Nonintegrable Systems Research Articles

Prior authorization for diabetes medications: Clinical outcomes and health disparities

BackgroundPrior authorization (PA) is a utilization management strategy used by health plans to ensure affordable, cost-effective care; however, PA may lead to therapy delay/abandonment and exacerbate health disparities. The purpose of this observational study was to assess the clinical outcomes and any health disparities associated with PA for diabetes mellitus (DM) medications. Materials and methodsThis was a cohort study of US adult patients from health plans with integrated and non-integrated system providers who were prescribed a DM medication that required a PA. Patients were categorized into three groups: received the requested DM medication (PA Med) or a new, alternative DM medication (DM Med), or did not receive the requested or new DM medication (No Med). The primary outcome was change in hemoglobin A1c (HbA1c). Adjusted and unadjusted analyses were performed. Patient characteristics associated with the No Med group were identified, also, with multivariable logistic regression modeling. Results6305 patients were included: 2434, 1323, and 2548 in the PA Med, DM Med, and No Med groups, respectively. Patients in the PA Med (−0.9 %) and DM Med (−1.0 %) groups had statistically significantly greater reductions in HbA1c compared to the No Med group (−0.4 %) in both unadjusted and adjusted analyses (all p < 0.05). Patients who were Hispanic/Latino, had a non-integrated system prescriber, and had a higher burden of chronic disease were statistically significantly associated with the No Med group. ConclusionsReceiving a new DM medication following PA was associated with better clinical outcomes but health disparities were present in the PA process.

Nonlinear interaction of head-on solitary waves in integrable and nonintegrable systems

This study numerically investigates the nonlinear interaction of head-on solitary waves in a granular chain (a nonintegrable system) and compares the simulation results with the theoretical results in fluid (an integrable system). Three stages (the pre-in-phase traveling stage, the central-collision stage, and the post-in-phase traveling stage) are identified to describe the nonlinear interaction processes in the granular chain. The nonlinear scattering effect occurs in the central-collision stage, which decreases the amplitude of the incident solitary waves. Compared with the leading-time phase in the incident and separation collision processes, the lagging-time phase in the separation collision process is smaller. This asymmetrical nonlinear collision results in an occurrence of leading phase shifts of time and space in the post-in-phase traveling stage. We next find that the solitary wave amplitude does not influence the immediate space-phase shift in the granular chain. The space-phase shift of the post-in-phase traveling stage is only determined by the measurement position rather than the wave amplitude. The results are reversed in the fluid. An increase in solitary wave amplitude leads to decreased attachment, detachment, and residence times for granular chains and fluid. For the immediate time-phase shift, leading and lagging phenomena appear in the granular chain and the fluid, respectively. These results offer new knowledge for designing mechanical metamaterials and energy-mitigating systems.

Integration of carbon dioxide sensor with GNSS receiver for dynamic air quality monitoring applications

Air pollution is a significant problem in big cities due to the rapid increase of anthropogenic activities and severe traffic congestion. Therefore, real-time and micro tools for air monitoring are urgently necessary for fast and better policy decision-making. The current city air monitoring tool is typically static and serves a macro area. This study introduces technology development to integrate the air quality sensor with the satellite-based navigation receiver. This study used a carbon dioxide (CO2) MH-Z19C sensor and real-time kinematic global navigation satellite system (RTK GNSS) U-Blox F9P with GNSS Trimble NetR9 receiver. The field air quality monitoring (CO2 observed in ppm) and the movement velocity (vehicle speed observed in km/h) were recorded on two main roads of Jakarta by using a survey vehicle. The study compares the observation results of the non-integrated system (NIS) and integrated technology system (IS). The two systems generated the CSV database (CO2 and vehicle speed); however, IS generated the automatic synchronized and error-free data output. The statistical regression analysis of CSV data (CO2 and vehicle speed) between the NIS and IS reported significant results, which means both are reliable. Still, the NIS did not require manual synchronization, with some possibility of error. The R square values show a significant gap (speed 0.99 over CO2 0.144), indicating that IS needs further development as the CO2 data varies due to technicality. The finding presents that integrating the CO2 sensor and GNSS receiver generates a more effective time synchronization process and a reliable error removal technique in developing the CSV data. This finding is a significant reference in developing the integrated satellite-based receiver system with external environmental sensors.

