Effect of Short-term and High-resolution Load Forecasting Errors on Microgrid Operation Costs

The aim of this paper is to evaluate the effect of the load forecasting errors to the operation costs of a grid-connected microgrid. To this end, a microgrid energy scheduling optimization model was tested with deterministic and stochastic formulations under two solution approaches i.e., day-ahead and rolling horizon optimization. In total, twelve simulation test cases were designed receiving as input the forecasts provided by one of the three implemented machine learning models: linear regression, artificial neural network with backpropagation, and long short-term memory. Simulation results of the weekly operation of a real residential building (HSB Living Lab)showed no significant differences among the costs of the test cases for a daily mean absolute percentage forecast error of about 12%. These results suggest that operators of similar microgrid systems could use simplifying approaches, such as day-ahead deterministic optimization, and forecasts of similar, non-negligible accuracy without substantially affecting the microgrid\u27s total cost as compared to the ideal case of perfect forecast. Improving the accuracy would mainly reduce the microgrid\u27s peak power cost as shown by its 20.2% increase in comparison to the ideal case

Effect of Short-term and High-resolution Load Forecasting Errors on Microgrid Operation Costs

The aim of this paper is to evaluate the effect of the load forecasting errors to the operation costs of a grid-connected microgrid. To this end, a microgrid energy scheduling optimization model was tested with deterministic and stochastic formulations under two solution approaches i.e., day-ahead and rolling horizon optimization. In total, twelve simulation test cases were designed receiving as input the forecasts provided by one of the three implemented machine learning models: linear regression, artificial neural network with backpropagation, and long short-term memory. Simulation results of the weekly operation of a real residential building (HSB Living Lab)showed no significant differences among the costs of the test cases for a daily mean absolute percentage forecast error of about 12%. These results suggest that operators of similar microgrid systems could use simplifying approaches, such as day-ahead deterministic optimization, and forecasts of similar, non-negligible accuracy without substantially affecting the microgrid\u27s total cost as compared to the ideal case of perfect forecast. Improving the accuracy would mainly reduce the microgrid\u27s peak power cost as shown by its 20.2% increase in comparison to the ideal case

Hidden symmetry and knot solitons in a charged two-condensate Bose system

We show that a charged two-condensate Ginzburg-Landau model or equivalently a Gross-Pitaevskii functional for two charged Bose condensates, can be mapped onto a version of the nonlinear O(3) $\sigma$-model. This implies in particular that such a system possesses a hidden O(3) symmetry and allows for the formation of stable knotted solitons. The results, in particular, should be relevant to the superconducting MgB_2.Comment: This version will appear in Phys. Rev. B, added a comment on the case when condensates in two bands do not independently conserve, also added a figure and references to experimental papers on MgB_2 (for which our study is relevant). Miscellaneous links on knot solitons are also available at the homepage of one of the authors http://www.teorfys.uu.se/PEOPLE/egor/ . Animations of knot solitons are available at http://users.utu.fi/h/hietarin/knots/c45_p2.mp

Modelling the Spatial Dynamics of Culture Spreading in the Presence of Cultural Strongholds

Cultural competition has throughout our history shaped and reshaped the geography of boundaries between humans. Language and culture are intimately connected and linguists often use distinctive keywords to quantify the dynamics of information spreading in societies harbouring strong culture centres. One prominent example, which is addressed here, is Kyoto's historical impact on Japanese culture. We construct a first minimal model, based on shared properties of linguistic maps, to address the interplay between information flow and geography. In particular, we show that spreading of information over Japan in the pre-modern time can be described as a Eden growth process, with noise levels corresponding to coherent spatial patches of sizes given by a single days walk, and with patch-to-patch communication time comparable to the time between human generations.Comment: 5 pages, 4 figure

Equivalent gambling warning labels are perceived differently

Background and Aims The same information may be perceived differently, depending on how it is described. The risk information given on many gambling warning labels tends to accentuate what a gambler might expect to win, e.g. ‘This game has an average percentage payout of 90%’ (return-to-player), rather than what a gambler might expect to lose, e.g. ‘This game keeps 10% of all money bet on average’ (house-edge). We compared gamblers’ perceived chances of winning and levels of warning label understanding under factually equivalent return-to-player and house-edge formats. Design Online surveys: experiment 1 was designed to test how gamblers’ perceived chances of winning would vary under equivalent warning labels, and experiment 2 explored how often equivalent warning labels were correctly understood by gamblers. Setting United Kingdom. Participants UK nationals, aged 18 years and over and with experience of virtual on-line gambling games, such as on-line roulette, were recruited from an on-line crowd-sourcing panel (experiment 1, n = 399; experiment 2, n = 407). Measurements The main dependent variables were a gambler's perceived chances of winning on a seven-point Likert scale (experiment 1) and a multiple-choice measure of warning label understanding (experiment 2). Findings The house-edge label led to lower perceived chances of winning in experiment 1, F(1, 388) = 19.03, P < 0.001. In experiment 2, the house-edge warning label was understood by more gamblers [66.5, 95% confidence interval (CI) = 60.0%, 73.0%] than the return-to-player warning label (45.6%, 95% CI = 38.8%, 52.4%, z = 4.22, P < 0.001). Conclusions House-edge warning labels on electronic gambling machines and on-line casino games, which explain what a gambler might expect to lose, could help gamblers to pay greater attention to product risk and would be better understood by gamblers than equivalent return-to-player labels

