The Hamiltonian cycle and path problems are fundamental in graph theory and useful in modelling real-life problems. Research in this area is directed toward designing better and better algorithms for general problems, but also toward defining new special cases for which exact polynomial-time algorithms exist. In the paper, such new classes of digraphs are proposed. The classes include, among others, quasi-adjoint graphs, which are a superclass of adjoints, directed line graphs, and graphs modelling a DNA sequencing problem. PDF XML
哈密顿循环和路径问题是图论中的基本问题，在模拟现实问题时非常有用。该领域的研究方向是为一般问题设计出越来越好的算法，同时也为存在精确多项式时间算法的新特例定义算法。本文提出了这类新的数字图。这些类别包括准相邻图（相邻图的超类）、有向线图和 DNA 测序问题建模图等。PDF XML
{"title":"Beyond Quasi-Adjoint Graphs: On Polynomial-Time Solvable Cases of the Hamiltonian Cycle and Path Problems","authors":"Marta Kasprzak","doi":"10.15388/24-infor568","DOIUrl":"https://doi.org/10.15388/24-infor568","url":null,"abstract":"The Hamiltonian cycle and path problems are fundamental in graph theory and useful in modelling real-life problems. Research in this area is directed toward designing better and better algorithms for general problems, but also toward defining new special cases for which exact polynomial-time algorithms exist. In the paper, such new classes of digraphs are proposed. The classes include, among others, quasi-adjoint graphs, which are a superclass of adjoints, directed line graphs, and graphs modelling a DNA sequencing problem.\u0000PDF XML","PeriodicalId":56292,"journal":{"name":"Informatica","volume":"4 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142248890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aušrys Kilčiauskas, Antanas Bendoraitis, Eligijus Sakalauskas
One of the main trends for the monitoring and control of business processes is to implement these processes via private blockchain systems. These systems must ensure data privacy and verifiability for the entire network here denoted by ‘Net’. In addition, every business activity should be declared to a trusted third party (TTP), such as an Audit Authority (AA), for tax declaration and collection purposes.We present a solution for a confidential and verifiable realization of transactions based on the Unspent Transaction Output (UTxO) paradigm. This means that the total sum of transaction inputs (incomes) $In$ must be equal to the total sum of transaction outputs (expenses) $Ex$, satisfying the balance equation $In=Ex$. Privacy in a private blockchain must be achieved through the encryption of actual transaction values. However, it is crucial that all participants in the network be able to verify the validity of the transaction balance equation. This poses a challenge with probabilistically encrypted data. Moreover, the inputs and outputs are encrypted with different public keys. With the introduction of the AA, the number of different public keys for encryption can be reduced to two. Incomes are encrypted with the Receiver’s public key and expenses with the AA’s public key.The novelty of our realization lies in taking additively-multiplicative, homomorphic ElGamal encryption and integrating it with a proposed paradigm of modified Schnorr identification providing a non-interactive zero-knowledge proof (NIZKP) using a cryptographically secure h-function. Introducing the AA as a structural element in a blockchain system based on the UTxO enables effective verification of encrypted transaction data for the Net. This is possible because the proposed NIZKP is able to prove the equivalency of two ciphertexts encrypted with two different public keys and different actors.This integration allows all users on the Net to check the UTxO-based transaction balance equation on encrypted data. The security considerations of the proposed solution are presented. PDF XML