Generation and modulation of shock waves in two-dimensional polariton condensates

Due to the ability of exciton-polariton condensates formed in semiconductor microcavities to be achieved at room temperature and their characteristics such as non-equilibrium and strong interactions, they have become an ideal platform for studying the nonlinear properties of non-equilibrium quantum systems. In 2013, the research group led by L. Dominici observed two-dimensional symmetric shock waves in the polariton condensate driven by coherent pump. However, owing to the characteristics of this system, theoretical researches have lagged behind. In one-dimensional polariton condensates, disregarding cross-interaction of the system, a type of asymmetric shock wave was respectively discovered by A. M. Kamchatnov in 2012 and A. M. Belounis in 2017. In 2023, utilizing the adiabatic approximation, our research team not only uncovered sparse wave, symmetric, and asymmetric shock waves in the system, but also revealed that the symmetric shock waves are triggered by cross-interaction. At present, there is no theoretical research on shock waves in two-dimensional polariton condensate. In this paper, spectral methods and fourth-order Runge-Kutta methods are used to explore the generation and control of shock waves in two-dimensional polariton condensates. It is found that when the cross-interaction between the condensate and the polariton thermal reservoir is quenched at high condensation rates, the initially prepared bright solitons can be modulated into two types of rotationally symmetric shock waves with different velocities, while the initial dark-like solitons can only transform into a single velocity rotationally symmetric shock wave. If quenching the external potential, the dark-like solitons can be transformed into anisotropic supersonic shock waves, and the dependence of shock wave on the width of the external potential is also shown. When the external potential and incoherent pumping are controlled at low condensation rates, multiple anisotropic shock waves can be excited in a uniform condensate, and their amplitudes can be used to control the wave number and amplitude of the shock waves and the range of widths for the external potential or incoherent pumping to excite shock waves is also demonstrated. The proposed methods in this paper not only provide theoretical guidance for the generation and control of shock waves in exciton-polariton condensates, but also find symmetric shock waves similar to experiments (&lt;ext-link ext-link-type="uri" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.nature.com/articles/ncomms9993"&gt;&lt;i&gt;Nat. Commun.&lt;/i&gt; &lt;b&gt;6&lt;/b&gt; , 8993&lt;/ext-link&gt;) without adopting any approximation, and open up a universal pathway for exciting shock waves in non-equilibrium or non-integrable systems, which may become a paradigm for transforming solitons into shock waves and significantly propel the rapid development of shock wave theory in different domains.

Critical Risk Factors of Stakeholder Collaboration Impacting BIM Implementation in High‐Rise Residential Building Projects Under the DBB System: A Delphi Survey

Although the design‐bid‐build (DBB) system has poor stakeholder collaboration due to the separation between architects, engineers, and contractors in its linear process, resulting in longer schedules and cost overruns, DBB remains the most widely used project delivery system due to its benefits, such as higher competition and the owner’s absolute control over the project. Researchers and practitioners expect building information modeling (BIM) implementation to improve stakeholder collaboration due to its potential to bridge the collaboration gap between these stakeholders, ensuring better coordination and motivating cost reduction. However, the fragmented nature of DBB still poses significant challenges to effective stakeholder collaboration, impacting BIM implementation negatively. Therefore, the objective of this study is to identify and rank critical risk factors (CRFs) related to stakeholder collaboration impacting BIM implementation in the context of high‐rise residential building projects delivered by DBB. By adopting a Delphi procedure, this study identified such CRFs by triangulating the knowledge from the literature and the experience of an expert panel recruited from the construction industry. Seven CRFs were selected and ranked through three rounds of a Delphi survey. Analysis revealed that the rankings remained unchanged despite the increasing degree of consensus among experts. The highest‐ranking negative CRFs were “Inappropriate mindset of BIM collaboration process,” “Awareness of additional roles and responsibilities,” and “Disconnection in the information flow and BIM process.” A matrix of nine recommended solutions that can be applied across different CRFs was collected from the expert panel to improve the productivity of BIM collaboration under DBB. This study provides an in‐depth understanding of the CRFs of BIM‐based collaboration between stakeholders under a nonintegrated delivery system like DBB. The findings of this study can ensure successful project completion by creating awareness and allowing professionals and researchers to develop practical strategies for delivering BIM‐based DBB projects.

