Manipulator trajectory planning using a MOEA

Generating manipulator trajectories considering multiple objectives and obstacle avoidance is a non-trivial optimization problem. In this paper a multi-objective genetic algorithm based technique is proposed to address this problem. Multiple criteria are optimized considering up to five simultaneous objectives. Simulation results are presented for robots with two and three degrees of freedom, considering two and five objectives optimization. A subsequent analysis of the spread and solutions distribution along the converged non-dominated Pareto front is carried out, in terms of the achieved diversity.

Conceção, seleção e implementação de um sistema de informação: ERP - enterprise resource planning

As organizações são entidades de natureza sistémica, composta, na sua maioria por várias pessoas que interagindo entre si, se propõem atingir objetivos comuns. Têm, frequentemente, de responder a alterações da envolvente externa através de processos de mudança organizacional, sendo fundamentalmente adaptativas, pois, para sobreviver, precisam de se reajustar continuamente às condições mutáveis do meio. O sucesso das organizações depende da sua capacidade de interação com o meio envolvente, ou seja, da sua capacidade de inovar e operar local ou globalmente, criando novas oportunidades de negócio que importa aproveitar. As tecnologias e os sistemas de informação e a forma como são utilizadas são fatores determinantes nesses processos de evolução e mudança. É necessário que a estratégia de TI esteja alinhada com os objetivos de negócio e que a sua utilização contribua para aumentos de produtividade e de eficiência no seu desempenho. Este trabalho descreve a análise, conceção, seleção e implementação de um Sistema de Informação na Portgás, S.A. baseado de um ERP - Enterprise Resource Planning, capaz de suportar a mudança organizacional e melhorar o desempenho global da organização. Promovendo numa primeira fase um crescimento exponencial do negócio e, de seguida, a adaptação da organização ao mercado concorrencial. O caso descreve o trabalho realizado pelo candidato e por equipas internas e externas, de levantamentos de requisitos gerais, técnicos e funcionais, desenvolvimento de um caderno de encargos, seleção, implementação e exploração de um ERP SAP. A apresentação e discussão do caso são enquadradas numa revisão de literatura sobre o papel das TI nos processos de mudança organizativa, alinhamento estratégico e vantagem competitiva das TI, contributo das TI para o aumento da produtividade, processos adoção e difusão das TI, fatores críticos de sucesso e BPM –Business Process Management

Strategic Planning and Organizational Effectiveness in Social Service Organizations in Portugal

This study aims to understand the reality of social service organizations, the level of implementation of the strategic planning as well as the impact of its application on organizational effectiveness. At first, we will group organizations in clusters according to the level of strategic planning implementation and its degree of effectiveness. Secondly, we will analyse all the different groups. Given the growing number of social service organizations and the consequent complexity of their structures, it turns out the need for these organizations adopt formal management techniques. Strategic planning is a valuable strategic management tool and one of its main objectives is to make organizations more effective. Therefore, the research has been conducted in order to determine if strategic planning is implemented in social service organizations and which effects has its application on organizational effectiveness. The survey, applied to 220 social service organizations, allowed us to gather them into different clusters, showing that different levels of strategic planning determine distinct degrees of organizational efficiency. Finally, it should be noted that findings of this research may be essential to decision makers of these organizations, because it was shown that the adoption of strategic planning has a positive influence on organizational effectiveness of social service organizations.

Optimization of antioxidants extraction from coffee silverskin, aroasting by-product, having in view a sustainable process

Coffee silverskin is a major roasting by-product that could be valued as a source of antioxidant compounds. The effect of the major variables (solvent polarity, temperature and extraction time) affecting the extraction yields of bioactive compounds and antioxidant activity of silverskin extracts was evaluated. The extracts composition varied significantly with the extraction conditions used. A factorial experimental design showed that the use of a hydroalcoholic solvent (50%:50%) at 40 °C for 60 min is a sustainable option to maximize the extraction yield of bioactive compounds and the antioxidant capacity of extracts. Using this set of conditions it was possible to obtain extracts containing total phenolics (302.5 ± 7.1 mg GAE/L), tannins (0.43 ± 0.06 mg TAE/L), and flavonoids (83.0 ± 1.4 mg ECE/L), exhibiting DPPHradical dot scavenging activity (326.0 ± 5.7 mg TE/L) and ferric reducing antioxidant power (1791.9 ± 126.3 mg SFE/L). These conditions allowed, in comparison with other “more effective” for some individual parameters, a cost reduction, saving time and energy.

