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Comparative analysis of profits from Bitcoin and its derivatives using artificial intelligence for hedge 利用人工智能对冲比特币及其衍生品利润的比较分析
IF 2.8 3区 物理与天体物理 Q2 PHYSICS, MULTIDISCIPLINARY Pub Date : 2024-10-11 DOI: 10.1016/j.physa.2024.130159
Qing Zhu , Jianhua Che , Shan Liu
Because there is a discrepancy between how individual investors and investment institutions choose Bitcoin and its new derivatives and Exchange-Traded Funds (ETFs), this paper used Bitcoin and ProShares Bitcoin Strategy ETF (BITO) data and a mixed variational mode decomposition and bidirectional gated cycle unit model to examine the interconnections between Bitcoin and its new derivative ETFs, from which actionable recommendations were developed. As well as conducting financial simulation trading using Bitcoin and BITO, the study expanded to examine other major ETFs. It was found that: (1) Bitcoin data could be employed to forecast and describe BITO; (2) under T+0 trading, Bitcoin was more volatile, profitable, and risky than BITO; and (3) under T+1 trading, Bitcoin was less volatile, profitable, and risky than BITO; however, the T+1 trading was found to have higher volatility, profits, and risk than T+0 trading. This study, therefore, builds a bridge from theory to practice for the prediction and description of new ETFs. Different from previous studies, this study explored the relationships between Bitcoin and BITO using Artificial Intelligence and quantitative financial simulations, which extends the practical and theoretical understanding of the Bitcoin market.
由于个人投资者和投资机构在如何选择比特币及其新衍生品和交易所交易基金(ETF)之间存在差异,本文使用比特币和ProShares比特币策略ETF(BITO)数据以及混合变异模式分解和双向门控周期单元模型来研究比特币及其新衍生品ETF之间的相互联系,并从中提出可操作的建议。除了使用比特币和 BITO 进行金融模拟交易外,该研究还扩展到其他主要 ETF。研究发现(1) 比特币数据可用于预测和描述 BITO;(2) 在 T+0 交易下,比特币的波动性、盈利性和风险性高于 BITO;(3) 在 T+1 交易下,比特币的波动性、盈利性和风险性低于 BITO;然而,T+1 交易的波动性、盈利性和风险性高于 T+0 交易。因此,本研究为预测和描述新的 ETF 搭建了一座从理论到实践的桥梁。与以往研究不同的是,本研究利用人工智能和定量金融模拟探索了比特币和 BITO 之间的关系,拓展了对比特币市场的实践和理论认识。
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引用次数: 0
Ethereum futures and the efficiency of cryptocurrency spot markets 以太坊期货和加密货币现货市场的效率
IF 2.8 3区 物理与天体物理 Q2 PHYSICS, MULTIDISCIPLINARY Pub Date : 2024-10-11 DOI: 10.1016/j.physa.2024.130161
Werner Kristjanpoller , Ramzi Nekhili , Elie Bouri
This paper examines the impact of the introduction of Ethereum futures contracts on the market efficiency of major cryptocurrency (Bitcoin, Ethereum, Ripple, Litecoin, and Dogecoin) spot prices. Using a multifractality-based approach and daily data from September 4, 2017 to February 16, 2024, the main results show a slight improvement in market efficiency. Specifically, the degree of multifractality persistence decreases, implying reduced market inefficiencies in major cryptocurrencies. The temporal linear correlation effect and thick tail effect are less pronounced post-launch. The asymmetry of the generalized Hurst exponent increases after the launch of Ethereum futures, with a higher persistence under the downward trend of cryptocurrencies noted. This downward trend emerges after the launch of Ethereum futures, coinciding with the final stage of the COVID-19 pandemic. Additional analysis shows that fat tails and temporal linear correlations are the main sources of multifractality. The results highlight the influence of introducing financial derivatives into the relatively new and volatile cryptocurrency area, which should concern traders, hedgers, investors, and regulators.