A dynamical system approach to relaxation in glass-forming liquids.

The "classical" thermodynamic and statistical mechanical theories of Gibbs and Boltzmann are both predicated on axiomatic assumptions whose applicability is hard to ascertain. Theoretical objections and an increasing number of observed deviations from these theories have led to sustained efforts to develop an improved mathematical and physical foundation for them, and the search for appropriate extensions that are generally applicable to condensed materials at low temperatures (T) and high material densities where the assumptions of these theories start to become particularly questionable. These theoretical efforts have largely focused on minimal models of condensed material systems, such as the Fermi-Ulam-Pasta-Tsingou model, and other simplified models of condensed materials that are amenable to numerical and analytic treatments and that can serve to illuminate essential features of relaxation processes in condensed materials under conditions approaching integrable dynamics where clear departures from classical thermodynamics and dynamics can be generally expected. These studies indicate an apparently general multi-step relaxation process, corresponding to an initial "fast" relaxation process (termed the fast β-relaxation in the context of cooled liquids), followed by a longer "equipartition time", namely, the α-relaxation time τα in the context of cooled liquids. This relaxation timescale can be enormously longer than the fast β-relaxation time τβ so that τα is the primary parameter governing the rate at which the material comes into equilibrium, and thus is a natural focus of theoretical attention. Since the dynamics of these simplified dynamical systems, originally intended as simplified models of real crystalline materials exhibiting anharmonic interactions, greatly resemble the observed relaxation dynamics of both heated crystals and cooled liquids, we adapt this dynamical system approach to the practical matter of estimating relaxation times in both cooled liquids and crystals at elevated temperatures, which we identify as weakly non-integrable dynamical systems.

CONSTRUCTION AND PERFORMANCE EVALUATION OF AN INTEGRATED SOLAR COOKING AND DRYING SYSTEM

An integrated solar cooking and solar drying system was developed using locally available materials. The system performs both functions of cooking and drying simultaneously. Performance evaluation of the system was carried out using tomatoes for drying; while rice, beans and eggs were used to carryout cooking experiment. For the purpose of performance evaluation, total global radiation, ambient temperature, humidity, water temperature were monitored, taken and recorded. Results obtained from the system and that of the non-integrated systems were compared using excel as a statistical tool for analysis to ascertain the performance of the integrated system. The average temperatures recorded in the integrated system during drying were 45.3, 46.0 and 45.9, while that of the non-integrated system were 40.2, 39.9 and 39.7. The average temperatures recorded during cooking of egg, beans and rice using the integrated system were 83.1, 83.4 and 78.2, while that of the non-integrated system were 68.8, 86.3 and 65.0. This indicates higher heat generation and faster drying and cooking rates in the integrated system than the non-integrated system. The system has a total cost estimate of N30,600 with an added advantage of cooking and drying simultaneously. It is portable and can help in improving the ambient air quality. Furthermore, the integrated system will occupy less space and gives higher efficiency compared to the conventional single use systems.

Unusual ergodic and chaotic properties of trapped hard rods.

We investigate ergodicity, chaos, and thermalization for a one-dimensional classical gas of hard rods confined to an external quadratic or quartic trap, which breaks microscopic integrability. To quantify the strength of chaos in this system, we compute its maximal Lyapunov exponent numerically. The approach to thermal equilibrium is studied by considering the time evolution of particle position and velocity distributions and comparing the late-time profiles with the Gibbs state. Remarkably, we find that quadratically trapped hard rods are highly nonergodic and do not resemble a Gibbs state even at extremely long times, despite compelling evidence of chaos for four or more rods. On the other hand, our numerical results reveal that hard rods in a quartic trap exhibit both chaos and thermalization, and equilibrate to a Gibbs state as expected for a nonintegrable many-body system.

