Symbolic Data Research Articles

Interval-Valued Random Matrices

This paper introduces a novel approach that combines symbolic data analysis with matrix theory through the concept of interval-valued random matrices. This framework is designed to address the complexities of real-world data, offering enhanced statistical modeling techniques particularly suited for large and complex datasets where traditional methods may be inadequate. We develop both frequentist and Bayesian methods for the statistical inference of interval-valued random matrices, providing a comprehensive analytical framework. We conduct extensive simulations to compare the performance of these methods, demonstrating that Bayesian estimators outperform maximum likelihood estimators under the Frobenius norm loss function. The practical utility of our approach is further illustrated through an application to climatology and temperature data, highlighting the advantages of interval-valued random matrices in real-world scenarios.

Immigrant groups in the Luxembourgish labour market: A Symbolic Data Analysis approach

Immigrant groups in the Luxembourgish labour market: A Symbolic Data Analysis approach

Recommendation systems with user and item profiles based on symbolic modal data

Recommendation systems with user and item profiles based on symbolic modal data

Incremental attribute reduction for dynamic fuzzy decision information systems based on fuzzy knowledge granularity

Rough set-based attribute reduction is a powerful technique for data preprocessing in data mining. Knowledge granularity, as a reliable measure for assessing uncertainty in decision information systems (DIS), finds applicability in attribute reduction within such systems. Nevertheless, the limitation arises from the fact that static attribute reduction methods fail to effectively utilize the information contained in acquired data and promptly update knowledge due to the continuous evolution of data. In addition, existing incremental methods based on knowledge granularity are designed exclusively for symbolic data and lack the capability to handle real-valued data. Inspired by this, our study focuses on the attribute reduction approach for fuzzy decision information systems (FDIS) that encompass object variations by utilizing fuzzy knowledge granularity. Firstly, fuzzy knowledge granulation is defined to quantify uncertainty within FDIS, and utilized to determine the importance of attributes for attribute reduction. Additionally, the incremental mechanisms and attribute reduction algorithms are investigated for adding an object and an object set to FDIS, respectively. Moreover, an explication of how the incremental mechanism for increasing an object set can be viewed as a generalization of the mechanism used for a single object is provided. Finally, comparative experiments on various datasets are conducted to validate the effectiveness and efficiency of the proposed incremental algorithms. The results demonstrate that our algorithms achieve superior classification accuracy and while requiring minimal computing time when compared to the comparative algorithms.

Factorizers for distributed sparse block codes

Distributed sparse block codes (SBCs) exhibit compact representations for encoding and manipulating symbolic data structures using fixed-width vectors. One major challenge however is to disentangle, or factorize, the distributed representation of data structures into their constituent elements without having to search through all possible combinations. This factorization becomes more challenging when SBCs vectors are noisy due to perceptual uncertainty and approximations made by modern neural networks to generate the query SBCs vectors. To address these challenges, we first propose a fast and highly accurate method for factorizing a more flexible and hence generalized form of SBCs, dubbed GSBCs. Our iterative factorizer introduces a threshold-based nonlinear activation, conditional random sampling, and an ℓ ∞ -based similarity metric. Its random sampling mechanism, in combination with the search in superposition, allows us to analytically determine the expected number of decoding iterations, which matches the empirical observations up to the GSBC’s bundling capacity. Secondly, the proposed factorizer maintains a high accuracy when queried by noisy product vectors generated using deep convolutional neural networks (CNNs). This facilitates its application in replacing the large fully connected layer (FCL) in CNNs, whereby C trainable class vectors, or attribute combinations, can be implicitly represented by our factorizer having F-factor codebooks, each with C F fixed codevectors. We provide a methodology to flexibly integrate our factorizer in the classification layer of CNNs with a novel loss function. With this integration, the convolutional layers can generate a noisy product vector that our factorizer can still decode, whereby the decoded factors can have different interpretations based on downstream tasks. We demonstrate the feasibility of our method on four deep CNN architectures over CIFAR-100, ImageNet-1K, and RAVEN datasets. In all use cases, the number of parameters and operations are notably reduced compared to the FCL.

New skills in symbolic data analysis for official statistics

The paper draws attention to the use of Symbolic Data Analysis (SDA) in the field of Official Statistics. It is composed of three sections presenting three pilot techniques in the field of SDA. The three contributions range from a technique based on the notion of exactly unified summaries for the creation of symbolic objects, a model-based approach for interval data as an innovative parametric strategy in this context, and measures of similarity defined between a class and a collection of classes based on the frequency of the categories which characterize them. The paper shows the effectiveness of the proposed approaches as prototypes of numerous techniques developed within the SDA framework and opens to possible further developments.