本文研究了以太坊期货合约的推出对主要加密货币(比特币、以太坊、瑞波币、莱特币和狗狗币)现货价格市场效率的影响。利用基于多分形的方法和2017年9月4日至2024年2月16日的每日数据,主要结果显示市场效率略有提高。具体来说,多分叉持续性程度降低,这意味着主要加密货币的市场效率降低。发射后,时间线性相关效应和厚尾效应不那么明显。以太坊期货推出后,广义赫斯特指数的不对称性增加,在加密货币下行趋势下的持续性更高。这种下降趋势在以太坊期货推出后出现,与 COVID-19 大流行的最后阶段相吻合。其他分析表明,肥尾和时间线性相关是多分形的主要来源。结果凸显了在相对较新且波动较大的加密货币领域引入金融衍生品的影响,交易者、套期保值者、投资者和监管者都应关注这一点。
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引用次数: 0
Impact of surface-roughness and fractality on electrical conductivity of SnS thin films 表面通透度和碎裂度对 SnS 薄膜导电性的影响
IF 2.8 3区 物理与天体物理 Q2 PHYSICS, MULTIDISCIPLINARY Pub Date : 2024-10-11 DOI: 10.1016/j.physa.2024.130165
Vinita , Chandra Kumar , R.P. Yadav , B.K. Singh
Mono- and multi-fractal geometry have been used to explore the surface characteristics of scanning electron microscopy (SEM) micrographs of the SnS films with thicknesses of 100 nm (SnS1) to 600 nm (SnS4), respectively. For this investigation, the SnS thin films have been grown on fluorine-doped tin oxide (FTO)-coated glass substrate through the thermal evaporation route, and surface morphologies are captured by SEM. Two-dimensional multi-fractal detrended fluctuation analysis (MFDFA) based on the partition function is used to examine whether the surfaces have a multi-fractal nature or not. The partition function is applied to extract the generalized Hurst exponent from the segment size. It has been found that surfaces with higher surface roughness induce substantial nonlinearity and a wider width of the multi-fractal spectrum. The multi-fractal spectrum acquired from the analysis of the geometry and shape of the singularity spectrum is used to quantify the irregularity and complexity of surfaces. Minkowski functionals (MFs) parameters such as volume, boundary, and connectivity were measured for each thin film. Moreover, we tried to correlate the electrical conductivity with the mono- and multi-fractal parameters such as fractal dimension (Df), singularity strength function (Δα), singularity spectrum Δf(α), and it is observed that the conductivity of a thin film decreases with decreasing fractal dimension. The minimum (maximum) resistivity (conductivity) was observed for the surface having a larger fractal dimension. The present investigation suggests that such SnS surfaces, having minimal resistivity and maximum conductivity on the roughest surface, indicate enhanced light trapping capacity and can be utilized as active layers for advanced optoelectronics devices.
单分形和多分形几何图形被用来探索厚度分别为 100 nm(SnS1)至 600 nm(SnS4)的 SnS 薄膜的扫描电子显微镜(SEM)显微照片的表面特征。在这项研究中,SnS 薄膜是通过热蒸发途径在掺氟氧化锡(FTO)涂层玻璃基底上生长的,并通过扫描电子显微镜捕捉其表面形貌。利用基于分区函数的二维多分形去趋势波动分析(MFDFA)来检验表面是否具有多分形性质。分区函数用于从分段大小中提取广义赫斯特指数。研究发现,表面粗糙度越高的表面,其非线性越大,多分形谱的宽度也越宽。通过分析奇异谱的几何和形状获得的多分形谱可用于量化表面的不规则性和复杂性。我们测量了每种薄膜的闵科夫斯基函数(MFs)参数,如体积、边界和连通性。此外,我们还尝试将电导率与分形维度 (Df)、奇异强度函数 (Δα)、奇异谱 Δf(α)等单分形和多分形参数相关联。分形维数较大的表面的电阻率(电导率)最小(最大)。本研究表明,这种在最粗糙表面上电阻率最小、电导率最大的 SnS 表面显示出更强的光捕获能力,可用作先进光电器件的有源层。
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引用次数: 0
Role of delay in brain dynamics 延迟在大脑动力学中的作用
IF 2.8 3区 物理与天体物理 Q2 PHYSICS, MULTIDISCIPLINARY Pub Date : 2024-10-11 DOI: 10.1016/j.physa.2024.130166
Yuval Meir , Ofek Tevet , Yarden Tzach , Shiri Hodassman , Ido Kanter
Significant variations of delays among connecting neurons cause an inevitable disadvantage of asynchronous brain dynamics compared to synchronous deep learning. However, this study demonstrates that this disadvantage can be converted into a computational advantage using a network with a single output and M multiple delays between successive layers, thereby generating a polynomial time-series outputs with M. The proposed role of delay in brain dynamics (RoDiB) model, is capable of learning increasing number of classified labels using a fixed architecture, and overcomes the inflexibility of the brain to update the learning architecture using additional neurons and connections. Moreover, the achievable accuracies of the RoDiB system are comparable with those of its counterpart tunable single delay architectures with M outputs. Further, the accuracies are significantly enhanced when the number of output labels exceeds its fully connected input size. The results are mainly obtained using simulations of VGG-6 on CIFAR datasets and also include multiple label inputs. However, currently only a small fraction of the abundant number of RoDiB outputs is utilized, thereby suggesting its potential for advanced computational power yet to be discovered.
