48 research outputs found
Demand-Side Management in a Micro-Grid with Multiple Retailers:A Coalitional Game Approach
This paper deals with the design and analysis of a novel on-line pricing mechanism based on coalitional game theory. The proposed architecture consists of a micro-grid (MG) where the power demand can be fulfilled by multiple competing energy retailers trying to attract consumers by announcing a price in a hierarchical leader-follower structure. The existence of a Stackelberg equilibrium in such game is shown, leading to a guaranteed consumption value given a price. The coalition formation is then extended to a minimum spanning tree game that affects the rational decision of the players involved. The stability analysis for the resulting coalitions is performed and the steps in the game are presented. Simulations provide a comparison of the profits generated by the proposed scheme against a more traditional single retailer scheme, while simultaneously showing convergence towards steady-state equilibrium
Online pricing for demandâside management in a lowâvoltage resistive microâgrid via a Stackelberg game with incentive strategies
It has been demonstrated that online pricing mechanisms are a viable solution for demand side management in power systems. This study deals with the analysis and design of a droop-controlled low-voltage resistive AC micro-grid network system. Such a system is subjected to a dynamic demand obtained from an online pricing mechanism, which is proposed as a novelty in the study of micro-grids. This mechanism is derived from a variation of the Stackelberg game, which includes the use of incentive strategies. First, a configuration in which a supplier announces an incentive function and (Formula presented.) -consumersâ reaction to the resulting personalised price is presented. Then, a detailed stability analysis of the micro-grid is presented as a result of the interaction with the aforementioned online pricing mechanism. The units of the micro-grid (generators as the supplier and loads as the consumers) operate under either conventional or bounded droop control. The novelty of the approach is that it bridges the gap between the physical and the market layers of the problem. The ways in which the existence of multiple equilibrium points is guaranteed for both the consumer's load and the supplier's announced incentive are shown. A detailed design process for the profit functions of the players is shown in conjunction with the parameter selection for their implementation. Finally, simulations that demonstrate the system stability and its convergence to different equilibria are implemented under scenarios with one and multiple consumers
Transient dynamics of heterogeneous micro grids using second order consensus
This paper deals with a network of interconnected micro grids. The transient dynamics is modelled as an averaging process involving dynamic agents in a network. An analysis of the convergence of the consensus dynamics is provided using a network model based approach and by exploiting the properties of the corresponding graph-Laplacian matrix. Furthermore an investigation of the transient dynamics is carried out for different damping and inertial parameters and under different time-varying topologies. Finally a simulation is performed based on a model calibrated on an existing network in the UK under parameter uncertainties
The role of C957T, TaqI and Ser311Cys polymorphisms of the DRD2 gene in schizophrenia: systematic review and meta-analysis
Additional file 3. Sensitivity analysis and cumulative meta-analysis
Las percepciones de crianza materna podrĂan influenciar las conductas autolesivas en adolescentes con diagnĂłstico de trastornos de la conducta alimentaria.
Objective: To explore the perceived parental rearing behavior in adolescents diagnosed with an eating disorder, and to identify eventual differences with altered eating and self-injurious behaviors. Material and methods: A total of 45 adolescents diagnosed with some eating disorder (11 diagnosed with anorexia nervosa, 23 with bulimia nervosa and 11 with binge eating disorder), recruited from the outpatient and hospitalization areas of the Juan N Navarro Childrenâs Psychiatric Hospital, were included. Results: It was found that the greater the memories of favoritism (r = 0.41, p-value = 0.005) or rejection (r = 0.36, p-value = 0.016) by the father, the higher the scores on the Eating Attitude Scale. Differences were also found in the motherâs warmth dimension, between the adolescents who presented self-injuries (mean = 39.6, de = 11.3) and those who did not present them (mean = 47.4, de = 8.8) (t =-2.6, value p = 0.015). Conclusions: Adolescents with a diagnosis of eating disorders presented differences in their perception of parental rearing, a factor that may decisively influence the manifestation of other psychopathological behaviors.Objetivo: Explorar las percepciones de crianza parental en adolescentes diagnosticados con algĂșn trastorno de la conducta alimentaria, e identificar posibles diferencias con alteraciones de la conducta alimentaria y conductas autolesivas. Material y mĂ©todos: Un total de 45 adolescentes con algĂșn tipo de trastorno de la conducta alimentaria (TCA) (11 diagnosticados con anorexia nervosa, 23 con bulimia nervosa y 11 con trastorno âpor atracĂłnâ), pacientes en ĂĄreas de consulta externa y hospitalizaciĂłn del Hospital PsiquiĂĄtrico Infantil Juan N. Navarro fueron sistemĂĄticamente estudiados. Resultados: Se encontrĂł que cuĂĄnto mayores las percepciones de favoritismo (r =0,41, valor p = 0,005) o rechazo (r = 0,36, valor p = 0,016) del padre, mayores fueron tambiĂ©n los puntajes en la Escala de Actitudes Alimentarias. Se encontraron asimismo diferencias en la dimensiĂłn de calidez de la madre, entre los adolescentes que presentaron autolesiones (media = 39,6, d.e = 11,3) comparados con aquĂ©llos que no las presentaron (media = 47,4, d.e = 8.8) (t = -2,6, valor p = 0,015). Conclusiones: Los adolescentes con diagnĂłstico de TCA presentaron diferencias en la percepciĂłn de crianza parental, factor que puede influenciar decisivamente la manifestaciĂłn de otras conductas psicopatolĂłgicas
Prevalence of Anxiety and Depression among Outpatients with Type 2 Diabetes in the Mexican Population
