WorldWideScience

Sample records for day-ahead lmp peak

  1. 75 FR 42411 - Orders Finding That the SP-15 Financial Day-Ahead LMP Peak Daily Contract; SP-15 Financial Day...

    Science.gov (United States)

    2010-07-21

    ... COMMODITY FUTURES TRADING COMMISSION Orders Finding That the SP-15 Financial Day-Ahead LMP Peak Daily Contract; SP-15 Financial Day-Ahead LMP Off-Peak Daily Contract; SP-15 Financial Swap Real Time...-Peak Daily (``SQP'') contract; SP-15 Financial Swap Real Time LMP-Peak Daily (``SRP'') contract; NP-15...

  2. 75 FR 42380 - Orders Finding That the SP-15 Financial Day-Ahead LMP Peak Contract and SP-15 Financial Day-Ahead...

    Science.gov (United States)

    2010-07-21

    ... to encouraging competition in the Western power markets * * * WTPF strives to reduce the long-run... 15, along with the Pacific DC Intertie running far to the east, completes an important transmission... . \\18\\ The third 500 kV line was installed between 2003 and 2004 in order to relieve constraints on the...

  3. Day-ahead tariffs for the alleviation of distribution grid congestion from electric vehicles

    DEFF Research Database (Denmark)

    O'Connell, Niamh; Wu, Qiuwei; Østergaard, Jacob

    2012-01-01

    An economically efficient day-ahead tariff (DT) is proposed with the purpose of preventing the distribution grid congestion resulting from electric vehicle (EV) charging scheduled on a dayahead basis. The DT concept developed herein is derived from the locational marginal price (LMP), in particular...

  4. Day-Ahead Electricity Price Forecasting Using a Hybrid Principal Component Analysis Network

    Directory of Open Access Journals (Sweden)

    Ching-Ping Wu

    2012-11-01

    Full Text Available Bidding competition is one of the main transaction approaches in a deregulated electricity market. Locational marginal prices (LMPs resulting from bidding competition and system operation conditions indicate electricity values at a node or in an area. The LMP reveals important information for market participants in developing their bidding strategies. Moreover, LMP is also a vital indicator for the Security Coordinator to perform market redispatch for congestion management. This paper presents a method using a principal component analysis (PCA network cascaded with a multi-layer feedforward (MLF network for forecasting LMPs in a day-ahead market. The PCA network extracts essential features from periodic information in the market. These features serve as inputs to the MLF network for forecasting LMPs. The historical LMPs in the PJM market are employed to test the proposed method. It is found that the proposed method is capable of forecasting day-ahead LMP values efficiently.

  5. Day-Ahead Self-Scheduling of Thermal Generator in Competitive Electricity Market Using Hybrid PSO

    DEFF Research Database (Denmark)

    Pindoriya, N.M.; Singh, Sri Niwas; Østergaard, Jacob

    2009-01-01

    in day-ahead energy market subject to operational constraints and 2) at the same time, to minimize the risk due to uncertainty in price forecast. Therefore, it is a conflicting biobjective optimization problem which has both binary and continuous optimization variables considered as constrained mixed......This paper presents a hybrid particle swarm optimization algorithm (HPSO) to solve the day-ahead selfscheduling for thermal power producer in competitive electricity market. The objective functions considered to model the selfscheduling problem are: 1) to maximize the profit from selling energy...... integer nonlinear programming. To demonstrate the effectiveness of the proposed method for self-scheduling in a dayahead energy market, the locational margin price (LMP) forecast uncertainty in PJM electricity market is considered. An adaptive wavelet neural network (AWNN) is used to forecast the dayahead...

  6. Risk premiums in the German day-ahead Electricity Market

    International Nuclear Information System (INIS)

    Viehmann, Johannes

    2011-01-01

    This paper conducts an empirical analysis of risk premiums in the German day-ahead Electricity Wholesale Market. We compare hourly price data of the European Energy Exchange (EEX) auction and of the continuous over-the-counter (OTC) market which takes place prior to the EEX auction. Data provided by the Energy Exchange Austria (EXAA) has been used as a snapshot of the OTC market two hours prior to the EEX auction. Ex post analysis found market participants are willing to pay both significant positive and negative premiums for hourly contracts. The largest positive premiums were paid for high demand evening peak hours on weekdays during winter months. By contrast, night hours on weekends featuring lowest demand levels display negative premiums. Additionally, ex ante analysis found a strong positive correlation between the expected tightness of the system and positive premiums. For this purpose, a tightness factor has been introduced that includes expectations of fundamental factors such as power plant availability, wind power production and demand. Hence, findings by can be supported that power traders in liberalised markets behave like risk-averse rational economic agents. - Research highlights: →Analysis of hourly risk premiums in the German day-ahead Electricity Wholesale Market. →Market participants are willing to pay both significant positive and negative premiums for hourly contracts. →A strong correlation exists between the expected tightness of the power system and premiums.

  7. Hourly Electricity Prices in Day-Ahead Markets

    NARCIS (Netherlands)

    R. Huisman (Ronald); C. Huurman; R.J. Mahieu (Ronald)

    2007-01-01

    textabstractThis paper focuses on the characteristics of hourly electricity prices in day-ahead markets. In these markets, quotes for day-ahead delivery of electricity are submitted simultaneously for all hours in the next day. The same information set is used for quoting all hours of the day. The

  8. Powernext Day-AheadTM statistics - June 30, 2006

    International Nuclear Information System (INIS)

    2006-01-01

    The introduction of a power exchange in France is a direct response to the opening up of the European electricity markets. Powernext SA is a Multilateral Trading Facility in charge of managing an optional and anonymous organised exchange offering: - Day-ahead contracts for the management of volume risk on Powernext Day-Ahead TM since 21 November 2001, - Medium term contracts for the management of price risk on Powernext Futures TM since 18 June 2004. This document presents in a series of tables and graphics the June 30, 2006 update of Powernext Day-Ahead TM statistics: daily traded volumes and base-load prices from November 2001 to June 2006, monthly overview from June 2005 to June 2006 (volumes and prices), weekly overview from March to June 2006 (volumes and prices), daily and hourly overview and market resilience for June 2006, power consumption in May and June 2006 (average consumption, average forecasted consumption and average price on Powernext Day-Ahead TM ), power consumption on the French hub from July 2005 to May 2006 and Powernext Day-Ahead TM prices, transfer capacities in June 2006 (auction results for France-Germany, France-Belgium, France-UK, France-Spain and France-Italy, and daily capacity allocation for France-Switzerland), temperature variations in France from January 2005 to June 2006 and base-load Powernext Day-Ahead TM prices, and balancing mechanism for April, May and June 2006 (half-hourly imbalance settlement prices). (J.S.)

  9. Day-Ahead Load Forecasting Using Exponential Smoothing

    Directory of Open Access Journals (Sweden)

    R. Bindiu

    2009-12-01

    Full Text Available The existence of a liberated market for electricity implies the necessity of using load forecasting in order to optimize and reduce the costs for the electric energy consumption. Different strategies for the purchase of electrical energy require precise load forecasting. The Day Ahead Market makes possible the acquisition of electricity for one day in advance. This reduces the risk of making electrical energy transactions on Balance Market, which means buying at a very high price and selling at a very low price. This paper presents a Day Ahead Load Forecasting approach for an industrial costumer using exponential smoothing method. The purpose of this paper is to present a new method for day ahead load forecasting.

  10. Powernext Day-AheadTM products and market organization

    International Nuclear Information System (INIS)

    2004-06-01

    The introduction of a power exchange in France is a direct response to the opening up of the European electricity markets. Powernext SA is a Multilateral Trading Facility in charge of managing the French power exchange through an optional and anonymous organised exchange offering: - Day-ahead contracts for the management of volume risk on Powernext Day-Ahead TM since 21 November 2001, - Medium term contracts for the management of price risk on Powernext Futures TM since 18 June 2004. This document presents the principle of the trading of hourly contracts on Powernext Day-Ahead TM , the accessibility of the market, the SAPRI trading platform operated by Nord Pool, the Scandinavian power exchange, the validation of the auction results, the collaboration with LCH.Clearnet SA to secure and facilitate the transactions, and the delivery guarantee implemented by RTE (the French energy transport network). (J.S.)

  11. Simulation of regional day-ahead PV power forecast scenarios

    DEFF Research Database (Denmark)

    Nuno, Edgar; Koivisto, Matti Juhani; Cutululis, Nicolaos Antonio

    2017-01-01

    at the expense of a high computational burden. Alternatively, some power system applications may require realistic forecasts rather than actual estimates; able to capture the uncertainty of weatherdriven generation. To this end, we propose a novel methodology to generate day-ahead forecast scenarios of regional...

  12. Powernext Day-AheadTM. Powernext futuresTM. Activity report - 2004

    International Nuclear Information System (INIS)

    2004-01-01

    The introduction of a power exchange in France is a direct response to the opening up of the European electricity markets. Powernext SA is a Multilateral Trading Facility in charge of managing the French power exchange through an optional and anonymous organised exchange offering: - Day-ahead contracts for the management of volume risk on Powernext Day-Ahead TM since 21 November 2001, - Medium term contracts for the management of price risk on Powernext Futures TM since 18 June 2004. This document is the 2004 activity report of Powernext SA, it presents the key figures of the power market and of Powernext in 2004: - Increasing volumes: Powernext Day-Ahead TM 's traded volumes increased by 89%, from 7.48 to 14.18 TWh. Powernext Futures TM kicks off to a promising debut with 12.86 TWh traded in less than 7 months. - Less volatile prices: During 2004, the base price averaged 28.13 euro/MWh, and the peak prices averaged 33.71 euro/MWh. Compared to 2003, these prices decreased by an average of 3.7% on base-load and 10.9% on peak-load. In comparison to the two previous years, the daily volatility has noticeably settled down with 27% on base-load and 37% on peak-load. - Increasing liquidity: 10 new members joined Powernext Day-Ahead TM in 2004. The activity level of the members remains very high as 89% of them trade on an actual daily basis during 2004. The market resiliency stays strong. In December, an additional market 50 MW order on each hour resulted in a balance price variation of only 0.16 euro/MWh, or 0.53% of this balance price. For a 100 MW order, the resiliency is 0.32 euro/MWh, or 1.07% of the balance price. Thus, in 2004, Powernext Day-Ahead TM consolidates its role as a short term reference price. Moreover, in 2004, Powernext launched a futures market, Powernext Futures TM . This new market segment proposes contracts tradable up to 2 years ahead of delivery

  13. Day-Ahead Wind Speed Forecasting Using Relevance Vector Machine

    Directory of Open Access Journals (Sweden)

    Guoqiang Sun

    2014-01-01

    Full Text Available With the development of wind power technology, the security of the power system, power quality, and stable operation will meet new challenges. So, in this paper, we propose a recently developed machine learning technique, relevance vector machine (RVM, for day-ahead wind speed forecasting. We combine Gaussian kernel function and polynomial kernel function to get mixed kernel for RVM. Then, RVM is compared with back propagation neural network (BP and support vector machine (SVM for wind speed forecasting in four seasons in precision and velocity; the forecast results demonstrate that the proposed method is reasonable and effective.

  14. Customer response to day-ahead market hourly pricing: Choices and performance

    International Nuclear Information System (INIS)

    Hopper, Nicole; Goldman, Charles; Bharvirkar, Ranjit; Neenan, Bernie

    2006-01-01

    Real-time pricing (RTP) has been advocated to address extreme price volatility and market power in electricity markets. This study of Niagara Mohawk Power Corporation's largest customers analyzes their choices and performance in response to day-ahead, default-service RTP. Overall price response is modest: 119 customers are estimated to reduce their peak demand by about 10% at high prices. Manufacturing customers are most responsive with a price elasticity of 0.16, followed by government/education customers (0.11), while commercial/retail, healthcare and public works customers are, at present, relatively unresponsive. Within market segments, individual customer response varies significantly. (author)

  15. Support vector machine for day ahead electricity price forecasting

    Science.gov (United States)

    Razak, Intan Azmira binti Wan Abdul; Abidin, Izham bin Zainal; Siah, Yap Keem; Rahman, Titik Khawa binti Abdul; Lada, M. Y.; Ramani, Anis Niza binti; Nasir, M. N. M.; Ahmad, Arfah binti

    2015-05-01

    Electricity price forecasting has become an important part of power system operation and planning. In a pool- based electric energy market, producers submit selling bids consisting in energy blocks and their corresponding minimum selling prices to the market operator. Meanwhile, consumers submit buying bids consisting in energy blocks and their corresponding maximum buying prices to the market operator. Hence, both producers and consumers use day ahead price forecasts to derive their respective bidding strategies to the electricity market yet reduce the cost of electricity. However, forecasting electricity prices is a complex task because price series is a non-stationary and highly volatile series. Many factors cause for price spikes such as volatility in load and fuel price as well as power import to and export from outside the market through long term contract. This paper introduces an approach of machine learning algorithm for day ahead electricity price forecasting with Least Square Support Vector Machine (LS-SVM). Previous day data of Hourly Ontario Electricity Price (HOEP), generation's price and demand from Ontario power market are used as the inputs for training data. The simulation is held using LSSVMlab in Matlab with the training and testing data of 2004. SVM that widely used for classification and regression has great generalization ability with structured risk minimization principle rather than empirical risk minimization. Moreover, same parameter settings in trained SVM give same results that absolutely reduce simulation process compared to other techniques such as neural network and time series. The mean absolute percentage error (MAPE) for the proposed model shows that SVM performs well compared to neural network.

  16. Optimal day-ahead operational planning of microgrids

    International Nuclear Information System (INIS)

    Hosseinnezhad, Vahid; Rafiee, Mansour; Ahmadian, Mohammad; Siano, Pierluigi

    2016-01-01

    Highlights: • A new multi-objective model for optimal day-ahead operational planning of microgrids is proposed. • A new concept called seamlessness is introduced to control the sustainability of microgrid. • A new method is developed to manage the load and renewable energy resources estimation errors. • A new solution based on a combination of numerical and evolutionary approaches is proposed. - Abstract: Providing a cost-efficient, eco-friendly and sustainable energy is one of the main issues in modern societies. In response to this demand, new features of microgrid technology have provided huge potentials while distributing electricity more effectively, economically and securely. Accordingly, this paper presents a new multi-objective generation management model for optimal day-ahead operational planning of medium voltage microgrids. The proposed model optimizes both pollutant emission and operating cost of a microgrid by using multi-objective optimization. Besides, a seamlessness-selective algorithm is integrated into the model, which can be adopted to achieve the desired self-sufficiency level for microgrids along a specified planning horizon. Furthermore, the model is characterized by a reserve-assessment strategy developed to handle the load and renewable energy resources estimation errors. The introduced model is solved using a combination of numerical and evolutionary methods of species-based quantum particle swarm optimization to find the optimal scheduling scheme and minos-based optimal power flow to optimize the operating cost and emission. In addition, the suggested solution approach also incorporates an efficient mechanism for considering energy storage systems and coding the candidate solutions in the evolutionary algorithm. The proposed model is implemented on a test microgrid and is investigated through simulations to study the different aspects of the problem. The results show significant improvements and benefits which are obtained by

  17. Day-Ahead Energy Planning with 100% Electric Vehicle Penetration in the Nordic Region by 2050

    Directory of Open Access Journals (Sweden)

    Zhaoxi Liu

    2014-03-01

    Full Text Available This paper presents the day-ahead energy planning of passenger cars with 100% electric vehicle (EV penetration in the Nordic region by 2050. EVs will play an important role in the future energy systems which can both reduce the greenhouse gas (GHG emissions from the transport sector and provide the demand side flexibility required by smart grids. On the other hand, the EVs will increase the electricity consumption. In order to quantify the electricity consumption increase due to the 100% EV penetration in the Nordic region to facilitate the power system planning studies, the day-ahead energy planning of EVs has been investigated with different EV charging scenarios. Five EV charging scenarios have been considered in the energy planning analysis which are: uncontrolled charging all day, uncontrolled charging at home, timed charging, spot price based charging all day and spot price based charging at home. The demand profiles of the five charging analysis show that timed charging is the least favorable charging option and the spot priced based EV charging might induce high peak demands. The EV charging demand will have a considerable share of the energy consumption in the future Nordic power system.

  18. Feedback, competition and stochasticity in a day ahead electricity market

    International Nuclear Information System (INIS)

    Giabardo, Paolo; Zugno, Marco; Pinson, Pierre; Madsen, Henrik

    2010-01-01

    Major recent changes in electricity markets relate to the process for their deregulation, along with increasing participation of renewable (stochastic) generation e.g. wind power. Our general objective is to model how feedback, competition and stochasticity (on the production side) interact in electricity markets, and eventually assess what their effects are on both the participants and the society. For this, day ahead electricity markets are modeled as dynamic closed loop systems, in which the feedback signal is the market price. In parallel, the Cournot competition model is considered. Mixed portfolios with significant share of renewable energy are based on stochastic threshold cost functions. Regarding trading strategies, it is assumed that generators are looking at optimizing their individual profits. The point of view of the society is addressed by analyzing market behavior and stability. The performed simulations show the beneficial effects of employing long term bidding strategies for both generators and society. Sensitivity analyses are performed in order to evaluate the effects of demand elasticity. It is shown that increase in demand elasticity reduces the possibility for the generators to exploit their market power. Furthermore, the results suggest that introduction of wind power generation in the market is beneficial both for the generators and the society.

  19. The impact of renewable energies on EEX day-ahead electricity prices

    OpenAIRE

    Schürle, Michael; Paraschiv, Florentina

    2014-01-01

    We analyze the impact of renewable energies, wind and photovoltaic, on the formation of day-ahead electricity prices at EEX. We give an overview of the policy decisions concerning the promotion of renewable energy sources in Germany, and discuss their consequences on day-ahead prices. An analysis of electricity spot prices reveals that the introduction of renewable energies enhances extreme price changes. In the frame of a dynamic fundamental model, we show that there has been a continuous el...

  20. 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...

  1. Everything you need to know to operate on Day-Ahead{sup TM}; Tout ce que vous devez savoir pour intervenir sur Powernext Day-Ahead{sup TM}

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-05-15

    The introduction of a power exchange in France is a direct response to the opening up of the European electricity markets. Powernext SA is a Multilateral Trading Facility in charge of managing the French power exchange through an optional and anonymous organised exchange offering: - Day-ahead contracts for the management of volume risk on Powernext Day-Ahead{sup TM} since 21 November 2001, - Medium term contracts for the management of price risk on Powernext Futures{sup TM} since 18 June 2004. This document is the user's guide of Powernext Day-Ahead{sup TM}. It presents: 1 - the power exchange in France (market model, Powernext's regulatory environment, general market operations, 2 - Powernext Day-Ahead{sup TM} members (membership, agreement, start-up notification, tariffs, standing obligations, membership termination), 3 - Powernext Day-Ahead{sup TM} products (specifications, management), 4 - trading (connections, system flow chart, ElWeb client installation and daily connections, portfolio-management, single bidding, type of order, submitting, importing, saving, sending, modifying or canceling an order form, transmission problems, block bidding block bid characteristics, sending, saving, transmitting, modifying and canceling a block bid, price calculations, blind auction procedure, example, taking into account block bids, rounding off rules, consulting and saving the results, sample documents, auction validation), 5 - clearing (LCH.Clearnet SA, legal framework, clearing agreement, PP-DPES agreement, market security, initial margin, daily adjustments, additional margin calls, trade-related financial flows, net financial position, value-added tax, settlement statements, general idea, characteristics and transmission method of settlement statements sample Documents, cash calls, settlement, default, sample cash call documents, financial Reports), 6 - delivery (balance responsible entity, file characteristics and transmission, imbalance settlement

  2. Incentive-based demand response programs designed by asset-light retail electricity providers for the day-ahead market

    International Nuclear Information System (INIS)

    Fotouhi Ghazvini, Mohammad Ali; Faria, Pedro; Ramos, Sergio; Morais, Hugo; Vale, Zita

    2015-01-01

    Following the deregulation experience of retail electricity markets in most countries, the majority of the new entrants of the liberalized retail market were pure REP (retail electricity providers). These entities were subject to financial risks because of the unexpected price variations, price spikes, volatile loads and the potential for market power exertion by GENCO (generation companies). A REP can manage the market risks by employing the DR (demand response) programs and using its' generation and storage assets at the distribution network to serve the customers. The proposed model suggests how a REP with light physical assets, such as DG (distributed generation) units and ESS (energy storage systems), can survive in a competitive retail market. The paper discusses the effective risk management strategies for the REPs to deal with the uncertainties of the DAM (day-ahead market) and how to hedge the financial losses in the market. A two-stage stochastic programming problem is formulated. It aims to establish the financial incentive-based DR programs and the optimal dispatch of the DG units and ESSs. The uncertainty of the forecasted day-ahead load demand and electricity price is also taken into account with a scenario-based approach. The principal advantage of this model for REPs is reducing the risk of financial losses in DAMs, and the main benefit for the whole system is market power mitigation by virtually increasing the price elasticity of demand and reducing the peak demand. - Highlights: • Asset-light electricity retail providers subject to financial risks. • Incentive-based demand response program to manage the financial risks. • Maximizing the payoff of electricity retail providers in day-ahead market. • Mixed integer nonlinear programming to manage the risks

  3. What day-ahead reserves are needed in electric grids with high levels of wind power?

    International Nuclear Information System (INIS)

    Mauch, Brandon; Apt, Jay; Jaramillo, Paulina; Carvalho, Pedro M S

    2013-01-01

    Day-ahead load and wind power forecasts provide useful information for operational decision making, but they are imperfect and forecast errors must be offset with operational reserves and balancing of (real time) energy. Procurement of these reserves is of great operational and financial importance in integrating large-scale wind power. We present a probabilistic method to determine net load forecast uncertainty for day-ahead wind and load forecasts. Our analysis uses data from two different electric grids in the US with similar levels of installed wind capacity but with large differences in wind and load forecast accuracy, due to geographic characteristics. We demonstrate that the day-ahead capacity requirements can be computed based on forecasts of wind and load. For 95% day-ahead reliability, this required capacity ranges from 2100 to 5700 MW for ERCOT, and 1900 to 4500 MW for MISO (with 10 GW of installed wind capacity), depending on the wind and load forecast values. We also show that for each MW of additional wind power capacity for ERCOT, 0.16–0.30 MW of dispatchable capacity will be used to compensate for wind uncertainty based on day-ahead forecasts. For MISO (with its more accurate forecasts), the requirement is 0.07–0.13 MW of dispatchable capacity for each MW of additional wind capacity. (letter)

  4. Day-ahead wind speed forecasting using f-ARIMA models

    International Nuclear Information System (INIS)

    Kavasseri, Rajesh G.; Seetharaman, Krithika

    2009-01-01

    With the integration of wind energy into electricity grids, it is becoming increasingly important to obtain accurate wind speed/power forecasts. Accurate wind speed forecasts are necessary to schedule dispatchable generation and tariffs in the day-ahead electricity market. This paper examines the use of fractional-ARIMA or f-ARIMA models to model, and forecast wind speeds on the day-ahead (24 h) and two-day-ahead (48 h) horizons. The models are applied to wind speed records obtained from four potential wind generation sites in North Dakota. The forecasted wind speeds are used in conjunction with the power curve of an operational (NEG MICON, 750 kW) turbine to obtain corresponding forecasts of wind power production. The forecast errors in wind speed/power are analyzed and compared with the persistence model. Results indicate that significant improvements in forecasting accuracy are obtained with the proposed models compared to the persistence method. (author)

  5. Stochastic coordination of joint wind and photovoltaic systems with energy storage in day-ahead market

    International Nuclear Information System (INIS)

    Gomes, I.L.R.; Pousinho, H.M.I.; Melício, R.; Mendes, V.M.F.

    2017-01-01

    This paper presents an optimal bid submission in a day-ahead electricity market for the problem of joint operation of wind with photovoltaic power systems having an energy storage device. Uncertainty not only due to the electricity market price, but also due to wind and photovoltaic powers is one of the main characteristics of this submission. The problem is formulated as a two-stage stochastic programming problem. The optimal bids and the energy flow in the batteries are the first-stage variables and the energy deviation is the second stage variable of the problem. Energy storage is a way to harness renewable energy conversion, allowing the store and discharge of energy at conveniently market prices. A case study with data from the Iberian day-ahead electricity market is presented and a comparison between joint and disjoint operations is discussed. - • Joint wind and PV systems with energy storage. • Electricity markets. • Stochastic optimization. • Day-ahead market.

  6. Powernext Day-Ahead. Powernext Futures. Powernext Carbon. Powernext Weather. Activity assessment first-half 2006

    International Nuclear Information System (INIS)

    2006-01-01

    Powernext SA is a Multilateral Trading Facility which organizes and warrants the transactions on the European power exchange and CO 2 exchange markets. This activity report presents the highlights of the market and of Powernext in the first half of 2006: market conditions, prices and traded volumes on Powernext (Powernext Day-Ahead TM in the case of day-ahead contracts, Powernext Futures TM in the case of medium-term contracts, and Powernext Carbon in the case of CO 2 ), new active members, and liquidity on the power market. (J.S.)

  7. Day-Ahead Energy Planning with 100% Electric Vehicle Penetration in the Nordic Region by 2050

    DEFF Research Database (Denmark)

    Liu, Zhaoxi; Wu, Qiuwei; Nielsen, Arne Hejde

    2014-01-01

    This paper presents the day-ahead energy planning of passenger cars with 100% electric vehicle (EV) penetration in the Nordic region by 2050. EVs will play an important role in the future energy systems which can both reduce the greenhouse gas (GHG) emission from the transport sector and provide...... demand side flexibility required by the smart grids. On the other hand, the EVs will increase the electricity consumption. In order to quantify the electricity consumption increase due to the 100% EV penetration in the Nordic region to facilitate the power system planning studies, the day-ahead energy...

  8. The effect of contingency analysis on the nodal prices in the day-ahead market

    International Nuclear Information System (INIS)

    Murphy, Frederic H.; Mudrageda, Murthy; Soyster, Allen L.; Saric, Andrija T.; Stankovic, Aleksandar M.

    2010-01-01

    We look at the effect of modeling branch-outage contingencies on locational marginal prices. To model contingencies in the day-ahead auction, we formulate a two-stage stochastic program. Rather than follow the current practice of including a list of possible contingencies that must be satisfied, we incorporate a larger set of contingencies in the model and allow contingencies to result in load reductions/outages at a cost. The model can be used and interpreted in two ways. One is to look at the tradeoff between reliability and outage costs. Another is to consider the load losses resulting from a contingency to be consumer offers of load reductions in response to line outages as part of the day-ahead auction. In analyzing the model structure, we find that the prices in the model closer in definition to those currently used in the day-ahead auction do not maximize expected surplus because the day-ahead auction produces prices that assume shortages will never occur. This raises issues with the design of auctions with important stochastic elements in the market. We present results for a 68-node grid with 86 branches (lines and transformers) to illustrate how prices and expected values change as the costs of outages are varied. (author)

  9. Demand Response from Day-Ahead Hourly Pricing for Large Customers

    International Nuclear Information System (INIS)

    Hopper, Nicole; Goldman, Charles; Neenan, Bernie

    2006-01-01

    Day-ahead default-service RTP for large customers not only improves the linkage between wholesale and retail markets, but also promotes the development of retail competition. The default service sets a standard for competitive alternatives and its structure shapes the types of retail market products that develop. (author)

  10. Day-ahead resource scheduling including demand response for electric vehicles

    DEFF Research Database (Denmark)

    Soares, Joao; Morais, Hugo; Sousa, Tiago

    2014-01-01

    the intensive use of distributed generation and V2G. The main focus is the comparison of different EV management approaches in the day-ahead energy resources management, namely uncontrolled charging, smart charging, V2G and Demand Response (DR) programs in the V2G approach. Three different DR programs...

  11. Multi-objective parallel particle swarm optimization for day-ahead Vehicle-to-Grid scheduling

    DEFF Research Database (Denmark)

    Soares, Joao; Vale, Zita; Canizes, Bruno

    2013-01-01

    This paper presents a methodology for multi-objective day-ahead energy resource scheduling for smart grids considering intensive use of distributed generation and Vehicle-To-Grid (V2G). The main focus is the application of weighted Pareto to a multi-objective parallel particle swarm approach aiming...

  12. Predictive densities for day-ahead electricity prices using time-adaptive quantile regression

    DEFF Research Database (Denmark)

    Jónsson, Tryggvi; Pinson, Pierre; Madsen, Henrik

    2014-01-01

    A large part of the decision-making problems actors of the power system are facing on a daily basis requires scenarios for day-ahead electricity market prices. These scenarios are most likely to be generated based on marginal predictive densities for such prices, then enhanced with a temporal...

  13. Day-ahead distributed energy resource scheduling using differential search algorithm

    DEFF Research Database (Denmark)

    Soares, J.; Lobo, C.; Silva, M.

    2015-01-01

    considers that energy resources are managed by a VPP which establishes contracts with their owners. The full AC power flow calculation included in the model takes into account network constraints. This paper presents an application of differential search algorithm (DSA) for solving the day-ahead scheduling...

  14. Thermal energy storage for electricity-driven space heating in a day-ahead electricity market

    DEFF Research Database (Denmark)

    Pensini, Alessandro

    2012-01-01

    Thermal Energy Storage (TES) in a space heating (SH) application was investigated. The study aimed to determine the economic benefits of introducing TES into an electricity-driven SH system under a day-ahead electricity market. The performance of the TES was assessed by comparing the cost...

  15. The impact of renewable energies on EEX day-ahead electricity prices

    International Nuclear Information System (INIS)

    Paraschiv, Florentina; Erni, David; Pietsch, Ralf

    2014-01-01

    In this paper, we analyze the impact of renewable energies, wind and photovoltaic, on the formation of day-ahead electricity prices at EEX. We give an overview of the policy decisions concerning the promotion of renewable energy sources in Germany and discuss their consequences on day-ahead prices. An analysis of electricity spot prices reveals that the introduction of renewable energies enhances extreme price changes. In the frame of a dynamic fundamental model, we show that there has been a continuous electricity price adaption process to market fundamentals. Furthermore, the fundamental drivers of prices differ among hours with different load profiles. Our results imply that renewable energies decrease market spot prices and have implications on the traditional fuel mix for electricity production. However, the prices for the final consumers increased overall because they must pay in addition the feed-in tariffs for the promotion of renewable energy. - Highlights: • We analyze the impact of renewable energies on the day-ahead electricity prices at EEX. • We discuss the impact of renewables on day-ahead prices. • We show a continuous electricity price adaption process to market fundamentals. • Renewable energies decrease market spot prices and shift the merit order curve. • The prices for the final consumers however increased because of feed-in tariffs

  16. Can a wind farm with CAES survive in the day-ahead market?

    International Nuclear Information System (INIS)

    Mauch, Brandon; Carvalho, Pedro M.S.; Apt, Jay

    2012-01-01

    We investigate the economic viability of coupling a wind farm with compressed air energy storage (CAES) to participate in the day-ahead electricity market at a time when renewable portfolio standards are not binding and wind competes freely in the marketplace. In our model, the CAES is used to reduce the risk of committing uncertain quantities of wind energy and to shift dispatch of wind generation to high price periods. Other sources of revenue (capacity markets, ancillary services, price arbitrage) are not included in the analysis. We present a model to calculate profit maximizing day-ahead dispatch schedules based on wind forecasts. Annual profits are determined with dispatch schedules and actual wind generation values. We find that annual income for the modeled wind–CAES system would not cover annualized capital costs using market prices from the years 2006 to 2009. We also estimate market prices with a carbon price of $20 and $50 per tonne CO 2 and find that revenue would still not cover the capital costs. The implied cost per tonne of avoided CO 2 to make a wind–CAES profitable from trading on the day-ahead market is roughly $100, with large variability due to electric power prices. - Highlights: ► We modeled a wind farm participating in the day-ahead electricity market. ► We calculated optimal day-ahead market offers based on wind forecasts. ► Revenue is then calculated using measured wind power. ► We find that revenue is insufficient to cover capital costs at current market prices.

  17. Everything you need to know to operate on Day-AheadTM

    International Nuclear Information System (INIS)

    2005-05-01

    The introduction of a power exchange in France is a direct response to the opening up of the European electricity markets. Powernext SA is a Multilateral Trading Facility in charge of managing the French power exchange through an optional and anonymous organised exchange offering: - Day-ahead contracts for the management of volume risk on Powernext Day-Ahead TM since 21 November 2001, - Medium term contracts for the management of price risk on Powernext Futures TM since 18 June 2004. This document is the user's guide of Powernext Day-Ahead TM . It presents: 1 - the power exchange in France (market model, Powernext's regulatory environment, general market operations, 2 - Powernext Day-Ahead TM members (membership, agreement, start-up notification, tariffs, standing obligations, membership termination), 3 - Powernext Day-Ahead TM products (specifications, management), 4 - trading (connections, system flow chart, ElWeb client installation and daily connections, portfolio-management, single bidding, type of order, submitting, importing, saving, sending, modifying or canceling an order form, transmission problems, block bidding block bid characteristics, sending, saving, transmitting, modifying and canceling a block bid, price calculations, blind auction procedure, example, taking into account block bids, rounding off rules, consulting and saving the results, sample documents, auction validation), 5 - clearing (LCH.Clearnet SA, legal framework, clearing agreement, PP-DPES agreement, market security, initial margin, daily adjustments, additional margin calls, trade-related financial flows, net financial position, value-added tax, settlement statements, general idea, characteristics and transmission method of settlement statements sample Documents, cash calls, settlement, default, sample cash call documents, financial Reports), 6 - delivery (balance responsible entity, file characteristics and transmission, imbalance settlement, interconnection access), contacts and

  18. Powernext Day-Ahead. Powernext Futures. Powernext Carbon. Powernext Weather. 2006 activity assessment

    International Nuclear Information System (INIS)

    2006-01-01

    Powernext SA is a Multilateral Trading Facility which organizes and warrants the transactions on the European power exchange and CO 2 exchange markets. This activity report presents the highlights of the market and of Powernext in 2006: market conditions (prices on the electricity market, prices on the CO 2 emission allowances market, weather conditions, institutional aspects of the CO 2 market, power generation and consumption, situation at the borders, fuel prices), traded volumes on Powernext (Powernext Day-Ahead TM in the case of day-ahead contracts, Powernext Futures TM in the case of medium-term contracts, and Powernext Carbon in the case of CO 2 ), new active members, and Powernext liquidity on the power market. (J.S.)

  19. A regime-switching copula approach to modeling day-ahead prices in coupled electricity markets

    DEFF Research Database (Denmark)

    Pircalabu, Anca; Benth, Fred Espen

    2017-01-01

    The recent price coupling of many European electricity markets has triggered a fundamental change in the interaction of day-ahead prices, challenging additionally the modeling of the joint behavior of prices in interconnected markets. In this paper we propose a regime-switching AR–GARCH copula...... to model pairs of day-ahead electricity prices in coupled European markets. While capturing key stylized facts empirically substantiated in the literature, this model easily allows us to 1) deviate from the assumption of normal margins and 2) include a more detailed description of the dependence between...... prices. We base our empirical study on four pairs of prices, namely Germany–France, Germany–Netherlands, Netherlands–Belgium and Germany–Western Denmark. We find that the marginal dynamics are better described by the flexible skew t distribution than the benchmark normal distribution. Also, we find...

  20. Optimal scheduling for electric heat booster under day-ahead electricity and heat pricing

    DEFF Research Database (Denmark)

    Cai, Hanmin; You, Shi; Bindner, Henrik W.

    2017-01-01

    Multi-energy system (MES) operation calls for active management of flexible resources across energy sectors to improve efficiency and meet challenging environmental targets. Electric heat booster, a solution for Domestic Hot Water (DHW) preparation under Low-Temperature-District-Heating (LTDH......) context, is identified as one of aforementioned flexible resources for electricity and heat sectors. This paper extends the concept of optimal load scheduling under day-ahead pricing from electricity sector only to both electricity and heat sectors. A case study constructing day-ahead energy prices...... to shift energy consumption to low carbon content energy is provided. Results show that 0.5 DKK/kWhel add-ons on top of electricity spot price makes electricity and heat price not comparable such that electricity price variation will have no impact on load scheduling. This result suggests aforementioned...

  1. Coordination of bidding strategies in day-ahead energy and spinning reserve markets

    International Nuclear Information System (INIS)

    Fushuan Wen; David, A.K.

    2002-01-01

    In this paper, the problem of building optimally coordinated bidding strategies for competitive suppliers in day-ahead energy and spinning reserve markets is addressed. It is assumed that each supplier bids 24 linear energy supply functions and 24 linear spinning reserve supply functions, one for each hour, into the energy and spinning reserve markets, respectively, and each market is cleared separately and simultaneously for all the 24 delivery hours. Each supplier makes decisions on unit commitment and chooses the coefficients in the linear energy and spinning reserve supply functions to maximise total benefits, subject to expectations about how rival suppliers will bid in both markets. Two different bidding schemes have been suggested for each hour, and based on them an overall coordinated bidding strategy in the day-ahead energy and spinning reserve market is then developed. Stochastic optimisation models are first developed to describe these two different bidding schemes and a genetic algorithm (GA) is then used to build the optimally coordinated bidding strategies for each scheme and to develop an overall bidding strategy for the day-ahead energy and spinning reserve markets. A numerical example is utilised to illustrate the essential features of the method. (Author)

  2. Optimal operation and forecasting policy for pump storage plants in day-ahead markets

    International Nuclear Information System (INIS)

    Muche, Thomas

    2014-01-01

    Highlights: • We investigate unit commitment deploying stochastic and deterministic approaches. • We consider day-ahead markets, its forecast and weekly price based unit commitment. • Stochastic and deterministic unit commitment are identical for the first planning day. • Unit commitment and bidding policy can be based on the deterministic approach. • Robust forecasting models should be estimated based on the whole planning horizon. - Abstract: Pump storage plants are an important electricity storage technology at present. Investments in this technology are expected to increase. The necessary investment valuation often includes expected cash flows from future price-based unit commitment policies. A price-based unit commitment policy has to consider market price uncertainty and the information revealing nature of electricity markets. For this environment stochastic programming models are suggested to derive the optimal unit commitment policy. For the considered day-ahead price electricity market stochastic and deterministic unit commitment policies are comparable suggesting an application of easier implementable deterministic models. In order to identify suitable unit commitment and forecasting policies, deterministic unit commitment models are applied to actual day-ahead electricity prices of a whole year. As a result, a robust forecasting model should consider the unit commitment planning period. This robust forecasting models result in expected cash flows similar to realized ones allowing a reliable investment valuation

  3. Comparative analysis of features of Polish and Lithuanian Day-ahead electricity market prices

    International Nuclear Information System (INIS)

    Bobinaite, Viktorija; Juozapaviciene, Aldona; Staniewski, Marcin; Szczepankowski, Piotr

    2013-01-01

    The goal of this article is to better understand the processes of electricity market price formation in Poland and Lithuania through an analysis of the features (volatility and spikes) of Lithuanian and Polish day-ahead electricity market prices and to assess how acquired electricity price features could affect the achievement of the main goals of the national energy policy. The following indicators have been calculated to determine electricity market price volatility: the oscillation coefficient, the coefficient of variation, an adjusted coefficient of variation, the standard deviation indicator, the daily velocity indicator (based on the overall average price) and the daily velocity indicator (based on the daily average price). Critical values for electricity market price have been calculated to evaluate price spikes. This analysis reveals that electricity market-price volatility is moderate in Poland and high in Lithuania. Electricity price spikes have been an observable phenomenon both in Lithuanian and in Polish day-ahead electricity markets, but they are more common in Lithuania, encompassing 3.15% of the time period analysed in Poland and 4.68% of the time period analysed in Lithuania. Volatile, spiking and increasing electricity prices in day-ahead electricity markets in Lithuania and Poland create preconditions and substantiate the relevance of implementation of the national energy policies and measures. - Highlights: • Moderate and seasonal volatility. • spiking market price and. • stable average price

  4. Customer Strategies for Responding to Day-Ahead Market HourlyElectricity Pricing

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, Chuck; Hopper, Nicole; Bharvirkar, Ranjit; Neenan,Bernie; Boisvert, Dick; Cappers, Peter; Pratt, Donna; Butkins, Kim

    2005-08-25

    Real-time pricing (RTP) has been advocated as an economically efficient means to send price signals to customers to promote demand response (DR) (Borenstein 2002, Borenstein 2005, Ruff 2002). However, limited information exists that can be used to judge how effectively RTP actually induces DR, particularly in the context of restructured electricity markets. This report describes the second phase of a study of how large, non-residential customers' adapted to default-service day-ahead hourly pricing. The customers are located in upstate New York and served under Niagara Mohawk, A National Grid Company (NMPC)'s SC-3A rate class. The SC-3A tariff is a type of RTP that provides firm, day-ahead notice of hourly varying prices indexed to New York Independent System Operator (NYISO) day-ahead market prices. The study was funded by the California Energy Commission (CEC)'s PIER program through the Demand Response Research Center (DRRC). NMPC's is the first and longest-running default-service RTP tariff implemented in the context of retail competition. The mix of NMPC's large customers exposed to day-ahead hourly prices is roughly 30% industrial, 25% commercial and 45% institutional. They have faced periods of high prices during the study period (2000-2004), thereby providing an opportunity to assess their response to volatile hourly prices. The nature of the SC-3A default service attracted competitive retailers offering a wide array of pricing and hedging options, and customers could also participate in demand response programs implemented by NYISO. The first phase of this study examined SC-3A customers' satisfaction, hedging choices and price response through in-depth customer market research and a Constant Elasticity of Substitution (CES) demand model (Goldman et al. 2004). This second phase was undertaken to answer questions that remained unresolved and to quantify price response to a higher level of granularity. We accomplished these

  5. Probabilistic Price Forecasting for Day-Ahead and Intraday Markets: Beyond the Statistical Model

    Directory of Open Access Journals (Sweden)

    José R. Andrade

    2017-10-01

    Full Text Available Forecasting the hourly spot price of day-ahead and intraday markets is particularly challenging in electric power systems characterized by high installed capacity of renewable energy technologies. In particular, periods with low and high price levels are difficult to predict due to a limited number of representative cases in the historical dataset, which leads to forecast bias problems and wide forecast intervals. Moreover, these markets also require the inclusion of multiple explanatory variables, which increases the complexity of the model without guaranteeing a forecasting skill improvement. This paper explores information from daily futures contract trading and forecast of the daily average spot price to correct point and probabilistic forecasting bias. It also shows that an adequate choice of explanatory variables and use of simple models like linear quantile regression can lead to highly accurate spot price point and probabilistic forecasts. In terms of point forecast, the mean absolute error was 3.03 €/MWh for day-ahead market and a maximum value of 2.53 €/MWh was obtained for intraday session 6. The probabilistic forecast results show sharp forecast intervals and deviations from perfect calibration below 7% for all market sessions.

  6. 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.

  7. Explanatory Information Analysis for Day-Ahead Price Forecasting in the Iberian Electricity Market

    Directory of Open Access Journals (Sweden)

    Claudio Monteiro

    2015-09-01

    Full Text Available This paper presents the analysis of the importance of a set of explanatory (input variables for the day-ahead price forecast in the Iberian Electricity Market (MIBEL. The available input variables include extensive hourly time series records of weather forecasts, previous prices, and regional aggregation of power generations and power demands. The paper presents the comparisons of the forecasting results achieved with a model which includes all these available input variables (EMPF model with respect to those obtained by other forecasting models containing a reduced set of input variables. These comparisons identify the most important variables for forecasting purposes. In addition, a novel Reference Explanatory Model for Price Estimations (REMPE that achieves hourly price estimations by using actual power generations and power demands of such day is described in the paper, which offers the lowest limit for the forecasting error of the EMPF model. All the models have been implemented using the same technique (artificial neural networks and have been satisfactorily applied to the real-world case study of the Iberian Electricity Market (MIBEL. The relative importance of each explanatory variable is identified for the day-ahead price forecasts in the MIBEL. The comparisons also allow outlining guidelines of the value of the different types of input information.

  8. Optimal Day-ahead Scheduling for Microgrid Participation in Frequency Regulation Markets

    Energy Technology Data Exchange (ETDEWEB)

    Baone, Chaitanya [General Electric; Acharya, Naresh [General Electric; Wiegman, Herman [General Electric

    2016-09-09

    As microgrid installations are steadily growing in the United States and around the world, widespread adoption of commercial microgrids would rely upon the economic benefit to the owners and operators. With the introduction of new market mechanisms and growing penetration of non-traditional generation assets, there is an increasing need and interest in allowing distributed assets to participate in traditional grid services such as frequency regulation. This paper considers the problem of determining the optimal balance of energy and ancillary services for individual microgrid generation assets to participate in such markets. An optimization framework that maximizes the predicted performance of the microgrid over a day-ahead time horizon while accounting for individual asset constraints is proposed. Simulation results on a realistic test system with practical considerations are presented.

  9. Modeling the transient security constraints of natural gas network in day-ahead power system scheduling

    DEFF Research Database (Denmark)

    Yang, Jingwei; Zhang, Ning; Kang, Chongqing

    2017-01-01

    accurately, they are hard to be embedded into the power system scheduling model, which consists of algebraic equations and inequations. This paper addresses this dilemma by proposing an algebraic transient model of natural gas network which is similar to the branch-node model of power network. Based......The rapid deployment of gas-fired generating units makes the power system more vulnerable to failures in the natural gas system. To reduce the risk of gas system failure and to guarantee the security of power system operation, it is necessary to take the security constraints of natural gas...... pipelines into account in the day-ahead power generation scheduling model. However, the minute- and hour-level dynamic characteristics of gas systems prevents an accurate decision-making simply with the steady-state gas flow model. Although the partial differential equations depict the dynamics of gas flow...

  10. Optimal Day-ahead Charging Scheduling of Electric Vehicles through an Aggregative Game Model

    DEFF Research Database (Denmark)

    Liu, Zhaoxi; Wu, Qiuwei; Huang, Shaojun

    2017-01-01

    The electric vehicle (EV) market has been growing rapidly around the world. With large scale deployment of EVs in power systems, both the grid and EV owners will benefit if the flexible demand of EV charging is properly managed through the electricity market. When EV charging demand is considerable...... in a grid, it will impact spot prices in the electricity market and consequently influence the charging scheduling itself. The interaction between the spot prices and the EV demand needs to be considered in the EV charging scheduling, otherwise it will lead to a higher charging cost. A day-ahead EV charging...... scheduling based on an aggregative game model is proposed in this paper. The impacts of the EV demand on the electricity prices are formulated with the game model in the scheduling considering possible actions of other EVs. The existence and uniqueness of the pure strategy Nash equilibrium are proved...

  11. Day-Ahead Scheduling Considering Demand Response as a Frequency Control Resource

    Directory of Open Access Journals (Sweden)

    Yu-Qing Bao

    2017-01-01

    Full Text Available The development of advanced metering technologies makes demand response (DR able to provide fast response services, e.g., primary frequency control. It is recognized that DR can contribute to the primary frequency control like thermal generators. This paper proposes a day-ahead scheduling method that considers DR as a frequency control resource, so that the DR resources can be dispatched properly with other resources. In the proposed method, the objective of frequency control is realized by defining a frequency limit equation under a supposed contingency. The frequency response model is used to model the dynamics of system frequency. The nonlinear frequency limit equation is transformed to a linear arithmetic equation by piecewise linearization, so that the problem can be solved by mixed integer linear programming (MILP. Finally, the proposed method is verified on numerical examples.

  12. Price forecasting of day-ahead electricity markets using a hybrid forecast method

    International Nuclear Information System (INIS)

    Shafie-khah, M.; Moghaddam, M. Parsa; Sheikh-El-Eslami, M.K.

    2011-01-01

    Research highlights: → A hybrid method is proposed to forecast the day-ahead prices in electricity market. → The method combines Wavelet-ARIMA and RBFN network models. → PSO method is applied to obtain optimum RBFN structure for avoiding over fitting. → One of the merits of the proposed method is lower need to the input data. → The proposed method has more accurate behavior in compare with previous methods. -- Abstract: Energy price forecasting in a competitive electricity market is crucial for the market participants in planning their operations and managing their risk, and it is also the key information in the economic optimization of the electric power industry. However, price series usually have a complex behavior due to their nonlinearity, nonstationarity, and time variancy. In this paper, a novel hybrid method to forecast day-ahead electricity price is proposed. This hybrid method is based on wavelet transform, Auto-Regressive Integrated Moving Average (ARIMA) models and Radial Basis Function Neural Networks (RBFN). The wavelet transform provides a set of better-behaved constitutive series than price series for prediction. ARIMA model is used to generate a linear forecast, and then RBFN is developed as a tool for nonlinear pattern recognition to correct the estimation error in wavelet-ARIMA forecast. Particle Swarm Optimization (PSO) is used to optimize the network structure which makes the RBFN be adapted to the specified training set, reducing computation complexity and avoiding overfitting. The proposed method is examined on the electricity market of mainland Spain and the results are compared with some of the most recent price forecast methods. The results show that the proposed hybrid method could provide a considerable improvement for the forecasting accuracy.

  13. A day-ahead market for electricity in Alberta : is there a case to be made?

    International Nuclear Information System (INIS)

    Fronimos, P.

    2006-01-01

    Following the success of the introduction of competition in several heavily regulated industries in the 1980s and 1990s, traditional utilities were broken up and markets were introduced for their respective services. Some of these markets evolved into complex structures with multiple sub-markets for installed capacity, energy, transmission and for all types of reserves. Electricity submarkets now operate in a similar manner in different timeframes comprising two settlement systems: the Day Ahead (DA) market, operating a day ahead of the actual generation and consumption of electricity and one that operates in real time, the Real-Time (RT) or Balancing market. This paper explored the case for a binding DA market for electricity in Alberta, by looking at the challenges facing the marketplace and examining how using a DA market would affect them. This paper hypothesized that a correctly designed and implemented, financially binding DA market would enhance the fidelity of the price signal in Alberta by providing an information rich environment for participants and the system operator. The paper defined and discussed both types of settlement systems. It then discussed the DA market in Alberta in terms of risk management, reliability, price fidelity and demand response. It was noted that some of the benefits of using a DA market could also be achieved by improvements to the existing market. Alberta faces several challenges, such as merit order instability and price volatility which are likely due to market design and operations rather than the inherent inability of a power exchange to address them. 31 refs., 1 tab., 3 figs

  14. Optimizing Hydropower Day-Ahead Scheduling for the Oroville-Thermalito Project

    Science.gov (United States)

    Veselka, T. D.; Mahalik, M.

    2012-12-01

    Under an award from the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Water Power Program, a team of national laboratories is developing and demonstrating a suite of advanced, integrated analytical tools to assist managers and planners increase hydropower resources while enhancing the environment. As part of the project, Argonne National Laboratory is developing the Conventional Hydropower Energy and Environmental Systems (CHEERS) model to optimize day-ahead scheduling and real-time operations. We will present the application of CHEERS to the Oroville-Thermalito Project located in Northern California. CHEERS will aid California Department of Water Resources (CDWR) schedulers in making decisions about unit commitments and turbine-level operating points using a system-wide approach to increase hydropower efficiency and the value of power generation and ancillary services. The model determines schedules and operations that are constrained by physical limitations, characteristics of plant components, operational preferences, reliability, and environmental considerations. The optimization considers forebay and afterbay implications, interactions between cascaded power plants, turbine efficiency curves and rough zones, and operator preferences. CHEERS simultaneously considers over time the interactions among all CDWR power and water resources, hydropower economics, reservoir storage limitations, and a set of complex environmental constraints for the Thermalito Afterbay and Feather River habitats. Power marketers, day-ahead schedulers, and plant operators provide system configuration and detailed operational data, along with feedback on model design and performance. CHEERS is integrated with CDWR data systems to obtain historic and initial conditions of the system as the basis from which future operations are then optimized. Model results suggest alternative operational regimes that improve the value of CDWR resources to the grid while

  15. Powernext Day-Ahead. Powernext Futures. Powernext Carbon. Powernext Weather. Activity assessment first-half 2006; Powernext Day-Ahead. Powernext Futures. Powernext Carbon. Powernext Weather. Bilan d'activite premier semestre 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    Powernext SA is a Multilateral Trading Facility which organizes and warrants the transactions on the European power exchange and CO{sub 2} exchange markets. This activity report presents the highlights of the market and of Powernext in the first half of 2006: market conditions, prices and traded volumes on Powernext (Powernext Day-Ahead{sup TM} in the case of day-ahead contracts, Powernext Futures{sup TM} in the case of medium-term contracts, and Powernext Carbon in the case of CO{sub 2}), new active members, and liquidity on the power market. (J.S.)

  16. Customer response to day-ahead wholesale market electricity prices: Case study of RTP program experience in New York

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, C.; Hopper, N.; Sezgen, O.; Moezzi, M.; Bharvirkar, R.; Neenan, B.; Boisvert, R.; Cappers, P.; Pratt, D.

    2004-07-01

    There is growing interest in policies, programs and tariffs that encourage customer loads to provide demand response (DR) to help discipline wholesale electricity markets. Proposals at the retail level range from eliminating fixed rate tariffs as the default service for some or all customer groups to reinstituting utility-sponsored load management programs with market-based inducements to curtail. Alternative rate designs include time-of-use (TOU), day-ahead real-time pricing (RTP), critical peak pricing, and even pricing usage at real-time market balancing prices. Some Independent System Operators (ISOs) have implemented their own DR programs whereby load curtailment capabilities are treated as a system resource and are paid an equivalent value. The resulting load reductions from these tariffs and programs provide a variety of benefits, including limiting the ability of suppliers to increase spot and long-term market-clearing prices above competitive levels (Neenan et al., 2002; Boren stein, 2002; Ruff, 2002). Unfortunately, there is little information in the public domain to characterize and quantify how customers actually respond to these alternative dynamic pricing schemes. A few empirical studies of large customer RTP response have shown modest results for most customers, with a few very price-responsive customers providing most of the aggregate response (Herriges et al., 1993; Schwarz et al., 2002). However, these studies examined response to voluntary, two-part RTP programs implemented by utilities in states without retail competition.1 Furthermore, the researchers had limited information on customer characteristics so they were unable to identify the drivers to price response. In the absence of a compelling characterization of why customers join RTP programs and how they respond to prices, many initiatives to modernize retail electricity rates seem to be stymied.

  17. Day-ahead resource scheduling of a renewable energy based virtual power plant

    International Nuclear Information System (INIS)

    Zamani, Ali Ghahgharaee; Zakariazadeh, Alireza; Jadid, Shahram

    2016-01-01

    Highlights: • Simultaneous energy and reserve scheduling of a VPP. • Aggregate uncertainties of electricity prices, renewable generation and load demand. • Develop a stochastic scheduling model using the point estimate method. - Abstract: The evolution of energy markets is accelerating in the direction of a greater reliance upon distributed energy resources (DERs). To manage this increasing two-way complexity, virtual power plants (VPPs) are being deployed today all over the world. In this paper, a probabilistic model for optimal day ahead scheduling of electrical and thermal energy resources in a VPP is proposed where participation of energy storage systems and demand response programs (DRPs) are also taken into account. In the proposed model, energy and reserve is simultaneously scheduled considering the uncertainties of market prices, electrical demand and intermittent renewable power generation. The Point Estimate Method (PEM) is applied in order to model the uncertainties of VPP’s scheduling problem. Moreover, the optimal reserve scheduling of VPP is presented which efficiently decreases VPP’s risk facing the unexpected fluctuations of uncertain parameters at the power delivery time. The results demonstrated that implementation of demand response programs (DRPs) would decrease total operation costs of VPP as well as its dependency on the upstream network.

  18. Generators' bidding behavior in the NYISO day-ahead wholesale electricity market

    International Nuclear Information System (INIS)

    Zhang, Ning

    2009-01-01

    This paper proposes a statistical and econometric model to analyze the generators' bidding behavior in the NYISO day-ahead wholesale electricity market. The generator level bidding data show very strong persistence in generators' grouping choices over time. Using dynamic random effect ordered probit model, we find that persistence is characterized by positive state dependence and unobserved heterogeneity and state dependence is more important than unobserved heterogeneity. The finding of true state dependence suggests a scope for economic policy intervention. If NYISO can implement an effective policy to switch generators from higher price groups to lower price groups, the effect is likely to be lasting. As a result, the market price can be lowered in the long-run. Generators' offered capacity is estimated by a two-stage sample selection model. The estimated results show that generators in higher-priced groups tend to withhold their capacity strategically to push up market prices. It further confirms the importance of an effective policy to turn generators into lower price groups in order to mitigate unexpected price spikes. The simulated market prices based on our estimated aggregate supply curve can replicate most volatility of actual DA market prices. Applying our models to different demand assumptions, we find that demand conditions can affect market prices significantly. It validates the importance of introducing demand side management during the restructure of electricity industry. (author)

  19. Optimal Bidding Strategies for Wind Power Producers in the Day-ahead Electricity Market

    Directory of Open Access Journals (Sweden)

    Xiaolin Liu

    2012-11-01

    Full Text Available Wind Power Producers (WPPs seek to maximize profit and minimize the imbalance costs when bidding into the day-ahead market, but uncertainties in the hourly available wind and forecasting errors make the bidding risky. This paper assumes that hourly wind power output given by the forecast follows a normal distribution, and proposes three different bidding strategies, i.e., the expected profit-maximization strategy (EPS, the chance-constrained programming-based strategy (CPS and the multi-objective bidding strategy (ECPS. Analytical solutions under the three strategies are obtained. Comparisons among the three strategies are conducted on a hypothetical wind farm which follows the Spanish market rules. Results show that bid under the EPS is highly dependent on market clearing price, imbalance prices, and also the mean value and standard deviation of wind forecast, and that bid under the CPS is largely driven by risk parameters and the mean value and standard deviation of the wind forecast. The ECPS combining both EPS and CPS tends to choose a compromise bid. Furthermore, the ECPS can effectively control the tradeoff between expected profit and target profit for WPPs operating in volatile electricity markets.

  20. Day-Ahead Congestion Management in Distribution Systems through Household Demand Response and Distribution Congestion Prices

    DEFF Research Database (Denmark)

    Liu, Weijia; Wu, Qiuwei; Wen, Fushuan

    2014-01-01

    With the development of smart grid technologies, some of the electric demands which are traditionally considered fixed and inflexible will become promising distributed energy resources (DERs) in future power systems. However, the participation of small scale or household energy sources...... into balancing power might challenge the operation of electric distribution systems and cause congestions. This paper presents a distribution congestion price (DCP) based market mechanism to alleviate possible distribution system congestions. By employing the loca- tional marginal pricing (LMP) model......, the proposed DCPs are able to reflect the real congestion cost and further direct the schedule of the responses of electric demands. Based on the NordPool Spot market structure, the interactions between aggregators and the distribution system operator (DSO) are discussed, and the procedure for calculating DCPs...

  1. Energy and Reserve under Distributed Energy Resources Management-Day-Ahead, Hour-Ahead and Real-Time

    DEFF Research Database (Denmark)

    Soares, Tiago; Silva, Marco; Sousa, Tiago

    2017-01-01

    and evaluates a generic model for day-ahead, intraday (hour-ahead) and real-time scheduling, considering the joint optimization of energy and reserve in the scope of the virtual power player concept. The model aims to minimize the operation costs in the point of view of one aggregator agent taking into account...

  2. Hybrid Particle Swarm Optimization based Day-Ahead Self-Scheduling for Thermal Generator in Competitive Electricity Market

    DEFF Research Database (Denmark)

    Pindoriya, Naran M.; Singh, S.N.; Østergaard, Jacob

    2009-01-01

    This paper presents a hybrid particle swarm optimization algorithm (HPSO) to solve the day-ahead self-scheduling for thermal power producer in competitive electricity market. The objective functions considered to model the self-scheduling problem are 1) to maximize the profit from selling energy...

  3. Powernext Day-Ahead. Powernext Futures. Powernext Carbon. Powernext Weather. 2006 activity assessment; Powernext Day-Ahead. Powernext Futures. Powernext Carbon. Powernext Weather. Bilan d'activite 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    Powernext SA is a Multilateral Trading Facility which organizes and warrants the transactions on the European power exchange and CO{sub 2} exchange markets. This activity report presents the highlights of the market and of Powernext in 2006: market conditions (prices on the electricity market, prices on the CO{sub 2} emission allowances market, weather conditions, institutional aspects of the CO{sub 2} market, power generation and consumption, situation at the borders, fuel prices), traded volumes on Powernext (Powernext Day-Ahead{sup TM} in the case of day-ahead contracts, Powernext Futures{sup TM} in the case of medium-term contracts, and Powernext Carbon in the case of CO{sub 2}), new active members, and Powernext liquidity on the power market. (J.S.)

  4. 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)

  5. Agent-Based Modeling of Day-Ahead Real Time Pricing in a Pool-Based Electricity Market

    Directory of Open Access Journals (Sweden)

    Sh. Yousefi

    2011-09-01

    Full Text Available In this paper, an agent-based structure of the electricity retail market is presented based on which day-ahead (DA energy procurement for customers is modeled. Here, we focus on operation of only one Retail Energy Provider (REP agent who purchases energy from DA pool-based wholesale market and offers DA real time tariffs to a group of its customers. As a model of customer response to the offered real time prices, an hourly acceptance function is proposed in order to represent the hourly changes in the customer’s effective demand according to the prices. Here, Q-learning (QL approach is applied in day-ahead real time pricing for the customers enabling the REP agent to discover which price yields the most benefit through a trial-and-error search. Numerical studies are presented based on New England day-ahead market data which include comparing the results of RTP based on QL approach with that of genetic-based pricing.

  6. Application of a Gradient Descent Continuous Actor-Critic Algorithm for Double-Side Day-Ahead Electricity Market Modeling

    Directory of Open Access Journals (Sweden)

    Huiru Zhao

    2016-09-01

    Full Text Available An important goal of China’s electric power system reform is to create a double-side day-ahead wholesale electricity market in the future, where the suppliers (represented by GenCOs and demanders (represented by DisCOs compete simultaneously with each other in one market. Therefore, modeling and simulating the dynamic bidding process and the equilibrium in the double-side day-ahead electricity market scientifically is not only important to some developed countries, but also to China to provide a bidding decision-making tool to help GenCOs and DisCOs obtain more profits in market competition. Meanwhile, it can also provide an economic analysis tool to help government officials design the proper market mechanisms and policies. The traditional dynamic game model and table-based reinforcement learning algorithm have already been employed in the day-ahead electricity market modeling. However, those models are based on some assumptions, such as taking the probability distribution function of market clearing price (MCP and each rival’s bidding strategy as common knowledge (in dynamic game market models, and assuming the discrete state and action sets of every agent (in table-based reinforcement learning market models, which are no longer applicable in a realistic situation. In this paper, a modified reinforcement learning method, called gradient descent continuous Actor-Critic (GDCAC algorithm was employed in the double-side day-ahead electricity market modeling and simulation. This algorithm can not only get rid of the abovementioned unrealistic assumptions, but also cope with the Markov decision-making process with continuous state and action sets just like the real electricity market. Meanwhile, the time complexity of our proposed model is only O(n. The simulation result of employing the proposed model in the double-side day-ahead electricity market shows the superiority of our approach in terms of participant’s profit or social welfare

  7. A Modified Feature Selection and Artificial Neural Network-Based Day-Ahead Load Forecasting Model for a Smart Grid

    OpenAIRE

    Ahmad, Ashfaq; Javaid, Nadeem; Alrajeh, Nabil; Khan, Zahoor; Qasim, Umar; Khan, Abid

    2015-01-01

    In the operation of a smart grid (SG), day-ahead load forecasting (DLF) is an important task. The SG can enhance the management of its conventional and renewable resources with a more accurate DLF model. However, DLF model development is highly challenging due to the non-linear characteristics of load time series in SGs. In the literature, DLF models do exist; however, these models trade off between execution time and forecast accuracy. The newly-proposed DLF model will be able to accurately ...

