Is the cryptocurrency market a hedge against stock market risk? A Wavelet and GARCH approach

This study analyses six major cryptocurrencies and four global stock markets to explore the role of cryptocurrencies as a hedge, safe haven, and diversifier in stock markets. The study employs ADCC-GARCH and Wavelet Coherence Technique, using daily data from 4 January 2017 to 28 February 2023. The study has found that stock returns and unstable cryptocurrency returns have high volatility persistence in the long run. Besides, while unstable digital currencies (Bitcoin, Ethereum, Binance Coin, and Dogecoin) serve as a hedge during stable economic periods, they have not been a hedge during economic turmoil in the stock markets. Conversely, stablecoins (Tether and USD Coin) have been shown to have acted as a hedge during normal economic times and have offered a safe haven during economic downturns. Except for Tether, all cryptocurrencies' diversification capacity is time-varying. In stable economic conditions, they serve as diversifiers, but during turmoil, they do not. However, Tether serves as a diversifier regardless of the financial situation. Finally, the present investigation is expected to offer crucial information on hedge, safe haven and diversification for quasi-investors.     

数控机床技术发展趋势分析

对数控机床的现状进行分析,并指出了数控机床的发展趋势。     

Reducing complexity and compliance costs: a simplification safe harbour for the global minimum tax

I present a simplification safe harbour based on tax administrative guidance for Pillar Two, the global minimum tax, developed together with Cedric Döllefeld, Joachim Englisch, Simon Harst and Felix Siegel. It aims at reducing unnecessary compliance costs by avoiding effective tax rate (ETR) calculations if a minimum tax of 15 per cent has already been paid. The simplification safe harbour consists of a two-level test to determine if a full GloBE ETR calculation is required from a multinational enterprise (MNE) or if a simplified ETR calculation or no calculation at all is sufficient. The test consists of a country-level test and – only if necessary – an MNE-level test. The country-level test assesses a country's tax system. It seeks to determine whether the national tax system's nominal tax rates are (too) low and whether significant deviations between a country's tax base and the GloBE income exist. The second level, the MNE-level test, is only carried out if the country-level test has identified potential ‘red flags’. Even if this second test is required, the simplification safe harbour offers a significant reduction in compliance costs. This reduction is achieved by relying on national tax data, which are readily available in firms, instead of highly adjusted accounting data.     

政府审计能提升国有企业并购重组业绩承诺可靠性吗？——基于审计署央企审计结果公告的经验证据

以我国沪深A股中央国有上市公司2012—2020年的数据为样本，将审计署实施的审计监管事件作为一个准自然实验，利用多时点双重差分模型实证检验政府审计对国有企业并购和重大资产重组中业绩承诺可靠性的影响和作用机制。研究发现：（1）政府审计的实施能够显著提升国有企业并购重组业绩承诺的可靠性水平，这一结论在全部并购重组样本中和剔除业绩达标在5%以内的样本后均得到了有效验证，且经过多种稳健性和内生性检验后依然成立；（2）进一步的机制检验结果表明，政府审计能够通过“监督”效应和“增量”效应促进国企并购重组业绩承诺可靠性的提升，但并没有对未接受审计的同行业企业起到很好的“溢出”效应；（3）在业绩承诺到期后的经济后果上，政府审计显著提升了业绩承诺达标企业的长期绩效表现，同时降低了其商誉减值风险，但对于业绩承诺未达标企业的影响效果并不明显。     

中小型水利工程安全运行管理对策

水利工程建设质量安全在一定程度上掌握着国民经济的命脉,也是一项系统性较强的工程,而在实际施工期间,中小型水利工程建设具有项目庞大、工艺较难、内容复杂,以及不确定性等特点,在特殊的施工条件及施工环境下,我们对于中小型水利工程安全事故防控要求也相对较高。因此中小型工程施工管理过程中,施工单位应秉承着“安全第一,预防为主”的原则。     

一种低复杂度的多元LDPC译码算法

针对多元低密度奇偶校验（LDPC）码译码复杂度高、时延大等问题，提出了一种基于硬信息的低复杂度多元LDPC译码算法。来自信道的接收信号在初始化时，先进行非均匀量化预处理。在迭代过程中，校验节点端只需传输单个比特的二进制硬可靠度信息至变量节点。在变量节点端，可靠度信息按比特位进行简单的累加和更新，无需任何的系数修正操作。同时，变量节点使用了全信息的方式将信息传输至与其相邻的校验节点。仿真结果显示，与基于比特可靠度（BRB）的多元LDPC译码算法相比，提出的算法在较低量化比特情况下，能获得约0.3 dB的译码性能增益，且译码复杂度更低。     

农户林权抵押贷款意愿影响因素分析

从林贷需求的角度，分析了影响林农参与林权抵押贷款意愿的因素，并通过多元回归分析，找出影响林农林贷意愿的显著性因子及其大小，分别针对政府、金融机构、林农等方面为制定林贷发展政策提供相关政策建议。     

土地储备项目风险预警控制模型

研究目的：定量测量土地储备项目风险，提出土地储备项目风险预警控制方法，判断多土地储备项目风险值的波动与土地储备机构决策者的决策心理趋势。研究方法：文献资料法，数学模型法，实证分析法。研究结果：利用不可修复可靠性串联模型与休哈特控制图建立预警控制界限，建立时间序列回归判别模型。研究结论：通过西安某市土地储备项目的风险测度、预控和时间序列回归判别验证了该方法的有效性。     

基于可靠度的混凝土企业成本质量模型研究

根据可靠度的一般概念,在分析了产品可靠度影响因素的基础上提出了以设计强度为标准的混凝土产品可靠度模型。同时给出了成本计算公式与质量波动计算公式,并在此基础上建立了成本-可靠度模型、质量波动-可靠度模型,从而为探寻直接成本、质量波动在可靠度方面的原因提供了依据。通过对企业大量业务数据的分析验证了上述2个模型。