Computational Theory Research Articles

On-premises superconducting quantum computer for education and research

With a growing interest in quantum technology globally, there is an increasing need for accessing relevant physical systems for education and research. In this paper we introduce a commercially available on-site quantum computer utilizing superconducting technology, offering insights into its fundamental hardware and software components. We show how this system can be used in education to teach quantum concepts and deepen understanding of quantum theory and quantum computing. It offers learning opportunities for future talent and contributes to technological progress. Additionally, we demonstrate its use in research by replicating some notable recent achievements.

The influence of catalyst structure on acidic strength of –SO3H groups for alkyl levulinate synthesis from biomass–derived feedstocks using sulfonic acid functionalized flexible MOF catalyst

A Brönsted acidic BUT−8(Cr)–SO3H metal–organic framework was used for the synthesis of ethyl levulinate from two different biomass–derived platform chemicals viz. furfuryl alcohol and levulinic acid. The catalyst was well characterized using various methods such as PXRD, FTIR spectroscopy, acid–base titration, NH3–TPD, TGA–DTA, SEM, TEM as well as the computational density functional theory (DFT) method. The performance of BUT–8(Cr)–SO3H catalysts was found to be superior to other catalysts (HZSM–5, H–Beta, and amberlyst –15) taken in this study. The sulfonic acid moieties bound to the aromatic naphthalene structure of BUT–8(Cr)–SO3H MOF were found to have a much stronger influence on the catalytic performance than the sulfonic acid moieties bound to the styrene framework of amberlyst–15. The key discoveries regarding the Brönsted acidic characteristics were computed via DFT incorporating the hydrogen removal energy, molecular electrostatic potential maps, and stability of the conjugate base of –SO3H moieties. The trend in the DFT–derived values was in the following order: BUT–8(Cr)–SO3H > Linker–naph –SO3H > Amberlyst–15. The results also indicate the influence of Cr metal on MOF structure to increase the acidic strength of the –SO3H group. The reaction optimization using DOE, recyclability, leaching study, and substrate scope study for both pathways using BUT–8(Cr)–SO3H were obtained.

Time-Controlled Authentication Strategies for Molecular Information Transfer.

Modern cryptography based on computational complexity theory is mainly constructed with silicon-based circuits. As DNA nanotechnology penetrates the molecular domain, utilizing molecular cryptography for data access protection in the biomolecular domain becomes a unique approach to information security. However, building security devices and strategies with robust security and compatibility is still challenging. Here, this study reports a time-controlled molecular authentication strategy using DNAzyme and DNA strand displacement as the basic framework. A time limit exists for authorization and access, and this spontaneous shutdown design further protects secure access. Multiple hierarchical authentications, temporal Boolean logic authentication, and enzyme authentication strategies are constructed based on DNA networks'good compatibility and programmability. This study gives proof of concept for the detection and protection of bioinformation about single nucleotide variants and miRNA, highlighting their potential in biosensing and security protection.

Combining Scattering Experiments and Colloid Theory to Characterize Charge Effects in Concentrated Antibody Solutions.

Charges and their contribution to protein-protein interactions are essential for the key structural and dynamic properties of monoclonal antibody (mAb) solutions. In fact, they influence the apparent molecular weight, the static structure factor, the collective diffusion coefficient, or the relative viscosity, and their concentration dependence. Further, charges play an important role in the colloidal stability of mAbs. There exist standard experimental tools to characterize mAb net charges, such as the measurement of the electrophoretic mobility, the second virial coefficient, or the diffusion interaction parameter. However, the resulting values are difficult to directly relate to the actual overall net charge of the antibody and to theoretical predictions based on its known molecular structure. Here, we report the results of a systematic investigation of the solution properties of a charged IgG1 mAb as a function of concentration and ionic strength using a combination of electrophoretic measurements, static and dynamic light scattering, small-angle X-ray scattering, and tracer particle-based microrheology. We analyze and interpret the experimental results using established colloid theory and coarse-grained computer simulations. We discuss the potential and limits of colloidal models for the description of the interaction effects of charged mAbs, in particular pointing out the importance of incorporating shape and charge anisotropy when attempting to predict structural and dynamic solution properties at high concentrations.

