With the appearance of electricity markets, the variation of the price of electricity will influence usage custom of electric energy. This will complicate short-term load forecasting and challenge ...the existing forecasting methods that are applied to a fixed-price environment. In regard to the influence of real-time electricity prices on short-term load, a model to forecast short-term load is established by combining the radial basis function (RBF) neural network with the adaptive neural fuzzy inference system (ANFIS). The model first makes use of the nonlinear approaching capacity of the RBF network to forecast the load on the prediction day with no account of the factor of electricity price, and then, based on the recent changes of the real-time price, it uses the ANFIS system to adjust the results of load forecasting obtained by RBF network. This system integration will improve forecasting accuracy and overcome the defects of the RBF network. As shown in this paper by the results of an example of factual forecasting, the model presented can work effectively.
In the last hundred years, analyses of grain size have been widely performed, and numerous powerful tools have been published. The unmixing of grain size distributions is a popular topic in recent ...research. As one kind of decomposition method, single-sample unmixing (SSU) is usually regarded as not genetically meaningful with another unmixing method, end-member modeling analysis (EMMA), although it is still widely used. Some recent studies have noted that EMMA also has limits, and different EMMA algorithms may yield various results. However, no research has discussed the similarities and differences between EMMA and SSU and provided objective conclusions regarding their ranges of application. In this study, a detailed discussion is given regarding the similarities and differences of these methods based on the corresponding mathematical models, and detailed explanations of their features are presented based on numerical optimization and information theory. In addition, the ranges of application are objectively constrained, and we suggest that SSU may have greater potential, although the corresponding fitting process is more complex and difficult. We also highlight the importance of a comprehensive analysis. Traditional methods and geological settings are also important for the interpretation of grain size distributions. An easy-to-use software for the comprehensive analysis of grain size distributions called QGrain is introduced; it not only integrates many traditional analysis tools but also provides new high-performance EMMA and SSU algorithms. Compared to other EMMA algorithms, our EMMA algorithm exhibits outstanding performance. Furthermore, our SSU algorithm can overcome the shortcomings of the traditional method and can compete and collaborate with EMMA algorithms.
This book is devoted to a comprehensive treatment of this important field, a grand challenge for future networking research. It covers results from the authors as well as other researchers. Topics ...covered include Independent Case Analysis and its applications.
Aims A field experiment was conducted to investigate the effect of biochar on maize yield and greenhouse gases (GHGs) in a calcareous loamy soil poor in organic carbon from Henan, central great ...plain, China. Methods Biochar was applied at rates of 0, 20 and 40 tha−1 with or without N fertilization. With N fertilization, urea was applied at 300 kg N ha−1, of which 60% was applied as basal fertilizer and 40% as supplementary fertilizer during crop growth. Soil emissions of CO2, CH4 and N2O were monitored using closed chambers at 7 days intervals throughout the whole maize growing season (WMGS). Results Biochar amendments significantly increased maize production but decreased GHGs. Maize yield was increased by 15.8% and 7.3% without N fertilization, and by 8.8% and 12.1% with N fertilization under biochar amendment at 20 tha−1 and 40 tha−1, respectively. Total N2O emission was decreased by 10.7% and by 41.8% under biochar amendment at 20 tha−1 and 40 tha−1 compared to no biochar amendment with N fertilization. The high rate of biochar (40 tha−1) increased the total CO2 emission by 12% without N fertilization. Overall, biochar amendments of 20 tha−1 and 40 tha−1 decreased the total global warming potential (GWP) of CH4 and N2O by 9.8% and by 41.5% without N fertilization, and by 23.8% and 47.6% with N fertilization, respectively. Biochar amendments also decreased soil bulk density and increased soil total N contents but had no effect on soil mineral N. Conclusions These results suggest that application of biochar to calcareous and infertile dry croplands poor in soil organic carbon will enhance crop productivity and reduce GHGs emissions.
Aeolian dust deposits from continent and ocean have been extensively investigated to reflect past changes in source aridity and atmospheric circulations. Aeolian flux (AF) as a quantitative dust ...proxy has been widely used in both palaeoenvironmental reconstruction and numerical simulation. However, available AF data on the Chinese Loess Plateau (CLP) is too limited to assess the temporal-spatial variations at glacial-interglacial timescales, and therefore cannot be used as robust input parameters in palaeoclimate models. Here we investigate eight loess profiles along two N-S-aligned transects on the CLP to quantitatively estimate the AF variations over the last glacial-interglacial cycle. We first establish a refined chronological framework based on optically stimulated luminescence chronology and pedostratigraphic correlation. AF was then estimated by multiplying the sedimentation rate and bulk density. The results show that the AF increases from 2-18 g cm-2 ka-1 in the southeastern CLP to 14-105 g cm-2 ka-1 in the northwestern CLP. At glacial-interglacial scales, the AF varies from 2-20 g cm-2 ka-1 during the last interglacial to 8-105 g cm-2 ka-1 in the last glaciation. Due to more spatial coverage and better age constraints, our AF data can be used to refine other AF datasets and to improve the proxy-model comparison.