Anti-PAD4 autoantibodies in rheumatoid arthritis: levels in serum over time and impact on PAD4 activity as measured with a small synthetic substrate

Isoform 4 of the human peptidylarginine deiminase (hPAD4) enzyme may be responsible for the citrullination of antigens in rheumatoid arthritis (RA) and has been shown to be itself the target of disease-specific autoantibodies. Here, we have tested whether the level of serum anti-hPAD4 antibodies in RA patients is stable over a period of 10 years and whether the antibodies influence hPAD4-mediated deimination of the small substrate N-α-Benzoyl-l-arginine ethyl ester. RA sera (n = 128) obtained at baseline and after 10 years were assessed for anti-hPAD4 antibodies by a specific immunoassay. For 118 RA patients, serum anti-hPAD4 IgG levels were stable over 10 years. Seven patients who were negative for anti-PAD4 IgG at baseline had become positive after 10 years. Further, total IgG from selected RA patients and controls were purified, and a fraction was depleted for anti-hPAD4 antibodies. Kinetic deimination assays were performed with total IgG and depleted fractions. The kcat and Km values of hPAD4-mediated deimination of N-α-Benzoyl-l-arginine ethyl ester were not affected by the depletion of the anti-hPAD4 antibodies from the total IgG pool. In conclusion, RA patients remain positive for anti-hPAD4 antibodies over time and some patients who are initially anti-hPAD4 negative become positive later in the disease course. The anti-hPAD4 antibodies did not affect the enzymatic activity of hPAD4 when the small substrate N-α-Benzoyl-l-arginine ethyl ester was used. However, this finding may not exclude an effect of these autoantibodies on citrullination of protein substrates in RA

Limits to the muon flux from WIMP annihilation in the center of the Earth with the AMANDA detector

A search for nearly vertical up-going muon-neutrinos from neutralino annihilations in the center of the Earth has been performed with the AMANDA-B10 neutrino detector. The data sample collected in 130.1 days of live-time in 1997, ~10^9 events, has been analyzed for this search. No excess over the expected atmospheric neutrino background is oberved. An upper limit at 90% confidence level on the annihilation rate of neutralinos in the center of the Earth is obtained as a function of the neutralino mass in the range 100 GeV-5000 GeV, as well as the corresponding muon flux limit.Comment: 14 pages, 11 figures. Version accepted for publication in Physical Review

Visions of Utopia: Sweden, the BBC and the Welfare State

Drawing on manuscripts and transcripts of BBC programme output, and material from the Radio Times, and the BBC’s The Listener magazine, this article analyses radio talks and programmes that focused on Sweden in the immediate years after the Second World War when the Swedish model was widely popularised abroad. The article argues that BBC output entangled domestic politics and transnational ideas around post-war reconstruction and welfare. Sweden was used as a lens through which a modern welfare state could be visualised and justified. This was however Utopia in two senses since the image of Sweden presented was in itself a highly idealised representation

Belief formation in a signaling game without common prior: an experiment

Using belief elicitation, the paper investigates the process of belief formation and evolution in a signaling game in which a common prior is not induced. Both prior and posterior beliefs of Receivers about Senders' types are elicited, as well as beliefs of Senders about Receivers' strategies. In the experiment, subjects often start with diffuse uniform beliefs and update them in view of observations. However, the speed of updating is influenced by the strength of initial beliefs. An interesting result is that beliefs about the prior distribution of types are updated slower than posterior beliefs, which incorporate Senders' strategies. In the medium run, for some specifications of game parameters, this leads to outcomes being significantly different from the outcomes of the game in which a common prior is induced. It is also shown that elicitation of beliefs does not considerably change the pattern of play in this game

IdeS: A Bacterial Proteolytic Enzyme with Therapeutic Potential

Background: IdeS, a proteinase from Streptococcus pyogenes, cleaves immunoglobulin (Ig)G antibodies with a unique degree of specificity. Pathogenic IgG antibodies constitute an important clinical problem contributing to the pathogenesis of a number of autoimmune conditions and acute transplant rejection. To be able to effectively remove such antibodies is therefore an important clinical challenge. Methodology/Principal Findings: IdeS was found to specifically and efficiently cleave IgG in human blood in vitro (20 mg of IdeS caused a complete degradation of IgG in one ml of human whole blood in 15 minutes) and to clear IgG from the blood stream of rabbits in vivo (no IgG was detected six hours following an intravenous injection of 5 mg of IdeS) without any side effects. In a mouse model of immune thrombocytopenic purpura (ITP), polyclonal IgG antibodies against platelet surface antigens were used to induce a lethal disease. These profoundly thrombocytopenic animals were treated and cured by a single injection of IdeS. Conclusions/Significance: Novel information is provided concerning the IgG-cleaving activity of IdeS in vitro and in vivo. The highly specific and rapid elimination of IgG in vivo, the dramatic effect in a mouse model of ITP, and the lack of sid