Generic Scenario Research Articles

Creation of quantum knots and links driven by minimal surfaces

Using an improved numerical code we investigate the creation and evolution of quantum knots and links as defects of the Gross–Pitaevskii equation. The particular constraints put on quantum hydrodynamics make this an ideal context for application of geometric and topological methods to investigate dynamical properties. Evolutionary processes are classified into three generic scenarios representing (i) direct topological cascade and collapse, (ii) structural and topological cycles, and (iii) inverse topological cascade of complex structures. Several examples and test cases are studied; the head-on collision of quantum vortex rings and the creation of a trefoil knot from initially unlinked, unknotted loops are realized for the first time. Each type of scenario is studied by carrying out a detailed evaluation of fundamental geometric and dynamical properties associated with evolution. Direct topological cascade that governs the decay of complex structures to small-scale vortex rings is identified by writhe measures, while picks of total curvature are found to provide a clear signature of reconnection events. We demonstrate that isophase minimal surfaces spanning knots and links have a privileged role in the decay process by detecting surface energy relaxation of complex structures. Minimal surfaces are shown to be critical markers for energy and prove to be appropriate detectors for the evolution of complex systems.

Determination of Individual Building Performance Targets to Achieve Community-Level Social and Economic Resilience Metrics

The retrofit of wood-frame residential buildings is a relatively effective strategy to mitigate damage caused by windstorms. However, little is known about the effect of modifying building performance for intense events such as a tornado and the subsequent social and economic impacts that result at the community level following an event. This paper presents a method that enables a community to select residential building performance levels representative of either retrofitting or adopting a new design code that computes target community metrics for the effects on the economy and population. Although not a full risk analysis, a series of generic tornado scenarios for different Enhanced Fujita (EF) ratings are simulated, and five resilience metrics are assigned to represent community goals based on economic and population stability. To accomplish this, the functionality of the buildings following the simulated tornado is used as input to a computable general equilibrium (CGE) economics model that predicts household income, employment, and domestic supply at the community level. Population dislocation as a function of building damage and detailed sociodemographic US census-based data is also predicted and serves as a core community resilience metric. Finally, this proposed methodology demonstrates how the metrics can help meet community-level resilience objectives for decision support based on a level of design code improvement or retrofit level. The method is demonstrated for Joplin, Missouri. All analyses and data have been developed and made available on the open-source IN-CORE modeling environment. The proposed multidisciplinary methodology requires continued research to characterize the uncertainty in the decision support results.

On the maximum volume of collapsing structures

In many cosmological models, including the ΛCDM concordance model, there exist theoretical upper bounds on the size of collapsing structures. The most common formulations in the literature refer to a turnaround radius in spherical symmetry or a turnaround surface, defined as the zero-expansion boundary separating the outer Hubble flow from the inner flow of a collapsing fluid. In order to access a generic scenario, we propose an improvement of this cosmological test in terms of the maximum volume of the cosmological structures, which is equivalent to a zero-averaged expansion — instead of the zero-local expansion. By combining the Lagrangian perturbations method and the scalar averaging of Einstein's equations, we obtain a maximum volume for a collapse model without any restricting symmetries.We compare this result with some exact, inhomogeneous solutions and discuss further potential developments.

Double-cohesion learning based multiview and discriminant palmprint recognition

Palmprint recognition has been widely used in security authentication. However, most of the existing palmprint representation methods are focused on a special application scenario using the hand-crafted features from a single-view. If the features become weak as the application scenario changes, the recognition performance will be degraded. To address this problem, we propose to comprehensively exploit palmprint features from multiple views to improve the recognition performance in generic scenarios. In this paper, a novel double-cohesion learning based multiview and discriminant palmprint recognition (DC_MDPR) method is proposed, which imposes a double-cohesion strategy to reduce the inter-view margins for each subject and the intra-class margins for each view. In this way, for each subject, the features from different views can be closer to each other in the binary-label space. Meanwhile, for each view, the features sharing the same label information can move towards each other by imposing a neighbor graph regularization. The proposed method can be flexibly applied to any type of palmprint feature fusion. Moreover, it presents the multiview features in a low-dimensionality sub-space, effectively reducing the computational complexity. Experimental results on various palmprint databases have shown that the proposed method can always achieve the best recognition performance compared to other state-of-the-art algorithms.

