Large-scale unit commitment under uncertainty: an updated literature survey

The Unit Commitment problem in energy management aims at finding the optimal production schedule of a set of generation units, while meeting various system-wide constraints. It has always been a large-scale, non-convex, difficult problem, especially in view of the fact that, due to operational requirements, it has to be solved in an unreasonably small time for its size. Recently, growing renewable energy shares have strongly increased the level of uncertainty in the system, making the (ideal) Unit Commitment model a large-scale, non-convex and uncertain (stochastic, robust, chance-constrained) program. We provide a survey of the literature on methods for the Uncertain Unit Commitment problem, in all its variants. We start with a review of the main contributions on solution methods for the deterministic versions of the problem, focussing on those based on mathematical programming techniques that are more relevant for the uncertain versions of the problem. We then present and categorize the approaches to the latter, while providing entry points to the relevant literature on optimization under uncertainty. This is an updated version of the paper "Large-scale Unit Commitment under uncertainty: a literature survey" that appeared in 4OR 13(2), 115--171 (2015); this version has over 170 more citations, most of which appeared in the last three years, proving how fast the literature on uncertain Unit Commitment evolves, and therefore the interest in this subject

Qualidade de vida no trabalho e distúrbios osteomusculares relacionados ao trabalho entre profissionais de enfermagem Calidad de vida en el trabajo y disturbios osteomusculares relacionados al trabajo entre profesionales de enfermería Quality of work life and work-related musculoskeletal disorders among nursing professionals

OBJETIVO: Avaliar a associação de Qualidade de Vida no Trabalho (QVT) com os distúrbios osteomusculares (DORT) entre profissionais de enfermagem que trabalham em bloco cirúrgico. MÉTODOS: Estudo de abordagem quantitativa, descritivo, transversal e correlacional, do qual participaram 211 trabalhadores de Enfermagem de 11 hospitais de Londrina-PR, Brasil. Para coleta de dados, foram utilizados três instrumentos: caracterização sociodemográfica e profissional, Escala Visual Analógica e o Questionário Nórdico. RESULTADOS: A maioria dos participantes era de auxiliares de enfermagem (62,6%), do sexo feminino (87,1%), casados (54,5%), com idade média de 40 anos. Dentre os participantes, 38,9% apresentavam queixas osteomusculares na região inferior das costas e 37,9%, na região dos ombros. Neste estudo, a QVT obteve associação estatisticamente significante com os distúrbios osteomusculares na região lombar e dos ombros nos últimos 12 meses (p=0,00). CONCLUSÃO: A ausência de lombalgia contribuiu significativamente para elevar a medida de QVT (p=0,010), embora o modelo final de regressão tenha explicado, apenas 22,6% da variância da medida de QVT.<br>OBJETIVO: Evaluar la asociación de Calidad de Vida en el Trabajo (CVT) con los disturbios osteomusculares (DORT) entre profesionales de enfermería que trabajan en una área quirúrgica. MÉTODOS: Estudio de abordaje cuantitativa, descriptiva, transversal y correlacional, en la que participaron 211 trabajadores de Enfermería de 11 hospitales de Londrina-PR, Brasil. Para la recolección de los datos, fueron utilizados tres instrumentos: caracterización sociodemográfica y profesional, Escala Visual Analógica y el Cuestionario Nórdico. RESULTADOS: La mayoría de los participantes era de auxiliares de enfermería (62,6%), del género femenino (87,1%), casados (54,5%), con edad promedio de 40 años. De los participantes, 38,9% presentaban quejas osteomusculares en la región inferior de la espalda y 37,9%, en la región de los hombros. En este estudio, la CVT obtuvo asociación estadísticamente significativa con los disturbios osteomusculares en la región lumbar y de los hombros en los últimos 12 meses (p=0,00). CONCLUSIÓN: La ausencia de lumbalgia contribuyó significativamente a elevar la medida de CVT (p=0,010), a pesar que el modelo final de regresión haya explicado, apenas el 22,6% de la varianza de la medida de CVT.<br>OBJECTIVE: To evaluate the association of Quality of Work Life (QWL) with musculoskeletal disorders (MSDs) among nursing professionals working in the surgical unit. METHODS: A quantitative descriptive, cross-sectional and correlational approach, in which 211 nursing workers participated, from 11 hospitals in Londrina, Paraná, Brazil. For data collection, three instruments were used: sociodemographic and professional characteristics, the Visual Analogue Scale, and the Nordic Questionnaire. RESULTS: The majority of participants were auxiliary nurses (62.6%), female gender (87.1%), married (54.5%), with a mean age of 40 years. Among the participants, 38.9% presented with musculoskeletal complaints in the lumbar region and 37.9% in the shoulder region. In this study, the QWL obtained a statistically significant association with the musculoskeletal disorders in the lumbar region and shoulders over the past 12 months (p = 0.00). CONCLUSION: The absence of lumbar pain contributed significantly to elevating the measure of QWL (p = 0.010), although the final regression model explained only 22.6% of the variance of the measure of QWL