Depression and anxiety are common in diabetic patients; however, in recent years the frequency of these symptoms has markedly increased worldwide. Therefore, it is necessary to establish the frequency and factors associated with depression and anxiety, since they can be responsible for premature morbidity, mortality, risk of developing comorbidities, complications, suffering of patients, as well as escalation of costs. We studied the frequency of depression and anxiety in Mexican outpatients with type 2 diabetes and identified the risk factors for depression and anxiety.We performed a study in 820 patients with type 2 diabetes. The prevalence of depression and anxiety was estimated using the Hamilton Depression Rating Scale and the Hamilton Anxiety Rating Scale, respectively. We calculated the proportions for depression and anxiety and, after adjusting for confounding variables, we performed multivariate analysis using multiple logistic regressions to evaluate the combined effect of the various factors associated with anxiety and depression among persons with type 2 diabetes. The rates for depression and anxiety were 48.27% (95% CI: 44.48â52.06) and 55.10% (95% CI: 51.44â58.93), respectively. Occupation and complications in diabetes were the factors associated with anxiety, whereas glucose level and complications in diabetes were associated with depression. Complications in diabetes was a factor common to depression and anxiety (p<0.0001; OR 1.79, 95% CI 1.29â2.4).Our findings demonstrate that a large proportion of diabetic patients present depression and/or anxiety. We also identified a significant association between complications in diabetes with depression and anxiety. Interventions are necessary to hinder the appearance of complications in diabetes and in consequence prevent depression and anxiety
No association between COMT val158met polymorphism and suicidal behavior: meta-analysis and new data
Stability Analysis for the Implementation of Game Theory-based On-Line Pricing Schemes in Micro-Grids
An existing challenge in power systems is the implementation of optimal demand management through dynamic pricing. This research project deals with on-line pricing schemes for electricity in micro-grid network systems and the ways in which their implementation affects the physical system's response. Two approaches were devised in this study: First, the ways in which micro-grid networks can be modelled as less prescriptive multi-agent consensus systems; examining their response under uncertainties and gaining insights on the relation between the network topology, the heterogeneous parameters of its components, and the system's response. Secondly, deriving game-theoretic novel pricing schemes and integrating them with the physical system model to perform a stability analysis. The proposed schemes consider the rational behaviour of the end-users and the entailing tension with the energy supplier(s); demonstrating the ways in which the decisions of the players involved influence the physical system. The study aims to clarify the interconnection between the market and physical layers of the problem, leading to a better future implementation of such schemes. The first part of this thesis studies networks of heterogeneous micro-grids, treating them as agents and modelling their dynamics as an averaging process that is subject to uncertain non-linear parameters. The second part introduces a pricing scheme based on the Stackelberg game with incentive strategies in a micro-grid, where the leader is the energy supplier, and the follower the consumer. The scheme is then improved and carried out in a droop-controlled low-voltage resistive AC micro-grid. The final part of this research is about the design of a scheme based on coalitional game theory, where there are multiple competing energy retailers attracting consumers. For all the propositions above, analysis and simulations that illustrate system stability, agent rationality, profit improvement, and the convergence to different equilibria in the physical and market responses are implemented
Online pricing for demand-side management in a low-voltage resistive micro-grid via a Stackelberg game with incentive strategies
It has been demonstrated that online pricing mechanisms are a viable solution for demand side management in power systems. This study deals with the analysis and design of a droop-controlled low-voltage resistive AC micro-grid network system. Such a system is subjected to a dynamic demand obtained from an online pricing mechanism, which is proposed as a novelty in the study of micro-grids. This mechanism is derived from a variation of the Stackelberg game, which includes the use of incentive strategies. First, a configuration in which a supplier announces an incentive function and (Formula presented.) -consumersâ reaction to the resulting personalised price is presented. Then, a detailed stability analysis of the micro-grid is presented as a result of the interaction with the aforementioned online pricing mechanism. The units of the micro-grid (generators as the supplier and loads as the consumers) operate under either conventional or bounded droop control. The novelty of the approach is that it bridges the gap between the physical and the market layers of the problem. The ways in which the existence of multiple equilibrium points is guaranteed for both the consumer's load and the supplier's announced incentive are shown. A detailed design process for the profit functions of the players is shown in conjunction with the parameter selection for their implementation. Finally, simulations that demonstrate the system stability and its convergence to different equilibria are implemented under scenarios with one and multiple consumers
Demand-side management in a micro-grid with multiple retailers : a coalitional game approach
This paper deals with the design and analysis of a novel on-line pricing mechanism based on coalitional game theory. The proposed architecture consists of a micro-grid (MG) where the power demand can be fulfilled by multiple competing energy retailers trying to attract consumers by announcing a price in a hierarchical leader-follower structure. The existence of a Stackelberg equilibrium in such game is shown, leading to a guaranteed consumption value given a price. The coalition formation is then extended to a minimum spanning tree game that affects the rational decision of the players involved. The stability analysis for the resulting coalitions is performed and the steps in the game are presented. Simulations provide a comparison of the profits generated by the proposed scheme against a more traditional single retailer scheme, while simultaneously showing convergence towards steady-state equilibrium