Schiff baseAlkyne precursor for1,2,3-Triazole functionalized organosiliconas a PotentialSensor for Zn(II)andAntioxidantActivity

Schiff base linked1,2,3-triazole silane5has been synthesized through the Schiff base terminated alkyne with azido via click chemistry,the compound4 structure elucidated through X-ray crystallography, and the compound5 is well characterized through different techniques such asFT-IR, 1H and 13C NMR and Mass spectrometry. UV–visible sensing studies of synthesized compounds4 and5 have been performed, and both are efficient in detectingZn(II) ion, but compound 5 has imparted a higher mode of attraction to Zn(II) with limit of detection (LOD) value (1.4 x 10-6M) wherethe compound 4 is calculated to be (1.25 x 10-5M). By Job's method, the stoichiometric ratio of compound5 and Zn(II) iscalculated to bea 1:1 ratio. The complex of compound 5 with Zn(II) was prepared. A radical and oxidative species are responsible for the deteriorating of stabilized molecules. The synthesized compound 5hasantioxidant propertiesthat can potentially scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. Further to verify the mode of binding interaction between compound 5andZn(II), computational Density functional theory (DFT) study was evaluated.

On Sequences of Geophine Triples Involving Padovan and Bernstein Polynomial with Propitious Property

Objective: To bring forth a new conception in the time-honoured field of Diophantine triples, namely “Geophine triple”. To examine the feasibility of proliferating an unending sequence of Geophine triples from Geophine pairs with the property comprising Padovan and Bernstein polynomial. Method: Established Geophine triples employing Padovan and Bernstein polynomial by the method of polynomial manipulations. Findings: An unending sequences of Geophine triples and with the property and are promulgated from Geophine pairs, precisely involving Padovan and Bernstein polynomials and few numerical representation of the sequences are computed using MATLAB. Novelty: This article carries an innovative approach of determining this definite type of triples using Geometric mean and thereby, two infinite sequences of Geophine triples with the property are ascertained. Also, few numerical representations of the sequences utilizing MATLAB program are figured out, thus broadening the scope of computational Number Theory. Keywords: Polynomial Diophantine triple, Geophine triple, Bernstein polynomial, Padovan polynomials, Pell’s equation, Special Polynomials

Nanofibrous Covalent Organic Frameworks Based Hierarchical Porous Separators for Fast‐Charging and Thermally Stable Lithium Metal Batteries

AbstractEngineering multifunctional smart separators are important for the ongoing pursuit of fast‐charging and safe batteries. Herein, a novel nanofibrous covalent organic framework (COF) based separator with well‐designed hierarchical porous channels is fabricated to effectively regulate mass transport for fast‐charging and thermally stable lithium metal batteries (LMBs). Such a hierarchical porous separator consists of electrospun polyacrylonitrile nanofibers with macroporous channels (average diameter of 323 nm) and mesoporous channels (≈7 nm) created between amide‐group‐bonded COF nanoparticles with intrinsic 1.6 nm lithiophilic microporous channels (PAN/AM‐COF). Computational fluid dynamics and density functional theory calculations demonstrate that PAN/AM‐COF can simultaneously facilitate high‐speed and selective transport of Li+, as well as homogeneous deposition of Li, achieving high conductivity (3.33 mS cm−1) and high Li+ transference number (0.79). As a result, Li || LFP full cell with PAN/AM‐COF displays superior cycling stability at 10 C with an acceptable capacity attenuation (0.037% per cycle) over 1000 cycles. Moreover, when operating under an extreme temperature of 100 °C, the Li || LFP full cell with PAN/AM‐COF can still operate stably for 300 cycles at 30 C, highlighting its potential processing scalability for ultrafast‐charging energy storage systems. This study gives insights into designing functional separators for fast‐charging LMBs.