Análise e optimização de processos numa empresa do sector automóvel

Trabalho de Projeto

Impact of Distributed Generation in the Transmission System Expansion Planning

In this work, the impact of distributed generation in the transmission expansion planning will be simulated through the performance of an optimization process for three different scenarios: the first without distributed generation, the second with distributed generation equivalent to 1% of the load, and the third with 5% of distributed generation. For modeling the expanding problem the load flow linearized method using genetic algorithms for optimization has been chosen. The test circuit used is a simplification of the south eastern Brazilian electricity system with 46 buses.

Association between dairy product intake and abdominal obesity in Azorean adolescents

BACKGROUND: Some studies have reported an inverse association between dairy product (DP) consumption and weight or fat mass loss. OBJECTIVES: The objective of our study was to assess the association between DP intake and abdominal obesity (AO) among Azorean adolescents. SUBJECTS/METHODS: This study was a cross-sectional analysis. A total of 903 adolescents (370 boys) aged 15--16 years was evaluated. Anthropometric measurements were collected (weight, height and waist circumference (WC)) and McCarthy’s cut-points were used to categorize WC. AO was defined when WC was X90th percentile. Adolescent food intake was assessed using a self-administered semiquantitative food frequency questionnaire and DP intake was categorized in o2 and X2 servings/day. Data were analyzed separately for girls and boys, and logistical regression was used to estimate the association between DPs and AO adjusting for potential confounders. RESULTS: The prevalence of AO was 54.9% (boys: 32.1% and girls: 70.7%, Po0.001). For boys and girls, DP consumption was 2.3±1.9 and 2.1±1.6 servings/day (P¼0.185), respectively. In both genders, the proportion of adolescents with WC o90th percentile was higher among individuals who reported a dairy intake of X2 servings/day compared with those with an intake o2 servings/day (boys: 71% vs 65% and girls: 36% vs 24%, Po0.05). After adjustments for confounders, two or more DP servings per day were a negative predictor of AO (odds ratio, 0.217; 95% confidence interval, 0.075 -- 0.633) only in boys. CONCLUSION: We found a protective association between DP intake and AO only in boys.

Voltammetric analysis of mancozeb and its degradation product ethylenethiourea

The purpose of this work was to develop a reliable alternative method for the determination of the dithiocarbamate pesticide mancozeb (MCZ) in formulations. Furthermore, a method for the analysis of MCZ's major degradation product, ethylenethiourea (ETU), was also proposed. Cyclic voltammetry was used to characterize the electrochemical behavior of MCZ and ETU, and square-wave adsorptive stripping voltammetry (SWAdSV) was employed for MCZ quantification in commercial formulations. It was found that both MCZ and ETU are irreversibly reduced (− 0.6 V and − 0.5 V vs Ag/AgCl, respectively) at the surface of a glassy carbon electrode in a mainly diffusion-controlled process, presenting maximum peak current intensities at pH 7.0 (in phosphate buffered saline electrolyte). Several parameters of the SWAdSV technique were optimized and linear relationships between concentration and peak current intensity were established between 10–90 μmol L− 1 and 10–110 μmol L− 1 for MCZ and ETU, respectively. The limits of detection were 7.0 μmol L− 1 for MCZ and 7.8 μmol L− 1 for ETU. The optimized method for MCZ was successfully applied to the quantification of this pesticide in two commercial formulations. The developed procedures provided accurate and precise results and could be interesting alternatives to the established methods for quality control of the studied products, as well as for analysis of MCZ and ETU in environmental samples.

HIV Voluntary Testing among Portuguese Women Attending Family Planning Clinics: Implications for HIV Prevention Education and Testing

Objectives: The aim of this article is to analyze the factors associated with HIV testing among 767 sexually active women. Methods: Participants were administered several self-report questionnaires that assessed behavioral and psychosocial measures. Results: Overall, 59.8% of the participants reported ever having tested for HIV. Results show that higher levels of education, being pregnant or having been pregnant, concern about AIDS, AIDS knowledge, self-efficacy in condom negotiation and perception of no risk in partner significantly predicted the likelihood of testing among women. Attending the mass was negatively associated with HIV testing. Conclusions: These findings provide information that can be used in the development of a focused gender sensitive HIV prevention program to increase HIV testing.