监测和控制业务流程的主要趋势之一是通过私有区块链系统实施这些流程。这些系统必须确保整个网络的数据隐私和可验证性，这里用 "Net "表示。此外，每项业务活动都应向可信第三方（TTP）（如审计机构（AA））申报，以达到申报和收税的目的。我们提出了一种基于未花费交易输出（UTxO）范式的保密且可验证的交易实现解决方案。这意味着交易输入（收入）总和$In$必须等于交易输出（支出）总和$Ex$，满足平衡方程$In=Ex$。私人区块链的隐私必须通过对实际交易值加密来实现。但是，网络中的所有参与者都必须能够验证交易平衡方程的有效性。这给概率加密数据带来了挑战。此外，输入和输出是用不同的公开密钥加密的。引入 AA 后，用于加密的不同公开密钥的数量可减少到两个。我们实现的新颖之处在于采用了加法-乘法、同态的 ElGamal 加密，并将其与使用加密安全 h 函数提供非交互式零知识证明（NIZKP）的改良施诺尔识别范式相结合。在基于UTxO的区块链系统中引入AA作为结构元素，可以有效验证网络的加密交易数据。之所以能做到这一点，是因为所提出的 NIZKP 能够证明用两个不同的公钥和不同的行为者加密的两个密码文本的等价性。这种集成使网络上的所有用户都能在加密数据上检查基于 UTxO 的交易平衡方程。本文介绍了拟议解决方案的安全考虑因素。PDF XML
{"title":"Confidential Transaction Balance Verification by the Net Using Non-Interactive Zero-Knowledge Proofs","authors":"Aušrys Kilčiauskas, Antanas Bendoraitis, Eligijus Sakalauskas","doi":"10.15388/24-infor564","DOIUrl":"https://doi.org/10.15388/24-infor564","url":null,"abstract":"One of the main trends for the monitoring and control of business processes is to implement these processes via private blockchain systems. These systems must ensure data privacy and verifiability for the entire network here denoted by ‘Net’. In addition, every business activity should be declared to a trusted third party (TTP), such as an Audit Authority (AA), for tax declaration and collection purposes.We present a solution for a confidential and verifiable realization of transactions based on the Unspent Transaction Output (UTxO) paradigm. This means that the total sum of transaction inputs (incomes) <span><span>$In$</span></span> must be equal to the total sum of transaction outputs (expenses) <span><span>$Ex$</span></span>, satisfying the balance equation <span><span>$In=Ex$</span></span>. Privacy in a private blockchain must be achieved through the encryption of actual transaction values. However, it is crucial that all participants in the network be able to verify the validity of the transaction balance equation. This poses a challenge with probabilistically encrypted data. Moreover, the inputs and outputs are encrypted with different public keys. With the introduction of the AA, the number of different public keys for encryption can be reduced to two. Incomes are encrypted with the Receiver’s public key and expenses with the AA’s public key.The novelty of our realization lies in taking additively-multiplicative, homomorphic ElGamal encryption and integrating it with a proposed paradigm of modified Schnorr identification providing a non-interactive zero-knowledge proof (NIZKP) using a cryptographically secure h-function. Introducing the AA as a structural element in a blockchain system based on the UTxO enables effective verification of encrypted transaction data for the Net. This is possible because the proposed NIZKP is able to prove the equivalency of two ciphertexts encrypted with two different public keys and different actors.This integration allows all users on the Net to check the UTxO-based transaction balance equation on encrypted data. The security considerations of the proposed solution are presented.\u0000PDF XML","PeriodicalId":56292,"journal":{"name":"Informatica","volume":"61 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142205375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The growing popularity of mobile and cloud computing raises new challenges related to energy efficiency. This work evaluates four various SQL and NoSQL database solutions in terms of energy efficiency. Namely, Cassandra, MongoDB, Redis, and MySQL are taken into consideration. This study measures energy efficiency of the chosen data storage solutions on a selected set of physical and virtual computing nodes by leveraging Intel RAPL (Running Average Power Limit) technology. Various database usage scenarios are considered in this evaluation including both local usage and remote offloading. Different workloads are benchmarked through the use of YCSB (Yahoo! Cloud Serving Benchmark) tool. Extensive experimental results show that (i) Redis and MongoDB are more efficient in energy consumption under most usage scenarios, (ii) remote offloading saves energy if the network latency is low and destination CPU is significantly more powerful, and (iii) computationally weaker CPUs may sometimes demonstrate higher energy efficiency in terms of J/ops. An energy efficiency measurement framework is proposed in order to evaluate and compare different database solutions based on the obtained experimental results. PDF XML
