Hybrid approaches to optimization and machine learning methods

This paper conducts a comprehensive literature review concerning hybrid techniques that combine optimization and machine learning approaches for clustering and classification problems. The aim is to identify the potential benefits of integrating these methods to address challenges in both fields. The paper outlines optimization and machine learning methods and provides a quantitative overview of publications since 1970. Additionally, it offers a detailed review of recent advancements in the last three years. The study includes a SWOT analysis of the top ten most cited algorithms from the collected database, examining their strengths and weaknesses as well as uncovering opportunities and threats explored through hybrid approaches. Through this research, the study highlights significant findings in the realm of hybrid methods for clustering and classification, showcasing how such integrations can enhance the shortcomings of individual techniques.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES (PIDDAC) to CeDRI (UIDB/05757/2020 and UIDP/05757/2020), Algoritmi (UIDB/00319/2020) and SusTEC (LA/P/0007/2021). Beatriz Flamia Azevedo is supported by FCT Grant Reference SFRH/BD/07427/2021

A collaborative multi-objective approach for clustering task based on distance measures and clustering validity indices

First Online: 28 December 2023Clustering algorithm has the task of classifying a set of elements so that the elements within the same group are as similar as possible and, in the same way, that the elements of different groups (clusters) are as different as possible. This paper presents the Multi-objective Clustering Algorithm (MCA) combined with the NSGA-II, based on two intra- and three inter-clustering measures, combined 2-to-2, to define the optimal number of clusters and classify the elements among these clusters. As the NSGA-II is a multi-objective algorithm, the results are presented as a Pareto front in terms of the two measures considered in the objective functions. Moreover, a procedure named Cluster Collaborative Indices Procedure (CCIP) is proposed, which aims to analyze and compare the Pareto front solutions generated by different criteria (Elbow, Davies-Bouldin, Calinski-Harabasz, CS, and Dumn indices) in a collaborative way. The most appropriate solution is suggested for the decision-maker to support their final choice, considering all solutions provided by the measured combination. The methodology was tested in a benchmark dataset and also in a real dataset, and in both cases, the results were satisfactory to define the optimal number of clusters and to classify the elements of the dataset.This work has been supported by FCT Fundação para a Ciência e Tecnologia within the R &D Units Project Scope UIDB/00319/2020, UIDB/05757/2020, UIDP/05757/2020 and Erasmus Plus KA2 within the project 2021-1-PT01-KA220-HED-000023288. Beatriz Flamia Azevedo is supported by FCT Grant Reference SFRH/BD/07427/2021

Evaluating student behaviour on the MathE Platform - clustering algorithms approaches

The MathE platform is an online educational platform that aims to help students who struggle to learn college mathematics as well as students who wish to deepen their knowledge on subjects that rely on a strong mathematical background, at their own pace. The MathE platform is currently being used by a significant number of users, from all over the world, as a tool to support and engage students, ensuring new and creative ways to encourage them to improve their mathematical skills. This paper is addressed to evaluate the students’ performance on the Linear Algebra topic, which is a specific topic of the MathE platform. In order to achieve this goal, four clustering algorithms were considered; three of them based on different bio-inspired techniques and the k-means algorithm. The results showed that most students choose to answer only basic level questions, and even within that subset, they make a lot of mistakes. When students take the risk of answering advanced questions, they make even more mistakes, which causes them to return to the basic level questions. Considering these results, it is now necessary to carry out an in-depth study to reorganize the available questions according to other levels of difficulty, and not just between basic and advanced levels as it is.FCT - Fundação para a Ciência e a Tecnologia(2021-1-PT01-KA220-HED-000023288)This work has been supported by FCT Fundação para a Ciência e Tecnologia within the R&D Units Project Scope UIDB/00319/2020 and UIDB/05757/2020. Beatriz Flamia Azevedo is supported by FCT Grant Reference SFRH/BD/07427/202

Análise quantitativa de rna mensageiros, proteínas e atividades enzimáticas no estudo da rede de regulação controlada pelo gene Opaco-2

