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

An overview of the ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) project: aerosol–cloud–radiation interactions in the southeast Atlantic basin

This is the final version. Available on open access from the European Geosciences Union via the DOI in this recordData availability: All ORACLES data are accessible via the digital object identifiers (DOIs) provided under ORACLES Science Team (2020a–d) references: https://doi.org/10.5067/Suborbital/ORACLES/P3/2018_V2 (ORACLES Science Team, 2020a), https://doi.org/10.5067/Suborbital/ORACLES/P3/2017_V2 (ORACLES Science Team, 2020b), https://doi.org/10.5067/Suborbital/ORACLES/P3/2016_V2 (ORACLES Science Team, 2020c), and https://doi.org/10.5067/Suborbital/ORACLES/ER2/2016_V2 (ORACLES Science Team, 2020d). The only exceptions are noted as footnotes to Table B2.Southern Africa produces almost a third of the Earth's biomass burning (BB) aerosol particles, yet the fate of these particles and their influence on regional and global climate is poorly understood. ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) is a 5-year NASA EVS-2 (Earth Venture Suborbital-2) investigation with three intensive observation periods designed to study key atmospheric processes that determine the climate impacts of these aerosols. During the Southern Hemisphere winter and spring (June–October), aerosol particles reaching 3–5 km in altitude are transported westward over the southeast Atlantic, where they interact with one of the largest subtropical stratocumulus (Sc) cloud decks in the world. The representation of these interactions in climate models remains highly uncertain in part due to a scarcity of observational constraints on aerosol and cloud properties, as well as due to the parameterized treatment of physical processes. Three ORACLES deployments by the NASA P-3 aircraft in September 2016, August 2017, and October 2018 (totaling ∼350 science flight hours), augmented by the deployment of the NASA ER-2 aircraft for remote sensing in September 2016 (totaling ∼100 science flight hours), were intended to help fill this observational gap. ORACLES focuses on three fundamental science themes centered on the climate effects of African BB aerosols: (a) direct aerosol radiative effects, (b) effects of aerosol absorption on atmospheric circulation and clouds, and (c) aerosol–cloud microphysical interactions. This paper summarizes the ORACLES science objectives, describes the project implementation, provides an overview of the flights and measurements in each deployment, and highlights the integrative modeling efforts from cloud to global scales to address science objectives. Significant new findings on the vertical structure of BB aerosol physical and chemical properties, chemical aging, cloud condensation nuclei, rain and precipitation statistics, and aerosol indirect effects are emphasized, but their detailed descriptions are the subject of separate publications. The main purpose of this paper is to familiarize the broader scientific community with the ORACLES project and the dataset it produced.NAS

Risk factors associated with suicide attempts and other self-injury among Hong Kong adolescents

This study examined 1,361 Chinese adolescents who reported self-injurious behaviors. Groups A and B both acknowledged deliberate self-injury, but only Group A had made a suicide attempt. Group C reported accidental self-injury. Deliberate self-injurers (Groups A and B) were more frequently girls, older, and with more suicidal ideation. Group A had more psychopathology, environmental and suicide-related risk factors than group B and C. Group C had higher depressive symptoms than noninjured controls. The study clarifies differences among self-injurious behavior groups based on expressed deliberate self-injury and self-reported suicide attempt. These three groups appear to present a continuum of risk. © 2007 The American Association of Suicidology.link_to_subscribed_fulltex

Knowledge, attitudes and behaviors associated with mental illness among the working population in Hong Kong: a cross-sectional telephone survey

Mental health-related issues such as stress and depressive symptoms are common in the workplace and costly to both employees and employers. Stigma against mental illness limits oneâ s help-seeking attitudes and behavior, thereby leading to social isolation and deteriorating performance in the workplace. This study aimed at examining what aspects of knowledge, attitude and previous contacts with people with mental illness influence working adultsâ intention to have future contact with people (e.g., to work with, to live nearby) with mental illness. A total of 1031 employees across eight industries were telephone-interviewed. Descriptive analysis and hierarchical logistic regression were performed. The patterns of knowledge, attitude and behaviors were similar across industries. Higher education and lower income level were associated with higher intention to have contact with people with mental illness. Previous contacts were significant predictors of intention of future contacts. The attitude that people with mental health problems are less reliable was significantly associated with lower intention, and the knowledge that people with severe mental health problems can fully recover was significantly associated with higher intended contacts with people with mental illness. The implication of the findings and the cultural and contextual influences are discussed.link_to_subscribed_fulltex

Risk factors associated with suicide attempts and other self-injury among Hong Kong adolescents

This study examined 1,361 Chinese adolescents who reported self-injurious behaviors. Groups A and B both acknowledged deliberate self-injury, but only Group A had made a suicide attempt. Group C reported accidental self-injury. Deliberate self-injurers (Groups A and B) were more frequently girls, older, and with more suicidal ideation. Group A had more psychopathology, environmental and suicide-related risk factors than group B and C. Group C had higher depressive symptoms than noninjured controls. The study clarifies differences among self-injurious behavior groups based on expressed deliberate self-injury and self-reported suicide attempt. These three groups appear to present a continuum of risk. © 2007 The American Association of Suicidology.link_to_subscribed_fulltex

Body dissatisfaction and depressive symptoms in Hong Kong adolescents

Poster no.

