Study of hybrid strategies for multi-objective optimization using gradient based methods and evolutionary algorithms

Most of the optimization problems encountered in engineering have conflicting objectives. In order to solve these problems, genetic algorithms (GAs) and gradient-based methods are widely used. GAs are relatively easy to implement, because these algorithms only require first-order information of the objectives and constraints. On the other hand, GAs do not have a standard termination condition and therefore they may not converge to the exact solutions. Gradient-based methods, on the other hand, are based on first- and higher-order information of the objectives and constraints. These algorithms converge faster to the exact solutions in solving single-objective optimization problems, but are inefficient for multi-objective optimization problems (MOOPs) and unable to solve those with non-convex objective spaces. The work in this dissertation focuses on developing a hybrid strategy for solving MOOPs based on feasible sequential quadratic programming (FSQP) and nondominated sorting genetic algorithm II (NSGA-II). The hybrid algorithms developed in this dissertation are tested using benchmark problems and evaluated based on solution distribution, solution accuracy, and execution time. Based on these performance factors, the best hybrid strategy is determined and found to be generally efficient with good solution distributions in most of the cases studied. The best hybrid algorithm is applied to the design of a crushing tube and is shown to have relatively well-distributed solutions and good efficiency compared to solutions obtained by NSGA-II and FSQP alone

The obstacles to energy saving in residential buildings in Nigeria : stakeholders’ perspectives

Over the past three decades research on energy use in buildings has become significant due to increasing scientific and political pressure on issues concerning global warming and climate change. As part of the impact by climate change, tropical nations are faced with several challenges in achieving energy savings, particularly the energy consumption behaviour of building occupants, with very little research coming from Africa. Previous research has shown that variations due to occupant behaviour is substantial. To address these challenges in line with the objectives of some of the UN Sustainable Development Goals (SDGs) (namely, clean and sustainable energy, as well as climate action) in residential buildings, this paper explores the perceptions of stakeholders by identifying the barriers which affect energy use from different cultural perspectives. Qualitative data were collected using semi-structured telephone interviews with experts in the energy and construction fields in Nigeria. The purpose of the interviews was to provide an insight into residential energy consumption behaviour and the barriers faced in the adoption of sustainable energy sources. The results were analysed using an energy cultural framework. An analysis of the results shows that continuous awareness of energy saving behavioural change, government subsidies for renewable energy, government checks, and the standardization of energy-efficient appliances imported into the country can improve people’s trust regarding sustainable choices and can promote efficient energy use. The outcome from this work is expected to give a better understanding of energy use behaviour and inform future energy policies and interventions related to household energy saving. Keywords: Barriers; Energy saving; Energy culture framework; Stakeholders

The Role Of RNA Binding Proteins And CRISPR/CAS9 As A Gene Editing Tool In Drosophila Nociception

Drosophila melanogaster is a powerful model organism to study nociception. The compact and easily manipulated genome provides an opportunity to determine the function of molecules involved in basal and sensitized nociception in both larval and adult animals. Using the GAL4/UAS system, genetic knockdown with RNAi and knockout with CRISPR/Cas9 are possible to pinpoint specific molecular mechanisms and cellular processes within nociceptors that are implicated in nociception. The three main objectives of this work were to: elucidate the impact that three RNA binding proteins have on basal nociception, establish a transgenic fly line capable of inducing Cas9-mediated knockout of specific genes, and to validate a protocol based on a previously published assay to measure thermal nociception in adults. The expression of SC35, an exon-inclusion splicing factor; LaRP4B, a translation stimulator; and eIF2a, a translation regulator, were each required for thermal nociception. Cas9 expression led to sgRNA-independent effects such as severe defects in dendrite morphology. The adult thermal nociception assay was validated and similar results to the original publication were reproduced. Importantly, the findings made with the Drosophila model can be directly applicable to chronic pain in humans due to DNA sequence homology and the conserved function of proteins across species

VCU Brew

VCU Brew is an innovative proposal to create a VCU branded signature beer. The Campus Connectors will present a rationale showing how this proposal will i) potentially generate revenue to benefit VCU scholarships and academic programs, ii) create opportunities for experiential learning by engaging VCU students in product development, branding, labeling, marketing, business, and awareness of responsible drinking, iii) and guide the process of partnering with local breweries to provide practical expertise and stimulate entrepreneurship initiatives that lead to distribution at VCU athletic, community and Alumni events, while increasing ties with the community and national prominence