Bounding the Frobenius norm of a q-deformed commutator

For two n×n complex matrices A and B, we define the q-deformed commutator as [A,B]q:=AB−qBA for a real parameter q. In this paper, we investigate a generalization of the Böttcher-Wenzel inequality which gives the sharp upper bound of the (Frobenius) norm of the commutator. In our generalisation, we investigate sharp upper bounds on the q-deformed commutator. This generalization can be studied in two different scenarios: firstly bounds for general matrices, and secondly for traceless matrices. For both scenarios, partial answers and conjectures are given for positive and negative q. In particular, denoting the Frobenius norm by ||.||F, when A or B is normal, we prove the following inequality to be true and sharp: ||[A,B]q||F2≤(1+q2)||A||F2||B||F2 for positive q. Also, we conjecture that the same bound is true for positive q when A or B is traceless. For negative q, we conjecture other sharp upper bounds to be true for the generic scenarios and the scenario when A or B is traceless. All conjectures are supported with numerics and proved for n=2.

T violation in nonstandard neutrino oscillation scenarios

We discuss time reversal ($T$) violation in neutrino oscillations in generic new physics scenarios. A general parametrization is adopted to describe flavor evolution, which captures a wide range of new physics effects, including nonstandard neutrino interactions, nonunitarity, and sterile neutrinos in a model-independent way. In this framework, we discuss general properties of time reversal in the context of long-baseline neutrino experiments. Special attention is given to fundamental versus environmental $T$ violation in the presence of generic new physics. We point out that $T$ violation in the disappearance channel requires new physics, which modifies flavor mixing at neutrino production and detection. We use time-dependent perturbation theory to study the effect of nonconstant matter density along the neutrino path and quantify the effects for the well-studied baselines of the DUNE, T2HK, and T2HKK projects. The material presented here provides the phenomenological background for the model-independent test of $T$ violation proposed by us in [T. Schwetz and A. Segarra, Model-Independent Test of $T$ Violation in Neutrino Oscillations, Phys. Rev. Lett. 128, 091801 (2022).].

Modelling Automated Planning Problems for Teams of Mobile Manipulators in a Generic Industrial Scenario

Flexible control strategies are required in industrial scenarios to coordinate the actions of mobile manipulators (e.g., robots and humans). Temporal planning approaches can be used as such control strategies because they can generate those actions for the agents that must be executed to reach the goals, from any given state of the world. To deploy such approaches, planning models must be formulated. Although available in the literature, these models are not generic enough such that they can be easily transferred to new use cases. In this work, a generic industrial scenario is derived from real scenarios. For this scenario, a generic planning problem is developed. To demonstrate their generality, the two constructs are configured for a new scenario, where custom grippers are assembled. Lastly, a validation methodology is developed for the generic planning problem. The results show that the generic industrial scenario and the generic planning problem can be easily instantiated for new use cases, without any new modelling. Further, the proposed validation methodology guarantees that these planning problems are complete enough to be used in industrial use cases. The generic scenario, the planning problems, and the validation methodology are proposed as standards for use when deploying temporal planning in industrial scenarios with mobile manipulators.

Modelling Automated Planning Problems for Teams of Mobile Manipulators in a Generic Industrial Scenario

Modelling Automated Planning Problems for Teams of Mobile Manipulators in a Generic Industrial Scenario

Security and Privacy in Unified Communication

The use of unified communication; video conferencing, audio conferencing, and instant messaging has skyrocketed during the COVID-19 pandemic. However, security and privacy considerations have often been neglected. This article provides a comprehensive survey of security and privacy in Unified Communication (UC). We systematically analyze security and privacy threats and mitigations in a generic UC scenario. Based on this, we analyze security and privacy features of the major UC market leaders, and we draw conclusions on the overall UC landscape. While confidentiality in communication channels is generally well protected through encryption, other privacy properties are mostly lacking on UC platforms.

Higgs Boson-Induced Reheating and Dark Matter Production

We discuss a perturbative and non-instantaneous reheating model, adopting a generic post-inflationary scenario with an equation of state w. In particular, we explore the Higgs boson-induced reheating, assuming that it is achieved through a cubic inflaton-Higgs coupling ϕ|H|2. In the presence of such coupling, the Higgs doublet acquires a ϕ-dependent mass and a non-trivial vacuum–expectation–value that oscillates in time and breaks the Standard Model gauge symmetry. Furthermore, we demonstrate that the non-standard cosmologies and the inflaton-induced mass of the Higgs field modify the radiation production during the reheating period.This, in turn, affects the evolution of a thermal bath temperature, which has remarkable consequences for the ultraviolet freeze-in dark matter production.

