5,294 research outputs found
An Evolutionary Analysis of Investment in Electricity Markets
Electricity markets are being liberalised and open to private competition in several countries. These liberalized electricity markets are very complex as the interactions between demand and supply are subject to several technicalities arising from the commodity being traded: electricity. One of these technicalities is that generators cannot store electricity: this fact implies that it needs to generate its production real-time. A second problem with this market are the different generation technologies used at different levels of demand, which implies that at different times of the day different generation costs are supported to meet demand: due to ramp-rate constraints, capacity available, and fixed and start-up costs. In this paper we analyze the issue of investment and the electricity system’s long-term security in an industry where a regulator controls the short-term prices, imposing a perfect competition outcome for “low†demand hours and a price cap at times where load is shed. We look at the following research questions: a) How does the oligopolistic structure of the market interact with the value of the different technologies? b) How do players define their investment strategies? c) How do the regulatory policies affect the investment in generation? Do they work similarly under perfect competition and oligopoly? d) Can markets invest enough capacity to ensure the long run security of the market? The main results of our analysis are following: 1. The impact of a given investment on the market price is independent of the player investing. 2. The impact of an investment on price is a function of the technology in which the investment takes place and of the cycle to which the price refers to. 3. The impact of price caps on the evolution of the market structure is non-linear, it cannot be too low or too high. 4. An oligopolistic electricity market fails to deliver the needed investment unless the regulators intervene. 5. The higher the reserve margin the higher the total investment. However, this instrument by itself was not able to provide the incentive needed to ensure the long-term security of the system, as in any of the experiments analyzed the peak demand is not completely satisfied. 6. Even a slight increase in demand, due to the reserve margin, leads to important changes on the relative value of the different technologies. 7. The main task of the regulatory authorities is to define a level of capacity payments that give the necessary incentive to investment, at the minimum cost: Capacity Payments are very important in shaping the generation structure. 8. Uncertainty reduces the value of Peak plants: this result clearly contradicts any common sense in these matters, as one would expect the presence of price uncertainty to be beneficial to Peak plants. The proportion invested in baseload plants increases with uncertainty of the energy price, decreasing the investment in shoulder plant.agent-based, electricity markets, evolution, investment, regulation, simulation
Capacity expansion under uncertainty in an oligopoly using indirect reinforcement-learning.
We model capacity expansion in oligopolistic markets, with endogenous prices, under uncertainty, considering multiple production technologies. As this environment is complex, capacity expansion is the outcome of a learning process by individual firms. We propose indirect reinforcement-learning to model the interaction between price determination and capacity decisions, in the context of an oligopoly game. We apply our model to the analysis of the Iberian electricity market, considering multiple technologies, focusing on how subsidies, the prices of CO2 emissions and gas affect the capacity expansion policies
Association between Bipolar Affective Disorder and Periodontal Diseases
Periodontitis, an inflammatory disease of periodontal tissues, is characterized by the progressive loss of support tissue and the insertion of teeth. It derives from the infection and interaction of specific bacterial species with host response components in susceptible individuals. A growing number of observational and epidemiological studies have been published, in the last decades, pointing to a possible association between stress, anxiety, and depression with the development and progression of periodontal diseases. One of the possible mechanisms of influence of stress and of the psychosocial factors, in the periodontal conditions, is the modification of the individual’s behavior. The studies that assessed the association between stress, depression, and periodontal disease are numerous in different types of design, yet their data are still conflicting. Another recurrent serious condition of mental health, frequently associated with high rates of morbidity and mortality, is the bipolar affective disorder (BPAD). Although little investigated and with conflicting data, BPAD is a behavioral factor associated to the periodontal disease. In addition, little is known about its interference with the microbial and immunological response to periodontitis. The aim of this chapter is to describe the main scientific evidence of the association between BPAD and periodontitis
Spatio-temporal conjecture for diffusion
We present here a conjecture about the equivalence between the noise density
of states of a system governed by a generalized Langevin equation and the
fluctuation in the energy density of states in a Hamiltonian system. We present
evidence of this for a disordered Heisenberg system.Comment: 6 pages, 1 figure. Submitted to Physica
Desafíos encarados para superar la brecha digital indígena en Brasil
El objetivo de este trabajo es identificar el nivel de
inclusión digital realizado por el programa brasileño
de inclusión digital Gobierno Electrónico - Servicio de
Atención al Ciudadano (Governo Eletrônico - Serviço de
Atendimento ao Cidadão - Gesac) en tierras indígenas. Nos
guiamos por el sistema de inclusión digital del sociólogo
brasileño Bernardo Sorj, quien identifica cinco niveles: 1)
la existencia de una infraestructura física de transmisión,
2) la disponibilidad de equipamiento/conexión, 3)
capacitación en el uso de herramientas informáticas e
internet, 4) la capacidad intelectual e la integración social,
e 5) la producción y uso de contenidos específicos.
