نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشگاه آزاد اسلامی، واحد تهران جنوب
2 دانشگاه آزاد اسلامی واحد تهران جنوب،تهران ،ایران
چکیده
در این تحقیق به بررسی تأثیر تحریمها، بر فرار مالیاتی معاملات اشخاص وابسته بر اساس ترکیب رویکرد گراف کاوی-فراابتکاری فازی پرداخته شد. در این پژوهش تعداد1،780 شرکت دارای معاملات وابسته شامل 523 شرکت واقع در مناطق آزاد تجاری و 1،257 شرکت واقع در خارج از مناطق آزاد که دارای عضو هیأت مدیره مشترک و فعالیت اقتصادی تولیدی یا بازرگانی بوده انتخاب شدهاند. دراین پژوهش دادههای مالی ومالیاتی سالهای 1395 لغایت 1399 ازاظهارنامههای مالیاتی و سامانههای سازمان امور مالیاتی کشور مورد استفاده قرار گرفته است. این پژوهش از نظر هدف، کاربردی میباشد. جهت برآورد مدل از نرم افزار پایتون و پکیج NetworkX و متلب 2021 بهره گرفته شده است. جهت پیشبینی فرار مالیاتی معاملات اشخاص وابسته از الگوریتمهای فراابتکاری فازی غیرخطی از نوع لجستیک نوع 3 شفر نوع 4 بهره گرفته شد. بر اساس نتایج رویکرد مدل جگوار در مدلسازی گراف مابین شاخصهای معاملات اشخاص وابسته با فرار مالیاتی از دقت بالاتری برخوردار بود؛ بر اساس نتایج معاملات اشخاص وابسته قبل از ورود مدل به تحریم موجب افزایش 389/0 درصد در فرار مالیاتی و بعد از ورود تحریم موجب افزایش 414/0 درصدی در فرار مالیاتی گردید. به عبارتی ورود تحریم به مدل موجب گردیده است؛ معاملات بیشتری در حوزه معاملات وابسته مشکوک در حوزه فرار مالیاتی شناسایی نموده است.
کلیدواژهها
موضوعات
عنوان مقاله [English]
The Impact of Sanctions on Tax Evasion in Related-Party Transactions: A Hybrid Graph Mining-Fuzzy Metaheuristic Approach
نویسندگان [English]
- Amin Ahmadpour 1
- Seyedeh Mahboobeh Jafari 2
- Fatemeh Sarraf 1
1 Islamic Azad University, South Tehran Branch, Tehran, Iran
2 Islamic Azad University , South Tehran Branch,
چکیده [English]
This study investigates the impact of economic sanctions on tax evasion facilitated through Related-Party Transactions (RPTs) in Iran. Utilizing a novel hybrid framework that integrates graph mining, Principal Component Analysis (PCA), and advanced fuzzy metaheuristic optimization, we analyze financial data from 1,780 companies (2016-2020). Graph mining is employed to map and detect suspicious transaction networks, particularly those involving Free Trade Zones (FTZs). A sanctions intensity index is constructed using PCA from 10 macroeconomic variables. The core predictive modeling leverages a Jaguar-optimized Type-3 Sheffer-like Type-4 fuzzy logic system to handle data uncertainty and non-linear relationships. Results indicate that sanctions exacerbate RPT-based tax evasion, increasing its magnitude from 0.389% to 0.414%. The proposed Jaguar model demonstrated superior performance with 98.8% accuracy (MSFE: 0.012), significantly outperforming traditional detection methods. Post-sanctions network topology analysis revealed a marked increase in suspicious clusters and nodes, with prevalent evasion patterns including multi-layer transfer pricing and abnormal profitability in FTZ subsidiaries. This research offers a robust, scalable tool for tax authorities to prioritize audits and enhances the understanding of how macroeconomic shocks influence illicit financial behaviors within corporate networks.
