Symbolic Tools Research Articles

On nonclassical symmetries, Painlevé analysis and singular, periodic and solitary wave solutions of generalized Hirota-Satsuma coupled KdV system

In this work, we investigate the generalized Hirota-Satsuma coupled KdV system which is materialized in the theory of shallow water waves. Nonclassical symmetries of governing system are derived using Bluman and Cole method. The obtained symmetries are in the form of Jacobi elliptic functions, which are more generalized than earlier obtained symmetries for the governing system. Some new singular, periodic and solitary wave solutions of the governing system are also derived by assuming the Jacobi elliptic function type solutions. The obtained exact solutions for the considered system are verified by graphical representation. The Painlevé property of the considered system is also checked with the help of Kruksal’s method and symbolic computational tool Maple which shows the integrable behaviour of the considered system.

Learning transport processes with machine intelligence

Transport processes ruled by complex micro-physics and impractical to theoretical investigation may exhibit emergent behavior describable by mathematical expressions. Such information, while implicitly contained in the results of microscopic-scale numerical simulations close to first principles or experiments is not in a form suitable for macroscopic modelling. Here we present a machine learning approach that leverages such information to deploy micro-physics informed transport flux representations applicable to a continuum mechanics description. One issue with deep neural networks, arguably providing the most generic of such representations, is their noisiness which is shown to break the performance of numerical schemes. The matter is addressed and a methodology suitable for schemes characterised by second order convergence rate is presented. The capability of the methodology is demonstrated through an idealized study of the long standing problem of heat flux suppression relevant to fusion and cosmic plasmas. Symbolic representations, although potentially less generic, are straightforward to use in numerical schemes and theoretical analysis, and can be even more accurate as shown by the application to the same problem of an advanced symbolic regression tool. These results are a promising initial step to filling the gap between micro and macro in this important area of modeling.

Dynamic Assessment of Creativity for Diagnostic Purposes

Abstract. The present paper aims to propose the dynamic assessment of creativity for diagnostic purposes, which combines the sociocultural approach to creativity with the findings of creative cognition research. A traditional theorization viewed creativity mainly as an ability of individuals and its expression depending on the extent to which their environment allows and supports it. According to the individualistic approach of creativity, static testing has been its predominant psychological assessment. However, the traditional approach to creativity has been criticized from a sociocultural theoretical perspective that regards creativity as distributed cognition between the mind and culture in recent years. Based on sociocultural theory, dynamic assessment of creativity is an alternative process to static testing for assessing creative potential. Besides testing, in dynamic assessment, the cognitive strategies of creativity that creative cognition research has revealed are mediated in children as symbolic tools or signs. Therefore, in dynamic assessment, sociocultural theory is combined with creative cognition. In the present paper, initially, we present the relevant theory and research on dynamic assessment and creative cognition. Next, studies applying dynamic assessment to children of different ages and devising the mediation protocol will be discussed. Finally, we will consider the psychological and educational implications of dynamic assessment of children’s creativity.

Pastoral Ministry in Unsettled Times: A Qualitative Study of the Experiences of Clergy During the COVID-19 Pandemic.

BackgroundCOVID-19 and its associated restrictions around in-person gatherings have created unprecedented challenges for religious congregations and those who lead them. While several surveys have attempted to describe how pastors and congregations responded to COVID-19, these provide a relatively thin picture of how COVID-19 is impacting religious life. There is scant qualitative data describing the lived reality of religious leaders and communities during the pandemic.Purpose and methodsThis paper provides a more detailed look at how pastors and congregations experienced and responded to COVID-19 and its associated restrictions in the early period of the pandemic. To do so, we draw from 26 in-depth interviews with church-appointed United Methodist pastors conducted between June and August 2020. Pastors were asked to describe how their ministry changed as a result of COVID-19 and interviews were analyzed using applied thematic analysis approaches to identify the most common emergent themes.ResultsPastors reported that COVID-19 fundamentally unsettled routine ways of doing ministry. This disruption generated both challenges and opportunities for clergy and their congregations. In the findings, we describe how clergy responded in key areas of ministry–worship and pastoral care–and analyze how the pandemic is (re)shaping the way that clergy understood their role as pastors and envisioned the future of the Church. We argue for the value of examining the pandemic as an “unsettled” cultural period (Swidler 1986) in which religious leaders found creative ways to (re)do ministry in the context of social distancing. Rather than starting from scratch, we found that pastors drew from and modified existing symbolic and practical tools to fit pandemic-related constraints on religious life. Notably, however, we found that “redoing” ministry was easier and more effective in some areas (worship) than others (pastoral care).Conclusions and ImplicationsThe impact of COVID-19 on pastors and congregations is complex and not fully captured by survey research. This study provides a baseline for investigating similarities and differences in the responses of pastors within and across denominations and traditions. It also provides a baseline for assessing whether changes in ministry implemented during the early stages of the pandemic remain in place in the post-COVID world.

