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Sample records for term electricity spot

  1. A method for short term electricity spot price forecasting

    International Nuclear Information System (INIS)

    Koreneff, G.; Seppaelae, A.; Lehtonen, M.; Kekkonen, V.; Laitinen, E.; Haekli, J.; Antila, E.

    1998-01-01

    In Finland, the electricity market was de-regulated in November 1995. For the electricity purchase of power companies this has caused big changes, since the old tariff based contracts of bulk power supply have been replaced by negotiated bilateral short term contracts and by power purchase from the spot market. In the spot market, in turn, there are at the present two strong actors: The electricity exchange of Finland and the Nordic power pool which is run by the Swedish and Norwegian companies. Today, the power companies in Finland have short term trade with both of the electricity exchanges. The aim of this chapter is to present methods for spot price forecasting in the electricity exchange. The main focus is given to the Finnish circumstances. In the beginning of the presentation, the practices of the electricity exchange of Finland are described, and a brief presentation is given on the different contracts, or electricity products, available in the spot market. For comparison, the practices of the Nordic electricity exchange are also outlined. A time series technique for spot price forecasting is presented. The structure of the model is presented, and its validity is tested using real case data obtained from the Finnish power market. The spot price forecasting model is a part of a computer system for distribution energy management (DEM) in a de-regulated power market

  2. A method for short term electricity spot price forecasting

    Energy Technology Data Exchange (ETDEWEB)

    Koreneff, G; Seppaelae, A; Lehtonen, M; Kekkonen, V [VTT Energy, Espoo (Finland); Laitinen, E; Haekli, J [Vaasa Univ. (Finland); Antila, E [ABB Transmit Oy (Finland)

    1998-08-01

    In Finland, the electricity market was de-regulated in November 1995. For the electricity purchase of power companies this has caused big changes, since the old tariff based contracts of bulk power supply have been replaced by negotiated bilateral short term contracts and by power purchase from the spot market. In the spot market, in turn, there are at the present two strong actors: The electricity exchange of Finland and the Nordic power pool which is run by the Swedish and Norwegian companies. Today, the power companies in Finland have short term trade with both of the electricity exchanges. The aim of this chapter is to present methods for spot price forecasting in the electricity exchange. The main focus is given to the Finnish circumstances. In the beginning of the presentation, the practices of the electricity exchange of Finland are described, and a brief presentation is given on the different contracts, or electricity products, available in the spot market. For comparison, the practices of the Nordic electricity exchange are also outlined. A time series technique for spot price forecasting is presented. The structure of the model is presented, and its validity is tested using real case data obtained from the Finnish power market. The spot price forecasting model is a part of a computer system for distribution energy management (DEM) in a de-regulated power market

  3. Robust estimation and forecasting of the long-term seasonal component of electricity spot prices

    International Nuclear Information System (INIS)

    Nowotarski, Jakub; Tomczyk, Jakub; Weron, Rafał

    2013-01-01

    We present the results of an extensive study on estimation and forecasting of the long-term seasonal component (LTSC) of electricity spot prices. We consider a battery of over 300 models, including monthly dummies and models based on Fourier or wavelet decomposition combined with linear or exponential decay. We find that the considered wavelet-based models are significantly better in terms of forecasting spot prices up to a year ahead than the commonly used monthly dummies and sine-based models. This result questions the validity and usefulness of stochastic models of spot electricity prices built on the latter two types of LTSC models. - Highlights: • First comprehensive study on the forecasting of the long-term seasonal components • Over 300 models examined, including commonly used and new approaches • Wavelet-based models outperform sine-based and monthly dummy models. • Validity of stochastic models built on sines or monthly dummies is questionable

  4. Spot markets vs. long-term contracts - modelling tools for regional electricity generating utilities

    International Nuclear Information System (INIS)

    Grohnheit, P.E.

    1999-01-01

    A properly organised market for electricity requires that some information will be available for all market participants. Also a range of generally available modelling tools are necessary. This paper describes a set of simple models based on published data for analyses of the long-term revenues of regional utilities with combined heat and power generation (CHP), who will operate a competitive international electricity market and a local heat market. The future revenues from trade on the spot market is analysed using a load curve model, in which marginal costs are calculated on the basis of short-term costs of the available units and chronological hourly variations in the demands for electricity and heat. Assumptions on prices, marginal costs and electricity generation by the different types of generating units are studied for selected types of local electricity generators. The long-term revenue requirements to be met by long-term contracts are analysed using a traditional techno-economic optimisation model focusing on technology choice and competition among technologies over 20.30 years. A possible conclusion from this discussion is that it is important for the economic and environmental efficiency of the electricity market that local or regional generators of CHP, who are able to react on price signals, do not conclude long-term contracts that include fixed time-of-day tariff for sale of electricity. Optimisation results for a CHP region (represented by the structure of the Danish electricity and CHP market in 1995) also indicates that a market for CO 2 tradable permits is unlikely to attract major non-fossil fuel technologies for electricity generation, e.g. wind power. (au)

  5. Electricity spot price dynamics: Beyond financial models

    International Nuclear Information System (INIS)

    Guthrie, Graeme; Videbeck, Steen

    2007-01-01

    We reveal properties of electricity spot prices that cannot be captured by the statistical models, commonly used to model financial asset prices, that are increasingly used to model electricity prices. Using more than eight years of half-hourly spot price data from the New Zealand Electricity Market, we find that the half-hourly trading periods fall naturally into five groups corresponding to the overnight off-peak, the morning peak, daytime off-peak, evening peak, and evening off-peak. The prices in different trading periods within each group are highly correlated with each other, yet the correlations between prices in different groups are lower. Models, adopted from the modeling of security prices, that are currently applied to electricity spot prices are incapable of capturing this behavior. We use a periodic autoregression to model prices instead, showing that shocks in the peak periods are larger and less persistent than those in off-peak periods, and that they often reappear in the following peak period. In contrast, shocks in the off-peak periods are smaller, more persistent, and die out (perhaps temporarily) during the peak periods. Current approaches to modeling spot prices cannot capture this behavior either. (author)

  6. A hybrid model for electricity spot prices

    International Nuclear Information System (INIS)

    Anderson, C.L.D.

    2004-01-01

    Electricity prices were highly regulated prior to the deregulation of the electric power industry. Prices were predictable, allowing generators and wholesalers to calculate their production costs and revenues. With deregulation, electricity has become the most volatile of all commodities. Electricity must be consumed as soon as it is generated due to the inability to store it in any sufficient quantity. Economic uncertainty exists because the supply of electricity cannot shift as quickly as the demand, which is highly variable. When demand increases quickly, the price must respond. Therefore, price spikes occur that are orders of magnitude higher than the base electricity price. This paper presents a robust and realistic model for spot market electricity prices used to manage risk in volatile markets. The model is a hybrid of a top down data driven method commonly used for financial applications, and a bottom up system driven method commonly used in regulated electricity markets. The advantage of the model is that it incorporates primary system drivers and demonstrates their effects on final prices. The 4 primary modules of the model are: (1) a model for forced outages, (2) a model for maintenance outages, (3) an electrical load model, and (4) a price model which combines the results of the previous 3 models. The performance of each model was tested. The forced outage model is the first of its kind to simulate the system on an aggregate basis using Weibull distributions. The overall spot price model was calibrated to, and tested with, data from the electricity market in Pennsylvania, New Jersey and Maryland. The model performed well in simulated market prices and adapted readily to changing system conditions and new electricity markets. This study examined the pricing of derivative contracts on electrical power. It also compared a range of portfolio scenarios using a Cash Flow at Risk approach

  7. A hybrid model for electricity spot prices

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, C.L.D.

    2004-07-01

    Electricity prices were highly regulated prior to the deregulation of the electric power industry. Prices were predictable, allowing generators and wholesalers to calculate their production costs and revenues. With deregulation, electricity has become the most volatile of all commodities. Electricity must be consumed as soon as it is generated due to the inability to store it in any sufficient quantity. Economic uncertainty exists because the supply of electricity cannot shift as quickly as the demand, which is highly variable. When demand increases quickly, the price must respond. Therefore, price spikes occur that are orders of magnitude higher than the base electricity price. This paper presents a robust and realistic model for spot market electricity prices used to manage risk in volatile markets. The model is a hybrid of a top down data driven method commonly used for financial applications, and a bottom up system driven method commonly used in regulated electricity markets. The advantage of the model is that it incorporates primary system drivers and demonstrates their effects on final prices. The 4 primary modules of the model are: (1) a model for forced outages, (2) a model for maintenance outages, (3) an electrical load model, and (4) a price model which combines the results of the previous 3 models. The performance of each model was tested. The forced outage model is the first of its kind to simulate the system on an aggregate basis using Weibull distributions. The overall spot price model was calibrated to, and tested with, data from the electricity market in Pennsylvania, New Jersey and Maryland. The model performed well in simulated market prices and adapted readily to changing system conditions and new electricity markets. This study examined the pricing of derivative contracts on electrical power. It also compared a range of portfolio scenarios using a Cash Flow at Risk approach.

  8. A new index for electricity spot markets

    International Nuclear Information System (INIS)

    Falbo, Paolo; Fattore, Marco; Stefani, Silvana

    2010-01-01

    Different indexes are used in electricity markets worldwide to represent the daily behavior of spot prices. However, the peculiarities of these markets require a careful choice of the index, based on mathematical formulation and its statistical properties. Choosing a bad index may influence the financial policies of market players, since derivative pricing and hedging performance can be deeply affected. In this paper with an initial theoretical analysis, we intend to show that the most widely used indexes (simple arithmetic average and weighted average with current volumes) are poor representatives of the spot market. We will then perform an analysis of the hedging strategy on a derivative instrument (an Asian option) written on a reference index. The resulting simulations, applied to OMEL (Spain) and EEX (Germany), are sufficiently clear cut to suggest that the decision to adopt an index to represent properly a market must be taken very carefully. Finally we will propose a new index (FAST index) and, after comparing it with the previous indexes, will show that both theoretically and practically this index can be taken as a good electricity market synthetic indicator.

  9. Competition in electricity spot markets. Economic theory and international experience

    Energy Technology Data Exchange (ETDEWEB)

    Fehr, Nils-Henrik von der; Harbord, David

    1998-09-01

    This publication gives a survey of economic theory and international experience connected to electricity spot markets. The main purpose is to consider the attempts that have been made to apply economic theory and empirical methods to the analysis of electricity markets, and to evaluate them in light of theoretical considerations and empirical evidence. The publication describes in simple terms the basic pool pricing mechanism, and experience with pools in a number of countries. It is worth emphasizing that it is not the purpose to treat in extensive detail the structure of electricity pools around the world. Key factors of the markets in England and Wales, Norway and Australia are described in order to allow for a comparison of design issues and evaluation of competitive performance. 80 refs., 14 figs., 15 tabs.

  10. Stochastic factor model for electricity spot price-the case of the Nordic market

    International Nuclear Information System (INIS)

    Vehvilaeinen, Iivo; Pyykkoenen, Tuomas

    2005-01-01

    This paper presents a stochastic factor based approach to mid-term modeling of spot prices in deregulated electricity markets. The fundamentals affecting the spot price are modeled independently and a market equilibrium model combines them to form spot price. Main advantage of the model is the transparency of the generated prices because each underlying factor and the dynamics between factors can be modeled and studied in detail. Paper shows realistic numerical examples on the forerunner Scandinavian electricity market. The model is used to price an exotic electricity derivative

  11. Stochastic factor model for electricity spot price - the case of the Nordic market

    International Nuclear Information System (INIS)

    Vehvilainen, I.; Pyykkoenen, T.

    2005-01-01

    This paper presents a stochastic factor based approach to mid-term modeling of spot prices in deregulated electricity markets. The fundamentals affecting the spot price are modeled independently and a market equilibrium model combines them to form spot price. Main advantage of the model is the transparency of the generated prices because each underlying factor and the dynamics between factors can be modeled and studied in detail. Paper shows realistic numerical examples on the forerunner Scandinavian electricity market. The model is used to price an exotic electricity derivative. (author)

  12. A rough multi-factor model of electricity spot prices

    International Nuclear Information System (INIS)

    Bennedsen, Mikkel

    2017-01-01

    We introduce a new continuous-time mathematical model of electricity spot prices which accounts for the most important stylized facts of these time series: seasonality, spikes, stochastic volatility, and mean reversion. Empirical studies have found a possible fifth stylized fact, roughness, and our approach explicitly incorporates this into the model of the prices. Our setup generalizes the popular Ornstein–Uhlenbeck-based multi-factor framework of and allows us to perform statistical tests to distinguish between an Ornstein–Uhlenbeck-based model and a rough model. Further, through the multi-factor approach we account for seasonality and spikes before estimating – and making inference on – the degree of roughness. This is novel in the literature and we present simulation evidence showing that these precautions are crucial for accurate estimation. Lastly, we estimate our model on recent data from six European energy exchanges and find statistical evidence of roughness in five out of six markets. As an application of our model, we show how, in these five markets, a rough component improves short term forecasting of the prices. - Highlights: • Statistical modeling of electricity spot prices • Multi-factor decomposition • Roughness • Electricity price forecasting

  13. Parameter estimation of electricity spot models from futures prices

    NARCIS (Netherlands)

    Aihara, ShinIchi; Bagchi, Arunabha; Imreizeeq, E.S.N.; Walter, E.

    We consider a slight perturbation of the Schwartz-Smith model for the electricity futures prices and the resulting modified spot model. Using the martingale property of the modified price under the risk neutral measure, we derive the arbitrage free model for the spot and futures prices. We estimate

  14. Modeling spot markets for electricity and pricing electricity derivatives

    Science.gov (United States)

    Ning, Yumei

    Spot prices for electricity have been very volatile with dramatic price spikes occurring in restructured market. The task of forecasting electricity prices and managing price risk presents a new challenge for market players. The objectives of this dissertation are: (1) to develop a stochastic model of price behavior and predict price spikes; (2) to examine the effect of weather forecasts on forecasted prices; (3) to price electricity options and value generation capacity. The volatile behavior of prices can be represented by a stochastic regime-switching model. In the model, the means of the high-price and low-price regimes and the probabilities of switching from one regime to the other are specified as functions of daily peak load. The probability of switching to the high-price regime is positively related to load, but is still not high enough at the highest loads to predict price spikes accurately. An application of this model shows how the structure of the Pennsylvania-New Jersey-Maryland market changed when market-based offers were allowed, resulting in higher price spikes. An ARIMA model including temperature, seasonal, and weekly effects is estimated to forecast daily peak load. Forecasts of load under different assumptions about weather patterns are used to predict changes of price behavior given the regime-switching model of prices. Results show that the range of temperature forecasts from a normal summer to an extremely warm summer cause relatively small increases in temperature (+1.5%) and load (+3.0%). In contrast, the increases in prices are large (+20%). The conclusion is that the seasonal outlook forecasts provided by NOAA are potentially valuable for predicting prices in electricity markets. The traditional option models, based on Geometric Brownian Motion are not appropriate for electricity prices. An option model using the regime-switching framework is developed to value a European call option. The model includes volatility risk and allows changes

  15. Space-time modeling of electricity spot prices

    DEFF Research Database (Denmark)

    Abate, Girum Dagnachew; Haldrup, Niels

    In this paper we derive a space-time model for electricity spot prices. A general spatial Durbin model that incorporates the temporal as well as spatial lags of spot prices is presented. Joint modeling of space-time effects is necessarily important when prices and loads are determined in a network...... in the spot price dynamics. Estimation of the spatial Durbin model show that the spatial lag variable is as important as the temporal lag variable in describing the spot price dynamics. We use the partial derivatives impact approach to decompose the price impacts into direct and indirect effects and we show...... that price effects transmit to neighboring markets and decline with distance. In order to examine the evolution of the spatial correlation over time, a time varying parameters spot price spatial Durbin model is estimated using recursive estimation. It is found that the spatial correlation within the Nord...

  16. Reliability of copper based alloys for electric resistance spot welding

    International Nuclear Information System (INIS)

    Jovanovicj, M.; Mihajlovicj, A.; Sherbedzhija, B.

    1977-01-01

    Durability of copper based alloys (B-5 and B-6) for electric resistance spot-welding was examined. The total amount of Be, Ni and Zr was up to 2 and 1 wt.% respectively. Good durability and satisfactory quality of welded spots were obtained in previous laboratory experiments carried out on the fixed spot-welding machine of an industrial type (only B-5 alloy was examined). Electrodes made of both B-5 and B-6 alloy were tested on spot-welding grips and fixed spot-welding machines in Tvornica automobila Sarajevo (TAS). The obtained results suggest that the durability of electrodes made of B-5 and B-6 alloys is more than twice better than of that used in TAS

  17. Spikes and memory in (Nord Pool) electricity price spot prices

    DEFF Research Database (Denmark)

    Proietti, Tomasso; Haldrup, Niels; Knapik, Oskar

    Electricity spot prices are subject to transitory sharp movements commonly referred to as spikes. The paper aims at assessing their effects on model based inferences and predictions, with reference to the Nord Pool power exchange. We identify a spike as a price value which deviates substantially...

  18. Forecasting Electricity Spot Prices Accounting for Wind Power Predictions

    DEFF Research Database (Denmark)

    Jónsson, Tryggvi; Pinson, Pierre; Nielsen, Henrik Aalborg

    2013-01-01

    A two-step methodology for forecasting of electricity spot prices is introduced, with focus on the impact of predicted system load and wind power generation. The nonlinear and nonstationary influence of these explanatory variables is accommodated in a first step based on a nonparametric and time...

  19. The relationship between spot and futures prices in the Nord Pool electricity market

    International Nuclear Information System (INIS)

    Botterud, Audun; Kristiansen, Tarjei; Ilic, Marija D.

    2010-01-01

    We analyze 11 years of historical spot- and futures prices from the hydro-dominated Nord Pool electricity market. We find that futures prices tend to be higher than spot prices. The average convenience yield is therefore negative, but varies by season and depends on the storage levels in hydro reservoirs. The average realized return on holding a long position in the futures market is also negative. The negative convenience yield and risk premium contrast empirical findings in most other commodity markets. We argue that differences between the supply and demand sides in terms of risk preferences and the ability to take advantage of short-term price variations can contribute to explain the observed relationship between spot- and futures prices. In addition, our analysis shows that the relationship between spot and futures prices is clearly linked to the physical state of the system, such as hydro inflow, reservoir levels, and demand. (author)

  20. Price dynamics among U.S. electricity spot markets

    International Nuclear Information System (INIS)

    Park, Haesun; Mjelde, James W.; Bessler, David A.

    2006-01-01

    Combining recent advances in causal flows with time series analysis, relationships among 11 U.S. spot market electricity prices are examined. Results suggest that the relationships among the markets vary by time frame. In contemporaneous time, the western markets are separated from the eastern markets and the Electricity Reliability Council of Texas. At longer time frames these separations disappear, even though electricity transmission between the regions is limited. It appears the relationships among markets are not only a function of physical assets (such as transmissions lines among markets), but by similar and dissimilar institutional arrangements among the markets. (Author)

  1. Measuring competitiveness of the EPEX spot market for electricity

    International Nuclear Information System (INIS)

    Graf, Christoph; Wozabal, David

    2013-01-01

    The issue of market concentration in electricity markets and resulting possible anti-competitive behavior of producers is a much discussed topic in many countries. We investigate the day-ahead market for electricity at the EPEX, the largest central European market for electricity. To analyze whether generating companies use their market power to influence prices, we use a conjectural variations approach as well as a direct approach to construct marginal costs of electricity production. Given the available data, we cannot reject the hypothesis that there was no systematic abuse of market power by the suppliers of electricity on the EPEX day-ahead spot market for the years 2007–2010. These results are essentially robust when restricting the sample to high load hours, which are generally considered to be the most prone to market manipulation. -- Highlights: •We investigate the efficiency of the German spot market for electricity. •We employ a conjectural variations approach and a fundamental market model. •Peak load hours and base load hours are analyzed separately. •We find that the market was competitive from 2007 to 2010 for both base and peak hours. •Policies to promote market transparency in Germany can be regarded as successful

  2. Value assessment of hydrogen-based electrical energy storage in view of electricity spot market

    DEFF Research Database (Denmark)

    You, Shi; Hu, Junjie; Zong, Yi

    2016-01-01

    electricity spot market that has high price volatility due to its high share of wind power. An economic dispatch model is developed as a mixed-integer programming (MIP) problem to support the estimation of variable cost of such a system taking into account a good granularity of the technical details. Based...

  3. HMM filtering and parameter estimation of an electricity spot price model

    International Nuclear Information System (INIS)

    Erlwein, Christina; Benth, Fred Espen; Mamon, Rogemar

    2010-01-01

    In this paper we develop a model for electricity spot price dynamics. The spot price is assumed to follow an exponential Ornstein-Uhlenbeck (OU) process with an added compound Poisson process. In this way, the model allows for mean-reversion and possible jumps. All parameters are modulated by a hidden Markov chain in discrete time. They are able to switch between different economic regimes representing the interaction of various factors. Through the application of reference probability technique, adaptive filters are derived, which in turn, provide optimal estimates for the state of the Markov chain and related quantities of the observation process. The EM algorithm is applied to find optimal estimates of the model parameters in terms of the recursive filters. We implement this self-calibrating model on a deseasonalised series of daily spot electricity prices from the Nordic exchange Nord Pool. On the basis of one-step ahead forecasts, we found that the model is able to capture the empirical characteristics of Nord Pool spot prices. (author)

  4. Identifying spikes and seasonal components in electricity spot price data: A guide to robust modeling

    International Nuclear Information System (INIS)

    Janczura, Joanna; Trück, Stefan; Weron, Rafał; Wolff, Rodney C.

    2013-01-01

    An important issue in fitting stochastic models to electricity spot prices is the estimation of a component to deal with trends and seasonality in the data. Unfortunately, estimation routines for the long-term and short-term seasonal pattern are usually quite sensitive to extreme observations, known as electricity price spikes. Improved robustness of the model can be achieved by (a) filtering the data with some reasonable procedure for outlier detection, and then (b) using estimation and testing procedures on the filtered data. In this paper we examine the effects of different treatments of extreme observations on model estimation and on determining the number of spikes (outliers). In particular we compare results for the estimation of the seasonal and stochastic components of electricity spot prices using either the original or filtered data. We find significant evidence for a superior estimation of both the seasonal short-term and long-term components when the data have been treated carefully for outliers. Overall, our findings point out the substantial impact the treatment of extreme observations may have on these issues and, therefore, also on the pricing of electricity derivatives like futures and option contracts. An added value of our study is the ranking of different filtering techniques used in the energy economics literature, suggesting which methods could be and which should not be used for spike identification. - Highlights: • First comprehensive study on the impact of spikes on seasonal pattern estimation • The effects of different treatments of spikes on model estimation are examined. • Cleaning spot prices for outliers yields superior estimates of the seasonal pattern. • Removing outliers provides better parameter estimates for the stochastic process. • Rankings of filtering techniques suggested in the literature are provided

  5. Structuring spot, short and long term gas contracts

    International Nuclear Information System (INIS)

    Gretener, N.M.

    1996-01-01

    A review of the core clauses of the modern natural gas purchase and sales contracts, was presented. There exists a wide variety of terms which can be used by a seller and a buyer to customize such a contract to suit particular circumstances. On the basis of length of term, gas contracts may classified as spot contracts having a term of 30 days or less, short term contracts having a term of 30 days to one to two years, and long term contracts having terms greater than two years. The three key elements which are applicable to all gas sales contracts are the contract price, the seller's obligation to deliver, and the buyer's obligation to accept. Other provisions that may be included in any gas sales contract in addition to the basic three were reviewed, including market pricing, load factor incentive pricing, seasonal pricing, pipeline demand charges, market shares, and the seller's right to decontract

  6. The market value and impact of offshore wind on the electricity spot market: Evidence from Germany

    International Nuclear Information System (INIS)

    Ederer, Nikolaus

    2015-01-01

    Highlights: • Market value of offshore wind based on feed-in and weather data is assessed. • Merit order effect caused by wind energy is simulated for 2006–2014. • Results indicate same impact of on- and offshore wind on market price and value. • Steadier wind resource offshore imposes less variability on market price. • Characteristic of variable wind feed-in cannot be blamed for price deterioration. - Abstract: Although the expansion of offshore wind has recently increased in Germany, as in other countries, it is still forced to defend its role in long-term energy policy plans, particularly against its onshore counterpart, to secure future expansion targets and financial support. The objective of this article is to investigate the economic effects of offshore wind on the electricity spot market and thus open up another perspective that has not been part of the debate about offshore vs. onshore wind thus far. A comprehensive assessment based on a large amount of market, feed-in and weather data in Germany revealed that the market value of offshore wind is generally higher than that of onshore wind. Simulating the merit order effect on the German day-ahead electricity market for the short term and long term in the years 2006–2014 aimed to identify the reason for this observation and show whether it is also an indication of a lower impact on the electricity spot market due to a steadier wind resource prevailing offshore. Although the results suggest no difference regarding the impact on market price and value, they indeed reveal that offshore wind imposes less variability on the spot market price than onshore wind. In addition, the long-term simulation proved that the ongoing price deterioration cannot be blamed on the characteristic of variable wind production

  7. On the correlation of electricity spot market prices and photovoltaic electricity generation

    International Nuclear Information System (INIS)

    Meyer, Tim; Luther, Joachim

    2004-01-01

    Discussions about market introduction of grid connected photovoltaics (PV) and its costs usually concentrate only on the gross energy produced without taking the time dependency of electricity prices and, thus, the time dependency of the value of PV electricity into account. To make a first approximation of what the effect of the time variance of electricity cost on the value of PV electricity is, the correlation with spot market prices is analysed in this paper. PV is not dispatchable by nature, but is relatively well predictable in the range of one day, if the average of spatially dispersed systems is considered. Thus, this correlation gives a good indication for the additional value of PV electricity

  8. On the correlation of electricity spot market prices and photovoltaic electricity generation

    International Nuclear Information System (INIS)

    Meyer, T.; Luther, J.

    2004-01-01

    Discussions about market introduction of grid connected photovoltaics (PV) and its costs usually concentrate only on the gross energy produced without taking the time dependency of electricity prices and, thus, the time dependency of the value of PV electricity into account. To make a first approximation of what the effect of the time variance of electricity cost on the value of PV electricity is, the correlation with spot market prices is analysed in this paper. PV is not dispatchable by nature, but is relatively well predictable in the range of one day, if the average of spatially dispersed systems is considered. Thus, this correlation gives a good indication for the additional value of PV electricity. (Author)

  9. The impact of heat waves on electricity spot markets

    International Nuclear Information System (INIS)

    Pechan, Anna; Eisenack, Klaus

    2014-01-01

    Thermoelectric power plants depend on cooling water drawn from water bodies. Low river run-off and/or high water temperatures limit a plant's production capacity. This problem may intensify with climate change. Our study quantifies the impact of forced capacity reductions on market prices, production costs, consumer and producer surplus, as well as emissions by means of a bottom-up power generation system model. First, we simulate the German electricity spot market during the heat wave of 2006. Then we conduct a sensitivity study that accounts for future climatic and technological conditions. We find an average price increase of 11% during the heat wave 2006, which is even more pronounced during times of peak demand. Production costs accumulate to an additional but moderate 16 m. Due to the price increase, producers gain from the heat wave, whereas consumers disproportionately bear the costs. Carbon emissions in the German electricity sector increase during the heat wave. The price and cost effects are more pronounced and increase significantly if assumptions on heat-sensitive demand, hydropower capacity, net exports, and capacity reductions are tightened. These are potential additional effects of climate change. Hence, if mitigation fails or is postponed globally, the impacts on the current energy system are very likely to rise. Increases in feed-in from renewable resources and demand-side management can counter the effects to a considerable degree. Countries with a shift toward a renewable energy supply can be expected to be much less susceptible to cooling water scarcity than those with a high share of nuclear and coal-fired power plants. - Highlights: • We quantify the impact of thermal capacity reductions on the electricity market. • German heat wave 2006 caused moderate rise in production costs. • Capacity reductions have substantial impact on prices and raise producer surplus. • Impacts on prices, production cost and surplus amplify under climate

  10. Automatic demand response referred to electricity spot price. Demo description

    International Nuclear Information System (INIS)

    Grande, Ove S.; Livik, Klaus; Hals, Arne

    2006-05-01

    This report presents background, technical solution and results from a test project (Demo I) developed in the DRR Norway) project. Software and technology from two different vendors, APAS and Powel ASA, are used to demonstrate a scheme for Automatic Demand Response (ADR) referred to spot price level and a system for documentation of demand response and cost savings. Periods with shortage of energy supply and hardly any investments in new production capacity have turned focus towards the need for increased price elasticity on the demand side in the Nordic power market. The new technology for Automatic Meter Reading (AMR) and Remote Load Control (RLC) provides an opportunity to improve the direct market participation from the demand side by introducing automatic schemes that reduce the need for customer attention to hourly market prices. The low prioritized appliances, and not the total load, are in this report defined as the Demand Response Objects, based on the assumption that there is a limit for what the customers are willing to pay for different uses of electricity. Only disconnection of residential water heaters is included in the demo, due to practical limitations. The test was performed for a group of single family houses over a period of 2 months. All the houses were equipped with a radio controlled 'Ebox' unit attached to the water heater socket. The settlement and invoicing were based on hourly metered values (kWh/h), which means that the customer benefit is equivalent to the accumulated changes in the electricity cost per hour. The actual load reduction is documented by comparison between the real meter values for the period and a reference curve. The curves show significant response to the activated control in the morning hours. In the afternoon it is more difficult to register the response, probably due to 'disturbing' activities like cooking etc. Demo I shows that load reduction referred to spot price level can be done in a smooth way. The experiences

  11. Electricity spot price forecasting in free power market

    International Nuclear Information System (INIS)

    Lilleberg, J.; Laitinen, E.K.

    1998-01-01

    Deregulation has brought many changes to the electricity market. Freedom of choice has been granted to both the consumers and the utilities. Consumers may choose the seller of their energy. Utilities have a wider array of sources to acquire their electricity from. Also the types of sales contracts used are changing to fill the needs of this new situation. The consumers' right to choose has introduced a new risk uncertainty of volume, which was not true during the times of monopoly. As sold volume is unsure and the energy is not sold on same terms as it is bought, a price risk has to be dealt with also. The electric utility has to realize this, select a risk level that suits its business strategy and optimize its actions according to the selected risk level. The number of participants will grow as the electricity market integrates into a common market for Scandinavia and even Europe. Big customers are also taking a more active role in the market, further increasing the number of participants. This makes old bilateral arrangements outdated. New tools are needed to control the new business environment. The goal of this project has been to develop a theoretical model to predict the price in the Finnish electricity exchange, El-Ex Oy. An extensive literature review was conducted in order to (1) examine the solutions in deregulation of electricity markets in other countries, esp. in Norway and UK, (2) find similarities and differences in electricity exchange and exchanges generally and (3) find major sources of problems and inefficiency in the market

  12. Electricity spot price forecasting in free power market

    Energy Technology Data Exchange (ETDEWEB)

    Lilleberg, J; Laitinen, E K [Vaasa Univ. (Finland)

    1998-08-01

    Deregulation has brought many changes to the electricity market. Freedom of choice has been granted to both the consumers and the utilities. Consumers may choose the seller of their energy. Utilities have a wider array of sources to acquire their electricity from. Also the types of sales contracts used are changing to fill the needs of this new situation. The consumers` right to choose has introduced a new risk uncertainty of volume, which was not true during the times of monopoly. As sold volume is unsure and the energy is not sold on same terms as it is bought, a price risk has to be dealt with also. The electric utility has to realize this, select a risk level that suits its business strategy and optimize its actions according to the selected risk level. The number of participants will grow as the electricity market integrates into a common market for Scandinavia and even Europe. Big customers are also taking a more active role in the market, further increasing the number of participants. This makes old bilateral arrangements outdated. New tools are needed to control the new business environment. The goal of this project has been to develop a theoretical model to predict the price in the Finnish electricity exchange, El-Ex Oy. An extensive literature review was conducted in order to (1) examine the solutions in deregulation of electricity markets in other countries, esp. in Norway and UK, (2) find similarities and differences in electricity exchange and exchanges generally and (3) find major sources of problems and inefficiency in the market

  13. The Renewables Influence on Market Splitting: the Iberian Spot Electricity Market

    OpenAIRE

    Nuno Carvalho Figueiredo; Patrícia Pereira da Silva; Pedro Cerqueira

    2014-01-01

    This paper aims to assess the influence of wind power generation on the market splitting behaviour of the Iberian electricity spot markets. We use logit models to express the probability response for market splitting of day-ahead spot electricity prices together with explanatory variables like, wind speed, available transmission capacity and electricity demand. The results show that the probability of market splitting increases with the increase of wind power generation. The European intercon...

  14. Optimal methodology for a machining process scheduling in spot electricity markets

    International Nuclear Information System (INIS)

    Yusta, J.M.; Torres, F.; Khodr, H.M.

    2010-01-01

    Electricity spot markets have introduced hourly variations in the price of electricity. These variations allow the increase of the energy efficiency by the appropriate scheduling and adaptation of the industrial production to the hourly cost of electricity in order to obtain the maximum profit for the industry. In this article a mathematical optimization model simulates costs and the electricity demand of a machining process. The resultant problem is solved using the generalized reduced gradient approach, to find the optimum production schedule that maximizes the industry profit considering the hourly variations of the price of electricity in the spot market. Different price scenarios are studied to analyze the impact of the spot market prices for electricity on the optimal scheduling of the machining process and on the industry profit. The convenience of the application of the proposed model is shown especially in cases of very high electricity prices.

  15. Price signals and investment incentives in wholesale electricity spot markets

    International Nuclear Information System (INIS)

    Vassilopoulos, Philippe

    2007-01-01

    We look at how prices from energy-only power markets can send the right signals and give the correct incentives for investments in production capacity. Through numerical simulations of spot prices over 2003-2005 we compare the investment signal sent by observed electricity prices in France and what would be competitive prices with an optimal mix and with the installed capacity. Observed prices tend to overestimate profitability for the base-load, making the signal too strong and underestimate profitability for the peak load, making the signal too weak. However, as a large share of consumers is still paying regulated tariffs, scarcity rents are capped. We simulate future prices for France for 2010 to 2020 to understand the incentives to invest. When the entry is free, the incentives to invest given by the future prices are consistent with the optimal mix including the interconnections and nuclear build is strong. With political or regulatory barriers to the construction of new power plants for new entrants (i.e. finding new sites), there are no incentives for the incumbent (that owns all existing base-load and peak load capacity) to add more nuclear capacity. In this situation, new entry would have to be coal or gas except if units are bid strategically to maintain profitability and market share. Moreover, it can also be profitable to limit prices and restrain entry in order to receive higher future revenues. When the base-load is less concentrated and instead of a dominant firm the nuclear capacity is divided into five (equal share) firms, the incentives to invest reappear and the threat of entry becomes more credible. (author) [fr

  16. Anti-correlation and multifractal features of Spain electricity spot market

    NARCIS (Netherlands)

    Norouzzadeh, Payam; Dullaert, W.; Rahmani, Bahareh

    2007-01-01

    We use multifractal detrended fluctuation analysis (MF-DFA) to numerically investigate correlation, persistence, multifractal properties and scaling behavior of the hourly spot prices for the Spain electricity exchange-Compania O Peradora del Mercado de Electricidad (OMEL). Through multifractal

  17. Optimal operation strategies of compressed air energy storage (CAES) on electricity spot markets with fluctuating prices

    DEFF Research Database (Denmark)

    Lund, Henrik; Salgi, Georges; Elmegaard, Brian

    2009-01-01

    on electricity spot markets by storing energy when electricity prices are low and producing electricity when prices are high. In order to make a profit on such markets, CAES plant operators have to identify proper strategies to decide when to sell and when to buy electricity. This paper describes three...... plants will not be able to achieve such optimal operation, since the fluctuations of spot market prices in the coming hours and days are not known. Consequently, two simple practical strategies have been identified and compared to the results of the optimal strategy. This comparison shows that...... independent computer-based methodologies which may be used for identifying the optimal operation strategy for a given CAES plant, on a given spot market and in a given year. The optimal strategy is identified as the one which provides the best business-economic net earnings for the plant. In practice, CAES...

  18. The impact of Australian ETS news on wholesale spot electricity prices. An exploratory analysis

    International Nuclear Information System (INIS)

    Chevallier, Julien

    2010-01-01

    This article investigates the impact of news concerning the development of emissions trading in Australia (such as the Carbon Pollution Reduction Scheme (CPRS)) on wholesale electricity spot prices, by using a database of 117 news announcements from December 1, 1998 to July 1, 2009. As power producers constitute the bulk of the participants of the proposed Australian emissions trading scheme, regulatory changes (about allocation, banking, coverage, targets) are indeed likely to affect the five interconnected electricity markets in New South Wales, Queensland, South Australia, Victoria, and Tasmania. We assess these effects with an ARMA(1,1)-GARCH(1,1) model, where daily electricity spot prices are regressed against exogenous variables in the mean and variance equations. This article constitutes the first empirical analysis of Australian ETS news effects on electricity wholesale spot prices. Our results show two asymmetric types of news effects, depending on their information content. (author)

  19. The impact of Australian ETS news on wholesale spot electricity prices. An exploratory analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chevallier, Julien [Universite Paris Dauphine, Place du Marechal de Lattre de Tassigny, 75775 Paris Cedex 16 (France)

    2010-08-15

    This article investigates the impact of news concerning the development of emissions trading in Australia (such as the Carbon Pollution Reduction Scheme (CPRS)) on wholesale electricity spot prices, by using a database of 117 news announcements from December 1, 1998 to July 1, 2009. As power producers constitute the bulk of the participants of the proposed Australian emissions trading scheme, regulatory changes (about allocation, banking, coverage, targets) are indeed likely to affect the five interconnected electricity markets in New South Wales, Queensland, South Australia, Victoria, and Tasmania. We assess these effects with an ARMA(1,1)-GARCH(1,1) model, where daily electricity spot prices are regressed against exogenous variables in the mean and variance equations. This article constitutes the first empirical analysis of Australian ETS news effects on electricity wholesale spot prices. Our results show two asymmetric types of news effects, depending on their information content. (author)

  20. The impact of Australian ETS news on wholesale spot electricity prices: An exploratory analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chevallier, Julien, E-mail: julien.chevallier@dauphine.f [Universite Paris Dauphine, Place du Marechal de Lattre de Tassigny, 75775 Paris Cedex 16 (France)

    2010-08-15

    This article investigates the impact of news concerning the development of emissions trading in Australia (such as the Carbon Pollution Reduction Scheme (CPRS)) on wholesale electricity spot prices, by using a database of 117 news announcements from December 1, 1998 to July 1, 2009. As power producers constitute the bulk of the participants of the proposed Australian emissions trading scheme, regulatory changes (about allocation, banking, coverage, targets) are indeed likely to affect the five interconnected electricity markets in New South Wales, Queensland, South Australia, Victoria, and Tasmania. We assess these effects with an ARMA(1,1)-GARCH(1,1) model, where daily electricity spot prices are regressed against exogenous variables in the mean and variance equations. This article constitutes the first empirical analysis of Australian ETS news effects on electricity wholesale spot prices. Our results show two asymmetric types of news effects, depending on their information content.

  1. Rough electricity: a new fractal multi-factor model of electricity spot prices

    DEFF Research Database (Denmark)

    Bennedsen, Mikkel

    We introduce a new mathematical model of electricity spot prices which accounts for the most important stylized facts of these time series: seasonality, spikes, stochastic volatility and mean reversion. Empirical studies have found a possible fifth stylized fact, fractality, and our approach...... explicitly incorporates this into the model of the prices. Our setup generalizes the popular Ornstein Uhlenbeck-based multi-factor framework of Benth et al. (2007) and allows us to perform statistical tests to distinguish between an Ornstein Uhlenbeck-based model and a fractal model. Further, through...... the multi-factor approach we account for seasonality and spikes before estimating - and making inference on - the degree of fractality. This is novel in the literature and we present simulation evidence showing that these precautions are crucial to accurate estimation. Lastly, we estimate our model...

  2. Analyzing power pools and understanding the spot market based approach to electricity trading

    Energy Technology Data Exchange (ETDEWEB)

    Goulding, D. [Ontario Hydro, Toronto, ON (Canada)

    1997-12-31

    Highlights of the evolution of the electricity industry from franchised monopoly to commoditized markets were presented. Trends in commoditized markets include increased competition, a decline in profit margins and increases in price volatility. Examples of highly regulated industries that have commoditized include long distance telephone, airline and the trucking industries. Models of possible market structures for electricity were reviewed, among them: (1) mandatory one-sided spot market, (2) mandatory spot market, less central control, (3) optional two-sided spot market, and (4) physical bilateral based market. Management of the marketplace regardless of the model used, must assure system security and system reliability and meet real-time demand on the system. Possible roles for the Independent System Operator were discussed. The principal role was predicted to be the operation of an electronic exchange for forward contracts, operation of the spot market, and acting as a clearinghouse for buyers and sellers of forward contracts. 1 tab., 4 figs.

  3. Time-varying convergence in European electricity spot markets and their association with carbon and fuel prices

    International Nuclear Information System (INIS)

    Menezes, Lilian M. de; Houllier, Melanie A.; Tamvakis, Michael

    2016-01-01

    Long-run dynamics of electricity prices are expected to reflect fuel price developments, since fuels generally account for a large share in the cost of generation. As an integrated European market for electricity develops, wholesale electricity prices should be converging as a result of market coupling and increased interconnectivity. Electricity mixes are also changing, spurred by a drive to significantly increase the share of renewables. Consequently, the electricity wholesale price dynamics are evolving, and the fuel–electricity price nexus that has been described in the literature is likely to reflect this evolution. This study investigates associations between spot prices from the British, French and Nordpool markets with those in connected electricity markets and fuel input prices, from December 2005 to October 2013. In order to assess the time-varying dynamics of electricity spot price series, localized autocorrelation functions are used. Electricity spot prices in the three markets are found to have stationary and non-stationary periods. When a trend in spot prices is observed, it is likely to reflect the trend in fuel prices. Cointegration analysis is then used to assess co-movement between electricity spot prices and fuel inputs to generation. The results show that British electricity spot prices are associated with fuel prices and not with price developments in connected markets, while the opposite is observed in the French and Nordpool day-ahead markets. - Highlights: • Electricity market integration policies may have altered EU spot electricity prices. • LACF is used to assess the changing nature of electricity spot prices. • EU electricity spot prices show both stationary and non-stationary periods. • Carbon and fuel prices have greater impact on British spot prices. • In continental Europe, electricity prices have decoupled from fuel prices.

  4. Elspot: Nord Pool Spot Integration in MASCEM Electricity Market Simulator

    DEFF Research Database (Denmark)

    Fernandes, Ricardo; Santos, Gabriel; Praca, Isabel

    2014-01-01

    The energy sector in industrialized countries has been restructured in the last years, with the purpose of decreasing electricity prices through the increase in competition, and facilitating the integration of distributed energy resources. However, the restructuring process increased the complexi...

  5. Forecasting electricity spot-prices using linear univariate time-series models

    International Nuclear Information System (INIS)

    Cuaresma, Jesus Crespo; Hlouskova, Jaroslava; Kossmeier, Stephan; Obersteiner, Michael

    2004-01-01

    This paper studies the forecasting abilities of a battery of univariate models on hourly electricity spot prices, using data from the Leipzig Power Exchange. The specifications studied include autoregressive models, autoregressive-moving average models and unobserved component models. The results show that specifications, where each hour of the day is modelled separately present uniformly better forecasting properties than specifications for the whole time-series, and that the inclusion of simple probabilistic processes for the arrival of extreme price events can lead to improvements in the forecasting abilities of univariate models for electricity spot prices. (Author)

  6. Generation Companies’ Operative Strategies in the Spot Electricity Market

    Directory of Open Access Journals (Sweden)

    Tovar-Hernández J.H.

    2012-07-01

    Full Text Available In traditional regulation the obligation to meet the consumer demand was assumed, this guaranteed to generation companies the full recovery of their costs. However, in order to achieve greater efficiency, reduce the price of electricity, meet the continuously growing electricity consumption, and equalize prices in different regions, a new structure of the electricity industry has been created, where electric energy is traded through a market. Generation company’s future cash flows depend on day to day market participation, in order to satisfy all of their financial and economic requirements. In this paper, future cash flows required to fulfill with economic and financial commitments by a generation company immerse in this new market structure are studied. For this purpose, future cash flows are considered to be dependent on a single asset: electricity. Several scenarios with different fuel prices are generated in order to estimate the generation company’s future cash flows. The response of the competing generation companies is taken into account at each scenario. The fuel price changes are modelled using a concurrent binary tree.

  7. The charging security study of electric vehicle charging spot based on automatic testing platform

    Science.gov (United States)

    Li, Yulan; Yang, Zhangli; Zhu, Bin; Ran, Shengyi

    2018-03-01

    With the increasing of charging spots, the testing of charging security and interoperability becomes more and more urgent and important. In this paper, an interface simulator for ac charging test is designed, the automatic testing platform for electric vehicle charging spots is set up and used to test and analyze the abnormal state during the charging process. On the platform, the charging security and interoperability of ac charging spots and IC-CPD can be checked efficiently, the test report can be generated automatically with No artificial reading error. From the test results, the main reason why the charging spot is not qualified is that the power supply cannot be cut off in the prescribed time when the charging anomaly occurs.

  8. Electricity storages - optimised operation based on spot market prices; Stromspeicher. Optimierte Fahrweise auf Basis der Spotmarktpreise

    Energy Technology Data Exchange (ETDEWEB)

    Bernhard, Dominik; Roon, Serafin von [FfE Forschungsstelle fuer Energiewirtschaft e.V., Muenchen (Germany)

    2010-06-15

    With its integrated energy and climate package the last federal government set itself ambitious goals for the improvement of energy efficiency and growth of renewable energy production. These goals were confirmed by the new government in its coalition agreement. However, they can only be realised if the supply of electricity from fluctuating renewable sources can be made to coincide with electricity demand. Electricity storages are therefore an indispensable component of the future energy supply system. This article studies the optimised operation of an electricity storage based on spot market prices and the influence of wind power production up to the year 2020.

  9. Periodic Seasonal Reg-ARFIMA-GARCH Models for Daily Electricity Spot Prices

    NARCIS (Netherlands)

    Ooms, M.; Koopman, S.J.; Carnero, A.M.

    2007-01-01

    Novel periodic extensions of dynamic long-memory regression models with autoregressive conditional heteroscedastic errors are considered for the analysis of daily electricity spot prices. The parameters of the model with mean and variance specifications are estimated simultaneously by the method of

  10. Forward and Spot Prices in Multi-Settlement Wholesale Electricity Markets

    Science.gov (United States)

    Larrieu, Jeremy

    In organized wholesale electricity markets, power is sold competitively in a multi-unit multi-settlement single-price auction comprised of a forward and a spot market. This dissertation attempts to understand the structure of the forward premium in these markets, and to identify the factors that may lead forward and spot prices to converge or diverge. These markets are unique in that the forward demand is price-sensitive, while spot residual demand is perfectly inelastic and must be met in full, a crucial design feature the literature often glosses over. An important contribution of this dissertation is the explicit modeling of each market separately in order to understand how generation and load choose to act in each one, and the consequences of these actions on equilibrium prices and quantities given that firms maximize joint profits over both markets. In the first essay, I construct a two-settlement model of electricity prices in which firms that own asymmetric capacity-constrained units facing convex costs compete to meet demand from consumers, first in quantities, then in prices. I show that the forward premium depends on the costliness of spot production relative to firms' ability to exercise market power by setting quantities in the forward market. In the second essay, I test the model from the first essay with unit-level capacity and marginal cost data from the California Independent System Operator (CAISO). I show that the model closely replicates observed price formation in the CAISO. In the third essay, I estimate a time series model of the CAISO forward premium in order to measure the impact that virtual bidding has had on forward and spot price convergence in California between April 2009 and March 2014. I find virtual bidding to have caused forward and spot prices to diverge due to the large number of market participants looking to hedge against - or speculate on - the occurrence of infrequent but large spot price spikes by placing virtual demand bids.

  11. Influence of TCSC on congestion and spot price in electricity market with bilateral contract

    International Nuclear Information System (INIS)

    Acharya, Naresh; Mithulananthan, Nadarajah

    2007-01-01

    This paper presents a quantitative analysis of the effect of TCSC on congestion and spot price in deregulated electricity markets. The paper could also be considered as a comprehensive tutorial on the influence of TCSC in electricity market. A voluntary pool market, where the market participants can trade electricity either via a pool or through bilateral contracts is considered. The electricity market is modeled in an optimal power flow framework with the objective of maximizing the social welfare. In such formulation, the Lagrange operators associated with the equality constraints associated with real power balance give the spot prices of energy at each bus of the system. Studies are carried out with and without TCSC at peak and low loading conditions to capture the influence and to see the effectiveness of TCSC at different loading conditions. The paper further explores the effect of TCSC compensation level on the spot prices and the congestion under varying pool and bilateral loading conditions. A 5-bus test system is used for numerical studies and to showcase the influence of TCSC in an electricity market environment. (author)

  12. A bid solicitation and selection method for developing a competitive spot priced electric market

    International Nuclear Information System (INIS)

    Ancona, J.J.

    1997-01-01

    The electric utility industry is in the beginning throes of a transformation from a cost-based regulated structure to a more market based less regulated system. Traditional unit commitment and economic dispatch methodologies can continue to provide reliable least-cost solutions, providing they are modified to accommodate a larger sphere of market participants. This paper offers a method for an entity such as an Independent System Operator (ISO) to solicit and evaluate bids for developing a spot priced electric market by replicating existing utility practices that are effective and efficient, while creating an open and equitable competitive marketplace for electricity

  13. Evaluating the market splitting determinants: evidence from the Iberian spot electricity prices

    International Nuclear Information System (INIS)

    Figueiredo, Nuno Carvalho; Silva, Patrícia Pereira da; Cerqueira, Pedro A.

    2015-01-01

    This paper aims to assess the main determinants on the market splitting behaviour of the Iberian electricity spot markets. Iberia stands as an ideal case-study, where the high level deployment of wind power is observed, together with the implementation of the market splitting arrangement between the Portuguese and the Spanish spot electricity markets. Logit and non-parametric models are used to express the probability response for market splitting of day-ahead spot electricity prices as a function of the explanatory variables representing the main technologies in the generation mix: wind, hydro, thermal and nuclear power, together with the available transfer capacity and electricity demand. Logit models give preliminary indications about market splitting behaviour, and then, notwithstanding the demanding computational challenge, a non-parametric model is applied in order to overcome the limitations of the former models. Results show an increase of market splitting probability with higher wind power generation or, more generally, with higher availability of low marginal cost electricity such as nuclear power generation. The European interconnection capacity target of 10% of the peak demand of the smallest interconnected market might be insufficient to maintain electricity market integration. Therefore, pro-active coordination policies, governing both interconnections and renewables deployment, should be further developed. -- Highlights: •Assess determinants on market splitting behaviour of Iberian electricity markets. •Logit and non-parametric models to express market splitting probability response. •Explanatory variables: wind, hydro, thermal and nuclear power; ATC and demand. •Results: increase of market splitting probability with higher availability of low marginal cost electricity. •Coordination policies governing both interconnections and renewables deployment

  14. Electricity deregulation, spot price patterns and demand-side management

    International Nuclear Information System (INIS)

    Li, Y.; Flynn, P.C.

    2006-01-01

    This paper examines extensive hourly or half-hourly power price data from 14 deregulated power markets. It analyzes average diurnal patterns, relationship to system load, volatility, and consistency over time. Diurnal patterns indicate the average price spread between off-peak and on-peak and weekend vs. weekday power consumption. Volatility is measured by price velocity: the average normalized hourly change in power price, calculated daily. The calculated price velocity is broken down into an expected component that arises from the diurnal pattern and an unexpected component that arises from unknown factors. The analysis reveals significant differences among markets, suggesting that demand-side management (DSM) of power consumption is far more difficult in some markets than in others. At one extreme, Spain, Britain and Scandinavia show consistent diurnal price patterns, a stable relationship between price and system load, and a low unexplained component of price volatility. A power consumer in these markets could form a reasonable expectation of a reward for DSM of elective power consumption. At the other extreme, two markets in Australia show erratic diurnal price patterns from year to year, low correlation between price and system load, and a high amount of unexpected price velocity. A power consumer in these markets would have far greater difficulty in realizing a benefit from DSM. Markets that experienced one period of very high prices without a clear external cause, such as California and Alberta, appear to have a significant longer-term erosion of public support for deregulation. (author)

  15. High penetration wind generation impacts on spot prices in the Australian national electricity market

    International Nuclear Information System (INIS)

    Cutler, Nicholas J.; Boerema, Nicholas D.; MacGill, Iain F.; Outhred, Hugh R.

    2011-01-01

    This paper explores wind power integration issues for the South Australian (SA) region of the Australian National Electricity Market (NEM) by assessing the interaction of regional wind generation, electricity demand and spot prices over 2 recent years of market operation. SA's wind energy penetration has recently surpassed 20% and it has only a limited interconnection with other regions of the NEM. As such, it represents an interesting example of high wind penetration in a gross wholesale pool market electricity industry. Our findings suggest that while electricity demand continues to have the greatest influence on spot prices in SA, wind generation levels have become a significant secondary influence, and there is an inverse relationship between wind generation and price. No clear relationship between wind generation and demand has been identified although some periods of extremely high demand may coincide with lower wind generation. Periods of high wind output are associated with generally lower market prices, and also appear to contribute to extreme negative price events. The results highlight the importance of electricity market and renewable policy design in facilitating economically efficient high wind penetrations. - Highlights: → In South Australia (SA) wind generation is having an influence on market prices. → Little or no correlation is found between wind generation and demand. → Wind farms in SA are receiving a lower average price than in other States. → The results highlight the importance of appropriate electricity market design.

  16. New types of contracts. Part 1. Too high prices on the spot market for electricity

    International Nuclear Information System (INIS)

    Van Gelder, J.W.

    1999-01-01

    In two articles, the state of the art of new types of contract such as swaps, futures and spot contracts is covered. What is the situation of the Dutch deregulating market in this respect? In this first article the focus is on the spot market for electricity, while the second article in the next month's issue will deal with the gas market. Four foreign brokers are active in the Dutch electricity market in addition to Amsterdam Power Exchange (APX). The four major power producing companies, being subject to a Protocol, are not allowed to trade their power directly on the APX. That's why most of the power traded through the APX comes from outside the Netherlands. Thus, the foreign brokers complement the service package of the APX

  17. Transmission of prices and price volatility in Australian electricity spot markets: a multivariate GARCH analysis

    International Nuclear Information System (INIS)

    Worthington, A.; Kay-Spratley, A.; Higgs, H.

    2005-01-01

    This paper examines the transmission of spot electricity prices and price volatility among the five regional electricity markets in the Australian National Electricity Market: namely, New South Wales, Queensland, South Australia, the Snowy Mountains Hydroelectric Scheme and Victoria. A multivariate generalised autoregressive conditional heteroskedasticity model is used to identify the source and magnitude of price and price volatility spillovers. The results indicate the presence of positive own mean spillovers in only a small number of markets and no mean spillovers between any of the markets. This appears to be directly related to the physical transfer limitations of the present system of regional interconnection. Nevertheless, the large number of significant own-volatility and cross-volatility spillovers in all five markets indicates the presence of strong autoregressive conditional heteroskedasticity and generalised autoregressive conditional heteroskedasticity effects. This indicates that shocks in some markets will affect price volatility in others. Finally, and contrary to evidence from studies in North American electricity markets, the results also indicate that Australian electricity spot prices are stationary. (author)

  18. Interactions between the German Electricity Spot Market and the Reserve Energy Market

    International Nuclear Information System (INIS)

    Graeber, Bernhardt

    2005-01-01

    Eight years after market opening, Germany has well established spot and future markets for electricity. Besides OTC and Internet broker platforms the main market place is the European Energy Exchange in Leipzig (EEX) with its spot and future market. Less known is the reserve energy market in Germany. The four German transmission system operators (TSOs) EnBW, EON, RWE and Vattenfall purchase network services on the reserve energy market. Products with specific technical requirements are primary, secondary and tertiary reserve. (Details about the technical requirements and typical means for providing the required services will be presented.) Each TSO organises a separate auction for these products - for primary and secondary reserve half-yearly, for tertiary reserve daily. Due to the technical requirements the liquidity on these markets is limited, but especially on the tertiary reserve market it is recently growing significantly due to new participants marketing several smaller municipal and industrial reserve power plants as combined bids which meet the 30 MW min. capacity requirement. Every power plant or interruptible load could not only be offered as capacity on the reserve market but could also be dispatched for the spot market. Therefore the developments of prices on these markets are not independent and opportunity costs against the spot market can be estimated for different type of plants bidding in the reserve market. Another interaction between reserve and spot market is caused by the balancing price system in Germany. Prices for balancing energy meeting deviations between load, trading balance and production of a market participant are based on quarter-hourly reserve energy costs encountered by the TSO. As unbiased load and production forecasts are not strictly enforced by the TSOs so far, part of the planned demand could be met with balancing energy if EEX spot market prices rise above expected balancing energy prices. This interrelationship has a

  19. Bilateral contracts and the spot market for electricity: some observations on the British and the NordPool experiences

    International Nuclear Information System (INIS)

    Herguera, Inigo

    2000-01-01

    The performance of the futures and the spot market for electricity in England and Wales (EW) and in the Nordic countries have significant differences in terms of volumes traded and evolution of prices. Even though the institutional arrangements show significant differences and the data collected has important limitations we observe in EW for 1990-199 that as the coverage via bilateral contracts diminished, spot prices tended to increase, there was higher price volatility and an increasing number of plants were declared unavailable. In the NordPool, by contrast, market structure is more distributed, the bilateral contract price has tended to smooth the volatility in the spot price and a very diverse pattern behavior of prices has been observed. We interpret these observations as additional support in favor of the theoretical result by and Vila (Journal of Economic Theory 59 (1993) 1), but hint at the possibility of strategies by the firms that can diminish the welfare enhancing properties of this new bilateral market. (Author)

  20. Development of educational Web-based simulator for the electricity spot market in Korea

    International Nuclear Information System (INIS)

    Lee, J.W.; Yang, K.M.; Jeong, Y.W.; Park, J.B.; Shin, J.R.

    2006-01-01

    Market simulation approaches are used frequently by electric utilities to resolve the spot market-related problems that are often encountered in competitive electricity markets. A well constructed market simulator offers the possibility to foresee the effect of new market structures or rules before they are actually implemented. This paper presented a newly developed educational market simulator that simulates the power exchange methods and market rules of the Two Way Bidding Pool (TWBP) in Korea. It allows users to set information related with market and market entities. In particular, it is an educational tool that enables interaction between lecturers and students via Web-based programs. Students can learn the effectiveness of an electricity spot market by bidding and examining the market with lecturers. Measures have been taken to address the problem of multi-users trying to manage the complex data sets. The developed application program is composed of 3 tiers where the middle tier is logically divided into 2 kinds of application programs. The divided application programs are interconnected by using the Web-service based on Extended Markup Technology and Hyper Text Transfer Protocol which make the distributed computing technology possible. Unlike most existing educational simulators, this one has the advantage of allowing students to make bids just like in a real market, thus showing them how the real electricity market runs and how market participants make their revenues. 10 refs., 4 tabs., 13 figs

  1. Development of educational Web-based simulator for the electricity spot market in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.W.; Yang, K.M.; Jeong, Y.W.; Park, J.B.; Shin, J.R. [Konkuk Univ., Seoul (Korea, Republic of). Dept. of Electrical Engineering

    2006-07-01

    Market simulation approaches are used frequently by electric utilities to resolve the spot market-related problems that are often encountered in competitive electricity markets. A well constructed market simulator offers the possibility to foresee the effect of new market structures or rules before they are actually implemented. This paper presented a newly developed educational market simulator that simulates the power exchange methods and market rules of the Two Way Bidding Pool (TWBP) in Korea. It allows users to set information related with market and market entities. In particular, it is an educational tool that enables interaction between lecturers and students via Web-based programs. Students can learn the effectiveness of an electricity spot market by bidding and examining the market with lecturers. Measures have been taken to address the problem of multi-users trying to manage the complex data sets. The developed application program is composed of 3 tiers where the middle tier is logically divided into 2 kinds of application programs. The divided application programs are interconnected by using the Web-service based on Extended Markup Technology and Hyper Text Transfer Protocol which make the distributed computing technology possible. Unlike most existing educational simulators, this one has the advantage of allowing students to make bids just like in a real market, thus showing them how the real electricity market runs and how market participants make their revenues. 10 refs., 4 tabs., 13 figs.

  2. The impact of wind generation on the electricity spot-market price level and variance: The Texas experience

    International Nuclear Information System (INIS)

    Woo, C.K.; Horowitz, I.; Moore, J.; Pacheco, A.

    2011-01-01

    The literature on renewable energy suggests that an increase in intermittent wind generation would reduce the spot electricity market price by displacing high fuel-cost marginal generation. Taking advantage of a large file of Texas-based 15-min data, we show that while rising wind generation does indeed tend to reduce the level of spot prices, it is also likely to enlarge the spot-price variance. The key policy implication is that increasing use of price risk management should accompany expanded deployment of wind generation. - Highlights: → Rising wind generation in ERCOT tends to reduce electricity spot prices. → Rising wind generation in ERCOT is also likely to enlarge the spot-price variance. → Increased price risk management should accompany expanded wind power deployment.