Introduction
Economic sanctions are coercive measures imposed by states to restrict international activities of target nations, offering a lower-risk alternative to military conflict (Cordesman et al., 2011). Iran exemplifies this, facing escalating sanctions that incentivize tax evasion through Related-Party Transactions (RPTs). Under sanctions, firms exploit legal gaps and accrual accounting to manipulate profits (Abeysekera, 2003; Arabi et al., 2018), transforming Iran’s financial market into a complex network (Soleimani et al., 2014). Traditional analytical methods fail against such complexity, while metaheuristic models excel. Graph mining uniquely uncovers hidden dimensions in sanctioned markets by analyzing network structures and variable relationships (Hu et al., 2022), especially where information asymmetry impedes tax authorities (Iacovacci & Lacasa, 2019; Yang & Xu, 2024).RPTs occur in nested networks with non-linear relationships (e.g., shared boards, cross-ownership) (Ruan et al., 2019). Sanctions amplify complexity through layered tactics like free trade zones (FTZs) and multi-layer transfer pricing (e.g., sequential sales at non-arm’s length prices) (Chan et al., 2016; Tian et al., 2016). Non-disclosure of ~68% key RPT information (e.g., pricing logic) exacerbates tax avoidance (Barokah, 2013), enabling profit shifting to foreign affiliates and eroding tax bases (Yang & Xu, 2024).Although RPTs can be economically justified (Gordon et al., 2004a), they risk abuse for private gain (Djankov et al., 2008; Barokah, 2013). In Iran, firms use subsidiaries in FTZs (e.g., Kish, Chabahar) and transfer pricing under Article 132-T of Iran’s Direct Taxation Law to shift profits: e.g., selling goods below market to affiliates, which then export at global prices, registering profits offshore. Weak oversight and fragmented databases hinder monitoring, but Iran’s Taxpayers’ Integrated System (TIS) provides foundational data for analysis.This study proposes a novel framework combining graph mining (to detect high-risk FTZ firms) and Type-3 Sheffer-like Type-4 fuzzy logic (to model tax data uncertainty) optimized by the Jaguar metaheuristic algorithm. It identifies suspicious groups exhibiting structural (e.g., nested ownership) and behavioral (e.g., abnormal pricing) tax evasion patterns, aligning with Iran’s Comprehensive Tax Plan for risk-based audits.
Research Questions:
Do economic sanctions increase RPT-based tax evasion?
How can advanced data analytics identify and model these hidden patterns?
Theoretical Framework
2.1. Related-Party Transactions (RPTs)
Per Iranian Accounting Standard 12 (Audit Organization, 2020), RPTs involve entities with control/influence over financial decisions. Key groups include:
Parent/subsidiary entities under shared control.
Key management personnel and relatives.
Entities with significant economic/management ties.
Two theoretical perspectives exist:
- Agency Theory:RPTs enable opportunism by insiders (Jensen & Meckling, 1976), e.g., underpriced asset sales (Cheung et al., 2006).
- Efficiency View: RPTs reduce transaction costs (Gordon et al., 2004a) but require disclosure to mitigate information asymmetry (Kohlbeck & Mayhew, 2010).
Empirical evidence confirms RPTs facilitate tax avoidance via transfer pricing (Harris et al., 1993; Jian & Wong, 2010), especially in low-tax jurisdictions (Barker et al., 2016).
2.2. Sanctions’ Economic Impact
Sanctions restrict input access, raise production costs (Parsa et al., 2013), contract import-reliant sectors (Caetano et al., 2023), and reduce total factor productivity (Nosratabadi, 2023). They incentivize shifting activities to the informal economy, causing technical inefficiency (Markus, 2024).
Methodology
3.1. Data & Variables
- Dependent Variable: Tax evasion, measured by the tax gap (difference between declared and final tax) per OECD standards (Slemrod & Weber, 2012).
- Independent Variable: RPT volume (Iranian Accounting Standard 12).
- Moderator: Sanctions index (PCA-derived from 10 macroeconomic variables, Table 1).
Data: 16,756 RPTs from 1,780 Iranian firms (2016–2020), including:
523 firms in FTZs (zero tax rate under Article 132-T).
1,257 non-FTZ firms with shared boards.
Financial data (net sales, COGS, operating profit) sourced confidentially from Iran’s National Tax Administration (INTA).
3.2. Integrated Framework
Graph Mining:
Construct transaction networks (nodes = firms; edges = RPTs weighted by price deviation).
Identify high-risk clusters(e.g., firms in FTZs with below-market pricing).
PCA for Sanctions Index:
- Combine 10 macroeconomic variables (e.g., oil exports, currency volatility) into a unified index.
- 2 principal components explain 85% variance (Table 1, Chart 3).
Fuzzy Metaheuristic Optimization:
- Apply Type-3 Sheffer-like Type-4 fuzzy logic to model data uncertainty (e.g., transfer pricing discrepancies).
