seem to exist any specific values or data for pregnant women. Neither the indication to use the standard values is mentioned or stated. Therefore, the main objective of this study is to evaluate if the default data and the current anthropometric tools are appropriate to be used on pregnant women. In this study, we analysed and evaluated the morphologic characterization and the body composition of pregnant women using existing anthropometric restricted profile methods. The tools considered in this study were: Body Mass Index, Somatotype, Conicity Index, AbdominalHip Ratio and Waist-Height Ratio. Some tools do not demonstrate efficiency in the anthropometric evaluation such as Body Mass Index by placing the pregnant women within risk levels that do not correspond to reality. However, other methods are plausible to be used, such as Conicity, Index Abdominal-Hip and Waist-Height Ratios were the values obtained within the expected range. In conclusion, the existing anthropometric tools need further study when characterizing pregnant women. DOI: https:/doi.org/10.24243/JMEB/2.5.176 2018. Published by Rational Publication. This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this license, visit https://creativecommons.org/licenses/by/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA. Research Article

A hybrid multi-objective GRASP+SA algorithm with incorporation of preferences

A hybrid multi-objective approach based on GRASP (Greedy Randomized Adaptive Search Procedure) and SA (Simulated Annealing) meta-heuristics is proposed to provide decision support in a direct load control problem in electricity distribution networks. The main contributions of this paper are new techniques for the incorporation of preferences in these meta-heuristics and their hybridization. Preferences are included in the construction phase of multi-objective GRASP, in SA, as well as in the selection of solutions that go to the next generation, with the aim to obtain solutions more in accordance with the preferences elicited from a decision maker. The incorporation of preferences is made operational using the principles of the ELECTRE TRI method, which is based on the exploitation of an outranking relation in the framework of the sorting problem.