Anisotropic time-dependent behaviors of shale under direct shearing and associated empirical creep models

Understanding the anisotropic creep behaviors of shale under direct shearing is a challenging issue.In this context,we conducted shear-creep and steady-creep tests on shale with five bedding orientations (i.e.0°,30°,45°,60°,and 90°),under multiple levels of direct shearing for the first time.The results show that the anisotropic creep of shale exhibits a significant stress-dependent behavior.Under a low shear stress,the creep compliance of shale increases linearly with the logarithm of time at all bedding orientations,and the increase depends on the bedding orientation and creep time.Under high shear stress conditions,the creep compliance of shale is minimal when the bedding orientation is 0°,and the steady-creep rate of shale increases significantly with increasing bedding orientations of 30°,45°,60°,and 90°.The stress-strain values corresponding to the inception of the accelerated creep stage show an increasing and then decreasing trend with the bedding orientation.A semilogarithmic model that could reflect the stress dependence of the steady-creep rate while considering the hardening and damage process is proposed.The model minimizes the deviation of the calculated steady-state creep rate from the observed value and reveals the behavior of the bedding orientation's influence on the steady-creep rate.The applicability of the five classical empirical creep models is quantitatively evaluated.It shows that the logarithmic model can well explain the experimental creep strain and creep rate,and it can accurately predict long-term shear creep deformation.Based on an improved logarithmic model,the variations in creep parameters with shear stress and bedding orientations are discussed.With abovementioned findings,a mathematical method for constructing an anisotropic shear creep model of shale is proposed,which can characterize the nonlinear dependence of the anisotropic shear creep behavior of shale on the bedding orientation.

Incorporating empirical knowledge into data-driven variable selection for quantitative analysis of coal ash content by laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy(LIBS)has become a widely used atomic spectroscopic technique for rapid coal analysis.However,the vast amount of spectral information in LIBS contains signal uncertainty,which can affect its quantification performance.In this work,we propose a hybrid variable selection method to improve the performance of LIBS quantification.Important variables are first identified using Pearson's correlation coefficient,mutual information,least absolute shrinkage and selection operator(LASSO)and random forest,and then filtered and combined with empirical variables related to fingerprint elements of coal ash content.Subsequently,these variables are fed into a partial least squares regression(PLSR).Additionally,in some models,certain variables unrelated to ash content are removed manually to study the impact of variable deselection on model performance.The proposed hybrid strategy was tested on three LIBS datasets for quantitative analysis of coal ash content and compared with the corresponding data-driven baseline method.It is significantly better than the variable selection only method based on empirical knowledge and in most cases outperforms the baseline method.The results showed that on all three datasets the hybrid strategy for variable selection combining empirical knowledge and data-driven algorithms achieved the lowest root mean square error of prediction(RMSEP)values of 1.605,3.478 and 1.647,respectively,which were significantly lower than those obtained from multiple linear regression using only 12 empirical variables,which are 1.959,3.718 and 2.181,respectively.The LASSO-PLSR model with empirical support and 20 selected variables exhibited a significantly improved performance after variable deselection,with RMSEP values dropping from 1.635,3.962 and 1.647 to 1.483,3.086 and 1.567,respectively.Such results demonstrate that using empirical knowledge as a support for datadriven variable selection can be a viable approach to improve the accuracy and reliability of LIBS quantification.

Empirical likelihood for spatial cross-sectional data models with matrix exponential spatial specification

In this paper,we study spatial cross-sectional data models in the form of matrix exponential spatial specification(MESS),where MESS appears in both dependent and error terms.The empirical likelihood(EL)ratio statistics are established for the parameters of the MESS model.It is shown that the limiting distributions of EL ratio statistics follow chi-square distributions,which are used to construct the confidence regions of model parameters.Simulation experiments are conducted to compare the performances of confidence regions based on EL method and normal approximation method.