  3. Pricing of reserves. Valuing system reserve capacity against spot prices in electricity markets

    International Nuclear Information System (INIS)

    Just, Sebastian; Weber, Christoph

    2008-01-01

    This paper models the interdependencies between markets for secondary reserve capacity and spot electricity to derive the pricing of reserves under equilibrium conditions. Starting with the indifference condition between offering in both markets, the reservation price is derived from the opportunity cost consideration and the unit commitment conditions in a fundamental interrelated market framework. The reserve market examined compares widely to the German market for secondary reserves, but the general approach may also be used to investigate other reserve markets. The approach explores and formalizes the influence of reserve capacity on the spot market supply function. A numerical solution procedure is provided to this non-trivial case of market interaction. The model is used to estimate the expected reservation price development over the last years in Germany. (author)

  4. Forecasting electricity spot market prices with a k-factor GIGARCH process

    International Nuclear Information System (INIS)

    Diongue, Abdou Ka; Guegan, Dominique; Vignal, Bertrand

    2009-01-01

    In this article, we investigate conditional mean and conditional variance forecasts using a dynamic model following a k-factor GIGARCH process. Particularly, we provide the analytical expression of the conditional variance of the prediction error. We apply this method to the German electricity price market for the period August 15, 2000-December 31, 2002 and we test spot prices forecasts until one-month ahead forecast. The forecasting performance of the model is compared with a SARIMA-GARCH benchmark model using the year 2003 as the out-of-sample. The proposed model outperforms clearly the benchmark model. We conclude that the k-factor GIGARCH process is a suitable tool to forecast spot prices, using the classical RMSE criteria. (author)

  5. Artificial neural networks applied to the prediction of spot prices in the market of electric energy

    International Nuclear Information System (INIS)

    Rodrigues, Alcantaro Lemes; Grimoni, Jose Aquiles Baesso

    2010-01-01

    The commercialization of electricity in Brazil as well as in the world has undergone several changes over the past 20 years. In order to achieve an economic balance between supply and demand of the good called electricity, stakeholders in this market follow both rules set by society (government, companies and consumers) and set by the laws of nature (hydrology). To deal with such complex issues, various studies have been conducted in the area of computational heuristics. This work aims to develop a software to forecast spot market prices in using artificial neural networks (ANN). ANNs are widely used in various applications especially in computational heuristics, where non-linear systems have computational challenges difficult to overcome because of the effect named 'curse of dimensionality'. This effect is due to the fact that the current computational power is not enough to handle problems with such a high combination of variables. The challenge of forecasting prices depends on factors such as: (a) foresee the demand evolution (electric load); (b) the forecast of supply (reservoirs, hydrology and climate), capacity factor; and (c) the balance of the economy (pricing, auctions, foreign markets influence, economic policy, government budget and government policy). These factors are considered be used in the forecasting model for spot market prices and the results of its effectiveness are tested and huge presented. (author)

  6. An empirical comparison of alternate regime-switching models for electricity spot prices

    Energy Technology Data Exchange (ETDEWEB)

    Janczura, Joanna [Hugo Steinhaus Center, Institute of Mathematics and Computer Science, Wroclaw University of Technology, 50-370 Wroclaw (Poland); Weron, Rafal [Institute of Organization and Management, Wroclaw University of Technology, 50-370 Wroclaw (Poland)

    2010-09-15

    One of the most profound features of electricity spot prices are the price spikes. Markov regime-switching (MRS) models seem to be a natural candidate for modeling this spiky behavior. However, in the studies published so far, the goodness-of-fit of the proposed models has not been a major focus. While most of the models were elegant, their fit to empirical data has either been not examined thoroughly or the signs of a bad fit ignored. With this paper we want to fill the gap. We calibrate and test a range of MRS models in an attempt to find parsimonious specifications that not only address the main characteristics of electricity prices but are statistically sound as well. We find that the best structure is that of an independent spike 3-regime model with time-varying transition probabilities, heteroscedastic diffusion-type base regime dynamics and shifted spike regime distributions. Not only does it allow for a seasonal spike intensity throughout the year and consecutive spikes or price drops, which is consistent with market observations, but also exhibits the 'inverse leverage effect' reported in the literature for spot electricity prices. (author)

  7. An empirical comparison of alternate regime-switching models for electricity spot prices

    International Nuclear Information System (INIS)

    Janczura, Joanna; Weron, Rafal

    2010-01-01

    One of the most profound features of electricity spot prices are the price spikes. Markov regime-switching (MRS) models seem to be a natural candidate for modeling this spiky behavior. However, in the studies published so far, the goodness-of-fit of the proposed models has not been a major focus. While most of the models were elegant, their fit to empirical data has either been not examined thoroughly or the signs of a bad fit ignored. With this paper we want to fill the gap. We calibrate and test a range of MRS models in an attempt to find parsimonious specifications that not only address the main characteristics of electricity prices but are statistically sound as well. We find that the best structure is that of an independent spike 3-regime model with time-varying transition probabilities, heteroscedastic diffusion-type base regime dynamics and shifted spike regime distributions. Not only does it allow for a seasonal spike intensity throughout the year and consecutive spikes or price drops, which is consistent with market observations, but also exhibits the 'inverse leverage effect' reported in the literature for spot electricity prices. (author)

  8. Forecasting day ahead electricity spot prices: The impact of the EXAA to other European electricity markets

    OpenAIRE

    Ziel, Florian; Steinert, Rick; Husmann, Sven

    2015-01-01

    In our paper we analyze the relationship between the day-ahead electricity price of the Energy Exchange Austria (EXAA) and other day-ahead electricity prices in Europe. We focus on markets, which settle their prices after the EXAA, which enables traders to include the EXAA price into their calculations. For each market we employ econometric models to incorporate the EXAA price and compare them with their counterparts without the price of the Austrian exchange. By employing a forecasting study...

  9. Are daily and weekly load and spot price dynamics in Australia's National Electricity Market governed by episodic nonlinearity?

    International Nuclear Information System (INIS)

    Wild, Phillip; Hinich, Melvin J.; Foster, John

    2010-01-01

    In this article, we use half hourly spot electricity prices and load data for the National Electricity Market (NEM) of Australia for the period from December 1998 to June 2009 to test for episodic nonlinearity in the dynamics governing daily and weekly cycles in load and spot price time series data. We apply the portmanteau correlation, bicorrelation and tricorrelation tests introduced in Hinich (1996) to the time series of half hourly spot prices and load demand from 7/12/1998 to 30/06/2009 using a FORTRAN 95 program. We find the presence of significant third and fourth-order (nonlinear) serial dependence in the weekly load and spot price data in particular, but to a much more marginal extent, in the daily data. (author)

  10. Modeling of electric and heat processes in spot resistance welding of cross-wire steel bars

    Science.gov (United States)

    Iatcheva, Ilona; Darzhanova, Denitsa; Manilova, Marina

    2018-03-01

    The aim of this work is the modeling of coupled electric and heat processes in a system for spot resistance welding of cross-wire reinforced steel bars. The real system geometry, dependences of material properties on the temperature, and changes of contact resistance and released power during the welding process have been taken into account in the study. The 3D analysis of the coupled AC electric and transient thermal field distributions is carried out using the finite element method. The novel feature is that the processes are modeled for several successive time stages, corresponding to the change of contact area, related contact resistance, and reduction of the released power, occurring simultaneously with the creation of contact between the workpieces. The values of contact resistance and power changes have been determined on the basis of preliminary experimental and theoretical investigations. The obtained results present the electric and temperature field distributions in the system. Special attention has been paid to the temperature evolution at specified observation points and lines in the contact area. The obtained information could be useful for clarification of the complicated nature of interrelated electric, thermal, mechanical, and physicochemical welding processes. Adequate modeling is also an opportunity for proper control and improvement of the system.

  11. An empirical comparison of alternative schemes for combining electricity spot price forecasts

    International Nuclear Information System (INIS)

    Nowotarski, Jakub; Raviv, Eran; Trück, Stefan; Weron, Rafał

    2014-01-01

    In this comprehensive empirical study we critically evaluate the use of forecast averaging in the context of electricity prices. We apply seven averaging and one selection scheme and perform a backtesting analysis on day-ahead electricity prices in three major European and US markets. Our findings support the additional benefit of combining forecasts of individual methods for deriving more accurate predictions, however, the performance is not uniform across the considered markets and periods. In particular, equally weighted pooling of forecasts emerges as a simple, yet powerful technique compared with other schemes that rely on estimated combination weights, but only when there is no individual predictor that consistently outperforms its competitors. Constrained least squares regression (CLS) offers a balance between robustness against such well performing individual methods and relatively accurate forecasts, on average better than those of the individual predictors. Finally, some popular forecast averaging schemes – like ordinary least squares regression (OLS) and Bayesian Model Averaging (BMA) – turn out to be unsuitable for predicting day-ahead electricity prices. - Highlights: • So far the most extensive study on combining forecasts for electricity spot prices • 12 stochastic models, 8 forecast combination schemes and 3 markets considered • Our findings support the additional benefit of combining forecasts for deriving more accurate predictions • Methods that allow for unconstrained weights, such as OLS averaging, should be avoided • We recommend a backtesting exercise to identify the preferred forecast averaging method for the data at hand

  12. Structuring spot, short and long term gas contracts; CD-ROM ed.

    Energy Technology Data Exchange (ETDEWEB)

    Gretener, N.M.

    1996-05-01

    A review of the core clauses of the modern natural gas purchase and sales contracts, was presented. There exists a wide variety of terms which can be used by a seller and a buyer to customize such a contract to suit particular circumstances. On the basis of length of term, gas contracts may classified as spot contracts having a term of 30 days or less, short term contracts having a term of 30 days to one to two years, and long term contracts having terms greater than two years. The three key elements which are applicable to all gas sales contracts are the contract price, the seller`s obligation to deliver, and the buyer`s obligation to accept. Other provisions that may be included in any gas sales contract in addition to the basic three were reviewed, including market pricing, load factor incentive pricing, seasonal pricing, pipeline demand charges, market shares, and the seller`s right to decontract.

  13. Analysis of M-stationary points to an EPEC modeling oligopolistic competition in an electricity spot market

    Czech Academy of Sciences Publication Activity Database

    Henrion, R.; Outrata, Jiří; Surowiec, T.

    2012-01-01

    Roč. 18, č. 2 (2012), s. 295-317 ISSN 1292-8119 R&D Projects: GA ČR GA201/09/1957 Institutional support: RVO:67985556 Keywords : Equilibrium problems with equilibrium constraints * EPEC * M-stationary solutions * electricity spot market * calmness Subject RIV: BA - General Mathematics Impact factor: 1.282, year: 2012 http://library.utia.cas.cz/separaty/2012/MTR/outrata-analysis of m-stationary points to an epec modeling oligopolistic competition in an electricity spot market.pdf

  14. Modelling price and volatility inter-relationships in the Australian wholesale spot electricity markets

    International Nuclear Information System (INIS)

    Higgs, Helen

    2009-01-01

    This paper examines the inter-relationships of wholesale spot electricity prices among the four regional electricity markets in the Australian National Electricity Market (NEM): namely, New South Wales, Queensland, South Australia and Victoria using the constant conditional correlation and Tse and Tsui's (Tse, Y.K., Tsui, A.K.C., 2002. A multivariate generalised autoregressive conditional heteroscedasticity model with time-varying correlations. Journal of Business and Economic Statistics 20 (3), 351-362.) and Engle's (Engle, R., 2002. Dynamic conditional correlation: a sample class of multivariate generalized autoregressive conditional heteroskedasticity models. Journal of Business and Economic Statistics 20 (3), 339-350.) dynamic conditional correlation multivariate GARCH models. Tse and Tsui's (Tse, Y.K., Tsui, A.K.C., 2002. A multivariate generalised autoregressive conditional heteroscedasticity model with time-varying correlations. Journal of Business and Economic Statistics 20 (3), 351-362.) dynamic conditional correlation multivariate GARCH model which takes account of the Student t specification produces the best results. At the univariate GARCH(1,1) level, the mean equations indicate the presence of positive own mean spillovers in all four markets and little evidence of mean spillovers from the other lagged markets. In the dynamic conditional correlation equation, the highest conditional correlations are evident between the well-connected markets indicating the presence of strong interdependence between these markets with weaker interdependence between the not so well-interconnected markets. (author)

  15. Aggregators’ Optimal Bidding Strategy in Sequential Day-Ahead and Intraday Electricity Spot Markets

    Directory of Open Access Journals (Sweden)

    Xiaolin Ayón

    2017-04-01

    Full Text Available This paper proposes a probabilistic optimization method that produces optimal bidding curves to be submitted by an aggregator to the day-ahead electricity market and the intraday market, considering the flexible demand of his customers (based in time dependent resources such as batteries and shiftable demand and taking into account the possible imbalance costs as well as the uncertainty of forecasts (market prices, demand, and renewable energy sources (RES generation. The optimization strategy aims to minimize the total cost of the traded energy over a whole day, taking into account the intertemporal constraints. The proposed formulation leads to the solution of different linear optimization problems, following the natural temporal sequence of electricity spot markets. Intertemporal constraints regarding time dependent resources are fulfilled through a scheduling process performed after the day-ahead market clearing. Each of the different problems is of moderate dimension and requires short computation times. The benefits of the proposed strategy are assessed comparing the payments done by an aggregator over a sample period of one year following different deterministic and probabilistic strategies. Results show that probabilistic strategy reports better benefits for aggregators participating in power markets.

  16. Legal market abuse regulations of WpHG (law on stock trading) and the REMIT-VO in the electricity spot trading

    International Nuclear Information System (INIS)

    Retsch, Alexander T.

    2014-01-01

    The thesis on legal market abuse regulations of WpHG (law on stock trading) and the REMIT-VO in the electricity spot trading include the discussion of the following issues: market abuse, its forms of appearance (market manipulation, insider trade, insider information), electricity spot trading, relevant legislative frame, market abuse regulations (WpHG), interdiction of market manipulation and related regulations.

  17. Stochastic price modeling of high volatility, mean-reverting, spike-prone commodities: The Australian wholesale spot electricity market

    International Nuclear Information System (INIS)

    Higgs, Helen; Worthington, Andrew

    2008-01-01

    It is commonly known that wholesale spot electricity markets exhibit high price volatility, strong mean-reversion and frequent extreme price spikes. This paper employs a basic stochastic model, a mean-reverting model and a regime-switching model to capture these features in the Australian national electricity market (NEM), comprising the interconnected markets of New South Wales, Queensland, South Australia and Victoria. Daily spot prices from 1 January 1999 to 31 December 2004 are employed. The results show that the regime-switching model outperforms the basic stochastic and mean-reverting models. Electricity prices are also found to exhibit stronger mean-reversion after a price spike than in the normal period, and price volatility is more than fourteen times higher in spike periods than in normal periods. The probability of a spike on any given day ranges between 5.16% in NSW and 9.44% in Victoria

  18. How do electricity consumption excluding power intensive manufacturing, react on changes in the spot price?; Hvordan reagerer stroemforbruket i alminnelig forsyning paa endringer i spotpris?

    Energy Technology Data Exchange (ETDEWEB)

    Holstad, Magne; Pettersen, Finn Erik L.

    2011-05-15

    The purpose of this report is to analyse how electricity consumption excluding power intensive manufacturing will react on changes in the spot price on the basis of monthly data of the period 1996-2010 and an econometric error correction model. General consumption accounts for approximately 70 percent of the total net consumption of electricity in Norway. Households, services and other manufacturing than the power intensive account for the majority of this consumption. In order to estimate the net effect of the spot price on general electricity consumption, it is important to control for other variables that also affect the consumption. Since much of the electricity in general consumption is used for heating, one obvious and important explanatory variable is temperature. In addition to electricity price and temperature we assume that general consumption also depends on economic activity, price on light heating oil, the share of working days in the current month and a summer holiday dummy. In the consumption equation price can not be considered as an exogenous explanatory variable, since consumption affects price and vice versa. Hence, we have added a price equation that can be considered as an inverted supply equation. Both the consumption and the supply equation are specified dynamically in order to allow for slow adjustment of supply and consumption. The two equations of the model are estimated by two stage least square (2SLS). Full information maximum likelihood (FIML) is the most efficient estimation method in large samples, but a crucial assumption for consistent FIML-estimation is that the disturbance terms are normally distributed. A Jarque-Bera test of the error terms does not support this assumption in our data. R2 in the consumption equation is high. 96 per cent of the variation in the relative change in consumption is explained. In the price equation R2 is considerably lower. We find that if the spot price for Norway increases by 1 percent from one month

  19. JST Thesaurus Headwords and Synonyms: tomato spotted wilt virus [MeCab user dictionary for science technology term[Archive

    Lifescience Database Archive (English)

    Full Text Available MeCab user dictionary for science technology term tomato spotted wilt virus 名詞 一般 *... * * * トマト黄化壊疽ウイルス トマトオウカエソウイルス トマトーウカエソーイルス Thesaurus2015 200906028155287444 C LS07 UNKNOWN_2 tomato spotted wilt virus

  20. Short-term evolution and coexistence of spots, plages and flare activity on LQ Hydrae

    Science.gov (United States)

    Flores Soriano, M.; Strassmeier, K. G.

    2017-01-01

    Aims: We aim to study the short-term evolution of the chromospheric and photospheric activity of the young, single K2 dwarf LQ Hya. Methods: Four months of quasi-simultaneous spectroscopic and photometric observations were used to study the variations of the photometric light curve, the evolution of the chromospheric activity from the Hα and Hβ lines, and the distribution of cool spots from Doppler maps. Results: During our observations one side of the star was more active than the other. The equivalent width of the Hα line from the least active hemisphere increased from ≈0.7 Å at the beginning of the observation to 1.0 Å at the end. The basal emission of the most active hemisphere remained roughly constant at EWHαt1.0 Å. Intense flare activity was observed during the first twenty days, where at least four different events were detected. The line asymmetries of the Hα line suggest that one of the flares could have produced a mass ejection with a maximum projected speed of 70kms-1. The rotational modulation of the V-band photometry showed clear anti-correlation with the chromospheric activity. The difference in brightness between the opposite hemispheres decreased from 0.m16 to 0.m09 in two months. Three spots gradually moving apart from each other are dominating the photospheric Doppler maps. The comparison between the maps and the Hα line as the star rotates reveals the spatial coexistence of chromospheric Hα emission and photospheric spots. Conclusions: Our results indicate that the active regions of LQ Hya can live for at least four months. The detected changes in the photometric light curve and the spectroscopic Doppler images seem to be more a consequence of the spatial redistribution of the active regions rather than due to changes in their strength. Only one of the active regions shows significant changes in its chromospheric emission. Based on data obtained with the STELLA robotic telescope in Tenerife, an AIP facility jointly operated by AIP

  1. Long-term Spot-Coverage Variations of 13 BY Dra G-K Dwarfs

    Science.gov (United States)

    Alekseev, I. Yu.; Kozhevnikova, A. V.

    2018-06-01

    The results of spot-coverage modeling for 13 active G-K dwarf stars based on many-year photometric observations are presented. The results of UBV RI observations of eight stars performed at the Crimean Astrophysical Observatory were used together with data from the literature in this analysis. The spot-coverage parameters for 13 selected BY Dra active red dwarfs have been redetermined to improve the zonal spot-coverage model for the stellar photospheres, which currently allows for the presence of two active longitudes. Time variations of the spot-activity characteristics of these systems were analyzed with the aim of searching for possible cyclic variations. All the stars, with the exception of OU Gem and BE Cet, show fairly strong correlations between variations in the spot latitudes and spot areas, with absolute values of the correlation coefficients, R(, S), ranging from 0.38 to 0.92. For five stars, an anti-correlation between the mean latitude and area of the spots was found ( R(, S) from-0.24 to-0.73). This behavior may reflect the drift of spots toward the equator in the course of their development. Eight stars feature positive correlations, i.e. the spots drift towards the pole as their areas increase. Nine stars demonstrate activity cycles, which are reflected in photometric variations as well as variations of the spot areas and mean latitudes. The periods of the latitude drift of the spots are found for five stars; the magnitudes of the spot-latitude drift rates are lower than the corresponding value for sunspots by a factor of 1.5-3.

  2. Comparison of extended mean-reversion and time series models for electricity spot price simulation considering negative prices

    International Nuclear Information System (INIS)

    Keles, Dogan; Genoese, Massimo; Möst, Dominik; Fichtner, Wolf

    2012-01-01

    This paper evaluates different financial price and time series models, such as mean reversion, autoregressive moving average (ARMA), integrated ARMA (ARIMA) and general autoregressive conditional heteroscedasticity (GARCH) process, usually applied for electricity price simulations. However, as these models are developed to describe the stochastic behaviour of electricity prices, they are extended by a separate data treatment for the deterministic components (trend, daily, weekly and annual cycles) of electricity spot prices. Furthermore price jumps are considered and implemented within a regime-switching model. Since 2008 market design allows for negative prices at the European Energy Exchange, which also occurred for several hours in the last years. Up to now, only a few financial and time series approaches exist, which are able to capture negative prices. This paper presents a new approach incorporating negative prices. The evaluation of the different approaches presented points out that the mean reversion and the ARMA models deliver the lowest mean root square error between simulated and historical electricity spot prices gained from the European Energy Exchange. These models posses also lower mean average errors than GARCH models. Hence, they are more suitable to simulate well-fitting price paths. Furthermore it is shown that the daily structure of historical price curves is better captured applying ARMA or ARIMA processes instead of mean-reversion or GARCH models. Another important outcome of the paper is that the regime-switching approach and the consideration of negative prices via the new proposed approach lead to a significant improvement of the electricity price simulation. - Highlights: ► Considering negative prices improves the results of time-series and financial models for electricity prices. ► Regime-switching approach captures the jumps and base prices quite well. ► Removing and separate modelling of deterministic annual, weekly and daily

  3. Hot spot model of MagLIF implosions: Nernst term effect on magnetic flux losses

    Science.gov (United States)

    Garcia Rubio, Fernando; Sanz Recio, Javier; Betti, Riccardo

    2016-10-01

    An analytical model of a collisional plasma being compressed by a cylindrical liner is proposed and solved in a magnetized liner inertial fusion-like context. The implosion is assumed to be isobaric, and the magnetic diffusion is confined to a thin layer near the liner. Both unmagnetized and magnetized plasma cases are considered. The model reduces to a system of two partial differential equations for temperature and magnetic field. Special attention is given to the effect of the Nernst term on the evolution of the magnetic field. Scaling laws for temperature, magnetic field, hot spot mass increase and magnetic field losses are obtained. The temperature and magnetic field spatial profiles tend to a self-similar state. It is found that when the Nernst term is taken into account, the magnetic field is advected towards the liner, and the magnetic flux losses are independent of the magnetic Lewis number. Research supported by the Spanish Ministerio de Economía y Competitividad, Project No. ENE2014-54960R. Acknowledgements to the Laboratory of Laser Energetics (Rochester) for its hospitality.

  4. Research on spot power market equilibrium model considering the electric power network characteristics

    International Nuclear Information System (INIS)

    Wang, Chengmin; Jiang, Chuanwen; Chen, Qiming

    2007-01-01

    Equilibrium is the optimum operational condition for the power market by economics rule. A realistic spot power market cannot achieve the equilibrium condition due to network losses and congestions. The impact of the network losses and congestion on spot power market is analyzed in this paper in order to establish a new equilibrium model considering the network loss and transmission constraints. The OPF problem formulated according to the new equilibrium model is solved by means of the equal price principle. A case study on the IEEE-30-bus system is provided in order to prove the effectiveness of the proposed approach. (author)

  5. Long-term impacts of battery electric vehicles on the German electricity system

    Science.gov (United States)

    Heinrichs, H. U.; Jochem, P.

    2016-05-01

    The emerging market for electric vehicles gives rise to an additional electricity demand. This new electricity demand will affect the electricity system. For quantifying those impacts a model-based approach, which covers long-term time horizons is necessary in order to consider the long lasting investment paths in electricity systems and the market development of electric mobility. Therefore, we apply a bottom-up electricity system model showing a detailed spatial resolution for different development paths of electric mobility in Germany until 2030. This model is based on a linear optimization which minimizes the discounted costs of the electricity system. We observe an increase of electricity exchange between countries and electricity generated by renewable energy sources. One major result turns out to be that electric vehicles can be integrated in the electricity system without increasing the system costs when a controlled (postponing) charging strategy for electric vehicles is applied. The impact on the power plant portfolio is insignificant. Another important side effect of electric vehicles is their substantial contribution to decreasing CO2 emissions of the German transport sector. Hence, electric mobility might be an integral part of a sustainable energy system of tomorrow.

  6. Consistent melanophore spot patterns allow long-term individual recognition of Atlantic salmon Salmo salar.

    Science.gov (United States)

    Stien, L H; Nilsson, J; Bui, S; Fosseidengen, J E; Kristiansen, T S; Øverli, Ø; Folkedal, O

    2017-12-01

    The present study shows that permanent melanophore spot patterns in Atlantic salmon Salmo salar make it possible to use images of the operculum to keep track of individual fish over extended periods of their life history. Post-smolt S. salar (n = 246) were initially photographed at an average mass of 98 g and again 10 months later after rearing in a sea cage, at an average mass of 3088 g. Spots that were present initially remained and were the most overt (largest) 10 months later, while new and less overt spots had developed. Visual recognition of spot size and position showed that fish with at least four initial spots were relatively easy to identify, while identifying fish with less than four spots could be challenging. An automatic image analysis method was developed and shows potential for fast match processing of large numbers of fish. The current findings promote visual recognition of opercular spots as a welfare-friendly alternative to tagging in experiments involving salmonid fishes. © The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of The Fisheries Society of the British Isles.

  7. Impacts of subsidized renewable electricity generation on spot market prices in Germany: evidence from a Garch model with panel data

    International Nuclear Information System (INIS)

    Pham, Thao; Lemoine, Killian

    2015-01-01

    Electricity generated by renewable energy sources creates a downward pressure on wholesale prices through - the so-called 'merit order effect'. This effect tends to lower average power prices and average market revenue that renewables producers should have received, making integration costs of renewables very high at large penetration rate. It is therefore crucial to determine the amplitude of this merit order effect particularly in the context of increasing burden of renewable support policies borne by final consumers. Using hourly data for the period 2009-2012 in German electricity wholesale market for GARCH model under panel data framework, we find that wind and solar power generation injected into German electricity network during this period induces a decrease of electricity spot prices and a slight increase of their volatility. The model-based results suggest that the merit-order effect created by renewable production ranges from 3.86 to 8.34 euro/MWh which implies to the annual volume of consumers' surplus from 1.89 to 3.92 billion euros. However this surplus has not been re-distributed equally among different types of electricity consumers. (authors)

  8. Long-term Comparison of a Large Spot Vacuum Assisted Handpiece vs the Small Spot Size Traditional Handpiece of the 800 nm Diode Laser.

    Science.gov (United States)

    Youssef, Nour J; Rizk, Alain G; Ibrahimi, Omar A; Tannous, Zeina S

    2017-09-01

    BACKGROUND The 800 nm long-pulsed diode laser machine is safe and effective for permanent hair reduction. Traditionally, most long-pulsed diode lasers used for hair removal had a relatively small spot size. Recently, a long-pulsed diode laser with a large spot size and vacuum assisted suction handpiece was introduced. The treatment parameters of each type of handpiece differ. Short and long-term clinical efficacy, treatment associated pain, and patient satisfaction are important factors to be considered. This study aims to conduct a direct head to head comparison of both handpieces of the 800nm long-pulsed diode laser by evaluating long term hair reduction, treatment associated pain and patient satisfaction. Thirteen subjects were enrolled in this prospective, self-controlled, single-center study of axillary laser hair removal. The study involved 4 treatments using a long pulsed diode laser with a large spot size HS handpiece (single pass), HS handpiece (double pass), and a small spot size ET handpiece according to a randomized choice. The treatment sessions were done at 4-8 week intervals with follow up visits taken at 6 and 12 months after the last treatment session. Hair clearance and thickness analysis were assessed using macro hair count photographs taken at baseline visit, at each treatment session visit and at follow up visits. Other factors including pain, treatment duration, and patients' preference were secondary study endpoints. At 6 months follow up visits after receiving four laser treatments, there was statistically significant hair clearance in the three treatment arms with 66.1 % mean percentage hair reduction with the ET handpiece, 43.6% with the HSS (single pass) and 64.1 % with the HSD (double). However, at one year follow up, the results significantly varied from the 6 months follow up. The mean percentage hair reduction was 57.8% with the ET handpiece treated axillas (n=9), 16.5% with the HSS (single pass) handpiece treated axillas (n=7), and

  9. A long-term risk management tool for electricity markets using swarm intelligence

    International Nuclear Information System (INIS)

    Azevedo, F.; Vale, Z.A.; Khodr, H.M.; Oliveira, P.B. Moura

    2010-01-01

    This paper addresses the optimal involvement in derivatives electricity markets of a power producer to hedge against the pool price volatility. To achieve this aim, a swarm intelligence meta-heuristic optimization technique for long-term risk management tool is proposed. This tool investigates the long-term opportunities for risk hedging available for electric power producers through the use of contracts with physical (spot and forward contracts) and financial (options contracts) settlement. The producer risk preference is formulated as a utility function (U) expressing the trade-off between the expectation and the variance of the return. Variance of return and the expectation are based on a forecasted scenario interval determined by a long-term price range forecasting model. This model also makes use of particle swarm optimization (PSO) to find the best parameters allow to achieve better forecasting results. On the other hand, the price estimation depends on load forecasting. This work also presents a regressive long-term load forecast model that make use of PSO to find the best parameters as well as in price estimation. The PSO technique performance has been evaluated by comparison with a Genetic Algorithm (GA) based approach. A case study is presented and the results are discussed taking into account the real price and load historical data from mainland Spanish electricity market demonstrating the effectiveness of the methodology handling this type of problems. Finally, conclusions are dully drawn. (author)

  10. Near-Term Electric Vehicle Program. Phase II: Mid-Term Summary Report.

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-08-01

    The Near Term Electric Vehicle (NTEV) Program is a constituent elements of the overall national Electric and Hybrid Vehicle Program that is being implemented by the Department of Energy in accordance with the requirements of the Electric and Hybrid Vehicle Research, Development, and Demonstration Act of 1976. Phase II of the NTEV Program is focused on the detailed design and development, of complete electric integrated test vehicles that incorporate current and near-term technology, and meet specified DOE objectives. The activities described in this Mid-Term Summary Report are being carried out by two contractor teams. The prime contractors for these contractor teams are the General Electric Company and the Garrett Corporation. This report is divided into two discrete parts. Part 1 describes the progress of the General Electric team and Part 2 describes the progress of the Garrett team.

  11. A combined modeling approach for wind power feed-in and electricity spot prices

    International Nuclear Information System (INIS)

    Keles, Dogan; Genoese, Massimo; Möst, Dominik; Ortlieb, Sebastian; Fichtner, Wolf

    2013-01-01

    Wind power generation and its impacts on electricity prices has strongly increased in the EU. Therefore, appropriate mark-to-market evaluation of new investments in wind power and energy storage plants should consider the fluctuant generation of wind power and uncertain electricity prices, which are affected by wind power feed-in (WPF). To gain the input data for WPF and electricity prices, simulation models, such as econometric models, can serve as a data basis. This paper describes a combined modeling approach for the simulation of WPF series and electricity prices considering the impacts of WPF on prices based on an autoregressive approach. Thereby WPF series are firstly simulated for each hour of the year and integrated in the electricity price model to generate an hourly resolved price series for a year. The model results demonstrate that the WPF model delivers satisfying WPF series and that the extended electricity price model considering WPF leads to a significant improvement of the electricity price simulation compared to a model version without WPF effects. As the simulated series of WPF and electricity prices also contain the correlation between both series, market evaluation of wind power technologies can be accurately done based on these series. - Highlights: • Wind power feed-in can be directly simulated with stochastic processes. • Non-linear relationship between wind power feed-in and electricity prices. • Price reduction effect of wind power feed-in depends on the actual load. • Considering wind power feed-in effects improves the electricity price simulation. • Combined modeling of both parameters delivers a data basis for evaluation tools

  12. Near-term electric vehicle program: Phase I, final report

    Energy Technology Data Exchange (ETDEWEB)

    Rowlett, B. H.; Murry, R.

    1977-08-01

    A final report is given for an Energy Research and Development Administration effort aimed at a preliminary design of an energy-efficient electric commuter car. An electric-powered passenger vehicle using a regenerative power system was designed to meet the near-term ERDA electric automobile goals. The program objectives were to (1) study the parameters that affect vehicle performance, range, and cost; (2) design an entirely new electric vehicle that meets performance and economic requirements; and (3) define a program to develop this vehicle design for production in the early 1980's. The design and performance features of the preliminary (baseline) electric-powered passenger vehicle design are described, including the baseline power system, system performance, economic analysis, reliability and safety, alternate designs and options, development plan, and conclusions and recommendations. All aspects of the baseline design were defined in sufficient detail to verify performance expectations and system feasibility.

  13. The effects of habitat, climate, and Barred Owls on long-term demography of Northern Spotted Owls

    Science.gov (United States)

    Dugger, Catherine; Forsman, Eric D.; Franklin, Alan B.; Davis, Raymond J.; White, Gary C.; Schwarz, Carl J.; Burnham, Kenneth P.; Nichols, James D.; Hines, James E.; Yackulic, Charles B.; Doherty, Paul F.; Bailey, Larissa; Clark, Darren A.; Ackers, Steven H.; Andrews, Lawrence S.; Augustine, Benjamin; Biswell, Brian L.; Blakesley, Jennifer; Carlson, Peter C.; Clement, Matthew J.; Diller, Lowell V.; Glenn, Elizabeth M.; Green, Adam; Gremel, Scott A.; Herter, Dale R.; Higley, J. Mark; Hobson, Jeremy; Horn, Rob B.; Huyvaert, Kathryn P.; McCafferty, Christopher; McDonald, Trent; McDonnell, Kevin; Olson, Gail S.; Reid, Janice A.; Rockweit, Jeremy; Ruiz, Viviana; Saenz, Jessica; Sovern, Stan G.

    2016-01-01

    covariates. In contrast, meta-analysis results suggested that Spotted Owl survival was higher across all study areas when the Pacific Decadal Oscillation (PDO) was in a warming phase and the Southern Oscillation Index (SOI) was negative, with a strongly negative SOI indicative of El Niño events. The best model that included the Barred Owl covariate (BO) was ranked 4th and also included the PDO covariate, but the BO effect was strongly negative. Our results indicated that Northern Spotted Owl populations were declining throughout the range of the subspecies and that annual rates of decline were accelerating in many areas. We observed strong evidence that Barred Owls negatively affected Spotted Owl populations, primarily by decreasing apparent survival and increasing local territory extinction rates. However, the amount of suitable owl habitat, local weather, and regional climatic patterns also were related to survival, occupancy (via colonization rate), recruitment, and, to a lesser extent, fecundity, although there was inconsistency in regard to which covariates were important for particular demographic parameters or across study areas. In the study areas where habitat was an important source of variation for Spotted Owl demographics, vital rates were generally positively associated with a greater amount of suitable owl habitat. However, Barred Owl densities may now be high enough across the range of the Northern Spotted Owl that, despite the continued management and conservation of suitable owl habitat on federal lands, the long-term prognosis for the persistence of Northern Spotted Owls may be in question without additional management intervention. Based on our study, the removal of Barred Owls from the Green Diamond Resources (GDR) study area had rapid, positive effects on Northern Spotted Owl survival and the rate of population change, supporting the hypothesis that, along with habitat conservation and management, Barred Owl removal may be able to slow or reverse

  14. MODELADO DEL PRECIO SPOT DE LA ELECTRICIDAD EN BRASIL USANDO UNA RED NEURONAL AUTORREGRESIVA ELECTRICITY SPOT PRICE MODELLING IN BRASIL USING AN AUTOREGRESSIVE NEURAL NETWORK

    Directory of Open Access Journals (Sweden)

    Juan D Velásquez

    2008-12-01

    Full Text Available Una red neuronal autorregresiva es estimada para el precio mensual brasileño de corto plazo de la electricidad, la cual describe mejor la dinámica de los precios que un modelo lineal autorregresivo y que un perceptrón multicapa clásico que usan las mismas entradas y neuronas en la capa oculta. El modelo propuesto es especificado usando un procedimiento estadístico basado en el contraste del radio de verosimilitud. El modelo pasa una batería de pruebas de diagnóstico. El procedimiento de especificación propuesto permite seleccionar el número de unidades en la capa oculta y las entradas a la red neuronal, usando pruebas estadísticas que tienen en cuenta la cantidad de los datos y el ajuste del modelo a la serie de precios. La especificación del modelo final demuestra que el precio para el próximo mes es una función no lineal del precio actual, de la energía afluente actual y de la energía almacenada en el embalse equivalente en el mes actual y dos meses atrás.An autoregressive neural network model is estimated for the monthly Brazilian electricity spot price, which describes the prices dynamics better than a linear autoregressive model and a classical multilayer perceptron using the same input and neurons in the hidden layer. The proposed model is specified using a statistical procedure based on a likelihood ratio test. The model passes a battery of diagnostic tests. The proposed specification procedure allows us to select the number of units in hidden layer and the inputs to the neural network based on statistical tests, taking into account the number of data and the model fitting to the price time series. The final model specification demonstrates that the price for the next month is a nonlinear function of the current price, the current energy inflow, and the energy saved in the equivalent reservoir in the current month and two months ago.

  15. Volatility spillover from world oil spot markets to aggregate and electricity stock index returns in Turkey

    International Nuclear Information System (INIS)

    Soytas, Ugur; Oran, Adil

    2011-01-01

    This study examines the inter-temporal links between world oil prices, ISE 100 and ISE electricity index returns unadjusted and adjusted for market effects. The traditional approaches could not detect a causal relationship running from oil returns to any of the stock returns. However, when we examine the causality using Cheung-Ng approach we discover that world oil prices Granger cause electricity index and adjusted electricity index returns in variance, but not the aggregate market index returns. Hence, our results show that the Cheung-Ng procedure with the use of disaggregated stock index returns can uncover new information that went unnoticed with the traditional causality tests using aggregated market indices. (author)

  16. A study on electricity export capability of the μCHP system with spot price

    DEFF Research Database (Denmark)

    You, Shi; Træholt, Chresten; Poulsen, Bjarne

    2009-01-01

    of the muCHP unit, which influence the export capability of muCHP system, is firstly carried out in the intraday case study, followed by the annual case study which explores the annual system performance. The results show that the electricity export capability of a muCHP system is closely related to its...

  17. Forecasting spot electricity prices : Deep learning approaches and empirical comparison of traditional algorithms

    NARCIS (Netherlands)

    Lago Garcia, J.; De Ridder, Fjo; De Schutter, B.H.K.

    2018-01-01

    In this paper, a novel modeling framework for forecasting electricity prices is proposed. While many predictive models have been already proposed to perform this task, the area of deep learning algorithms remains yet unexplored. To fill this scientific gap, we propose four different deep learning

  18. Multistate Models Reveal Long-Term Trends of Northern Spotted Owls in the Absence of a Novel Competitor.

    Directory of Open Access Journals (Sweden)

    Andrew J Kroll

    Full Text Available Quantifying spatial and temporal variability in population trends is a critical aspect of successful management of imperiled species. We evaluated territory occupancy dynamics of northern spotted owls (Strix occidentalis caurina, California, USA, 1990-2014. The study area possessed two unique aspects. First, timber management has occurred for over 100 years, resulting in dramatically different forest successional and structural conditions compared to other areas. Second, the barred owl (Strix varia, an exotic congener known to exert significant negative effects on spotted owls, has not colonized the study area. We used a Bayesian dynamic multistate model to evaluate if territory occupancy of reproductive spotted owls has declined as in other study areas. The state-space approach for dynamic multistate modeling imputes the number of territories for each nesting state and allows for the estimation of longer-term trends in occupied or reproductive territories from longitudinal studies. The multistate approach accounts for different detection probabilities by nesting state (to account for either inherent differences in detection or for the use of different survey methods for different occupancy states and reduces bias in state assignment. Estimated linear trends in the number of reproductive territories suggested an average loss of approximately one half territory per year (-0.55, 90% CRI: -0.76, -0.33, in one management block and a loss of 0.15 per year (-0.15, 90% CRI: -0.24, -0.07, in another management block during the 25 year observation period. Estimated trends in the third management block were also negative, but substantial uncertainty existed in the estimate (-0.09, 90% CRI: -0.35, 0.17. Our results indicate that the number of territories occupied by northern spotted owl pairs remained relatively constant over a 25 year period (-0.07, 90% CRI: -0.20, 0.05; -0.01, 90% CRI: -0.19, 0.16; -0.16, 90% CRI: -0.40, 0.06. However, we cannot exclude

  19. Multistate Models Reveal Long-Term Trends of Northern Spotted Owls in the Absence of a Novel Competitor.

    Science.gov (United States)

    Kroll, Andrew J; Jones, Jay E; Stringer, Angela B; Meekins, Douglas J

    2016-01-01

    Quantifying spatial and temporal variability in population trends is a critical aspect of successful management of imperiled species. We evaluated territory occupancy dynamics of northern spotted owls (Strix occidentalis caurina), California, USA, 1990-2014. The study area possessed two unique aspects. First, timber management has occurred for over 100 years, resulting in dramatically different forest successional and structural conditions compared to other areas. Second, the barred owl (Strix varia), an exotic congener known to exert significant negative effects on spotted owls, has not colonized the study area. We used a Bayesian dynamic multistate model to evaluate if territory occupancy of reproductive spotted owls has declined as in other study areas. The state-space approach for dynamic multistate modeling imputes the number of territories for each nesting state and allows for the estimation of longer-term trends in occupied or reproductive territories from longitudinal studies. The multistate approach accounts for different detection probabilities by nesting state (to account for either inherent differences in detection or for the use of different survey methods for different occupancy states) and reduces bias in state assignment. Estimated linear trends in the number of reproductive territories suggested an average loss of approximately one half territory per year (-0.55, 90% CRI: -0.76, -0.33), in one management block and a loss of 0.15 per year (-0.15, 90% CRI: -0.24, -0.07), in another management block during the 25 year observation period. Estimated trends in the third management block were also negative, but substantial uncertainty existed in the estimate (-0.09, 90% CRI: -0.35, 0.17). Our results indicate that the number of territories occupied by northern spotted owl pairs remained relatively constant over a 25 year period (-0.07, 90% CRI: -0.20, 0.05; -0.01, 90% CRI: -0.19, 0.16; -0.16, 90% CRI: -0.40, 0.06). However, we cannot exclude small

  20. Legal market abuse regulations of WpHG (law on stock trading) and the REMIT-VO in the electricity spot trading; Marktmissbrauchsrechtliche Regelungen des WpHG und der REMIT-VO im Stromspothandel

    Energy Technology Data Exchange (ETDEWEB)

    Retsch, Alexander T.

    2014-07-01

    The thesis on legal market abuse regulations of WpHG (law on stock trading) and the REMIT-VO in the electricity spot trading include the discussion of the following issues: market abuse, its forms of appearance (market manipulation, insider trade, insider information), electricity spot trading, relevant legislative frame, market abuse regulations (WpHG), interdiction of market manipulation and related regulations.

  1. Long-term uncertainty evaluation of pool electricity markets

    International Nuclear Information System (INIS)

    Alvarez Lopez, Juan; Ponnambalam, Kumaraswamy

    2010-01-01

    Pool electricity markets are cleared under the strong assumption of having a perfectly known future; in real life, this is anything but true. The inability to predict the random parameters of the supply and the demand function introduces risk into the market clearing process. Therefore, the main interest is to minimize such risk by means of a trade-off of the mean and the variance of the social cost function. This paper considers random variations on the levels and on the slopes of the quadratic supply and demand functions. Correlation is considered between the corresponding coefficients of the supply and demand curves. By means of the mean-variance Markowitz theory, the risk introduced by these random variations is analyzed. A comprehensive analysis on the effects that the mean-variance Markowitz theory has on the nodal spot prices and on the point-elasticities of the supply and demand curves is made. The non-linear optimization model presented in this paper is validated through a three-, a six-, and a 21-node system. (author)

  2. Long-term uncertainty evaluation of pool electricity markets

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez Lopez, Juan [Network Analysis Department, Electric Research Institute (Mexico); Ponnambalam, Kumaraswamy [Systems Design Engineering, University of Waterloo, 200 University Ave. West, N2L 3G1, Waterloo, Ontario (Canada)

    2010-02-15

    Pool electricity markets are cleared under the strong assumption of having a perfectly known future; in real life, this is anything but true. The inability to predict the random parameters of the supply and the demand function introduces risk into the market clearing process. Therefore, the main interest is to minimize such risk by means of a trade-off of the mean and the variance of the social cost function. This paper considers random variations on the levels and on the slopes of the quadratic supply and demand functions. Correlation is considered between the corresponding coefficients of the supply and demand curves. By means of the mean-variance Markowitz theory, the risk introduced by these random variations is analyzed. A comprehensive analysis on the effects that the mean-variance Markowitz theory has on the nodal spot prices and on the point-elasticities of the supply and demand curves is made. The non-linear optimization model presented in this paper is validated through a three-, a six-, and a 21-node system. (author)

  3. Liver spots

    Science.gov (United States)

    ... skin changes - liver spots; Senile or solar lentigines; Skin spots - aging; Age spots ... Liver spots are changes in skin color that occur in older skin. The coloring may be due to aging, exposure to the sun ...

  4. Short-term electric load forecasting using computational intelligence methods

    OpenAIRE

    Jurado, Sergio; Peralta, J.; Nebot, Àngela; Mugica, Francisco; Cortez, Paulo

    2013-01-01

    Accurate time series forecasting is a key issue to support individual and organizational decision making. In this paper, we introduce several methods for short-term electric load forecasting. All the presented methods stem from computational intelligence techniques: Random Forest, Nonlinear Autoregressive Neural Networks, Evolutionary Support Vector Machines and Fuzzy Inductive Reasoning. The performance of the suggested methods is experimentally justified with several experiments carried out...

  5. Long-term memory in electricity prices: Czech market evidence

    Czech Academy of Sciences Publication Activity Database

    Krištoufek, Ladislav; Luňáčková, P.

    2013-01-01

    Roč. 63, č. 5 (2013), s. 407-424 ISSN 0015-1920 R&D Projects: GA ČR GA402/09/0965 Grant - others:GA ČR(CZ) GAP402/11/0948 Program:GA Institutional support: RVO:67985556 Keywords : electricity * long-term memory Subject RIV: AH - Economics Impact factor: 0.358, year: 2013 http://library.utia.cas.cz/separaty/2014/E/kristoufek-0427660.pdf

  6. Short-term electric power demand forecasting based on economic-electricity transmission model

    Science.gov (United States)

    Li, Wenfeng; Bai, Hongkun; Liu, Wei; Liu, Yongmin; Wang, Yubin Mao; Wang, Jiangbo; He, Dandan

    2018-04-01

    Short-term electricity demand forecasting is the basic work to ensure safe operation of the power system. In this paper, a practical economic electricity transmission model (EETM) is built. With the intelligent adaptive modeling capabilities of Prognoz Platform 7.2, the econometric model consists of three industrial added value and income levels is firstly built, the electricity demand transmission model is also built. By multiple regression, moving averages and seasonal decomposition, the problem of multiple correlations between variables is effectively overcome in EETM. The validity of EETM is proved by comparison with the actual value of Henan Province. Finally, EETM model is used to forecast the electricity consumption of the 1-4 quarter of 2018.

  7. Electricity demand and spot price forecasting using evolutionary computation combined with chaotic nonlinear dynamic model

    International Nuclear Information System (INIS)

    Unsihuay-Vila, C.; Zambroni de Souza, A.C.; Marangon-Lima, J.W.; Balestrassi, P.P.

    2010-01-01

    This paper proposes a new hybrid approach based on nonlinear chaotic dynamics and evolutionary strategy to forecast electricity loads and prices. The main idea is to develop a new training or identification stage in a nonlinear chaotic dynamic based predictor. In the training stage five optimal parameters for a chaotic based predictor are searched through an optimization model based on evolutionary strategy. The objective function of the optimization model is the mismatch minimization between the multi-step-ahead forecasting of predictor and observed data such as it is done in identification problems. The first contribution of this paper is that the proposed approach is capable of capturing the complex dynamic of demand and price time series considered resulting in a more accuracy forecasting. The second contribution is that the proposed approach run on-line manner, i.e. the optimal set of parameters and prediction is executed automatically which can be used to prediction in real-time, it is an advantage in comparison with other models, where the choice of their input parameters are carried out off-line, following qualitative/experience-based recipes. A case study of load and price forecasting is presented using data from New England, Alberta, and Spain. A comparison with other methods such as autoregressive integrated moving average (ARIMA) and artificial neural network (ANN) is shown. The results show that the proposed approach provides a more accurate and effective forecasting than ARIMA and ANN methods. (author)

  8. A study of the long-term properties of Jovian hot spots from HST and ground-based observations between 1994 and 1998

    Science.gov (United States)

    Arregui, E.; Rojas, J. F.; Sanchez-Lavega, A.; Lecacheux, J.; Colas, F.; Miyazaki, I.; Parker, D.

    2000-10-01

    We have used the HST-WFPC2 archived images of Jupiter in the period 1994-1998 together with a large set of CCD ground based images, to study the zonal distribution, long-term motions, lifetimes, interactions and other properties of the hot spot - plume regions at 7 degrees North. Red and near infrared filters covering the wavelength range 650 - 953 nm have been used since they show the hot spots with a high contrast. We have found that the hot spots have velocities ranging from 95 to 112 m/s and are grouped typically in families of three to six members. We do not found any correlation between their velocity and wavenumber. The long-term survey allowed us to identify mergers and splitting of the hot spots areas. The Spanish team was supported by Gobierno Vasco PI 034/97. The French team was supported by the "Programme National de Planetologie."

  9. Stacking Ensemble Learning for Short-Term Electricity Consumption Forecasting

    Directory of Open Access Journals (Sweden)

    Federico Divina

    2018-04-01

    Full Text Available The ability to predict short-term electric energy demand would provide several benefits, both at the economic and environmental level. For example, it would allow for an efficient use of resources in order to face the actual demand, reducing the costs associated to the production as well as the emission of CO 2 . To this aim, in this paper we propose a strategy based on ensemble learning in order to tackle the short-term load forecasting problem. In particular, our approach is based on a stacking ensemble learning scheme, where the predictions produced by three base learning methods are used by a top level method in order to produce final predictions. We tested the proposed scheme on a dataset reporting the energy consumption in Spain over more than nine years. The obtained experimental results show that an approach for short-term electricity consumption forecasting based on ensemble learning can help in combining predictions produced by weaker learning methods in order to obtain superior results. In particular, the system produces a lower error with respect to the existing state-of-the art techniques used on the same dataset. More importantly, this case study has shown that using an ensemble scheme can achieve very accurate predictions, and thus that it is a suitable approach for addressing the short-term load forecasting problem.

  10. Modeling long-term dynamics of electricity markets

    International Nuclear Information System (INIS)

    Olsina, Fernando; Garces, Francisco; Haubrich, H.-J.

    2006-01-01

    In the last decade, many countries have restructured their electricity industries by introducing competition in their power generation sectors. Although some restructuring has been regarded as successful, the short experience accumulated with liberalized power markets does not allow making any founded assertion about their long-term behavior. Long-term prices and long-term supply reliability are now center of interest. This concerns firms considering investments in generation capacity and regulatory authorities interested in assuring the long-term supply adequacy and the stability of power markets. In order to gain significant insight into the long-term behavior of liberalized power markets, in this paper, a simulation model based on system dynamics is proposed and the underlying mathematical formulations extensively discussed. Unlike classical market models based on the assumption that market outcomes replicate the results of a centrally made optimization, the approach presented here focuses on replicating the system structure of power markets and the logic of relationships among system components in order to derive its dynamical response. The simulations suggest that there might be serious problems to adjust early enough the generation capacity necessary to maintain stable reserve margins, and consequently, stable long-term price levels. Because of feedback loops embedded in the structure of power markets and the existence of some time lags, the long-term market development might exhibit a quite volatile behavior. By varying some exogenous inputs, a sensitivity analysis is carried out to assess the influence of these factors on the long-run market dynamics

  11. Long-term Nash equilibria in electricity markets

    International Nuclear Information System (INIS)

    Pozo, David; Contreras, Javier; Caballero, Angel; de Andres, Antonio

    2011-01-01

    In competitive electricity markets, companies simultaneously offer their productions to obtain the maximum profits on a daily basis. In the long run, the strategies utilized by the electric companies lead to various long-term equilibria that can be analyzed with the appropriate tools. We present a methodology to find plausible long-term Nash equilibria in pool-based electricity markets. The methodology is based on an iterative market Nash equilibrium model in which the companies can decide upon their offer strategies. An exponential smoothing of the bids submitted by the companies is applied to facilitate the convergence of the iterative procedure. In each iteration of the model the companies face residual demand curves that are accurately modeled by Hermite interpolating polynomials. We introduce the concept of meta-game equilibrium strategies to allow companies to have a range of offer strategies where several pure and mixed meta-game Nash equilibria are possible. With our model it is also possible to model uncertainty or to generate price scenarios for financial models that assess the value of a generating unit by real options analysis. The application of the proposed methodology is illustrated with several realistic case studies. (author)

  12. Near-term electric-vehicle program. Phase II. Mid-term review summary report

    Energy Technology Data Exchange (ETDEWEB)

    1978-07-27

    The general objective of the Near-Term Electric Vehicle Program is to confirm that, in fact, the complete spectrum of requirements placed on the automobile (e.g., safety, producibility, utility, etc.) can still be satisfied if electric power train concepts are incorporated in lieu of contemporary power train concepts, and that the resultant set of vehicle characteristics are mutually compatible, technologically achievable, and economically achievable. The focus of the approach to meeting this general objective involves the design, development, and fabrication of complete electric vehicles incorporating, where necessary, extensive technological advancements. A mid-term summary is presented of Phase II which is a continuation of the preliminary design study conducted in Phase I of the program. Information is included on vehicle performance and performance simulation models; battery subsystems; control equipment; power systems; vehicle design and components for suspension, steering, and braking; scale model testing; structural analysis; and vehicle dynamics analysis. (LCL)

  13. Artificial neural networks applied to the prediction of spot prices in the market of electric energy; Redes neurais artificiais aplicadas na previsao de precos spot no mercado de energia eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Alcantaro Lemes; Grimoni, Jose Aquiles Baesso [Univesidade de Sao Paulo (USP), SP (Brazil). Inst. de Eletrotecnica e Energia], emails: alcantaro@iee.usp.br, aquiles@iee.usp.br

    2010-07-01

    The commercialization of electricity in Brazil as well as in the world has undergone several changes over the past 20 years. In order to achieve an economic balance between supply and demand of the good called electricity, stakeholders in this market follow both rules set by society (government, companies and consumers) and set by the laws of nature (hydrology). To deal with such complex issues, various studies have been conducted in the area of computational heuristics. This work aims to develop a software to forecast spot market prices in using artificial neural networks (ANN). ANNs are widely used in various applications especially in computational heuristics, where non-linear systems have computational challenges difficult to overcome because of the effect named 'curse of dimensionality'. This effect is due to the fact that the current computational power is not enough to handle problems with such a high combination of variables. The challenge of forecasting prices depends on factors such as: (a) foresee the demand evolution (electric load); (b) the forecast of supply (reservoirs, hydrology and climate), capacity factor; and (c) the balance of the economy (pricing, auctions, foreign markets influence, economic policy, government budget and government policy). These factors are considered be used in the forecasting model for spot market prices and the results of its effectiveness are tested and huge presented. (author)

  14. Effects of long-term contracts on firms exercising market power in transmission constrained electricity markets

    International Nuclear Information System (INIS)

    Nam, Young Woo; Yoon, Yong Tae; Park, Jong-Keun; Hur, Don; Kim, Sung-Soo

    2006-01-01

    The electricity markets with only few large firms are often vulnerable to less competitive behaviors than the desired. The presence of transmission constraints further restrict the competition among firms and provide more opportunities for firms to exercise market power. While it is generally acknowledged that the long-term contracts provide good measures for mitigating market power in the spot market (thus reducing undesired price spikes), it is not even more clear how effective these contracts are if the market is severely limited due to transmission constraints. In this paper, an analytical approach through finding a Nash equilibrium is presented to investigate the effects of long-term contracts on firms exercising market power in a bid-based pool with transmission constraints. Surprisingly the analysis in this paper shows that the presence of long-term contracts may result in the reduced expected social welfare. A straightforward consequence of the analysis presented in this paper will be helpful for the regulators in Korea to reconsider offering vesting contracts to generating companies in the near future. (author)

  15. Electric power from near-term fusion reactors

    International Nuclear Information System (INIS)

    Longhurst, G.R.; Deis, G.A.; Miller, L.G.

    1981-01-01

    This paper examines requirements and possbilities of electric power production on near-term fusion reactors using low temperature cycle technology similar to that used in some geothermal power systems. Requirements include the need for a working fluid with suitable thermodynamics properties and which is free of oxygen and hydrogen to facilitate tritium management. Thermal storage will also be required due to the short system thermal time constants on near-time reactors. It is possbile to use the FED shield in a binary power cycle, and results are presented of thermodynamic analyses of this system

  16. Spots on electrodes and images of a gap during pulsed discharges in an inhomogeneous electric field at elevated pressures of air, nitrogen and argon

    International Nuclear Information System (INIS)

    Shao, Tao; Yang, Wenjin; Zhang, Cheng; Yan, Ping; Tarasenko, Victor F; Beloplotov, Dmitry V; Lomaev, Mikhail I; Sorokin, Dmitry A

    2014-01-01

    Pulsed discharge in a nonuniform electric field accompanied by the appearance of bright spots due to explosive electron emission on electrodes has been investigated. The experiments were carried out using three experimental setups, a voltage pulse duration at a matched load of 2 ns, 40 ns, and 130 ns, respectively. Data on the formation of electrode spots during diffuse discharges in tube-plate or needle-plate gap configurations filled with gases at elevated pressures (air, nitrogen and argon) were obtained. It was found that in the air and other gases, bright spots arise on the flat electrode, and on the negative polarity of the electrode with a small radius of curvature, during the direction change of the current through the gap and the increase of the voltage pulse duration. It was shown that at the positive polarity of the electrode with a small radius of curvature, bright spots on the flat electrode arise due to the participation of the dynamic displacement current in the gap conductance. (paper)

  17. Australia's long-term electricity demand forecasting using deep neural networks

    OpenAIRE

    Hamedmoghadam, Homayoun; Joorabloo, Nima; Jalili, Mahdi

    2018-01-01

    Accurate prediction of long-term electricity demand has a significant role in demand side management and electricity network planning and operation. Demand over-estimation results in over-investment in network assets, driving up the electricity prices, while demand under-estimation may lead to under-investment resulting in unreliable and insecure electricity. In this manuscript, we apply deep neural networks to predict Australia's long-term electricity demand. A stacked autoencoder is used in...

  18. The merit-order effect: A detailed analysis of the price effect of renewable electricity generation on spot market prices in Germany

    International Nuclear Information System (INIS)

    Sensfuss, Frank; Ragwitz, Mario; Genoese, Massimo

    2008-01-01

    The German feed-in support of electricity generation from renewable energy sources has led to high growth rates of the supported technologies. Critics state that the costs for consumers are too high. An important aspect to be considered in the discussion is the price effect created by renewable electricity generation. This paper seeks to analyse the impact of privileged renewable electricity generation on the electricity market in Germany. The central aspect to be analysed is the impact of renewable electricity generation on spot market prices. The results generated by an agent-based simulation platform indicate that the financial volume of the price reduction is considerable. In the short run, this gives rise to a distributional effect which creates savings for the demand side by reducing generator profits. In the case of the year 2006, the volume of the merit-order effect exceeds the volume of the net support payments for renewable electricity generation which have to be paid by consumers. (author)

  19. Short-term occupancy and abundance dynamics of the Oregon spotted frog (Rana pretiosa) across its core range

    Science.gov (United States)

    Adams, Michael J.; Pearl, Christopher A.; Mccreary, Brome; Galvan, Stephanie

    2014-01-01

    The Oregon spotted frog (Rana pretiosa) occupies only a fraction of its original range and is listed as Threatened under the Endangered Species Act. We surveyed 93 sites in a rotating frame design (2010–13) in the Klamath and Deschutes Basins, Oregon, which encompass most of the species’ core extant range. Oregon spotted frogs are declining in abundance and probability of site occupancy. We did not find an association between the probability that Oregon spotted frogs disappear from a site (local extinction) and any of the variables hypothesized to affect Oregon spotted frog occupancy. This 4-year study provides baseline data, but the 4-year period was too short to draw firm conclusions. Further study is essential to understand how habitat changes and management practices relate to the status and trends of this species.

  20. Perspectives for long-term competition in the central European electricity market

    International Nuclear Information System (INIS)

    Haas, Reinhard

    2005-01-01

    In this paper we focus on the Central European electricity market and analyse whether liberalization, deregulation, and privatization are sufficient to bring about real competition. Moreover, we discuss the relevance of the following conditions to bring about real competition and to avoid market power: 1) A rigorous correct un bundling; 2) excess capacities in transmission; 3) excess capacities in generation; 4) a large number of generators and suppliers; 5) the balanced existence of short-term (e.g. spot markets) and long-term markets (e.g. bilateral contracts, forwards); 6) full liberalization; Some major findings of this analysis are: 1) Currently, demand is continuously increasing while capacities are shut down. At least in 2009 demand will have caught up with generation capacities. This could lead to severe price spikes. 2) The Central European electricity market is separated from other markets by means of limited transmission capacities; 3) With respect to effective competition in Central Europe the major problems are: i) a very small (and continuously decreasing) number of generators, and ii) a lack of serious un bundling between generation and transmission mainly in Germany; This leads to cross-subsidization of generation by the network operation and to a heavy discrimination of other and new generators; 4) Moreover, a crucial condition for active competition is a sufficiently large transmission grid. Yet, currently especially at the border to the new EU member countries transmission capacities are rather scarce and there are no signs of extensions of the grid. This also limits the access of countries with potential excess capacities like Ukraine, Bulgaria, Romania to the Central European market The major conclusion of this analysis is: All conditions investigated above must be fulfilled simultaneously to bring about a competitive electricity market in Western Europe and the extended European Union. If only one of these conditions is missing, competition

  1. Short term electric load forecast, 1991/92-2011/12

    International Nuclear Information System (INIS)

    1991-01-01

    A long-term forecast is presented predicting electricity requirements to 2011/12. Total sales to the B.C. Hydro service area are projected to increase from 43,805 GWh in 1990/91 to 57,366 GWh in 2011/12, for an annual growth of 1.7%. Total gross generation requirements increase from 45,805 GWh in 1990/91 to 68,037 GWh in 2011/12 for an annual average growth of 1.9%. Integrated peak system demand is projected to increase from 8401 MW in 1990/91 to 11,981 MW in 2011/12. Residential sales are projected to increase from 11,783 GWh to 14,870 GWh for a growth rate of 1.7%. Commercial sector sales are projected to increase from 10,588 GWh to 17,116 GWh representing a growth rate of 2.3%. Industrial sector sales are projected to increase from 17,962 GWh to 25,380 GWh. The economic assumptions underlying the forecast, sensitivity analysis, impact of Power Smart programs, and a sectoral analysis of projected sales are presented. 10 figs., 5 tabs

  2. Spot Scanning-Based Proton Therapy for Intracranial Meningioma: Long-Term Results From the Paul Scherrer Institute

    International Nuclear Information System (INIS)

    Weber, Damien C.; Schneider, Ralf; Goitein, Gudrun; Koch, Tamara; Ares, Carmen; Geismar, Jan H.; Schertler, Andreas; Bolsi, Alessandra; Hug, Eugen B.

    2012-01-01

    Background: To assess the long-term clinical results of spot scanning proton therapy (PT) in the treatment of intracranial meningiomas. Patients and Methods: Thirty-nine patients with meningioma (histologically proven 34/39) were treated with PT between July 1997 and January 2010. Thirty-two (82.1%) patients were treated as primary treatment (exclusive PT, n = 8; postoperative PT, n = 24). Mean age was 48.3 ± 17.9 years and 32 (82.1%) patients had skull base lesions. For patients undergoing surgery, 24 patients had a diagnosis of World Health Organization (WHO) Grade I and 10 of a WHO Grade II/III meningioma, respectively. The female-to-male ratio was 3.3. The median administered dose was 56.0 Gy (relative biologic effectiveness [RBE]) (range, 52.2–66.6) at 1.8–2.0 Gy (RBE) per fraction. Gross tumor volume (GTV) ranged from 0.76 to 546.5 cm 3 (median, 21.5). Late toxicity was assessed according to Common Terminology Criteria for Adverse Events version 3.0. Mean follow-up time was 62.0 months and all patients were followed for >6 months. Results: Six patients presented with tumor recurrence and 6 patients died during follow-up, of which 4 of tumor progression. Five-year actuarial local control and overall survival rates were 84.8% and 81.8%, respectively, for the entire cohort and 100% for benign histology. Cumulative 5-year Grade ≥3 late toxicity-free survival was 84.5%. On univariate analysis, LC was negatively influenced by WHO grade (p = 0.001), GTV (p = 0.013), and male gender (p = 0.058). Conclusions: PT is a safe and effective treatment for patients with untreated, recurrent, or incompletely resected intracranial meningiomas. WHO grade and tumor volume was an adverse prognostic factor for local control.

  3. Spot Scanning-Based Proton Therapy for Intracranial Meningioma: Long-Term Results From the Paul Scherrer Institute

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Damien C., E-mail: damien.weber@unige.ch [Radiation Oncology, Geneva University Hospital, Geneva (Switzerland); Schneider, Ralf; Goitein, Gudrun; Koch, Tamara; Ares, Carmen; Geismar, Jan H.; Schertler, Andreas; Bolsi, Alessandra; Hug, Eugen B. [Center for Proton Therapy, Paul Scherrer Institute, Viligen (Switzerland)

    2012-07-01

    Background: To assess the long-term clinical results of spot scanning proton therapy (PT) in the treatment of intracranial meningiomas. Patients and Methods: Thirty-nine patients with meningioma (histologically proven 34/39) were treated with PT between July 1997 and January 2010. Thirty-two (82.1%) patients were treated as primary treatment (exclusive PT, n = 8; postoperative PT, n = 24). Mean age was 48.3 {+-} 17.9 years and 32 (82.1%) patients had skull base lesions. For patients undergoing surgery, 24 patients had a diagnosis of World Health Organization (WHO) Grade I and 10 of a WHO Grade II/III meningioma, respectively. The female-to-male ratio was 3.3. The median administered dose was 56.0 Gy (relative biologic effectiveness [RBE]) (range, 52.2-66.6) at 1.8-2.0 Gy (RBE) per fraction. Gross tumor volume (GTV) ranged from 0.76 to 546.5 cm{sup 3} (median, 21.5). Late toxicity was assessed according to Common Terminology Criteria for Adverse Events version 3.0. Mean follow-up time was 62.0 months and all patients were followed for >6 months. Results: Six patients presented with tumor recurrence and 6 patients died during follow-up, of which 4 of tumor progression. Five-year actuarial local control and overall survival rates were 84.8% and 81.8%, respectively, for the entire cohort and 100% for benign histology. Cumulative 5-year Grade {>=}3 late toxicity-free survival was 84.5%. On univariate analysis, LC was negatively influenced by WHO grade (p = 0.001), GTV (p = 0.013), and male gender (p = 0.058). Conclusions: PT is a safe and effective treatment for patients with untreated, recurrent, or incompletely resected intracranial meningiomas. WHO grade and tumor volume was an adverse prognostic factor for local control.