与同步深度学习相比,连接神经元之间延迟的显著变化导致异步大脑动力学不可避免地存在劣势。然而,本研究证明,利用具有单个输出和连续层之间 M 个多重延迟的网络,可以将这一劣势转化为计算优势,从而生成具有 M 个多项式时间序列输出的网络。此外,RoDiB 系统可达到的准确度可与具有 M 个输出的可调单延迟架构相媲美。此外,当输出标签的数量超过完全连接的输入规模时,系统的准确度会显著提高。这些结果主要是通过模拟 CIFAR 数据集上的 VGG-6 获得的,也包括多标签输入。不过,目前只利用了 RoDiB 大量输出中的一小部分,这表明其高级计算能力的潜力还有待发掘。
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引用次数: 0
Can Bitcoin trigger speculative pressures on the US Dollar? A novel ARIMA-EGARCH-Wavelet Neural Networks 比特币能否引发美元投机压力?新型 ARIMA-EGARCH 小波神经网络
IF 2.8 3区 物理与天体物理 Q2 PHYSICS, MULTIDISCIPLINARY Pub Date : 2024-10-11 DOI: 10.1016/j.physa.2024.130140
David Alaminos , M. Belén Salas-Compás , Manuel Á. Fernández-Gámez
In recent years, Bitcoin has garnered attention as a digital currency, prompting increasing debate regarding its effects on traditional financial markets, particularly the US dollar. This study investigates the relationship between Bitcoin and the US dollar, especially in the contexts of speculative attacks, where investors attempt to devalue a currency, and short squeezes, where rapid price rises force short sellers to quickly buy back assets to avoid further losses. The study employs a novel hybrid model combining an autoregressive moving average, Generalized Autoregressive Conditional Heteroskedasticity, and Wavelet Neural Networks techniques with neural networks approaches. The results suggest that significant trading activity in Bitcoin/US dollar, particularly during speculative attacks and short squeezes, can substantially impact the US dollar/EUR market, increasing price volatility as traders adjust their strategies. These adjustments, along with risk management strategies, drive higher trading volumes and further volatility. Our findings demonstrate that our novel hybrid model combined with Quantum Recurrent Neural Networks provides the most accurate predictions, offering valuable insights to inform trading strategies in both Bitcoin/US dollar and US dollar/EUR markets. This study has important implications for policymakers and market participants, emphasising the need to understand the relationship between Bitcoin and the US dollar for financial stability and effective policy formulation. It also highlights the necessity of advanced modeling techniques to accurately predict cryptocurrency market behavior.