Body dissatisfaction, maternal appraisal, and depressive symptoms in Hong Kong adolescents

Body dissatisfaction, its risk factors and association with depressed mood have been well investigated in the West. However, more studies are needed to examine further the relation between body dissatisfaction and depressive symptoms and the factors influencing body dissatisfaction in non-Western cultures. The present study examined in a sample of Hong Kong Chinese adolescents the relation between body dissatisfaction and depressive symptoms, and the relation of maternal appraisal of their adolescent's figure to the adolescent's body dissatisfaction and depressive symptoms. We obtained information from 379 boys and 254 girls about their body dissatisfaction and depressive symptoms. Their mothers provided information about their appraisal of their adolescent's body shape and size compared to ideal. Body dissatisfaction was related to depressive symptoms in girls (B=2.58, p<.01), but not in boys (B=-0.08, p<.10). Negative maternal appraisal did not have direct effects on adolescents' depressive symptoms (B=0.14, p=.75), but the association between negative maternal appraisal and body dissatisfaction was significantly stronger in adolescents whose ideal was smaller than they perceived themselves to be (B=0.32, p<.01) than those whose ideal was larger than their own perception (B=0.14, p<.01). Our findings suggest that maternal appraisal had indirect effects on mood, acting through adolescents' body dissatisfaction, and that body dissatisfaction may be a sex-specific risk factor for depression. This study points to the need for testing and adapting programs to reduce body dissatisfaction particularly in girls at risk for depression, and to raise mothers' awareness of the link between their negative appraisals and their adolescents' body dissatisfaction and depressive symptoms. © 2010 International Union of Psychological Science.link_to_subscribed_fulltex

Exposure to suicide and suicidal behaviors among Hong Kong adolescents

Suicidal behaviors (deliberate self-injury with the intent to hurt or kill oneself) have been little examined outside the West. The aims of this study were to (a) determine the correlates of suicidal behaviors, and (b) examine whether depression and suicide ideation moderated the effects of exposure to completed and attempted suicide on suicidal behaviors among a community sample of Hong Kong youth ages 12-17. Adolescents responded to questions regarding self-injurious behaviors, and also indicated presence of intention to hurt or kill themselves in the past 12 months. Based on their responses, two groups of interest were formed: 96 youths reported both self-injurious behaviors and the intent to hurt or kill themselves, and formed the "suicidal behaviors" group; and, 1213 adolescents reported neither self-injurious behaviors nor intent to hurt self or die, and formed the control group. The participants also responded to questions about depressive symptoms, anxiety, suicidal ideation and attempt, alcohol/drug use, stressful life events, and family relationships. They indicated whether anyone they knew had attempted or completed suicide in the previous 12 months. Logistic regression indicated that depressive symptoms, stressful life events, suicidal ideation and exposure to suicide attempt (but not completed suicide) contributed unique variance to the presence of suicidal behaviors, after controlling for demographic variables. Depression (and at trend levels, suicidal ideation) moderated the effect of exposure to suicide attempt by others on suicidal behaviors. Our results indicate that completed suicide in the social network increases risk for suicidal behaviors, but not when other risk factors are controlled. By contrast, a suicide attempt independently increases risk for suicidal behaviors. Furthermore, those youths who experience depressive symptoms or suicidal ideation are at particularly high risk for engaging in suicidal behaviors when an exposure to suicide attempt occurs. © 2005 Elsevier Ltd. All rights reserved.link_to_subscribed_fulltex

How do today's parents and teachers view adolescent health issues differently from adolescents?

Abstrac

The Association Between Adolescents' Depressive Symptoms, Maternal Negative Affect, and Family Relationships in Hong Kong: Cross-Sectional and Longitudinal Findings

This study investigated the bidirectional relationships of adolescents' and maternal mood, and the moderating effect by gender and perceived family relationships on these relationships. Data were obtained from 626 adolescent-mother dyads and follow-up data were collected one year later from a subset. Adolescents reported their depressive symptoms, and their mothers reported their negative affect. Adolescents described their perception of family relationships. Maternal negative affect and adolescents' depressive symptoms were significantly correlated at baseline. This association was moderated by gender and family relationships. The association was stronger in mother-daughter compared to mother-son dyads. In families where relationships were reported to be poor, adolescent depressive symptoms were uniformly high, regardless of maternal negative affect. However, in families where relationships were good, maternal negative affect was associated with higher adolescents' depressive symptoms. In longitudinal analyses, adolescents' mood at baseline was found to relate to maternal negative affect at follow-up. Family relationships at baseline were also associated with adolescents' depressive symptoms at follow-up. However, there was no prediction from maternal negative affect at baseline to adolescents' depressive symptoms at follow-up. Gender and quality of family relationships did not moderate the longitudinal relationships between adolescents' depressive symptoms and maternal negative affect in either direction. © 2009 American Psychological Association.link_to_subscribed_fulltex