Revealing the corporate contribution to sustainable development goals through integrated reporting: a worldwide perspective

Purpose This study aims to contribute to the existing literature by presenting new knowledge about sustainable development goals’ (SDGs) reporting practices through integrated reporting (IR). This paper’s ultimate goal is to dig to light companies’ main approaches to incorporating SDG disclosures into IRs. Design/methodology/approach This study puts forward both deductive content analysis and an inductive thematic analysis on a sample of worldwide leading IR adopters to assess what SDGs they disclose and how they integrate SDGs into the reports. Meaningful narratives and graphical illustrations are selected, categorised and discussed from a symbolic/substantive legitimacy perspective. Findings The results of this study highlighted that although a fair number of leading IR adopters addressed SDG issues, their pathways to disclosure were not uniform. In some cases, SDGs inspired substantive changes to internal management and process, communicated through an integrated approach. However, there was a persistent trend of using SDGs as camouflage and symbolic tool to enhance company’s reputation and obtain a licence to operate. Originality/value To the best of the authors’ knowledge, this was the first study that performed a deductive/inductive thematic analysis to engender insight into the most meaningful patterns followed by leading IR reporters worldwide to disclose their contributions to SDGs and address their legitimacy.

Reynolds-averaged stress and scalar-flux closures via symbolic regression for vertical natural convection

Turbulent natural convection is characterised by mutual coupling effects between velocity and thermal fields. This inter-coupling induces simulation errors with linear and non-coupled turbulence closures commonly used in many Reynolds–averaged Navier–Stokes (RANS) approaches. In this paper, we re-examine the buoyancy-accounting algebraic scalar-flux model proposed by Kenjereš et al., Int. J. Heat Fluid Flow, Vol. 26, pp. 569–586 (2005). Using a term-by-term analysis on the model with the aid of high-fidelity datasets for natural convection flow between two differentially heated vertical plates, it is demonstrated that there are significant discrepancies in the predicted turbulent heat fluxes once the model is combined with the existing algebraic Reynolds stress models. As a result, we suggest including the quadratic terms in buoyancy-extended explicit algebraic Reynolds stress models, and have developed non-linear Reynolds-stress and heat-flux closure models via an in–house symbolic regression tool based on gene expression programming (GEP). The evaluation of these GEP-developed models shows significant improvements in the prediction of mean quantities and second-moments in an a priori stage and in an a posteriori stage, with the latter being realized by embedding the new models into the elliptic relaxation v2‾/k-f-k-ε-θ2‾ equations, for vertical natural convection with Rayleigh numbers in the range of 106 to 109.

Compositional noninterference on hardware weak memory models

Weak memory models are employed by all modern multicore processors to improve their performance. For most code, the effects of such memory models can be largely ignored by the programmer. However, for low-level operating system or library code which can include data races for efficiency, these effects may lead to information leaks which cannot be detected without taking the specific memory model into account. While there have been some efforts to develop information flow logics which can detect such leaks, the existing approaches are either not compositional, hindering scalability, or support only a limited form of compositionality, reducing applicability to programs with only simple interactions between threads. This paper is the first to provide a compositional logic for enforcing noninterference properties on more complex concurrent algorithms, while taking into account the underlying hardware memory model. It uses rely/guarantee reasoning to establish how security classifications may be modified by concurrent threads, and considers effects of out-of-order execution allowed on modern multicore processors. The results have been formalised and proved sound in the Isabelle/HOL theorem prover, and automated in a prototype symbolic execution tool. • Weak memory models can invalidate rely/guarantee reasoning. • Structured rely/guarantees with additional checks can support general reasoning. • Rely/guarantee reasoning supports compositional information flow analysis.