Labeled sample compression schemes for complexes of oriented matroids

We show that the topes of a complex of oriented matroids (abbreviated COM) of VC-dimension d admit a proper labeled sample compression scheme of size d. This considerably extends results of Moran and Warmuth on ample classes, of Ben-David and Litman on affine arrangements of hyperplanes, and of the authors on complexes of uniform oriented matroids, and is a step towards the sample compression conjecture – one of the oldest open problems in computational learning theory. On the one hand, our approach exploits the rich combinatorial cell structure of COMs via oriented matroid theory. On the other hand, viewing tope graphs of COMs as partial cubes creates a fruitful link to metric graph theory.

Editorial - Artificial Intelligence, Legal Theory and the Judiciary

Artificial Intelligence (AI) plays a pivotal role at the intersection of modern-day legal theory and legal practice. On the one hand, it encompasses automated reasoning, Natural Language Process (NLP) models, and computational legal theory, influencing and helping various aspects of legal operations. On the other, it also optimizes the judiciary with efficient, transparent, and rights-preserving procedures. Thus, AI is both seen as a research topic, a bureaucratic advantage, and a constitutional threat, which shows its significance in the legal landscape.

Analysis of the structural reliability of communication networks supporting protective switching mechanisms for one protected section and one backup section

Objectives. The service level agreement is an important tool used in building reasonable relations between subscribers and operators of telecommunication networks. This includes the quality of services provided. One key component is reliability as assessed by the availability factor. The most suitable model for assessing the reliability of the service provided is a random graph model based on the service contour. This is the set of technical resources involved in the provision of this service. In this formulation, the assessment of the reliability of the service is based on the reliability of elements which constitute the telecommunications network (graph), nodes (vertices) and communication lines (edges). At the same time, the availability factors of nodes and lines are determined by the design features of the distribution environment, as well as the technical means used to organize them. The purpose of this work is to develop an approach to analyzing the reliability of telecommunication networks which support protective switching mechanisms for one protected and one backup sections.Methods. The following methods are used: theory of random graphs, matrices, probabilities and computer modeling.Results. The elements of the route, both basic and reserving, are divided into three groups. The first indicates permanent unchangeable parts of the paths, the second group identifies the reserved sections, and the third group indicates the reserving sections. At the same time, each of the reserved and reserving sections is formed on the basis of specified preferences. They are usually aimed at increasing the resulting reliability, although other rules may be used. In the case of protective switching schemes for one protected section and one backup sections, a variant of forming routes used for further calculations of the reliability indicator is shown.Conclusions. Using the example of a backbone network, the study shows that the use of protective switching mechanisms for the case of one required transmission route demonstrates a significant increase in reliability, with the exception of the use of protective switching in sections. This is primarily due to the topology features of the network under consideration.

Causal learning by infants and young children: From computational theories to language practices.

Causal reasoning-the ability to reason about causal relations between events-is fundamental to understanding how the world works. This paper reviews two prominent theories on early causal learning and offers possibilities for theory bridging. Both theories grow out of computational modeling and have significant areas of overlap while differing in several respects. Explanation-Based Learning (EBL) focuses on young infants' learning about causal concepts of physical objects and events, whereas Bayesian models have been used to describe causal reasoning beyond infancy across various concept domains. Connecting the two models offers a more integrated approach to clarifying the developmental processes in causal reasoning from early infancy through later childhood. We further suggest that everyday language practices offer a promising space for theory bridging. We provide a review of selective work on caregiver-child conversations, in particular, on the use of scaffolding language including causal talk and pedagogical questions. Linking the research on language practices to the two cognitive theories, we point out directions for further research to integrate EBL and Bayesian models and clarify how causal learning unfolds in real life. This article is categorized under: Psychology > Learning Cognitive Biology > Cognitive Development.