- Optimize via Jaguar algorithm (multi-objective: minimize prediction error [MSFE], maximize detection accuracy).
- Output: Dynamic risk index (transaction volume, price deviation, geographic concentration).
Results & Discussion
- The analysis confirmed that sanctions significantly intensified RPT-based tax evasion, elevating its level from 0.389% (pre-sanctions) to 0.414% (post-sanctions). This 0.025% increase, though seemingly small, represents a substantial rise in hidden economic activity within the constrained environment.
- The Jaguar model achieved 98.8% accuracy (error rate: 0.012), outperforming traditional methods (40% vs. 74.6% detection rate).
- Graph analysis revealed post-sanctions topological shifts: increased suspicious nodes/clusters (Chart 4).
- Key evasion patterns:
- Multi-layer transfer pricing (e.g., mother → FTZ subsidiary → export).
- Abnormal profitability in FTZ subsidiaries.
- Geographic concentration in low-tax areas.
Conclusion & Policy Implications
5.1. Key Findings
Sanctions intensify RPT-based tax evasion by incentivizing complex, hidden transaction networks. The integrated graph-fuzzy-jaguar framework proves superior to linear models in detecting evasion under data uncertainty.
5.2. Innovations
- First application of Type-3 fuzzy logic in taxation.
- Dynamic risk index for audit prioritization.
- Operational compatibility with INTA’s existing systems (e.g., TIS).
5.3. Recommendations
- To INTA:Integrating the model into a blockchain-based real-time monitoring platform and Develop an AI dashboard with risk-tiered visualization (green/yellow/red).
- Domestic Policy: Mandating disclosure of transfer pricing logic and topological RPT networks and establishing a National Networked Data Analysis Center.
- International Cooperation:Leveraging double-taxation agreements for cross-border data exchange.
- Future Research: Extending the model to multinational contexts and designing "tax resilience indices" for sanction-affected economies.
کلیدواژهها [English]
- Graph Mining
- Jaguar Algorithm
- Tax Evasion
- Economic Sanctions
- Related-Party Transactions
- پارسا امیدعلی، مهرکام مهرداد، حصنی مقدم فاطمه. تأثیر تحریمهای اقتصادی و ارتباطات سیاسی با تأکید بر درآمدها و شکاف مالیاتی: آزمون تئوری اقتصاد سیاسی. پژوهشنامه مالیات. ۱۳۹۹; ۲۸ (۴۸): ۸۳-۱۰۸ URL: http://taxjournal.ir/article-۱-۱۹۲۶-fa.html
- جوادیان کوتنائی، اکبر، پورآقاجان سرحمامی، عباسعلی، و حسینی شیروانی، میرسعید. (1399). ارائه مدل شناسایی تقلب مالیاتی بر مبنای ترکیب الگوریتم درخت تصمیم ID3 بهبودیافته و شبکههای عصبی پرسپترون چندلایه. حسابداری مدیریت،13(46)، 53-70. https://sid.ir/paper/951443/fa
- سلیمانی سروستانی، سجاد، سیدمحمدرضا، داوودی، خردمند، علی، (1403)، پرتفوی بهینه نوسان روزانه مبتنی بر پیشبینی ارزش بازهای با رویکرد خودرگرسیون برداری، فصلنامه بورس اوراق بهادار، 17(65)، 69-86. doi:10.22034/jse.2024.12118.2073
- صداقتی، صمد، فرهادی، روح الله و فلاح شمس، میرفیض. (1403). سرایت پویایی توپولوژیکی درشبکه بازار سهام ایران. دانش سرمایهگذاری، 13(49)، 279-298.http://www.jik-ifea.ir/article_22057.html
- عباس زاده، محمدرضا، رجبعلی زاده، جواد و قناد، مصطفی. (1398). ارتباطات سیاسی، معاملات با اشخاص وابسته و مدیریت سود در شرکتهای پذیرفتهشده در بورس اوراق بهادار تهران. مطالعات تجربی حسابداری مالی، 16(63)، 129-155. doi: 10.22054/qjma.2019.10649