•Incremental costs of the EETA account for a large proportion of total incremental costs of green buildings.•The EETA on green buildings can bring incremental economic and environmental ...benefits.•Financial evaluation results of the EETA have not market investment potential.•The most sensitive factor on financial evaluation results of the EETA is power price.
In order to initiate economic evaluation of green buildings and foster their development, this article conducts the cost–benefit evaluation of energy efficiency technology application (EETA) on green buildings in China. Based on the economic evaluation theory of construction project (EETCP), the authors first establishes the theoretical framework system of cost–benefit evaluation of the EETA on green buildings and then develops the analysis methods of incremental costs and quantitative calculation formula of incremental benefits of the EETA on green buildings. Using these theories and methods, this article takes the Wanke City project in China as a study case, conducts the cost–benefit empirical analysis of the EETA on green buildings, and draws the following important conclusions: (1) the incremental costs of the EETA account for a large proportion of total incremental costs of green buildings, which are more than 50% in this case; (2) the EETA on green buildings can bring incremental economic benefits, as well as environmental benefits; (3) if only consider the incremental economic benefits of the EETA on green buildings, the financial evaluation indexes show green buildings do not have market investment potential; (4) among all the factors influencing the financial evaluation results of the EETA on green buildings, power price is the most sensitive factor, followed by the unit incremental costs, and the lifetime has the smallest influence.
In the process of oil reservoir development, clay minerals in the pores of a reservoir swell because of water absorption, blocking the pore channels, and decreasing the reservoir permeability. This ...phenomenon is referred to as reservoir water sensitivity. To develop and protect oil and gas fields more scientifically and effectively and save development cost, we examine the water sensitivity of the low-permeability conglomerate reservoir of the Lower Karamay Formation in the 530-well area of District 8 of the Karamay oil field. Based on multiple linear regression and neural network methods, the quantitative calculation of different types of clay minerals was performed by comprehensively using natural gamma ray, neutron, density, sonic transit time, and X-ray diffraction (XRD) analysis data. The water sensitivity experiment was performed in the study area, and the logging interpretation method of reservoir water sensitivity was established by considering the clay mineral content as the medium; moreover, the reservoir water sensitivity degree was quantitatively explained.
The internet of things (IoT) makes it possible to measure physical variables and acquire data in places that were impossible a few years ago, such as transmission lines and electrical substations. ...Monitoring and fault diagnosis strategies can then be applied. A battery or an energy harvesting system charging a rechargeable battery typically powers IoT devices. The energy harvesting unit and rechargeable battery supply the sensors and wireless communications modules. Therefore, the energy harvesting unit must be correctly sized to optimize the availability and reliability of IoT devices. This paper applies a power balance of the entire IoT device, including the energy harvesting module that includes two thermoelectric generators and a DC-DC converter, the battery, and the sensors and communication modules. Due to the small currents typical of the different communication phases and their fast-switching nature, it is not trivial to measure the energy in each phase, requiring very specific instrumentation. This work shows that using conventional instrumentation it is possible to measure the energy involved in the different modes of communication. A detailed energy balance of the battery is also carried out during charge and discharge cycles, as well as communication modes, from which the maximum allowable data transfer rate is determined. The approach presented here can be generalized to many other smart grid IoT devices.
Two different stratiomyomorphan larvae are described and illustrated based on two well-preserved specimens from the mid-Cretaceous amber of Myanmar. They both exhibit the diagnostic feature of the ...Stratiomyomorpha: integument hardened and shagreened with small rounded facets. One of the larvae (form 1) presents distinctive morphological characters of both Stratiomyidae and Xylomyidae: prothoracic and mesothoracic segments with normal shagreened pattern on dorsum and venter, a transverse row of teeth developed before the anal cleft, and anal plates bordered with a row of similar teeth. These features may indicate that form 1 occupies a basal position within the clade Xylomyidae + Stratiomyidae. This new material is the first record of stratiomyomorphan larvae from Burmese amber.
•Dynamic line rating (DLR) allows the full capacity of the lines to be utilized.•We study the effect of emissivity on the DLR rating of transmission line conductors.•We also propose model-based ...method for measuring the emissivity value.•Experimental results show that aged conductors perform better than new ones.
Emissivity and absorptivity are important parameters in overhead power line conductors that depend on the conductor surface condition, so their values change as the conductors age. They have an important effect on their thermal behavior, so it is important to know their value when designing dynamic line rating (DLR) strategies. DLR methods are becoming increasingly important, especially in areas with congested power lines, as they allow the full capacity of the lines to be utilized by dynamically determining their maximum allowable currents without exceeding the safe temperature limits of the conductors, thus ensuring that they operate within safe limits. However, measuring emissivity and absorptivity is non-trivial and requires complex tests that cannot be performed in the field. Using simulations based on a realistic thermoelectric model and experimental tests performed on three types of transmission line conductors in a high-current laboratory, this paper shows the importance and effect of emissivity on conductor temperature. It also presents a method for measuring the emissivity value based on adjusting the emissivity and absorptivity values in the thermoelectric model to match the experimental values. The results presented show that aged conductors allow an increase in the maximum current carrying capacity compared to new conductors in the order of 5–14 %, depending on the conductor type considered and the operating conditions.
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