  4. Spot market for uranium

    International Nuclear Information System (INIS)

    Colhoun, C.

    1982-01-01

    The spot market is always quoted for the price of uranium because little information is available about long-term contracts. A review of the development of spot market prices shows the same price curve swings that occur with all raw materials. Future long-term contracts will probably be lower to reflect spot market prices, which are currently in the real-value range of $30-$35. An upswing in the price of uranium could come in the next few months as utilities begin making purchases and trading from stockpiles. The US, unlike Europe and Japan, has already reached a supply and demand point where the spot market share is increasing. Forecasters cannot project the market price, they can only predict the presence of an oscillating spot or a secondary market. 5 figures

  5. Revisiting short-term price and volatility dynamics in day-ahead electricity markets with rising wind power

    International Nuclear Information System (INIS)

    Li, Yuanjing

    2015-01-01

    This paper revisits the short-term price and volatility dynamics in day-ahead electricity markets in consideration of an increasing share of wind power, using an example of the Nord Pool day-ahead market and the Danish wind generation. To do so, a GARCH process is applied, and market coupling and the counterbalance effect of hydropower in the Scandinavian countries are additionally accounted for. As results, we found that wind generation weakly dampens spot prices with an elasticity of 0.008 and also reduces price volatility with an elasticity of 0.02 in the Nordic day-ahead market. The results shed lights on the importance of market coupling and interactions between wind power and hydropower in the Nordic system through cross-border exchanges, which play an essential role in price stabilization. Additionally, an EGARCH specification confirms an asymmetric influence of the price innovations, whereby negative shocks produce larger volatility in the Nordic spot market. While considering heavy tails in error distributions can improve model fits significantly, the EGARCH model outperforms the GARCH model on forecast evaluations. (author)

  6. Medium-term electric power demand forecasting based on economic-electricity transmission model

    Science.gov (United States)

    Li, Wenfeng; Bao, Fangmin; Bai, Hongkun; Liu, Wei; Liu, Yongmin; Mao, Yubin; Wang, Jiangbo; Liu, Junhui

    2018-06-01

    Electric demand forecasting is a basic work to ensure the safe operation of power system. Based on the theories of experimental economics and econometrics, this paper introduces Prognoz Platform 7.2 intelligent adaptive modeling platform, and constructs the economic electricity transmission model that considers the economic development scenarios and the dynamic adjustment of industrial structure to predict the region's annual electricity demand, and the accurate prediction of the whole society's electricity consumption is realized. Firstly, based on the theories of experimental economics and econometrics, this dissertation attempts to find the economic indicator variables that drive the most economical growth of electricity consumption and availability, and build an annual regional macroeconomic forecast model that takes into account the dynamic adjustment of industrial structure. Secondly, it innovatively put forward the economic electricity directed conduction theory and constructed the economic power transfer function to realize the group forecast of the primary industry + rural residents living electricity consumption, urban residents living electricity, the second industry electricity consumption, the tertiary industry electricity consumption; By comparing with the actual value of economy and electricity in Henan province in 2016, the validity of EETM model is proved, and the electricity consumption of the whole province from 2017 to 2018 is predicted finally.

  7. Long-term projections for electricity and gas prices

    International Nuclear Information System (INIS)

    Borggrefe, Frieder; Lochner, Stefan

    2009-01-01

    The article analyses potential developments of wholesale electricity prices in Germany until 2030. The relevant determinants and their effects on prices are shown. Several projections demonstrate the impact of future fuel prices taking the political framework into account. The importance of carbon and gas prices - and the latter's relationship to oil prices - are discussed extensively. Although forecasting electricity prices is associated with great uncertainties, the article illustrates the relative impacts of the various price determinants and their interactions. (orig.)

  8. The effects of habitat, climate, and Barred Owls on long-term demography of Northern Spotted Owls

    Science.gov (United States)

    Katie M. Dugger; Eric D. Forsman; Alan B. Franklin; Raymond J. Davis; Gary C. White; Carl J. Schwarz; Kenneth P. Burnham; James D. Nichols; James E. Hines; Charles B. Yackulic; Paul F. Doherty; Larissa Bailey; Darren A. Clark; Steven H. Ackers; Lawrence S. Andrews; Benjamin Augustine; Brian L. Biswell; Jennifer Blakesley; Peter C. Carlson; Matthew J. Clement; Lowell V. Diller; Elizabeth M. Glenn; Adam Green; Scott A. Gremel; Dale R. Herter; J. Mark Higley; Jeremy Hobson; Rob B. Horn; Kathryn P. Huyvaert; Christopher McCafferty; Trent McDonald; Kevin McDonnell; Gail S. Olson; Janice A. Reid; Jeremy Rockweit; Viviana Ruiz; Jessica Saenz; Stan G. Sovern

    2016-01-01

    Estimates of species’ vital rates and an understanding of the factors affecting those parameters over time and space can provide crucial information for management and conservation. We used mark–recapture, reproductive output, and territory occupancy data collected during 1985–2013 to evaluate population processes of Northern Spotted Owls (Strix occidentalis...

  9. Long-term clinical evaluation of a 800-nm long-pulsed diode laser with a large spot size and vacuum-assisted suction for hair removal.

    Science.gov (United States)

    Ibrahimi, Omar A; Kilmer, Suzanne L

    2012-06-01

    The long-pulsed diode (800-810-nm) laser is one of the most commonly used and effective lasers for hair removal. Limitations of currently available devices include a small treatment spot size, treatment-associated pain, and the need for skin cooling. To evaluate the long-term hair reduction capabilities of a long-pulsed diode laser with a large spot size and vacuum assisted suction. Thirty-five subjects were enrolled in a prospective, self-controlled, single-center study of axillary hair removal. The study consisted of three treatments using a long-pulsed diode laser with a large spot size and vacuum-assisted suction at 4- to 6-week intervals with follow-up visits 6 and 15 months after the last treatment. Hair clearance was quantified using macro hair-count photographs taken at baseline and at 6- and 15-month follow-up visits. Changes in hair thickness and color, levels of treatment-associated pain, and adverse events were additional study endpoints. There was statistically significant hair clearance at the 6 (54%) and 15-month (42%) follow-up visits. Remaining hairs were thinner and lighter at the 15-month follow-up visit, and the majority of subjects reported feeling up to mild to moderate pain during treatment without the use of pretreatment anesthesia or skin cooling. A long-pulsed diode laser with a large spot size and vacuum-assisted suction is safe and effective for long-term hair removal. This is the largest prospective study to evaluate long-term hair removal and the first to quantify decreases in hair thickness and darkness with treatment. © 2012 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

  10. Do the seagull terms really survive for the electric polarizability of the nucleon?

    International Nuclear Information System (INIS)

    Saito, S.

    1998-01-01

    The seagull terms for the electric polarizability of the nucleon are shown indeed to vanish, if one introduces fluctuations around the Skyrmion configuration, and the origin of the electric polarizability cannot after all be attributed to the seagull terms in the Skyrme model. (orig.)

  11. Nucleon electric polarizability in soliton models and the role of the seagull terms

    International Nuclear Information System (INIS)

    Scoccola, N.N.; Cohen, T.D.

    1996-01-01

    The full Hamiltonian of the soliton models contains no electric seagull terms. Here it is shown that if one restricts the fields to the collective subspace then electric seagull terms are induced in the effective Hamiltonian. These effective seagull contributions are consistent with gauge invariance. They also reproduce the leading non-analytic behavior of a large N c chiral perturbation theory calculation of the electric polarizability. (orig.)

  12. Plasma parameters of the cathode spot explosive electron emission cell obtained from the model of liquid-metal jet tearing and electrical explosion

    Science.gov (United States)

    Tsventoukh, M. M.

    2018-05-01

    A model has been developed for the explosive electron emission cell pulse of a vacuum discharge cathode spot that describes the ignition and extinction of the explosive pulse. The pulse is initiated due to hydrodynamic tearing of a liquid-metal jet which propagates from the preceding cell crater boundary and draws the ion current from the plasma produced by the preceding explosion. Once the jet neck has been resistively heated to a critical temperature (˜1 eV), the plasma starts expanding and decreasing in density, which corresponds to the extinction phase. Numerical and analytical solutions have been obtained that describe both the time behavior of the pulse plasma parameters and their average values. For the cell plasma, the momentum per transferred charge has been estimated to be some tens of g cm/(s C), which is consistent with the known measurements of ion velocity, ion erosion rate, and specific recoil force. This supports the model of the pressure-gradient-driven plasma acceleration mechanism for the explosive cathode spot cells. The ohmic electric field within the explosive current-carrying plasma has been estimated to be some tens of kV/cm, which is consistent with the known experimental data on cathode potential fall and explosive cell plasma size. This supports the model that assumes the ohmic nature of the cathode potential fall in a vacuum discharge.

  13. Modeling methods for GenCo bidding strategy optimization in the liberalized electricity spot market-A state-of-the-art review

    International Nuclear Information System (INIS)

    Li, Gong; Shi, Jing; Qu, Xiuli

    2011-01-01

    The electricity market has since 1980s been gradually evolving from a monopoly market into a liberalized one for encouraging competition and improving efficiency. This brings the opportunity for generation companies (GenCos) to make more profits while embracing more risks of not being dispatched. Therefore, it has become a core interest for the GenCos to develop optimal bidding strategies to maximize the profits and minimize the risks while participating in such a competitive market. The literature pertaining to this issue has grown rapidly in recent years, and many different modeling approaches, such as mathematical programming, game theory, and agent-based models, have been investigated under the liberalized market environment. Meanwhile, along with the increasing penetration of renewable energy, the electricity market is facing more complexity and stochasticity from both uncertain generation and dynamic demands. The intermittent and unsteady nature of these renewable power sources motivates the GenCos to further optimize their bidding strategy by considering the new constraints. This paper presents a comprehensive literature analysis on the state-of-the-art research of bidding strategy modeling methods. -- Highlights: → Publications on bidding in electricity spot markets are comprehensively reviewed. → Insights on the evolution of solution methodologies of recent 10 years are provided. → The pros and cons of these solution approaches are also discussed. → Future research directions, with renewable energy participations, are pointed out.

  14. Bier spots

    OpenAIRE

    Ahu Yorulmaz,; Seray Kulcu Cakmak; Esra Ar?; Ferda Artuz

    2015-01-01

    Also called as physiologic anemic macules, Bier spots are small, hypopigmented irregularly shaped macules against a background of diffuse erythema, which creates an appearance of speckled vascular mottling of the skin. Bier spots most commonly appear on distal portions of the limbs though there are case reports describing diffuse involvement, which also affect trunk and mucous membranes of the patient. Although the exact pathophysiological mechanisms underlying Bier spots still need to be elu...

  15. Long-term water demand for electricity, industry and households

    NARCIS (Netherlands)

    Bijl, David L.; Bogaart, Patrick W.; Kram, Tom; de Vries, Bert J M; van Vuuren, Detlef P.

    2016-01-01

    Better water demand projections are needed in order to better assess water scarcity. The focus in this paper is on non-agricultural water demand, as this is the fastest-growing and least well-modelled demand component. We describe an end use-oriented model for future water demand in the electricity,

  16. Effective electrical energy policies in terms of DSM

    Energy Technology Data Exchange (ETDEWEB)

    Song, Hyunah

    2010-09-15

    This paper investigates how well energy policies are adopted and operated. In terms of DSM or the Demand Side Management, ways of modifying energy demand are introduced. Also their effects are showed. Furthermore future plans of DSM are illustrated shortly.

  17. European Short-term Electricity Market Designs under High Penetration of Wind Power

    NARCIS (Netherlands)

    Chaves Avila, J.P.

    2014-01-01

    The EU has ambitious policies for decarbonization of the electricity sector. Due to recent technological developments, wind power already represents a significant share of the generation mix in some European countries. As a result, short-term electricity markets and balancing arrangements must be

  18. Bier spots

    Directory of Open Access Journals (Sweden)

    Ahu Yorulmaz,

    2015-10-01

    Full Text Available Also called as physiologic anemic macules, Bier spots are small, hypopigmented irregularly shaped macules against a background of diffuse erythema, which creates an appearance of speckled vascular mottling of the skin. Bier spots most commonly appear on distal portions of the limbs though there are case reports describing diffuse involvement, which also affect trunk and mucous membranes of the patient. Although the exact pathophysiological mechanisms underlying Bier spots still need to be elucidated, Bier spots have been suggested to be a vascular anomaly caused by vasoconstriction of small vessels. In addition, several diseases have been proposed to be associated with Bier spots, including scleroderma renal crisis, cryoglobulinemia, Peutz-Jeghers syndrome, alopecia areata and hypoplasia of the aorta, although it has not been shown whether these associations are casual or coincidental. The clinical presentation of Bier spots is quite typical. These tiny whitish macules easily become prominent when the affected limb is placed in a dependent position and fade away when the limb is raised. Here we report a case of Bier spots in a 32-year-old male patient with characteristical clinical manifestations.

  19. Stochastic Optimal Wind Power Bidding Strategy in Short-Term Electricity Market

    DEFF Research Database (Denmark)

    Hu, Weihao; Chen, Zhe; Bak-Jensen, Birgitte

    2012-01-01

    Due to the fluctuating nature and non-perfect forecast of the wind power, the wind power owners are penalized for the imbalance costs of the regulation, when they trade wind power in the short-term liberalized electricity market. Therefore, in this paper a formulation of an imbalance cost...... minimization problem for trading wind power in the short-term electricity market is described, to help the wind power owners optimize their bidding strategy. Stochastic optimization and a Monte Carlo method are adopted to find the optimal bidding strategy for trading wind power in the short-term electricity...... market in order to deal with the uncertainty of the regulation price, the activated regulation of the power system and the forecasted wind power generation. The Danish short-term electricity market and a wind farm in western Denmark are chosen as study cases due to the high wind power penetration here...

  20. Understanding the Electrical Behavior of the Action Potential in Terms of Elementary Electrical Sources

    Science.gov (United States)

    Rodriguez-Falces, Javier

    2015-01-01

    A concept of major importance in human electrophysiology studies is the process by which activation of an excitable cell results in a rapid rise and fall of the electrical membrane potential, the so-called action potential. Hodgkin and Huxley proposed a model to explain the ionic mechanisms underlying the formation of action potentials. However,…

  1. Age Spots

    Science.gov (United States)

    ... for Every Season How to Choose the Best Skin Care Products In This Section Dermatologic Surgery What is dermatologic ... for Every Season How to Choose the Best Skin Care Products Age Spots Treatment Options Learn more about treatment ...

  2. Spotted inflation

    International Nuclear Information System (INIS)

    Matsuda, Tomohiro

    2010-01-01

    We describe new scenarios for generating curvature perturbations when inflaton (curvaton) has significant interactions. We consider a ''spot'', which arises from interactions associated with an enhanced symmetric point (ESP) on the trajectory. Our first example uses the spot to induce a gap in the field equation. We observe that the gap in the field equation may cause generation of curvature perturbation if it does not appear simultaneous in space. The mechanism is similar to the scenario of inhomogeneous phase transition. Then we observe that the spot interactions may initiate warm inflation in the cold Universe. Creation of cosmological perturbation is discussed in relation to the inflaton dynamics and the modulation associated with the spot interactions

  3. EDF Group - Annual Report 2011. Electricity, long-term choices

    International Nuclear Information System (INIS)

    2012-01-01

    The EDF Group is one of the world's leading energy companies, active in all areas from generation to trading and network management. It has a sound business model, evenly balanced between regulated and deregulated activities. With its first-rate human resources, R and D capability, expertise in engineering and operating generation plants and networks, as well as its energy eco-efficiency offers, the Group delivers competitive solutions that help ensure sustainable economic development and climate protection. The EDF Group is the leader in the French and UK electricity markets and has solid positions in Italy and numerous other European countries, as well as industrial operations in Asia and the United States. Everywhere it operates, the Group is a model of quality public service for the energy sector. This document is EDF Group's annual report for the year 2011. It contains information about Group profile, governance, business, development strategy, sales and marketing, positions in Europe and international activities. The document is made of several reports: the Activity and Sustainable Development Report, the Financial Report, the Management Report, the Report by the Chairman of EDF Board of Directors on corporate governance and internal control procedures, the Milestones report, the 'EDF at a glance' report, and the Sustainable Development Indicators

  4. Electric vehicles and India's low carbon passenger transport: A long-term co-benefits assessment

    DEFF Research Database (Denmark)

    Dhar, Subash; Pathak, Minal; Shukla, Priyadarshi

    2017-01-01

    Electric vehicles have attracted the attention of India's policy makers as clean technology alternatives due to their multiple advantages like higher efficiency and lower air pollution in short to medium term and reduced CO2 emissions as electricity gets decarbonized in the long-run under low......) are related to sourcing of raw materials for batteries and battery reprocessing and disposal. The findings show that: i) in the reference scenario, the EVs 2-wheelers will achieve a significant share by 2050. Electric 4-wheelers though would have a small share even in 2050; ii) EV push policies though lead...... to significant diffusion of electric 2- wheelers in India by 2030. These policies enhance diffusion of electric 4-wheelers only if financial incentives are sustained in the long-term, iii) the application of global carbon price on the Indian economy in the 2° C stabilization scenario increases competitiveness...

  5. Electric Chern-Simons term, enlarged exotic Galilei symmetry and noncommutative plane

    International Nuclear Information System (INIS)

    Olmo, Mariano A. del; Plyushchay, Mikhail S.

    2006-01-01

    The extended exotic planar model for a charged particle is constructed. It includes a Chern-Simons-like term for a dynamical electric field, but produces usual equations of motion for the particle in background constant uniform electric and magnetic fields. The electric Chern-Simons term is responsible for the noncommutativity of the boost generators in the 10-dimensional enlarged exotic Galilei symmetry algebra of the extended system. The model admits two reduction schemes by the integrals of motion, one of which reproduces the usual formulation for the charged particle in external constant electric and magnetic fields with associated field-deformed Galilei symmetry, whose commuting boost generators are identified with the nonlocal in time Noether charges reduced on-shell. Another reduction scheme, in which electric field transmutes into the commuting space translation generators, extracts from the model a free particle on the noncommutative plane described by the twofold centrally extended Galilei group of the nonrelativistic anyons

  6. Hybrid ARIMAX quantile regression method for forecasting short term electricity consumption in east java

    Science.gov (United States)

    Prastuti, M.; Suhartono; Salehah, NA

    2018-04-01

    The need for energy supply, especially for electricity in Indonesia has been increasing in the last past years. Furthermore, the high electricity usage by people at different times leads to the occurrence of heteroscedasticity issue. Estimate the electricity supply that could fulfilled the community’s need is very important, but the heteroscedasticity issue often made electricity forecasting hard to be done. An accurate forecast of electricity consumptions is one of the key challenges for energy provider to make better resources and service planning and also take control actions in order to balance the electricity supply and demand for community. In this paper, hybrid ARIMAX Quantile Regression (ARIMAX-QR) approach was proposed to predict the short-term electricity consumption in East Java. This method will also be compared to time series regression using RMSE, MAPE, and MdAPE criteria. The data used in this research was the electricity consumption per half-an-hour data during the period of September 2015 to April 2016. The results show that the proposed approach can be a competitive alternative to forecast short-term electricity in East Java. ARIMAX-QR using lag values and dummy variables as predictors yield more accurate prediction in both in-sample and out-sample data. Moreover, both time series regression and ARIMAX-QR methods with addition of lag values as predictor could capture accurately the patterns in the data. Hence, it produces better predictions compared to the models that not use additional lag variables.

  7. Global long-term cost dynamics of offshore wind electricity generation

    NARCIS (Netherlands)

    Gernaat, David E H J; Van Vuuren, Detlef P.; Van Vliet, Jasper; Sullivan, Patrick; Arent, Douglas J.

    2014-01-01

    Using the IMAGE/TIMER (The Targets IMage Energy Regional) long-term integrated assessment model, this paper explores the regional and global potential of offshore wind to contribute to global electricity production. We develop long-term cost supply curve for offshore wind, a representation of the

  8. Mid-Term Electricity Market Clearing Price Forecasting with Sparse Data: A Case in Newly-Reformed Yunnan Electricity Market

    Directory of Open Access Journals (Sweden)

    Chuntian Cheng

    2016-10-01

    Full Text Available For the power systems, for which few data are available for mid-term electricity market clearing price (MCP forecasting at the early stage of market reform, a novel grey prediction model (defined as interval GM(0, N model is proposed in this paper. Over the traditional GM(0, N model, three major improvements of the proposed model are: (i the lower and upper bounds are firstly identified to give an interval estimation of the forecasting value; (ii a novel whitenization method is then established to determine the definite forecasting value from the forecasting interval; and (iii the model parameters are identified by an improved particle swarm optimization (PSO instead of the least square method (LSM for the limitation of LSM. Finally, a newly-reformed electricity market in Yunnan province of China is studied, and input variables are contrapuntally selected. The accuracy of the proposed model is validated by observed data. Compared with the multiple linear regression (MLR model, the traditional GM(0, N model and the artificial neural network (ANN model, the proposed model gives a better performance and its superiority is further ensured by the use of the modified Diebold–Mariano (MDM test, suggesting that it is suitable for mid-term electricity MCP forecasting in a data-sparse electricity market.

  9. Flexibility and reliability in long-term planning exercises dedicated to the electricity sector

    Energy Technology Data Exchange (ETDEWEB)

    Maizi, Nadia; Drouineau, Mathilde; Assoumou, Edi; Mazauric, Vincent

    2010-09-15

    Long-term planning models are useful to build plausible options for future energy systems and must consequently address the technological feasibility and associated cost of these options. This paper focuses on the electricity sector and on problems of flexibility and reliability in power systems in order to improve results provided by long-term planning exercises: flexibility needs are integrated as an additional criterion for new investment decisions and, reliability requirements are assessed through the level of electrical losses they induced and a related cost. These approaches are implemented in a long-term planning model and demonstrated through a study of the Reunion Island.

  10. Medium-term energy hub management subject to electricity price and wind uncertainty

    International Nuclear Information System (INIS)

    Najafi, Arsalan; Falaghi, Hamid; Contreras, Javier; Ramezani, Maryam

    2016-01-01

    Highlights: • A new model for medium-term energy hub management is proposed. • Risk aversion is considered in medium-term energy hub management. • Stochastic programing is used to solve the medium-term energy hub management problem. • Electricity price and wind uncertainty are considered. - Abstract: Energy hubs play an important role in implementing multi-carrier energy systems. More studies are required in both their modeling and operating aspects. In this regard, this paper attempts to develop medium-term management of an energy hub in restructured power systems. A model is presented to manage an energy hub which has electrical energy and natural gas as inputs and electrical and heat energy as outputs. Electricity is procured in various ways, either purchasing it from a pool-based market and bilateral contracts, or producing it from a Combined Heat and Power (CHP) unit, a diesel generator unit and Wind Turbine Generators (WTGs). Pool prices and wind turbine production are subject to uncertainty, which makes energy management a complex puzzle. Heat demand is also procured by a furnace and a CHP unit. Energy hub managers should make decisions whether to purchase electricity from the electricity market and gas from the gas network or to produce electricity using a set of generators to meet the electrical and heat demands in the presence of uncertainties. The energy management objective is to minimize the total cost subject to several technical constraints using stochastic programming. Conditional Value at Risk (CVaR), a well-known risk measure, is used to reduce the unfavorable risk of costs. In doing so, the proposed model is illustrated using a sample test case with actual prices, load and wind speed data. The results show that the minimum cost is obtained by the best decisions involving the electricity market and purchasing natural gas for gas facilities. Considering risk also increases the total expected cost and decreases the CVaR.

  11. Short-term electricity prices forecasting in a competitive market: A neural network approach

    International Nuclear Information System (INIS)

    Catalao, J.P.S.; Mariano, S.J.P.S.; Mendes, V.M.F.; Ferreira, L.A.F.M.

    2007-01-01

    This paper proposes a neural network approach for forecasting short-term electricity prices. Almost until the end of last century, electricity supply was considered a public service and any price forecasting which was undertaken tended to be over the longer term, concerning future fuel prices and technical improvements. Nowadays, short-term forecasts have become increasingly important since the rise of the competitive electricity markets. In this new competitive framework, short-term price forecasting is required by producers and consumers to derive their bidding strategies to the electricity market. Accurate forecasting tools are essential for producers to maximize their profits, avowing profit losses over the misjudgement of future price movements, and for consumers to maximize their utilities. A three-layered feedforward neural network, trained by the Levenberg-Marquardt algorithm, is used for forecasting next-week electricity prices. We evaluate the accuracy of the price forecasting attained with the proposed neural network approach, reporting the results from the electricity markets of mainland Spain and California. (author)

  12. A new assessment of combined geothermal electric generation and desalination in western Saudi Arabia: targeted hot spot development

    KAUST Repository

    Missimer, Thomas M.

    2014-07-17

    High heat flow associated with the tectonic spreading of the Red Sea make western Saudi Arabia a region with high potential for geothermal energy development. The hydraulic properties of the Precambrian-age rocks occurring in this region are not conducive to direct production of hot water for heat exchange, which will necessitate use of the hot dry rock (HDR) heat harvesting method. This would require the construction of coupled deep wells; one for water injection and the other for steam recovery. There are some technological challenges in the design, construction, and operation of HDR geothermal energy systems. Careful geotechnical evaluation of the heat reservoir must be conducted to ascertain the geothermal gradient at the chosen site to allow pre-design modeling of the system for assessment of operational heat flow maintenance. Also, naturally occurring fractures or faults must be carefully evaluated to make an assessment of the potential for induced seismicity. It is anticipated that the flow heat exchange capacity of the system will require enhancement by the use of horizontal drilling and hydraulic fracturing in the injection well with the production well drilled into the fracture zone to maximum water recovery efficiency and reduce operating pressure. The heated water must be maintained under pressure and flashed to steam at surface to produce to the most effective energy recovery. Most past evaluations of geothermal energy development in this region have been focused on the potential for solely electricity generation, but direct use of produced steam could be coupled with thermally driven desalination technologies such as multi-effect distillation, adsorption desalination, and/or membrane distillation to provide a continuous source of heat to allow very efficient operation of the plants. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.

  13. A new assessment of combined geothermal electric generation and desalination in western Saudi Arabia: targeted hot spot development

    KAUST Repository

    Missimer, Thomas M.; Mai, Martin; Ghaffour, NorEddine

    2014-01-01

    High heat flow associated with the tectonic spreading of the Red Sea make western Saudi Arabia a region with high potential for geothermal energy development. The hydraulic properties of the Precambrian-age rocks occurring in this region are not conducive to direct production of hot water for heat exchange, which will necessitate use of the hot dry rock (HDR) heat harvesting method. This would require the construction of coupled deep wells; one for water injection and the other for steam recovery. There are some technological challenges in the design, construction, and operation of HDR geothermal energy systems. Careful geotechnical evaluation of the heat reservoir must be conducted to ascertain the geothermal gradient at the chosen site to allow pre-design modeling of the system for assessment of operational heat flow maintenance. Also, naturally occurring fractures or faults must be carefully evaluated to make an assessment of the potential for induced seismicity. It is anticipated that the flow heat exchange capacity of the system will require enhancement by the use of horizontal drilling and hydraulic fracturing in the injection well with the production well drilled into the fracture zone to maximum water recovery efficiency and reduce operating pressure. The heated water must be maintained under pressure and flashed to steam at surface to produce to the most effective energy recovery. Most past evaluations of geothermal energy development in this region have been focused on the potential for solely electricity generation, but direct use of produced steam could be coupled with thermally driven desalination technologies such as multi-effect distillation, adsorption desalination, and/or membrane distillation to provide a continuous source of heat to allow very efficient operation of the plants. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.

  14. Long-term forecasting of hourly electricity load: Identification of consumption profiles and segmentation of customers

    DEFF Research Database (Denmark)

    Møller Andersen, Frits; Larsen, Helge V.; Boomsma, Trine Krogh

    2013-01-01

    , to model and forecast long-term changes in the aggregated electricity load profile, we identify profiles for different categories of customers and link these to projections of the aggregated annual consumption by categories of customers. Long-term projection of the aggregated load is important for future......Data for aggregated hourly electricity demand shows systematic variations over the day, week, and seasons, and forecasting of aggregated hourly electricity load has been the subject of many studies. With hourly metering of individual customers, data for individual consumption profiles is available....... Using this data and analysing the case of Denmark, we show that consumption profiles for categories of customers are equally systematic but very different for distinct categories, that is, distinct categories of customers contribute differently to the aggregated electricity load profile. Therefore...

  15. SPOT Program

    Science.gov (United States)

    Smith, Jason T.; Welsh, Sam J.; Farinetti, Antonio L.; Wegner, Tim; Blakeslee, James; Deboeck, Toni F.; Dyer, Daniel; Corley, Bryan M.; Ollivierre, Jarmaine; Kramer, Leonard; hide

    2010-01-01

    A Spacecraft Position Optimal Tracking (SPOT) program was developed to process Global Positioning System (GPS) data, sent via telemetry from a spacecraft, to generate accurate navigation estimates of the vehicle position and velocity (state vector) using a Kalman filter. This program uses the GPS onboard receiver measurements to sequentially calculate the vehicle state vectors and provide this information to ground flight controllers. It is the first real-time ground-based shuttle navigation application using onboard sensors. The program is compact, portable, self-contained, and can run on a variety of UNIX or Linux computers. The program has a modular objec-toriented design that supports application-specific plugins such as data corruption remediation pre-processing and remote graphics display. The Kalman filter is extensible to additional sensor types or force models. The Kalman filter design is also strong against data dropouts because it uses physical models from state and covariance propagation in the absence of data. The design of this program separates the functionalities of SPOT into six different executable processes. This allows for the individual processes to be connected in an a la carte manner, making the feature set and executable complexity of SPOT adaptable to the needs of the user. Also, these processes need not be executed on the same workstation. This allows for communications between SPOT processes executing on the same Local Area Network (LAN). Thus, SPOT can be executed in a distributed sense with the capability for a team of flight controllers to efficiently share the same trajectory information currently being computed by the program. SPOT is used in the Mission Control Center (MCC) for Space Shuttle Program (SSP) and International Space Station Program (ISSP) operations, and can also be used as a post -flight analysis tool. It is primarily used for situational awareness, and for contingency situations.

  16. Short-term electricity prices forecasting in a competitive market by a hybrid intelligent approach

    Energy Technology Data Exchange (ETDEWEB)

    Catalao, J.P.S. [Department of Electromechanical Engineering, University of Beira Interior, R. Fonte do Lameiro, 6201-001 Covilha (Portugal); Center for Innovation in Electrical and Energy Engineering, Instituto Superior Tecnico, Technical University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Pousinho, H.M.I. [Department of Electromechanical Engineering, University of Beira Interior, R. Fonte do Lameiro, 6201-001 Covilha (Portugal); Mendes, V.M.F. [Department of Electrical Engineering and Automation, Instituto Superior de Engenharia de Lisboa, R. Conselheiro Emidio Navarro, 1950-062 Lisbon (Portugal)

    2011-02-15

    In this paper, a hybrid intelligent approach is proposed for short-term electricity prices forecasting in a competitive market. The proposed approach is based on the wavelet transform and a hybrid of neural networks and fuzzy logic. Results from a case study based on the electricity market of mainland Spain are presented. A thorough comparison is carried out, taking into account the results of previous publications. Conclusions are duly drawn. (author)

  17. Short-term electricity prices forecasting in a competitive market by a hybrid intelligent approach

    International Nuclear Information System (INIS)

    Catalao, J.P.S.; Pousinho, H.M.I.; Mendes, V.M.F.

    2011-01-01

    In this paper, a hybrid intelligent approach is proposed for short-term electricity prices forecasting in a competitive market. The proposed approach is based on the wavelet transform and a hybrid of neural networks and fuzzy logic. Results from a case study based on the electricity market of mainland Spain are presented. A thorough comparison is carried out, taking into account the results of previous publications. Conclusions are duly drawn. (author)

  18. Electric vehicles and India's low carbon passenger transport: A long-term co-benefits assessment

    DEFF Research Database (Denmark)

    Dhar, Subash; Pathak, Minal; Shukla, Priyadarshi

    2017-01-01

    Electric vehicles have attracted the attention of India's policy makers as clean technology alternatives due to their multiple advantages like higher efficiency and lower air pollution in short to medium term and reduced CO2 emissions as electricity gets decarbonized in the long-run under low...... carbon scenarios. This paper uses an energy system model ANSWER-MARKAL to analyse the role of electric vehicles (EV) in India. The modelling assessment spans the period 2010 to 2050 and analyses future EV demand in India under three scenarios: i) a ‘Reference’ scenario which includes the continuation...

  19. Turkey's short-term gross annual electricity demand forecast by fuzzy logic approach

    International Nuclear Information System (INIS)

    Kucukali, Serhat; Baris, Kemal

    2010-01-01

    This paper aims to forecast Turkey's short-term gross annual electricity demand by applying fuzzy logic methodology while general information on economical, political and electricity market conditions of the country is also given. Unlike most of the other forecast models about Turkey's electricity demand, which usually uses more than one parameter, gross domestic product (GDP) based on purchasing power parity was the only parameter used in the model. Proposed model made good predictions and captured the system dynamic behavior covering the years of 1970-2014. The model yielded average absolute relative errors of 3.9%. Furthermore, the model estimates a 4.5% decrease in electricity demand of Turkey in 2009 and the electricity demand growth rates are projected to be about 4% between 2010 and 2014. It is concluded that forecasting the Turkey's short-term gross electricity demand with the country's economic performance will provide more reliable projections. Forecasting the annual electricity consumption of a country could be made by any designer with the help of the fuzzy logic procedure described in this paper. The advantage of this model lies on the ability to mimic the human thinking and reasoning.

  20. Turkey's short-term gross annual electricity demand forecast by fuzzy logic approach

    Energy Technology Data Exchange (ETDEWEB)

    Kucukali, Serhat [Civil Engineering Department, Zonguldak Karaelmas University, Incivez 67100, Zonguldak (Turkey); Baris, Kemal [Mining Engineering Department, Zonguldak Karaelmas University, Incivez 67100, Zonguldak (Turkey)

    2010-05-15

    This paper aims to forecast Turkey's short-term gross annual electricity demand by applying fuzzy logic methodology while general information on economical, political and electricity market conditions of the country is also given. Unlike most of the other forecast models about Turkey's electricity demand, which usually uses more than one parameter, gross domestic product (GDP) based on purchasing power parity was the only parameter used in the model. Proposed model made good predictions and captured the system dynamic behavior covering the years of 1970-2014. The model yielded average absolute relative errors of 3.9%. Furthermore, the model estimates a 4.5% decrease in electricity demand of Turkey in 2009 and the electricity demand growth rates are projected to be about 4% between 2010 and 2014. It is concluded that forecasting the Turkey's short-term gross electricity demand with the country's economic performance will provide more reliable projections. Forecasting the annual electricity consumption of a country could be made by any designer with the help of the fuzzy logic procedure described in this paper. The advantage of this model lies on the ability to mimic the human thinking and reasoning. (author)

  1. Long-term power generation expansion planning with short-term demand response: Model, algorithms, implementation, and electricity policies

    Science.gov (United States)

    Lohmann, Timo

    Electric sector models are powerful tools that guide policy makers and stakeholders. Long-term power generation expansion planning models are a prominent example and determine a capacity expansion for an existing power system over a long planning horizon. With the changes in the power industry away from monopolies and regulation, the focus of these models has shifted to competing electric companies maximizing their profit in a deregulated electricity market. In recent years, consumers have started to participate in demand response programs, actively influencing electricity load and price in the power system. We introduce a model that features investment and retirement decisions over a long planning horizon of more than 20 years, as well as an hourly representation of day-ahead electricity markets in which sellers of electricity face buyers. This combination makes our model both unique and challenging to solve. Decomposition algorithms, and especially Benders decomposition, can exploit the model structure. We present a novel method that can be seen as an alternative to generalized Benders decomposition and relies on dynamic linear overestimation. We prove its finite convergence and present computational results, demonstrating its superiority over traditional approaches. In certain special cases of our model, all necessary solution values in the decomposition algorithms can be directly calculated and solving mathematical programming problems becomes entirely obsolete. This leads to highly efficient algorithms that drastically outperform their programming problem-based counterparts. Furthermore, we discuss the implementation of all tailored algorithms and the challenges from a modeling software developer's standpoint, providing an insider's look into the modeling language GAMS. Finally, we apply our model to the Texas power system and design two electricity policies motivated by the U.S. Environment Protection Agency's recently proposed CO2 emissions targets for the

  2. Energy Systems Scenario Modelling and Long Term Forecasting of Hourly Electricity Demand

    DEFF Research Database (Denmark)

    Alberg Østergaard, Poul; Møller Andersen, Frits; Kwon, Pil Seok

    2015-01-01

    . The results show that even with a limited short term electric car fleet, these will have a significant effect on the energy system; the energy system’s ability to integrate wind power and the demand for condensing power generation capacity in the system. Charging patterns and flexibility have significant...... or inflexible electric vehicles and individual heat pumps, and in the long term it is investigated what the effects of changes in the load profiles due to changing weights of demand sectors are. The analyses are based on energy systems simulations using EnergyPLAN and demand forecasting using the Helena model...... effects on this. Likewise, individual heat pumps may affect the system operation if they are equipped with heat storages. The analyses also show that the long term changes in electricity demand curve profiles have little impact on the energy system performance. The flexibility given by heat pumps...

  3. Price-signals and long term equilibrium. Reconsidering the organisation of electricity markets

    International Nuclear Information System (INIS)

    Finon, Dominique; Defeuilley, Christophe; Marty, Frederic

    2009-11-01

    The purpose of this article is to show that the reform of the electricity sector, based on a framework of interpretation in which the short-term/long-term articulation is made by the market price, does not result in an efficient result in terms of investment. After a presentation of a bibliographical review on investment in an uncertain context, the authors present a model of decentralised electricity markets which backs reforms. They highlight issues related to production investment which remain unresolved, and which may result in socially inefficient choices on the long term. They report an analysis of two solutions of industrial organisations, long term contracts and vertical and horizontal integration, which could solve these problems

  4. Short-Term Wind Electric Power Forecasting Using a Novel Multi-Stage Intelligent Algorithm

    Directory of Open Access Journals (Sweden)

    Haoran Zhao

    2018-03-01

    Full Text Available As the most efficient renewable energy source for generating electricity in a modern electricity network, wind power has the potential to realize sustainable energy supply. However, owing to its random and intermittent instincts, a high permeability of wind power into a power network demands accurate and effective wind energy prediction models. This study proposes a multi-stage intelligent algorithm for wind electric power prediction, which combines the Beveridge–Nelson (B-N decomposition approach, the Least Square Support Vector Machine (LSSVM, and a newly proposed intelligent optimization approach called the Grasshopper Optimization Algorithm (GOA. For data preprocessing, the B-N decomposition approach was employed to disintegrate the hourly wind electric power data into a deterministic trend, a cyclic term, and a random component. Then, the LSSVM optimized by the GOA (denoted GOA-LSSVM was applied to forecast the future 168 h of the deterministic trend, the cyclic term, and the stochastic component, respectively. Finally, the future hourly wind electric power values can be obtained by multiplying the forecasted values of these three trends. Through comparing the forecasting performance of this proposed method with the LSSVM, the LSSVM optimized by the Fruit-fly Optimization Algorithm (FOA-LSSVM, and the LSSVM optimized by Particle Swarm Optimization (PSO-LSSVM, it is verified that the established multi-stage approach is superior to other models and can increase the precision of wind electric power prediction effectively.

  5. The economic benefit of short-term forecasting for wind energy in the UK electricity market

    International Nuclear Information System (INIS)

    Barthelmie, R.J.; Murray, F.; Pryor, S.C.

    2008-01-01

    In the UK market, the total price of renewable electricity is made up of the Renewables Obligation Certificate and the price achieved for the electricity. Accurate forecasting improves the price if electricity is traded via the power exchange. In order to understand the size of wind farm for which short-term forecasting becomes economically viable, we develop a model for wind energy. Simulations were carried out for 2003 electricity prices for different forecast accuracies and strategies. The results indicate that it is possible to increase the price obtained by around pound 5/MWh which is about 14% of the electricity price in 2003 and about 6% of the total price. We show that the economic benefit of using short-term forecasting is also dependant on the accuracy and cost of purchasing the forecast. As the amount of wind energy requiring integration into the grid increases, short-term forecasting becomes more important to both wind farm owners and the transmission/distribution operators. (author)

  6. Short-Term City Electric Load Forecasting with Considering Temperature Effects: An Improved ARIMAX Model

    Directory of Open Access Journals (Sweden)

    Herui Cui

    2015-01-01

    Full Text Available Short-term electric load is significantly affected by weather, especially the temperature effects in summer. External factors can result in mutation structures in load data. Under the influence of the external temperature factors, city electric load cannot be easily forecasted as usual. This research analyzes the relationship between electricity load and daily temperature in city. An improved ARIMAX model is proposed in this paper to deal with the mutation data structures. It is found that information amount of the improved ARIMAX model is smaller than that of the classic method and its relative error is less than AR, ARMA and Sigmoid-Function ANN models. The forecasting results are more accurately fitted. This improved model is highly valuable when dealing with mutation data structure in the field of load forecasting. And it is also an effective technique in forecasting electric load with temperature effects.

  7. The current situation and mid-term prospects for European electricity markets

    International Nuclear Information System (INIS)

    Helm, Dieter

    2013-01-01

    This analysis of the current situation and mid-term prospects for European electricity markets presents: the objectives of energy policy, the historical legacy, the attempts at European integration and the Internal Energy Market (IEM), the coming of the Climate Change Package, the impact of the world economic and Euro-zone crises, the impact of shale gas and the new world of fossil fuel abundance, the impact of renewables on emissions, the impact of renewables on electricity markets, the EU emissions trading system (EU ETS) and the renewables and the electricity markets, the coming of capacity crunch in some cases, the capacity markets, the return of central buyers and national energy policies, and what is to be done for the world electricity markets

  8. Long-term program up to fiscal 1993 of electric power source development

    International Nuclear Information System (INIS)

    Kawakami, Shin-ichi

    1984-01-01

    The long-term, ten years, program up to fiscal 1993 of electric power source development, determined by the Government aims at stable power supply and the expansion of utilization of petroleum-substitute energy. The annual growth in the gross national product (GNP) during the ten years was taken as about 4 %. So, the total electric power demand in fiscal 1993 is scheduled to be 731,000 million kwh, about 34 % up from 547,000 million kwh in fiscal 1983. The structure of electric power sources at the end of fiscal 1993 will be hydraulic 19.7 %, thermal 58.3 %, and nuclear 21.9 %. The development of electric power sources to be initiated in fiscal 1984 is hydraulic 500 MW, thermal 2,000 MW, and nuclear 6,000 MW. (Mori, K.)

  9. Statistical hot spot analysis of reactor cores

    International Nuclear Information System (INIS)

    Schaefer, H.

    1974-05-01

    This report is an introduction into statistical hot spot analysis. After the definition of the term 'hot spot' a statistical analysis is outlined. The mathematical method is presented, especially the formula concerning the probability of no hot spots in a reactor core is evaluated. A discussion with the boundary conditions of a statistical hot spot analysis is given (technological limits, nominal situation, uncertainties). The application of the hot spot analysis to the linear power of pellets and the temperature rise in cooling channels is demonstrated with respect to the test zone of KNK II. Basic values, such as probability of no hot spots, hot spot potential, expected hot spot diagram and cumulative distribution function of hot spots, are discussed. It is shown, that the risk of hot channels can be dispersed equally over all subassemblies by an adequate choice of the nominal temperature distribution in the core

  10. Short-Term Forecasting of Electric Energy Generation for a Photovoltaic System

    Directory of Open Access Journals (Sweden)

    Dinh V.T.

    2018-01-01

    Full Text Available This article presents a short-term forecast of electric energy output of a photovoltaic (PV system towards Tomsk city, Russia climate variations (module temperature and solar irradiance. The system is located at Institute of Non-destructive Testing, Tomsk Polytechnic University. The obtained results show good agreement between actual data and prediction values.

  11. Performance of batteries for electric vehicles on short and longer term

    NARCIS (Netherlands)

    Gerssen - Gondelach, Sarah|info:eu-repo/dai/nl/355262436; Faaij, André P C|info:eu-repo/dai/nl/10685903X

    2012-01-01

    In this work, the prospects of available and new battery technologies for battery electric vehicles (BEVs) are examined. Five selected battery technologies are assessed on battery performance and cost in the short, medium and long term. Driving cycle simulations are carried out to assess the

  12. Performance of Batteries for electric vehicles on shorter and longer term

    NARCIS (Netherlands)

    Gerssen-Gondelach, S.J.; Faaij, A.P.C.

    2012-01-01

    In this work, the prospects of available and new battery technologies for battery electric vehicles (BEVs) are examined. Five selected battery technologies are assessed on battery performance and cost in the short, medium and long term. Driving cycle simulations are carried out to assess the

  13. A new cascade NN based method to short-term load forecast in deregulated electricity market

    International Nuclear Information System (INIS)

    Kouhi, Sajjad; Keynia, Farshid

    2013-01-01

    Highlights: • We are proposed a new hybrid cascaded NN based method and WT to short-term load forecast in deregulated electricity market. • An efficient preprocessor consist of normalization and shuffling of signals is presented. • In order to select the best inputs, a two-stage feature selection is presented. • A new cascaded structure consist of three cascaded NNs is used as forecaster. - Abstract: Short-term load forecasting (STLF) is a major discussion in efficient operation of power systems. The electricity load is a nonlinear signal with time dependent behavior. The area of electricity load forecasting has still essential need for more accurate and stable load forecast algorithm. To improve the accuracy of prediction, a new hybrid forecast strategy based on cascaded neural network is proposed for STLF. This method is consists of wavelet transform, an intelligent two-stage feature selection, and cascaded neural network. The feature selection is used to remove the irrelevant and redundant inputs. The forecast engine is composed of three cascaded neural network (CNN) structure. This cascaded structure can be efficiently extract input/output mapping function of the nonlinear electricity load data. Adjustable parameters of the intelligent feature selection and CNN is fine-tuned by a kind of cross-validation technique. The proposed STLF is tested on PJM and New York electricity markets. It is concluded from the result, the proposed algorithm is a robust forecast method

  14. Integrating spot short-term measurements of carbon emissions and backward dietary energy partition calculations to estimate intake in lactating dairy cows fed ad libitum or restricted.

    Science.gov (United States)

    Pereira, A B D; Utsumi, S A; Dorich, C D; Brito, A F

    2015-12-01

    The objective of this study was to use spot short-term measurements of CH4 (QCH4) and CO2 (QCO2) integrated with backward dietary energy partition calculations to estimate dry matter intake (DMI) in lactating dairy cows. Twelve multiparous cows averaging 173±37d in milk and 4 primiparous cows averaging 179±27d in milk were blocked by days in milk, parity, and DMI (as a percentage of body weight) and, within each block, randomly assigned to 1 of 2 treatments: ad libitum intake (AL) or restricted intake (RI=90% DMI) according to a crossover design. Each experimental period lasted 22d with 14d for treatments adaptation and 8d for data and sample collection. Diets contained (dry matter basis): 40% corn silage, 12% grass-legume haylage, and 48% concentrate. Spot short-term gas measurements were taken in 5-min sampling periods from 15 cows (1 cow refused sampling) using a portable, automated, open-circuit gas quantification system (GreenFeed, C-Lock Inc., Rapid City, SD) with intervals of 12h between the 2daily samples. Sampling points were advanced 2h from a day to the next to yield 16 gas samples per cow over 8d to account for diurnal variation in QCH4 and QCO2. The following equations were used sequentially to estimate DMI: (1) heat production (MJ/d)=(4.96 + 16.07 ÷ respiratory quotient) × QCO2; respiratory quotient=0.95; (2) metabolizable energy intake (MJ/d)=(heat production + milk energy) ± tissue energy balance; (3) digestible energy (DE) intake (MJ/d)=metabolizable energy + CH4 energy + urinary energy; (4) gross energy (GE) intake (MJ/d)=DE + [(DE ÷ in vitro true dry matter digestibility) - DE]; and (5) DMI (kg/d)=GE intake estimated ÷ diet GE concentration. Data were analyzed using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC) and Fit Model procedure in JMP (α=0.05; SAS Institute Inc.). Cows significantly differed in DMI measured (23.8 vs. 22.4kg/d for AL and RI, respectively). Dry matter intake estimated using QCH4 and QCO2 coupled with

  15. Energy systems scenario modelling and long term forecasting of hourly electricity demand

    Directory of Open Access Journals (Sweden)

    Poul Alberg Østergaard

    2015-06-01

    Full Text Available The Danish energy system is undergoing a transition from a system based on storable fossil fuels to a system based on fluctuating renewable energy sources. At the same time, more of and more of the energy system is becoming electrified; transportation, heating and fuel usage in industry and elsewhere. This article investigates the development of the Danish energy system in a medium year 2030 situation as well as in a long-term year 2050 situation. The analyses are based on scenario development by the Danish Climate Commission. In the short term, it is investigated what the effects will be of having flexible or inflexible electric vehicles and individual heat pumps, and in the long term it is investigated what the effects of changes in the load profiles due to changing weights of demand sectors are. The analyses are based on energy systems simulations using EnergyPLAN and demand forecasting using the Helena model. The results show that even with a limited short-term electric car fleet, these will have a significant effect on the energy system; the energy system’s ability to integrated wind power and the demand for condensing power generation capacity in the system. Charging patterns and flexibility have significant effects on this. Likewise, individual heat pumps may affect the system operation if they are equipped with heat storages. The analyses also show that the long-term changes in electricity demand curve profiles have little impact on the energy system performance. The flexibility given by heat pumps and electric vehicles in the long-term future overshadows any effects of changes in hourly demand curve profiles.

  16. Improving the principles of short-term electric load forecasting of the Irkutsk region

    Directory of Open Access Journals (Sweden)

    Kornilov Vladimir

    2017-01-01

    Full Text Available Forecasting of electric load (EL is an important task for both electric power entities and large consumers of electricity [1]. Large consumers are faced with the need to compose applications for the planned volume of EL, and the deviation of subsequent real consumption from previously announced leads to the appearance of penalties from the wholesale market. In turn, electricity producers are interested in forecasting the demand for electricity for prompt response to its fluctuations and for the purpose of optimal infrastructure development. The most difficult and urgent task is the hourly forecasting of EL, which is extremely important for the successful solution of problems of optimization of generating capacities, minimization of power losses, dispatching control, security assessment of power supply, etc. Ultimately, such forecasts allow optimizing the cash costs for electricity and fuel or water consumption during generation. This paper analyzes the experience of the branch of JSC "SO UPS" Irkutsk Regional Dispatch Office of the procedure for short-term forecasting of the EL of the Irkutsk region.

  17. Performance of fuzzy approach in Malaysia short-term electricity load forecasting

    Science.gov (United States)

    Mansor, Rosnalini; Zulkifli, Malina; Yusof, Muhammad Mat; Ismail, Mohd Isfahani; Ismail, Suzilah; Yin, Yip Chee

    2014-12-01

    Many activities such as economic, education and manafucturing would paralyse with limited supply of electricity but surplus contribute to high operating cost. Therefore electricity load forecasting is important in order to avoid shortage or excess. Previous finding showed festive celebration has effect on short-term electricity load forecasting. Being a multi culture country Malaysia has many major festive celebrations such as Eidul Fitri, Chinese New Year and Deepavali but they are moving holidays due to non-fixed dates on the Gregorian calendar. This study emphasis on the performance of fuzzy approach in forecasting electricity load when considering the presence of moving holidays. Autoregressive Distributed Lag model was estimated using simulated data by including model simplification concept (manual or automatic), day types (weekdays or weekend), public holidays and lags of electricity load. The result indicated that day types, public holidays and several lags of electricity load were significant in the model. Overall, model simplification improves fuzzy performance due to less variables and rules.

  18. EDF - Activity and sustainable development 2011 - electricity, choices on the long term

    International Nuclear Information System (INIS)

    2012-05-01

    This publication notably contains a set of articles about choices on the long term related to electricity production and distribution. Different aspects are addressed: arbitration (the diversity of the French energy mix), grids (investments and evolution towards smart grids), electricity cost (for households and for industry), nuclear energy (actions and results regarding safety and availability, the EPR project), renewable energies, the design and construction of a dam (Nam Theun 2) in Thailand with an important human development dimension in the project, thermal energy (the future of flame-based power stations using gas or biomass for example), and EDF's commercial policy

  19. Identifying ecological "sweet spots" underlying cyanobacteria functional group dynamics from long-term observations using a statistical machine learning approach

    Science.gov (United States)

    Nelson, N.; Munoz-Carpena, R.; Phlips, E. J.

    2017-12-01

    Diversity in the eco-physiological adaptations of cyanobacteria genera creates challenges for water managers who are tasked with developing appropriate actions for controlling not only the intensity and frequency of cyanobacteria blooms, but also reducing the potential for blooms of harmful taxa (e.g., toxin producers, N2 fixers). Compounding these challenges, the efficacy of nutrient management strategies (phosphorus-only versus nitrogen-and-phosphorus) for cyanobacteria bloom abatement is the subject of an ongoing debate, which increases uncertainty associated with bloom mitigation decision-making. In this work, we analyze a unique long-term (17-year) dataset composed of monthly observations of cyanobacteria genera abundances, zooplankton abundances, water quality, and flow from Lake George, a bloom-impacted flow-through lake of the St. Johns River (FL, USA). Using the Random Forests machine learning algorithm, an assumption-free ensemble modeling approach, the dataset was evaluated to quantify and characterize relationships between environmental conditions and seven cyanobacteria groupings: five genera (Anabaena, Cylindrospermopsis, Lyngbya, Microcystis, and Oscillatoria) and two functional groups (N2 fixers and non-fixers). Results highlight the selectivity of nitrogen in describing genera and functional group dynamics, and potential for physical effects to limit the efficacy of nutrient management as a mechanism for cyanobacteria bloom mitigation.

  20. Modelling the long-term deployment of electricity storage in the global energy system

    International Nuclear Information System (INIS)

    Despres, Jacques

    2015-01-01

    The current development of wind and solar power sources calls for an improvement of long-term energy models. Indeed, high shares of variable wind and solar productions have short- and long-term impacts on the power system, requiring the development of flexibility options: fast-reacting power plants, demand response, grid enhancement or electricity storage. Our first main contribution is the modelling of electricity storage and grid expansion in the POLES model (Prospective Outlook on Long-term Energy Systems). We set up new investment mechanisms, where storage development is based on several combined economic values. After categorising the long-term energy models and the power sector modelling tools in a common typology, we showed the need for a better integration of both approaches. Therefore, the second major contribution of our work is the yearly coupling of POLES to a short-term optimisation of the power sector operation, with the European Unit Commitment and Dispatch model (EUCAD). The two-way data exchange allows the long-term coherent scenarios of POLES to be directly backed by the short-term technical detail of EUCAD. Our results forecast a strong and rather quick development of the cheapest flexibility options: grid interconnections, pumped hydro storage and demand response programs, including electric vehicle charging optimisation and vehicle-to-grid storage. The more expensive battery storage presumably finds enough system value in the second half of the century. A sensitivity analysis shows that improving the fixed costs of batteries impacts more the investments than improving their efficiency. We also show the explicit dependency between storage and variable renewable energy sources. (author) [fr

  1. Short-Term Load Forecast in Electric Energy System in Bulgaria

    Directory of Open Access Journals (Sweden)

    Irina Asenova

    2010-01-01

    Full Text Available As the accuracy of the electricity load forecast is crucial in providing better cost effective risk management plans, this paper proposes a Short Term Electricity Load Forecast (STLF model with high forecasting accuracy. Two kind of neural networks, Multilayer Perceptron network model and Radial Basis Function network model, are presented and compared using the mean absolute percentage error. The data used in the models are electricity load historical data. Even though the very good performance of the used model for the load data, weather parameters, especially the temperature, take important part for the energy predicting which is taken into account in this paper. A comparative evaluation between a traditional statistical method and artificial neural networks is presented.

  2. Long term forecasting of hourly electricity consumption in local areas in Denmark

    DEFF Research Database (Denmark)

    Møller Andersen, Frits; Larsen, Helge V.; Gaardestrup, R.B.

    2013-01-01

    . The model describes the entire profile of hourly consumption and is a first step towards differentiated local predictions of electricity consumption.The model is based on metering of aggregated hourly consumption at transformer stations covering selected local areas and on national statistics of hourly......Long term projections of hourly electricity consumption in local areas are important for planning of the transmission grid. In Denmark, at present the method used for grid planning is based on statistical analysis of the hour of maximum load and for each local area the maximum load is projected...... to change proportional to changes in the aggregated national electricity consumption. That is, specific local conditions are not considered. Yet, from measurements of local consumption we know that:. •consumption profiles differ between local areas,•consumption by categories of customers contribute...

  3. Market structure in the US electricity industry: a long-term perspective

    International Nuclear Information System (INIS)

    Kamerschen, D.R.

    2005-01-01

    We estimate changes in market structure in the US electric power industry during the last three decades using two independent approaches. First, we estimate an industry-wide conjectural-variations parameter. We find that industry concentration was generally rising during the 1970s but has been gradually and consistently falling since the early 1980s. To check the robustness of these results, we then use a translog production function to estimate the Lerner Index. The results confirm that the industry was becoming less concentrated during the 1980s, though the Lerner Index tended to fluctuate during the late 1980s and early 1990s. Our results suggest that the current state of the electricity industry may have more to do with long-term changes in market structure than recent attempts to establish competitive wholesale electricity markets. (author)

  4. Adaptive short-term electricity price forecasting using artificial neural networks in the restructured power markets

    International Nuclear Information System (INIS)

    Yamin, H.Y.; Shahidehpour, S.M.; Li, Z.

    2004-01-01

    This paper proposes a comprehensive model for the adaptive short-term electricity price forecasting using Artificial Neural Networks (ANN) in the restructured power markets. The model consists: price simulation, price forecasting, and performance analysis. The factors impacting the electricity price forecasting, including time factors, load factors, reserve factors, and historical price factor are discussed. We adopted ANN and proposed a new definition for the MAPE using the median to study the relationship between these factors and market price as well as the performance of the electricity price forecasting. The reserve factors are included to enhance the performance of the forecasting process. The proposed model handles the price spikes more efficiently due to considering the median instead of the average. The IEEE 118-bus system and California practical system are used to demonstrate the superiority of the proposed model. (author)

  5. Electric long-term behaviour of polyethylene insulations for medium-voltage cables cross-linked chemically or by radiation

    International Nuclear Information System (INIS)

    Scharff, C.; Eberhardt, M.

    1989-01-01

    The electric long-term behaviour of cross-linked polyethylene (CLPE) was studied at room temperature by measuring the channel operating time under needling and the total charge before channel operation. It is found that the decomposition products formed in CLPE act as tension stabilizers. They have a dominating influence on the electric long-term behaviour

  6. Simulation of demand side participation in Spanish short term electricity markets

    International Nuclear Information System (INIS)

    Valencia-Salazar, I.; Alvarez, C.; Escriva-Escriva, G.; Alcazar-Ortega, M.

    2011-01-01

    Highlights: → Benefits from customer active participation can be obtained with a proper generation of bids and offers. → Simulation of Spanish customers' participation is shown in daily, intra-daily and balancing markets. → Market efficiency and economics profits arise in balancing markets by using customer load reductions. → Real market prices and real customers' consumptions profiles are used in the simulations. -- Abstract: Demand response resources management is one of the most investigated solutions oriented to improve the efficiency in electricity markets. In this paper, the capability of customers to participate in short term markets is analyzed. An available methodology to analyze the daily and monthly energy consumptions of large customers is used to create energy offers and bids. This allows customers to participate in energy markets in order to buy, as first step, the usual electricity consumption and, additionally, to offer demand reductions in the short term electricity markets. Additionally, this paper shows the customer potential to participate in the Spanish electricity markets.

  7. Describing Long-Term Electricity Demand Scenarios in the Telecommunications Industry: A Case Study of Japan

    Directory of Open Access Journals (Sweden)

    Yusuke Kishita

    2016-01-01

    Full Text Available Due to the rapid expansion of information and communication technology (ICT usage, the telecommunications industry is faced with a challenge to promote green ICT toward achieving a low-carbon society. One critical obstacle in planning long-term strategies for green ICT is the uncertainty of various external factors, such as consumers’ lifestyle and technological advancement. To tackle this issue, this paper employs a scenario planning method to analyze electricity consumption in the telecommunications industry, where both changes in various external factors and energy-saving measures are assumed. We propose a model to estimate future electricity consumption of the telecommunications industry using a statistical approach. In a case study, we describe four scenarios that differ in the diffusion of ICT and the technological advancement of ICT equipment in order to analyze the electricity consumption in Japan’s telecommunications industry to 2030. The results reveal that the electricity consumption in 2030 becomes 0.7–1.6-times larger than the 2012 level (10.7 TWh/year. It is also shown that the most effective measures to reduce the electricity consumption include improving the energy efficiency of IP (Internet Protocol communication equipment and mobile communication equipment.

  8. Prices on electricity and transmission of electricity

    International Nuclear Information System (INIS)

    2003-01-01

    This publication contains data on prices of electric energy and transmission of electricity valid from 1 January 2003. The purpose is to illustrate the price changes on the electricity market in terms of prices for different customer categories. All companies holding network concessions for areas and all companies trading in electricity are included in this report, which is produced on an annual basis.The prices for transmission services 1 January 2003 were on the whole unchanged compared to the preceding year. For households the mean annual cost was SEK 882 for flats, SEK 4 335 for one- or two-family houses with electric heating and SEK 1 925 for those without electric heating. Electricity prices rose considerably on 1 January 2003 compared to the year before. The mean price per kWh for households with standard agreements was SEK 0.519 for deliveries to flats, SEK 0.447 for one- or two-family houses with electric heating and SEK 0.471 without electric heating. As a result, the mean annual cost increased by SEK 326 for flats, SEK 3 012 for one- or two-family houses with electric heating, and by SEK 774 for those houses without electric heating. The high costs of electricity may be explained in part by the development on the Nordic Power Exchange (Nord Pool), where the spot price increased by about 290 per cent during 2002 (1 USD is about 8 SEK)

  9. Ionospheric hot spot at high latitudes

    International Nuclear Information System (INIS)

    Schunk, R.W.; Sojka, J.J.

    1982-01-01

    A hot spot (or spots) can occur in the high-latitude ionosphere depending on the plasma convection pattern. The hot spot corresponds to a small magnetic local time-magnetic latitude region of elevated ion temperatures located near the dusk and/or dawn meridians. For asymmetric convection electric field patterns, with enhanced flow in either the dusk or dawn sector of the polar cap, a single hot spot should occur in association with the strong convection cell. However, on geomagnetically disturbed days, two strong convection cells can occur, and hence, two hot spots should exist. The hot spot should be detectable when the electric field in the strong convection cell exceeds about 40 mV m -1 . For electric fields of the order of 100 mV m -1 in the convection cell, the ion temperature in the hot spot is greatest at low altitudes, reaching 4000 0 K at 160 km, and decreases with altitude in the F-region. An ionospheric hot spot (or spots) can be expected at all seasons and for a wide range of solar cycle conditions

  10. The electric dipole moment of the deuteron from the QCD {theta}-term

    Energy Technology Data Exchange (ETDEWEB)

    Bsaisou, J.; Liebig, S. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Center for Hadron Physics, Juelich (Germany); Hanhart, C.; Nogga, A.; Wirzba, A. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Center for Hadron Physics, Juelich (Germany); Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich (Germany); Forschungszentrum Juelich, JARA - Forces And Matter Experiments, Juelich (Germany); Meissner, U.G. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Center for Hadron Physics, Juelich (Germany); Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich (Germany); Forschungszentrum Juelich, JARA - Forces And Matter Experiments, Juelich (Germany); Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Universitaet Bonn, Bethe Center for Theoretical Physics, Bonn (Germany)

    2013-03-15

    The two-nucleon contributions to the electric dipole moment (EDM) of the deuteron, induced by the QCD {theta}-term, are calculated in the framework of effective field theory up-to-and-including next-to-next-to-leading order. In particular we find for the difference of the deuteron EDM and the sum of proton and neutron EDM induced by the QCD {theta}-term a value of (- 5.4 {+-}3.9) anti {theta} x 10{sup -} {sup 4} e fm. The by far dominant uncertainty comes from the CP- and isospin-violating {pi}NN coupling constant. (orig.)