Assessment of the three representative empirical models for zenith tropospheric delay(ZTD)using the CMONOC data

The precise correction of atmospheric zenith tropospheric delay(ZTD)is significant for the Global Navigation Satellite System(GNSS)performance regarding positioning accuracy and convergence time.In the past decades,many empirical ZTD models based on whether the gridded or scattered ZTD products have been proposed and widely used in the GNSS positioning applications.But there is no comprehensive evaluation of these models for the whole China region,which features complicated topography and climate.In this study,we completely assess the typical empirical models,the IGGtropSH model(gridded,non-meteorology),the SHAtropE model(scattered,non-meteorology),and the GPT3 model(gridded,meteorology)using the Crustal Movement Observation Network of China(CMONOC)network.In general,the results show that the three models share consistent performance with RMSE/bias of 37.45/1.63,37.13/2.20,and 38.27/1.34 mm for the GPT3,SHAtropE and IGGtropSH model,respectively.However,the models had a distinct performance regarding geographical distribution,elevation,seasonal variations,and daily variation.In the southeastern region of China,RMSE values are around 50 mm,which are much higher than that in the western region,approximately 20 mm.The SHAtropE model exhibits better performance for areas with large variations in elevation.The GPT3 model and the IGGtropSH model are more stable across different months,and the SHAtropE model based on the GNSS data exhibits superior performance across various UTC epochs.

Research on the longitudinal protection of a through-type cophase traction direct power supply system based on the empirical wavelet transform

This paper proposes a longitudinal protection scheme utilizing empirical wavelet transform(EWT)for a through-type cophase traction direct power supply system,where both sides of a traction network line exhibit a distinctive boundary structure.This approach capitalizes on the boundary’s capacity to attenuate the high-frequency component of fault signals,resulting in a variation in the high-frequency transient energy ratio when faults occur inside or outside the line.During internal line faults,the high-frequency transient energy at the checkpoints located at both ends surpasses that of its neighboring lines.Conversely,for faults external to the line,the energy is lower compared to adjacent lines.EWT is employed to decompose the collected fault current signals,allowing access to the high-frequency transient energy.The longitudinal protection for the traction network line is established based on disparities between both ends of the traction network line and the high-frequency transient energy on either side of the boundary.Moreover,simulation verification through experimental results demonstrates the effectiveness of the proposed protection scheme across various initial fault angles,distances to faults,and fault transition resistances.

Variational Mode Decomposition-Informed Empirical Wavelet Transform for Electric Vibrator Noise Analysis

Electric vibrators find wide applications in reliability testing, waveform generation, and vibration simulation, making their noise characteristics a topic of significant interest. While Variational Mode Decomposition (VMD) and Empirical Wavelet Transform (EWT) offer valuable support for studying signal components, they also present certain limitations. This article integrates the strengths of both methods and proposes an enhanced approach that integrates VMD into the frequency band division principle of EWT. Initially, the method decomposes the signal using VMD, determining the mode count based on residuals, and subsequently employs EWT decomposition based on this information. This addresses mode aliasing issues in the original method while capitalizing on VMD’s adaptability. Feasibility was confirmed through simulation signals and ultimately applied to noise signals from vibrators. Experimental results demonstrate that the improved method not only resolves EWT frequency band division challenges but also effectively decomposes signal components compared to the VMD method.

Empirical Analysis of the ESG and Financial Performance:Evidence from Chinese Technology Enterprises

To date,the concept of sustainable development has gained global attention from companies and investors.One important reason for this is the increasing interest of investors in incorporating environmental,social,and governance(ESG)elements into their investments.The purpose of this dissertation is to analyze the correlation between ESG factor performance and corporate financial performance in Chinese technology enterprises.Additionally,the study focuses on Internet and medical technology companies to ensure relevance.The findings of the study provide guidance on ESG investment and sustainability for both companies and individual investors.

Security Risk Assessment in Container Terminals:Empirical Evidence from Greece

The most prominent risk assessment techniques are founded on the values of measuring and controlling the frequency and the consequences of risks in order to assure an“acceptable level”of“safeness”mainly in the lines of environmental,health and hygiene and port product issues.This paper examines security risk assessment approaches within the emerging role of ports.This paper contributes to the current literature by considering the ports of Greece as a case in point and by measuring the degree of its security risk orientation based on certain valid risk factors drawn from the current literature.Moreover,it presents a security risk assessment methodology into the domain of port container terminals.Their potential for ports were quantitatively and qualitatively assessed by discussing issues of security approaches within the maritime industry,in order to facilitate improvement strategies.A two-dimension empirical study was conducted,in a time range of ten years(2010-2020)in order to provide evidence regarding security risk assessment in the port container terminal of Thessaloniki,in Greece.The findings of this study have significant strategic policy implications and shed more light on the role of security risks in the overall risk orientation of container terminals in practice.Finally,further research directions in security risk in ports are proposed.