Minding impacting events in a model of stochastic variance

We introduce a generalisation of the well-known ARCH process, widely used for generating uncorrelated stochastic time series with long-term non-Gaussian distributions and long-lasting correlations in the (instantaneous) standard deviation exhibiting a clustering profile. Specifically, inspired by the fact that in a variety of systems impacting events are hardly forgot, we split the process into two different regimes: a first one for regular periods where the average volatility of the fluctuations within a certain period of time is below a certain threshold and another one when the local standard deviation outnumbers it. In the former situation we use standard rules for heteroscedastic processes whereas in the latter case the system starts recalling past values that surpassed the threshold. Our results show that for appropriate parameter values the model is able to provide fat tailed probability density functions and strong persistence of the instantaneous variance characterised by large values of the Hurst exponent is greater than 0.8, which are ubiquitous features in complex systems.Comment: 18 pages, 5 figures, 1 table. To published in PLoS on

Environmental health : reflexions of the Brazilian Association of Post-Graduation in Collective Health - ABRASCO

O Brasil, apesar de sua extraordinária biodiversidade e do enorme potencial instalado para desenvolver ações integradas na temática do ambiente, não tem dado, do ponto de vista programático, a prioridade que o tema ambiente merece. A Associação Brasileira de Pós-Graduação em Saúde Coletiva-ABRASCO reconheceu a importância de organizar um Grupo Temático “Saúde e Ambiente” para, de maneira mais organizada, participar da luta pelo desenvolvimento sustentável, através da ação política no campo da saúde coletiva, em busca de ambientes saudáveis e da promoção da saúde. O objetivo principal deste Grupo Temático-GT foi contribuir para que o tema da saúde ambiental seja internalizado no campo da Saúde Coletiva. Método: O Grupo escolheu três eixos para discussão em uma oficina do V Congresso Brasileiro de Epidemiologia, em Curitiba, no ano de 2002. O resultado resultado do debate ocorrido foi apresentado segundo três eixos: identificação do campo teórico-conceitual em Saúde Ambiente; a política de saúde e ambiente; o caminho metodológico. A conclusão foi apresentada no formato de uma agenda do GT para o biênio 2002-2004. _______________________________________________________________________________________ ABSTRACTNot with standing its extraordinary biodiversity and enormous installed potential to develop actions integrated in to the topic of environmental health, Brazil has not given the environmental the priority the subject deserves from the programmatic, point of view. The Brazilian Association of Post-Graduation in Collective Health - ABRASCO recognized the importance of organizing a Thematic Group “Health and Environment” in order to, in a more organized fashion, participate in the struggle for sustainable development, through political action in collective health, oriented to wards health environments and health promotion. The main objective of this Thematic Group was to facilitate the subject of the environmental health to be internalized in to the field of the Collective Health. Method: The theme was debated in a workshop during the V Brazilian Congress of Epidemiology in Curitiba, in 2002. Results were presented according to three axes: 1- Identification of the theoretical-conceptual field in Environmental Health; 2- the politics of health and environment; 3- methodological route. The general conclusion was presented as an agenda for ABRASCO’s Thematic Group in Environmental Health for the biennial 2002-2004

No contribution of GSTM1 and GSTT1 null genotypes to the risk of neutropenia due to benzene exposure in Southeastern Brazil

Exposure to benzene has been associated with haematological diseases such as neutropenia (NEB) and acute myeloid leukaemia (AML). We tested whether the null genotypes of the GSTM1 and GSTT1 genes, involved in benzene inactivation, altered the risk for NEB in southeastern Brazil. Genomic DNA from 55 NEB patients and 330 controls was analysed by multiplex-polymerase chain reaction. The frequency of the GSTM1, GSTT1 and combined null genotypes was similar in patients and controls (GSTM1, 27.3% vs. 38.8%, p = 0.16; GSTT1, 25.5% vs. 19.7%, p = 0.24; GSTM1/GSTT1, 12.7% vs. 6.7%, p = 0.26; respectively). The distribution of genotype classes in NEB patients was similar to normal controls, suggesting that GSTM1 and GSTT1 null genotypes make no specific contribution to the risk of NEB. As the GSTM1 and GSTT1 null genotypes were previously associated with increased risk for AML in Brazil and elsewhere, we hypothesise that different thresholds of chemical exposure relative to distinct GSTM1 and GSTT1 genotypes may determine whether AML or NEB manifests in benzene exposed individuals from southeastern Brazil. Although indicative, our results still require support by prospective and large scale epidemiological studies, with rigorous assessment of daily chemical exposures and control of the possible contribution of other polymorphic genes involved in benzene metabolism

Resistance to acid attack, abrasion and leaching behavior of alkali-activated mine waste binders

This paper report results of a research project on the development of alkali-activated binders using mine wastes. Abrasion and acid resistance of two ordinary Portland cement (OPC) strength class concrete mixtures (C20/25 and C30/37) and several mine waste (MW) mixtures were compared. This study indicates that MW binders possess higher acid and abrasion resistance than OPC based concrete mixtures.The leaching assessment of the MW binders shows it can be considered an inert material which indicates that it could be used as a building material