- عرب مازار علی اکبر، باقری بهروز، جعفری پرور مصطفی. رویکرد مالیاتی به قیمتگذاری انتقالات و بررسی آن در ایران. پژوهشنامه مالیات. ۱۳۹۳; ۲۲ (۲۱): ۹-۳۸
- URL: http://taxjournal.ir/article-۱-۲۵۳-fa.html
- عربی، مهدی، تقوی، مهدی، رؤیایی، رمضانعلی و بنی مهد، بهمن. (1397). محتوای اطلاعاتی صورتهای مالی در فرایند تشدید تحریمهای اقتصادی بر ایران. بررسیهای حسابداری و حسابرسی، 25(1)، 91-112. doi: 10.22059/acctgrev.2018.234823.1007626
- قنبری نژاد، جواد، صالحی، مهدی، پیفه، احمد. (2023). بررسی عوامل فرار مالیاتی در مناطق آزاد تجاری-اقتصادی. اقتصاد محاسباتی،4(2)،69-95. https://sanad.iau.ir/Journal/ecomag/Article/1045581/FullText
- مقری گردرودباری، محسن، داداشی، ایمان، و محسنی ملکی، بهرام. (1404). اثر فرار مالیاتی بر مودیان، حسابرسان مالیاتی و شاخصهای کلان اقتصادی. مطالعات بین رشتهای اقتصاد، 1(1)، 89-114. doi: 10.22091/ise.2025.12736.1025
- نسل موسوی سیدحسین، حسینی شیروانی میرسعید، نظرپور محمود. ارائه مدل پیشبینی فرار مالیاتی برمبنای الگوریتم درخت تصمیم ID3 و شبکه بیزین. پژوهشنامه مالیات. ۱۳۹۹؛ ۲۸ (۴۵): ۵۹-۸۷ URL: http://taxjournal.ir/article-1-1820-fa.html
- نمازی، محمد و صادق زاده مهارلویی، محمد. (1397). بررسی سودمندی روش انتخاب متغیر ریلیف در بهبود نتایج پیشبینی فرار مالیاتی با استفاده از دادهکاوی. پژوهشهای کاربردی در گزارشگری مالی، 7(2).7-44.https://www.arfr.ir/article_85299. html?lang=fa
- یوخنه القیانی، ماریام، بحری ثالث، جمال، جبارزاده کنگرلوئی، سعید و زواری رضایی، اکبر. (1400). تبیین گزارشگری مالی- مالیاتی متقلبانه شرکتها: رویکرد ترکیبی دادهکاوی کلاسیک، ANFIS و الگوریتمهای فراابتکاری. مطالعات تجربی حسابداری مالی، 18(71)، 87-112. doi: 10.22054/qjma.2021.59092.2234
- Abeysekera, I. (2003). Political Economy of Accounting in Intellectual Capital Reporting. The European Journal of Management and Public Policy, 2(1), 65-79
- Tselykh, A., Knyazeva, M., Popkova, E., Durfee, A., & Tselykh., A. (2016, July) An attributed graph mining approach to detect transfer pricing fraud. In Proceedings of the 9th International Conference on Security of Information and Networks, 72–75.
- Barker, J., & Asare, K., & Brickman, S. (2016). Transfer Pricing As a Vehicle in Corporate Tax Avoidance. Journal of Applied Business Research (JABR), 33, 9.
- Barro, R. J., & Lee, J. W. (1993). International Comparisons of Educational Attainment. Journal of Monetary Economics, 32(3), 363-394.
- Barokah, Z. (2013). An Analysis of Corporate Related-Party Disclosure in the Asia-Pacific Region [Doctoral dissertation, Queensland University of Technology]. Accessed January 31, 2018. https://eprints.qut.edu.au/60847/.
- Barokah, Z., & Sari, N. N. (2024). Cross-border related party sales, tax avoidance, and tunneling: Regulatory impacts on Indonesian manufacturing. The Indonesian Journal of Accounting Research, 27 (2), 307–334. https://doi.org/10.33312/ijar.801
- Caetano, J., Galego, A., & Caleiro, A. (2023). On the Determinants of Sanctions Effectiveness: An Empirical Analysis by Using Duration Models. Economies 11, 136. https://doi.org/10.3390/ economies11050136
- Caruso, R. (2003). The Impact of International Economic Sanctions on Trade: An Empirical Analysis. Peace Economics, Peace Science and Public Policy, 9(2), 1-34.
- Chan, K. H., Mo, P. L., & Tang, T. (2016). Tax Avoidance and Tunneling: Empirical Analysis from an Agency Perspective. Journal of International Accounting Research,15, 49- 66.