Anomaly detection based on system text logs of virtual network functions

In virtual network environments building secure and effective systems is crucial for its correct functioning, and so the anomaly detection task is at its core. To uncover and predict abnormalities in the behavior of a virtual machine, it is desirable to extract relevant information from system text logs. The main issue is that text is unstructured and symbolic data, and also very expensive to process. However, recent advances in deep learning have shown remarkable capabilities of handling such data. In this work, we propose using a simple LSTM recurrent network on top of a pre-trained Sentence-BERT, which encodes the system logs into fixed-length vectors. We trained the model in an unsupervised fashion to learn the likelihood of the represented sequences of logs. This way, the model can trigger a warning with an accuracy of 81% when a virtual machine generates an abnormal sequence. Our model approach is not only easy to train and computationally cheap, it also generalizes to the content of any input.

Image Feature Extraction Using Symbolic Data of Cumulative Distribution Functions

Symbolic data analysis is an emerging field in statistics with great potential to become a standard inferential technique. This research introduces a new approach to image feature extraction using the empirical cumulative distribution function (ECDF) and distribution function of distribution values (DFDV) as symbolic data. The main objective is to reduce the dimension of huge pixel data by organizing them into more coherent pixel-intensity distributions. We propose a partitioning method with different breakpoints to capture pixel intensity variations effectively. This results in an ECDF representing the proportion of pixel intensities and a DFDV representing the probability distribution at specific points. The novelty of this approach lies in using ECDF and DFDV as symbolic features, thus summarizing the data and providing a more informative representation of the pixel value distribution, facilitating image classification analysis based on intensity distribution. The experimental results underscore the potential of this method in distinguishing image characteristics among existing image classes. Image features extracted using this approach promise image classification analysis with more informative image representations. In addition, theoretical insights into the properties of DFDV distribution functions are gained.

Artificial Intelligence: A Quick Overview of Speech Recognition System

Abstract: The study of intelligent behaviour is known as artificial intelligence. Wagner said, "We build intelligent machines in science." By this, he implied that the primary goal is to teach these sophisticated devices, such as computers, to examine and comprehend human conduct. numerous believed that human intelligence might be understood through the construction of several programmes, while other researchers believed that numerous basics should be required in order to accomplish the intended objective. We can carry out or replicate any type of task we conduct using a computer. Therefore, computers are the ideal devices for developing artificial intelligence. In the hopes that they will outperform computers in several other areas, some researchers created additional computing devices. Billions of dollars were invested in creating new devices that surpassed the speed of the computer used to simulate software. However, the computers and the code both need to be extremely quick. As you learn about artificial intelligence, you may wonder, what really is intelligence? How is intelligence measured? Turn become something quite significant. In this case, the programme that evaluates its surroundings acts as the intelligent agent. Modern digital computers and human minds are comparable to one other in ways such as symbolic information processing systems. Both use symbolic data as input, change it in accordance with predetermined guidelines, and then use the results to solve issues. In order to mechanically replicate intelligent human activity, artificial intelligence researchers have programmed some algorithms to recognise intelligent human behaviour. Human conduct in language processing, chess, and other games, as well as medical diagnostics, may be used to monitor this activity. Voice recognition is a key component of AI. A certain voice may be recognised using voice recognition technology. The cornerstone for speaker identification is voice signals. Voice targeting is applicable to a wide range of applications, including voice mail, database access, phone banking, and phone purchasing. The ability to enter one's voice for verification is among the most potent uses of voice recognition for security. The fundamental means of interpersonal communication is speech. The technique of translating voice sounds into appropriate text is known as speech recognition. Over the past few years, speech recognition technology has advanced significantly. Nonetheless, there are other significant study obstacles, such as variations in speaker and language, ambient sound, word size, etc. This study aims to give a comprehensive overview of speech acceptance by summarising the several approaches utilised in the standard speech system and describing the numerous processes involved

Music Genre Classification Based on VMD-IWOA-XGBOOST

Music genre classification is significant to users and digital platforms. To enhance the classification accuracy, this study proposes a hybrid model based on VMD-IWOA-XGBOOST for music genre classification. First, the audio signals are transformed into numerical or symbolic data, and the crucial features are selected using the maximal information coefficient (MIC) method. Second, an improved whale optimization algorithm (IWOA) is proposed for parameter optimization. Third, the inner patterns of these selected features are extracted by IWOA-optimized variational mode decomposition (VMD). Lastly, all features are put into the IWOA-optimized extreme gradient boosting (XGBOOST) classifier. To verify the effectiveness of the proposed model, two open music datasets are used, i.e., GTZAN and Bangla. The experimental results illustrate that the proposed hybrid model achieves better performance than the other models in terms of five evaluation criteria.

