Desirable Mode Research Articles

Altering control modes of complex networks by reversing edges

Controlling complex networks are one of the ultimate goals in network science. Previous works have found there exist two distinct control modes when controlling the dense networks: distributed and centralized modes. How to change the control mode of a network is a challenging problem. This paper presents an efficient algorithm to alter a network from distributed mode to centralized mode by reversing the direction of a few edges. We first analyze four possible cases when reversing an edge and then design an efficient algorithm to change the control mode of a network. We prove that our algorithm does not affect the control scheme of the network after mode change. We evaluate the performance of our algorithm on both synthetic and real networks. The results show that the control mode of most networks can be easily changed by reversing very few edges. Furthermore, the number of the possible driver nodes of the network after mode change is dramatically decreased, which means these networks are easier to control. Our algorithm provides the ability to design the desired control mode of a network for different control scenarios, which may be used in many applications.

Family Planning in Liver Transplant: Patient and Provider Knowledge and Practices.

Fertility is often impaired in adolescents and women with cirrhosis, but it is rapidly restored after liver transplantation (LT). Early and unplanned pregnancies confer increased risks to maternal, fetal, and graft health, underscoring the need for reproductive counseling. However, data on reproductive practices or counseling in the LT setting are limited. An anonymous online Qualtrics (Provo, UT) survey was sent to transplant patients and providers to gauge knowledge and practices surrounding contraception and pregnancy. Eligible participants included transplant patients aged 14-45years and their transplant providers. Patient response was 50.0% (74/148), 14 of whom were pre-LT patients and 60 of whom were post-LT patients. Counseling occurred in 37% of patients prior to transplant and 82% after transplant. Most patients (86%) considered family planning a high priority in their transplant care. Contraception- and pregnancy-specific counseling was provided by LT providers in 60% and 44% of patients, respectively. The most desired mode of counseling by patients was in-person discussion with an LT provider (89%). Despite most post-LT patients receiving counseling, only 41% used contraception during the first year after LT, of whom 32% relied on high failure methods. Of the 31/43 (72.1%) provider responses, 96% voiced interest in additional reproductive education. Most providers (90%) correctly advised that patients delay pregnancy during the first year after LT, although misconceptions about safety of estrogen and intrauterine devices were selected by 53% and 42%, respectively. Some favored resources by providers were educational pamphlets in clinic (88%) and automated note templates to prompt family planning inquiry (72%). Transplant patients and providers have key deficiencies in their knowledge of contraception and corresponding practices. Most post-LT patients receive counseling, yet contraception practices are inadequate for preventing unplanned pregnancy. Discussion with transplant providers was the most favored counseling modality by patients, underscoring our critical role in optimizing post-LT reproductive care.

Electromagnetically tunable cholesterics with oblique helicoidal structure [Invited

Cholesteric liquid crystals form a right-angle helicoidal structure with the pitch in the submicrometer and micrometer range. Because of the periodic modulation of the refractive index, the structure is capable of Bragg and Raman-Nath diffraction and mirrorless lasing. An attractive feature of cholesterics for optical applications is that the pitch and thus the wavelength of diffraction respond to temperature or chemical composition changes. However, the most desired mode of pitch control, by electromagnetic fields, has so far been elusive. Synthesis of bent-shape flexible dimer molecules resulted in an experimental realization of a new cholesteric state with an oblique helicoidal structure, abbreviated as ChOH. The ChOH state forms when the material is acted upon by the electric or magnetic field and aligns its axis parallel to the field. The principal advantage of ChOH is that the field changes the pitch but preserves the single-harmonic heliconical structure. As a result, the material shows an extraordinarily broad range of electrically or magnetically tunable robust selective reflection of light, from ultraviolet to visible and infrared, and efficient tunable lasing. The ChOH structure also responds to molecular reorientation at bounding plates and optical torques. This brief review discusses the recently established features of ChOH electro-optics and problems to solve.

Bipolar electroactive conducting polymers for wireless cell stimulation

Conventional organic conducting polymers (CPs)-based electrical stimulation (ES) systems have been extensively explored in modulation of cell and tissue functions for biomedical applications. Bipolar electrochemistry could offer an effective pathway to modify these ES systems into a more desirable contactless mode. In this study, we present for the first time the development of a CP-based bipolar electrostimulation (BPES) system for living cells. Polypyrrole (PPy) films with different dopants have been utilised to demonstrate reversible and recoverable bipolar electrochemical activity under a low driving DC voltage (<5.5 V). A BPES prototype enabling wireless and programmable cell stimulation has been devised using PPy co-doped with dextran sulfate (DS) and collagen (PPy-DS/collagen) as a bipolar electrode and rat pheochromocytoma cells as a model cell line. Significantly, wireless stimulation enhances cell proliferation and differentiation. The work establishes a new paradigm for the electrostimulation of living cells using CPs as the bipolar electrodes, which provides an attractive wireless approach to advance the field of medical bionics.