Soliton molecules in Fermi–Pasta–Ulam–Tsingou lattice: Gardner equation approach

We revisit the Fermi–Pasta–Ulam–Tsingou lattice (FPUT) with quadratic and cubic nonlinear interactions in the continuous limit by deducing the Gardner equation. Through the Hirota bilinear method, the fundamental as well as multi-soliton, particularly two-, three- and four-soliton, solutions are obtained for the Gardner equation. Based on these multi-soliton solutions, we show the excitation of an interesting class of table-top soliton molecules in the FPUT lattice through the velocity resonance mechanism. Depending on the condition on the free parameters, which determine the bond length between the soliton atoms, we classify them as dissociated and synthetic type molecules. The main feature of the table-top soliton molecules is that they do not exhibit oscillations in the coalescence region. This property ensures that they are distinct from the soliton molecules, having retrieval force, of the nonlinear Schrödinger family of systems. Further, to study the stability of the soliton molecule we allow it to interact with a single (or multi) soliton(s). The asymptotic analysis shows that their structures remain constant, though the bond length varies, throughout the collision process. Then, from the relative separation distance calculation we also observe that the bond length of each of the soliton molecules is not maintained during soliton molecule–molecule interaction while their structures are preserved. In addition, we consider the FPUT lattice with quadratic nonlinear interaction and FPUT lattice with cubic nonlinearity as sub-cases and point out the nature of the soliton molecules for these cases also systematically. We achieve this based on the interconnections between the solutions of the Gardner, modified Korteweg–de Vries and Korteweg–de Vries equations. Finally, in order to validate the existence of all the soliton structures, especially reported for the Gardner equation in the continuous limit, we simulate the corresponding FPUT chain and verified these various structures numerically and analytically as well. We believe that the present study can be extended to other integrable and non-integrable systems with applications in fluid dynamics, Bose–Einstein condensates, nonlinear optics, and plasma physics.

On Krylov complexity in open systems: an approach via bi-Lanczos algorithm

Continuing the previous initiatives [1, 2], we pursue the exploration of operator growth and Krylov complexity in dissipative open quantum systems. In this paper, we resort to the bi-Lanczos algorithm generating two bi-orthogonal Krylov spaces, which individually generate non-orthogonal subspaces. Unlike the previously studied Arnoldi iteration, this algorithm renders the Lindbladian into a purely tridiagonal form, thus opening up a possibility to study a wide class of dissipative integrable and non-integrable systems by computing Krylov complexity at late times. Our study relies on two specific systems, the dissipative transverse-field Ising model (TFIM) and the dissipative interacting XXZ chain. We find that, for the weak coupling, initial Lanczos coefficients can efficiently distinguish integrable and chaotic evolution before the dissipative effect sets in, which results in more fluctuations in higher Lanczos coefficients. This results in the equal saturation of late-time complexity for both integrable and chaotic cases, making the notion of late-time chaos dubious.

Overview: Regularization and Numerical methods in Celestial Mechanics and Dynamical Astronomy

"The relevant study of the n-body problem (predicting individual motions of a group of celestial objects interacting with each other gravitational) is substantial in space dynamics. Further, the various perturbations effects, the collisions or the close encounters between celestial bodies are trajectory modifiers. In the digital age, the behaviour of non-integrable systems is usually and primarily studied with restricted models or coupled with the help of numerical integrators. Over time, these numerical integrators progressed, and the numerical challenge led to the introduction of many new techniques. The question is, which numerical algorithm to choose for the correct research? Is what we get through numerical integration close to the proper orbit? In other words, how can one be sure that the obtained trajectories reflect reality and that their prediction can be taken into account for a long time? This paper presents some analytical and numerical methods with highly accurate computations, such as regularization methods and symplectic integrators, which can be useful in obtaining the corresponding more accurate results."

Ergodicity of complex dynamics and quantum tunneling in nonintegrable systems.