Permutation Jensen-Shannon distance: A versatile and fast symbolic tool for complex time-series analysis.

The main motivation of this paper is to introduce the permutation Jensen-Shannon distance, a symbolic tool able to quantify the degree of similarity between two arbitrary time series. This quantifier results from the fusion of two concepts, the Jensen-Shannon divergence and the encoding scheme based on the sequential ordering of the elements in the data series. The versatility and robustness of this ordinal symbolic distance for characterizing and discriminating different dynamics are illustrated through several numerical and experimental applications. Results obtained allow us to be optimistic about its usefulness in the field of complex time-series analysis. Moreover, thanks to its simplicity, low computational cost, wide applicability, and less susceptibility to outliers and artifacts, this ordinal measure can efficiently handle large amounts of data and help to tackle the current big data challenges.

Honourable Businessmen: Respectability and ‘Gentlemanly Capitalism’ in Spain, 1840–1880

AbstractRevolution can lead to the complete political and social reconfiguration of a society. Such readjustment is often especially significant amongst the society's elites, as when ancient aristocrats had to converge with a newly emerging bourgeoisie. This article argues that over the course of the nineteenth century there was a steady process of negotiation that saw the evolution of a new form of elite, one defined by a new characteristic: respectability. This change saw successful businessmen, particularly magnates or tycoons, climbing to the top of the social ladder, as the culmination of a process that began in the eighteenth century. To illustrate this thesis, I discuss the case of Spain. I draw upon the lives of a large and diverse range of great Spanish bankers, industrialists, and businessmen. Traditionally, historiography has studied such men individually and from an economic history perspective. Here, a global, cultural approach is adopted. The chronology of the events described is not straightforward. Although the men studied are not all from a single birth cohort or even the same generation, I consider that they lived through the same social processes. The years between 1840 and 1880 were a period of intense industrial and business development in Spain during which modern economic practices were introduced. For the purposes of this article, I first situate the concept of respectability within the Spanish historiographical context, before analysing the discursive strategies that Spanish business magnates used to turn themselves into legitimate members of the county's new social elite. Finally, I study the three main symbolic tools that they employed to demonstrate their respectability and prove their status.

The Train Delay Model Developed by the Genetic Programming Algorithm

The paper discusses the problem of probability distribution category identification of train delay data by a genetic programming algorithm. This train delay frequency function and the probability distribution simply derived from it are significant to train traffic modelling and management. The genetic programming algorithm was used as an uninformed tool to prevent the influence of a priori information, which should be biased. The real traffic data were aggregated into predefined bins and then the frequencies of the individual delays were computed. The genetic programming algorithm was used in the next step as a symbolic regression tool to discover their frequency function in the form of an algebraic expression. The results concluded that although data has no known distribution, their distributions are similar to exponential ones.

Second-order cascode-based filters

In this paper, we report on the design of a class of analog filters based on the cascode circuit structure surrounded by four impedances. The proposed topology is systematically investigated using two-port network techniques and symbolic math CAD tools. A total of 106 second-order filter circuits can be obtained from this class including 9 low-pass filters, 6 high-pass filters, 73 bandpass filters, 6 band-stop filters, and 12 gain equalizer/all-pass filters. Post-layout simulations in 65-nm CMOS technology of selected members of this family of filters are provided and prove its correct functionality.