  8. Assessment of the Impact of Stochastic Day-Ahead SCUC on Economic and Reliability Metrics at Multiple Timescales: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wu, H.; Ela, E.; Krad, I.; Florita, A.; Zhang, J.; Hodge, B. M.; Ibanez, E.; Gao, W.

    2015-03-01

    This paper incorporates the stochastic day-ahead security-constrained unit commitment (DASCUC) within a multi-timescale, multi-scheduling application with commitment, dispatch, and automatic generation control. The stochastic DASCUC is solved using a progressive hedging algorithm with constrained ordinal optimization to accelerate the individual scenario solution. Sensitivity studies are performed in the RTS-96 system, and the results show how this new scheduling application would impact costs and reliability with a closer representation of timescales of system operations in practice.

  9. BINARY CLASSIFICATION OF DAY-AHEAD DEREGULATED ELECTRICITY MARKET PRICES USING NEURAL NETWORK INPUT FEATURED BY DCT

    Directory of Open Access Journals (Sweden)

    S. Anbazhagan

    2012-07-01

    Full Text Available There is a general consensus that the movement of electricity price is crucial for electricity market. The binary electricity price classification method is as an alternative to numerical electricity price forecasting due to high forecasting errors in various approaches. This paper proposes a binary classification of day-ahead electricity prices that could be realized using discrete cosine transforms (DCT based neural network (NN approach (DCT-NN. These electricity price classifications are important because all market participants do not to know the exact value of future prices in their decision-making process. In this paper, classifications of electricity market prices with respect to pre-specified electricity price threshold are used. In this proposed approach, all time series (historical price series are transformed from time domain to frequency domain using DCT. These discriminative spectral co-efficient forms the set of input features and are classified using NN. The binary classification NN and the proposed DCT-NN were developed and compared to check the performance. The simulation results show that the proposed method provides a better and efficient method for day-ahead deregulated electricity market of mainland Spain.

  10. Optimal bidding in Turkey day ahead electricity market for wind energy and pumped storage hydro power plant

    Directory of Open Access Journals (Sweden)

    Ceyhun Yıldız

    2016-10-01

    Full Text Available In electrical grid; when the demand power increases energy prices increase, when the demand decreases energy prices decrease. For this reason; to increase the total daily income, it is required to shift generations to the hours that high demand power values occurred. Wind Power Plants (WPP have unstable and uncontrollable generation characteristic. For this reason, energy storage systems are needed to shift the generations of WPPs in time scale. In this study, four wind power plants (WPP which are tied to the Turkish interconnected grid and a pumped hydro storage power plant (PSPP that meets the energy storage requirement of these power plants are investigated in Turkey day ahead energy market. An optimization algorithm is developed using linear programming technique to maximize the day ahead market bids of these plants which are going to generate power together. When incomes and generations of the plants that are operated with optimization strategy is analyzed, it is seen that annual income increased by 2.737% compared with WPPs ‘s alone operation and generations are substantially shifted to the high demand power occurred hours.

  11. Day-ahead electricity prices forecasting by a modified CGSA technique and hybrid WT in LSSVM based scheme

    International Nuclear Information System (INIS)

    Shayeghi, H.; Ghasemi, A.

    2013-01-01

    Highlights: • Presenting a hybrid CGSA-LSSVM scheme for price forecasting. • Considering uncertainties for filtering in input data and feature selection to improve efficiency. • Using DWT input featured LSSVM approach to classify next-week prices. • Used three real markets to illustrate performance of the proposed price forecasting model. - Abstract: At the present time, day-ahead electricity market is closely associated with other commodity markets such as fuel market and emission market. Under such an environment, day-ahead electricity price forecasting has become necessary for power producers and consumers in the current deregulated electricity markets. Seeking for more accurate price forecasting techniques, this paper proposes a new combination of a Feature Selection (FS) technique based mutual information (MI) technique and Wavelet Transform (WT) in this study. Moreover, in this paper a new modified version of Gravitational Search Algorithm (GSA) optimization based chaos theory, namely Chaotic Gravitational Search Algorithm (CGSA) is developed to find the optimal parameters of Least Square Support Vector Machine (LSSVM) to predict electricity prices. The performance and price forecast accuracy of the proposed technique is assessed by means of real data from Iran’s, Ontario’s and Spain’s price markets. The simulation results from numerical tables and figures in different cases show that the proposed technique increases electricity price market forecasting accuracy than the other classical and heretical methods in the scientific researches

  12. Offering strategy of a price-maker energy storage system in day-ahead and balancing markets

    DEFF Research Database (Denmark)

    Vespermann, Niklas Peter René Erich; Delikaraoglou, Stefanos; Pinson, Pierre

    2017-01-01

    . The offering strategy of a price-maker ESS operator is formulated as a bilevel model, where the upper-level problem represents the profit maximization of the ESS operator and the lower-level problem simulates the market-clearing outcome. This methodological framework can be used either to assess market......Energy storage systems (ESS) are considered as a promising solution to improve power system flexibility and facilitate the integration of renewables in electricity markets. This paper investigates the impact of strategic offering by an ESS operator in the day-ahead and balancing market...... efficiency distortion or as a trading strategy from the perspective of the ESS operator. Our analysis shows that adopting strategic behavior may improve ESS expected profit but reduces social welfare, especially for high ESS energy-to-power ratios....

  13. Incentive-based demand response programs designed by asset-light retail electricity providers for the day-ahead market

    DEFF Research Database (Denmark)

    Fotouhi Ghazvini, Mohammad Ali; Faria, Pedro; Ramos, Sergio

    2015-01-01

    Following the deregulation experience of retail electricity markets in most countries, the majority of the new entrants of the liberalized retail market were pure REP (retail electricity providers). These entities were subject to financial risks because of the unexpected price variations, price...... spikes, volatile loads and the potential for market power exertion by GENCO (generation companies). A REP can manage the market risks by employing the DR (demand response) programs and using its' generation and storage assets at the distribution network to serve the customers. The proposed model suggests...... to hedge the financial losses in the market. A two-stage stochastic programming problem is formulated. It aims to establish the financial incentive-based DR programs and the optimal dispatch of the DG units and ESSs. The uncertainty of the forecasted day-ahead load demand and electricity price is also...

  14. On Setting Day-Ahead Equity Trading Risk Limits: VaR Prediction at Market Close or Open?

    Directory of Open Access Journals (Sweden)

    Ana-Maria Fuertes

    2016-09-01

    Full Text Available This paper investigates the information content of the ex post overnight return for one-day-ahead equity Value-at-Risk (VaR forecasting. To do so, we deploy a univariate VaR modeling approach that constructs the forecast at market open and, accordingly, exploits the available overnight close-to-open price variation. The benchmark is the bivariate VaR modeling approach proposed by Ahoniemi et al. that constructs the forecast at the market close instead and, accordingly, it models separately the daytime and overnight return processes and their covariance. For a small cap portfolio, the bivariate VaR approach affords superior predictive ability than the ex post overnight VaR approach whereas for a large cap portfolio the results are reversed. The contrast indicates that price discovery at the market open is less efficient for small capitalization, thinly traded stocks.

  15. Day-ahead stochastic economic dispatch of wind integrated power system considering demand response of residential hybrid energy system

    International Nuclear Information System (INIS)

    Jiang, Yibo; Xu, Jian; Sun, Yuanzhang; Wei, Congying; Wang, Jing; Ke, Deping; Li, Xiong; Yang, Jun; Peng, Xiaotao; Tang, Bowen

    2017-01-01

    Highlights: • Improving the utilization of wind power by the demand response of residential hybrid energy system. • An optimal scheduling of home energy management system integrating micro-CHP. • The scattered response capability of consumers is aggregated by demand bidding curve. • A stochastic day-ahead economic dispatch model considering demand response and wind power. - Abstract: As the installed capacity of wind power is growing, the stochastic variability of wind power leads to the mismatch of demand and generated power. Employing the regulating capability of demand to improve the utilization of wind power has become a new research direction. Meanwhile, the micro combined heat and power (micro-CHP) allows residential consumers to choose whether generating electricity by themselves or purchasing from the utility company, which forms a residential hybrid energy system. However, the impact of the demand response with hybrid energy system contained micro-CHP on the large-scale wind power utilization has not been analyzed quantitatively. This paper proposes an operation optimization model of the residential hybrid energy system based on price response, integrating micro-CHP and smart appliances intelligently. Moreover, a novel load aggregation method is adopted to centralize scattered response capability of residential load. At the power grid level, a day-ahead stochastic economic dispatch model considering demand response and wind power is constructed. Furthermore, simulation is conducted respectively on the modified 6-bus system and IEEE 118-bus system. The results show that with the method proposed, the wind power curtailment of the system decreases by 78% in 6-bus system. In the meantime, the energy costs of residential consumers and the operating costs of the power system reduced by 10.7% and 11.7% in 118-bus system, respectively.

  16. Demand side management in a day-ahead wholesale market: A comparison of industrial & social welfare approaches

    International Nuclear Information System (INIS)

    Jiang, Bo; Farid, Amro M.; Youcef-Toumi, Kamal

    2015-01-01

    Highlights: • We compare two demand side management in a day-ahead electricity wholesale market. • We develop and reconcile social welfare & industrial DSM mathematical models. • We show the industrial netload has an additional forecast quantity of baseline. • We analytically and numerically show the model equivalence with accurate baseline. • We numerically demonstrate the baseline errors lead to higher and costlier dispatch. - Abstract: The intermittent nature of renewable energy has been discussed in the context of the operational challenges that it brings to electrical grid reliability. Demand side management (DSM) with its ability to allow customers to adjust electricity consumption in response to market signals has often been recognized as an efficient way to mitigate the variable effects of renewable energy as well as to increase system efficiency and reduce system costs. However, the academic & industrial literature have taken divergent approaches to DSM implementation. While the popular approach among academia adopts a social welfare maximization formulation, the industrial practice compensates customers according to their load reduction from a predefined electricity consumption baseline that would have occurred without DSM. This paper rigorously compares these two different approaches in a day-ahead wholesale market context analytically and in a test case using the same system configuration and mathematical formalism. The comparison of the two models showed that a proper reconciliation of the two models might make them mitigate the stochastic netload in fundamentally the same way, but only under very specific conditions which are rarely met in practice. While the social welfare model uses a stochastic net load composed of two terms, the industrial DSM model uses a stochastic net load composed of three terms including the additional baseline term. DSM participants are likely to manipulate the baseline in order to receive greater financial

  17. A Unified Trading Model Based on Robust Optimization for Day-Ahead and Real-Time Markets with Wind Power Integration

    DEFF Research Database (Denmark)

    Jiang, Yuewen; Chen, Meisen; You, Shi

    2017-01-01

    In a conventional electricity market, trading is conducted based on power forecasts in the day-ahead market, while the power imbalance is regulated in the real-time market, which is a separate trading scheme. With large-scale wind power connected into the power grid, power forecast errors increase...... in the day-ahead market which lowers the economic efficiency of the separate trading scheme. This paper proposes a robust unified trading model that includes the forecasts of real-time prices and imbalance power into the day-ahead trading scheme. The model is developed based on robust optimization in view...... swarm algorithm (QPSO). Finally, the impacts of associated parameters on the separate trading and unified trading model are analyzed to verify the superiority of the proposed model and algorithm....

  18. Day-Ahead Coordination of Vehicle-to-Grid Operation and Wind Power in Security Constraints Unit Commitment (SCUC

    Directory of Open Access Journals (Sweden)

    Mohammad Javad Abdollahi

    2015-08-01

    Full Text Available In this paper security constraints unit commitment (SCUC in the presence of wind power resources and electrical vehicles to grid is presented. SCUC operation prepare an optimal time table for generation unit commitment in order to maximize security, minimize operation cost and satisfy the constraints of networks and units in a period of time, as one of the most important research interest in power systems. Today, the relationship between power network and energy storage systems is interested for many researchers and network operators. Using Electrical Vehicles (PEVs and wind power for energy production is one of the newest proposed methods for replacing fossil fuels.One of the effective strategies for analyzing of the effects of Vehicle 2 Grid (V2G and wind power in optimal operation of generation is running of SCUC for power systems that are equipped with V2G and wind power resources. In this paper, game theory method is employed for deterministic solution of day-ahead unit commitment with considering security constraints in the simultaneous presence of V2G and wind power units. This problem for two scenarios of grid-controlled mode and consumer-controlled mode in three different days with light, medium and heavy load profiles is analyzed. Simulation results show the effectiveness of the presence of V2G and wind power for decreasing of generation cost and improving operation indices of power systems.

  19. Day-ahead price forecasting of electricity markets by a new feature selection algorithm and cascaded neural network technique

    International Nuclear Information System (INIS)

    Amjady, Nima; Keynia, Farshid

    2009-01-01

    With the introduction of restructuring into the electric power industry, the price of electricity has become the focus of all activities in the power market. Electricity price forecast is key information for electricity market managers and participants. However, electricity price is a complex signal due to its non-linear, non-stationary, and time variant behavior. In spite of performed research in this area, more accurate and robust price forecast methods are still required. In this paper, a new forecast strategy is proposed for day-ahead price forecasting of electricity markets. Our forecast strategy is composed of a new two stage feature selection technique and cascaded neural networks. The proposed feature selection technique comprises modified Relief algorithm for the first stage and correlation analysis for the second stage. The modified Relief algorithm selects candidate inputs with maximum relevancy with the target variable. Then among the selected candidates, the correlation analysis eliminates redundant inputs. Selected features by the two stage feature selection technique are used for the forecast engine, which is composed of 24 consecutive forecasters. Each of these 24 forecasters is a neural network allocated to predict the price of 1 h of the next day. The whole proposed forecast strategy is examined on the Spanish and Australia's National Electricity Markets Management Company (NEMMCO) and compared with some of the most recent price forecast methods. (author)

  20. Influence of feasibility constrains on the bidding strategy selection in a day-ahead electricity market session

    International Nuclear Information System (INIS)

    Borghetti, Alberto; Massucco, Stefano; Silvestro, Federico

    2009-01-01

    Large part of liberalized electricity markets, including the Italian one, features an auction mechanism, called day-ahead energy market, which matches producers' and buyers' simple bids, consisting of energy quantity and price pairs. The match is achieved by a merit-order economic dispatch procedure independently applied for each of the hours of the following day. Power plants operation should, however, take into account several technical constraints, such as maximum and minimum production bounds, ramp constraints and minimum up and downs times, as well as no-load and startup costs. The presence of these constraints forces to adjust the scheduling provided by the market in order to obtain a feasible scheduling. The paper presents an analysis of the possibility and the limits of taking into account the power plants technical constraints in the bidding strategy selection procedure of generating companies (Gencos). The analysis is carried out by using a computer procedure based both on a simple static game-theory approach and on a cost-minimization unit-commitment algorithm. For illustrative purposes, we present the results obtained for a system with three Gencos, each owning several power plants, trying to model the bidding behaviour of every generator in the system. This approach, although complex from the computational point of view, allows an analysis of both price and quantity bidding strategies and appears to be applicable to markets having different rules and features. (author)

  1. Security-constrained self-scheduling of generation companies in day-ahead electricity markets considering financial risk

    International Nuclear Information System (INIS)

    Amjady, Nima; Vahidinasab, Vahid

    2013-01-01

    Highlights: ► A security-constrained self-scheduling is presented. ► The proposed framework takes into account the uncertainty of the predicted market prices. ► We model the risk and profit tradeoff of a GENCO based on an efficient multi-objective model. ► Unit commitment and inter-temporal constraints of generators are considered in an MIP model. ► Simulation results are presented on the IEEE 30-bus and IEEE 118-bus test systems. - Abstract: In this paper, a new security-constrained self-scheduling framework incorporating the transmission flow limits in both steady state conditions and post-contingent states is presented to produce efficient bidding strategy for generation companies (GENCOs) in day-ahead electricity markets. Moreover, the proposed framework takes into account the uncertainty of the predicted market prices and models the risk and profit tradeoff of a GENCO based on an efficient multi-objective model. Furthermore, unit commitment and inter-temporal constraints of generators are considered in the suggested model converting it to a mixed-integer programming (MIP) optimization problem. Sensitivity of the proposed framework with respect to both the level of the market prices and adopted risk level is also evaluated in the paper. Simulation results are presented on the IEEE 30-bus and IEEE 118-bus test systems illustrating the performance of the proposed self-scheduling model.

  2. Decision support tool for Virtual Power Players: Hybrid Particle Swarm Optimization applied to Day-ahead Vehicle-To-Grid Scheduling

    DEFF Research Database (Denmark)

    Soares, João; Valle, Zita; Morais, Hugo

    2013-01-01

    of a new hybrid method combing a particle swarm approach and a deterministic technique based on mixedinteger linear programming (MILP) to solve the day-ahead scheduling minimizing total operation costs from the aggregator point of view. A realistic mathematical formulation, considering the electric network...

  3. A Modified Feature Selection and Artificial Neural Network-Based Day-Ahead Load Forecasting Model for a Smart Grid

    Directory of Open Access Journals (Sweden)

    Ashfaq Ahmad

    2015-12-01

    Full Text Available In the operation of a smart grid (SG, day-ahead load forecasting (DLF is an important task. The SG can enhance the management of its conventional and renewable resources with a more accurate DLF model. However, DLF model development is highly challenging due to the non-linear characteristics of load time series in SGs. In the literature, DLF models do exist; however, these models trade off between execution time and forecast accuracy. The newly-proposed DLF model will be able to accurately predict the load of the next day with a fair enough execution time. Our proposed model consists of three modules; the data preparation module, feature selection and the forecast module. The first module makes the historical load curve compatible with the feature selection module. The second module removes redundant and irrelevant features from the input data. The third module, which consists of an artificial neural network (ANN, predicts future load on the basis of selected features. Moreover, the forecast module uses a sigmoid function for activation and a multi-variate auto-regressive model for weight updating during the training process. Simulations are conducted in MATLAB to validate the performance of our newly-proposed DLF model in terms of accuracy and execution time. Results show that our proposed modified feature selection and modified ANN (m(FS + ANN-based model for SGs is able to capture the non-linearity(ies in the history load curve with 97 . 11 % accuracy. Moreover, this accuracy is achieved at the cost of a fair enough execution time, i.e., we have decreased the average execution time of the existing FS + ANN-based model by 38 . 50 % .

  4. Inexact stochastic risk-aversion optimal day-ahead dispatch model for electricity system management with wind power under uncertainty

    International Nuclear Information System (INIS)

    Ji, Ling; Huang, Guo-He; Huang, Lu-Cheng; Xie, Yu-Lei; Niu, Dong-Xiao

    2016-01-01

    High penetration of wind power generation and deregulated electricity market brings a great challenge to the electricity system operators. It is crucial to make optimal strategy among various generation units and spinning reserve for supporting the system safety operation. By integrating interval two-stage programming and stochastic robust programming, this paper proposes a novel robust model for day-ahead dispatch and risk-aversion management under uncertainties. In the proposed model, the uncertainties are expressed as interval values with different scenario probability. The proposed method requires low computation, and still retains the complete information. A case study is to validate the effectiveness of this approach. Facing the uncertainties of future demand and electricity price, the system operators need to make optimal dispatch strategy for thermal power units and wind turbine, and arrange proper spinning reserve and flexible demand response program to mitigate wind power forecasting error. The optimal strategies provide the system operators with better trade-off between the maximum benefits and the minimum system risk. In additional, two different market rules are compared. The results show that extra financial penalty for the wind power dispatch deviation is another efficient way to enhance the risk consciousness of decision makers and lead to more conservative strategy. - Highlights: • An inexact two-stage stochastic robust programming model for electricity system with wind power penetration. • Uncertainties expressed as discrete intervals and probability distributions. • Demand response program was introduced to adjust the deviation in real-time market. • Financial penalty for imbalance risk from wind power generation was evaluated.

  5. Not All Large Customers are Made Alike: Disaggregating Response to Default-Service Day-Ahead Market Pricing

    International Nuclear Information System (INIS)

    Hopper, Nicole; Goldman, Charles; Neenan, Bernie

    2006-01-01

    For decades, policymakers and program designers have gone on the assumption that large customers, particularly industrial facilities, are the best candidates for realtime pricing (RTP). This assumption is based partly on practical considerations (large customers can provide potentially large load reductions) but also on the premise that businesses focused on production cost minimization are most likely to participate and respond to opportunities for bill savings. Yet few studies have examined the actual price response of large industrial and commercial customers in a disaggregated fashion, nor have factors such as the impacts of demand response (DR) enabling technologies, simultaneous emergency DR program participation and price response barriers been fully elucidated. This second-phase case study of Niagara Mohawk Power Corporation (NMPC)'s large customer RTP tariff addresses these information needs. The results demonstrate the extreme diversity of large customers' response to hourly varying prices. While two-thirds exhibit some price response, about 20 percent of customers provide 75-80 percent of the aggregate load reductions. Manufacturing customers are most price-responsive as a group, followed by government/education customers, while other sectors are largely unresponsive. However, individual customer response varies widely. Currently, enabling technologies do not appear to enhance hourly price response; customers report using them for other purposes. The New York Independent System Operator (NYISO)'s emergency DR programs enhance price response, in part by signaling to customers that day-ahead prices are high. In sum, large customers do currently provide moderate price response, but there is significant room for improvement through targeted programs that help customers develop and implement automated load-response strategies

  6. Evaluation of Price-Sensitive Loads\\' Impacts on LMP and Market Power using LMP Decomposition

    Directory of Open Access Journals (Sweden)

    S. M. Sadr

    2016-06-01

    Full Text Available This paper presents a novel approach for evaluating impacts of price-sensitive loads on electricity price and market power. To accomplish this aim an analytical method along with agent-based computational economics are used. At first, Nash equilibrium is achieved by computational approach of Q-learning then based on the optimal bidding strategies of GenCos, which are figured out by Q-learning, ISO's social welfare maximization is restated considering demand side bidding. In this research, it was demonstrated that Locational Marginal Price (LMP at each node of system can be decomposed into five components. The first constitutive part is a constant value for the respective bus, while the next two components are related to GenCos and the last two parts are associated to Load Serving Entities (LSEs. Market regulators can acquire valuable information from the proposed LMP decomposition. First, sensitivity of electricity price at each bus and Lerner index of GenCos to the bidding strategies and maximum pricesensitive demand of LSEs are revealed through weighting coefficients of the last two terms in the decomposed LMP. Moreover, the decomposition of LMP expresses contribution of LSEs to the electricity price. The simulation results on two test systems confirm the capability of the proposed approach.

  7. Development and validation of a 5-day-ahead hay fever forecast for patients with grass-pollen-induced allergic rhinitis

    Science.gov (United States)

    de Weger, Letty A.; Beerthuizen, Thijs; Hiemstra, Pieter S.; Sont, Jacob K.

    2014-08-01

    One-third of the Dutch population suffers from allergic rhinitis, including hay fever. In this study, a 5-day-ahead hay fever forecast was developed and validated for grass pollen allergic patients in the Netherlands. Using multiple regression analysis, a two-step pollen and hay fever symptom prediction model was developed using actual and forecasted weather parameters, grass pollen data and patient symptom diaries. Therefore, 80 patients with a grass pollen allergy rated the severity of their hay fever symptoms during the grass pollen season in 2007 and 2008. First, a grass pollen forecast model was developed using the following predictors: (1) daily means of grass pollen counts of the previous 10 years; (2) grass pollen counts of the previous 2-week period of the current year; and (3) maximum, minimum and mean temperature ( R 2 = 0.76). The second modeling step concerned the forecasting of hay fever symptom severity and included the following predictors: (1) forecasted grass pollen counts; (2) day number of the year; (3) moving average of the grass pollen counts of the previous 2 week-periods; and (4) maximum and mean temperatures ( R 2 = 0.81). Since the daily hay fever forecast is reported in three categories (low-, medium- and high symptom risk), we assessed the agreement between the observed and the 1- to 5-day-ahead predicted risk categories by kappa, which ranged from 65 % to 77 %. These results indicate that a model based on forecasted temperature and grass pollen counts performs well in predicting symptoms of hay fever up to 5 days ahead.

  8. On the effectiveness of the anti-gaming policy between the day-ahead and real-time electricity markets in The Netherlands

    International Nuclear Information System (INIS)

    Boogert, A.; Dupont, D.

    2005-01-01

    In the paper, we study the linkage between two related markets for electricity in The Netherlands: the day-ahead market and the real-time market. The Dutch regulator wants to prevent trading across these two markets and has set up a dual pricing system for this purpose. In this paper, we test the effectiveness of this policy by studying the ex post profitability of trading strategies spanning the two markets over various time segments. Our results show that profits generated by these strategies are rarely positive on average and always characterized by very large potential losses, which dwarf the mean profit when the latter is positive. (author)

  9. Price Forecasting in the Day-Ahead Energy Market by an Iterative Method with Separate Normal Price and Price Spike Frameworks

    Directory of Open Access Journals (Sweden)

    Jarmo Partanen

    2013-11-01

    Full Text Available A forecasting methodology for prediction of both normal prices and price spikes in the day-ahead energy market is proposed. The method is based on an iterative strategy implemented as a combination of two modules separately applied for normal price and price spike predictions. The normal price module is a mixture of wavelet transform, linear AutoRegressive Integrated Moving Average (ARIMA and nonlinear neural network models. The probability of a price spike occurrence is produced by a compound classifier in which three single classification techniques are used jointly to make a decision. Combined with the spike value prediction technique, the output from the price spike module aims to provide a comprehensive price spike forecast. The overall electricity price forecast is formed as combined normal price and price spike forecasts. The forecast accuracy of the proposed method is evaluated with real data from the Finnish Nord Pool Spot day-ahead energy market. The proposed method provides significant improvement in both normal price and price spike prediction accuracy compared with some of the most popular forecast techniques applied for case studies of energy markets.

  10. A Hybrid Multi-Step Model for Forecasting Day-Ahead Electricity Price Based on Optimization, Fuzzy Logic and Model Selection

    Directory of Open Access Journals (Sweden)

    Ping Jiang

    2016-08-01

    Full Text Available The day-ahead electricity market is closely related to other commodity markets such as the fuel and emission markets and is increasingly playing a significant role in human life. Thus, in the electricity markets, accurate electricity price forecasting plays significant role for power producers and consumers. Although many studies developing and proposing highly accurate forecasting models exist in the literature, there have been few investigations on improving the forecasting effectiveness of electricity price from the perspective of reducing the volatility of data with satisfactory accuracy. Based on reducing the volatility of the electricity price and the forecasting nature of the radial basis function network (RBFN, this paper successfully develops a two-stage model to forecast the day-ahead electricity price, of which the first stage is particle swarm optimization (PSO-core mapping (CM with self-organizing-map and fuzzy set (PCMwSF, and the second stage is selection rule (SR. The PCMwSF stage applies CM, fuzzy set and optimized weights to obtain the future price, and the SR stage is inspired by the forecasting nature of RBFN and effectively selects the best forecast during the test period. The proposed model, i.e., CM-PCMwSF-SR, not only overcomes the difficulty of reducing the high volatility of the electricity price but also leads to a superior forecasting effectiveness than benchmarks.

  11. Deriving Optimal End of Day Storage for Pumped-Storage Power Plants in the Joint Energy and Reserve Day-Ahead Scheduling

    Directory of Open Access Journals (Sweden)

    Manuel Chazarra

    2017-06-01

    Full Text Available This paper presents a new methodology to maximise the income and derive the optimal end of day storage of closed-loop and daily-cycle pumped-storage hydropower plants. The plants participate in the day-ahead energy market as a price-taker and in the secondary regulation reserve market as a price-maker, in the context of the Iberian electricity system. The real-time use of the committed reserves is considered in the model formulation. The operation of the plants with the proposed methodology is compared to the ones that use an end of day storage of an empty reservoir or half of the storage capacity. Results show that the proposed methodology increases the maximum theoretical income in all the plants analysed both if they only participate in the day-ahead energy market and if they also participate in the secondary regulation service. It is also shown that the increase in the maximum theoretical income strongly depends on the size of the plant. In addition, it is proven that the end of day storages change notably in the new reserve-driven strategies of pumped-storage hydropower plants and that the proposed methodology is even more recommended if the secondary regulation service is considered.

  12. Study of the Effect of Time-Based Rate Demand Response Programs on Stochastic Day-Ahead Energy and Reserve Scheduling in Islanded Residential Microgrids

    DEFF Research Database (Denmark)

    Vahedipour-Dahraie, Mostafa; Najafi, Hamid Reza; Anvari-Moghaddam, Amjad

    2017-01-01

    In recent deregulated power systems, demand response (DR) has become one of the most cost-effective and efficient solutions for smoothing the load profile when the system is under stress. By participating in DR programs, customers are able to change their energy consumption habits in response...... to energy price changes and get incentives in return. In this paper, we study the effect of various time-based rate (TBR) programs on the stochastic day-ahead energy and reserve scheduling in residential islanded microgrids (MGs). An effective approach is presented to schedule both energy and reserve...... in presence of renewable energy resources (RESs) and electric vehicles (EVs). An economic model of responsive load is also proposed on the basis of elasticity factor to model the behavior of customers participating in various DR programs. A two-stage stochastic programming model is developed accordingly...

  13. Reduced Expression of the Antigen Processing Machinery Components TAP2, LMP2, and LMP7 in Tonsillar and Base of Tongue Cancer and Implications for Clinical Outcome

    Directory of Open Access Journals (Sweden)

    Nikolaos Tertipis

    2015-02-01

    Full Text Available OBJECTIVES: Patients with human papillomavirus (HPV–positive tonsillar squamous cell carcinoma (TSCC and base of tongue squamous cell carcinoma (BOTSCC have a better clinical outcome than those with corresponding HPV-negative tumors. Moreover, there is a strong positive correlation between absent/low as opposed to strong HLA class I expression and favorable clinical outcome for HPV-positive tumors, while the reverse applies to HPV-negative tumors. The expression of the antigen processing machinery (APM components TAP1, TAP2, LMP2, and LMP7 in these tumors in relation to HPV status, HLA class I expression, each other, and clinical outcome was therefore investigated. MATERIAL AND METHODS: Formalin-fixed paraffin-embedded TSCC and BOTSCC, derived from 151 patients and previously analyzed for HPV DNA, HLA class I, and LMP10 expression were stained by immunohistochemistry for TAP1, TAP2, LMP2, and LMP7. RESULTS: Absent/low TAP2, LMP2, and LMP7 expression, similar to HLA class I and LMP10, was common in TSCC and BOTSCC, irrespective of HPV status. Expression of TAP1 and TAP2 was correlated, as was LMP2 to LMP7. LMP2 and LMP7 expression was also associated to HLA class I expression. Moreover, absence of LMP7 was linked to increased disease-free survival in both HPV-positive and HPV-negative cases. CONCLUSION: Reduced expression of TAP2, LMP2, and LMP7 was frequent in TSCC and BOTSCC and their expression as well as that of TAP1 was often interrelated. Furthermore, low LMP7 expression correlated to better clinical outcome and may, together with HPV status, potentially be used for prediction of treatment response.

  14. A Comparison of the Performance of Advanced Statistical Techniques for the Refinement of Day-ahead and Longer NWP-based Wind Power Forecasts

    Science.gov (United States)

    Zack, J. W.

    2015-12-01

    Predictions from Numerical Weather Prediction (NWP) models are the foundation for wind power forecasts for day-ahead and longer forecast horizons. The NWP models directly produce three-dimensional wind forecasts on their respective computational grids. These can be interpolated to the location and time of interest. However, these direct predictions typically contain significant systematic errors ("biases"). This is due to a variety of factors including the limited space-time resolution of the NWP models and shortcomings in the model's representation of physical processes. It has become common practice to attempt to improve the raw NWP forecasts by statistically adjusting them through a procedure that is widely known as Model Output Statistics (MOS). The challenge is to identify complex patterns of systematic errors and then use this knowledge to adjust the NWP predictions. The MOS-based improvements are the basis for much of the value added by commercial wind power forecast providers. There are an enormous number of statistical approaches that can be used to generate the MOS adjustments to the raw NWP forecasts. In order to obtain insight into the potential value of some of the newer and more sophisticated statistical techniques often referred to as "machine learning methods" a MOS-method comparison experiment has been performed for wind power generation facilities in 6 wind resource areas of California. The underlying NWP models that provided the raw forecasts were the two primary operational models of the US National Weather Service: the GFS and NAM models. The focus was on 1- and 2-day ahead forecasts of the hourly wind-based generation. The statistical methods evaluated included: (1) screening multiple linear regression, which served as a baseline method, (2) artificial neural networks, (3) a decision-tree approach called random forests, (4) gradient boosted regression based upon an decision-tree algorithm, (5) support vector regression and (6) analog ensemble

  15. Optimal operational strategies for a day-ahead electricity market in the presence of market power using multi-objective evolutionary algorithms

    Science.gov (United States)

    Rodrigo, Deepal

    2007-12-01

    This dissertation introduces a novel approach for optimally operating a day-ahead electricity market not only by economically dispatching the generation resources but also by minimizing the influences of market manipulation attempts by the individual generator-owning companies while ensuring that the power system constraints are not violated. Since economic operation of the market conflicts with the individual profit maximization tactics such as market manipulation by generator-owning companies, a methodology that is capable of simultaneously optimizing these two competing objectives has to be selected. Although numerous previous studies have been undertaken on the economic operation of day-ahead markets and other independent studies have been conducted on the mitigation of market power, the operation of a day-ahead electricity market considering these two conflicting objectives simultaneously has not been undertaken previously. These facts provided the incentive and the novelty for this study. A literature survey revealed that many of the traditional solution algorithms convert multi-objective functions into either a single-objective function using weighting schemas or undertake optimization of one function at a time. Hence, these approaches do not truly optimize the multi-objectives concurrently. Due to these inherent deficiencies of the traditional algorithms, the use of alternative non-traditional solution algorithms for such problems has become popular and widely used. Of these, multi-objective evolutionary algorithms (MOEA) have received wide acceptance due to their solution quality and robustness. In the present research, three distinct algorithms were considered: a non-dominated sorting genetic algorithm II (NSGA II), a multi-objective tabu search algorithm (MOTS) and a hybrid of multi-objective tabu search and genetic algorithm (MOTS/GA). The accuracy and quality of the results from these algorithms for applications similar to the problem investigated here

  16. A Hybrid Forecasting Model Based on Bivariate Division and a Backpropagation Artificial Neural Network Optimized by Chaos Particle Swarm Optimization for Day-Ahead Electricity Price

    Directory of Open Access Journals (Sweden)

    Zhilong Wang

    2014-01-01

    Full Text Available In the electricity market, the electricity price plays an inevitable role. Nevertheless, accurate price forecasting, a vital factor affecting both government regulatory agencies and public power companies, remains a huge challenge and a critical problem. Determining how to address the accurate forecasting problem becomes an even more significant task in an era in which electricity is increasingly important. Based on the chaos particle swarm optimization (CPSO, the backpropagation artificial neural network (BPANN, and the idea of bivariate division, this paper proposes a bivariate division BPANN (BD-BPANN method and the CPSO-BD-BPANN method for forecasting electricity price. The former method creatively transforms the electricity demand and price to be a new variable, named DV, which is calculated using the division principle, to forecast the day-ahead electricity by multiplying the forecasted values of the DVs and forecasted values of the demand. Next, to improve the accuracy of BD-BPANN, chaos particle swarm optimization and BD-BPANN are synthesized to form a novel model, CPSO-BD-BPANN. In this study, CPSO is utilized to optimize the initial parameters of BD-BPANN to make its output more stable than the original model. Finally, two forecasting strategies are proposed regarding different situations.

  17. Evaluating the effectiveness of mixed-integer linear programming for day-ahead hydro-thermal self-scheduling considering price uncertainty and forced outage rate

    International Nuclear Information System (INIS)

    Esmaeily, Ali; Ahmadi, Abdollah; Raeisi, Fatima; Ahmadi, Mohammad Reza; Esmaeel Nezhad, Ali; Janghorbani, Mohammadreza

    2017-01-01

    A new optimization framework based on MILP model is introduced in the paper for the problem of stochastic self-scheduling of hydrothermal units known as HTSS Problem implemented in a joint energy and reserve electricity market with day-ahead mechanism. The proposed MILP framework includes some practical constraints such as the cost due to valve-loading effect, the limit due to DRR and also multi-POZs, which have been less investigated in electricity market models. For the sake of more accuracy, for hydro generating units’ model, multi performance curves are also used. The problem proposed in this paper is formulated using a model on the basis of a stochastic optimization technique while the objective function is maximizing the expected profit utilizing MILP technique. The suggested stochastic self-scheduling model employs the price forecast error in order to take into account the uncertainty due to price. Besides, LMCS is combined with roulette wheel mechanism so that the scenarios corresponding to the non-spinning reserve price and spinning reserve price as well as the energy price at each hour of the scheduling are generated. Finally, the IEEE 118-bus power system is used to indicate the performance and the efficiency of the suggested technique. - Highlights: • Characterizing the uncertainties of price and FOR of units. • Replacing the fixed ramping rate constraints with the dynamic ones. • Proposing linearized model for the valve-point effects of thermal units. • Taking into consideration the multi-POZs relating to the thermal units. • Taking into consideration the multi-performance curves of hydroelectric units.

  18. High molecular weight complex analysis of Epstein-Barr virus Latent Membrane Protein 1 (LMP-1): structural insights into LMP-1's homo-oligomerization and lipid raft association.

    Science.gov (United States)

    Wrobel, Christopher M; Geiger, Timothy R; Nix, Rebecca N; Robitaille, Aaron M; Weigand, Sandra; Cervantes, Alfredo; Gonzalez, Miguel; Martin, Jennifer M

    2013-12-26

    LMP-1 is a constitutively active Tumor Necrosis Factor Receptor analog encoded by Epstein-Barr virus. LMP-1 activation correlates with oligomerization and raft localization, but direct evidence of LMP-1 oligomers is limited. We report that LMP-1 forms multiple high molecular weight native LMP-1 complexes when analyzed by BN-PAGE, the largest of which are enriched in detergent resistant membranes. The largest of these high molecular weight complexes are not formed by purified LMP-1 or by loss of function LMP-1 mutants. Consistent with these results we find a dimeric form of LMP-1 that can be stabilized by disulfide crosslinking. We identify cysteine 238 in the C-terminus of LMP-1 as the crosslinked cysteine. Disulfide crosslinking occurs post-lysis but the dimer can be crosslinked in intact cells with membrane permeable crosslinkers. LMP-1/C238A retains wild type LMP-1 NF-κB activity. LMP-1's TRAF binding, raft association and oligomerization are associated with the dimeric form of LMP-1. Our results suggest the possibility that the observed dimeric species results from inter-oligomeric crosslinking of LMP-1 molecules in adjacent core LMP-1 oligomers. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Logistics Modernization Program Increment 2 (LMP Inc 2)

    Science.gov (United States)

    2016-03-01

    DoD Enterprise Transition Plan objectives; support the applicable DoD and Army Enterprise Resource Planning ( ERP ) integration efforts; and support...Army Prepositioned Stock planning, NMP, and the expansion and refinement of the integration between ERP systems. The LMP has approximately 21,000...The determination of the development/integration contract type was based on cost risk associated with the estimated cost of satisfying the

  20. The viral oncoprotein LMP1 exploits TRADD for signaling by masking its apoptotic activity.

    Directory of Open Access Journals (Sweden)

    Frank Schneider

    2008-01-01

    Full Text Available The tumor necrosis factor (TNF-receptor 1-associated death domain protein (TRADD mediates induction of apoptosis as well as activation of NF-kappaB by cellular TNF-receptor 1 (TNFR1. TRADD is also recruited by the latent membrane protein 1 (LMP1 oncoprotein of Epstein-Barr virus, but its role in LMP1 signaling has remained enigmatic. In human B lymphocytes, we have generated, to our knowledge, the first genetic knockout of TRADD to investigate TRADD's role in LMP1 signal transduction. Our data from TRADD-deficient cells demonstrate that TRADD is a critical signaling mediator of LMP1 that is required for LMP1 to recruit and activate I-kappaB kinase beta (IKKbeta. However, in contrast to TNFR1, LMP1-induced TRADD signaling does not induce apoptosis. Searching for the molecular basis for this observation, we characterized the 16 C-terminal amino acids of LMP1 as an autonomous and unique virus-derived TRADD-binding domain. Replacing the death domain of TNFR1 by LMP1's TRADD-binding domain converts TNFR1 into a nonapoptotic receptor that activates NF-kappaB through a TRAF6-dependent pathway, like LMP1 but unlike wild-type TNFR1. Thus, the unique interaction of LMP1 with TRADD encodes the transforming phenotype of viral TRADD signaling and masks TRADD's pro-apoptotic function.

  1. The viral oncoprotein LMP1 exploits TRADD for signaling by masking its apoptotic activity.

    Science.gov (United States)

    Schneider, Frank; Neugebauer, Julia; Griese, Janine; Liefold, Nicola; Kutz, Helmut; Briseño, Cinthia; Kieser, Arnd

    2008-01-01

    The tumor necrosis factor (TNF)-receptor 1-associated death domain protein (TRADD) mediates induction of apoptosis as well as activation of NF-kappaB by cellular TNF-receptor 1 (TNFR1). TRADD is also recruited by the latent membrane protein 1 (LMP1) oncoprotein of Epstein-Barr virus, but its role in LMP1 signaling has remained enigmatic. In human B lymphocytes, we have generated, to our knowledge, the first genetic knockout of TRADD to investigate TRADD's role in LMP1 signal transduction. Our data from TRADD-deficient cells demonstrate that TRADD is a critical signaling mediator of LMP1 that is required for LMP1 to recruit and activate I-kappaB kinase beta (IKKbeta). However, in contrast to TNFR1, LMP1-induced TRADD signaling does not induce apoptosis. Searching for the molecular basis for this observation, we characterized the 16 C-terminal amino acids of LMP1 as an autonomous and unique virus-derived TRADD-binding domain. Replacing the death domain of TNFR1 by LMP1's TRADD-binding domain converts TNFR1 into a nonapoptotic receptor that activates NF-kappaB through a TRAF6-dependent pathway, like LMP1 but unlike wild-type TNFR1. Thus, the unique interaction of LMP1 with TRADD encodes the transforming phenotype of viral TRADD signaling and masks TRADD's pro-apoptotic function.

  2. Optimal trading strategy for GenCo in LMP-based and bilateral ...

    African Journals Online (AJOL)

    GenCo) in multi-market environment including day-ahead spot and long term bilateral contract markets using self-organising hierarchical particle swarm optimisation with time-varying acceleration coefficients (SPSO-TVAC). The proposed trading ...

  3. A novel immune evasion mechanism of LMP-1, an EBV-primary oncogene, in nasopharyngeal carcinoma.

    Science.gov (United States)

    Yoshizaki, Tomokazu

    2011-01-01

    Nasopharyngeal carcinoma is an Epstein-Barr virus (EBV)-associated tumor. Viruses that are associated with malignant transformation have evolved unique mechanisms to interfere with this interaction to evade antiviral T cell responses. EBV exploits many immune evasive strategies to successfully establish a latent infection in B cells. CD8+ T cell responses to LMP-1 are generally very low and rarely detected in healthy virus carriers. Activation of the NF-kB pathway by EBV-LMP-1 leads to an upregulation of the MHC class I antigen-processing pathway. Paradoxically, LMP-1itself induces a subdominant CD8+ T cell response and appears to have evolved to avoid immune recognition. An expression of LMP-1 in human cells enhanced the trans-presentation of CD8+ T cell epitopes; however, cis-presentation of LMP-1-derived epitopes was severely impaired. Deletion of the first transmembrane domain of LMP-1, which prevented self-aggregation, significantly enhanced the cis-presentation of T cell epitopes from this protein, whereas it lost its ability to upregulate trans-presentation. These results delineate a novel mechanism of immune evasion, which renders a virally encoded oncogene inaccessible to the conventional MHC class I pathway limiting its cis-presentation. Copyright © 2011 S. Karger AG, Basel.

  4. Analysis of Immunogenicity of Intracellular CTAR Fragments of Epstein-Barr Virus Latent Phase Protein LMP1.

    Science.gov (United States)

    Lomakin, Ya A; Shmidt, A A; Bobik, T V; Chernov, A S; Pyrkov, A Yu; Aleksandrova, N M; Okunola, D O; Vaskina, M I; Ponomarenko, N A; Telegin, G B; Dubina, M V; Belogurov, A A

    2017-10-01

    Intracellular fragments of latent phase protein LMP1 of Epstein-Barr virus, denoted as CTAR1/2/3, can trigger a variety of cell cascades and contribute to the transforming potential of the virus. Generation of recombinant proteins CTAR1/2/3 is expected to yield more ample data on functional and immunogenic characteristics of LMP1. We created genetic constructs for prokaryotic expression of LMP1 CTAR fragments and selected optimal conditions for their production and purification. Using a new library of LMP1 CTAR fragments, we carried out epitope mapping of a diagnostic anti-LMP1 antibody S12. Analysis of polyclonal serum antibodies from mice immunized with full-length LMP1 confirmed immunogenicity of CTAR elements comparable with that of full-length protein.

  5. Day-Ahead Wind Power Forecasting Using a Two-Stage Hybrid Modeling Approach Based on SCADA and Meteorological Information, and Evaluating the Impact of Input-Data Dependency on Forecasting Accuracy

    Directory of Open Access Journals (Sweden)

    Dehua Zheng

    2017-12-01

    Full Text Available The power generated by wind generators is usually associated with uncertainties, due to the intermittency of wind speed and other weather variables. This creates a big challenge for transmission system operators (TSOs and distribution system operators (DSOs in terms of connecting, controlling and managing power networks with high-penetration wind energy. Hence, in these power networks, accurate wind power forecasts are essential for their reliable and efficient operation. They support TSOs and DSOs in enhancing the control and management of the power network. In this paper, a novel two-stage hybrid approach based on the combination of the Hilbert-Huang transform (HHT, genetic algorithm (GA and artificial neural network (ANN is proposed for day-ahead wind power forecasting. The approach is composed of two stages. The first stage utilizes numerical weather prediction (NWP meteorological information to predict wind speed at the exact site of the wind farm. The second stage maps actual wind speed vs. power characteristics recorded by SCADA. Then, the wind speed forecast in the first stage for the future day is fed to the second stage to predict the future day’s wind power. Comparative selection of input-data parameter sets for the forecasting model and impact analysis of input-data dependency on forecasting accuracy have also been studied. The proposed approach achieves significant forecasting accuracy improvement compared with three other artificial intelligence-based forecasting approaches and a benchmark model using the smart persistence method.

  6. Measurement of CD8+ and CD4+ T Cell Frequencies Specific for EBV LMP1 and LMP2a Using mRNA-Transfected DCs.

    Directory of Open Access Journals (Sweden)

    Dae-Hee Sohn

    Full Text Available An EBV-specific cellular immune response is associated with the control of EBV-associated malignancies and lymphoproliferative diseases, some of which have been successfully treated by adoptive T cell therapy. Therefore, many methods have been used to measure EBV-specific cellular immune responses. Previous studies have mainly used autologous EBV-transformed B-lymphoblastoid cell lines (B-LCLs, recombinant viral vectors transfected or peptide pulsed dendritic cells (DCs as stimulators of CD8(+ and CD4(+ T lymphocytes. In the present study, we used an interferon-γ (IFN-γ enzyme-linked immunospot (ELISPOT assay by using isolated CD8(+ and CD4(+ T cells stimulated with mRNA-transfected DCs. The frequency of latent membrane protein 1 (LMP1-specific IFN-γ producing CD4(+ T cells was significantly higher than that of LMP2a. The frequency of IFN-γ producing CD4(+ T cells was significantly correlated with that of CD8(+ T cells in LMP1-specific immune responses (r = 0.7187, Pc < 0.0001. To determine whether there were changes in LMP1- or LMP2a-specific immune responses, subsequent peripheral blood mononuclear cells (PBMCs samples were analyzed. Significant changes were observed in 5 of the 10 donors examined, and CD4(+ T cell responses showed more significant changes than CD8(+ T cell responses. CD8(+ and CD4(+ T cells from EBV-seropositive donors secreted only the Th1 cytokines IFN-γ, TNF-α, and IL-2, while Th2 (IL-4 and Th17 (IL-17a cytokines were not detected. CD4(+ T cells secreted significantly higher cytokine levels than did CD8(+ T cells. Analysis of EBV-specific T cell responses using autologous DCs transfected with mRNA might provide a comprehensive tool for monitoring EBV infection and new insights into the pathogenesis of EBV-associated diseases.

  7. LMP1-mediated glycolysis induces myeloid-derived suppressor cell expansion in nasopharyngeal carcinoma

    Science.gov (United States)

    Cai, Ting-Ting; Ye, Shu-Biao; Liu, Yi-Na; He, Jia; Chen, Qiu-Yan; Mai, Hai-Qiang; Zhang, Chuan-Xia; Cui, Jun; Zhang, Xiao-Shi; Zeng, Yi-Xin

    2017-01-01

    Myeloid-derived suppressor cells (MDSCs) are expanded in tumor microenvironments, including that of Epstein–Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC). The link between MDSC expansion and EBV infection in NPC is unclear. Here, we show that EBV latent membrane protein 1 (LMP1) promotes MDSC expansion in the tumor microenvironment by promoting extra-mitochondrial glycolysis in malignant cells, which is a scenario for immune escape initially suggested by the frequent, concomitant detection of abundant LMP1, glucose transporter 1 (GLUT1) and CD33+ MDSCs in tumor sections. The full process has been reconstituted in vitro. LMP1 promotes the expression of multiple glycolytic genes, including GLUT1. This metabolic reprogramming results in increased expression of the Nod-like receptor family protein 3 (NLRP3) inflammasome, COX-2 and P-p65 and, consequently, increased production of IL-1β, IL-6 and GM-CSF. Finally, these changes in the environment of malignant cells result in enhanced NPC-derived MDSC induction. One key step is the physical interaction of LMP1 with GLUT1 to stabilize the GLUT1 protein by blocking its K48-ubiquitination and p62-dependent autolysosomal degradation. This work indicates that LMP1-mediated glycolysis regulates IL-1β, IL-6 and GM-CSF production through the NLRP3 inflammasome, COX-2 and P-p65 signaling pathways to enhance tumor-associated MDSC expansion, which leads to tumor immunosuppression in NPC. PMID:28732079

  8. 75 FR 38469 - Orders Finding That the Mid-C Financial Peak Contract and Mid-C Financial Off-Peak Contract...

    Science.gov (United States)

    2010-07-02

    ... website. The peak-hour electricity price index on a particular day is calculated as the volume-weighted... price of electricity at a particular point on the grid is called the locational marginal price (``LMP... market establishes prices for electricity that is to be delivered during the specified hour on the...

  9. Latent Membrane Protein 1 (LMP1) and LMP2A Collaborate To Promote Epstein-Barr Virus-Induced B Cell Lymphomas in a Cord Blood-Humanized Mouse Model but Are Not Essential.

    Science.gov (United States)

    Ma, Shi-Dong; Tsai, Ming-Han; Romero-Masters, James C; Ranheim, Erik A; Huebner, Shane M; Bristol, Jillian A; Delecluse, Henri-Jacques; Kenney, Shannon C

    2017-04-01

    Epstein-Barr virus (EBV) infection is associated with B cell lymphomas in humans. The ability of EBV to convert human B cells into long-lived lymphoblastoid cell lines (LCLs) in vitro requires the collaborative effects of EBNA2 (which hijacks Notch signaling), latent membrane protein 1 (LMP1) (which mimics CD40 signaling), and EBV-encoded nuclear antigen 3A (EBNA3A) and EBNA3C (which inhibit oncogene-induced senescence and apoptosis). However, we recently showed that an LMP1-deleted EBV mutant induces B cell lymphomas in a newly developed cord blood-humanized mouse model that allows EBV-infected B cells to interact with CD4 T cells (the major source of CD40 ligand). Here we examined whether the EBV LMP2A protein, which mimics constitutively active B cell receptor signaling, is required for EBV-induced lymphomas in this model. We find that the deletion of LMP2A delays the onset of EBV-induced lymphomas but does not affect the tumor phenotype or the number of tumors. The simultaneous deletion of both LMP1 and LMP2A results in fewer tumors and a further delay in tumor onset. Nevertheless, the LMP1/LMP2A double mutant induces lymphomas in approximately half of the infected animals. These results indicate that neither LMP1 nor LMP2A is absolutely essential for the ability of EBV to induce B cell lymphomas in the cord blood-humanized mouse model, although the simultaneous loss of both LMP1 and LMP2A decreases the proportion of animals developing tumors and increases the time to tumor onset. Thus, the expression of either LMP1 or LMP2A may be sufficient to promote early-onset EBV-induced tumors in this model. IMPORTANCE EBV causes human lymphomas, but few models are available for dissecting how EBV causes lymphomas in vivo in the context of a host immune response. We recently used a newly developed cord blood-humanized mouse model to show that EBV can cooperate with human CD4 T cells to cause B cell lymphomas even when a major viral transforming protein, LMP1, is deleted

  10. Treatment of experimental colitis in mice with LMP-420, an inhibitor of TNF transcription

    Directory of Open Access Journals (Sweden)

    Cianciolo George

    2008-03-01

    Full Text Available Abstract Background LMP-420 is a boronic acid-containing purine nucleoside analogue that transcriptionally inhibits TNF production but is non-cytotoxic to TNF-producing cells. Methods This study investigated the efficacy of LMP-420 as an anti-inflammatory agent in acute and chronic colitis induced by oral administration of dextran sulfate sodium (DSS to mice and in chronic colitis following piroxicam administration to IL-10-deficient mice. The severity of colon inflammation was assessed histologically. TNF levels were measured by enzyme immunoassay. Results Administration of DSS for 7 days resulted in severe acute colitis that was associated with a marked increase in stool and colon tissue TNF levels. Initiation of therapy with intraperitoneal (i.p. LMP-420 on day 4 of DSS exposure decreased colonic TNF to near normal levels on day 7. However, neither i.p. nor oral treatment with LMP-420 affected the development or severity of acute DSS colitis. Initiation of LMP-420 therapy after 3 cycles of DSS administration to establish chronic colitis also had no effect on the severity of chronic colitis. Analysis of colonic TNF combined with longitudinal analysis of TNF and TNF receptor (TNF-RII levels in stool during the development of chronic DSS colitis demonstrated that the initially elevated colonic TNF levels returned to normal despite intense on-going inflammation in mice with chronic colitis. RAG-2-/- mice deficient in T and B cells also developed severe ongoing colitis in response to 3 cycles of DSS, but showed marked differences vs. wild type mice in stool TNF and TNF-RII in response to DSS exposure. Systemic and oral LMP-420 treatment for 16 days decreased colonic TNF levels in IL-10-deficient mice with chronic colitis, with a trend to decreased histologic inflammation for oral LMP-420. Conclusion These studies demonstrate that short-term treatment with a transcriptional inhibitor of TNF production can decrease systemic and local colonic levels

  11. Blockage of LMP1-modulated store-operated Ca(2+) entry reduces metastatic potential in nasopharyngeal carcinoma cell.

    Science.gov (United States)

    Wei, Jiazhang; Zhang, Jinyan; Si, Yongfeng; Kanada, Masamitsu; Zhang, Zhe; Terakawa, Susumu; Watanabe, Hiroshi

    2015-05-01

    Epstein-Barr virus (EBV)-encoded latent membrane proteins (LMPs) expedite progression of EBV-relevant cancers. Of the full set of LMPs, latent membrane protein 1 (LMP1) was identified to uniquely augment store-operated Ca(2+) entry (SOCE). Previously, we reported that the suppression of SOCE exhibited inhibitory effects on cell migration and the extravasation from vasculature in EBV-negative nasopharyngeal carcinoma (NPC) cells. In this follow-up study, we aimed to expand our understanding of the modulation of SOCE by LMP1 and test the possibility that blockage of LMP1-modulated SOCE affects the LMP1-promoted metastatic potential. Here we showed that suppressions of the LMP1-boosted SOCE blunted the LMP1-promoted cell migration, VEGF-mediated angiogenesis and permeabilization in vitro. Blockage of SOCE inhibited vasculature-invasion of circulating cells and distant metastatic colonization in vivo. Notably, utilizing VEGFR2-EGFP-tag zebrafish we revealed that the LMP1-expressing cells arrested in a small-caliber vessel mobilized surrounding endothelial cells to facilitate vasculature-invasion. Thus, the LMP1-boosted SOCE promotes metastatic potential of NPC cells by solidifying their collaborations with the nearby non-cancer cells through the manipulation of oncogenic Ca(2+) signaling. Our study highlights the advantage of using both conventional mammal and transgenic zebrafish for developing a novel therapeutic strategy targeting the multiple steps of invasion-metastasis cascade. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Optimal trading strategy for GenCo in LMP-based and bilateral ...

    African Journals Online (AJOL)

    cboonchu

    As the simulation is performed on the MATLAB environment, the DCOPF model is conveniently solved by 'fmincon' function included in the software package. To reduce the computing effort, an artificial neural network (ANN) is used to approximate the LMP. The simulation is performed on a 2.8 GHz Pentium IV personal ...

  13. Proteasome LMP2/β1i subunit as biomarker for human uterine leiomyosarcoma

    Directory of Open Access Journals (Sweden)

    Takuma Hayashi

    2014-02-01

    Full Text Available Uterine leiomyosarcoma (Ut-LMS develops more frequently in the myometrium of the uterine body than in the uterine cervix. Although the development of gynecological tumors is often correlated with the secretion of female hormones that of Ut-LMS does not, and its risk factor(s remain unknown. Importantly, a diagnostic biomarker that can distinguish malignant tumor Ut-LMS from benign tumor leiomyoma (LMA, has yet to be established. Therefore, the risk factor(s associated with Ut-LMS need to be examined in order to establish a diagnosis and clinical treatment method. Mice with a homozygous deficiency for the proteasome b-ring subunit, low-molecular mass polypeptide (LMP2/b1i spontaneously develop Ut-LMS, with a disease prevalence of ~40% by 14 months of age. In recent studies, we showed that LMP2/b1i expression was absent in human Ut-LMS, but present in other human uterine mesenchymal tumors including uterine LMA. Moreover, LMP2/b1i is also known to negatively regulate human Ut-LMS tumorigenesis. Additional experiments furthermore revealed the differential expression of cyclin E and calponin h1 in human uterine mesenchymal tumors. Therefore, LMP2/b1i is a potential diagnostic biomarker when combined with the candidate molecules, cyclin E and calponin h1 for human Ut-LMS, and may be a targeted molecule for a new therapeutic approach.---------------------------------------------Cite this article as: Hayashi T, Horiuchi A Aburatani H, Ishiko O, Yaegashi N, Kanai Y, Zharhary D, Tonegawa S, Konishi I. Proteasome LMP2/ß1i subunit as biomarker for human uterine leiomyosarcoma. Int J Cancer Ther Oncol 2014; 2(1:02018.DOI: http://dx.doi.org/10.14319/ijcto.0201.8

  14. Association of LMP/TAP gene polymorphisms with tuberculosis susceptibility in Li population in China.

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    Danmei Wang

    Full Text Available BACKGROUND: Tuberculosis (TB is a contagious disease affected by multiple genetic and environmental factors. Several association studies have suggested that cellular immune response is vital for controlling and preventing of tuberculosis infection. Low molecular weight polypeptides (LMPs and transporters with antigen processing (TAPs are the main molecules in the processing and presentation pathway for intracellular antigens. This study was performed to elucidate whether these antigen-processing genes (LMP/TAP polymorphisms could be associated with the risk of tuberculosis infection in China. METHODOLOGY/PRINCIPAL FINDINGS: We recruited 205 active pulmonary tuberculosis patients and 217 normal controls from Li population for this study. Four polymorphisms of LMP/TAP genes were determined by PCR-RFLP assay and haplotypes were constructed by software PHASE 1.0. Of the total four polymorphisms, genotype frequencies of LMP7 AA homozygote and CA heterozygote were significantly greater among cases compared to controls, with odds ratio of 3.77 (95% CI: 1.60-8.89; P = 0.002 and 2.97 (95% CI: 1.80-4.90; P<0.0001, respectively. The genotypes of TAP1-2 GG homozygote and AG heterozygote were more frequent in subjects with TB than in controls, with odds ratio of 3.94 (95% CI: 1.82-8.53; P = 0.001 and 2.87 (95% CI: 1.75-4.71; P<0.0001, respectively. Similarly, we found that haplotype B which carried LMP7 and TAP1-2 variations significantly increased the susceptibility to TB (OR = 3.674, 95% CI: 2.254-5.988; P<0.0001. Moreover, it is noteworthy that the homozygote of wild haplotype A (A/A may be a strong protection for TB infection. CONCLUSIONS: Our findings suggested that LMP/TAP gene polymorphisms might be risk factors for TB infection among Li population in China.