The instanton approximation is a widely used approach to construct the semiclassical theory of tunneling. The instanton path bridges the regions that are not connected by classical dynamics, but the connection can be achieved only if the two regions have the same energy. This is a major obstacle when applying the instanton method to nonintegrable systems. Here we show that the ergodicity of complex orbits in the Julia set ensures the connection between arbitrary regions and thus provides an alternative to the instanton path in the nonintegrable system. This fact is verified using the ultra-near integrable system in which none of the visible structures inherent in nonintegrability exist in the classical phase space, yet nonmonotonic tunneling tails emerge in the corresponding wave functions. The simplicity of the complex phase space allows us to explore the origin of the nontrivial tunneling tails in terms of semiclassical analysis in the time domain. In particular, it is shown that not only the imaginary part but also the real part of the classical action plays a role in creating the characteristic step structure of the tunneling tail that appears as a result of the quantum resonance.

Global and local stability for ghosts coupled to positive energy degrees of freedom

Negative kinetic energies correspond to ghost degrees of freedom, which are potentially of relevance for cosmology, quantum gravity, and high energy physics. We present a novel wide class of stable mechanical systems where a positive energy degree of freedom interacts with a ghost. These theories have Hamiltonians unbounded from above and from below, are integrable, and contain free functions. We show analytically that their classical motion is bounded for all initial data. Moreover, we derive conditions allowing for Lyapunov stable equilibrium points. A subclass of these stable systems has simple polynomial potentials with stable equilibrium points entirely due to interactions with the ghost. All these findings are fully supported by numerical computations which we also use to gather evidence for stability in various nonintegrable systems.

Investigation of Integrated and Non-Integrated Thermoelectric Systems for Buildings—A Review

Countless years have been spent researching the strategies necessary for improving the energy consumption of buildings globally. There have been numerous attempts at achieving both passive solutions and enhancing and optimising the existing active systems. This paper seeks to review, analyse and summarise the possibilities of using thermoelectricity in two different contexts to the integration with buildings, integrated thermoelectric systems, and non-integrated thermoelectric systems. The utilisation of thermoelectricity in cohorts with existing renewable technologies and the utilisation of thermoelectric systems that operate individually, both have the potential to provide the occupants of a building with conditions pertinent to thermal and visual comfort. The results in this paper are classified according to the integration types of thermoelectric systems within different parts of the fabric of a building while maintaining an active role in enhancing the building envelope and self-contained thermoelectric systems that sustain a passive role for the same. The introduction to this paper also gives a very broad and surface-level insight into categorisation of different kinds of thermoelectric systems that are being studied and researched across the world.

Generalized Thermalization in Quantum-Chaotic Quadratic Hamiltonians.

Thermalization (generalized thermalization) in nonintegrable (integrable) quantum systems requires two ingredients: equilibration and agreement with the predictions of the Gibbs (generalized Gibbs) ensemble. We prove that observables that exhibit eigenstate thermalization in single-particle sector equilibrate in many-body sectors of quantum-chaotic quadratic models. Remarkably, the same observables do not exhibit eigenstate thermalization in many-body sectors (we establish that there are exponentially many outliers). Hence, the generalized Gibbs ensemble is generally needed to describe their expectation values after equilibration, and it is characterized by Lagrange multipliers that are smooth functions of single-particle energies.

Rare rogue fluctuations could be generic to strongly nonlinear and non-integrable systems

We explore the possible existence of sufficiently large energy or rogue fluctuations (RFs) at late times in the strongly nonlinear regime of the classic β Fermi–Pasta–Ulam–Tsingou (FPUT) type systems. Our studies build on a study of RFs in the non-dissipative granular chain system and suggest that rare RFs could be generic to the time evolution of non-integrable strongly nonlinear systems at late enough times. Given the nonlinearity and the nonintegrability, analytical studies are largely inaccessible. The studies have hence been carried out using extensive dynamical simulations. We comment on the role of initial conditions and the surprising influence of harmonic forces on these strongly nonlinear systems. The RFs under focus here are distinct from the well known Peregrine solitons used to describe rogue waves via the weakly nonlinear Schrödinger equation.

