Complex network

复杂网络
  • 文章类型: Journal Article
    本研究提出了一个基于有向无环图(DAG)的广义方差分解框架,用于调查2011年至2023年中国34家上市金融机构中金融系统的异质收益溢出效应,并衡量金融机构的系统重要性。研究结果表明,由于同时期的因果关系,同一部门内的机构之间存在明显的信息溢出效应。静态和动态金融网络分析都突出了证券行业的重要性。动态结构特征与宏观经济发展相一致,对内外部冲击敏感。系统重要性评估表明,市场规模本身并不能决定重要性,银行业和非银行部门之间存在显著差异。国有和股份制商业银行在银行业中发挥着至关重要的作用,而地方政府和私人资本控制的机构在证券领域至关重要。这项研究有助于监管努力保持平衡的监管环境,确保市场效率,降低运营成本。
    This study proposes a directed acyclic graph (DAG)-based framework for generalized variance decomposition for investigating the heterogeneous return spillovers in financial system and measuring the systemic importance of financial institutions among 34 listed Chinese financial institutions from 2011 to 2023. Findings indicate pronounced information spillovers among institutions within the same sector due to contemporaneous causal relationships. Both static and dynamic financial network analyses highlight the significance of the securities sector. Dynamic structural characteristics align with macroeconomic development and are sensitive to internal and external shocks. Systemic importance assessment reveals that market size alone doesn\'t determine importance, with notable disparities between banking and non-banking sectors. State-owned and joint-stock commercial banks play a vital role in banking, while local government and private capital-controlled institutions are crucial in the securities sector. This research aids regulatory efforts in maintaining a balanced regulatory environment, ensuring market efficiency, and reducing operational costs.
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  • 文章类型: Journal Article
    动态传播会影响网络结构的变化。不同的网络受到信息迭代传播的影响程度不同。网络中信息的迭代传播改变了节点之间链边的连接强度。大多数关于时间网络的研究基于时间特征构建网络,信息在网络中的迭代传播也能反映网络演化的时间特征。网络结构的变化是时间特征的宏观表现,而网络中的动力学是时间特征的微观表现。如何具体可视化受传播动力学特性影响的网络结构变化已成为本文的研究重点。链边的出现是网络结构的微观变化,社区的划分是网络结构的宏观变化。基于此,提出了节点参与量化不同用户对网络中信息传播的影响,它在不同类型的网络中进行模拟。通过分析信息的迭代传播,构建了基于信息迭代传播的不同网络的加权网络。最后,分析了网络中的链边和社区划分,以达到量化网络传播对复杂网络结构影响的目的。
    Dynamic propagation will affect the change of network structure. Different networks are affected by the iterative propagation of information to different degrees. The iterative propagation of information in the network changes the connection strength of the chain edge between nodes. Most studies on temporal networks build networks based on time characteristics, and the iterative propagation of information in the network can also reflect the time characteristics of network evolution. The change of network structure is a macromanifestation of time characteristics, whereas the dynamics in the network is a micromanifestation of time characteristics. How to concretely visualize the change of network structure influenced by the characteristics of propagation dynamics has become the focus of this article. The appearance of chain edge is the micro change of network structure, and the division of community is the macro change of network structure. Based on this, the node participation is proposed to quantify the influence of different users on the information propagation in the network, and it is simulated in different types of networks. By analyzing the iterative propagation of information, the weighted network of different networks based on the iterative propagation of information is constructed. Finally, the chain edge and community division in the network are analyzed to achieve the purpose of quantifying the influence of network propagation on complex network structure.
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  • 文章类型: Journal Article
    复杂网络的可控性是网络研究的核心问题。评估网络在破坏性攻击下的可控性鲁棒性具有重要的实际意义。本文从恶意攻击的角度研究网络的可控性。提出了一种新的攻击模型来评估和挑战网络的可控性。该方法通过识别和定位关键候选节点,以高精度破坏网络可控性。将该模型与传统攻击方法进行了比较,包括基于学位的,基于中间性,基于亲密关系,基于pagerank,和等级攻击。结果表明,该模型在中断有效性和计算效率上都优于这些方法。在合成和现实世界网络上进行的大量实验验证了这种方法的优越性能。这项研究为识别对保持网络可控性至关重要的关键节点提供了有价值的见解。它还提供了一个坚实的框架,用于增强网络抵御恶意攻击的能力。
    The controllability of complex networks is a core issue in network research. Assessing the controllability robustness of networks under destructive attacks holds significant practical importance. This paper studies the controllability of networks from the perspective of malicious attacks. A novel attack model is proposed to evaluate and challenge network controllability. This method disrupts network controllability with high precision by identifying and targeting critical candidate nodes. The model is compared with traditional attack methods, including degree-based, betweenness-based, closeness-based, pagerank-based, and hierarchical attacks. Results show that the model outperforms these methods in both disruption effectiveness and computational efficiency. Extensive experiments on both synthetic and real-world networks validate the superior performance of this approach. This study provides valuable insights for identifying key nodes crucial for maintaining network controllability. It also offers a solid framework for enhancing network resilience against malicious attacks.