  11. The electricity supply industry in England and Wales. Medium term development plan 1986-93

    International Nuclear Information System (INIS)

    1986-09-01

    The main objective of the Electricity Supply Industry in England and Wales is to develop and maintain electricity supplies to meet customers' needs as cheaply as possible. Over the medium term, 1986 - 1993, the goal is to reduce the real average price per kWh sold, whilst maintaining high standards of service and meeting financial obligations. The strategy set out comprises reducing controllable costs per kWh sold to 1992/3, pursuing a vigorous and selective marketing strategy so that an expected sales increase of 10% is achieved, securing a long term supply of coal at minimum cost by developing the commercial relationship with British Coal, increasing the proportion of electrical energy supplied by nuclear energy to 25% by 1992/3 and being environmentally concerned. The introduction outlines the medium term business, energy and economic environment, financial targets and price prospects. Plans to support the strategy outlined are presented. Each section sets out the objectives and the plans to achieve these. The strategy for new power stations is to develop fossil-fueled and nuclear as well as to develop alternative technologies. (UK)

  12. Forecast of electric power market to short-term: a time series approcah

    International Nuclear Information System (INIS)

    Costa, Roberio Neves Pelinca da.

    1994-01-01

    Three different time series approaches are analysed by this dissertation in the Brazilian electricity markert context. The aim is to compare the predictive performance of these approaches from a simulated exercise using the main series of the Brazilian consumption of electricity: Total Consumption, Industrial Consumption, Residencial Consumption and Commercial Consumption. One concludes that these appraches offer an enormous potentiality to the short-term planning system of the Electric Sector. Among the univariate models, the results for the analysed period point out that the forecast produced by Holt-Winter's models are more accurate than those produced by ARIMA and structural models. When explanatory variables are introduced in the last models, one can notice, in general, an improvement in the predictive performance of the models, although there is no sufficient evidence to consider that they are superior to Holt-Winter's models. The models with explanatory variables can be particularly useful, however, when one intends either to build scenarios or to study the effects of some variables on the consumption of electricity. (author). 73 refs., 19 figs., 13 tabs

  13. Planning India's long-term energy shipment infrastructures for electricity and coal

    International Nuclear Information System (INIS)

    Bowen, Brian H.; Canchi, Devendra; Lalit, Vishal Agarwal; Preckel, Paul V.; Sparrow, F.T.; Irwin, Marty W.

    2010-01-01

    The Purdue Long-Term Electricity Trading and Capacity Expansion Planning Model simultaneously optimizes both transmission and generation capacity expansions. Most commercial electricity system planning software is limited to only transmission planning. An application of the model to India's national power grid, for 2008-2028, indicates substantial transmission expansion is the cost-effective means of meeting the needs of the nation's growing economy. An electricity demand growth rate of 4% over the 20-year planning horizon requires more than a 50% increase in the Government's forecasted transmission capacity expansion, and 8% demand growth requires more than a six-fold increase in the planned transmission capacity expansion. The model minimizes the long-term expansion costs (operational and capital) for the nation's five existing regional power grids and suggests the need for large increases in load-carrying capability between them. Changes in coal policy affect both the location of new thermal power plants and the optimal pattern inter-regional transmission expansions.

  14. Rocky Mountain spotted fever

    Science.gov (United States)

    ... spotted fever on the foot Rocky Mountain spotted fever, petechial rash Antibodies Deer and dog tick References McElligott SC, Kihiczak GG, Schwartz RA. Rocky Mountain spotted fever and other rickettsial infections. In: Lebwohl MG, Heymann ...

  15. Quantitative and experimental analysis of investment incentive mechanisms in electricity markets: short- and long-term analysis of actors' strategies

    International Nuclear Information System (INIS)

    Khalfallah, Mohamed Haikel

    2009-01-01

    In this thesis, we deal with the question of reliability of electricity system and particularly the problem of generation capacity adequacy in electricity markets, characterized by uncertain and volatile demand. This question is currently the object of many politics and economics debates in the European Commission of energy. It occurs within the context of de-regulations and reforms of liberalization operated in western countries. This deregulation was caused many shortages and crisis in many electricity markets in the world. Failures are caused by several factors such as, the presence of uncertainties on future demand and fuel prices, the risk-averse behavior of investors and the market power exercised by existing generators. They had led to high spot market prices and a fundamental imbalance between the steadily growing demand for power and the limited increases, due to the lack of investments, in generation capacities. Many mechanisms, additional to the energy market, that ensure an adequate incentive for investments and a stable and socially acceptable electricity prices have been proposed. In this work, we compare different investment incentive mechanisms, in terms of long-term capacity adequacy in an uncertain environment, cost effectiveness and the ability of reducing market power. In the literature, the problem of long-term system reliability has been largely studied in qualitative terms. A few works attempt to model the quantitative effects of those market designs. The contribution of this work is to propose a quantitative analysis based on dynamics models. Competition is considered by using the principles of game theory. Stochastic dynamic programming is used to deal with the stochastic environment of the market and mixed complementarity problem and variational inequality formulations are employed to find Nash equilibrium. In addition to the analytic analysis, an experimental study is carried out in order to include a larger diversity of strategy. The

  16. Assessing long-term effects of demand response policies in wholesale electricity markets

    International Nuclear Information System (INIS)

    Cepeda, Mauricio; Saguan, Marcelo

    2014-05-01

    This paper deals with the practical problems related to long-term issues in electricity markets in the presence of demand response development. Different policies have been implemented around the world aiming to develop demand response potential. Externalities, in particular the CO_2 externality, have been one of the key elements in the debate on the effectiveness of different policies regarding demand response development. Policy makers have several options to deal with this externality. The most direct one is to correct the externality by setting a CO_2 price at a level that corresponds to the cost to society of the corresponding CO_2 emissions. One alternative solution could be to subsidize carbon-free technologies as demand response. In this paper we examine potential long-term impacts of these two policies. We rely on a long-term market simulation model that characterizes expansion decisions in a competitive regime. We test for each policy two different scenarios regarding the possibility of internalization of the CO_2 externality. The results show that differences in development policies affect both investments and social costs in the wholesale electricity market and confirm previous findings that a market-driven development of demand response with the internalization of the CO_2 externality is the most efficient approach. (authors)

  17. Long-term electrical resistivity monitoring of recharge-induced contaminant plume behavior.

    Science.gov (United States)

    Gasperikova, Erika; Hubbard, Susan S; Watson, David B; Baker, Gregory S; Peterson, John E; Kowalsky, Michael B; Smith, Meagan; Brooks, Scott

    2012-11-01

    Geophysical measurements, and electrical resistivity tomography (ERT) data in particular, are sensitive to properties that are related (directly or indirectly) to hydrological processes. The challenge is in extracting information from geophysical data at a relevant scale that can be used to gain insight about subsurface behavior and to parameterize or validate flow and transport models. Here, we consider the use of ERT data for examining the impact of recharge on subsurface contamination at the S-3 ponds of the Oak Ridge Integrated Field Research Challenge (IFRC) site in Tennessee. A large dataset of time-lapse cross-well and surface ERT data, collected at the site over a period of 12 months, is used to study time variations in resistivity due to changes in total dissolved solids (primarily nitrate). The electrical resistivity distributions recovered from cross-well and surface ERT data agrees well, and both of these datasets can be used to interpret spatiotemporal variations in subsurface nitrate concentrations due to rainfall, although the sensitivity of the electrical resistivity response to dilution varies with nitrate concentration. Using the time-lapse surface ERT data interpreted in terms of nitrate concentrations, we find that the subsurface nitrate concentration at this site varies as a function of spatial position, episodic heavy rainstorms (versus seasonal and annual fluctuations), and antecedent rainfall history. These results suggest that the surface ERT monitoring approach is potentially useful for examining subsurface plume responses to recharge over field-relevant scales. Published by Elsevier B.V.

  18. On Long-Term Transmission Rights in the Nordic Electricity Markets

    Directory of Open Access Journals (Sweden)

    Petr Spodniak

    2017-03-01

    Full Text Available In vein with the new energy market rules drafted in the EU this paper presents and discusses two contract types for hedging the risks connected to long-term transmission rights, the financial transmission right (FTR and the electricity price area differentials (EPAD that are used in the Nordic electricity markets. The possibility to replicate the FTR contracts with a combination of EPAD contracts is presented and discussed. Based on historical evidence and empirical analysis of ten Nordic interconnectors and twenty bidding areas, we investigate the pricing accuracy of the replicated FTR contracts by quantifying ex-post forward risk premia. The results show that the majority of the studied FTR contain a negative risk premium, especially the monthly and the quarterly contracts. Reverse flow (unnatural pricing was identified for two interconnectors. From a theoretical policy point of view the results imply that it may be possible to continue with the EPAD-based system by using EPAD Combos in the Nordic countries, even if FTR contracts would prevail elsewhere in the EU. In practice the pricing of bi-directional EPAD contracts is more complex and may not always be very efficient. The efficiency of the EPAD market structure should be discussed from various points of view before accepting their status quo as a replacement for FTRs in the Nordic electricity markets.

  19. A New Two-Stage Approach to Short Term Electrical Load Forecasting

    Directory of Open Access Journals (Sweden)

    Dragan Tasić

    2013-04-01

    Full Text Available In the deregulated energy market, the accuracy of load forecasting has a significant effect on the planning and operational decision making of utility companies. Electric load is a random non-stationary process influenced by a number of factors which make it difficult to model. To achieve better forecasting accuracy, a wide variety of models have been proposed. These models are based on different mathematical methods and offer different features. This paper presents a new two-stage approach for short-term electrical load forecasting based on least-squares support vector machines. With the aim of improving forecasting accuracy, one more feature was added to the model feature set, the next day average load demand. As this feature is unknown for one day ahead, in the first stage, forecasting of the next day average load demand is done and then used in the model in the second stage for next day hourly load forecasting. The effectiveness of the presented model is shown on the real data of the ISO New England electricity market. The obtained results confirm the validity advantage of the proposed approach.

  20. On the effect of long-term electrical stimulation on three-dimensional cell cultures: Hen embryo brain spheroids

    OpenAIRE

    Uroukov, Ivan S; Bull, Larry

    2008-01-01

    A comprehensive dataset of multielectrode array recordings was collected from three-dimensional hen embryo brain cell cultures, termed spheroids, under long-term electrical stimulation. The aim is to understand the ongoing changes in the spiking activity under electrical stimulation within the lifetime of 14–72DIV of the neuronal networks contained therein. The spiking dynamics were analyzed and behavioral characteristics derived. Some effects on spiking patterns and exhaustion were followed ...

  1. Development of near-term batteries for electric vehicles. Summary report, October 1977-September 1979

    Energy Technology Data Exchange (ETDEWEB)

    Rajan, J.B. (comp.)

    1980-06-01

    The status and results through FY 1979 on the Near-Term Electric Vehicle Battery Project of the Argonne National Laboratory are summarized. This project conducts R and D on lead-acid, nickel/zinc and nickel/iron batteries with the objective of achieving commercialization in electric vehicles in the 1980's. Key results of the R and D indicate major technology advancements and achievement of most of FY 1979 performance goals. In the lead-acid system the specific energy was increased from less than 30 Wh/kg to over 40 Wh/kg at the C/3 rate; the peak power density improved from 70 W/kg to over 110 W/kg at the 50% state of charge; and over 200 deep-discharge cycle life demonstrated. In the nickel/iron system a specific energy of 48 Wh/kg was achieved; a peak power of about 100 W/kg demonstrated and a life of 36 cycles obtained. In the nickel/zinc system, specific energies of up to 64 Wh/kg were shown; peak powers of 133 W/kg obtained; and a life of up to 120 cycles measured. Future R and D will emphasize increased cycle life for nickel/zinc batteries and increased cycle life and specific energy for lead-acid and nickel/iron batteries. Testing of 145 cells was completed by NBTL. Cell evaluation included a full set of performance tests plus the application of a simulated power profile equivalent to the power demands of an electric vehicle in stop-start urban driving. Simplified test profiles which approximate electric vehicle demands are also described.

  2. Electricity and long term supply security. Search for power market respectful legal instruments

    International Nuclear Information System (INIS)

    Finon, D.; Pignon, V.

    2006-01-01

    This paper, also published in 'ISMEA Economie et Societe' Journal (Energy series 2006, no.10), deals with theoretical aspects of long term electricity supply security. Market prices and contractual arrangements on the physical and financial electricity markets do not allow to create sufficient incentives to invest in adequate capacity for guaranteeing the appropriate level of supply in every circumstance. The long term security of supply by capacity adequacy must be conceptualized as a collective good. Alternative solutions to reach capacity adequacy which have been adopted in different markets are successively considered: public procurement of strategic reserves, capacity payment, capacity obligation with exchangeable rights. Each one presents theoretical limits and practical drawbacks when implemented in complex markets. That brings out the interest of mechanism of centralized auctions for forward capacity contracts (or reliability options); it combines controls by quantity and by price while stabilizing investment in peak power plants and is compatible with energy and reserves markets, that is not the case of the three other instruments. (authors)

  3. Multi criteria analysis for the long term planning of the mexican electrical system expansion - 337

    International Nuclear Information System (INIS)

    Martin-del-Campo, C.; Guadarrama, R.; Francois, J.L.

    2010-01-01

    A multi-criteria analysis was applied to the long term electricity expansion planning for Mexico for the 2008-2030 period. This methodology is based on a fuzzy logic inference system, which allows for the definition of a decision function that takes into account all the evaluation parameters. This function permits one to rank the alternative expansion plans in order to determine the most attractive option. In this study four evaluation parameters were considered: (a) the total generating cost obtained from an optimization expansion using the WASP-IV model, (b) the economic risk associated with fuel prices increases, (c) the diversity of technologies in the mix, and (d) the external costs. The analysis was applied to a base case and to three additional expansion cases, which are very similar to the base case, but each of them excludes the addition of a certain type of candidate technology in the optimization planning. The base case is Plan A which has six candidate technologies available for the optimization planning. Plan B excludes coal; Plan C excludes oil, and Plan D excludes nuclear energy. After the decision analysis was made it was found that Plan B is best followed by Plan A, then Plan C and finally Plan D. The worst plan expansion was obtained when the nuclear candidate was excluded in the program of additions during the time period. The primary conclusion is that nuclear energy must participate in the mix of electricity generation. This result can be used to define the energy policy for electricity production in Mexico in the medium-long term scenario. (authors)

  4. Ecological and biomedical effects of effluents from near-term electric vehicle storage battery cycles

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    An assessment of the ecological and biomedical effects due to commercialization of storage batteries for electric and hybrid vehicles is given. It deals only with the near-term batteries, namely Pb/acid, Ni/Zn, and Ni/Fe, but the complete battery cycle is considered, i.e., mining and milling of raw materials, manufacture of the batteries, cases and covers; use of the batteries in electric vehicles, including the charge-discharge cycles; recycling of spent batteries; and disposal of nonrecyclable components. The gaseous, liquid, and solid emissions from various phases of the battery cycle are identified. The effluent dispersal in the environment is modeled and ecological effects are assessed in terms of biogeochemical cycles. The metabolic and toxic responses by humans and laboratory animals to constituents of the effluents are discussed. Pertinent environmental and health regulations related to the battery industry are summarized and regulatory implications for large-scale storage battery commercialization are discussed. Each of the seven sections were abstracted and indexed individually for EDB/ERA. Additional information is presented in the seven appendixes entitled; growth rate scenario for lead/acid battery development; changes in battery composition during discharge; dispersion of stack and fugitive emissions from battery-related operations; methodology for estimating population exposure to total suspended particulates and SO/sub 2/ resulting from central power station emissions for the daily battery charging demand of 10,000 electric vehicles; determination of As air emissions from Zn smelting; health effects: research related to EV battery technologies. (JGB)

  5. Environmental implications of electricity generation in an integrated long-term planning framework

    International Nuclear Information System (INIS)

    Turner, Graham M.; West, James

    2012-01-01

    Long-term, integrated modelling of electricity generation capacity and its operational requirements is important for coherent energy policy because of the multi-decadal lifespan of such plant, and because related fuel requirements, water consumption, and greenhouse gas emissions impact other sectors. This paper describes a physical model of electricity generation designed for long-term simulations, including the reproduction of decades of historical data, and its application to key policy questions. The simulation uses a dynamic, physical input–output model for the basic material and energy industries, embedded in an economy-wide stocks and flows framework (SFF). The historical reproduction, illustrated for the state of Victoria, is based on integrating bottom-up technical data on physical processes as inputs, and validating output against top-down aggregate data. We show that while greenhouse gas emissions would decrease significantly with the aggressive introduction of cleaner generation technology, long-term reductions are difficult to maintain against ongoing growth in consumption. Additionally, our sensitivity analysis identifies the importance of rapid action due to the age structure of operating power stations. We also identify significant imposts of alternative power generation on land and water resources, though a business-as-usual scenario would impose greater losses of water resources. - Highlights: ► System-wide dynamic analysis is needed to avoid unintended adverse environmental outcomes. ► Dynamics of long-lived plant is important in transitions for reducing greenhouse gas emissions. ► Large gains in GHG emissions efficiency of generation portfolios fail to maintain low emissions.

  6. Electricity

    CERN Document Server

    Basford, Leslie

    2013-01-01

    Electricity Made Simple covers the fundamental principles underlying every aspect of electricity. The book discusses current; resistance including its measurement, Kirchhoff's laws, and resistors; electroheat, electromagnetics and electrochemistry; and the motor and generator effects of electromagnetic forces. The text also describes alternating current, circuits and inductors, alternating current circuits, and a.c. generators and motors. Other methods of generating electromagnetic forces are also considered. The book is useful for electrical engineering students.

  7. Access to long-term capacity for electric interconnections: towards a single European set of rules

    International Nuclear Information System (INIS)

    2010-05-01

    Guaranteeing firmness of interconnection capacity (or compensating curtailments based on the daily market prices) is a key element to the design of the integrated European electricity market. However, although the European energy regulators are on the way to reaching a consensus on the target to be met in terms of firmness, there is less consensus on how this target can be reached, which means the two following key questions will have to be duly addressed: - How can we improve confidence in the daily price references used to compensate interconnection capacity holders in cases of curtailment? - How can we encourage transmission system operators to allocate a maximum of financially firm capacity, at a lesser cost for network users? In the short-term, in the absence of appropriate incentive mechanisms to maximise capacity, the regulators have no other choice but to guarantee transmission system operators that costs related to firmness of capacity allocated at the different time frames will be covered. In this perspective, transitory solutions can be implemented by regulators in order to limit the risk borne by network users (for example, by introducing caps on price differentials and/or on the budget available for compensating curtailments). The choices in terms of capacity and how it is distributed between the different time frames (daily, monthly, annual and multi-annual) are also important decision variables, as these could limit the risk borne by network users. In such, as they are responsible for guaranteeing the interests of network users, the regulators should decide what level of capacity should be made available to the market. This decision should be taken in close collaboration with the network operators, who have all the expertise needed in terms of calculating capacity. Finally, on the interconnections where a market-coupling mechanism exists, the regulators should ask the transmission system operators to allocate the long-term interconnection capacity in

  8. Stochastic short-term maintenance scheduling of GENCOs in an oligopolistic electricity market

    International Nuclear Information System (INIS)

    Fotouhi Ghazvini, Mohammad Ali; Canizes, Bruno; Vale, Zita; Morais, Hugo

    2013-01-01

    Highlights: ► Decision making under uncertainty. ► Stochastic Mixed Integer Quadratic Programming applied to short-term maintenance scheduling. ► Outage scheduling in Oligopolistic electricity markets. ► Generation companies maintenance scheduling. -- Abstract: In the proposed model, the independent system operator (ISO) provides the opportunity for maintenance outage rescheduling of generating units before each short-term (ST) time interval. Long-term (LT) scheduling for 1 or 2 years in advance is essential for the ISO and the generation companies (GENCOs) to decide their LT strategies; however, it is not possible to be exactly followed and requires slight adjustments. The Cournot-Nash equilibrium is used to characterize the decision-making procedure of an individual GENCO for ST intervals considering the effective coordination with LT plans. Random inputs, such as parameters of the demand function of loads, hourly demand during the following ST time interval and the expected generation pattern of the rivals, are included as scenarios in the stochastic mixed integer program defined to model the payoff-maximizing objective of a GENCO. Scenario reduction algorithms are used to deal with the computational burden. Two reliability test systems were chosen to illustrate the effectiveness of the proposed model for the ST decision-making process for future planned outages from the point of view of a GENCO.

  9. Density prediction and dimensionality reduction of mid-term electricity demand in China: A new semiparametric-based additive model

    International Nuclear Information System (INIS)

    Shao, Zhen; Yang, Shan-Lin; Gao, Fei

    2014-01-01

    Highlights: • A new stationary time series smoothing-based semiparametric model is established. • A novel semiparametric additive model based on piecewise smooth is proposed. • We model the uncertainty of data distribution for mid-term electricity forecasting. • We provide efficient long horizon simulation and extraction for external variables. • We provide stable and accurate density predictions for mid-term electricity demand. - Abstract: Accurate mid-term electricity demand forecasting is critical for efficient electric planning, budgeting and operating decisions. Mid-term electricity demand forecasting is notoriously complicated, since the demand is subject to a range of external drivers, such as climate change, economic development, which will exhibit monthly, seasonal, and annual complex variations. Conventional models are based on the assumption that original data is stable and normally distributed, which is generally insignificant in explaining actual demand pattern. This paper proposes a new semiparametric additive model that, in addition to considering the uncertainty of the data distribution, includes practical discussions covering the applications of the external variables. To effectively detach the multi-dimensional volatility of mid-term demand, a novel piecewise smooth method which allows reduction of the data dimensionality is developed. Besides, a semi-parametric procedure that makes use of bootstrap algorithm for density forecast and model estimation is presented. Two typical cases in China are presented to verify the effectiveness of the proposed methodology. The results suggest that both meteorological and economic variables play a critical role in mid-term electricity consumption prediction in China, while the extracted economic factor is adequate to reveal the potentially complex relationship between electricity consumption and economic fluctuation. Overall, the proposed model can be easily applied to mid-term demand forecasting, and

  10. Long-term aging and loss-of-coolant accident (LOCA) testing of electrical cables

    International Nuclear Information System (INIS)

    Nelson, C.F.; Gauthier, G.; Carlin, F.

    1996-10-01

    Experiments were performed to assess the aging degradation and loss-of-coolant accident (LOCA) behavior of electrical cables subjected to long-term aging exposures. Four different cable types were tested in both the U.S. and France: (1) U.S. 2 conductor with ethylene propylene rubber (EPR) insulation and a Hypalon jacket. (2) U.S. 3 conductor with cross-linked polyethylene (XLPE) insulation and a Hypalon jacket. (3) French 3 conductor with EPR insulation and a Hypalon jacket. (4) French coaxial with polyethylene (PE) insulation and a PE jacket. The data represent up to 5 years of simultaneous aging where the cables were exposed to identical aging radiation doses at either 40 degrees C or 70 degrees C; however, the dose rate used for the aging irradiation was varied over a wide range (2-100 Gy/hr). Aging was followed by exposure to simulated French LOCA conditions. Several mechanical, electrical, and physical-chemical condition monitoring techniques were used to investigate the degradation behavior of the cables. All the cables, except for the French PE cable, performed acceptably during the aging and LOCA simulations. In general, cable degradation at a given dose was highest for the lowest dose rate, and the amount of degradation decreased as the dose rate was increased

  11. Hamiltonian term for a uniform dc electric field under the adiabatic approximation

    Science.gov (United States)

    Siu, Zhuo Bin; Jalil, Mansoor B. A.; Tan, Seng Ghee

    2018-02-01

    In this work, we show that the disorder-free Kubo formula for the nonequilibrium value of an observable due to a dc electric field, represented by Exx ̂ in the Hamiltonian, can be interpreted as the standard time-independent theory response of the observable due to a time- and position-independent perturbation HMF. We derive the explicit expression for HMF and show that it originates from the adiabatic approximation to Kubo formula and the time-independent perturbation theory, as well as the Sundaram-Niu wave-packet formalism, we show that HMF reproduces the effect of the E field, i.e., Exx ̂ , up to the first order. This replacement suggests the emergence of a spin current term that is not captured by the standard Kubo formula spin current calculation. We illustrate this via the exemplary spin current for the heavy-hole spin-3/2 Luttinger system.

  12. Feasibility demonstration of using wire electrical-discharge machining, abrasive flow honing, and laser spot welding to manufacture high-precision triangular-pitch Zircaloy-4 fuel-rod-support grids

    International Nuclear Information System (INIS)

    Horwood, W.A.

    1982-05-01

    Results are reported supporting the feasibility of manufacturing high precision machined triangular pitch Zircaloy-4 fuel rod support grids for application in water cooled nuclear power reactors. The manufacturing processes investigated included wire electrical discharge machining of the fuel rod and guide tube cells in Zircaloy plate stock to provide the grid body, multistep pickling of the machined grid to provide smooth and corrosion resistant surfaces, and laser welding of thin Zircaloy cover plates to both sides of the grid body to capture separate AM-350 stainless steel insert springs in the grid body. Results indicated that dimensional accuracy better than +- 0.001 and +- 0.002 inch could be obtained on cell shape and position respectively after wire EDM and surface pickling. Results on strength, corrosion resistance, and internal quality of laser spot welds are provided

  13. Using forward markets to improve electricity market design

    International Nuclear Information System (INIS)

    Ausubel, Lawrence M.; Cramton, Peter

    2010-01-01

    Forward markets, both medium term and long term, complement the spot market for wholesale electricity. The forward markets reduce risk, mitigate market power, and coordinate new investment. In the medium term, a forward energy market lets suppliers and demanders lock in energy prices and quantities for one to three years. In the long term, a forward reliability market assures adequate resources are available when they are needed most. The forward markets reduce risk for both sides of the market, since they reduce the quantity of energy that trades at the more volatile spot price. Spot market power is mitigated by putting suppliers and demanders in a more balanced position at the time of the spot market. The markets also reduce transaction costs and improve liquidity and transparency. Recent innovations to the Colombia market illustrate the basic elements of the forward markets and their beneficial role. (author)

  14. Using forward markets to improve electricity market design

    Energy Technology Data Exchange (ETDEWEB)

    Ausubel, Lawrence M.; Cramton, Peter [University of Maryland, College Park, MD 20742 (United States)

    2010-12-15

    Forward markets, both medium term and long term, complement the spot market for wholesale electricity. The forward markets reduce risk, mitigate market power, and coordinate new investment. In the medium term, a forward energy market lets suppliers and demanders lock in energy prices and quantities for one to three years. In the long term, a forward reliability market assures adequate resources are available when they are needed most. The forward markets reduce risk for both sides of the market, since they reduce the quantity of energy that trades at the more volatile spot price. Spot market power is mitigated by putting suppliers and demanders in a more balanced position at the time of the spot market. The markets also reduce transaction costs and improve liquidity and transparency. Recent innovations to the Colombia market illustrate the basic elements of the forward markets and their beneficial role. (author)

  15. The spot market and the spot price: applicability and limitations

    International Nuclear Information System (INIS)

    White, G. Jr.

    1987-01-01

    The subject of spot prices and their relationship to long-term contracting is addressed. The author is associated with Nuexco, which originally was called the Nuclear Exchange Corporation. They use the term Exchange Value which originated in the idea that Nuexco operated an exchange 'bank' - those with too much uranium could 'bank it', those with short-term needs could borrow from the 'bank'. If the borrower repaid slightly more or less the difference was settled using the 'exchange value'. This became used for longer-term transactions and now settling the monthly value is an important part of Nuexco's activities. The exact nature of the Exchange Value is defined. Now more and more buyers are insisting on spot market related pricing even where this is not meaningfully related to uranium production costs. (U.K.)

  16. SpotADAPT

    DEFF Research Database (Denmark)

    Kaulakiene, Dalia; Thomsen, Christian; Pedersen, Torben Bach

    2015-01-01

    by Amazon Web Services (AWS). The users aiming for the spot market are presented with many instance types placed in multiple datacenters in the world, and thus it is difficult to choose the optimal deployment. In this paper, we propose the framework SpotADAPT (Spot-Aware (re-)Deployment of Analytical...... of typical analytical workloads and real spot price traces. SpotADAPT's suggested deployments are comparable to the theoretically optimal ones, and in particular, it shows good cost benefits for the budget optimization -- on average SpotADAPT is at most 0.3% more expensive than the theoretically optimal...

  17. Projection of primary energy in electricity generation with evaluation of demand and supply of energy in the medium-term horizon (2020), long-term (2035) and very long term (2060)

    International Nuclear Information System (INIS)

    Mafra, Olga Y.; Alvim, Carlos Feu; Eidelman, Frida; Guimaraes, Leonam dos Santos

    2013-01-01

    The Global Energy demand and the participation of electricity in scenarios of medium (2020), long (2035) and very long (2060) terms are estimated. It is also evaluated the share of different primary energies in electricity generation and their availability in the country. Three economic scenarios were considered and different hypothesis regarding the participation of nuclear energy were analyzed. (author)

  18. Assessment of short/long term electric field strength measurements for a pilot district

    Science.gov (United States)

    Kurnaz, Cetin; Yildiz, Dogan; Karagol, Serap

    2018-03-01

    The level of electromagnetic radiation (EMR) exposure increases day by day as natural consequences of technological developments. In recent years, the increasing use of cellular systems has made it necessary to measure and evaluate EMR originating from base stations. In this study, broadband and band selective electric field strength (E) measurements were taken at four different times in order to evaluate the change of short term E in Atakum district of Samsun, Turkey. The measurements were collected from 46 different locations using a SRM 3006 and a PMM 8053 EMR meter in a band from 100 kHz to 3 GHz, and the maximum E (Emax) and the average E (Eavg) were recorded. The highest values have been noticed in these measurements at 9.45 V/m and 17.53 V/m for Eavg and Emax respectively. Apart from these measurements, 24 hour long term E measurements were taken at a location where the highest value was observed and analyzed, to observe the change of Es during a day. At the end of the study, a tentative mathematical model that helps in computing the total E of the medium with 95% accuracy, was obtained.

  19. Postfatigue potentiation of the paralyzed soleus muscle: evidence for adaptation with long-term electrical stimulation training

    OpenAIRE

    Shields, Richard K.; Dudley-Javoroski, Shauna; Littmann, Andrew E.

    2006-01-01

    Understanding the torque output behavior of paralyzed muscle has important implications for the use of functional neuromuscular electrical stimulation systems. Postfatigue potentiation is an augmentation of peak muscle torque during repetitive activation after a fatigue protocol. The purposes of this study were 1) to quantify postfatigue potentiation in the acutely and chronically paralyzed soleus and 2) to determine the effect of long-term soleus electrical stimulation training on the potent...

  20. Rocky Mountain Spotted Fever

    Science.gov (United States)

    ... with facebook share with twitter share with linkedin Rocky Mountain Spotted Fever Credit: CDC A male cayenne tick, Amblyomma cajennense, ... and New Mexico. Why Is the Study of Rocky Mountain Spotted Fever a Priority for NIAID? Tickborne diseases are becoming ...

  1. The long-term forecast of Pakistan's electricity supply and demand: An application of long range energy alternatives planning

    International Nuclear Information System (INIS)

    Perwez, Usama; Sohail, Ahmed; Hassan, Syed Fahad; Zia, Usman

    2015-01-01

    The long-term forecasting of electricity demand and supply has assumed significant importance in fundamental research to provide sustainable solutions to the electricity issues. In this article, we provide an overview of structure of electric power sector of Pakistan and a summary of historical electricity demand & supply data, current status of divergent set of energy policies as a framework for development and application of a LEAP (Long-range Energy Alternate Planning) model of Pakistan's electric power sector. Pakistan's LEAP model is used to analyze the supply policy selections and demand assumptions for future power generation system on the basis of economics, technicality and implicit environmental implications. Three scenarios are enacted over the study period (2011–2030) which include BAU (Business-As-Usual), NC (New Coal) & GF (Green Future). The results of these scenarios are compared in terms of projected electricity demand & supply, net present cost analysis (discount rate at 4%, 7% and 10%) and GHG (greenhouse gas) emission reductions, along with sensitivity analysis to study the effect of varying parameters on total cost. A concluding section illustrates the policy implications of model for futuristic power generation and environmental policies in Pakistan. - Highlights: • Pakistan-specific electricity demand model is presented. • None of the scenarios exceeded the price of 12 US Cents/kWh. • By 2030, fuel cost is the most dominant factor to influence electricity per unit cost. • By 2030, CO_2 emissions per unit electricity will increase significantly in coal scenario relative to others. • By 2030, the penetration of renewable energy and conservation policies can save 70.6 tWh electricity.

  2. Price formation in electricity forward markets and the relevance of systematic forecast errors

    International Nuclear Information System (INIS)

    Redl, Christian; Haas, Reinhard; Huber, Claus; Boehm, Bernhard

    2009-01-01

    Since the liberalisation of the European electricity sector, forward and futures contracts have gained significant interest of market participants due to risk management reasons. For pricing of these contracts an important fact concerns the non-storability of electricity. In this case, according to economic theory, forward prices are related to the expected spot prices which are built on fundamental market expectations. In the following article the crucial impact parameters of forward electricity prices and the relationship between forward and future spot prices will be assessed by an empirical analysis of electricity prices at the European Energy Exchange and the Nord Pool Power Exchange. In fact, price formation in the considered markets is influenced by historic spot market prices yielding a biased forecasting power of long-term contracts. Although market and risk assessment measures of market participants and supply and demand shocks can partly explain the futures-spot bias inefficiencies in the analysed forward markets cannot be ruled out. (author)

  3. Effectiveness and Safety of Spot Scanning Proton Radiation Therapy for Chordomas and Chondrosarcomas of the Skull Base: First Long-Term Report

    International Nuclear Information System (INIS)

    Ares, Carmen; Hug, Eugen B.; Lomax, Antony J.; Bolsi, Alessandra; Timmermann, Beate; Rutz, Hans Peter; Schuller, Jan C.; Pedroni, Eros; Goitein, Gudrun

    2009-01-01

    Purpose: To evaluate effectiveness and safety of spot-scanning-based proton radiotherapy (PT) in skull-base chordomas and chondrosarcomas. Methods and Materials: Between October 1998 and November 2005, 64 patients with skull-base chordomas (n = 42) and chondrosarcomas (n = 22) were treated at Paul Scherrer Institute with PT using spot-scanning technique. Median total dose for chordomas was 73.5 Gy(RBE) and 68.4 Gy(RBE) for chondrosarcomas at 1.8-2.0 Gy(RBE) dose per fraction. Local control (LC), disease specific survival (DSS), and overall survival (OS) rates were calculated. Toxicity was assessed according to CTCAE, v. 3.0. Results: Mean follow-up period was 38 months (range, 14-92 months). Five patients with chordoma and one patient with chondrosarcoma experienced local recurrence. Actuarial 5-year LC rates were 81% for chordomas and 94% for chondrosarcomas. Brainstem compression at the time of PT (p = 0.007) and gross tumor volume >25 mL (p = 0.03) were associated with lower LC rates. Five years rates of DSS and OS were 81% and 62% for chordomas and 100% and 91% for chondrosarcomas, respectively. High-grade late toxicity consisted of one patient with Grade 3 and one patient with Grade 4 unilateral optic neuropathy, and two patients with Grade 3 central nervous system necrosis. No patient experienced brainstem toxicity. Actuarial 5-year freedom from high-grade toxicity was 94%. Conclusions: Our data indicate safety and efficacy of spot-scanning based PT for skull-base chordomas and chondrosarcomas. With target definition, dose prescription and normal organ tolerance levels similar to passive-scattering based PT series, complication-free, tumor control and survival rates are at present comparable.

  4. Long-term effects of electrical neurostimulation in patients with unstable angina : Refractory to conventional therapies

    NARCIS (Netherlands)

    de Vries, Jessica; DeJongste, Mike J. L.; Zijlstra, Felix; Staal, Michiel

    2007-01-01

    Background. Patients with unstable angina pectoris may become refractory to conventional therapies. Electrical neurostimulation with transcutaneous electrical stimulation and/or spinal cord stimulation has been shown to be effective for patients with refractory unstable angina pectoris in hospital

  5. Long term electricity expansion analysis to define energy policies for Mexico

    International Nuclear Information System (INIS)

    Martin del Campo, C.; Guadarrama, R.; Sanchez, O.; Francois, J. L.; Estrada, G.; Izarra, J.; Perez, A.

    2010-10-01

    A new multi-criteria decision making process based on regret behavior is described. The name we gave it is position vector of minimum regret. A reference which combines the best values of all the criteria is created and positioned in the center of the coordinates of the n-dimensional space; n being the number of criteria. Every alternative is represented by a vector and the magnitude of the position vector is the minimum distance to the reference. The smaller the magnitude of the position vector, the better the corresponding alternative, given that we are looking for the minimum regret. Different weights can be assigned to the criteria. The position vector of minimum regret was applied to the long term electricity expansion planning for Mexico. The study evaluates four parameters: the total generating cost obtained from the objective function after the WASP-IV optimization, the economic risk associated with fuel prices increases, the diversity of fuels participating in the mix of electricity generation, and the external costs associated with health and environmental impacts. The WASP-IV code was used for finding the optimal expansion plan for the Mexican power generating system over the 2008 to 2030 period, under certain restrictions. We decided to study a base case and four additional expansion cases, which are similar to the base case, but each does not consider a certain candidate technology which uses a particular fuel. The reason of studying these five contrasting cases is to quantify the impact, on the evaluation parameters, when a particular fuel is omitted in the expansion plan, and this is very useful for the definition of energy polices concerning diversification by means of nuclear and other CO 2 free options in the mix. The base case is plan A which considers six candidates for expanding the generation system. Plan B does not consider coal, plan C does not consider oil, plan D excludes nuclear energy, and plan E natural gas. After the decision analysis

  6. Long-term impacts of electricity generation systems. Draft technical report

    International Nuclear Information System (INIS)

    1998-01-01

    Estimation of health and environmental impacts in a distant future driven by current electricity generation systems is not a well established scientific field. This issue includes many uncertainties which are seen in many processes of the impact estimation such as valuation techniques of environmental impacts for a long-term, and technology choice and policy options for a long run. When the IAEA held the Technical Committee Meeting on Estimating and Comparing Risks from Energy Systems in the Far Future in October 1997 in Vienna, there were many questions raised up from the participants on these issues. The purpose of this document is to introduce typical discussions at the Meeting, and to give a guidance to the methodological approaches for the readers. The decision making process is not central to this technical document. The main issue explained in the document is the ways of presenting health and environmental impacts in a distant future for decision makers. The primarily targeted readers of this document are, therefore, experts who will make the impact assessment and document the results to governmental offices and/or representatives of general public. For those who further implement decision making study, several documents are available from the IAEA. (in preparation 29]). To provide an effective guidance to the methodological approaches, several issues which are currently recognized as typical examples of the impacts on future generations were chosen. Global climate change, nuclear and non-nuclear wastes, long lived radionuclides dispersing world-wide, land use, and resource depletion are briefly discussed to illustrate several technical difficulties in estimating the impacts in the far future. About technology choice, the discussions illustrated in this document are based on only marginal increase of currently available electricity production systems. For smooth introduction of currently available methodological approaches to readers, issues like future

  7. Prices on electricity and transmission of electricity

    International Nuclear Information System (INIS)

    2002-01-01

    This publication contains data on prices of electric energy and transmission of electricity valid on 1 January 2002. The purpose is to illustrate the price changes on the electricity market in terms of prices for different customer categories. All companies holding network concessions for areas and all companies trading in electricity are included in this report, which is produced on an annual basis. The prices for transmission services 1 January 2002 were on the whole unchanged compared to the preceding year. For households the mean annual cost was SEK 856 for flats, SEK 4,194 one- or two-family houses with electric heating and SEK 1,881 without electric heating. (1 SEK ∼ 0.1 USD). Electricity prices rose considerably on 1 January 2002 compared to the year before. The mean price per kWh for households according to standard agreement was SEK 0.356 for deliveries to flats, SEK 0.296 for apartments in one- or two-family houses with electric heating and SEK 0.316 without electric heating. That means that the mean annual cost increased by SEK 171 for flats. For one- or two-family houses with electric heating, costs increased by SEK 1,424, and by SEK 379 for those houses without electric heating. The high costs of electricity may be explained in part by the development on the Nordic Power Exchange (Nord Pool), where the spot price increased by 75 per cent during 2001. The price development for household customers during 1996-2002 is shown in a diagram

  8. Short-term optimal wind power generation capacity in liberalized electricity markets

    International Nuclear Information System (INIS)

    Olsina, Fernando; Roescher, Mark; Larisson, Carlos; Garces, Francisco

    2007-01-01

    Mainly because of environmental concerns and fuel price uncertainties, considerable amounts of wind-based generation capacity are being added to some deregulated power systems. The rapid wind development registered in some countries has essentially been driven by strong subsidizing programs. Since wind investments are commonly isolated from market signals, installed wind capacity can be higher than optimal, leading to distortions of the power prices with a consequent loss of social welfare. In this work, the influence of wind generation on power prices in the framework of a liberalized electricity market has been assessed by means of stochastic simulation techniques. The developed methodology allows investigating the maximal wind capacity that would be profitably deployed if wind investments were subject to market conditions only. For this purpose, stochastic variables determining power prices are accurately modeled. A test system resembling the size and characteristics of the German power system has been selected for this study. The expected value of the optimal, short-term wind capacity is evaluated for a considerable number of random realizations of power prices. The impact of dispersing the wind capacity over statistical independent wind sites has also been evaluated. The simulation results reveal that fuel prices, installation and financing costs of wind investments are very influential parameters on the maximal wind capacity that might be accommodated in a market-based manner

  9. A New Neural Network Approach to Short Term Load Forecasting of Electrical Power Systems

    Directory of Open Access Journals (Sweden)

    Farshid Keynia

    2011-03-01

    Full Text Available Short-term load forecast (STLF is an important operational function in both regulated power systems and deregulated open electricity markets. However, STLF is not easy to handle due to the nonlinear and random-like behaviors of system loads, weather conditions, and social and economic environment variations. Despite the research work performed in the area, more accurate and robust STLF methods are still needed due to the importance and complexity of STLF. In this paper, a new neural network approach for STLF is proposed. The proposed neural network has a novel learning algorithm based on a new modified harmony search technique. This learning algorithm can widely search the solution space in various directions, and it can also avoid the overfitting problem, trapping in local minima and dead bands. Based on this learning algorithm, the suggested neural network can efficiently extract the input/output mapping function of the forecast process leading to high STLF accuracy. The proposed approach is tested on two practical power systems and the results obtained are compared with the results of several other recently published STLF methods. These comparisons confirm the validity of the developed approach.

  10. Towards smart energy systems: application of kernel machine regression for medium term electricity load forecasting.

    Science.gov (United States)

    Alamaniotis, Miltiadis; Bargiotas, Dimitrios; Tsoukalas, Lefteri H

    2016-01-01

    Integration of energy systems with information technologies has facilitated the realization of smart energy systems that utilize information to optimize system operation. To that end, crucial in optimizing energy system operation is the accurate, ahead-of-time forecasting of load demand. In particular, load forecasting allows planning of system expansion, and decision making for enhancing system safety and reliability. In this paper, the application of two types of kernel machines for medium term load forecasting (MTLF) is presented and their performance is recorded based on a set of historical electricity load demand data. The two kernel machine models and more specifically Gaussian process regression (GPR) and relevance vector regression (RVR) are utilized for making predictions over future load demand. Both models, i.e., GPR and RVR, are equipped with a Gaussian kernel and are tested on daily predictions for a 30-day-ahead horizon taken from the New England Area. Furthermore, their performance is compared to the ARMA(2,2) model with respect to mean average percentage error and squared correlation coefficient. Results demonstrate the superiority of RVR over the other forecasting models in performing MTLF.

  11. Assessment of the turkey’s electric power policies in terms of sustainability

    Directory of Open Access Journals (Sweden)

    Atis Selcuk

    2014-01-01

    Full Text Available This study, using statistical data published by the Turkish Electricity Transmission Company, analyzes key parameters such as installed capacity and energy demand growth rates, investment plans and emission rates, taking into consideration the expected increase in use through the year 2023. The results of the analyses were compared to relevant data from around the world. The weight of domestic - and especially renewable - resources in investment plans for the next 10 years was discussed. Recommendations for an investment plan to support sustainable development in Turkey are listed. Consequently, the lack of investment in domestic and renewable energy projects decreases the competitive power of Turkey vis-à-vis Organisation for Economic Co-Operation and Development countries in terms of many parameters. For a sustainable development, the country must make significant changes in its foreign-dependent energy production policies. Any future policies must encourage supplying local resources to meet the continuously increasing demand. Qualifications for incentive mechanisms applied to investments in renewable energy should be developed. The impact of the private sector on the installation of new plants must also be increased by quickly completing the privatization process.

  12. Optimal short-term operation schedule of a hydropower plant in a competitive electricity market

    International Nuclear Information System (INIS)

    Perez-Diaz, Juan I.; Wilhelmi, Jose R.; Arevalo, Luis A.

    2010-01-01

    This paper presents a dynamic programming model to solve the short-term scheduling problem of a hydropower plant that sells energy in a pool-based electricity market with the objective of maximizing the revenue. This is a nonlinear and non-concave problem subject to strong technical and strategic constraints, and in which discrete and continuous variables take part. The model described in this paper determines, in each hour of the planning horizon (typically from one day to one week), both the optimal number of units in operation (unit commitment) and the power to be generated by the committed units (generation dispatch). The power generated by each unit is considered as a nonlinear function of the actual water discharge and volume of the associated reservoir. The dependence of the units' efficiency and operating limits with the available gross head is also accounted for in this model. The application of this model to a real hydropower plant demonstrates its capabilities in providing the operation schedule that maximizes the revenue of the hydro plant while satisfying several constraints of different classes. In addition, the use of this model as a supporting tool to estimate the economic feasibility of a hydropower plant development project is also analyzed in the paper. (author)

  13. Application of fuzzy – Neuro to model weather parameter variability impacts on electrical load based on long-term forecasting

    Directory of Open Access Journals (Sweden)

    Danladi Ali

    2018-03-01

    Full Text Available Long-term load forecasting provides vital information about future load and it helps the power industries to make decision regarding electrical energy generation and delivery. In this work, fuzzy – neuro model is developed to forecast a year ahead load in relation to weather parameter (temperature and humidity in Mubi, Adamawa State. It is observed that: electrical load increased with increase in temperature and relative humidity does not show notable effect on electrical load. The accuracy of the prediction is obtained at 98.78% with the corresponding mean absolute percentage error (MAPE of 1.22%. This confirms that fuzzy – neuro is a good tool for load forecasting. Keywords: Electrical load, Load forecasting, Fuzzy logic, Back propagation, Neuro-fuzzy, Weather parameter

  14. Can We "Predict" Long-Term Outcome for Ambulatory Transcutaneous Electrical Nerve Stimulation in Patients with Chronic Pain?

    NARCIS (Netherlands)

    Koke, A.J.; Smeets, R.J.E.M.; Perez, R.S.G.M.; Kessels, A.; Winkens, B.; van Kleef, M.; Patijn, J.

    2015-01-01

    Background: Evidence for effectiveness of transcutaneous electrical nerve stimulation (TENS) is still inconclusive. As heterogeneity of chronic pain patients might be an important factor for this lack of efficacy, identifying factors for a successful long-term outcome is of great importance.

  15. Electricity pricing: optimal operation and investment by industrial consumers

    Energy Technology Data Exchange (ETDEWEB)

    Outhred, H.R.; Kaye, R.J.; Sutanto, D.; Manimaran, R.; Bannister, C.H.; Lee, Y.B.

    1988-08-01

    Ongoing research in the areas of economically efficient electricity pricing and industrial consumer response is described. A new electricity pricing theory is described that incorporates future uncertainty and intertemporal linkages between decisions. It indicates that electricity prices should contain two terms - short-run marginal cost plus a term that reflects how each particular decision is likely to affect future global welfare. A practical implementation using spot prices and forward contracts plus financial instruments for risk sharing and decision coordination is explored, and a procedure for developing long-term pricing policy is considered. The operation of industrial plant has been investigated and models developed to optimize plant behaviour in response to spot prices and forward contracts for electricity. These models are described and results of simulation studies discussed. The economic efficiency and risk sharing advantages of this advanced tariff structure compared with a conventional time-of-use tariff are illustrated.

  16. Electricity

    International Nuclear Information System (INIS)

    Tombs, F.

    1983-01-01

    The subject is discussed, with particular reference to the electricity industry in the United Kingdom, under the headings; importance and scope of the industry's work; future fuel supplies (estimated indigenous fossil fuels reserves); outlook for UK energy supplies; problems of future generating capacity and fuel mix (energy policy; construction programme; economics and pricing; contribution of nuclear power - thermal and fast reactors; problems of conversion of oil-burning to coal-burning plant). (U.K.)

  17. An integrated model for long-term power generation planning toward future smart electricity systems

    International Nuclear Information System (INIS)

    Zhang, Qi; Mclellan, Benjamin C.; Tezuka, Tetsuo; Ishihara, Keiichi N.

    2013-01-01

    Highlights: • An integrated model for planning future smart electricity systems was developed. • The model consists of an optimization model and an hour-by-hour simulation model. • The model was applied to Tokyo area, Japan in light of the Fukushima Accident. • Paths to best generation mixes of smart electricity systems were obtained. • Detailed hourly operation patterns in smart electricity systems were obtained. - Abstract: In the present study, an integrated planning model was developed to find economically/environmentally optimized paths toward future smart electricity systems with high level penetration of intermittent renewable energy and new controllable electric devices at the supply and demand sides respectively for regional scale. The integrated model is used to (i) plan the best power generation and capacity mixes to meet future electricity demand subject to various constraints using an optimization model; (ii) obtain detailed operation patterns of power plants and new controllable electric devices using an hour-by-hour simulation model based on the obtained optimized power generation mix. As a case study, the model was applied to power generation planning in the Tokyo area, Japan, out to 2030 in light of the Fukushima Accident. The paths toward best generation mixes of smart electricity systems in 2030 based on fossil fuel, hydro power, nuclear and renewable energy were obtained and the feasibility of the integrated model was proven

  18. The Natural Gas Dilemma in New England's Electricity Sector: Experts' Perspectives on Long Term Climate Issues and Policy Opportunities

    Science.gov (United States)

    Griffith, Steven

    This thesis is an interpretive analysis of experts' perspectives on the climate implications of New England's reliance on natural gas for electricity generation. Specifically, this research, conducted through interviews and literature review, examines experts' opinions on the desired role of natural gas within the regional electricity sector, alternative energy resources, and state and regional policy opportunities toward the achievement of New England's ambitious long-term greenhouse gas reduction goals. Experts expressed concern about the climate dilemma posed by a dependence on natural gas. However, interviews revealed that short-term reliability and cost considerations are paramount for many experts, and therefore a reliance on natural gas is the existing reality. To incentivize renewable generation technologies for the purposes of long-term climate stabilization, experts advocated for the expanded implementation of renewable portfolio standard, net metering, and feed-in tariff policies. More broadly, interviewees expressed the need for an array of complementary state and regional policies.

  19. Hot Spot Removal System: System description

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    Hazardous wastes contaminated with radionuclides, chemicals, and explosives exist across the Department of Energy complex and need to be remediated due to environmental concerns. Currently, an opportunity is being developed to dramatically reduce remediation costs and to assist in the acceleration of schedules associated with these wastes by deploying a Hot Spot Removal System. Removing the hot spot from the waste site will remove risk driver(s) and enable another, more cost effective process/option/remedial alternative (i.e., capping) to be applied to the remainder of the site. The Hot Spot Removal System consists of a suite of technologies that will be utilized to locate and remove source terms. Components of the system can also be used in a variety of other cleanup activities. This Hot Spot Removal System Description document presents technologies that were considered for possible inclusion in the Hot Spot Removal System, technologies made available to the Hot Spot Removal System, industrial interest in the Hot Spot Removal System`s subsystems, the schedule required for the Hot Spot Removal System, the evaluation of the relevant technologies, and the recommendations for equipment and technologies as stated in the Plan section.

  20. Hot Spot Removal System: System description

    International Nuclear Information System (INIS)

    1997-09-01

    Hazardous wastes contaminated with radionuclides, chemicals, and explosives exist across the Department of Energy complex and need to be remediated due to environmental concerns. Currently, an opportunity is being developed to dramatically reduce remediation costs and to assist in the acceleration of schedules associated with these wastes by deploying a Hot Spot Removal System. Removing the hot spot from the waste site will remove risk driver(s) and enable another, more cost effective process/option/remedial alternative (i.e., capping) to be applied to the remainder of the site. The Hot Spot Removal System consists of a suite of technologies that will be utilized to locate and remove source terms. Components of the system can also be used in a variety of other cleanup activities. This Hot Spot Removal System Description document presents technologies that were considered for possible inclusion in the Hot Spot Removal System, technologies made available to the Hot Spot Removal System, industrial interest in the Hot Spot Removal System''s subsystems, the schedule required for the Hot Spot Removal System, the evaluation of the relevant technologies, and the recommendations for equipment and technologies as stated in the Plan section

  1. Short-Term Multiple Forecasting of Electric Energy Loads for Sustainable Demand Planning in Smart Grids for Smart Homes

    Directory of Open Access Journals (Sweden)

    Adeshina Y. Alani

    2017-10-01

    Full Text Available Energy consumption in the form of fuel or electricity is ubiquitous globally. Among energy types, electricity is crucial to human life in terms of cooking, warming and cooling of shelters, powering of electronic devices as well as commercial and industrial operations. Users of electronic devices sometimes consume fluctuating amounts of electricity generated from smart-grid infrastructure owned by the government or private investors. However, frequent imbalance is noticed between the demand and supply of electricity, hence effective planning is required to facilitate its distribution among consumers. Such effective planning is stimulated by the need to predict future consumption within a short period. Although several interesting classical techniques have been used for such predictions, they still require improvement for the purpose of reducing significant predictive errors when used for short-term load forecasting. This research develops a near-zero cooperative probabilistic scenario analysis and decision tree (PSA-DT model to address the lacuna of enormous predictive error faced by the state-of-the-art models. The PSA-DT is based on a probabilistic technique in view of the uncertain nature of electricity consumption, complemented by a DT to reinforce the collaboration of the two techniques. Based on detailed experimental analytics on residential, commercial and industrial data loads, the PSA-DT model outperforms the state-of-the-art models in terms of accuracy to a near-zero error rate. This implies that its deployment for electricity demand planning will be of great benefit to various smart-grid operators and homes.

  2. Benefits for wind energy in electricity markets from using short term wind power prediction tools: a simulation study

    International Nuclear Information System (INIS)

    Usaola, J.; Ravelo, O.; Gonzalez, G.; Soto, F.; Davila, M.C.; Diaz-Guerra, B.

    2004-01-01

    One of the characteristics of wind energy, from the grid point of view, is its non-dispatchability, i.e. generation cannot be ordered, hence integration in electrical networks may be difficult. Short-term wind power prediction-tools could make this integration easier, either by their use by the grid System Operator, or by promoting the participation of wind farms in the electricity markets and using prediction tools to make their bids in the market. In this paper, the importance of a short-term wind power-prediction tool for the participation of wind energy systems in electricity markets is studied. Simulations, according to the current Spanish market rules, have been performed to the production of different wind farms, with different degrees of accuracy in the prediction tool. It may be concluded that income from participation in electricity markets is increased using a short-term wind power prediction-tool of average accuracy. This both marginally increases income and also reduces the impact on system operation with the improved forecasts. (author)

  3. A study of the contract terms offered by the regional electricity companies to generators of renewable energy outside the NFFO

    International Nuclear Information System (INIS)

    Williams, N.C.; Limbrick, A.J.

    1996-01-01

    The aim of this study was to review the terms and conditions of contract for the purchase of renewable energy currently offered by the Regional Electricity Companies (RECs) outside the Non-Fossil Fuel Obligation (NFFO), through consultation with electricity generators. It focused on projects contracted under the first and second tranches of the NFFO, and those which have been developed outside this support mechanism (both renewable and fossil-fuelled), but which are characterised by being ''embedded'' in the RECs' distribution networks. (UK)

  4. Estimating short and long-term residential demand for electricity. New evidence from Sri Lanka

    International Nuclear Information System (INIS)

    Athukorala, P.P.A Wasantha; Wilson, Clevo

    2010-01-01

    This study investigates the short-run dynamics and long-run equilibrium relationship between residential electricity demand and factors influencing demand - per capita income, price of electricity, price of kerosene oil and price of liquefied petroleum gas - using annual data for Sri Lanka for the period, 1960-2007. The study uses unit root, cointegration and error-correction models. The long-run demand elasticities of income, own price and price of kerosene oil (substitute) were estimated to be 0.78, - 0.62, and 0.14 respectively. The short-run elasticities for the same variables were estimated to be 0.32, - 0.16 and 0.10 respectively. Liquefied petroleum (LP) gas is a substitute for electricity only in the short-run with an elasticity of 0.09. The main findings of the paper support the following (1) increasing the price of electricity is not the most effective tool to reduce electricity consumption (2) existing subsidies on electricity consumption can be removed without reducing government revenue (3) the long-run income elasticity of demand shows that any future increase in household incomes is likely to significantly increase the demand for electricity and (4) any power generation plans which consider only current per capita consumption and population growth should be revised taking into account the potential future income increases in order to avoid power shortages in the country. (author)

  5. Estimating short and long-term residential demand for electricity. New evidence from Sri Lanka

    Energy Technology Data Exchange (ETDEWEB)

    Athukorala, P.P.A Wasantha; Wilson, Clevo [School of Economics and Finance, Queensland University of Technology, Brisbane (Australia)

    2010-09-15

    This study investigates the short-run dynamics and long-run equilibrium relationship between residential electricity demand and factors influencing demand - per capita income, price of electricity, price of kerosene oil and price of liquefied petroleum gas - using annual data for Sri Lanka for the period, 1960-2007. The study uses unit root, cointegration and error-correction models. The long-run demand elasticities of income, own price and price of kerosene oil (substitute) were estimated to be 0.78, - 0.62, and 0.14 respectively. The short-run elasticities for the same variables were estimated to be 0.32, - 0.16 and 0.10 respectively. Liquefied petroleum (LP) gas is a substitute for electricity only in the short-run with an elasticity of 0.09. The main findings of the paper support the following (1) increasing the price of electricity is not the most effective tool to reduce electricity consumption (2) existing subsidies on electricity consumption can be removed without reducing government revenue (3) the long-run income elasticity of demand shows that any future increase in household incomes is likely to significantly increase the demand for electricity and (4) any power generation plans which consider only current per capita consumption and population growth should be revised taking into account the potential future income increases in order to avoid power shortages in the country. (author)

  6. Volume higher; spot price ranges widen

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    This article is the October 1994 uranium market summary. During this reporting period, volume on the spot concentrates market doubled. Twelve deals took place: three in the spot concentrates market, one in the medium and long-term market, four in the conversion market, and four in the enrichment market. The restricted price range widened due to higher prices at the top end of the range, while the unrestricted price range widened because of lower prices at the bottom end. Spot conversion prices were higher, and enrichment prices were unchanged

  7. MASCEM: EPEX SPOT Day-Ahead market integration and simulation

    DEFF Research Database (Denmark)

    Santos, Gabriel; Fernandes, Ricardo; Pinto, Tiago

    2015-01-01

    . It is crucial to MASCEM to have the ability to simulate as many market models and player types as possible, thus enhancing the ability to recreate the electricity markets reality in its maximum possible extent. This paper presents the EPEX Spot Day-Ahead market integration in MASCEM. EPEX Spot SE's mission...

  8. Developing long-term scenario forecasts to support electricity generation investment decisions

    CSIR Research Space (South Africa)

    Koen, Renée

    2014-09-01

    Full Text Available Many decisions regarding capital investment in electricity generation technologies need to be made well in advance, usually when there is still a large amount of uncertainty regarding the favourability of future conditions. There may be uncertainty...

  9. Project finance and its limitations in terms of difficult political and structural horizons - the case of electricity generation

    International Nuclear Information System (INIS)

    Fiancette, Georges; Penz, Philippe

    1994-01-01

    Illustrations are given of the kinds of difficulties attendant on the project financing of electricity generation in some developing countries and former socialist countries of Eastern Europe. There are risks due to the instability of the legal framework because of political considerations and also because the organization and regulation of the electricity supply industry is still being developed. Problems may arise because of the gap between the relatively short term of the repayable debt (10 to 12 years) and the lifetime of a typical project (of the order of 30 years). Project investment is usually entrusted to an independent body which often relies on the local electricity company to operate the power station. In this situation, the two bodies involved cannot mutually insure the risks. Exchange rates generate problems associated with convertibility on the one hand and fluctuations on the other. The particular problems which occur in the project financing of power station restoration are discussed. (UK)

  10. Short and long-term carbon balance of bioenergy electricity production fueled by forest treatments.

    Science.gov (United States)

    Kelsey, Katharine C; Barnes, Kallie L; Ryan, Michael G; Neff, Jason C

    2014-01-01

    Forests store large amounts of carbon in forest biomass, and this carbon can be released to the atmosphere following forest disturbance or management. In the western US, forest fuel reduction treatments designed to reduce the risk of high severity wildfire can change forest carbon balance by removing carbon in the form of biomass, and by altering future potential wildfire behavior in the treated stand. Forest treatment carbon balance is further affected by the fate of this biomass removed from the forest, and the occurrence and intensity of a future wildfire in this stand. In this study we investigate the carbon balance of a forest treatment with varying fates of harvested biomass, including use for bioenergy electricity production, and under varying scenarios of future disturbance and regeneration. Bioenergy is a carbon intensive energy source; in our study we find that carbon emissions from bioenergy electricity production are nearly twice that of coal for the same amount of electricity. However, some emissions from bioenergy electricity production are offset by avoided fossil fuel electricity emissions. The carbon benefit achieved by using harvested biomass for bioenergy electricity production may be increased through avoided pyrogenic emissions if the forest treatment can effectively reduce severity. Forest treatments with the use of harvested biomass for electricity generation can reduce carbon emissions to the atmosphere by offsetting fossil fuel electricity generation emissions, and potentially by avoided pyrogenic emissions due to reduced intensity and severity of a future wildfire in the treated stand. However, changes in future wildfire and regeneration regimes may affect forest carbon balance and these climate-induced changes may influence forest carbon balance as much, or more, than bioenergy production.

  11. Comparison of Long-Term Contracts and Vertical Integration in Decentralised Electricity Markets

    OpenAIRE

    MEADE, Richard; O'CONNOR, Seini

    2009-01-01

    Decentralised electricity systems require effective price and quantity risk management mechanisms, but the nature of such systems poses particular problems for satisfying those requirements. Among these problems are investment hold-up risks rooted in the competition facing both electricity retailers and large industrial firms. Additional problems include those of load profile, information and bargaining mismatches between generators and customers. Significantly, hold-up risks exist not only b...