  15. Piperlongumine inhibits LMP1/MYC-dependent mouse B-lymphoma cells

    International Nuclear Information System (INIS)

    Han, Seong-Su; Tompkins, Van S.; Son, Dong-Ju; Kamberos, Natalie L.; Stunz, Laura L.; Halwani, Ahmad; Bishop, Gail A.; Janz, Siegfried

    2013-01-01

    Highlights: •Mouse model of human Burkitt lymphoma revealed cancer inhibition by PL. •Treatment with PL led to apoptosis of malignant but not normal B cells. •PL inhibited LMP1–NF-κB–Myc-dependent target genes including p21-encoding Cdkn1a. •PL holds promise for new interventions approaches to hematologic malignancies. -- Abstract: Piperlongumine (PL), isolated from the fruit of Long pepper, Piper longum, is a cancer-inhibiting compound that selectively kills tumor cells while sparing their normal counterparts. Here we evaluated the efficacy with which PL suppresses malignant B cells derived from a newly developed, double-transgenic mouse model of human endemic Burkitt lymphoma (BL), designated mCD40-LMP1/iMyc Eμ . PL inhibited tumor cell proliferation in a concentration-dependent manner and induced apoptosis of neoplastic but not normal B cells. Treatment with PL resulted in downregulation of EBV-encoded LMP1, cellular Myc, constitutive NF-κB activity, and a host of LMP1-Myc-NF-κB-regulated target genes including Aurka, Bcat1, Bub1b, Ccnb1, Chek1, Fancd2, Tfrc and Xrcc6. Of note, p21 Cip1 -encoding Cdkn1a was suppressed independent of changes in Trp53 mRNA levels and p53 DNA-binding activity. Considering the central role of the LMP1–NF-κB–Myc axis in B-lineage neoplasia, these findings further our understanding of the mechanisms by which PL inhibits B-lymphoma and provide a preclinical rationale for the inclusion of PL in new interventions in blood cancers

  16. Piperlongumine inhibits LMP1/MYC-dependent mouse B-lymphoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seong-Su; Tompkins, Van S. [Department of Pathology, University of Iowa Carver College of Medicine, Iowa City, IA (United States); Son, Dong-Ju [Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA (United States); Kamberos, Natalie L. [Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, IA (United States); Stunz, Laura L. [Deparment of Microbiology, University of Iowa Carver College of Medicine, Iowa City, IA (United States); Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA (United States); Iowa City VAMC, Iowa City, IA (United States); Halwani, Ahmad [Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA (United States); Bishop, Gail A. [Deparment of Microbiology, University of Iowa Carver College of Medicine, Iowa City, IA (United States); Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA (United States); Iowa City VAMC, Iowa City, IA (United States); Janz, Siegfried, E-mail: siegfried-janz@uiowa.edu [Department of Pathology, University of Iowa Carver College of Medicine, Iowa City, IA (United States)

    2013-07-12

    Highlights: •Mouse model of human Burkitt lymphoma revealed cancer inhibition by PL. •Treatment with PL led to apoptosis of malignant but not normal B cells. •PL inhibited LMP1–NF-κB–Myc-dependent target genes including p21-encoding Cdkn1a. •PL holds promise for new interventions approaches to hematologic malignancies. -- Abstract: Piperlongumine (PL), isolated from the fruit of Long pepper, Piper longum, is a cancer-inhibiting compound that selectively kills tumor cells while sparing their normal counterparts. Here we evaluated the efficacy with which PL suppresses malignant B cells derived from a newly developed, double-transgenic mouse model of human endemic Burkitt lymphoma (BL), designated mCD40-LMP1/iMyc{sup Eμ}. PL inhibited tumor cell proliferation in a concentration-dependent manner and induced apoptosis of neoplastic but not normal B cells. Treatment with PL resulted in downregulation of EBV-encoded LMP1, cellular Myc, constitutive NF-κB activity, and a host of LMP1-Myc-NF-κB-regulated target genes including Aurka, Bcat1, Bub1b, Ccnb1, Chek1, Fancd2, Tfrc and Xrcc6. Of note, p21{sup Cip1}-encoding Cdkn1a was suppressed independent of changes in Trp53 mRNA levels and p53 DNA-binding activity. Considering the central role of the LMP1–NF-κB–Myc axis in B-lineage neoplasia, these findings further our understanding of the mechanisms by which PL inhibits B-lymphoma and provide a preclinical rationale for the inclusion of PL in new interventions in blood cancers.

  17. Latent membrane protein 1 (LMP1) expression in Hodgkin lymphoma and its correlation with clinical and histologic parameters.

    Science.gov (United States)

    Hashmi, Atif Ali; Hussain, Zubaida Fida; Hashmi, Kashif Ali; Zafar, Muhammad Irfan; Edhi, Muhammad Muzzammil; Faridi, Naveen; Khan, Mehmood

    2017-04-20

    Hodgkin lymphoma is one of the most prevalent lymphoproliferative disorders in Pakistan; however, no risk factors for this disease have yet to be established in our population. Epstein-Barr virus (EBV) is a well-known risk factor for Hodgkin lymphoma in endemic regions of the world; however, frequency of its association in our population has not been widely studied. Latent membrane protein 1 (LMP1) expression by immunohistochemistry (IHC) is a surrogate marker of EBV in Hodgkin lymphoma. Therefore, we aimed to evaluate the frequency of expression of LMP1 in cases of Hodgkin lymphoma at our institute and its correlation with other clinical and histologic parameters. The study included 66 cases of Hodgkin lymphoma diagnosed at Liaquat National Hospital over a duration of 2 years from January 2014 to December 2015. The slides and blocks of all cases were retrieved, and representative blocks were selected for LMP1 by IHC. LMP1 expression of >10% of cells was considered as positive expression and correlated with histologic subtypes and clinical parameters like age, gender, and site of involvement. The mean age of patients was 35.11 (+20.22). LMP1 expression was found in 68.1% (45/66) of cases of Hodgkin lymphoma. Mean age of the patients with LMP1 expression was 32.04 (+21.02). LMP1 expression was found in 40% cases of lymphocyte-rich, 66.7% of lymphocyte-depleted, 73.9% of mixed cellularity, 66.7% of nodular sclerosis, and 73.7% of classic Hodgkin lymphoma, NOS. No significant correlation of LMP1 expression with any clinical or histological parameter could be established in our studied patient population. A high frequency of expression of LMP1 is seen in cases of Hodgkin lymphoma at our setup comparable to endemic regions of the world; therefore, preventive and treatment protocols should be designed accordingly.

  18. TRAF1 Coordinates Polyubiquitin Signaling to Enhance Epstein-Barr Virus LMP1-Mediated Growth and Survival Pathway Activation.

    Directory of Open Access Journals (Sweden)

    Hannah Greenfeld

    2015-05-01

    Full Text Available The Epstein-Barr virus (EBV encoded oncoprotein Latent Membrane Protein 1 (LMP1 signals through two C-terminal tail domains to drive cell growth, survival and transformation. The LMP1 membrane-proximal TES1/CTAR1 domain recruits TRAFs to activate MAP kinase, non-canonical and canonical NF-kB pathways, and is critical for EBV-mediated B-cell transformation. TRAF1 is amongst the most highly TES1-induced target genes and is abundantly expressed in EBV-associated lymphoproliferative disorders. We found that TRAF1 expression enhanced LMP1 TES1 domain-mediated activation of the p38, JNK, ERK and canonical NF-kB pathways, but not non-canonical NF-kB pathway activity. To gain insights into how TRAF1 amplifies LMP1 TES1 MAP kinase and canonical NF-kB pathways, we performed proteomic analysis of TRAF1 complexes immuno-purified from cells uninduced or induced for LMP1 TES1 signaling. Unexpectedly, we found that LMP1 TES1 domain signaling induced an association between TRAF1 and the linear ubiquitin chain assembly complex (LUBAC, and stimulated linear (M1-linked polyubiquitin chain attachment to TRAF1 complexes. LMP1 or TRAF1 complexes isolated from EBV-transformed lymphoblastoid B cell lines (LCLs were highly modified by M1-linked polyubiqutin chains. The M1-ubiquitin binding proteins IKK-gamma/NEMO, A20 and ABIN1 each associate with TRAF1 in cells that express LMP1. TRAF2, but not the cIAP1 or cIAP2 ubiquitin ligases, plays a key role in LUBAC recruitment and M1-chain attachment to TRAF1 complexes, implicating the TRAF1:TRAF2 heterotrimer in LMP1 TES1-dependent LUBAC activation. Depletion of either TRAF1, or the LUBAC ubiquitin E3 ligase subunit HOIP, markedly impaired LCL growth. Likewise, LMP1 or TRAF1 complexes purified from LCLs were decorated by lysine 63 (K63-linked polyubiqutin chains. LMP1 TES1 signaling induced K63-polyubiquitin chain attachment to TRAF1 complexes, and TRAF2 was identified as K63-Ub chain target. Co-localization of M1- and K63

  19. Latent Membrane Protein LMP2A Impairs Recognition of EBV-Infected Cells by CD8+ T Cells.

    Directory of Open Access Journals (Sweden)

    Chiara Rancan

    2015-06-01

    Full Text Available The common pathogen Epstein-Barr virus (EBV transforms normal human B cells and can cause cancer. Latent membrane protein 2A (LMP2A of EBV supports activation and proliferation of infected B cells and is expressed in many types of EBV-associated cancer. It is not clear how latent EBV infection and cancer escape elimination by host immunity, and it is unknown whether LMP2A can influence the interaction of EBV-infected cells with the immune system. We infected primary B cells with EBV deleted for LMP2A, and established lymphoblastoid cell lines (LCLs. We found that CD8+ T cell clones showed higher reactivity against LMP2A-deficient LCLs compared to LCLs infected with complete EBV. We identified several potential mediators of this immunomodulatory effect. In the absence of LMP2A, expression of some EBV latent antigens was elevated, and cell surface expression of MHC class I was marginally increased. LMP2A-deficient LCLs produced lower amounts of IL-10, although this did not directly affect CD8+ T cell recognition. Deletion of LMP2A led to several changes in the cell surface immunophenotype of LCLs. Specifically, the agonistic NKG2D ligands MICA and ULBP4 were increased. Blocking experiments showed that NKG2D activation contributed to LCL recognition by CD8+ T cell clones. Our results demonstrate that LMP2A reduces the reactivity of CD8+ T cells against EBV-infected cells, and we identify several relevant mechanisms.

  20. Evaluation of a rapid LMP-based approach for calculating marginal unit emissions

    International Nuclear Information System (INIS)

    Rogers, Michelle M.; Wang, Yang; Wang, Caisheng; McElmurry, Shawn P.; Miller, Carol J.

    2013-01-01

    Graphical abstract: Display Omitted - Highlights: • Pollutant emissions estimated based on locational marginal price and eGRID data. • Stochastic model using IEEE RTS-96 system used to evaluate LMP approach. • Incorporating membership function enhanced reliability of pollutant estimate. • Error in pollutant estimate typically 2 and X and SO 2 . - Abstract: To evaluate the sustainability of systems that draw power from electrical grids there is a need to rapidly and accurately quantify pollutant emissions associated with power generation. Air emissions resulting from electricity generation vary widely among power plants based on the types of fuel consumed, the efficiency of the plant, and the type of pollution control systems in service. To address this need, methods for estimating real-time air emissions from power generation based on locational marginal prices (LMPs) have been developed. Based on LMPs the type of the marginal generating unit can be identified and pollutant emissions are estimated. While conceptually demonstrated, this LMP approach has not been rigorously tested. The purpose of this paper is to (1) improve the LMP method for predicting pollutant emissions and (2) evaluate the reliability of this technique through power system simulations. Previous LMP methods were expanded to include marginal emissions estimates using an LMP Emissions Estimation Method (LEEM). The accuracy of emission estimates was further improved by incorporating a probability distribution function that characterize generator fuel costs and a membership function (MF) capable of accounting for multiple marginal generation units. Emission estimates were compared to those predicted from power flow simulations. The improved LEEM was found to predict the marginal generation type approximately 70% of the time based on typical system conditions (e.g. loads and fuel costs) without the use of a MF. With the addition of a MF, the LEEM was found to provide emission estimates with

  1. Induction of Epstein-Barr Virus Oncoprotein LMP1 by Transcription Factors AP-2 and Early B Cell Factor

    Science.gov (United States)

    Noda, Chieko; Narita, Yohei; Watanabe, Takahiro; Yoshida, Masahiro; Ashio, Keiji; Sato, Yoshitaka; Goshima, Fumi; Kanda, Teru; Yoshiyama, Hironori; Tsurumi, Tatsuya; Kimura, Hiroshi

    2016-01-01

    ABSTRACT Latent membrane protein 1 (LMP1) is a major oncogene essential for primary B cell transformation by Epstein-Barr virus (EBV). Previous studies suggested that some transcription factors, such as PU.1, RBP-Jκ, NF-κB, and STAT, are involved in this expression, but the underlying mechanism is unclear. Here, we identified binding sites for PAX5, AP-2, and EBF in the proximal LMP1 promoter (ED-L1p). We first confirmed the significance of PU.1 and POU domain transcription factor binding for activation of the promoter in latency III. We then focused on the transcription factors AP-2 and early B cell factor (EBF). Interestingly, among the three AP-2-binding sites in the LMP1 promoter, two motifs were also bound by EBF. Overexpression, knockdown, and mutagenesis in the context of the viral genome indicated that AP-2 plays an important role in LMP1 expression in latency II in epithelial cells. In latency III B cells, on the other hand, the B cell-specific transcription factor EBF binds to the ED-L1p and activates LMP1 transcription from the promoter. IMPORTANCE Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) is crucial for B cell transformation and oncogenesis of other EBV-related malignancies, such as nasopharyngeal carcinoma and T/NK lymphoma. Its expression is largely dependent on the cell type or condition, and some transcription factors have been implicated in its regulation. However, these previous reports evaluated the significance of specific factors mostly by reporter assay. In this study, we prepared point-mutated EBV at the binding sites of such transcription factors and confirmed the importance of AP-2, EBF, PU.1, and POU domain factors. Our results will provide insight into the transcriptional regulation of the major oncogene LMP1. PMID:26819314

  2. Twin Peaks

    Science.gov (United States)

    1997-01-01

    The two hills in the distance, approximately one to two kilometers away, have been dubbed the 'Twin Peaks' and are of great interest to Pathfinder scientists as objects of future study. The white areas on the left hill, called the 'Ski Run' by scientists, may have been formed by hydrologic processes.The image was taken by the Imager for Mars Pathfinder (IMP) after its deployment on Sol 3. Mars Pathfinder was developed and managed by the Jet Propulsion Laboratory (JPL) for the National Aeronautics and Space Administration. The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  3. Characterization of a Suppressive Cis-acting Element in the Epstein–Barr Virus LMP1 Promoter

    Directory of Open Access Journals (Sweden)

    Masahiro Yoshida

    2017-11-01

    Full Text Available Latent membrane protein 1 (LMP1 is a major oncogene encoded by Epstein–Barr virus (EBV and is essential for immortalization of B cells by the virus. Previous studies suggested that several transcription factors, such as PU.1, RBP-Jκ, NFκB, EBF1, AP-2 and STAT, are involved in LMP1 induction; however, the means by which the oncogene is negatively regulated remains unclear. Here, we introduced short mutations into the proximal LMP1 promoter that includes recognition sites for the E-box and Ikaros transcription factors in the context of EBV-bacterial artificial chromosome. Upon infection, the mutant exhibited increased LMP1 expression and EBV-mediated immortalization of B cells. However, single mutations of either the E-box or Ikaros sites had limited effects on LMP1 expression and transformation. Our results suggest that this region contains a suppressive cis-regulatory element, but other transcriptional repressors (apart from the E-box and Ikaros transcription factors may remain to be discovered.

  4. Aberrant Expression of ID2 protein and its correlation with EBV-LMP1 and P16(INK4A) in Classical Hodgkin Lymphoma in China

    International Nuclear Information System (INIS)

    Zhao, Po; Lu, Yali; Liu, Lin; Zhong, Mei

    2008-01-01

    The relationships between the expression of ID2, EBV-LMP1 and P16(INK4A) in Chinese classical Hodgkin lymphoma are unknown and need exploring. Samples of classical Hodgkin lymphoma from 60 Chinese patients were analyzed for the expression of ID2, EBV-LMP1 and p16(INK4A) proteins by immunohistochemistry. ID2 protein was expressed in 83.3% of this group of classical Hodgkin lymphoma, staining strongly in both cytoplasm and nucleus of the Hodgkin and Reed-Sternberg (HRS) cells. EBV-LMP1 and P16(INK4A) were overexpressed in 85.0% and 71.7% of Hodgkin lymphoma, respectively. EBV-LMP1 was noted in the cytoplasm, membrane and nucleus of HRS cells; P16(INK4A) was in the nucleus and cytoplasm. Microscopically, ID2, EBV-LMP1 and P16(INK4A) staining distinguished the HRS cells from the complex background of lymphocytes. ID2 was positively correlated with EBV-LMP1(P < 0.01), but P16(INK4A) was inversely related to EBV-LMP1 (P < 0.05). It is suggested that ID2, EBV-LMP1 and P16(INK4A) could play an important role in the evolution of classical Hodgkin lymphoma, and be considered as potential adjunct markers to identify HRS cells in diagnosis

  5. Epstein-Barr Virus Latent Membrane Protein 2A (LMP2A) enhances IL-10 production through the activation of Bruton's tyrosine kinase and STAT3.

    Science.gov (United States)

    Incrocci, Ryan; Barse, Levi; Stone, Amanda; Vagvala, Sai; Montesano, Michael; Subramaniam, Vijay; Swanson-Mungerson, Michelle

    2017-01-01

    Previous data demonstrate that Epstein-Barr Virus Latent Membrane Protein 2A (LMP2A) enhances IL-10 to promote the survival of LMP2A-expressing B cell lymphomas. Since STAT3 is an important regulator of IL-10 production, we hypothesized that LMP2A activates a signal transduction cascade that increases STAT3 phosphorylation to enhance IL-10. Using LMP2A-negative and -positive B cell lines, the data indicate that LMP2A requires the early signaling molecules of the Syk/RAS/PI3K pathway to increase IL-10. Additional studies indicate that the PI3K-regulated kinase, BTK, is responsible for phosphorylating STAT3, which ultimately mediates the LMP2A-dependent increase in IL-10. These data are the first to show that LMP2A signaling results in STAT3 phosphorylation in B cells through a PI3K/BTK-dependent pathway. With the use of BTK and STAT3 inhibitors to treat B cell lymphomas in clinical trials, these findings highlight the possibility of using new pharmaceutical approaches to treat EBV-associated lymphomas that express LMP2A. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Genetic diversity of EBV-encoded LMP1 in the Swiss HIV Cohort Study and implication for NF-Κb activation.

    Directory of Open Access Journals (Sweden)

    Emilie Zuercher

    Full Text Available Epstein-Barr virus (EBV is associated with several types of cancers including Hodgkin's lymphoma (HL and nasopharyngeal carcinoma (NPC. EBV-encoded latent membrane protein 1 (LMP1, a multifunctional oncoprotein, is a powerful activator of the transcription factor NF-κB, a property that is essential for EBV-transformed lymphoblastoid cell survival. Previous studies reported LMP1 sequence variations and induction of higher NF-κB activation levels compared to the prototype B95-8 LMP1 by some variants. Here we used biopsies of EBV-associated cancers and blood of individuals included in the Swiss HIV Cohort Study (SHCS to analyze LMP1 genetic diversity and impact of sequence variations on LMP1-mediated NF-κB activation potential. We found that a number of variants mediate higher NF-κB activation levels when compared to B95-8 LMP1 and mapped three single polymorphisms responsible for this phenotype: F106Y, I124V and F144I. F106Y was present in all LMP1 isolated in this study and its effect was variant dependent, suggesting that it was modulated by other polymorphisms. The two polymorphisms I124V and F144I were present in distinct phylogenetic groups and were linked with other specific polymorphisms nearby, I152L and D150A/L151I, respectively. The two sets of polymorphisms, I124V/I152L and F144I/D150A/L151I, which were markers of increased NF-κB activation in vitro, were not associated with EBV-associated HL in the SHCS. Taken together these results highlighted the importance of single polymorphisms for the modulation of LMP1 signaling activity and demonstrated that several groups of LMP1 variants, through distinct mutational paths, mediated enhanced NF-κB activation levels compared to B95-8 LMP1.

  7. Differential Expression of LMP2/AND#946;1i: As A Potential Biomarker of Human Uterine Mesenchymal Tumors

    Directory of Open Access Journals (Sweden)

    Takuma Hayashi

    2013-06-01

    Full Text Available Uterine leiomyosarcoma (Ut-LMS develops more often in myometrium of the uterine body than in the uterine cervix. The development of gynecologic tumors is often correlated with female hormone secretion; however, the development of Ut-LMS is not substantially correlated with hormonal conditions, and the risk factor(s are not yet known. Importantly, a diagnostic-biomarker, which distinguishes malignant tumor Ut-LMS from benign tumor leiomyoma (LMA, is yet to be established. Accordingly, it is necessary to examine risk factor(s associated with Ut-LMS, to establish a clinical treatment method. The mice with a homozygous deficiency for proteasome subunit, low-molecular mass polypeptide (LMP2/b1i spontaneously develop Ut-LMS, with a disease prevalence of ~40% by 14 months of age. In the recent study, we found LMP2/b1i expression to be absent in human Ut-LMS, but present in human uterine LMA. Moreover, LMP2/b1i is reported to negatively regulate human Ut-LMS tumorigenesis. Therefore, LMP2/b1i is a potential diagnostic-biomarker for human Ut-LMS, and may be a targeted-molecule for a new therapeutic approach. [J Interdiscipl Histopathol 2013; 1(3.000: 153-159

  8. KSHV LANA and EBV LMP1 induce the expression of UCH-L1 following viral transformation

    Energy Technology Data Exchange (ETDEWEB)

    Bentz, Gretchen L.; Bheda-Malge, Anjali; Wang, Ling [Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill (United States); Shackelford, Julia [Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill (United States); Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill (United States); Damania, Blossom [Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill (United States); Departments of Medicine and of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC (United States); Pagano, Joseph S., E-mail: joseph_pagano@med.unc.edu [Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill (United States); Departments of Medicine and of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC (United States)

    2014-01-05

    Ubiquitin C-terminal Hydrolase L1 (UCH-L1) has oncogenic properties and is highly expressed during malignancies. We recently documented that Epstein-Barr virus (EBV) infection induces uch-l1 expression. Here we show that Kaposi's Sarcoma-associated herpesvirus (KSHV) infection induced UCH-L1 expression, via cooperation of KSHV Latency-Associated Nuclear Antigen (LANA) and RBP-Jκ and activation of the uch-l1 promoter. UCH-L1 expression was also increased in Primary Effusion Lymphoma (PEL) cells co-infected with KSHV and EBV compared with PEL cells infected only with KSHV, suggesting EBV augments the effect of LANA on uch-l1. EBV latent membrane protein 1 (LMP1) is one of the few EBV products expressed in PEL cells. Results showed that LMP1 was sufficient to induce uch-l1 expression, and co-expression of LMP1 and LANA had an additive effect on uch-l1 expression. These results indicate that viral latency products of both human γ-herpesviruses contribute to uch-l1 expression, which may contribute to the progression of lymphoid malignancies. - Highlights: • Infection of endothelial cells with KSHV induced UCH-L1 expression. • KSHV LANA is sufficient for the induction of uch-l1. • Co-infection with KSHV and EBV (observed in some PELs) results in the additive induction of uch-l1. • EBV LMP1 also induced UCH-L1 expression. • LANA- and LMP1-mediated activation of the uch-l1 promoter is in part through RBP-Jκ.

  9. Analysis of the Epstein-Barr virus (EBV) latent membrane protein 1 (LMP-1) gene and promoter in Hodgkin's disease isolates

    DEFF Research Database (Denmark)

    Sandvej, K; Andresen, B S; Zhou, X G

    2000-01-01

    AIMS: To study the distribution of Epstein-Barr virus (EBV) variants containing mutations in the latent membrane protein 1 (LMP-1) oncogene and promoter in EBV associated Hodgkin's disease and infectious mononucleosis compared with previous findings in asymptomatic EBV carriers. METHODS: Sequence...... analysis of the EBV LMP-1 promoter and gene in isolates from Danish patients with Hodgkin's disease (n = 61) and infectious mononucleosis (n = 10). RESULTS: Viruses (previously designated group D) that contain two mutations in the activating transcription factor/cAMP response element (ATF/CRE) in the LMP-1...... promoter, which are known to decrease promoter activity greatly, were significantly less frequent in Hodgkin's disease than in both infectious mononucleosis (p = 0.0081) and asymptomatic EBV carriers (p = 0.0084). In some cases, the LMP-1 gene contained mutations in a recently identified cytotoxic T cell...

  10. Epstein-Barr virus LMP2A signaling in statu nascendi mimics a B cell antigen receptor-like activation signal

    Directory of Open Access Journals (Sweden)

    Engels Niklas

    2012-04-01

    Full Text Available Abstract Background The latent membrane protein (LMP 2A of Epstein-Barr virus (EBV is expressed during different latency stages of EBV-infected B cells in which it triggers activation of cytoplasmic protein tyrosine kinases. Early studies revealed that an immunoreceptor tyrosine-based activation motif (ITAM in the cytoplasmic N-terminus of LMP2A can trigger a transient increase of the cytosolic Ca2+ concentration similar to that observed in antigen-activated B cells when expressed as a chimeric transmembrane receptor. Even so, LMP2A was subsequently ascribed an inhibitory rather than an activating function because its expression seemed to partially inhibit B cell antigen receptor (BCR signaling in EBV-transformed B cell lines. However, the analysis of LMP2A signaling has been hampered by the lack of cellular model systems in which LMP2A can be studied without the influence of other EBV-encoded factors. Results We have reanalyzed LMP2A signaling using B cells in which LMP2A is expressed in an inducible manner in the absence of any other EBV signaling protein. This allowed us for the first time to monitor LMP2A signaling in statu nascendi as it occurs during the EBV life cycle in vivo. We show that mere expression of LMP2A not only stimulated protein tyrosine kinases but also induced phospholipase C-γ2-mediated Ca2+ oscillations followed by activation of the extracellular signal-regulated kinase (Erk mitogen-activated protein kinase pathway and induction of the lytic EBV gene bzlf1. Furthermore, expression of the constitutively phosphorylated LMP2A ITAM modulated rather than inhibited BCR-induced Ca2+ mobilization. Conclusion Our data establish that LMP2A expression has a function beyond the putative inhibition of the BCR by generating a ligand-independent cellular activation signal that may provide a molecular switch for different EBV life cycle stages and most probably contributes to EBV-associated lymphoproliferative disorders.

  11. Triptolide inhibits proliferation of Epstein–Barr virus-positive B lymphocytes by down-regulating expression of a viral protein LMP1

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Heng [Department of Pathogen Biology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Guo, Wei [Department of Pathology and Physiology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Long, Cong; Wang, Huan; Wang, Jingchao [Department of Pathogen Biology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Sun, Xiaoping, E-mail: xsun6@whu.edu.cn [Department of Pathogen Biology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); State Key Laboratory of Virology, Wuhan University, Wuhan 430072 (China)

    2015-01-16

    Highlights: • Triptolide inhibits proliferation of EBV-positive lymphoma cells in vitro and in vivo. • Triptolide reduces expression of LMP1 by decreasing its transcription level. • Triptolide inhibits ED-L1 promoter activity. - Abstract: Epstein–Barr virus (EBV) infects various types of cells and mainly establishes latent infection in B lymphocytes. The viral latent membrane protein 1 (LMP1) plays important roles in transformation and proliferation of B lymphocytes infected with EBV. Triptolide is a compound of Tripterygium extracts, showing anti-inflammatory, immunosuppressive, and anti-cancer activities. In this study, it is determined whether triptolide inhibits proliferation of Epstein–Barr virus-positive B lymphocytes. The CCK-8 assays were performed to examine cell viabilities of EBV-positive B95-8 and P3HR-1 cells treated by triptolide. The mRNA and protein levels of LMP1 were examined by real time-PCR and Western blotting, respectively. The activities of two LMP1 promoters (ED-L1 and TR-L1) were determined by Dual luciferase reportor assay. The results showed that triptolide inhibited the cell viability of EBV-positive B lymphocytes, and the over-expression of LMP1 attenuated this inhibitory effect. Triptolide decreased the LMP1 expression and transcriptional levels in EBV-positive B cells. The activity of LMP1 promoter ED-L1 in type III latent infection was strongly suppressed by triptolide treatment. In addition, triptolide strongly reduced growth of B95-8 induced B lymphoma in BALB/c nude mice. These results suggest that triptolide decreases proliferation of EBV-induced B lymphocytes possibly by a mechanism related to down-regulation of the LMP1 expression.

  12. Correlation of LMP10 expression and clinical outcome in Human Papillomavirus (HPV positive and HPV-Negative tonsillar and base of tongue cancer.

    Directory of Open Access Journals (Sweden)

    Nikolaos Tertipis

    Full Text Available To examine LMP10 expression and its possible impact on clinical outcome in human papillomavirus (HPV positive and HPV-negative tonsillar and base of tongue squamous cell carcinoma (TSCC and BOTSCC.Outcome is better in HPV-positive TSCC and BOTSCC compared to matching HPV-negative tumours, with roughly 80% vs. 40% 5-year disease free survival (DFS with less aggressive treatment than today's chemoradiotherapy. Since current treatment often results in harmful side effects, less intensive therapy, with sustained patient survival would be an attractive alternative. However, other markers together with HPV status are necessary to select patients and for this purpose LMP10 expression is investigated here in parallel to HPV status and clinical outcome.From 385 patients diagnosed between 2000 and 2007 at the Karolinska University Hospital, 278 formalin fixed paraffin embedded TSCC and BOTSCC biopsies, with known HPV DNA status, were tested for LMP10 nuclear and cytoplasmic expression (fraction of positive cells and staining intensity. The data was then correlated to clinical outcome.An absent/low compared to a moderate/high LMP10 nuclear fraction of positive cells was correlated to a better 3-year DFS in the HPV-positive group of patients (log-rank p = 0.005, but not in the HPV-negative group. In the HPV-negative group of patients, in contrast to the HPV-positive group, moderate/high LMP10 cytoplasmic fraction and weak/moderate/high LMP10 cytoplasmic intensity correlated to a better 3-year DFS (p = 0.003 and p = 0.001 and 3-year overall survival (p = 0.001 and 0.009.LMP10 nuclear expression in the HPV-positive group and LMP10 cytoplasmic expression in the HPV-negative group of patients correlated to better clinical outcome.

  13. Correlation of LMP10 expression and clinical outcome in Human Papillomavirus (HPV) positive and HPV-Negative tonsillar and base of tongue cancer.

    Science.gov (United States)

    Tertipis, Nikolaos; Haeggblom, Linnea; Nordfors, Cecilia; Grün, Nathalie; Näsman, Anders; Vlastos, Andrea; Dalianis, Tina; Ramqvist, Torbjörn

    2014-01-01

    To examine LMP10 expression and its possible impact on clinical outcome in human papillomavirus (HPV) positive and HPV-negative tonsillar and base of tongue squamous cell carcinoma (TSCC and BOTSCC). Outcome is better in HPV-positive TSCC and BOTSCC compared to matching HPV-negative tumours, with roughly 80% vs. 40% 5-year disease free survival (DFS) with less aggressive treatment than today's chemoradiotherapy. Since current treatment often results in harmful side effects, less intensive therapy, with sustained patient survival would be an attractive alternative. However, other markers together with HPV status are necessary to select patients and for this purpose LMP10 expression is investigated here in parallel to HPV status and clinical outcome. From 385 patients diagnosed between 2000 and 2007 at the Karolinska University Hospital, 278 formalin fixed paraffin embedded TSCC and BOTSCC biopsies, with known HPV DNA status, were tested for LMP10 nuclear and cytoplasmic expression (fraction of positive cells and staining intensity). The data was then correlated to clinical outcome. An absent/low compared to a moderate/high LMP10 nuclear fraction of positive cells was correlated to a better 3-year DFS in the HPV-positive group of patients (log-rank p = 0.005), but not in the HPV-negative group. In the HPV-negative group of patients, in contrast to the HPV-positive group, moderate/high LMP10 cytoplasmic fraction and weak/moderate/high LMP10 cytoplasmic intensity correlated to a better 3-year DFS (p = 0.003 and p = 0.001) and 3-year overall survival (p = 0.001 and 0.009). LMP10 nuclear expression in the HPV-positive group and LMP10 cytoplasmic expression in the HPV-negative group of patients correlated to better clinical outcome.

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

    DEFF Research Database (Denmark)

    Santos, Gabriel; Fernandes, Ricardo; Pinto, Tiago

    2015-01-01

    emerged. Decision support tools that facilitate the study and comprehension of these markets became extremely useful, providing players with competitive advantage. MASCEM (Multi-Agent Simulator of Competitive Electricity Markets) arises in this context, modeling and simulating real electricity markets...

  15. Powernext Day-Ahead. Powernext Futures. Activity report - 2004

    International Nuclear Information System (INIS)

    2004-01-01

    Powernext SA is a Multilateral Trading Facility which organizes and warrants the transactions on the European power exchange market. This activity report presents the highlights of the market and of Powernext in 2004: market conditions (more reasonable and less volatile prices, steadier market conditions (climate conditions, power consumption, correlation between French and German prices), increasing liquidity, start-up of Powernext Futures TM for medium-term contracts and introduction of futures price curve, promising volumes to start, and liquidity of the futures market. (J.S)

  16. Forecasting Day-Ahead Electricity Prices: Utilizing Hourly Prices

    OpenAIRE

    Raviv, Eran; Bouwman, Kees E.; van Dijk, Dick

    2013-01-01

    This discussion paper led to a publication in 'Energy Economics' , 2015, 50, 227-239. The daily average price of electricity represents the price of electricity to be delivered over the full next day and serves as a key reference price in the electricity market. It is an aggregate that equals the average of hourly prices for delivery during each of the 24 individual hours. This paper demonstrates that the disaggregated hourly prices contain useful predictive information for the daily average ...

  17. Forecasting Day-Ahead Electricity Prices : Utilizing Hourly Prices

    NARCIS (Netherlands)

    E. Raviv (Eran); K.E. Bouwman (Kees); D.J.C. van Dijk (Dick)

    2013-01-01

    textabstractThe daily average price of electricity represents the price of electricity to be delivered over the full next day and serves as a key reference price in the electricity market. It is an aggregate that equals the average of hourly prices for delivery during each of the 24 individual

  18. Osteogenesis and mineralization in a rabbit mandibular distraction osteogenesis model is promoted by the human LMP-1 gene.

    Science.gov (United States)

    Jiang, Xiaowen; Chen, Yanzhe; Fan, Xiaosheng; Zhang, Hao; Kun, Lu

    2015-04-01

    To observe the effects of LIM mineralization protein-1 (LMP-1) on bone regeneration in the distraction zone based on gene transduction, 36 New Zealand white rabbits underwent mandibular lengthening with a distraction rate of 2 mm/day. The animals were then randomly divided into group A and group B (n = 18, each). At the end of the distraction, Ad5-EGFP viruses and Ad5-LMP-1/EGFP viruses were injected into the distraction gaps in groups A and B, respectively. Seven days later, five randomly selected animals from each group were sacrificed to evaluate the survival of the virus. Four and 8 weeks after distraction osteogenesis (DO), six samples randomly selected from each group underwent CT scanning and dual energy X-ray absorptiometry detection. Eight weeks after DO, the rabbits were sacrificed, and the distracted mandibles were harvested. Six animals from each group processed for radiography, micro-CT, histology, and the rest samples were taken three-point bend testing. Using this model, better bone formation and mineralization in the distracted callus were observed in group B when compared with those in group A. The results suggest local transduction with LMP-1 gene promotes osteogenesis and mineralization in DO. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  19. The Power of Weather: Some Empirical Evidence on Predicting Day-ahead Power Prices through Day-ahead Weather Forecasts

    NARCIS (Netherlands)

    F. Ravazzolo (Francesco); C. Zhou (Chen); C. Huurman

    2007-01-01

    textabstractIn the literature the effects of weather on electricity sales are well-documented. However, studies that have investigated the impact of weather on electricity prices are still scarce (e.g. Knittel and Roberts, 2005), partly because the wholesale power markets have only recently been

  20. Powernext Day-Ahead. Powernext Futures. Activity report - 2004; Powernext Day-Ahead. Powernext Futures. Bilan statistique 2004

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    Powernext SA is a Multilateral Trading Facility which organizes and warrants the transactions on the European power exchange market. This activity report presents the highlights of the market and of Powernext in 2004: market conditions (more reasonable and less volatile prices, steadier market conditions (climate conditions, power consumption, correlation between French and German prices), increasing liquidity, start-up of Powernext Futures{sup TM} for medium-term contracts and introduction of futures price curve, promising volumes to start, and liquidity of the futures market. (J.S)

  1. Ekspresi mRNA LMP2A Epstein-Barr Virus dari Biopsi Jaringan dalam Blok Parafin Berpotensi sebagai Biomarka dalam Diagnosis Karsinoma Nasofaring

    Directory of Open Access Journals (Sweden)

    Roni Afriansya

    2017-08-01

    Full Text Available Karsinoma nasofaring (KNF merupakan tumor epitel yang terletak di nasofaring dan merupakan penyakit genetik multifaktor yang endemik. Penyebab utama KNF adalah infeksi oleh Virus Epstein-Barr (EBV. Keberadaan EBV pada penderita KNF dapat diketahui dengan ditemukannya DNA EBV dalam spesimen biopsi jaringan penderita KNF. Genom EBV dan ekspresi sebagian dari produk gen laten virus secara konsisten terdeteksi hampir di setiap sel dalam kanker ini, salah satunya adalah gen Latent Membrant Protein (LMP. Aktivitas mRNA EBV lebih mencerminkan patogenesis KNF yang  sesungguhnya dari pada diagnosis serologi dan pengukuran DNA EBV di sirkulasi. Penelitian dilakukan di Laboratorium PA RSUD Margono Seokarjo, Purwokerto/Lab PA Fakultas Kedokteran dan laboratorium genetika/molekuler Universitas Jenderal Soedirman Purwokerto. Analisis Ekspresi mRNA LMP2A EBV dengan teknik one step RT-PCR dan produk RT-PCR (amplikon cDNA divisualisasi dengan elektroforesis gel agarosa 1%. Hasil ekspresi mRNA LMP2A EBV adalah 27,3% (6 dari 22 sampel. Kesimpulan, metode one step RT-PCR dapat digunakan untuk menganalisis ekspresi mRNA LMP2A EBV dari sampel biopsi jaringan KNF dalam blok paraffin dan hasil positivitas ekspresi mRNA LMP2A EBV sedang, sehingga berpotensi digunakan sebagai petanda biologi molekul diagnosis KNF.

  2. Epstein-Barr virus-encoded LMP2A stimulates migration of nasopharyngeal carcinoma cells via the EGFR/Ca2+/calpain/ITGβ4 axis

    Directory of Open Access Journals (Sweden)

    Jiezhen Liang

    2017-06-01

    Full Text Available Epstein-Barr virus (EBV-encoded latent membrane protein 2A (LMP2A promotes the motility of nasopharyngeal carcinoma (NPC cells. Previously, we have shown that the localization of integrin β4 (ITGβ4 is regulated by LMP2A, with ITGβ4 concentrated at the cellular protrusions in LMP2A-expressing NPC cells. In the present study, we aim to further investigate mechanisms involved in this process and its contribution to cell motility. We show that expression of LMP2A was correlated with increased epidermal growth factor receptor (EGFR activation, elevated levels of intracellular Ca2+, calpain activation and accelerated cleavage of ITGβ4. Activation of EGFR and calpain activity was responsible for a redistribution of ITGβ4 from the basal layer of NPC cells to peripheral membrane structures, which correlated with an increased migratory capacity of NPC cells. Furthermore, we demonstrated that the calpain inhibitor calpastatin was downregulated in NPC primary tumors. In conclusion, our results point to LMP2A-mediated targeting of the EGFR/Ca2+/calpain/ITGβ4 signaling system as a mechanism underlying the increased motility of NPC cells. We suggest that calpain-facilitated cleavage of ITGβ4 contributes to the malignant phenotype of NPC cells.

  3. Modulation of LMP2A Expression by a Newly Identified Epstein-Barr Virus-Encoded MicroRNA miR-BART22

    Directory of Open Access Journals (Sweden)

    Raymond Wai-Ming Lung

    2009-11-01

    Full Text Available Infection with the Epstein-Barr virus (EBV is a strong predisposing factor in the development of nasopharyngeal carcinoma (NPC. Many viral gene products including EBNA1, LMP1, and LMP2 have been implicated in NPC tumorigenesis, although the de novo control of these viral oncoproteins remains largely unclear. The recent discovery of EBV-encoded viral microRNA (miRNA in lymphoid malignancies has prompted us to examine the NPC-associated EBV miRNA. Using large-scale cloning analysis on EBV-positive NPC cells, two novel EBV miRNA, now named miR-BART21 and miR-BART22, were identified. These two EBV-encoded miRNA are abundantly expressed in most NPC samples. We found two nucleotide variations in the primary transcript of miR-BART22, which we experimentally confirmed to augment its biogenesis in vitro and thus may underline the high and consistent expression of miR-BART22 in NPC tumors. More importantly, we determined that the EBV latent membrane protein 2A (LMP2A is the putative target of miR-BART22. LMP2A is a potent immunogenic viral antigen that is recognized by the cytotoxic T cells; down-modulation of LMP2A expression by miR-BART22 may permit escape of EBV-infected cells from host immune surveillance. Taken together, we demonstrated that two newly identified EBV-encoded miRNA are highly expressed in NPC. Specific sequence variations on the prevalent EBV strain in our locality might contribute to the higher miR-BART22 expression level in our NPC samples. Our findings emphasize the role of miR-BART22 in modulating LMP2A expression, which may facilitate NPC carcinogenesis by evading the host immune response.

  4. Epstein-Barr virus LMP2A suppresses MHC class II expression by regulating the B-cell transcription factors E47 and PU.1.

    Science.gov (United States)

    Lin, Jiun-Han; Lin, Ju-Yin; Chou, Ya-Ching; Chen, Mei-Ru; Yeh, Te-Huei; Lin, Chung-Wu; Lin, Sue-Jane; Tsai, Ching-Hwa

    2015-04-02

    Oncogenic Epstein-Barr virus (EBV) uses various approaches to escape host immune responses and persist in B cells. Such persistent infections may provide the opportunity for this virus to initiate tumor formation. Using EBV-immortalized lymphoblastoid cell lines (LCLs) as a model, we found that the expression of major histocompatibility complex (MHC) class II and CD74 in B cells is repressed after EBV infection. Class II transactivator (CIITA) is the master regulator of MHC class II-related genes. As expected, CIITA was downregulated in LCLs. We showed that downregulation of CIITA is caused by EBV latent membrane protein 2A (LMP2A) and driven by the CIITA-PIII promoter. Furthermore, we demonstrated that LMP2A-mediated E47 and PU.1 reduction resulted in CIITA suppression. Mechanistically, the LMP2A immunoreceptor tyrosine-based activation motif was critical for the repression of E47 and PU.1 promoter activity via Syk, Src, and the phosphatidylinositol 3-kinase/Akt pathway. Elimination of LMP2A in LCLs using a shLMP2A approach showed that the expression levels of E47, PU.1, CIITA, MHC class II, and CD74 are reversed. These data indicated that the LMP2A may reduce MHC class II expression through interference with the E47/PU.1-CIITA pathway. Finally, we demonstrated that MHC class II may be detected in tonsils and EBV-negative Hodgkin disease but not in EBV-associated posttransplant lymphoproliferative disease and Hodgkin disease. © 2015 by The American Society of Hematology.

  5. Peak flow meter (image)

    Science.gov (United States)

    A peak flow meter is commonly used by a person with asthma to measure the amount of air that can be ... become narrow or blocked due to asthma, peak flow values will drop because the person cannot blow ...

  6. SPLUNC1 regulates cell progression and apoptosis through the miR-141-PTEN/p27 pathway, but is hindered by LMP1.

    Directory of Open Access Journals (Sweden)

    Pan Chen

    Full Text Available Little is known about the role of the host defensive protein short palate, lung and nasal epithelium clone 1 (SPLUNC1 in the carcinogenesis of nasopharyngeal carcinoma (NPC. Here we report that SPLUNC1 plays a role at a very early stage of NPC carcinogenesis. SPLUNC1 regulates NPC cell proliferation, differentiation and apoptosis through miR-141, which in turn regulates PTEN and p27 expression. This signaling axis is negatively regulated by the EBV-coded gene LMP1. Therefore we propose that SPLUNC1 suppresses NPC tumor formation and its inhibition by LMP1 provides a route for NPC tumorigenesis.

  7. Peak Experience Project

    Science.gov (United States)

    Scott, Daniel G.; Evans, Jessica

    2010-01-01

    This paper emerges from the continued analysis of data collected in a series of international studies concerning Childhood Peak Experiences (CPEs) based on developments in understanding peak experiences in Maslow's hierarchy of needs initiated by Dr Edward Hoffman. Bridging from the series of studies, Canadian researchers explore collected…

  8. A Rapid Embryonic Stem Cell-Based Mouse Model for B-cell Lymphomas Driven by Epstein-Barr Virus Protein LMP1.

    Science.gov (United States)

    Ba, Zhaoqing; Meng, Fei-Long; Gostissa, Monica; Huang, Pei-Yi; Ke, Qiang; Wang, Zhe; Dao, Mai N; Fujiwara, Yuko; Rajewsky, Klaus; Zhang, Baochun; Alt, Frederick W

    2015-06-01

    The Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) contributes to oncogenic human B-cell transformation. Mouse B cells conditionally expressing LMP1 are not predisposed to B-cell malignancies, as LMP1-expressing B cells are eliminated by T cells. However, mice with conditional B-cell LMP1 expression and genetic elimination of α/β and γ/δ T cells ("CLT" mice) die early in association with B-cell lymphoproliferation and lymphomagenesis. Generation of CLT mice involves in-breeding multiple independently segregating alleles. Thus, although introduction of additional activating or knockout mutations into the CLT model is desirable for further B-cell expansion and immunosurveillance studies, doing such experiments by germline breeding is time-consuming, expensive, and sometimes unfeasible. To generate a more tractable model, we generated clonal CLT embryonic stem (ES) cells from CLT embryos and injected them into RAG2-deficient blastocysts to generate chimeric mice, which, like germline CLT mice, harbor splenic CLT B cells and lack T cells. CLT chimeric mice generated by this RAG2-deficient blastocyst complementation ("RDBC") approach die rapidly in association with B-cell lymphoproliferation and lymphoma. Because CLT lymphomas routinely express the activation-induced cytidine deaminase (AID) antibody diversifier, we tested potential AID roles by eliminating the AID gene in CLT ES cells and testing them via RDBC. We found that CLT and AID-deficient CLT ES chimeras had indistinguishable phenotypes, showing that AID is not essential for LMP1-induced lymphomagenesis. Beyond expanding accessibility and utility of CLT mice as a cancer immunotherapy model, our studies provide a new approach for facilitating generation of genetically complex mouse cancer models. ©2015 American Association for Cancer Research.

  9. Peak power ratio generator

    Science.gov (United States)

    Moyer, R.D.

    A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

  10. Peak Oil, Peak Coal and Climate Change

    Science.gov (United States)

    Murray, J. W.

    2009-05-01

    Research on future climate change is driven by the family of scenarios developed for the IPCC assessment reports. These scenarios create projections of future energy demand using different story lines consisting of government policies, population projections, and economic models. None of these scenarios consider resources to be limiting. In many of these scenarios oil production is still increasing to 2100. Resource limitation (in a geological sense) is a real possibility that needs more serious consideration. The concept of 'Peak Oil' has been discussed since M. King Hubbert proposed in 1956 that US oil production would peak in 1970. His prediction was accurate. This concept is about production rate not reserves. For many oil producing countries (and all OPEC countries) reserves are closely guarded state secrets and appear to be overstated. Claims that the reserves are 'proven' cannot be independently verified. Hubbert's Linearization Model can be used to predict when half the ultimate oil will be produced and what the ultimate total cumulative production (Qt) will be. US oil production can be used as an example. This conceptual model shows that 90% of the ultimate US oil production (Qt = 225 billion barrels) will have occurred by 2011. This approach can then be used to suggest that total global production will be about 2200 billion barrels and that the half way point will be reached by about 2010. This amount is about 5 to 7 times less than assumed by the IPCC scenarios. The decline of Non-OPEC oil production appears to have started in 2004. Of the OPEC countries, only Saudi Arabia may have spare capacity, but even that is uncertain, because of lack of data transparency. The concept of 'Peak Coal' is more controversial, but even the US National Academy Report in 2007 concluded only a small fraction of previously estimated reserves in the US are actually minable reserves and that US reserves should be reassessed using modern methods. British coal production can be

  11. Peak regulation right

    International Nuclear Information System (INIS)

    Gao, Z. |; Ren, Z.; Li, Z.; Zhu, R.

    2005-01-01

    A peak regulation right concept and corresponding transaction mechanism for an electricity market was presented. The market was based on a power pool and independent system operator (ISO) model. Peak regulation right (PRR) was defined as a downward regulation capacity purchase option which allowed PRR owners to buy certain quantities of peak regulation capacity (PRC) at a specific price during a specified period from suppliers. The PRR owner also had the right to decide whether or not they would buy PRC from suppliers. It was the power pool's responsibility to provide competitive and fair peak regulation trading markets to participants. The introduction of PRR allowed for unit capacity regulation. The PRR and PRC were rated by the supplier, and transactions proceeded through a bidding process. PRR suppliers obtained profits by selling PRR and PRC, and obtained downward regulation fees regardless of whether purchases are made. It was concluded that the peak regulation mechanism reduced the total cost of the generating system and increased the social surplus. 6 refs., 1 tab., 3 figs

  12. Peak-interviewet

    DEFF Research Database (Denmark)

    Raalskov, Jesper; Warming-Rasmussen, Bent

    Peak-interviewet er en særlig effektiv metode til at gøre ubevidste menneskelige ressourcer bevidste. Fokuspersonen (den interviewede) interviewes om en selvvalgt, personlig succesoplevelse. Terapeuten/coachen (intervieweren) spørger ind til processen, som ledte hen til denne succes. Herved afdæk...

  13. Automated asteroseismic peak detections

    Science.gov (United States)

    García Saravia Ortiz de Montellano, Andrés; Hekker, S.; Themeßl, N.

    2018-05-01

    Space observatories such as Kepler have provided data that can potentially revolutionize our understanding of stars. Through detailed asteroseismic analyses we are capable of determining fundamental stellar parameters and reveal the stellar internal structure with unprecedented accuracy. However, such detailed analyses, known as peak bagging, have so far been obtained for only a small percentage of the observed stars while most of the scientific potential of the available data remains unexplored. One of the major challenges in peak bagging is identifying how many solar-like oscillation modes are visible in a power density spectrum. Identification of oscillation modes is usually done by visual inspection that is time-consuming and has a degree of subjectivity. Here, we present a peak-detection algorithm especially suited for the detection of solar-like oscillations. It reliably characterizes the solar-like oscillations in a power density spectrum and estimates their parameters without human intervention. Furthermore, we provide a metric to characterize the false positive and false negative rates to provide further information about the reliability of a detected oscillation mode or the significance of a lack of detected oscillation modes. The algorithm presented here opens the possibility for detailed and automated peak bagging of the thousands of solar-like oscillators observed by Kepler.

  14. Epstein - Barr virus transforming protein LMP-1 alters B cells gene expression by promoting accumulation of the oncoprotein ΔNp73α.

    Directory of Open Access Journals (Sweden)

    Rosita Accardi

    2013-03-01

    Full Text Available Many studies have proved that oncogenic viruses develop redundant mechanisms to alter the functions of the tumor suppressor p53. Here we show that Epstein-Barr virus (EBV, via the oncoprotein LMP-1, induces the expression of ΔNp73α, a strong antagonist of p53. This phenomenon is mediated by the LMP-1 dependent activation of c-Jun NH2-terminal kinase 1 (JNK-1 which in turn favours the recruitment of p73 to ΔNp73α promoter. A specific chemical inhibitor of JNK-1 or silencing JNK-1 expression strongly down-regulated ΔNp73α mRNA levels in LMP-1-containing cells. Accordingly, LMP-1 mutants deficient to activate JNK-1 did not induce ΔNp73α accumulation. The recruitment of p73 to the ΔNp73α promoter correlated with the displacement of the histone-lysine N-methyltransferase EZH2 which is part of the transcriptional repressive polycomb 2 complex. Inhibition of ΔNp73α expression in lymphoblastoid cells (LCLs led to the stimulation of apoptosis and up-regulation of a large number of cellular genes as determined by whole transcriptome shotgun sequencing (RNA-seq. In particular, the expression of genes encoding products known to play anti-proliferative/pro-apoptotic functions, as well as genes known to be deregulated in different B cells malignancy, was altered by ΔNp73α down-regulation. Together, these findings reveal a novel EBV mechanism that appears to play an important role in the transformation of primary B cells.

  15. Epstein-Barr virus from Burkitt Lymphoma biopsies from Africa and South America share novel LMP-1 promoter and gene variations.

    Science.gov (United States)

    Lei, Haiyan; Li, Tianwei; Li, Bingjie; Tsai, Shien; Biggar, Robert J; Nkrumah, Francis; Neequaye, Janet; Gutierrez, Marina; Epelman, Sidnei; Mbulaiteye, Sam M; Bhatia, Kishor; Lo, Shyh-Ching

    2015-11-23

    Epstein Barr virus (EBV) sequence variation is thought to contribute to Burkitt lymphoma (BL), but lack of data from primary BL tumors hampers efforts to test this hypothesis. We directly sequenced EBV from 12 BL biopsies from Ghana, Brazil, and Argentina, aligned the obtained reads to the wild-type (WT) EBV reference sequence, and compared them with 100 published EBV genomes from normal and diseased people from around the world. The 12 BL EBVs were Type 1. Eleven clustered close to each other and to EBV from Raji BL cell line, but away from 12 EBVs reported from other BL-derived cell lines and away from EBV from NPC and healthy people from Asia. We discovered 23 shared novel nucleotide-base changes in the latent membrane protein (LMP)-1 promoter and gene (associated with 9 novel amino acid changes in the LMP-1 protein) of the 11 BL EBVs. Alignment of this region for the 112 EBV genomes revealed four distinct patterns, tentatively termed patterns A to D. The distribution of BL EBVs was 48%, 8%, 24% and 20% for patterns A to D, respectively; the NPC EBV's were Pattern B, and EBV-WT was pattern D. Further work is needed to investigate the association between EBV LMP-1 patterns with BL.

  16. Twin Peaks - 3D

    Science.gov (United States)

    1997-01-01

    The two hills in the distance, approximately one to two kilometers away, have been dubbed the 'Twin Peaks' and are of great interest to Pathfinder scientists as objects of future study. 3D glasses are necessary to identify surface detail. The white areas on the left hill, called the 'Ski Run' by scientists, may have been formed by hydrologic processes.The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

  17. Sunset over Twin Peaks

    Science.gov (United States)

    1997-01-01

    This image was taken by the Imager for Mars Pathfinder (IMP) about one minute after sunset on Mars on Sol 21. The prominent hills dubbed 'Twin Peaks' form a dark silhouette at the horizon, while the setting sun casts a pink glow over the darkening sky. The image was taken as part of a twilight study which indicates how the brightness of the sky fades with time after sunset. Scientists found that the sky stays bright for up to two hours after sunset, indicating that Martian dust extends very high into the atmosphere.Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  18. Peak flow meter use - slideshow

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/presentations/100202.htm Peak flow meter use - Series—Peak flow meter use - part one To use the sharing ... slide 7 out of 7 Overview A peak flow meter helps you check how well your asthma ...

  19. PR-924, a selective inhibitor of the immunoproteasome subunit LMP-7, blocks multiple myeloma cell growth both in vitro and in vivo.

    Science.gov (United States)

    Singh, Ajita V; Bandi, Madhavi; Aujay, Monette A; Kirk, Christopher J; Hark, David E; Raje, Noopur; Chauhan, Dharminder; Anderson, Kenneth C

    2011-01-01

    PR-924 is an LMP-7-selective tripeptide epoxyketone proteasome inhibitor that covalently modifies proteasomal N-terminal threonine active sites. In the present study, we show that PR-924 inhibits growth and triggers apoptosis in multiple myeloma (MM) cell lines and primary patient MM cells, without significantly affecting normal peripheral blood mononuclear cells. PR-924-induced apoptosis in MM cells is associated with activation of caspase-3, caspase-8, caspase-9, BID, PARP and cytochrome-c release. In vivo administration of PR-924 inhibits tumour growth in human plasmacytoma xenografts. Results from SCID-hu model show a significant reduction in the shIL-6R levels in mice treated with PR-924 versus vehicle-control. PR-924 treatment was well tolerated as evidenced by the lack of weight loss. Importantly, treatment of tumour-bearing mice with PR-924, but not vehicle alone, prolonged survival. Our preclinical findings therefore validate immunoproteasome LMP-7 subunit as a novel therapeutic target in MM. © 2010 Blackwell Publishing Ltd.

  20. The Safety and Immunological Effects of rAd5-EBV-LMP2 Vaccine in Nasopharyngeal Carcinoma Patients: A Phase I Clinical Trial and Two-Year Follow-Up.

    Science.gov (United States)

    Si, Yongfeng; Deng, Zhuoxia; Lan, Guiping; Du, Haijun; Wang, Yongli; Si, Jinyuan; Wei, Jiazhang; Weng, Jingjin; Qin, Yangda; Huang, Bo; Yang, Yong; Qin, Ying

    2016-01-01

    Epstein-Barr virus (EBV)-encoded latent membrane protein 2 (LMP2) promotes nasopharyngeal carcinoma (NPC) progression. Previously, we reported that the dendritic cells (DCs) transfected with EBV-LMP2 recombinant serotype 5 adenoviruses (rAd5) induced anti-tumor effect by eliciting cytotoxic T lymphocytes (CTLs)-mediated immune response in vitro and the adenoviral vaccine of EBV-LMP2 (rAd5-EBV-LMP2) stimulated antigen-specific cellular immunity in mice. However, the safety and immunological effect of rAd5-EBV-LMP2 vaccine in human still remained unknown. Here we conducted a single-center, non-randomized, open-label, single-arm phase I clinical trial to clarify this unsolved issue. A total of 24 patients with regional advanced NPC were sequentially enrolled into three dose level groups (2×10(9), 2×10(10), 2×10(11) vp). The rAd5-EBV-LMP2 vaccines were intramuscularly injected for four times within 28 d (D0, D7, D14, D28). Blood samples were harvested immediately before every vaccination, one week and one month after the last vaccination (D0, D7, D14, D28, D35, D58). All the vaccine inoculation-related toxicities presented as grade I/II adverse events. The most frequent systemic adverse reactions were fatigue (33.0%, 8/24), myalgia (29.2%, 7/24) and cough (29.2%, 7/24), while the most common regional adverse reaction was tenderness in the inoculation site (54.2%, 13/24). In addition, proportion of CD(3+)CD(4+) cells in peripheral blood was significantly increased in the high dose group (2×10(11) vp). The rAd5-EBV-LMP2 vaccine was generally well-tolerated and the high dose (2×10(11) vp) is recommended to be adopted in phase II studies. The long-term outcome of rAd5-EBV-LMP2 vaccine inoculation is required to be determined in following placebo-controlled trials.

  1. PEAK SHAVING CONSIDERING STREAMFLOW UNCERTAINTIES

    African Journals Online (AJOL)

    user

    Abstract. The main thrust of this paper is peak shaving with a Stochastic hydro model. In peak sharing, the amount of hydro energy scheduled may be a minimum but it serves to replace less efficient thermal units. The sample system is die Kainji hydro plant and the thermal units of the National Electric. Power Authority.

  2. Twin and triple peaks papilledema.

    Science.gov (United States)

    Mehta, Jodhbir S; Plant, Gordon T; Acheson, James F

    2005-07-01

    To describe 2 adult patients who presented with papilledema after band atrophy (i.e., twin and triple peaks papilledema). Retrospective small case series. Two outpatients. Observations made on 2 patients whose cases were reviewed in the neuro-ophthalmology clinic. The first patient had a pituitary tumor presenting with papilledema, causing a triple peaks clinical sign. Color photographs, optical coherence tomograms, and magnetic resonance images are shown. The second patient developed twin peaks papilledema due to a chiasmal glioma causing secondary raised intracranial pressure. Twin peaks papilledema is a rare clinical sign that may develop in adults as well as in children. The first report and optical coherence tomography features of triple peaks papilledema illustrate a new clinical sign.

  3. 75 FR 42399 - Orders Finding That the PJM WH Real Time Peak Daily Contract, PJM WH Real Time Off-Peak Daily...

    Science.gov (United States)

    2010-07-21

    ... well as a real-time market. The day-ahead market establishes prices for electricity that is to be..., market participants view ICE as a price discovery market for certain electricity contracts. The study did... electricity prices at PJM Interconnection's Western Hub when conducting cash deals. Power prices in other...

  4. 75 FR 42390 - Orders Finding That the PJM WH Real Time Peak Contract and PJM WH Real Time Off-Peak Contract...

    Science.gov (United States)

    2010-07-21

    ... well as a real-time market. The day-ahead market establishes prices for electricity that is to be..., market participants view ICE as a price discovery market for certain electricity contracts. The study did... abreast of the electricity prices at PJM's Western Hub when conducting cash deals. These traders look to a...

  5. Scalable electron correlation methods I.: PNO-LMP2 with linear scaling in the molecular size and near-inverse-linear scaling in the number of processors.

    Science.gov (United States)

    Werner, Hans-Joachim; Knizia, Gerald; Krause, Christine; Schwilk, Max; Dornbach, Mark

    2015-02-10

    We propose to construct electron correlation methods that are scalable in both molecule size and aggregated parallel computational power, in the sense that the total elapsed time of a calculation becomes nearly independent of the molecular size when the number of processors grows linearly with the molecular size. This is shown to be possible by exploiting a combination of local approximations and parallel algorithms. The concept is demonstrated with a linear scaling pair natural orbital local second-order Møller-Plesset perturbation theory (PNO-LMP2) method. In this method, both the wave function manifold and the integrals are transformed incrementally from projected atomic orbitals (PAOs) first to orbital-specific virtuals (OSVs) and finally to pair natural orbitals (PNOs), which allow for minimum domain sizes and fine-grained accuracy control using very few parameters. A parallel algorithm design is discussed, which is efficient for both small and large molecules, and numbers of processors, although true inverse-linear scaling with compute power is not yet reached in all cases. Initial applications to reactions involving large molecules reveal surprisingly large effects of dispersion energy contributions as well as large intramolecular basis set superposition errors in canonical MP2 calculations. In order to account for the dispersion effects, the usual selection of PNOs on the basis of natural occupation numbers turns out to be insufficient, and a new energy-based criterion is proposed. If explicitly correlated (F12) terms are included, fast convergence to the MP2 complete basis set (CBS) limit is achieved. For the studied reactions, the PNO-LMP2-F12 results deviate from the canonical MP2/CBS and MP2-F12 values by <1 kJ mol(-1), using triple-ζ (VTZ-F12) basis sets.

  6. Measuring Your Peak Flow Rate

    Science.gov (United States)

    ... your child so they can help monitor your child's asthma symptoms . Why Should I Measure My Flow Rate? ... help parents determine what might be triggering their child's asthma. How Do You Use a Peak Flow Meter? ...