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  • 文章类型: Journal Article
    研究金融复杂网络中的重要“角色”及其稳定性对于防范金融风险具有重要意义。一方面,本文初步构建了基于互信息理论和阈值方法的股市复杂网络模型,结合股票的收盘价回报。然后,它分析了该网络的基本拓扑特征,并通过改变阈值来检查其在随机和有针对性的攻击下的稳定性。另一方面,用系统风险熵作为量化股市稳定性的指标,本文验证了COVID-19大流行的影响,网络稳定性上的意外事件。研究结果表明,这种复杂网络具有小世界特征,但不能严格归类为无标度网络。在这个网络中,工业部门发挥了关键作用,媒体和信息服务,制药和医疗保健,交通运输,和公用事业。在降低阈值时,网络对随机攻击的抵御能力相应增强。动态地,从2000年到2022年,重要工业股票市场的系统性风险显著增加。从静态的角度来看,2019年左右,受COVID-19大流行影响,经历了最剧烈的波动。与2000年相比,2022年的系统性风险熵增加了近六倍,进一步表明在这个复杂的网络中越来越不稳定。
    Investigating the significant \"roles\" within financial complex networks and their stability is of great importance for preventing financial risks. On one hand, this paper initially constructs a complex network model of the stock market based on mutual information theory and threshold methods, combined with the closing price returns of stocks. It then analyzes the basic topological characteristics of this network and examines its stability under random and targeted attacks by varying the threshold values. On the other hand, using systemic risk entropy as a metric to quantify the stability of the stock market, this paper validates the impact of the COVID-19 pandemic as a widespread, unexpected event on network stability. The research results indicate that this complex network exhibits small-world characteristics but cannot be strictly classified as a scale-free network. In this network, key roles are played by the industrial sector, media and information services, pharmaceuticals and healthcare, transportation, and utilities. Upon reducing the threshold, the network\'s resilience to random attacks is correspondingly strengthened. Dynamically, from 2000 to 2022, systemic risk in significant industrial share markets significantly increased. From a static perspective, the period around 2019, affected by the COVID-19 pandemic, experienced the most drastic fluctuations. Compared to the year 2000, systemic risk entropy in 2022 increased nearly sixtyfold, further indicating an increasing instability within this complex network.
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  • 文章类型: Journal Article
    在基于竞争的可控性方法中,没有工具来识别大规模网络的驱动节点。本研究提出了一种新的大规模网络计算方法。它在名为Drivergen.net的新Cytoscape插件应用程序中实现了该方法。该软件在大规模生物分子网络上的实验显示出出色的速度和计算能力。有趣的是,在这些网络上发现的前10个驱动节点中,有86.67%是抗癌药物靶基因,这些基因主要位于网络的最内部K核。最后,将该方法与其他5名研究人员的方法进行了比较,证实了该方法在鉴定抗癌药物靶基因方面优于其他方法。一起来看,Drivergen.net是一种可靠的工具,不仅可以有效地检测生物分子网络中的药物靶基因,还可以检测大规模复杂网络的驱动节点。带有用户手册和示例数据集的Drivergen.net可用https://github.com/tinhpd/Drivergene。git.
    There are no tools to identify driver nodes of large-scale networks in approach of competition-based controllability. This study proposed a novel method for this computation of large-scale networks. It implemented the method in a new Cytoscape plug-in app called Drivergene.net. Experiments of the software on large-scale biomolecular networks have shown outstanding speed and computing power. Interestingly, 86.67% of the top 10 driver nodes found on these networks are anticancer drug target genes that reside mostly at the innermost K-cores of the networks. Finally, compared method with those of five other researchers and confirmed that the proposed method outperforms the other methods on identification of anticancer drug target genes. Taken together, Drivergene.net is a reliable tool that efficiently detects not only drug target genes from biomolecular networks but also driver nodes of large-scale complex networks. Drivergene.net with a user manual and example datasets are available https://github.com/tinhpd/Drivergene.git.