The Opaque-2 (O2) gene encodes a transcriptional activator specifically expressed for grain development of maize. o2 mutants have an opaque and chalky kernel, with a decrease in zein storage protein content, and an increase in the proportions of lysine and tryptophan. In this review, we present recent results investigating genetic properties of the O2 network, using transcriptome and proteome approaches, associated with measurements of activities of enzymes of the aspartate pathway and lysine degradation. The structural polymorphism at the O2 locus was investigated by RFLP in a collection of 51 maize inbred lines. Most polymorphic sites were found outside the coding regions. We then searched for relationships between RFLP polymorphism and (i) mRNA abundance of O2 and of known or suspected target genes, (ii) activity of SDH and (iii) amount of zein isoforms. Polymorphic restriction sites in the 5' upstream regions of the O2 gene were found associated with O2 mRNA abundance (three sites) and the amount of two 19 kDa alpha-zein isoforms (two sites). One restriction site on the 3' side of the O2 gene was found associated with Lor/Sdh mRNA abundance. Our results indicate relationships between polymorphism at the O2 locus and the expression of some of its target genes. Evidence of these associations has to be confirmed on larger samples, and the analysis of the O2 gene sequence should allow more precise testing of the actual involvement of O2 polymorphism in its own transcriptional expression, and in the expression of its target genes.O gene Opaco-2 (O2), expresso especificamente no grão de milho, transcreve para um fator de transcrição da família "leucine-zipper". Mutantes o2 apresentam grãos opacos, redução na quantidade de zeínas e aumento na proporção de lisina e triptofano. Genes cuja expressão é controlada diretamente pelo O2 são conhecidos (alfa-zeínas de 22 kDa, beta-zeínas de 14 kDa, b-32 e cyPpdk1). Nesta revisão, nós apresentamos resultados da caracterização genética de genes relacionados com o O2, através de abordagens de transcritoma, proteoma e de atividades enzimáticas da via metabólica do aspartato e da degradação da lisina. O polimorfismo do locus O2 foi avaliado utilisando-se a técnica de RFLP em 51 linhagens de milho. A maioria dos polimorfismos foi observada nas regiões não codificadoras da proteína. Análises de correlação foram realizadas entre os polimorfismos de RFLP e (i) quantidade de RNAm do O2, cyPpdk, Lor/Sdh e Ahas (ii) quantidade de isoformas de zeínas e (iii) atividade da enzima SDH. Sítios polimórficos foram correlacionados com a quantidade de RNAm do próprio O2, do gene Lor/Sdh e com a quantidade de duas isoformas de a-zeinas de 19 kDa. Nossos resultados indicam a presença de relações entre o polimorfismo do locus O2 e o nível de expressão de genes sob o seu controle. A utilização de um maior número de linhagens e o uso de dados de seqüência do O2 permitirá uma análise precisa da conseqüência do polimorfismo deste fator de transcrição sobre o controle do seu próprio nível de expressão e dos genes por ele controlados

Development of a rapid and simple approach for kid carcass evaluation by vídeo image analysis.

objective of this work is the development of a simple and cost-effective video image analysis (VIA) system to evaluate kid carcass in small slaughter units. To achieve this objective a trial was conducted with 42 kid carcasses (6.6±2.6 kg) and models to predict carcass composition from VIA were established. While the carcasses were hanging in the gambrel an image of the dorsal view of each carcass was obtained with a digital camera (Sony, DCR-TRV460). For imaging, carcasses were placed in front of a non-glare black surface and illuminated with standard lighting. The camera was placed perpendicular to the carcass long axis. A total of 44 geometric measurements (linear and area) were obtained after carcass image analysis with the ImageJ 1.39J software

Physical capacity, quality of life and body composition of postmenopausal osteoporotic women