Nuestra hipótesis es que, a pesar del discurso oficial
alineado con los debates sobre las sociedades del
conocimiento, en la práctica, Gesac todavía está operado
por un determinismo tecnológico. Para probar esta
hipótesis, realizamos la observación del punto de acceso
a internet en la escuela indígena Pamáali, ubicado en la
zona noroccidental de la Amazonia brasileña. También
hemos discutido y llevado a cabo entrevistas con los
actores involucrados en la implementación de programas
de inclusión digital dirigida a los pueblos indígenas: los
ministerios y funcionarios de la Fundación Nacional del
Indio (FUNAI), representantes del tercer sector y los
propios indígenas.
Los desafíos que identificamos llevan a la conclusión de
que la brecha digital indígena es sólo una de las varias
brechas a que los grupos indígenas son sometidos
desde tiempos coloniales, siendo una consecuencia más
de estas divisiones a la vez que también las acentúa.
Mientras las acciones de inclusión digital del gobierno
brasileño dirigidos a los pueblos indígenas no se hagan
e implementen como parte de una política indígena más
amplia y no tengan en cuenta las especificidades de estos
grupos, estas iniciativas se limitaran a brindar conexión a
internet y la donación de equipos que serán subutilizados
o se deterioran rápidamente.This paper’s objective is to identify the level of digital
inclusion made possible by Brazilian digital divide program
Electronic Government – Citizen Attention Service (Governo
Eletrônico – Serviço de Atendimento ao Cidadão – Gesac)
on indigenous lands. We are guided by Brazilian sociologist
Bernardo Sorj’s five level digital inclusion system: 1) the
existence of physical transmission infrastructure, 2) the
availability of equipment/connection, 3) training in the
use of computing tools and the internet, 4) the intellectual
ability and social integration, and 5) the production and
use of specific content.
Our hypothesis is that, despite an official discourse
aligned with the discussions on the knowledge societies,
in practice, Gesac is still operated by a technological
determinism. To test this hypothesis, we performed the
observation of the internet access point in the indigenous
school Pamáali, of Baniwa and Coripaco ethnicities, located
in the northwestern area of the Brazilian Amazon. We also
discussed and conducted interviews with actors involved
in the implementation of digital inclusion programs aimed
at indigenous peoples: ministries and Indian National
Foundation (FUNAI) officials, representatives of the third
sector and indigenous themselves.
The challenges we identify lead to the conclusion that
indigenous digital divide is just one of the several divides
to which indigenous groups are subjected since colonial
times, being one more consequence of these divides at
the same time that it also accentuates them. As long as
Brazilian government’s digital inclusion actions aimed
at indigenous peoples are not created and implemented
as part of a broader indigenous policy and do not take
into consideration the specificities of these groups, these
initiatives will be limited to providing internet connection
and donating equipment that shall either remain underused
or will rapidly deteriorate
Desenho de experiências - estratégicas
O desenvolvimento de produtos e processos pressupõe a realização de experiências que conduzam à sua optimização ao menor custo possível. As estratégias a utilizar na condução das experiências, bem como o tratamento estatístico dos resultados alcançados, deverão conduzir às melhores condições de realização dos ensaios necessários à prossecução deste objectivo. O método de Taguchi permite obter informação relevante, com um número reduzido de experiências, conforme se demonstra nos casos de estudo apresentados
Macrostructural changes of polymer replicated open cell cordierite based foams upon sintering
The goal of this work was to clarify the macrostructural changes that take place upon sintering of open cell cordierite based foams. A methodology, based on optical image analysis, was developed to assess the structure of open-cell foams, which allowed evaluating the macrostructure of both cordierite based foams obtained by the replication process and their polymeric templates. The parameters used to describe the structures were the size of the cell and the window, the window shape factor, the strut thickness and the volume fraction of the material. The experimental evidence gathered opened the way to understand the physical/chemical transformations involved in the polymer burnout and the ceramic sintering processes, as well as their influence on the ceramic final structure. The observed trends provide guidance for tailoring ‘replicated’ cordierite based foams, in view of the required application
Mobile robot for autonomous golf balls picking
This paper describes a robot to collect golf balls in a driving range, operating as autonomous and/or remotely operated. It uses a set of sensors which gives the robot capacities of surrounding environment perception and digital image processing to search for the balls in places with higher concentrations of balls. This system avoids stopping the players for ball collection permitting a higher use rate of the field
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