Electromagnetic Models for Passive Detection and Localization of Multiple Bodies

The paper proposes a multi-body electromagnetic (EM) model for the quantitative evaluation of the influence of multiple human bodies in the surroundings of a radio link. Modeling of human-induced fading is the key element for the development of real-time Device-Free (or passive) Localization (DFL) and body occupancy tracking systems based on the processing of the Received Signal Strength (RSS) data recorded by radio-frequency devices. The proposed physical-statistical model, is able to relate the RSS measurements to the position, size, orientation, and random movements of people located in the link area. This novel EM model is thus instrumental for crowd sensing, occupancy estimation and people counting applications for indoor and outdoor scenarios. The paper presents the complete framework for the generic N-body scenario where the proposed EM model is based on the knife-edge approach that is generalized here for multiple targets. The EM-equivalent size of each target is then optimized to reproduce the body-induced alterations of the free space radio propagation. The predicted results are then compared against the full EM simulations obtained with a commercially available simulator. Finally, experiments are carried out to confirm the validity the proposed model using IEEE 802.15.4-compliant industrial radio devices.

Improved analysis and optimal priority assignment for communicating threads on uni-processor

This paper studies the system of communicating threads, which can be modeled as a set of task chains with each thread segment described as a task. Different from conventional approaches that assume the communication only happens at the end of thread executions, we assume a very generic scenario that the communication can happen at anytime during the execution. Under this scenario, the timing analysis and the priority assignment require carefully studying the possible execution dependencies among thread segments. We provide a more accurate timing analysis for the case that threads are communicating with message-based mechanisms. We prove that this analysis and the previously proposed one for synchronous communication are compliant with Audsley’s algorithm, which opens the possibility to use it to find an optimal priority assignment. We further propose two priority assignment algorithms that maximize the system’s robustness metrics. Finally, we evaluate our contributions in terms of both synthetic benchmarks and an industrial case study.

Maturity model for evaluating disaster and humanitarian operations

PurposeThis paper proposes a maturity model (MM) for assessing disaster operations and identifying strategies for organisations to evolve their maturity stages.Design/methodology/approachThis study applies a systematic literature review to identify state-of-the-art work related to maturity models for disaster operations. In addition, the study develops a case study to validate the proposed maturity model in a generic scenario and two real-life scenarios.FindingsThe analysis of 158 papers in the literature resulted in identifying 8 maturity models for disaster operations. Based on their structure, the authors proposed a new model with five maturity stages suitable for any of the four phases of the disaster life cycle (i.e. mitigation, preparedness, response and recovery). In addition, the research identified and presents 24 strategies for improving disaster operations according to each maturity stage transition. Finally, the research presents a case study that evaluates the disaster response operations from a Civil Defense organisation considering a response scenario disaster in general, a flood scenario, and the COVID-19 pandemic scenario.Originality/valueThis study provides the following three main contributions useful for academics and practitioners in the disaster operations area: a new maturity model for assessing disaster operations, a strategy guide for improving disaster operations based on a maturity evolution and an empirical study exploring the approximation between academia and professionals involved in real-life disaster operations management.

Learning Dual Memory Dictionaries for Blind Face Restoration.

Blind face restoration is a challenging task due to the unknown, unsynthesizable and complex degradation, yet is valuable in many practical applications. To improve the performance of blind face restoration, recent works mainly treat the two aspects, i.e., generic and specific restoration, separately. In particular, generic restoration attempts to restore the results through general facial structure prior, while on the one hand, cannot generalize to real-world degraded observations due to the limited capability of direct CNNs' mappings in learning blind restoration, and on the other hand, fails to exploit the identity-specific details. On the contrary, specific restoration aims to incorporate the identity features from the reference of the same identity, in which the requirement of proper reference severely limits the application scenarios. Generally, it is a challenging and intractable task to improve the photo-realistic performance of blind restoration and adaptively handle the generic and specific restoration scenarios with a single unified model. Instead of implicitly learning the mapping from a low-quality image to its high-quality counterpart, this paper suggests a DMDNet by explicitly memorizing the generic and specific features through dual dictionaries. First, the generic dictionary learns the general facial priors from high-quality images of any identity, while the specific dictionary stores the identity-belonging features for each person individually. Second, to handle the degraded input with or without specific reference, dictionary transform module is suggested to read the relevant details from the dual dictionaries which are subsequently fused into the input features. Finally, multi-scale dictionaries are leveraged to benefit the coarse-to-fine restoration. The whole framework including the generic and specific dictionaries is optimized in an end-to-end manner and can be flexibly plugged into different application scenarios. Moreover, a new high-quality dataset, termed CelebRef-HQ, is constructed to promote the exploration of specific face restoration in the high-resolution space. Experimental results demonstrate that the proposed DMDNet performs favorably against the state of the arts in both quantitative and qualitative evaluation, and generates more photo-realistic results on the real-world low-quality images. The codes, models and the CelebRef-HQ dataset will be publicly available at https://github.com/csxmli2016/DMDNet.

