Topological Paradigm Research Articles

Topological broadband invisibility

AbstractWhen an electromagnetic wave is incident onto an object, the scattering from the object leads to its exposure. An invisibility cloak can bend the electromagnetic wave around the object with phase velocities exceeding the light speed in free space, which seems only possible over a narrow bandwidth, as manifested in the existing approaches, such as transformation optics and scattering cancellation. Here, it is experimentally demonstrated that this bandwidth limitation can be overcome by strategically positioning objects at topological nodes, characterized by minimal electromagnetic field amplitudes and indeterminate phases. This is accomplished using all‐dielectric photonic crystal slabs, which are engineered to exhibit a pair of topological nodes at fixed planes across an extensive bandwidth. This bandwidth expansion is facilitated not by resonance, but by the enforcement of mirror and time‐reversal symmetry. These findings thus introduce a novel topological paradigm for the broadband invisibility devices.

Architectural Form Finding and Computational Design of Tall Building Applying Topology Optimization against Lateral Loads

The hierarchy of a building is created from the hermeneutics aspects changing from a typology to a topology paradigm. As tall buildings are growing rapidly, engineering science is experiencing developments such as the finite-element method. The present research creates a platform for architects using the topology optimization method as an assistant designer. This platform serves as a starter for a common language of these two professions in the early stages of design. Architects can use this platform to produce the final topological optimized form by defining their shape plans, lateral loads, height, and the target ratio of models as platform inputs. This paper highlights the importance of the bidirectional evolutionary structural optimization method simultaneously in architectural and structural contexts to reduce the total weight of the structure while keeping the displacement of the structure in an acceptable range. The reduction will be made by eliminating the structural material zones with lower stress with an effective method for achieving the structural efficiency of a tall building, considering architectural aspects.

Ontogeny of the trigeminal system and associated structures in Alligator mississippiensis.

From the appearance of the vertebrate head, the trigeminal system has played a role in behavioral and ecological adaptation. The trigeminal nerve is the primary cranial somatosensory nerve, also innervating the jaw muscles. In crocodylians, the trigeminal nerve plays a role in modulating the high bite force and unique integumentary sensation. In association with these behaviors, crocodylians are known for large trigeminal nerves, a high volume of trigeminal-innervated musculature, and densely packed, specialized sensory receptors. These innovations also occurred in concert with a restructuring of the lateral braincase wall. These morphologies have previously been investigated in phylogenetic and evolutionary contexts, but an ontogenetic, whole-system investigation of trigeminal tissue and associated musculature, cartilage, and bone is lacking, as is an understanding of developmental timing of morphologies significant to hypotheses of homology. Here, we use contrast-enhanced computed tomographyimaging to provide description and analysis of the trigeminal system in an ontogenetic series of Alligator mississippiensis from embryonic to adult form. We explore growth rates and allometric relationships of structures and discuss the significance to hypotheses of homology. We find a high growth rate and allometric trajectory of the trigeminal nerve in comparison to other cranial nerves, likely associated with the large volume of trigeminal musculature and high densities of sensory receptors. We identify a similar trend in the pterygoideus dorsalis muscle, the highest contributor to bite force. We narrow ontogenetic timing of features related to the trigeminal topological paradigm and the undeveloped epipterygoid. Overall, we provide a basis for understanding trigeminal development in crocodylians, which upon comparison across reptiles will reveal ontogenetic origins of morphological variation.

Topological descendants of a multicritical Dirac semimetal with magnetism and strain

The past decades have seen an ever increasing rise in classification and characterization of topological materials. One of the most important questions is how to control and manipulate topological phases. Here, the authors predict a multicritical topological paradigm in EuTl${}_{2}$. Starting from a paramagnetic Dirac semimetallic phase, a plethora of descendant topological phases are accessible with magnetism and strain, including Dirac and Weyl magnetic semimetals, axion insulators, and a variety of other topological crystalline insulators protected by different symmetries.