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  • 文章类型: English Abstract
    基于多维多目标生物网络的系统解构,模块化药理学解释了疾病的复杂机制和多靶点药物的相互作用。在疾病的发病机制方面取得了进展,疾病的生物学基础和中医证候,多靶点草药的药理机制,公式的兼容性,中药复方新药的发现。然而,多组学数据和生物网络的复杂性给药物网络的模块化解构和分析带来了挑战。这里,我们构建了模块化药理学计算平台在线分析系统,可以实现网络建设的功能,模块识别,模块判别分析,集线器模块分析,模块内和模块间关系分析,以及基于定量表达谱和蛋白质-蛋白质相互作用(PPI)数据的网络拓扑可视化。该工具为通过模块化药理学研究复杂疾病和多靶点药物机制提供了强大的工具。该平台在疾病模块化识别和关联机制方面可能具有广泛的应用,解释中医科学原理,分析中药和配方的复杂机制,多靶点药物的发现。
    Based on the systematic deconstruction of multi-dimensional and multi-target biological networks, modular pharmacology explains the complex mechanism of diseases and the interactions of multi-target drugs. It has made progress in the fields of pathogenesis of disease, biological basis of disease and traditional Chinese medicine(TCM) syndrome, pharmacological mechanism of multi-target herbs, compatibility of formulas, and discovery of new drug of TCM compound. However, the complexity of multi-omics data and biological networks brings challenges to the modular deconstruction and analysis of the drug networks. Here, we constructed the "Computing Platform for Modular Pharmacology" online analysis system, which can implement the function of network construction, module identification, module discriminant analysis, hub-module analysis, intra-module and inter-module relationship analysis, and topological visualization of network based on quantitative expression profiles and protein-protein interaction(PPI) data. This tool provides a powerful tool for the research on complex diseases and multi-target drug mechanisms by means of modular pharmacology. The platform may have broad range of application in disease modular identification and correlation mechanism, interpretation of scientific principles of TCM, analysis of complex mechanisms of TCM and formulas, and discovery of multi-target drugs.
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  • 文章类型: Journal Article
    该研究提出了一种基于图论的肺部听诊新技术,强调图形参数在区分肺音和支持早期检测各种呼吸病理方面的潜力。通过使用功率谱密度(PSD)图和小波scalogram对85个支气管(BS)和胸膜摩擦(PS)肺音的分析,可以揭示频率扩展和分量大小。低频传播,在从气管的均匀横截面区域发出的BS声音中,可以看到高强度频率分量的持久性。胸膜之间的摩擦摩擦导致PS信号中低强度间歇频率分量的较高频率扩展。从BS和PS的复杂网络中,提取的图形特征是-图形密度([公式:见文本],传递性([公式:见正文],度中心性([公式:见正文]),中间性中心性([公式:见正文],特征向量中心性([公式:见文本]),和图熵(En)。[公式:见文本]和[公式:见文本]的高值显示出源于一致的横截面气管直径的BS信号的不同段之间的强相关性,因此,产生高强度低扩展频率分量。PS信号中间歇性的低强度和相对较大的频率扩展出现为高[公式:见正文],[公式:见正文],[公式:见正文],和[公式:见文本]值。有了这些复杂的网络参数作为输入属性,有监督的机器学习技术-判别分析,支持向量机,k-最近的邻居,和神经网络模式识别(PRNN)-对信号进行分类,准确率超过90%,PRNN在隐藏层中有25个神经元达到最高(98.82%)。
    The study presents a novel technique for lung auscultation based on graph theory, emphasizing the potential of graph parameters in distinguishing lung sounds and supporting earlier detection of various respiratory pathologies. The frequency spread and the component magnitudes are revealed from the analysis of eighty-five bronchial (BS) and pleural rub (PS) lung sounds employing the power spectral density (PSD) plot and wavelet scalogram. The low-frequency spread, and persistence of the high-intensity frequency components are visible in BS sounds emanating from the uniform cross-sectional area of the trachea. The frictional rub between the pleurae causes a higher frequency spread of low-intensity intermittent frequency components in PS signals. From the complex networks of BS and PS, the extracted graph features are - graph density ([Formula: see text], transitivity ([Formula: see text], degree centrality ([Formula: see text]), betweenness centrality ([Formula: see text], eigenvector centrality ([Formula: see text]), and graph entropy (En). The high values of [Formula: see text] and [Formula: see text] show a strong correlation between distinct segments of the BS signal originating from a consistent cross-sectional tracheal diameter and, hence, the generation of high-intense low-spread frequency components. An intermittent low-intense and a relatively greater frequency spread in PS signal appear as high [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] values. With these complex network parameters as input attributes, the supervised machine learning techniques- discriminant analyses, support vector machines, k-nearest neighbors, and neural network pattern recognition (PRNN)- classify the signals with more than 90% accuracy, with PRNN having 25 neurons in the hidden layer achieving the highest (98.82%).