移动和云计算的日益普及带来了与能效有关的新挑战。这项工作从能效角度评估了四种不同的 SQL 和 NoSQL 数据库解决方案。即 Cassandra、MongoDB、Redis 和 MySQL。本研究利用英特尔 RAPL（平均运行功耗限制）技术，在一组选定的物理和虚拟计算节点上测量了所选数据存储解决方案的能效。评估中考虑了各种数据库使用场景，包括本地使用和远程卸载。通过使用 YCSB（雅虎云服务基准）工具对不同的工作负载进行了基准测试。广泛的实验结果表明：(i) Redis 和 MongoDB 在大多数使用场景下的能耗效率更高；(ii) 如果网络延迟较低且目标 CPU 性能明显更强，则远程卸载可节省能耗；(iii) 计算能力较弱的 CPU 有时可能在 J/ops 方面表现出更高的能效。本文提出了一个能效测量框架，以便根据获得的实验结果评估和比较不同的数据库解决方案。PDF XML
{"title":"Offloaded Data Processing Energy Efficiency Evaluation","authors":"Victor Prokhorenko, Muhammad Ali Babar","doi":"10.15388/24-infor567","DOIUrl":"https://doi.org/10.15388/24-infor567","url":null,"abstract":"The growing popularity of mobile and cloud computing raises new challenges related to energy efficiency. This work evaluates four various SQL and NoSQL database solutions in terms of energy efficiency. Namely, Cassandra, MongoDB, Redis, and MySQL are taken into consideration. This study measures energy efficiency of the chosen data storage solutions on a selected set of physical and virtual computing nodes by leveraging Intel RAPL (Running Average Power Limit) technology. Various database usage scenarios are considered in this evaluation including both local usage and remote offloading. Different workloads are benchmarked through the use of YCSB (Yahoo! Cloud Serving Benchmark) tool. Extensive experimental results show that (i) Redis and MongoDB are more efficient in energy consumption under most usage scenarios, (ii) remote offloading saves energy if the network latency is low and destination CPU is significantly more powerful, and (iii) computationally weaker CPUs may sometimes demonstrate higher energy efficiency in terms of J/ops. An energy efficiency measurement framework is proposed in order to evaluate and compare different database solutions based on the obtained experimental results.\u0000PDF XML","PeriodicalId":56292,"journal":{"name":"Informatica","volume":"67 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141770626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Frequent gradual pattern extraction is an important problem in computer science widely studied by the data mining community. Such a pattern reflects a co-variation between attributes of a database. The applications of the extraction of the gradual patterns concern several fields, in particular, biology, finances, health and metrology. The algorithms for extracting these patterns are greedy in terms of memory and computational resources. This clearly poses the problem of improving their performance. This paper proposes a new approach for the extraction of gradual and frequent patterns based on the reduction of candidate generation and processing costs by exploiting frequent itemsets whose size is a power of two to generate all candidates. The analysis of the complexity, in terms of CPU time and memory usage, and the experiments show that the obtained algorithm outperforms the previous ones and confirms the interest of the proposed approach. It is sometimes at least 5 times faster than previous algorithms and requires at most half the memory. PDF XML
频繁渐变模式提取是数据挖掘领域广泛研究的计算机科学中的一个重要问题。这种模式反映了数据库属性之间的共同变化。渐变模式提取的应用涉及多个领域，特别是生物、金融、健康和计量学。提取这些模式的算法在内存和计算资源方面比较贪婪。这显然提出了提高算法性能的问题。本文提出了一种提取渐变和频繁模式的新方法，其基础是利用大小为 2 的频繁项集生成所有候选项，从而降低候选项的生成和处理成本。从 CPU 时间和内存使用方面对复杂性的分析以及实验表明，所获得的算法优于之前的算法，并证实了所提方法的意义。有时，它比以前的算法至少快 5 倍，所需的内存也最多只有以前的一半。