Performance Prediction Method for Stream Computing Platform Based on Time Series

As one of the most popular high-performance data processing technology, existing task and resource scheduling strategies for stream computing platforms are suffering from the problem of triggering hysteresis, which seriously affects the cluster performance. To address this problem, the idea of performance prediction based on timeline series data is proposed. Firstly, the performance variation rule of the stream processing platform is analyzed, which provides a basis for proposing the performance prediction model. Secondly, the basic topology paradigm, periodic load prediction model, and real-time throughput prediction model are proposed as the theoretical foundation for performance prediction. Thirdly, the performance prediction algorithm is proposed to predict the variation trend of the processing load and throughput of the cluster. The processing load is predicted periodically while the throughput of the cluster is predicted in a real-time manner. Finally, the performance evaluation algorithm is proposed to evaluate the cluster performance based on the prediction results and trigger the corresponding scheduling strategies in advance. The experimental results showed that the prediction accuracy of the proposed algorithm meets the requirements in practical applications. Meanwhile, the proposed method improves the performance of stream computing performance by triggering the scheduling strategies in advance.

Symmetry-protected hierarchy of anomalous multipole topological band gaps in nonsymmorphic metacrystals

Symmetry and topology are two fundamental aspects of many quantum states of matter. Recently new topological materials, higher-order topological insulators, were discovered, featuring bulk–edge–corner correspondence that goes beyond the conventional topological paradigms. Here we discover experimentally that the nonsymmorphic p4g acoustic metacrystals host a symmetry-protected hierarchy of topological multipoles: the lowest band gap has a quantized Wannier dipole and can mimic the quantum spin Hall effect, whereas the second band gap exhibits quadrupole topology with anomalous Wannier bands. Such a topological hierarchy allows us to observe experimentally distinct, multiplexed topological phenomena and to reveal a topological transition triggered by the geometry transition from the p4g group to the C4v group, which demonstrates elegantly the fundamental interplay between symmetry and topology. Our study demonstrates that classical systems with controllable geometry can serve as powerful simulators for the discovery of novel topological states of matter and their phase transitions.

Choreographed entanglement dances: Topological states of quantum matter

It has long been thought that all different phases of matter arise from symmetry breaking. Without symmetry breaking, there would be no pattern, and matter would be featureless. However, it is now clear that for quantum matter at zero temperature, even symmetric disordered liquids can have features, giving rise to topological phases of quantum matter. Some of the topological phases are highly entangled (that is, have topological order), whereas others are weakly entangled (that is, have symmetry-protected trivial order). This Review provides a brief summary of these zero-temperature states of matter and their emergent properties, as well as their importance in unifying some of the most basic concepts in nature.

IEEE Access Special Section Editorial: Recent Advances in Computational Intelligence Paradigms for Security and Privacy for Fog and Mobile Edge Computing

Today, cloud computing services are undeniably becoming parts of modern information and communication systems in our daily lives. Cloud computing has proven to be an incredible technology for provisioning quickly deployed and scalable information technology (IT) solutions at reduced infrastructure costs. Cloud computing is unable to meet the requirements of low latency, location awareness, and mobility support. To solve this problem, researchers have introduced a trusted and dependable solution through fog and mobile edge computing (FMEC) to put the services and resources of the cloud closer to users, which facilitates the leveraging of available services and resources in the edge networks. Organizations are beginning to look at FMEC as the answer to the cloud computing problem. FMEC consists of putting micro data centers or even small, purpose-built high-performance data analytics machines in remote offices and locations in order to gain real-time insights from the data collected, or to promote data thinning at the edge, by dramatically reducing the amount of data that needs to be transmitted to a central data center. Without having to move unnecessary data to a central data center, analytics at the edge can simplify and drastically speed analysis while also cutting costs. FMEC pushes applications, data, and computing power (services) away from centralized points to the logical extremes of a network. FMEC replicates fragments of information across distributed networks of web servers, which may be vast. As a topological paradigm, edge computing is also referred to as mesh computing, peer-to-peer computing, autonomic (self-healing) computing, grid computing, and other names implying non-centralized, node-less availability.