Count-free Weisfeiler–Leman and group isomorphism

We investigate the power of counting in Group Isomorphism. We first leverage the count-free variant of the Weisfeiler–Leman Version I algorithm for groups [J. Brachter and P. Schweitzer, On the Weisfeiler–Leman dimension of finite groups, in 35th Annual ACM/IEEE Symp. Logic in Computer Science, eds. H. Hermanns, L. Zhang, N. Kobayashi and D. Miller, Saarbrucken, Germany, July 8–11, 2020 (ACM, 2020), pp. 287–300, doi:10.1145/3373718.3394786] in tandem with bounded non-determinism and limited counting to improve the parallel complexity of isomorphism testing for several families of groups. These families include: • Direct products of non-Abelian simple groups. • Coprime extensions, where the normal Hall subgroup is Abelian and the complement is an [Formula: see text]-generated solvable group with solvability class [Formula: see text]. This notably includes instances where the complement is an [Formula: see text]-generated nilpotent group. This problem was previously known to be in [Formula: see text] [Y. Qiao, J. M. N. Sarma and B. Tang, On isomorphism testing of groups with normal Hall subgroups, in Proc. 28th Symp. Theoretical Aspects of Computer Science, Dagstuhl Castle, Leibniz Center for Informatics, 2011), pp. 567–578, doi:10.4230/LIPIcs. STACS.2011.567], and the complexity was recently improved to [Formula: see text] [J. A. Grochow and M. Levet, On the parallel complexity of group isomorphism via Weisfeiler–Leman, in 24th Int. Symp. Fundamentals of Computation Theory, eds. H. Fernau and K. Jansen, Lecture Notes in Computer Science, Vol. 14292, September 18–21, 2023, Trier, Germany (Springer, 2023), pp. 234–247]. • Graphical groups of class 2 and exponent [Formula: see text] [A. H. Mekler, Stability of nilpotent groups of class 2 and prime exponent, J. Symb. Logic 46(4) (1981) 781–788] arising from the CFI and twisted CFI graphs [J.-Y. Cai, M. Fürer and N. Immerman, An optimal lower bound on the number of variables for graph identification, Combinatorica 12(4) (1992) 389–410], respectively. In particular, our work improves upon previous results of Brachter and Schweitzer [On the Weisfeiler–Leman dimension of finite groups, in 35th Annual ACM/IEEE Symp. Logic in Computer Science, eds. H. Hermanns, L. Zhang, N. Kobayashi and D. Miller, Saarbrucken, Germany, July 8–11, 2020 (ACM, 2020), pp. 287–300, doi:10.1145/3373718.3394786]. Notably, each of these families was previously known to be identified by the counting variant of the more powerful Weisfeiler–Leman Version II algorithm. We finally show that the q-ary count-free pebble game is unable to even distinguish Abelian groups. This extends the result of Grochow and Levet (ibid), who established the result in the case of [Formula: see text]. The general theme is that some counting appears necessary to place [Formula: see text] into [Formula: see text].

Similarity in evoked responses does not imply similarity in macroscopic network states.

It is commonplace in neuroscience to assume that if two tasks activate the same brain areas in the same way, then they are recruiting the same underlying networks. Yet computational theory has shown that the same pattern of activity can emerge from many different underlying network representations. Here we evaluated whether similarity in activation necessarily implies similarity in network architecture by comparing region-wise activation patterns and functional correlation profiles from a large sample of healthy subjects (N = 242). Participants performed two executive control tasks known to recruit nearly identical brain areas, the color-word Stroop task and the Multi-Source Interference Task (MSIT). Using a measure of instantaneous functional correlations, based on edge time series, we estimated the task-related networks that differed between incongruent and congruent conditions. We found that the two tasks were much more different in their network profiles than in their evoked activity patterns at different analytical levels, as well as for a wide range of methodological pipelines. Our results reject the notion that having the same activation patterns means two tasks engage the same underlying representations, suggesting that task representations should be independently evaluated at both node and edge (connectivity) levels.