Evaluation and Empirical Research on Teachers’ Information Literacy in the Context of Smart Education

The development of smart education has led to the integration of emerging technologies such as artificial intelligence with education.It is a prerequisite for teachers to have high information literacy for conducting education and teaching work.This study conducted a questionnaire survey on 412 teachers in a certain area.The results showed that teachers’information literacy is above the middle level,and there are significant differences in information literacy between teaching experience and educational background.The evaluation showed that information ethics,information awareness,and information application have a significant positive impact on professional development,and information knowledge and information awareness have a positive predictive effect on information ethics.

An Empirical Evaluation of the Impact of Moral and Law Course Teaching on the Effectiveness of University Students’Ideals and Beliefs Education

The Moral and Law course serves as a critical platform for educating university students about ideals and beliefs,and it has a significant impact on the effectiveness of ideals and beliefs education.This paper establishes a mechanism through which Moral and Law course teaching influences the effectiveness of ideals and beliefs education and conducts an empirical evaluation.The results reveal that factors such as the relevance and applicability of the teaching content,the integration of theory and practice,the innovation,interactivity,and participation of teaching methods,as well as classroom atmosphere,teaching facilities,and campus culture,all have a significant positive impact on the effectiveness of ideals and beliefs education for university students.

Random noise attenuation by f–x spatial projection-based complex empirical mode decomposition predictive filtering

The frequency–space（f–x） empirical mode decomposition（EMD） denoising method has two limitations when applied to nonstationary seismic data. First, subtracting the first intrinsic mode function（IMF） results in signal damage and limited denoising. Second, decomposing the real and imaginary parts of complex data may lead to inconsistent decomposition numbers. Thus, we propose a new method named f–x spatial projection-based complex empirical mode decomposition（CEMD） prediction filtering. The proposed approach directly decomposes complex seismic data into a series of complex IMFs（CIMFs） using the spatial projection-based CEMD algorithm and then applies f–x predictive filtering to the stationary CIMFs to improve the signal-to-noise ratio. Synthetic and real data examples were used to demonstrate the performance of the new method in random noise attenuation and seismic signal preservation.

EMPIRICAL STUDY ON CAPITAL STRUCTURE OF LISTED COMPANIES IN CHINESE STOCK MARKET

Capital structure decision is an important issue of corporate finance.Theories show that,the corporate debt ratio is determined by many factors.This study conducts empirical work on capital structure theories,focusing on the corporate data of Chinese listed companies,by considering the intrinsic characteristics,utilizing the principal factor analysis and the ridge regression method.Our results suggest that a firms debt ratio has a positive relationship with its size,profitability and operating risk and has a negative relationship with its growth and non debt tax shield,while the long term leverage has a positive relationship with its collateral value of assets.

Empirical Bayes Estimation for the Parameter of Two-dimen sional One-side Truncated Distribution Families with Linex Loss

In this paper, we construct the EB estim ation for the parameter of the two-dimensional one side truncat ed distribution fam ilies using Linex loss. The convergence rate of EB estimation is given and it is shown that the proposed empirical Bayes estimaiton can be arbitrarily close to 1 under certain conditions.

An Empirical Study on the Concept of“Honesty and Integrity”between Chinese and Westerners

Language and culture have been mutually dependent through their history. The moral principle—honesty and integrity isone of the most significant categories of human's culture.The author does a literary review of the relationship between language andculture. Then she makes an analysis of an empirical study on Chinese and Western concepts of"honesty and integrity".In light ofthe empirical study, the author has found that Chinese mainly come into contact with the idea of"honesty and integrity"from theirparents, while the Westerners learn this concept mostly from school education.