  12. Short-term electricity price forecast based on the improved hybrid model

    International Nuclear Information System (INIS)

    Dong Yao; Wang Jianzhou; Jiang He; Wu Jie

    2011-01-01

    Highlights: → The proposed models can detach high volatility and daily seasonality of electricity price. → The improved hybrid forecast models can make full use of the advantages of individual models. → The proposed models create commendable improvements that are relatively satisfactorily for current research. → The proposed models do not require making complicated decisions about the explicit form. - Abstract: Half-hourly electricity price in power system are volatile, electricity price forecast is significant information which can help market managers and participants involved in electricity market to prepare their corresponding bidding strategies to maximize their benefits and utilities. However, the fluctuation of electricity price depends on the common effect of many factors and there is a very complicated random in its evolution process. Therefore, it is difficult to forecast half-hourly prices with traditional only one model for different behaviors of half-hourly prices. This paper proposes the improved forecasting model that detaches high volatility and daily seasonality for electricity price of New South Wales in Australia based on Empirical Mode Decomposition, Seasonal Adjustment and Autoregressive Integrated Moving Average. The prediction errors are analyzed and compared with the ones obtained from the traditional Seasonal Autoregressive Integrated Moving Average model. The comparisons demonstrate that the proposed model can improve the prediction accuracy noticeably.

  13. Short-term electricity price forecast based on the improved hybrid model

    Energy Technology Data Exchange (ETDEWEB)

    Dong Yao, E-mail: dongyao20051987@yahoo.cn [School of Mathematics and Statistics, Lanzhou University, Lanzhou 730000 (China); Wang Jianzhou, E-mail: wjz@lzu.edu.cn [School of Mathematics and Statistics, Lanzhou University, Lanzhou 730000 (China); Jiang He; Wu Jie [School of Mathematics and Statistics, Lanzhou University, Lanzhou 730000 (China)

    2011-08-15

    Highlights: {yields} The proposed models can detach high volatility and daily seasonality of electricity price. {yields} The improved hybrid forecast models can make full use of the advantages of individual models. {yields} The proposed models create commendable improvements that are relatively satisfactorily for current research. {yields} The proposed models do not require making complicated decisions about the explicit form. - Abstract: Half-hourly electricity price in power system are volatile, electricity price forecast is significant information which can help market managers and participants involved in electricity market to prepare their corresponding bidding strategies to maximize their benefits and utilities. However, the fluctuation of electricity price depends on the common effect of many factors and there is a very complicated random in its evolution process. Therefore, it is difficult to forecast half-hourly prices with traditional only one model for different behaviors of half-hourly prices. This paper proposes the improved forecasting model that detaches high volatility and daily seasonality for electricity price of New South Wales in Australia based on Empirical Mode Decomposition, Seasonal Adjustment and Autoregressive Integrated Moving Average. The prediction errors are analyzed and compared with the ones obtained from the traditional Seasonal Autoregressive Integrated Moving Average model. The comparisons demonstrate that the proposed model can improve the prediction accuracy noticeably.

  14. Standard for supply security. A minimum standard to guarantee the balance between electricity demand and supply for the long term

    International Nuclear Information System (INIS)

    Scheepers, M.J.J.; Van Werven, M.J.N.; Seebregts, A.J.; Poort, J.P.; De Nooij, M.; Baarsma, B.E.

    2004-05-01

    The development and use of a minimum reliability standard in the Dutch electricity market to guarantee an adequate balance between electricity demand and supply in the longer term are discussed. This standard can be based on the duration of a power outage and the related costs for society relative to the costs to prevent the power outage. The reliability standard can be translated in an adequacy standard when the reliability of foreign electricity supply to the Dutch market is taken into account. With a theoretical analysis and an assessment of the use of standards in foreign electricity markets and other sectors this study provides a survey of the use of standards in securing public interests. In electricity markets reliability standards can be used obligatory or only to inform market participants of the adequacy of supply preferred by consumers. If no standard is used, the market should rely on the economic incentives provided by contracts and liability. This study proposes to use a reliability standard for calculating the required generation capacity in an ex-ante market analysis using different future scenarios. On the basis of several market indicators, expected market developments can be monitored. Assessment of the market developments relative to the required generation capacity will give a signal to market participants with respect to the expected adequacy in the longer term (7 to 10 years). The assessment and the resulting signal should help to improve market transparency and assist producers, suppliers and consumers in their decisions towards an effective and efficient response on long-term market developments. Market monitoring results can be used by the government to take specific action, if necessary, to reduce barriers to invest. However, more general policy measures should not be linked to the monitoring results since this could provoke strategic behaviour [nl

  15. Purchase of power by State Electricity Boards from biomass gasifier systems: formulating a long term national policy

    International Nuclear Information System (INIS)

    Jain, B.C.

    1992-01-01

    Current policy for purchase of power from renewable sources of energy by State Electricity Boards in India is examined and certain changes in that policy are suggested. State Electricity Boards are reluctant to buy power from renewables as such a purchase is seen by the Boards as being of against their economic interests. But if socio-environmental and climatological costs of power of thermal plants are taken into consideration, it becomes imperative that a long term policy for power purchase from renewables by electricity boards will have to be followed. Such a policy is outlined. After giving formulae for unit cost of generation from thermal power plants, diesel generation (DG) sets and biomass gasification, it is recommended that basis for the purchase price for power generated through biomass gas should be the cost of generation through DG sets or cost of generation through biomass gasification whichever is lower. A clause for automatic price escalation should also be a part of such policy. Some measures to compensate electricity boards for purchase of power from renewables are suggested. They include levying of a special surcharge by boards on their electricity sales and funding by the Central Government. (M.G.B.)

  16. Comparison of percutaneous electrical nerve stimulation with transcutaneous electrical nerve stimulation for long-term pain relief in patients with chronic low back pain.

    Science.gov (United States)

    Yokoyama, Masataka; Sun, Xiaohui; Oku, Satoru; Taga, Naoyuki; Sato, Kenji; Mizobuchi, Satoshi; Takahashi, Toru; Morita, Kiyoshi

    2004-06-01

    The long-term effect of percutaneous electrical nerve stimulation (PENS) on chronic low back pain (LBP) is unclear. We evaluated the number of sessions for which PENS should be performed to alleviate chronic LBP and how long analgesia is sustained. Patients underwent treatment on a twice-weekly schedule for 8 wk. Group A (n = 18) received PENS for 8 wk, group B (n = 17) received PENS for the first 4 wk and transcutaneous electrical nerve stimulation (TENS) for the second 4 wk, and group C (n = 18) received TENS for 8 wk. Pain level, degree of physical impairment, and the daily intake of nonsteroidal antiinflammatory drugs (NSAIDs) were assessed before the first treatment, 3 days after Week 2, Week 4, and Week 8 treatments, and at 1 and 2 mo after the sessions. During PENS therapy, the pain level decreased significantly from Week 2 in Groups A and B (P pain level decreased significantly only at Week 8 (P TENS for chronic LBP but must be continued to sustain the analgesic effect. A cumulative analgesic effect was observed in patients with chronic low back pain (LBP) after repeated percutaneous electrical nerve stimulation (PENS), but this effect gradually faded after the treatment was terminated. Results indicate that although PENS is effective for chronic LBP, treatments need to be continued to sustain analgesia.

  17. Short-Term Load Forecasting Based on the Analysis of User Electricity Behavior

    Directory of Open Access Journals (Sweden)

    Yuancheng Li

    2016-11-01

    Full Text Available The smart meter is an important part of the smart grid, and in order to take full advantage of smart meter data, this paper mines the electricity behaviors of smart meter users to improve the accuracy of load forecasting. First, the typical day loads of users are calculated separately according to different date types (ordinary workdays, day before holidays, holidays. Second, the similarity between user electricity behaviors is mined and the user electricity loads are clustered to classify the users with similar behaviors into the same cluster. Finally, the load forecasting model based on the Online Sequential Extreme Learning Machine (OS-ELM is applied to different clusters to conduct load forecasting and the load forecast is summed to obtain the system load. In order to prove the validity of the proposed method, we performed simulation experiments on the MATLAB platform using smart meter data from the Ireland electric power cooperation. The experimental results show that the proposed method is able to mine the user electricity behaviors deeply, improve the accuracy of load forecasting by the reasonable clustering of users, and reveal the relationship between forecasting accuracy and cluster numbers.

  18. Electrical Rating of Concentrated Photovoltaic (CPV) Systems: Long-Term Performance Analysis and Comparison to Conventional PV Systems

    KAUST Repository

    Burhan, Muhammad

    2016-02-29

    The dynamic nature of meteorological data and the commercial availability of diverse photovoltaic systems, ranging from single-junction silicon-based PV panels to concentrated photovoltaic (CPV) systems utilizing multi-junction solar cells and a two-axis solar tracker, demand a simple but accurate methodology for energy planners and PV system designers to understand the economic feasibility of photovoltaic or renewable energy systems. In this paper, an electrical rating methodology is proposed that provides a common playing field for planners, consumers and PV manufacturers to evaluate the long-term performance of photovoltaic systems, as long-term electricity rating is deemed to be a quick and accurate method to evaluate economic viability and determine plant sizes and photovoltaic system power production. A long-term performance analysis based on monthly and electrical ratings (in kWh/m2/year) of two developed CPV prototypes, the Cassegrain mini dish and Fresnel lens CPVs with triple-junction solar cells operating under the meteorological conditions of Singapore, is presented in this paper. Performances are compared to other conventional photovoltaic systems.

  19. Short-Term Forecasting of Electric Loads Using Nonlinear Autoregressive Artificial Neural Networks with Exogenous Vector Inputs

    Directory of Open Access Journals (Sweden)

    Jaime Buitrago

    2017-01-01

    Full Text Available Short-term load forecasting is crucial for the operations planning of an electrical grid. Forecasting the next 24 h of electrical load in a grid allows operators to plan and optimize their resources. The purpose of this study is to develop a more accurate short-term load forecasting method utilizing non-linear autoregressive artificial neural networks (ANN with exogenous multi-variable input (NARX. The proposed implementation of the network is new: the neural network is trained in open-loop using actual load and weather data, and then, the network is placed in closed-loop to generate a forecast using the predicted load as the feedback input. Unlike the existing short-term load forecasting methods using ANNs, the proposed method uses its own output as the input in order to improve the accuracy, thus effectively implementing a feedback loop for the load, making it less dependent on external data. Using the proposed framework, mean absolute percent errors in the forecast in the order of 1% have been achieved, which is a 30% improvement on the average error using feedforward ANNs, ARMAX and state space methods, which can result in large savings by avoiding commissioning of unnecessary power plants. The New England electrical load data are used to train and validate the forecast prediction.

  20. A Drosophila wing spot test

    International Nuclear Information System (INIS)

    Ayaki, Toshikazu; Yoshikawa, Isao; Niikawa, Norio; Hoshi, Masaharu.

    1986-01-01

    A Drosophila wing spot test system was used to investigate the effects of low doses of X-rays, gamma rays, and both 2.3 and 14.1 MeV neutrons on somatic chromosome mutation (SCM) induction. The incidence of SCM was significantly increased with any type of radiation, with evident linear dose-response relationship within the range of 3 to 20 cGy. It was estimated that relative biological effectiveness value for SCM induction of 2.3 MeV neutrons to X-rays and gamma rays is much higher than that of 14.1 MeV neutrons to those photons (2.4 vs 8.0). The Drosophila wing spot test system seems to become a promising in vivo experimental method for higher animals in terms of the lack of necessity for a marvelously large number of materials required in conventional test system. (Namekawa, K.)

  1. Estimation of Recharge from Long-Term Monitoring of Saline Tracer Transport Using Electrical Resistivity Tomography

    DEFF Research Database (Denmark)

    Haarder, Eline Bojsen; Jensen, Karsten Høgh; Binley, Andrew

    2015-01-01

    The movement of a saline tracer added to the soil surface was monitored in the unsaturated zone using cross-borehole electrical resistivity tomography (ERT) and subjected to natural rainfall conditions. The ERT data were inverted and corrected for subsurface temperature changes, and spatial moment...... methods. In September 2011, a saline tracer was added across a 142-m2 area at the surface at an application rate mimicking natural infiltration. The movement of the saline tracer front was monitored using cross-borehole electrical resistivity tomography (ERT); data were collected on a daily to weekly...

  2. How many years should I be married: Long-term power contracts in the electric utility industry in Texas

    Science.gov (United States)

    Levy Ferre, Alberto

    1998-12-01

    This dissertation deals with the effects of long-term power contracts in the electric utility in Texas on consumer welfare, investigating economic and legal aspects of price formation. The study focuses on the institutions---vertical integration and contractual arrangements---that govern the transactions between the different links in the electricity provision chain and its effects on retail electricity prices for residential, commercial and industrial customers. The main hypothesis is that long-term power contracts serve as an uncertainty reduction mechanism to the buyer by clearly defining the conditions of the exchange for a significant period of time. In turn, this reduction of uncertainty is compensated by a premium to the seller in the form of higher prices. It is found that long-term wholesale power contracts present varying levels of flexibility in the terms of the exchange that are directly translated into prices and bills, providing support to the main hypothesis. Control variables include the role of new technologies, degree of competition and population demographics. Each control variable has differing impacts of different customer classes, depending on their demand elasticity. The study poses several interesting policy implications. First, the institutions that will govern and supervise the functioning of the market have an important weight in its success. The results indicate that competition cannot be a policy objective in itself There is a balancing act between the additional needs of a functional market in terms of infrastructure, information and coordination, and the inefficiencies that occur for lack of consumer options. Second, all customers are not equal. Some customer classes have fewer alternatives than others do, their consumption patterns differ and their dependence on electricity varies. Therefore, a policy that treats all customer classes the same will produce an inferior outcome. Third, the relevant environment matters. Legislative

  3. Short Term Electric Production Technology Switching Under Carbon Cap and Trade

    Directory of Open Access Journals (Sweden)

    Donald F. Larson

    2012-10-01

    Full Text Available This study examines fuel switching in electricity production following the introduction of the European Union’s Emissions Trading System (EU ETS for greenhouse gas emissions. A short-run restricted cost equation is estimated with carbon permits, high-carbon fuels, and low carbon fuels as variable inputs. Shadow values and substitution elasticities for carbon-free energy resources from nuclear, hydroelectric and renewable sources are imputed from the cost equation. The empirical analysis examines 12 European countries using monthly data on fuel use, prices, and electricity generation during the first phase of the European Emissions Trading System. Despite low emission permit prices, this study finds statistically significant substitution between fossil fuels and carbon free sources of energy for electric power production. Significant substitution between fossil fuels and nuclear energy also was found. Still, while 18 of the 20 substitution elasticities are statistically significant, they are all less than unity, consistent with limited substitution. Overall, these results suggest that prices for carbon emission permits relative to prices for carbon and carbon free sources of energy do matter but that electric power producers have limited operational flexibility in the short-run to satisfy greenhouse gas emission limits.

  4. Long term energy and emission implications of a global shift to electricity-based public rail transportation system

    International Nuclear Information System (INIS)

    Chaturvedi, Vaibhav; Kim, Son H.

    2015-01-01

    With high reliance on light-duty vehicles in the present, the future of global transportation system is also geared towards private modes, which has significant energy and emission implications. Public transportation has been argued as an alternative strategy for meeting the rising transportation demands of the growing world, especially the poor, in a sustainable and energy efficient way. The present study analyzes an important yet under-researched question – what are the long-term energy and emission implications of an electric rail based passenger transportation system for meeting both long and short distance passenter transportation needs? We analyze a suite of electric rail share scenarios with and without climate policy. In the reference scenario, the transportation system will evolve towards dominance of fossil based light-duty vehicles. We find that an electric rail policy is more successful than an economy wide climate policy in reducing transport sector energy demand and emissions. Economy wide emissions however can only be reduced through a broader climate policy, the cost of which can be reduced by hundreds of billions of dollars across the century when implemented in combination with the transport sector focused electric rail policy. Moreover, higher share of electric rail enhances energy security for oil importing nations and reduces vehicular congestion and road infrastructure requirement as well. -- Highlights: •Economy wide carbon price policy will have little impact on transportation emissions. •Focused energy and emission mitigation policies required for transportation sector. •Large global shift towards electric rail based public transport is one possible option. •Transport sector focused policy will have marginal impact on total global emissions. •A combined transport sector and economy wide policy can reduce costs significantly

  5. The share of nuclear energy in the long-term electricity generation development in Poland

    International Nuclear Information System (INIS)

    Lipko, Krzysztof; Kwiatkowski, Mieczyslaw

    1999-01-01

    Polish power sector is currently undergoing rapid restructuring changes and according to new energy legislation electricity begins to be recognized as other tradable goods. Simultaneously an awareness of interdependencies between power generation expansion and a protection of the environment increases. Presented paper shows these interdependencies against the background of current and future electricity demand satisfying plans determined in Development Office of Polish Power Grid Company in the time range up to the year 2020. Special consideration is given to constraints assumed for power generation sector, relating to emissions of air pollutants, and their influence on possible changes in the mix of fuels used for power generation. In the first part of the paper an applied methodology of drawing up demand satisfying plans consistent with the rules of integrated resource planning (IRP) is described. Accepted macroeconomic assumptions (including these concerning electricity demand forecast) and development constraints related to emissions of air pollutants consistent with national legislation as well as signed international agreements are presented. The set of new generation technologies considered in development studies is described. Two scenarios of the power generation expansion plants developed for a high electricity demand growth are presented. One of them takes into account CO 2 emission constraint while the other neglects it. In the paper it is proved that the above constraint has great influence on the future mix of power plants. In the case when this constraint is taken into account the expansion of electricity generation beyond the year 2010 is based on technologies which do not increase CO 2 emissions, as for example, nuclear power. (author)

  6. Plasma spot welding of ferritic stainless steels

    International Nuclear Information System (INIS)

    Lesnjak, A.; Tusek, J.

    2002-01-01

    Plasma spot wedding of ferritic stainless steels studied. The study was focused on welding parameters, plasma and shieldings and the optimum welding equipment. Plasma-spot welded overlap joints on a 0.8 mm thick ferritic stainless steel sheet were subjected to a visual examination and mechanical testing in terms of tension-shear strength. Several macro specimens were prepared Plasma spot welding is suitable to use the same gas as shielding gas and as plasma gas , i. e. a 98% Ar/2% H 2 gas mixture. Tension-shear strength of plasma-spot welded joint was compared to that of resistance sport welded joints. It was found that the resistance welded joints withstand a somewhat stronger load than the plasma welded joints due to a large weld sport diameter of the former. Strength of both types of welded joints is approximately the same. (Author) 32 refs

  7. Relationship between hot spot residues and ligand binding hot spots in protein-protein interfaces.

    Science.gov (United States)

    Zerbe, Brandon S; Hall, David R; Vajda, Sandor; Whitty, Adrian; Kozakov, Dima

    2012-08-27

    In the context of protein-protein interactions, the term "hot spot" refers to a residue or cluster of residues that makes a major contribution to the binding free energy, as determined by alanine scanning mutagenesis. In contrast, in pharmaceutical research, a hot spot is a site on a target protein that has high propensity for ligand binding and hence is potentially important for drug discovery. Here we examine the relationship between these two hot spot concepts by comparing alanine scanning data for a set of 15 proteins with results from mapping the protein surfaces for sites that can bind fragment-sized small molecules. We find the two types of hot spots are largely complementary; the residues protruding into hot spot regions identified by computational mapping or experimental fragment screening are almost always themselves hot spot residues as defined by alanine scanning experiments. Conversely, a residue that is found by alanine scanning to contribute little to binding rarely interacts with hot spot regions on the partner protein identified by fragment mapping. In spite of the strong correlation between the two hot spot concepts, they fundamentally differ, however. In particular, while identification of a hot spot by alanine scanning establishes the potential to generate substantial interaction energy with a binding partner, there are additional topological requirements to be a hot spot for small molecule binding. Hence, only a minority of hot spots identified by alanine scanning represent sites that are potentially useful for small inhibitor binding, and it is this subset that is identified by experimental or computational fragment screening.

  8. Metallurgical Effects of Shunting Current on Resistance Spot-Welded Joints of AA2219 Sheets

    Science.gov (United States)

    Jafari Vardanjani, M.; Araee, A.; Senkara, J.; Jakubowski, J.; Godek, J.

    2016-08-01

    Shunting effect is the loss of electrical current via the secondary circuit provided due to the existence of previous nugget in a series of welding spots. This phenomenon influences on metallurgical aspects of resistance spot-welded (RSW) joints in terms of quality and performance. In this paper RSW joints of AA2219 sheets with 1 mm thickness are investigated metallurgically for shunted and single spots. An electro-thermal finite element analysis is performed on the RSW process of shunted spot and temperature distribution and variation are obtained. These predictions are then compared with experimental micrographs. Three values of 5 mm, 20 mm, and infinite (i.e., single spot) are assumed for welding distance. Numerical and experimental results are matching each other in terms of nugget and HAZ geometry as increasing distance raised nugget size and symmetry of HAZ. In addition, important effect of shunting current on nugget thickness, microstructure, and Copper segregation on HAZ grain boundaries were discovered. A quantitative analysis is also performed about the influence of welding distance on important properties including ratio of nugget thickness and diameter ( r t), ratio of HAZ area on shunted and free side of nugget ( r HA), and ratio of equivalent segregated and total amount of Copper, measured in sample ( r Cu) on HAZ. Increasing distance from 5 mm to infinite, indicated a gain of 111.04, -45.55, and -75.15% in r t, r HA, and r Cu, respectively, while obtained ratios for 20 mm welding distance was suitable compared to single spot.

  9. ESA uncovers Geminga's `hot spot'

    Science.gov (United States)

    2004-07-01

    16 July 2004 Astronomers using ESA’s X-ray observatory XMM-Newton have detected a small, bright ‘hot spot’ on the surface of the neutron star called Geminga, 500 light-years away. The hot spot is the size of a football field and is caused by the same mechanism producing Geminga’s X-ray tails. This discovery identifies the missing link between the X-ray and gamma-ray emission from Geminga. hi-res Size hi-res: 1284 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot This figure shows the effects of charged particles accelerated in the magnetosphere of Geminga. Panel (a) shows an image taken with the EPIC instrument on board the XMM-Newton observatory. The bright tails, made of particles kicked out by Geminga’s strong magnetic field, trail the neutron star as it moves about in space. Panel (b) shows how electrically charged particles interact with Geminga’s magnetic field. For example, if electrons (blue) are kicked out by the star, positrons (in red) hit the star’s magnetic poles like in an ‘own goal’. Panel (c) illustrates the size of Geminga’s magnetic field (blue) compared to that of the star itself at the centre (purple). The magnetic field is tilted with respect to Geminga’s rotation axis (red). Panel (d) shows the magnetic poles of Geminga, where charged particles hit the surface of the star, creating a two-million degrees hot spot, a region much hotter than the surroundings. As the star spins on its rotation axis, the hot spot comes into view and then disappears, causing the periodic colour change seen by XMM-Newton. An animated version of the entire sequence can be found at: Click here for animated GIF [low resolution, animated GIF, 5536 KB] Click here for AVI [high resolution, AVI with DIVX compression, 19128 KB] hi-res Size hi-res: 371 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot, panel (a) Panel (a) shows an image taken with the EPIC instrument on board the XMM-Newton observatory. The bright tails, made of

  10. Clinically apparent long-term electric disturbances in the acute and very long-term of patent foramen ovale device-based closure.

    Science.gov (United States)

    Rigatelli, Gianluca; Zuin, Marco; Pedon, Luigi; Zecchel, Roberto; Dell'Avvocata, Fabio; Carrozza, Antonio; Zennaro, Marco; Pastore, Gianni; Zanon, Francesco

    2017-03-01

    Incidence of electrical disturbances in patients submitted to transcatheter patent foramen ovale (PFO) closure has not been fully clarified in a large population. The aim of the study is to assess the incidence of atrial fibrillation, supraventricular tachi-arrhythmias, and atrio-ventricular block in the acute and very long-term follow-up. We reviewed the medical and instrumental data of 1000 consecutive patients (mean age 47.3±17.1years) prospectively enrolled in two centers over a 13-year period (February 1999 to February 2012) for right-to-left (R-to-L) shunt ICE-aided catheter-based closure using different devices. Successful transcatheter PFO closure was achieved in 99.8% of the patients. Implanted devices were: Amplatzer PFO Occluder in 463 patients (46.3%), Amplatzer ASD Cribriform Occluder in 420 patients (42.0%), Premere Occlusion System in 95 patients (9.5%), and Biostar Occluder in 22 patients (2.2%). Postprocedural electrical complications occurred in 5.9% of patients. The only independent predictors of electrophysiological complications were female gender (OR 2.3, 0.5-5.1 [95% CI], p30mm (OR 5.0, 1.2-7.2 [95% CI], pgender (OR 2.3, 0.5-5.1 [95% CI], p30mm (OR 5.0, 1.2-7.2 [95% CI], p<0.001). Device-based closure of PFO using different devices, appeared very safe from an electrophysiological point of view with low incidence of electrical disturbances even in the very long-term follow-up. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Short-Term Synaptic Plasticity Regulation in Solution-Gated Indium-Gallium-Zinc-Oxide Electric-Double-Layer Transistors.

    Science.gov (United States)

    Wan, Chang Jin; Liu, Yang Hui; Zhu, Li Qiang; Feng, Ping; Shi, Yi; Wan, Qing

    2016-04-20

    In the biological nervous system, synaptic plasticity regulation is based on the modulation of ionic fluxes, and such regulation was regarded as the fundamental mechanism underlying memory and learning. Inspired by such biological strategies, indium-gallium-zinc-oxide (IGZO) electric-double-layer (EDL) transistors gated by aqueous solutions were proposed for synaptic behavior emulations. Short-term synaptic plasticity, such as paired-pulse facilitation, high-pass filtering, and orientation tuning, was experimentally emulated in these EDL transistors. Most importantly, we found that such short-term synaptic plasticity can be effectively regulated by alcohol (ethyl alcohol) and salt (potassium chloride) additives. Our results suggest that solution gated oxide-based EDL transistors could act as the platforms for short-term synaptic plasticity emulation.

  12. Near-term electric test vehicle ETV-2. Phase II. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-04-01

    A unique battery-powered passenger vehicle has been developed that provides a significant improvement over conventional electric vehicle performance, particularly during stop-and-go driving. The vehicle is unique in two major respects: (1) the power system incorporates a flywheel that stores energy during regenerative braking and makes possible the acceleration capability needed to keep up with traffic without reducing range to unacceptable values; and (2) lightweight plastic materials are used for the vehicle unibody to minimize weight and increase range. These features were analyzed and demonstrated in an electric test vehicle, ETV-2. Characteristics of this vehicle are summarized. Information is presented on: vehicle design, fabrication, safety testing, and performance testing; power system design and operation; flywheel; battery pack performance; and controls and electronic equipment. (LCL)

  13. Mononucleosis spot test

    Science.gov (United States)

    Monospot test; Heterophile antibody test; Heterophile agglutination test; Paul-Bunnell test; Forssman antibody test ... The mononucleosis spot test is done when symptoms of mononucleosis are ... Fatigue Fever Large spleen (possibly) Sore throat Tender ...

  14. Modeling sustainable long-term electricity supply-demand in Africa

    International Nuclear Information System (INIS)

    Ouedraogo, Nadia S.

    2017-01-01

    Highlights: • This study is one of the first detailed and complete representation of the African power system. • It models, within LEAP, possible future paths for the regional power systems. • All the end-users and supply side activities and actors are considered. • Three scenarios are examined: the baseline, the renewable energy, and the energy efficiency. • The energy efficiency scenario has allowed to draw a sustainable pathway for electrification. - Abstract: This paper develops a scenario-based model to identify and provide an array of electricity demand in Africa, and to derive them from the African power system of development. A system-based approach is performed by applying the scenario methodology developed by Schwartz in the context of the energy-economic modeling platform ‘Long-range Energy Alternative Planning’. Four scenarios are investigated. The Business as Usual scenario (BAU) replicates the regional and national Master Plans. The renewable-promotion scenario increases the share of renewable energy in the electricity mix. The demand and supply side efficiency scenarios investigate the impact of energy efficiency measures on the power system. The results show an increase in electricity demand by 4% by 2040, supply shortages and high emissions of Greenhouse Gases. Contrary to expectations, the renewable energy scenario did not emerge as the best solution to a sustainable electrification of the region. The energy efficiency scenarios have allowed us to draw a sustainable pathway for electrification.

  15. Arc cathode spots

    International Nuclear Information System (INIS)

    Schrade, H.O.

    1989-01-01

    Arc spots are usually highly unstable and jump statistically over the cathode surface. In a magnetic field parallel to the surface, preferably they move in the retrograde direction; i.e., opposite to the Lorentzian rule. If the field is inclined with respect to the surface, the spots drift away at a certain angle with respect to the proper retrograde direction (Robson drift motion). These well-known phenomena are explained by one stability theory

  16. Single spot albumin to creatinine ratio: A simple marker of long-term prognosis in non-ST segment elevation acute coronary syndromes.

    Science.gov (United States)

    Higa, Claudio Cesar; Novo, Fedor Anton; Nogues, Ignacio; Ciambrone, Maria Graciana; Donato, Maria Sol; Gambarte, Maria Jimena; Rizzo, Natalia; Catalano, Maria Paula; Korolov, Eugenio; Comignani, Pablo Dino

    2016-01-01

    Microalbuminuria is a known risk factor for cardiovascular morbidity and mortality suggesting that it should be a marker of endothelial dysfunction. Albumin to creatinine ratio (ACR) is an available and rapid test for microalbuminuria determination, with a high correlation with the 24-h urine collection method. There is no prospective study that evaluates the prognostic value of ACR in patients with non ST-segment elevation acute coronary syndromes (NSTE-ACS). The purpose of our study was to detect the long-term prognostic value of ACR in patients with NSTE-ACS. Albumin to creatinine ratio was estimated in 700 patients with NSTE-ACS at admission. Median follow-up time was 18 months. The best cutoff point of ACR for death or acute myocardial infarction was 20 mg/g. Twenty-two percent of patients had elevated ACR. By multivariable Cox regression analysis, ACR was an independent predictor of the clinical endpoint: odds ratio 5.8 (95% confidence interval [CI] 2-16), log-rank 2 p 65 years, female gender, diabetes mellitus, creatinine clearance, glucose levels at admission, elevated cardiac markers (troponin T/CK-MB) and ST segment depression. The addition of ACR significantly improved GRACE score C-statistics from 0.69 (95% CI 0.59-0.83) to 0.77 (95% CI 0.65-0.88), SE 0.04, 2 p = 0.03, with a good calibration with both models. Albumin to creatinine ratio is an independent and accessible predictor of long-term adverse outcomes in NSTE-ACS, providing additional value for risk stratification.

  17. Technoeconomic assumptions adopted for the development of a long-term electricity supply model for Cyprus.

    Science.gov (United States)

    Taliotis, Constantinos; Taibi, Emanuele; Howells, Mark; Rogner, Holger; Bazilian, Morgan; Welsch, Manuel

    2017-10-01

    The generation mix of Cyprus has been dominated by oil products for decades. In order to conform with European Union and international legislation, a transformation of the supply system is called for. Energy system models can facilitate energy planning into the future, but a large volume of data is required to populate such models. The present data article provides information on key modelling assumptions and input data adopted with the aim of representing the electricity supply system of Cyprus in a separate research article. Data in regards to renewable energy technoeconomic characteristics and investment cost projections, fossil fuel price projections, storage technology characteristics and system operation assumptions are described in this article.

  18. Long-term price and environmental effects in a liberalised electricity market

    International Nuclear Information System (INIS)

    Lise, Wietze; Kruseman, Gideon

    2008-01-01

    This paper studies the effects of endogenous investment decisions in a liberalised electricity market on prices and the environment in the time horizon 2000-2050. Therefore, a computational, game-theoretic, recursive dynamic model is developed. Simulations with the model indicate that perfect competition leads to lower prices and benefits the environment in the form of lower acid and smog emissions. Continued exercise of market power leads to postponed investments and more diversity in the technology portfolio, while under perfect competition there is an earlier switch to gas-based technologies. (author)

  19. Novel effects of demand side management data on accuracy of electrical energy consumption modeling and long-term forecasting

    International Nuclear Information System (INIS)

    Ardakani, F.J.; Ardehali, M.M.

    2014-01-01

    Highlights: • Novel effects of DSM data on electricity consumption forecasting is examined. • Optimal ANN models based on IPSO and SFL algorithms are developed. • Addition of DSM data to socio-economic indicators data reduces MAPE by 36%. - Abstract: Worldwide implementation of demand side management (DSM) programs has had positive impacts on electrical energy consumption (EEC) and the examination of their effects on long-term forecasting is warranted. The objective of this study is to investigate the effects of historical DSM data on accuracy of EEC modeling and long-term forecasting. To achieve the objective, optimal artificial neural network (ANN) models based on improved particle swarm optimization (IPSO) and shuffled frog-leaping (SFL) algorithms are developed for EEC forecasting. For long-term EEC modeling and forecasting for the U.S. for 2010–2030, two historical data types used in conjunction with developed models include (i) EEC and (ii) socio-economic indicators, namely, gross domestic product, energy imports, energy exports, and population for 1967–2009 period. Simulation results from IPSO-ANN and SFL-ANN models show that using socio-economic indicators as input data achieves lower mean absolute percentage error (MAPE) for long-term EEC forecasting, as compared with EEC data. Based on IPSO-ANN, it is found that, for the U.S. EEC long-term forecasting, the addition of DSM data to socio-economic indicators data reduces MAPE by 36% and results in the estimated difference of 3592.8 MBOE (5849.9 TW h) in EEC for 2010–2030

  20. Mid-term evaluation of the NRECA (National Rural Electric Cooperative Association) Central America Rural Electrification Support Program (CARES)

    Energy Technology Data Exchange (ETDEWEB)

    Perlack, R.D. (Oak Ridge National Lab., TN (USA)); Jones, H.G. (Oak Ridge Associated Universities, Inc., TN (USA)); Garcia, A. III (Texas A and M Univ., College Station, TX (USA). Dept. of Agricultural Engineering); Flores, E. (Flores (Edgar), Guatemala City (Guatemala))

    1990-09-01

    Oak Ridge National Laboratory was requested by the Regional Office for Central America and Panama to conduct a mid-term evaluation of the Cares Project, which is being implemented by the National Rural Electric Cooperative Association. This evaluation was conducted over a three week period by a four person team. Overall, the project has had numerous successes and is highly valued by local counterpart utilities and USAID Missions. Notwithstanding the significant results of the project, changes can be made in certain operating procedures and in the direction of some programmatic activities that can lead to an even more effective project.

  1. Consequences of long-term power outages and high electricity prices lasting for months

    International Nuclear Information System (INIS)

    2005-01-01

    Several areas in the world have experienced electricity outages for longer periods of time, but the consequences of these are sparsely documented. There is a need for further analysis of the socioeconomic consequences of the outages. In addition to KILE (Quality adjusted revenue framework for un supplied energy) costs one has to take into account that the costs often increase proportionally with the durance of the outage, and that KILE tariffs do not reflect lost consumer's surplus for products that are not produced during an outage. A good example is the public underground transport, where the company's economical loss can be significantly smaller than the loss of utility value for the travellers. If the authorities act with reasonability it is difficult to see that periods with very high prices represent a big problem. The most important problems are related to diffused effects, especially for households with a weak economy. These problems can be solved with improved contractual forms (price guarantees) or by transfers to the households, without weakening the incentives for electricity economising (ml)

  2. Techno-economic analysis of concentrated solar power plants in terms of levelized cost of electricity

    Science.gov (United States)

    Musi, Richard; Grange, Benjamin; Sgouridis, Sgouris; Guedez, Rafael; Armstrong, Peter; Slocum, Alexander; Calvet, Nicolas

    2017-06-01

    Levelized Cost of Electricity (LCOE) is an important metric which provides one way to compare the economic competitiveness of different electricity generation systems, calculated simply by dividing lifetime costs by lifetime production. Hidden behind the simplicity of this formula are various assumptions which may significantly alter results. Different LCOE studies exist in the literature, although their assumptions are rarely explicitly stated. This analysis gives all formulas and assumptions which allow for inter-study comparisons. The results of this analysis indicate that CSP LCOE is reducing markedly over time and that given the right location and market conditions, the SunShot 6¢/kWh 2020 target can be reached. Increased industrial cooperation is needed to advance the CSP market and continue to drive down LCOE. The results also indicate that there exist a country and technology level learning effect, either when installing an existing CSP technology in a new country or when using a new technology in an existing CSP country, which seems to impact market progress.

  3. Detection and analysis of black spots with even small accident figures. Contribution to the Seminar on Short-term and Area-wide Evaluation of Safety Measures, Amsterdam, April 19-21, 1982, p. 75-84.

    NARCIS (Netherlands)

    Oppe, S.

    1982-01-01

    In order to detect accident black spots we have to know the probability of an accident for a traffic situation of some kind, or the mean number of accidents for some unit of time. In almost all procedures known to us, the various road locations are treated as isolated spots. With small accident

  4. Designing the input vector to ANN-based models for short-term load forecast in electricity distribution systems

    International Nuclear Information System (INIS)

    Santos, P.J.; Martins, A.G.; Pires, A.J.

    2007-01-01

    The present trend to electricity market restructuring increases the need for reliable short-term load forecast (STLF) algorithms, in order to assist electric utilities in activities such as planning, operating and controlling electric energy systems. Methodologies such as artificial neural networks (ANN) have been widely used in the next hour load forecast horizon with satisfactory results. However, this type of approach has had some shortcomings. Usually, the input vector (IV) is defined in a arbitrary way, mainly based on experience, on engineering judgment criteria and on concern about the ANN dimension, always taking into consideration the apparent correlations within the available endogenous and exogenous data. In this paper, a proposal is made of an approach to define the IV composition, with the main focus on reducing the influence of trial-and-error and common sense judgments, which usually are not based on sufficient evidence of comparative advantages over previous alternatives. The proposal includes the assessment of the strictly necessary instances of the endogenous variable, both from the point of view of the contiguous values prior to the forecast to be made, and of the past values representing the trend of consumption at homologous time intervals of the past. It also assesses the influence of exogenous variables, again limiting their presence at the IV to the indispensable minimum. A comparison is made with two alternative IV structures previously proposed in the literature, also applied to the distribution sector. The paper is supported by a real case study at the distribution sector. (author)

  5. Medium-Term Probabilistic Forecasting of Extremely Low Prices in Electricity Markets: Application to the Spanish Case

    Directory of Open Access Journals (Sweden)

    Antonio Bello

    2016-03-01

    Full Text Available One of the most relevant challenges that have arisen in electricity markets during the last few years is the emergence of extremely low prices. Trying to predict these events is crucial for market agents in a competitive environment. This paper proposes a novel methodology to simultaneously accomplish punctual and probabilistic hourly predictions about the appearance of extremely low electricity prices in a medium-term scope. The proposed approach for making real ex ante forecasts consists of a nested compounding of different forecasting techniques, which incorporate Monte Carlo simulation, combined with spatial interpolation techniques. The procedure is based on the statistical identification of the process key drivers. Logistic regression for rare events, decision trees, multilayer perceptrons and a hybrid approach, which combines a market equilibrium model with logistic regression, are used. Moreover, this paper assesses whether periodic models in which parameters switch according to the day of the week can be even more accurate. The proposed techniques are compared to a Markov regime switching model and several naive methods. The proposed methodology empirically demonstrates its effectiveness by achieving promising results on a real case study based on the Spanish electricity market. This approach can provide valuable information for market agents when they face decision making and risk-management processes. Our findings support the additional benefit of using a hybrid approach for deriving more accurate predictions.

  6. On the importance of the long-term seasonal component in day-ahead electricity price forecasting

    International Nuclear Information System (INIS)

    Nowotarski, Jakub; Weron, Rafał

    2016-01-01

    In day-ahead electricity price forecasting (EPF) the daily and weekly seasonalities are always taken into account, but the long-term seasonal component (LTSC) is believed to add unnecessary complexity to the already parameter-rich models and is generally ignored. Conducting an extensive empirical study involving state-of-the-art time series models we show that (i) decomposing a series of electricity prices into a LTSC and a stochastic component, (ii) modeling them independently and (iii) combining their forecasts can bring – contrary to a common belief – an accuracy gain compared to an approach in which a given time series model is calibrated to the prices themselves. - Highlights: • A new class of Seasonal Component AutoRegressive (SCAR) models is introduced. • Electricity prices are decomposed into a trend-seasonal and a stochastic component. • Both components are modeled independently, their forecasts are combined. • Significant accuracy gains can be achieved compared to commonly used approaches.

  7. A three-stage short-term electric power planning procedure for a generation company in a liberalized market

    International Nuclear Information System (INIS)

    Nabona, Narcis; Pages, Adela

    2007-01-01

    In liberalized electricity markets, generation companies bid their hourly generation in order to maximize their profit. The optimization of the generation bids over a short-term weekly period must take into account the action of the competing generation companies and the market-price formation rules and must be coordinated with long-term planning results. This paper presents a three stage optimization process with a data analysis and parameter calculation, a linearized unit commitment, and a nonlinear generation scheduling refinement. Although the procedure has been developed from the experience with the Spanish power market, with minor adaptations it is also applicable to any generation company participating in a competitive market system. (author)

  8. Technoeconomic assumptions adopted for the development of a long-term electricity supply model for Cyprus

    Directory of Open Access Journals (Sweden)

    Constantinos Taliotis

    2017-10-01

    Full Text Available The generation mix of Cyprus has been dominated by oil products for decades. In order to conform with European Union and international legislation, a transformation of the supply system is called for. Energy system models can facilitate energy planning into the future, but a large volume of data is required to populate such models. The present data article provides information on key modelling assumptions and input data adopted with the aim of representing the electricity supply system of Cyprus in a separate research article. Data in regards to renewable energy technoeconomic characteristics and investment cost projections, fossil fuel price projections, storage technology characteristics and system operation assumptions are described in this article.

  9. An enhanced radial basis function network for short-term electricity price forecasting

    International Nuclear Information System (INIS)

    Lin, Whei-Min; Gow, Hong-Jey; Tsai, Ming-Tang

    2010-01-01

    This paper proposed a price forecasting system for electric market participants to reduce the risk of price volatility. Combining the Radial Basis Function Network (RBFN) and Orthogonal Experimental Design (OED), an Enhanced Radial Basis Function Network (ERBFN) has been proposed for the solving process. The Locational Marginal Price (LMP), system load, transmission flow and temperature of the PJM system were collected and the data clusters were embedded in the Excel Database according to the year, season, workday and weekend. With the OED applied to learning rates in the ERBFN, the forecasting error can be reduced during the training process to improve both accuracy and reliability. This would mean that even the ''spikes'' could be tracked closely. The Back-propagation Neural Network (BPN), Probability Neural Network (PNN), other algorithms, and the proposed ERBFN were all developed and compared to check the performance. Simulation results demonstrated the effectiveness of the proposed ERBFN to provide quality information in a price volatile environment. (author)

  10. A potention of renewable energy sources in Slovakia in term of production of electricity

    Directory of Open Access Journals (Sweden)

    Štefan Kuzevič

    2005-11-01

    Full Text Available Electro-energetics of Slovak Republic is in this time in state of re-structuralization consequent from responsibilities which SR has with integration to the EU and on the other hand with actual status of production capacities of fossil fuels using in heat power stations and heat stations also the utilization of nuclear energy in nuclear power stations Jaslovské Bohunice and Mochovce. Paradoxically slim representation in production capacities have renewable energy sources, while only one relevant one is utilization of water in small hydro power stations. According to fact, that to the year 2010, the share of renewable sources of energy using in comparing with electric energy has to achieve 21,7% (direction of EU 77/2001. It is necessary to evaluate possibilities of utilization and to specify potential of utilization from technical and economical aspect.

  11. Auroral Substorms: Search for Processes Causing the Expansion Phase in Terms of the Electric Current Approach

    Science.gov (United States)

    Akasofu, Syun-Ichi

    2017-10-01

    Auroral substorms are mostly manifestations of dissipative processes of electromagnetic energy. Thus, we consider a sequence of processes consisting of the power supply (dynamo), transmission (currents/circuits) and dissipations (auroral substorms-the end product), namely the electric current line approach. This work confirms quantitatively that after accumulating magnetic energy during the growth phase, the magnetosphere unloads the stored magnetic energy impulsively in order to stabilize itself. This work is based on our result that substorms are caused by two current systems, the directly driven (DD) current system and the unloading system (UL). The most crucial finding in this work is the identification of the UL (unloading) current system which is responsible for the expansion phase. A very tentative sequence of the processes leading to the expansion phase (the generation of the UL current system) is suggested for future discussions. (1) The solar wind-magnetosphere dynamo enhances significantly the plasma sheet current when its power is increased above 10^{18} erg/s (10^{11} w). (2) The magnetosphere accumulates magnetic energy during the growth phase, because the ionosphere cannot dissipate the increasing power because of a low conductivity. As a result, the magnetosphere is inflated, accumulating magnetic energy. (3) When the power reaches 3-5× 10^{18} erg/s (3-5× 10^{11} w) for about one hour and the stored magnetic energy reaches 3-5×10^{22} ergs (10^{15} J), the magnetosphere begins to develop perturbations caused by current instabilities (the current density {≈}3× 10^{-12} A/cm2 and the total current {≈}106 A at 6 Re). As a result, the plasma sheet current is reduced. (4) The magnetosphere is thus deflated. The current reduction causes partial B/partial t > 0 in the main body of the magnetosphere, producing an earthward electric field. As it is transmitted to the ionosphere, it becomes equatorward-directed electric field which drives both

  12. Long-term scenario alternatives and their implications: LEAP model application of Panama's electricity sector

    International Nuclear Information System (INIS)

    McPherson, Madeleine; Karney, Bryan

    2014-01-01

    Panama recently enacted a new law, which aims to promote wind energy by mandating long term power purchase tenders. The implications of this new law lend some uncertainty to Panama's electricity development pathway. This paper quantitatively analyzes the current status of power generation in Panama, and explores various potential future scenarios and the associated impacts on the system marginal cost, global warming potential, and resource diversity index. To this end, this study applies the scenario development methodology developed by Schwartz in the context of the energy-economic modeling platform ‘Long-range Energy Alternative Planning’ (LEAP). Four scenarios are developed and analyzed. The Business as Usual scenario extrapolates the electricity generation trend that has been observed over the last decade; it is compared to three alternative scenarios which have more specific objectives. Scenario 1 encourages climate mitigation without incorporating new technologies in the generation mix, Scenario 2 maximizes resource diversity, and Scenario 3 minimizes global warming potential. For each scenario, the composition of the electricity generation profile, system marginal cost, global warming potential, and resource diversity is predicted quantitatively. These scenarios to not attempt to forecast likely developments, but rather illuminate the tradeoffs that different development pathways entail. - Highlights: • This paper models Panama's electricity sector using the LEAP model platform. • Four scenarios are developed and analyzed. • Impact analysis includes: system cost, global warming potential, resource diversity index. • Panama can achieve a sustainable grid with existing technologies and costs. • There is an tradeoff between the resource diversity and global warming potential

  13. Short-Term Electricity-Load Forecasting Using a TSK-Based Extreme Learning Machine with Knowledge Representation

    Directory of Open Access Journals (Sweden)

    Chan-Uk Yeom

    2017-10-01

    Full Text Available This paper discusses short-term electricity-load forecasting using an extreme learning machine (ELM with automatic knowledge representation from a given input-output data set. For this purpose, we use a Takagi-Sugeno-Kang (TSK-based ELM to develop a systematic approach to generating if-then rules, while the conventional ELM operates without knowledge information. The TSK-ELM design includes a two-phase development. First, we generate an initial random-partition matrix and estimate cluster centers for random clustering. The obtained cluster centers are used to determine the premise parameters of fuzzy if-then rules. Next, the linear weights of the TSK fuzzy type are estimated using the least squares estimate (LSE method. These linear weights are used as the consequent parameters in the TSK-ELM design. The experiments were performed on short-term electricity-load data for forecasting. The electricity-load data were used to forecast hourly day-ahead loads given temperature forecasts; holiday information; and historical loads from the New England ISO. In order to quantify the performance of the forecaster, we use metrics and statistical characteristics such as root mean squared error (RMSE as well as mean absolute error (MAE, mean absolute percent error (MAPE, and R-squared, respectively. The experimental results revealed that the proposed method showed good performance when compared with a conventional ELM with four activation functions such sigmoid, sine, radial basis function, and rectified linear unit (ReLU. It possessed superior prediction performance and knowledge information and a small number of rules.

  14. Long-term dynamics of investment decisions in electricity markets with variable renewables development and adequacy objectives

    International Nuclear Information System (INIS)

    Petitet, Marie

    2016-01-01

    In liberalised electricity systems, power markets are expected to ensure the long-term coordination of investments in order to guarantee security of supply, sustainability and competitiveness. In the reference energy-only market, it relies on the ability of power markets - where the hourly price is aligned with the marginal cost of the system - to provide an adequate price-signal for investors. However, in practice, questions have been raised about its ability to trigger investments in Low-Carbon Technologies (LCT) including in particular Renewable Energy Sources of Electricity (RES-E), and its ability to ensure capacity adequacy. After a characterisation of these market failures, this dissertation tackles the two research topics within a methodological framework based on a System Dynamics model developed to simulate private investment decisions in power markets. First, the results show that substituting out-of-market support mechanisms for RES-E by market-based investments helped by the sole implementation of a carbon price appears as a feasible solution to trigger RES-E development providing that there is a political commitment on a high carbon price. Second, it also appears that the energy-only market with price cap is ineffective to ensure capacity adequacy in a context of mature markets with conventional thermal power plants under transition paths which involve a stable electricity demand thank to energy efficiency efforts and the exogenous development of RES-E thanks to support mechanisms in the absence of a high and fixed carbon price. Adding a capacity market or removing the price cap both bring benefits in terms of Loss Of Load Expectation (LOLE) and social welfare. Moreover, considering two various energy transition scenarios and different assumptions about the risk aversion of private investors, the capacity market is identified as the best option for regulators among the considered market designs. (author) [fr

  15. Time-Series Prediction: Application to the Short-Term Electric Energy Demand

    OpenAIRE

    Troncoso Lora, Alicia; Riquelme Santos, Jesús Manuel; Riquelme Santos, José Cristóbal; Gómez Expósito, Antonio; Martínez Ramos, José Luis

    2003-01-01

    This paper describes a time-series prediction method based on the kNN technique. The proposed methodology is applied to the 24-hour load forecasting problem. Also, based on recorded data, an alternative model is developed by means of a conventional dynamic regression technique, where the parameters are estimated by solving a least squares problem. Finally, results obtained from the application of both techniques to the Spanish transmission system are compared in terms of maximum, average and ...

  16. Electricity Theory

    International Nuclear Information System (INIS)

    Gong, Ha Soung

    2006-12-01

    The text book composed of five parts, which are summary of this book, arrangement of electricity theory including electricity nad magnetism, a direct current, and alternating current. It has two dictionary electricity terms for a synonym. The last is an appendix. It is for preparing for test of officer, electricity engineer and fire fighting engineer.

  17. Analysis of an underground electric heating system with short-term energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Ramadan, B.H. [Michigan State Univ., East Lansing, MI (United States). Dept. of Mechanical Engineering

    1994-12-31

    The principal commercially active heat storage application in which concrete is used as the storage medium is in the use of subfloor electric heaters embedded in a layer of sand. The resistance heaters are energized when utility offpeak rates are in effect. The sand bed and the concrete floor are then heated to some predetermined temperature, and the floor releases heat slowly and remains warm during the subsequent period of high demand. Analysis of the slab-heating system for varying design parameters, such as the depth of the placement of the heaters, the sand properties, the energy input, and the insulation thickness, was considered. The system was also optimized based on life-cycle costs. The suitability of using this system for heating a warehouse in four representative cities in the United States was also considered The response of the system was found to be greatly influenced by the depth of the placement of the heaters, the sand`s moisture content, and the heating strategy. Optimum insulation levels were determined for the prototypical building in all four of the representative cities. Because of the difficulty of controlling the energy release from the heating mats, this system may not be suitable for heating residential and office buildings but may be more appropriate for heating maintenance and storage facilities.

  18. Short-term electricity demand and gas price forecasts using wavelet transforms and adaptive models

    International Nuclear Information System (INIS)

    Nguyen, Hang T.; Nabney, Ian T.

    2010-01-01

    This paper presents some forecasting techniques for energy demand and price prediction, one day ahead. These techniques combine wavelet transform (WT) with fixed and adaptive machine learning/time series models (multi-layer perceptron (MLP), radial basis functions, linear regression, or GARCH). To create an adaptive model, we use an extended Kalman filter or particle filter to update the parameters continuously on the test set. The adaptive GARCH model is a new contribution, broadening the applicability of GARCH methods. We empirically compared two approaches of combining the WT with prediction models: multicomponent forecasts and direct forecasts. These techniques are applied to large sets of real data (both stationary and non-stationary) from the UK energy markets, so as to provide comparative results that are statistically stronger than those previously reported. The results showed that the forecasting accuracy is significantly improved by using the WT and adaptive models. The best models on the electricity demand/gas price forecast are the adaptive MLP/GARCH with the multicomponent forecast; their NMSEs are 0.02314 and 0.15384 respectively. (author)

  19. Servo-controlled hind-limb electrical stimulation for short-term arterial pressure control.

    Science.gov (United States)

    Kawada, Toru; Shimizu, Shuji; Yamamoto, Hiromi; Shishido, Toshiaki; Kamiya, Atsunori; Miyamoto, Tadayoshi; Sunagawa, Kenji; Sugimachi, Masaru

    2009-05-01

    Autonomic neural intervention is a promising tool for modulating the circulatory system thereby treating some cardiovascular diseases. In 8 pentobarbital-anesthetized cats, it was examined whether the arterial pressure (AP) could be controlled by acupuncture-like hind-limb electrical stimulation (HES). With a 0.5-ms pulse width, HES monotonically reduced AP as the stimulus current increased from 1 to 5 mA, suggesting that the stimulus current could be a primary control variable. In contrast, the depressor effect of HES showed a nadir approximately 10 Hz in the frequency range between 1 and 100 Hz. Dynamic characteristics of the AP response to HES approximated a second-order low-pass filter with dead time (gain: -10.2 +/- 1.6 mmHg/mA, natural frequency: 0.040 +/- 0.004 Hz, damping ratio 1.80 +/- 0.24, dead time: 1.38 +/- 0.13 s, mean +/- SE). Based on these dynamic characteristics, a servo-controlled HES system was developed. When a target AP value was set at 20 mmHg below the baseline AP, the time required for the AP response to reach 90% of the target level was 38 +/- 10 s. The steady-state error between the measured and target AP values was 1.3 +/- 0.1 mmHg. Autonomic neural intervention by acupuncture-like HES might provide an additional modality to quantitatively control the circulatory system.

  20. Short-term memory and electrical restitution in the canine transmural ventricle

    International Nuclear Information System (INIS)

    Zhang, Hong; Ueyama, Takeshi; Lin, Shien-Fong; Wang, Juan; Wu, Rui-Juan

    2011-01-01

    Cardiac short-term memory is an intrinsic property of paced myocardium that reflects the influence of pacing history. Using an optical mapping method to record membrane voltage and intracellular calcium (Ca 2+ i ), this study investigated the properties and mechanisms of short-term memory in isolated and perfused canine wedge preparations. In addition to the dynamic and S1S2 pacing protocols, a perturbed downsweep pacing protocol was used to get a complete overview of the restitution portrait. Abrupt changes in basic cycle length (BCL) were applied to investigate the accommodation process of action potential duration (APD). The results showed unobvious differences of memory among the epi-, mid- and endo-myocytes, implying an insignificant memory-induced transient heterogeneity in APD across the transmural canine hearts. With the decrease of pacing rate S1, memory gradually elevated and achieved a maximum around 400 ms, and then reduced as S1 decreased further, indicating a non-monotonic relationship between memory and the pacing rate. After suppressing the Ca 2+ i transient with ryanodine (3 µmol l −1 ), the accommodation process of APD to a new BCL significantly abbreviated (τ = 37.41 ± 4.42 stimuli before ryanodine, τ = 15.84 ± 4.74 stimuli after ryanodine, p < 0.01). Therefore, Ca 2+ i cycling was suggested to play an important role in memory during dynamic pacing

  1. Experimental Study of Tensile Test in Resistance Spot Welding Process

    Directory of Open Access Journals (Sweden)

    Lebbal Habib

    Full Text Available Abstract Resistance spot welding (RSW is a widely used joining process for fabricating sheet metal assemblies in automobile industry .In comparison with other welding processes the RSW is faster and easier for automation. This process involves electrical, thermal and mechanical interactions. Resistance spot welding primarily takes place by localized melting spot at the interface of the sheets followed by its quick solidification under sequential control of pressure water-cooled electrode and flow of required electric current for certain duration. In this work the tensile tests were studied, the results obtained show that the type material, the overlap length, the angle of the rolling direction and the thickness of the sheet have an influence in resistance spot welding process.

  2. Volume dips; spot price ranges narrow

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    This article is the September 1994 uranium market summary. Volume in the spot concentrates market fell below 1 million lbs U3O8. In total, twelve deals took place compared to 28 deals in August. Of the twelve deals, three took place in the spot concentrates market, two took place in the medium and long-term market, three in the conversion market, and four in the enrichment market. Restricted prices weakened, but unrestricted prices firmed slightly. The enrichment price range narrowed a bit

  3. TV spots' impact.

    Science.gov (United States)

    El-bakly, S

    1994-09-01

    The Information, Education and Communication (IEC) Center of the State Information Service was established in 1979 for the purpose of providing information to the people on the population issue. The Ministry of Information has accorded the State Information Service free TV and radio air time for family planning dramas and spots. In the early years information campaigns were organized to make people aware of the population problem by slogans, songs, and cartoons. Around 1984 misconceptions about family planning and contraceptives were attacked through a number of TV and radio spots. A few years later 21 spots on specific contraceptive methods were broadcast which were aired for three years over 3000 times. They were extremely successful. The impact of these TV spots was one of the major reasons why the contraceptive prevalence rate increased from 30% in 1984 to 38% in 1988 and 47% in 1992. Spots were also broadcast about the social implications of large families. The TV soap opera "And The Nile Flows On", with the family planning message interwoven into it, was very well received by the target audience. A program entitled "Wedding of the Month" features couples who know family planning well. The most successful radio program is a 15-20 minute long quiz show for residents of the villages where the Select Villages Project is being implemented. The State Information Service has 60 local information centers in the 26 governorates of Egypt that make plans for the family planning campaign. In 1992 the Minya Initiative, a family planning project was implemented in the Minya Governorate. As a result, the contraceptive prevalence rate rose from 22% to 30% over 18 months. A new project, the Select Village Project, was developed in 1993 that replicates the Minya Initiative on the village level in other governorates. This new project that was implemented in sixteen governorates.

  4. Artificial intelligence in short term electric load forecasting: a state-of-the-art survey for the researcher

    Energy Technology Data Exchange (ETDEWEB)

    Metaxiotis, K.; Kagiannas, A.; Askounis, D.; Psarras, J. [National Technical University of Athens, Zografou (Turkey). Dept. of Electrical and Computer Engineering

    2003-06-01

    Intelligent solutions, based on artificial intelligence (AI) technologies, to solve complicated practical problems in various sectors are becoming more and more widespread nowadays. AI-based systems are being developed and deployed worldwide in myriad applications, mainly because of their symbolic reasoning, flexibility and explanation capabilities. This paper provides an overview for the researcher of AI technologies, as well as their current use in the field of short term electric load forecasting (STELF). The history of AI in STELF is outlined, leading to a discussion of the various approaches as well as the current research directions. The paper concludes by sharing thoughts and estimations on AI future prospects in this area. This review reveals that although still regarded as a novel methodology, AI technologies are shown to have matured to the point of offering real practical benefits in many of their applications. (Author)

  5. How much extra spot gas is there?

    International Nuclear Information System (INIS)

    Bros, Th.

    2007-01-01

    With the increase of European gas demand and the sharp decrease of local supply, security of supply is becoming an ever greater issue. However, liberalization tilts the traditional equilibrium based on long term 'take or pay' contracts between big suppliers and national distribution companies. Today, buying gas on the spot market is becoming more and more important to balance supply portfolio with a fast moving market share. But the way gas spot markets are operating is not well documented. It is very difficult to assess its impact on the European security of supply. Therefore, the aim of this article is to evaluate the amount of 'spot' liquefied natural gas (LNG) that could be found in case of a major supply disruption in pipe gas delivered to Europe

  6. Roth spots in pernicious anaemia

    OpenAIRE

    Macauley, Mavin; Nag, Satyajit

    2011-01-01

    Roth spots are white-centred retinal haemorrhages, previously thought to be pathognomonic for subacute bacterial endocarditis. A number of other conditions can be associated with Roth spots. In this case, the authors describe the association of Roth spots and pernicious anaemia. This association has been rarely described in the medical literature. Correct diagnosis and treatment with intramuscular vitamin B12 injections resulted in complete resolution of the anaemia and Roth spots. The author...

  7. Distributional modeling and short-term forecasting of electricity prices by Generalized Additive Models for Location, Scale and Shape

    International Nuclear Information System (INIS)

    Serinaldi, Francesco

    2011-01-01

    In the context of the liberalized and deregulated electricity markets, price forecasting has become increasingly important for energy company's plans and market strategies. Within the class of the time series models that are used to perform price forecasting, the subclasses of methods based on stochastic time series and causal models commonly provide point forecasts, whereas the corresponding uncertainty is quantified by approximate or simulation-based confidence intervals. Aiming to improve the uncertainty assessment, this study introduces the Generalized Additive Models for Location, Scale and Shape (GAMLSS) to model the dynamically varying distribution of prices. The GAMLSS allow fitting a variety of distributions whose parameters change according to covariates via a number of linear and nonlinear relationships. In this way, price periodicities, trends and abrupt changes characterizing both the position parameter (linked to the expected value of prices), and the scale and shape parameters (related to price volatility, skewness, and kurtosis) can be explicitly incorporated in the model setup. Relying on the past behavior of the prices and exogenous variables, the GAMLSS enable the short-term (one-day ahead) forecast of the entire distribution of prices. The approach was tested on two datasets from the widely studied California Power Exchange (CalPX) market, and the less mature Italian Power Exchange (IPEX). CalPX data allow comparing the GAMLSS forecasting performance with published results obtained by different models. The study points out that the GAMLSS framework can be a flexible alternative to several linear and nonlinear stochastic models. - Research Highlights: ► Generalized Additive Models for Location, Scale and Shape (GAMLSS) are used to model electricity prices' time series. ► GAMLSS provide the entire dynamicaly varying distribution function of prices resorting to a suitable set of covariates that drive the instantaneous values of the parameters

  8. Poisson Spot with Magnetic Levitation

    Science.gov (United States)

    Hoover, Matthew; Everhart, Michael; D'Arruda, Jose

    2010-01-01

    In this paper we describe a unique method for obtaining the famous Poisson spot without adding obstacles to the light path, which could interfere with the effect. A Poisson spot is the interference effect from parallel rays of light diffracting around a solid spherical object, creating a bright spot in the center of the shadow.

  9. Competition in decentralized electricity markets: Three papers on electricity auctions

    Science.gov (United States)

    Harbord, David William Cameron

    This thesis consists of three self-contained papers on the analysis of electricity auctions written over a period of twelve years. The first paper models price competition in a decentralized wholesale market for electricity as a first-price, sealed-bid, multi-unit auction. In both the pure and mixed-strategy equilibria of the model, above marginal cost pricing and inefficient despatch of generating units occur. An alternative regulatory pricing rule is considered and it is shown that offering to supply at marginal cost can be induced as a dominant strategy for all firms. The second paper analyses strategic interaction between long-term contracts and price competition in the British electricity wholesale market, and confirms that forward contracts will tend to put downward pressure on spot market prices. A 'strategic commitment' motive for selling forward contracts is also identified: a generator may commit itself to bidding lower prices into the spot market in order to ensure that it will be despatched with its full capacity. The third paper characterizes bidding behavior and market outcomes in uniform and discriminatory electricity auctions. Uniform auctions result in higher average prices than discriminatory auctions, but the ranking in terms of productive efficiency is ambiguous. The comparative effects of other market design features, such as the number of steps in suppliers' bid functions, the duration of bids and the elasticity of demand are analyzed. The paper also clarifies some methodological issues in the analysis of electricity auctions. In particular we show that analogies with continuous share auctions are misplaced so long as firms are restricted to a finite number of bids.