Osteoporosis is a systemic skeletal disease that has great influence on functional independence and quality of life, leading to reduced bone mass, microarchitectural deterioration, increased bone fragility, bone fractures with minimal trauma, decreased bone mineral density and decrease bone quality. This quality is defined by the bone health of it and is closely related to physical activity and body composition, genetic and hormonal factors and nutrition. Under normal conditions, bone mineral density evolves, increased up to 27 years, leveling up to 40. From here begins to decrease and there is a sharp decline in the menopausal stage and after it keeps a sharp downward trend. Thus we aim to evaluate the physical condition of postmenopausal osteoporotic women, assessing their functional status, different manifestations of strength and body composition. After approval by the Ethics Committee of the North Health Region, we identified women diagnosed with osteoporosis by dual-energy bone densitometry (DEXA), which showed inclusion criteria and who wanted to participate in the study of their own free will. After assessment of blood pressure and heart rate were subjected to: a) Demographic variables b) Quality of life evaluated with the osteoporosis assessment questionnaire (OPAQ) – 1 to 5 points represented by numeric scale from 1 to 5, in which 1 represents better quality of life and 5 represents poor quality of life c) Tinetti Falls Efficacy Scale [1] d) Physical activity: short version of IPAQ (International Physical Activity Questionnaire). e) Functional capacity: timed up and go test; 30 sec sit to stand; unipodal balance eyes shut f) Height: stadiometer Seca g) Handgrip strength of both hands: Jamar h) Key pinch strength with digital dynamometer Baseline hand dynamometer i) Body composition: bioelectric impedance on Tanita Ironman Body Composition Monitor The 18 women studied have an average age of 66,8±6,4 years, 148,2±5,3 cm of height and 57,4±6,2 Kg of weight which represents a BMI of 26,2±3,3. In the OPAQ the evaluated women achieved 3,1±0,7 points and in the FES achieved 79,3±21,1 points. In the IPAQ 14 women were with low level of physical activity and 4 with moderated physical activity (average physical activity of 387,5±294,9METs). The average result of the timed up and go test was 9,4±2,7 seconds, in the 30 sec sit to stand was 10,1±2,9 repetitions and in the unipodal balance test was 4,1±6,9 seconds. When evaluating strength, we found 16,8±6,4 Kg/f for right handgrip strength and 16,2±5,8 Kg/f for left handgrip strength. When evaluating key pinch strength we found 6,6±5,0 Kg/f and 6,3±5,2 Kg/f for the right and left hand, respectively. Analyzing the body composition average values, we have 33,6±6,0% for total body fat, 47,5±4,3% to body water, 2,0±0,2Kg to bone mass and 36,2±3,2 Kg to muscular mass. Once established correlations between different variables, we can highlight some of the most important: ® Weight correlates with total body fat (0,561*) and with body water (-,470*); BMI correlates with average OPAQ (0,529*), total body fat (0,732**) and body water (-0,709**); timed up and go test correlates with average age (0,633**), sit to stand (-0,583*), handgrip right and left (- 0,581*; -0,504*)The participants in this study show similar values when compared with the population with similar characteristics. The BMI value means that the participants are averagely overweight. Most of the women of the study have reduced physical activity levels and none of them have high physical activity levels. We also can conclude that weight as an important role on body composition and the timed up and go test is an easy and cheap test that gives us much information about the physical functioning of these osteoporotic postmenopausal women

An integer programming approach for sensor location in a forest fire monitoring system

Forests worldwide have been devastated by fires. Forest fires cause incalculable damage to fauna and flora. In addition, a forest fire can lead to the death of people and financial damage in general, among other problems. To avoid wildfire catastrophes is fundamental to detect fire ignitions in the early stages, which can be achieved by monitoring ignitions through sensors. This work presents an integer programming approach to decide where to locate such sensors to maximize the coverage provided by them, taking into account different types of sensors, fire hazards, and technological and budget constraints. We tested the proposed approach in a real-world forest with around 7500 locations to be covered and about 1500 potential locations for sensors, showing that it allows obtaining optimal solutions in less than 20 min.This work has been supported by FCT Fundação para a Ciência e Tecnologia within the R&D Units Project Scope UIDB/00319/2020 and within project PCIF/GRF/0141/2019 “O3F - An Optimization Framework to reduce Forest Fire” and also the project UIDB/05757/2020 and Forest Alert Monitoring System (SAFe) Project through PROMOVE - Funda¸c˜ao La Caixa. Beatriz Flamia Azevedo is supported by FCT Grant Reference SFRH/BD/07427/2021, Thadeu Brito was supported by FCT PhD grant SFRH/BD/08598/2020