{"title":"An Improved Algorithm for Extracting Frequent Gradual Patterns","authors":"Edith Belise Kenmogne, Idriss Tetakouchom, Clémentin Tayou Djamegni, Roger Nkambou, Laurent Cabrel Tabueu Fotso","doi":"10.15388/24-infor566","DOIUrl":"https://doi.org/10.15388/24-infor566","url":null,"abstract":"Frequent gradual pattern extraction is an important problem in computer science widely studied by the data mining community. Such a pattern reflects a co-variation between attributes of a database. The applications of the extraction of the gradual patterns concern several fields, in particular, biology, finances, health and metrology. The algorithms for extracting these patterns are greedy in terms of memory and computational resources. This clearly poses the problem of improving their performance. This paper proposes a new approach for the extraction of gradual and frequent patterns based on the reduction of candidate generation and processing costs by exploiting frequent itemsets whose size is a power of two to generate all candidates. The analysis of the complexity, in terms of CPU time and memory usage, and the experiments show that the obtained algorithm outperforms the previous ones and confirms the interest of the proposed approach. It is sometimes at least 5 times faster than previous algorithms and requires at most half the memory.\u0000PDF XML","PeriodicalId":56292,"journal":{"name":"Informatica","volume":"30 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141770625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper attempts to demystify the stability of CoCoSo ranking method via a comprehensive simulation experiment. In the experiment, matrices of different dimensions are generated via Python with fuzzy data. Stability is investigated via adequacy and partial adequacy tests. The test passes if the ranking order does not change even after changes are made to entities, and the partial pass signifies that the top ranked alternative remains intact. Results infer that CoCoSo method has better stability with respect to change of alternatives compared to criteria; and CoCoSo method shows better stability with respect to partial adequacy test for criteria. PDF XML
本文试图通过一个综合模拟实验来揭开 CoCoSo 排序方法稳定性的神秘面纱。在实验中，不同维度的矩阵通过 Python 生成模糊数据。稳定性通过充分性和部分充分性测试进行研究。如果即使对实体进行了更改，排名顺序也不会发生变化，则测试通过；如果排名靠前的备选方案保持不变，则部分通过。结果推断，与标准相比，CoCoSo 方法在备选方案发生变化时具有更好的稳定性；与标准的部分充分性测试相比，CoCoSo 方法显示出更好的稳定性。PDF XML
{"title":"Demystifying the Stability and the Performance Aspects of CoCoSo Ranking Method under Uncertain Preferences","authors":"Sundararajan Dhruva, Raghunathan Krishankumar, Dragan Pamucar, Edmundas Kazimieras Zavadskas, Kattur Soundarapandian Ravichandran","doi":"10.15388/24-infor565","DOIUrl":"https://doi.org/10.15388/24-infor565","url":null,"abstract":"This paper attempts to demystify the stability of CoCoSo ranking method via a comprehensive simulation experiment. In the experiment, matrices of different dimensions are generated via Python with fuzzy data. Stability is investigated via adequacy and partial adequacy tests. The test passes if the ranking order does not change even after changes are made to entities, and the partial pass signifies that the top ranked alternative remains intact. Results infer that CoCoSo method has better stability with respect to change of alternatives compared to criteria; and CoCoSo method shows better stability with respect to partial adequacy test for criteria.\u0000PDF XML","PeriodicalId":56292,"journal":{"name":"Informatica","volume":"15 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141770719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rafał Brociek, Mateusz Goik, Jakub Miarka, Mariusz Pleszczyński, Christian Napoli