  10. Genetic characterization of angular leaf spot resistance in selected ...

    African Journals Online (AJOL)

    Mr Tryphone

    2015-10-28

    Oct 28, 2015 ... Angular leaf spot disease (ALS) caused by Pseudocercospora griseola is one ... Author(s) agree that this article remains permanently open access under the terms ... that results in shrivelled seeds of reduced size and quality.

  11. On the Spot: Oceans

    OpenAIRE

    Male, Alan; Butterfield, Moira

    2000-01-01

    This a children's non-fiction, knowledge bearing picture book that is part of a Reader's Digest series called 'On the Spot'. The series deals with a range of topics related to the natural world and this one introduces its young audience to the ecosystems of the oceans. \\ud The publication was illustrated and designed by the author (Alan Male) and is technically described as a board book with interactive 'pop up' features, specifically conceived to engage children's discovery and learning thro...

  12. Operation of Modern Distribution Power Systems in Competitive Electricity Markets

    DEFF Research Database (Denmark)

    Hu, Weihao

    , DG units, loads and electricity price are studied. Further, the effect of energy storage systems will be considered, and an optimal operation strategy for energy storage devices in a large scale wind power system in the electricity market is proposed. The western Danish power system, which has large...... strategy for trading wind power in the Danish short-term electricity market in order to minimize the imbalance costs for regulation. A load optimization method based on spot price for demand side management in Denmark is proposed in order to save the energy costs for 3 types of typical Danish consumers...... maximum profit of the BESS is proposed. Two kinds of BESS, based on polysulfide-bromine (PSB) and vanadium redox (VRB) battery technologies, are studied. Optimal operation strategies of PEV in the spot market are then proposed in order to decrease the energy cost for PEV owners. Furthermore...

  13. El spot electoral negativo

    Directory of Open Access Journals (Sweden)

    Palma Peña-Jiménez

    2011-01-01

    Full Text Available l spot político tiene durante la campaña un objetivo final inequívoco: la consecución del voto favorable. Se dirige al cuerpo electoral a través de la televisión y de Internet, y presenta, en muchos casos, un planteamiento negativo, albergando mensajes destinados a la crítica frontal contra el adversario, más que a la exposición de propuestas propias. Este artículo se centra en el análisis del spot electoral negativo, en aquellas producciones audiovisuales construidas sin más causa que la reprobación del contrincante. Se trata de vídeos que, lejos de emplearse en difundir las potencialidades de la organización y las virtudes de su candidato –además de su programa electoral–, consumen su tiempo en descalificar al oponente mediante la transmisión de mensajes, muchas veces, ad hominem. Repasamos el planteamiento negativo del spot electoral desde su primera manifestación, que en España data de 1996, año de emisión del conocido como vídeo del dóberman, sin olvidar otros ejemplos que completan el objeto de estudio.

  14. Roth spots in pernicious anaemia.

    Science.gov (United States)

    Macauley, Mavin; Nag, Satyajit

    2011-04-19

    Roth spots are white-centred retinal haemorrhages, previously thought to be pathognomonic for subacute bacterial endocarditis. A number of other conditions can be associated with Roth spots. In this case, the authors describe the association of Roth spots and pernicious anaemia. This association has been rarely described in the medical literature. Correct diagnosis and treatment with intramuscular vitamin B(12) injections resulted in complete resolution of the anaemia and Roth spots. The authors hope to alert clinicians to think of various differentials of Roth spots, and initiate prompt investigation and management.

  15. The kinematic advantage of electric cars

    Science.gov (United States)

    Meyn, Jan-Peter

    2015-11-01

    Acceleration of a common car with with a turbocharged diesel engine is compared to the same type with an electric motor in terms of kinematics. Starting from a state of rest, the electric car reaches a distant spot earlier than the diesel car, even though the latter has a better specification for engine power and average acceleration from 0 to 100 km h-1. A three phase model of acceleration as a function of time fits the data of the electric car accurately. The first phase is a quadratic growth of acceleration in time. It is shown that the tenfold higher coefficient for the first phase accounts for most of the kinematic advantage of the electric car.

  16. The prerequisites for effective competition in restructured wholesale electricity markets

    International Nuclear Information System (INIS)

    Haas, R.; Auer, H.

    2006-01-01

    This paper argues that effective competition in reformed wholesale electricity markets can only be achieved if the following six prerequisites are met: (1) separation of the grid from generation and supply; (2) wholesale price deregulation; (3) sufficient transmission capacity for a competitive market and non-discriminating grid access; (4) excess generation capacity developed by a large number of competing generators; (5) an equilibrium relationship between short-term spot markets and the long-term financial instruments that marketers use to manage spot-market price volatility; (6) an essentially hands-off government policy that encompasses reduced oversight and privatization. The absence of any one of the first five conditions may result in an oligopoly or monopoly market whose economic performance does not meet the efficiency standards of a competently managed regulated electrical utility. (author)

  17. Diseño y construcción de un reloj/termómetro electrónico con visor gigante

    OpenAIRE

    Sánchez Gutiérrez, Jorge Alfredo; Yapur Auad, Miguel Eduardo

    2014-01-01

    El crecimiento de la industria electrónica debido a los sistemas muy pequeños, de bajo costo, relativamente complejos, conocidos como circuitos integrados a muy grande escala, ha permitido que en un solo circuito podamos tener una calculadora o un reloj electrónico que remplaza al tradicional reloj mecánico de resorte o al de péndulo. Los termómetros digitales han remplazado a los tradicionales termómetros de mercurio y vidrio; son mucho más precisos y portátiles y pueden brindar algunas f...

  18. Efficiency and fairness of the terms and conditions under which electricity is sold to British manufacturing establishments. [Optimality of Bulk Supply Tariff questioned

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, C M

    1977-06-01

    This paper reports on an inquiry into three aspects of the terms and conditions under which electricity is sold to manufacturing establishments. These aspects are the adequacy of information services; the fairness of the pricing behavior of electricity boards; and the efficiency of one schedule of charges agreed with a large industrial consumer. Except the charge for night-time units, the schedule of charges agreed with the large consumer appears to be efficient. However, regional statistics on the percentage of high-voltage customers that pay agreed terms rather than published tariffs suggest that the pricing behavior by boards is often unfair.

  19. The Spotting Distribution of Wildfires

    Directory of Open Access Journals (Sweden)

    Jonathan Martin

    2016-06-01

    Full Text Available In wildfire science, spotting refers to non-local creation of new fires, due to downwind ignition of brands launched from a primary fire. Spotting is often mentioned as being one of the most difficult problems for wildfire management, because of its unpredictable nature. Since spotting is a stochastic process, it makes sense to talk about a probability distribution for spotting, which we call the spotting distribution. Given a location ahead of the fire front, we would like to know how likely is it to observe a spot fire at that location in the next few minutes. The aim of this paper is to introduce a detailed procedure to find the spotting distribution. Most prior modelling has focused on the maximum spotting distance, or on physical subprocesses. We will use mathematical modelling, which is based on detailed physical processes, to derive a spotting distribution. We discuss the use and measurement of this spotting distribution in fire spread, fire management and fire breaching. The appendix of this paper contains a comprehensive review of the relevant underlying physical sub-processes of fire plumes, launching fire brands, wind transport, falling and terminal velocity, combustion during transport, and ignition upon landing.

  20. Emerging hot spot analysis

    DEFF Research Database (Denmark)

    Reinau, Kristian Hegner

    Traditionally, focus in the transport field, both politically and scientifically, has been on private cars and public transport. Freight transport has been a neglected topic. Recent years has seen an increased focus upon congestion as a core issue across Europe, resulting in a great need for know...... speed data for freight. Secondly, the analytical methods used, space-time cubes and emerging hot spot analysis, are also new in the freight transport field. The analysis thus estimates precisely how fast freight moves on the roads in Northern Jutland and how this has evolved over time....

  1. Analysis of the Syrian long-term energy and electricity demand projection using the end-use methodology

    International Nuclear Information System (INIS)

    Hainoun, A.; Seif-Eldin, M.K.; Almoustafa, S.

    2006-01-01

    A comprehensive analysis of the possible future long-term development of Syrian energy and electricity demand covering the period 1999-2030 is presented. The analysis was conducted using the IAEA's model MAED, which relies upon the end-use approach. This model has been validated during the last two decades through the successful application in many developing countries, even those having partial market economy and energy subsidy. Starting from the base year, final energy consumption distributed by energy forms and consumption sectors, the future energy and electricity demand has been projected according to three different scenarios reflecting the possible future demographic, socio-economic and technological development of the country. These scenarios are constructed to cover a plausible range, in which future evolution factors affecting energy demand are expected to lie. The first is a high economy scenario (HS) representing the reference case, which is characterized by high gross domestic product (GDP) growth rate (average annual about 6%) and moderate improved technologies in the various consumption sectors. The second is an energy efficiency scenario (ES), which is identical to HS in all main parameters except these relating to the efficiency improvement and conservation measures. Here, high technology improvement and more effective conservation measures in all consumption sectors are proposed and the role of solar to substitute fossil energy for heating purposes is considered effectively. The third is a low economy scenario (LS) with low GDP growth rate (average annual about 3.5%) and less technology improvement in the consumption sectors. As a consequence, the improvement in the energy efficiency is low and the influence of conservation measures is less effective. Starting from about 10.5mtoe final energy in the base year, the analysis shows that the projected energy demand will grow annually at average rates of 5%, 4.5% and 3% for the HS, ES and LS

  2. Electrical storm is an independent predictor of adverse long-term outcome in the era of implantable defibrillator therapy.

    Science.gov (United States)

    Gatzoulis, Konstantinos A; Andrikopoulos, George K; Apostolopoulos, Theodoros; Sotiropoulos, Elias; Zervopoulos, George; Antoniou, John; Brili, Stella; Stefanadis, Christodoulos I

    2005-03-01

    Electrical storm (ES) is a life-threatening arrhythmia complication affecting patients treated with an implantable cardioverter defibrillator (ICD). Despite its increasing importance, existing data on prognosis and management of ICD patients affected by ES are limited and conflicting. We prospectively studied 169 consecutive patients receiving an ICD. Thirty-two patients presented with at least one episode of ES during the period of observation (33+/-26 months). ES patients were older (64+/-9 vs. 59+/-13 years, P=0.013) with more advanced congestive heart failure (CHF) but a similar incidence of an underlying organic heart disease. Long-term total and cardiac mortality were both increased among ES patients. Seventeen of the 32 ES patients died as opposed to 19 of the 137 ICD patients without ES (53 vs. 14%, P<0.001). In multivariate Cox regression analysis adjusted for the main confounders, history of ES was significantly and independently associated with total and cardiac mortality (risk ratio (RR)=2.13, P=0.031 and RR=2.59, P=0.019, respectively). ES is a relatively frequent complication affecting ICD patients treated for secondary prevention of sudden cardiac death (SCD). Although the acute management of this serious arrhythmia complication is usually successful, occurrence of ES is a strong independent predictor of poor outcome in ICD patients.

  3. New Approaches for Very Short-term Steady-State Analysis of An Electrical Distribution System with Wind Farms

    Directory of Open Access Journals (Sweden)

    Antonio Bracale

    2010-04-01

    Full Text Available Distribution networks are undergoing radical changes due to the high level of penetration of dispersed generation. Dispersed generation systems require particular attention due to their incorporation of uncertain energy sources, such as wind farms, and due to the impacts that such sources have on the planning and operation of distribution networks. In particular, the foreseeable, extensive use of wind turbine generator units in the future requires that distribution system engineers properly account for their impacts on the system. Many new technical considerations must be addressed, including protection coordination, steady-state analysis, and power quality issues. This paper deals with the very short-term, steady-state analysis of a distribution system with wind farms, for which the time horizon of interest ranges from one hour to a few hours ahead. Several wind-forecasting methods are presented in order to obtain reliable input data for the steady-state analysis. Both deterministic and probabilistic methods were considered and used in performing deterministic and probabilistic load-flow analyses. Numerical applications on a 17-bus, medium-voltage, electrical distribution system with various wind farms connected at different busbars are presented and discussed.

  4. Dungeness 'A' Nuclear Power Station. The findings of NII's assessment of Nuclear Electric's long term safety review

    International Nuclear Information System (INIS)

    1994-01-01

    The assessment is reported of Nuclear Electrics' Long Term Safety Reviews (LTSR) of the Dungeness A magnox reactors. The assessment was undertaken by the Health and Safety Executive's Nuclear Installations Inspectorate (NII) which is responsible for regulating the safety of nuclear installations in the United Kingdom. This was one of a programme of LTSRs for all the UK magnox reactors. The LTSR for each plant was proceeded by a Generic Issues programme. The results of both the LTSR and the Generic Issues programme have been used by NII in forming the conclusions of this assessment. Overall the safety case for Dungeness A is satisfactory for continued operation. A programme of additional modifications and inspections has been put in place which further enhances the safety justification. Reactor operations will continue to be monitored and regulated in accordance with the inspections required under the licensing arrangements. Provided these requirements and the agreed further analysis, improvements and inspections give satisfactory results it is expected that the station will be able to operate safely till each reactor is at least 30 years old. Beyond this point a further Periodic Safety Review will be required. (UK)

  5. Hot spots and heavily dislocated regions in multicrystalling silicon cells

    International Nuclear Information System (INIS)

    Simo, A.; Martinuzzi, S.

    1990-01-01

    The formation mechanism and the electrical consequences of hot spots have been investigated in multicrystalline solar cells. The hot spots were revealed by means of an infrared camera when the cells are reverse biassed in the dark. The minority carrier diffusion length (L n ), the photovoltage (V oc ) and the photocurrent (J sc ) were measured in the hot spot area and far from this zone thanks to mesa diodes. Dark forward I-V curves lead to values of ideality factor (M) and reverse saturation current (J o ). It is found that J o and M are higher in the hot spot area, while J sc , V oc and at a less extent L n are smaller. Large densities of dislocations and lineages structures are revealed in the abnormally heated regions

  6. Near-term hybrid vehicle program, phase 1. Appendix B: Design trade-off studies. [various hybrid/electric power train configurations and electrical and mechanical drive-line components

    Science.gov (United States)

    1979-01-01

    The relative attractiveness of various hybrid/electric power train configurations and electrical and mechanical drive-line components was studied. The initial screening was concerned primarily with total vehicle weight and economic factors and identified the hybrid power train combinations which warranted detailed evaluation over various driving cycles. This was done using a second-by-second vehicle simulation program which permitted the calculations of fuel economy, electricity usage, and emissions as a function of distance traveled in urban and highway driving. Power train arrangement possibilities were examined in terms of their effect on vehicle handling, safety, serviceability, and passenger comfort. A dc electric drive system utilizing a separately excited motor with field control and battery switching was selected for the near term hybrid vehicle. Hybrid vehicle simulations showed that for the first 30 mi (the electric range of the vehicle) in urban driving, the fuel economy was 80 mpg using a gasoline engine and 100 mpg using a diesel engine. In urban driving the hybrid would save about 75% of the fuel used by the conventional vehicle and in combined urban/highway driving the fuel saving is about 50%.

  7. The crucial relationship among energy commodity prices: Evidence from the Spanish electricity market

    International Nuclear Information System (INIS)

    Moutinho, Victor; Vieira, Joel; Carrizo Moreira, Antonio

    2011-01-01

    The main purpose of this article is twofold to analyze: (a) the long-term relation among the commodities prices and between spot electricity market price and commodity prices, and (b) the short-term dynamics among commodity prices and between electricity prices and commodity prices. Data between 2002 and 2005 from the Spanish electricity market was used. Econometric methods were used in the analysis of the commodity spot price, namely the vector autoregression model, the vector error correction model and the granger causality test. The co-integration approach was used to analyze the long-term relationship between the common stochastic trends of four fossil fuel prices. One of the findings in the long-term relation is that the prices of fuel and the prices of Brent are intertwined, though the prices of Brent ten to 'move' to reestablish the price equilibrium. Another finding is that the price of electricity is explained by the evolution of the natural gas series. - Highlights: → We model energy commodity prices in the Spanish electricity market. → We examine the short and long-term relationships among commodities prices. → We examine short and long-term relationships using co-integration techniques. → We found that in the long run the prices of fuel and Brent are intertwined. → The evolution of price of electricity is explained by the evolution of price of gas.

  8. Model for calculation of spot prices and uncertainties integration; Modelo de calculo de precos spot e integracao de incertezas

    Energy Technology Data Exchange (ETDEWEB)

    Saraiva, J. Tome [Instituto de Engenharia de Sistemas e Computadores (INESC), Porto (Portugal). E-mail: jsaraiva@inescn.pt

    1999-07-01

    This paper presents a model for systematic and structured impact evaluation of the uncertainties existent in the load powers, on the spot prices on the various bars of a electric power system. The application developed allows the specification of load power as inaccurate trapezoidal numbers and adopts the DC model for the representation of system exploration conditions. Considering the influence of the loss power on the formulation of a spot prices spatial distribution, the model allows the inclusion of transmission network loss estimation. The results correspond to appurtenance functions of spot prices in each barm, consisting of a discrete set of ordered pais which integrates the spot price values and the appurtenance or compatibility level, in accordance with Fuzzy Sets.

  9. Spot Welding Characterizations With Time Variable

    International Nuclear Information System (INIS)

    Abdul Hafid; Pinitoyo, A.; History; Paidjo, Andryansyah; Sagino, Sudarmin; Tamzil, M.

    2001-01-01

    For obtain spot welding used effective data, this research is made, so that time operational of machine increasing. Welding parameters are material classification, electrical current, and weld time. All of the factors are determined welding quality. If the plate more thick, the time must be longer when the current constant. Another factor as determined welding quality are surface condition of electrode, surface condition of weld material, and material classifications. In this research, the weld machine type IP32A2 VI (110 V), Rivoira trademark is characterized

  10. Medium- and long-term electric power demand forecasting based on the big data of smart city

    Science.gov (United States)

    Wei, Zhanmeng; Li, Xiyuan; Li, Xizhong; Hu, Qinghe; Zhang, Haiyang; Cui, Pengjie

    2017-08-01

    Based on the smart city, this paper proposed a new electric power demand forecasting model, which integrates external data such as meteorological information, geographic information, population information, enterprise information and economic information into the big database, and uses an improved algorithm to analyse the electric power demand and provide decision support for decision makers. The data mining technology is used to synthesize kinds of information, and the information of electric power customers is analysed optimally. The scientific forecasting is made based on the trend of electricity demand, and a smart city in north-eastern China is taken as a sample.

  11. On the electrical contact and long-term behavior of compression-type connections with conventional and high-temperature conductor ropes with low sag

    International Nuclear Information System (INIS)

    Hildmann, Christian

    2016-01-01

    of hexagonal compression connections with stranded overhead transmission line conductors was calculated with the finite element method. The compression forces and the residual contact forces were determined for all contacts between barrel and conductor as well as between the wires of the conductor. It was shown, that high compression and residual contact forces are the main cause of good electrical contact behaviour. The physical relations are discussed. The electrical long-term behaviour was furthermore investigated in experiments. The results confirm the influence of the residual contact force on the long-term behaviour qualitatively. Those compression connections, which had only small residual contact forces, were less stable in the long-term tests.

  12. Jumping-droplet electronics hot-spot cooling

    International Nuclear Information System (INIS)

    Oh, Junho; Birbarah, Patrick; Foulkes, Thomas; Yin, Sabrina L.; Rentauskas, Michelle

    2017-01-01

    Demand for enhanced cooling technologies within various commercial and consumer applications has increased in recent decades due to electronic devices becoming more energy dense. This study demonstrates jumping-droplet based electric-field-enhanced (EFE) condensation as a potential method to achieve active hot spot cooling in electronic devices. To test the viability of EFE condensation, we developed an experimental setup to remove heat via droplet evaporation from single and multiple high power gallium nitride (GaN) transistors acting as local hot spots (4.6 mm x 2.6 mm). An externally powered circuit was developed to direct jumping droplets from a copper oxide (CuO) nanostructured superhydrophobic surface to the transistor hot spots by applying electric fields between the condensing surface and the transistor. Heat transfer measurements were performed in ambient air (22-25°C air temperature, 20-45% relative humidity) to determine the effect of gap spacing (2-4 mm), electric field (50-250 V/cm), and heat flux (demonstrated to 13 W/cm"2). EFE condensation was shown to enhance the heat transfer from the local hot spot by ≈ 200% compared to cooling without jumping and by 20% compared to non-EFE jumping. Dynamic switching of the electric field for a two-GaN system reveals the potential for active cooling of mobile hot spots. The opportunity for further cooling enhancement by the removal of non-condensable gases promises hot spot heat dissipation rates approaching 120 W/cm"2. Finally, this work provides a framework for the development of active jumping droplet based vapor chambers and heat pipes capable of spatial and temporal thermal dissipation control.

  13. Jumping-droplet electronics hot-spot cooling

    Science.gov (United States)

    Oh, Junho; Birbarah, Patrick; Foulkes, Thomas; Yin, Sabrina L.; Rentauskas, Michelle; Neely, Jason; Pilawa-Podgurski, Robert C. N.; Miljkovic, Nenad

    2017-03-01

    Demand for enhanced cooling technologies within various commercial and consumer applications has increased in recent decades due to electronic devices becoming more energy dense. This study demonstrates jumping-droplet based electric-field-enhanced (EFE) condensation as a potential method to achieve active hot spot cooling in electronic devices. To test the viability of EFE condensation, we developed an experimental setup to remove heat via droplet evaporation from single and multiple high power gallium nitride (GaN) transistors acting as local hot spots (4.6 mm × 2.6 mm). An externally powered circuit was developed to direct jumping droplets from a copper oxide (CuO) nanostructured superhydrophobic surface to the transistor hot spots by applying electric fields between the condensing surface and the transistor. Heat transfer measurements were performed in ambient air (22-25 °C air temperature, 20%-45% relative humidity) to determine the effect of gap spacing (2-4 mm), electric field (50-250 V/cm) and applied heat flux (demonstrated to 13 W/cm2). EFE condensation was shown to enhance the heat transfer from the local hot spot by ≈200% compared to cooling without jumping and by 20% compared to non-EFE jumping. Dynamic switching of the electric field for a two-GaN system reveals the potential for active cooling of mobile hot spots. The opportunity for further cooling enhancement by the removal of non-condensable gases promises hot spot heat dissipation rates approaching 120 W/cm2. This work provides a framework for the development of active jumping droplet based vapor chambers and heat pipes capable of spatial and temporal thermal dissipation control.

  14. Short-Term Interferential Transabdominal Electrical Stimulation Did Not Change Oral-Rectal Transit Time in Piglets.

    Science.gov (United States)

    Tan, Andre Y F; Sourial, Magdy; Hutson, John M; Southwell, Bridget R

    2018-03-02

    Transcutaneous electrical stimulation (TES) using interferential current (IFC) is a new therapeutic treatment for constipation. Clinical studies show that TES-IFC for 3-6 months improves colonic transit, but it is not clear if short-term stimulation affects transit or the effect requires longer to develop. The aim of this study was to determine if TES-IFC for only four days affects oral-rectal transit time in healthy pigs. Twenty-two 4-5-week old large white female piglets had transit studies during week 4 and week 5 by placing a capsule containing 18 radiopaque plastic markers in the esophagus under anesthetic followed by x-rays at 6, 30, 54, and 78 hours. Animals were randomly assigned to active or control groups. The active group received TES for 30 min daily for four days. Interferential current was applied through four electrodes (4 × 4 cm), with two para-spinal just below the last rib and two on the belly at the same level. Stimulation was at 4000 Hz and 4080-4160 Hz with currents crossing through the abdominal cavity. Whole bowel transit times ranged from 7.7 to 72.2 hours, stomach transit from transit time from 5 to 53 hours. Transit times were the same for the control (median 28.4 hours) and TES-IFC (23.0 hours) groups in the prestimulation and stimulation weeks (control 23.0, TES-IFC 19.8 hours) with no change within or between groups. Four days of half-hour TES-IFC daily in healthy 5-week-old piglets did not change oral-rectal transit time. © 2018 International Neuromodulation Society.

  15. Economic Dispatch of Hydrogen Systems in Energy Spot Markets

    DEFF Research Database (Denmark)

    You, Shi; Nørgård, Per Bromand

    2015-01-01

    of energy spot markets. The generic hydrogen system is comprised of an electrolysis for hydrogen production, a hydrogen storage tank and a fuel cell system for cogeneration of electricity and heat. A case study is presented with information from practical hydrogen systems and the Nordic energy markets...

  16. Market data analysis and short-term price forecasting in the Iran electricity market with pay-as-bid payment mechanism

    International Nuclear Information System (INIS)

    Bigdeli, N.; Afshar, K.; Amjady, N.

    2009-01-01

    Market data analysis and short-term price forecasting in Iran electricity market as a market with pay-as-bid payment mechanism has been considered in this paper. The data analysis procedure includes both correlation and predictability analysis of the most important load and price indices. The employed data are the experimental time series from Iran electricity market in its real size and is long enough to make it possible to take properties such as non-stationarity of market into account. For predictability analysis, the bifurcation diagrams and recurrence plots of the data have been investigated. The results of these analyses indicate existence of deterministic chaos in addition to non-stationarity property of the system which implies short-term predictability. In the next step, two artificial neural networks have been developed for forecasting the two price indices in Iran's electricity market. The models' input sets are selected regarding four aspects: the correlation properties of the available data, the critiques of Iran's electricity market, a proper convergence rate in case of sudden variations in the market price behavior, and the omission of cumulative forecasting errors. The simulation results based on experimental data from Iran electricity market are representative of good performance of the developed neural networks in coping with and forecasting of the market behavior, even in the case of severe volatility in the market price indices. (author)

  17. Glosario de términos utilizados en las licencias de revistas electrónicas Glossary of terms used for electronic journals licenses

    Directory of Open Access Journals (Sweden)

    Susana Romanos de Tiratel

    2006-12-01

    Full Text Available Se presentan dos listados del vocabulario utilizado en la redacción de licencias para acceder a revistas electrónicas: 1 los términos en español con sus equivalencias en inglés seguidas de sus definiciones y 2 los términos en inglés con sus equivalencias en español.Two lists of the vocabulary use for the writing of a license to access electronic journals are presented: 1 terms in both Spanish and English followed by their corresponding definition; 2 terms in English followed by their equivalent terms in Spanish.

  18. Management of post-orthodontic white spot lesions

    DEFF Research Database (Denmark)

    Sonesson, Mikael; Bergstrand, Fredrik; Gizani, Sotiria

    2016-01-01

    BACKGROUND/OBJECTIVES: The management of post-orthodontic white spot lesions is based on remineralization strategies or a minimal-invasive camouflage of the lesions. AIM: The aim of this systematic review was to identify and assess the quality of evidence for the various clinical technologies......-orthodontic white spot lesions. Further well-performed controlled clinical trials with long-term follow-up are needed to establish best clinical practice....

  19. Models of spots and flares

    International Nuclear Information System (INIS)

    Mullan, D.J.

    1983-01-01

    Laboratory experiments in recent years have shown that there are many more ways to drive a plasma out of equilibrium than to preserve equilibrium. In that sense, it is perhaps easier to understand why flares should occur in a stellar atmosphere than why a long-lived feature such as a dark spot should persist. The author summarizes work on the equilibrium structure of cool spots in the sun and stars. Since spots involve complex interactions between convective flows and magnetic fields, he needs to refer to observations for help in identifying the dominant processes which should enter into the modelling. His summary therefore begins by discussing certain relevant properties of spots in the solar atmosphere. The next sections deal with the magnetic fields in spots, the stability of spots, spot cooling and missing flux. The author concludes that spots should be viewed not simply as cool areas, but rather as engines which do the work of converting the energy of convective flows into flare-compatible form. (Auth.)

  20. Black-spot poison ivy.

    Science.gov (United States)

    Schram, Sarah E; Willey, Andrea; Lee, Peter K; Bohjanen, Kimberly A; Warshaw, Erin M

    2008-01-01

    In black-spot poison ivy dermatitis, a black lacquerlike substance forms on the skin when poison ivy resin is exposed to air. Although the Toxicodendron group of plants is estimated to be the most common cause of allergic contact dermatitis in the United States, black-spot poison ivy dermatitis is relatively rare.

  1. Rocky Mountain spotted fever, Colombia.

    Science.gov (United States)

    Hidalgo, Marylin; Orejuela, Leonora; Fuya, Patricia; Carrillo, Pilar; Hernandez, Jorge; Parra, Edgar; Keng, Colette; Small, Melissa; Olano, Juan P; Bouyer, Donald; Castaneda, Elizabeth; Walker, David; Valbuena, Gustavo

    2007-07-01

    We investigated 2 fatal cases of Rocky Mountain spotted fever that occurred in 2003 and 2004 near the same locality in Colombia where the disease was first reported in the 1930s. A retrospective serosurvey of febrile patients showed that > 21% of the serum samples had antibodies aaainst spotted fever group rickettsiae.

  2. Advances in spot curing technology

    International Nuclear Information System (INIS)

    Burga, R.

    1999-01-01

    A brief review of spot curing technology was presented. The process which a spot of energy of a specific wavelength bandwidth and irradiance is used to cause a coating, encapsulant or adhesive to change from a liquid to a solid state

  3. Projection of primary energy in electricity generation with evaluation of demand and supply of energy in the medium-term horizon (2020), long-term (2035) and very long term (2060); Projecao das energias primarias na geracao de eletricidade com avaliacao da demanda e oferta de energia, em horizonte de medio prazo (2020), longo prazo (2035) e muito longo prazo (2060)

    Energy Technology Data Exchange (ETDEWEB)

    Mafra, Olga Y.; Alvim, Carlos Feu; Eidelman, Frida [Brasil e Economia (Brazil); Guimaraes, Leonam dos Santos [Eletrobras Eletronuclear, Rio de Janeiro, RJ (Brazil)

    2013-01-15

    The Global Energy demand and the participation of electricity in scenarios of medium (2020), long (2035) and very long (2060) terms are estimated. It is also evaluated the share of different primary energies in electricity generation and their availability in the country. Three economic scenarios were considered and different hypothesis regarding the participation of nuclear energy were analyzed. (author)

  4. Two tests of electric fields, second-order in source-velocity terms of closed, steady currents: (1) an electron beam; (2) a superconducting coil

    International Nuclear Information System (INIS)

    Kenyon, C.S.

    1980-01-01

    One particular prediction of Maxwell's theory that has been previously neglected is that the motion of charges traveling in closed loops produces no constant electric fields. This study presents and analyzes the results of two new experiments designed to test for second-order, source-velocity electric fields from steady, closed currents and analyzes another experiment in light of these fields. The first experiment employed an electron beam. The second used a niobium-titanium coil designed so that the voltage measurement configuration could be easily switched from a Faraday to a non-faraday configuration between sets of runs. The implications of the observation of a null charge on magnetically suspended superconducting spheres vis-a-vis the second-order, source-velocity fields were discussed as the third case. The observation of a null potential corresponding to a null effective charge from a hypothetical velocity-squared field in both the beam and the coil experiment placed the upper bound on a field term at 0.02 with respect a Coulomb term. An observed null charge on the suspended spheres reduced this bound to 0.001. Such an upper bound is strong evidence against alternative theories predicting a relative contribution of the order of unity for a simple velocity-squared term. A simple velocity-squared electric field would be indistinguishable from a velocity-squared charge variation. The latter test limits such a charge variation to 0.001 of the total charge. The suspended-spheres test allowed the previously neglected issue of a general second-order, source-velocity electric field to be addressed. The observed null charge in this test contradicts and thus eliminates a hypothesized, general, electric field expression containing three second-order, source-velocity terms

  5. An analysis of long-term scenarios for the transition to renewable energy in the Korean electricity sector

    International Nuclear Information System (INIS)

    Park, Nyun-Bae; Yun, Sun-Jin; Jeon, Eui-Chan

    2013-01-01

    This paper analyzes the energy, environmental and economic influences of three electricity scenarios in Korea by 2050 using the “Long-range Energy Alternatives Planning system” (LEAP) model. The reference year was 2008. Scenarios include the baseline (BL), new governmental policy (GP) and sustainable society (SS) scenarios. The growth rate of electricity demand in the GP scenario was higher than that of the BL scenario while the growth rate in the SS scenario was lower than that of the BL scenario. Greenhouse gas emissions from electricity generation in 2050 in the BL and GP scenarios were similar with current emissions. However, emissions in 2050 in the SS scenario were about 80% lower than emissions in 2008, because of the expansion of renewable electricity in spite of the phase-out of nuclear energy. While nuclear and coal-fired power plants accounted for most of the electricity generated in the BL and GP scenarios in 2050, the SS scenario projected that renewable energy would generate the most electricity in 2050. It was found that the discounted cumulative costs from 2009 to 2050 in the SS scenario would be 20 and 10% higher than that of the BL and GP scenarios, respectively. - Highlights: ► This paper analyzed three kinds of electricity scenarios in Korea by 2050 using LEAP model. Baseline and governmental policy scenarios focus on the electricity supply through nuclear expansion. ► Sustainable Society scenario focuses on demand management and renewable electricity. ► The latter improves energy security and reduces more GHG with the affordable cost.

  6. Gas-based electricity production: which possibilities? - Thermal plants with steam generator; Perspectives for mini-cogeneration in collective housing; Electricity production by gas plants: which orientations on a middle term?

    International Nuclear Information System (INIS)

    Charrier, M.; Hubert, Charles-Emile; Lu, Long; Maire, Jacques; Bornard, Pierre; Garnier, Philippe-Jean; Jamme, Dominique; Cheylus, Jean-Christophe

    2012-01-01

    A set of articles proposes a comparison between coal fired and natural gas fired power stations, discusses the perspectives of low power cogeneration installations for collective housing (some examples are evoked). It also reports interventions of a meeting on middle-term orientation for gas-based electricity production during which interveners addressed several issues such as the opportunity of investment in new infrastructures, the evolution of the gas sector, modulation means

  7. Spotting psychopaths using technology.

    Science.gov (United States)

    Hulbert, Sarah; Adeli, Hojjat

    2015-01-01

    For the past three and a half decades, the Psychopathy Checklist-Revised (PCL-R) and the self-report Psychopathic Personality Inventory-Revised (PPI-R) have been the standard measures for the diagnosis of psychopathy. Technological approaches can enhance these diagnostic methodologies. The purpose of this paper is to present a state-of-the-art review of various technological approaches for spotting psychopathy, such as electroencephalogram (EEG), magnetic resonance imaging (MRI), functional MRI (fMRI), transcranial magnetic stimulation (TMS), and other measures. Results of EEG event-related potential (ERP) experiments support the theory that impaired amygdala function may be responsible for abnormal fear processing in psychopathy, which can ultimately manifest as psychopathic traits, as outlined by the PCL-R or PPI-R. Imaging studies, in general, point to reduced fear processing capabilities in psychopathic individuals. While the human element, introduced through researcher/participant interactions, can be argued as unequivocally necessary for diagnosis, these purely objective technological approaches have proven to be useful in conjunction with the subjective interviewing and questionnaire methods for differentiating psychopaths from non-psychopaths. Furthermore, these technologies are more robust than behavioral measures, which have been shown to fail.

  8. Analysis of electricity price in Danish competitive electricity market

    DEFF Research Database (Denmark)

    Hu, Weihao; Chen, Zhe; Bak-Jensen, Birgitte

    2012-01-01

    electricity markets in some ways, is chosen as the studied power system. 10 year actual data from the Danish competitive electricity market are collected and analyzed. The relationship among the electricity price (both the spot price and the regulation price), the consumption and the wind power generation...... in an electricity market is investigated in this paper. The spot price and the regulation price generally decrease when the wind power penetration in the power system increases or the consumption of the power system decreases. The statistical characteristics of the spot price and the regulation price for different...... consumption periods and wind power penetration are analyzed. Simulation results show that the findings of this paper are useful for wind power generation companies to make the optimal bidding strategy so that the imbalance cost of trading wind power on the electricity market could be reduced....

  9. Auction approaches of long-term contracts to ensure generation investment in electricity markets: Lessons from the Brazilian and Chilean experiences

    International Nuclear Information System (INIS)

    Moreno, R.; Barroso, L.A.; Rudnick, H.; Mocarquer, S.; Bezerra, B.

    2010-01-01

    The implementation of auctions of long-term electricity contracts is arising as an alternative to ensure generation investment and therefore achieve a reliable electricity supply. The aim is to reconcile generation adequacy with efficient energy purchase, correct risk allocation among investors and consumers, and the politico-economic environment of the country. In this paper, a generic proposal for a long-term electricity contracts approach is made, including practical design concepts for implementation. This proposal is empirically derived from the auctions implemented in Brazil and Chile during the last 6 years. The study is focused on practices and lessons which are especially useful for regulators and policy makers that want to facilitate the financing of new desirable power plants in risky environments and also efficiently allocate supply contracts among investors at competitive prices. Although this mechanism is generally seen as a significant improvement in market regulation, there are questions and concerns on auction performance that require careful design and which are identified in this paper. In addition, the experiences and proposal described can serve to derive further mechanisms in order to promote the entrance of particular generation technologies, e.g. renewables, in the developed world and therefore achieve a clean electricity supply.

  10. A comparative assessment of the long term electricity expansion plans in Mexico by using the position vector of minimum regret analysis

    International Nuclear Information System (INIS)

    Martindelcampo, C.; Gonzalezbello, C. R.

    2012-01-01

    A comparative assessment of alternative expansion plans for the Mexican electricity generating system was made by applying the Position Vector of Minimum Regret Analysis (PVMRA) as a decision analysis tool. Four expansion plans were ranked according to the following decision criteria: The cost which calculates the cumulated cost of electricity generation during the time period studied. The external cost which brings into play the costs associated with the impact on health and the environment. The risk which takes into account the economic impact associated with incremental fuel prices from the baseline scenario to the high scenario. The diversity which evaluates the generation park diversity in terms of the Shannon-Weaner Index. The foreign-capital fraction in investment using foreign inputs. The carbon-free fraction which evaluates electricity generation that contributes to climate change policies. The cost of severe-accidents which is the sum of full chain damage costs and external costs of severe accidents with at least 10 injured. Optimizations were made by internalizing the external cost into the objective function of the WASP-IV model, the cost of externalise of the operation and maintenance cost, and these expansions were compared with those that did not. Special attention was paid to studying the convenience of including nuclear power in the electricity generation mix. Furthermore, better electricity expansion plans, with lower internal and external costs, were also found when the optimization had included externalise

  11. A Novel Hybrid Model Based on Extreme Learning Machine, k-Nearest Neighbor Regression and Wavelet Denoising Applied to Short-Term Electric Load Forecasting

    Directory of Open Access Journals (Sweden)

    Weide Li

    2017-05-01

    Full Text Available Electric load forecasting plays an important role in electricity markets and power systems. Because electric load time series are complicated and nonlinear, it is very difficult to achieve a satisfactory forecasting accuracy. In this paper, a hybrid model, Wavelet Denoising-Extreme Learning Machine optimized by k-Nearest Neighbor Regression (EWKM, which combines k-Nearest Neighbor (KNN and Extreme Learning Machine (ELM based on a wavelet denoising technique is proposed for short-term load forecasting. The proposed hybrid model decomposes the time series into a low frequency-associated main signal and some detailed signals associated with high frequencies at first, then uses KNN to determine the independent and dependent variables from the low-frequency signal. Finally, the ELM is used to get the non-linear relationship between these variables to get the final prediction result for the electric load. Compared with three other models, Extreme Learning Machine optimized by k-Nearest Neighbor Regression (EKM, Wavelet Denoising-Extreme Learning Machine (WKM and Wavelet Denoising-Back Propagation Neural Network optimized by k-Nearest Neighbor Regression (WNNM, the model proposed in this paper can improve the accuracy efficiently. New South Wales is the economic powerhouse of Australia, so we use the proposed model to predict electric demand for that region. The accurate prediction has a significant meaning.

  12. Spot Welding of Honeycomb Structures

    Science.gov (United States)

    Cohal, V.

    2017-08-01

    Honeycomb structures are used to prepare meals water jet cutting machines for textile. These honeycomb structures are made of stainless steel sheet thickness of 0.1-0.2 mm. Corrugated sheet metal strips are between two gears with special tooth profile. Hexagonal cells for obtaining these strips are welded points between them. Spot welding device is three electrodes in the upper part, which carries three welding points across the width of the strip of corrugated sheet metal. Spot welding device filled with press and advance mechanisms. The paper presents the values of the regime for spot welding.

  13. Modelling the benchmark spot curve for the Serbian

    Directory of Open Access Journals (Sweden)

    Drenovak Mikica

    2010-01-01

    Full Text Available The objective of this paper is to estimate Serbian benchmark spot curves using the Svensson parametric model. The main challenges that we tackle are: sparse data, different currency denominations of short and longer term maturities, and infrequent transactions in the short-term market segment vs daily traded medium and long-term market segment. We find that the model is flexible enough to account for most of the data variability. The model parameters are interpreted in economic terms.

  14. Analysis and validation of laser spot weld-induced distortion

    Energy Technology Data Exchange (ETDEWEB)

    Knorovsky, G.A.; Kanouff, M.P.; Maccallum, D.O.; Fuerschbach, P.W.

    1999-12-09

    Laser spot welding is an ideal process for joining small parts with tight tolerances on weld size, location, and distortion, particularly those with near-by heat sensitive features. It is also key to understanding the overlapping laser spot seam welding process. Rather than attempting to simulate the laser beam-to-part coupling (particularly if a keyhole occurs), it was measured by calorimetry. This data was then used to calculate the thermal and structural response of a laser spot welded SS304 disk using the finite element method. Five combinations of process parameter values were studied. Calculations were compared to experimental data for temperature and distortion profiles measured by thermocouples and surface profiling. Results are discussed in terms of experimental and modeling factors. The authors then suggest appropriate parameters for laser spot welding.

  15. Long-term exposure to mobile communication radiation: An analysis of time-variability of electric field level in GSM900 down-link channels

    International Nuclear Information System (INIS)

    Miclaus, S.; Bechet, P.; Gheorghevici, M.

    2013-01-01

    Interest for knowing long-term human exposure levels due to mobile communications has increased in the last years. It has been shown that short-term exposure assessment made under standard procedural restrictions is not reliable when it comes to conclusions on long-term exposure levels. The present work is the result of a several week analysis of time variability of electric field level inside traffic and control channels of the GSM900 mobile communication down-link band and it indicates that a temporal model to allow future predictions of exposure on the long run is obtainable. Collecting, processing and statistically analysing the data provide expression of the maximum and weighted field strengths and their evolution in time. Specific electromagnetic footprints of the channels have been extracted, differentiations between their characteristics have been emphasised and practical advice is provided, with the scope of contributing to the development of reliable procedures for long-term exposure assessment. (authors)

  16. Plasma spot welding of ferritic stainless steels

    Directory of Open Access Journals (Sweden)

    Lešnjak, A.

    2002-06-01

    Full Text Available Plasma spot welding of ferritic stainless steels is studied. The study was focused on welding parameters, plasma and shielding gases and the optimum welding equipment. Plasma-spot welded overlap joints on a 0.8 mm thick ferritic stainless steel sheet were subjected to a visual examination and mechanical testing in terms of tension-shear strength. Several macro specimens were prepared. Plasma spot welding is suitable to use the same gas as shielding gas and as plasma gas, i.e., a 98 % Ar/2 % H 2 gas mixture. Tension-shear strength of plasma-spot welded joints was compared to that of resistance-spot welded joints. It was found that the resistance welded joints withstand a somewhat stronger load than the plasma welded joints due to a larger weld spot diameter of the former. Strength of both types of welded joints is approximately the same.

    El artículo describe el proceso de soldeo de aceros inoxidables ferríticos por puntos con plasma. La investigación se centró en el establecimiento de los parámetros óptimos de la soldadura, la definición del gas de plasma y de protección más adecuado, así como del equipo óptimo para la realización de la soldadura. Las uniones de láminas de aceros inoxidables ferríticos de 0,8 mm de espesor, soldadas a solape por puntos con plasma, se inspeccionaron visualmente y se ensayaron mecánicamente mediante el ensayo de cizalladura por tracción. Se realizaron macro pulidos. Los resultados de la investigación demostraron que la solución más adecuada para el soldeo por puntos con plasma es elegir el mismo gas de plasma que de protección. Es decir, una mezcla de 98 % de argón y 2 % de hidrógeno. La resistencia a la cizalladura por tracción de las uniones soldadas por puntos con plasma fue comparada con la resistencia de las uniones soldadas por resistencia por puntos. Se llegó a la conclusión de que las uniones soldadas por resistencia soportan una carga algo mayor que la uniones

  17. The possibilities are very limited - The supply of electricity in Switzerland cannot be guaranteed in the long-term

    International Nuclear Information System (INIS)

    Veit, J.

    2004-01-01

    This article discusses the various factors influencing the security of supply of electricity in Switzerland. The author briefly reviews the present-day situation with power being produced by hydroelectric and nuclear power stations. Five possible options for action for ensuring electricity supply in the future are proposed: The increased import of power from neighbouring countries is looked at, the replacement or refurbishment of existing nuclear plant is considered, as is the augmentation and replacement of hydropower installations. A fourth option - the building of gas-fired, combined-cycle plant is discussed, as is the possibility of using renewable forms of energy such as solar, wind and geothermal energy

  18. Electricity and Man (Rev.)

    Energy Technology Data Exchange (ETDEWEB)

    Asimov, Isaac

    1974-01-01

    Our whole industrial civilization depends upon cheap energy streaking out in all directions and under fingertip controls—and that would be very difficult without electric current. It would take enormous ingenuity to find substitutes. If all electricity were shut off, then all electronic devices would be dead. Electric lights would darken. Aluminum would become a rare metal. All factories would have to develop power sources on the spot and would have to switch to primitive, mechanical controls. Every house and every farm would have to give up items we have come to take for granted—not only electric lights, but electric irons, electric toasters, electric water pumps, electric control of furnaces, and so on.

  19. Teaching Electricity.

    Science.gov (United States)

    Iona, Mario

    1982-01-01

    To clarify the meaning of electrical terms, a chart is used to compare electrical concepts and relationships with a more easily visualized system in which water flows from a hilltop reservoir through a pipe to drive a mill at the bottom of the hill. A diagram accompanies the chart. (Author/SK)

  20. PENGARUH KURS SPOT DAN KURS FORWARD DALAM MEMPREDIKSI FUTURE SPOT PADA PASAR VALAS KAWASAN ASIA TENGGARA

    Directory of Open Access Journals (Sweden)

    I Gusti Ayu Kade Diana Yanthi

    2013-10-01

    Full Text Available The importance of the activity in foreign exchange occur as the result of the development of international trading and increased international money and capital movement. The vast development of international economic  caused  economic relationship  among  countries  will  be  linked  to  each other  and  subsequently improve trading activities in their goods, money and capital flows. The variables used in this study are spot, forward  and future  spot. Based  on  the result  of Regression  Estimation  applied in  hypothesis on foreign currencies exchange which done simultaneously are proven able to predict future spot. The investor and international economic  actor could use spot  exchange rate and forward  exchange rate as a  short terms predictor for the next trimester in 2011.

  1. On-road magnetic emissions prediction of electric cars in terms of driving dynamics using neural networks

    NARCIS (Netherlands)

    Wefky, Ahmed M.; Espinosa, Felipe; Leferink, Frank Bernardus Johannes; Gardel, Alfredo; Vogt-Ardatjew, R.A.

    2013-01-01

    This paper presents a novel artificial neural network (ANN) model estimating vehicle-level radiated magnetic emissions of an electric car as a function of the corresponding driving pattern. Real world electromagnetic interference (EMI) experiments have been realized in a semi-anechoic chamber using

  2. Electrical and chemical signals involved in short-term systemic photosynthetic responses of tobacco plants to local burning

    Czech Academy of Sciences Publication Activity Database

    Hlaváčková, V.; Krchňák, P.; Nauš, J.; Novák, Ondřej; Špundová, M.; Strnad, Miroslav

    2006-01-01

    Roč. 225, č. 1 (2006), s. 235-244 ISSN 0032-0935 R&D Projects: GA ČR GA206/05/0894 Institutional research plan: CEZ:AV0Z50380511 Keywords : Abscisic acid * Electrical signals * Gas exchange Subject RIV: CE - Biochemistry Impact factor: 2.963, year: 2006

  3. Predicting Short-Term Electricity Demand by Combining the Advantages of ARMA and XGBoost in Fog Computing Environment

    Directory of Open Access Journals (Sweden)

    Chuanbin Li

    2018-01-01

    Full Text Available With the rapid development of IoT, the disadvantages of Cloud framework have been exposed, such as high latency, network congestion, and low reliability. Therefore, the Fog Computing framework has emerged, with an extended Fog Layer between the Cloud and terminals. In order to address the real-time prediction on electricity demand, we propose an approach based on XGBoost and ARMA in Fog Computing environment. By taking the advantages of Fog Computing framework, we first propose a prototype-based clustering algorithm to divide enterprise users into several categories based on their total electricity consumption; we then propose a model selection approach by analyzing users’ historical records of electricity consumption and identifying the most important features. Generally speaking, if the historical records pass the test of stationarity and white noise, ARMA is used to model the user’s electricity consumption in time sequence; otherwise, if the historical records do not pass the test, and some discrete features are the most important, such as weather and whether it is weekend, XGBoost will be used. The experiment results show that our proposed approach by combining the advantage of ARMA and XGBoost is more accurate than the classical models.

  4. Forecasting electricity market pricing using artificial neural networks

    International Nuclear Information System (INIS)

    Pao, Hsiao-Tien

    2007-01-01

    Electricity price forecasting is extremely important for all market players, in particular for generating companies: in the short term, they must set up bids for the spot market; in the medium term, they have to define contract policies; and in the long term, they must define their expansion plans. For forecasting long-term electricity market pricing, in order to avoid excessive round-off and prediction errors, this paper proposes a new artificial neural network (ANN) with single output node structure by using direct forecasting approach. The potentials of ANNs are investigated by employing a rolling cross validation scheme. Out of sample performance evaluated with three criteria across five forecasting horizons shows that the proposed ANNs are a more robust multi-step ahead forecasting method than autoregressive error models. Moreover, ANN predictions are quite accurate even when the length of the forecast horizon is relatively short or long

  5. Is there a water–energy nexus in electricity generation? Long-term scenarios for the western United States

    International Nuclear Information System (INIS)

    Ackerman, Frank; Fisher, Jeremy

    2013-01-01

    Water is required for energy supply, and energy is required for water supply, creating problems as demand for both resources grows. We analyze this “water–energy nexus” as it affects long-run electricity planning in the western United States. We develop four scenarios assuming: no new constraints; limits on carbon emissions; limits on water use; and combined carbon and water limits. We evaluate these scenarios through 2100 under a range of carbon and water prices. The carbon-reducing scenarios become cost-effective at carbon prices of about $50–$70 per ton of CO 2 , moderately high but plausible within the century. In contrast, the water-conserving scenarios are not cost-effective until water prices reach thousands of dollars per acre-foot, well beyond foreseeable levels. This is due in part to the modest available water savings: our most and least water-intensive scenarios differ by less than 1% of the region's water consumption. Under our assumptions, Western electricity generation could be reshaped by the cost of carbon emissions, but not by the cost of water, over the course of this century. Both climate change and water scarcity are of critical importance, but only in the former is electricity generation central to the problem and its solutions. - Highlights: • We model long-run electricity supply and demand for the western United States. • We evaluate the costs of carbon-reducing and water-conserving scenarios. • Carbon-reducing scenarios become cost-effective at carbon prices of $50–70 per ton CO 2 . • Water-conserving scenarios are only cost-effective above $4000/acre-foot of water. • Electricity planning is central to climate policy, but much less so to water planning

  6. Demographic response of northern spotted owls to barred owl removal

    Science.gov (United States)

    Diller, V. Lowell; Hamm, Keith A; Early, Desiree A; Lamphear, David W; Dugger, Katie M.; Yackulic, Charles B.; Schwarz, Carl J.; Carlson, Peter C.; McDonald, Trent L.

    2016-01-01

    Federally listed as threatened in 1990 primarily because of habitat loss, the northern spotted owl (Strix occidentalis caurina) has continued to decline despite conservation efforts resulting in forested habitat being reserved throughout its range. Recently, there is growing evidence the congeneric invasive barred owl (Strix varia) may be responsible for the continued decline primarily by excluding spotted owls from their preferred habitat. We used a long-term demographic study for spotted owls in coastal northern California as the basis for a pilot barred owl removal experiment. Our demography study used capture–recapture, reproductive output, and territory occupancy data collected from 1990 to 2013 to evaluate trends in vital rates and populations. We used a classic before-after-control-impact (BACI) experimental design to investigate the demographic response of northern spotted owls to the lethal removal of barred owls. According to the best 2-species dynamic occupancy model, there was no evidence of differences in barred or northern spotted owl occupancy prior to the initiation of the treatment (barred owl removal). After treatment, barred owl occupancy was lower in the treated relative to the untreated areas and spotted owl occupancy was higher relative to the untreated areas. Barred owl removal decreased spotted owl territory extinction rates but did not affect territory colonization rates. As a result, spotted owl occupancy increased in the treated area and continued to decline in the untreated areas. Prior to and after barred owl removal, there was no evidence that average fecundity differed on the 2 study areas. However, the greater number of occupied spotted owl sites on the treated areas resulted in greater productivity in the treated areas based on empirical counts of fledged young. Prior to removal, survival was declining at a rate of approximately 0.2% per year for treated and untreated areas. Following treatment, estimated survival was 0.859 for

  7. Numerical optimisation in spot detector design

    NARCIS (Netherlands)

    van der Heijden, Ferdinand; Apperloo, W.; Spreeuwers, Lieuwe Jan

    1997-01-01

    Spots are image details resulting from objects, the projections of which are so small that the inner structure of these objects cannot be resolved from their image. Spot detectors are image operators aiming at the detection and localisation of spots in the image. Most spot detectors can be tuned

  8. Managing emerging threats to spotted owls

    Science.gov (United States)

    Ho Yi Wan; Joseph L. Ganey; Christina D. Vojta; Samuel A. Cushman

    2018-01-01

    The 3 spotted owl (Strix occidentalis) subspecies in North America (i.e., northern spotted owl [S. o. caurina], California spotted owl [S. o. occidentalis], Mexican spotted owl [S. o. lucida]) have all experienced population declines over the past century due to habitat loss and fragmentation from logging. Now, the emerging influences of climate change, high-severity...

  9. 9 CFR 149.4 - Spot audit.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Spot audit. 149.4 Section 149.4... LIVESTOCK IMPROVEMENT VOLUNTARY TRICHINAE CERTIFICATION PROGRAM § 149.4 Spot audit. (a) In addition to regularly scheduled site audits, certified production sites will be subject to spot audits. (1) Random spot...

  10. Gis-based procedures for hydropower potential spotting

    Energy Technology Data Exchange (ETDEWEB)

    Larentis, Dante G.; Collischonn, Walter; Tucci, Carlos E.M. [Instituto de Pesquisas Hidraulicas da UFRGS, Av. Bento Goncalves, 9500, CEP 91501-970, Caixa Postal 15029, Porto Alegre, RS (Brazil); Olivera, Francisco (Texas A and M University, Zachry Department of Civil Engineering 3136 TAMU, College Station, TX 77843-3136, US)

    2010-10-15

    The increasing demand for energy, especially from renewable and sustainable sources, spurs the development of small hydropower plants and encourages investment in new survey studies. Preliminary hydropower survey studies usually carry huge uncertainties about the technical, economic and environmental feasibility of the undeveloped potential. This paper presents a methodology for large-scale survey of hydropower potential sites to be applied in the inception phase of hydroelectric development planning. The sequence of procedures to identify hydropower sites is based on remote sensing and regional streamflow data and was automated within a GIS-based computational program: Hydrospot. The program allows spotting more potential sites along the drainage network than it would be possible in a traditional survey study, providing different types of dam-powerhouse layouts and two types (operating modes) of projects: run-of-the-river and storage projects. Preliminary results from its applications in a hydropower-developed basin in Brazil have shown Hydrospot's limitations and potentialities in giving support to the mid-to-long-term planning of the electricity sector. (author)

  11. New maintenance strategy of Tokyo Electric Power Company and Fukushima Dai-ichi Nuclear Power Plant for effective ageing management and safe long-term operation

    International Nuclear Information System (INIS)

    Inagaki, Takeyuki; Yamashita, Norimichi

    2009-01-01

    Fukushima Dai-ichi Nuclear Power Plant is the oldest among three nuclear power plants owned and operated by Tokyo Electric Power Company, which consists of six boiling water reactor units. The commercial operation of Unit 1 was commenced in 1971 (37 years old) and Unit 6 in 1978 (29 years old). Currently ageing degradations of systems, structures and components are managed through maintenance programs, component replacement/refurbishment programs and long-term maintenance plans. The long-term maintenance plans are established through ageing management component replacement/refurbishment programs reviews performed before the 30th year of operation and they are for safe and reliable operation after 30 years (long-term operation). However the past maintenance actions and past component replacement/refurbishment programs were not always proactive and past operational experience and maintenance practices suggest that effective/proactive ageing management programs be introduced in earlier stage of the plant operation. In this circumstance, Tokyo Electric Power Company and Fukushima Dai-ichi Nuclear Power Plant are setting up a new maintenance strategy that includes 1) improving the normal maintenance programs by using ageing degradation data, 2) effective use of information on internal/external operational experience and maintenance practices related to ageing, and 3) proactive component/equipment refurbishment programs during a refreshment outage for safe and reliable long-term operation. To accomplish the goal of this strategy, strengthening engineering capability of plant staff members is a crucial required for the plant. The objective of this paper is to briefly explain main results ageing management reviews, past and current significant ageing issues and management programs against them, and the new maintenance strategy established by Tokyo Electric Power Company and Fukushima Dai-ichi Nuclear Power Plant. (author)

  12. On the origin of delta spots

    International Nuclear Information System (INIS)

    Tang, F.

    1983-01-01

    Mount Wilson sunspot drawings from 1966 through 1980 were used in conjunction with Hα filtergrams from Big Bear Solar Observatory to examine the origin of delta spots, spots with bipolar umbrae within one penumbra. Of the six cases we studied, five were formed by the union of non-paired spots. They are either shoved into one another by two neighboring growing bipoles or by a new spot born piggy-back style on an existing spot of opposite polarity. Proper motions of the growing spots take on curvilinear paths around one another to avoid a collision. This is the shear motion observed in delta spots (Tanaka, 1979). In the remaining case, the delta spot was formed by spots that emerged as a pair. Our findings indicate no intrinsic differences in the formation or the behavior between delta spots of normal magnetic configuration. (orig.)

  13. Electric system management through hydrogen production - A market driven approach in the French context

    International Nuclear Information System (INIS)

    Mansilla, C.; Dautremont, S.; Thais, F.; Louyrette, J.; Martin, J.; Albou, S.; Barbieri, G.; Collignon, N.; Bourasseau, C.; Salasc, B.; Valentin, S.

    2012-01-01

    Hydrogen is usually presented as a promising energy carrier that has a major role to play in low carbon transportation, through the use of fuel cells. However, such a development is not expected in the short term. In the meantime, hydrogen may also contribute to reduce carbon emissions in diverse sectors among which methanol production. Methanol can be produced by combining carbon dioxide and hydrogen, hence facilitating carbon dioxide emission mitigation while providing a beneficial tool to manage the electric system, if hydrogen is produced by alkaline electrolysis operated in a variable way driven by the spot and balancing electricity markets. Such a concept is promoted by the VItESSE project (Industrial and Energy value of CO 2 through Efficient use of CO 2 -free electricity - Electricity Network System Control and Electricity Storage). Through the proposed market driven approach, hydrogen production offers a possibility to help managing the electric system, together with an opportunity to reduce hydrogen production costs. (authors)

  14. 18 CFR 42.1 - Requirement that Transmission Organizations with Organized Electricity Markets Offer Long-Term...

    Science.gov (United States)

    2010-04-01

    ... prevailing cost allocation methods for upgrades or expansions. (4) Long-term firm transmission rights must be... other direct assignment of congestion costs for the period covered and quantity specified. Once... must have priority over non-load serving entities in the allocation of long-term firm transmission...

  15. Spot market activity remains weak as prices continue to fall

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    A summary of financial data for the uranium spot market in November 1996 is provided. Price ranges for the restricted and unrestricted markets, conversion, and separative work are listed, and total market volume and new contracts are noted. Transactions made are briefly described. Deals made and pending in the spot concentrates, medium and long-term, conversion, and markets are listed for U.S. and non-U.S. buyers. Spot market activity increased in November with just over 1.0 million lbs of U3O8 equivalent being transacted compared to October's total of 530,000 lbs of U3O8 equivalent. The restricted uranium spot market price range slipped from $15.50-$15.70/lb U3O8 last month to $14.85/lb - $15.25/lb U3O8 this month. The unrestricted uranium spot market price range also slipped to $14.85/lb - $15.00/lb this month from $15.00/lb - $15.45/lb in October. Spot prices for conversion and separative work units remained at their October levels

  16. Short-Term Price Forecasting Models Based on Artificial Neural Networks for Intraday Sessions in the Iberian Electricity Market

    Directory of Open Access Journals (Sweden)

    Claudio Monteiro

    2016-09-01

    Full Text Available This paper presents novel intraday session models for price forecasts (ISMPF models for hourly price forecasting in the six intraday sessions of the Iberian electricity market (MIBEL and the analysis of mean absolute percentage errors (MAPEs obtained with suitable combinations of their input variables in order to find the best ISMPF models. Comparisons of errors from different ISMPF models identified the most important variables for forecasting purposes. Similar analyses were applied to determine the best daily session models for price forecasts (DSMPF models for the day-ahead price forecasting in the daily session of the MIBEL, considering as input variables extensive hourly time series records of recent prices, power demands and power generations in the previous day, forecasts of demand, wind power generation and weather for the day-ahead, and chronological variables. ISMPF models include the input variables of DSMPF models as well as the daily session prices and prices of preceding intraday sessions. The best ISMPF models achieved lower MAPEs for most of the intraday sessions compared to the error of the best DSMPF model; furthermore, such DSMPF error was very close to the lowest limit error for the daily session. The best ISMPF models can be useful for MIBEL agents of the electricity intraday market and the electric energy industry.

  17. CO2-emission trading and green markets for renewable electricity. WILMAR - deliverable 4.1

    International Nuclear Information System (INIS)

    Azuma-Dicke, N.; Weber, C.; Morthorst, P.E.; Ravn, H.F.; Schmidt, R.

    2004-06-01

    This report is Deliverable 4.1 of the EU project 'Wind Power Integration in Liberalised Electricity Markets' (WILMAR) and de-scribes the application of two policy instruments, Tradable Emissions Permits (TEPs) and Tradable Green Certificates (TGCs) for electricity produced from renewable energy sources in the European Union and the implications for implementation in the Wilmar model. The introduction of a common emission-trading system in the EU is expected to have an upward effect on the spot prices at the electric-ity market. The variations of the spot price imply that some types of power generation may change the situation from earning money to losing money despite the increasing spot price. Heavy restrictions on emissions penalise the fossil-fuelled technologies significantly, and the associated increase in the spot price need not compensate for this. Therefore, a market of TEPs is expected to have a significant influence on the electricity spot price. However, the expected price level of TEPs are met with great uncertainty and a study of a number of economical studies shows a price span between zero and 270 USD per ton of CO 2 depending on the participation or non-participation of countries in the scheme. The price-determination at the TGC market is expected to be closely related to the price at the power spot market as the RE-producers of electricity will have expectations to the total price paid for the energy produced, i.e., for the price of electricity at the spot market plus the price per kWh obtained at the green certificate mar-ket. In the Wilmar model, the TGC market can either be handled exogenously, i.e., the increase in renewable capacity and an average annual TGC price are determined outside the model, or a simple TGC module is developed, including the long-term supply functions for the most relevant renewable technologies and an overall TGC quota. Both solutions are rather simple, but to develop a more advanced model for the TGC market seems to be

  18. The prediction of the impact of climatic factors on short-term electric power load based on the big data of smart city

    Science.gov (United States)

    Qiu, Yunfei; Li, Xizhong; Zheng, Wei; Hu, Qinghe; Wei, Zhanmeng; Yue, Yaqin

    2017-08-01

    The climate changes have great impact on the residents’ electricity consumption, so the study on the impact of climatic factors on electric power load is of significance. In this paper, the effects of the data of temperature, rainfall and wind of smart city on short-term power load is studied to predict power load. The authors studied the relation between power load and daily temperature, rainfall and wind in the 31 days of January of one year. In the research, the authors used the Matlab neural network toolbox to establish the combinational forecasting model. The authors trained the original input data continuously to get the internal rules inside the data and used the rules to predict the daily power load in the next January. The prediction method relies on the accuracy of weather forecasting. If the weather forecasting is different from the actual weather, we need to correct the climatic factors to ensure accurate prediction.