Democratic Republic of Georgia as an Object of the Historical Politics of Memory in Georgia (2018–2020)

This article presents an attempt to analyse historical politics as politics of memory in modern Georgia in the context of perception of the images and heritage of the Democratic Republic of Georgia (DRG). The aim of the study is to analyse the images of the Democratic Republic of Georgia between 2018 and 2020 as part of the history and genealogy of the modern project of Georgian statehood in historical politics. The article is based on the methods used in studies of the politics of memory (historical politics) in modern interdisciplinary historiography. The article describes the features of the instrumentalisation of DRG images in the historical and political cultures of Georgia. The article examines the forms of participation of modern elites in the politics of memory in contexts of jubilee celebrations, memorial, and commemorative events that inspired the actualisation of the DRG images in the cultural and public spaces of Georgia. It is revealed that modern elites and heirs of DRG politicians became actors of historical politics and actual “battles for history”. As a result, the author concludes that images of the DRG became a symbolic resource for the consolidation of society and the development of the political identity of Georgian statehood. It is assumed that images of the DRG are integrated into the symbolic tools that political elites used in their attempts to correct identity and historical memory in modern Georgia. It is demonstrated that by initiating memorial celebrations dedicated to the 100th anniversary of the DRG in 2018, Georgian elites launched a series of commemorative events planned until 2024 solving political problems, localising, and interpreting historical traumas in the politics of memory proposed by the state as the main former of the official historical canon.

Detecting and determining preserved measures and integrals of birational maps

<p style='text-indent:20px;'>In this paper we use the method of discrete Darboux polynomials to calculate preserved measures and integrals of rational maps. The approach is based on the use of cofactors and Darboux polynomials and relies on the use of symbolic algebra tools. Given sufficient computing power, most, if not all, rational preserved integrals can be found (and even some non-rational ones). We show, in a number of examples, how it is possible to use this method to both determine and detect preserved measures and integrals of the considered rational maps, thus lending weight to a previous ansatz [<xref ref-type="bibr" rid="b2">2</xref>]. Many of the examples arise from the Kahan-Hirota-Kimura discretization of completely integrable systems of ordinary differential equations.</p>

Investigating Contributions of Total Column Ozone Variation on Some Meteorological Parameters in Nigeria

The relationship between some meteorological parameters and variation of total column ozone (TCO) concentration in Nigeria is studied from 1998-2012. The results using a descriptive analysis revealed a seasonal ozone variation having the same trend in all the stations during the period of study. High variability of TCO occurred between December and March coinciding with the period of dry season and low variability of TCO was observed in August coinciding with the period of rainy season. The observed trends in all the stations show that the TCO variation in Nigeria is mostly caused by natural occurrences. Calabar and Port Harcourt stations showed a high percent of TCO variability, while Kano and Maiduguri indicated a low percentage of TCO variability. Using Spearman correlation analysis, TCO concentration has a strong negative correlation with temperature in some stations with correlation coefficient (r) (-0.8392, -0.8531, -0.7832, -8881 and -0.7902) for Calabar, Port Harcourt, Makurdi, Lagos and Ilorin respectively. Kano and Maiduguri showed a weak positive correlation coefficient (r) 0.4965 and 0.3776 respectively. Positive correlation observed in Kano and Maiduguri could be as a result of high dehydration of water vapour in these stations due to seasonal harmattan and latitudinal effects. Probably, some of the substances that could deplete ozone such as HCl, aerosol are soluble in water thereby being washed off by rain during wet season leading to maximum TCO concentration during rainy season. Consequently, the observed phenomenon is through transportation of ozone content through the influence of Brewer-Dobson circulation. Again, during wet season, there is the mechanism of low pressure and lower tropopause height phenomenon, therefore, total ozone enhancement. Interestingly, variation in TCO is part of symbolic tools for tropospheric meteorology alteration and this invariably leads to climate change.

Tanúhegyek – avagy felhívás „keringőre”

The Hungarian Pedagogical Association has always considered drawing on the examples and strengths of notable predecessors to contemporary pedagogy to be a vital mission which can help teachers who struggle with everyday challenges and, at times, are vulnerable to burnout. A symbolic tool for taking up this task is the publication activity of the Association. The book ‘Tanúhegyek’ (Witness Hills in English - a metaphor) was published in 2018 with support from several municipalities and institutions of higher education. The book contains more than fifty portraits of famous Hungarian drama educators, puppeteers, musicians, and radio personalities, such as music and dance teachers.