The article focuses on the presentation and comparison of selected heuristic algorithms for solving the inverse problem for the anomalous diffusion model. Considered mathematical model consists of time-space fractional diffusion equation with initial boundary conditions. Those kind of models are used in modelling the phenomena of heat flow in porous materials. In the model, Caputo’s and Riemann-Liouville’s fractional derivatives were used. The inverse problem was based on identifying orders of the derivatives and recreating fractional boundary condition. Taking into consideration the fact that inverse problems of this kind are ill-conditioned, the problem should be considered as hard to solve. Therefore,to solve it, metaheuristic optimization algorithms popular in scientific literature were used and their performance were compared: Group Teaching Optimization Algorithm (GTOA), Equilibrium Optimizer (EO), Grey Wolf Optimizer (GWO), War Strategy Optimizer (WSO), Tuna Swarm Optimization (TSO), Ant Colony Optimization (ACO), Jellyfish Search (JS) and Artificial Bee Colony (ABC). This paper presents computational examples showing effectiveness of considered metaheuristic optimization algorithms in solving inverse problem for anomalous diffusion model. PDF XML
文章重点介绍并比较了用于求解反常扩散模型逆问题的选定启发式算法。所考虑的数学模型包括带有初始边界条件的时空分数扩散方程。这类模型用于模拟多孔材料中的热流现象。模型中使用了 Caputo 和 Riemann-Liouville 分数导数。逆问题的基础是确定导数的阶数和重新创建分数边界条件。考虑到这类逆问题的条件不完善，应将其视为难以解决的问题。因此，为了解决该问题，我们采用了科学文献中流行的元启发式优化算法，并对其性能进行了比较：这些算法包括：群教优化算法（GTOA）、均衡优化算法（EO）、灰狼优化算法（GWO）、战争策略优化算法（WSO）、金枪鱼群优化算法（TSO）、蚁群优化算法（ACO）、水母搜索算法（JS）和人工蜂群算法（ABC）。本文通过计算实例展示了所考虑的元启发式优化算法在解决异常扩散模型逆问题中的有效性。PDF XML
{"title":"Solution of Inverse Problem for Diffusion Equation with Fractional Derivatives Using Metaheuristic Optimization Algorithm","authors":"Rafał Brociek, Mateusz Goik, Jakub Miarka, Mariusz Pleszczyński, Christian Napoli","doi":"10.15388/24-infor563","DOIUrl":"https://doi.org/10.15388/24-infor563","url":null,"abstract":"The article focuses on the presentation and comparison of selected heuristic algorithms for solving the inverse problem for the anomalous diffusion model. Considered mathematical model consists of time-space fractional diffusion equation with initial boundary conditions. Those kind of models are used in modelling the phenomena of heat flow in porous materials. In the model, Caputo’s and Riemann-Liouville’s fractional derivatives were used. The inverse problem was based on identifying orders of the derivatives and recreating fractional boundary condition. Taking into consideration the fact that inverse problems of this kind are ill-conditioned, the problem should be considered as hard to solve. Therefore,to solve it, metaheuristic optimization algorithms popular in scientific literature were used and their performance were compared: Group Teaching Optimization Algorithm (GTOA), Equilibrium Optimizer (EO), Grey Wolf Optimizer (GWO), War Strategy Optimizer (WSO), Tuna Swarm Optimization (TSO), Ant Colony Optimization (ACO), Jellyfish Search (JS) and Artificial Bee Colony (ABC). This paper presents computational examples showing effectiveness of considered metaheuristic optimization algorithms in solving inverse problem for anomalous diffusion model.\u0000PDF XML","PeriodicalId":56292,"journal":{"name":"Informatica","volume":"8 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141717762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Neural networks (NNs) are well established and widely used in time series forecasting due to their frequent dominance over other linear and nonlinear models. Thus, this paper does not question their appropriateness in forecasting cryptocurrency prices; rather, it compares the most commonly used NNs, i.e. feedforward neural networks (FFNNs), long short-term memory (LSTM) and convolutional neural networks (CNNs). This paper contributes to the existing literature by defining the appropriate NN structure comparable across different