The application of multidimensional scaling of data to determining changes in retailer customers’ preferences

The COVID-19 pandemic has significantly affected several aspects of human activity, including the functioning of different markes, therefore it is important to research its impact. The aim of the study discussed in this paper is to determine which of the three approaches within the method of multidimensional scaling (i.e. multidimensional scaling of classical, symbolic interval-valued or symbolic histogram data) is most adequate for capturing the shifts in retailer customers' preferences that took place during the pandemic. The research concerned the health and beauty market. It was based on the data on orders for beauty products from a Polish producer of cosmetics of a global reach placed by 18 small, mainly family-managed, health and beauty retailers from Lower Silesia. The shops were selected through convenient sampling. Such shops are not a part of large health and beauty retailer chains, therefore they are more vulnerable to all the fluctuations and shifts on the market. The results of this study indicate that in 2020 and 2021, important changes took place on the Lower Silesian health and beauty market as compared to 2019. These changes involved cosmetics for eyes and eybrows gaining popularity at the expense of cosmetics for lips and cheeks. Multidimensional scaling of symbolic histogram data turned out to be the most effective method (in the sense of the measure of fit and the Pearson correlation coefficient) of capturing and analysing changes happening on a market over a period of time.

Computer Algebra in R Bridges a Gap Between Symbolic Mathematics and Data in the Teaching of Statistics and Data Science

Computer Algebra in R Bridges a Gap Between Symbolic Mathematics and Data in the Teaching of Statistics and Data Science

CURRENT STATE OF ENVIRONMENTAL AWARENESS OF TRANSPORT SERVICE STAKEHOLDERS AND END-CUSTOMERS IN THE INTERMODAL TRANSPORT CHAIN

Despite all the measures already taken and those still underway, pollution remains a major global problem, as the transport sector is the one where emissions are expected to increase in the coming years. Companies and policy makers are under increasing pressure to reduce the impact of their logistics activities in order to make transportation more environmentally friendly. One of the solutions to reduce emissions from intermodal transport is to choose the “right” mode of transport for each step in the transport chain. Such a measure increases the complexity of the transport chain and places an additional burden on transport companies in planning and organising transport for the entire transport chain. Additional difficulties arise from the fragmentation of information on emissions emitted for a single transport link and the lack of a unified approach to measuring and estimating transport chain emissions. As a result, this work finds that there is a lack of knowledge among users about the environmental impacts of transportation, despite the desire to contribute to greener transportation by paying more for a product or transportation service. The current research fills the gap in stakeholders’ understanding of the negative environmental impacts for individual transportation and for the entire transport chain. In addition, the study reveals a need for a systematically regulated and adapted way of informing users of intermodal transport chains due to the lack of transparency and comparison between different intermodal transport chains. To successfully address the challenges, the study proposes a 2-pillar approach. The 1st pillar approach focuses on designing a set of necessary measures (combination of top-down and bottom-up approach) for the transition to a low-carbon transport chain, while the 2nd pillar mainly focuses on mapping the level of green transport for easy comparison of similar products or services. The results of the research study show that the combination of numerical data with symbolic data is best suited to provide information on the level of green transport.

Generalized linear models for symbolic polygonal data

Symbolic data analysis data has provided several advances in regression models concerning the type of symbolic variable. Due to the advantages of using symbolic polygonal data, this paper introduces a linear regression approach for polygonal data based on the generalize linear model theory that provides a unified method to broad range of modeling problems for different types of response as asymmetric continuous and discrete. Ordinary polygonal residuals and a way for finding model inadequacies are presented. Moreover, a quality measure of fit for polygons is also proposed in this paper. Experimental evaluation results illustrate the usefulness of the proposed approach regarding synthetic and real polygonal data.

Analyzing Biomedical Datasets with Symbolic Tree Adaptive Resonance Theory

Biomedical datasets distill many mechanisms of human diseases, linking diseases to genes and phenotypes (signs and symptoms of disease), genetic mutations to altered protein structures, and altered proteins to changes in molecular functions and biological processes. It is desirable to gain new insights from these data, especially with regard to the uncovering of hierarchical structures relating disease variants. However, analysis to this end has proven difficult due to the complexity of the connections between multi-categorical symbolic data. This article proposes symbolic tree adaptive resonance theory (START), with additional supervised, dual-vigilance (DV-START), and distributed dual-vigilance (DDV-START) formulations, for the clustering of multi-categorical symbolic data from biomedical datasets by demonstrating its utility in clustering variants of Charcot–Marie–Tooth disease using genomic, phenotypic, and proteomic data.