- Chan, K. H., Mo, P. L. L., & Zhou, A. Y. (2016). Government Ownership, Corporate Governance and Tax Avoidance: Evidence from China. Journal of International Accounting, Auditing and Taxation, 27, 1-15.
- Chang, S. J., & Hong, J. (2000). Economic performance of groupaffiliated companies in Korea: Intragroup resource sharing and internal business transaction. Academy of Management Journal, 43(3), 429-448.
- Cheung, Y.-L., Rau, P. R., & Stouraitisc, A. (2006). Tunneling, Propping, and Expropriation: Evidence from Connected Party Transactions in Hong Kong. Journal of Financial Economics, 82, 343-386.
- Cordesman, A. H., Bosserman, B., D’Amato, J., & Gagel, A. (2011, October 6). U.S. and Iranian strategic competition: The sanctions game—Energy, arms control, and regime change. Center for Strategic and International Studies.https://www.csis.org/analysis/us-and-iranian-strategic-competition-sanctions-game-energy-arms-control-and-regime-change
- Djankov, S., La Porta, R., Lopez-de-Silanes, F., & Shleifer, A. (2008). The law and economics of self-dealing. Journal of Financial Economics, 88(3), 430–465. https://doi.org/10.1016/j.jfineco.2007.02.007
- Gordon, E., Henry, E., & Palia, D. (2004). Related party transactions: Associations with corporate governance and firm value. Retrieved from http://ssrn.com/abstract=558993
- Elizabeth A. Gordon & Elaine Henry & Darius Palia, 2004. "Related Party Transactions And Corporate Governance," Advances in Financial Economics, in: Corporate Governance, pages 1-27, Emerald Group Publishing Limited.
- Harris, D. G., Morck, R., Slemrod, J., & Yeung, B. (1993). Income shifting in U.S. multinational corporations. In J. M. Poterba (Ed.), Tax policy and the economy (Vol. 7, pp. 111–140). The MIT Press.
- Healy, P. M., & Palepu, K. G. (2001). Information asymmetry, corporate disclosure, and the capital markets: A review of the empirical disclosure literature. Journal of Accounting and Economics, *31*(1), 405–440. https://doi.org/10.1016/S0165-4101(01)00018-0
- Hendratama, T. D., & Barokah, Z. (2020). Related party transactions and firm value: The moderating role of corporate social responsibility reporting. China Journal of Accounting Research, 13(2), 223–236. https://doi.org/10.1016/j.cjar.2020.04.002
- Hu, Y., & Xiao, F. (2022). A novel method for forecasting time series based on directed visibility graph and improved random walk. Physica A: Statistical Mechanics and its Applications, 594, 127029. https://doi.org/10.1016/j.physa.2022.127029
- Huizinga, H., & Laeven, L. (2008). International profit shifting within European multinationals. Journal of Public Economics, 92(5–6), 1164–1182. https://doi.org/10.1016/j.jpubeco.2007.11.002
- Iacovacci, J., & Lacasa, L. (2020). Visibility graphs for image processing. IEEE Transactions on Pattern Analysis and Machine Intelligence, 42 (4), 974–987. https://doi.org/10.1109/TPAMI.2019.2891742
- Jian, M., Wong, T.J. Propping through related party transactions. Rev Account Stud 15, 70–105 (2010). https://doi.org/10.1007/s11142-008-9081-4
- Ruan, J., Yan, Z., Dong, B., Zheng, Q., & Qian, B. (2019). Identifying suspicious groups of affiliated-transaction-based tax evasion in big data. Information Sciences, 477, 508–532. https://doi.org/10.1016/j.ins.2018.11.008
- Jensen, M. C., & Meckling, W. H. (1976). Theory of the firm: Managerial behavior, agency costs and ownership structure. Journal of Financial Economics, 3(4), 305–360. https://doi.org/10.1016/0304-405X(76)90026-X
- Jolliffe Ian, T., &Cadima Jorge.2016Principal component analysis: a review and recent developmentsPhil. Trans. R. Soc. A.37420150202https://doi.org/10.1098/rsta.2015.0202
- Kohlbeck, Mark J. and Mayhew, Brian W., Are Related Party Transactions Red Flags? (March 1, 2016). Available at SSRN: https://ssrn.com/abstract=2427439 or http://dx.doi.org/10.2139/ssrn.2427439