Influence of guide vane opening on channel vortex and pressure pulsation in Francis turbine runners

In order to investigate the impact of guide vane opening on channel vortex and pressure pulsation within the runner of a Francis turbine, this research examines the cavitation phenomenon, channel vortex phenomenon, and flow field characteristics of a power station's turbine in China. The investigation is conducted using computational fluid dynamics theory. Furthermore, the analysis focuses on the influence of changes in guide vane opening on the flow state within the turbine runner. The findings indicate that the occurrence of rotor cavitation is severe when the opening is small, and increasing the opening reduces the cavitation capacity of the rotor. The presence of a lobe vortex phenomenon is mainly observed within a small range of guide vane openings, and altering the opening modifies both the range of influence and flow characteristics of the lobe vortex. In the middle range of guide vane openings, vortex pressure pulsation dominates within the rotor, with the highest amplitude of pressure pulsation occurring at a 60% opening. In the large opening range, pressure pulsation mainly occurs in the lobe frequency pressure pulsation of the rotor within the lobe-less area. The amplitude of blade frequency is typically small, indicating good hydraulic stability of the unit. These study results elucidate the interval of stable operating conditions for the unit and offer valuable insights for maintaining its stable operation.

Changing the logic without changing the subject: the case of computability

Abstract In this paper, I argue against the thesis that the meaning of ‘computability’ is logic-dependent. I do this from a category-theoretic perspective. Applying a method due to Mortensen and Lavers [26], I show that we can dualize the internal logic of the effective topos, in order to obtain a model of paraconsistent computability theory. Since the dualization leaves the structural properties of universal constructions in the topos unchanged, in particular the properties of the natural numbers object, I conclude that, at least in this case, changing the logic does not change our characterization of computability.

Prioritising national healthcare service issues from free text feedback – A computational text analysis & predictive modelling approach

Patient experience surveys have become a key source of evidence for supporting decision-making and continuous quality improvement within healthcare services. To harness free-text feedback collected as part of these surveys for additional insights, text analytics methods are increasingly employed when the data collected is not amenable to traditional qualitative analysis due to volume. However, while text analytics techniques offer good predictive capabilities, they have limited explanatory features often required in formal decision-making contexts, such as programme monitoring or evaluation. To overcome these limitations, this study integrates computational text and predictive modelling as part of a Computational Grounded Theory method to determine the effect of quality gaps in care dimensions and their prioritisation from free-text feedback. The feedback was collected as part of a national survey to support decisions on continuous improvement in Maternity Services in Ireland. Our approach enables (1) operationalising the service quality lexicon in the context of maternity care to explain the effect of quality gaps in care dimensions on overall satisfaction from free-text comments; and (2) extending the service quality lexicon with two organisational and political decision-making concepts: “Salience” and “Valence”, for prioritising perceived quality gaps. These methodological affordances enable the extension of service quality theory to explicitly support the prioritisation of improvement decisions which before now required additional decision frameworks. Results show that tangibles-, process-, and reliability-related care issues have the highest importance in our study context. We also find that hospital contexts partly determine the relative importance of gaps in care dimensions.

The Ginsburg–Sands theorem and computability theory

The Ginsburg–Sands theorem from topology states that every infinite topological space has an infinite subspace homeomorphic to exactly one of the following five topologies on ω: indiscrete, discrete, initial segment, final segment, and cofinite. The original proof is nonconstructive, and features an interesting application of Ramsey's theorem for pairs (RT22). We analyze this principle in computability theory and reverse mathematics, using Dorais's formalization of CSC spaces. Among our results are that the Ginsburg–Sands theorem for CSC spaces is equivalent to ACA0, while for Hausdorff spaces it is provable in RCA0. Furthermore, if we enrich a CSC space by adding the closure operator on points, then the Ginsburg–Sands theorem turns out to be equivalent to the chain/antichain principle (CAC). The most surprising case is that of the Ginsburg–Sands theorem restricted to T1 spaces. Here, we show that the principle lies strictly between ACA0 and RT22, yielding arguably the first natural theorem from outside logic to occupy this interval. As part of our analysis of the T1 case we introduce a new class of purely combinatorial principles below ACA0 and not implied by RT22 which form a hierarchy generalizing the stable Ramsey's theorem for pairs (SRT22). We show that one of these, the Σ20 subset principle (Σ20-Subset), has the property that it, together with the cohesive principle (COH), is equivalent over RCA0 to the Ginsburg–Sands theorem for T1 CSC spaces.