An archaeology of korean sport for international development discourse in Korea International Cooperation Agency (KOICA)

ABSTRACT In April 1991, South Korea began its full-fledged participation in international development with the establishment of the Korea International Cooperation Agency (KOICA). Since then, KOICA has implemented a variety of overseas sport volunteer programmes, Taekwondo-specific programmes and sport aid projects in the Global South. Our analysis aims to identify the rules of Korean-specific discursive formations framing these KOICA programmes, which generate particular iterations of the Korean sport for international development discourse. Six different sets of KOICA documents published from 1991 to 2017 were collected and analysed using Foucault’s (1972) archaeology and its categories of rules of formation of objects, enunciative modalities, concepts and strategies. The findings reveal that elite sport and elite athletes in recipient countries were visible as objects. Korean instructors were given the subject position of legitimate expert through the formation of enunciative modalities. Two concepts, input-oriented volunteering and output-oriented volunteering, incorporated values of compassion and a spirit of sharing and respect along with personal achievement. Lastly, the transfer of Korean (sport) development knowledge and experience emerged as sport-oriented and non-sport-oriented strategies. The conclusion offers critical reflections that distinguish Korean sport for international development from Western SFD through a focus on the relationship between former colonies, and on Taekwondo as a symbolic national tool for SFD.

Analog Circuit Design Using Symbolic Math Toolboxes: Demonstrative Examples

In this article, a synthesis methodology for analog circuit design is presented. This methodology utilizes symbolic math tools to systematically and exhaustively search for candidate analog circuits avoiding tedious manual work. The two-port network matrix representation of active devices, such as MOS transistors, paves the way for efficiently using advanced symbolic math toolboxes (e.g., in MAPLE or MATLAB) to automate the generation of new analog circuits and further investigate the effects of nonidealities and parasitics. Using this synthesis methodology new amplifiers, filters, and oscillators can be obtained starting from a predefined structure. This article aims to motivate and provide an overview of the current status of research in this area. In addition, two detailed design examples of a family of differential filters and a family of differential oscillators along with their simulations and measurement results are provided to illustrate and verify the synthesis methodology.

Applying interval PCA and clustering to quantile estimates: empirical distributions of fertilizer cost estimates for yearly crops in European Countries

The decision to adopt one or another of the sustainable land management alternatives should not be based solely on their respective benefits in terms of climate change mitigation but also based on the performances of the productive systems used by farm holdings, assessing their environmental impacts through the cost of fertilizer resources used. This communication uses the symbolic clustering tools in order to analyze the conditional quantile estimates of the fertilizer costs of yearly crop productions in agriculture, as a replacement proxy for internal soil erosion costs. After recalling the conceptual framework of the estimation of agricultural production costs, we present the empirical data model, the quantile regression approach and the interval principal component analysis clustering tools used to obtain typologies of European countries on the basis of the conditional quantile distributions of fertilizer cost empirical estimates. The comparative analysis of econometric results for yearly crops between European countries illustrates the relevance of the typologies obtained for international comparisons to assess land management alternatives based on their impact on agricultural carbon sequestration in soils.

Excess Entropies Suggest the Physiology of Neurons to Be Primed for Higher-Level Computation.

Biological neuronal networks excel over artificial ones in many ways, but the origin of this is still unknown. Our symbolic dynamics-based tool of excess entropies suggests that neuronal cultures naturally implement data structures of a higher level than what we expect from artificial neural networks, or from close-to-biology neural networks. This points to a new pathway for improving artificial neural networks towards a level demonstrated by biology.

Polarization-sensitive imaging based on incoherent holography.

The polarization-sensitive imaging technology is proposed based on incoherent holography. The distribution of state of polarization (SoP) of the object light field can be reconstructed by measuring the phase difference and amplitude ratio of two components of the Jones vector on the basis of incoherent self-interference theory and the accurate point spread function (PSF) of the incoherent holographic system. In the analysis of Fresnel diffraction, we develop a new method to greatly simplify the calculation of the accurate PSF by means of imaging property of lens and symbolic mathematics tools. In the recording process, we utilize the automation of phase shift, photography, and synthesization of color hologram to greatly shorten the total recording time of a group of phase-shifted holograms. The experimental results show that the proposed technology can accurately realize polarization-sensitive imaging and it is much simpler for complete linearly polarized light.