- Kohlbeck, M. J., & Mayhew, B. W. (2017). Are related party transactions red flags? Contemporary Accounting Research, 34(2), 900–928. https://doi.org/10.1111/1911-3846.12296
- Leite, R., Gschwandtner, T., Miksch, S., Kriglstein, S., Pohl, M., Gstrein, E., & Kuntner, J. (2017). EVA: Visual analytics to identify fraudulent events. IEEE Transactions on Visualization and Computer Graphics, 24(1), 330-339. https://doi.org/10.1109/TVCG.2017.2744758
- Wolf, M. A. (2024). Persistent or temporary? Effects of social assistance benefit sanctions on employment quality. Socio-Economic Review, 22 (3), 1531–1557. https://doi.org/10.1093/ser/mwad073
- McCahery, J., & Vermeulen, E. (2005). Corporate governance crises and related party transactions: A post-Parmalat agenda. In K. Hopt, E. Wymeersch, H. Kanda, & H. Baum (Eds.), Corporate governance in context: Corporations, states, and markets in Europe, Japan, and the US (pp. 217-244). Oxford University Press. https://doi.org/10.1093/acprof:oso/9780199290703.003.0012
- Nosratabadi, J. (2023). The effect of trade sanctions on employment through total factor productivity. International Economics and Economic Policy, 20(1), 163–187.https://doi.org/10.1007/s10368-023-00555-y
- OECD. (2017). Measuring tax gaps: Tax gap initiatives in OECD countries. OECD Publishing. https://www.oecd.org/tax/forum-on-tax-administration/publications-and-products/measuring-tax-gaps-tax-gap-initiatives-in-oecd-countries.htm
- Slemrod, J., & Weber, C. (2012). Evidence of the invisible: Toward a credibility revolution in the empirical analysis of tax evasion and the informal economy. International Tax and Public Finance, 19(1), 25–53. https://doi.org/10.1007/s10797-011-9181-0
- Taylor, G., & Richardson, G. (2012). International corporate tax avoidance practices: Evidence from Australian firms. The International Journal of Accounting, 47 (4), 469–496. https://doi.org/10.1016/j.intacc.2012.10.004
- Tian, F., Lan, T., Chao, K.-M., Godwin, N., Zheng, Q., Shah, N., & Zhang, F. (2016). Mining Suspicious Tax Evasion Groups in Big Data. IEEE Transactions on Knowledge and Data Engineering, 28(10), 2651 - 2664. https://doi.org/10.1109/TKDE.2016.2571686
- Torbat, A. E. (2005). Impacts of the U.S. trade and financial sanctions on Iran. The World Economy, 28 (3), 407–434. https://doi.org/10.1111/j.1467-9701.2005.00671.x
- Lo, A. W. Y., Wong, R. M. K., & Firth, M. (2010). Can corporate governance deter management from manipulating earnings? Evidence from related-party sales transactions in China. Journal of Corporate Finance, 16 (2), 225–235. https://doi.org/10.1016/j.jcorpfin.2009.11.002
- Lin, Y., Wong, K., Wang, Y., Zhang, R., Dong, B., Qu, H., & Zheng, Q. (2020). TaxThemis: Interactive Mining and Exploration of Suspicious Tax Evasion Group. arXiv. https://doi.org/10.48550/arXiv.2009.03179
- Yang, B., & Xu, T. (2024). Assessing the Influence of Country-by-Country Reporting (CbCr) on Cross-Border Related Party Transactions: Insights from China. Journal of the Knowledge Economy, 16, 4855–4897. https://doi.org/10.1007/s13132-024-02024-6
- Zamani, M., Haji, G., Fotros, M. H., & Ghafari Ashtiani, P. (2024). The effects of economic sanctions on Iran's employment and economic growth according to the Markov switching model. International Journal of Nonlinear Analysis and Applications, 15(5), 23-34. doi: 10.22075/ijnaa.2022.28124.3807
- Zhou, F., Zhou, H., Yang, Z., & Yang, L. (2019). EMD2FNN: A strategy combining empirical mode decomposition and factorization machine based neural network for stock market trend prediction. Expert Systems With Applications, 115, 136–151. https://doi.org/10.1016/J.ESWA.2018.07.065
- Zou, Y., Donner, R. V., Marwan, N., Donges, J. F., & Kurths, J. (2019). Complex network approaches to nonlinear time series analysis. Physics Reports, 787, 1–97. https://doi.org/10.1016/j.physrep.2018.10.005