NN architectures, which yields the optimal NN model for Bitcoin return forecasting. Moreover, by incorporating turbulent events such as COVID and war, this paper emerges as a stress test for NNs. Finally, inputs are carefully selected, mostly covering macroeconomic and market variables, as well as different attractiveness measures, the importance of which in cryptocurrency forecasting is tested. The main results indicate that all NNs perform the best in an environment of bullish market, where CNNs stand out as the optimal models for continuous dataset, and LSTMs emerge as optimal in direction forecasting. In the downturn periods, CNNs stand out as the best models. Additionally, Tweets, as an attractiveness measure, enabled the models to attain superior performance. PDF XML
由于神经网络（NN）经常主导其他线性和非线性模型，因此在时间序列预测中得到了确立和广泛应用。因此，本文并不质疑它们在预测加密货币价格方面的适当性；相反，本文比较了最常用的神经网络，即前馈神经网络（FFNN）、长短期记忆（LSTM）和卷积神经网络（CNN）。本文通过定义不同神经网络架构之间可比较的适当神经网络结构，为现有文献做出了贡献，从而为比特币回报预测提供了最佳神经网络模型。此外，通过纳入 COVID 和战争等动荡事件，本文成为对 NN 的压力测试。最后，本文对输入进行了精心选择，主要涵盖宏观经济和市场变量以及不同的吸引力指标，并测试了这些指标在加密货币预测中的重要性。主要结果表明，在市场看涨的环境中，所有 NN 的表现都是最好的，其中 CNN 是连续数据集的最佳模型，而 LSTM 则是方向预测的最佳模型。在市场低迷时期，CNNs 则成为最佳模型。此外，推文作为一种吸引力度量，使模型获得了卓越的性能。PDF XML
{"title":"Identification of the Optimal Neural Network Architecture for Prediction of Bitcoin Return","authors":"Tea Šestanović, Tea Kalinić Milićević","doi":"10.15388/24-infor561","DOIUrl":"https://doi.org/10.15388/24-infor561","url":null,"abstract":"Neural networks (NNs) are well established and widely used in time series forecasting due to their frequent dominance over other linear and nonlinear models. Thus, this paper does not question their appropriateness in forecasting cryptocurrency prices; rather, it compares the most commonly used NNs, i.e. feedforward neural networks (FFNNs), long short-term memory (LSTM) and convolutional neural networks (CNNs). This paper contributes to the existing literature by defining the appropriate NN structure comparable across different NN architectures, which yields the optimal NN model for Bitcoin return forecasting. Moreover, by incorporating turbulent events such as COVID and war, this paper emerges as a stress test for NNs. Finally, inputs are carefully selected, mostly covering macroeconomic and market variables, as well as different attractiveness measures, the importance of which in cryptocurrency forecasting is tested. The main results indicate that all NNs perform the best in an environment of bullish market, where CNNs stand out as the optimal models for continuous dataset, and LSTMs emerge as optimal in direction forecasting. In the downturn periods, CNNs stand out as the best models. Additionally, Tweets, as an attractiveness measure, enabled the models to attain superior performance.\u0000PDF XML","PeriodicalId":56292,"journal":{"name":"Informatica","volume":"32 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141572879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Francisco de Arriba-Pérez, Silvia García-Méndez, Fátima Leal, Benedita Malheiro, Juan C. Burguillo
Spam reviews are a pervasive problem on online platforms due to its significant impact on reputation. However, research into spam detection in data streams is scarce. Another concern lies in their need for transparency. Consequently, this paper addresses those problems by proposing an online solution for identifying and explaining spam reviews, incorporating data drift adaptation. It integrates (i) incremental profiling, (ii) data drift detection & adaptation, and (iii) identification of spam reviews employing Machine Learning. The explainable mechanism displays a visual and textual prediction explanation in a dashboard. The best results obtained reached up to 87% spam F-measure. PDF XML