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  • 文章类型: Journal Article
    含有多种活性成分,白花蛇舌草(H.diffusa)可以治疗多种肿瘤。我们研究的目的是基于现实世界的数据和实验水平,双重证明白花蛇舌草治疗肺腺癌(LUAD)的疗效和可能的分子机制。
    从SymMap数据库中提取表型-基因型和草药-靶标关联。从MalaCards数据库中提取疾病基因关联。进一步对与中医相关的基因收集和与疾病和症状相关的基因收集进行了基于分子网络的相关性分析。然后,网络分离SAB指标用于评估中医与症状之间的网络接近关系.最后,细胞凋亡实验,蛋白质印迹,和Real-timePCR用于生物实验水平验证分析。
    研究中包括85,437份电子病历(318例LUAD患者)。LUAD组含有白花蛇舌草的处方比例远高于非LUAD组(p<0.005)。我们统计了该组和未使用白花蛇舌草的患者的症状缓解情况:除了疲劳等症状,心悸,头晕,使用组的症状改善率高于未使用组。我们选择了使用组中最常见的五种症状,即,咳嗽,咳痰,疲劳,胸闷和喘息。我们将上述五个症状基因合并为一组。获得的重叠基因是CTNNB1、STAT3、CASP8和APC。生物学实验选择CTNNB1靶点显示,药物干预组LUADA549细胞增殖率显著低于对照组,它是浓度依赖性的。H.diffusa可促进A549细胞凋亡,高浓度药物组的细胞凋亡率明显高于低浓度药物组。药物干涉组CTNNB1基因的转录和表达程度显著下降。
    H.白花蛇抑制LUADA549细胞增殖并促进其凋亡,这可能与白花蛇舌草能调节CTNNB1的表达有关。
    UNASSIGNED: With a variety of active ingredients, Hedyotis Diffusa (H. diffusa) can treat a variety of tumors. The purpose of our study is based on real-world data and experimental level, to double demonstrate the efficacy and possible molecular mechanism of H. diffusa in the treatment of lung adenocarcinom (LUAD).
    UNASSIGNED: Phenotype-genotype and herbal-target associations were extracted from the SymMap database. Disease-gene associations were extracted from the MalaCards database. A molecular network-based correlation analysis was further conducted on the collection of genes associated with TCM and the collection of genes associated with diseases and symptoms. Then, the network separation SAB metrics were applied to evaluate the network proximity relationship between TCM and symptoms. Finally, cell apoptosis experiment, Western blot, and Real-time PCR were used for biological experimental level validation analysis.
    UNASSIGNED: Included in the study were 85,437 electronic medical records (318 patients with LUAD). The proportion of prescriptions containing H. diffusa in the LUAD group was much higher than that in the non-LUAD group (p < 0.005). We counted the symptom relief of patients in the group and the group without the use of H. diffusa: except for symptoms such as fatigue, palpitations, and dizziness, the improvement rate of symptoms in the user group was higher than that in the non-use group. We selected the five most frequently occurring symptoms in the use group, namely, cough, expectoration, fatigue, chest tightness and wheezing. We combined the above five symptom genes into one group. The overlapping genes obtained were CTNNB1, STAT3, CASP8, and APC. The selection of CTNNB1 target for biological experiments showed that the proliferation rate of LUAD A549 cells in the drug intervention group was significantly lower than that in the control group, and it was concentration-dependent. H. diffusa can promote the apoptosis of A549 cells, and the apoptosis rate of the high-concentration drug group is significantly higher than that of the low-concentration drug group. The transcription and expression level of CTNNB1 gene in the drug intervention group were significantly decreased.
    UNASSIGNED: H. diffusa inhibits the proliferation and promotes apoptosis of LUAD A549 cells, which may be related to the fact that H. diffusa can regulate the expression of CTNNB1.