  7. Investigação da LMP1 do EBV e a coinfeçcão do HPV em lesões genitais de pacientes infectados ou não pelo HIV Investigation of the LMP1 EBV and co-infection by HPV in genital lesions of patients infected or not by HIV

    Directory of Open Access Journals (Sweden)

    Fabiana Resende Rodrigues

    2010-10-01

    Full Text Available INTRODUÇÃO: Vários estudos têm demonstrado associação do vírus Epstein-Barr (EBV com neoplasias malignas, inclusive genitais, em que o papilomavírus humano (HPV é o principal vírus associado às neoplasias epiteliais benignas e malignas. OBJETIVO: Investigar a presença do EBV e do HPV em lesões genitais de ambos os sexos, em pacientes soropositivos (grupo A ou não (grupo B para o vírus da imunodeficiência humana (HIV. MATERIAL E MÉTODO: Selecionados 126 pacientes e 135 lesões anogenitais, sendo 67 pacientes (53% e 75 lesões (56% no grupo A e 59 pacientes (47% e 60 lesões (44% no grupo B, para análise imuno-histoquímica (IHQ por meio dos anticorpos monoclonais antiproteína latente de membrana 1 (LMP1 e HPV (DAKO®. RESULTADOS: A análise mostrou que o número total de lesões com imunopositividade para o HPV e para a LMP1 foi maior no grupo A (32 e 35, respectivamente quando comparado ao B (16 e seis, respectivamente. A análise estatística (nível de significância de 5% mostrou que as proporções para o HPV não são estatisticamente significativas (z = 1,93; valor p = 0,053. Entretanto, para a LMP1, a diferença (47% no grupo A e 10% no B é significativa (z = 4,60; valor p = 4,2×10-6. Do mesmo modo, a associação HPV-LMP1 (21% no grupo A e 7% no B também mostrou diferença estatisticamente significativa (z = 2,38; valor p = 0,017. CONCLUSÃO: Esses resultados indicam a possibilidade de sinergismo da infecção pelo EBV e a coinfecção EBV-HPV em lesões epiteliais genitais, particularmente em pacientes soropositivos para o HIV. Entretanto, investigações com metodologia de maior especificidade e sensibilidade são necessárias para a verificação da real participação do EBV na patogênese de lesões epiteliais genitais.INTRODUCTION: Several studies have demonstrated the association between Epstein-Barr virus (EBV and malignant neoplasias, including genital lesions, in which the human papillomavirus (HPV is the

  8. Ultrasonic Transducer Peak-to-Peak Optical Measurement

    Directory of Open Access Journals (Sweden)

    Pavel Skarvada

    2012-01-01

    Full Text Available Possible optical setups for measurement of the peak-to-peak value of an ultrasonic transducer are described in this work. The Michelson interferometer with the calibrated nanopositioner in reference path and laser Doppler vibrometer were used for the basic measurement of vibration displacement. Langevin type of ultrasonic transducer is used for the purposes of Electro-Ultrasonic Nonlinear Spectroscopy (EUNS. Parameters of produced mechanical vibration have to been well known for EUNS. Moreover, a monitoring of mechanical vibration frequency shift with a mass load and sample-transducer coupling is important for EUNS measurement.

  9. Optimal Day-Ahead Scheduling of a Hybrid Electric Grid Using Weather Forecasts

    Science.gov (United States)

    2013-12-01

    energy marketing, electrical and power engineering . We focus in this literature review on the optimization of the HEG in terms of design and operating...nacelle to rotate into the wind with an optimal angle β. The yawing mechanism can be passive, like a tail vane on smaller wind turbines, or active with...gCONTRIB ON g k k k warmup k k       (Eq. 13) , , : gg k gCON InitialCTRIB g k

  10. A New Quantile Regression Model to forecast one-day-ahead Value-at-Risk

    OpenAIRE

    Steine, Sturla Aavik; Eliassen, Markus Thorsø

    2014-01-01

    This master thesis focuses on the problem of forecasting volatility and Value-at-Risk (VaR) in the nancial markets. There are numerous methods for calculating VaR. However, research in this area has not currently reached one universally accepted method that can produce good VaR estimates across dierent data series, and VaR prediction and quality testing is still a very challenging statistical problem. The thesis has two main purposes, the rst is to propose a simple quantile regression mod...

  11. Day ahead price forecasting of electricity markets by a mixed data model and hybrid forecast method

    International Nuclear Information System (INIS)

    Amjady, Nima; Keynia, Farshid

    2008-01-01

    In a competitive electricity market, forecast of energy prices is a key information for the market participants. However, price signal usually has a complex behavior due to its nonlinearity, nonstationarity, and time variancy. In spite of all performed researches on this area in the recent years, there is still an essential need for more accurate and robust price forecast methods. In this paper, a combination of wavelet transform (WT) and a hybrid forecast method is proposed for this purpose. The hybrid method is composed of cascaded forecasters where each forecaster consists of a neural network (NN) and an evolutionary algorithms (EA). Both time domain and wavelet domain features are considered in a mixed data model for price forecast, in which the candidate input variables are refined by a feature selection technique. The adjustable parameters of the whole method are fine-tuned by a cross-validation technique. The proposed method is examined on PJM electricity market and compared with some of the most recent price forecast methods. (author)

  12. Forecasting day-ahead electricity prices in Europe : The importance of considering market integration

    NARCIS (Netherlands)

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

    2018-01-01

    Motivated by the increasing integration among electricity markets, in this paper we propose two different methods to incorporate market integration in electricity price forecasting and to improve the predictive performance. First, we propose a deep neural network that considers features from

  13. New approach to bidding strategies of generating companies in day ahead energy market

    International Nuclear Information System (INIS)

    Soleymani, S.; Ranjbar, A.M.; Shirani, A.R.

    2008-01-01

    In the restructured power systems, generating companies (Genco) are responsible for selling their product in the energy market. In this condition, the question is how much and for what price must each Genco generate to maximize its profit. Therefore, this paper intends to propose a rational method to answer this question. In the proposed methodology, the hourly forecasted market clearing price (FMCP) is used as a reference to model the possible and probable price strategies of Gencos. The forecasted price is the basis of the bidding strategies of each Genco, which can be achieved by solving a bi-level optimization problem using GAMS (general algebraic modeling system) language. The first level, called upper sub-problem is used to maximize the individual Genco's payoffs for obtaining the optimal offered quantity of Gencos. The second one, hereafter called the lower sub-problem uses the results of the upper sub-problem and minimizes the consumer's payment with regard to the technical and network constraints, which leads to the awarded generation of the Gencos. Similar to the other game problems, the Nash equilibrium strategies are the optimum bidding strategies of Gencos. A six bus system is employed to illustrate the application of the proposed method and to show its high precision and capabilities. (author)

  14. Simultaneous day-ahead forecasting of electricity price and load in smart grids

    International Nuclear Information System (INIS)

    Shayeghi, H.; Ghasemi, A.; Moradzadeh, M.; Nooshyar, M.

    2015-01-01

    Highlights: • This paper presents a novel MIMO-based support vector machine for forecasting. • Considered uncertainties for better simulation for filtering in input data. • Used LSSVM technique for learning. • Proposed a new modification for standard artificial bee colony algorithm to optimize LSSVM engine. - Abstract: In smart grids, customers are promoted to change their energy consumption patterns by electricity prices. In fact, in this environment, the electricity price and load consumption are highly corrected such that the market participants will have complex model in their decisions to maximize their profit. Although the available forecasting mythologies perform well in electricity market by way of little or no load and price interdependencies, but cannot capture load and price dynamics if they exist. To overcome this shortage, a Multi-Input Multi-Output (MIMO) model is presented which can consider the correlation between electricity price and load. The proposed model consists of three components known as a Wavelet Packet Transform (WPT) to make valuable subsets, Generalized Mutual Information (GMI) to select best input candidate and Least Squares Support Vector Machine (LSSVM) based on MIMO model, called LSSVM-MIMO, to make simultaneous load and price forecasts. Moreover, the LSSVM-MIMO parameters are optimized by a novel Quasi-Oppositional Artificial Bee Colony (QOABC) algorithm. Some forecasting indices based on error factor are considered to evaluate the forecasting accuracy. Simulations carried out on New York Independent System Operator, New South Wales (NSW) and PJM electricity markets data, and showing that the proposed hybrid algorithm has good potential for simultaneous forecasting of electricity price and load

  15. Day-ahead load forecast using random forest and expert input selection

    International Nuclear Information System (INIS)

    Lahouar, A.; Ben Hadj Slama, J.

    2015-01-01

    Highlights: • A model based on random forests for short term load forecast is proposed. • An expert feature selection is added to refine inputs. • Special attention is paid to customers behavior, load profile and special holidays. • The model is flexible and able to handle complex load signal. • A technical comparison is performed to assess the forecast accuracy. - Abstract: The electrical load forecast is getting more and more important in recent years due to the electricity market deregulation and integration of renewable resources. To overcome the incoming challenges and ensure accurate power prediction for different time horizons, sophisticated intelligent methods are elaborated. Utilization of intelligent forecast algorithms is among main characteristics of smart grids, and is an efficient tool to face uncertainty. Several crucial tasks of power operators such as load dispatch rely on the short term forecast, thus it should be as accurate as possible. To this end, this paper proposes a short term load predictor, able to forecast the next 24 h of load. Using random forest, characterized by immunity to parameter variations and internal cross validation, the model is constructed following an online learning process. The inputs are refined by expert feature selection using a set of if–then rules, in order to include the own user specifications about the country weather or market, and to generalize the forecast ability. The proposed approach is tested through a real historical set from the Tunisian Power Company, and the simulation shows accurate and satisfactory results for one day in advance, with an average error exceeding rarely 2.3%. The model is validated for regular working days and weekends, and special attention is paid to moving holidays, following non Gregorian calendar

  16. Day-ahead price forecasting in restructured power systems using artificial neural networks

    International Nuclear Information System (INIS)

    Vahidinasab, V.; Jadid, S.; Kazemi, A.

    2008-01-01

    Over the past 15 years most electricity supply companies around the world have been restructured from monopoly utilities to deregulated competitive electricity markets. Market participants in the restructured electricity markets find short-term electricity price forecasting (STPF) crucial in formulating their risk management strategies. They need to know future electricity prices as their profitability depends on them. This research project classifies and compares different techniques of electricity price forecasting in the literature and selects artificial neural networks (ANN) as a suitable method for price forecasting. To perform this task, market knowledge should be used to optimize the selection of input data for an electricity price forecasting tool. Then sensitivity analysis is used in this research to aid in the selection of the optimum inputs of the ANN and fuzzy c-mean (FCM) algorithm is used for daily load pattern clustering. Finally, ANN with a modified Levenberg-Marquardt (LM) learning algorithm are implemented for forecasting prices in Pennsylvania-New Jersey-Maryland (PJM) market. The forecasting results were compared with the previous works and showed that the results are reasonable and accurate. (author)

  17. Congestion management of distribution networks with day-ahead dynamic grid tariffs

    DEFF Research Database (Denmark)

    Huang, Shaojun; Wu, Qiuwei

    In order to reduce CO2 emissions and alleviate the global warming issue, many countries are setting goals to increase the percentage of renewable energy in the total energy consumption. In this process, a large number of distributed energy resources (DER), distributed generation (DG), electric...... vehicles (EV) and heat pumps (HP), will be largely deployed in electrical distribution networks. Congestion management will be important in the future active distribution networks. In the IDE4L project, work package 5 is dedicated to develop different kinds of congestion management methods. Demand response...

  18. Short-term operation scheduling of a hydropower plant in the day-ahead electricity market

    International Nuclear Information System (INIS)

    Perez-Diaz, Juan I.; Wilhelmi, Jose R.; Sanchez-Fernandez, Jose Angel

    2010-01-01

    This paper presents a novel approach to solve the short-term operation scheduling problem of a hydropower plant that sells energy in a deregulated electricity market with the objective of maximizing its revenue. This paper proposes a nonlinear programming based scheduling model that determines both the optimal unit commitment (start-ups and shut-downs scheduling) and the generation dispatch of the committed units (hourly power output). The power generated by each hydro unit is considered as a nonlinear function of the water discharge and the volume of the associated reservoir. The dependence of the units' operating limits (maximum and minimum water flows) on the actual gross head has been also taken into account in this model. The results from a case study are also presented to illustrate the application of the proposed approach in a real hydro plant. (author)

  19. Optimal energy exchange of an industrial cogeneration in a day-ahead electricity market

    International Nuclear Information System (INIS)

    Yusta, J.M.; De Oliveira-De Jesus, P.M.; Khodr, H.M.

    2008-01-01

    This paper addresses an optimal strategy for the daily energy exchange of a 22-MW combined-cycle cogeneration plant of an industrial factory operating in a liberalized electricity market. The optimization problem is formulated as a Mixed-Integer Linear Programming Problem (MILP) that maximizes the profit from energy exchange of the cogeneration, and is subject to the technical constraints and the industrial demand profile. The integer variables are associated with export or import of electricity whereas the real variables relate to the power output of gas and steam turbines, and to the electricity purchased from or sold to the market. The proposal is applied to a real cogeneration plant in Spain where the detailed cost function of the process is obtained. The problem is solved using a large-scale commercial package and the results are discussed and compared with different predefined scheduling strategies. (author)

  20. Toward multi-day-ahead forecasting of suspended sediment concentration using ensemble models.

    Science.gov (United States)

    Alizadeh, Mohamad Javad; Jafari Nodoushan, Ehsan; Kalarestaghi, Naghi; Chau, Kwok Wing

    2017-12-01

    This study explores two ideas to made an improvement on the artificial neural network (ANN)-based models for suspended sediment forecasting in several time steps ahead. In this regard, both observed and forecasted time series are incorporated as input variables of the models when applied for more than one lead time. Secondly, least-square ensemble models employing multiple wavelet-ANN models are developed to increase the performance of the single model. For this purpose, different wavelet families are linked with the ANN model and performance of each model is evaluated using error measures. The Skagit River near Mount Vernon in Washington county is selected as the case study. The daily flow discharge and suspended sediment concentration (SSC) in the current day are considered as input variables to predict suspended sediment concentration in the next day. For more lead times, the input structure is updated by adding the forecast of SSC in the previous time step. Results of this study demonstrate that incorporating both observed and predicted variables in the input structure improves performance of conventional models in which those only employ observed time series as input variables. Moreover, ensemble model developed for each lead time outperforms the best single wavelet-ANN model which indicates superiority of the ensemble model over the other one. Findings of this study reveal that acceptable forecasts of daily suspended sediment concentration up to 3 days in advance can be achieved using the proposed methodology.

  1. Day-Ahead Scheduling of a Photovoltaic Plant by the Energy Management of a Storage System

    DEFF Research Database (Denmark)

    Marinelli, Mattia; Sossan, Fabrizio; Isleifsson, Fridrik Rafn

    2013-01-01

    The paper discusses and describes a system for energy management of a 10 kW PV plant coupled with a 15 kW - 190 kWh storage system. The overall idea is, by knowing the meteorological forecast for the next 24h, to dispatch the PV system and to be able to grant the scheduled hourly energy profile b...... facility at DTU Risø Campus and part of PowerLabDK. Both the PV and the storage are connected to the local network and are fully controllable through the SCADA system. The control management and the models are implemented in Matlab-Simulink, which can be interfaced with SYSLAB....

  2. Day-Ahead Crude Oil Price Forecasting Using a Novel Morphological Component Analysis Based Model

    Science.gov (United States)

    Zhu, Qing; Zou, Yingchao; Lai, Kin Keung

    2014-01-01

    As a typical nonlinear and dynamic system, the crude oil price movement is difficult to predict and its accurate forecasting remains the subject of intense research activity. Recent empirical evidence suggests that the multiscale data characteristics in the price movement are another important stylized fact. The incorporation of mixture of data characteristics in the time scale domain during the modelling process can lead to significant performance improvement. This paper proposes a novel morphological component analysis based hybrid methodology for modeling the multiscale heterogeneous characteristics of the price movement in the crude oil markets. Empirical studies in two representative benchmark crude oil markets reveal the existence of multiscale heterogeneous microdata structure. The significant performance improvement of the proposed algorithm incorporating the heterogeneous data characteristics, against benchmark random walk, ARMA, and SVR models, is also attributed to the innovative methodology proposed to incorporate this important stylized fact during the modelling process. Meanwhile, work in this paper offers additional insights into the heterogeneous market microstructure with economic viable interpretations. PMID:25061614

  3. Novel Epstein-Barr virus-like particles incorporating gH/gL-EBNA1 or gB-LMP2 induce high neutralizing antibody titers and EBV-specific T-cell responses in immunized mice.

    Science.gov (United States)

    Perez, Elizabeth M; Foley, Joslyn; Tison, Timelia; Silva, Rute; Ogembo, Javier Gordon

    2017-03-21

    Previous Epstein-Barr virus (EBV) prophylactic vaccines based on the major surface glycoprotein gp350/220 as an immunogen have failed to block viral infection in humans, suggesting a need to target other viral envelope glycoproteins. In this study, we reasoned that incorporating gH/gL or gB, critical glycoproteins for viral fusion and entry, on the surface of a virus-like particle (VLP) would be more immunogenic than gp350/220 for generating effective neutralizing antibodies to prevent viral infection of both epithelial and B cell lines. To boost the humoral response and trigger cell-mediated immunity, EBV nuclear antigen 1 (EBNA1) and latent membrane protein 2 (LMP2), intracellular latency proteins expressed in all EBV-infected cells, were also included as critical components of the polyvalent EBV VLP. gH/gL-EBNA1 and gB-LMP2 VLPs were efficiently produced in Chinese hamster ovary cells, an FDA-approved vehicle for mass-production of biologics. Immunization with gH/gL-EBNA1 and gB-LMP2 VLPs without adjuvant generated both high neutralizing antibody titers in vitro and EBV-specific T-cell responses in BALB/c mice. These data demonstrate that will be invaluable not only in preventing EBV infection, but importantly, in preventing and treating the 200,000 cases of EBV-associated cancers that occur globally every year.

  4. Neurofeedback training for peak performance

    OpenAIRE

    Marek Graczyk; Maria Pąchalska; Artur Ziółkowski; Grzegorz Mańko; Beata Łukaszewska; Kazimierz Kochanowicz; Andrzej Mirski; Iurii D. Kropotov

    2014-01-01

    [b]aim[/b]. One of the applications of the Neurofeedback methodology is peak performance in sport. The protocols of the neurofeedback are usually based on an assessment of the spectral parameters of spontaneous EEG in resting state conditions. The aim of the paper was to study whether the intensive neurofeedback training of a well-functioning Olympic athlete who has lost his performance confidence after injury in sport, could change the brain functioning reflected in changes in spontaneou...

  5. Twin Peaks (B/W)

    Science.gov (United States)

    1997-01-01

    The Twin Peaks are modest-size hills to the southwest of the Mars Pathfinder landing site. They were discovered on the first panoramas taken by the IMP camera on the 4th of July, 1997, and subsequently identified in Viking Orbiter images taken over 20 years ago. The peaks are approximately 30-35 meters (-100 feet) tall. North Twin is approximately 860 meters (2800 feet) from the lander, and South Twin is about a kilometer away (3300 feet). The scene includes bouldery ridges and swales or 'hummocks' of flood debris that range from a few tens of meters away from the lander to the distance of the South Twin Peak. The large rock at the right edge of the scene is nicknamed 'Hippo'. This rock is about a meter (3 feet) across and 25 meters (80 feet) distant.Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  6. Drivers of peak sales for pharmaceutical brands

    NARCIS (Netherlands)

    Fischer, Marc; Leeflang, Peter S. H.; Verhoef, Peter C.

    2010-01-01

    Peak sales are an important metric in the pharmaceutical industry. Specifically, managers are focused on the height-of-peak-sales and the time required achieving peak sales. We analyze how order of entry and quality affect the level of peak sales and the time-to-peak-sales of pharmaceutical brands.

  7. Binding of the heterogeneous ribonucleoprotein K (hnRNP K to the Epstein-Barr virus nuclear antigen 2 (EBNA2 enhances viral LMP2A expression.

    Directory of Open Access Journals (Sweden)

    Henrik Gross

    Full Text Available The Epstein-Barr Virus (EBV -encoded EBNA2 protein, which is essential for the in vitro transformation of B-lymphocytes, interferes with cellular processes by binding to proteins via conserved sequence motifs. Its Arginine-Glycine (RG repeat element contains either symmetrically or asymmetrically di-methylated arginine residues (SDMA and ADMA, respectively. EBNA2 binds via its SDMA-modified RG-repeat to the survival motor neurons protein (SMN and via the ADMA-RG-repeat to the NP9 protein of the human endogenous retrovirus K (HERV-K (HML-2 Type 1. The hypothesis of this work was that the methylated RG-repeat mimics an epitope shared with cellular proteins that is used for interaction with target structures. With monoclonal antibodies against the modified RG-repeat, we indeed identified cellular homologues that apparently have the same surface structure as methylated EBNA2. With the SDMA-specific antibodies, we precipitated the Sm protein D3 (SmD3 which, like EBNA2, binds via its SDMA-modified RG-repeat to SMN. With the ADMA-specific antibodies, we precipitated the heterogeneous ribonucleoprotein K (hnRNP K. Specific binding of the ADMA- antibody to hnRNP K was demonstrated using E. coli expressed/ADMA-methylated hnRNP K. In addition, we show that EBNA2 and hnRNP K form a complex in EBV- infected B-cells. Finally, hnRNP K, when co-expressed with EBNA2, strongly enhances viral latent membrane protein 2A (LMP2A expression by an unknown mechanism as we did not detect a direct association of hnRNP K with DNA-bound EBNA2 in gel shift experiments. Our data support the notion that the methylated surface of EBNA2 mimics the surface structure of cellular proteins to interfere with or co-opt their functional properties.

  8. Neurofeedback training for peak performance.

    Science.gov (United States)

    Graczyk, Marek; Pąchalska, Maria; Ziółkowski, Artur; Mańko, Grzegorz; Łukaszewska, Beata; Kochanowicz, Kazimierz; Mirski, Andrzej; Kropotov, Iurii D

    2014-01-01

    One of the applications of the Neurofeedback methodology is peak performance in sport. The protocols of the neurofeedback are usually based on an assessment of the spectral parameters of spontaneous EEG in resting state conditions. The aim of the paper was to study whether the intensive neurofeedback training of a well-functioning Olympic athlete who has lost his performance confidence after injury in sport, could change the brain functioning reflected in changes in spontaneous EEG and event related potentials (ERPs). The case is presented of an Olympic athlete who has lost his performance confidence after injury in sport. He wanted to resume his activities by means of neurofeedback training. His QEEG/ERP parameters were assessed before and after 4 intensive sessions of neurotherapy. Dramatic and statistically significant changes that could not be explained by error measurement were observed in the patient. Neurofeedback training in the subject under study increased the amplitude of the monitoring component of ERPs generated in the anterior cingulate cortex, accompanied by an increase in beta activity over the medial prefrontal cortex. Taking these changes together, it can be concluded that that even a few sessions of neurofeedback in a high performance brain can significantly activate the prefrontal cortical areas associated with increasing confidence in sport performance.

  9. Neurofeedback training for peak performance

    Directory of Open Access Journals (Sweden)

    Marek Graczyk

    2014-11-01

    Full Text Available [b]aim[/b]. One of the applications of the Neurofeedback methodology is peak performance in sport. The protocols of the neurofeedback are usually based on an assessment of the spectral parameters of spontaneous EEG in resting state conditions. The aim of the paper was to study whether the intensive neurofeedback training of a well-functioning Olympic athlete who has lost his performance confidence after injury in sport, could change the brain functioning reflected in changes in spontaneous EEG and event related potentials (ERPs. [b]case study[/b]. The case is presented of an Olympic athlete who has lost his performance confidence after injury in sport. He wanted to resume his activities by means of neurofeedback training. His QEEG/ERP parameters were assessed before and after 4 intensive sessions of neurotherapy. Dramatic and statistically significant changes that could not be explained by error measurement were observed in the patient. [b]conclusion[/b]. Neurofeedback training in the subject under study increased the amplitude of the monitoring component of ERPs generated in the anterior cingulate cortex, accompanied by an increase in beta activity over the medial prefrontal cortex. Taking these changes together, it can be concluded that that even a few sessions of neurofeedback in a high performance brain can significantly activate the prefrontal cortical areas associated with increasing confidence in sport performance.

  10. Inhibition of the Immunoproteasome Subunit LMP7 with ONX 0914 Ameliorates Graft-versus-Host Disease in an MHC-Matched Minor Histocompatibility Antigen-Disparate Murine Model.

    Science.gov (United States)

    Zilberberg, Jenny; Matos, Jennifer; Dziopa, Eugenia; Dziopa, Leah; Yang, Zheng; Kirk, Christopher J; Assefnia, Shahin; Korngold, Robert

    2015-09-01

    In the current study we evaluated the effects of immunoproteasome inhibition using ONX 0914 (formerly PR-957) to ameliorate graft-versus-host disease (GVHD). ONX 0914, an LMP7-selective epoxyketone inhibitor of the immunoproteasome, has been shown to reduce cytokine production in activated monocytes and T cells and attenuate disease progression in mouse models of rheumatoid arthritis, colitis, systemic lupus erythematosus, and, more recently, encephalomyelitis. Inhibition of LMP7 with ONX 0914 in the B10.BR→CBA MHC-matched/minor histocompatibility antigen (miHA)-disparate murine blood and marrow transplant (BMT) model caused a modest but significant improvement in the survival of mice experiencing GVHD. Concomitant with these results, in vitro mixed lymphocyte cultures revealed that stimulator splenocytes, but not responder T cells, treated with ONX 0914 resulted in decreased IFN-γ production by allogeneic T cells in both MHC-disparate (B10.BR anti-B6) and miHA-mismatched (B10.BR anti-CBA) settings. In addition, a reduction in the expression of the MHC class I-restricted SIINFEKL peptide was observed in splenocytes from transgenic C57BL/6-Tg(CAG-OVA)916Jen/J mice exposed to ONX 0914. Taken together, these data support that LMP7 inhibition in the context of BMT modulates allogeneic responses by decreasing endogenous miHA presentation and that the consequential reduction in allogeneic stimulation and cytokine production reduces GVHD development. Copyright © 2015 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  11. Facility Location with Double-peaked Preferences

    DEFF Research Database (Denmark)

    Filos-Ratsikas, Aris; Li, Minming; Zhang, Jie

    2015-01-01

    We study the problem of locating a single facility on a real line based on the reports of self-interested agents, when agents have double-peaked preferences, with the peaks being on opposite sides of their locations. We observe that double-peaked preferences capture real-life scenarios and thus...... complement the well-studied notion of single-peaked preferences. We mainly focus on the case where peaks are equidistant from the agents’ locations and discuss how our results extend to more general settings. We show that most of the results for single-peaked preferences do not directly apply to this setting...

  12. Automated Critical PeakPricing Field Tests: 2006 Pilot ProgramDescription and Results

    Energy Technology Data Exchange (ETDEWEB)

    Piette, Mary Ann; Watson, David; Motegi, Naoya; Kiliccote, Sila

    2007-06-19

    During 2006 Lawrence Berkeley National Laboratory (LBNL) and the Demand Response Research Center (DRRC) performed a technology evaluation for the Pacific Gas and Electric Company (PG&E) Emerging Technologies Programs. This report summarizes the design, deployment, and results from the 2006 Automated Critical Peak Pricing Program (Auto-CPP). The program was designed to evaluate the feasibility of deploying automation systems that allow customers to participate in critical peak pricing (CPP) with a fully-automated response. The 2006 program was in operation during the entire six-month CPP period from May through October. The methodology for this field study included site recruitment, control strategy development, automation system deployment, and evaluation of sites' participation in actual CPP events through the summer of 2006. LBNL recruited sites in PG&E's territory in northern California through contacts from PG&E account managers, conferences, and industry meetings. Each site contact signed a memorandum of understanding with LBNL that outlined the activities needed to participate in the Auto-CPP program. Each facility worked with LBNL to select and implement control strategies for demand response and developed automation system designs based on existing Internet connectivity and building control systems. Once the automation systems were installed, LBNL conducted communications tests to ensure that the Demand Response Automation Server (DRAS) correctly provided and logged the continuous communications of the CPP signals with the energy management and control system (EMCS) for each site. LBNL also observed and evaluated Demand Response (DR) shed strategies to ensure proper commissioning of controls. The communication system allowed sites to receive day-ahead as well as day-of signals for pre-cooling, a DR strategy used at a few sites. Measurement of demand response was conducted using two different baseline models for estimating peak load savings. One

  13. Passive radio frequency peak power multiplier

    Science.gov (United States)

    Farkas, Zoltan D.; Wilson, Perry B.

    1977-01-01

    Peak power multiplication of a radio frequency source by simultaneous charging of two high-Q resonant microwave cavities by applying the source output through a directional coupler to the cavities and then reversing the phase of the source power to the coupler, thereby permitting the power in the cavities to simultaneously discharge through the coupler to the load in combination with power from the source to apply a peak power to the load that is a multiplication of the source peak power.

  14. The geomorphic structure of the runoff peak

    Directory of Open Access Journals (Sweden)

    R. Rigon

    2011-06-01

    Full Text Available This paper develops a theoretical framework to investigate the core dependence of peak flows on the geomorphic properties of river basins. Based on the theory of transport by travel times, and simple hydrodynamic characterization of floods, this new framework invokes the linearity and invariance of the hydrologic response to provide analytical and semi-analytical expressions for peak flow, time to peak, and area contributing to the peak runoff. These results are obtained for the case of constant-intensity hyetograph using the Intensity-Duration-Frequency (IDF curves to estimate extreme flow values as a function of the rainfall return period. Results show that, with constant-intensity hyetographs, the time-to-peak is greater than rainfall duration and usually shorter than the basin concentration time. Moreover, the critical storm duration is shown to be independent of rainfall return period as well as the area contributing to the flow peak. The same results are found when the effects of hydrodynamic dispersion are accounted for. Further, it is shown that, when the effects of hydrodynamic dispersion are negligible, the basin area contributing to the peak discharge does not depend on the channel velocity, but is a geomorphic propriety of the basin. As an example this framework is applied to three watersheds. In particular, the runoff peak, the critical rainfall durations and the time to peak are calculated for all links within a network to assess how they increase with basin area.

  15. Peak Shaving Considering Streamflow Uncertainties | Iwuagwu ...

    African Journals Online (AJOL)

    The main thrust of this paper is peak shaving with a Stochastic hydro model. In peak sharing, the amount of hydro energy scheduled may be a minimum but it serves to replace less efficient thermal units. The sample system is die Kainji hydro plant and the thermal units of the National Electric Power Authority. The random ...

  16. Automated Peak Picking and Peak Integration in Macromolecular NMR Spectra Using AUTOPSY

    Science.gov (United States)

    Koradi, Reto; Billeter, Martin; Engeli, Max; Güntert, Peter; Wüthrich, Kurt

    1998-12-01

    A new approach for automated peak picking of multidimensional protein NMR spectra with strong overlap is introduced, which makes use of the program AUTOPSY (automatedpeak picking for NMRspectroscopy). The main elements of this program are a novel function for local noise level calculation, the use of symmetry considerations, and the use of lineshapes extracted from well-separated peaks for resolving groups of strongly overlapping peaks. The algorithm generates peak lists with precise chemical shift and integral intensities, and a reliability measure for the recognition of each peak. The results of automated peak picking of NOESY spectra with AUTOPSY were tested in combination with the combined automated NOESY cross peak assignment and structure calculation routine NOAH implemented in the program DYANA. The quality of the resulting structures was found to be comparable with those from corresponding data obtained with manual peak picking.

  17. Bayesian Peak Picking for NMR Spectra

    KAUST Repository

    Cheng, Yichen

    2014-02-01

    Protein structure determination is a very important topic in structural genomics, which helps people to understand varieties of biological functions such as protein-protein interactions, protein–DNA interactions and so on. Nowadays, nuclear magnetic resonance (NMR) has often been used to determine the three-dimensional structures of protein in vivo. This study aims to automate the peak picking step, the most important and tricky step in NMR structure determination. We propose to model the NMR spectrum by a mixture of bivariate Gaussian densities and use the stochastic approximation Monte Carlo algorithm as the computational tool to solve the problem. Under the Bayesian framework, the peak picking problem is casted as a variable selection problem. The proposed method can automatically distinguish true peaks from false ones without preprocessing the data. To the best of our knowledge, this is the first effort in the literature that tackles the peak picking problem for NMR spectrum data using Bayesian method.

  18. Global Earthquake Hazard Distribution - Peak Ground Acceleration

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Earthquake Hazard Distribution-Peak Ground Acceleration is a 2.5 by 2.5 minute grid of global earthquake hazards developed using Global Seismic Hazard Program...

  19. Helping System Engineers Bridge the Peaks

    Science.gov (United States)

    Rungta, Neha; Tkachuk, Oksana; Person, Suzette; Biatek, Jason; Whalen, Michael W.; Castle, Joseph; Castle, JosephGundy-Burlet, Karen

    2014-01-01

    In our experience at NASA, system engineers generally follow the Twin Peaks approach when developing safety-critical systems. However, iterations between the peaks require considerable manual, and in some cases duplicate, effort. A significant part of the manual effort stems from the fact that requirements are written in English natural language rather than a formal notation. In this work, we propose an approach that enables system engineers to leverage formal requirements and automated test generation to streamline iterations, effectively "bridging the peaks". The key to the approach is a formal language notation that a) system engineers are comfortable with, b) is supported by a family of automated V&V tools, and c) is semantically rich enough to describe the requirements of interest. We believe the combination of formalizing requirements and providing tool support to automate the iterations will lead to a more efficient Twin Peaks implementation at NASA.

  20. Bayesian Peak Picking for NMR Spectra

    Directory of Open Access Journals (Sweden)

    Yichen Cheng

    2014-02-01

    Full Text Available Protein structure determination is a very important topic in structural genomics, which helps people to understand varieties of biological functions such as protein-protein interactions, protein–DNA interactions and so on. Nowadays, nuclear magnetic resonance (NMR has often been used to determine the three-dimensional structures of protein in vivo. This study aims to automate the peak picking step, the most important and tricky step in NMR structure determination. We propose to model the NMR spectrum by a mixture of bivariate Gaussian densities and use the stochastic approximation Monte Carlo algorithm as the computational tool to solve the problem. Under the Bayesian framework, the peak picking problem is casted as a variable selection problem. The proposed method can automatically distinguish true peaks from false ones without preprocessing the data. To the best of our knowledge, this is the first effort in the literature that tackles the peak picking problem for NMR spectrum data using Bayesian method.

  1. How to use your peak flow meter

    Science.gov (United States)

    ... attack . This can tell you how bad your asthma attack is and if your medicine is working. Any ... Make peak flow a habit! Signs of an asthma attack Stay away from asthma triggers Review Date 2/ ...

  2. Global Earthquake Hazard Distribution - Peak Ground Acceleration

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Earthquake Hazard Distribution-peak ground acceleration is a 2.5 minute grid of global earthquake hazards developed using Global Seismic Hazard Program...

  3. Peak-Seeking Control for Trim Optimization

    Data.gov (United States)

    National Aeronautics and Space Administration — Innovators have developed a peak-seeking algorithm that can reduce drag and improve performance and fuel efficiency by optimizing aircraft trim in real time. The...

  4. Improved peak shape fitting in alpha spectra

    OpenAIRE

    POMME Stefaan; CARO MARROYO BELEN

    2014-01-01

    Peak overlap is a recurrent issue ina lpha-particle spectrometry, not only in routine analyses but also in the high-resolution spectra from which reference values for alpha emission probabilities are derived. In this work, improved peak shape formulae are presented for the deconvolution of alpha-particle spectra. They have been implemented as fit functions in a spreadsheet application and optimum fit parameters were searched with built-in optimisation routines. Deconvolution results are shown...

  5. Instream flow needs below peaking hydroelectric projects

    International Nuclear Information System (INIS)

    Milhous, R.T.

    1991-01-01

    This paper reports on a method developed to assist in the determination of instream flow needs below hydroelectric projects operated in a peaking mode. Peaking hydroelectric projects significantly change streamflow over a short period of time; consequently, any instream flow methodology must consider the dual flows associated with peaking projects. The dual flows are the lowest flow and the maximum generation flow of a peaking cycle. The methodology is based on elements of the Physical Habitat Simulation System of the U.S. Fish and Wildlife Service and uses habitat, rather than fish numbers or biomas, as at basic response variable. All aquatic animals are subject to the rapid changes in streamflow which cause rapid swings in habitat quality. Some aquatic organisms are relatively fixed in location in the stream while others can move when flows change. The habitat available from a project operated in peaking mode is considered to be the minimum habitat occurring during a cycle of habitat change. The methodology takes in to consideration that some aquatic animals can move and others cannot move during a peaking cycle

  6. Predicting Peak Flows following Forest Fires

    Science.gov (United States)

    Elliot, William J.; Miller, Mary Ellen; Dobre, Mariana

    2016-04-01

    Following forest fires, peak flows in perennial and ephemeral streams often increase by a factor of 10 or more. This increase in peak flow rate may overwhelm existing downstream structures, such as road culverts, causing serious damage to road fills at stream crossings. In order to predict peak flow rates following wildfires, we have applied two different tools. One is based on the U.S.D.A Natural Resource Conservation Service Curve Number Method (CN), and the other is by applying the Water Erosion Prediction Project (WEPP) to the watershed. In our presentation, we will describe the science behind the two methods, and present the main variables for each model. We will then provide an example of a comparison of the two methods to a fire-prone watershed upstream of the City of Flagstaff, Arizona, USA, where a fire spread model was applied for current fuel loads, and for likely fuel loads following a fuel reduction treatment. When applying the curve number method, determining the time to peak flow can be problematic for low severity fires because the runoff flow paths are both surface and through shallow lateral flow. The WEPP watershed version incorporates shallow lateral flow into stream channels. However, the version of the WEPP model that was used for this study did not have channel routing capabilities, but rather relied on regression relationships to estimate peak flows from individual hillslope polygon peak runoff rates. We found that the two methods gave similar results if applied correctly, with the WEPP predictions somewhat greater than the CN predictions. Later releases of the WEPP model have incorporated alternative methods for routing peak flows that need to be evaluated.

  7. Finding diversity for building one-day ahead Hydrological Ensemble Prediction System based on artificial neural network stacks

    Science.gov (United States)

    Brochero, Darwin; Anctil, Francois; Gagné, Christian; López, Karol

    2013-04-01

    In this study, we addressed the application of Artificial Neural Networks (ANN) in the context of Hydrological Ensemble Prediction Systems (HEPS). Such systems have become popular in the past years as a tool to include the forecast uncertainty in the decision making process. HEPS considers fundamentally the uncertainty cascade model [4] for uncertainty representation. Analogously, the machine learning community has proposed models of multiple classifier systems that take into account the variability in datasets, input space, model structures, and parametric configuration [3]. This approach is based primarily on the well-known "no free lunch theorem" [1]. Consequently, we propose a framework based on two separate but complementary topics: data stratification and input variable selection (IVS). Thus, we promote an ANN prediction stack in which each predictor is trained based on input spaces defined by the IVS application on different stratified sub-samples. All this, added to the inherent variability of classical ANN optimization, leads us to our ultimate goal: diversity in the prediction, defined as the complementarity of the individual predictors. The stratification application on the 12 basins used in this study, which originate from the second and third workshop of the MOPEX project [2], shows that the informativeness of the data is far more important than the quantity used for ANN training. Additionally, the input space variability leads to ANN stacks that outperform an ANN stack model trained with 100% of the available information but with a random selection of dataset used in the early stopping method (scenario R100P). The results show that from a deterministic view, the main advantage focuses on the efficient selection of the training information, which is an equally important concept for the calibration of conceptual hydrological models. On the other hand, the diversity achieved is reflected in a substantial improvement in the scores that define the probabilistic quality of the HEPS. Except one basin that shows an atypical behaviour, and two other basins that represent the difficulty of prediction in semiarid areas, the average gain obtained with the new scheme relative to the R100P scenario is around 8%, 134%, 72%, and 69% for the mean CRPS, the mean ignorance score, the MSE evaluated on the reliability diagram, and the delta ratio respectively. Note that in all cases, the CRPS is less than the MAE, which indicates that the ensemble of neural networks performs better when taken as a whole than when aggregated in a single averaged predictor. Finally, we consider appropriate to complement the proposed methodology in two fronts: one deterministic, in which prediction could come from a Bayesian combination, and the second probabilistic, in which scores optimization could be based on an "overproduce and select" process. Also, in the case of the basins in semiarid areas, the results found by Vos [5] with echo state networks using the same database analysed in this study, leads us to consider the need to include various structures in the ANN stack. References [1] Corne, D. W. and Knowles, J. D.: No free lunch and free leftovers theorems for multiobjective optimisation problems. in Proceedings of the 2nd international conference on Evolutionary multi-criterion optimization, Springer-Verlag, 327-341, 2003. [2] Duan, Q.; Schaake, J.; Andréassian, V.; Franks, S.; Goteti, G.; Gupta, H.; Gusev, Y.; Habets, F.; Hall, A.; Hay, L.; Hogue, T.; Huang, M.; Leavesley, G.; Liang, X.; Nasonova, O.; Noilhan, J.; Oudin, L.; Sorooshian, S.; Wagener, T. and Wood, E.: Model Parameter Estimation Experiment (MOPEX): An overview of science strategy and major results from the second and third workshops. J. Hydrol., 320, 3-17, 2006. [3] Kuncheva, L. I.: Combining Pattern Classifiers: Methods and Algorithms, Wiley-Interscience, 2004. [4] Pappenberger, F., Beven, K. J., Hunter, N. M., Bates, P. D., Gouweleeuw, B. T., Thielen, J., and de Roo, A. P. J.: Cascading model uncertainty from medium range weather forecasts (10 days) through a rainfall-runoff model to flood inundation predictions within the European Flood Forecasting System (EFFS), Hydrol. Earth Syst. Sci., 9, 381-393, 2005. [5] de Vos, N. J.: Reservoir computing as an alternative to traditional artificial neural networks in rainfall-runoff modelling Hydrol. Earth Syst. Sci. Discuss., 9, 6101-6134, 2012.

  8. The evolution of electricity price on the German day-ahead market before and after the energy switch

    NARCIS (Netherlands)

    A. Khoshrou (Abdolrahman); E.J. Pauwels (Eric); A.B. Dorsman (Andre)

    2017-01-01

    textabstractIn Europe, Germany is taking the lead in the switch from fossil and nuclear energy to renewables. This creates new challenges as wind and solar energy are fundamentally intermittent and to some degree, unpredictable. It is therefore of considerable interest to investigate what effect

  9. Day-Ahead Coordination of Vehicle-to-Grid Operation and Wind Power in Security Constraints Unit Commitment (SCUC)

    OpenAIRE

    Mohammad Javad Abdollahi; Majid Moazzami

    2015-01-01

    In this paper security constraints unit commitment (SCUC) in the presence of wind power resources and electrical vehicles to grid is presented. SCUC operation prepare an optimal time table for generation unit commitment in order to maximize security, minimize operation cost and satisfy the constraints of networks and units in a period of time, as one of the most important research interest in power systems. Today, the relationship between power network and energy storage systems is interested...

  10. A Convex Model of Risk-Based Unit Commitment for Day-Ahead Market Clearing Considering Wind Power Uncertainty

    DEFF Research Database (Denmark)

    Zhang, Ning; Kang, Chongqing; Xia, Qing

    2015-01-01

    The integration of wind power requires the power system to be sufficiently flexible to accommodate its forecast errors. In the market clearing process, the scheduling of flexibility relies on the manner in which the wind power uncertainty is addressed in the unit commitment (UC) model. This paper...... and are considered in both the objective functions and the constraints. The RUC model is shown to be convex and is transformed into a mixed integer linear programming (MILP) problem using relaxation and piecewise linearization. The proposed RUC model is tested using a three-bus system and an IEEE RTS79 system...... that the risk modeling facilitates a strategic market clearing procedure with a reasonable computational expense....

  11. Price-Maker Wind Power Producer Participating in a Joint Day-Ahead and Real-Time Market

    DEFF Research Database (Denmark)

    Delikaraoglou, Stefanos; Papakonstantinou, Athanasios; Ordoudis, Christos

    2015-01-01

    The large scale integration of stochastic renewable energy introduces significant challenges for power system operators and disputes the efficiency of the current market design. Recent research embeds the uncertain nature of renewable sources by modelling electricity markets as a two...... Constraints (MPEC) that is reformulated as a single-level Mixed-Integer Linear Program (MILP), which can be readily solved. Our analysis shows that adopting strategic behaviour may improve producer’s expected profit as the share of wind power increases. However, this incentive diminishes in power systems...... where available flexible capacity is high enough to ensure an efficient market operation....

  12. Distinguishing high and low flow domains in urban drainage systems 2 days ahead using numerical weather prediction ensembles

    DEFF Research Database (Denmark)

    Courdent, Vianney Augustin Thomas; Grum, Morten; Mikkelsen, Peter Steen

    2018-01-01

    to transform the forecasted rainfall into forecasted flow series and evaluate three different approaches to establishing the relative operating characteristics (ROC) diagram of the forecast, which is a plot of POD against POFD for each fraction of concordant ensemble members and can be used to select......Precipitation constitutes a major contribution to the flow in urban storm- and wastewater systems. Forecasts of the anticipated runoff flows, created from radar extrapolation and/or numerical weather predictions, can potentially be used to optimize operation in both wet and dry weather periods...... prediction (NWP) model subject to three different ensemble post-processing approaches can be used to forecast flow exceedance in a combined sewer for a wide range of ratios between the probability of detection (POD) and the probability of false detection (POFD). We use a hydrological rainfall-runoff model...

  13. Distinguishing high and low flow domains in urban drainage systems 2 days ahead using numerical weather prediction ensembles

    Science.gov (United States)

    Courdent, Vianney; Grum, Morten; Mikkelsen, Peter Steen

    2018-01-01

    Precipitation constitutes a major contribution to the flow in urban storm- and wastewater systems. Forecasts of the anticipated runoff flows, created from radar extrapolation and/or numerical weather predictions, can potentially be used to optimize operation in both wet and dry weather periods. However, flow forecasts are inevitably uncertain and their use will ultimately require a trade-off between the value of knowing what will happen in the future and the probability and consequence of being wrong. In this study we examine how ensemble forecasts from the HIRLAM-DMI-S05 numerical weather prediction (NWP) model subject to three different ensemble post-processing approaches can be used to forecast flow exceedance in a combined sewer for a wide range of ratios between the probability of detection (POD) and the probability of false detection (POFD). We use a hydrological rainfall-runoff model to transform the forecasted rainfall into forecasted flow series and evaluate three different approaches to establishing the relative operating characteristics (ROC) diagram of the forecast, which is a plot of POD against POFD for each fraction of concordant ensemble members and can be used to select the weight of evidence that matches the desired trade-off between POD and POFD. In the first approach, the rainfall input to the model is calculated for each of 25 ensemble members as a weighted average of rainfall from the NWP cells over the catchment where the weights are proportional to the areal intersection between the catchment and the NWP cells. In the second approach, a total of 2825 flow ensembles are generated using rainfall input from the neighbouring NWP cells up to approximately 6 cells in all directions from the catchment. In the third approach, the first approach is extended spatially by successively increasing the area covered and for each spatial increase and each time step selecting only the cell with the highest intensity resulting in a total of 175 ensemble members. While the first and second approaches have the disadvantage of not covering the full range of the ROC diagram and being computationally heavy, respectively, the third approach leads to both a broad coverage of the ROC diagram range at a relatively low computational cost. A broad coverage of the ROC diagram offers a larger selection of prediction skill to choose from to best match to the prediction purpose. The study distinguishes itself from earlier research in being the first application to urban hydrology, with fast runoff and small catchments that are highly sensitive to local extremes. Furthermore, no earlier reference has been found on the highly efficient third approach using only neighbouring cells with the highest threat to expand the range of the ROC diagram. This study provides an efficient and robust approach to using ensemble rainfall forecasts affected by bias and misplacement errors for predicting flow threshold exceedance in urban drainage systems.

  14. Optimal day-ahead wind-thermal unit commitment considering statistical and predicted features of wind speeds

    International Nuclear Information System (INIS)

    Sun, Yanan; Dong, Jizhe; Ding, Lijuan

    2017-01-01

    Highlights: • A day–ahead wind–thermal unit commitment model is presented. • Wind speed transfer matrix is formed to depict the sequential wind features. • Spinning reserve setting considering wind power accuracy and variation is proposed. • Verified study is performed to check the correctness of the program. - Abstract: The increasing penetration of intermittent wind power affects the secure operation of power systems and leads to a requirement of robust and economic generation scheduling. This paper presents an optimal day–ahead wind–thermal generation scheduling method that considers the statistical and predicted features of wind speeds. In this method, the statistical analysis of historical wind data, which represents the local wind regime, is first implemented. Then, according to the statistical results and the predicted wind power, the spinning reserve requirements for the scheduling period are calculated. Based on the calculated spinning reserve requirements, the wind–thermal generation scheduling is finally conducted. To validate the program, a verified study is performed on a test system. Then, numerical studies to demonstrate the effectiveness of the proposed method are conducted.

  15. Optimal bidding in Turkey day ahead electricity market for wind energy and pumped storage hydro power plant

    OpenAIRE

    Ceyhun Yıldız; Mustafa Şekkeli

    2016-01-01

    In electrical grid; when the demand power increases energy prices increase, when the demand decreases energy prices decrease. For this reason; to increase the total daily income, it is required to shift generations to the hours that high demand power values occurred. Wind Power Plants (WPP) have unstable and uncontrollable generation characteristic. For this reason, energy storage systems are needed to shift the generations of WPPs in time scale. In this study, four wind power plants (WPP) wh...

  16. Analysis of fuel end-temperature peaking

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Z.; Jiang, Q.; Lai, L.; Shams, M. [CANDU Energy Inc., Fuel Engineering Dept., Mississauga, Ontario (Canada)

    2013-07-01

    During normal operation and refuelling of CANDU® fuel, fuel temperatures near bundle ends will increase due to a phenomenon called end flux peaking. Similar phenomenon would also be expected to occur during a postulated large break LOCA event. The end flux peaking in a CANDU fuel element is due to the fact that neutron flux is higher near a bundle end, in contact with a neighbouring bundle or close to heavy water coolant, than in the bundle mid-plane, because of less absorption of thermal neutrons by Zircaloy or heavy water than by the UO{sub 2} material. This paper describes Candu Energy experience in analysing behaviour of bundle due to end flux peaking using fuel codes FEAT, ELESTRES and ELOCA. (author)

  17. Norfolk Schools Talked to Astronaut Tim Peake

    Science.gov (United States)

    Grant, Stephanie

    2016-01-01

    Tim Peake's mission to the International Space Station captured the imagination of the UK and this article describes a live radio link with him, to help him to reach out to pupils across the country and inspire them in STEM subjects. It describes the project, from bidding for the opportunity to host it, to the planning and realisation of the…

  18. Generalized Eck peak in inhomogeneous Josephson junctions

    Science.gov (United States)

    Fistul, Mikhail V.; Giuliani, Gabriele F.

    1997-02-01

    In inhomogeneous Josephson junctions the Eck peak characterizing the current-voltage characteristics is predicted to be replaced by a rather different yet prominent feature whose location and shape strongly depend on the strength of the applied magnetic field and the spatial correlations of the associated distorted Abrikosov flux lattice.

  19. Prediction of peak overlap in NMR spectra

    International Nuclear Information System (INIS)

    Hefke, Frederik; Schmucki, Roland; Güntert, Peter

    2013-01-01

    Peak overlap is one of the major factors complicating the analysis of biomolecular NMR spectra. We present a general method for predicting the extent of peak overlap in multidimensional NMR spectra and its validation using both, experimental data sets and Monte Carlo simulation. The method is based on knowledge of the magnetization transfer pathways of the NMR experiments and chemical shift statistics from the Biological Magnetic Resonance Data Bank. Assuming a normal distribution with characteristic mean value and standard deviation for the chemical shift of each observable atom, an analytic expression was derived for the expected overlap probability of the cross peaks. The analytical approach was verified to agree with the average peak overlap in a large number of individual peak lists simulated using the same chemical shift statistics. The method was applied to eight proteins, including an intrinsically disordered one, for which the prediction results could be compared with the actual overlap based on the experimentally measured chemical shifts. The extent of overlap predicted using only statistical chemical shift information was in good agreement with the overlap that was observed when the measured shifts were used in the virtual spectrum, except for the intrinsically disordered protein. Since the spectral complexity of a protein NMR spectrum is a crucial factor for protein structure determination, analytical overlap prediction can be used to identify potentially difficult proteins before conducting NMR experiments. Overlap predictions can be tailored to particular classes of proteins by preparing statistics from corresponding protein databases. The method is also suitable for optimizing recording parameters and labeling schemes for NMR experiments and improving the reliability of automated spectra analysis and protein structure determination.

  20. Influenza-like illness-related emergency department visits: Christmas and New Year holiday peaks and relationships with laboratory-confirmed respiratory virus detections, Edmonton, Alberta, 2004-2014.

    Science.gov (United States)

    Martin, Leah J; Im, Cindy; Dong, Huiru; Lee, Bonita E; Talbot, James; Meurer, David P; Mukhi, Shamir N; Drews, Steven J; Yasui, Yutaka

    2017-01-01

    Emergency department (ED) visit volumes can be especially high during the Christmas-New Year holidays, a period occurring during the influenza season in Canada. Using daily data, we examined the relationship between ED visits for the chief complaint "cough" (for Edmonton, Alberta residents) and laboratory detections for influenza A and respiratory syncytial virus (RSV) (for Edmonton and surrounding areas), lagged 0-5 days ahead, for non-pandemic years (2004-2008 and 2010-2014) using multivariable linear regression adjusting for temporal variables. We defined these cough-related visits as influenza-like illness (ILI)-related ED visits and, for 2004-2014, compared Christmas-New Year holiday (December 24-January 3) and non-holiday volumes during the influenza season (October-April). Adjusting for temporal variables, ILI-related ED visits were significantly associated with laboratory detections for influenza A and RSV. During non-pandemic years, the highest peak in ILI-related visit volumes always occurred during the holidays. The median number of holiday ILI-related visits/day (42.5) was almost twice the non-holiday median (24) and was even higher in 2012-2013 (80) and 2013-2014 (86). Holiday ILI-related ED visit volumes/100 000 population ranged from 56.0 (2010-2011) to 117.4 (2012-2013). In contrast, lower visit volumes occurred during the holidays of pandemic-affected years (2008-2010). During non-pandemic years, ILI-related ED visit volumes were associated with variations in detections for influenza A and RSV and always peaked during the Christmas-New Year holidays. This predictability should be used to prepare for, and possibly prevent, this increase in healthcare use; however, interventions beyond disease prevention strategies are likely needed. © 2016 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

  1. Effect of gear ratio on peak power and time to peak power in BMX cyclists.

    Science.gov (United States)

    Rylands, Lee P; Roberts, Simon J; Hurst, Howard T

    2017-03-01

    The aim of this study was to ascertain if gear ratio selection would have an effect on peak power and time to peak power production in elite Bicycle Motocross (BMX) cyclists. Eight male elite BMX riders volunteered for the study. Each rider performed three, 10-s maximal sprints on an Olympic standard indoor BMX track. The riders' bicycles were fitted with a portable SRM power meter. Each rider performed the three sprints using gear ratios of 41/16, 43/16 and 45/16 tooth. The results from the 41/16 and 45/16 gear ratios were compared to the current standard 43/16 gear ratio. Statistically, significant differences were found between the gear ratios for peak power (F(2,14) = 6.448; p = .010) and peak torque (F(2,14) = 4.777; p = .026), but no significant difference was found for time to peak power (F(2,14) = 0.200; p = .821). When comparing gear ratios, the results showed a 45/16 gear ratio elicited the highest peak power,1658 ± 221 W, compared to 1436 ± 129 W and 1380 ± 56 W, for the 43/16 and 41/16 ratios, respectively. The time to peak power showed a 41/16 tooth gear ratio attained peak power in -0.01 s and a 45/16 in 0.22 s compared to the 43/16. The findings of this study suggest that gear ratio choice has a significant effect on peak power production, though time to peak power output is not significantly affected. Therefore, selecting a higher gear ratio results in riders attaining higher power outputs without reducing their start time.

  2. Improved peak shape fitting in alpha spectra.

    Science.gov (United States)

    Pommé, S; Caro Marroyo, B

    2015-02-01

    Peak overlap is a recurrent issue in alpha-particle spectrometry, not only in routine analyses but also in the high-resolution spectra from which reference values for alpha emission probabilities are derived. In this work, improved peak shape formulae are presented for the deconvolution of alpha-particle spectra. They have been implemented as fit functions in a spreadsheet application and optimum fit parameters were searched with built-in optimisation routines. Deconvolution results are shown for a few challenging spectra with high statistical precision. The algorithm outperforms the best available routines for high-resolution spectrometry, which may facilitate a more reliable determination of alpha emission probabilities in the future. It is also applicable to alpha spectra with inferior energy resolution. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. Peak Oil, Food Systems, and Public Health

    Science.gov (United States)

    Parker, Cindy L.; Kirschenmann, Frederick L.; Tinch, Jennifer; Lawrence, Robert S.

    2011-01-01

    Peak oil is the phenomenon whereby global oil supplies will peak, then decline, with extraction growing increasingly costly. Today's globalized industrial food system depends on oil for fueling farm machinery, producing pesticides, and transporting goods. Biofuels production links oil prices to food prices. We examined food system vulnerability to rising oil prices and the public health consequences. In the short term, high food prices harm food security and equity. Over time, high prices will force the entire food system to adapt. Strong preparation and advance investment may mitigate the extent of dislocation and hunger. Certain social and policy changes could smooth adaptation; public health has an essential role in promoting a proactive, smart, and equitable transition that increases resilience and enables adequate food for all. PMID:21778492

  4. First diffraction peak in alkali metaphosphate glasses

    Science.gov (United States)

    Beaufils, S.; Bionducci, M.; Ecolivet, C.; Marchand, R.; Le Sauze, A.

    2000-11-01

    The structure factor of the alkali metaphosphate glasses LiPO 3 and Na 0.5Li 0.5PO 3 has been measured at 300 K for both systems and up to 800 K for the latter. The first diffraction peak of alkali metaphosphate glasses merges at lower Q (around 1.1 Å -1) than in other covalent glasses, with the highest intensity for Li-containing glasses. These points are discussed following the hypothesis of voids ordering in the structure and contrasts effects due to the negative neutron Li scattering length. The intensity of the prepeak is significantly growing with temperature, in case of Na 0.5Li 0.5PO 3, in contrast to the other peaks of the structure factor. This point is discussed in relation with literature data from flow birefringence indicating structural changes in these glassy systems.

  5. Reducing Peak Power in Automated Weapon Laying

    Science.gov (United States)

    2016-02-01

    LAYING Joshua Stapp Matthew Tomik February 2016 Approved for public release; distribution is unlimited...PEAK POWER IN AUTOMATED WEAPON LAYING 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHORS Joshua Stapp and...aiming a weapon is referred to as gun laying . This report describes a method to calculate motion profiles that reach a given lay within the least

  6. METing SUSY on the Z peak

    International Nuclear Information System (INIS)

    Barenboim, G.; Bernabeu, J.; Vives, O.; Mitsou, V.A.; Romero, E.

    2016-01-01

    Recently the ATLAS experiment announced a 3 σ excess at the Z-peak consisting of 29 pairs of leptons together with two or more jets, E T miss > 225 GeV and HT > 600 GeV, to be compared with 10.6 ± 3.2 expected lepton pairs in the Standard Model. No excess outside the Z-peak was observed. By trying to explain this signal with SUSY we find that only relatively light gluinos, m g or similar 400 GeV decaying predominantly to Z-boson plus a light gravitino, such that nearly every gluino produces at least one Z-boson in its decay chain, could reproduce the excess. We construct an explicit general gauge mediation model able to reproduce the observed signal overcoming all the experimental limits. Needless to say, more sophisticated models could also reproduce the signal, however, any model would have to exhibit the following features: light gluinos, or heavy particles with a strong production cross section, producing at least one Z-boson in its decay chain. The implications of our findings for the Run II at LHC with the scaling on the Z peak, as well as for the direct search of gluinos and other SUSY particles, are pointed out. (orig.)

  7. Ten Reasons to Take Peak Oil Seriously

    Directory of Open Access Journals (Sweden)

    Robert J. Brecha

    2013-02-01

    Full Text Available Forty years ago, the results of modeling, as presented in The Limits to Growth, reinvigorated a discussion about exponentially growing consumption of natural resources, ranging from metals to fossil fuels to atmospheric capacity, and how such consumption could not continue far into the future. Fifteen years earlier, M. King Hubbert had made the projection that petroleum production in the continental United States would likely reach a maximum around 1970, followed by a world production maximum a few decades later. The debate about “peak oil”, as it has come to be called, is accompanied by some of the same vociferous denials, myths and ideological polemicizing that have surrounded later representations of The Limits to Growth. In this review, we present several lines of evidence as to why arguments for a near-term peak in world conventional oil production should be taken seriously—both in the sense that there is strong evidence for peak oil and in the sense that being societally unprepared for declining oil production will have serious consequences.

  8. METing SUSY on the Z peak

    Energy Technology Data Exchange (ETDEWEB)

    Barenboim, G.; Bernabeu, J.; Vives, O. [Universitat de Valencia, Departament de Fisica Teorica, Burjassot (Spain); Universitat de Valencia-CSIC, Parc Cientific U.V., IFIC, Paterna (Spain); Mitsou, V.A.; Romero, E. [Universitat de Valencia-CSIC, Parc Cientific U.V., IFIC, Paterna (Spain)

    2016-02-15

    Recently the ATLAS experiment announced a 3 σ excess at the Z-peak consisting of 29 pairs of leptons together with two or more jets, E{sub T}{sup miss} > 225 GeV and HT > 600 GeV, to be compared with 10.6 ± 3.2 expected lepton pairs in the Standard Model. No excess outside the Z-peak was observed. By trying to explain this signal with SUSY we find that only relatively light gluinos, m{sub g} or similar 400 GeV decaying predominantly to Z-boson plus a light gravitino, such that nearly every gluino produces at least one Z-boson in its decay chain, could reproduce the excess. We construct an explicit general gauge mediation model able to reproduce the observed signal overcoming all the experimental limits. Needless to say, more sophisticated models could also reproduce the signal, however, any model would have to exhibit the following features: light gluinos, or heavy particles with a strong production cross section, producing at least one Z-boson in its decay chain. The implications of our findings for the Run II at LHC with the scaling on the Z peak, as well as for the direct search of gluinos and other SUSY particles, are pointed out. (orig.)