Longitudinal patterns of scientific collaboration in doctoral studies

Doctoral studies play a vital role in socializing young individuals in science as they navigate the challenges of modern knowledge-based societies. Taking various forms and intensities, the mentor–mentee relationship is integral to this process. The paper therefore addresses the temporal patterns of scientific collaboration between mentors and mentees, as well as among co-mentors, given that understanding the characteristics of mentoring collaborations is essential for developing successful higher education strategies for attracting potential doctoral students and designing effective science policies. Patterns of collaboration were identified using a symbolic data clustering approach and described using linear discriminant analysis. The data come from national information systems in Slovenia and cover the period between 1991 and 2020. On the mentor–mentee level, six types of scientific collaborations were identified and classified in three broader categories: study-limited, already established, and born and raised. The most common, born and raised, is characterized by students who are isolated from the scientific community at the beginning of their studies and have become well integrated into the scientific community and highly productive researchers by the time they complete their doctoral studies. The study-limited collaboration pattern is becoming increasingly popular and more common in the natural and technical sciences. The already established is more common among older mentees. The notion that mentoring promotes long-term scientific collaboration between mentors is not confirmed by the presented study. However, higher levels of collaboration between mentors are associated with younger age, working in the same scientific discipline, and younger mentors.

Isolation Forests for Symbolic Data as a Tool for Outlier Mining

Aim: Outlier detection is a key part of every data analysis. Although there are many definitions of outliers that can be found in the literature, all of them emphasise that outliers are objects that are in some way different from other objects in the dataset. There are many different approaches that have been proposed, compared, and analysed for the case of classical data. However, there are only few studies that deal with the problem of outlier detection in symbolic data analysis. The paper aimed to propose how to adapt isolation forest for symbolic data cases. Methodology: An isolation forest for symbolic data is used to detect outliers in four different artificial datasets with a known cluster structure and a known number of outliers Results: The results show that the isolation forest for symbolic data is a fast and efficient tool for outlier mining. Implications and recommendations: As the isolation forest for symbolic data appears to be an efficient tool for outlier detection for artificial data, further studies should focus on real data sets that contain outliers (i.e. credit card fraud dataset), and this approach should be compared with other outlier mining tools (i.e. DBCSAN). The authors recommend using the same initial settings for the isolation forest for symbolic data as the settings that are proposed for the isolation forest for classical data. Originality/value: This paper is the first of its kind, focusing not only on the problem of outlier detection in general, but also extending the well-known isolation forest model for symbolic data cases.

Unraveling the formation of oxygen vacancies on the surface of transition metal-doped ceria utilizing artificial intelligence.

Ceria has been extensively utilized in different fields, with surface oxygen vacancies playing a central role. However, versatile oxygen vacancy regulation is still in its infancy. In this work, we propose an effective strategy to manipulate the oxygen vacancy formation energy via transition metal doping by combining first-principles calculations and analytical learning. We elucidate the underlying mechanism driving the formation of oxygen vacancies using combined symbolic regression and data analytics techniques. The results show that the Fermi level of the system and the electronegativity of the dopants are the paramount parameters (features) influencing the formation of oxygen vacancies. These insights not only enhance our understanding of the oxygen vacancy formation mechanism in ceria-based materials to improve their functionality but also potentially lay the groundwork for future strategies in the rational design of other transition metal oxide-based catalysts.

Dimension reduction and visualization of multiple time series data: a symbolic data analysis approach

Dimension reduction and visualization of multiple time series data: a symbolic data analysis approach

New Interval Improved Fuzzy Partitions Fuzzy C-Means Clustering Algorithms under Different Distance Measures for Symbolic Interval Data Analysis

Symbolic interval data analysis (SIDA) has been successfully applied in a wide range of fields, including finance, engineering, and environmental science, making it a valuable tool for many researchers for the incorporation of uncertainty and imprecision in data, which are often present in real-world scenarios. This paper proposed the interval improved fuzzy partitions fuzzy C-means (IIFPFCM) clustering algorithm from the viewpoint of fast convergence that independently combined with Euclidean distance and city block distance. The two proposed methods both had a faster convergence speed than the traditional interval fuzzy c-means (IFCM) clustering method in SIDA. Moreover, there was a problem regarding large and small group division for symbolic interval data. The proposed methods also had better performance results than the traditional interval fuzzy c-means clustering method in this problem. In addition, the traditional IFCM clustering method will be affected by outliers. This paper also proposed the IIFPFCM algorithm to deal with outliers from the perspective of interval distance measurement. From experimental comparative analysis, the proposed IIFPFCM clustering algorithm with the city block distance measure was found to be suitable for dealing with SIDA with outliers. Finally, nine symbolic interval datasets were assessed in the experimental results. The statistical results of convergence and efficiency on performance revealed that the proposed algorithm has better results.