scholarly journals Correction to: Distributionally robust optimization with multiple time scales: valuation of a thermal power plant

2019 ◽  
Vol 17 (3) ◽  
pp. 387-387
Author(s):  
Wim van Ackooij ◽  
Debora Daniela Escobar ◽  
Martin Glanzer ◽  
Georg Ch. Pflug
2019 ◽  
Vol 17 (3) ◽  
pp. 357-385
Author(s):  
Wim van Ackooij ◽  
Debora Daniela Escobar ◽  
Martin Glanzer ◽  
Georg Ch. Pflug

AbstractThe valuation of a real option is preferably done with the inclusion of uncertainties in the model, since the value depends on future costs and revenues, which are not perfectly known today. The usual value of the option is defined as the maximal expected (discounted) profit one may achieve under optimal management of the operation. However, also this approach has its limitations, since quite often the models for costs and revenues are subject to model error. Under a prudent valuation, the possible model error should be incorporated into the calculation. In this paper, we consider the valuation of a power plant under ambiguity of probability models for costs and revenues. The valuation is done by stochastic dynamic programming and on top of it, we use a dynamic ambiguity model for obtaining the prudent minimax valuation. For the valuation of the power plant under model ambiguity we introduce a distance based on the Wasserstein distance. Another highlight of this paper is the multiscale approach, since decision stages are defined on a weekly basis, while the random costs and revenues appear on a much finer scale. The idea of bridging stochastic processes is used to link the weekly decision scale with the finer simulation scale. The applicability of the introduced concepts is broad and not limited to the motivating valuation problem.


2012 ◽  
Vol 58 (4) ◽  
pp. 351-356
Author(s):  
Mincho B. Hadjiski ◽  
Lyubka A. Doukovska ◽  
Stefan L. Kojnov

Abstract Present paper considers nonlinear trend analysis for diagnostics and predictive maintenance. The subject is a device from Maritsa East 2 thermal power plant a mill fan. The choice of the given power plant is not occasional. This is the largest thermal power plant on the Balkan Peninsula. Mill fans are main part of the fuel preparation in the coal fired power plants. The possibility to predict eventual damages or wear out without switching off the device is significant for providing faultless and reliable work avoiding the losses caused by planned maintenance. This paper addresses the needs of the Maritsa East 2 Complex aiming to improve the ecological parameters of the electro energy production process.


2013 ◽  
Vol 12 (2) ◽  
pp. 337-342 ◽  
Author(s):  
Firuta Goga ◽  
Roxana Dudric ◽  
Calin Cormos ◽  
Florica Imre ◽  
Liliana Bizo ◽  
...  

Author(s):  
V. I. Minina ◽  
Yu. A. Nelyubova ◽  
Ya. A. Savchenko ◽  
A. A. Timofeeva ◽  
Ye. A. Astafieva ◽  
...  

Introduction. Coal heat power stations are characterized by severe hazardous eff ect of occupational environment on workers. Objective. To analyze chromosomal disorders in workers of thermal power plant working on coal from Kuznetsk coal fi eld (West Siberia). Materials and methods. Th e authors studied level and specter of chromosomal aberrations in blood lymphocytes of 185 workers of Kemerovo thermal power plant and 218 inhabitants of the same location, not working on industrial enterprises (Kemerovo, Russia). For every individual, average number of 200 metaphase plates of high quality was analyzed. Results. Findings are that the workers of thermal power plant have levels of chromosomal aberrations signifi cantly higher than those of reference group (3,01±0,13% vs. 1,45±0,08%; р<0,00001). With that, increased frequency is seen both for chromatid aberrations and for chromosomal ones — that indicates complex exposure to chemical and radiation factors. Conclusions. Th e results obtained necessitate elaboration of measures to decrease genotoxic hazards in the occupational environment.


Author(s):  
Ye. G. Polenok ◽  
S. A. Mun ◽  
L. A. Gordeeva ◽  
A. A. Glushkov ◽  
M. V. Kostyanko ◽  
...  

Introduction.Coal dust and coal fi ring products contain large amounts of carcinogenic chemicals (specifically benz[a]pyrene) that are different in influence on workers of coal mines and thermal power plants. Specific immune reactions to benz[a]pyrene therefore in these categories of workers can have specific features.Objective.To reveal features of antibodies specifi c to benz[a]pyrene formation in workers of coal mines and thermal power plants.Materials and methods.The study covered A and G class antibodies against benz[a]pyrene (IgA-Bp and IgG-Bp) in serum of 705 males: 213 donors of Kemerovo blood transfusion center (group 1, reference); 293 miners(group 2) and 199 thermal power plant workers (group 3). Benz[a]pyrene conjugate with bovine serum albumin as an adsorbed antigen was subjected to immune-enzyme assay.Results.IgA-Bp levels in the miners (Me = 2.7) did not differ from those in the reference group (Me = 2.9), but in the thermal power plant workers (Me = 3.7) were reliably higher than those in healthy men and in the miners (p<0.0001). Levels of IgG-Bp in the miners (Me = 5.0) appeared to be lower than those in the reference group (Me = 6.4; (p = 0.05). IgG-Bb level in the thermal power plantworkers (Me = 7.4) exceeded the parameters in the healthy donors and the miners (p<0.0001). Non-industrial factors (age and smoking) appeared tohave no influence on specific immune reactions against benz[a]pyrene in the miners and the thermal power plant workers.Conclusions.Specific immune reactions against benz[a]pyrene in the miners and the thermal power plant workers are characterized by peculiarities: the miners demonstrate lower levels of class A serum antibodies to benz[a]pyrene; the thermal power plant workers present increased serum levels of class G antibodies to benz[a]pyrene. These peculiarities result from only the occupational features, but do not depend on such factors as age, smoking and length of service at hazardous production. It is expedient to study specific immune reactions to benz[a]pyrene in workers of coal mines and thermal power plants, to evaluate individual oncologic risk and if malignancies occur.


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