  9. Chinese emissions peak: Not when, but how

    International Nuclear Information System (INIS)

    Spencer, Thomas; Colombier, Michel; Wang, Xin; Sartor, Oliver; Waisman, Henri

    2016-07-01

    It seems highly likely that China will overachieve its 2020 and 2030 targets, and peak its emissions before 2030 and possibly at a lower level than often assumed. This paper argues that the debate on the timing of the peak is misplaced: what matters is not when by why. For the peak to be seen as a harbinger of deep transformation, it needs to be based on significant macro-economic reform and restructuring, with attendant improvement in energy intensity. The Chinese economic model has been extraordinarily investment and resource intensive, and has driven the growth in GHG emissions. That model is no longer economically or environmentally sustainable. Therefore Chinese policy-makers are faced with a trade-off between slower short-term growth and economic reform, versus supporting short-term growth but slowing economic reform. The outcome will be crucial for the transition to a low-carbon economy. Overall, the 13. FYP (2016-2020) gives the impression of a cautious reflection of the new normal paradigm on the economic front, and a somewhat conservative translation of this shift into the energy and climate targets. Nonetheless, the 13. FYP targets set China well on the way to overachieving its 2020 pledge undertaken at COP15 in Copenhagen, and to potentially overachieving its INDC. It thus seems likely that China will achieve its emissions peak before 2030. However, the crucial question is not when China peaks, but whether the underlying transformation of the Chinese economy and energy system lays the basis for deep decarbonization thereafter. Thorough assessments of the implications of the 'new normal' for Chinese emissions and energy system trajectories, taking into account the link with the Chinese macro-economy, are needed. Scenarios provide a useful framework and should focus on a number of short-term uncertainties. Most energy system and emissions scenarios published today assume a continuity of trends between 2010-2015 and 2015-2020, which is at odds

  10. Practical load management - Peak shaving using photovoltaics; Peak Shaving mit der Fotovoltaik. Praktisches Lastmanagement

    Energy Technology Data Exchange (ETDEWEB)

    Berger, W.

    2009-07-01

    This article takes a look at how photovoltaic (PV) power generation can be used in a practical way to meet peak demands for electricity. Advice is provided on how photovoltaics can provide peak load 'shaving' through the correlation between its production and the peak loads encountered during the day. The situation regarding feed-in tariffs in Italy is discussed, as are further examples of installations in Germany and Austria. Further, an initiative of the American Southern California Edison utility is discussed which foresees the installation of large PV plant on the roofs of commercial premises to provide local generation of peak energy and thus relieve demands on their power transportation network.

  11. New View of Twin Peaks Region

    Science.gov (United States)

    1997-01-01

    This image taken on Sol 74 ( September 17) from the Sojourner rover's right front camera shows areas of the Pathfinder landing site never before seen. The shadow of the rover and its antenna is visible in the foreground. On the horizon at right are the Twin Peaks, about 1 kilometer away.Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  12. Recent considerations of the GSI positron peaks

    International Nuclear Information System (INIS)

    Soff, G.; Reinhardt, J.; Reus, J. de; Ionescu, D.; Schramm, S.; Mueller, B.; Greiner, W.

    1987-08-01

    In this report we examine various attempts to explain the GSI positron peaks. After the presentation of recent experimental data we briefly sketch theoretical investigations concerning the new particle hypothesis. The failure of standard models employing a linear coupling led to more exotic scenarios for particle production. One exciting recent idea is outlined. After that we treat the possible formation of a resonance in ordinary Bhabha scattering which could represent a time-reversed channel to the observations in heavy-ion collisions. Finally we discuss the poly-positronium model and a purely atomic physics model to interprete the GSI positron events. (orig./HSI)

  13. Engineering training-success at Comanche Peak

    International Nuclear Information System (INIS)

    Oliver, M.G.; Preston, W.D.; McMahon, J.F.

    1993-01-01

    The engineering training program at Comanche Peak steam electric station (CPSES) has received favorable industry recognition. The Institute of Nuclear Power Operations has recommended the CPSES program as a source of information for plants trying to build their own successful programs and has featured the program in an article in the spring 1993 issue of The Nuclear Professional. The U.S. Nuclear Regulatory Commission described the program as superior in a preoperational review and assessment team inspection report and in the most recent systematic assessment of licensee performance. This industry recognition is an important measure of the program's success

  14. Electromechanical Peak Devices of Distributed Power Generation

    Directory of Open Access Journals (Sweden)

    S. V. Konstantinova

    2011-01-01

    Full Text Available The power world crises (1973, 1979 have demonstrated that mankind entered the expensive energy epoch. More and more attitude is given to power saving problem by including renewable power sources in energy balance of the countries. The paper analyzes a power system inBelarusand a typical chart of the active load is cited in the paper. Equalization of load chart is considered as one of measures directed on provision of higher operational efficiency of power system and power saving.  This purpose can be obtained while including electromechanical peak devices of the distributed generation in the energy balance.

  15. Particle creation by peak electric field

    Energy Technology Data Exchange (ETDEWEB)

    Adorno, T.C. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); Gavrilov, S.P. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); Herzen State Pedagogical University of Russia, Department of General and Experimental Physics, St. Petersburg (Russian Federation); Gitman, D.M. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); P. N. Lebedev Physical Institute, Moscow (Russian Federation); University of Sao Paulo, Institute of Physics, CP 66318, Sao Paulo, SP (Brazil)

    2016-08-15

    The particle creation by the so-called peak electric field is considered. The latter field is a combination of two exponential parts, one exponentially increasing and another exponentially decreasing. We find exact solutions of the Dirac equation with the field under consideration with appropriate asymptotic conditions and calculate all the characteristics of particle creation effect, in particular, differential mean numbers of created particle, total number of created particles, and the probability for a vacuum to remain a vacuum. Characteristic asymptotic regimes are discussed in detail and a comparison with the pure asymptotically decaying field is considered. (orig.)

  16. Probable Values of Current Solar Cycle Peak

    Directory of Open Access Journals (Sweden)

    V. M. Silbergleit

    2012-01-01

    Full Text Available An analysis of multiple linear regression method applied to solar cycles 4 to 23 using lagged values of smoothed monthly mean sunspot numbers as independent variables is presented. According to that, the amplitude of current solar cycle 24 is estimated providing a quantitative prediction result. Our adjustment shows that the current cycle would have a sunspot peak less than the biggest one observed during the cycle 19 giving an additional support to the declination in solar activity which is currently happening.

  17. PeakVizor: Visual Analytics of Peaks in Video Clickstreams from Massive Open Online Courses.

    Science.gov (United States)

    Chen, Qing; Chen, Yuanzhe; Liu, Dongyu; Shi, Conglei; Wu, Yingcai; Qu, Huamin

    2016-10-01

    Massive open online courses (MOOCs) aim to facilitate open-access and massive-participation education. These courses have attracted millions of learners recently. At present, most MOOC platforms record the web log data of learner interactions with course videos. Such large amounts of multivariate data pose a new challenge in terms of analyzing online learning behaviors. Previous studies have mainly focused on the aggregate behaviors of learners from a summative view; however, few attempts have been made to conduct a detailed analysis of such behaviors. To determine complex learning patterns in MOOC video interactions, this paper introduces a comprehensive visualization system called PeakVizor. This system enables course instructors and education experts to analyze the "peaks" or the video segments that generate numerous clickstreams. The system features three views at different levels: the overview with glyphs to display valuable statistics regarding the peaks detected; the flow view to present spatio-temporal information regarding the peaks; and the correlation view to show the correlation between different learner groups and the peaks. Case studies and interviews conducted with domain experts have demonstrated the usefulness and effectiveness of PeakVizor, and new findings about learning behaviors in MOOC platforms have been reported.

  18. Outreach Plans for Storm Peak Laboratory

    Science.gov (United States)

    Hallar, A. G.; McCubbin, I. B.

    2006-12-01

    The Desert Research Institute (DRI) operates a high elevation facility, Storm Peak Laboratory (SPL), located on the west summit of Mt. Werner in the Park Range near Steamboat Springs, Colorado at an elevation 10,500 ft. SPL provides an ideal location for long-term research on the interactions of atmospheric aerosol and gas- phase chemistry with cloud and natural radiation environments. SPL includes an office-type laboratory room for computer and instrumentation setup with outside air ports and cable access to the roof deck, a full kitchen and two bunk rooms with sleeping space for nine persons. We plan to create a unique summer undergraduate education experiences for students of diversity at Storm Peak Laboratory. As stressed by the College Pathways to Science Education Standards [Siebert and McIntosh, 2001], to support changes in K-12 science education transformations must first be made at the college level, including inquiry-oriented opportunities to engage in meaningful research. These workshops will be designed to allow students to experience the excitement of science, increasing their likelihood of pursing careers within the fields of scientific education or research.

  19. Peak heart rates at extreme altitudes

    DEFF Research Database (Denmark)

    Lundby, C; Van Hall, Gerrit

    2001-01-01

    We have measured maximal heart rate during a graded maximal bicycle exercise test to exhaustion in five healthy climbers before and during an expedition to Mt. Everest. Maximal heart rates at sea level were 186 (177-204) beats/min(-1) at sea level and 170 (169-182) beats/min(-1) with acute hypoxia....... After 1, 4 and 6 weeks of acclimatization to 5400 m, maximal heart rates were 155 (135-182), 158 (144-182), and 155 (140-183) beats/min(-1), respectively. Heart rates of two of the climbers were measured during their attempt to reach the summit of Mt. Everest without the use of supplemental oxygen....... The peak heart rates at 8,750 m for the two climbers were 142 and 144 beats/min(-1), which were similar to their maximal heart rates during exhaustive bicycle exercise at 5,400 m, the values being 144 and 148 beats/min(-1), respectively. The peak heart rates at 8,750 m are in agreement with other field...

  20. Monitoring device for local power peaking coefficient

    International Nuclear Information System (INIS)

    Mitsuhashi, Ishi

    1987-01-01

    Purpose: To monitor the local power peaking coefficients obtained by the method not depending on the combination of fuel types. Method: A plurality of representative values for the local power distribution determined by the nuclear constant calculation for one fuel assembly are memorized regarding each of the burn-up degree and the void coefficient on every positions and fuel types in fuel rod assemblies. While on the other hand, the representative values for the local power distribution as described above are compensated by a compensation coefficient considering the effect of adjacent segments and a control rod compensation coefficient considering the effect due to the control rod insertion relative to the just-mentioned compensation coefficient. Then, the maximum value among them is selected to determine the local power peaking coefficient at each of the times and each of the segments, which is monitored. According to this system, the calculation and the working required for the fitting work depending on the combination of fuel types are no more required at all to facilitate the maintenance as well. (Horiuchi, T.)

  1. Peak capacity and peak capacity per unit time in capillary and microchip zone electrophoresis.

    Science.gov (United States)

    Foley, Joe P; Blackney, Donna M; Ennis, Erin J

    2017-11-10

    The origins of the peak capacity concept are described and the important contributions to the development of that concept in chromatography and electrophoresis are reviewed. Whereas numerous quantitative expressions have been reported for one- and two-dimensional separations, most are focused on chromatographic separations and few, if any, quantitative unbiased expressions have been developed for capillary or microchip zone electrophoresis. Making the common assumption that longitudinal diffusion is the predominant source of zone broadening in capillary electrophoresis, analytical expressions for the peak capacity are derived, first in terms of migration time, diffusion coefficient, migration distance, and desired resolution, and then in terms of the remaining underlying fundamental parameters (electric field, electroosmotic and electrophoretic mobilities) that determine the migration time. The latter expressions clearly illustrate the direct square root dependence of peak capacity on electric field and migration distance and the inverse square root dependence on solute diffusion coefficient. Conditions that result in a high peak capacity will result in a low peak capacity per unit time and vice-versa. For a given symmetrical range of relative electrophoretic mobilities for co- and counter-electroosmotic species (cations and anions), the peak capacity increases with the square root of the electric field even as the temporal window narrows considerably, resulting in a significant reduction in analysis time. Over a broad relative electrophoretic mobility interval [-0.9, 0.9], an approximately two-fold greater amount of peak capacity can be generated for counter-electroosmotic species although it takes about five-fold longer to do so, consistent with the well-known bias in migration time and resolving power for co- and counter-electroosmotic species. The optimum lower bound of the relative electrophoretic mobility interval [μ r,Z , μ r,A ] that provides the maximum

  2. Peak Wind Tool for General Forecasting

    Science.gov (United States)

    Barrett, Joe H., III

    2010-01-01

    The expected peak wind speed of the day is an important forecast element in the 45th Weather Squadron's (45 WS) daily 24-Hour and Weekly Planning Forecasts. The forecasts are used for ground and space launch operations at the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS). The 45 WS also issues wind advisories for KSC/CCAFS when they expect wind gusts to meet or exceed 25 kt, 35 kt and 50 kt thresholds at any level from the surface to 300 ft. The 45 WS forecasters have indicated peak wind speeds are challenging to forecast, particularly in the cool season months of October - April. In Phase I of this task, the Applied Meteorology Unit (AMU) developed a tool to help the 45 WS forecast non-convective winds at KSC/CCAFS for the 24-hour period of 0800 to 0800 local time. The tool was delivered as a Microsoft Excel graphical user interface (GUI). The GUI displayed the forecast of peak wind speed, 5-minute average wind speed at the time of the peak wind, timing of the peak wind and probability the peak speed would meet or exceed 25 kt, 35 kt and 50 kt. For the current task (Phase II ), the 45 WS requested additional observations be used for the creation of the forecast equations by expanding the period of record (POR). Additional parameters were evaluated as predictors, including wind speeds between 500 ft and 3000 ft, static stability classification, Bulk Richardson Number, mixing depth, vertical wind shear, temperature inversion strength and depth and wind direction. Using a verification data set, the AMU compared the performance of the Phase I and II prediction methods. Just as in Phase I, the tool was delivered as a Microsoft Excel GUI. The 45 WS requested the tool also be available in the Meteorological Interactive Data Display System (MIDDS). The AMU first expanded the POR by two years by adding tower observations, surface observations and CCAFS (XMR) soundings for the cool season months of March 2007 to April 2009. The POR was expanded

  3. Peak Electric Load Relief in Northern Manhattan

    Directory of Open Access Journals (Sweden)

    Hildegaard D. Link

    2014-08-01

    Full Text Available The aphorism “Think globally, act locally,” attributed to René Dubos, reflects the vision that the solution to global environmental problems must begin with efforts within our communities. PlaNYC 2030, the New York City sustainability plan, is the starting point for this study. Results include (a a case study based on the City College of New York (CCNY energy audit, in which we model the impacts of green roofs on campus energy demand and (b a case study of energy use at the neighborhood scale. We find that reducing the urban heat island effect can reduce building cooling requirements, peak electricity loads stress on the local electricity grid and improve urban livability.

  4. Twin Peaks in 360-degree panorama

    Science.gov (United States)

    1997-01-01

    The prominent hills dubbed 'Twin Peaks' approximately 1-2 kilometers away were imaged by the Imager for Mars Pathfinder (IMP) as part of a 360-degree color panorama, taken over sols 8, 9 and 10. A lander petal and deflated airbag are at the bottom of the image.Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  5. Tim Peake and Britain's road to space

    CERN Document Server

    Seedhouse, Erik

    2017-01-01

    This book puts the reader in the flight suit of Britain’s first male astronaut, Tim Peake. It chronicles his life, along with the Principia mission and the down-to-the-last-bolt descriptions of life aboard the ISS, by way of the hurdles placed by the British government and the rigors of training at Russia’s Star City military base. In addition, this book discusses the learning curves required in astronaut and mission training and the complexity of the technologies required to launch an astronaut and keep them alive for months on end. This book underscores the fact that technology and training, unlike space, do not exist in a vacuum; complex technical systems, like the ISS, interact with the variables of human personality, and the cultural background of the astronauts. .

  6. Comparison of five portable peak flow meters

    Directory of Open Access Journals (Sweden)

    Glaucia Nency Takara

    2010-01-01

    Full Text Available OBJECTIVE: To compare the measurements of spirometric peak expiratory flow (PEF from five different PEF meters and to determine if their values are in agreement. Inaccurate equipment may result in incorrect diagnoses of asthma and inappropriate treatments. METHODS: Sixty-eight healthy, sedentary and insufficiently active subjects, aged from 19 to 40 years, performed PEF measurements using Air Zone®, Assess®, Galemed®, Personal Best® and Vitalograph® peak flow meters. The highest value recorded for each subject for each device was compared to the corresponding spirometric values using Friedman's test with Dunn's post-hoc (p<0.05, Spearman's correlation test and Bland-Altman's agreement test. RESULTS: The median and interquartile ranges for the spirometric values and the Air Zone®, Assess®, Galemed®, Personal Best® and Vitalograph® meters were 428 (263-688 L/min, 450 (350-800 L/min, 420 (310-720 L/min, 380 (300-735 L/min, 400 (310-685 L/min and 415 (335-610 L/min, respectively. Significant differences were found when the spirometric values were compared to those recorded by the Air Zone® (p<0.001 and Galemed ® (p<0.01 meters. There was no agreement between the spirometric values and the five PEF meters. CONCLUSIONS: The results suggest that the values recorded from Galemed® meters may underestimate the actual value, which could lead to unnecessary interventions, and that Air Zone® meters overestimate spirometric values, which could obfuscate the need for intervention. These findings must be taken into account when interpreting both devices' results in younger people. These differences should also be considered when directly comparing values from different types of PEF meters.

  7. Comparison of five portable peak flow meters.

    Science.gov (United States)

    Takara, Glaucia Nency; Ruas, Gualberto; Pessoa, Bruna Varanda; Jamami, Luciana Kawakami; Di Lorenzo, Valéria Amorim Pires; Jamami, Mauricio

    2010-05-01

    To compare the measurements of spirometric peak expiratory flow (PEF) from five different PEF meters and to determine if their values are in agreement. Inaccurate equipment may result in incorrect diagnoses of asthma and inappropriate treatments. Sixty-eight healthy, sedentary and insufficiently active subjects, aged from 19 to 40 years, performed PEF measurements using Air Zone, Assess, Galemed, Personal Best and Vitalograph peak flow meters. The highest value recorded for each subject for each device was compared to the corresponding spirometric values using Friedman's test with Dunn's post-hoc (p<0.05), Spearman's correlation test and Bland-Altman's agreement test. The median and interquartile ranges for the spirometric values and the Air Zone, Assess, Galemed, Personal Best and Vitalograph meters were 428 (263-688 L/min), 450 (350-800 L/min), 420 (310-720 L/min), 380 (300-735 L/min), 400 (310-685 L/min) and 415 (335-610 L/min), respectively. Significant differences were found when the spirometric values were compared to those recorded by the Air Zone(R) (p<0.001) and Galemed (p<0.01) meters. There was no agreement between the spirometric values and the five PEF meters. The results suggest that the values recorded from Galemed meters may underestimate the actual value, which could lead to unnecessary interventions, and that Air Zone meters overestimate spirometric values, which could obfuscate the need for intervention. These findings must be taken into account when interpreting both devices' results in younger people. These differences should also be considered when directly comparing values from different types of PEF meters.

  8. Peak expiratory flow rate and Pulse Pressure values during the ...

    African Journals Online (AJOL)

    This study assessed the peak expiratory flow rate and pulse pressure during the luteal and menstruation phases of the menstrual cycle. The peak expiratory flow rate and pulse pressure were measured using the Wright's Peak Flow Meter and Mercury Sphygmomanometer respectively. The peak expiratory flow rate and ...

  9. Peak-valley-peak pattern of histone modifications delineates active regulatory elements and their directionality

    DEFF Research Database (Denmark)

    Pundhir, Sachin; Bagger, Frederik Otzen; Lauridsen, Felicia Kathrine Bratt

    2016-01-01

    Formation of nucleosome free region (NFR) accompanied by specific histone modifications at flanking nucleosomes is an important prerequisite for enhancer and promoter activity. Due to this process, active regulatory elements often exhibit a distinct shape of histone signal in the form of a peak......-valley-peak (PVP) pattern. However, different features of PVP patterns and their robustness in predicting active regulatory elements have never been systematically analyzed. Here, we present PARE, a novel computational method that systematically analyzes the H3K4me1 or H3K4me3 PVP patterns to predict NFRs. We show...

  10. OccuPeak: ChIP-Seq peak calling based on internal background modelling

    NARCIS (Netherlands)

    de Boer, Bouke A.; van Duijvenboden, Karel; van den Boogaard, Malou; Christoffels, Vincent M.; Barnett, Phil; Ruijter, Jan M.

    2014-01-01

    ChIP-seq has become a major tool for the genome-wide identification of transcription factor binding or histone modification sites. Most peak-calling algorithms require input control datasets to model the occurrence of background reads to account for local sequencing and GC bias. However, the

  11. Can You Hear That Peak? Utilization of Auditory and Visual Feedback at Peak Limb Velocity

    Science.gov (United States)

    Loria, Tristan; de Grosbois, John; Tremblay, Luc

    2016-01-01

    Purpose: At rest, the central nervous system combines and integrates multisensory cues to yield an optimal percept. When engaging in action, the relative weighing of sensory modalities has been shown to be altered. Because the timing of peak velocity is the critical moment in some goal-directed movements (e.g., overarm throwing), the current study…

  12. Lander petal & Twin Peaks - 3D

    Science.gov (United States)

    1997-01-01

    Many prominent rocks near the Sagan Memorial Station are featured in this image, taken in stereo by the Imager for Mars Pathfinder (IMP) on Sol 3. 3D glasses are necessary to identify surface detail. The two hills in the distance, approximately one to two kilometers away, have been dubbed the 'Twin Peaks' and are of great interest to Pathfinder scientists as objects of future study. The white areas on the left hill, called the 'Ski Run' by scientists, may have been formed by hydrologic processes. A lander petal, airbag, and the rear ramp are at the lower area of the image.The image was taken by the Imager for Mars Pathfinder (IMP) after its deployment on Sol 3. Mars Pathfinder was developed and managed by the Jet Propulsion Laboratory (JPL) for the National Aeronautics and Space Administration. The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

  13. North Twin Peak in super resolution

    Science.gov (United States)

    1997-01-01

    This pair of images shows the result of taking a sequence of 25 identical exposures from the Imager for Mars Pathfinder (IMP) of the northern Twin Peak, with small camera motions, and processing them with the Super-Resolution algorithm developed at NASA's Ames Research Center.The upper image is a representative input image, scaled up by a factor of five, with the pixel edges smoothed out for a fair comparison. The lower image allows significantly finer detail to be resolved.Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.The super-resolution research was conducted by Peter Cheeseman, Bob Kanefsky, Robin Hanson, and John Stutz of NASA's Ames Research Center, Mountain View, CA. More information on this technology is available on the Ames Super Resolution home page athttp://ic-www.arc.nasa.gov/ic/projects/bayes-group/ group/super-res/

  14. Prediction of iodine activity peak during refuelling

    International Nuclear Information System (INIS)

    Hozer, Z.; Vajda, N.

    2001-01-01

    The increase of fission product activities in the primary circuit of a nuclear power plant indicates the existence of defects in some fuel rods. The power change leads to the cooling down of the fuel and results in the fragmentation of the UO 2 pellets, which facilitates the release of fission products from the intergranular regions. Furthermore the injection of boric acid after shutdown will increase the primary activity, due to the solution of deposited fission products from the surface of the core components. The calculation of these phenomena usually is based on the evaluation of activity measurements and power plant data. The estimation of iodine spiking peak during reactor transients is based on correlation with operating parameters, such as reactor power and primary pressure. The approach used in the present method was applied for CANDU reactors. The VVER-440 specific correlations were determined using the activity measurements of the Paks NPP and the data provided by the Russian fuel supplier. The present method is used for the evaluation of the iodine isotopes, as well as the noble gases. A numerical model has been developed for iodine spiking simulation and has been validated against several shutdown transients, measured at Paks NPP. (R.P.)

  15. Human behavioral complexity peaks at age 25

    Science.gov (United States)

    Brugger, Peter

    2017-01-01

    Random Item Generation tasks (RIG) are commonly used to assess high cognitive abilities such as inhibition or sustained attention. They also draw upon our approximate sense of complexity. A detrimental effect of aging on pseudo-random productions has been demonstrated for some tasks, but little is as yet known about the developmental curve of cognitive complexity over the lifespan. We investigate the complexity trajectory across the lifespan of human responses to five common RIG tasks, using a large sample (n = 3429). Our main finding is that the developmental curve of the estimated algorithmic complexity of responses is similar to what may be expected of a measure of higher cognitive abilities, with a performance peak around 25 and a decline starting around 60, suggesting that RIG tasks yield good estimates of such cognitive abilities. Our study illustrates that very short strings of, i.e., 10 items, are sufficient to have their complexity reliably estimated and to allow the documentation of an age-dependent decline in the approximate sense of complexity. PMID:28406953

  16. Human behavioral complexity peaks at age 25.

    Directory of Open Access Journals (Sweden)

    Nicolas Gauvrit

    2017-04-01

    Full Text Available Random Item Generation tasks (RIG are commonly used to assess high cognitive abilities such as inhibition or sustained attention. They also draw upon our approximate sense of complexity. A detrimental effect of aging on pseudo-random productions has been demonstrated for some tasks, but little is as yet known about the developmental curve of cognitive complexity over the lifespan. We investigate the complexity trajectory across the lifespan of human responses to five common RIG tasks, using a large sample (n = 3429. Our main finding is that the developmental curve of the estimated algorithmic complexity of responses is similar to what may be expected of a measure of higher cognitive abilities, with a performance peak around 25 and a decline starting around 60, suggesting that RIG tasks yield good estimates of such cognitive abilities. Our study illustrates that very short strings of, i.e., 10 items, are sufficient to have their complexity reliably estimated and to allow the documentation of an age-dependent decline in the approximate sense of complexity.

  17. Fast clustering using adaptive density peak detection.

    Science.gov (United States)

    Wang, Xiao-Feng; Xu, Yifan

    2017-12-01

    Common limitations of clustering methods include the slow algorithm convergence, the instability of the pre-specification on a number of intrinsic parameters, and the lack of robustness to outliers. A recent clustering approach proposed a fast search algorithm of cluster centers based on their local densities. However, the selection of the key intrinsic parameters in the algorithm was not systematically investigated. It is relatively difficult to estimate the "optimal" parameters since the original definition of the local density in the algorithm is based on a truncated counting measure. In this paper, we propose a clustering procedure with adaptive density peak detection, where the local density is estimated through the nonparametric multivariate kernel estimation. The model parameter is then able to be calculated from the equations with statistical theoretical justification. We also develop an automatic cluster centroid selection method through maximizing an average silhouette index. The advantage and flexibility of the proposed method are demonstrated through simulation studies and the analysis of a few benchmark gene expression data sets. The method only needs to perform in one single step without any iteration and thus is fast and has a great potential to apply on big data analysis. A user-friendly R package ADPclust is developed for public use.

  18. Research Opportunities at Storm Peak Laboratory

    Science.gov (United States)

    Hallar, A. G.; McCubbin, I. B.

    2006-12-01

    The Desert Research Institute (DRI) operates a high elevation facility, Storm Peak Laboratory (SPL), located on the west summit of Mt. Werner in the Park Range near Steamboat Springs, Colorado at an elevation of 3210 m MSL (Borys and Wetzel, 1997). SPL provides an ideal location for long-term research on the interactions of atmospheric aerosol and gas- phase chemistry with cloud and natural radiation environments. The ridge-top location produces almost daily transition from free tropospheric to boundary layer air which occurs near midday in both summer and winter seasons. Long-term observations at SPL document the role of orographically induced mixing and convection on vertical pollutant transport and dispersion. During winter, SPL is above cloud base 25% of the time, providing a unique capability for studying aerosol-cloud interactions (Borys and Wetzel, 1997). A comprehensive set of continuous aerosol measurements was initiated at SPL in 2002. SPL includes an office-type laboratory room for computer and instrumentation setup with outside air ports and cable access to the roof deck, a cold room for precipitation and cloud rime ice sample handling and ice crystal microphotography, a 150 m2 roof deck area for outside sampling equipment, a full kitchen and two bunk rooms with sleeping space for nine persons. The laboratory is currently well equipped for aerosol and cloud measurements. Particles are sampled from an insulated, 15 cm diameter manifold within approximately 1 m of its horizontal entry point through an outside wall. The 4 m high vertical section outside the building is capped with an inverted can to exclude large particles.

  19. Choquet and Shilov Boundaries, Peak Sets, and Peak Points for Real Banach Function Algebras

    Directory of Open Access Journals (Sweden)

    Davood Alimohammadi

    2013-01-01

    Full Text Available Let be a compact Hausdorff space and let be a topological involution on . In 1988, Kulkarni and Arundhathi studied Choquet and Shilov boundaries for real uniform function algebras on . Then in 2000, Kulkarni and Limaye studied the concept of boundaries and Choquet sets for uniformly closed real subspaces and subalgebras of or . In 1971, Dales obtained some properties of peak sets and p-sets for complex Banach function algebras on . Later in 1990, Arundhathi presented some results on peak sets for real uniform function algebras on . In this paper, while we present a brief account of the work of others, we extend some of their results, either to real subspaces of or to real Banach function algebras on .

  20. Improving EEG signal peak detection using feature weight learning ...

    Indian Academy of Sciences (India)

    Asrul Adam

    Neural network with random weights (NNRW); feature weight learning (FWL); electroencephalogram (EEG); peak detection algorithm; pattern recognition; particle swarm optimization (PSO). 1. Introduction. The utilization of peak detection algorithms has emerged as a useful tool in several physiological signal applications,.

  1. PEAK TRACKING WITH A NEURAL NETWORK FOR SPECTRAL RECOGNITION

    NARCIS (Netherlands)

    COENEGRACHT, PMJ; METTING, HJ; VANLOO, EM; SNOEIJER, GJ; DOORNBOS, DA

    1993-01-01

    A peak tracking method based on a simulated feed-forward neural network with back-propagation is presented. The network uses the normalized UV spectra and peak areas measured in one chromatogram for peak recognition. It suffices to train the network with only one set of spectra recorded in one

  2. Assessing peak aerobic capacity in Dutch law enforcement officers.

    NARCIS (Netherlands)

    Wittink, H.; Takken, T.; Groot, J.F. de; Reneman, M.; Peters, R.; Vanhees, L.

    2015-01-01

    Objectives: To cross-validate the existing peak rate of oxygen consumption (VO2peak) prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report

  3. Assessing peak aerobic capacity in Dutch law enforcement officers

    NARCIS (Netherlands)

    Wittink, Harriet; Takken, Tim; de Groot, Janke; Reneman, Michiel; Peters, Roelof; Vanhees, Luc

    2015-01-01

    Objectives: To cross-validate the existing peak rate of oxygen consumption (VO2peak) prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report

  4. Determination of the upper limit of a peak area

    International Nuclear Information System (INIS)

    Helene, O.

    1990-03-01

    This paper reports the procedure to extract an upper limit of a peak area in a multichannel spectrum. This procedure takes into account the finite shape of the peak and the uncertanties in the background and in the expected position of the peak. (author) [pt

  5. Automatic Peak Selection by a Benjamini-Hochberg-Based Algorithm

    KAUST Repository

    Abbas, Ahmed

    2013-01-07

    A common issue in bioinformatics is that computational methods often generate a large number of predictions sorted according to certain confidence scores. A key problem is then determining how many predictions must be selected to include most of the true predictions while maintaining reasonably high precision. In nuclear magnetic resonance (NMR)-based protein structure determination, for instance, computational peak picking methods are becoming more and more common, although expert-knowledge remains the method of choice to determine how many peaks among thousands of candidate peaks should be taken into consideration to capture the true peaks. Here, we propose a Benjamini-Hochberg (B-H)-based approach that automatically selects the number of peaks. We formulate the peak selection problem as a multiple testing problem. Given a candidate peak list sorted by either volumes or intensities, we first convert the peaks into p-values and then apply the B-H-based algorithm to automatically select the number of peaks. The proposed approach is tested on the state-of-the-art peak picking methods, including WaVPeak [1] and PICKY [2]. Compared with the traditional fixed number-based approach, our approach returns significantly more true peaks. For instance, by combining WaVPeak or PICKY with the proposed method, the missing peak rates are on average reduced by 20% and 26%, respectively, in a benchmark set of 32 spectra extracted from eight proteins. The consensus of the B-H-selected peaks from both WaVPeak and PICKY achieves 88% recall and 83% precision, which significantly outperforms each individual method and the consensus method without using the B-H algorithm. The proposed method can be used as a standard procedure for any peak picking method and straightforwardly applied to some other prediction selection problems in bioinformatics. The source code, documentation and example data of the proposed method is available at http://sfb.kaust.edu.sa/pages/software.aspx. © 2013

  6. Particle in cell simulation of peaking switch for breakdown evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Umbarkar, Sachin B.; Bindu, S.; Mangalvedekar, H.A.; Saxena, A.; Singh, N.M., E-mail: sachin.b.umbarkar@gmail.com [Department of Electric Engineering, Veermata Jijabai Technological Institute, Mumbai (India); Sharma, Archana; Saroj, P.C.; Mittal, K.C. [Accelerator Pulse Power Division, Bhabha Atomic Research Centre, Mumbai (India)

    2014-07-01

    Marx generator connected to peaking capacitor and peaking switch can generate Ultra-Wideband (UWB) radiation. A new peaking switch is designed for converting the existing nanosecond Marx generator to a UWB source. The paper explains the particle in cell (PIC) simulation for this peaking switch, using MAGIC 3D software. This peaking switch electrode is made up of copper tungsten material and is fixed inside the hermitically sealed derlin material. The switch can withstand a gas pressure up to 13.5 kg/cm{sup 2}. The lower electrode of the switch is connected to the last stage of the Marx generator. Initially Marx generator (without peaking stage) in air; gives the output pulse with peak amplitude of 113.75 kV and pulse rise time of 25 ns. Thus, we design a new peaking switch to improve the rise time of output pulse and to pressurize this peaking switch separately (i.e. Marx and peaking switch is at different pressure). The PIC simulation gives the particle charge density, current density, E counter plot, emitted electron current, and particle energy along the axis of gap between electrodes. The charge injection and electric field dependence on ionic dissociation phenomenon are briefly analyzed using this simulation. The model is simulated with different gases (N{sub 2}, H{sub 2}, and Air) under different pressure (2 kg/cm{sup 2}, 5 kg/cm{sup 2}, 10 kg/cm{sup 2}). (author)

  7. QRS peak detection for heart rate monitoring on Android smartphone

    Science.gov (United States)

    Pambudi Utomo, Trio; Nuryani, Nuryani; Darmanto

    2017-11-01

    In this study, Android smartphone is used for heart rate monitoring and displaying electrocardiogram (ECG) graph. Heart rate determination is based on QRS peak detection. Two methods are studied to detect the QRS complex peak; they are Peak Threshold and Peak Filter. The acquisition of ECG data is utilized by AD8232 module from Analog Devices, three electrodes, and Microcontroller Arduino UNO R3. To record the ECG data from a patient, three electrodes are attached to particular body’s surface of a patient. Patient’s heart activity which is recorded by AD8232 module is decoded by Arduino UNO R3 into analog data. Then, the analog data is converted into a voltage value (mV) and is processed to get the QRS complex peak. Heart rate value is calculated by Microcontroller Arduino UNO R3 uses the QRS complex peak. Voltage, heart rate, and the QRS complex peak are sent to Android smartphone by Bluetooth HC-05. ECG data is displayed as the graph by Android smartphone. To evaluate the performance of QRS complex peak detection method, three parameters are used; they are positive predictive, accuracy and sensitivity. Positive predictive, accuracy, and sensitivity of Peak Threshold method is 92.39%, 70.30%, 74.62% and for Peak Filter method are 98.38%, 82.47%, 83.61%, respectively.

  8. Gamma-Ray Peak Integration: Accuracy and Precision

    International Nuclear Information System (INIS)

    Richard M. Lindstrom

    2000-01-01

    The accuracy of singlet gamma-ray peak areas obtained by a peak analysis program is immaterial. If the same algorithm is used for sample measurement as for calibration and if the peak shapes are similar, then biases in the integration method cancel. Reproducibility is the only important issue. Even the uncertainty of the areas computed by the program is trivial because the true standard uncertainty can be experimentally assessed by repeated measurements of the same source. Reproducible peak integration was important in a recent standard reference material certification task. The primary tool used for spectrum analysis was SUM, a National Institute of Standards and Technology interactive program to sum peaks and subtract a linear background, using the same channels to integrate all 20 spectra. For comparison, this work examines other peak integration programs. Unlike some published comparisons of peak performance in which synthetic spectra were used, this experiment used spectra collected for a real (though exacting) analytical project, analyzed by conventional software used in routine ways. Because both components of the 559- to 564-keV doublet are from 76 As, they were integrated together with SUM. The other programs, however, deconvoluted the peaks. A sensitive test of the fitting algorithm is the ratio of reported peak areas. In almost all the cases, this ratio was much more variable than expected from the reported uncertainties reported by the program. Other comparisons to be reported indicate that peak integration is still an imperfect tool in the analysis of gamma-ray spectra

  9. Reference Values for Peak Exercise Cardiac Output in Healthy Individuals.

    Science.gov (United States)

    Agostoni, Piergiuseppe; Vignati, Carlo; Gentile, Piero; Boiti, Costanza; Farina, Stefania; Salvioni, Elisabetta; Mapelli, Massimo; Magrì, Damiano; Paolillo, Stefania; Corrieri, Nicoletta; Sinagra, Gianfranco; Cattadori, Gaia

    2017-06-01

    Cardiac output (Q˙) is a key parameter in the assessment of cardiac function, its measurement being crucial for the diagnosis, treatment, and prognostic evaluation of all heart diseases. Until recently, Q˙ determination at peak exercise has been possible through invasive methods, so that normal values were obtained in studies based on small populations. Nowadays, peak Q˙ can be measured noninvasively by means of the inert gas rebreathing (IGR) technique. The present study was undertaken to provide reference values for peak Q˙ in the normal general population and to obtain a formula able to estimate peak exercise Q˙ from measured peak oxygen uptake (V˙o 2 ). We studied 500 normal subjects (age, 44.9 ± 1.5 years; range, 18-77 years; 260 men, 240 women) who underwent a maximal cardiopulmonary exercise test with peak Q˙ measurement by IGR. In the overall study sample, peak Q˙ was 13.2 ± 3.5 L/min (men, 15.3 ± 3.3 L/min; women, 11.0 ± 2.0 L/min; P exercise was (4.4 × peak V˙o 2 ) + 4.3 in the overall study cohort, (4.3 × peak V˙o 2 ) + 4.5 in men, and (4.9 × peak V˙o 2 ) + 3.6 in women. The simultaneous measurement of Q˙ and V˙o 2 at peak exercise in a large sample of healthy subjects provided an equation to predict peak Q˙ from peak V˙o 2 values. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  10. Effect of cardiac function on aortic peak time and peak enhancement during coronary CT angiography

    International Nuclear Information System (INIS)

    Sakai, Shuji; Yabuuchi, Hidetake; Chishaki, Akiko; Okafuji, Takashi; Matsuo, Yoshio; Kamitani, Takeshi; Setoguchi, Taro; Honda, Hiroshi

    2010-01-01

    Purpose: To examine the manner in which cardiac function affects the magnitude and timing of aortic contrast enhancement during coronary CT angiography (CTA). Materials and methods: Twenty-nine patients (21 men, 8 women; mean age, 64.4 ± 13.4 years; mean weight, 59.4 ± 10.3 kg) underwent measurement of cardiac output within 2 weeks of coronary CTA. The cardiac output of each patient was measured by the thermodilution technique and the cardiac index was calculated from the body surface area. During coronary CTA, attenuation of the descending aorta was measured at the workstation every 3 s. The aortic peak time (APT) and aortic peak enhancement (APE) of each patient were calculated. Pearson's correlation coefficient analysis was used to investigate the relationships between the cardiac output or cardiac index and APT or APE. Furthermore, the relationship between patient factors or parameters on test bolus injection and APT or APE was also evaluated. Results: The range of cardiac output, cardiac index, APT, and APE was 1.55-10.46 L/min (mean: 4.77 ± 2.13), 1.11-5.30 L/(min-m 2 ) (mean: 3.28 ± 1.08), 25-51 s (mean: 38.3 ± 7.5), and 273.1-598.1 HU (mean: 390.4 ± 72.1), respectively. With an increase in the cardiac index, both APT (r = -0.698, p < 0.0001) and APE (r = -0.573, p = 0.0009) decreased. There were significant correlations between the patient body weight and APT and APE with the test bolus injection, and with APT and APE during coronary CTA. Conclusion: The APT and APE during coronary CTA are closely related to cardiac function.

  11. Evaluation of peak power prediction equations in male basketball players.

    Science.gov (United States)

    Duncan, Michael J; Lyons, Mark; Nevill, Alan M

    2008-07-01

    This study compared peak power estimated using 4 commonly used regression equations with actual peak power derived from force platform data in a group of adolescent basketball players. Twenty-five elite junior male basketball players (age, 16.5 +/- 0.5 years; mass, 74.2 +/- 11.8 kg; height, 181.8 +/- 8.1 cm) volunteered to participate in the study. Actual peak power was determined using a countermovement vertical jump on a force platform. Estimated peak power was determined using countermovement jump height and body mass. All 4 prediction equations were significantly related to actual peak power (all p jump prediction equations, 12% for the Canavan and Vescovi equation, and 6% for the Sayers countermovement jump equation. In all cases peak power was underestimated.

  12. Group Elevator Peak Scheduling Based on Robust Optimization Model

    OpenAIRE

    ZHANG, J.; ZONG, Q.

    2013-01-01

    Scheduling of Elevator Group Control System (EGCS) is a typical combinatorial optimization problem. Uncertain group scheduling under peak traffic flows has become a research focus and difficulty recently. RO (Robust Optimization) method is a novel and effective way to deal with uncertain scheduling problem. In this paper, a peak scheduling method based on RO model for multi-elevator system is proposed. The method is immune to the uncertainty of peak traffic flows, optimal scheduling is re...

  13. Nonlinear preprocessing method for detecting peaks from gas chromatograms

    Directory of Open Access Journals (Sweden)

    Min Hyeyoung

    2009-11-01

    Full Text Available Abstract Background The problem of locating valid peaks from data corrupted by noise frequently arises while analyzing experimental data. In various biological and chemical data analysis tasks, peak detection thus constitutes a critical preprocessing step that greatly affects downstream analysis and eventual quality of experiments. Many existing techniques require the users to adjust parameters by trial and error, which is error-prone, time-consuming and often leads to incorrect analysis results. Worse, conventional approaches tend to report an excessive number of false alarms by finding fictitious peaks generated by mere noise. Results We have designed a novel peak detection method that can significantly reduce parameter sensitivity, yet providing excellent peak detection performance and negligible false alarm rates from gas chromatographic data. The key feature of our new algorithm is the successive use of peak enhancement algorithms that are deliberately designed for a gradual improvement of peak detection quality. We tested our approach with real gas chromatograms as well as intentionally contaminated spectra that contain Gaussian or speckle-type noise. Conclusion Our results demonstrate that the proposed method can achieve near perfect peak detection performance while maintaining very small false alarm probabilities in case of gas chromatograms. Given the fact that biological signals appear in the form of peaks in various experimental data and that the propose method can easily be extended to such data, our approach will be a useful and robust tool that can help researchers highlight valid signals in their noisy measurements.

  14. Evaluation of peak-fitting software for gamma spectrum analysis

    International Nuclear Information System (INIS)

    Zahn, Guilherme S.; Genezini, Frederico A.; Moralles, Mauricio

    2009-01-01

    In all applications of gamma-ray spectroscopy, one of the most important and delicate parts of the data analysis is the fitting of the gamma-ray spectra, where information as the number of counts, the position of the centroid and the width, for instance, are associated with each peak of each spectrum. There's a huge choice of computer programs that perform this type of analysis, and the most commonly used in routine work are the ones that automatically locate and fit the peaks; this fit can be made in several different ways - the most common ways are to fit a Gaussian function to each peak or simply to integrate the area under the peak, but some software go far beyond and include several small corrections to the simple Gaussian peak function, in order to compensate for secondary effects. In this work several gamma-ray spectroscopy software are compared in the task of finding and fitting the gamma-ray peaks in spectra taken with standard sources of 137 Cs, 60 Co, 133 Ba and 152 Eu. The results show that all of the automatic software can be properly used in the task of finding and fitting peaks, with the exception of GammaVision; also, it was possible to verify that the automatic peak-fitting software did perform as well as - and sometimes even better than - a manual peak-fitting software. (author)

  15. Determination of kinetic energy release from metastable peak widths

    DEFF Research Database (Denmark)

    Petersen, Allan Christian; Sølling, Theis Ivan

    2017-01-01

    The kinetic energy that is released upon bond rupture is often represented as T1/2. A value that is derived from the FWHM of a fragment peak by the use of two different conversion formulas. The choice of formula depends on whether the peak is recorded by scanning a magnetic sector or an electrost......The kinetic energy that is released upon bond rupture is often represented as T1/2. A value that is derived from the FWHM of a fragment peak by the use of two different conversion formulas. The choice of formula depends on whether the peak is recorded by scanning a magnetic sector...

  16. Assessing peak aerobic capacity in Dutch law enforcement officers

    Directory of Open Access Journals (Sweden)

    Harriet Wittink

    2015-06-01

    Full Text Available Objectives: To cross-validate the existing peak rate of oxygen consumption (VO2peak prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report normative absolute and relative VO2peak values of a sample of law enforcement officers in the Netherlands. Material and Methods: The peak rate of oxygen consumption (ml×kg–1×min–1 was measured using a maximal incremental bicycle test in 1530 subjects, including 1068 male and 461 female police officers. Validity of the prediction equations for groups was assessed by comparing predicted VO2peak with measured VO2peak using paired t-tests. For individual differences limits of agreement (LoA were calculated. Equations were considered valid for individuals when the difference between measured and predicted VO2peak did not exceed ±1 metabolic equivalent (MET in 95% of individuals. Results: None of the equations met the validity criterion of 95% of individuals having ±1 MET difference or less than the measured value. Limits of agreement (LoAs were large in all predictions. At the individual level, none of the equations were valid predictors of VO2peak (ml×kg–1×min–1. Normative values for Dutch law enforcement officers were presented. Conclusions: Substantial differences between measured and predicted VO2peak (ml×kg–1×min–1 were found. Most tested equations were invalid predictors of VO2peak at group level and all were invalid at individual levels.

  17. Cadence, peak vertical acceleration, and peak loading rate during ambulatory activities: implications for activity prescription for bone health.

    Science.gov (United States)

    Rowlands, Alex V; Schuna, John M; Stiles, Victoria H; Tudor-Locke, Catrine

    2014-09-01

    Previous research has reported peak vertical acceleration and peak loading rate thresholds beneficial to bone mineral density (BMD). Such thresholds are difficult to translate into meaningful recommendations for physical activity. Cadence (steps/min) is a more readily interpretable measure of ambulatory activity. To examine relationships between cadence, peak vertical acceleration and peak loading rate during ambulation and identify the cadence associated with previously reported bone-beneficial thresholds for peak vertical acceleration (4.9 g) and peak loading rate (43 BW/s). Ten participants completed 8 trials each of: slow walking, brisk walking, slow running, and fast running. Acceleration data were captured using a GT3×+ accelerometer worn at the hip. Peak loading rate was collected via a force plate. Strong relationships were identified between cadence and peak vertical acceleration (r = .96, P acceleration and 43 BW/s peak loading rate thresholds, respectively. Cadences ≥ 2.0 to 2.6 steps/s equate to acceleration and loading rate thresholds related to bone health. Further research is needed to investigate whether the frequency of daily occurrences of this cadence is associated with BMD.

  18. Peak effect in surface resistance at microwave frequencies in Dy ...

    Indian Academy of Sciences (India)

    In the measurements at both frequencies the induced microwave current was always less than the critical current of the films. The reason for observation of this peak effect in these films has been explained in our earlier publication [5]. Comparing figures 1 and 2, it is observed that the peaks in sample S1 are broader and.

  19. Psychological Preparation for Peak Performance in Sports Competition

    Science.gov (United States)

    Ohuruogu, Ben; Jonathan, Ugwuanyi I.; Ikechukwu, Ugwu Jude

    2016-01-01

    This paper attempts to make an overview of various techniques, sport psychologist adopt in psychological preparation of athletes for peak performance. To attain peak performance in sports competitions, coaches and athletes should not base their prospect on physical training on sport skills alone rather should integrate both the mental and physical…

  20. Online junction temperature measurement using peak gate current

    DEFF Research Database (Denmark)

    Baker, Nick; Munk-Nielsen, Stig; Iannuzzo, Francesco

    2015-01-01

    A new method for junction temperature measurement of MOS-gated power semiconductor switches is presented. The measurement method involves detecting the peak voltage over the external gate resistor of an IGBT or MOSFET during turn-on. This voltage is directly proportional to the peak gate current...

  1. Flood Peak Estimation Using Rainfall Run off Models | Matondo ...

    African Journals Online (AJOL)

    The design of hydraulic structures such as road culverts, road bridges and dam spillways requires the determination of the design food peak. Two approaches are available in the determination of the design flood peak and these are: flood frequency analysis and rainfall runoff models. Flood frequency analysis requires a ...

  2. Probabilistic Analysis of Peak Daily Rainfall for Prediction purposes ...

    African Journals Online (AJOL)

    The obtained peak daily rainfall values were subjected to Gumbel, Log-Gumbel, Normal, Log-Normal, Pearson and Log-Pearson probability distributions. Mathematical equation for probability distribution functions were established for each town and used to predict peak rainfall. The predicted values were subjected to ...

  3. Peak Expiratory Flow Rate In Cigarette Smokers | Ukoli | Highland ...

    African Journals Online (AJOL)

    Objective: To compare lung function between smokers and non-smokers using Peak Expiratory Flow Rate (PEFR). Methods: This study examines the peak expiratory flow rate (PEFR) of three hundred and forty cigarette smokers, age and sex-matched with PEFR of equal number of non-smokers. Results: The mean PEFR of ...

  4. Diffraction peaks in x-ray spectroscopy: Friend or foe?

    International Nuclear Information System (INIS)

    Tissot, R.G.; Goehner, R.P.

    1992-01-01

    Diffraction peaks can occur as unidentifiable peaks in the energy spectrum of an x-ray spectrometric analysis. Recently, there has been increased interest in oriented polycrystalline films and epitaxial films on single crystal substrates for electronic applications. Since these materials diffract x-rays more efficiently than randomly oriented polycrystalline materials, diffraction peaks are being observed more frequently in x-ray fluorescent spectra. In addition, micro x-ray spectrometric analysis utilizes a small, intense, collimated x-ray beam that can yield well defined diffraction peaks. In some cases these diffraction peaks can occur at the same position as elemental peaks. These diffraction peaks, although a possible problem in qualitative and quantitative elemental analysis, can give very useful information about the crystallographic structure and orientation of the material being analyzed. The observed diffraction peaks are dependent on the geometry of the x-ray spectrometer, the degree of collimation and the distribution of wavelengths (energies) originating from the x-ray tube and striking the sample

  5. Quality Assurance in the Determination of Overlapping Peak Areas

    DEFF Research Database (Denmark)

    Christensen, L.H.; Heydorn, K.

    1987-01-01

    The ability of different computer programs to yield accurate peak areas in statistical control in the case of partially overlapping photopeaks has been tested by the Analysis of Precision. A modified Covell method, two commercially available peak-fitting programs from Nuclear Data and Ortec, and ...

  6. Limitations of middle cerebral artery peak systolic velocity in the ...

    African Journals Online (AJOL)

    We present a case of a mother with severe pre-eclampsia at 32 weeks' gestation and non-immune fetal hydrops without obvious cause. Since the. MCA peak systolic velocity (PSV) was ... Limitations of middle cerebral artery peak systolic velocity .... [7] found MCA PSV of value in 9 women with chronic abruption, but in 5.

  7. Single-peak solitary wave solutions for the variant Boussinesq ...

    Indian Academy of Sciences (India)

    ∈ H1 loc(R). (iii) Similar to the proof of the above (ii),we omit it here. This completes the proof. 3. Smooth and cusped single-peak solitary wave solutions. Theorem 2.4 gives a classification for all single-peak solitary wave solutions for eq. (2.4).

  8. Identification of peaks in multidimensional coincidence {gamma}-ray spectra

    Energy Technology Data Exchange (ETDEWEB)

    Morhac, Miroslav E-mail: fyzimiro@savba.sk; Kliman, Jan; Matousek, Vladislav; Veselsky, Martin; Turzo, Ivan

    2000-03-21

    In the paper a new algorithm to find peaks in two, three and multidimensional spectra, measured in large multidetector {gamma}-ray arrays, is derived. Given the dimension m, the algorithm is selective to m-fold coincidence peaks. It is insensitive to intersections of lower-fold coincidences, hereinafter called ridges.

  9. quasi hyperrigidity and weak peak points for non-commutative ...

    Indian Academy of Sciences (India)

    7

    The concepts of peak point and Choquet boundary play an important role in several areas of classical ... theory studied extensively with the concept of Korovkin (hyperrigid sets) sets. The idea of peak points was .... An operator system S in a C∗-algebra A is a self-adjoint linear subspace of A containing the iden- tity of A ...

  10. Determination of gaussian peaks in gamma spectra by iterative regression

    International Nuclear Information System (INIS)

    Nordemann, D.J.R.

    1987-05-01

    The parameters of the peaks in gamma-ray spectra are determined by a simple iterative regression method. For each peak, the parameters are associated with a gaussian curve (3 parameters) located above a linear continuum (2 parameters). This method may produces the complete result of the calculation of statistical uncertainties and an accuracy higher than others methods. (author) [pt

  11. Daily Nigerian peak load forecasting using artificial neural network ...

    African Journals Online (AJOL)

    A daily peak load forecasting technique that uses artificial neural network with seasonal indices is presented in this paper. A neural network of relatively smaller size than the main prediction network is used to predict the daily peak load for a period of one year over which the actual daily load data are available using one ...

  12. Mazama and Glacier Peak Volcanic Ash Layers: Relative Ages.

    Science.gov (United States)

    Fryxell, R

    1965-03-12

    Physiographic and stratigraphic evidence supports the regional correlation of two volcanic ash layers with extinct Mount Mazama at Crater Lake, Oregon, and Glacier Peak in the northern Cascade Range of Washington. A radiocarbon age of 12,000 +/- 310 years confirms geological evidence that ash derived from the Glacier Peak eruption is substantially older than ash from the Mazama eruption of 6600 years ago.

  13. Impact of Smart Grid Technologies on Peak Load to 2050

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    The IEA's Smart Grids Technology Roadmap identified five global trends that could be effectively addressed by deploying smart grids. These are: increasing peak load (the maximum power that the grid delivers during peak hours), rising electricity consumption, electrification of transport, deployment of variable generation technologies (e.g. wind and solar PV) and ageing infrastructure. Along with this roadmap, a new working paper -- Impact of Smart Grid Technologies on Peak Load to 2050 -- develops a methodology to estimate the evolution of peak load until 2050. It also analyses the impact of smart grid technologies in reducing peak load for four key regions; OECD North America, OECD Europe, OECD Pacific and China. This working paper is a first IEA effort in an evolving modelling process of smart grids that is considering demand response in residential and commercial sectors as well as the integration of electric vehicles.

  14. Reliability of peak treadmill exercise tests in mild Alzheimer disease.

    Science.gov (United States)

    Anderson, Heather S; Kluding, Patricia M; Gajewski, Byron J; Donnelly, Joseph E; Burns, Jeffrey M

    2011-08-01

    The purpose of this study was to determine the reliability of treadmill peak exercise testing in people with very mild-to-mild Alzheimer disease (AD). Sixteen subjects with very mild-to-mild AD performed graded peak treadmill exercise tests twice within a 14-day period. Heart rate, oxygen consumption, and respiratory exchange ratio (RER) were continuously monitored. Peak values were analyzed for absolute level of agreement. Fourteen participants (87.5%) completed testing. Reliability was excellent with total peak oxygen consumption (VO2peak) (ml/kg/min) highly correlated across the two tests (r = 0.94, p exercise testing on a treadmill is reliable in the early stages of AD.

  15. Diffraction peak shift in MgO small crystallites

    Science.gov (United States)

    Gielen, P.

    1998-08-01

    A linear relationship is found between peak position and peak width for the X-ray diffraction peaks of MgO very small crystallites. The sign of the peak shift is explained. The peak shape is asymmetrical, the more asymmetrical the broader it is. The second Heisenberg's uncertainty relation is reinterpreted. L'auteur trouve une relation linéaire entre la position des pics et la largeur des pics de diffraction des rayons X pour de très petites cristallites de MgO. Il explique le signe du déplacement des pics. La forme des pics est asymétrique, d'autant plus asymétrique qu'ils sont plus larges. La seconde relation d'incertitude de Heisenberg est réinterprétée.

  16. Peak broadening in paper chromatography and related techniques : III. Peak broadening in thin-layer chromatography on cellulose powder

    NARCIS (Netherlands)

    Ligny, C.L. de; Remijnse, A.G.

    1968-01-01

    The mechanism of peak broadening in thin-layer chromatography on cellulose powder was investigated by comparing the peak widths obtained in chromatography with those caused only by diffusion in the cellulose powder, for a set of amino acids of widely differing RF values and six kinds of cellulose

  17. Dual Peak Cholera transmission in South Asia: A Hydroclimatological Explanation

    Science.gov (United States)

    Akanda, A. S.; Jutla, A.; Islam, S.

    2009-04-01

    Cholera has reemerged as a global killer with the world witnessing an unprecedented rise in cholera infection and transmission since the 1990s. Cholera outbreaks across most affected areas show infection patterns with a single annual peak. However, cholera incidences in the Bengal Delta region, the native homeland of cholera, show bi-annual peaks. The mechanisms behind this unique seasonal dual peak phenomenon in cholera dynamics, especially the role of climatic and hydrologic variables, are not fully understood. We disaggregate regional streamflow and sea surface temperature data into seasonal components, and analyze their correlation with the two seasonal peaks in Bangladesh cholera incidence records. Low flow in the Brahmaputra and the Ganges during spring is associated with inward plankton transport from the ocean and the first cholera outbreaks of the year. Peak streamflow of these rivers, on the other hand, create a different cholera transmission environment; peak flood volumes and extent of flood-affected areas during monsoon are responsible for widespread water contamination and subsequent cholera outbreaks. Our preliminary results demonstrate that the seasonality and dual peaks of cholera transmission in this region may be explained by two distinctly different hydroclimatological drivers. We will quantify the roles of these processes and explain the nature of these drivers.

  18. Modeled future peak streamflows in four coastal Maine rivers

    Science.gov (United States)

    Hodgkins, Glenn A.; Dudley, Robert W.

    2013-01-01

    To safely and economically design bridges and culverts, it is necessary to compute the magnitude of peak streamflows that have specified annual exceedance probabilities (AEPs). Annual precipitation and air temperature in the northeastern United States are, in general, projected to increase during the 21st century. It is therefore important for engineers and resource managers to understand how peak flows may change in the future. This report, prepared in cooperation with the Maine Department of Transportation (MaineDOT), presents modeled changes in peak flows at four basins in coastal Maine on the basis of projected changes in air temperature and precipitation. To estimate future peak streamflows at the four basins in this study, historical values for climate (temperature and precipitation) in the basins were adjusted by different amounts and input to a hydrologic model of each study basin. To encompass the projected changes in climate in coastal Maine by the end of the 21st century, air temperatures were adjusted by four different amounts, from -3.6 degrees Fahrenheit (ºF) (-2 degrees Celsius (ºC)) to +10.8 ºF (+6 ºC) of observed temperatures. Precipitation was adjusted by three different percentage values from -15 percent to +30 percent of observed precipitation. The resulting 20 combinations of temperature and precipitation changes (includes the no-change scenarios) were input to Precipitation-Runoff Modeling System (PRMS) watershed models, and annual daily maximum peak flows were calculated for each combination. Modeled peak flows from the adjusted changes in temperature and precipitation were compared to unadjusted (historical) modeled peak flows. Annual daily maximum peak flows increase or decrease, depending on whether temperature or precipitation is adjusted; increases in air temperature (with no change in precipitation) lead to decreases in peak flows, whereas increases in precipitation (with no change in temperature) lead to increases in peak flows. As

  19. System dynamics model of Hubbert Peak for China's oil

    International Nuclear Information System (INIS)

    Tao Zaipu; Li Mingyu

    2007-01-01

    American geophysicist M. King Hubbert in 1956 first introduced a logistic equation to estimate the peak and lifetime production for oil of USA. Since then, a fierce debate ensued on the so-called Hubbert Peak, including also its methodology. This paper proposes to use the generic STELLA model to simulate Hubbert Peak, particularly for the Chinese oil production. This model is demonstrated as being robust. We used three scenarios to estimate the Chinese oil peak: according to scenario 1 of this model, the Hubbert Peak for China's crude oil production appears to be in 2019 with a value of 199.5 million tonnes, which is about 1.1 times the 2005 output. Before the peak comes, Chinese oil output will grow by about 1-2% annually, after the peak, however, the output will fall. By 2040, the annual production of Chinese crude oil would be equivalent to the level of 1990. During the coming 20 years, the crude oil demand of China will probably grow at the rate of 2-3% annually, and the gap between domestic supply and total demand may be more than half of this demand

  20. Two density peaks in low magnetic field helicon plasma

    Science.gov (United States)

    Wang, Y.; Zhao, G.; Liu, Z. W.; Ouyang, J. T.; Chen, Q.

    2015-09-01

    In this paper, we report two density peaks in argon helicon plasma under an axial magnetic field from 0 G to 250 G with Boswell-type antenna driven by radio frequency (RF) power of 13.56 MHz. The first peak locates at 40-55 G and the second one at 110-165 G, as the RF power is sustainably increased from 100 W to 250 W at Ar pressure of 0.35 Pa. The absorbed power of two peaks shows a linear relationship with the magnetic field. End views of the discharge taken by intensified charge coupled device reveal that, when the first peak appeared, the discharge luminance moves to the edge of the tube as the magnetic field increases. For the second peak, the strong discharge area is centered at the two antenna legs after the magnetic field reaches a threshold value. Comparing with the simulation, we suggest that the efficient power absorption of two peaks at which the efficient power absorption mainly appears in the near-antenna region is due to the mode conversion in bounded non-uniform helicon plasma. The two low-field peaks are caused, to some extent, by the excitation of Trivelpiece-Gould wave through non-resonance conversion.

  1. Generation of sub-nanosecond pulses using peaking capacitor

    Directory of Open Access Journals (Sweden)

    Madhu Palati

    2017-05-01

    Full Text Available This paper discusses the analysis, simulation and design of a peaking circuit comprising of a peaking capacitor, spark gap and load circuit. The peaking circuit is used along with a 200 kV, 20 J Marx generator for generation of sub-nanosecond pulses. A high pressure chamber to accommodate the peaking circuit was designed and fabricated and tested upto a pressure of 70 kg/cm2. Total estimated values of the capacitance and inductance of the peaking circuit are 10 pF and 72 nH respectively. At full charging voltage, the peaking capacitor gets charged to a peak voltage of 394.6 kV in 15 ns. The output switch is closed at this instant. From Analysis & Simulation, the output current & rise time (with a matched load of 85 Ω are 2.53 kA and 0.62 ns.