近年来,比特币作为一种数字货币备受关注,引发了越来越多关于其对传统金融市场(尤其是美元)影响的讨论。本研究探讨了比特币与美元之间的关系,尤其是在投机性攻击(投资者试图使货币贬值)和空头挤压(价格快速上涨迫使卖空者迅速回购资产以避免进一步损失)的情况下。该研究采用了一种新颖的混合模型,将自回归移动平均线、广义自回归条件异方差和小波神经网络技术与神经网络方法相结合。研究结果表明,比特币/美元的大量交易活动,尤其是在投机性攻击和空头挤压期间,会对美元/欧元市场产生重大影响,并随着交易者调整策略而增加价格波动。这些调整以及风险管理策略推动了更高的交易量和进一步的波动。我们的研究结果表明,我们的新型混合模型与量子递归神经网络相结合,可以提供最准确的预测,为比特币/美元和美元/欧元市场的交易策略提供有价值的见解。这项研究对政策制定者和市场参与者具有重要意义,强调了理解比特币和美元之间的关系对于金融稳定和有效政策制定的必要性。它还强调了先进建模技术对准确预测加密货币市场行为的必要性。
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引用次数: 0
A double quantum dot quantum battery controlled with a Markovian feedback 用马尔可夫反馈控制的双量子点量子电池
IF 2.8 3区 物理与天体物理 Q2 PHYSICS, MULTIDISCIPLINARY Pub Date : 2024-10-11 DOI: 10.1016/j.physa.2024.130153
Oscar Bohórquez
A battery is a device that stores energy in the form of work for later use by other devices. In this work, we study the realization of a quantum battery in a double quantum dot in series, charged by two electrodes at different chemical potentials and optimized by a Markovian quantum feedback protocol. Using the concept of ergotropy as a figure of merit, we first establish a simple expression for the maximum ergotropy in a two-level system, and then find the parameters under which Markovian feedback can achieve this optimal ergotropy. We find that quantum coherence can be used as an energy storage resource, and we study the influence of interactions with a phonon environment to mitigate the discharge process with the environment by fine-tuning the system parameters.
电池是一种以功的形式储存能量供其他设备以后使用的装置。在这项工作中,我们研究了在双量子点串联中实现量子电池的问题,双量子点由处于不同化学势的两个电极充电,并通过马尔可夫量子反馈协议进行优化。利用各向异性的概念,我们首先建立了两级系统中最大各向异性的简单表达式,然后找到了马尔可夫反馈能够实现最佳各向异性的参数。我们发现量子相干可以作为一种能量存储资源,并研究了与声子环境相互作用的影响,通过微调系统参数来减轻与环境的放电过程。
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引用次数: 0
The effect of building bottlenecks on crowd dynamics involving individuals with simulated disabilities 建筑物瓶颈对涉及模拟残疾人的人群动态的影响
IF 2.8 3区 物理与天体物理 Q2 PHYSICS, MULTIDISCIPLINARY Pub Date : 2024-10-11 DOI: 10.1016/j.physa.2024.130157
Yangjian He , Libi Fu , Qiyi Chen , Yu Zhang , Chenxin Shen , Yongqian Shi , Shuchao Cao
With the development of urbanization and the growth of population, there is a growing demand for safety in public building facilities. As one of the essential building components of urban architecture, bottlenecks have a significant impact on the evacuation efficiency of crowds. Furthermore, the heterogeneity of crowds also contributes to the complexity of crowd movement through bottlenecks, while aggravating the magnitude of congestion induced by bottlenecks. The objective of this paper is to explore the movement characteristics of heterogeneous crowds passing through a corridor with a bottleneck by conducting a controlled experiment. There were three variables in this experiment, namely the individual categories (i.e., able-bodied individuals, simulated individuals on crutches and simulated wheelchair users), bottleneck width (i.e., 1.2, 1.6 and 2.0 m) and proportion of simulated disabilities in crowds (i.e., 0 %, 5 % and 10 %). Then offset angle, passing efficiency, fundamental diagram, etc., were analyzed. In trials involving simulated individuals on crutches, a higher detouring degree is observed compared to trials involving simulated wheelchair users or mixed groups of two types of simulated disabilities. There is an increase in flow rate induced by increasing the bottleneck width and decreasing the proportion of simulated disabilities. The passing efficiency at the upstream of the bottleneck in all tests is primarily influenced by the bottleneck width, while by the type and proportion of simulated disabilities at the downstream or inside the bottleneck. The findings are intended to complement the dynamic theory of heterogeneous crowds at building bottlenecks, while providing a reference for congestion control of crowds at bottlenecks.
