The article discusses the features of the solving the forecasting problems using machine learning techniques. The issues of accounting and correctly processing non-linear non-stationary processes in the problems of mo...
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ISBN:
(数字)9781728132143
ISBN:
(纸本)9781728132150
The article discusses the features of the solving the forecasting problems using machine learning techniques. The issues of accounting and correctly processing non-linear non-stationary processes in the problems of modeling and forecasting time series in various areas are considered. The analysis of stages and methods for solving machine learning problems. As an example, consider the problem of predicting currency pairs based on historical data. A comparative analysis of the normalization methods in data clustering is given. For the six currency pairs a short-term forecast is proposed.
Nitrogen-vacancy (N-V) centers in diamond have developed into a powerful solid-state platform for compact quantum sensors. However, high-sensitivity measurements usually come with additional constraints on the pumping...
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Nitrogen-vacancy (N-V) centers in diamond have developed into a powerful solid-state platform for compact quantum sensors. However, high-sensitivity measurements usually come with additional constraints on the pumping intensity of the laser and the pulse control applied. Here, we demonstrate high-sensitivity N-V-ensemble-based magnetic field measurements with low-intensity optical excitation. Direct current magnetometry methods such as continuous-wave optically detected magnetic resonance and continuously excited Ramsey measurements combined with lock-in detection are compared to achieve an optimization. Gradiometry is also investigated as a step towards unshielded measurements of unknown gradients. The magnetometer demonstrates a minimum detectable field of 0.3–0.7 pT in a 73-s measurement when a flux guide with a sensing dimension of 2 mm is applied, corresponding to a magnetic field sensitivity of 2.6–6 pT/Hz. Combined with our previous efforts on diamond ac magnetometry, the diamond magnetometer is promising for performing wide-bandwidth magnetometry with picotesla sensitivity and a cubic-millimeter sensing volume under ambient conditions.
Human migration during the Chinese Spring Festival (SF) is the largest collective human activity of its kind in the modern era-involving about one-tenth of the world population and over six percent of the earth's ...
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Solar energy is increasingly becoming a significant source of clean energy. It harnesses a lot of benefits including the social, environmental, and economic aspects, and increases the progress toward the United Nation...
Solar energy is increasingly becoming a significant source of clean energy. It harnesses a lot of benefits including the social, environmental, and economic aspects, and increases the progress toward the United Nation’s Sustainable Development Goals (SDGs). Photovoltaic (PV) system installations in rural areas and deserts suffer from dust accumulation on PV surfaces reducing the solar radiation penetration, thus reducing the output generated from the PV system. As a result, in order to maintain consistent performance, PV panels must be cleaned on a frequent and efficient basis. The objective of this paper is to provide a review of dust cleaning methods for solar PV panels with an emphasis on a sustainable perspective for dust separation. There are various cleaning methods, including passive, active, and manual cleaning. This paper shows the progress of current cleaning methods through extensive research. Plenty of research has been done on various cleaning techniques for solar photovoltaic panels. The optimum cleaning method mainly depends on various parameters and the available budget. However, researchers are generally promoting nanofilm coating and robotic systems while considering PV plant size, design, tilt angle, location, water availability at the site, and type of dust.
The nearby radio galaxy M87 is a prime target for studying black hole accretion and jet formation1,2. Event Horizon Telescope observations of M87 in 2017, at a wavelength of 1.3 mm, revealed a ring-like structure, whi...
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Post-pandemic green recovery is pivotal in achieving global sustainable development goals by simultaneously revitalizing economies and reducing greenhouse gas emissions, air pollution and improving public welfare. How...
Post-pandemic green recovery is pivotal in achieving global sustainable development goals by simultaneously revitalizing economies and reducing greenhouse gas emissions, air pollution and improving public welfare. However, subnational and city-level understanding of green recovery, its efficacy and its alignment with public health is poorly understood. Here we focus on post-COVID-19 low-carbon recovery—economic growth combined with reduced carbon emissions—and explore health co-benefits in Chinese cities. A novel near-real-time daily carbon emission dataset of 48 cities in China is developed, coupled with detailed health and economic municipal statistics and models. We find that, on average, six low-carbon-recovery cities, mainly megacities, saved 1.2 times as many lives per 100,000 population compared with the 42 other cities, and their annual monetary avoided premature deaths per 100,000 population was 1.5 times more than the 42 other cities. The accumulated monetary health co-benefits for low-carbon-recovery cities were US$ 4.2 billion (95% confidence interval, 2.1–6.3) during the post-COVID-19 period. We show that government spending on electric vehicles increases the likelihood of achieving low-carbon recovery in Chinese cities. Our results underscore the significant health co-benefits of low-carbon recovery, pointing to synergies between advancing local welfare and global environmental objectives.
The nearby radio galaxy M87 is a prime target for studying black hole accretion and jet formation. Event Horizon Telescope observations of M87 in 2017, at a wavelength of 1.3 mm, revealed a ring-like structure, which ...
The nearby radio galaxy M87 is a prime target for studying black hole accretion and jet formation. Event Horizon Telescope observations of M87 in 2017, at a wavelength of 1.3 mm, revealed a ring-like structure, which was interpreted as gravitationally lensed emission around a central black hole. Here we report images of M87 obtained in 2018, at a wavelength of 3.5 mm, showing that the compact radio core is spatially resolved. High-resolution imaging shows a ring-like structure of [Formula: see text] Schwarzschild radii in diameter, approximately 50% larger than that seen at 1.3 mm. The outer edge at 3.5 mm is also larger than that at 1.3 mm. This larger and thicker ring indicates a substantial contribution from the accretion flow with absorption effects, in addition to the gravitationally lensed ring-like emission. The images show that the edge-brightened jet connects to the accretion flow of the black hole. Close to the black hole, the emission profile of the jet-launching region is wider than the expected profile of a black-hole-driven jet, suggesting the possible presence of a wind associated with the accretion flow.
Nitrogen vacancy (NV) centers in diamond have developed into a powerful solid-state platform for compact quantum sensors. However, high sensitivity measurements usually come with additional constraints on the pumping ...
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This paper presents the design and implementation of incremental backstepping (IBS) flight control laws for the attitude control and stabilization on a fixed-wing aircraft. The design consists of multiple functionalit...
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This paper describes the design, implementation and flight testing of flight control laws based on Incremental Nonlinear Dynamic Inversion (INDI). The method compares com- manded and measured accelerations to compute ...
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