TESTING OF CAPITAL ASSET PRICING MODEL: AN EMPIRICIAL ANALYSIS BASED ON THE SHANGHAI AND HONG KONG STOCK MAEKETS

The CAPM model attempts to represent people's complex investment decisions through a series of rigorous assumptions about the real stock market. The CAPM model attempts to express people's complex investment decisions in terms of numerically calculated utility values. However, the conditional assumptions of the CAPM model cannot really be met, even in more mature equity markets. As an important theory of financial asset pricing, the applicability of the CAPM model in real capital markets is naturally attracted to research. In this paper, the Shanghai and Hong Kong stock markets are used as the subject of study to test the validity of the CAPM model for the period 27 November 2016 - 21 November 2021. The test is based on the Fama-Macbeth Approach, in which the portfolios are no longer grouped in order of β size, but a representative market portfolio is selected as the portfolio for time series regression and cross-sectional regression on market indicators (method from Wei, 2016). The regression results show that in the time series regression, both the Shanghai equity market and the Hong Kong equity market exhibit a linear relationship between the excess returns of the portfolio and the excess returns of the market, but in the cross-sectional regression, the linear relationship shown by the CAPM model exists in the Shanghai equity market for only one time period, while in the analysis of the Hong Kong equity market, there are two time periods that conform to the CAPM model. In contrast, the CAPM model is more valid in the Hong Kong market than in the Shanghai equity market, but overall, the CAPM model is not applicable to both markets

TESTING OF CAPITAL ASSET PRICING MODEL: AN EMPIRICIAL ANALYSIS BASED ON THE SHANGHAI AND HONG KONG STOCK MAEKETS

The CAPM model attempts to represent people's complex investment decisions through a series of rigorous assumptions about the real stock market. The CAPM model attempts to express people's complex investment decisions in terms of numerically calculated utility values. However, the conditional assumptions of the CAPM model cannot really be met, even in more mature equity markets. As an important theory of financial asset pricing, the applicability of the CAPM model in real capital markets is naturally attracted to research. In this paper, the Shanghai and Hong Kong stock markets are used as the subject of study to test the validity of the CAPM model for the period 27 November 2016 - 21 November 2021. The test is based on the Fama-Macbeth Approach, in which the portfolios are no longer grouped in order of β size, but a representative market portfolio is selected as the portfolio for time series regression and cross-sectional regression on market indicators (method from Wei, 2016). The regression results show that in the time series regression, both the Shanghai equity market and the Hong Kong equity market exhibit a linear relationship between the excess returns of the portfolio and the excess returns of the market, but in the cross-sectional regression, the linear relationship shown by the CAPM model exists in the Shanghai equity market for only one time period, while in the analysis of the Hong Kong equity market, there are two time periods that conform to the CAPM model. In contrast, the CAPM model is more valid in the Hong Kong market than in the Shanghai equity market, but overall, the CAPM model is not applicable to both markets

Percolation Theories for Quantum Networks

Quantum networks have experienced rapid advancements in both theoretical and experimental domains over the last decade, making it increasingly important to understand their large-scale features from the viewpoint of statistical physics. This review paper discusses a fundamental question: how can entanglement be effectively and indirectly (e.g., through intermediate nodes) distributed between distant nodes in an imperfect quantum network, where the connections are only partially entangled and subject to quantum noise? We survey recent studies addressing this issue by drawing exact or approximate mappings to percolation theory, a branch of statistical physics centered on network connectivity. Notably, we show that the classical percolation frameworks do not uniquely define the network's indirect connectivity. This realization leads to the emergence of an alternative theory called ``concurrence percolation,'' which uncovers a previously unrecognized quantum advantage that emerges at large scales, suggesting that quantum networks are more resilient than initially assumed within classical percolation contexts, offering refreshing insights into future quantum network design

Targeted next-generation sequencing of dedifferentiated chondrosarcoma in the skull base reveals combined TP53 and PTEN mutations with increased proliferation index, an implication for pathogenesis