随着城市化的发展和人口的增长,人们对公共建筑设施的安全要求越来越高。作为城市建筑的重要组成部分之一,瓶颈对人群疏散效率有着重要影响。此外,人群的异质性也增加了人群通过瓶颈流动的复杂性,同时加剧了瓶颈引起的拥堵程度。本文旨在通过控制实验,探讨异质人群通过瓶颈通道时的运动特征。实验中有三个变量,即个体类别(即健全人、拄拐杖的模拟人和坐轮椅的模拟人)、瓶颈宽度(即 1.2 米、1.6 米和 2.0 米)和人群中模拟残疾人的比例(即 0%、5% 和 10%)。然后对偏移角度、通过效率、基本图等进行分析。在涉及拄拐杖的模拟人的试验中,与涉及模拟轮椅使用者或两种模拟残疾混合群体的试验相比,观察到的绕行程度更高。增加瓶颈宽度和减少模拟残疾人的比例会导致流量增加。在所有测试中,瓶颈上游的通过效率主要受瓶颈宽度的影响,而下游或瓶颈内部的模拟残疾类型和比例则对通过效率有影响。研究结果旨在补充建筑物瓶颈处异质人群的动态理论,同时为瓶颈处人群的拥堵控制提供参考。
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引用次数: 0
A network perspective on J.S Bach’s 6 violin sonatas and partitas, BWV 1001 - 1006 从网络角度看巴赫的 6 首小提琴奏鸣曲和 Partitas,BWV 1001 - 1006
IF 2.8 3区 物理与天体物理 Q2 PHYSICS, MULTIDISCIPLINARY Pub Date : 2024-10-10 DOI: 10.1016/j.physa.2024.130124
Dima Mrad , Sara Najem , Pablo Padilla , Francis Knights
Complex networks and statistical physics have been proposed as powerful frameworks and tools in the analysis of the properties of complex systems and in particular musical pieces. They can reveal variations in musical features such as harmony, melody, rhythm as well as the composer’s style. The empirical study of a wide range of digitized scores of Western classical music and their corresponding networks brought to light quantitative evidence for changes in harmonic complexity. We complement the common topological analysis of these networks with musicological or music-theoretical considerations. We illustrate this by studying J. S. Bach’s sonatas and partitas for solo violin by constructing duration-weighted transition matrices between notes, or melody networks, as well as harmony networks, which are transition matrices between the chords, or equivalently synchronously played notes. We further propose statistical physics measures that were first introduced in the study of socio-economic networks: the partition function and communicability and provide evidence for their significance. Our findings and observations include: the detection of three main communities centered around the tonic, the dominant, and submediant in most of the pieces; the association of the nodes with the highest betweenness centrality, the lowest clustering coefficient and highest in and out degrees respectively with the tonic and the dominant; the high similarity between pieces which share the same key or when the key of one is the dominant of the other; finally, the association of the highest partition function, the shortest average path length, and the highest communicability with the Fugues.
复杂网络和统计物理学被认为是分析复杂系统,特别是音乐作品属性的强大框架和工具。它们可以揭示和声、旋律、节奏以及作曲家风格等音乐特征的变化。通过对大量西方古典音乐数字化乐谱及其相应网络的实证研究,我们发现了和声复杂性变化的量化证据。我们从音乐学或音乐理论的角度对这些网络的常见拓扑分析进行了补充。我们通过研究巴赫(J. S. Bach)的小提琴独奏奏鸣曲和部分奏鸣曲,构建了音符之间的时长加权转换矩阵,即旋律网络,以及和声网络,即和弦之间的转换矩阵,或等同于同步演奏的音符之间的转换矩阵,来说明这一点。我们进一步提出了首次在社会经济网络研究中引入的统计物理测量方法:分区函数和可传播性,并为其重要性提供了证据。我们的发现和观察结果包括:在大多数乐曲中发现了以调性、主音和副主音为中心的三个主要群落;具有最高间度中心性、最低聚类系数和最高进出度的节点分别与调性和主音相关;具有相同调性的乐曲或其中一个调性是另一个调性的乐曲之间具有高度相似性;最后,具有最高分区函数、最短平均路径长度和最高可传播性的乐曲与赋格相关。
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引用次数: 0
Elucidation of characteristics of networks where every node has its own lifetime 阐明每个节点都有自己寿命的网络的特点
IF 2.8 3区 物理与天体物理 Q2 PHYSICS, MULTIDISCIPLINARY Pub Date : 2024-10-10 DOI: 10.1016/j.physa.2024.130149
Nobutoshi Ikeda