  19. Swiss Solutions for Providing Electrical Power in Cases of Long-Term Black-Out of the Grid

    International Nuclear Information System (INIS)

    Altkind, Franz; Schmid, Daniel

    2015-01-01

    A better understanding of nuclear power plant electrical system robustness and defence-in-depth may be derived from comparing design and operating practices in member countries. In pursuing this goal, the current paper will focus on Switzerland. It will present in general the protective measures implemented in the Swiss nuclear power plants to ensure power supply, which comply with the 'Defence-in-depth' principle by means of several layers of protection. In particular it will present the measures taken in case of a total station blackout. The different layers supplying electricity may be summed up as follows. The first layer consists of the external main grid, which the plant generators feed into. The second layer is the auxiliary power supply when the power plant is in island mode in case of a failure of the main grid. A third layer is provided by the external reserve grid in case of both a failure of the external main grid and of the auxiliary power supply in island mode. As a fourth layer there exists an emergency electrical power supply. This is supplied either from an emergency diesel generator or a direct feed from a hydroelectric power plant. In the fifth layer, the special emergency electrical power supply from bunkered emergency diesel generators power the special emergency safety system and is activated upon the loss of all external feeds. A sixth layer consists of accident management equipment. Since the Fukushima event, the sixth layer has been reinforced and a seventh layer with off-site accident management equipment has been newly added. The Swiss nuclear safety regulator has analysed the accident. It reviewed the Swiss plants' protection against earthquakes as well as flooding and demanded increased precautionary measures from the Swiss operators in the hypothetical case of a total station blackout, when all the first five layers of supply would fail. In the immediate, a centralized storage with severe accident management equipment

  20. Short-term forecasting of individual household electricity loads with investigating impact of data resolution and forecast horizon

    Directory of Open Access Journals (Sweden)

    Yildiz Baran

    2018-01-01

    Full Text Available Smart grid components such as smart home and battery energy management systems, high penetration of renewable energy systems, and demand response activities, require accurate electricity demand forecasts for the successful operation of the electricity distribution networks. For example, in order to optimize residential PV generation and electricity consumption and plan battery charge-discharge regimes by scheduling household appliances, forecasts need to target and be tailored to individual household electricity loads. The recent uptake of smart meters allows easier access to electricity readings at very fine resolutions; hence, it is possible to utilize this source of available data to create forecast models. In this paper, models which predominantly use smart meter data alongside with weather variables, or smart meter based models (SMBM, are implemented to forecast individual household loads. Well-known machine learning models such as artificial neural networks (ANN, support vector machines (SVM and Least-Square SVM are implemented within the SMBM framework and their performance is compared. The analysed household stock consists of 14 households from the state of New South Wales, Australia, with at least a year worth of 5 min. resolution data. In order for the results to be comparable between different households, our study first investigates household load profiles according to their volatility and reveals the relationship between load standard deviation and forecast performance. The analysis extends previous research by evaluating forecasts over four different data resolution; 5, 15, 30 and 60 min, each resolution analysed for four different horizons; 1, 6, 12 and 24 h ahead. Both, data resolution and forecast horizon, proved to have significant impact on the forecast performance and the obtained results provide important insights for the operation of various smart grid applications. Finally, it is shown that the load profile of some

  1. Short-term forecasting of individual household electricity loads with investigating impact of data resolution and forecast horizon

    Science.gov (United States)

    Yildiz, Baran; Bilbao, Jose I.; Dore, Jonathon; Sproul, Alistair B.

    2018-05-01

    Smart grid components such as smart home and battery energy management systems, high penetration of renewable energy systems, and demand response activities, require accurate electricity demand forecasts for the successful operation of the electricity distribution networks. For example, in order to optimize residential PV generation and electricity consumption and plan battery charge-discharge regimes by scheduling household appliances, forecasts need to target and be tailored to individual household electricity loads. The recent uptake of smart meters allows easier access to electricity readings at very fine resolutions; hence, it is possible to utilize this source of available data to create forecast models. In this paper, models which predominantly use smart meter data alongside with weather variables, or smart meter based models (SMBM), are implemented to forecast individual household loads. Well-known machine learning models such as artificial neural networks (ANN), support vector machines (SVM) and Least-Square SVM are implemented within the SMBM framework and their performance is compared. The analysed household stock consists of 14 households from the state of New South Wales, Australia, with at least a year worth of 5 min. resolution data. In order for the results to be comparable between different households, our study first investigates household load profiles according to their volatility and reveals the relationship between load standard deviation and forecast performance. The analysis extends previous research by evaluating forecasts over four different data resolution; 5, 15, 30 and 60 min, each resolution analysed for four different horizons; 1, 6, 12 and 24 h ahead. Both, data resolution and forecast horizon, proved to have significant impact on the forecast performance and the obtained results provide important insights for the operation of various smart grid applications. Finally, it is shown that the load profile of some households vary

  2. Long-Term Outcomes of Catheter Ablation of Electrical Storm in Nonischemic Dilated Cardiomyopathy Compared With Ischemic Cardiomyopathy.

    Science.gov (United States)

    Muser, Daniele; Liang, Jackson J; Pathak, Rajeev K; Magnani, Silvia; Castro, Simon A; Hayashi, Tatsuya; Garcia, Fermin C; Supple, Gregory E; Riley, Michael P; Lin, David; Dixit, Sanjay; Zado, Erica S; Frankel, David S; Callans, David J; Marchlinski, Francis E; Santangeli, Pasquale

    2017-07-01

    The goal of this study was to determine the long-term outcomes of catheter ablation (CA) of electrical storm in patients with nonischemic dilated cardiomyopathy (NIDCM) compared with patients with ischemic cardiomyopathy (ICM). CA of ventricular tachycardia (VT) electrical storm has been shown to improve VT-free survival in patients with ICM. Data on the outcomes of CA of electrical storm in patients with NIDCM are insufficient. The study included 267 consecutive patients with NIDCM (n = 71; ejection fraction 32 ± 14%) and ICM (n = 196; ejection fraction 28 ± 12%). Endo-epicardial CA was performed in 59 (22%) patients. CA was guided by activation and entrainment mapping for tolerated VT and pacemapping/targeting of abnormal substrate for unmappable VT. After a median follow-up of 45 (25th to 75th percentile: 9 to 71) months and 1 (25th to 75th percentile: 1 to 8) procedures, 76 (29%) patients died, 25 (9%) underwent heart transplantation, 87 (33%) experienced VT recurrence, and 13 (5%) had recurrence of electrical storm. Overall VT-free survival was 54% at 60 months (48% in NIDCM and 54% in ICM; p = 0.128). Patients with VT recurrence experienced a median of 2 (1 to 10) VT episodes in the 5 (1 to 14) months after the procedure. Death/transplantation-free survival was 62% at 60 months (53% in NIDCM and 64% in ICM; p = 0.067). Persistent inducibility of any VT with cycle length ≥250 ms at programmed stimulation at the end of the procedure was the only independent predictor of VT recurrence. Low ejection fraction, New York Heart Association functional class, and VT recurrence over follow-up independently predicted death/transplantation. CA of electrical storm was similarly effective in patients with NIDCM compared with patients with ICM, with elimination of electrical storm in 95% of cases and achievement of complete VT control at long-term follow-up in most patients. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc

  3. Tuning temperature and size of hot spots and hot-spot arrays.

    Science.gov (United States)

    Saïdi, Elika; Babinet, Nicolas; Lalouat, Loïc; Lesueur, Jérôme; Aigouy, Lionel; Volz, Sébastian; Labéguerie-Egéa, Jessica; Mortier, Michel

    2011-01-17

    By using scanning thermal microscopy, it is shown that nanoscale constrictions in metallic microwires deposited on an oxidized silicon substrate can be tuned in terms of temperature and confinement size. High-resolution temperature maps indeed show that submicrometer hot spots and hot-spot arrays are obtained when the SiO(2) layer thickness decreases below 100 nm. When the SiO(2) thickness becomes larger, heat is less confined in the vicinity of the constrictions and laterally spreads all along the microwire. These results are in good agreement with numerical simulations, which provide dependences between silica-layer thickness and nanodot shape and temperature. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Poisson's spot and Gouy phase

    Science.gov (United States)

    da Paz, I. G.; Soldati, Rodolfo; Cabral, L. A.; de Oliveira, J. G. G.; Sampaio, Marcos

    2016-12-01

    Recently there have been experimental results on Poisson spot matter-wave interferometry followed by theoretical models describing the relative importance of the wave and particle behaviors for the phenomenon. We propose an analytical theoretical model for Poisson's spot with matter waves based on the Babinet principle, in which we use the results for free propagation and single-slit diffraction. We take into account effects of loss of coherence and finite detection area using the propagator for a quantum particle interacting with an environment. We observe that the matter-wave Gouy phase plays a role in the existence of the central peak and thus corroborates the predominantly wavelike character of the Poisson's spot. Our model shows remarkable agreement with the experimental data for deuterium (D2) molecules.

  5. Catheter ablation for the treatment of electrical storm in patients with implantable cardioverter-defibrillators: short- and long-term outcomes in a prospective single-center study.

    Science.gov (United States)

    Carbucicchio, Corrado; Santamaria, Matteo; Trevisi, Nicola; Maccabelli, Giuseppe; Giraldi, Francesco; Fassini, Gaetano; Riva, Stefania; Moltrasio, Massimo; Cireddu, Manuela; Veglia, Fabrizio; Della Bella, Paolo

    2008-01-29

    Electrical storm (ES) caused by recurrent episodes of ventricular tachycardia (VT) can cause sudden death in patients with implantable cardioverter-defibrillators and adversely affects prognosis in survivors. Catheter ablation has been proposed for treating ES, but its long-term effect in a large population has never been verified. Ninety-five consecutive patients with coronary artery disease (72 patients), idiopathic dilated cardiomyopathy (10 patients), and arrhythmogenic right ventricular dysplasia/cardiomyopathy (13 patients) undergoing catheter ablation for drug-refractory ES were prospectively evaluated. Short-term efficacy was defined by a complete protocol of programmed electric stimulation and by in-hospital outcome; long-term analysis addressed ES recurrence, cardiac mortality, and VT recurrence. Pleomorphic/nontolerated VTs required electroanatomic and noncontact mapping in 48 and 22 patients, respectively, and percutaneous cardiopulmonary support in 10 patients. An epicardial approach was used in 10 patients. After 1 to 3 procedures, induction of any clinical VT(s) by programmed electrical stimulation was prevented in 85 patients (89%). ES was acutely suppressed in all patients; a minimum period of 7 days with stable rhythm was required before hospital discharge. At a median follow-up of 22 months (range, 1 to 43 months), 87 patients (92%) were free of ES and 63 patients (66%) were free of VT recurrence. Eight of 10 patients with persistent inducibility of clinical VT(s) had ES recurrence; 4 of them died suddenly despite appropriate implantable cardioverter-defibrillator intervention. All together, 11 of 95 patients (12%) died of cardiac-related reasons. In the group of patients presenting with all clinical VTs acutely abolished, no ES recurrence was documented, and cardiac mortality was significantly lower compared with the group of patients showing > or = 1 clinical VT still inducible after catheter ablation. Advanced strategies of catheter ablation

  6. Laser based spot weld characterization

    Science.gov (United States)

    Jonietz, Florian; Myrach, Philipp; Rethmeier, Michael; Suwala, Hubert; Ziegler, Mathias

    2016-02-01

    Spot welding is one of the most important joining technologies, especially in the automotive industry. Hitherto, the quality of spot welded joints is tested mainly by random destructive tests. A nondestructive testing technique offers the benefit of cost reduction of the testing procedure and optimization of the fabrication process, because every joint could be examined. This would lead to a reduced number of spot welded joints, as redundancies could be avoided. In the procedure described here, the spot welded joint between two zinc-coated steel sheets (HX340LAD+Z100MB or HC340LA+ZE 50/50) is heated optically on one side. Laser radiation and flash light are used as heat sources. The melted zone, the so called "weld nugget" provides the mechanical stability of the connection, but also constitutes a thermal bridge between the sheets. Due to the better thermal contact, the spot welded joint reveals a thermal behavior different from the surrounding material, where the heat transfer between the two sheets is much lower. The difference in the transient thermal behavior is measured with time resolved thermography. Hence, the size of the thermal contact between the two sheets is determined, which is directly correlated to the size of the weld nugget, indicating the quality of the spot weld. The method performs well in transmission with laser radiation and flash light. With laser radiation, it works even in reflection geometry, thus offering the possibility of testing with just one-sided accessibility. By using heating with collimated laser radiation, not only contact-free, but also remote testing is feasible. A further convenience compared to similar thermographic approaches is the applicability on bare steel sheets without any optical coating for emissivity correction. For this purpose, a proper way of emissivity correction was established.

  7. Short run pricing in competitive electricity markets

    International Nuclear Information System (INIS)

    Ring, B. J.; Read, E. G.

    1996-01-01

    In response to the need for more responsive, competitive and decentralized pricing strategies forced upon the industry by deregulation, this study reviewed the type of electricity pricing required to coordinate a competitive wholesale electricity market over time periods typically of the order of one hour. It was found that nodal spot pricing can provide a straight-forward mechanism for providing the correct signals to market participants, while reflecting the costs and complexities of transmission network operation. Provided that all binding constraints are represented in the pricing model, and assuming that they are used in conjunction with long term contracts and capacity rights, such pricing can potentially deliver most of the benefits promised by perfect coordination, while allowing competition to flourish. 4 refs

  8. The compass rose pattern in electricity prices.

    Science.gov (United States)

    Batten, Jonathan A; Hamada, Mahmoud

    2009-12-01

    The "compass rose pattern" is known to appear in the phase portraits, or scatter diagrams, of the high-frequency returns of financial series. We first show that this pattern is also present in the returns of spot electricity prices. Early researchers investigating these phenomena hoped that these patterns signaled the presence of rich dynamics, possibly chaotic or fractal in nature. Although there is a definite autoregressive and conditional heteroscedasticity structure in electricity returns, we find that after simple filtering no pattern remains. While the series is non-normal in terms of their distribution and statistical tests fail to identify significant chaos, there is evidence of fractal structures in periodic price returns when measured over the trading day. The phase diagram of the filtered returns provides a useful visual check on independence, a property necessary for pricing and trading derivatives and portfolio construction, as well as providing useful insights into the market dynamics.

  9. Empirical analysis of the spot market implications of price-responsive demand

    International Nuclear Information System (INIS)

    Siddiqui, A.S.

    2006-01-01

    Although electricity is theoretically an inelastic good in the short term, the steep slope of the supply stack implies that even modest response by demand could translate into reduced capacity requirements and significant price decreases. This article examined the effect of price-responsive demand strategies in an actual deregulated electricity industry. Auction data from the New York Independent System Operator (NYISO) day-ahead electricity market were used to form supply stacks for various zones. A simple linear demand function was used to determine the effect of price responsiveness on equilibrium spot market price and consumption. The aim was to quantify the benefits from the pricing protocol and to determine whether modest levels of price elasticity can significantly lower prices and consumption. Market-clearing prices and quantities were estimated using various supply curves in order to quantify the responsiveness necessary to achieve given price reductions. Price response was induced in the demand curve by varying its slope. Estimates were then used to estimate the average level of slope needed to reduce the average market-clearing price during the year by a certain percentage. Results showed that an average slope of -50.04 was necessary for prices to be reduced by 25 per cent. Results also showed that necessary price responses can be ascertained for any desired reduction in the market-clearing price or quantity. Although price responsiveness unambiguously reduces the spot market price and quantity, its effect on the forward price is not yet clear. It was concluded that a separate analysis of peak hours may reveal the effectiveness of enhanced price response. 8 refs., 1 tab., 8 figs

  10. Short-term electricity prices forecasting based on support vector regression and Auto-regressive integrated moving average modeling

    International Nuclear Information System (INIS)

    Che Jinxing; Wang Jianzhou

    2010-01-01

    In this paper, we present the use of different mathematical models to forecast electricity price under deregulated power. A successful prediction tool of electricity price can help both power producers and consumers plan their bidding strategies. Inspired by that the support vector regression (SVR) model, with the ε-insensitive loss function, admits of the residual within the boundary values of ε-tube, we propose a hybrid model that combines both SVR and Auto-regressive integrated moving average (ARIMA) models to take advantage of the unique strength of SVR and ARIMA models in nonlinear and linear modeling, which is called SVRARIMA. A nonlinear analysis of the time-series indicates the convenience of nonlinear modeling, the SVR is applied to capture the nonlinear patterns. ARIMA models have been successfully applied in solving the residuals regression estimation problems. The experimental results demonstrate that the model proposed outperforms the existing neural-network approaches, the traditional ARIMA models and other hybrid models based on the root mean square error and mean absolute percentage error.

  11. Terms of transactions monitoring on the French wholesale electricity and gas markets. Public consultation. Synthesis of contributions

    International Nuclear Information System (INIS)

    2008-01-01

    In its communication dated 16 April 2008, CRE published its practical methods used to monitor transactions concluded on the French electricity and gas markets. CRE invited any companies to comment on the practical arrangements of such monitoring activities. The monitoring system described by CRE is divided into two steps. In the first step, CRE wants to be able to request any information concerning transactions for physical delivery concluded after 1 January 2007. CRE will make an initial request that will focus on: - for electricity: transactions concluded in 2007 on yearly products for delivery in 2008 and 2009, base-load and peak-load; - for gas: transactions concluded in 2007 on seasonal and yearly products for delivery in 2008 and 2009, base-load and peak-load. The second step, based on feedback received, will see CRE liaise with market players and consider the possibility of setting up systematic procedures to gather transactions data. A final decision will be made by the end of 2008. 17 contributors responded to the public consultation. The remarks made on the practical methods used to gather data can be summarized along the following themes: Preamble: the monitoring principle; Theme 1: scope of transactions monitoring; Theme 2: content and format of requested data; Theme 3: procedures, transmission deadlines and confidentiality issues; Theme 4: stage II of systematic data gathering

  12. The long term plan for the integration of nuclear power plants into the Turkish Electrical Power System

    International Nuclear Information System (INIS)

    Kutukcuoglu, A.

    1974-03-01

    The report covers in detail the study of the expansion of the Turkish Electric Power System for the period 1980-1987. Load forecast is done by sectors and regions and inter-regions power balances gave the basis for the high voltage network configurations. Expansion alternatives are defined giving priority to hydroelectric projects, to local resources and nuclear power plants concurrently with conventional plants (lignite and oil). Several reactor strategies are analysed with LWR, HWR, FBR and HTGR power plants. Present worth value method is used for comparison of alternatives and sensitivity analysis is done for those ranked in the first places. Load flow, transient stability and frequency deviation studies of the power system are studied carefully by means of A.C. calculator and digital computer codes in order to see the influence of the introduction of large-sized power plants (600-750MW(e)) and their location in the power system. A 600MW(e) nuclear plant in 1983 and a second one of 750MW(e) in 1987 should, it is found, be commissioned into the system. The economic optimization was done with two computer programmes developed by KFA (Juelich): IACO for fuelling nuclear plant and RESTRAPO for power system with high hydroelectric component. The report is bound in three volumes: Volume I: Summary and Conclusions; Volume II: System Planning; Volume III: Electrical Survey

  13. Financing investment in the European electricity transmission network: Consequences on long-term sustainability of the TSOs financial structure

    International Nuclear Information System (INIS)

    Henriot, Arthur

    2013-01-01

    This article focuses on the ability of European TSOs to meet the demand for substantial investments in the electricity transmission grid over the next two decades. We employ quantitative analysis to assess the impact of the required capital expenditures under a set of alternative financing strategies. We consider a best-case scenario of full cooperation between the European TSOs. It appears that under current trends in the evolution of transmission tariffs, only half the volumes of investment currently planned could be funded. A highly significant increase in transmission tariffs will be required to ensure the whole-scale investments can be delivered. Finally, alternative strategies can dampen the impact on tariffs but they can only partially substitute for this increase in charges paid by network users. -- Highlights: •We applied balance-sheet modelling to a single European Electricity TSO. •Investments planned will not be achievable under current tariffs evolution. •A three-fold higher growth of transmission network tariffs would be necessary. •New financing strategies can dampen the impact on tariffs, to a minor extent

  14. Is this Red Spot the Blue Spot (locus ceruleum)?

    Energy Technology Data Exchange (ETDEWEB)

    Choe, Won Sick; Lee, Yu Kyung; Lee, Min Kyung; Hwang, Kyung Hoon [Gachon University Gil Hospital, Incheon (Korea, Republic of)

    2010-06-15

    The authors report brain images of 18F-FDG-PET in a case of schizophrenia. The images showed strikingly increased bilateral uptake in the locus ceruleum. The locus ceruleum is called the blue spot and known to be a center of the norepinephrinergic system.

  15. Is this Red Spot the Blue Spot (locus ceruleum)?

    International Nuclear Information System (INIS)

    Choe, Won Sick; Lee, Yu Kyung; Lee, Min Kyung; Hwang, Kyung Hoon

    2010-01-01

    The authors report brain images of 18F-FDG-PET in a case of schizophrenia. The images showed strikingly increased bilateral uptake in the locus ceruleum. The locus ceruleum is called the blue spot and known to be a center of the norepinephrinergic system.

  16. Equilibrium pricing in electricity markets with wind power

    Science.gov (United States)

    Rubin, Ofir David

    precision is still low. Therefore, it is crucial that the uncertainty in forecasting wind power is considered when modeling trading behavior. Our theoretical framework is based on finding a symmetric Cournot-Nash equilibrium in double-sided auctions in both forwards and spot electricity markets. The theoretical framework allows for the first time, to the best of our knowledge, a model of electricity markets that explain two main empirical findings; the existence of forwards premium and spot market mark-ups. That is a significant contribution since so far forward premiums have been explained exclusively by the assumption of risk-averse behavior while spot mark-ups are the outcome of the body of literature assuming oligopolistic competition. In the next step, we extend the theoretical framework to account for deregulated electricity markets with wind power. Modeling a wind-integrated electricity market allows us to analyze market outcomes with respect to three main factors; the introduction of uncertainty from the supply side, ownership of wind power capacity and the geographical diversification of wind power capacity. For the purpose of modeling trade in electricity forwards one should simulate the information agents have regarding future availability of aggregate wind power. This is particularly important for modeling accurately traders' ability to predict the spot price distribution. We develop a novel numerical methodology for the simulation of the conditional distribution of regional wind power at the time of trading short-term electricity forwards. Finally, we put the theoretical framework and the numerical methodology developed in this study to work by providing a detailed computational experiment examining electricity market outcomes for a particular expansion path of wind power capacity.

  17. Predictive Value of CTA Spot Sign on Hematoma Expansion in Intracerebral Hemorrhage Patients

    Directory of Open Access Journals (Sweden)

    Wen-Jie Peng

    2017-01-01

    Full Text Available Hematoma expansion (HE occurs in approximately one-third of patients with intracerebral hemorrhage and leads to high rates of mortality and morbidity. Currently, contrast extravasation within hematoma, termed the spot sign on computed tomography angiography (CTA, has been identified as a strong independent predictor of early hematoma expansion. Past studies indicate that the spot sign is a dynamic entity and is indicative of active hemorrhage. Furthermore, to enhance the spot sign’s accuracy of predicting HE, spot parameters observed on CTA or dynamic CTA were used for its quantification. In addition, spot signs detected on multiphase CTA and dynamic CTA are shown to have higher sensitivity and specificity when compared with simple standardized spot sign detection in recent studies. Based on the spot sign, novel methods such as leakage sign and rate of contrast extravasation were explored to redefine HE prediction in combination with clinical characteristics and spot sign on CTA to assist clinical judgment. The spot sign is an accepted independent predictor of active hemorrhage and is used in both secondary intracerebral hemorrhage and the process of surgical assessment for hemorrhagic risk in patients with ischemic stroke. Spot sign predicts patients at high risk for hematoma expansion.

  18. Nest reuse by Northern Spotted Owls on the east slope of the Cascade Range, Washington

    Science.gov (United States)

    Stan G. Sovern; Margaret Taylor; Eric D. Forsman

    2011-01-01

    During a long-term demography study of Northern Spotted Owls (Strix occidentalis caurina) in the eastern Cascade Range of Washington State in 1989 to 2008, we documented 276 nests of Northern Spotted Owls at 73 different territories. Of these nests, 90.2% were on platforms, mostly in clumps of deformed limbs caused by dwarf mistletoe (primarily...

  19. A trend fixed on firstly and seasonal adjustment model combined with the ε-SVR for short-term forecasting of electricity demand

    International Nuclear Information System (INIS)

    Wang Jianzhou; Zhu Wenjin; Zhang Wenyu; Sun Donghuai

    2009-01-01

    Short-term electricity demand forecasting has always been an essential instrument in power system planning and operation by which an electric utility plans and dispatches loading so as to meet system demand. The accuracy of the dispatching system, derived from the accuracy of demand forecasting and the forecasting algorithm used, will determines the economic of the power system operation as well as the stability of the whole society. This paper presents a combined ε-SVR model considering seasonal proportions based on development tendencies from history data. We use one-order moving averages to produce a comparatively smooth data series, taking the averaging period as the interval that can effectively eliminate the seasonal variation. We used the smoothed data series as the training set input for the ε-SVR model and obtained the corresponding forecasting value. Afterward, we accounted for the previously removed seasonal variation. As a case, we forecast northeast electricity demand of China using the new method. We demonstrated that this simple procedure has very satisfactory overall performance by an analysis of variance with relative verification and validation. Significant reductions in forecast errors were achieved.

  20. A trend fixed on firstly and seasonal adjustment model combined with the epsilon-SVR for short-term forecasting of electricity demand

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jianzhou [School of Mathematics and Statistics, Lanzhou University, Lanzhou 730000 (China); Zhu Wenjin, E-mail: crying.1@hotmail.co [School of Mathematics and Statistics, Lanzhou University, Lanzhou 730000 (China); Zhang Wenyu [College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000 (China); Sun Donghuai [Key Laboratory of Western Chinas Environmental Systems (Ministry of Education) College of Earth and Environment Sciences, Lanzhou University, Lanzhou 730000 (China)

    2009-11-15

    Short-term electricity demand forecasting has always been an essential instrument in power system planning and operation by which an electric utility plans and dispatches loading so as to meet system demand. The accuracy of the dispatching system, derived from the accuracy of demand forecasting and the forecasting algorithm used, will determines the economic of the power system operation as well as the stability of the whole society. This paper presents a combined epsilon-SVR model considering seasonal proportions based on development tendencies from history data. We use one-order moving averages to produce a comparatively smooth data series, taking the averaging period as the interval that can effectively eliminate the seasonal variation. We used the smoothed data series as the training set input for the epsilon-SVR model and obtained the corresponding forecasting value. Afterward, we accounted for the previously removed seasonal variation. As a case, we forecast northeast electricity demand of China using the new method. We demonstrated that this simple procedure has very satisfactory overall performance by an analysis of variance with relative verification and validation. Significant reductions in forecast errors were achieved.

  1. A trend fixed on firstly and seasonal adjustment model combined with the {epsilon}-SVR for short-term forecasting of electricity demand

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jianzhou; Zhu, Wenjin [School of Mathematics and Statistics, Lanzhou University, Lanzhou 730000 (China); Zhang, Wenyu [College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000 (China); Sun, Donghuai [Key Laboratory of Western Chinas Environmental Systems (Ministry of Education) College of Earth and Environment Sciences, Lanzhou University, Lanzhou 730000 (China)

    2009-11-15

    Short-term electricity demand forecasting has always been an essential instrument in power system planning and operation by which an electric utility plans and dispatches loading so as to meet system demand. The accuracy of the dispatching system, derived from the accuracy of demand forecasting and the forecasting algorithm used, will determines the economic of the power system operation as well as the stability of the whole society. This paper presents a combined {epsilon}-SVR model considering seasonal proportions based on development tendencies from history data. We use one-order moving averages to produce a comparatively smooth data series, taking the averaging period as the interval that can effectively eliminate the seasonal variation. We used the smoothed data series as the training set input for the {epsilon}-SVR model and obtained the corresponding forecasting value. Afterward, we accounted for the previously removed seasonal variation. As a case, we forecast northeast electricity demand of China using the new method. We demonstrated that this simple procedure has very satisfactory overall performance by an analysis of variance with relative verification and validation. Significant reductions in forecast errors were achieved. (author)

  2. Natural gas's hottest spot

    International Nuclear Information System (INIS)

    Peterson, T.

    1993-01-01

    This paper reviews the growing power and economic strength of Enron Corp., a natural gas distributor and exploration company. The paper reviews the policy of the company to exploit deregulation at home and privatization of all sorts of energy companies abroad. Enron is actively building its own power plants in the US and has successfully boosted their profits by 20 percent in what was considered a flat natural gas market. The paper goes on to discuss the company's view of the new energy tax and how it should benefit natural gas companies as a whole. Finally the paper reviews the contracting procedures of the company to secure long-term fixed price contracts in a volatile market which precludes most companies from taking the risk

  3. Applying mathematical finance tools to the competitive Nordic electricity market

    OpenAIRE

    Vehviläinen, Iivo

    2004-01-01

    This thesis models competitive electricity markets using the methods of mathematical finance. Fundamental problems of finance are market price modelling, derivative pricing, and optimal portfolio selection. The same questions arise in competitive electricity markets. The thesis presents an electricity spot price model based on the fundamental stochastic factors that affect electricity prices. The resulting price model has sound economic foundations, is able to explain spot market price mo...

  4. Forecasting short-term power prices in the Ontario Electricity Market (OEM) with a fuzzy logic based inference system

    International Nuclear Information System (INIS)

    Arciniegas, Alvaro I.; Arciniegas Rueda, Ismael E.

    2008-01-01

    The Ontario Electricity Market (OEM), which opened in May 2002, is relatively new and is still under change. In addition, the bidding strategies of the participants are such that the relationships between price and fundamentals are non-linear and dynamic. The lack of market maturity and high complexity hinders the use of traditional statistical methodologies (e.g., regression analysis) for price forecasting. Therefore, a flexible model is needed to achieve good forecasting in OEM. This paper uses a Takagi-Sugeno-Kang (TSK) fuzzy inference system in forecasting the one-day-ahead real-time peak price of the OEM. The forecasting results of TSK are compared with those obtained by traditional statistical and neural network based forecasting. The comparison suggests that TSK has considerable value in forecasting one-day-ahead peak price in OEM. (author)

  5. Differentiated long term projections of the hourly electricity consumption in local areas. The case of Denmark West

    DEFF Research Database (Denmark)

    Møller Andersen, Frits; Larsen, Helge V.; Juul, Nina

    2014-01-01

    .000 and 100.000 customers. Data for the hourly electricity consumption at transformer stations shows that the profile of consumption differs considerably between local areas, and this is partly due to a different weight of categories of customers in the different areas. Categories of customers have quite...... distinct consumption profiles and contribute quite differently to the aggregated load profile. In forecasts, demand by categories of customers is expected to develop differently implying that both the level and the profile of consumption at each transformer stations are expected to change differently...... consumption by categories of customers and data for the hourly consumption at each transformer station for the years 2009–2011. Applying the model for load forecasts, a major conclusion is that different transformer stations will experience different changes both in the level - and in the hourly profile...

  6. Chiral symmetry in the strong color-electric field in terms of Nambu-Jona-Lasinio model

    International Nuclear Information System (INIS)

    Suganuma, Hideo

    1990-01-01

    We examine the behavior of chiral symmetry in an external gluon field using Nambu-Jona-Lasinio model, which is an effective theory of QCD. The Dyson equation for the dynamical quark mass in the presence of the external color-electric field is obtained. By solving it in the color flux tube inside mesons, chiral symmetry would be restored in the flux tube of mesons and this result supports Chiral Bag picture for mesons. Next we consider the flux tubes formed in the central region for ultra-relativistic heavy-ion collisions, and find the chiral restoration occurs there, so that the current quark mass seems to be suitable in calculating the q-q-bar pair creation rate by the Schwinger formula in the flux-tube picture. (author)

  7. Creating a vision for the future. Long-term R and D on a short sighted electricity market

    International Nuclear Information System (INIS)

    Markussen, P.; Darsoe, L.

    2005-01-01

    Historically well-established networks among the politicians, power companies, industry, and research institutions have with success dominated innovation in the energy sector. As a consequence of the liberalization in the late 90s, long-term investments have been reduced and because of the increased competition R and D in power companies around Europe is dominated by short-term projects focusing on technological performance and efficiency of the power stations. The energy sector is, however, still faced with long-term problems such as security of supply, environmental responsibilities and economic performance, and these challenges demand new solutions, which, in our opinion, should be obtained through collaboration and co-creation. This calls for social innovation based on new types of relations between research institutions, politicians and the energy supply sector. Thus the goals of this paper are to: 1) suggest a preject phase (Darsoe, 2001), where it is possible and legitimate for the stakeholders to discuss longterm visions that encompass a diversity of technologies, and 2) use scenario techniques as tools for conceptualizing and prototyping this vision. The main question is: How can we create a long-term vision for the Danish energy system that is meaningful to multiple stakeholders? (au)

  8. Creating a vision for the future. Long-term R and D on a short sighted electricity market

    Energy Technology Data Exchange (ETDEWEB)

    Markussen, P. [Elsam (Denmark); Darsoe, L. [Learning Lab. Denmark (Denmark)

    2005-06-01

    Historically well-established networks among the politicians, power companies, industry, and research institutions have with success dominated innovation in the energy sector. As a consequence of the liberalization in the late 90s, long-term investments have been reduced and because of the increased competition R and D in power companies around Europe is dominated by short-term projects focusing on technological performance and efficiency of the power stations. The energy sector is, however, still faced with long-term problems such as security of supply, environmental responsibilities and economic performance, and these challenges demand new solutions, which, in our opinion, should be obtained through collaboration and co-creation. This calls for social innovation based on new types of relations between research institutions, politicians and the energy supply sector. Thus the goals of this paper are to: 1) suggest a preject phase (Darsoe, 2001), where it is possible and legitimate for the stakeholders to discuss longterm visions that encompass a diversity of technologies, and 2) use scenario techniques as tools for conceptualizing and prototyping this vision. The main question is: How can we create a long-term vision for the Danish energy system that is meaningful to multiple stakeholders? (au)

  9. Experimental Study of Ignition by Hot Spot in Internal Combustion Engines

    Science.gov (United States)

    Serruys, Max

    1938-01-01

    In order to carry out the contemplated study, it was first necessary to provide hot spots in the combustion chamber, which could be measured and whose temperature could be changed. It seemed difficult to realize both conditions working solely on the temperature of the cooling water in a way so as to produce hot spots on the cylinder wall capable of provoking autoignition. Moreover, in the majority of practical cases, autoignition is produced by the spark plug, one of the least cooled parts in the engine. The first procedure therefore did not resemble that which most generally occurs in actual engine operation. All of these considerations caused us to reproduce similar hot spots at the spark plugs. The hot spots produced were of two kinds and designated with the name of thermo-electric spark plug and of metallic hot spot.

  10. Rocky Mountain spotted fever, Panama.

    Science.gov (United States)

    Estripeaut, Dora; Aramburú, María Gabriela; Sáez-Llorens, Xavier; Thompson, Herbert A; Dasch, Gregory A; Paddock, Christopher D; Zaki, Sherif; Eremeeva, Marina E

    2007-11-01

    We describe a fatal pediatric case of Rocky Mountain spotted fever in Panama, the first, to our knowledge, since the 1950s. Diagnosis was established by immunohistochemistry, PCR, and isolation of Rickettsia rickettsii from postmortem tissues. Molecular typing demonstrated strong relatedness of the isolate to strains of R. rickettsii from Central and South America.

  11. Long-term energy and climate implications of carbon capture and storage deployment strategies in the US coal-fired electricity fleet.

    Science.gov (United States)

    Sathre, Roger; Masanet, Eric

    2012-09-04

    To understand the long-term energy and climate implications of different implementation strategies for carbon capture and storage (CCS) in the US coal-fired electricity fleet, we integrate three analytical elements: scenario projection of energy supply systems, temporally explicit life cycle modeling, and time-dependent calculation of radiative forcing. Assuming continued large-scale use of coal for electricity generation, we find that aggressive implementation of CCS could reduce cumulative greenhouse gas emissions (CO(2), CH(4), and N(2)O) from the US coal-fired power fleet through 2100 by 37-58%. Cumulative radiative forcing through 2100 would be reduced by only 24-46%, due to the front-loaded time profile of the emissions and the long atmospheric residence time of CO(2). The efficiency of energy conversion and carbon capture technologies strongly affects the amount of primary energy used but has little effect on greenhouse gas emissions or radiative forcing. Delaying implementation of CCS deployment significantly increases long-term radiative forcing. This study highlights the time-dynamic nature of potential climate benefits and energy costs of different CCS deployment pathways and identifies opportunities and constraints of successful CCS implementation.

  12. Electrodynamic energy harvester for electrical transformer's ...

    Indian Academy of Sciences (India)

    Electrical transformer; electrodynamic; energy harvester; self-powered ...... Kennedy S P and Gordner T 2013 Hot spot studies for sheet wound transformer wind- ... and Lambert F 2011 Powering low-cost utility sensors using energy harvesting.

  13. Uranium ... long-term confidence

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Half way through 1983 the outlook for the world's uranium producers was far from bright if one takes a short term view. The readily accessible facts present a gloomy picture. The spot prices of uranium over the past few years decreased from a high of $42-$43/lb to a low of $17 in 1982. It now hovers between $23 and $24. the contract prices negotiated between producers and consumers are not so accessible but they do not reflect the spot price. The reasons why contractual uranium prices do not follow the usual dictates of supply and demand are related to the position in which uranium and associated power industries find themselves. There is public reaction with strong emotional overtones as well as much reduced expectations about the electric power needs of the world. Furthermore the supply of uranium is not guaranteed despite present over production. However the people in the industry, taking the medium- and long-term view, are not despondent

  14. Hybrid Electricity Markets with Long-Term Risk-Sharing Arrangements: Adapting Market Design to Security of Supply and decarbonization Objectives

    International Nuclear Information System (INIS)

    ROQUES, Fabien; FINON, Dominique

    2017-01-01

    The re-emergence of policy interventionism in electricity markets raises questions as to how market design can best be adapted to meeting the investment challenge associated with security of supply (SoS) and decarbonization objectives. This paper takes an institutionalist approach in terms of modularity of the market design, and reviews the standard historical approach towards competitive markets, in order to analyse the roles and interactions of the initial and additional market 'modules'. We argue that a number of additional modules is required to achieve long-term policy objectives, such as decarbonization and security of supply (SoS). But, in turn, they destabilise the initial modules of the market design, in particular by the entries of renewables. We review the international experience with hybrid market design and draw a number of policy recommendations at to best practices, as well as suggesting ways in which the initial market modules can be improved to prevent inconsistencies with the new modules. The move towards a hybrid market regime, which relies on a combination of planning, long-term risk sharing arrangements and improved markets entrenched in a function of short-term coordination, appears to be unavoidable where decarbonization policies are adopted. (authors)

  15. Restructuring in Ontario : electricity sector reform

    International Nuclear Information System (INIS)

    Pospisil, S.

    2004-01-01

    Ontario's electricity reform strategy was outlined along with challenge facing Ontario's electricity supply and demand with particular focus on the issue of replacing coal-fired generation. According to reports by the Independent Electricity Market Operator, short-term reserve margins were higher in 2004 than they were in 2003 due to the return to service of some nuclear generating units and planned capacity additions. Ontario's long-term supply and demand situation was also examined. It was noted that lenders hesitate to finance the expansion of generation companies selling into the spot market. Many lenders are requiring that half of the project's output be sold in advance on contract. Other challenges include Ontario's aging generation infrastructure and rising energy prices. The presentation included graphs that compared electricity costs for residential and small business customers across various provinces and states. The main supply and conservation challenges revolve around the large investments required by 2020 to replace coal plants, retire nuclear plants and projected load growth. Ontario's current generation capacity is 154 TWh and the mix is represented by 40 per cent nuclear, 25 per cent coal, 25 per cent hydro, 8 per cent natural gas, 1 per cent oil, and 1 per cent biomass and other renewable energy sources. This paper also addressed the issue of coal generation and air pollution and emphasized the importance of looking at the broad externalities associated with air emissions. tabs., figs

  16. Estimación del precio de oferta de la energía eléctrica en Colombia mediante inteligencia artificial || Estimating the Spot Market Price Bid in Colombian Electricity Market by Using Artificial Intelligence

    Directory of Open Access Journals (Sweden)

    Hurtado Moreno, Laura

    2014-12-01

    Full Text Available Uno de los sectores económicos estratégicos más importantes en cualquier economía es el Mercado de Energía Mayorista, cuya característica fundamental es que se trata de un mercado oligopolístico, provocado por la barrera de entrada que supone tener economías de escala. De esta manera, los agentes pueden presentar comportamientos estratégicos que contribuyen a la maximización de sus utilidades, los cuales se ven reflejados en la oferta diaria del precio y de la cantidad de energía por hora en cada una de sus centrales de generación. En este trabajo se presenta una metodología para la estimación de los precios diarios a los que ofertan la energía que producen los principales recursos hídricos y térmicos en Colombia. Se emplean dos herramientas de Inteligencia Artificial: la Lógica Difusa y las Redes Neuronales. Dichas técnicas resultan ser parcialmente efectivas para seguir las tendencias de dichos precios. También se comparan los resultados con los de modelos autorregresivos, que resultan ser inapropiados para el caso de estudio. || One of the most important economic strategic sectors in any economy is the electricity market. Its main feature is its oligopolistic character favoured by the returns to scale which act as an entry barrier. As a result, the energy generators can use their power market in order to increase their benefits through the daily offered price and quantity of energy for each of their power plants. This paper presents a methodology for estimating the daily offered price of the most important power stations in Colombia (hydraulic and thermal by applying artificial intelligence techniques: Fuzzy Logic and Neural Networks. Such techniques are found to be partially useful particularly for price tendencies. It also compares the results with autoregressive models that turned out inappropriate for the case of study.

  17. Charge-Spot Model for Electrostatic Forces in Simulation of Fine Particulates

    Science.gov (United States)

    Walton, Otis R.; Johnson, Scott M.

    2010-01-01

    The charge-spot technique for modeling the static electric forces acting between charged fine particles entails treating electric charges on individual particles as small sets of discrete point charges, located near their surfaces. This is in contrast to existing models, which assume a single charge per particle. The charge-spot technique more accurately describes the forces, torques, and moments that act on triboelectrically charged particles, especially image-charge forces acting near conducting surfaces. The discrete element method (DEM) simulation uses a truncation range to limit the number of near-neighbor charge spots via a shifted and truncated potential Coulomb interaction. The model can be readily adapted to account for induced dipoles in uncharged particles (and thus dielectrophoretic forces) by allowing two charge spots of opposite signs to be created in response to an external electric field. To account for virtual overlap during contacts, the model can be set to automatically scale down the effective charge in proportion to the amount of virtual overlap of the charge spots. This can be accomplished by mimicking the behavior of two real overlapping spherical charge clouds, or with other approximate forms. The charge-spot method much more closely resembles real non-uniform surface charge distributions that result from tribocharging than simpler approaches, which just assign a single total charge to a particle. With the charge-spot model, a single particle may have a zero net charge, but still have both positive and negative charge spots, which could produce substantial forces on the particle when it is close to other charges, when it is in an external electric field, or when near a conducting surface. Since the charge-spot model can contain any number of charges per particle, can be used with only one or two charge spots per particle for simulating charging from solar wind bombardment, or with several charge spots for simulating triboelectric charging

  18. Electric drives

    Energy Technology Data Exchange (ETDEWEB)

    1986-10-01

    Several electric vehicles have been tested in long-term tests, i.e. an electric passenger car (maximum speed 115 km/h) and several busses for use in pedestrians' zones, spas, airports, natural reserves, and urban transportation (DUO busses). The ICE high-speed train is discussed in some detail, i.e. its aeroacoustic and aerodynamic design, running gear, computer-controlled drives and brakes, diagnostic systems, and electrical equipment. The Berlin Maglev system is mentioned as well as current inverters in rail vehicles. (HWJ).

  19. Particle-wave discrimination in Poisson spot experiments

    International Nuclear Information System (INIS)

    Reisinger, T; Bracco, G; Holst, B

    2011-01-01

    Matter-wave interferometry has been used extensively over the last few years to demonstrate the quantum-mechanical wave nature of increasingly larger and more massive particles. We have recently suggested the use of the historical Poisson spot setup to test the diffraction properties of larger objects. In this paper, we present the results of a classical particle van der Waals (vdW) force model for a Poisson spot experimental setup and compare these to Fresnel diffraction calculations with a vdW phase term. We include the effect of disc-edge roughness in both models. Calculations are performed with D 2 and with C 70 using realistic parameters. We find that the sensitivity of the on-axis interference/focus spot to disc-edge roughness is very different in the two cases. We conclude that by measuring the intensity on the optical axis as a function of disc-edge roughness, it can be determined whether the objects behave as de Broglie waves or classical particles. The scaling of the Poisson spot experiment to larger molecular masses is, however, not as favorable as in the case of near-field light-grating-based interferometers. Instead, we discuss the possibility of studying the Casimir-Polder potential using the Poisson spot setup.

  20. Long-term evolution of brainstem electrical evoked responses to sound after restricted ablation of the auditory cortex.

    Directory of Open Access Journals (Sweden)

    Verónica Lamas

    Full Text Available INTRODUCTION: This study aimed to assess the top-down control of sound processing in the auditory brainstem of rats. Short latency evoked responses were analyzed after unilateral or bilateral ablation of auditory cortex. This experimental paradigm was also used towards analyzing the long-term evolution of post-lesion plasticity in the auditory system and its ability to self-repair. METHOD: Auditory cortex lesions were performed in rats by stereotactically guided fine-needle aspiration of the cerebrocortical surface. Auditory Brainstem Responses (ABR were recorded at post-surgery day (PSD 1, 7, 15 and 30. Recordings were performed under closed-field conditions, using click trains at different sound intensity levels, followed by statistical analysis of threshold values and ABR amplitude and latency variables. Subsequently, brains were sectioned and immunostained for GAD and parvalbumin to assess the location and extent of lesions accurately. RESULTS: Alterations in ABR variables depended on the type of lesion and post-surgery time of ABR recordings. Accordingly, bilateral ablations caused a statistically significant increase in thresholds at PSD1 and 7 and a decrease in waves amplitudes at PSD1 that recover at PSD7. No effects on latency were noted at PSD1 and 7, whilst recordings at PSD15 and 30 showed statistically significant decreases in latency. Conversely, unilateral ablations had no effect on auditory thresholds or latencies, while wave amplitudes only decreased at PSD1 strictly in the ipsilateral ear. CONCLUSION: Post-lesion plasticity in the auditory system acts in two time periods: short-term period of decreased sound sensitivity (until PSD7, most likely resulting from axonal degeneration; and a long-term period (up to PSD7, with changes in latency responses and recovery of thresholds and amplitudes values. The cerebral cortex may have a net positive gain on the auditory pathway response to sound.

  1. Laser Pyrometer For Spot Temperature Measurements

    Science.gov (United States)

    Elleman, D. D.; Allen, J. L.; Lee, M. C.

    1988-01-01

    Laser pyrometer makes temperature map by scanning measuring spot across target. Scanning laser pyrometer passively measures radiation emitted by scanned spot on target and calibrated by similar passive measurement on blackbody of known temperature. Laser beam turned on for active measurements of reflectances of target spot and reflectance standard. From measurements, temperature of target spot inferred. Pyrometer useful for non-contact measurement of temperature distributions in processing of materials.

  2. Laser Spot Detection Based on Reaction Diffusion

    OpenAIRE

    Alejandro Vázquez-Otero; Danila Khikhlukha; J. M. Solano-Altamirano; Raquel Dormido; Natividad Duro

    2016-01-01

    Center-location of a laser spot is a problem of interest when the laser is used for processing and performing measurements. Measurement quality depends on correctly determining the location of the laser spot. Hence, improving and proposing algorithms for the correct location of the spots are fundamental issues in laser-based measurements. In this paper we introduce a Reaction Diffusion (RD) system as the main computational framework for robustly finding laser spot centers. The method presente...

  3. Canine generalized demodicosis treated with varying doses of a 2.5% moxidectin+10% imidacloprid spot-on and oral ivermectin: parasiticidal effects and long-term treatment outcomes.

    Science.gov (United States)

    Paterson, Tara E; Halliwell, Richard E; Fields, Paul J; Louw, Marta Lanza; Ball, Geoff; Louw, Jakobus; Pinckney, Rhonda

    2014-10-15

    Advocate(®) (2.5% moxidectin+10% imidacloprid) (Bayer HealthCare, Leverkusen, Germany) is a multiparasiticidal spot-on authorized for treating canine demodicosis in many countries. This blinded, randomized three-phase clinical trial compared its efficacy employing different dosing regimens with that of ivermectin. In the blinded first phase, 58 dogs suffering from generalized demodicosis were randomly assigned to one of four groups and treated with monthly, biweekly or weekly applications of Advocate(®), or with oral ivermectin (IVR) at 500 μg/kg daily. Dogs were evaluated clinically and multiple skin scrapings undertaken every 4 weeks until parasitological cure was achieved (defined as two consecutive series of deep skin scrapings at monthly intervals negative for all life forms). Forty dogs completed the 16-week initial blinded phase, with 5 cases achieving parasitological cure. Five dogs were deemed treatment failures and subsequently treated with ivermectin. The treatment protocol was then changed for the remaining 35 dogs and this cross-over phase (Phase 2) was maintained for a further 8 weeks with an additional 9 dogs achieving parasitological cure. Thereafter, all remaining animals were treated with IVR until cured (Phase 3). Overall, 26 dogs achieved parasitological cure during the clinical investigation. Of these, 23 remained disease-free for at least 12 months while two were lost to follow up and one died of unrelated causes. A total of 32 (55.2%) dogs were withdrawn at various stages of the investigation including the 5 dogs that were judged treatment failures. Other reasons for withdrawal included: non-compliance, lost to follow-up, ivermectin toxicity or reasons unrelated to the investigation. No adverse effects were attributable to the use of Advocate(®). Parasiticidal efficacy was assessed by changes in mite counts (live adult, juvenile and egg) and skin lesion extent & severity scores. Statistical significance was assessed using ANCOVA with

  4. Long term strategy for electricity generation in Peninsular Malaysia – Analysis of cost and carbon footprint using MESSAGE

    International Nuclear Information System (INIS)

    Fairuz, S.M.C.; Sulaiman, M.Y.; Lim, C.H.; Mat, S.; Ali, B.; Saadatian, O.; Ruslan, M.H.; Salleh, E.; Sopian, K.

    2013-01-01

    Malaysia envisages becoming a developed nation by 2020. To sustain industrial expansion and attract investments Malaysia must introduce new energy strategies. These strategies should also moderate carbon footprint. The new energy strategies introduced by the government are (i) installation of nuclear power plant by 2021, (ii) import of Sarawak hydropower from 2015 and (iii) enhancement of use of renewable energy from 2015. In this paper we analyze the cost and resulting carbon footprint of energy expansion for 12 energy scenes (inclusive of new strategies) to produce electricity for Peninsular Malaysia for the period 2009–2030. We use a computer model MESSAGE to provide optimization. The best strategy is for the following accumulated percentage of energy resource in the fuel mix: 49.3% (natural gas), 28.4% (coal), 4.06% (nuclear), 2.98% (hydropower), 4.45% (renewable), 10.82% (import hydropower). The minimum cost of expanding this strategy from 2009 until 2030 is USD6.090B. The CO 2 emission index of this strategy is 0.329 t/MWh. The accumulated carbon dioxide emission for this period is 1825.96 Mton CO 2 eq. -- Highlights: •We analyzed the cost of energy expansion and resulting carbon emission using software MESSAGE. •We studied the energy situation for the next 20 years beginning 2009 for Peninsular Malaysia. •We maintained the present energy resources of natural gas, coal and internal hydropower. •We included nuclear, hydropower import and renewable energy as new strategies

  5. 7 CFR 1421.11 - Spot checks.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Spot checks. 1421.11 Section 1421.11 Agriculture... ASSISTANCE LOANS AND LOAN DEFICIENCY PAYMENTS FOR 2008 THROUGH 2012 General § 1421.11 Spot checks. (a) CCC... CCC access to the farm and storage facility as necessary to conduct collateral inspections, or “spot...

  6. 21 CFR 886.1435 - Maxwell spot.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Maxwell spot. 886.1435 Section 886.1435 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1435 Maxwell spot. (a) Identification. A Maxwell spot is an AC...

  7. Independent power and cogeneration in Ontario's new competitive electricity market

    International Nuclear Information System (INIS)

    Barnstable, A.G.

    1999-01-01

    The factors influencing the initial market pricing in the early years of Ontario's new electricity market were discussed with particular insight on the potential for near term development of independent power and cogeneration. The major factors influencing prices include: (1) no increase in retail prices, (2) financial restructuring of Ontario Hydro, (3) the Market Power Mitigation Agreement, (4) tighter power plant emissions standards, and (5) an electricity supply and demand balance. Generation competition is not expected to influence market pricing in the early years of the new electricity market. Prices will instead reflect the restructuring decisions of the Ontario government. The decision to have Ontario Power Generation Inc. (OPGI) as a single generator for Ontario Hydro's generation assets will ensure that average spot market pricing in the early market years will be close to a 3.8 c/kWh revenue cap

  8. Spot på samtalen:

    DEFF Research Database (Denmark)

    Danneris, Sophie; Jensen, Tanja Dall; Caswell, Dorte

    Spot på samtalen sætter fokus på det, der konkret foregår i samtaler mellem borgere og de beskæftigelsesfaglige medarbejdere i jobcentrene. Da de udsatte grupper i mange tilfælde er langt fra arbejdsmarkedet, er interessen rettet mod, hvilke forhold i kontakten med beskæftigelsessystemet, der...... har betydning hvilke indsatser ledige modtager, men også hvordan de modtager dem. Her rettes blikket mod den centrale del af den beskæftigelsespolitiske indsats som samtalerne udgør. I Spot på samtalen er blikket rettet mod de dynamikker, mønstre og mekanismer, der kommer i spil i samtalerne i...

  9. Managing Rocky Mountain spotted fever.

    Science.gov (United States)

    Minniear, Timothy D; Buckingham, Steven C

    2009-11-01

    Rocky Mountain spotted fever is caused by the tick-borne bacterium Rickettsia rickettsii. Symptoms range from moderate illness to severe illness, including cardiovascular compromise, coma and death. The disease is prevalent in most of the USA, especially during warmer months. The trademark presentation is fever and rash with a history of tick bite, although tick exposure is unappreciated in over a third of cases. Other signature symptoms include headache and abdominal pain. The antibiotic therapy of choice for R. rickettsii infection is doxycycline. Preventive measures for Rocky Mountain spotted fever and other tick-borne diseases include: wearing long-sleeved, light colored clothing; checking for tick attachment and removing attached ticks promptly; applying topical insect repellent; and treating clothing with permethrin.

  10. 2500 km on solar-electric bike: let’s congratulate them by giving a donation to the Long-Term Collections

    CERN Multimedia

    Staff Association

    2013-01-01

    On 15th July, the adventure on “solar-electric bike” to promote solar and eco-mobility of our colleagues, Céline and Jean had to be interrupted in Odessa, Ukraine, for health reasons. In about four weeks, they already had crossed eight countries: Switzerland, France, Italy, Slovenia, Hungary, Romania, Moldavia and Ukraine. On their request, you can show your solidarity by subscribing to a humanitarian action in which you commit yourself to give a minimum of 30 CHF and a maximum of 80 CHF (10 CHF for each crossed country) to the Long-Term Collections (for further information on the Long-Term Collections, see their website: http://cern.ch/staffassoc/CLT/). Participate to this action by registering yourself on the following website: https://cern.ch/staff-association/content/soutien-celine-jean. You will then receive a payment slip that will allow you to pay the amount of your choice into the account of the Long-Term Collections. We congratulate our colleagues and champions, C&a...

  11. 2500 km on solar-electric bike: let’s congratulate them by giving a donation to the Long-Term Collections

    CERN Multimedia

    Staff Association

    2013-01-01

    On 15th July, the adventure on “solar-electric bike” to promote solar and eco-mobility of our colleagues, Céline and Jean had to be interrupted in Odessa, Ukraine, for health reasons. In about four weeks, they already had crossed eight countries: Switzerland, France, Italy, Slovenia, Hungary, Romania, Moldavia and Ukraine. On their request, you can show your solidarity by subscribing to a humanitarian action in which you commit yourself to give a minimum of 30 CHF and a maximum of 80 CHF (10 CHF for each crossed country) to the Long-Term Collections (for further information on the Long-Term Collections, see their website: http://cern.ch/staffassoc/CLT/). Participate to this action by registering yourself on the following website: https://cern.ch/staff-association/content/soutien-celine-jean. You will then receive a payment slip that will allow you to pay the amount of your choice into the account of the Long-Term Collections. We congratulate our colleagues and champions,...

  12. Transition Heat Transfer Modeling Based on the Characteristics of Turbulent Spots

    Science.gov (United States)

    Simon, Fred; Boyle, Robert

    1998-01-01

    While turbulence models are being developed which show promise for simulating the transition region on a turbine blade or vane, it is believed that the best approach with the greatest potential for practical use is the use of models which incorporate the physics of turbulent spots present in the transition region. This type of modeling results in the prediction of transition region intermittency which when incorporated in turbulence models give a good to excellent prediction of the transition region heat transfer. Some models are presented which show how turbulent spot characteristics and behavior can be employed to predict the effect of pressure gradient and Mach number on the transition region. The models predict the spot formation rate which is needed, in addition to the transition onset location, in the Narasimha concentrated breakdown intermittency equation. A simplified approach is taken for modeling turbulent spot growth and interaction in the transition region which utilizes the turbulent spot variables governing transition length and spot generation rate. The models are expressed in terms of spot spreading angle, dimensionless spot velocity, dimensionless spot area, disturbance frequency and Mach number. The models are used in conjunction with a computer code to predict the effects of pressure gradient and Mach number on the transition region and compared with VKI experimental turbine data.

  13. Measurement of laser spot quality

    Science.gov (United States)

    Milster, T. D.; Treptau, J. P.

    1991-01-01

    Several ways of measuring spot quality are compared. We examine in detail various figures of merit such as full width at half maximum (FWHM), full width at 1/(e exp 2) maximum, Strehl ratio, and encircled energy. Our application is optical data storage, but results can be applied to other areas like space communications and high energy lasers. We found that the optimum figure of merit in many cases is Strehl ratio.

  14. Sweet Spots and Door Stops

    Science.gov (United States)

    Thompson, Michael; Tsui, Stella; Leung, Chi Fan

    2011-01-01

    A sweet spot is referred to in sport as the perfect place to strike a ball with a racquet or bat. It is the point of contact between bat and ball where maximum results can be produced with minimal effort from the hand of the player. Similar physics can be applied to the less inspiring examples of door stops; the perfect position of a door stop is…

  15. Glare Spot Phase Doppler Anemometry

    OpenAIRE

    Hespel, Camille; Ren, Kuan Fang; Gréhan, Gérard; Onofri, Fabrice

    2006-01-01

    International audience; The Phase Doppler anemometry has been developed to measure simultaneously the velocity and the size of droplets. The measurement of the refractive index is also necessary since it depends on the temperature and the composition of the particle and its measurement permits both to increase the quality of the diameter measurement and to obtain information on the temperature and/or the composition of the droplets. In this paper, we introduce a Glare Spot Phase Doppler Anemo...

  16. Long-term energy planning of Croatian power system using multi-objective optimization with focus on renewable energy and integration of electric vehicles

    International Nuclear Information System (INIS)

    Prebeg, Pero; Gasparovic, Goran; Krajacic, Goran; Duic, Neven

    2016-01-01

    Highlights: • Optimization of supply side long-term energy planning of large power system. • Integration of renewable sources and electrical vehicles in large power system. • Multi-level, multi-objective optimization for a design of energy system. • Historical river flow data analysis for modeling of aggregated hydropower potential. - Abstract: Due to the stochastic nature and variability of renewable energy sources (RES), it is necessary to integrate still expensive storage capacities into an energy system with a high share of RES and to model appropriate energy market. The study presented here considers all energy carriers, however, only the electricity carrier is modeled in detail, with notion taken for the heating demand that is covered but without proper modeling of storage. A proposed two-level approach with multi-objective optimization on the global level, was used to design a Croatian Energy System (CES), where electric vehicles (EVs) are integrated to serve as battery storage in Vehicle-to-Grid (V2G) mode, for a scenario between 2015 and 2050. In addition, case study includes nine aggregated hydro power plants, one for each river basin in Croatia. Also, case study includes solar and wind power plants modeled for six locations in Croatia: Osijek, Zagreb, Rijeka, Sibenik, Split and Dubrovnik. The resulting Pareto front suggests that with assumed future costs of fuels and technology certain level of conventional energy sources will have to remain in the energy system to take into the account unfavourable weather conditions and to cover heating demand, which also results in significantly lower load factors for those power plants. Also, variants with more RES share have lower total energy system load factor and significantly higher installed capacity.

  17. Justifications shape ethical blind spots.

    Science.gov (United States)

    Pittarello, Andrea; Leib, Margarita; Gordon-Hecker, Tom; Shalvi, Shaul

    2015-06-01

    To some extent, unethical behavior results from people's limited attention to ethical considerations, which results in an ethical blind spot. Here, we focus on the role of ambiguity in shaping people's ethical blind spots, which in turn lead to their ethical failures. We suggest that in ambiguous settings, individuals' attention shifts toward tempting information, which determines the magnitude of their lies. Employing a novel ambiguous-dice paradigm, we asked participants to report the outcome of the die roll appearing closest to the location of a previously presented fixation cross on a computer screen; this outcome would determine their pay. We varied the value of the die second closest to the fixation cross to be either higher (i.e., tempting) or lower (i.e., not tempting) than the die closest to the fixation cross. Results of two experiments revealed that in ambiguous settings, people's incorrect responses were self-serving. Tracking participants' eye movements demonstrated that people's ethical blind spots are shaped by increased attention toward tempting information. © The Author(s) 2015.

  18. A good long-term electricity storage. Biomethanisation by Power-to-Gas; Ein guter Langzeitstromspeicher. Biomethanisierung durch Power-to-Gas

    Energy Technology Data Exchange (ETDEWEB)

    Finck, Christian

    2013-10-15

    With the Power-to-Gas process, the Centre for Solar Energy and Hydrogen Research Baden-Wuerttemberg (ZSW) developed in cooperation with the Fraunhofer IWES, in 2009, a technique that would enable to store electricity from renewable energy plants (EEA) for a long term. The underlying Sabatier process is old, the inclusion of renewable energy to biomethanisation is new. The Power-to-Gas process uses electricity produced from wind turbines for the electrolysis of water to produce hydrogen and oxygen. In a subsequent synthesis with the emitted CO{sub 2} from the biogas plants biomethane is produced with an energy efficiency of >65% kWh{sub SNG}/kWh{sub el}. [German] Mit dem Power-to-Gas-Verfahren entwickelte das Zentrum fuer Sonnenenergie und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), in Zusammenarbeit mit der Fraunhofer IWES, im Jahr 2009 eine Technik, die es ermoeglichen wuerde, Strom aus Erneuerbaren Energieanlagen (EEA) langfristig zu speichern. Der zugrunde liegende Sabatierprozess ist alt, die Einbeziehung der EE zur Biomethanisierung ist neu. Das Power-to-Gas-Verfahren nutzt den produzierten Strom aus Windenergieanlagen, um das Wasser elektrolytisch in Wasserstoff und Sauerstoff zu spalten. In einer anschliessenden Synthese mit dem emittierten CO{sub 2} aus den Biogasanlagen wird Biomethan, mit einem energetischen Wirkungsgrad >65% kWh{sub SNG}/kWh{sub el}, produziert.