Overlap of two topological phases in the antiferromagnetic Potts model.

By controlling the vortex core energy, the three-state ferromagnetic Potts model can exhibit two types of topological paradigms, including the quasi-long-range ordered phase and the vortex lattice phase [Phys. Rev. Lett. 116, 097206 (2016)PRLTAO0031-900710.1103/PhysRevLett.116.097206]. Here, using Monte Carlo simulations using an efficient worm algorithm, we show that by controlling the vortex core energy, the antiferromagnetic Potts model can also exhibit the two topological phases, and, more interestingly, the two topological phases can overlap with each other.

When Crisis Becomes Form: Athens as a Paradigm

Documenta 14 (d14) was an undoubtedly important exhibition which triggered endless debate and controversy that continues today.[1] The choice of Athens as a topological paradigm by Adam Szymczyk, an ingenious curator with expected and unexpected virtues, initially fired people’s appetite and enthusiasm. Yet what it ultimately managed to do was demythicize the event itself in a way, as well as demonstrate a series of dangers in the operation of the institution. At the same time it brought to light a series of innate ailments and fantasies of contemporary culture in Greece, which manifested themselves in a distorted and sometimes aggressive fashion. This is not without significance, since it functioned complementarily to—rather than independently of—the exhibition. In short, d14 served as a kind of double mirror with which we could see the cultural relation of Greece with Europe and the world, but also the reverse: that of Europe with Greece. So what was d14 in Athens? For now we must necessarily sidestep its contribution to making Athens and Greek culture a temporary center of international attention in order to focus on what must not be overlooked. The series of arguments below can be read individually or successively as a network of alternating commentary, but also through their diagonal intersections, ruptures, disagreements, and connections, where meaning is produced in a syncretic or dialectical way. D14 is the symptom from which all discourse around it begins.

Discovering the Whole by the Coarse: A topological paradigm for data analysis

The increasing interest in big data applications is ushering in a large effort in seeking new, efficient, and adapted data models to reduce complexity, while preserving maximal intrinsic information. Graph-based models have recently been getting a lot of attention on account of their intuitive and direct connection to the data [43]. The cost of these models, however, is to some extent giving up geometric insight as well as algebraic flexibility.

Matching monocular lightweight features using N-gram techniques for topological location identification

SUMMARYIn SLAM (simultaneous localization and mapping), the topological paradigm provides a more natural and compact solution that scales better with the size of the environment. Computer vision has always been regarded as the ideal sensor technology for topological feature extraction and description and several methods have been proposed in the literature, but they are either time-consuming, require plenty of different sensors, or are very sensitive to perceptual aliasing, all of which limit their application scope.This paper presents a fast-to-compute collection of features extracted from monocular images, and an adaptive matching procedure for location identification in structured indoor environments inspired by the natural language processing field. Although only dominant vertical lines, color histograms, and a reduced number of keypoints are employed in this paper, the matching framework introduced allows for the incorporation of almost any other type of feature. The results of the experiments carried out in a home and an office environment suggest that the proposed method could be used for real-time topological scene recognition even if the environment changes moderately over time. Due to the combination of complementary features, high precision can be achieved within reasonable computation time by using weaker but faster descriptors.