Empirical Study on Management of Flowers Tourism

The paper had illustrated the construction of Yanling Famous Flowers and Trees Science Park and highlighted its important position as scalized,standardized and corporatization demonstration based on development of flower industry and basic condition of the park.Through interview and sample survey of flower enterprises,it concluded that the park had vigorous support from government,good service concept,strong consciousness for developing flowers tourism,and scaled development.And meantime,it pointed out three problems in park's management which were problems about enterprise's flower production characteristic,about the concept of farmers of land transference,and about enterprises.Finally,from the perspective of park's management,it put forward some suggestions on flowers tourism development.In terms of flowers tourism development,it should enhance characterization,scale and standardization of enterprises production,explore diversified methods for land transference,and strengthen peasant-workers' skill and thought training.In terms of supportive policy,it should intensify the park's identification,pay attention to protection of ecological environment,create tourist products of local feature,enhance publicity and highlight participation and experience projects.

Empirical Research on Tourism Authenticity of Ancient Cultural City——A Case Study of Lijiang Ancient City in China

On the basis of tourism authenticity theory and field investigation and analysis of Lijiang ancient city, the paper had explored tourists' tourism authenticity, and further revealed the inner relation between tourism authenticity and tourism motivation of ancient cultural cities. It was found that ancient cultural cities generally had the highest objective authenticity, followed by existential, constructive and post-modern authenticity. As for tourism motivation, motivation of knowledge function, of reward maximization, of punishment minimization, of self-esteem and of self-fulfillment presented to diminish progressively. Relationships between four types of tourism authenticity and five types of tourism motivations also varied from each other. It had enriched empirical quantitative research results of domestic tourism authenticity in theory, and provided application value for the research on realistic tourism market and planning activity based on tourists in practice.

The Empirical Research of Native Thinking in the Process of English Composition

The method of questionnaire is employed to investigate the impact of Chinese thinking in the writing processes of 80 college English majors.It reveals that the English writing process is a bilingual event(namely,English writers have both Chinese and English at their disposal when they are composing in English).And no matter whether the English proficiency of the learners is high or low,the learners have a great dependence on Chinese thinking in the process of English writing.In the categories of task reacting and content organizing,there is no great difference between the high and low English proficiency students.But in the category of linguistic form,the influence of Chinese thinking on the low level students is far greater than the high level students.

从美国EMPIRE软件看大型高功率脉冲电磁等离子体程序研发趋势

EMPIRE软件是美国针对下一代高性能计算平台开发的电磁等离子体模拟软件,可用于高置信度地开展高功率脉冲产生、传输以及与物质互作用的全过程模拟。解读EMPIRE软件的研制进展对发展大型高功率脉冲电磁等离子体软件具有重要借鉴意义。首先分析了EMPIRE软件的架构及数学物理方案,然后着重讨论了其性能可移植性的软件特征和各子模块的算法特点,最后结合具体的应用案例展示了EMPIRE的强大计算能力。解读EMPIRE的启示包括如下几点:使用异构架构是实现未来E级(百亿亿次级)计算能力部署的关键点;研制灵活的功能模块,开展分层级的建模计算,最后拉通整个物理过程链条模拟,能够有效发挥装置指标的数值评估作用;多团队协作共同开发是丰富软件功能的基础;软件的置信度需要全方位的验证与确认。

Empirical Bayes Absolute Error Loss Estimation for Parameter of One-Side Truncation Distribution Families

In this paper we propose an absolute error loss EB estimator for parameter of one-side truncation distribution families. Under some conditions we have proved that the convergence rates of its Bayes risk is o, where 0<λ,r≤1,Mn≤lnln n (for large n),Mn→∞ as n→∞.

An Empirical Research on Integrating Chinese Traditional Culture into College English Teaching

198 non-English freshmen students from Shandong Yingcai College were selected as research subjects.The subjects were divided into the experimental group(EG) and the control group(CG).The students in EG were taught English integrated Chinese traditional culture for three semesters,while the ones in CG were taught as usual.The results indicate that the integration of Chinese culture broadens the students' horizons and improves the students' ability to express Chinese culture in English and intercultural communicative competence.