12,453 research outputs found

    Coordinated Generation and Transmission Maintenance Scheduling Considering Network Constraints via GGDF and ODF

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    This paper proposes a coordinated generation and transmission maintenance scheduling by incorporating network constraints. The main advantage of the proposed approach is that maintenance is scheduled at the optimal period of the lowest possible operating cost while satisfying all the specified constraints. In this approach, sensitivity factors (GGDFs and ODFs) which are based on DC approximation are applied to calculate the line flows in normal and maintenance conditions. They are applied due to their simplicity, linearity, physical comprehension and rapidity of computation. To simulate the effect of network constraint on maintenance schedule and operating cost, several cases are studied with and without transmission limit constraints. To ensure the accuracy of these sensitivity factors, power flows on each line are compared with the one obtained from a PSSE simulator. The result shows that generators and transmission lines are scheduled at periods that satisfy the transmission capacity limit

    Pilot-scale spinning and sucrose-tetra-aldehydes-crosslinking of feather-derived protein fibers with improved mechanical properties and water resistance

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    Pliable and water-resistant protein fibers from feathers were developed via continuous one-step spinning and crosslinking using sucrose-tetra-aldehydes. Though flexible protein fibers from feathers were developed, poor wet stability and low tenacity still limit the large and high-end applications of feather-derived fibers. Despite that saccharide aldehydes are considered as an efficient and sustainable crosslinker, substantial concerns such as generation of formaldehyde, high consumption of modifiers, loss of mechanical properties, yellowing, and decline in dyeability of fibers, exist after crosslinking. In this work, we controlled structures of crosslinkers and incorporated disaccharide-tetra-aldehydes into a continuous wet-spinning line. No formaldehyde was generated in the whole process. Protein fibers with controlled aldimine crosslinkages had not only a 92% tenacity retention after immersed in water for 1 week but also a substantial increase in mechanical properties. The dry and wet tenacity of feather-derived fibers was 120% and 90% of wool, respectively. Moreover, crosslinking from disaccharide-tetra-aldehydes retained the color of fibers and minimized the consumption of amine groups, the dyeing sites, on keratin. No toxicity was introduced by crosslinking. This work promotes resource recovery from poultry wastes, decreases the reliance of fiber industry on petroleum-based products, and diminishes environmental impact of fiber industries

    A field-theoretical approach to the extended Hubbard model

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    We transform the quartic Hubbard terms in the extended Hubbard model to a quadratic form by making the Hubbard-Stratonovich transformation for the electron operators. This transformation allows us to derive exact results for mass operator and charge-charge and spin-spin correlation functions for s-wave superconductivity. We discuss the application of the method to the d-wave superconductivity

    Convert index trading to option strategies via LSTM architecture

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    AbstractIn the past, most strategies were mainly designed to focus on stocks or futures as the trading target. However, due to the enormous number of companies in the market, it is not easy to select a set of stocks or futures for investment. By investigating each company's financial situation and the trend of the overall financial market, people can invest precisely in the market and choose to go long or short. Moreover, how to determine the position size of the transaction is also a problematic issue. In the past, many money management theories were based on the Kelly criterion. And they put a certain percentage of their total funds into the market for trading. Nonetheless, three massive problems cannot be overcome. First, futures are leveraged transactions, and extra funds must be deposited as margin. It causes that the position size is hard to be estimated by the Kelly criterion. The second point is that the trading strategy is difficult to determine the winning rate in the financial market and cannot be brought into the Kelly criterion to calculate the optimal fraction. Last, the financial data are always massive. A big data technique should be applied to resolve this issue and enhance the performance of the framework to reveal knowledge in the financial data. Therefore, in this paper, a concept of converting the original futures trading strategy into options trading is proposed. An LSTM (long short-term memory)-based framework is proposed to predict the profit probability of the original futures strategy and convert the corresponding daily take-profit and stop-loss points according to the delta value of the options. Finally, the proposed framework brings the results into the Kelly criterion to get the optimal fraction of options trading. The final research results show that options trading is closer to the optimal fraction calculated by the Kelly criterion than futures trading. If the original futures trading strategy can profit, the benefits after converting to options trading can be further superior
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