Meta contrastive label correction for financial time series

Financial applications such as stock price forecasting, usually face an issue that under the predefined labeling rules, it is hard to accurately predict the directions of stock movement. This is because traditional ways of labeling, taking Triple Barrier Method, for example, usually gives us inaccurate or even corrupted labels. To address this issue, we focus on two main goals. One is that our proposed method can automatically generate correct labels for noisy time series patterns, while at the same time, the method is capable of boosting classification performance on this new labeled dataset. Based on the aforementioned goals, our approach has the following three novelties: First, we fuse a new contrastive learning algorithm into the meta-learning framework to estimate correct labels iteratively when updating the classification model inside. Moreover, we utilize images generated from time series data through Gramian angular field and representative learning. Most important of all, we adopt multi-task learning to forecast temporal-variant labels. In the experiments, we work on 6% clean data and the rest unlabeled data. It is shown that our method is competitive and outperforms a lot compared with benchmarks

Physiological effects of combined NaCl and NaHCO3 stress on the seedlings of two maple species

Salt stress impacts growth and physiological processes in plants, and some plants exposed to salt stress will produce physiological mechanisms to adapt to the new environment. However, the effects of combined NaCl and NaHCO3 stress on the seedlings of Acer species are understudied. In this study, we designed an experiment to measure physiological characteristics by establishing a range of NaCl and NaHCO3 concentrations (0, 25, 50, 75, and 100 mmol L-1) to estimate the compound salt tolerance of Acer ginnala and Acer palmatum. When the concentrations of NaCl and NaHCO3 were 25 mmol L-1, the leaf water content, relative conductivity, malondialdehyde (MDA) content, proline content, soluble sugar content, and chlorophyll did not change (p > 0.05) in two maple seedlings. At concentrations greater than 50 mmol L-1, the relative conductivity and MDA content increased, proline and soluble sugars accumulated, and the potential activity of PS II (Fv/Fo), potential photochemical efficiency of PS II (Fv/Fm), PS II actual photochemical efficiency (Yield), and photosynthetic electron transfer efficiency (ETR) decreased (p < 0.05). The superoxide dismutase (SOD) and catalase (CAT) activities showed the same trend of first increasing and then decreasing (p < 0.05). The peroxidase (POD) activity increased only when concentrations of NaCl and NaHCO3 were 100 mmol L-1, while there was no statistical difference between the other treatments and the control. Therefore, the two maple seedlings adjusted their osmotic balance and alleviated oxidative stress by accumulating proline, soluble sugars and increasing CAT and SOD activities. Further analysis showed that both species are salt tolerant and the salt tolerance of Acer ginnala is better than that of Acer palmatum

Seizing the window of opportunity to mitigate the impact of climate change on the health of Chinese residents

The health threats posed by climate change in China are increasing rapidly. Each province faces different health risks. Without a timely and adequate response, climate change will impact lives and livelihoods at an accelerated rate and even prevent the achievement of the Healthy and Beautiful China initiatives. The 2021 China Report of the Lancet Countdown on Health and Climate Change is the first annual update of China’s Report of the Lancet Countdown. It comprehensively assesses the impact of climate change on the health of Chinese households and the measures China has taken. Invited by the Lancet committee, Tsinghua University led the writing of the report and cooperated with 25 relevant institutions in and outside of China. The report includes 25 indicators within five major areas (climate change impacts, exposures, and vulnerability; adaptation, planning, and resilience for health; mitigation actions and health co-benefits; economics and finance; and public and political engagement) and a policy brief. This 2021 China policy brief contains the most urgent and relevant indicators focusing on provincial data: The increasing health risks of climate change in China; mixed progress in responding to climate change. In 2020, the heatwave exposures per person in China increased by 4.51 d compared with the 1986–2005 average, resulting in an estimated 92% increase in heatwave-related deaths. The resulting economic cost of the estimated 14500 heatwave-related deaths in 2020 is US$176 million. Increased temperatures also caused a potential 31.5 billion h in lost work time in 2020, which is equivalent to 1.3% of the work hours of the total national workforce, with resulting economic losses estimated at 1.4% of China’s annual gross domestic product. For adaptation efforts, there has been steady progress in local adaptation planning and assessment in 2020, urban green space growth in 2020, and health emergency management in 2019. 12 of 30 provinces reported that they have completed, or were developing, provincial health adaptation plans. Urban green space, which is an important heat adaptation measure, has increased in 18 of 31 provinces in the past decade, and the capacity of China’s health emergency management increased in almost all provinces from 2018 to 2019. As a result of China’s persistent efforts to clean its energy structure and control air pollution, the premature deaths due to exposure to ambient particulate matter of 2.5 μm or less (PM2.5) and the resulting costs continue to decline. However, 98% of China’s cities still have annual average PM2.5 concentrations that are more than the WHO guideline standard of 10 μg/m3. It provides policymakers and the public with up-to-date information on China’s response to climate change and improvements in health outcomes and makes the following policy recommendations. (1) Promote systematic thinking in the related departments and strengthen multi-departmental cooperation. Sectors related to climate and development in China should incorporate health perspectives into their policymaking and actions, demonstrating WHO’s and President Xi Jinping’s so-called health-in-all-policies principle. (2) Include clear goals and timelines for climate-related health impact assessments and health adaptation plans at both the national and the regional levels in the National Climate Change Adaptation Strategy for 2035. (3) Strengthen China’s climate mitigation actions and ensure that health is included in China’s pathway to carbon neutrality. By promoting investments in zero-carbon technologies and reducing fossil fuel subsidies, the current rebounding trend in carbon emissions will be reversed and lead to a healthy, low-carbon future. (4) Increase awareness of the linkages between climate change and health at all levels. Health professionals, the academic community, and traditional and new media should raise the awareness of the public and policymakers on the important linkages between climate change and health.</p

