Precision measurement of the return distribution property of the Chinese stock market index

Systematical and precise analysis on the 1-min datasets over the 17-year period 2005-2021 for both the Shanghai Stock Exchange and the Shenzhen Stock Exchange composite index is conducted in this paper. Here we precisely measure the property of return distributions of composite indices over time scale $\Delta t$ ranging from 1 min up to almost 4,000 min, to reveal the difference between the Chinese stock market and the mature stock market in developed countries. The return distributions of composite indices for both exchanges show similar behavior. Main findings in this paper are as follows. (1) The central part of return distribution is well described by symmetrical L$\acute{e}$vy $\alpha$-stable process with stability parameter comparable with the value of about 1.4 extracted in the U.S. stock market. (2) Distinctively, the stability parameter shows a potential change when $\Delta t$ increases, and thus a crossover region located at 15 $< \Delta t <$ 60 min is observed, which is different from the finding in the U.S. stock market where a single value of about 1.4 holds over 1 $\le \Delta t \le$ 1,000 min. (3) Return distributions can be also well described by the student's distribution within wider return range than the L$\acute{e}$vy $\alpha$-stable distribution. (4) The tail distributions of returns at small $\Delta t$ decay as asymptotic power law with exponents being about 3, which is a value widely existed in mature stock markets. However, it decays exponentially for $\Delta t \ge$ 240 min, which is not observed in mature markets. (5) The return distributions slowly converge to Gaussian along with $\Delta t$ increasing, which is also different from the finding of a critical $\Delta t = 4$ days in the U.S. stock market

Heavy-tailed distributions of confirmed COVID-19 cases and deaths in spatiotemporal space

This paper conducts a systematic statistical analysis of the characteristics of the geographical empirical distribution for the numbers of both cumulative and daily confirmed COVID-19 cases and deaths at county, city, and state levels over a time span from January 2020 to June 2022. The mathematical heavy-tailed distributions can be used for fitting the empirical distributions observed in different temporal stages and geographical scales. According to the characteristics of the heavy-tailed distributions, the evolution course of the geographical empirical distribution can be divided into three distinct phases, namely the power-law phase, the lognormal phase I, and the lognormal phase II. These three phases could serve as an indicator of the severity degree of the COVID-19 pandemic within an area. The empirical results suggest important intrinsic dynamics of a human infectious virus spread in the human interconnected physical complex network. The findings extend previous empirical studies and could provide more strict constraints for current mathematical and physical modeling studies. In the future, the distribution patterns observed in this study would provide macroscopic implications for the design of containment measures and the allocation of resources among different places if a new pandemic breaks out

NATURE OF THE LATE CARBONIFEROUS TO TRIASSIC MAGMATISM ALONG THE NORTHERN MARGIN OF THE NORTH CHINA BLOCK: LINK WITH THE EVOLUTION OF THE CENTRAL ASIAN OROGEN

There are two episodes of magmatism along the northern margin of the North China block during the Late Carboniferous to Late Triassic, one at 310–250 Ma (Late Carboniferous to Permian) and the other at 235–210 Ma (Late Triassic). The former group comprises plutonic rocks (gabbro-diorite-monzodioritemonzogranite-granite), mafic to intermediate dykes (diorite to dolerite) and a few felsic volcanics (andesite to dacite).There are two episodes of magmatism along the northern margin of the North China block during the Late Carboniferous to Late Triassic, one at 310–250 Ma (Late Carboniferous to Permian) and the other at 235–210 Ma (Late Triassic). The former group comprises plutonic rocks (gabbro-diorite-monzodioritemonzogranite-granite), mafic to intermediate dykes (diorite to dolerite) and a few felsic volcanics (andesite to dacite)

Model-free screening procedure for ultrahigh-dimensional survival data based on Hilbert-Schmidt independence criterion

How to select the active variables which have significant impact on the event of interest is a very important and meaningful problem in the statistical analysis of ultrahigh-dimensional data. Sure independent screening procedure has been demonstrated to be an effective method to reduce the dimensionality of data from a large scale to a relatively moderate scale. For censored survival data, the existing screening methods mainly adopt the Kaplan--Meier estimator to handle censoring, which may not perform well for scenarios which have heavy censoring rate. In this article, we propose a model-free screening procedure based on the Hilbert-Schmidt independence criterion (HSIC). The proposed method avoids the complication to specify an actual model from a large number of covariates. Compared with existing screening procedures, this new approach has several advantages. First, it does not involve the Kaplan--Meier estimator, thus its performance is much more robust for the cases with a heavy censoring rate. Second, the empirical estimate of HSIC is very simple as it just depends on the trace of a product of Gram matrices. In addition, the proposed procedure does not require any complicated numerical optimization, so the corresponding calculation is very simple and fast. Finally, the proposed procedure which employs the kernel method is substantially more resistant to outliers. Extensive simulation studies demonstrate that the proposed method has favorable exhibition over the existing methods. As an illustration, we apply the proposed method to analyze the diffuse large-B-cell lymphoma (DLBCL) data and the ovarian cancer data