  2. Pressure dependence of the Boson peak in poly(butadiene)

    CERN Document Server

    Frick, B

    2002-01-01

    Variation of pressure and temperature in inelastic neutron scattering experiments allows us to separate density and thermal energy contributions. We summarise briefly the influence of pressure and temperature on the dynamic scattering law of the polymer glass former poly(butadiene) far below the glass transition. We also show the advantage of using a liquid-niobium pressure cell in such studies. The effect of pressure on the boson peak is to shift the peak towards higher energies and to reduce the low-frequency modes more strongly below the boson-peak maximum than above. A decrease in the Debye-Waller factor with increasing pressure is observed. (orig.)

  3. Determination of proper peaking time for Ultra-LEGe detector

    Energy Technology Data Exchange (ETDEWEB)

    Karabidak, S.M., E-mail: salihm@ktu.edu.t [Department of Physics, Karadeniz Technical University, 61080 Trabzon (Turkey); Department of Engineering Physics, Guemueshane University, 29100 Guemueshane (Turkey); Kaya, S. [Department of Engineering Physics, Guemueshane University, 29100 Guemueshane (Turkey); Cevik, U. [Department of Physics, Karadeniz Technical University, 61080 Trabzon (Turkey); Celik, A. [Department of Physics, Giresun University, 28049 Giresun (Turkey)

    2011-04-15

    Reducing count losses and pile-up pulse effects in quantitative and qualitative analysis is necessary for accuracy of analysis. Therefore, the proper peaking time for particular detector systems is important. The characteristic X-rays emitted from pure some elements were detected by using an Ultra-LEGe detector connecting a Tennelec TC 244 spectroscopy amplifier at different peaking time modes. Overall pulse widths were determined by an HM 203-7 oscilloscope connecting amplifier. The proper peaking time for Ultra-LEGe is determined as 3.84 {mu}s.

  4. OECD : Euroopa peaks laenuraha odava hoidma / Sirje Rank

    Index Scriptorium Estoniae

    Rank, Sirje, 1966-

    2002-01-01

    USA majanduse kiire toibumine võib varsti tuua laenuintresside tõusu, Euroopa Keskpank peaks vähemalt aasta lõpuni ootama ja laskma kasvul juurduda. Diagramm: OECD tõstis majanduskasvu prognoosi. Maksukoormus

  5. Reducing Electricity Demand Peaks by Scheduling Home Appliances Usage

    DEFF Research Database (Denmark)

    Rossello Busquet, Ana; Kardaras, Georgios; Iversen, Villy Bæk

    2011-01-01

    . On the contrary, the low priority devices have to pause their operation, when the algorithm dictates it, and resume it in the future. This can become beneficial for both energy companies and users. The electricity suppliers companies will be capable of regulating power generation during demand peaks periods....... Moreover, users can be granted lower electricity bill rates for accepting delaying the operation of some of their appliances. In order to analyze this scenario, teletraffic engineering theory, which is used in evaluating the performance of telecommunication networks, is used. A reversible fair scheduling......Nowadays there is a tendency to consume electricity during the same period of the day leading to demand peaks. Regular energy consumption habits lead to demand peaks at specific temporal intervals, because users consume power at the same time. In order to avoid demand peaks, users’ appliances...

  6. Audible thunder characteristic and the relation between peak ...

    Indian Academy of Sciences (India)

    Audible thunder characteristic and the relation between peak frequency and lightning parameters ... In recent summers, some natural lightning optical spectra and audible thunder signals were observed. ... School of Mathematics, Physics and Software Engineering, Lanzhou Jiaotong University, Lanzhou 730 070, China.

  7. Effects of equipment and technique on peak flow measurements

    Directory of Open Access Journals (Sweden)

    O'Driscoll B Ronan

    2006-06-01

    Full Text Available Abstract Background Different lung function equipment and different respiratory manoeuvres may produce different Peak Expiratory Flow (PEF results. Although the PEF is the most common lung function test, there have been few studies of these effects and no previous study has evaluated both factors in a single group of patients. Methods We studied 36 subjects (PEF range 80–570 l/min. All patients recorded PEF measurements using a short rapid expiration following maximal inspiration (PEF technique or a forced maximal expiration to residual volume (FVC technique. Measurements were made using a Wright's peak flow meter, a turbine spirometer and a Fleisch pneumotachograph spirometer. Results The mean PEF was 8.7% higher when the PEF technique was used (compared with FVC technique, p Conclusion Peak flow measurements are affected by the instruction given and by the device and Peak Flow scale used. Patient management decisions should not be based on PEF measurement made on different instruments.

  8. Potential of solar cooling systems for peak demand reduction

    Energy Technology Data Exchange (ETDEWEB)

    Pesaran, A A [National Renewable Energy Lab., Golden, CO (United States); Neymark, J [Neymark (Joel), Golden, CO (United States)

    1994-11-01

    We investigated the technical feasibility of solar cooling for peak demand reduction using a building energy simulation program (DOE2.1D). The system studied was an absorption cooling system with a thermal coefficient of performance of 0.8 driven by a solar collector system with an efficiency of 50% with no thermal storage. The analysis for three different climates showed that, on the day with peak cooling load, about 17% of the peak load could be met satisfactorily with the solar-assisted cooling system without any thermal storage. A performance availability analysis indicated that the solar cooling system should be designed for lower amounts of available solar resources that coincide with the hours during which peak demand reduction is required. The analysis indicated that in dry climates, direct-normal concentrating collectors work well for solar cooling; however, in humid climates, collectors that absorb diffuse radiation work better.

  9. The simple method of determination peaks areas in multiplets

    International Nuclear Information System (INIS)

    Loska, L.; Ptasinski, J.

    1991-01-01

    Semiconductor germanium detectors used in γ-spectrometry give spectra with well-separated peaks. However, in some cases, energies of γ-lines are too near, to produce resolved and undisturbed peaks. Then, there is a necessity to perform a mathematical separation. The method proposed here is based on the assumption, that areas of peaks composing the analysed multiplet are proportional to their heights. The method can be applied for any number of interfering peaks, providing, that the function of the background under the multiplet is accurately determined. The results of testing calculations performed on a simulated spectrum are given. The method works successfully in a computer program used for neutron activation analysis data processing. (author). 9 refs, 1 fig, 1 tab

  10. Desert Peak East Enhanced Geothermal Systems (EGS) Project

    Energy Technology Data Exchange (ETDEWEB)

    Zemach, Ezra [Ormat Technologies Inc., Reno, NV (United States); Drakos, Peter [Ormat Technologies Inc., Reno, NV (United States); Spielman, Paul [Ormat Technologies Inc., Reno, NV (United States); Akerley, John [Ormat Technologies Inc., Reno, NV (United States)

    2013-09-30

    This manuscript is a draft to replaced with a final version at a later date TBD. A summary of activities pertaining to the Desert Peak EGS project including the planning and resulting stimulation activities.

  11. Measurement of two-peak structure in fusion reaction history

    International Nuclear Information System (INIS)

    Wang Feng; Peng Xiaoshi; Liu Shenye; Liu Yonggang; Xu Tao; Chen Ming; Mei Yu; Kang Dongguo; Gu Jianfa

    2013-01-01

    The relationship of the roughness degree of ablation shell and the two peaks of fusion reaction rate was analyzed. We developed a system for fusion reaction history measurement with high temporal resolution, and applied this system to the SG-Ⅲ prototype for measuring fusion reaction rate. Fusion reaction rate history was measured for the first time with deuterium-tritium filled targets under neutron yields of about 10 10 . We anatomized possible influence factors during fusion reaction rate's measuring. The two peaks of reaction rate can be obtained from the simulation results, and have been confirmed with the experimental results. It is found that neutrons in our experiment are generated by the first peak which is called the shock peak. The simulation and experimental results can provide strong technical support for the research on fusion reaction rate in inertial confinement fusion. (authors)

  12. FHWA operations support : port peak pricing program evaluation

    Science.gov (United States)

    2009-01-01

    This report evaluates the applicability, Federal policy implications, and possible public and private sector roles related to peak pricing strategies at ports and intermodal facilities in the U.S. A number of ports and intermodal terminals are consid...

  13. Brian Eno Hollandi Festivali peakülaliseks

    Index Scriptorium Estoniae

    1999-01-01

    Inglise helilooja, videokunstnik ja muusikaprodutsent Brian Eno on 5.-26. juunini Amsterdamis toimuva avangardse Hollandi Festivali peakülaline, kelle videoinstallatsioon seatakse üles Stedelijki Muuseumis. Festivali programmist

  14. Advancements of ultra-high peak power laser diode arrays

    Science.gov (United States)

    Crawford, D.; Thiagarajan, P.; Goings, J.; Caliva, B.; Smith, S.; Walker, R.

    2018-02-01

    Enhancements of laser diode epitaxy in conjunction with process and packaging improvements have led to the availability of 1cm bars capable of over 500W peak power at near-infrared wavelengths (770nm to 1100nm). Advances in cooler design allow for multi-bar stacks with bar-to-bar pitches as low as 350μm and a scalable package architecture enabled a single diode assembly with total peak powers of over 1MegaWatt of peak power. With the addition of micro-optics, overall array brightness greater than 10kW/cm2 was achieved. Performance metrics of barbased diode lasers specifically engineered for high peak power and high brightness at wavelengths and pulse conditions commonly used to pump a variety of fiber and solid-state materials are presented.

  15. Peak globalization. Climate change, oil depletion and global trade

    International Nuclear Information System (INIS)

    Curtis, Fred

    2009-01-01

    The global trade in goods depends upon reliable, inexpensive transportation of freight along complex and long-distance supply chains. Global warming and peak oil undermine globalization by their effects on both transportation costs and the reliable movement of freight. Countering the current geographic pattern of comparative advantage with higher transportation costs, climate change and peak oil will thus result in peak globalization, after which the volume of exports will decline as measured by ton-miles of freight. Policies designed to mitigate climate change and peak oil are very unlikely to change this result due to their late implementation, contradictory effects and insufficient magnitude. The implication is that supply chains will become shorter for most products and that production of goods will be located closer to where they are consumed. (author)

  16. Peak globalization. Climate change, oil depletion and global trade

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, Fred [Department of Economics, Drew University, Madison, NJ 07940 (United States)

    2009-12-15

    The global trade in goods depends upon reliable, inexpensive transportation of freight along complex and long-distance supply chains. Global warming and peak oil undermine globalization by their effects on both transportation costs and the reliable movement of freight. Countering the current geographic pattern of comparative advantage with higher transportation costs, climate change and peak oil will thus result in peak globalization, after which the volume of exports will decline as measured by ton-miles of freight. Policies designed to mitigate climate change and peak oil are very unlikely to change this result due to their late implementation, contradictory effects and insufficient magnitude. The implication is that supply chains will become shorter for most products and that production of goods will be located closer to where they are consumed. (author)

  17. Households' hourly electricity consumption and peak demand in Denmark

    DEFF Research Database (Denmark)

    Møller Andersen, Frits; Baldini, Mattia; Hansen, Lars Gårn

    2017-01-01

    The electrification of residential energy demand for heating and transportation is expected to increase peak load and require additional generation and transmission capacities. Electrification also provides an opportunity to increase demand response. With a focus on household electricity......, for an individual household, the consumption of each of these technologies roughly doubles the household's consumption and considerably increases their potential for flexibility. Thus, in order to introduce incentives for demand flexibility, while considering reducing peak consumption, policy makers should...... consumption, we analyse the contribution of appliances and new services, such as individual heat pumps and electric vehicles, to peak consumption and the need for demand response incentives to reduce the peak.Initially, the paper presents a new model that represents the hourly electricity consumption profile...

  18. Bedrock Geologic Map of the Jay Peak, VT Quadrangle

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital data from VG99-1 Compilation bedrock geologic map of the Jay Peak quadrangle, Compiled by B. Doolan, 1999: VGS Open-File Report VG99-1, 1 plate, scale...

  19. Periodic transmission peak splitting in one dimensional disordered photonic structures

    Science.gov (United States)

    Kriegel, Ilka; Scotognella, Francesco

    2016-08-01

    In the present paper we present ways to modulate the periodic transmission peaks arising in disordered one dimensional photonic structures with hundreds of layers. Disordered structures in which the optical length nd (n is the refractive index and d the layer thickness) is the same for each layer show regular peaks in their transmission spectra. A proper variation of the optical length of the layers leads to a splitting of the transmission peaks. Notably, the variation of the occurrence of high and low refractive index layers, gives a tool to tune also the width of the peaks. These results are of highest interest for optical application, such as light filtering, where the manifold of parameters allows a precise design of the spectral transmission ranges.

  20. 1.55 Micron High Peak Power Fiber Amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal, we propose to demonstrate and build a 1.55 micron single frequency high energy and high peak power fiber amplifier by developing an innovative...

  1. Hubbert's Oil Peak Revisited by a Simulation Model

    International Nuclear Information System (INIS)

    Giraud, P.N.; Sutter, A.; Denis, T.; Leonard, C.

    2010-01-01

    As conventional oil reserves are declining, the debate on the oil production peak has become a burning issue. An increasing number of papers refer to Hubbert's peak oil theory to forecast the date of the production peak, both at regional and world levels. However, in our views, this theory lacks micro-economic foundations. Notably, it does not assume that exploration and production decisions in the oil industry depend on market prices. In an attempt to overcome these shortcomings, we have built an adaptative model, accounting for the behavior of one agent, standing for the competitive exploration-production industry, subjected to incomplete but improving information on the remaining reserves. Our work yields challenging results on the reasons for an Hubbert type peak oil, lying mainly 'above the ground', both at regional and world levels, and on the shape of the production and marginal cost trajectories. (authors)

  2. Energy loss minimization through peak shaving using energy storage

    Directory of Open Access Journals (Sweden)

    Vaiju Kalkhambkar

    2016-09-01

    Full Text Available This paper presents an optimal placement methodology of energy storage to improve energy loss minimization through peak shaving in the presence of renewable distributed generation. Storage sizing is modelled by considering the load profile and desired peak shaving. This storage is suitably divided into multiple storage units and optimally allocated at multiple sites with suitable charge discharge strategy. Thus the peak shaving for maximum loss reduction is explored here. Renewable distributed generation (RDG is modelled based on the seasonal variations of renewable resources e.g., solar or wind and these RDGs are placed at suitable locations. A high-performance Grey Wolf Optimization (GWO algorithm is applied to the proposed methodology. The results are compared with the well-known genetic algorithm. The proposed methodology is illustrated by various case studies on a 34-bus test system. Significant loss minimization is obtained by optimal location of multiple energy storage units through peak shaving.

  3. Trust and the Welfare State: The Twin Peaks Curve

    OpenAIRE

    Yann Algan; Pierre Cahuc; Marc Sangnier

    2014-01-01

    We show the existence of a twin peaks relation between trust and the size of the welfare state that stems from two opposing forces. Uncivic people support large welfare states because they expect to benefit from them without bearing their costs. But civic individuals support generous benefits and high taxes only when they are surrounded by trustworthy individuals. We provide empirical evidence for these behaviors and this twin peaks relation in the OECD countries.

  4. Converter for Measurement of non-sinusoidal current peak value

    DEFF Research Database (Denmark)

    Butvin, P.; Nielsen, Otto V; Brauer, Peter

    1997-01-01

    A linear-response toroid with core wound of rapidly quenched soft magnetic metallic ribbon and fitted with two windings is used to enable correct measurement of mean peak value of non-sinusoidal and not noise-free alternating current.......A linear-response toroid with core wound of rapidly quenched soft magnetic metallic ribbon and fitted with two windings is used to enable correct measurement of mean peak value of non-sinusoidal and not noise-free alternating current....

  5. Mineral Resources: Reserves, Peak Production and the Future

    OpenAIRE

    Lawrence D. Meinert; Gilpin R. Robinson; Nedal T. Nassar

    2016-01-01

    The adequacy of mineral resources in light of population growth and rising standards of living has been a concern since the time of Malthus (1798), but many studies erroneously forecast impending peak production or exhaustion because they confuse reserves with “all there is”. Reserves are formally defined as a subset of resources, and even current and potential resources are only a small subset of “all there is”. Peak production or exhaustion cannot be modeled accurately from reserves. Using ...

  6. Improvements to science operations at Kitt Peak National Observatory

    Science.gov (United States)

    Bohannan, Bruce

    1998-07-01

    In recent years Kitt Peak National Observatory has undertaken a number of innovative projects to optimize science operations with the suite of telescopes we operate on Kitt Peak, Arizona. Changing scientific requirements and expectations of our users, evolving technology and declining budgets have motivated the changes. The operations improvements have included telescope performance enhancements--with the focus on the Mayall 4-m--modes of observing and scheduling, telescope control and observing systems, planning and communication, and data archiving.

  7. Peak effect at microwave frequencies in swift heavy ion irradiated ...

    Indian Academy of Sciences (India)

    The vortex dynamics at microwave frequencies in YBa2Cu3O7- (YBCO) films have been studied. We observe a peak in the microwave (4.88 and 9.55 GHz) surface resistance in some films in magnetic fields up to 0.8 T. This is associated with the `peak-effect' phenomenon and reflects the order–disorder transformation of ...

  8. Peaking of world oil production: Impacts, mitigation, & risk management

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, R.L. (SAIC); Bezdek, Roger (MISI); Wendling, Robert (MISI)

    2005-02-01

    The peaking of world oil production presents the U.S. and the world with an unprecedented risk management problem. As peaking is approached, liquid fuel prices and price volatility will increase dramatically, and, without timely mitigation, the economic, social, and political costs will be unprecedented. Viable mitigation options exist on both the supply and demand sides, but to have substantial impact, they must be initiated more than a decade in advance of peaking.... The purpose of this analysis was to identify the critical issues surrounding the occurrence and mitigation of world oil production peaking. We simplified many of the complexities in an effort to provide a transparent analysis. Nevertheless, our study is neither simple nor brief. We recognize that when oil prices escalate dramatically, there will be demand and economic impacts that will alter our simplified assumptions. Consideration of those feedbacks will be a daunting task but one that should be undertaken. Our aim in this study is to-- • Summarize the difficulties of oil production forecasting; • Identify the fundamentals that show why world oil production peaking is such a unique challenge; • Show why mitigation will take a decade or more of intense effort; • Examine the potential economic effects of oil peaking; • Describe what might be accomplished under three example mitigation scenarios. • Stimulate serious discussion of the problem, suggest more definitive studies, and engender interest in timely action to mitigate its impacts.

  9. Dual peak cholera transmission in Bengal Delta: A hydroclimatological explanation

    Science.gov (United States)

    Akanda, Ali Shafqat; Jutla, Antarpreet Singh; Islam, Shafiqul

    2009-10-01

    Cholera has reemerged as a global killer with the world witnessing an unprecedented rise in cholera infection and transmission since the 1990s. Cholera outbreaks across most affected areas show infection patterns with a single annual peak. However, cholera incidences in the Bengal Delta region, the native homeland of cholera, show bi-annual peaks. The mechanisms behind this unique seasonal dual peak phenomenon in cholera dynamics, especially the role of climatic and hydrologic variables, are not fully understood. Here, we show that low flow in the Brahmaputra and the Ganges during spring is associated with the first outbreaks of cholera in Bangladesh; elevated spring cholera outbreaks are seen in low discharge years. Peak streamflow of these rivers, on the other hand, create a different cholera transmission environment; peak flood volumes and extent of flood-affected areas during monsoon are responsible for autumn cholera outbreaks. Our results demonstrate how regional hydroclimatology may explain the seasonality and dual peaks of cholera incidence in the Bengal Delta region. A quantitative understanding of the relationships among the hydroclimatological drivers and seasonal cholera outbreaks will help early cholera detection and prevention efforts.

  10. Predicting durations of online collective actions based on Peaks' heights

    Science.gov (United States)

    Lu, Peng; Nie, Shizhao; Wang, Zheng; Jing, Ziwei; Yang, Jianwu; Qi, Zhongxiang; Pujia, Wangmo

    2018-02-01

    Capturing the whole process of collective actions, the peak model contains four stages, including Prepare, Outbreak, Peak, and Vanish. Based on the peak model, one of the key variables, factors and parameters are further investigated in this paper, which is the rate between peaks and spans. Although the durations or spans and peaks' heights are highly diversified, it seems that the ratio between them is quite stable. If the rate's regularity is discovered, we can predict how long the collective action lasts and when it ends based on the peak's height. In this work, we combined mathematical simulations and empirical big data of 148 cases to explore the regularity of ratio's distribution. It is indicated by results of simulations that the rate has some regularities of distribution, which is not normal distribution. The big data has been collected from the 148 online collective actions and the whole processes of participation are recorded. The outcomes of empirical big data indicate that the rate seems to be closer to being log-normally distributed. This rule holds true for both the total cases and subgroups of 148 online collective actions. The Q-Q plot is applied to check the normal distribution of the rate's logarithm, and the rate's logarithm does follow the normal distribution.

  11. Proceedings of the Canadian Solar Industries Association Solar Forum 2005 : sunny days ahead : a forum on solar energy for government officials

    International Nuclear Information System (INIS)

    2006-01-01

    Solar energy is the fastest growing energy source in the world. Government involvement is critical in the deployment of solar energy. This forum focused on the application of solar energy in government facilities. The forum was divided into 3 sessions: (1) solar technologies and markets; (2) government initiatives that support solar energy; and (3) the use of solar energy on government facilities in Canada. The current state of solar technologies and products in Canada was reviewed. Solar thermal markets were discussed with reference to passive solar energy and photovoltaic applications. On-site solar generation for federal facilities was discussed, and various federal initiatives were reviewed. Issues concerning Ontario's standard offer contract program were discussed. Government users and buyers of solar products spoke of their experiences in using solar energy and the challenges that were faced. The role that solar energy can play in reducing government costs was discussed, as well as the impact of solar energy on the environment. Opportunities and barriers to the use of solar energy in Canada were explored. The conference featured 14 presentations, of which 2 have been catalogued separately for inclusion in this database. refs., tabs., figs

  12. One-day-ahead streamflow forecasting via super-ensembles of several neural network architectures based on the Multi-Level Diversity Model

    Science.gov (United States)

    Brochero, Darwin; Hajji, Islem; Pina, Jasson; Plana, Queralt; Sylvain, Jean-Daniel; Vergeynst, Jenna; Anctil, Francois

    2015-04-01

    Theories about generalization error with ensembles are mainly based on the diversity concept, which promotes resorting to many members of different properties to support mutually agreeable decisions. Kuncheva (2004) proposed the Multi Level Diversity Model (MLDM) to promote diversity in model ensembles, combining different data subsets, input subsets, models, parameters, and including a combiner level in order to optimize the final ensemble. This work tests the hypothesis about the minimisation of the generalization error with ensembles of Neural Network (NN) structures. We used the MLDM to evaluate two different scenarios: (i) ensembles from a same NN architecture, and (ii) a super-ensemble built by a combination of sub-ensembles of many NN architectures. The time series used correspond to the 12 basins of the MOdel Parameter Estimation eXperiment (MOPEX) project that were used by Duan et al. (2006) and Vos (2013) as benchmark. Six architectures are evaluated: FeedForward NN (FFNN) trained with the Levenberg Marquardt algorithm (Hagan et al., 1996), FFNN trained with SCE (Duan et al., 1993), Recurrent NN trained with a complex method (Weins et al., 2008), Dynamic NARX NN (Leontaritis and Billings, 1985), Echo State Network (ESN), and leak integrator neuron (L-ESN) (Lukosevicius and Jaeger, 2009). Each architecture performs separately an Input Variable Selection (IVS) according to a forward stepwise selection (Anctil et al., 2009) using mean square error as objective function. Post-processing by Predictor Stepwise Selection (PSS) of the super-ensemble has been done following the method proposed by Brochero et al. (2011). IVS results showed that the lagged stream flow, lagged precipitation, and Standardized Precipitation Index (SPI) (McKee et al., 1993) were the most relevant variables. They were respectively selected as one of the firsts three selected variables in 66, 45, and 28 of the 72 scenarios. A relationship between aridity index (Arora, 2002) and NN performance showed that wet basins are more easily modelled than dry basins. Nash-Sutcliffe (NS) Efficiency criterion was used to evaluate the performance of the models. Test results showed that in 9 of the 12 basins, the mean sub-ensembles performance was better than the one presented by Vos (2013). Furthermore, in 55 of 72 cases (6 NN structures x 12 basins) the mean sub-ensemble performance was better than the best individual performance, and in 10 basins the performance of the mean super-ensemble was better than the best individual super-ensemble member. As well, it was identified that members of ESN and L-ESN sub-ensembles have very similar and good performance values. Regarding the mean super-ensemble performance, we obtained an average gain in performance of 17%, and found that PSS preserves sub-ensemble members from different NN structures, indicating the pertinence of diversity in the super-ensemble. Moreover, it was demonstrated that around 100 predictors from the different structures are enough to optimize the super-ensemble. Although sub-ensembles of FFNN-SCE showed unstable performances, FFNN-SCE members were picked-up several times in the final predictor selection. References Anctil, F., M. Filion, and J. Tournebize (2009). "A neural network experiment on the simulation of daily nitrate-nitrogen and suspended sediment fluxes from a small agricultural catchment". In: Ecol. Model. 220.6, pp. 879-887. Arora, V. K. (2002). "The use of the aridity index to assess climate change effect on annual runoff". In: J. Hydrol. 265.164, pp. 164 -177 . Brochero, D., F. Anctil, and C. Gagn'e (2011). "Simplifying a hydrological ensemble prediction system with a backward greedy selection of members Part 1: Optimization criteria". In: Hydrol. Earth Syst. Sci. 15.11, pp. 3307-3325. Duan, Q., J. Schaake, V. Andr'eassian, S. Franks, G. Goteti, H. Gupta, Y. Gusev, F. Habets, A. Hall, L. Hay, T. Hogue, M. Huang, G. Leavesley, X. Liang, O. Nasonova, J. Noilhan, L. Oudin, S. Sorooshian, T. Wagener, and E. Wood (2006). "Model Parameter Estimation Experiment (MOPEX): An overview of science strategy and major results from the second and third workshops". In: J. Hydrol. 320.12, pp. 3-17. Duan, Q., V. Gupta, and S. Sorooshian (1993). "Shuffled complex evolution approach for effective and efficient global minimization". In: J. Optimiz. Theory App. 76.3, pp. 501-521. Hagan, M. T., H. B. Demuth, and M. Beale (1996). Neural network design . 1st ed. PWS Publishing Co., p. 730. Kuncheva, L. I. (2004). Combining Pattern Classifiers: Methods and Algorithms . Wiley-Interscience, p. 350. Leontaritis, I. and S. Billings (1985). "Input-output parametric models for non-linear systems Part I: deterministic non-linear systems". In: International Journal of Control 41.2, pp. 303-328. Lukosevicius, M. and H. Jaeger (2009). "Reservoir computing approaches to recurrent neural network training". In: Computer Science Review 3.3, pp. 127-149. McKee, T., N. Doesken, and J. Kleist (1993). The Relationship of Drought Frequency and Duration to Time Scales . In: Eighth Conference on Applied Climatology. Vos, N. J. de (2013). "Echo state networks as an alternative to traditional artificial neural networks in rainfall-runoff modelling". In: Hydrol. Earth Syst. Sci. 17.1, pp. 253-267. Weins, T., R. Burton, G. Schoenau, and D. Bitner (2008). Recursive Generalized Neural Networks (RGNN) for the Modeling of a Load Sensing Pump. In: ASME Joint Conference on Fluid Power, Transmission and Control.

  13. Automatic fitting of Gaussian peaks using abductive machine learning

    Science.gov (United States)

    Abdel-Aal, R. E.

    1998-02-01

    Analytical techniques have been used for many years for fitting Gaussian peaks in nuclear spectroscopy. However, the complexity of the approach warrants looking for machine-learning alternatives where intensive computations are required only once (during training), while actual analysis on individual spectra is greatly simplified and quickened. This should allow the use of simple portable systems for fast and automated analysis of large numbers of spectra, particularly in situations where accuracy may be traded for speed and simplicity. This paper proposes the use of abductive networks machine learning for this purpose. The Abductory Induction Mechanism (AIM) tool was used to build models for analyzing both single and double Gaussian peaks in the presence of noise depicting statistical uncertainties in collected spectra. AIM networks were synthesized by training on 1000 representative simulated spectra and evaluated on 500 new spectra. A classifier network determines the multiplicity of single/double peaks with an accuracy of 5.8%. With statistical uncertainties corresponding to a peak count of 100, average percentage absolute errors for the height, position, and width of single peaks are 4.9, 2.9, and 4.2%, respectively. For double peaks, these average errors are within 7.0, 3.1, and 5.9%, respectively. Models have been developed which account for the effect of a linear background on a single peak. Performance is compared with a neural network application and with an analytical curve-fitting routine, and the new technique is applied to actual data of an alpha spectrum.

  14. Peak Operation of Cascaded Hydropower Plants Serving Multiple Provinces

    Directory of Open Access Journals (Sweden)

    Jianjian Shen

    2015-10-01

    Full Text Available The bulk hydropower transmission via trans-provincial and trans-regional power networks in China provides great operational flexibility to dispatch power resources between multiple power grids. This is very beneficial to alleviate the tremendous peak load pressure of most provincial power grids. This study places the focus on peak operations of cascaded hydropower plants serving multiple provinces under a regional connected AC/DC network. The objective is to respond to peak loads of multiple provincial power grids simultaneously. A two-stage search method is developed for this problem. In the first stage, a load reconstruction strategy is proposed to combine multiple load curves of power grids into a total load curve. The purpose is to deal with different load features in load magnitudes, peaks and valleys. A mutative-scale optimization method is then used to determine the generation schedules of hydropower plants. In the second stage, an exterior point search method is established to allocate the generation among multiple receiving power grids. This method produces an initial solution using the load shedding algorithm, and further improves it by iteratively coordinating the generation among different power grids. The proposed method was implemented to the operations of cascaded hydropower plants on Xin-Fu River and another on Hongshui River. The optimization results in two cases satisfied the peak demands of receiving provincial power grids. Moreover, the maximum load difference between peak and valley decreased 12.67% and 11.32% in Shanghai Power Grid (SHPG and Zhejiang Power Grid (ZJPG, exceeding by 4.85% and 6.72% those of the current operational method, respectively. The advantage of the proposed method in alleviating peak-shaving pressure is demonstrated.

  15. The duration of pubertal growth peak among three skeletal classes

    Directory of Open Access Journals (Sweden)

    Waqar Jeelani

    Full Text Available ABSTRACT Introduction: Pubertal growth peak is closely associated with a rapid increase in mandibular length and offers a wide range of therapeutic modifiability. Objective: The aim of the present study was to determine and compare the mean ages of onset and duration of pubertal growth peak among three skeletal classes. Methods: A retrospective cross-sectional study was conducted using lateral cephalograms of 230 subjects with growth potential (110 males, 120 females. Subjects were categorized into three classes (Class I = 81, Class II = 82, Class III = 67, according to the sagittal relationship established between the maxilla and the mandible. The cervical vertebral maturation stage was recorded by means of Baccetti's method. The mean ages at CS3 and CS4 and the CS3-CS4 age interval were compared between boys and girls and among three skeletal classes. Results: Pubertal growth peak occurred on average four months earlier in girls than boys (p = 0.050. The average duration of pubertal growth peak was 11 months in Class I, seven months in Class II and 17 months in Class III subjects. Interclass differences were highly significant (Cohen's d > 0.08. However, no significant difference was found in the timing of pubertal growth peak onset among three skeletal classes (p = 0.126 in boys, p = 0.262 in girls. Conclusions: Girls enter pubertal growth peak on average four months earlier than boys. Moreover, the duration of pubertal growth peak is on average four months shorter in Class II and six months longer in Class III subjects as compared to Class I subjects.

  16. Superoxide dismutase levels and peak expiratory flow in asthmatic children

    Directory of Open Access Journals (Sweden)

    Arie Kurniasih

    2016-11-01

    Full Text Available Background Asthma is a chronic inflammatory process which involve variety of cells such as inflammatory mediators, reactive oxygen species (ROS, and cytokines. The inflammatory process would be exacerbated in the presence of oxidative stress. Superoxide dismutase (SOD is the first important enzyme to protect the respiratory tract against oxidative stress. The decreased of SOD has a correlation with increased of airway obstruction and bronchospasm. Objective To assess for a correlation between superoxide dismutase (SOD levels and peak expiratory flow, as well as to determine the impact of SOD levels for predicting asthma attacks. Methods We conducted a prospective cohort study at Dr. Sardjito Hospital, Yogyakarta, between February and April 2011 involving asthmatic children aged 5-18 years. Subjects’ serum SOD levels and peak expiratory flow were measured at the same time point. We then performed a prospective study following up on the same subjects to find out if they had a recurrent asthma attack within one month of the tests. We also reassessed their peak expiratory flow one month after blood specimens were obtained. Results Thirty-nine patients were enrolled in this study. There was no significant correlation between SOD level and peak expiratory flow [r=0.289; 95%CI -0.025 to 0.47; P=0.074]. However, older age was significantly associated with higher peak expiratory flow (=0.5; 95%CI 3.10 to 11.57; P=0.01. Lower levels of SOD increased the risk of asthma attacks in a month following the initial measurements (RR=5.5; 95%CI 1.6 to 18.9; P=0.009. Conclusion Superoxide dismutase (SOD level is not significantly associated with peak expiratory flow. However, we find a relationship between older age and higher peak expiratory flow and a relationship between lower SOD levels and risk of asthma attacks within one month following the tests.

  17. Managing peak loads in energy grids: Comparative economic analysis

    International Nuclear Information System (INIS)

    Zhuk, A.; Zeigarnik, Yu.; Buzoverov, E.; Sheindlin, A.

    2016-01-01

    One of the key issues in modern energy technology is managing the imbalance between the generated power and the load, particularly during times of peak demand. The increasing use of renewable energy sources makes this problem even more acute. Various existing technologies, including stationary battery energy storage systems (BESS), can be employed to provide additional power during peak demand times. In the future, integration of on-board batteries of the growing fleet of electric vehicles (EV) and plug-in hybrid electric vehicles (PHEV) into the grid can provide power during peak demand hours (vehicle-to-grid, or V2G technology). This work provides cost estimates of managing peak energy demands using traditional technologies, such as maneuverable power plants, conventional hydroelectric, pumped storage plants and peaker generators, as well as BESS and V2G technologies. The derived estimates provide both per kWh and kW year of energy supplied to the grid. The analysis demonstrates that the use of battery storage is economically justified for short peak demand periods of <1 h. For longer durations, the most suitable technology remains the use of maneuverable steam gas power plants, gas turbine,reciprocating gas engine peaker generators, conventional hydroelectric, pumped storage plants. - Highlights: • Cost of managing peak energy demand employing different technologies are estimated. • Traditional technologies, stationary battery storage and V2G are compared. • Battery storage is economically justified for peak demand periods of <1 h. • V2G appears to have better efficiency than stationary battery storage in low voltage power grids.

  18. Automatic fitting of Gaussian peaks using abductive machine learning

    International Nuclear Information System (INIS)

    Abdel-Aal, R.E.

    1998-01-01

    Analytical techniques have been used for many years for fitting Gaussian peaks in nuclear spectroscopy. However, the complexity of the approach warrants looking for machine-learning alternatives where intensive computations are required only once (during training), while actual analysis on individual spectra is greatly simplified and quickened. This should allow the use of simple portable systems for fast and automated analysis of large numbers of spectra, particularly in situations where accuracy may be traded for speed and simplicity. This paper proposes the use of abductive networks machine learning for this purpose. The Abductory Induction Mechanism (AIM) tool was used to build models for analyzing both single and double Gaussian peaks in the presence of noise depicting statistical uncertainties in collected spectra. AIM networks were synthesized by training on 1,000 representative simulated spectra and evaluated on 500 new spectra. A classifier network determines the multiplicity of single/double peaks with an accuracy of 98%. With statistical uncertainties corresponding to a peak count of 100, average percentage absolute errors for the height, position, and width of single peaks are 4.9, 2.9, and 4.2%, respectively. For double peaks, these average errors are within 7.0, 3.1, and 5.9%, respectively. Models have been developed which account for the effect of a linear background on a single peak. Performance is compared with a neural network application and with an analytical curve-fitting routine, and the new technique is applied to actual data of an alpha spectrum

  19. flowPeaks: a fast unsupervised clustering for flow cytometry data via K-means and density peak finding.

    Science.gov (United States)

    Ge, Yongchao; Sealfon, Stuart C

    2012-08-01

    For flow cytometry data, there are two common approaches to the unsupervised clustering problem: one is based on the finite mixture model and the other on spatial exploration of the histograms. The former is computationally slow and has difficulty to identify clusters of irregular shapes. The latter approach cannot be applied directly to high-dimensional data as the computational time and memory become unmanageable and the estimated histogram is unreliable. An algorithm without these two problems would be very useful. In this article, we combine ideas from the finite mixture model and histogram spatial exploration. This new algorithm, which we call flowPeaks, can be applied directly to high-dimensional data and identify irregular shape clusters. The algorithm first uses K-means algorithm with a large K to partition the cell population into many small clusters. These partitioned data allow the generation of a smoothed density function using the finite mixture model. All local peaks are exhaustively searched by exploring the density function and the cells are clustered by the associated local peak. The algorithm flowPeaks is automatic, fast and reliable and robust to cluster shape and outliers. This algorithm has been applied to flow cytometry data and it has been compared with state of the art algorithms, including Misty Mountain, FLOCK, flowMeans, flowMerge and FLAME. The R package flowPeaks is available at https://github.com/yongchao/flowPeaks. yongchao.ge@mssm.edu Supplementary data are available at Bioinformatics online.

  20. Analysis of Peak-to-Peak Current Ripple Amplitude in Seven-Phase PWM Voltage Source Inverters

    Directory of Open Access Journals (Sweden)

    Gabriele Grandi

    2013-08-01

    Full Text Available Multiphase systems are nowadays considered for various industrial applications. Numerous pulse width modulation (PWM schemes for multiphase voltage source inverters with sinusoidal outputs have been developed, but no detailed analysis of the impact of these modulation schemes on the output peak-to-peak current ripple amplitude has been reported. Determination of current ripple in multiphase PWM voltage source inverters is important for both design and control purposes. This paper gives the complete analysis of the peak-to-peak current ripple distribution over a fundamental period for multiphase inverters, with particular reference to seven-phase VSIs. In particular, peak-to-peak current ripple amplitude is analytically determined as a function of the modulation index, and a simplified expression to get its maximum value is carried out. Although reference is made to the centered symmetrical PWM, being the most simple and effective solution to maximize the DC bus utilization, leading to a nearly-optimal modulation to minimize the RMS of the current ripple, the analysis can be readily extended to either discontinuous or asymmetrical modulations, both carrier-based and space vector PWM. A similar approach can be usefully applied to any phase number. The analytical developments for all different sub-cases are verified by numerical simulations.

  1. An online peak extraction algorithm for ion mobility spectrometry data.

    Science.gov (United States)

    Kopczynski, Dominik; Rahmann, Sven

    2015-01-01

    Ion mobility (IM) spectrometry (IMS), coupled with multi-capillary columns (MCCs), has been gaining importance for biotechnological and medical applications because of its ability to detect and quantify volatile organic compounds (VOC) at low concentrations in the air or in exhaled breath at ambient pressure and temperature. Ongoing miniaturization of spectrometers creates the need for reliable data analysis on-the-fly in small embedded low-power devices. We present the first fully automated online peak extraction method for MCC/IMS measurements consisting of several thousand individual spectra. Each individual spectrum is processed as it arrives, removing the need to store the measurement before starting the analysis, as is currently the state of the art. Thus the analysis device can be an inexpensive low-power system such as the Raspberry Pi. The key idea is to extract one-dimensional peak models (with four parameters) from each spectrum and then merge these into peak chains and finally two-dimensional peak models. We describe the different algorithmic steps in detail and evaluate the online method against state-of-the-art peak extraction methods.

  2. Rotational and peak torque stiffness of rugby shoes.

    Science.gov (United States)

    Ballal, Moez S; Usuelli, Federico Giuseppe; Montrasio, Umberto Alfieri; Molloy, Andy; La Barbera, Luigi; Villa, Tomaso; Banfi, Giuseppe

    2014-09-01

    Sports people always strive to avoid injury. Sports shoe designs in many sports have been shown to affect traction and injury rates. The aim of this study is to demonstrate the differing stiffness and torque in rugby boots that are designed for the same effect. Five different types of rugby shoes commonly worn by scrum forwards were laboratory tested for rotational stiffness and peak torque on a natural playing surface generating force patterns that would be consistent with a rugby scrum. The overall internal rotation peak torque was 57.75±6.26 Nm while that of external rotation was 56.55±4.36 Nm. The Peak internal and external rotational stiffness were 0.696±0.1 and 0.708±0.06 Nm/deg respectively. Our results, when compared to rotational stiffness and peak torques of football shoes published in the literature, show that shoes worn by rugby players exert higher rotational and peak torque stiffness compared to football shoes when tested on the same natural surfaces. There was significant difference between the tested rugby shoes brands. In our opinion, to maximize potential performance and lower the potential of non-contact injury, care should be taken in choosing boots with stiffness appropriate to the players main playing role. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Energy Saving by Chopping off Peak Demand Using Day Light

    Directory of Open Access Journals (Sweden)

    Ashok Kumar Maitra

    2011-08-01

    Full Text Available An artificial intelligent technique has been implemented in this research using real time datas to calculate how much energy can be chopped from peak load demand. The results are based on real time data that are taken from power delivering centers. These datas do reflect the present condition of power and a solution to those critical conditions during the peak period. These are done in such a way such that helps in judicious scheduling of load. The time based load scheduling has been done so as to understand the basic criteria for solving power crisis during morning peak and early evening peak. The sunray availability and percentage of load that will use day light saving (DLS technique has been taken into account in this work. The results shows that about 0.5% to 1% of load can be shedded off from the peak load period which otherwise is reduction of power. Thus it otherwise also means that an equivalent amount of energy is saved which amounts to a large saving of national money. This result is obtained on monthly and even daily basis. Thus this paper justifies DLS gives a new renewable technique to save energy.

  4. Lightning peak current estimation using a system identification approach

    Science.gov (United States)

    Wern, T. L. T.; Mukerjee, R. N.

    2006-01-01

    A system identification-based lightning peak current estimation algorithm using upper-air radiosonde observations is developed. The preceding convective and precipitative process leading to thunder cloud formation followed by the cloud electrification and the leader processes together with return stroke and the discharge process, is identified by considering it as a deterministic dynamic system, whose undisturbed and unmeasurable output signal the lightning peak current, is contaminated with a stochastic disturbance. The model parameters determined thus, are used to predict the likely temporal lightning return stroke peak current magnitudes. Two alternative parametric estimation models namely Autoregressive with Exogeneous Input (ARX) and Autoregressive with Moving-Average Exogeneous Input (ARMAX) are used to estimate model parameters of the pilot study area and predict the likely lightning return stroke peak current in each case. The relative performances of the models are compared to determine the best model for application in 12-hour and 24-hour ahead predictions. For a short-term (12 hour) prediction, ARMAX2921 giving a best fit of 78.8429% turns out to be the most suitable model. For a longer (24 hour) prediction, the ARX291, giving a best fit of 75.0181% emerges to be the suitable model. These preliminary results indicate that lightning peak current may be estimated to a good performance using upper-air radiosonde observations.

  5. Group Elevator Peak Scheduling Based on Robust Optimization Model

    Directory of Open Access Journals (Sweden)

    ZHANG, J.

    2013-08-01

    Full Text Available Scheduling of Elevator Group Control System (EGCS is a typical combinatorial optimization problem. Uncertain group scheduling under peak traffic flows has become a research focus and difficulty recently. RO (Robust Optimization method is a novel and effective way to deal with uncertain scheduling problem. In this paper, a peak scheduling method based on RO model for multi-elevator system is proposed. The method is immune to the uncertainty of peak traffic flows, optimal scheduling is realized without getting exact numbers of each calling floor's waiting passengers. Specifically, energy-saving oriented multi-objective scheduling price is proposed, RO uncertain peak scheduling model is built to minimize the price. Because RO uncertain model could not be solved directly, RO uncertain model is transformed to RO certain model by elevator scheduling robust counterparts. Because solution space of elevator scheduling is enormous, to solve RO certain model in short time, ant colony solving algorithm for elevator scheduling is proposed. Based on the algorithm, optimal scheduling solutions are found quickly, and group elevators are scheduled according to the solutions. Simulation results show the method could improve scheduling performances effectively in peak pattern. Group elevators' efficient operation is realized by the RO scheduling method.

  6. Influenza?like illness?related emergency department visits: Christmas and New Year holiday peaks and relationships with laboratory?confirmed respiratory virus detections, Edmonton, Alberta, 2004?2014

    OpenAIRE

    Martin, Leah J.; Im, Cindy; Dong, Huiru; Lee, Bonita E.; Talbot, James; Meurer, David P.; Mukhi, Shamir N.; Drews, Steven J.; Yasui, Yutaka

    2016-01-01

    Background Emergency department (ED) visit volumes can be especially high during the Christmas?New Year holidays, a period occurring during the influenza season in Canada. Methods Using daily data, we examined the relationship between ED visits for the chief complaint ?cough? (for Edmonton, Alberta residents) and laboratory detections for influenza A and respiratory syncytial virus (RSV) (for Edmonton and surrounding areas), lagged 0?5?days ahead, for non?pandemic years (2004?2008 and 2010?20...

  7. A Multimethod analysis of the Phenomenon of Peak-Oil

    OpenAIRE

    Kerschner, Christian

    2012-01-01

    El concepto de Peak-Oil (el cénit del petróleo) es complejo y a menudo malentendido. Después de aclarar que el Peak-Oil es tanto un problema de estocs como de flujos, se ofrecen los conceptos de calidad y cantidad del recurso para facilitar la comprensión de la multitud de temas que influyen en el momento del cénit del petróleo y sus posibles impactos. Una revisión de la literatura y las últimas evidencias sugieren que hay un alto riesgo de que el Peak-Oil ocurra antes de 2020, dejando poco t...

  8. Maximizing utilization of sport halls during peak hours

    DEFF Research Database (Denmark)

    Iversen, Evald Bundgård; Forsberg, Peter

    the number of participants 7.5 persons higher pr. activity compared to club activities. This implies that clubs during peak hours could include more participants. Another possibility to increase utilization is if the management of sport facilities forced sport clubs and other organisers to adapt......BACKGROUNDDuring peak hours (4.30pm-8pm) demand for timeslots in sport halls in Denmark are high and there are few timeslots available. Further, focus on how public resources are spent most efficient is increasing (Iversen, 2013). This makes it interesting to analyse how utilization could...... be increased during peak hours. DATA AND METHODOLOGYData is collected by observation of activities during two weeks on for example whether halls are used or not; the amount of playing field used; and number of participants (Iversen, 2012). Data on 1.331 activities in 36 sport halls across 4 municipalities have...

  9. Shocked materials from the Dutch Peak diamictite, Utah

    Science.gov (United States)

    Hoerz, F.; Bunch, T. E.; Oberbeck, V. R.

    1994-01-01

    Evidence of shock metamorphism in the Dutch Peak diamictite in the Sheeprock Mountains, Utah, is reported. The Dutch Peak diamictite is of Proterozoic age and is a minor part of the Dutch Peak formation. A shocked sample, specimen A250, was collected during a brief visit of the Harker Canyon area of the Sheeprock Mountains. This sample consists of equant, anhedral grains of quartz, K-feldspar, and plagioclase. The crystallographic orientation of 244 lamellae systems in 106 grains was measured. It is presently difficult to evaluate the significance of this single specimen. Without additional and substantial field work, and petrographic characterization of this formation, a number of scenarios for the presence of a shocked clast and the emplacement of the entire formation remain viable.

  10. The Peak Pairs algorithm for strain mapping from HRTEM images

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, Pedro L. [Departamento de Lenguajes y Sistemas Informaticos, CASEM, Universidad de Cadiz, Pol. Rio San Pedro s/n. 11510, Puerto Real, Cadiz (Spain)], E-mail: pedro.galindo@uca.es; Kret, Slawomir [Institute of Physics, PAS, AL. Lotnikow 32/46, 02-668 Warsaw (Poland); Sanchez, Ana M. [Departamento de Ciencia de los Materiales e Ing. Metalurgica y Q. Inorganica, Facultad de Ciencias, Universidad de Cadiz, Pol. Rio San Pedro s/n. 11510, Puerto Real, Cadiz (Spain); Laval, Jean-Yves [Laboratoire de Physique du Solide, UPR5 CNRS-ESPCI, Paris (France); Yanez, Andres; Pizarro, Joaquin; Guerrero, Elisa [Departamento de Lenguajes y Sistemas Informaticos, CASEM, Universidad de Cadiz, Pol. Rio San Pedro s/n. 11510, Puerto Real, Cadiz (Spain); Ben, Teresa; Molina, Sergio I. [Departamento de Ciencia de los Materiales e Ing. Metalurgica y Q. Inorganica, Facultad de Ciencias, Universidad de Cadiz, Pol. Rio San Pedro s/n. 11510, Puerto Real, Cadiz (Spain)

    2007-11-15

    Strain mapping is defined as a numerical image-processing technique that measures the local shifts of image details around a crystal defect with respect to the ideal, defect-free, positions in the bulk. Algorithms to map elastic strains from high-resolution transmission electron microscopy (HRTEM) images may be classified into two categories: those based on the detection of peaks of intensity in real space and the Geometric Phase approach, calculated in Fourier space. In this paper, we discuss both categories and propose an alternative real space algorithm (Peak Pairs) based on the detection of pairs of intensity maxima in an affine transformed space dependent on the reference area. In spite of the fact that it is a real space approach, the Peak Pairs algorithm exhibits good behaviour at heavily distorted defect cores, e.g. interfaces and dislocations. Quantitative results are reported from experiments to determine local strain in different types of semiconductor heterostructures.

  11. An internal friction peak caused by hydrogen in maraging steel

    International Nuclear Information System (INIS)

    Usui, Makoto; Asano, Shigeru

    1996-01-01

    Internal friction in hydrogen-charged iron and steel has so far been studied by a large number of investigators. For pure iron, a well-defined peak of internal friction has been observed under the cold-worked and hydrogen-charged conditions. This is called the hydrogen cold-work peak, or the Snoek-Koester relaxation, which originates from the hydrogen-dislocation interaction. In the present study, a high-strength maraging steel (Fe-18Ni-9Co-5Mo) was chosen as another high-alloy steel which is known to be very susceptible to hydrogen embrittlement. The purpose of this paper is to show a new internal friction peak caused by hydrogen in the maraging steel and to compare it with those found in stainless steels which have so far been studied as typical engineering high-alloy materials

  12. Gnevyshev peaks in solar radio emissions at different frequencies

    Directory of Open Access Journals (Sweden)

    R. P. Kane

    2009-04-01

    Full Text Available Sunspots have a major 11-year cycle, but the years near the sunspot maximum show two or more peaks called GP (Gnevyshev Peaks. In this communication, it was examined whether these peaks in sunspots are reflected in other parameters such as Lyman-α (the chromospheric emission 121.6 nm, radio emissions 242–15 400 MHz emanating from altitude levels 2000–12 000 km, the low latitude (+45° to −45° solar open magnetic flux and the coronal green line emission (Fe XIV, 530.3 nm. In the different solar cycles 20–23, the similarity extended at least upto the level of 609 MHz, but in cycle 22, the highest level was of 242 MHz. The extension to the higher level in cycle 22 does not seem to be related to the cycle strength Rz(max, or to the cycle length.

  13. COPAR: A ChIP-Seq Optimal Peak Analyzer.

    Science.gov (United States)

    Tang, Binhua; Wang, Xihan; Jin, Victor X

    2017-01-01

    Sequencing data quality and peak alignment efficiency of ChIP-sequencing profiles are directly related to the reliability and reproducibility of NGS experiments. Till now, there is no tool specifically designed for optimal peak alignment estimation and quality-related genomic feature extraction for ChIP-sequencing profiles. We developed open-sourced COPAR, a user-friendly package, to statistically investigate, quantify, and visualize the optimal peak alignment and inherent genomic features using ChIP-seq data from NGS experiments. It provides a versatile perspective for biologists to perform quality-check for high-throughput experiments and optimize their experiment design. The package COPAR can process mapped ChIP-seq read file in BED format and output statistically sound results for multiple high-throughput experiments. Together with three public ChIP-seq data sets verified with the developed package, we have deposited COPAR on GitHub under a GNU GPL license.

  14. National energy peak leveling program (NEPLP). Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-12-01

    This multisectioned three-Volume report is responsive to the requirements of Contract E (04-3)-1152 to provide a detailed methodology, to include management, technology, and socio-economic aspects, of a voluntary community program of computer-assisted peak load leveling and energy conservation in commercial community facilities. The demonstration project established proof-of-concept in reducing the kW-demand peak by the unofficial goal of 10%, with concurrent kWh savings. This section of volume III contains appendixes of information on load shedding determination, analysis, socio-economic study, contractual cross references, and definitions.

  15. High-Average, High-Peak Current Injector Design

    CERN Document Server

    Biedron, S G; Virgo, M

    2005-01-01

    There is increasing interest in high-average-power (>100 kW), um-range FELs. These machines require high peak current (~1 kA), modest transverse emittance, and beam energies of ~100 MeV. High average currents (~1 A) place additional constraints on the design of the injector. We present a design for an injector intended to produce the required peak currents at the injector, eliminating the need for magnetic compression within the linac. This reduces the potential for beam quality degradation due to CSR and space charge effects within magnetic chicanes.

  16. Simple Formula Relating Frequencies of Twin-peak Quasiperiodic Oscillations

    Science.gov (United States)

    Torok, Gabriel

    2017-08-01

    Twin-peak quasiperiodic oscillations are observed in several low-mass X-ray binary systems containing neutron stars. Timing analysis of X-ray fluxes of more than dozen of such systems reveals remarkable correlations between frequencies of two characteristic peaks present in the power density spectra. Several attempts to model these correlations with simple geodesic orbital models or phenomenological relations have failed in the past. We find and explore a surprisingly simple analytic formula that well reproduces individual correlations for a large group of sources. We also discuss possible theoretical interpretation of this formula.

  17. Universal parametric correlations of conductance peaks in quantum dots

    International Nuclear Information System (INIS)

    Alhassid, Y.; Attias, H.

    1996-01-01

    We compute the parametric correlation function of the conductance peaks in chaotic and weakly disordered quantum dots in the Coulomb blockade regime and demonstrate its universality upon an appropriate scaling of the parameter. For a symmetric dot we show that this correlation function is affected by breaking time-reversal symmetry but is independent of the details of the channels in the external leads. We derive a new scaling which depends on the eigenfunctions alone and can be extracted directly from the conductance peak heights. Our results are in excellent agreement with model simulations of a disordered quantum dot. copyright 1996 The American Physical Society

  18. Identification and separation of DNA mixtures using peak area information

    DEFF Research Database (Denmark)

    Cowell, R.G.; Lauritzen, Steffen Lilholt; Mortera, J.

    We show how probabilistic expert systems can be used to analyse forensic identification problems involving DNA mixture traces using quantitative peak area information. Peak area is modelled with conditional Gaussian distributions. The expert system can be used for scertaining whether individuals......, whose profiles have been measured, have contributed to the mixture, but also to predict DNA profiles of unknown contributors by separating the mixture into its individual components. The potential of our methodology is illustrated on case data examples and compared with alternative approaces...

  19. Quasispecies evolution on a fitness landscape with a fluctuating peak

    OpenAIRE

    Nilsson, Martin; Snoad, Nigel

    2000-01-01

    A quasispecies evolving on a fitness landscape with a single peak of fluctuating height is studied. In the approximation that back mutations can be ignored, the rate equations can be solved analytically. It is shown that the error threshold on this class of dynamic landscapes is defined by the time average of the selection pressure. In the case of a periodically fluctuating fitness peak we also study the phase-shift and response amplitude of the previously documented low-pass filter effect. T...

  20. Peak heart rate decreases with increasing severity of acute hypoxia

    DEFF Research Database (Denmark)

    Lundby, C; Araoz, M; Van Hall, Gerrit

    2001-01-01

    The purpose of the present study was to investigate the degree to which peak heart rate is reduced during exhaustive exercise in acute hypoxia. Five sea-level lowlanders performed maximal exercise at normobaric normoxia and at three different levels of hypobaric hypoxia (barometric pressures of 518......, 459, and 404 mmHg) in a hypobaric chamber and while breathing 9% O(2) in N(2). These conditions were equivalent to altitudes of 3300, 4300, 5300, and 6300 m above sea level, respectively. At 4300 m, maximal exercise was also repeated after 4 and 8 h. Peak heart rate (HR) decreased from 191 (182...

  1. National energy peak leveling program (NEPLP). Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-12-01

    This three-volume report is responsive to the requirements of contract E (04-3)-1152 to provide a detailed methodology, to include management, technology, and socio-economic aspects, of a voluntary community program for computer-assisted peak load leveling and energy conservation in commercial community facilities. The demonstration project established proof-of-concept in reducing the kW-demand peak by the unofficial goal of 10%, with concurrent kWh savings. The report consists of the following three volumes: Volume I: management overview; Volume II: methodology and technology; and Volume III; appendices.

  2. Peak Oil and the Everyday Complexity of Human Progress Narratives

    Directory of Open Access Journals (Sweden)

    John C. Pruit

    2012-11-01

    Full Text Available The “big” story of human progress has polarizing tendencies featuring the binary options of progress or decline. I consider human progress narratives in the context of everyday life. Analysis of the “little” stories from two narrative environments focusing on peak oil offers a more complex picture of the meaning and contours of the narrative. I consider the impact of differential blog site commitments to peak oil perspectives and identify five narrative types culled from two narrative dimensions. I argue that the lived experience complicates human progress narratives, which is no longer an either/or proposition.

  3. Genetic and Dyanmic Analysis of Murine Peak Bone Density

    Science.gov (United States)

    1997-10-01

    years of age (1-3). As bone density decreases with age, the risk of osteoporotic fractures increases, especially when the density falls below the...fracture threshold. This relationship suggests that the risk of osteoporotic fracture can be defined in terms of two characteristics - the peak bone...two inbred strains of mice, C57BL/6J (B6) and C3H/HeJ (C3H), with highly significant differences in peak BMD in vertebrae (12%), tibia (20%), and

  4. National energy peak leveling program (NEPLP). Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-12-01

    This three-volume report is responsive to the requirements of Contract E (04-3)-1152 to provide a detailed methodology, to include management, technology, and socio-economic aspects, of a voluntary community program of computer-assisted peak load leveling and energy conservation in commercial community facilities. The demonstration project established proof-of-concept in reducing the kW-demand peak by the unofficial goal of 10%, with concurrent kWh savings. This section of the three volume report is a final report appendix with information on the financial management of load leveling, audit procedures, and building operating profiles.

  5. Peak metamorphic temperatures from cation diffusion zoning in garnet

    DEFF Research Database (Denmark)

    Smit, Matthijs Arjen; Scherer, Erik; Mezger, Klaus

    2013-01-01

    is robust and provides a reliable means of estimating peak temperatures for different types of high-grade metamorphic rock. The tool could be of particular advantage in rocks where critical assemblages for conventional thermometry do not occur or have been replaced during retrogression.......) to develop a tool that uses the diffusion zoning of these cations in garnet to constrain peak temperature conditions for garnet-bearing rocks. The thermometric approach was externally tested by applying it to garnet crystals from various metamorphic terranes worldwide and comparing the results to published...

  6. flowPeaks: a fast unsupervised clustering for flow cytometry data via K-means and density peak finding

    Science.gov (United States)

    Ge, Yongchao; Sealfon, Stuart C.

    2012-01-01

    Motivation: For flow cytometry data, there are two common approaches to the unsupervised clustering problem: one is based on the finite mixture model and the other on spatial exploration of the histograms. The former is computationally slow and has difficulty to identify clusters of irregular shapes. The latter approach cannot be applied directly to high-dimensional data as the computational time and memory become unmanageable and the estimated histogram is unreliable. An algorithm without these two problems would be very useful. Results: In this article, we combine ideas from the finite mixture model and histogram spatial exploration. This new algorithm, which we call flowPeaks, can be applied directly to high-dimensional data and identify irregular shape clusters. The algorithm first uses K-means algorithm with a large K to partition the cell population into many small clusters. These partitioned data allow the generation of a smoothed density function using the finite mixture model. All local peaks are exhaustively searched by exploring the density function and the cells are clustered by the associated local peak. The algorithm flowPeaks is automatic, fast and reliable and robust to cluster shape and outliers. This algorithm has been applied to flow cytometry data and it has been compared with state of the art algorithms, including Misty Mountain, FLOCK, flowMeans, flowMerge and FLAME. Availability: The R package flowPeaks is available at https://github.com/yongchao/flowPeaks. Contact: yongchao.ge@mssm.edu Supplementary information: Supplementary data are available at Bioinformatics online PMID:22595209

  7. Variant formula for predicting peak expiratory flow rate in pregnant ...

    African Journals Online (AJOL)

    Observed Peak expiratory flow rate (PEFR), Predicted and Variant PEFR values in 123 females at their reproductive ages, living in Kura local government area of Kano State, Nigeria and its environs were obtained. The prediction and variant formulae used were; PEFR= 0.36AGE – 0.47WT + 391.67 and K = mean CC x ...

  8. Characteristics of peaks of inhalation exposure to organic solvents

    NARCIS (Netherlands)

    Preller, L.; Burstyn, I.; Pater, N. de; Kromhout, H.

    2004-01-01

    Objectives: To determine which exposure metrics are sufficient to characterize 'peak' inhalation exposure to organic solvents (OS) during spraying operations. Methods: Personal exposure measurements (n = 27; duration 5-159 min) were collected during application of paints, primers, resins and glues

  9. A new sample of faint Gigahertz Peaked Spectrum radio sources

    NARCIS (Netherlands)

    Snellen, IAG; Schilizzi, RT; de Bruyn, AG; Miley, GK; Rengelink, RB; Rottgering, HJ

    The Westerbork Northern Sky Survey (WENSS) has been used to select a sample of Gigahertz Peaked Spectrum (GPS) radio sources at flux densities one to two orders of magnitude lower than bright GPS sources investigated in earlier studies. Sources with inverted spectra at frequencies above 325 MHz have

  10. PEAK EXPIRATORY FLOW AS A SURROGATE FOR HEALTH ...

    African Journals Online (AJOL)

    2014-06-01

    Jun 1, 2014 ... Proportions reported are based on the entire sample of patients. Sixty five percent of the patients had peak flow read- ings below the acceptable lower limit of normal (LLN) for their age and height (Table 2). The mean (SD) of predicted post bronchodilator (post BD) PEF, FEV1,. FVC and FEV1/FVC were ...

  11. East ad Central African Journal of Pharmaceutical Sciences Peak ...

    African Journals Online (AJOL)

    chromatographic peak purity. This is attributed to the capacity of the linear photodiode arrays to collect spectro-chromatographic data in the absorbance (A), wavelength (A) and time (t) matrix. Such instruments have in-built routine software that is easy to apply during post collection data manipulations. Examples of such.