Modeling and prescribed H-infinity tracking control for strict feedback nonlinear systems

By utilizing backstepping technique, an&nbsp;H∞&nbsp;robust controller with improved prescribed performance and dynamic surface control is designed for a class of strict feedback nonlinear systems. The transient and steady state performance for the tracking errors of nonlinear system can be guaranteed by using improved prescribed performance constraint. The dynamic surface control is used to overcome the differential explosion problem in the backstepping procedure. The impacts of uncertainties in the system are attenuated by&nbsp;H∞control. The performance and stability analysis proves that the controller design procedure is simple with low complexity and robustness. Finally, the simulation results verify the effectiveness of the controller. By comparing with the existing method, the proposed method has a faster convergence speed and better steady state performance, and also the controller design process is simpler

An Evaluation Model for the Influence of KOLs in Short Video Advertising Based on Uncertainty Theory

In the era of rapid growth in the short video industry, it is very important to find more accurate suitable advertising promoters, namely Key Opinion Leaders, to promote the development of short video commerce. A mathematical method is needed to grade and evaluate KOL’s abilities. Only in this way can advertisers better determine the value of KOL and determine whether it is suitable for promoting its products. Moreover, in the hierarchical evaluation of KOL, there is not only structured and quantifiable information, but also a large amount of unstructured and linguistic non-quantifiable information. Therefore, this article regards unquantifiable information as an uncertain variable and uses a comprehensive evaluation method based on uncertainty theory to handle subjective uncertainty in the evaluation process. Among them, all uncertain variables are symmetric. The main contribution of this article is the provision of a new evaluation method for KOL grading. Firstly, a two-level evaluation index system for KOL was established. Secondly, the importance and annotation of the Index set are set as uncertain variables, and the KOL evaluation model is constructed. Finally, two KOLs on TikTok were selected for comparative analysis to determine the importance ranking and KOL scores of each level of indicator, verifying the effectiveness and practicality of this method

Noninvasive evaluation of intracranial pressure in patients with traumatic brain injury by transcranial Doppler ultrasound

Abstract Introduction The purpose of this study was to investigate the relationship between pulsatility index (PI) or optic nerve sheath diameter (ONSD) and intracranial pressure (ICP) in patients with traumatic brain injury (TBI), and the ability of ONSD and ICP to predict intracranial hypertension. Methods A total of 68 patients with TBI were included in this retrospective study. After receiving surgery treatment, they underwent transcranial Doppler ultrasound (TCD). The statistical correlation between PI or ONSD and ICP 1 week after surgery was analyzed. Furthermore, the areas under the curve (AUCs) of ONSD or PI or a combination of them were calculated to predict intracranial hypertension. Results There was a correlation between ONSD and ICP. This correlation still remained at ONSD ≥ 5 mm. Furthermore, there was a strong correlation between PI and ICP. There was a moderate correlation between ICP and PI on days 3, 4, and 5 after surgery (r = 0.508, p < .001), and a strong correlation on days 6 and 7 after surgery (r = 0.645, p < .001). Moreover, for predicting intracranial hypertension with PI ≥ 1.2 mm or ONSD ≥ 5 mm or a combination of them, the AUC was 0.729, 0.900, and 0.943, respectively (p < .001). Conclusions The correlation between ONSD or PI and invasive ICP was different with different levels of ICP in different periods in patients with TBI after surgery. When ONSD ≥ 5 mm and PI ≥ 1.2, it could predict elevated ICP more accurately

Evolution Laws for Frozen Wall Formation under Conditions of Sudden Seepage

Sudden seepage is a special working condition affecting artificial ground freezing (AGF) in many projects which results in significant differences within the temperature field. In order to study the characteristics of frozen walls influenced by water flow, a series of model tests were carried out at different seepage velocities. The model test results show that a frozen wall will change from symmetrical to eccentric as the cooling energy absorption of the soil and the brine return temperature increase. In model tests, when the seepage velocity was 0∼30 m/d, the frozen wall was partially destroyed. When the seepage velocity exceeded 30 m/d, the frozen wall was completely destroyed. This study examines the expansion rate of the upstream and downstream freezing fronts, and the distribution law of the freezing temperature field, the average temperature change under different seepage speeds, and the bearing capacity of the freezing wall are analyzed. Research on these factors suggests that a frozen wall has a certain level of resistance to sudden seepage. When the flow velocity is small, the freezing effect will be strengthened. With an increase in the flow velocity, the freezing effect will gradually weaken. Based on these conclusions, the current study points out targeted solutions that should be adopted in cases of sudden seepage in a project

Formula Development and Application of Wall Protection Slurry for Long-distance Horizontal Freezing Boreholes and Thorough Piles

Since complex barriers need to be passed through during the process of drilling long-distance horizontal freezing boreholes, the stability of the borehole wall at the soft and hard stratum interface is the key in controlling the deflection of the horizontal boreholes. The author puts forward to establishing the stability mechanical model of horizontal freezing borehole walls with fluid loss as the control index, starting from the stability mechanism of horizontal freezing boreholes and combined with the working conditions of horizontal freezing boreholes; selects two optimal fluid loss additives from the perspective of the molecular structure of bentonite materials, and determines the optimal formula by formulation optimization by virtue of orthogonal tests; applies the optimal formula into the long-distance pile and borehole penetration test, and validates the reliability of wall protection slurry formula materials for horizontal boreholes via comparing the water loss and soil erosion at the pile interface and analyzing the deflection rules, which is of certain value in engineering promotion and application