Growth is regarded as an important mechanism for explaining the structures of real networks. However, when the increase in the number of nodes is suppressed owing to their lifetime, the growth property alone is not sufficient to explain even fundamental network properties, such as the scale-free property. In this paper, we propose a network model that considers the lifetime of nodes and the excess addition of local internal links as a mechanism that supports network structures. By investigating the model network, we aimed to elucidate the network characteristics supported by local interactions between nodes via their common neighbors even when the rates of node addition and deletion were balanced. We found that the stationary state of the number of nodes is characterized by a scale-free property with the power-law exponent γ1 and localization of the peaks at l=2 in the distance distributions of neighboring nodes (DDN) as the node degree k increases. The specific behavior of the DDN explains the very slow decrease in the clustering strength C(k) with k compared with the normal behavior C(k)k1 and the accelerated growth of the neighborhood graph of each node. Moreover, we showed that some real networks share local structures similar to those of the model network. These findings suggest that the same mechanism as that of the proposed model plays an essential role in supporting the local structures of some real networks.
增长被认为是解释真实网络结构的重要机制。然而,当节点数量的增长因节点寿命而受到抑制时,仅靠增长特性甚至不足以解释基本的网络特性,如无标度特性。在本文中,我们提出了一种网络模型,将节点的生命周期和局部内部链接的过度增加作为支持网络结构的机制。通过对模型网络的研究,我们旨在阐明即使在节点增减率平衡的情况下,节点之间通过其共同邻居进行的局部互动所支持的网络特性。我们发现,随着节点度 k 的增加,节点数的静止状态具有无标度特性,即幂律指数 γ≃1,并且相邻节点距离分布(DDN)的峰值定位在 l=2 处。DDN 的特殊行为解释了聚类强度 C(k) 随 k 下降的速度与正常行为 C(k)∼k-1 相比非常缓慢,以及每个节点的邻域图加速增长的原因。此外,我们还发现一些真实网络的局部结构与模型网络相似。这些发现表明,与模型相同的机制在支持某些真实网络的局部结构方面发挥了重要作用。
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引用次数: 0
Singularities of Taylor’s power law in the analysis of aggregation measures 分析总量时泰勒幂律的奇异性
IF 2.8 3区 物理与天体物理 Q2 PHYSICS, MULTIDISCIPLINARY Pub Date : 2024-10-10 DOI: 10.1016/j.physa.2024.130151
Samuele De Bartolo
Taylor’s law is a well-known power law (TPL) for analysing the scaling behaviour of many fluctuating physical phenomena in nature. The scaling exponent b of this law forms the basis of the aggregation process to which a precise probability density function corresponds. In some phenomena, TPL behaviour with periodic components of the aggregates has been observed for small partitions, especially for physical processes characterised by values of b=1 where fluctuation-related aggregation processes are supported by Poissonian distributions. We intend to show that for values of b very close to unity it is possible to find a trend, in the double logarithmic scale, of the TPL that there are ‘periodic patterns’ (components) between variance and mean. This behaviour is found in other binomial-type distributions, of which the Poissonian is a particular case, with mappings characterised by a variance close to 1.
泰勒定律是著名的幂律(TPL),用于分析自然界中许多波动物理现象的缩放行为。该定律的缩放指数 b 构成了精确概率密度函数所对应的聚集过程的基础。在某些现象中,我们观察到小分区的聚集体具有周期性成分的 TPL 行为,特别是对于 b=1 值的物理过程,其中与波动相关的聚集过程得到泊松分布的支持。我们打算证明,当 b 值非常接近统一时,有可能在 TPL 的双对数尺度中发现一种趋势,即在方差和均值之间存在 "周期模式"(成分)。这种行为在其他二项分布中也能发现,泊松分布是其中的一种特殊情况,其映射的特点是方差接近 1。
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引用次数: 0
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