Bidding decision in land auction using prospect theory

Land auction is widely practiced in company and government decisions, especially in China. Bidders are always faced with two or more auctions in the period of a decision cycle. The outcome of the auction is under high risk. The bidder's risk attitude and preference will have a great influence on his/her bidding price. Prospect theory is currently the main descriptive theory of decision under risk. In this paper, we will consider the preferences of the decision-makers in land bidding decisions with the multi-attribute additive utility and reference point method in cumulative prospect theory. Three land auction models are proposed based on the appearance time of the land auctions. The simultaneous model uses cumulative prospect theory without considering the relationships between the auctions. The time sequential model involves the exchange auction decisions at different time with the third-generation prospect theory. The event sequential model further considers the reference point prediction in sequential land auction decisions. The three models can help the decision-makers make better bidding price decision when they are faced with several land auctions in the period of a decision cycle. A case study illustrates the processes and results of our approaches

An Efficient End-to-End Transformer with Progressive Tri-modal Attention for Multi-modal Emotion Recognition

Recent works on multi-modal emotion recognition move towards end-to-end models, which can extract the task-specific features supervised by the target task compared with the two-phase pipeline. However, previous methods only model the feature interactions between the textual and either acoustic and visual modalities, ignoring capturing the feature interactions between the acoustic and visual modalities. In this paper, we propose the multi-modal end-to-end transformer (ME2ET), which can effectively model the tri-modal features interaction among the textual, acoustic, and visual modalities at the low-level and high-level. At the low-level, we propose the progressive tri-modal attention, which can model the tri-modal feature interactions by adopting a two-pass strategy and can further leverage such interactions to significantly reduce the computation and memory complexity through reducing the input token length. At the high-level, we introduce the tri-modal feature fusion layer to explicitly aggregate the semantic representations of three modalities. The experimental results on the CMU-MOSEI and IEMOCAP datasets show that ME2ET achieves the state-of-the-art performance. The further in-depth analysis demonstrates the effectiveness, efficiency, and interpretability of the proposed progressive tri-modal attention, which can help our model to achieve better performance while significantly reducing the computation and memory cost. Our code will be publicly available

A genetic variant of the sperm-specific SLO3 K+ channel has altered pH and Ca2+ sensitivities

To fertilize an oocyte, sperm must first undergo capacitation in which the sperm plasma membrane becomes hyperpolarized via activation of potassium (K(+)) channels and resultant K(+) efflux. Sperm-specific SLO3 K(+) channels are responsible for these membrane potential changes critical for fertilization in mouse sperm, and they are only sensitive to pH i However, in human sperm, the major K(+) conductance is both Ca(2+)- and pH i -sensitive. It has been debated whether Ca(2+)-sensitive SLO1 channels substitute for human SLO3 (hSLO3) in human sperm or whether human SLO3 channels have acquired Ca(2+) sensitivity. Here we show that hSLO3 is rapidly evolving and reveal a natural structural variant with enhanced apparent Ca(2+) and pH sensitivities. This variant allele (C382R) alters an amino acid side chain at a principal interface between the intramembrane-gated pore and the cytoplasmic gating ring of the channel. Because the gating ring contains sensors to intracellular factors such as pH and Ca(2+), the effectiveness of transduction between the gating ring and the pore domain appears to be enhanced. Our results suggest that sperm-specific genes can evolve rapidly and that natural genetic variation may have led to a SLO3 variant that differs from wild type in both pH and intracellular Ca(2+) sensitivities. Whether this physiological variation confers differences in fertility among males remains to be established.info:eu-repo/semantics/publishe

Guarding Embryo Development of Zebrafish by Shell Engineering: A Strategy to Shield Life from Ozone Depletion

Background: The reduced concentration of stratospheric ozone results in an increased flux of biologically damaging midultraviolet radiation (UVB, 280 to 320 nm) reaching earth surfaces. Environmentally relevant levels of UVB negatively impact various natural populations of marine organisms, which is ascribed to suppressed embryonic development by increased radiation. Methodology/Principal Findings: Inspired by strategies in the living systems generated by evolution, we induce an extra UVB-adsorbed coat on the chorion (eggshell surrounding embryo) of zebrafish, during the blastula period. Short and long UV exposure experiments show that the artificial mineral-shell reduces the UV radiation effectively and the enclosed embryos become more robust. In contrast, the uncoated embryos cannot survive under the enhanced UVB condition. Conclusions: We suggest that an engineered shell of functional materials onto biological units can be developed as a strategy to shield lives to counteract negative changes of global environment, or to provide extra protection for the living units in biological research