Reconsidering phonæsthemes: Submorphemic invariance in English ‘ sn- words’

I reconsider the English phonæstheme sn- in order to provide a principled explanation for the dyadic sn-/nasality relation, noted by many scholars, in words such as sneeze, sniff and snore. After discussing the structural aspects of this relation and the morphological status of phonæsthemes, I focus on the issue of meaning in a psychomechanical perspective, before analysing core invariance in phonosemantic ‘ sn-/n- doublets’ such as sniff/ niff. I then examine the notion of nasality within the framework of embodied semantics, and explore the cognitive status of phonæsthemes within a topological paradigm. I adduce a possible diachronic evolution between Old and Modern English (word-initial /xn/ > /n/ → /sn/) to account for the fact that one particular subset of ‘ sn- words’ has meanings related to biting, and investigate the issue of arbitrariness with respect to sn- and other phonæsthemes. Finally, in order to address the possible origins of the sn-/nasality relation within the phylogenetic perspective provided by semiogenesis, I adopt the gestural approach advocated by articulatory phonology and conclude, within a theory of the emergence and evolution of the linguistic sign (STEELS), that the naturally nasal quality of n may originally have endowed it with a metonymically based, self-referential capacity.

ChemInform Abstract: The Polyhex/Polypent Topological Paradigm: Regularities in the Isomer Numbers and Topological Properties of Select Subclasses of Benzenoid Hydrocarbons and Related Systems

AbstractReview: 95 refs.

ChemInform Abstract: The Current Status of Isomer Enumeration of Useful Benzenoids and a New Topological Paradigm

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The polyhex/polypent topological paradigm: regularities in the isomer numbers and topological properties of select subclasses of benzenoid hydrocarbons and related systems

The informatics on benzenoid hydrocarbons and related systems is reviewed. This informatics involves a collection of algorithms used to discover, process, and analyze patterns in structure/formula data sets. The unique organizational structure that emerges will be useful to chemists with an interest in polycyclic aromatic compounds, environmental chemists, material scientists, and other scientists wishing for a greater understanding of the formation of carbonaceous materials. This tutorial review will show that isomer enumeration can lead to significant chemical insights. The isomer number regularities will be shown to have a structural origin referred to as the polyhex/polypent topological paradigm.

On the Spectacular Structural Isomorphism between CnHs Monoradical and Cn+sHs+3 Diradical Benzenoid Hydrocarbons: From Reactive Intermediates to Vacancy (Hole) Defects in Graphite

The formula/structure informatics of monoradical and diradical benzenoid hydrocarbons that are potential reactive intermediates is studied. Some new enumeration and structural results with analytical expressions are presented. The topological paradigm and one-to-one correspondence between the monoradical and diradical constant-isomer series is demonstrated. Constant-isomer benzenoid monoradicals of the formula CnHs have a one-to-one correspondence in isomer number and topology to constant-isomer diradicals of the formula Cn+sHs+3. Some electronic properties of benzenoid radicals are delineated. Excising out a monoradical or diradical benzenoid carbon molecule from a perfect hexagonal graphite layer leaves a matching monoradical or diradical vacancy hole defect called an antimolecule; this observation can be generalized to include excising out all nondisjoint and obvious benzenoid polyradicals from a perfect (Kekuléan) hexagonal graphite layer. It is shown that the characteristics of graphite vacancies (antimolecules) can be deduced from knowledge about the carbon molecules removed in their formation.

Archosaur adductor chamber evolution: Integration of musculoskeletal and topological criteria in jaw muscle homology

The homologies of jaw muscles among archosaurs and other sauropsids have been unclear, confounding interpretation of adductor chamber morphology and evolution. Relevant topological patterns of muscles, nerves, and blood vessels were compared across a large sample of extant archosaurs (birds and crocodylians) and outgroups (e.g., lepidosaurs and turtles) to test the utility of positional criteria, such as the relative position of the trigeminal divisions, as predictors of jaw muscle homology. Anatomical structures were visualized using dissection, sectioning, computed tomography (CT), and vascular injection. Data gathered provide a new and robust view of jaw muscle homology and introduce the first synthesized nomenclature of sauropsid musculature using multiple lines of evidence. Despite the great divergences in cephalic morphology among birds, crocodylians, and outgroups, several key sensory nerves (e.g., n. anguli oris, n. supraorbitalis, n. caudalis) and arteries proved useful for muscle identification, and vice versa. Extant crocodylians exhibit an apomorphic neuromuscular pattern counter to the trigeminal topological paradigm: the maxillary nerve runs medial, rather than lateral to M. pseudotemporalis superficialis. Alternative hypotheses of homology necessitate less parsimonious interpretations of changes in topology. Sensory branches to the rictus, external acoustic meatus, supraorbital region, and other cephalic regions suggest conservative dermatomes among reptiles. Different avian clades exhibit shifts in some muscle positions, but maintain the plesiomorphic, diapsid soft-tissue topological pattern. Positional data suggest M. intramandibularis is merely the distal portion of M. pseudotemporalis separated by an intramuscular fibrocartilaginous sesamoid. These adductor chamber patterns indicate multiple topological criteria are necessary for interpretations of soft-tissue homology and warrant further investigation into character congruence and developmental connectivity.