Simplified Model-Dependent and Model-Independent Approaches for Dissolution Profile Comparison for Oral Products: Regulatory Perspective for Generic Product Development.

Dissolution profile comparison among different formulations plays a critical role during new drug as well as generic product development. In the generic product development, dissolution profile comparison is a mandate for biowaivers (BCS-based, for lower strengths and IVIVC-based biowaivers) and also from quality control perspective. Even though traditionally similarity factor or f2 is used as a metric for dissolution profile comparison, it comes with multiple limitations and requirements (e.g., number of time points and variability). To overcome this, regulatory agencies suggested model-independent (e.g., MSD) and model-dependent (e.g., zero order, Weibull) dissolution profile comparison methods. Although most of regulatory guidance documents mention about such approaches, their usage in reality is limited probably due to lack of clear, detailed, and step-wise procedure. In this context, the present article describes simplistic yet detailed procedures of dissolution profile comparison with case studies covering generic product development scenario's from a regulatory perspective. Detailed review of regulatory guidances from various agencies was made along with examples of such approaches in regulatory submissions. Data from three formulations-Formulations A, B, and C-were utilized to perform dissolution profile comparison using MSD, zero-order, and Weibull release profile-based comparisons. Dissolution profile comparisons were made using all of these three approaches complying with regulatory requirements. These examples demonstrated value and utility of these approaches and the simplified and detailed procedure explained in this manuscript can be adapted for generic product applications.

C→uνν¯ transitions of Bc mesons: 331 model facing Standard Model null tests

The Glashow-Iliopoulos-Maiani mechanism is extremely efficient to suppress the flavour-changing neutral current decays of charmed hadrons induced by the $c \to u$ transitions, making such processes particularly sensitive to phenomena beyond the Standard Model. In particular, $c \to u$ decays with a neutrino pair in the final state are theoretically appealing due to the small long-distance contributions. Moreover, in the framework of the Standard Model Effective Field Theory (SMEFT), the $SU(2)_L$ invariance allows to relate the Wilson coefficients in the effective Hamiltonian governing the $c \to u \nu {\bar \nu}$ decays to the coefficients in the $c \to u \ell^+ \ell^-$ Hamiltonian. We analyze the $B_c \to B^{(*)+} \nu {\bar \nu}$ decays, for which branching fractions of at most ${\cal O}(10^{-16})$ are predicted in the Standard Model including short- and long-distance contributions, so small that they can be considered as null tests. Using SMEFT and the relation to the $c \to u \ell^+ \ell^-$ processes we study the largest enhancement achievable in generic new physics scenarios. Then we focus on a particular extension of the Standard Model, the 331 model. SMEFT relations and the connection with $c \to u \ell^+ \ell^-$ imply that ${\cal B}(B_c \to B^{(*)+} \nu {\bar \nu})$ could even reach ${\cal O}(10^{-6})$, an extremely large enhancement. A less pronounced effect is found in the 331 model, with ${\cal O}(10^{-11})$ predicted branching fractions. Within the 331 model correlations exist among the $B_c \to B^{(*)+}\nu \bar \nu$ and $K\to \pi \nu \bar \nu$, $B\to (X_s, K, K^*) \nu \bar \nu$ channels.

Two-color optically addressed spatial light modulator as a generic spatiotemporal system.