Dedifferentiated chondrosarcoma (DDCS) is a rare disease with a dismal prognosis. DDCS consists of two morphologically distinct components: the cartilaginous and noncartilaginous components. Whether the two components originate from the same progenitor cells has been controversial. Recurrent DDCS commonly displays increased proliferation compared with the primary tumor. However, there is no conclusive explanation for this mechanism. In this paper, we present two DDCSs in the sellar region. Patient 1 exclusively exhibited a noncartilaginous component with a TP53 frameshift mutation in the pathological specimens from the first surgery. The tumor recurred after radiation therapy with an exceedingly increased proliferation index. Targeted next-generation sequencing (NGS) revealed the presence of both a TP53 mutation and a PTEN deletion in the cartilaginous and the noncartilaginous components of the recurrent tumor. Fluorescence in situ hybridization and immunostaining confirmed reduced DNA copy number and protein levels of the PTEN gene as a result of the PTEN deletion. Patient 2 exhibited both cartilaginous and noncartilaginous components in the surgical specimens. Targeted NGS of cells from both components showed neither TP53 nor PTEN mutations, making Patient 2 a naïve TP53 and PTEN control for comparison. In conclusion, additional PTEN loss in the background of the TP53 mutation could be the cause of increased proliferation capacity in the recurrent tumor

Exploring the impact of smartphone addiction on decision-making behavior in college students: an fNIRS study based on the Iowa Gambling Task

The pervasive use of smartphones, while enhancing accessibility to information and communication, has raised concerns about its potential negative effects on physical and mental health, including the impairment of decision-making abilities. This study investigates the influence of smartphone addiction on decision-making in college students. A sample of 80 individuals aged 17 to 26 was selected and divided into two groups based on their Smartphone Addiction Scale-Short Version (SAS-SV) scores. Participants underwent the Iowa Gambling Task (IGT) to evaluate their decision-making in risky and uncertain conditions, while fNIRS recorded their prefrontal cortex activity. The study found that individuals prone to smartphone addiction tend to make riskier choices in risky situations. However, when faced with decisions based on ambiguity, the smartphone addiction group showed increased brain activity in the dlPFC (specifically in channels 4, 9, and 11) compared to when making risky decisions. Despite this increased brain activation, there was no observable difference in behavior between the addiction-prone and control groups in ambiguous scenarios. Notably, the left dlPFC (e.g., channel 4) exhibited significantly higher activation in the addiction group compared to the control group. Findings suggest that smartphone addiction can detrimentally influence decision-making, behaviorally and neurologically, particularly in uncertain contexts. This study supports the classification of smartphone addiction as a genuine addiction and underscores its significance in psychiatric research. In essence, our research underscores the adverse effects of excessive smartphone use on decision-making processes, reinforcing the necessity to treat smartphone addiction as a pressing public health issue

Ethnic discordance in serum anti-Müllerian hormone in healthy women: a population study from China and Europe

Research question: Chinese women are known to have an earlier age of natural menopause than their European counterparts, but whether they also have a lower functional ovarian reserve is unknown. This study was designed to assess whether there are ethnic differences in anti-Müllerian hormone (AMH) concentrations in women of reproductive age. Design: Women in China and Europe with regular menstrual cycles, not on hormonal contraception and with no medical history of note, were recruited to provide a day 2–5 early follicular phase sample. AMH concentration was determined using the Roche Elecsys assay. Decline in AMH was modelled with linear, quadratic and quadratic with interaction on age equations to assess the impact of ethnicity. Results: A total of 887 European and 461 Chinese women participated in the study. Despite the Chinese population being slightly younger (34.1 ± 8.4 years) than their European counterparts (34.8±8.9 years), their median AMH was lower, at 1.87 ng/ml (interquartile range [IQR] 0.28–3.64) compared with 2.11 ng/ml (IQR 0.73–3.96), with evidence of increasing discordance from age 25 years. In all regression models of the age-related decline in AMH, there was evidence of a difference between Chinese and European women. Although AMH was 28.1% (95% confidence interval [CI] 18.2–36.7%) lower in the Chinese population at age 30, this decline increased to 79.4% (95% CI 75.4– 82.9%) at age 45. Conclusions: There were independent effects of age and ethnicity on serum AMH concentrations, with Chinese women having a substantially lower AMH in adult life than their European counterparts from age 25 onwards