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  • 文章类型: Journal Article
    本文通过调查股权关联网络在可持续发展中影响企业绿色转型的程度,为当前的研究做出了贡献。通过采用复杂的网络方法,以2013-2022年沪深A股上市工业企业前十大股东为基础构建共同持股网络。实证结果表明,更靠近股权联动网络中心的企业具有更高的绿色转型程度。这种影响是通过资本流动的三个机制渠道促进的,信息交流,和网络内的知识转移。我们发现处于网络核心的企业可以有效地降低其对企业的融资约束,减轻与外部环境不确定性和管理近视相关的风险,促进企业间知识交流和创新合作。我们还发现,股权网络的集中性对促进国有,大型企业,强区域环境法规可以增强污染较轻和网络效应的企业。上述发现不仅为政策制定者提供了引导企业绿色转型的政策建议,也为行业从业者提供了切实可行的路径和方向,有助于推动整个社会的绿色发展进程。
    This paper contributes current research by investigating the extent to which equity linkage networks impact enterprise green transition in sustainable development. By adopting a complex network approach, we constructed a common shareholding network based on the top ten shareholders of listed industrial enterprises in Shanghai and Shenzhen A-shares from 2013 to 2022. The empirical results indicate that enterprises closer to the centre of the equity linkage network tend to have higher degrees of green transition. This impact is facilitated through three mechanism channels of capital flow, information exchange, and knowledge transfer within the network. We find enterprises at the core of the network can effectively reduce their financing constraints on enterprises, mitigate risks associated with external environmental uncertainties and managerial myopia, and promote knowledge exchange and innovation cooperation between enterprises. We have also discovered that the centrality of equity network has a greater impact on promoting transition in state-owned, large-scale enterprises, and enterprises with less heavy pollution and the network effect can be enhanced by strong regional environmental regulations. The above findings not only provide policy makers with policy recommendations to guide the enterprises green transition, but also provide industry practitioners with practical paths and directions, which can help promote the green development process of the whole society.
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  • 文章类型: English Abstract
    By extracting the acupoint names and their main indications from cases in Chinese Acupuncture and Moxibustion Therapy and Practical Acupuncture and Moxibustion, the acupoints and their main indications are represented in a reduced dimension, establishing an \"acupoint-indication\" linkage. Using complex network detection results (node degree values), the specificity of acupoints was assessed. The small-world characteristics of the \"acupoint-indication\" network are utilized to analyze the consistency of acupoint selection in acupuncture prescriptions and strategies to avoid redundant acupoints. The results show that the \"acupoint-indication\" network formed by both texts exhibited an approximate \"long-tail\" distribution, with a large number of node degree values concentrated between 0 and 4 000, while a few nodes have degree values exceeding 10 000. There are significant differences in the number and distribution of nodes with degree values> 10 000 between the two texts. Chinese Acupuncture and Moxibustion Therapy includes 11 acupoints with multiple edges across the body, whereas Practical Acupuncture and Moxibustion contains only 2 such acupoints, located in the lower limbs. Clinically, some acupoints have a broad therapeutic effect and appear in numerous prescriptions. The division of acupoints based on node degree values can coarsely evaluate the body region specificity of acupoints\' regulatory effects. The \"acupoint-indication\" network of Chinese Acupuncture and Moxibustion Therapy has a higher number of edges than that of Practical Acupuncture and Moxibustion, which might be related to the different historical contexts of the two texts. In the future, diagnostic and therapeutic patterns with historical continuity can be utilized to optimize acupuncture prescriptions.
    提取《中国针灸治疗学》《实用针灸学》中病案的腧穴名称、主治病症,对穴位与主治病症进行降维表示,建立“穴-症”联系,采用复杂网络检测结果(节点度值)评估穴位的特异性,利用穴-症网络的“小世界”特性分析针灸处方选穴的一致性和避免冗余穴位的策略。结果显示,两本著作形成的“穴-症”网络均存在近似“长尾”的度分布,大量节点度值集中在0~4 000,少量节点的度值高达10 000以上。对于度值>10 000的节点出现了明显的个数与分布差异,《中国针灸治疗学》中包括11个具有多连边数的穴位,遍布全身,《实用针灸学》中仅有2个多连边数的穴位,位于下肢。临床中存在个别穴位具有广泛的治疗效应,出现在大量处方中,通过节点度值的穴位划分能够粗粒度地评估穴位调控作用的躯体区域特异性;《中国针灸治疗学》穴-症网络连边数高于《实用针灸学》穴-症网络,与2本著作不同的时代背景有关,今后可利用具有时代传承特征的诊疗规律优化针灸处方。.
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