Molecular Tectonics of Metal–Organic Frameworks (MOFs): A Rational Design Strategy for Unusual Mixed‐Connected Network Topologies

To systematically explore the higher-dimensional network structures with mixed connectivity, a series of two-dimensional (2D) and three-dimensional (3D) metal-organic frameworks (MOFs) with unusual (3,6)-connected net topologies are presented. These crystalline materials include [{[Mn(btza)2(H2O)2].2 H2O}n] (1), [{[Zn(btza)2(H2O)2].2 H2O}n] (2), [{[Cu(btza)2].H2O}n] (3), and [{[Cd(btza)2].3 H2O}n] (4), which have been successfully assembled through a predesigned three-connected organic component bis(1,2,4-triazol-1-yl)acetate (btza) with a variety of octahedral metal cores based on the modular synthetic methodology. The topological paradigms shown in this work cover the 2D CdCl2, 3D (4(2).6)2(4(4).6(2).8(7).10(2)), and pyrite (pyr) types. That is, when properly treated with the familiar first-row divalent metal ions, btza may perfectly furnish the coordination spheres for effective connectivity to result in diverse (3,6)-connected nets. Beyond this, a detailed analysis of network topology for all known 3D (3,6)-connected frameworks in both inorganic and inorganic-organic hybrid materials is described. Specific network connectivity of these MOFs indicates that the metal centers represent the most significant and alterable factor in structural assembly, although they show reliable and similar geometries. In this context, the combination of the distinct d10 AgI ion with btza in different solvents affords two isomorphous MOFs [{[Ag(btza)].glycol}n] (5) and [{[Ag(btza)]CH3OH}n] (6) with a binodal 4-connected 3D SrAl2 (sra) topology. The network structures of MOFs 1-3 and 5 turn out to be more complicated and interesting if one considers the hydrogen bonding between the host coordination frameworks and the intercalated solvent molecules. Furthermore, the role of the included solvents in the generation and stabilization of MOFs 1-6 is also investigated.

Automatic nested refinement: a technique for the generation of high quality multi-block structured grids for multi-scale problems using GridPro

A technique for the generation of conformal adaptive refinement of hex meshes is presented. Automatic nested refinement is a technique for generating recursively nested topology automatically. It can be applied inside GridPro’s topological paradigm to generate block structured grids, which can resolve tiny features in the problem while providing for a smooth and consistent way to transition to a larger scale. The selection of self-similar, ‘fractal-like’ topological templates makes the selection of number of levels easy, while making the technique feasible for infinite levels of adaptive refinement. The technique has been programmed and integrated into the GUI of GridPro, making it very accessible and easy to use. This method illustrates a way of generating structured grids in an unstructured way, made possible because of the topological paradigm of GridPro. Because the technique uses the topological paradigm, it inherits all the advantages the paradigm offers, including the ability to handle very complex geometries, parametric variation of surfaces, and the ease of use, speed and quality of GridPro. The technique has been illustrated using a variety of applications. This method has proved to be a fast, efficient, automatic and reliable means to perform physical simulations that have a disparity in scale.