  12. Scheduling Non-Preemptible Jobs to Minimize Peak Demand

    Directory of Open Access Journals (Sweden)

    Sean Yaw

    2017-10-01

    Full Text Available This paper examines an important problem in smart grid energy scheduling; peaks in power demand are proportionally more expensive to generate and provision for. The issue is exacerbated in local microgrids that do not benefit from the aggregate smoothing experienced by large grids. Demand-side scheduling can reduce these peaks by taking advantage of the fact that there is often flexibility in job start times. We focus attention on the case where the jobs are non-preemptible, meaning once started, they run to completion. The associated optimization problem is called the peak demand minimization problem, and has been previously shown to be NP-hard. Our results include an optimal fixed-parameter tractable algorithm, a polynomial-time approximation algorithm, as well as an effective heuristic that can also be used in an online setting of the problem. Simulation results show that these methods can reduce peak demand by up to 50% versus on-demand scheduling for household power jobs.

  13. Infrared Peak Splitting from Phonon Localization in Solid Hydrogen.

    Science.gov (United States)

    Magdău, Ioan B; Ackland, Graeme J

    2017-04-07

    We show that the isotope effect leads to a completely different spectroscopic signal in hydrogen-deuterium mixtures, compared to pure elements that have the same crystal structure. This is particularly true for molecular vibrations, which are the main source of information about the structure of high-pressure hydrogen. Mass disorder breaks translational symmetry, meaning that vibrations are localized almost to single molecules, and are not zone-center phonons. In mixtures, each observable infrared (IR) peak corresponds to a collection of many such molecular vibrations, which have a distribution of frequencies depending on local environment. Furthermore discrete groups of environments cause the peaks to split. We illustrate this issue by considering the IR spectrum of the high-pressure phase III structure of hydrogen, recently interpreted as showing novel phases in isotopic mixtures. We calculate the IR spectrum of hydrogen-deuterium mixtures in the C2/c and Cmca-12 structures, showing that isotopic disorder gives rise to mode localization of the high-frequency vibrons. The local coordination of the molecules leads to discrete IR peaks. The spread of frequencies is strongly enhanced with pressure, such that more peaks become resolvable at higher pressures, in agreement with the recent measurements.

  14. Measurement of peak temperature along an optical fiber

    International Nuclear Information System (INIS)

    Fox, R.J.

    1983-01-01

    A multimode silica-clad optical fiber with a liquid silicone core was used as a distributed-line peak-temperature sensor over a temperature range from ambient to 190 0 C. The maximum error was 2 0 C and was essentially independent of the length or position of the hot zone

  15. Biomechanical aspects of peak performance in human swimming

    NARCIS (Netherlands)

    Toussaint, H.M.; Truijens, M.J.

    2005-01-01

    Peak performances in sport require the full deployment of all the powers an athlete possesses. How factors such as mechanical power output, technique and drag, each individually, but also in concert, determine swimming performance is the subject of this enquiry. This overview of swimming

  16. Pikes Peak conceptual shuttle study : visitation trends and scenario planning

    Science.gov (United States)

    2016-04-01

    This study for the U.S. Forest Service provides a preliminary analysis and set of recommendations to support the agency's work moving forward to implement a shuttle system at Colorados popular Pikes Peak in Pike and San Isabel National Forests. Th...

  17. Blue Ice Tephra II - Brimstone Peak, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set is the result of a study of volcanic ash and rock fragment (tephra) layers in exposed blue ice areas on Brimstone Peak (75.888S 158.55E) in East...

  18. Peak effect at microwave frequencies in swift heavy ion irradiated ...

    Indian Academy of Sciences (India)

    few tens of Hz to a few MHz, probing the dynamics of the FLL revealed no frequency dependence of the peak position of the PE which is suggestive of a true thermodynamic phase transition. Studies of the vortex dynamics carried out at microwave and radio fre- quencies in low Tc and high Tc superconductors, do not report ...

  19. Focal F0 peak shape and sentence mode in Swedish

    DEFF Research Database (Denmark)

    Ambrazaitis, Gilbert; Buanzur, Tuarik C.; Niebuhr, Oliver

    2015-01-01

    Shape characteristics of rising-falling accentual F0 peaks of Stockholm Swedish Accent I words in narrow focus are studied in a corpus of 287 read sentences. The corpus includes statements and three types of polar questions. Results reveal a clear effect of sentence mode on the shape of the accen...

  20. High precision 16K, 16 channel peak sensing CAMAC ADC

    International Nuclear Information System (INIS)

    Jain, Mamta; Subramaniam, E.T

    2013-01-01

    A high density, peak sensing, analog to digital converter (ADC) double width module with CAMAC back plane has been developed for nuclear physics experiments with a large number of detectors. This module has sixteen independent channels in plug-in daughter card mother board mode

  1. Standardization of I-125. Sum-Peak Coincidence Counting

    International Nuclear Information System (INIS)

    Grau Carles, A.; Grau Malonda, A.

    2011-01-01

    I-125 is a nuclide which presents difficulties for standardization. The sum-peak method is one of the procedures used to standardize this radionuclide. Initially NaI (Tl)detectors and then the semiconductor detectors with higher resolution have been used.This paper describes the different methods based on the sum-peak procedure and the different expressions used to calculate the activity are deduced. We describe a general procedure for obtaining all of the above equations and many more. We analyze the influence of uncertainties in the used parameters in the uncertainty of the activity. We give a complete example of the transmission of uncertainty and the effects of correlations in the uncertainty of the activity of the sample. High-resolution spectra show an unresolved doublet of 62.0 keV and 62.8 keV. The paper presents two approaches to solve this problem. One is based on the calculation of area ratio and the sum of peak areas obtained from atomic and nuclear data, in the other we modify the equations so that the sum of the peak areas doublet, rather than its components, is present. (Author) 19 refs.

  2. Standardization of I-125. Sum-Peak Coincidence Counting

    Energy Technology Data Exchange (ETDEWEB)

    Grau Carles, A.; Grau Malonda, A.

    2011-07-01

    I-125 is a nuclide which presents difficulties for standardization. The sum-peak method is one of the procedures used to standardize this radionuclide. Initially NaI (Tl)detectors and then the semiconductor detectors with higher resolution have been used.This paper describes the different methods based on the sum-peak procedure and the different expressions used to calculate the activity are deduced. We describe a general procedure for obtaining all of the above equations and many more. We analyze the influence of uncertainties in the used parameters in the uncertainty of the activity. We give a complete example of the transmission of uncertainty and the effects of correlations in the uncertainty of the activity of the sample. High-resolution spectra show an unresolved doublet of 62.0 keV and 62.8 keV. The paper presents two approaches to solve this problem. One is based on the calculation of area ratio and the sum of peak areas obtained from atomic and nuclear data, in the other we modify the equations so that the sum of the peak areas doublet, rather than its components, is present. (Author) 19 refs.

  3. Robust peak-shaving for a neighborhood with electric vehicles

    NARCIS (Netherlands)

    Gerards, Marco Egbertus Theodorus; Hurink, Johann L.

    2016-01-01

    Demand Side Management (DSM) is a popular approach for grid-aware peak-shaving. The most commonly used DSM methods either have no look ahead feature and risk deploying flexibility too early, or they plan ahead using predictions, which are in general not very reliable. To counter this, a DSM approach

  4. Do leading indicators lead peaks more than troughs?

    NARCIS (Netherlands)

    R. Paap (Richard); R. Segers (René); D.J.C. van Dijk (Dick)

    2007-01-01

    textabstractWe develop a formal statistical approach to investigate the possibility that leading indicator variables have different lead times at business cycle peaks and troughs. For this purpose, we propose a novel Markov switching vector autoregressive model, where economic growth and leading

  5. quasi hyperrigidity and weak peak points for non-commutative ...

    Indian Academy of Sciences (India)

    7

    sentation. Several examples are provided to illustrate these notions. 1. Introduction. The concepts of peak point and Choquet boundary play an important role in several areas of classical (commutative) analysis. To be more precise the idea was to identify optimal subsets of a compact Hausdorff space X such that each and.

  6. Anatomy of simultaneous flood peaks at a lowland confluence

    Science.gov (United States)

    Hoitink, T.; Geertsema, T.; Teuling, R.; Uijlenhoet, R.; Torfs, P. J.; Weerts, A.

    2017-12-01

    Lowlands are vulnerable to flooding due to their mild topography in often densely populated areas with high social and economic value. Moreover, multiple physical processes coincide in lowland areas, such as those involved in river-sea interactions and in merging of rivers. Simultaneous occurrence of such processes can result in amplifying or attenuating effects on water levels. Our aim is to understand the mechanisms behind simultaneous occurrence of discharge waves in a river and its lowland tributaries, taking the confluence of the Meuse river with the joining tributaries of the Dommel and Aa as an example. Especially since the January 1995 flood at this confluence is the result of the simultaneous occurrence of discharge peaks in the main stream and the tributaries. Here, we introduce a new way of analyzing lowland discharge and water level dynamics, by tracing individual flood waves based on dynamic time warping. The analysis shows that the exact timing of the arrival of discharge peaks is little relevant, because of the long duration of a discharge wave compared to the time lags between peaks. The discharge waves last on average 9 days, whereas the typical lag time between discharge peaks in the main river and the tributaries is 3 days. Flood water levels are insensitive to the ongoing measures of water retention in the tributary catchment despite the backwaters that can rise up to 1.5 m over a distance of 4 km from the confluence.

  7. predicted peak expiratory flow in human and the clinical implication ...

    African Journals Online (AJOL)

    DR. AMINU

    values using formula developed by (Gregg, 1973) at 50th percentile for age, height and weight obtained from our study (Salisu ... Keywords: Peak expiratory flow, Asthma, Practice guidelines, reference values. INTRODUCTION. The National ... that the personal best PEF may be estimated after a. 2-to-3-week period in which ...

  8. Peak expiratory flow rate and respiratory symptoms following ...

    African Journals Online (AJOL)

    Peak expiratory flow rate (PEFR) of 350 rural women aged (20-70 years) in Edo State, Nigeria who actively used wood as a source of fuel for cooking was measured. The height, chest circumference, weight and blood pressure of the women were also measured. Respiratory symptoms of cough with sputum production, ...

  9. Simple area determination of strongly overlapping ion mobility peaks

    Czech Academy of Sciences Publication Activity Database

    Borovcová, L.; Hermannová, M.; Pauk, V.; Šimek, M.; Havlíček, Vladimír; Lemr, Karel

    2017-01-01

    Roč. 981, AUG 15 (2017), s. 71-79 ISSN 0003-2670 Grant - others:GA MŠk(CZ) LO1305 Institutional support: RVO:61388971 Keywords : Ion mobility-mass spectrometry * Fitting of mobility peaks * Analysis of isomers Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 4.950, year: 2016

  10. Analysis of multibeam-hydrosweep echo peaks for seabed characterisation

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.; Schenke, H.W.; Kodagali, V.N.; Hagen, R.

    , in general, Gaussian in nature except in the case of the Kainan Maru seamount summit (area D). The outer beams of the Enderby abyssal plain (area C) echo-peak PDF statistics reveal the highest possible large-scale feature dominance. Interestingly, Extremal...

  11. Rare terrestrial orchids on Mbeya Peak, Southern Tanzania | van ...

    African Journals Online (AJOL)

    Disa walteri, Satyrium aberrans, S. comptum and S. johnsonii are rare terrestrial orchids that co-occur and flower around the same time in southern Tanzania. We found the first three of these species on Mbeya Peak in March 2005, about 45 years after they were last recorded by botanists and present the first illustration of D.

  12. Statistical agglomeration: peak summarization for direct infusion lipidomics.

    Science.gov (United States)

    Smith, Rob; Anthonymuthu, Tamil S; Ventura, Dan; Prince, John T

    2013-10-01

    Quantification of lipids is a primary goal in lipidomics. In direct infusion/injection (or shotgun) lipidomics, accurate downstream identification and quantitation requires accurate summarization of repetitive peak measurements. Imprecise peak summarization multiplies downstream error by propagating into species identification and intensity estimation. To our knowledge, this is the first analysis of direct infusion peak summarization in the literature. We present two novel peak summarization algorithms for direct infusion samples and compare them with an off-machine ad hoc summarization algorithm as well as with the propriety Xcalibur algorithm. Our statistical agglomeration algorithm reduces peakwise error by 38% mass/charge (m/z) and 44% (intensity) compared with the ad hoc method over three datasets. Pointwise error is reduced by 23% (m/z). Compared with Xcalibur, our statistical agglomeration algorithm produces 68% less m/z error and 51% less intensity error on average on two comparable datasets. The source code for Statistical Agglomeration and the datasets used are freely available for non-commercial purposes at https://github.com/optimusmoose/statistical_agglomeration. Modified Bin Aggolmeration is freely available in MSpire, an open source mass spectrometry package at https://github.com/princelab/mspire/.

  13. Bragg peak and relative biological efficiency of different ions

    Czech Academy of Sciences Publication Activity Database

    Lokajíček st., Miloš; Judas, Libor; Kundrát, Pavel

    2002-01-01

    Roč. 64, Suppl. 1 (2002), S309-S309 ISSN 0167-8140 R&D Projects: GA AV ČR(CZ) KSK4055109 Keywords : Bragg peak * relative biological efficisncy * radiological mechanism Subject RIV: CC - Organic Chemistry Impact factor: 2.838, year: 2002

  14. Factors influencing peak expiratory flow in teenage boys | van ...

    African Journals Online (AJOL)

    Background. Peak expiratory flow (PEF) is a useful measure of pulmonary health status and is frequently utilised in asthm, management. Reduction in PEF is usually indicative of OIlS( of asthma symptoms. However, use can be made of PEF values only if normal values are known. The definition of normal range is always ...

  15. Analytical construction of peaked solutions for the nonlinear ...

    African Journals Online (AJOL)

    These results demonstrate the existence of peaked pulses propagating through a pair plasma. The algebraic decay rate of the pulses are determined analytically, as well. The method discussed here can be applied to approximate solutions to similar nonlinear partial differential equations of nonlinear Schrödinger type.

  16. Energy and Public Health: The Challenge of Peak Petroleum

    OpenAIRE

    Frumkin, Howard; Hess, Jeremy; Vindigni, Stephen

    2009-01-01

    Petroleum is a unique and essential energy source, used as the principal fuel for transportation, in producing many chemicals, and for numerous other purposes. Global petroleum production is expected to reach a maximum in the near future and to decline thereafter, a phenomenon known as “peak petroleum.”

  17. Daily peak electricity load forecasting in South Africa using a ...

    African Journals Online (AJOL)

    A multivariate adaptive regression splines (MARS) modelling approach towards daily peak electricity load forecasting in South Africa is presented in this paper for the period 2000 to 2009. MARS is a non-parametric multivariate regression method which is used in high-dimensional problems with complex model structures, ...

  18. Effect of Gymnema inodorum on postprandial peak plasma glucose ...

    African Journals Online (AJOL)

    Gymnema inodorum (GI), a vegetable widely used in a Northern Thai food, is known for not only its health nourishing effect, but also its hypoglycemic effect. But no scientific evidence on the hypoglycemic effect of GI has ever been reported in human. In this study, the effect of GI consumption on peak plasma glucose ...

  19. Daily peak electricity load forecasting in South Africa using a ...

    African Journals Online (AJOL)

    transmission substations, scheduling of startup times of peak stations, load flow analysis and power system security ... blackout. This NESO definition excludes the demand from people, companies, etc. who are willing (or unwilling) and able (or unable) to pay for electricity, but currently do not have access to electrical power.

  20. Radio spectra of Gigahertz Peaked Spectrum radio sources

    NARCIS (Netherlands)

    deVries, WH; Barthel, PD; ODea, CP

    A well defined sample of 72 Gigahertz Peaked Spectrum radio sources is compiled, having turnover frequencies in the range of 0.5 - 10 GHz. Using this sample, the canonical GPS radio spectrum is constructed, which is found to have a constant shape, independent of AGN type, redshift or radio

  1. Algorithm for systematic peak extraction from atomic pair distribution functions.

    Science.gov (United States)

    Granlund, L; Billinge, S J L; Duxbury, P M

    2015-07-01

    The study presents an algorithm, ParSCAPE, for model-independent extraction of peak positions and intensities from atomic pair distribution functions (PDFs). It provides a statistically motivated method for determining parsimony of extracted peak models using the information-theoretic Akaike information criterion (AIC) applied to plausible models generated within an iterative framework of clustering and chi-square fitting. All parameters the algorithm uses are in principle known or estimable from experiment, though careful judgment must be applied when estimating the PDF baseline of nanostructured materials. ParSCAPE has been implemented in the Python program SrMise. Algorithm performance is examined on synchrotron X-ray PDFs of 16 bulk crystals and two nanoparticles using AIC-based multimodeling techniques, and particularly the impact of experimental uncertainties on extracted models. It is quite resistant to misidentification of spurious peaks coming from noise and termination effects, even in the absence of a constraining structural model. Structure solution from automatically extracted peaks using the Liga algorithm is demonstrated for 14 crystals and for C60. Special attention is given to the information content of the PDF, theory and practice of the AIC, as well as the algorithm's limitations.

  2. Peak Expiratory Flow Rate in Petroleum Depot Workers and Petrol ...

    African Journals Online (AJOL)

    Peak Expiratory Flow Rate (PEFR) values in litres per minute were determined in petrol depot loaders, petrol station attendants and in control subjects. The PEFR values were 315 ± 94, 386 + 91 and 529 + 94 litres/min. in depot workers, petrol attendants and control subjects respectively. The value in the control subjects ...

  3. Monsoon onset over Kerala and pre monsoon rainfall peak

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.; Shenoi, S.S.C.; Shankar, D.

    degrees E, from 1st March to 31 May for the years 1979 to 2001. The monsoon onset dates over Kerala, as declared by India Meteorological Department has been used in the present study. For each year, the midday of the pentad with the rainfall peak...

  4. Size-independent peak shift between normal and upconversion ...

    Indian Academy of Sciences (India)

    2014-02-12

    Feb 12, 2014 ... In this article, we report size-dependent measurement of the shift in peak of upconversion photoluminescence spectra compared to that of normal photoluminescence using a 800 nm femtosecond laser and its second harmonic. It has been shown that the upconversion photoluminescence is always ...

  5. Optical spectroscopy of faint gigahertz peaked-spectrum sources

    NARCIS (Netherlands)

    Snellen, IAG; Schilizzi, RT; Miley, GK; de Bruyn, AG; Rottgering, HJA

    1999-01-01

    We present spectroscopic observations of a sample of faint gigahertz peaked-spectrum (GPS) radio sources drawn from the Westerbork Northern Sky Survey (WENSS), Redshifts have been determined for 19 (40 per cent) of the objects. The optical spectra of the GPS sources identified with low-redshift

  6. On the asymptotic behavior of flood peak distributions

    Directory of Open Access Journals (Sweden)

    E. Gaume

    2006-01-01

    Full Text Available This paper presents some analytical results and numerical illustrations on the asymptotic properties of flood peak distributions obtained through derived flood frequency approaches. It confirms and extends the results of previous works: i.e. the shape of the flood peak distributions are asymptotically controlled by the rainfall statistical properties, given limited and reasonable assumptions concerning the rainfall-runoff process. This result is partial so far: the impact of the rainfall spatial heterogeneity has not been studied for instance. From a practical point of view, it provides a general framework for analysis of the outcomes of previous works based on derived flood frequency approaches and leads to some proposals for the estimation of very large return-period flood quantiles. This paper, focussed on asymptotic distribution properties, does not propose any new approach for the extrapolation of flood frequency distribution to estimate intermediate return period flood quantiles. Nevertheless, the large distance between frequent flood peak values and the asymptotic values as well as the simulations conducted in this paper help quantifying the ill condition of the problem of flood frequency distribution extrapolation: it illustrates how large the range of possibilities for the shapes of flood peak distributions is.

  7. T(peak)T(end) interval in long QT syndrome

    DEFF Research Database (Denmark)

    Kanters, Jørgen Kim; Haarmark, Christian; Vedel-Larsen, Esben

    2008-01-01

    BACKGROUND: The T(peak)T(end) (T(p)T(e)) interval is believed to reflect the transmural dispersion of repolarization. Accordingly, it should be a risk factor in long QT syndrome (LQTS). The aim of the study was to determine the effect of genotype on T(p)T(e) interval and test whether it was related...

  8. Size-independent peak shift between normal and upconversion ...

    Indian Academy of Sciences (India)

    2014-02-12

    Feb 12, 2014 ... Abstract. In this article, we report size-dependent measurement of the shift in peak of upcon- version photoluminescence spectra compared to that of normal photoluminescence using a 800 nm femtosecond laser and its second harmonic. It has been shown that the upconversion photolumi- nescence is ...

  9. variant formula for predicting peak expiratory flow rate in pregnant ...

    African Journals Online (AJOL)

    DR. AMINU

    The graph illustrates close association of variant formula with the observed values of PEFR obtained from the study. Variant formula may be useful in clinical setting to assess people with respiratory disorders especially asthma. Key words: Variant formula, Peak expiratory flow rate, Pregnancy, Kura local government area.

  10. Changes in Peak Expiratory Flow Rate, Blood Pressure and Pulse ...

    African Journals Online (AJOL)

    We studied the effect of different concentrations of coffee on peak expiratory flow rate (PEFR), blood pressure and pulse rate in an attempt to determine some physiological effects of coffee intake. 18 apparently healthy adult males, age range 20 to 30 years, were recruited for the study over a three day period. Varying ...

  11. Automatic Locking of Laser Frequency to an Absorption Peak

    Science.gov (United States)

    Koch, Grady J.

    2006-01-01

    An electronic system adjusts the frequency of a tunable laser, eventually locking the frequency to a peak in the optical absorption spectrum of a gas (or of a Fabry-Perot cavity that has an absorption peak like that of a gas). This system was developed to enable precise locking of the frequency of a laser used in differential absorption LIDAR measurements of trace atmospheric gases. This system also has great commercial potential as a prototype of means for precise control of frequencies of lasers in future dense wavelength-division-multiplexing optical communications systems. The operation of this system is completely automatic: Unlike in the operation of some prior laser-frequency-locking systems, there is ordinarily no need for a human operator to adjust the frequency manually to an initial value close enough to the peak to enable automatic locking to take over. Instead, this system also automatically performs the initial adjustment. The system (see Figure 1) is based on a concept of (1) initially modulating the laser frequency to sweep it through a spectral range that includes the desired absorption peak, (2) determining the derivative of the absorption peak with respect to the laser frequency for use as an error signal, (3) identifying the desired frequency [at the very top (which is also the middle) of the peak] as the frequency where the derivative goes to zero, and (4) thereafter keeping the frequency within a locking range and adjusting the frequency as needed to keep the derivative (the error signal) as close as possible to zero. More specifically, the system utilizes the fact that in addition to a zero crossing at the top of the absorption peak, the error signal also closely approximates a straight line in the vicinity of the zero crossing (see Figure 2). This vicinity is the locking range because the linearity of the error signal in this range makes it useful as a source of feedback for a proportional + integral + derivative control scheme that

  12. Peak Dose Assessment for Proposed DOE-PPPO Authorized Limits

    Energy Technology Data Exchange (ETDEWEB)

    Maldonado, Delis [Oak Ridge Institute for Science and Education, Oak Ridge, TN (United States). Independent Environmental Assessment and Verification Program

    2012-06-01

    The Oak Ridge Institute for Science and Education (ORISE), a U.S. Department of Energy (DOE) prime contractor, was contracted by the DOE Portsmouth/Paducah Project Office (DOE-PPPO) to conduct a peak dose assessment in support of the Authorized Limits Request for Solid Waste Disposal at Landfill C-746-U at the Paducah Gaseous Diffusion Plant (DOE-PPPO 2011a). The peak doses were calculated based on the DOE-PPPO Proposed Single Radionuclides Soil Guidelines and the DOE-PPPO Proposed Authorized Limits (AL) Volumetric Concentrations available in DOE-PPPO 2011a. This work is provided as an appendix to the Dose Modeling Evaluations and Technical Support Document for the Authorized Limits Request for the C-746-U Landfill at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky (ORISE 2012). The receptors evaluated in ORISE 2012 were selected by the DOE-PPPO for the additional peak dose evaluations. These receptors included a Landfill Worker, Trespasser, Resident Farmer (onsite), Resident Gardener, Recreational User, Outdoor Worker and an Offsite Resident Farmer. The RESRAD (Version 6.5) and RESRAD-OFFSITE (Version 2.5) computer codes were used for the peak dose assessments. Deterministic peak dose assessments were performed for all the receptors and a probabilistic dose assessment was performed only for the Offsite Resident Farmer at the request of the DOE-PPPO. In a deterministic analysis, a single input value results in a single output value. In other words, a deterministic analysis uses single parameter values for every variable in the code. By contrast, a probabilistic approach assigns parameter ranges to certain variables, and the code randomly selects the values for each variable from the parameter range each time it calculates the dose (NRC 2006). The receptor scenarios, computer codes and parameter input files were previously used in ORISE 2012. A few modifications were made to the parameter input files as appropriate for this effort. Some of these changes

  13. Peak Dose Assessment for Proposed DOE-PPPO Authorized Limits

    International Nuclear Information System (INIS)

    Maldonado, Delis

    2012-01-01

    The Oak Ridge Institute for Science and Education (ORISE), a U.S. Department of Energy (DOE) prime contractor, was contracted by the DOE Portsmouth/Paducah Project Office (DOE-PPPO) to conduct a peak dose assessment in support of the Authorized Limits Request for Solid Waste Disposal at Landfill C-746-U at the Paducah Gaseous Diffusion Plant (DOE-PPPO 2011a). The peak doses were calculated based on the DOE-PPPO Proposed Single Radionuclides Soil Guidelines and the DOE-PPPO Proposed Authorized Limits (AL) Volumetric Concentrations available in DOE-PPPO 2011a. This work is provided as an appendix to the Dose Modeling Evaluations and Technical Support Document for the Authorized Limits Request for the C-746-U Landfill at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky (ORISE 2012). The receptors evaluated in ORISE 2012 were selected by the DOE-PPPO for the additional peak dose evaluations. These receptors included a Landfill Worker, Trespasser, Resident Farmer (onsite), Resident Gardener, Recreational User, Outdoor Worker and an Offsite Resident Farmer. The RESRAD (Version 6.5) and RESRAD-OFFSITE (Version 2.5) computer codes were used for the peak dose assessments. Deterministic peak dose assessments were performed for all the receptors and a probabilistic dose assessment was performed only for the Offsite Resident Farmer at the request of the DOE-PPPO. In a deterministic analysis, a single input value results in a single output value. In other words, a deterministic analysis uses single parameter values for every variable in the code. By contrast, a probabilistic approach assigns parameter ranges to certain variables, and the code randomly selects the values for each variable from the parameter range each time it calculates the dose (NRC 2006). The receptor scenarios, computer codes and parameter input files were previously used in ORISE 2012. A few modifications were made to the parameter input files as appropriate for this effort. Some of these changes

  14. Peak Running Intensity of International Rugby: Implications for Training Prescription.

    Science.gov (United States)

    Delaney, Jace A; Thornton, Heidi R; Pryor, John F; Stewart, Andrew M; Dascombe, Ben J; Duthie, Grant M

    2017-09-01

    To quantify the duration and position-specific peak running intensities of international rugby union for the prescription and monitoring of specific training methodologies. Global positioning systems (GPS) were used to assess the activity profile of 67 elite-level rugby union players from 2 nations across 33 international matches. A moving-average approach was used to identify the peak relative distance (m/min), average acceleration/deceleration (AveAcc; m/s 2 ), and average metabolic power (P met ) for a range of durations (1-10 min). Differences between positions and durations were described using a magnitude-based network. Peak running intensity increased as the length of the moving average decreased. There were likely small to moderate increases in relative distance and AveAcc for outside backs, halfbacks, and loose forwards compared with the tight 5 group across all moving-average durations (effect size [ES] = 0.27-1.00). P met demands were at least likely greater for outside backs and halfbacks than for the tight 5 (ES = 0.86-0.99). Halfbacks demonstrated the greatest relative distance and P met outputs but were similar to outside backs and loose forwards in AveAcc demands. The current study has presented a framework to describe the peak running intensities achieved during international rugby competition by position, which are considerably higher than previously reported whole-period averages. These data provide further knowledge of the peak activity profiles of international rugby competition, and this information can be used to assist coaches and practitioners in adequately preparing athletes for the most demanding periods of play.

  15. Peak-locking reduction for particle image velocimetry

    International Nuclear Information System (INIS)

    Michaelis, Dirk; Wieneke, Bernhard; Neal, Douglas R

    2016-01-01

    A parametric study of the factors contributing to peak-locking, a known bias error source in particle image velocimetry (PIV), is conducted using synthetic data that are processed with a state-of-the-art PIV algorithm. The investigated parameters include: particle image diameter, image interpolation techniques, the effect of asymmetric versus symmetric window deformation, number of passes and the interrogation window size. Some of these parameters are found to have a profound effect on the magnitude of the peak-locking error. The effects for specific PIV cameras are also studied experimentally using a precision turntable to generate a known rotating velocity field. Image time series recorded using this experiment show a linear range of pixel and sub-pixel shifts ranging from 0 to  ±4 pixels. Deviations in the constant vorticity field (ω z ) reveal how peak-locking can be affected systematically both by varying parameters of the detection system such as the focal distance and f -number, and also by varying the settings of the PIV analysis. A new a priori technique for reducing the bias errors associated with peak-locking in PIV is introduced using an optical diffuser to avoid undersampled particle images during the recording of the raw images. This technique is evaluated against other a priori approaches using experimental data and is shown to perform favorably. Finally, a new a posteriori anti peak-locking filter (APLF) is developed and investigated, which shows promising results for both synthetic data and real measurements for very small particle image sizes. (paper)

  16. 75 FR 38478 - Orders Finding That the Mid-C Financial Peak Daily Contract and Mid-C Financial Off-Peak Daily...

    Science.gov (United States)

    2010-07-02

    ... requested comment on the Mid-C Financial Peak (``MDC'') contract and Mid-C Financial Off-Peak (``OMC... the Mid-C Financial Peak (``MDC'') contract and Mid-C Financial Off-Peak (``OMC'') contract. The MDC and OMC contracts will be addressed in a separate Federal Register release. \\10\\ The Commission's Part...

  17. Revisiting the Correlations of Peak Luminosity with Spectral Lag and Peak Energy of the Observed Gamma-ray Bursts

    Directory of Open Access Journals (Sweden)

    Yun-A Jo

    2016-12-01

    Full Text Available An analysis of light curves and spectra of observed gamma-ray bursts in gamma-ray ranges is frequently demanded because the prompt emission contains immediate details regarding the central engine of gamma-ray bursts (GRBs. We have revisited the relationship between the collimation-corrected peak luminosity and the spectral lag, investigating the lag-luminosity relationships in great detail by focusing on spectral lags resulting from all possible combinations of channels. Firstly, we compiled the opening angle data and demonstrated that the distribution of opening angles of 205 long GRBs is represented by a double Gaussian function having maxima at ~ 0.1 and ~ 0.3 radians. We confirmed that the peak luminosity and the spectral lag are anti-correlated, both in the observer frame and in the source frame. We found that, in agreement with our previous conclusion, the correlation coefficient improves significantly in the source frame. It should be noted that spectral lags involving channel 2 (25-50 keV yield high correlation coefficients, where Swift/Burst Alert Telescope (BAT has four energy channels (channel 1: 15-25 keV, channel 2: 25-50 keV, channel 3: 50-100 keV, channel 4: 100-200 keV. We also found that peak luminosity is positively correlated with peak energy.

  18. Ionoacoustic characterization of the proton Bragg peak with submillimeter accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Assmann, W., E-mail: walter.assmann@lmu.de; Reinhardt, S.; Lehrack, S.; Edlich, A.; Thirolf, P. G.; Parodi, K. [Department for Medical Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching 85748 (Germany); Kellnberger, S.; Omar, M.; Ntziachristos, V. [Institute for Biological and Medical Imaging, Technische Universität München and Helmholtz Zentrum München, Ingolstädter Landstrasse 1, Neuherberg 85764 (Germany); Moser, M.; Dollinger, G. [Institute for Applied Physics and Measurement Technology, Universität der Bundeswehr, Werner-Heisenberg-Weg 39, Neubiberg 85577 (Germany)

    2015-02-15

    Purpose: Range verification in ion beam therapy relies to date on nuclear imaging techniques which require complex and costly detector systems. A different approach is the detection of thermoacoustic signals that are generated due to localized energy loss of ion beams in tissue (ionoacoustics). Aim of this work was to study experimentally the achievable position resolution of ionoacoustics under idealized conditions using high frequency ultrasonic transducers and a specifically selected probing beam. Methods: A water phantom was irradiated by a pulsed 20 MeV proton beam with varying pulse intensity and length. The acoustic signal of single proton pulses was measured by different PZT-based ultrasound detectors (3.5 and 10 MHz central frequencies). The proton dose distribution in water was calculated by Geant4 and used as input for simulation of the generated acoustic wave by the matlab toolbox k-WAVE. Results: In measurements from this study, a clear signal of the Bragg peak was observed for an energy deposition as low as 10{sup 12} eV. The signal amplitude showed a linear increase with particle number per pulse and thus, dose. Bragg peak position measurements were reproducible within ±30 μm and agreed with Geant4 simulations to better than 100 μm. The ionoacoustic signal pattern allowed for a detailed analysis of the Bragg peak and could be well reproduced by k-WAVE simulations. Conclusions: The authors have studied the ionoacoustic signal of the Bragg peak in experiments using a 20 MeV proton beam with its correspondingly localized energy deposition, demonstrating submillimeter position resolution and providing a deep insight in the correlation between the acoustic signal and Bragg peak shape. These results, together with earlier experiments and new simulations (including the results in this study) at higher energies, suggest ionoacoustics as a technique for range verification in particle therapy at locations, where the tumor can be localized by ultrasound

  19. Asthma-like peak flow variability in various lung diseases

    Directory of Open Access Journals (Sweden)

    Virendra Singh

    2012-01-01

    Full Text Available Background and Objectives: Bronchodilator reversibility and diurnal peak flow variability are considered characteristic of asthma patients. Patients with chronic obstructive pulmonary disease (COPD show poor reversibility. But reversibility and variability in other pulmonary diseases manifesting with airflow obstruction in not known. Therefore, we assessed reversibility and peak flow variability in patients with various lung diseases to recognize the pattern. Materials and Methods : Seventy consecutive patients with a diagnosis of lung diseases manifesting with airflow obstruction were recruited in the study. These included 23 patients with asthma, 11 patients with bronchiectasis, 16 patients with post-tubercular lung disease (PTLD, and 20 patients with COPD. Ten healthy matched control subjects were also selected to pair with asthmatic patients. Bronchodilator reversibility test was done initially and peak expiratory flow rate (PEFR was measured for a duration of 1 week by patients themselves on a chart that was given to them. The mean amplitude percentage of these records were analyzed. Results : The mean values of peak flow variability were 14.73% ± 6.1% in asthmatic patients, 11.98% ± 7.5% in patients with bronchiectasis, and 10.54% ± 5.3% in PTLD. The difference in the mean values of peak flow variability between asthma and bronchiectasis, that is, 14.73 (6.1 vs 11.98 (7.5 was not statistically significant (P > 0.05. Forced expiratory volume one second (FEV 1 reversibility values were 14.77% ± 26.93%, 11.24% ± 20.43%, 10.85% ± 13.02%, 16.83% ± 22.84%, and 5.47% ± 4.99% in asthma, COPD, PTLD, bronchiectasis, and healthy subjects, respectively. Conclusion: Both reversibility and diurnal peak flow variability were higher in patients with various lung diseases compared with normal healthy subjects. Although these are characteristic of asthma, some cases of bronchiectasis and PTLD patients may also manifest asthma-like PEFR variability

  20. Hurricane Mitch: Peak Discharge for Selected River Reachesin Honduras

    Science.gov (United States)

    Smith, Mark E.; Phillips, Jeffrey V.; Spahr, Norman E.

    2002-01-01

    Hurricane Mitch began as a tropical depression in the Caribbean Sea on 22 October 1998. By 26 October, Mitch had strengthened to a Category 5 storm as defined by the Saffir-Simpson Hurricane Scale (National Climate Data Center, 1999a), and on 27 October was threatening the northern coast of Honduras (fig. 1). After making landfall 2 days later (29 October), the storm drifted south and west across Honduras, wreaking destruction throughout the country before reaching the Guatemalan border on 31 October. According to the National Climate Data Center of the National Oceanic and Atmospheric Administration (National Climate Data Center, 1999b), Hurricane Mitch ranks among the five strongest storms on record in the Atlantic Basin in terms of its sustained winds, barometric pressure, and duration. Hurricane Mitch also was one of the worst Atlantic storms in terms of loss of life and property. The regionwide death toll was estimated to be more than 9,000; thousands of people were reported missing. Economic losses in the region were more than $7.5 billion (U.S. Agency for International Development, 1999). Honduras suffered the most widespread devastation during the storm. More than 5,000 deaths, and economic losses of more than $4 billion, were reported by the Government of Honduras. Honduran officials estimated that Hurricane Mitch destroyed 50 years of economic development. In addition to the human and economic losses, intense flooding and landslides scarred the Honduran landscape - hydrologic and geomorphologic processes throughout the country likely will be affected for many years. As part of the U.S. Government's response to the disaster, the U.S. Geological Survey (USGS) conducted post-flood measurements of peak discharge at 16 river sites throughout Honduras (fig. 2). Such measurements, termed 'indirect' measurements, are used to determine peak flows when direct measurements (using current meters or dye studies, for example) cannot be made. Indirect measurements of

  1. Determination of the diagnostic x-ray tube practical peak voltage (PPV) from average or average peak voltage measurements.

    Science.gov (United States)

    Hourdakis, C J

    2011-04-07

    The practical peak voltage (PPV) has been adopted as the reference measuring quantity for the x-ray tube voltage. However, the majority of commercial kV-meter models measure the average peak, Ū(P), the average, Ū, the effective, U(eff) or the maximum peak, U(P) tube voltage. This work proposed a method for determination of the PPV from measurements with a kV-meter that measures the average Ū or the average peak, Ū(p) voltage. The kV-meter reading can be converted to the PPV by applying appropriate calibration coefficients and conversion factors. The average peak k(PPV,kVp) and the average k(PPV,Uav) conversion factors were calculated from virtual voltage waveforms for conventional diagnostic radiology (50-150 kV) and mammography (22-35 kV) tube voltages and for voltage ripples from 0% to 100%. Regression equation and coefficients provide the appropriate conversion factors at any given tube voltage and ripple. The influence of voltage waveform irregularities, like 'spikes' and pulse amplitude variations, on the conversion factors was investigated and discussed. The proposed method and the conversion factors were tested using six commercial kV-meters at several x-ray units. The deviations between the reference and the calculated-according to the proposed method-PPV values were less than 2%. Practical aspects on the voltage ripple measurement were addressed and discussed. The proposed method provides a rigorous base to determine the PPV with kV-meters from Ū(p) and Ū measurement. Users can benefit, since all kV-meters, irrespective of their measuring quantity, can be used to determine the PPV, complying with the IEC standard requirements.

  2. Can double-peaked lines indicate merging effects in AGNs?

    Directory of Open Access Journals (Sweden)

    Popović L.Č.

    2000-01-01

    Full Text Available The influence of merging effects in the central part of an Active Galactic Nucleus (AGN on the emission spectral line shapes are discussed. We present a model of close binary Broad Line Region. The numerical experiments show that the merging effects can explain double peaked lines. The merging effects may also be present in the center of AGNs, although they emit slightly asymmetric as well as symmetric and relatively stable (in profile shape spectral lines. Depending on the black hole masses and their orbit elements such model may explain some of the line profile shapes observed in AGNs. This work shows that if one is looking for the merging effects in the central region as well as in the wide field structure of AGNs, he should first pay attention to objects which have double peaked lines.

  3. Kinematic evidence for downdip movement on the Mormon Peak detachment

    Science.gov (United States)

    Walker, Christopher D.; Anders, Mark H.; Christie-Blick, Nicholas

    2007-03-01

    The Mormon Peak detachment is considered to be one of the best examples of a rooted upper crustal detachment fault that propagated through the brittle crust at a low angle. The hanging wall of the detachment today consists of a number of isolated blocks that have been interpreted as remnants of a once-contiguous extensional allochthon. Here we present the results of a new study of directional indicators from the basal surfaces beneath these blocks. These measurements do not agree with the long-standing interpretation of a S75°W movement direction for the detachment hanging wall. Instead, the most recent movement on each section of the detachment took place approximately parallel to the present downdip direction. We conclude that the Mormon Peak detachment is best explained as the basal surfaces to a series of rootless gravity slides.

  4. How does economic theory explain the Hubbert peak oil model?

    International Nuclear Information System (INIS)

    Reynes, F.; Okullo, S.; Hofkes, M.

    2010-01-01

    The aim of this paper is to provide an economic foundation for bell shaped oil extraction trajectories, consistent with Hubbert's peak oil model. There are several reasons why it is important to get insight into the economic foundations of peak oil. As production decisions are expected to depend on economic factors, a better comprehension of the economic foundations of oil extraction behaviour is fundamental to predict production and price over the coming years. The investigation made in this paper helps us to get a better understanding of the different mechanisms that may be at work in the case of OPEC and non-OPEC producers. We show that profitability is the main driver behind production plans. Changes in profitability due to divergent trajectories between costs and oil price may give rise to a Hubbert production curve. For this result we do not need to introduce a demand or an exploration effect as is generally assumed in the literature.

  5. Estimating peak flow characteristics at ungaged sites by ridge regression

    Science.gov (United States)

    Tasker, Gary D.

    1982-01-01

    A regression simulation model, is combined with a multisite streamflow generator to simulate a regional regression of 50-year peak discharge against a set of basin characteristics. Monte Carlo experiments are used to compare the unbiased ordinary lease squares parameter estimator with Hoerl and Kennard's (1970a) ridge estimator in which the biasing parameter is that proposed by Hoerl, Kennard, and Baldwin (1975). The simulation results indicate a substantial improvement in parameter estimation using ridge regression when the correlation between basin characteristics is more than about 0.90. In addition, results indicate a strong potential for improving the mean square error of prediction of a peak-flow characteristic versus basin characteristics regression model when the basin characteristics are approximately colinear. The simulation covers a range of regression parameters, streamflow statistics, and basin characteristics commonly found in regional regression studies.

  6. Double peak effect in microdosimetric proportional counters and its interpretation

    International Nuclear Information System (INIS)

    Bednarek, B.; Olko, P.; Booz, J.

    1989-01-01

    In calibration measurements with low energy X-rays, a double peak effect appears in low pressure proportional counters with a helix, when used for simulation of tissue equivalent diameters considerably larger than 2 μm. An interpretation of this phenomenon is discussed, based upon electron capture and electric field perturbation at the counter helix. A description of the physical processes is presented showing that the double peak effect is a problem in the case of helix counters (called also Rossi counters) for all simulated diameters. Conclusions are drawn on systematic errors introduced by the counter helix into microdosimetric spectra and anti y D of photons and neutrons. The authors recommend to use cylindrical counters with optimized geometrical and electronic parameters rather than the spherical counters with a helix discussed. (orig.)

  7. In vivo dissolution measurement with indium-111 summation peak ratios

    International Nuclear Information System (INIS)

    Jay, M.; Woodward, M.A.; Brouwer, K.R.

    1985-01-01

    Dissolution of [ 111 In]labeled tablets was measured in vivo in a totally noninvasive manner by using a modification of the perturbed angular correlation technique known as the summation peak ratio method. This method, which requires the incorporation of only 10-12 microCi into the dosage form, provided reliable dissolution data after oral administration of [ 111 In]lactose tablets. These results were supported by in vitro experiments which demonstrated that the dissolution rate as measured by the summation peak ratio method was in close agreement with the dissolution rate of salicylic acid in a [ 111 In]salicylic acid tablet. The method has the advantages of using only one detector, thereby avoiding the need for complex coincidence counting systems, requiring less radioactivity, and being potentially applicable to a gamma camera imaging system

  8. The need for standardisation of peak flow charts

    OpenAIRE

    Reddel, H; Vincent, S; Civitico, J

    2005-01-01

    Peak expiratory flow (PEF) monitoring is recommended in asthma guidelines as a tool for assessing severity, monitoring response to treatment, detecting exacerbations, identifying triggers, and providing objective justification for treatment to the patient, but some clinicians have expressed concerns about its relevance in the management of asthma. We have identified a sevenfold variation in the scale of existing PEF charts, with resulting wide variation in the appearance of the same PEF date ...

  9. Degradation of the Bragg peak due to inhomogeneities.

    Science.gov (United States)

    Urie, M; Goitein, M; Holley, W R; Chen, G T

    1986-01-01

    The rapid fall-off of dose at the end of range of heavy charged particle beams has the potential in therapeutic applications of sparing critical structures just distal to the target volume. Here we explored the effects of highly inhomogeneous regions on this desirable depth-dose characteristic. The proton depth-dose distribution behind a lucite-air interface parallel to the beam was bimodal, indicating the presence of two groups of protons with different residual ranges, creating a step-like depth-dose distribution at the end of range. The residual ranges became more spread out as the interface was angled at 3 degrees, and still more at 6 degrees, to the direction of the beam. A second experiment showed little significant effect on the distal depth-dose of protons having passed through a mosaic of teflon and lucite. Anatomic studies demonstrated significant effects of complex fine inhomogeneities on the end of range characteristics. Monoenergetic protons passing through the petrous ridges and mastoid air cells in the base of skull showed a dramatic degradation of the distal Bragg peak. In beams with spread out Bragg peaks passing through regions of the base of skull, the distal fall-off from 90 to 20% dose was increased from its nominal 6 to well over 32 mm. Heavy ions showed a corresponding degradation in their ends of range. In the worst case in the base of skull region, a monoenergetic neon beam showed a broadening of the full width at half maximum of the Bragg peak to over 15 mm (compared with 4 mm in a homogeneous unit density medium). A similar effect was found with carbon ions in the abdomen, where the full width at half maximum of the Bragg peak (nominally 5.5 mm) was found to be greater than 25 mm behind gas-soft-tissue interfaces. We address the implications of these data for dose computation with heavy charged particles.

  10. Twin-Peak QPOs from Oscillating Torus with Cusp

    Science.gov (United States)

    Sramkova, Eva

    2017-08-01

    We propose a model of HF twin-peak quasi-periodic oscillations assuming an oscillating torus with cusp that changes location of its centre around radii very close to innermost stable circular orbit. The observed variability is assigned to global modes of accreted fluid motion that may give rise to strong modulation of both the accretion disc radiation and the accretion rate. We illustrate that predictions of the model well match observational data for a dozen of sources.

  11. Peak-counts blood flow model-errors and limitations

    International Nuclear Information System (INIS)

    Mullani, N.A.; Marani, S.K.; Ekas, R.D.; Gould, K.L.

    1984-01-01

    The peak-counts model has several advantages, but its use may be limited due to the condition that the venous egress may not be negligible at the time of peak-counts. Consequently, blood flow measurements by the peak-counts model will depend on the bolus size, bolus duration, and the minimum transit time of the bolus through the region of interest. The effect of bolus size on the measurement of extraction fraction and blood flow was evaluated by injecting 1 to 30ml of rubidium chloride in the femoral vein of a dog and measuring the myocardial activity with a beta probe over the heart. Regional blood flow measurements were not found to vary with bolus sizes up to 30ml. The effect of bolus duration was studied by injecting a 10cc bolus of tracer at different speeds in the femoral vein of a dog. All intravenous injections undergo a broadening of the bolus duration due to the transit time of the tracer through the lungs and the heart. This transit time was found to range from 4-6 second FWHM and dominates the duration of the bolus to the myocardium for up to 3 second injections. A computer simulation has been carried out in which the different parameters of delay time, extraction fraction, and bolus duration can be changed to assess the errors in the peak-counts model. The results of the simulations show that the error will be greatest for short transit time delays and for low extraction fractions

  12. Peak earthquake response of structures under multi-component excitations

    Science.gov (United States)

    Song, Jianwei; Liang, Zach; Chu, Yi-Lun; Lee, George C.

    2007-12-01

    Accurate estimation of the peak seismic responses of structures is important in earthquake resistant design. The internal force distributions and the seismic responses of structures are quite complex, since ground motions are multi-directional. One key issue is the uncertainty of the incident angle between the directions of ground motion and the reference axes of the structure. Different assumed seismic incidences can result in different peak values within the scope of design spectrum analysis for a given structure and earthquake ground motion record combination. Using time history analysis to determine the maximum structural responses excited by a given earthquake record requires repetitive calculations to determine the critical incident angle. This paper presents a transformation approach for relatively accurate and rapid determination of the maximum peak responses of a linear structure subjected to three-dimensional excitations within all possible seismic incident angles. The responses can be deformations, internal forces, strains and so on. An irregular building structure model is established using SAP2000 program. Several typical earthquake records and an artificial white noise are applied to the structure model to illustrate the variation of the maximum structural responses for different incident angles. Numerical results show that for many structural parameters, the variation can be greater than 100%. This method can be directly applied to time history analysis of structures using existing computer software to determine the peak responses without carrying out the analyses for all possible incident angles. It can also be used to verify and/or modify aseismic designs by using response spectrum analysis.

  13. Peak effect at microwave frequencies in swift heavy ion irradiated ...

    Indian Academy of Sciences (India)

    few tens of Hz to a few MHz, probing the dynamics of the FLL revealed no frequency dependence of the peak position of the PE .... 19, 217 (1969). [5] A I Larkin and Y N Ovchinnikov, J. Low Temp. Phys. 34, 409 (1979). [6] J I Gittleman and B Rosenblum, Phys. Rev. Lett. 16, 734 (1966). [7] A R Bhangale et al, Phys. Rev. B63 ...

  14. Implications of "peak oil" for atmospheric CO2 and climate

    OpenAIRE

    Kharecha, Pushker A.; Hansen, James E.

    2007-01-01

    Unconstrained CO2 emission from fossil fuel burning has been the dominant cause of observed anthropogenic global warming. The amounts of "proven" and potential fossil fuel reserves are uncertain and debated. Regardless of the true values, society has flexibility in the degree to which it chooses to exploit these reserves, especially unconventional fossil fuels and those located in extreme or pristine environments. If conventional oil production peaks within the next few decades, it may have a...

  15. General Merrill A. McPeak Leadership and Organizational Change

    Science.gov (United States)

    2001-06-01

    GENERAL MERRILL A. MCPEAK LEADERSHIP AND ORGANIZATIONAL CHANGE BY MAJOR THOMAS A. BUSSIERE A THESIS PRESENTED TO THE...Covered (from... to) - Title and Subtitle General Merrill A. McPeak Leadership and Organizational Change Contract Number Grant Number Program Element...General McPeak�s leadership. The sections of each case focus on the particular issues associated with organizational change and leadership. The

  16. Single-peak solitary wave solutions for the variant Boussinesq ...

    Indian Academy of Sciences (India)

    Zhang and Chen [6] obtained new types of cusped solitons of a partial differential equation by setting the partial differential equation under inhomogeneous .... (ii) For g = 0. If ψ(0) = 0, by eq. (2.8) we know ψ (0) exists. According to the definition of peak point, we have ψ (0) = 0. However, by eq. (2.8) we must have ψ(0) = A, ...

  17. Automatic acquisition and shape analysis of metastable peaks

    International Nuclear Information System (INIS)

    Maendli, H.; Robbiani, R.; Kuster, Th.; Seibl, J.

    1979-01-01

    A method for automatic acquisition and evaluation of metastable peaks due to transitions in the first field-free region of a double focussing mass spectrometer is presented. The data are acquired by computer-controlled repetitive scanning of the accelerating voltage and concomitant accumulation, the evaluation made by a mathematical derivatization of the resulting curve. Examples for application of the method are given. (Auth.)

  18. Peak signal-to-noise ratio revisited: Is simple beautiful?

    DEFF Research Database (Denmark)

    Korhonen, Jari; You, Junyong

    2012-01-01

    Heavy criticism has been directed against using peak signal-to-noise ratio (PSNR) as a full reference quality metric for digitally processed images and video, since many studies have shown a weak correlation between subjective quality scores and the respective PSNR values. In this paper, we show...... quality models known from the literature. Therefore, the use of PSNR may be justified for comparative quality assessment with fixed content....

  19. Implementing peak load reduction algorithms for household electrical appliances

    International Nuclear Information System (INIS)

    Dlamini, Ndumiso G.; Cromieres, Fabien

    2012-01-01

    Considering household appliance automation for reduction of household peak power demand, this study explored aspects of the interaction between household automation technology and human behaviour. Given a programmable household appliance switching system, and user-reported appliance use times, we simulated the load reduction effectiveness of three types of algorithms, which were applied at both the single household level and across all 30 households. All three algorithms effected significant load reductions, while the least-to-highest potential user inconvenience ranking was: coordinating the timing of frequent intermittent loads (algorithm 2); moving period-of-day time-flexible loads to off-peak times (algorithm 1); and applying short-term time delays to avoid high peaks (algorithm 3) (least accommodating). Peak reduction was facilitated by load interruptibility, time of use flexibility and the willingness of users to forgo impulsive appliance use. We conclude that a general factor determining the ability to shift the load due to a particular appliance is the time-buffering between the service delivered and the power demand of an appliance. Time-buffering can be ‘technologically inherent’, due to human habits, or realised by managing user expectations. There are implications for the design of appliances and home automation systems. - Highlights: ► We explored the interaction between appliance automation and human behaviour. ► There is potential for considerable load shifting of household appliances. ► Load shifting for load reduction is eased with increased time buffering. ► Design, human habits and user expectations all influence time buffering. ► Certain automation and appliance design features can facilitate load shifting.

  20. Cranial Indicators Identified for Peak Incidence of Otitis Media.

    Science.gov (United States)

    Pagano, Anthony S; Wang, Eugene; Yuan, Derek; Fischer, Daniel; Bluestone, Charles; Marquez, Samuel; Laitman, Jeffrey

    2017-10-01

    Acute otitis media (AOM) is one of the most common pediatric conditions worldwide. Peak age of occurrence for AOM has been identified within the first postnatal year and it remains frequent until approximately six postnatal years. Morphological differences between adults and infants in the cartilaginous Eustachian tube (CET) and associated structures may be responsible for development of this disease yet few have investigated normal growth trajectories. We tested hypotheses on coincidence of skeletal growth changes and known ages of peak AOM occurrence. Growth was divided into five dental eruption stages ranging from edentulous neonates (Stage 1) to adults with erupted third maxillary molars (Stage 5). A total of 32 three-dimensional landmarks were used and Generalized Procrustes Analysis was performed. Next, we performed principal components analysis and calculated univariate measures. It was found that growth change in Stage 1 was the most rapid and comprised the largest amount of overall growth in upper respiratory tract proportions (where time is represented by the natural logarithmic transformation of centroid size). The analysis of univariate measures showed that Stage 1 humans did indeed possess the relatively shortest and most horizontally oriented CET's with the greatest amount of growth change occurring at the transition to Stage 2 (eruption of deciduous dentition at five postnatal months, commencing peak AOM incidence) and ceasing by Stage 3 (approximately six postnatal years). Skeletal indicators appear related to peak ages of AOM incidence and may contribute to understanding of a nearly ubiquitous human disease. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 300:1721-1740, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  1. Remote Sensing and Modeling of Cyclone Monica near Peak Intensity

    Directory of Open Access Journals (Sweden)

    Stephen L. Durden

    2010-07-01

    Full Text Available Cyclone Monica was an intense Southern Hemisphere tropical cyclone of 2006. Although no in situ measurements of Monica’s inner core were made, microwave, infrared, and visible satellite instruments observed Monica before and during peak intensity through landfall on Australia’s northern coast. The author analyzes remote sensing measurements in detail to investigate Monica’s intensity. While Dvorak analysis of its imagery argues that it was of extreme intensity, infrared and microwave soundings indicate a somewhat lower intensity, especially as it neared landfall. The author also describes several numerical model runs that were made to investigate the maximum possible intensity for the observed environmental conditions; these simulations also suggest a lower intensity than estimates from Dvorak analysis alone. Based on the evidence from the various measurements and modeling, the estimated range for the minimum sea level pressure at peak intensity is 900 to 920 hPa. The estimated range for the one-minute averaged maximum wind speed at peak intensity is 72 to 82 m/s. These maxima were likely reached about 24 hours prior to landfall, with some weakening occurring afterward.

  2. Magnetospheric Multiscale Observations of Electron Scale Magnetic Peak

    Science.gov (United States)

    Yao, S. T.; Shi, Q. Q.; Guo, R. L.; Yao, Z. H.; Tian, A. M.; Degeling, A. W.; Sun, W. J.; Liu, J.; Wang, X. G.; Zong, Q. G.; Zhang, H.; Pu, Z. Y.; Wang, L. H.; Fu, S. Y.; Xiao, C. J.; Russell, C. T.; Giles, B. L.; Feng, Y. Y.; Xiao, T.; Bai, S. C.; Shen, X. C.; Zhao, L. L.; Liu, H.

    2018-01-01

    The sudden enhancements of magnetic strength, named magnetic peaks (MPs), are often observed in the magnetosheath of magnetized planets. They are usually identified as flux ropes (FRs) or magnetic mirror mode structures. Previous studies of MPs are mostly on the magnetohydrodynamics (MHD) scale. In this study, an electron scale MP is reported in the Earth magnetosheath. We present a typical case with a scale of 7 electron gyroradii and a duration of 0.18 s. A strong magnetic disturbance and associated electrical current are detected. Electron vortex is found perpendicular to the magnetic field line and is self-consist with the peak. We use multipoint spacecraft techniques to determine the propagation velocity of the MP structure and find that the magnetic peak does propagate relative to the plasma (ion) flow. This is very different from the magnetic mirror mode that does not propagate relative to the plasma flow. Furthermore, we developed an efficient method that can effectively distinguish "magnetic bottle like" and "FRs like" structures. The MP presented in this study is identified as magnetic bottle like type. The mechanism to generate the electron scale magnetic bottle like structure is still unclear, suggesting that new theory needs to be developed to understand such small-scale phenomena.

  3. Mineral Resources: Reserves, Peak Production and the Future

    Directory of Open Access Journals (Sweden)

    Lawrence D. Meinert

    2016-02-01

    Full Text Available The adequacy of mineral resources in light of population growth and rising standards of living has been a concern since the time of Malthus (1798, but many studies erroneously forecast impending peak production or exhaustion because they confuse reserves with “all there is”. Reserves are formally defined as a subset of resources, and even current and potential resources are only a small subset of “all there is”. Peak production or exhaustion cannot be modeled accurately from reserves. Using copper as an example, identified resources are twice as large as the amount projected to be needed through 2050. Estimates of yet-to-be discovered copper resources are up to 40-times more than currently-identified resources, amounts that could last for many centuries. Thus, forecasts of imminent peak production due to resource exhaustion in the next 20–30 years are not valid. Short-term supply problems may arise, however, and supply-chain disruptions are possible at any time due to natural disasters (earthquakes, tsunamis, hurricanes or political complications. Needed to resolve these problems are education and exploration technology development, access to prospective terrain, better recycling and better accounting of externalities associated with production (pollution, loss of ecosystem services and water and energy use.

  4. MERGERS IN DOUBLE-PEAKED [O III] ACTIVE GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    Fu Hai; Djorgovski, S. G.; Myers, Adam D.; Yan Lin

    2011-01-01

    As a natural consequence of galaxy mergers, binary active galactic nuclei (AGNs) should be commonplace. Nevertheless, observational confirmations are rare, especially for binaries with separations less than 10 kpc. Such a system may show two sets of narrow emission lines in a single spectrum owing to the orbital motion of the binary. We have obtained high-resolution near-infrared images of 50 double-peaked [O III]λ5007 AGNs with the Keck II laser guide star adaptive optics system. The Sloan Digital Sky Survey sample is compiled from the literature and consists of 17 type-1 AGNs between 0.18 BH -σ * relation because of overestimated stellar velocity dispersions, illustrating the importance of removing mergers from the samples defining the M BH -σ * relations. Finally, we find that the emission-line properties are indistinguishable for spatially resolved and unresolved sources, emphasizing that scenarios involving a single AGN can produce the same double-peaked line profiles and they account for at least 70% of the double-peaked [O III] AGNs.

  5. Mineral resources: Reserves, peak production and the future

    Science.gov (United States)

    Meinert, Lawrence D.; Robinson, Gilpin; Nassar, Nedal

    2016-01-01

    The adequacy of mineral resources in light of population growth and rising standards of living has been a concern since the time of Malthus (1798), but many studies erroneously forecast impending peak production or exhaustion because they confuse reserves with “all there is”. Reserves are formally defined as a subset of resources, and even current and potential resources are only a small subset of “all there is”. Peak production or exhaustion cannot be modeled accurately from reserves. Using copper as an example, identified resources are twice as large as the amount projected to be needed through 2050. Estimates of yet-to-be discovered copper resources are up to 40-times more than currently-identified resources, amounts that could last for many centuries. Thus, forecasts of imminent peak production due to resource exhaustion in the next 20–30 years are not valid. Short-term supply problems may arise, however, and supply-chain disruptions are possible at any time due to natural disasters (earthquakes, tsunamis, hurricanes) or political complications. Needed to resolve these problems are education and exploration technology development, access to prospective terrain, better recycling and better accounting of externalities associated with production (pollution, loss of ecosystem services and water and energy use).

  6. Predictors of the peak width for networks with exponential links

    Science.gov (United States)

    Troutman, B.M.; Karlinger, M.R.

    1989-01-01

    We investigate optimal predictors of the peak (S) and distance to peak (T) of the width function of drainage networks under the assumption that the networks are topologically random with independent and exponentially distributed link lengths. Analytical results are derived using the fact that, under these assumptions, the width function is a homogeneous Markov birth-death process. In particular, exact expressions are derived for the asymptotic conditional expectations of S and T given network magnitude N and given mainstream length H. In addition, a simulation study is performed to examine various predictors of S and T, including N, H, and basin morphometric properties; non-asymptotic conditional expectations and variances are estimated. The best single predictor of S is N, of T is H, and of the scaled peak (S divided by the area under the width function) is H. Finally, expressions tested on a set of drainage basins from the state of Wyoming perform reasonably well in predicting S and T despite probable violations of the original assumptions. ?? 1989 Springer-Verlag.

  7. Peak reduction for commercial buildings using energy storage

    Science.gov (United States)

    Chua, K. H.; Lim, Y. S.; Morris, S.