Predictors of consistent condom use among Portuguese women attending family planning clinics

Women account for 30% of all AIDS cases reported to the Health Ministry in Portugal and most infections are acquired through unprotected heterosexual sex with infected partners. This study analyzed socio-demographic and psychosocial predictors of consistent condom use and the role of education as a moderator variable among Portuguese women attending family planning clinics. A cross-sectional study using interviewer-administered fully structured questionnaires was conducted among 767 sexually active women (ages 18–65). Logistic regression analyses were used to explore the association between consistent condom use and the predictor variables. Overall, 78.7% of the women were inconsistent condom users. The results showed that consistent condom use was predicted by marital status (being not married), having greater perceptions of condom negotiation self-efficacy, having preparatory safer sexual behaviors, and not using condoms only when practicing abstinence. Living with a partner and having lack of risk perception significantly predicted inconsistent condom use. Less educated women were less likely to use condoms even when they perceive being at risk. The full model explained 53% of the variance in consistent condom use. This study emphasizes the need for implementing effective prevention interventions in this population showing the importance of taking education into consideration.

Minimização do impacto ambiental do processo de curtume de pele de bovino

O presente trabalho teve como objectivo a minimização do impacto ambiental do processo de curtume da pele de bovino. A indústria de curtumes transforma a pele, material putrescível, em couro, material nobre, termicamente estável e imputrescível. A transformação da pele em couro origina uma carga poluente apreciável quer quanto a efluentes líquidos quer quanto a resíduos sólidos. O fluxo produtivo da indústria de curtumes pode dividir-se em quatro sectores: ribeira, curtume, tinturaria e acabamento, sendo que os três primeiros geram efluentes líquidos com elevada carga poluente. Neste trabalho, foram avaliadas as fases do processo que geram efluentes líquidos: molho, caleiro, curtume e tinturaria. Na avaliação do processo do molho testou-se uma protease e uma lipase contra um molhante e um desengordurante tradicional, agentes químicos normalmente utilizados no molho mas menos biodegradáveis que as enzimas testadas. Salienta-se o bom resultado obtido quanto à eficiência do molho Na avaliação do processo de caleiro testaram-se várias alternativas no sentido da redução da quantidade de sulfureto de sódio utilizada e da minimização da carga poluente. Entre as alternativas, depilação por oxidação, depilação enzimática com e sem destruição do pêlo, elegeu-se a depilação enzimática sem destruição do pêlo que conduziu a resultados com menor impacto ambiental, nomeadamente a redução da % da quantidade de sulfureto de sódio, sendo a redução da carga poluente de 4,19 % de sulfureto, 32.80% de sólidos suspensos totais (SST),27.09% de sólidos totais (ST) e de 76.90% da carência química de oxigénio (CQO) no efluente de caleiro. No processo do curtume da pele é utilizado crómio como agente de curtume em cerca de 80% das peles tratadas, sendo este metal problemático em termos ambientais. No sentido de reduzir a quantidade de crómio utilizada no processo foi realizado um planeamento factorial onde as variáveis a estudar foram a concentração de crómio e a temperatura, tendo este como objectivo observar qual a quantidade mínima de crómio necessária para termos um produto final nas condições desejadas e gerando um menor impacto ambiental. Concluiu-se desenvolvendo um processo que mostra ser possível reduzir a quantidade de sal de crómio de 7% para 5%, além de ter um impacto ambiental claramente menos agressivo nos efluentes de curtume gerado. Este processo quando comparado com o processo tradicional permite a redução de 27% na CQO, 79% nos SST, 11% nos ST e 38% no teor de crómio Na avaliação do processo de tinturaria foi estudado um processo compacto contra o processo tradicional, tendo-se concluído pelo menor impacto ambiental do processo estudado, nomeadamente ao nível da redução do consumo de água e da carga poluente gerada. A comparação dos dois processos, no que respeita à carga poluente gerada, permitiu concluir por uma redução de 39% da CQO, 50% dos SST, e 12% dos ST quando aplicado o processo compacto Por fim foi feita uma avaliação do impacto ambiental do efluente global gerado pelos processos considerados com menor impacto ambiental contra o processo tradicional, normalmente aplicado na indústria. A aplicação do conjunto dos processos desenvolvidos, quando comparada com a aplicação do conjunto dos processos tradicionais, mostra uma redução de 1% no sulfureto, 40% na CQO, 60 % nos SST, 42 % no crómio e 11% nos ST, mostrando claramente que é possível reduzir a carga poluente da indústria de curtumes atuando no processo. Este trabalho mostrou a importância de atuar no processo para minimizar os custos de tratamento e mesmo de investimento dos efluentes da indústria de curtumes. Importa salientar que os processos desenvolvidos necessitam de validação a uma escala semi-industrial.