Complex dynamics on the one-dimensional quantum droplets via time piecewise PINNs

The dynamics of one-dimensional quantum droplets and the emerging applications of deep learning in landing technology have become prominent research areas. In this work, we present a novel methodology, termed time piecewise physics-informed neural networks (PINNs), to study the intricate dynamics of one-dimensional quantum droplets by solving the amended Gross–Pitaevskii equation. Our network model exhibits superior training performance in the long time domain compared to conventional PINNs, with each of its subnetwork operating independently and offering high adjustability. By employing time piecewise PINNs with scarce training points, we not only study intrinsic modulations of single droplet and collision between two droplets, but also excite the breather on droplet background. Intriguingly, we obtain an interference pattern from training result of collision between two droplets, which is a significant feature of the interplay of coherent matter waves. The numerical findings demonstrate that in a nonlinear non-integrable system, varying parameters can result in vastly different dynamic behaviors despite sharing the same initial conditions. Our results offer valuable insights and guidance for leveraging deep learning technology to facilitate intrinsic modulations of single droplet, droplets collision, and excitation of breather.

Pengembangan Sistem Informasi Laboratorium Untuk Meningkatkan Efisiensi dan Akurasi

The development of laboratory information systems has become a primary focus in efforts to enhance efficiency and accuracy in laboratory operations. This article discusses the need for system development and evaluates the existing systems, which may be inefficient or inaccurate. Through analysis, it is found that repetitive manual tasks, such as data entry, inventory tracking, and report generation, result in time wastage and increased human errors. Furthermore, fragmented and non-integrated systems in laboratories impede smooth information flow, reduce operational efficiency, and increase the risk of errors. Reporting is also limited and time-consuming. Based on this background, this journal aims to develop an efficient and accurate laboratory information system. The development methodology includes user requirement gathering, needs analysis, system design, development, and implementation. In the development process, tools and technologies such as RFID are employed to improve operational efficiency and data accuracy. Integration among system components is also enhanced to facilitate smoother information flow. The evaluation results demonstrate significant benefits of the laboratory information system development. Manual tasks can be reduced, operational efficiency is enhanced, and the risk of human errors is decreased. Tracking and monitoring become easier, while reporting becomes faster and more accurate. With the adoption of an integrated laboratory information system, laboratories can improve their efficiency and accuracy in operations. In conclusion, the development of a laboratory information system is a crucial step in enhancing efficiency and accuracy. Through appropriate approaches and the implementation of information technology, laboratories can reduce reliance on manual work, improve data accuracy, and facilitate smooth information flow. The implementation of an efficient laboratory information system will have a positive impact on productivity and service quality in laboratories.

Slow relaxation of out-of-time-ordered correlators in interacting integrable and nonintegrable spin- 12 XYZ chains

Out-of-time-ordered correlators (OTOCs) help characterize the scrambling of quantum information and are usually studied in the context of nonintegrable systems. In this work, we compare the relaxation dynamics of OTOCs in interacting integrable and nonintegrable spin-$\frac{1}{2}$ XYZ chains in regimes without a classical counterpart. In both kinds of chains, using the presence of symmetries such as $U(1)$ and supersymmetry, we consider regimes in which the OTOC operators overlap or not with the Hamiltonian. We show that the relaxation of the OTOCs is slow (fast) when there is (there is not) an overlap, independently of whether the chain is integrable or nonintegrable. When slow, we show that the OTOC dynamics follows closely that of the two-point correlators. We study the dynamics of OTOCs using numerical calculations, and gain analytical insights from the properties of the diagonal and of the off-diagonal matrix elements of the corresponding local operators in the energy eigenbasis.

Stable Kink-Kink and Metastable Kink-Antikink Solutions

We construct and study two kink theories. One contains a static 2-kink configuration with controllable binding energy. The other contains a locally stable non-topological solution, which we call a lavion. The new models are 1D analogs of non-integrable systems in higher dimensions such as the Skyrme model and realistic vortex systems. To help construct the theories, we derive a simple expression for the interaction energy between two kinks.