A computational and experimental study of cis-trans isomeric pesticides based on collision-induced dissociation of high-resolution mass spectrometry.

Pesticide isomers are widely available in agricultural production and may vary widely in biological activity, potency, and toxicity. Chromatographic and mass spectrometric analysis of pesticide isomers is challenging due to structural similarities. Based on liquid chromatography time-of-flight mass spectrometry, identification of cis-trans isomeric pesticides was achieved through retention time, characteristic fragment ions, and relative abundance ratio. Furthermore, theoretical and basic research has been conducted on the differences in characteristic fragment ions and their relative abundance ratios of cis-trans isomers. On the one hand, the cleavage pathways of six cis-trans isomers were elucidated through collision-induced dissociation to explain different fragment ions of the isomers. On the other hand, for those with the same fragment ions but different abundance ratios, energy-resolved mass spectrometry combined with computational chemical density functional theory in terms of kinetics, thermodynamics, and bond lengths was employed to explain the reasons for the differences in characteristic fragment ions and their abundance ratios. A high-resolution mass spectrometry method was developed for the separation and analysis of cis-trans isomers of pesticides in traditional Chinese medicine Radix Codonopsis, and six pesticide isomers were distinguished by retention time, product ions, and relative abundance ratios. The limits of quantification of the six pesticides were up to 10μg/kg, and the linear ranges of them were 10-200 μg/kg, with coefficients of determination (R2) > 0.99, which demonstrated the good linearity of the six pesticides. The recoveries of the pesticides at spiked concentrations of 10, 20, and 100 μg/kg reached 70-120% with relative standard deviations ≤20%. It was demonstrated that the application of the method was well suited for accurate qualitative and quantitative analysis for isomers with different structures, which could avoid false-negative results caused by ignoring other isomers effectively.

RESEARCH OF ALGORITHMS FOR SEARCHING PRIMITIVE ELEMENTS OF A FINITE FIELD OF HIGH ORDER

One of the most important unsolved and notoriously difficult problems in computational finite field theory is the development of a fast algorithm for constructing primitive roots in a finite field. It is known that for many applications, instead of a primitive root, just an element of high multiplicative order is sufficient. Such applications include, but are not limited to, cryptography, coding theory, pseudorandom number generation, and combinatorial schemes. Explicit constructions of high-order elements usually rely on combinatory methods that can provide a provable lower bound on the order, but this does not compute the exact order. Its execution usually implies knowledge of the factorization of the order. Ideally, we should be able to get a primitive element for any finite field in a reasonable amount of time. However, if the simple factorization of the group order is unknown, it is difficult to achieve the goal. Thus, we set the task of constructing an element, probably of a high order. This article discusses various algorithms that find a high-order element for general or special finite fields. This work also represents another contribution to the theory of Gauss periods over finite fields and their generalizations and analogues, which have already proven their usefulness for a number of different applications.

Snapshot spectral imaging: from spatial-spectral mapping to metasurface-based imaging

Abstract Snapshot spectral imaging technology enables the capture of complete spectral information of objects in an extremely short period of time, offering wide-ranging applications in fields requiring dynamic observations such as environmental monitoring, medical diagnostics, and industrial inspection. In the past decades, snapshot spectral imaging has made remarkable breakthroughs with the emergence of new computational theories and optical components. From the early days of using various spatial-spectral data mapping methods, they have evolved to later attempts to encode various dimensions of light, such as amplitude, phase, and wavelength, and then computationally reconstruct them. This review focuses on a systematic presentation of the system architecture and mathematical modeling of these snapshot spectral imaging techniques. In addition, the introduction of metasurfaces expands the modulation of spatial-spectral data and brings advantages such as system size reduction, which has become a research hotspot in recent years and is regarded as the key to the next-generation snapshot spectral imaging techniques. This paper provides a systematic overview of the applications of metasurfaces in snapshot spectral imaging and provides an outlook on future directions and research priorities.