Nonlinear spatiotemporal systems are the basis for countless physical phenomena in such diverse fields as ecology, optics, electronics, and neuroscience. The canonical approach to unify models originating from different fields is the normal form description, which determines the generic dynamical aspects and different bifurcation scenarios. Realizing different types of dynamical systems via one experimental platform that enables continuous transition between normal forms through tuning accessible system parameters is, therefore, highly relevant. Here, we show that a transmissive, optically addressed spatial light modulator under coherent optical illumination and optical feedback coupling allows tuning between pitchfork, transcritical, and saddle-node bifurcations of steady states. We demonstrate this by analytically deriving the system's dynamical equations in correspondence to the normal forms of the associated bifurcations and confirm these results via extensive numerical simulations. Our model describes a nematic liquid crystal device using nano-dimensional dichalcogenide (a-As 2S 3) glassy thin films as photo sensors and alignment layers, and we use device parameters obtained from experimental characterization. Optical coupling, for example, using diffraction, holography, or integrated unitary maps allows implementing a variety of system topologies of technological relevance for neural networks and potentially Ising or XY-Hamiltonian models with ultralow energy consumption.

On the Role of Density‐Driven Dissolution of CO2 in Phreatic Karst Systems

AbstractDensity‐driven dissolution of carbon dioxide in water is a well‐known and much described mechanism in geological sequestration of this greenhouse gas. It is remarkable that such enhanced dissolution does not receive attention in karst hydrology and speleology. Models and hypotheses on karst development are complex and consider many different processes. We focus here on the influence of CO2 partial gas pressures at the interface between atmosphere and karst water on the dynamics of dissolved CO2 concentrations below the water table. Seasonal variations of microbial soil activity and root respiration or barometric‐pressure changes cause fluctuations in CO2 partial pressures. Dependent on the existence and strength of a karst‐water background flow, fingering regimes might be triggered causing enhanced dissolution of CO2. This allows replenishment of CO2, and, thus, dissolutional power even deep in the water body without the need for percolating water to transport dissolved CO2. We present and discuss simplified and generic experimental and computational scenarios to strengthen our claim, and we try to give answers to: how much? and under which circumstances? The applied numerical model solves the Navier‐Stokes equation with water density dependent on CO2 concentration and temperature. We show that calculated CO2 mass fluxes into the water bodies are dependent on the ratio of Péclet to Rayleigh numbers (Pe/Ra) and show a local minimum around Pe/Ra = 1, i.e. when natural and forced convection are about equal. Concluding, we claim that there is sufficient reason to consider density‐driven dissolution as a process of relevance in karstification if circumstances are given.

Cross-link relations between π and ρ -meson channels and the QCD vacuum

We discuss cross-link relations between the $\ensuremath{\pi}$ and $\ensuremath{\rho}$-meson channels emerging from two different descriptions of the QCD vacuum: instanton physics and QCD sum rules with nonlocal condensates (NLCs). We derive in both schemes an intriguing linear relation between the $\ensuremath{\pi}$ and the ${\ensuremath{\rho}}^{\ensuremath{\parallel}}$-meson distribution amplitudes in terms of their conformal coefficients and work out the specific impact of the scalar NLC in these two channels. Using a simple model with Gaussian decay of the scalar NLC, we are able to relate it to the moments of the pion nonsinglet parton distribution function measurable in experiment---a highly nontrivial result. The implications for the pion and the ${\ensuremath{\rho}}^{\ensuremath{\parallel}}$-meson distribution amplitudes entailed by the obtained cross-link relations are outlined in terms of two generic scenarios.

Lepton-flavour non-universality of {bar{B}}rightarrow D^*ell {{bar{nu }}} angular distributions in and beyond the Standard Model

We analyze in detail the angular distributions in {bar{B}}rightarrow D^*ell {{bar{nu }}} decays, with a focus on lepton-flavour non-universality. We investigate the minimal number of angular observables that fully describes current and upcoming datasets, and explore their sensitivity to physics beyond the Standard Model (BSM) in the most general weak effective theory. We apply our findings to the current datasets, extract the non-redundant set of angular observables from the data, and compare to precise SM predictions that include lepton-flavour universality violating mass effects. Our analysis shows that the number of independent angular observables that can be inferred from current experimental data is limited to only four. These are insufficient to extract the full set of relevant BSM parameters. We uncover a sim 4sigma tension between data and predictions that is hidden in the redundant presentation of the Belle 2018 data on {bar{B}}rightarrow D^*ell {{bar{nu }}} decays. This tension specifically involves observables that probe e-mu lepton-flavour universality. However, we find inconsistencies in these data, which renders results based on it suspicious. Nevertheless, we discuss which generic BSM scenarios could explain the tension, in the case that the inconsistencies do not affect the data materially. Our findings highlight that e-mu non-universality in the SM, introduced by the finite muon mass, is already significant in a subset of angular observables with respect to the experimental precision.