A solution for funding the development of technology in oilwell drilling

This article proposes a novel methodology to solve an existing gap in benchmark definition by the adoption of statistically defined benchmarks as references to test products or technical procedures. In a win–win partnership, remuneration is made upon realistic bases of comparison being proportional to existing risks. However, establishing values for benchmarks is rarely unanimous if asked to different persons involved in drilling analysis. Conventional benchmarking, which enhances few results and leaves aside poor operational performances, produces references that do not properly represent the geological environment. Nonetheless, when testing new products, it serves as reference to remunerate suppliers. The review of an optimization program, which resulted in a world record of drilling rate of penetration, reveals the financial magnitude of the savings produced, proposing the method discussed as a reliable solution to the development of technology.publishedVersio

Active Flexible Films for Food Packaging: A Review

This article belongs to the Special Issue Active and Intelligent Food Packaging Polymers.Active food packaging is a dynamic area where the scientific community and industry have been trying to find new strategies to produce innovative packaging that is economically viable and compatible with conventional production processes. The materials used to develop active packaging can be organized into scavenging and emitting materials, and based on organic and inorganic materials. However, the incorporation of these materials in polymer-based flexible packaging is not always straightforward. The challenges to be faced are mainly related to active agents' sensitivity to high temperatures or difficulties in dispersing them in the high viscosity polymer matrix. This review provides an overview of methodologies and processes used in the production of active packaging, particularly for the production of active flexible films at the industrial level. The direct incorporation of active agents in polymer films is presented, focusing on the processing conditions and their effect on the active agent, and final application of the packaging material. Moreover, the incorporation of active agents by coating technologies and supercritical impregnation are presented. Finally, the use of carriers to help the incorporation of active agents and several methodologies is discussed. This review aims to guide academic and industrial researchers in the development of active flexible packaging, namely in the selection of the materials, methodologies, and process conditions.Conducted under the project “MobFood-Mobilizing scientific and technological knowledge in response to the challenges of the agri-food market” (POCI-01-0247-FEDER-024524), by “Mob Food” Consortium, and financed by European Regional Development Fund (ERDF), through the Incentive System to Research and Technological development, within the Portugal2020 Competi tiveness and Internationalization Operational Program. IPC researchers acknowledge also funding by National Funds through FCT-Portuguese Foundation for Science and Technology, References UIDB/05256/2020 and UIDP/05256/2020.info:eu-repo/semantics/publishedVersio

Diversidade da fauna de insectos fitófagos e de inimigos naturais em culturas frutícolas da ilha Terceira, Açores: a importância do maneio e da heterogeneidade ambiental

"A evidência mostra que os artrópodes constituem uma fracção importante da biodiversidade estrutural e funcional dos habitats terrestres (Kim, 1993). Por outro lado, só é possível conservar os processos ecológicos associados aos artrópodes promovendo a gestão correcta dos seus habitats. Para tal, é necessária uma correcta identificação e caracterização das suas comunidades de forma a promover a sua boa gestão. Durante os últimos anos têm sido realizados nos Açores vários estudos de inventariação e caracterização ecológica dos artrópodes em alguns dos habitats mais importantes destas ilhas: i) habitat cavernícola (Borges & Oromí, 1994); ii) pastagens semi-naturais e intensivas (Borges & Brown, 2001, 2003, 2004); iii) florestas nativas dos Açores (Borges et al., 2000, 2005a, b, 2006; Ribeiro et al., 2005). No entanto, na diversidade de usos do solo das ilhas açoreanas, as fruteiras constituem um habitat mal estudado em termos da cadeia trófica de artrópodes (contudo ver Oliveira, 2002). […]" (da Introdução)