垃圾评论是网络平台上一个普遍存在的问题，因为它会对声誉产生重大影响。然而，有关数据流中垃圾评论检测的研究却很少。另一个令人担忧的问题是垃圾评论需要透明。因此，本文针对这些问题提出了一种在线解决方案，用于识别和解释垃圾评论，并结合数据漂移适应。它整合了（i）增量剖析，（ii）数据漂移检测& 适应，以及（iii）利用机器学习识别垃圾评论。可解释机制在仪表板中显示可视化和文本预测解释。获得的最佳结果是，垃圾邮件 F-measure 高达 87%。PDF XML
{"title":"Online Detection and Infographic Explanation of Spam Reviews with Data Drift Adaptation","authors":"Francisco de Arriba-Pérez, Silvia García-Méndez, Fátima Leal, Benedita Malheiro, Juan C. Burguillo","doi":"10.15388/24-infor562","DOIUrl":"https://doi.org/10.15388/24-infor562","url":null,"abstract":"Spam reviews are a pervasive problem on online platforms due to its significant impact on reputation. However, research into spam detection in data streams is scarce. Another concern lies in their need for transparency. Consequently, this paper addresses those problems by proposing an online solution for identifying and explaining spam reviews, incorporating data drift adaptation. It integrates (<i>i</i>) incremental profiling, (<i>ii</i>) data drift detection & adaptation, and (<i>iii</i>) identification of spam reviews employing Machine Learning. The explainable mechanism displays a visual and textual prediction explanation in a dashboard. The best results obtained reached up to 87% spam <i>F</i>-measure.\u0000PDF XML","PeriodicalId":56292,"journal":{"name":"Informatica","volume":"23 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141511309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anett Erdmann, Morteza Yazdani, Jose Manuel Mas Iglesias, Cristina Marin Palacios
Artificial Intelligence (AI) in the price management process is being applied in business practice and research to a variety of pricing use cases that can be augmented or automated, providing opportunities as a forecasting tool or for price optimization. However, the complexity of evaluating the technology to prioritize implementation is challenging, especially for small and medium enterprises (SMEs), and guidance is sparse. Which are the relevant stakeholder criteria for a sustainable implementation of AI for pricing purpose? Which type of AI supported price functions meet these criteria best? Theoretically motivated by the hedonic price theory and advances in AI research, we identify nine criteria and eight AI supported price functions (AISPF). A multiple attribute decision model (MADM) using the fuzzy Best Worst Method (BWM) and fuzzy combined compromise solution (CoCoSo) is set up and evaluated by pricing experts from Germany and Spain. To validate our results and model stability, we carried out several random sensitivity analyses based on the weight of criteria exchange. The results suggest accuracy and reliability as the most prominent attribute to evaluate AISPF, while ethical and sustainable criteria are sorted as least important. The AISPF which best meet the criteria are financial prices followed by procurement prices. PDF XML
{"title":"Pricing Powered by Artificial Intelligence: An Assessment Model for the Sustainable Implementation of AI Supported Price Functions","authors":"Anett Erdmann, Morteza Yazdani, Jose Manuel Mas Iglesias, Cristina Marin Palacios","doi":"10.15388/24-infor559","DOIUrl":"https://doi.org/10.15388/24-infor559","url":null,"abstract":"Artificial Intelligence (AI) in the price management process is being applied in business practice and research to a variety of pricing use cases that can be augmented or automated, providing opportunities as a forecasting tool or for price optimization. However, the complexity of evaluating the technology to prioritize implementation is challenging, especially for small and medium enterprises (SMEs), and guidance is sparse. Which are the relevant stakeholder criteria for a sustainable implementation of AI for pricing purpose? Which type of AI supported price functions meet these criteria best? Theoretically motivated by the hedonic price theory and advances in AI research, we identify nine criteria and eight AI supported