TESTING OF CAPITAL ASSET PRICING MODEL: AN EMPIRICIAL ANALYSIS BASED ON THE SHANGHAI AND HONG KONG STOCK MAEKETS

The CAPM model attempts to represent people's complex investment decisions through a series of rigorous assumptions about the real stock market. The CAPM model attempts to express people's complex investment decisions in terms of numerically calculated utility values. However, the conditional assumptions of the CAPM model cannot really be met, even in more mature equity markets. As an important theory of financial asset pricing, the applicability of the CAPM model in real capital markets is naturally attracted to research. In this paper, the Shanghai and Hong Kong stock markets are used as the subject of study to test the validity of the CAPM model for the period 27 November 2016 - 21 November 2021. The test is based on the Fama-Macbeth Approach, in which the portfolios are no longer grouped in order of β size, but a representative market portfolio is selected as the portfolio for time series regression and cross-sectional regression on market indicators (method from Wei, 2016). The regression results show that in the time series regression, both the Shanghai equity market and the Hong Kong equity market exhibit a linear relationship between the excess returns of the portfolio and the excess returns of the market, but in the cross-sectional regression, the linear relationship shown by the CAPM model exists in the Shanghai equity market for only one time period, while in the analysis of the Hong Kong equity market, there are two time periods that conform to the CAPM model. In contrast, the CAPM model is more valid in the Hong Kong market than in the Shanghai equity market, but overall, the CAPM model is not applicable to both markets

TESTING OF CAPITAL ASSET PRICING MODEL: AN EMPIRICIAL ANALYSIS BASED ON THE SHANGHAI AND HONG KONG STOCK MAEKETS

The CAPM model attempts to represent people's complex investment decisions through a series of rigorous assumptions about the real stock market. The CAPM model attempts to express people's complex investment decisions in terms of numerically calculated utility values. However, the conditional assumptions of the CAPM model cannot really be met, even in more mature equity markets. As an important theory of financial asset pricing, the applicability of the CAPM model in real capital markets is naturally attracted to research. In this paper, the Shanghai and Hong Kong stock markets are used as the subject of study to test the validity of the CAPM model for the period 27 November 2016 - 21 November 2021. The test is based on the Fama-Macbeth Approach, in which the portfolios are no longer grouped in order of β size, but a representative market portfolio is selected as the portfolio for time series regression and cross-sectional regression on market indicators (method from Wei, 2016). The regression results show that in the time series regression, both the Shanghai equity market and the Hong Kong equity market exhibit a linear relationship between the excess returns of the portfolio and the excess returns of the market, but in the cross-sectional regression, the linear relationship shown by the CAPM model exists in the Shanghai equity market for only one time period, while in the analysis of the Hong Kong equity market, there are two time periods that conform to the CAPM model. In contrast, the CAPM model is more valid in the Hong Kong market than in the Shanghai equity market, but overall, the CAPM model is not applicable to both markets

Optimization and Analysis of a U-Shaped Linear Piezoelectric Ultrasonic Motor Using Longitudinal Transducers

A novel U-shaped piezoelectric ultrasonic motor that mainly focused on miniaturization and high power density was proposed, fabricated, and tested in this work. The longitudinal vibrations of the transducers were excited to form the elliptical movements on the driving feet. Finite element method (FEM) was used for design and analysis. The resonance frequencies of the selected vibration modes were tuned to be very close to each other with modal analysis and the movement trajectories of the driving feet were gained with transient simulation. The vibration modes and the mechanical output abilities were tested to evaluate the proposed motor further by a prototype. The maximum output speed was tested to be 416 mm/s, the maximum thrust force was 21 N, and the maximum output power was 5.453 W under frequency of 29.52 kHz and voltage of 100 Vrms. The maximum output power density of the prototype reached 7.59 W/kg, which was even greater than a previous similar motor under the exciting voltage of 200 Vrms. The proposed motor showed great potential for linear driving of large thrust force and high power density