    2017-11-01

    Battery-based energy storage has emerged as a cost-effective solution for peak reduction due to the decrement of battery’s price. In this study, a battery-based energy storage system is developed and implemented to achieve an optimal peak reduction for commercial customers with the limited energy capacity of the energy storage. The energy storage system is formed by three bi-directional power converter rated at 5 kVA and a battery bank with capacity of 64 kWh. Three control algorithms, namely fixed-threshold, adaptive-threshold, and fuzzy-based control algorithms have been developed and implemented into the energy storage system in a campus building. The control algorithms are evaluated and compared under different load conditions. The overall experimental results show that the fuzzy-based controller is the most effective algorithm among the three controllers in peak reduction. The fuzzy-based control algorithm is capable of incorporating a priori qualitative knowledge and expertise about the load characteristic of the buildings as well as the useable energy without over-discharging the batteries.

  8. The bias of weighted dark matter halos from peak theory

    CERN Document Server

    Verde, Licia; Simpson, Fergus; Alvarez-Gaume, Luis; Heavens, Alan; Matarrese, Sabino

    2014-01-01

    We give an analytical form for the weighted correlation function of peaks in a Gaussian random field. In a cosmological context, this approach strictly describes the formation bias and is the main result here. Nevertheless, we show its validity and applicability to the evolved cosmological density field and halo field, using Gaussian random field realisations and dark matter N-body numerical simulations. Using this result from peak theory we compute the bias of peaks (and dark matter halos) and show that it reproduces results from the simulations at the ${\\mathcal O}(10\\%)$ level. Our analytical formula for the bias predicts a scale-dependent bias with two characteristics: a broad band shape which, however, is most affected by the choice of weighting scheme and evolution bias, and a more robust, narrow feature localised at the BAO scale, an effect that is confirmed in simulations. This scale-dependent bias smooths the BAO feature but, conveniently, does not move it. We provide a simple analytic formula to des...

  9. 36Cl bomb peak: comparison of modeled and measured data

    Directory of Open Access Journals (Sweden)

    A. Eichler

    2009-06-01

    Full Text Available The extensive nuclear bomb testing of the fifties and sixties and the final tests in the seventies caused a strong 36Cl peak that has been observed in ice cores world-wide. The measured 36Cl deposition fluxes in eight ice cores (Dye3, Fiescherhorn, Grenzgletscher, Guliya, Huascarán, North GRIP, Inylchek (Tien Shan and Berkner Island were compared with an ECHAM5-HAM general circulation model simulation (1952–1972. We find a good agreement between the measured and the modeled 36Cl fluxes assuming that the bomb test produced global 36Cl input was ~80 kg. The model simulation indicates that the fallout of the bomb test produced 36Cl is largest in the subtropics and mid-latitudes due to the strong stratosphere-troposphere exchange. In Greenland the 36Cl bomb signal is quite large due to the relatively high precipitation rate. In Antarctica the 36Cl bomb peak is small but is visible even in the driest areas. The model suggests that the large bomb tests in the Northern Hemisphere are visible around the globe but the later (end of sixties and early seventies smaller tests in the Southern Hemisphere are much less visible in the Northern Hemisphere. The question of how rapidly and to what extent the bomb produced 36Cl is mixed between the hemispheres depends on the season of the bomb test. The model results give an estimate of the amplitude of the bomb peak around the globe.

  10. Martial arts striking hand peak acceleration, accuracy and consistency.

    Science.gov (United States)

    Neto, Osmar Pinto; Marzullo, Ana Carolina De Miranda; Bolander, Richard P; Bir, Cynthia A

    2013-01-01

    The goal of this paper was to investigate the possible trade-off between peak hand acceleration and accuracy and consistency of hand strikes performed by martial artists of different training experiences. Ten male martial artists with training experience ranging from one to nine years volunteered to participate in the experiment. Each participant performed 12 maximum effort goal-directed strikes. Hand acceleration during the strikes was obtained using a tri-axial accelerometer block. A pressure sensor matrix was used to determine the accuracy and consistency of the strikes. Accuracy was estimated by the radial distance between the centroid of each subject's 12 strikes and the target, whereas consistency was estimated by the square root of the 12 strikes mean squared distance from their centroid. We found that training experience was significantly correlated to hand peak acceleration prior to impact (r(2)=0.456, p =0.032) and accuracy (r(2)=0. 621, p=0.012). These correlations suggest that more experienced participants exhibited higher hand peak accelerations and at the same time were more accurate. Training experience, however, was not correlated to consistency (r(2)=0.085, p=0.413). Overall, our results suggest that martial arts training may lead practitioners to achieve higher striking hand accelerations with better accuracy and no change in striking consistency.

  11. A new record peak luminosity for the LHC

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Two weeks of dedicated machine development paid off last weekend when the LHC ran for physics with three nominal intensity (∼1011 protons) bunches in each beam.   This brought a new record peak luminosity of around 8×1029 cm-2 s-1, and allowed the LHC to double the integrated luminosity delivered to the experiments since 30 March from 16 to 32 inverse nanobarns over the weekend. After a few more fills in this configuration, the number of bunches will be raised to six per beam, which will in turn allow the peak luminosity to break the 1030 cm-2 s-1 barrier for the first time, well on the way to achieving the 2010 objective of 1032 cm-2 s-1. This peak luminosity goal requires 800 nominal bunches per beam squeezed to a beta of 3.5 metres. The plan for 2011 is to run the LHC in this configuration over about 10 months, thus achieving the objective of recording one inverse femtobarn of data in total. The machine development period also allowed the TOTEM detectors to be set up with 45...

  12. High peak power tubes and gate effect Klystrons

    International Nuclear Information System (INIS)

    Gerbelot, N.; Bres, M.; Faillon, G.; Buzzi, J.M.

    1993-01-01

    The conventional microwave tubes such as TWTs, Magnetrons, Klystrons... deliver the very high peak powers which are required by radar transmitters but more especially by many particle accelerators. In the range of a few hundred MHz to about 10 GHz, some dozen of MWs per unit are currently obtained and commercially available, according to the frequency and the pulse lengths. But peak power requirements are ever increasing, especially for the expected new linear particle acceleratores, where several hundred MWs per tube would be necessary. Also some special military transmitters begin to request GW pulses, with short pulse lengths - of course - but at nonnegligible repetition rates. Therefore several laboratories and microwave vacuum tube manufacturers have engaged - for several years - studies and development in the field of very high peak microwave power (HPM) toward two main directions: extended operation and extrapolation of the conventional tubes and devices; development of new concepts, among which the most promising are likely the high-current relativistic klystrons - that are also referred to as gate effect klystrons

  13. Noise distribution of a peak track and hold circuit

    Science.gov (United States)

    Seller, Paul; Hardie, Alec L.; Morrissey, Quentin

    2012-12-01

    Noise in linear electronic circuits is well characterised in terms of power spectral density in the frequency domain and the Normal probability density function in the time domain. For instance a charge preamplifier followed by a simple time independent pulse shaping circuit produces an output with a predictable, easily calculated Normal density function. By the Ergodic Principle this is true if the signal is sampled randomly in time or the experiment is run many times and measured at a fixed time after the circuit is released from reset. Apart from well defined cases, the time of the sample after release of reset does not affect the density function. If this signal is then passed through a peak track-and-hold circuit the situation is very different. The probability density function of the sampled signal is no longer Normal and the function changes with the time of the sample after release of reset. This density function can be classified by the Gumbel probability density function which characterises the Extreme Value Distribution of a defined number of Normally distributed values. The number of peaks in the signal is an important factor in the analysis. This issue is analysed theoretically and compared with a time domain noise simulation programme. This is then related to a real electronic circuit used for low-noise X-ray measurements and shows how the low-energy resolution of this system is significantly degraded when using a peak track-and-hold.

  14. Climate change and peak demand for electricity: Evaluating policies for reducing peak demand under different climate change scenarios

    Science.gov (United States)

    Anthony, Abigail Walker

    This research focuses on the relative advantages and disadvantages of using price-based and quantity-based controls for electricity markets. It also presents a detailed analysis of one specific approach to quantity based controls: the SmartAC program implemented in Stockton, California. Finally, the research forecasts electricity demand under various climate scenarios, and estimates potential cost savings that could result from a direct quantity control program over the next 50 years in each scenario. The traditional approach to dealing with the problem of peak demand for electricity is to invest in a large stock of excess capital that is rarely used, thereby greatly increasing production costs. Because this approach has proved so expensive, there has been a focus on identifying alternative approaches for dealing with peak demand problems. This research focuses on two approaches: price based approaches, such as real time pricing, and quantity based approaches, whereby the utility directly controls at least some elements of electricity used by consumers. This research suggests that well-designed policies for reducing peak demand might include both price and quantity controls. In theory, sufficiently high peak prices occurring during periods of peak demand and/or low supply can cause the quantity of electricity demanded to decline until demand is in balance with system capacity, potentially reducing the total amount of generation capacity needed to meet demand and helping meet electricity demand at the lowest cost. However, consumers need to be well informed about real-time prices for the pricing strategy to work as well as theory suggests. While this might be an appropriate assumption for large industrial and commercial users who have potentially large economic incentives, there is not yet enough research on whether households will fully understand and respond to real-time prices. Thus, while real-time pricing can be an effective tool for addressing the peak load

  15. Automated Critical Peak Pricing Field Tests: Program Descriptionand Results

    Energy Technology Data Exchange (ETDEWEB)

    Piette, Mary Ann; Watson, David; Motegi, Naoya; Kiliccote, Sila; Xu, Peng

    2006-04-06

    California utilities have been exploring the use of critical peak prices (CPP) to help reduce needle peaks in customer end-use loads. CPP is a form of price-responsive demand response (DR). Recent experience has shown that customers have limited knowledge of how to operate their facilities in order to reduce their electricity costs under CPP (Quantum 2004). While the lack of knowledge about how to develop and implement DR control strategies is a barrier to participation in DR programs like CPP, another barrier is the lack of automation of DR systems. During 2003 and 2004, the PIER Demand Response Research Center (DRRC) conducted a series of tests of fully automated electric demand response (Auto-DR) at 18 facilities. Overall, the average of the site-specific average coincident demand reductions was 8% from a variety of building types and facilities. Many electricity customers have suggested that automation will help them institutionalize their electric demand savings and improve their overall response and DR repeatability. This report focuses on and discusses the specific results of the Automated Critical Peak Pricing (Auto-CPP, a specific type of Auto-DR) tests that took place during 2005, which build on the automated demand response (Auto-DR) research conducted through PIER and the DRRC in 2003 and 2004. The long-term goal of this project is to understand the technical opportunities of automating demand response and to remove technical and market impediments to large-scale implementation of automated demand response (Auto-DR) in buildings and industry. A second goal of this research is to understand and identify best practices for DR strategies and opportunities. The specific objectives of the Automated Critical Peak Pricing test were as follows: (1) Demonstrate how an automated notification system for critical peak pricing can be used in large commercial facilities for demand response (DR). (2) Evaluate effectiveness of such a system. (3) Determine how customers

  16. A comparison of peak expiratory flow measured from forced vital capacity and peak flow meter manoeuvres in healthy volunteers

    Directory of Open Access Journals (Sweden)

    Agarwal Dipti

    2007-01-01

    Full Text Available Background: Spirometry measures the mechanical function of lungs, chest wall and respiratory muscles by assessing the total volume of air exhaled from total lung capacity to residual volume. Spirometry and peak flow measurements have usually been carried out on separate equipments using different expiratory maneuvers. Aims: The present study was carried out to determine whether there is a significant difference between peak expiratory flow (PEF derived from a short sharp exhalation (PEF maneuver and that derived from a full forced vital capacity (FVC maneuver in healthy volunteers. Settings: A medical college and tertiary level hospital. Materials and Methods: The present study was carried out during the period from January 2006 to July 2006. The study included 80 healthy volunteers with no coexisting illnesses, who were in the 15-45 years age group and belonging to either sex. They were asked to perform two sets of PEF and FVC maneuvers using the same turbine spirometer; the order was randomly assigned.th Statistical Analysis: The difference between PEF obtained from a peak flow maneuver (PEFPF and that obtained from a forced vital capacity maneuver (PEFVC in healthy volunteers was analyzed separately for males and females, as well as for both groups combined, and statistical significance of its correlations with study data parameters was analyzed.th Results: The difference between PEF obtained from a peak flow maneuver (PEFPF and that obtained from a forced vital capacity maneuver (PEFVC was statistically significant ( P < 0.001 in males and in females separately and also for both groups combined. PEFPF (517.25 ± 83.22 liters/min was significantly greater than PEFVC (511.09 ± 83.54 liters/min, as found on combined group mean analysis. However, the difference was small (6.16 + 7.09 liters/min. Conclusions: FVC maneuver can be used over spirometers to detect the PEF; and on follow-up subsequently, the same maneuver should be used to derive PEF

  17. Electrons' energy in GRB afterglows implied by radio peaks

    Science.gov (United States)

    Beniamini, Paz; van der Horst, Alexander J.

    2017-12-01

    Gamma-ray burst (GRB) afterglows have been observed across the electromagnetic spectrum, and physical parameters of GRB jets and their surroundings have been derived using broad-band modelling. While well-sampled light curves across the broad-band spectrum are necessary to constrain all the physical parameters, some can be strongly constrained by the right combination of just a few observables, almost independently of the other unknowns. We present a method involving the peaks of radio light curves to constrain the fraction of shock energy that resides in electrons, εe. This parameter is an important ingredient for understanding the microphysics of relativistic shocks. Based on a sample of 36 radio afterglows, we find εe has a narrow distribution centred around 0.13-0.15. Our method is suggested as a diagnostic tool for determining εe, and to help constrain the broad-band modelling of GRB afterglows. Some earlier measurements of the spreads in parameter values for εe, the kinetic energy of the shock and the density of the circumburst medium, based on broad-band modelling across the entire spectrum, are at odds with our analysis of radio peaks. This could be due to different modelling methods and assumptions, and possibly missing ingredients in past and current modelling efforts. Furthermore, we show that observations at ≳10 GHz performed 0.3-30 d after the GRB trigger are best suited for pinpointing the synchrotron peak frequency, and, consequently, εe. At the same time, observations at lower radio frequencies can pin down the synchrotron self-absorption frequency and help constrain the other physical parameters of GRB afterglows.

  18. Risk factors of low peak bone mass in Indonesian women

    Directory of Open Access Journals (Sweden)

    Ray Sugianto

    2014-10-01

    Full Text Available Background: Osteoporosis occurred in 64% of Indonesian women aged 60-64 years. The risk of osteoporosis can be reduced by achieving optimal peak bone mass in ages 25-32 years. However, 33.4% women had low peak bone mass (LPBM. Objective: We aimed to develop a tool to identify women at risk of developing LPBM in order to ameliorate this situation. Some risk/protective factors were explored in a case-control study. Method: We recruited 25 cases, those with LPBM (T-score <1 according to peripheral bone densitometry and 25 controls from Cengkareng District, West Jakarta. They were assessed using questionnaires to explore their historical intake of calcium, tea/coffee, and weight-bearing activity. We also measured BMI and body composition. Parameters among case and control groups were analyzed using independent T-test or Mann-Whitney, and odds ratio in relation to peak bone mass was also computed. Results: Between cases and controls, there were no differences observed in BMI, body composition, weight-bearing activity, and historical tea/coffee consumption. Calcium intake from sources other than milk and its derivatives were also found not to differ. Historical calcium index (HCI, measuring weekly calcium intake since childhood, was found lower in cases (median=160 vs 965; p=0.001. HCI cut-off analysis found that the values of 300 and 1000 yielded good specificity (80% and sensitivity (92% for LPBM. OR analysis identified those with HCI <1000 (OR=0.61; 95% CI: 2.05−54.95 as at moderate risk of developing LPBM, and HCI ≤ 300 as at higher risk. Conclusion: We concluded that, as low HCI was the risk factor for developing LPBM, calculation of HCI should be done to earlier identify women at risk, thus prompting earlier nutrition and lifestyle intervention to prevent the occurrence of LPBM and future osteoporosis.

  19. Effective precipitation duration for runoff peaks based on catchment modelling

    Science.gov (United States)

    Sikorska, A. E.; Viviroli, D.; Seibert, J.

    2018-01-01

    Despite precipitation intensities may greatly vary during one flood event, detailed information about these intensities may not be required to accurately simulate floods with a hydrological model which rather reacts to cumulative precipitation sums. This raises two questions: to which extent is it important to preserve sub-daily precipitation intensities and how long does it effectively rain from the hydrological point of view? Both questions might seem straightforward to answer with a direct analysis of past precipitation events but require some arbitrary choices regarding the length of a precipitation event. To avoid these arbitrary decisions, here we present an alternative approach to characterize the effective length of precipitation event which is based on runoff simulations with respect to large floods. More precisely, we quantify the fraction of a day over which the daily precipitation has to be distributed to faithfully reproduce the large annual and seasonal floods which were generated by the hourly precipitation rate time series. New precipitation time series were generated by first aggregating the hourly observed data into daily totals and then evenly distributing them over sub-daily periods (n hours). These simulated time series were used as input to a hydrological bucket-type model and the resulting runoff flood peaks were compared to those obtained when using the original precipitation time series. We define then the effective daily precipitation duration as the number of hours n, for which the largest peaks are simulated best. For nine mesoscale Swiss catchments this effective daily precipitation duration was about half a day, which indicates that detailed information on precipitation intensities is not necessarily required to accurately estimate peaks of the largest annual and seasonal floods. These findings support the use of simple disaggregation approaches to make usage of past daily precipitation observations or daily precipitation simulations

  20. Quantitative Characterization of Chicxulub Impact Basin Peak Ring Materials

    Science.gov (United States)

    King, B.; Nixon, C.; Kofman, R.; Schmitt, D. R.

    2017-12-01

    The exceptionally low seismic wave speeds determined by tomographic image models of the upper portions of the peak ring of the Chicxulub Impact Structure were largely confirmed by sonic and seismic borehole measurements from the IODP/ICDP Expedition 364 scientific drilling campaign. These low wave speeds result from the extensive damage to the peak ring rocks that, based on the results of numerical modelling, were likely displaced 20 km outwards and 10 km upwards after being subject to initial shock pressures as high as 60 GPa. Here, we describe a series of detailed petrophysical and wave speed measurements on select `granite' and `impact melt' cores from the borehole in order to better understand the nature of this damage To date, two granite and two impact melt samples have been studied. X-ray CT scans (30 mm voxel) reveal extensive micro-fracturing between and within the mineral grains in the granites (Fig. 1a) while highlighting the existence of relatively large, 1000 mm3, occluded pores (Fig. 1b). The porosities, as determined using a Hg-injection porosimeter, were also remarkably high with values of indicating the existence of pervasive microcracking. Even at the highest confining pressure of 200 MPa available to us, the observed VP is 4.5 km/s, a value much below the 6.0 km/s expected for the same nonporous rock. These observations suggest that the low wave speeds and densities within the peak ring differ based on whether the material is the original displaced granite or the intruded impact melt. Samples and data provided by IODP. Samples can be requested at http://web.iodp.tamu.edu/sdrm after 19 October 2017. Expedition 364 was funded by ECORD, IODP and ICDP with contributions and logistical support from the Yucatan State Government and Universidad Nacional Autónoma de México (UNAM).

  1. An analytical method for predicting postwildfire peak discharges

    Science.gov (United States)

    Moody, John A.

    2012-01-01

    An analytical method presented here that predicts postwildfire peak discharge was developed from analysis of paired rainfall and runoff measurements collected from selected burned basins. Data were collected from 19 mountainous basins burned by eight wildfires in different hydroclimatic regimes in the western United States (California, Colorado, Nevada, New Mexico, and South Dakota). Most of the data were collected for the year of the wildfire and for 3 to 4 years after the wildfire. These data provide some estimate of the changes with time of postwildfire peak discharges, which are known to be transient but have received little documentation. The only required inputs for the analytical method are the burned area and a quantitative measure of soil burn severity (change in the normalized burn ratio), which is derived from Landsat reflectance data and is available from either the U.S. Department of Agriculture Forest Service or the U.S. Geological Survey. The method predicts the postwildfire peak discharge per unit burned area for the year of a wildfire, the first year after a wildfire, and the second year after a wildfire. It can be used at three levels of information depending on the data available to the user; each subsequent level requires either more data or more processing of the data. Level 1 requires only the burned area. Level 2 requires the burned area and the basin average value of the change in the normalized burn ratio. Level 3 requires the burned area and the calculation of the hydraulic functional connectivity, which is a variable that incorporates the sequence of soil burn severity along hillslope flow paths within the burned basin. Measurements indicate that the unit peak discharge response increases abruptly when the 30-minute maximum rainfall intensity is greater than about 5 millimeters per hour (0.2 inches per hour). This threshold may relate to a change in runoff generation from saturated-excess to infiltration-excess overland flow. The

  2. Peaked and Smooth Solitons for K*(4,1 Equation

    Directory of Open Access Journals (Sweden)

    Yongan Xie

    2013-01-01

    Full Text Available This paper is contributed to explore all possible single peak solutions for the K*(4,1 equation ut=uxu2+2α(uuxxx+2uxuxx. Our procedure shows that the K*(4,1 equation either has peakon, cuspon, and smooth soliton solutions when sitting on a nonzero constant pedestal limξ→±∞u=A≠0 or possesses compacton solutions only when limξ→±∞u=A=0. We present a new smooth soliton solution in an explicit form. Mathematical analysis and numeric graphs are provided for those soliton solutions of the K*(4,1 equation.

  3. Estimate capital for operational risk using peak over threshold method

    Science.gov (United States)

    Saputri, Azizah Anugrahwati; Noviyanti, Lienda; Soleh, Achmad Zanbar

    2015-12-01

    Operational risk is inherent in bank activities. To cover this risk a bank reserves a fund called as capital. Often a bank uses Basic Indicator approach (BIA), Standardized Approach (SA), or Advanced Measurement Approach (AMA) for estimating the capital amount. BIA and SA are less-objective in comparison to AMA, since BIA and SA use non-actual loss data while AMA use the actual one. In this research, we define the capital as an OpVaR (i.e. the worst loss at a given confidence level) which will be estimated by Peak Over Threshold Method.

  4. Transverse Polarization for Energy Calibration at the Z peak

    CERN Document Server

    Koratzinos, M

    2015-01-01

    In this paper we deal with aspects of transverse polarization for the purpose of energy calibration of proposed circular colliders like the FCC-ee and the CEPC. The main issues of such a measurement will be discussed. The possibility of using this method to accurately determine the energy at the WW threshold as well as the Z peak will be addressed. The use of wigglers for reducing long polarization times will be discussed and a possible strategy will be presented for minimising the energy uncertainty error in these large machines.

  5. Sleepwalking into a problem. Peak oil conference in Cork, Ireland

    Energy Technology Data Exchange (ETDEWEB)

    Koppelaar, R.

    2007-11-15

    At the sixth annual conference of the Association for the Study of Peak Oil and Gas (ASPO), which was held in Cork, Ireland, September 17-18, 2007, experts from all over the world gathered to discuss energy trends and the implications this has on the world's future. It appears that the world needs to develop policies for oil conservation and implement renewable energy strategies. The following two questions were discussed: (1) is the oil situation really that dire?; and (2) if so, how can the challenge of diminishing oil supply be met.

  6. Sleepwalking into a problem. Peak oil conference in Cork, Ireland

    International Nuclear Information System (INIS)

    Koppelaar, R.

    2007-01-01

    At the sixth annual conference of the Association for the Study of Peak Oil and Gas (ASPO), which was held in Cork, Ireland, September 17-18, 2007, experts from all over the world gathered to discuss energy trends and the implications this has on the world's future. It appears that the world needs to develop policies for oil conservation and implement renewable energy strategies. The following two questions were discussed: (1) is the oil situation really that dire?; and (2) if so, how can the challenge of diminishing oil supply be met

  7. Reservoir Routing on Double-Peak Design Flood

    Directory of Open Access Journals (Sweden)

    Andrea Gioia

    2016-11-01

    Full Text Available This work investigates the routing effect provided by an artificial reservoir to a double-peak flood of a given return period. The present paper introduces a dimensionless form of the reservoir balance equation that describes the hydrologic-hydraulic processes that may occur and allows for the evaluation of the reservoir routing coefficient (RC. Exploiting this equation, an extensive sensitivity analysis based on the use of two simple parametric indices that depend on the storage capacity (SC of the reservoir, the discharge capacity (DC of the spillway (with fixed-crest and the hydrologic behavior of the basin was performed.

  8. Observations of High Peak Current 'lull' Lightning Flashes

    Science.gov (United States)

    Zhang, Y.; Krehbiel, P. R.; Edens, H. E.; Stock, M.

    2015-12-01

    A new and peculiar type of negative cloud-to-ground (-CG) lightning flash has been found from LMA observations of storms. Called a 'lull' flash, the discharge begins with a short duration (~5-10 ms), stepped leader and high peak current return stroke, followed by a brief period of inactivity. After a few tens to a few hundreds of milliseconds, the discharge reignites in the same location as a normal -CG. VHF observations show a complete lack of activity during the lull. The flashes were first identified from LMA observations during a 2008 lightning study in West Virginia (Krehbiel, 2012 ILDC), but are seen in other normally electrified storms. They are characterized by large negative peak currents (-50 to -150 kA) in NLDN data. Here we report detailed LMA, interferometer, and fast antenna observations of lull flashes obtained at Langmuir Laboratory in 2013. A series of six lull CGs occurred over an 11 min time interval in a small storm on August 5. Analysis of the observations shows the breakdown immediately produced a stepped leader that went straight to ground. The durations from initial breakdown to the return stroke (RS) was 2-15 ms, corresponding to leader speeds of 4×105 to 3×106 m/s. Peak currents of the RSs were -32 to -188 kA. The lulls began 10-29 ms after the RSs, and lasted 40-100 ms before the discharge reignited. By contrast, the durations, speeds and peak current values of the reignited first strokes were those of normal -CGs, namely, 9 to 105 ms, -11.5kA to 55.8kA, and 0.6×105 to 6.7×105 m/s. Further analysis indicates the lull flashes occurred when the storm had substantial negative charge but little lower positive charge, allowing the initial stroke to go straight to ground at a high speed. The energetic stroke somehow quenches the discharge a short time afterward while much negative charge remains, which leads to reignition and the second part of the discharge. Exactly how and why this happens remains an open question.

  9. Using Energy Peaks to Measure New Particle Masses

    CERN Document Server

    Agashe, Kaustubh; Kim, Doojin

    2014-01-01

    We discussed in arXiv:1209.0772 that the laboratory frame distribution of the energy of a massless particle from a two-body decay at a hadron collider has a peak whose location is identical to the value of this daughter's (fixed) energy in the rest frame of the corresponding mother particle. For that result to hold we assumed that the mother is unpolarized and has a generic boost distribution in the laboratory frame. In this work we discuss how this observation can be applied for determination of masses of new particles, without requiring a full reconstruction of their decay chains or information about the rest of the event. We focus on a two-step cascade decay of a massive particle that has one invisible particle in the final state: C -> Bb -> Aab, where C, B and A are new particles of which A is invisible and a, b are visible particles. Combining the measurements of the peaks of energy distributions of a and b with that of the edge in their invariant mass distribution, we demonstrate that it is in principle...

  10. Evaluation of peak-to-total ratio for germanium detectors

    International Nuclear Information System (INIS)

    Watanabe, Tamaki; Oi, Yoshihiro; Taki, Mitsumasa; Kawasaki, Katsuya; Yoshida, Makoto

    1999-01-01

    An equation for the peak-to-total ratio, P, of a germanium detector is proposed in the following form. P=ε p /ε t +a(V/A)+b(V/A) 2 /2 where ε p /ε t is the ratio of the photoelectric to the total detection efficiency for a germanium detector, V/A is the volume-to-surface ratio of the detector, and the parameters of a and b are experimentally given as a function of incident photon energy. The first term in the right side of the equation expresses the fractional single photoelectric-to-total interaction between photons and the detector. The second and third terms correspond to the multiple interactions. The peak-to-total ratios for the germanium detector with a sensitive volume up to 200 cm 3 were calculated by the equation. They coincide with the experimental values to within an uncertainty of several percent in the energy region 0.3-3 MeV

  11. Effective climate-energy solutions, escape routes and peak oil

    International Nuclear Information System (INIS)

    Bergh, Jeroen C.J.M. van den

    2012-01-01

    Many well-intended climate-energy strategies are ineffective in the absence of serious environmental regulation. This holds, among others, for direct support of clean energy, voluntary energy conservation, technical standards on a limited set of products, unilateral stringent carbon pricing, and awaiting peak oil as a climate strategy. All of these suffer from “escape routes” that indirectly increase CO 2 emissions and thus make the original strategy ineffective. On the other hand, environmental regulation alone may lead to a myopia-bias, stimulating early dominance of cost-effective technologies and a focus on incremental innovations associated with such technologies rather than on radical innovations. Although adopting a partial viewpoint keeps the analysis simple, we urgently need a more inclusive systems perspective on climate solutions. This will allow the formulation of an effective climate policy package that addresses the various escape routes. - Highlights: ► Many well-intended climate-energy strategies are ineffective because of escape routes. ► In this context the relationship between peak oil and climate policy receives attention. ► Environmental regulation alone creates myopia-bias, the resolution of which requires technology-specific policies. ► To formulate an effective climate policy package an inclusive systems perspective is needed.

  12. Power Peaking Effect of OTTO Fuel Scheme Pebble Bed Reactor

    Science.gov (United States)

    Setiadipura, T.; Suwoto; Zuhair; Bakhri, S.; Sunaryo, G. R.

    2018-02-01

    Pebble Bed Reactor (PBR) type of Hight Temperature Gas-cooled Reactor (HTGR) is a very interesting nuclear reactor design to fulfill the growing electricity and heat demand with a superior passive safety features. Effort to introduce the PBR design to the market can be strengthen by simplifying its system with the Once-through-then-out (OTTO) cycle PBR in which the pebble fuel only pass the core once. Important challenge in the OTTO fuel scheme is the power peaking effect which limit the maximum nominal power or burnup of the design. Parametric survey is perform in this study to investigate the contribution of different design parameters to power peaking effect of OTTO cycle PBR. PEBBED code is utilized in this study to perform the equilibrium PBR core analysis for different design parameter and fuel scheme. The parameters include its core diameter, height-per-diameter (H/D), power density, and core nominal power. Results of this study show that diameter and H/D effectsare stronger compare to the power density and nominal core power. Results of this study might become an importance guidance for design optimization of OTTO fuel scheme PBR.

  13. Gas inventory charges and peak-load reliability

    International Nuclear Information System (INIS)

    Lyon, T.P.; Hackett, S.C.

    1990-01-01

    The natural gas industry has historically been organized through a vertical sequence of long-term contracts, the first between wellhead producer and pipeline, and the second between pipeline and local distribution company (LDC). These long-term contracts contained provisions, variously called take-or-pay (TOP) clauses or minimum bills, that required buyers to pay for a minimum level of supply in all later time periods, regardless of the buyers' actual demand requirements. As a result, the pipeline's purchase obligation was typically offset by the distributor's purchase obligation, so that the pipeline essentially passed the minimum purchase requirement directly from producer to distributor. The authors focus on the role GICs (Gas Inventory Charges) can play in the provision of peak-load reliability, and the effects of GICs and their treatment by regulators on pipeline system design. In particular, they compare the various options available to local distribution companies (LDCs) for providing peak-load reliability, emphasizing the alternative downstream storage. They find that the ratemaking decisions of state regulators may distort LDC choices between different gas supply options, inducing what may be an inefficient demand for new storage facilities. GICs, when competitively prices, offer state regulators a means of circumventing these distortions

  14. Peaking for optimal performance: Research limitations and future directions.

    Science.gov (United States)

    Pyne, David B; Mujika, Iñigo; Reilly, Thomas

    2009-02-01

    A key element of the physical preparation of athletes is the taper period in the weeks immediately preceding competition. Existing research has defined the taper, identified various forms used in contemporary sport, and examined the prescription of training volume, load, intensity, duration, and type (progressive or step). Current limitations include: the lack of studies on team, combative, racquet, and precision (target) sports; the relatively small number of randomized controlled trials; the narrow focus on a single competition (single peak) compared with multiple peaking for weekly, multi-day or multiple events; and limited understanding of the physiological, neuromuscular, and biomechanical basis of the taper. Future research should address these limitations, together with the influence of prior training on optimal tapering strategies, and the interactions between the taper and long-haul travel, heat, and altitude. Practitioners seek information on how to prescribe tapers from season to season during an athlete's career, or a team's progression through a domestic league season, or multi-year Olympic or World Cup cycle. Practical guidelines for planning effective tapers for the Vancouver 2010 and London 2012 Olympics will evolve from both experimental investigations and modelling of successful tapers currently employed in a wide range of sports.

  15. Steam generator deposit control program assessment at Comanche Peak

    International Nuclear Information System (INIS)

    Stevens, J.; Fellers, B.; Orbon, S.

    2002-01-01

    Comanche Peak has employed a variety of methods to assess the effectiveness of the deposit control program. These include typical methods such as an extensive visual inspection program and detailed corrosion product analysis and trending. In addition, a recently pioneered technique, low frequency eddy current profile analysis (LFEC) has been utilized. LFEC provides a visual mapping of the magnetite deposit profile of the steam generator. Analysis of the LFEC results not only provides general area deposition rates, but can also provide local deposition patterns, which is indicative of steam generator performance. Other techniques utilized include trending of steam pressure, steam generator hideout-return, and flow assisted corrosion (FAC) results. The sum of this information provides a comprehensive assessment of the deposit control program effectiveness and the condition of the steam generator. It also provides important diagnostic and predictive information relative to steam generator life management and mitigative strategies, such as special cleaning procedures. This paper discusses the techniques employed by Comanche Peak Chemistry to monitor the effectiveness of the deposit control program and describes how this information is used in strategic planning. (authors)

  16. Acetaminophen overdose associated with double serum concentration peaks

    Directory of Open Access Journals (Sweden)

    Cristian Papazoglu

    2015-12-01

    Full Text Available Acetaminophen is the most commonly used analgesic–antipyretic medication in the United States. Acetaminophen overdose, a frequent cause of drug toxicity, has been recognized as the leading cause of fatal and non-fatal hepatic necrosis. N-Acetylcysteine is the recommended antidote for acetaminophen poisoning. Despite evidence on the efficacy of N-acetylcysteine for prevention of hepatic injury, controversy persists about the optimal duration of the therapy. Here, we describe the case of a 65-year-old male with acetaminophen overdose and opioid co-ingestion who developed a second peak in acetaminophen serum levels after completing the recommended 21-hour intravenous N-acetylcysteine protocol and when the standard criteria for monitoring drug levels was achieved. Prolongation of N-acetylcysteine infusion beyond the standard protocol, despite a significant gap in treatment, was critical for successful avoidance of hepatotoxicity. Delay in acetaminophen absorption may be associated with a second peak in serum concentration following an initial declining trend, especially in cases of concomitant ingestion of opioids. In patients with acetaminophen toxicity who co-ingest other medications that may potentially delay gastric emptying or in those with risk factors for delayed absorption of acetaminophen, we recommend close monitoring of aminotransferase enzyme levels, as well as trending acetaminophen concentrations until undetectable before discontinuing the antidote therapy.

  17. Changes in Peak Flow Value during Immunotherapy Administration

    International Nuclear Information System (INIS)

    Saporta, D.

    2012-01-01

    Nasal allergies are prevalent affecting a large percentage of the population. Not only the upper respiratory tract but the whole body is involved. Allergies produce morbidity (and even occasional mortality) as they can lead to asthma development, and increased number of accidents. Immunotherapy results can be evaluated by following symptom scores, medication use, and objective measurements. Using a Peak Flow Meter (Pf) to evaluate immunotherapy results, it became evident that patients with and without asthma exhibited an improvement in the Peak Flow (PF) value, suggesting that lower airway involvement in allergic patients could be more prevalent than assumed. A consecutive chart review was performed including patients of any age with nasal allergies (with or without asthma) treated with immunotherapy for at least 6 months that had at least 2 complete evaluations. When immunotherapy was successful, most patients exhibited an increase in the PF value regardless of asthma status. A very significant finding was that most allergy sufferers may have lower airway inflammation. The use of the PF value to assess immunotherapy results and the potential failure to diagnose asthma in allergy sufferers are discussed. A better diagnosis of lower airway inflammation could be substantial in the management of these patients pulmonary function

  18. GRB physics and cosmology with peak energy-intensity correlations

    Energy Technology Data Exchange (ETDEWEB)

    Sawant, Disha, E-mail: sawant@fe.infn.it [University of Ferrara, Via Saragat-1, Block C, Ferrara 44122 (Italy); University of Nice, 28 Avenue Valrose, Nice 06103 (France); IRAP Erasmus PhD Program, European Union and INAF - IASF Bologna, Via P. Gobetti 101, Bologna 41125 (Italy); Amati, Lorenzo, E-mail: amati@iasfbo.inaf.it [INAF - IASF Bologna, Via P. Gobetti 101, Bologna 41125 (Italy); ICRANet, Piazzale Aldo Moro-5, Rome 00185 (Italy)

    2015-12-17

    Gamma Ray Bursts (GRBs) are immensely energetic explosions radiating up to 10{sup 54} erg of energy isotropically (E{sub iso}) and they are observed within a wide range of redshift (from ∼ 0.01 up to ∼ 9). Such enormous power and high redshift point at these phenomena being highly favorable to investigate the history and evolution of our universe. The major obstacle in their application as cosmological study-tools is to find a way to standardize the GRBs, for instance similar to SNe Ia. With respect to this goal, the correlation between spectral peak energy (E{sub p,i}) and the “intensity” is a positively useful and investigated criterion. Moreover, it has been demonstrated that, through the E{sub p,i} – E{sub iso} correlation, the current data set of GRBs can already contribute to the independent evidence of the matter density Ω{sub M} being ∼ 0.3 for a flat universe scenario. We try to inspect and compare the correlations of E{sub p,i} with different intensity indicators (e.g., radiated energy, average and peak luminosity, bolometric vs. monochromatic quantities, etc.) both in terms of intrinsic dispersion and precise estimation of Ω{sub M}. The outcome of such studies are further analyzed in verifying the reliability of the correlations for both GRB physics and their standardization for cosmology.

  19. Simultaneous EEG and EMG biofeedback for peak performance in musicians.

    Science.gov (United States)

    Markovska-Simoska, Silvana; Pop-Jordanova, Nada; Georgiev, Dejan

    2008-07-01

    The aim of this study was to determine the effects of alpha neurofeedback and EMG biofeedback protocols for improvement of musical performance in violinists. The sample consisted of 12 music students (10 violinists and 2 viola players) from the Faculty of Music, Skopje (3 males, mean age of 20 +/- 0 and 9 females, mean age = 20.89 +/- 2.98). Six of them had a low alpha peak frequency (APF) ( 10 Hz). The sample was randomized in two groups. The students from the experimental group participated in 20 sessions of biofeedback (alpha/EMG), combined with music practice, while the students from the control group did only music practice. Average absolute power, interhemispheric coherence in the alpha band, alpha peak frequency (APF), individual alpha band width (IABW), amount of alpha suppression (AAS) and surface forehead integrated EMG power (IEMG), as well as a score on musical performance and inventories measuring anxiety, were assessed. Alpha-EEG/EMG-biofeedback was associated with a significant increase in average alpha power, APF and IABW in all the participants and with decreases in IEMG only in high-APF musicians. The biofeedback training success was positively correlated with the alpha power, IcoH, APF, IABW and baseline level of APF and IABW. Alpha-EEG/EMG biofeedback is capable of increasing voluntary self-regulation and the quality of musical performance. The efficiency of biofeedback training depends on the baseline EEG alpha activity status, in particular the APF.

  20. Emission scenarios in the face of fossil-fuel peaking

    International Nuclear Information System (INIS)

    Brecha, Robert J.

    2008-01-01

    Emissions scenarios used by the Intergovernmental Panel on Climate Change (IPCC) are based on detailed energy system models in which demographics, technology and economics are used to generate projections of future world energy consumption, and therefore, of greenhouse gas emissions. We propose in this paper that it is useful to look at a qualitative model of the energy system, backed by data from short- and medium-term trends, to gain a sense of carbon emission bounds. Here we look at what may be considered a lower bound for 21st century emissions given two assumptions: first, that extractable fossil-fuel resources follow the trends assumed by 'peak oil' adherents, and second, that no climate mitigation policies are put in place to limit emissions. If resources, and more importantly, extraction rates, of fossil fuels are more limited than posited in full energy-system models, a supply-driven emissions scenario results; however, we show that even in this 'peak fossil-fuel' limit, carbon emissions are high enough to surpass 550 ppm or 2 C climate protection guardrails. Some indicators are presented that the scenario presented here should not be disregarded, and comparisons are made to the outputs of emission scenarios used for the IPCC reports. (author)

  1. Old Metal-rich Globular Cluster Populations: Peak Color and Peak Metallicity Trends with Mass of Host Spheroids

    OpenAIRE

    Kravtsov, Valery V.

    2007-01-01

    We address the problem of the factors contributing to a peak color trend of old metal-rich globular cluster (MRGC) populations with mass of their hosts, early-type galaxies and spheroidal subsystems of spiral ones (spheroids). The color-mass trend is often converted to a metallicity-mass trend under the assumption that age effects are small or negligible. While direct estimates of the ages of MRGC populations neither can rule out nor reliably support the populations' age trend, key data on ti...

  2. Technical Potential for Peak Load Management Programs in New Jersey

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, B.J.

    2002-12-13

    Restructuring is attempting to bring the economic efficiency of competitive markets to the electric power industry. To at least some extent it is succeeding. New generation is being built in most areas of the country reversing the decades-long trend of declining reserve margins. Competition among generators is typically robust, holding down wholesale energy prices. Generators have shown that they are very responsive to price signals in both the short and long term. But a market that is responsive only on the supply side is only half a market. Demand response (elasticity) is necessary to gain the full economic advantages that restructuring can offer. Electricity is a form of energy that is difficult to store economically in large quantities. However, loads often have some ability to (1) conveniently store thermal energy and (2) defer electricity consumption. These inherent storage and control capabilities can be exploited to help reduce peak electric system consumption. In some cases they can also be used to provide system reliability reserves. Fortunately too, technology is helping. Advances in communications and control technologies are making it possible for loads ranging from residential through commercial and industrial to respond to economic signals. When we buy bananas, we don't simply take a dozen and wait a month to find out what the price was. We always ask about the price before we decide how many bananas we want. Technology is beginning to allow at least some customers to think about their electricity consumption the same way they think about most of their other purchases. And power system operators and regulators are beginning to understand that customers need to remain in control of their own destinies. Many customers (residential through industrial) are willing to respond to price signals. Most customers are not able to commit to specific responses months or years in advance. Electricity is a fluid market commodity with a volatile value to both

  3. Peak bone mass density among residents of Metro Manila

    International Nuclear Information System (INIS)

    Lim-Abrahan, M.A.B.; Guanzon, M.L.V.V.; Balderas, J.A.J.; Villaruel, C.M.; Santos, F.

    1996-01-01

    To determine the peak bone mass density among residents of Metro Manila using dual x-ray absorptiometry (DEXA).The design used is cross-sectional study. The study include 23 females and 22 males, with 3 to 4 subjects for each age range of 5. The methods used was bone mass density measurements on the lumbar spine and the femur using dual x-ray absorptiometry (DPXI lunar) were taken. The values were also age-matched and matched with that of a young adult based on programmed Caucasian norm provided by Lunar Co. The values were then scattered against age for each sex. Ten (10) cc of blood was also extracted from the patients, with 5 cc of blood separated for future studies. Patients were also interviewed as to their lifestyle, diet, use of contraceptive pill or hormonal replacement treatment, using a Filipino version of the revised questionnaire on the WHO Study on osteoporosis. The mean bone mass density at the L21.4 level for females was 1.12±0.11 g/cm 2 and 0,91±0.11 g/cm 2 at the femur. The highest BMD in both the lumbar spine femoral neck measurements among females was achieved between the ages 30-35 years of age with the lowest BMD occurring between 15-20 yrs. old and incidentally in 2 subjects with ages between 40-44. There seems to be little bone loss among beyond the age 35, unlike in the females. Bone mass density among a sample Metro Manila residents was determined using DEXA and the measurements on the lumbar spine and femoral neck. These were age-matched with that of young adult based on Caucasian norm provided by the Lunar Co. Peak bone mass density in the L2L4 level among the females is reached between the ages 30-35 years old, after which there is progressive bone loss with values in the 45-50 years old approximating the values in the 15-19 years old age range. A similar pattern is seen in the measurements taken at the femoral neck. Among males, the peak BMD is reached during the 30-35 years old, but there seems to be no rapid decline or rapid bone

  4. Peak-locking error reduction by birefringent optical diffusers

    Science.gov (United States)

    Kislaya, Ankur; Sciacchitano, Andrea

    2018-02-01

    The use of optical diffusers for the reduction of peak-locking errors in particle image velocimetry is investigated. The working principle of the optical diffusers is based on the concept of birefringence, where the incoming rays are subject to different deflections depending on the light direction and polarization. The performances of the diffusers are assessed via wind tunnel measurements in uniform flow and wall-bounded turbulence. Comparison with best-practice image defocusing is also conducted. It is found that the optical diffusers yield an increase of the particle image diameter up to 10 µm in the sensor plane. Comparison with reference measurements showed a reduction of both random and systematic errors by a factor of 3, even at low imaging signal-to-noise ratio.

  5. Hvordan gør musikken i Twin Peaks?

    Directory of Open Access Journals (Sweden)

    Ansa Lønstrup

    1992-08-01

    Full Text Available Det er almindelig erkendt, at musikken spiller en afgørende rolle for den totale oplevelse af film og TV. Men det glemmes ofte igen, især i fortolk- ninger, der focuserer på handlingen og ser bort fra musikken og måske også den visuelle formidling. Tendensen til at "glemme" musikken i fortolkningen skyldes især, at den er svær at beskrive og svær at analysere. Ansa Lønstrups analyse af musikkens rolle i TV-serien Twin Peaks er en eksemplarisk gennem- gang af hvorledes musikken skaber betydning. Den er samtidig et bidrag til forståelsen af netop denne serie, der bl.a. udmærker sig ved, at den næppe kan begribes uden at musikken bliver en del af oplevelse og tolk- ning.

  6. Sensitivity of peak dynamic responses to input factors

    International Nuclear Information System (INIS)

    O'Connell, W.J.

    1984-06-01

    We examine the sensitivity of calculated peak dynamic responses, such as acceleration and moment, to input parameters such as frequency and damping. These responses have been calculated for the Zion Unit 1 plant, using the SSMRP computer code SMACS, as part of the seismic probabilistic risk assessment performed by the Seismic Safety Margins Research Program (SSMRP). We use linear regression analysis (LRA) to develop a simple model of the SMACS calculations. The sensitivities of the responses are the coefficients from the LRA. The LRA provides an approximate but simple overview of the complex response behavior. Heavy equipment such as the pressurizer and the steam generators has a large influence on the response of attached piping. Piping damping is sometimes important to the piping response, but in those cases piping frequency is usually more important. Variability in the inputs introduces correlations among the affected responses. The soil damping, through the local site effect, strongly affects all the plant responses

  7. Mean and peak wind load reduction on heliostats

    Energy Technology Data Exchange (ETDEWEB)

    Peterka, J.A.; Tan, L.; Bienkiewcz, B.; Cermak, J.E.

    1987-09-01

    This report presents the results of wind-tunnel tests supported through the Solar Energy Research Institute (SERI) by the Office of Solar Thermal Technology of the US Department of Energy as part of the SERI research effort on innovative concentrators. As gravity loads on drive mechanisms are reduced through stretched-membrane technology, the wind-load contribution of the required drive capacity increases in percentage. Reduction of wind loads can provide economy in support structure and heliostat drive. Wind-tunnel tests have been directed at finding methods to reduce wind loads on heliostats. The tests investigated both mean and peak forces, and moments. A significant increase in ability to predict heliostat wind loads and their reduction within a heliostat field was achieved. In addition, a preliminary review of wind loads on parabolic dish collectors was conducted, resulting in a recommended research program for these type collectors. 42 refs., 38 figs., 1 tab.

  8. Feature Classification of NSO/Kitt Peak Magnetograms

    Science.gov (United States)

    Malanushenko, O.; Jones, H. P.; Pap, J. M.; Turmon, M.

    2008-05-01

    We present new segmentations of daily NASA/NSO Spectromagnetograph (SPM) multidimensional magnetograms obtained at the NSO/Kitt Peak Vacuum Telescope from 1992-2003. Full-disk images are divided into areas of quiet Sun, network, active regions, and sunspots using a three-dimensional adaptation of a statistical image classification method developed by Turmon, Pap, and Mukhtar (ApJ 568:396-407, 2002). Probability distributions for each feature class are derived from a training set of images independently segmented using thresholds in magnetic flux and continuum intensity. We summarize our analysis procedures and compare segmentations derived from class-conditional probabilities computed with Gaussian mixture models and histogram interpolation. We also compare our segmentations with features identified by other methods and with solar irradiance variation.

  9. Energy solutions for CO2 emission peak and subsequent decline

    DEFF Research Database (Denmark)

    Risø International Energy Conference 2009 took place 14 – 16 September 2009. The conference focused on: • Future global energy development options Scenario and policy issues • Measures to achieve CO2 emission peak in 2015 – 2020 and subsequent decline • Renewable energy supply technologies...... such as bioenergy, wind and solar • Centralized energy technologies such as clean coal technologies • Energy conversion, energy carriers and energy storage, including fuel cells and hydrogen technologies • Providing renewable energy for the transport sector • Systems aspects for the various regions throughout...... the world • End-use technologies, efficiency improvements in supply and end use • Energy savings The proceedings are prepared from papers presented at the conference and received with corrections, if any, until the final deadline on 3 August 2009....

  10. Europe and the Peak Oil, an emergency situation

    International Nuclear Information System (INIS)

    Durand, B.

    2011-01-01

    The author shows why, in the coming years, severe oil supply difficulties will emerge in countries like France and the majority of European countries which do not possess significant oil resources on their land. He also highlights the risks for the European Union if no action is undertaken in front of this perspective. He discusses the British example as the United Kingdom has been the first country to use fossil fuels in an industrial way, and also possessed important quantities of oil and natural gas in the Northern Sea. He discusses the various data concerning the Peak Oil, and outlines the rapid decrease of available oil quantities on the international market. He highlights the difficult situation which will soon face Europe, and that measures must me implemented in emergency

  11. Modeling the peak of emergence in systems: Design and katachi.

    Science.gov (United States)

    Cardier, Beth; Goranson, H T; Casas, Niccolo; Lundberg, Patric; Erioli, Alessio; Takaki, Ryuji; Nagy, Dénes; Ciavarra, Richard; Sanford, Larry D

    2017-12-01

    It is difficult to model emergence in biological systems using reductionist paradigms. A requirement for computational modeling is that individual entities can be recorded parametrically and related logically, but their transformation into whole systems cannot be captured this way. The problem stems from an inability to formally represent the implicit influences that inform emergent organization, such as context, shifts in causal agency or scale, and self-reference. This lack hampers biological systems modeling and its computational counterpart, indicating a need for new fundamental abstraction frameworks that support system-level characteristics. We develop an approach that formally captures these characteristics, focusing on the way they come together to enable transformation at the 'peak' of the emergent process. An example from virology is presented, in which two seemingly antagonistic systems - the herpes cold sore virus and its host - are capable of altering their basic biological objectives to achieve a new equilibrium. The usual barriers to modeling this process are overcome by incorporating mechanisms from practices centered on its emergent peak: design and katachi. In the Japanese science of form, katachi refers to the emergence of intrinsic structure from real situations, where an optimal balance between implicit influences is achieved. Design indicates how such optimization is guided by principles of flow. These practices leverage qualities of situated abstraction, which we understand through the intuitive method of physicist Kôdi Husimi. Early results indicate that this approach can capture the functional transformations of biological emergence, whilst being reasonably computable. Due to its geometric foundations and narrative-based extension to logic, the method will also generate speculative predictions. This research forms the foundations of a new biomedical modeling platform, which is discussed. Copyright © 2017. Published by Elsevier Ltd.

  12. Logistic curves, extraction costs and effective peak oil

    International Nuclear Information System (INIS)

    Brecha, Robert J.

    2012-01-01

    Debates about the possibility of a near-term maximum in world oil production have become increasingly prominent over the past decade, with the focus often being on the quantification of geologically available and technologically recoverable amounts of oil in the ground. Economically, the important parameter is not a physical limit to resources in the ground, but whether market price signals and costs of extraction will indicate the efficiency of extracting conventional or nonconventional resources as opposed to making substitutions over time for other fuels and technologies. We present a hybrid approach to the peak-oil question with two models in which the use of logistic curves for cumulative production are supplemented with data on projected extraction costs and historical rates of capacity increase. While not denying the presence of large quantities of oil in the ground, even with foresight, rates of production of new nonconventional resources are unlikely to be sufficient to make up for declines in availability of conventional oil. Furthermore we show how the logistic-curve approach helps to naturally explain high oil prices even when there are significant quantities of low-cost oil yet to be extracted. - Highlights: ► Extraction cost information together with logistic curves to model oil extraction. ► Two models of extraction sequence for different oil resources. ► Importance of time-delay and extraction rate limits for new resources. ► Model results qualitatively reproduce observed extraction cost dynamics. ► Confirmation of “effective” peak oil, even though resources are in ground.

  13. Space geodetic techniques for global modeling of ionospheric peak parameters

    Science.gov (United States)

    Alizadeh, M. Mahdi; Schuh, Harald; Schmidt, Michael

    The rapid development of new technological systems for navigation, telecommunication, and space missions which transmit signals through the Earth’s upper atmosphere - the ionosphere - makes the necessity of precise, reliable and near real-time models of the ionospheric parameters more crucial. In the last decades space geodetic techniques have turned into a capable tool for measuring ionospheric parameters in terms of Total Electron Content (TEC) or the electron density. Among these systems, the current space geodetic techniques, such as Global Navigation Satellite Systems (GNSS), Low Earth Orbiting (LEO) satellites, satellite altimetry missions, and others have found several applications in a broad range of commercial and scientific fields. This paper aims at the development of a three-dimensional integrated model of the ionosphere, by using various space geodetic techniques and applying a combination procedure for computation of the global model of electron density. In order to model ionosphere in 3D, electron density is represented as a function of maximum electron density (NmF2), and its corresponding height (hmF2). NmF2 and hmF2 are then modeled in longitude, latitude, and height using two sets of spherical harmonic expansions with degree and order 15. To perform the estimation, GNSS input data are simulated in such a way that the true position of the satellites are detected and used, but the STEC values are obtained through a simulation procedure, using the IGS VTEC maps. After simulating the input data, the a priori values required for the estimation procedure are calculated using the IRI-2012 model and also by applying the ray-tracing technique. The estimated results are compared with F2-peak parameters derived from the IRI model to assess the least-square estimation procedure and moreover, to validate the developed maps, the results are compared with the raw F2-peak parameters derived from the Formosat-3/Cosmic data.

  14. Prediction of Peaks in Wolf Numbers in Cycle 24 according to Actual ...

    Indian Academy of Sciences (India)

    Abstract. Previous investigations by Makarovet al.have shown a relation between the peaks in the number of polar faculae and the peaks in the. Wolf number. In cycles 20 and 22 the delay between peaks in polar faculae and Wolf number was 6.1 ± 0.1 year, north and south taken separately, as their peaks do not coincide.

  15. Amorphous chalcogenides as random octahedrally bonded solids: I. Implications for the first sharp diffraction peak, photodarkening, and Boson peak

    Science.gov (United States)

    Lukyanov, Alexey; Lubchenko, Vassiliy

    2017-09-01

    We develop a computationally efficient algorithm for generating high-quality structures for amorphous materials exhibiting distorted octahedral coordination. The computationally costly step of equilibrating the simulated melt is relegated to a much more efficient procedure, viz., generation of a random close-packed structure, which is subsequently used to generate parent structures for octahedrally bonded amorphous solids. The sites of the so-obtained lattice are populated by atoms and vacancies according to the desired stoichiometry while allowing one to control the number of homo-nuclear and hetero-nuclear bonds and, hence, effects of the mixing entropy. The resulting parent structure is geometrically optimized using quantum-chemical force fields; by varying the extent of geometric optimization of the parent structure, one can partially control the degree of octahedrality in local coordination and the strength of secondary bonding. The present methodology is applied to the archetypal chalcogenide alloys AsxSe1-x. We find that local coordination in these alloys interpolates between octahedral and tetrahedral bonding but in a non-obvious way; it exhibits bonding motifs that are not characteristic of either extreme. We consistently recover the first sharp diffraction peak (FSDP) in our structures and argue that the corresponding mid-range order stems from the charge density wave formed by regions housing covalent and weak, secondary interactions. The number of secondary interactions is determined by a delicate interplay between octahedrality and tetrahedrality in the covalent bonding; many of these interactions are homonuclear. The present results are consistent with the experimentally observed dependence of the FSDP on arsenic content, pressure, and temperature and its correlation with photodarkening and the Boson peak. They also suggest that the position of the FSDP can be used to infer the effective particle size relevant for the configurational equilibration in

  16. Decreased peak expiratory flow in pediatric passive smokers

    Directory of Open Access Journals (Sweden)

    Fitri Yanti

    2011-08-01

    Full Text Available Background Indonesia ranks fifth among countries with the highest aggregate levels of tobacco consumption in the world. Infants and children exposed to environmental tobacco smoke have increased rates of asthma, respiratory and ear infections, as well as reduced lung function. The effects of tobacco smoke exposure on lung function in children have been reported to be dependent on the source of smoke and the length and dose of exposure. Lung function may also be affected by a child’s gender and asthma status. Objective To compare peak expiratory flow (PEF in pediatric passive smokers to that of children not exposed to second hand smoke, and to define factors that may affect PEF in passive smokers. Methods In August 2009 we conducted a cross-sectional study at an elementary school in the Langkat district. Subjects were aged 6 to 12 years, and divided into two groups: passive smokers and those not exposed to secondhand smoke. Subjects’ PEFs were measured with a Mini-Wright peak flow meter. Measurements were performed in triplicate with the highest value recorded as the PEF. Demographic data including age, sex, weight, height, family income, parental education levels and occupations were obtained through questionnaires. Results Of the 170 participants, 100 were passive smokers and 70 were not exposed to secondhand smoke. Age distribution, weight and height were similar in both groups. We observed a significant difference in PEFs between the group of passive smokers and the group not exposed to secondhand smoke, 211.3 L/minute (SD 61.08 and 242.7 L/minute (SD 77.09, respectively (P < 0.005. The number of years of exposure to smoke (P = 0.079 and the number of cigarettes smoked daily in the household (P = 0.098 did not significantly influence PEF. Conclusion The PEF in pediatric passive smokers was significantly lower than that of children not exposed to secondhand smoke. PEF in passive smokers was not influenced by the number of years of smoke

  17. Damage detection using sideband peak count in spectral correlation domain

    Science.gov (United States)

    Liu, Peipei; Sohn, Hoon

    2017-12-01

    Nonlinear ultrasonic techniques have been proven to be more sensitive to the presence of an early-stage damage than linear techniques. Among various nonlinear techniques, laser nonlinear wave modulation spectroscopy (LNWMS) utilizes a pulse laser to exert a broadband input and a damage on the target structure exhibits nonlinear wave modulation among various input frequency components. A sideband peak count (SPC) technique in the spectral frequency domain was proposed to estimate the damage-induced nonlinearity. In this study, the SPC operation is conducted in the spectral correlation domain so that noise has less influence on damage detection performance and a higher sensitivity to damage can be achieved. In addition, through spatial comparison of SPC over an inspection area, damage can be detected without relying on the baseline data obtained from a pristine condition. The performance of the proposed technique is validated using a numerical simulation performed on an aluminum plate with a simulated crack, and experiments performed on an aluminum plate with a fatigue crack and a carbon fiber reinforced polymer plate with delamination.

  18. Textural Poaching Twin Peaks: The Audrey Horne Sweater Girl GIFs

    Directory of Open Access Journals (Sweden)

    Jennifer Gillan

    2016-12-01

    Full Text Available This article aims to widen the lens of analysis of participatory culture inspired by long-arc serials like Twin Peaks. It considers GIF creation as a form of textural poaching, a new reception practice involving skimming off and repurposing top-of-the-mind content: the most arresting elements of costuming, set design, and dialogue. This behavior has become more popular as more series rely on textural storytelling and are filled with moments of excess that feel separate from the story. After an introduction to GIFs and GIF creation, it contrasts the impression of the character and series conveyed by Audrey Horne GIFs and the actual dynamics in the “Audrey’s Dance” scene. It establishes that Audrey’s look is most visually aligned with the Sweater Girl type, but as an allusive characterization it creates excess and calls attention to itself. Part of the “cool pop” reputation of the series may stem from the wider circulation of iconic moments of excess especially given that the GIFs detach the images from the series’ uneven storytelling and its challenging surrealist sensibility.

  19. Sensitivity of peak dynamic responses to input factors

    International Nuclear Information System (INIS)

    O'Connell, W.J.

    1984-01-01

    The authors examine the sensitivity of calculated peak dynamic responses, such as acceleration and moment, to input parameters such as frequency and damping. These responses have been calculated for the Zion Unit 1 plant, using the SSMRP computer code SMACS, as part of the seismic probabilistic risk assessment performed by the Seismic Safety Margins Research Program (SSMRP), supported by the NRC Office of Nuclear Regulatory Research. They use linear regression analysis (LRA) to develop a simple model of the SMACS calculations. The sensitivities of the responses are the coefficients from the LRA. The LRA provides an approximate but simple overview of the complex response behavior. Heavy equipment such as the pressurizer and the steam generators has a large influence on the response of attached piping. Piping damping is sometimes important to the piping response, but in those cases piping frequency is usually more important. Variability in the inputs introduces correlations among the affected responses. The soil damping, through the local site effect, strongly affects all the plant responses

  20. Residential implementation of critical-peak pricing ofelectricity

    Energy Technology Data Exchange (ETDEWEB)

    Herter, Karen

    2006-06-29

    This paper investigates how critical-peak pricing (CPP)affects households with different usage and income levels, with the goalof informing policy makers who are considering the implementation of CPPtariffs in the residential sector. Using a subset of data from theCalifornia Statewide Pricing Pilot of 2003-2004, average load changeduring summer events, annual percent bill change, and post-experimentsatisfaction ratings are calculated across six customer segments,categorized by historical usage and income levels. Findings show thathigh-use customers respond significantly more in kW reduction than dolow-use customers, while low-use customers save significantly more inpercentage reduction of annual electricity bills than do high-usecustomers results that challenge the strategy of targeting only high-usecustomers for CPP tariffs. Across income levels, average load and billchanges were statistically indistinguishable, as were satisfaction ratesresults that are compatible with a strategy of full-scale implementationof CPP rates in the residential sector. Finally, the high-use customersearning less than $50,000 annually were the most likely of the groups tosee bill increases about 5 percent saw bill increases of 10 percent ormore suggesting that any residential CPP implementation might considertargeting this customer group for increased energy efficiencyefforts.