price functions (AISPF). A multiple attribute decision model (MADM) using the fuzzy Best Worst Method (BWM) and fuzzy combined compromise solution (CoCoSo) is set up and evaluated by pricing experts from Germany and Spain. To validate our results and model stability, we carried out several random sensitivity analyses based on the weight of criteria exchange. The results suggest accuracy and reliability as the most prominent attribute to evaluate AISPF, while ethical and sustainable criteria are sorted as least important. The AISPF which best meet the criteria are financial prices followed by procurement prices.\u0000PDF XML","PeriodicalId":56292,"journal":{"name":"Informatica","volume":"52 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141151491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ontologies are used to semantically enrich different types of information systems (IS), ensure a reasoning on their content and integrate heterogeneous IS at the semantical level. On the other hand, fuzzy theory is employed in IS for handling the uncertainty and fuzziness of their attributes, resulting in a fully fuzzy IS. As such, ontology- and fuzzy-based IS (i.e. ontology and fuzzy IS) are being developed. So, in this paper, we present a bibliometric analysis of the ontology and fuzzy IS concept to grasp its main ideas, and to increase its body of knowledge by providing a concept map for ontology and fuzzy IS. The main results obtained show that by adding ontologies and fuzzy theory to traditional ISs, they evolve into intelligent ISs capable of managing fuzzy and semantically rich (ontological) information and ensuring knowledge recognition in various fields of application. This bibliometric analysis would enable practitioners and researchers gain a comprehensive understanding of the ontology and fuzzy IS concept that they can eventually adopt for development of intelligent IS in their work. PDF XML
本体论用于从语义上丰富不同类型的信息系统（IS），确保对其内容进行推理，并在语义层面整合异构信息系统。另一方面，在信息系统中采用模糊理论来处理其属性的不确定性和模糊性，从而形成完全模糊的信息系统。因此，基于本体和模糊的 IS（即本体和模糊 IS）正在被开发出来。因此，在本文中，我们对本体和模糊 IS 概念进行了文献计量分析，以掌握其主要思想，并通过提供本体和模糊 IS 的概念图来增加其知识体系。得出的主要结果表明，通过在传统的 IS 中加入本体和模糊理论，IS 可以发展成为智能 IS，能够管理模糊和语义丰富的（本体）信息，并确保各应用领域的知识识别。这项文献计量分析有助于从业人员和研究人员全面了解本体论和模糊 IS 概念，并最终在工作中采用这些概念来开发智能 IS。
{"title":"Ontology and Fuzzy Theory Application in Information Systems: A Bibliometric Analysis","authors":"Diana Kalibatienė, Jolanta Miliauskaitė, Asta Slotkienė","doi":"10.15388/24-infor557","DOIUrl":"https://doi.org/10.15388/24-infor557","url":null,"abstract":"Ontologies are used to semantically enrich different types of information systems (IS), ensure a reasoning on their content and integrate heterogeneous IS at the semantical level. On the other hand, fuzzy theory is employed in IS for handling the uncertainty and fuzziness of their attributes, resulting in a fully fuzzy IS. As such, ontology- and fuzzy-based IS (<i>i.e.</i> ontology and fuzzy IS) are being developed. So, in this paper, we present a bibliometric analysis of the ontology and fuzzy IS concept to grasp its main ideas, and to increase its body of knowledge by providing a concept map for ontology and fuzzy IS. The main results obtained show that by adding ontologies and fuzzy theory to traditional ISs, they evolve into intelligent ISs capable of managing fuzzy and semantically rich (ontological) information and ensuring knowledge recognition in various fields of application. This bibliometric analysis would enable practitioners and researchers gain a comprehensive understanding of the ontology and fuzzy IS concept that they can eventually adopt for development of intelligent IS in their work.\u0000PDF XML","PeriodicalId":56292,"journal":{"name":"Informatica","volume":"59 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141061952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：