  19. Resistance Spot Welding of dissimilar Steels

    Directory of Open Access Journals (Sweden)

    Ladislav Kolařík

    2012-01-01

    Full Text Available This paper presents an analysis of the properties of resistance spot welds between low carbon steel and austenitic CrNi stainless steel. The thickness of the welded dissimilar materials was 2 mm. A DeltaSpot welding gun with a process tape was used for welding the dissimilar steels. Resistance spot welds were produced with various welding parameters (welding currents ranging from 7 to 8 kA. Light microscopy, microhardness measurements across the welded joints, and EDX analysis were used to evaluate the quality of the resistance spot welds. The results confirm the applicability of DeltaSpot welding for this combination of materials.

  20. Electricity generation and microbial community in response to short-term changes in stack connection of self-stacked submersible microbial fuel cell powered by glycerol

    DEFF Research Database (Denmark)

    Zhao, Nannan; Angelidaki, Irini; Zhang, Yifeng

    2017-01-01

    community. In this study, a self-stacked submersible microbial fuel cell (SSMFC) powered by glycerol was tested to elucidate this important issue. In series connection, the maximum voltage output reached to 1.15 V, while maximum current density was 5.73 mA in parallel. In both connections, the maximum power......Stack connection (i.e., in series or parallel) of microbial fuel cell (MFC) is an efficient way to boost the power output for practical application. However, there is little information available on short-term changes in stack connection and its effect on the electricity generation and microbial...... density increased with the initial glycerol concentration. However, the glycerol degradation was even faster in parallel connection. When the SSMFC was shifted from series to parallel connection, the reactor reached to a stable power output without any lag phase. Meanwhile, the anodic microbial community...

  1. A possibilistic model to determine the cost of environmental quality in mid/short term planning of an electricity distribution system

    International Nuclear Information System (INIS)

    Schweickardt, Gustavo Alejandro; Gimenez Alvarez, Juan Manuel

    2012-01-01

    This work presents a Possibilistic Optimization Model to determine the Dynamic Environmental Quality Cost, applied on an Electricity Distribution System and measured as Network System Visual Impact. The Mid/Short Term Planning is the Regulatory Control Period. A multicriteria optimization approach is proposed, and for each criterion, non-stochastic uncertainties are recognized and represented by mean the introduction of Fuzzy Sets. In this way, a possibility in the occurrence of criteria variables values is established. In addition, as consequence of uncertainties of criteria preference ranking, a Model to obtain criteria Priority Vector is introduced. The Environmental Quality Cost determination is based in the relationship between the Investment Cost and an Impact Index of Network System Environmental Quality, proposed in this work. Finally, a simulation on a real system and the most important conclusions are presented.

  2. Coral bleaching and ocean ''hot spots''

    Energy Technology Data Exchange (ETDEWEB)

    Goreau, T.J. (Global Coral Reef Alliance, Chappaqua, NY (United States)); Hayes, R.L. (Howard Univ., Washington, DC (United States). College of Medicine)

    1994-05-01

    Global sea-surface temperature maps show that mass coral-reef bleaching episodes between 1983 and 1991 followed positive anomalies more than 1 deg C above long-term monthly averages (''hot spots'') during the preceding warm season. Irregular formation, movement, and disappearance of hot spots make their detailed long-term prediction impossible, but they can be tracked in real time from satellite data. Monitoring of ocean hot spots and of coral bleaching is needed if the Framework Convention of Climate Change is to meet its goal of protecting the most temperature sensitive ecosystems. 47 refs, 3 figs

  3. Spot formation of radiation particles by electrochemical etching

    International Nuclear Information System (INIS)

    Nozaki, Tetsuya

    1999-01-01

    An electrochemical etching (ECE) spot formation from the top of chemical etching (CE) spot was confirmed by a series of experiments. One of polycarbonate (Iupilon) could not make the spot, because ECE spot had grown up before the microscope confirming the CE spot. Clear CEC spots by α-ray and neutron were found on Harzlas and Baryotrak, both improvements of CR-39. Under the same etching conditions, the growth of ECE spot on Harzlas was more rapid than Baryotrak, but both spots were almost the same. All CE spot by α-ray produced the CEC spots, but a part of CE circle spot by neutron formed them. (S.Y.)

  4. A Permutation Importance-Based Feature Selection Method for Short-Term Electricity Load Forecasting Using Random Forest

    Directory of Open Access Journals (Sweden)

    Nantian Huang

    2016-09-01

    Full Text Available The prediction accuracy of short-term load forecast (STLF depends on prediction model choice and feature selection result. In this paper, a novel random forest (RF-based feature selection method for STLF is proposed. First, 243 related features were extracted from historical load data and the time information of prediction points to form the original feature set. Subsequently, the original feature set was used to train an RF as the original model. After the training process, the prediction error of the original model on the test set was recorded and the permutation importance (PI value of each feature was obtained. Then, an improved sequential backward search method was used to select the optimal forecasting feature subset based on the PI value of each feature. Finally, the optimal forecasting feature subset was used to train a new RF model as the final prediction model. Experiments showed that the prediction accuracy of RF trained by the optimal forecasting feature subset was higher than that of the original model and comparative models based on support vector regression and artificial neural network.

  5. NMDA receptor-mediated long term modulation of electrically evoked field potentials in the rat medial vestibular nuclei.

    Science.gov (United States)

    Capocchi, G; Della Torre, G; Grassi, S; Pettorossi, V E; Zampolini, M

    1992-01-01

    The effect of high frequency stimulation (HFS) of the primary vestibular afferents on field potentials recorded in the ipsilateral Medial Vestibular Nuclei (MVN) was studied. Our results show that potentiation and depression can be induced in different portions of MVN, which are distinguishable by their anatomical organization. HFS induces potentiation of the monosynaptic component in the ventral portion of the MVN, whereas it provokes depression of the polysynaptic component in the dorsal portion of the same nucleus. The induction of both potentiation and depression was blocked under AP5 perfusion, thus demonstrating that NMDA receptor activation mediates both phenomena. Furthermore, the finding that the field potentials were not modified during perfusion with DL-AP5, as previously reported, supports the hypothesis that NMDA receptors are not involved in the normal synaptic transmission from the primary vestibular afferent fibres, but are only activated following hyperstimulation of this afferent system. Our results suggest that the mechanisms of long term modification of synaptic efficacy observed in MVN may underlie the plasticity phenomena occurring in vestibular nuclei.

  6. Long-term recognition memory of individual conspecifics is associated with telencephalic expression of Egr-1 in the electric fish Apteronotus leptorhynchus.

    Science.gov (United States)

    Harvey-Girard, Erik; Tweedle, Jessica; Ironstone, Joel; Cuddy, Martin; Ellis, William; Maler, Leonard

    2010-07-15

    Primates and songbirds can learn to recognize individual conspecifics based on complex sensory cues; this requires a large, highly differentiated dorsal telencephalon. Here we show that the electric fish Apteronotus leptorhynchus can learn to recognize individual conspecifics based on a simple cue, the beat frequency of their summed sinusoidal electric organ discharges (EOD). Male fish produce transient communication signals (chirps) in response to mimic EODs. The chirp response habituates over repeated stimulus presentations within one experimental session, continues to habituate over successive daily sessions and is nearly extinguished after 5-7 days. Habituation of the chirp response was specific to the presented beat frequency. The conversion of short- to long-term habituation could be disrupted by cooling the head 30 minutes after the daily habituation trials. Consolidation of long-term memory in mammals is thought to involve induced expression of an immediate early gene, Egr-1. We cloned the Apteronotid homolog of the Egr-1 gene and found that chirp-evoking stimuli induced strong expression of its mRNA within the dorsal (Dd), central (DC), and lateral (DL) subdivisions of the dorsal telencephalon. Interestingly, the dorsolateral region is hypothesized to be homologous to the amniote hippocampal formation. We conclude that A. leptorhynchus can learn to identify individual conspecifics based on their EOD frequency and can remember these frequencies for several days. We hypothesize that this form of learning, as in primates and songbirds, requires a subset of dorsal telencephalic areas and involves a consolidation-like process that includes the expression of the transcription factor AptEgr-1.

  7. Effect of the small accessary laser spots on the harmonic emission stimulated by self-focusing of a 10-micrometer scale laser spot

    International Nuclear Information System (INIS)

    Lin Zunqi; Zhang Huihuang; He Xingfa

    1992-01-01

    A novel group of experiments has shown that single 10-micrometer-radius-scale laser spot is not able to produce the 90 deg side emitted three half harmonic efficiently in a preformed laser plasmas. However, with the help of one or two accessory laser spots with the size similar to the main one, the side emitted three half can easily built up when some position and angle conditions for the accessory spots are fulfilled. The origin of these phenomena have been analyzed in terms of the two plasmon decay theory and dynamic self-focusing model

  8. Essays on competition in electricity markets

    Science.gov (United States)

    Bustos Salvagno, Ricardo Javier

    The first chapter shows how technology decisions affect entry in commodity markets with oligopolistic competition, like the electricity market. I demonstrate an entry deterrence effect that works through cost uncertainty. Technology's cost uncertainty affects spot market expected profits through forward market trades. Therefore, incentives to engage in forward trading shape firms' decisions on production technologies. I show that high-cost but low-risk technologies are adopted by risk-averse incumbents to deter entry. Strategic technology adoption can end in a equilibrium where high-cost technologies prevail over low-cost but riskier ones. In the case of incumbents who are less risk-averse than entrants, entry deterrence is achieved by choosing riskier technologies. The main results do not depend on who chooses their technology first. Chapter two examines the Chilean experience on auctions for long-term supply contracts in electricity markets from 2006 to 2011. Using a divisible-good auction model, I provide a theoretical framework that explains bidding behavior in terms of expected spot prices and contracting positions. The model is extended to include potential strategic behavior on contracting decisions. Empirical estimations confirm the main determinants of bidding behavior and show heterogeneity in the marginal cost of over-contracting depending on size and incumbency. Chapter three analyzes the lag in capacity expansion in the Chilean electricity market from 2000 to 2004. Regarded as a result of regulatory uncertainty, the role of delays in the construction of a large hydro-power plant has been overlooked by the literature. We argue that those delays postponed projected investment and gave small windows of opportunity that only incumbents could take advantage of. We are able to retrace the history of investments through real-time information from the regulator's reports and a simple model enables us to explain the effect of those delays on suggested and under

  9. Computational prediction of protein hot spot residues.

    Science.gov (United States)

    Morrow, John Kenneth; Zhang, Shuxing

    2012-01-01

    Most biological processes involve multiple proteins interacting with each other. It has been recently discovered that certain residues in these protein-protein interactions, which are called hot spots, contribute more significantly to binding affinity than others. Hot spot residues have unique and diverse energetic properties that make them challenging yet important targets in the modulation of protein-protein complexes. Design of therapeutic agents that interact with hot spot residues has proven to be a valid methodology in disrupting unwanted protein-protein interactions. Using biological methods to determine which residues are hot spots can be costly and time consuming. Recent advances in computational approaches to predict hot spots have incorporated a myriad of features, and have shown increasing predictive successes. Here we review the state of knowledge around protein-protein interactions, hot spots, and give an overview of multiple in silico prediction techniques of hot spot residues.

  10. Computational Prediction of Hot Spot Residues

    Science.gov (United States)

    Morrow, John Kenneth; Zhang, Shuxing

    2013-01-01

    Most biological processes involve multiple proteins interacting with each other. It has been recently discovered that certain residues in these protein-protein interactions, which are called hot spots, contribute more significantly to binding affinity than others. Hot spot residues have unique and diverse energetic properties that make them challenging yet important targets in the modulation of protein-protein complexes. Design of therapeutic agents that interact with hot spot residues has proven to be a valid methodology in disrupting unwanted protein-protein interactions. Using biological methods to determine which residues are hot spots can be costly and time consuming. Recent advances in computational approaches to predict hot spots have incorporated a myriad of features, and have shown increasing predictive successes. Here we review the state of knowledge around protein-protein interactions, hot spots, and give an overview of multiple in silico prediction techniques of hot spot residues. PMID:22316154

  11. Double electrical layer in the cathode spot / Двойной электрический слой в катодном пятне / Dvostruki električni sloj u katodnom spotu

    Directory of Open Access Journals (Sweden)

    Leonid I. Gretchikhin

    2016-07-01

    Full Text Available The paper describes a new phenomenon of the generation of the double electrical layer above the cathode spot surface. The neutralization of this layer leads to the reverse current of free electrons, generated due to negative ions ionization. The negatively charged flame of the cathode spot periodically ignites and attenuates, so the duration of the cathode spot existence is defined by this oscillating process. The reverse motion of the cathode spot in the longitudinal magnetic field takes place owing to the generation of the reverse high-power neutralization current of the double electrical layer by the electrons appearing during the negative ions ionization in the cathode flame. / Установлено новое явление, заключающееся в образовании над поверхностью катодного пятна двойного электрического слоя, нейтрализация которого приводит к обратному току свободными электронами, образующихся вследствие ионизации отрицательных ионов. Отрицательно заряженный факел из катодного пятна периодически пропадает и возникает. Этот колебательный процесс определяет длительность существования катодного пятна. Обратное движение катодного пятна в продольном магнитном поле происходит вследствие образования обратного мощного тока нейтрализации двойного электрического слоя электронами, возникающих при ионизации отрицательных ионов в катодном факеле. / U radu se opisuje novootkrivena pojava stvaranja dvostrukog

  12. Spot urine sodium excretion as prognostic marker in acutely decompensated heart failure: the spironolactone effect.

    Science.gov (United States)

    Ferreira, João Pedro; Girerd, Nicolas; Medeiros, Pedro Bettencourt; Santos, Mário; Carvalho, Henrique Cyrne; Bettencourt, Paulo; Kénizou, David; Butler, Javed; Zannad, Faiez; Rossignol, Patrick

    2016-06-01

    Loop diuretic resistance characterized by inefficient sodium excretion complicates many patients with acutely decompensated heart failure (ADHF). Mineralocorticoid receptor antagonists (MRAs) in natriuretic doses may improve spot urine sodium excretion and outcomes. Our primary aim was to assess the association of high-dose spironolactone with short-term spot urine sodium excretion, and our secondary aim was to determine if this higher short-term spot urine sodium excretion is associated with reduction in the composite clinical outcome (of cardiovascular mortality and/or ADHF hospitalization) event rate at 180 days. Single-centre, non-randomized, open-label study enrolling 100 patients with ADHF. Patients were treated with standard ADHF therapy alone (n = 50) or oral spironolactone 100 mg/day plus standard ADHF therapy (n = 50). Spot urine samples were collected at day 1 and day 3 of hospitalization. Spironolactone group had significantly higher spot urine sodium levels compared to standard care group at day 3 (84.13 ± 28.71 mmol/L vs 70.74 ± 34.43 mmol/L, p = 0.04). The proportion of patients with spot urinary sodium spot urinary sodium and urinary sodium/potassium ratio of >2 at day 3 (both, p spot urine sodium levels were associated with a lower event rate [HR for urinary sodium >100 mmol/L = 0.16 (0.06-0.42), p Spot urinary sodium levels >60 mmol/L and urinary sodium/potassium ratio >2 measured at day 3 of hospitalization for ADHF are associated with improved mid-term outcomes. Spironolactone is associated with increased spot urinary sodium and sodium/potassium ratio >2.

  13. Ultrasonic diagnosis of spot welding in thin plates

    International Nuclear Information System (INIS)

    Kim, No You; Hong, Min Sung

    2005-01-01

    Spot welding widely used in automotive and aerospace industries has made it possible to produce more precise and smaller electric part by robotization and systemization of welding process. The quality of welding depends upon the size of nugget between the overlapped steel plates. Recently, the thickness of the steel plates becomes much thinner and hence, it introduces the smaller size of nugget. Therefore, it is necessary to develop the criterion to evaluate the quality of weld in order to obtain the optimal welding conditions for the better performance. In this paper, a thin steel plates, 0.1 mm through 0.3 mm thickness, have been spot-welded at different welding conditions and the nugget sizes are examined by defocused scanning microscopy. The relationships between nugget sizes and weldability have been investigated experimentally. The result of ultrasonic technique shows the good agreement with that of the tensile test.

  14. Spot Markets Indices as Benchmarks of Formation of Future Price Trends in the Power Exchanges of Eastern Europe

    Directory of Open Access Journals (Sweden)

    Polikevych Nataliya I.

    2016-01-01

    Full Text Available The article is concerned with a theoretical generalization of the use of indices for electric power at the European spot exchanges and elaborating proposals on establishment of a similar spot index for the Ukrainian power exchange. 16 indices that are published daily by the power exchanges BSP Regional Energy Exchange, Power Exchange Central Europe, Polish Power Exchange and Opcom have been analyzed. It has been indicated that these indices are used for electricity price forecasting and monitoring the situation in the power market. The article examines the way spot indices are calculated by power exchanges, based on the value of the arithmetic average of market prices «day ahead». Imperfection of such way of calculation for price index values has been substantiated. The key characteristics of the future price index for Ukrainian spot market as benchmarks within the introduction of futures contracts for electricity have been identified.

  15. Quantitation of 5-Methyltetrahydrofolic Acid in Dried Blood Spots and Dried Plasma Spots by Stable Isotope Dilution Assays.

    Directory of Open Access Journals (Sweden)

    Markus Kopp

    Full Text Available Because of minimal data available on folate analysis in dried matrix spots (DMSs, we combined the advantages of stable isotope dilution assays followed by LC-MS/MS analysis with DMS sampling to develop a reliable method for the quantitation of plasma 5-methyltetrahydrofolic acid in dried blood spots (DBSs and dried plasma spots (DPSs as well as for the quantitation of whole blood 5-methyltetrahydrofolic acid in DBSs. We focused on two diagnostically conclusive parameters exhibited by the plasma and whole blood 5-methyltetrahydrofolic acid levels that reflect both temporary and long-term folate status. The method is performed using the [2H4]-labeled isotopologue of the vitamin as the internal standard, and three steps are required for the extraction procedure. Elution of the punched out matrix spots was performed using stabilization buffer including Triton X-100 in a standardized ultrasonication treatment followed by enzymatic digestion (whole blood only and solid-phase extraction with SAX cartridges. This method is sensitive enough to quantify 27 nmol/L whole blood 5-methyltetrahydrofolic acid in DBSs and 6.3 and 4.4 nmol/L plasma 5-methyltetrahydrofolic acid in DBSs and DPSs, respectively. The unprecedented accurate quantification of plasma 5-methyltetrahydrofolic acid in DBSs was achieved by thermal treatment prior to ultrasonication, inhibiting plasma conjugase activity. Mass screenings are more feasible and easier to facilitate for this method in terms of sample collection and storage compared with conventional clinical sampling for the assessment of folate status.

  16. Electricity prices and power derivatives: An affine jump diffusion approach with seasonal volatility and prices

    International Nuclear Information System (INIS)

    Nomikos, Nikos; Soldatos, Orestes; Tamvakis, Michael

    2005-01-01

    Deregulation and reforms in the electricity markets over the recent years have led to increasing volatility of electricity prices since prices in the market are now determined by the fundamental rules of supply and demand. The existence of price risk in the market leads to the increasing necessity of hedging using derivatives and the subsequent development of models to price and hedge electricity derivatives. However the non-storable nature of the market implies that ''traditional'' approaches for the pricing and hedging of commodity derivatives based on the theory of storage are not applicable to electricity markets. In this paper we propose a two-factor jump diffusion model with seasonal components in order to capture the systematic pattern in the forward curve and the volatility term structure. Our model is then calibrated for the spot and the financial contracts in the Nord Pool Exchange using Kalman filter techniques. The proposed model has several advantages. First it enables to select the risk neutral measure that best fits the term structure hence capturing the most significant distributional characteristics of both spot and forwards. Second, it explains the seasonal risk premium, and finally it provides a fit for the Volatility Term Structure. The resulting model is very promising, providing a very useful Financial Engineering tool to market participants for Risk Hedging and Derivatives Pricing in the highly volatile Power Markets. (Author)

  17. The evolution of electricity prices in an uncertain world. Contracting and managing the price risk

    International Nuclear Information System (INIS)

    Vassilopoulos, Ph.; Rapin, D.

    2004-01-01

    With the liberalization of the electricity market, the large industrial consumers saw their electric bill changing nature. Before, this price reflected a long term negotiation with the monopoly, now it is established in a free way via wholesale markets. This evolution marks a transfer of the management of price risk from the producer towards the consumer. This change is not in itself a problem if the hedging instruments are adapted. We note a contamination of the price of the derivative products by the spot while at the same time the traditional relation between cash and term is not always valid for electricity because of its non storability. When well even the price of the derivative products would be formed in an autonomous way, it poses a second problem: that of their indexing on price references like Platt's whose result is assimilated more to a survey of large producers than a true confrontation of supply and demand. This article proposes to examine this change of nature and behaviour of electricity prices. After having explained the intrinsically volatile characteristic of spot prices, we will recall that the products in the long term are not always optimal solutions to decrease this price risk. Lastly, we will highlight a solution of skirting at the risks mentioned above: contracting between producers and consumers. (authors)

  18. Electric deregulation in Canada

    International Nuclear Information System (INIS)

    Way, R.W.

    1996-01-01

    An outline of the electric power deregulation activities across Canada, particularly in Alberta, British Columbia, and Ontario, was presented. A central element of the restructuring is creation of a power pool which acts as an open spot market, and a transmission administrator that provides access to the generators, distribution companies, importers and exporters. Load forecasts, average daily load profile and hourly pool prices for TransAlta Corporation were presented as an example. 22 figs

  19. Comparing the spot prices from Powernext and EEX

    International Nuclear Information System (INIS)

    Galli, A.; Armstrong, M.

    2005-01-01

    Powernext SA is a Multilateral Trading Facility in charge of managing the French power exchange through an optional and anonymous organised exchange. Powernext started operating on 27 November 2001. Although the German exchange, EEX, has been functioning for much longer, the two have many common points. Both use the same system for fixing the day-ahead spot price, the one developed by NordPool. In contrast to Omel in Spain, power producers in France and Germany are not obliged to sell through the exchange. In addition, the cross-border transmission lines that physically link the French and German grids, not only make the electricity supply more reliable they also allow cross-border commercial transactions which should homogenize prices in both countries. So after nearly a year of operation it is interesting to compare the spot prices on the two exchanges in order to have a better understanding of the statistical properties of the prices in the two markets and the relationship between them. This information will be used when modelling the structure of the day-ahead spot prices. The data used to carry out the study consists of the (hourly) spot prices for electricity from Powernext and EEX, for the period from 1 January 2002 to 2 December 2002. Data from the first five weeks of trading were not included because traded volumes were relatively low initially and so these data are not necessarily representative. This report is divided into four sections. The first one presents the basic statistics, starting with the histograms of all the 8064 spot prices in the 336 days, for both exchanges. In time series data, it is usual to find three types of seasonality: daily, weekly and annual. As the available data cover less than one calendar year, it is too early to attempt to study annual trends. So we limit ourselves to studying daily and weekly fluctuations. Plotting the hourly average prices for each day of the week shows some interesting differences between Powernext and

  20. Watermarking spot colors in packaging

    Science.gov (United States)

    Reed, Alastair; Filler, TomáÅ.¡; Falkenstern, Kristyn; Bai, Yang

    2015-03-01

    In January 2014, Digimarc announced Digimarc® Barcode for the packaging industry to improve the check-out efficiency and customer experience for retailers. Digimarc Barcode is a machine readable code that carries the same information as a traditional Universal Product Code (UPC) and is introduced by adding a robust digital watermark to the package design. It is imperceptible to the human eye but can be read by a modern barcode scanner at the Point of Sale (POS) station. Compared to a traditional linear barcode, Digimarc Barcode covers the whole package with minimal impact on the graphic design. This significantly improves the Items per Minute (IPM) metric, which retailers use to track the checkout efficiency since it closely relates to their profitability. Increasing IPM by a few percent could lead to potential savings of millions of dollars for retailers, giving them a strong incentive to add the Digimarc Barcode to their packages. Testing performed by Digimarc showed increases in IPM of at least 33% using the Digimarc Barcode, compared to using a traditional barcode. A method of watermarking print ready image data used in the commercial packaging industry is described. A significant proportion of packages are printed using spot colors, therefore spot colors needs to be supported by an embedder for Digimarc Barcode. Digimarc Barcode supports the PANTONE spot color system, which is commonly used in the packaging industry. The Digimarc Barcode embedder allows a user to insert the UPC code in an image while minimizing perceptibility to the Human Visual System (HVS). The Digimarc Barcode is inserted in the printing ink domain, using an Adobe Photoshop plug-in as the last step before printing. Since Photoshop is an industry standard widely used by pre-press shops in the packaging industry, a Digimarc Barcode can be easily inserted and proofed.

  1. Collaboration spotting for dental science.

    Science.gov (United States)

    Leonardi, E; Agocs, A; Fragkiskos, S; Kasfikis, N; Le Goff, J M; Cristalli, M P; Luzzi, V; Polimeni, A

    2014-10-06

    The goal of the Collaboration Spotting project is to create an automatic system to collect information about publications and patents related to a given technology, to identify the key players involved, and to highlight collaborations and related technologies. The collected information can be visualized in a web browser as interactive graphical maps showing in an intuitive way the players and their collaborations (Sociogram) and the relations among the technologies (Technogram). We propose to use the system to study technologies related to Dental Science. In order to create a Sociogram, we create a logical filter based on a set of keywords related to the technology under study. This filter is used to extract a list of publications from the Web of Science™ database. The list is validated by an expert in the technology and sent to CERN where it is inserted in the Collaboration Spotting database. Here, an automatic software system uses the data to generate the final maps. We studied a set of recent technologies related to bone regeneration procedures of oro--maxillo--facial critical size defects, namely the use of Porous HydroxyApatite (HA) as a bone substitute alone (bone graft) or as a tridimensional support (scaffold) for insemination and differentiation ex--vivo of Mesenchymal Stem Cells. We produced the Sociograms for these technologies and the resulting maps are now accessible on--line. The Collaboration Spotting system allows the automatic creation of interactive maps to show the current and historical state of research on a specific technology. These maps are an ideal tool both for researchers who want to assess the state--of--the--art in a given technology, and for research organizations who want to evaluate their contribution to the technological development in a given field. We demonstrated that the system can be used for Dental Science and produced the maps for an initial set of technologies in this field. We now plan to enlarge the set of mapped

  2. Collaboration Spotting for oral medicine.

    Science.gov (United States)

    Leonardi, E; Agocs, A; Fragkiskos, S; Kasfikis, N; Le Goff, J M; Cristalli, M P; Luzzi, V; Polimeni, A

    2014-09-01

    The goal of the Collaboration Spotting project is to create an automatic system to collect information about publications and patents related to a given technology, to identify the key players involved, and to highlight collaborations and related technologies. The collected information can be visualized in a web browser as interactive graphical maps showing in an intuitive way the players and their collaborations (Sociogram) and the relations among the technologies (Technogram). We propose to use the system to study technologies related to oral medicine. In order to create a sociogram, we create a logical filter based on a set of keywords related to the technology under study. This filter is used to extract a list of publications from the Web of Science™ database. The list is validated by an expert in the technology and sent to CERN where it is inserted in the Collaboration Spotting database. Here, an automatic software system uses the data to generate the final maps. We studied a set of recent technologies related to bone regeneration procedures of oro-maxillo-facial critical size defects, namely the use of porous hydroxyapatite (HA) as a bone substitute alone (bone graft) or as a tridimensional support (scaffold) for insemination and differentiation ex vivo of mesenchymal stem cells. We produced the sociograms for these technologies and the resulting maps are now accessible on-line. The Collaboration Spotting system allows the automatic creation of interactive maps to show the current and historical state of research on a specific technology. These maps are an ideal tool both for researchers who want to assess the state-of-the-art in a given technology, and for research organizations who want to evaluate their contribution to the technological development in a given field. We demonstrated that the system can be used in oral medicine as is produced the maps for an initial set of technologies in this field. We now plan to enlarge the set of mapped technologies in

  3. Short-term action potential memory and electrical restitution: A cellular computational study on the stability of cardiac repolarization under dynamic pacing.

    Directory of Open Access Journals (Sweden)

    Massimiliano Zaniboni

    Full Text Available Electrical restitution (ER is a major determinant of repolarization stability and, under fast pacing rate, it reveals memory properties of the cardiac action potential (AP, whose dynamics have never been fully elucidated, nor their ionic mechanisms. Previous studies have looked at ER mainly in terms of changes in AP duration (APD when the preceding diastolic interval (DI changes and described dynamic conditions where this relationship shows hysteresis which, in turn, has been proposed as a marker of short-term AP memory and repolarization stability. By means of numerical simulations of a non-propagated human ventricular AP, we show here that measuring ER as APD versus the preceding cycle length (CL provides additional information on repolarization dynamics which is not contained in the companion formulation. We focus particularly on fast pacing rate conditions with a beat-to-beat variable CL, where memory properties emerge from APD vs CL and not from APD vs DI and should thus be stored in APD and not in DI. We provide an ion-currents characterization of such conditions under periodic and random CL variability, and show that the memory stored in APD plays a stabilizing role on AP repolarization under pacing rate perturbations. The gating kinetics of L-type calcium current seems to be the main determinant of this safety mechanism. We also show that, at fast pacing rate and under otherwise identical pacing conditions, a periodically beat-to-beat changing CL is more effective than a random one in stabilizing repolarization. In summary, we propose a novel view of short-term AP memory, differentially stored between systole and diastole, which opens a number of methodological and theoretical implications for the understanding of arrhythmia development.

  4. Energy is not Coffee. An assessment of blind spots on energy spot-markets

    International Nuclear Information System (INIS)

    Jepma, C.J.; Spijker, E.; Van der Gaast, W.; De Jong, F.; Overmars, P.

    2006-01-01

    This study was to be the first in a series of studies on the title subject. It specifically focuses on the differences and similarities with a number of other spot-markets and aims to frame the energy spot markets and their potential development into a broader perspective. Main conclusion is that energy spot-markets differ from several other physical and non-physical spot-markets in many ways. This implies that 'perfect' energy spot-markets may inherently be (much) less perfect than other spot-markets that have approximated the stage of theoretical perfection

  5. Effect of low frequency electrical stimulation on seizure-induced short- and long-term impairments in learning and memory in rats.

    Science.gov (United States)

    Esmaeilpour, Khadijeh; Sheibani, Vahid; Shabani, Mohammad; Mirnajafi-Zadeh, Javad

    2017-01-01

    Kindled seizures can impair learning and memory. In the present study the effect of low-frequency electrical stimulation (LFS) on kindled seizure-induced impairment in spatial learning and memory was investigated and followed up to one month. Animals were kindled by electrical stimulation of hippocampal CA1 area in a semi-rapid manner (12 stimulations per day). One group of animals received four trials of LFS at 30s, 6h, 24h, and 30h following the last kindling stimulation. Each LFS trial was consisted of 4 packages at 5min intervals. Each package contained 200 monophasic square wave pulses of 0.1ms duration at 1Hz. The Open field, Morris water maze, and novel object recognition tests were done 48h, 1week, 2weeks, and one month after the last kindling stimulation respectively. Kindled animals showed a significant impairment in learning and memory compared to control rats. LFS decreased the kindling-induced learning and memory impairments at 24h and one week following its application, but not at 2week or 1month after kindling. In the group of animals that received the same 4 trials of LFS again one week following the last kindling stimulation, the improving effect of LFS was observed even after one month. Obtained results showed that application of LFS in fully kindled animals has a long-term improving effect on spatial learning and memory. This effect can remain for a long duration (one month in this study) by increasing the number of applied LFS. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Long-term consequences of selected competitive strategies during deregulation of the United States electric utility industry: System dynamics modeling and simulation

    Science.gov (United States)

    Khalil, Yehia Fahim

    Currently, U.S. investor-owned utilities (IOUs) are facing major reforms in their business environment similar to the airlines, telecommunications, banking, and insurance industries. As a result, IOUs are gearing up for fierce price competition in the power generation sector, and are vying for electricity customers outside their franchised service territories. Energy experts predict that some IOUs may suffer fatal financial setbacks (especially those with nuclear plants), while others may thrive under competition. Both federal and state energy regulators anticipate that it may take from five to ten years to complete the transition of America's electric utility industry from a regulated monopoly to a market-driven business. During this transition, utility executives are pursuing aggressive business strategies to confront the upcoming price wars. The most compelling strategies focus on cutting operation and maintenance (O&M) costs of power production, downsizing the work force, and signing bilateral energy agreements with large price-sensitive customers to retain their business. This research assesses the impact of the three pivotal strategies on financial performance of utilities during transition to open market competition. A system-dynamics-based management flight simulator has been developed to predict the dynamic performance of a hypothetical IOU organization preparing for market competition. The simulation results show that while the three business strategies lead to short-lived gains, they also produce unanticipated long-term consequences that adversely impact the organization's operating revenues. Generally, the designed flight simulator serves as a learning laboratory which allows management to test new strategies before implementation.

  7. Birth-jump processes and application to forest fire spotting.

    Science.gov (United States)

    Hillen, T; Greese, B; Martin, J; de Vries, G

    2015-01-01

    Birth-jump models are designed to describe population models for which growth and spatial spread cannot be decoupled. A birth-jump model is a nonlinear integro-differential equation. We present two different derivations of this equation, one based on a random walk approach and the other based on a two-compartmental reaction-diffusion model. In the case that the redistribution kernels are highly concentrated, we show that the integro-differential equation can be approximated by a reaction-diffusion equation, in which the proliferation rate contributes to both the diffusion term and the reaction term. We completely solve the corresponding critical domain size problem and the minimal wave speed problem. Birth-jump models can be applied in many areas in mathematical biology. We highlight an application of our results in the context of forest fire spread through spotting. We show that spotting increases the invasion speed of a forest fire front.

  8. Ion distribution in the hot spot of an inertial confinement fusion plasma

    Science.gov (United States)

    Tang, Xianzhu; Guo, Zehua; Berk, Herb

    2012-10-01

    Maximizing the fusion gain of inertial confinement fusion (ICF) for inertial fusion energy (IFE) applications leads to the standard scenario of central hot spot ignition followed by propagating burn wave through the cold/dense assembled fuel. The fact that the hot spot is surrounded by cold but dense fuel layer introduces subtle plasma physics which requires a kinetic description. Here we perform Fokker-Planck calculations and kinetic PIC simulations for an ICF plasma initially in pressure balance but having large temperature gradient over a narrow transition layer. The loss of the fast ion tail from the hot spot, which is important for fusion reactivity, is quantified by Fokker-Planck models. The role of electron energy transport and the ambipolar electric field is investigated via kinetic simulations and the fluid moment models. The net effect on both hot spot ion temperature and the ion tail distribution, and hence the fusion reactivity, is elucidated.

  9. Effect of vacuum arc cathode spot distribution on breaking capacity of the arc-extinguishing chamber

    Science.gov (United States)

    Ding, Can; Yuan, Zhao; He, Junjia

    2017-10-01

    A DC circuit breaker performs a key function in breaking an intermediate-frequency (IF) current since breaking a pure IF current is equivalent to breaking a very small DC with a reverse IF current. In this study, it is found that cathode spots show a ring-shaped distribution at 2000 Hz. An arc with an uneven distribution of cathode spots has been simulated. The simulation results show that the distribution of cathode spots significantly affect the microparameter distribution of arc plasma. The current distribution on the anode side differs from that on the cathode side under the total radial electric field. Specifically, the anode current distribution is both uneven and concentrated. The applied axial magnetic field, which cannot reduce the concentrated anode current distribution effectively, might increase the concentration of the anode current. Finally, the uneven distribution of cathode spots reduces the breaking capacity of the arc-extinguishing chamber.

  10. Computation of spot prices and congestion costs in large interconnected power systems

    International Nuclear Information System (INIS)

    Mukerji, R.; Jordan, G.A.; Clayton, R.; Haringa, G.E.

    1995-01-01

    Foremost among the new paradigms for the US utility industry is the ''poolco'' concept proposed by Prof. William W. Hogan of Harvard University. This concept uses a central pool or power exchange in which physical power is traded based on spot prices or market clearing prices. The rapid and accurate calculation of these ''spot'' prices and associated congestion costs for large interconnected power systems is the central tenet upon which the poolco concept is based. The market clearing price would be the same throughout the system if there were no system losses and transmission limitations did not exist. System losses cause small differences in market clearing prices as the cost of supplying a MW at various load buses includes the cost of losses. Transmission limits may cause large differences in market clearing prices between regions as low cost generation is blocked by the transmission constraints from serving certain loads. In models currently in use in the electric power industry spot price calculations range from ''bubble diagram'' type contract path models to full electrical representation such as GE-MAPS. The modeling aspects of the full electrical representation are included in the Appendix. The problem with the bubble diagram representation is that these models are liable to produce unacceptably large errors in the calculation of spot prices and congestion costs. The subtleties of the calculation of spot prices and congestion costs are illustrated in this paper

  11. Solar 'hot spots' are still hot

    Science.gov (United States)

    Bai, Taeil

    1990-01-01

    Longitude distributions of solar flares are not random but show evidence for active zones (or hot spots) where flares are concentrated. According to a previous study, two hot spots in the northern hemisphere, which rotate with a synodic period of about 26.72 days, produced the majority of major flares, during solar cycles 20 and 21. The more prominent of these two hot spots is found to be still active during the rising part of cycle 22, producing the majority of northern hemisphere major flares. The synodic rotation period of this hot spot is 26.727 + or - 0.007 days. There is also evidence for hot spots in the southern hemisphere. Two hot spots separated by 180 deg are found to rotate with a period of 29.407 days, with one of them having persisted in the same locations during cycles 19-22 and the other, during cycles 20-22.

  12. Variable-spot ion beam figuring

    International Nuclear Information System (INIS)

    Wu, Lixiang; Qiu, Keqiang; Fu, Shaojun

    2016-01-01

    This paper introduces a new scheme of ion beam figuring (IBF), or rather variable-spot IBF, which is conducted at a constant scanning velocity with variable-spot ion beam collimated by a variable diaphragm. It aims at improving the reachability and adaptation of the figuring process within the limits of machine dynamics by varying the ion beam spot size instead of the scanning velocity. In contrast to the dwell time algorithm in the conventional IBF, the variable-spot IBF adopts a new algorithm, which consists of the scan path programming and the trajectory optimization using pattern search. In this algorithm, instead of the dwell time, a new concept, integral etching time, is proposed to interpret the process of variable-spot IBF. We conducted simulations to verify its feasibility and practicality. The simulation results indicate the variable-spot IBF is a promising alternative to the conventional approach.

  13. Solar hot spots are still hot

    International Nuclear Information System (INIS)

    Bai, T.

    1990-01-01

    Longitude distributions of solar flares are not random but show evidence for active zones (or hot spots) where flares are concentrated. According to a previous study, two hot spots in the northern hemisphere, which rotate with a synodic period of about 26.72 days, produced the majority of major flares, during solar cycles 20 and 21. The more prominent of these two hot spots is found to be still active during the rising part of cycle 22, producing the majority of northern hemisphere major flares. The synodic rotation period of this hot spot is 26.727 + or - 0.007 days. There is also evidence for hot spots in the southern hemisphere. Two hot spots separated by 180 deg are found to rotate with a period of 29.407 days, with one of them having persisted in the same locations during cycles 19-22 and the other, during cycles 20-22. 14 refs

  14. Spot and Runway Departure Advisor

    Science.gov (United States)

    Jung, Yoon Chul

    2013-01-01

    The Spot and Runway Departure Advisor (SARDA) is a research prototype of a decision support tool for ATC tower controllers to assist in manging and controlling traffic on the surface of an airport. SARDA employs a scheduler to generate an optimal runway schedule and gate push-back - spot release sequence and schedule that improves efficiency of surface operations. The advisories for ATC tower controllers are displayed on an Electronic Flight Strip (EFS) system. The human-in-the-loop simulation of the SARDA tool was conducted for east operations of Dallas-Ft. Worth International Airport (DFW) to evaluate performance of the SARDA tool and human factors, such as situational awareness and workload. The results indicates noticeable taxi delay reduction and fuel savings by using the SARDA tool. Reduction in controller workload were also observed throughout the scenario runs. The future plan includes modeling and simulation of the ramp operations of the Charlotte International Airport, and develop a decision support tool for the ramp controllers.

  15. X-ray spot filmer

    International Nuclear Information System (INIS)

    1975-01-01

    An X-ray apparatus is described which includes a spot filmer for feeding sheets of unexposed film one at a time into a vacuum evacuable cassette for exposure, and for returning exposed film sheets to an exposed film magazine. The spot filmer has a housing defining a light-tight enclosure. The film magazines are insertable through a door into the housing and into a film feed mechanism. The film feed mechanism unlatches, opens and positions the magazines; it then feeds a sheet of unexposed film into the vacuum evacuable cassette, releases the film sheet so the cassette can position the film sheet for exposure, and closes the film magazines. An orthogonal drive system positions the vacuum evacuable cassette to expose selected film sheet portions and returns the cassette to a retracted position. The film feed mechanism opens the magazines, feeds the exposed film sheet into the exposed film magazine, and closes the magazines. A film identification system is provided for forming an identifying image on a marginal portion of each film sheet

  16. Glare Spot Phase Doppler Anemometry

    Science.gov (United States)

    Hespel, Camille; Ren, Kuanfang; Gréhan, Gérard; Onofri, Fabrice

    2007-06-01

    The Phase Doppler anemometry has been developed to measure simultaneously the velocity and the size of droplets. The measurement of the refractive index would be also interesting since it depends on the temperature and the composition of the particle and its measurement permits both to increase the quality of the diameter measurement and to obtain information on the temperature and/or the composition of the droplets. In this paper, we introduce a Glare Spot Phase Doppler Anemometry which uses two large beams. In this case, the images of the particle formed by the reflected and refracted light, known as glare spots, are separated in space. When a particle passes in the probe volume, the two parts in a signal obtained by a detector in forward direction are then separated in time. If two detectors are used the phase differences between two signals, the distance and the intensity ratio of reflected and refracted parts can be obtained and they provide rich information about the particle diameter and its refractive index, as well as its velocity. This paper is devoted to the numerical study of such a configuration with two theoretical models: geometrical optics and rigorous electromagnetism solution.

  17. Oil futures and spot markets

    International Nuclear Information System (INIS)

    Samii, M.V.

    1992-01-01

    In the last decade, the oil futures market has risen to prominence and has become a major factor in influencing oil market psychology and the crude oil market. On a normal day, over 92 thousand contracts, the equivalent of 92 million barrels per day, change hands on the New York Mercantile Exchange, NYMEX. This market has provided a vehicle for hedging against risk. At the same time, it has also created opportunities for speculation. Those who previously were unable to participate in oil market transactions can now become involved through the futures market. The large number of participants in the future market and the availability of information has made this market more efficient and transparent, relative to the crude oil market. While there has been considerable in-depth analysis of other future markets, relatively little theoretical attention has focused on that of oil. This paper looks at the following issues. First, what is the relationship between futures and spot oil prices? And secondly, are futures prices a good predictor of spot crude prices in the future? (author)

  18. Computed tomography angiography spot sign predicts intraprocedural aneurysm rupture in subarachnoid hemorrhage.

    Science.gov (United States)

    Burkhardt, Jan-Karl; Neidert, Marian Christoph; Stienen, Martin Nikolaus; Schöni, Daniel; Fung, Christian; Roethlisberger, Michel; Corniola, Marco Vincenzo; Bervini, David; Maduri, Rodolfo; Valsecchi, Daniele; Tok, Sina; Schatlo, Bawarjan; Bijlenga, Philippe; Schaller, Karl; Bozinov, Oliver; Regli, Luca

    2017-07-01

    To analyze whether the computed tomography angiography (CTA) spot sign predicts the intraprocedural rupture rate and outcome in patients with aneurysmal subarachnoid hemorrhage (aSAH). From a prospective nationwide multicenter registry database, 1023 patients with aneurysmal subarachnoid hemorrhage (aSAH) were analyzed retrospectively. Descriptive statistics and logistic regression analysis were used to compare spot sign-positive and -negative patients with aneurysmal intracerebral hemorrhage (aICH) for baseline characteristics, aneurysmal and ICH imaging characteristics, treatment and admission status as well as outcome at discharge and 1-year follow-up (1YFU) using the modified Rankin Scale (mRS). A total of 218 out of 1023 aSAH patients (21%) presented with aICH including 23/218 (11%) patients with spot sign. Baseline characteristics were comparable between spot sign-positive and -negative patients. There was a higher clip-to-coil ratio in patients with than without aICH (both spot sign positive and negative). Median aICH volume was significantly higher in the spot sign-positive group (50 ml, 13-223 ml) than in the spot sign-negative group (18 ml, 1-416; p spot sign-positive aICH thus were three times as likely as those with spot sign-negative aICH to show an intraoperative aneurysm rupture [odds ratio (OR) 3.04, 95% confidence interval (CI) 1.04-8.92, p = 0.046]. Spot sign-positive aICH patients showed a significantly worse mRS at discharge (p = 0.039) than patients with spot sign-negative aICH (median mRS 5 vs. 4). Logistic regression analysis showed that the spot sign was an aICH volume-dependent predictor for outcome. Both spot sign-positive and -negative aICH patients showed comparable rates of hospital death, death at 1YFU and mRS at 1YFU. In this multicenter data analysis, patients with spot sign-positive aICH showed higher aICH volumes and a higher rate of intraprocedural aneurysm rupture, but comparable long-term outcome to spot sign

  19. Integrating sustainable hunting in biodiversity protection in Central Africa: hot spots, weak spots, and strong spots.

    Directory of Open Access Journals (Sweden)

    John E Fa

    Full Text Available Wild animals are a primary source of protein (bushmeat for people living in or near tropical forests. Ideally, the effect of bushmeat harvests should be monitored closely by making regular estimates of offtake rate and size of stock available for exploitation. However, in practice, this is possible in very few situations because it requires both of these aspects to be readily measurable, and even in the best case, entails very considerable time and effort. As alternative, in this study, we use high-resolution, environmental favorability models for terrestrial mammals (N = 165 in Central Africa to map areas of high species richness (hot spots and hunting susceptibility. Favorability models distinguish localities with environmental conditions that favor the species' existence from those with detrimental characteristics for its presence. We develop an index for assessing Potential Hunting Sustainability (PHS of each species based on their ecological characteristics (population density, habitat breadth, rarity and vulnerability, weighted according to restrictive and permissive assumptions of how species' characteristics are combined. Species are classified into five main hunting sustainability classes using fuzzy logic. Using the accumulated favorability values of all species, and their PHS values, we finally identify weak spots, defined as high diversity regions of especial hunting vulnerability for wildlife, as well as strong spots, defined as high diversity areas of high hunting sustainability potential. Our study uses relatively simple models that employ easily obtainable data of a species' ecological characteristics to assess the impacts of hunting in tropical regions. It provides information for management by charting the geography of where species are more or less likely to be at risk of extinction from hunting.

  20. New public dataset for spotting patterns in medieval document images

    Science.gov (United States)

    En, Sovann; Nicolas, Stéphane; Petitjean, Caroline; Jurie, Frédéric; Heutte, Laurent

    2017-01-01

    With advances in technology, a large part of our cultural heritage is becoming digitally available. In particular, in the field of historical document image analysis, there is now a growing need for indexing and data mining tools, thus allowing us to spot and retrieve the occurrences of an object of interest, called a pattern, in a large database of document images. Patterns may present some variability in terms of color, shape, or context, making the spotting of patterns a challenging task. Pattern spotting is a relatively new field of research, still hampered by the lack of available annotated resources. We present a new publicly available dataset named DocExplore dedicated to spotting patterns in historical document images. The dataset contains 1500 images and 1464 queries, and allows the evaluation of two tasks: image retrieval and pattern localization. A standardized benchmark protocol along with ad hoc metrics is provided for a fair comparison of the submitted approaches. We also provide some first results obtained with our baseline system on this new dataset, which show that there is room for improvement and that should encourage researchers of the document image analysis community to design new systems and submit improved results.

  1. Portfolio optimization in electricity markets

    International Nuclear Information System (INIS)

    Liu, Min; Wu, Felix F.

    2007-01-01

    In a competitive electricity market, Generation companies (Gencos) face price risk and delivery risk that affect their profitability. Risk management is an important and essential part in the Genco's decision making. In this paper, risk management through diversification is considered. The problem of energy allocation between spot markets and bilateral contracts is formulated as a general portfolio optimization problem with a risk-free asset and n risky assets. Historical data of the PJM electricity market are used to demonstrate the approach. (author)

  2. Effect of the small-scale auxiliary laser spots on the 3ω0/2 harmonic emission

    International Nuclear Information System (INIS)

    Lin, Z.; Zhang, H.; He, X.; Lin, K.; Wang, X.; Zhuang, Y.; Wang, L.; Wei, X.; Lu, Q.; Shi, A.; Dai, M.; Tian, L.; Fan, G.; Li, J.

    1992-01-01

    Experiments have shown that a single 10-μm-radius laser spot is not able to produce the 90 degree side-emitted 3/2 harmonic efficiently in a preformed laser plasma. However, with the help of one or two auxiliary laser spots with a size similar to that of the main spot, the side-emitted 3/2 harmonic can frequently be detected when some positional and angular conditions for the auxiliary spots are met. The origin of these phenomena has been analyzed in terms of a proposed reflected laser photon-coupling model

  3. Design and cost of near-term OTEC (Ocean Thermal Energy Conversion) plants for the production of desalinated water and electric power. [Ocean Thermal Energy Conversion (OTEC)

    Energy Technology Data Exchange (ETDEWEB)

    Rabas, T.; Panchal, C.; Genens, L.

    1990-01-01

    There currently is an increasing need for both potable water and power for many islands in the Pacific and Caribbean. The Ocean Thermal Energy Conversion (OTEC) technology fills these needs and is a viable option because of the unlimited supply of ocean thermal energy for the production of both desalinated water and electricity. The OTEC plant design must be flexible to meet the product-mix demands that can be very different from site to site. This paper describes different OTEC plants that can supply various mixes of desalinated water and vapor -- the extremes being either all water and no power or no water and all power. The economics for these plants are also presented. The same flow rates and pipe sizes for both the warm and cold seawater streams are used for different plant designs. The OTEC plant designs are characterized as near-term because no major technical issues need to be resolved or demonstrated. The plant concepts are based on DOE-sponsored experiments dealing with power systems, advanced heat exchanger designs, corrosion and fouling of heat exchange surfaces, and flash evaporation and moisture removal from the vapor using multiple spouts. In addition, the mature multistage flash evaporator technology is incorporated into the plant designs were appropriate. For the supply and discharge warm and cold uncertainties do exist because the required pipe sizes are larger than the maximum currently deployed -- 40-inch high-density polyethylene pipe at Keahole Point in Hawaii. 30 refs., 6 figs., 8 tabs.

  4. Comparison of the Short-Term Forecasting Accuracy on Battery Electric Vehicle between Modified Bass and Lotka-Volterra Model: A Case Study of China

    Directory of Open Access Journals (Sweden)

    Shunxi Li

    2017-01-01

    Full Text Available The potential demand of battery electric vehicle (BEV is the base of the decision-making to the government policy formulation, enterprise manufacture capacity expansion, and charging infrastructure construction. How to predict the future amount of BEV accurately is very important to the development of BEV both in practice and in theory. The present paper tries to compare the short-term accuracy of a proposed modified Bass model and Lotka-Volterra (LV model, by taking China’s BEV development as the case study. Using the statistics data of China’s BEV amount of 21 months from Jan 2015 to Sep 2016, we compare the simulation accuracy based on the value of mean absolute percentage error (MAPE and discuss the forecasting capacity of the two models according to China’s government expectation. According to the MAPE value, the two models have good prediction accuracy, but the Bass model is more accurate than LV model. Bass model has only one dimension and focuses on the diffusion trend, while LV model has two dimensions and mainly describes the relationship and competing process between the two populations. In future research, the forecasting advantages of Bass model and LV model should be combined to get more accurate predicting effect.

  5. SU-E-T-510: Interplay Between Spots Sizes, Spot / Line Spacing and Motion in Spot Scanning Proton Therapy

    International Nuclear Information System (INIS)

    Lee, TK

    2015-01-01

    Purpose In proton beam configuration for spot scanning proton therapy (SSPT), one can define the spacing between spots and lines of scanning as a ratio of given spot size. If the spacing increases, the number of spots decreases which can potentially decrease scan time, and so can whole treatment time, and vice versa. However, if the spacing is too large, the uniformity of scanned field decreases. Also, the field uniformity can be affected by motion during SSPT beam delivery. In the present study, the interplay between spot/ line spacing and motion is investigated. Methods We used four Gaussian-shape spot sizes with 0.5cm, 1.0cm, 1.5cm, and 2.0cm FWHM, three spot/line spacing that creates uniform field profile which are 1/3*FWHM, σ/3*FWHM and 2/3*FWHM, and three random motion amplitudes within, +/−0.3mm, +/−0.5mm, and +/−1.0mm. We planned with 2Gy uniform single layer of 10×10cm2 and 20×20cm2 fields. Then, mean dose within 80% area of given field size, contrubuting MU per each spot assuming 1cGy/MU calibration for all spot sizes, number of spots and uniformity were calculated. Results The plans with spot/line spacing equal to or smaller than 2/3*FWHM without motion create ∼100% uniformity. However, it was found that the uniformity decreases with increased spacing, and it is more pronounced with smaller spot sizes, but is not affected by scanned field sizes. Conclusion It was found that the motion during proton beam delivery can alter the dose uniformity and the amount of alteration changes with spot size which changes with energy and spot/line spacing. Currently, robust evaluation in TPS (e.g. Eclipse system) performs range uncertainty evaluation using isocenter shift and CT calibration error. Based on presented study, it is recommended to add interplay effect evaluation to robust evaluation process. For future study, the additional interplay between the energy layers and motion is expected to present volumetric effect

  6. Cosmicflows-3: Cold Spot Repeller?

    Energy Technology Data Exchange (ETDEWEB)

    Courtois, Hélène M.; Graziani, Romain; Dupuy, Alexandra [University of Lyon, UCB Lyon 1, CNRS/IN2P3, IPN, Lyon (France); Tully, R. Brent [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Hoffman, Yehuda [Racah Institute of Physics, Hebrew University, Jerusalem, 91904 (Israel); Pomarède, Daniel [Institut de Recherche sur les Lois Fondamentales de l’Univers, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France)

    2017-09-20

    The three-dimensional gravitational velocity field within z ∼ 0.1 has been modeled with the Wiener filter methodology applied to the Cosmicflows-3 compilation of galaxy distances. The dominant features are a basin of attraction and two basins of repulsion. The major basin of attraction is an extension of the Shapley concentration of galaxies. One basin of repulsion, the Dipole Repeller, is located near the anti-apex of the cosmic microwave background dipole. The other basin of repulsion is in the proximate direction toward the “Cold Spot” irregularity in the cosmic microwave background. It has been speculated that a vast void might contribute to the amplitude of the Cold Spot from the integrated Sachs–Wolfe effect.

  7. 1997 begins quietly in the spot market as prices continue to drop

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    A summary of financial data for the uranium spot market in January 1997 is provided. Price ranges for the restricted and unrestricted markets, conversion, and separative work are listed, and total market volume and new contracts are noted. Transactions made are briefly described. Deals made and pending in the spot concentrates, medium and long-term, conversion, and markets are listed for U.S. and non-U.S. buyers

  8. Spot volume nearly 5 million lbs; restricted price hits $11.00

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    A summary of financial data for the uranium spot market in March 1995 is provided. Price ranges for the restricted and unrestricted markets, conversion, and separative work are listed, and total market volume and new contracts are noted. The 40 transactions made for the month are described separately for each market. Deals made in the spot concentrates, medium and long-term, conversion, and enrichment markets are further detailed for U.S. and non-U.S. buyers

  9. Rigorous assessment and integration of the sequence and structure based features to predict hot spots

    Directory of Open Access Journals (Sweden)

    Wang Yong

    2011-07-01

    Full Text Available Abstract Background Systematic mutagenesis studies have shown that only a few interface residues termed hot spots contribute significantly to the binding free energy of protein-protein interactions. Therefore, hot spots prediction becomes increasingly important for well understanding the essence of proteins interactions and helping narrow down the search space for drug design. Currently many computational methods have been developed by proposing different features. However comparative assessment of these features and furthermore effective and accurate methods are still in pressing need. Results In this study, we first comprehensively collect the features to discriminate hot spots and non-hot spots and analyze their distributions. We find that hot spots have lower relASA and larger relative change in ASA, suggesting hot spots tend to be protected from bulk solvent. In addition, hot spots have more contacts including hydrogen bonds, salt bridges, and atomic contacts, which favor complexes formation. Interestingly, we find that conservation score and sequence entropy are not significantly different between hot spots and non-hot spots in Ab+ dataset (all complexes. While in Ab- dataset (antigen-antibody complexes are excluded, there are significant differences in two features between hot pots and non-hot spots. Secondly, we explore the predictive ability for each feature and the combinations of features by support vector machines (SVMs. The results indicate that sequence-based feature outperforms other combinations of features with reasonable accuracy, with a precision of 0.69, a recall of 0.68, an F1 score of 0.68, and an AUC of 0.68 on independent test set. Compared with other machine learning methods and two energy-based approaches, our approach achieves the best performance. Moreover, we demonstrate the applicability of our method to predict hot spots of two protein complexes. Conclusion Experimental results show that support vector machine

  10. Rigorous assessment and integration of the sequence and structure based features to predict hot spots

    Science.gov (United States)

    2011-01-01

    Background Systematic mutagenesis studies have shown that only a few interface residues termed hot spots contribute significantly to the binding free energy of protein-protein interactions. Therefore, hot spots prediction becomes increasingly important for well understanding the essence of proteins interactions and helping narrow down the search space for drug design. Currently many computational methods have been developed by proposing different features. However comparative assessment of these features and furthermore effective and accurate methods are still in pressing need. Results In this study, we first comprehensively collect the features to discriminate hot spots and non-hot spots and analyze their distributions. We find that hot spots have lower relASA and larger relative change in ASA, suggesting hot spots tend to be protected from bulk solvent. In addition, hot spots have more contacts including hydrogen bonds, salt bridges, and atomic contacts, which favor complexes formation. Interestingly, we find that conservation score and sequence entropy are not significantly different between hot spots and non-hot spots in Ab+ dataset (all complexes). While in Ab- dataset (antigen-antibody complexes are excluded), there are significant differences in two features between hot pots and non-hot spots. Secondly, we explore the predictive ability for each feature and the combinations of features by support vector machines (SVMs). The results indicate that sequence-based feature outperforms other combinations of features with reasonable accuracy, with a precision of 0.69, a recall of 0.68, an F1 score of 0.68, and an AUC of 0.68 on independent test set. Compared with other machine learning methods and two energy-based approaches, our approach achieves the best performance. Moreover, we demonstrate the applicability of our method to predict hot spots of two protein complexes. Conclusion Experimental results show that support vector machine classifiers are quite

  11. 7 CFR 28.412 - Strict Middling Light Spotted Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Strict Middling Light Spotted Color. 28.412 Section 28... Light Spotted Color. Strict Middling Light Spotted Color is color which in spot or color, or both, is between Strict Middling Color and Strict Middling Spotted Color. ...

  12. 7 CFR 28.415 - Low Middling Light Spotted Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Low Middling Light Spotted Color. 28.415 Section 28... Spotted Color. Low Middling Light Spotted Color is color which in spot or color, or both, is between Low Middling Color and Low Middling Spotted Color. ...

  13. 7 CFR 28.411 - Good Middling Light Spotted Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Good Middling Light Spotted Color. 28.411 Section 28... Light Spotted Color. Good Middling Light Spotted Color is color which in spot or color, or both, is between Good Middling Color and Good Middling Spotted Color. ...

  14. 7 CFR 28.413 - Middling Light Spotted Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Middling Light Spotted Color. 28.413 Section 28.413... Spotted Color. Middling Light Spotted Color is color which in spot or color, or both, is between Middling Color and Middling Spotted Color. ...

  15. Rocky Mountain spotted fever in children.

    Science.gov (United States)

    Woods, Charles R

    2013-04-01

    Rocky Mountain spotted fever is typically undifferentiated from many other infections in the first few days of illness. Treatment should not be delayed pending confirmation of infection when Rocky Mountain spotted fever is suspected. Doxycycline is the drug of choice even for infants and children less than 8 years old. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Rocky Mountain Spotted Fever: Statistics and Epidemiology

    Science.gov (United States)

    ... Search Form Controls Cancel Submit Search the CDC Rocky Mountain Spotted Fever (RMSF) Note: Javascript is disabled or is not ... message, please visit this page: About CDC.gov . Rocky Mountain Spotted Fever (RMSF) Transmission Signs and Symptoms Diagnosis and Testing ...

  17. Crack imaging by pulsed laser spot thermography

    International Nuclear Information System (INIS)

    Li, T; Almond, D P; Rees, D A S; Weekes, B

    2010-01-01

    A surface crack close to a spot heated by a laser beam impedes lateral heat flow and produces alterations to the shape of the thermal image of the spot that can be monitored by thermography. A full 3D simulation has been developed to simulate heat flow from a laser heated spot in the proximity of a crack. The modelling provided an understanding of the ways that different parameters affect the thermal images of laser heated spots. It also assisted in the development of an efficient image processing strategy for extracting the scanned cracks. Experimental results show that scanning pulsed laser spot thermography has considerable potential as a remote, non-contact crack imaging technique.

  18. Laser Spot Detection Based on Reaction Diffusion.

    Science.gov (United States)

    Vázquez-Otero, Alejandro; Khikhlukha, Danila; Solano-Altamirano, J M; Dormido, Raquel; Duro, Natividad

    2016-03-01

    Center-location of a laser spot is a problem of interest when the laser is used for processing and performing measurements. Measurement quality depends on correctly determining the location of the laser spot. Hence, improving and proposing algorithms for the correct location of the spots are fundamental issues in laser-based measurements. In this paper we introduce a Reaction Diffusion (RD) system as the main computational framework for robustly finding laser spot centers. The method presented is compared with a conventional approach for locating laser spots, and the experimental results indicate that RD-based computation generates reliable and precise solutions. These results confirm the flexibility of the new computational paradigm based on RD systems for addressing problems that can be reduced to a set of geometric operations.

  19. Laser Spot Detection Based on Reaction Diffusion

    Directory of Open Access Journals (Sweden)

    Alejandro Vázquez-Otero

    2016-03-01

    Full Text Available Center-location of a laser spot is a problem of interest when the laser is used for processing and performing measurements. Measurement quality depends on correctly determining the location of the laser spot. Hence, improving and proposing algorithms for the correct location of the spots are fundamental issues in laser-based measurements. In this paper we introduce a Reaction Diffusion (RD system as the main computational framework for robustly finding laser spot centers. The method presented is compared with a conventional approach for locating laser spots, and the experimental results indicate that RD-based computation generates reliable and precise solutions. These results confirm the flexibility of the new computational paradigm based on RD systems for addressing problems that can be reduced to a set of geometric operations.

  20. Rocky Mountain spotted fever in Argentina.

    Science.gov (United States)

    Paddock, Christopher D; Fernandez, Susana; Echenique, Gustavo A; Sumner, John W; Reeves, Will K; Zaki, Sherif R; Remondegui, Carlos E

    2008-04-01

    We describe the first molecular confirmation of Rickettsia rickettsii, the cause of Rocky Mountain spotted fever (RMSF), from a tick vector, Amblyomma cajennense, and from a cluster of fatal spotted fever cases in Argentina. Questing A. cajennense ticks were collected at or near sites of presumed or confirmed cases of spotted fever rickettsiosis in Jujuy Province and evaluated by polymerase chain reaction assays for spotted fever group rickettsiae. DNA of R. rickettsii was amplified from a pool of A. cajennense ticks and from tissues of one of four patients who died during 2003-2004 after illnesses characterized by high fever, severe headache, myalgias, and petechial rash. The diagnosis of spotted fever rickettsiosis was confirmed in the other patients by indirect immunofluorescence antibody and immunohistochemical staining techniques. These findings show the existence of RMSF in Argentina and emphasize the need for clinicians throughout the Americas to consider RMSF in patients with febrile rash illnesses.