Dual-Polarized 2-D Beam Mode Orthogonal Multiplexing Antenna System for the Nonfar Region

Here, we propose a dual linear polarized slot array antenna with monopulse corporate-feed waveguides for rectangular-coordinate orbital multiplexing transmission systems in the near-field region. In this article, we design and fabricate an eight-multiplexing $16\times16$ slot array antenna with uniform excitation in the 60 GHz band. We designed corporate-feed waveguides, the $2 \times 2$ slot subarray, and the 2-D monopulse circuits, and analyzed the $16\times16$ slot monopulse array combined in the radiating elements, the corporate-feed circuits, and the 2-D monopulse circuits. We fabricated two identical antennas by plate-laminated diffusion bonding techniques. The 6.8% bandwidth (59.8–64.0 GHz) of VSWR below 2.0, and the isolation of 22 dB or more between the two input ports are achieved. The transmitted power normalized by the input power between the two antennas was measured, and the average transmitted power between desired same modes is about −5 dB, with an average interference to the other seven modes of about −25 dB for a distance of 200 mm.

Design Considerations for Frequency Shifts in a Laterally Finite FBAR Sensor in Contact With the Newtonian Liquid.

Mode-coupled vibrations in a thickness-shear (TSh) mode and laterally finite film bulk acoustic resonator (FBAR) with one face in contact with Newtonian (linearly viscous and compressional) liquid are investigated. With boundary conditions and interface continuity conditions, exact dispersion curves in FBAR sensors contacting with two kinds of liquids are obtained, and they are compared with the dispersion curves in a bare sensor without liquid contact. Frequency spectra, describing mode couplings between the main TSh modal branch and undesirable modal branches, are calculated by employing weak boundary conditions at lateral free edges constructed based on the variational principle. Mode shapes of mechanical displacements in both the sensor and liquid layer are presented, and mode transformations are observed due to the liquid contact and lateral edge effect. The effect of liquid thickness on frequency spectra is also studied. Numerical results reveal that the generation of shear wave in the liquid layer results in the shifts of spectrum curves along the frequency axis and hence it is the main factor of frequency shifts of FBAR sensors. The compressional wave causes the shifts of spectrum curves along the lateral aspect ratio axis. Then for a given FBAR sensor, the liquid thickness changes could also cause frequency shifts. Therefore, desirable vibration modes should be chosen based on the frequency spectra to avoid strong mode couplings and to eliminate frequency shifts induced by the liquid thickness changes in real applications.

Analysing the Vibration of Bicycles on Various Road Surfaces in the City of Zilina

Over recent years, cycling has emerged as a particularly desirable mode of transport in Europe. Many local authorities, together with cycling lobbyist and advocating groups strive to get cycling to accepted perceived level of urban mobility. Some movements have already introduced the citizens’ science approach aimed at improving the local conditions for cyclists with crowd-sourced data collection. With this in mind, this paper presents an entry-level analysis of vibration from various surfaces which might affect the comfort of cyclists in the city of Zilina. The emphasis is focused on analysis of the road surface with a smartphone application and a so-called instrumental or probe bicycle. The results of testing are explained in the context of the problematic issues that occur in the infrastructure. The results are aimed at drawing attention to the fact that not all infrastructure is properly built, designed or maintained. There is a relationship between properly planned and built cycling infrastructure and the cycling traffic. An Android smartphone with the Phyphox application was used in the analysis as the example of citizens science.

Flexural Strengthening of RC Continuous T-Beams Using CFRP

In this paper, experimental investigations for strengthening reinforced concrete (RC) continuous beams were performed. Eighteen T-beams were cast, twelve of which were inverted T-beams where the flange portion of the T-beam was subjected to positive flexure to represent the support region of a continuous beam. Six of the T-beams were non-inverted where the web is subjected to positive flexure. Carbon fiber reinforced polymer (CFRP) sheets with different widths were considered, and different strengthening configurations with the same area of CFRP were investigated. The use of one-layer, multiple layers, or multiple strips of CFRP were evaluated to investigate the effect of these configurations on the ultimate capacity and ductility of the strengthened beams. From the experimental observation of the non-inverted beams, it was found that the ultimate load capacities of the CFRP-strengthened beams were enhanced by 4% to 90% compared to the control beam. Using multiple layers of CFRP sheets enhanced the stiffness of the beams by 4% to 46%, depending on the CFRP area and configurations. The debonding of CFRP before the ultimate failure provided additional ductility to the tested beams. For the strengthening of the inverted beams, it was found that the addition of CFRP strips did not increase the strength of the beams when the width of CFRP to beam width ratio was less than 0.25, but the ductility of the beam was enhanced slightly. The use of multiple strips was found to be a more effective way for the strengthening of the negative moment region than using multiple layers. This can also provide more desirable modes of failure than when applying CFRP in multiple layers. Ductility was found to be lower if multiple layers were used compared to other configurations. Moreover, it was observed that as the compressive strength of concrete increased the addition of the CFRP improved the beams ductility.

Compact dual‐band balanced SIW bandpass filter with two adjustable closed‐passbands

A new compact multilayer dual-band-balanced bandpass filter (BPF) with two flexibly adjustable closed-passbands based on substrate-integrated waveguide (SIW) resonator is proposed in this letter. Both TE102-mode and TE201-mode of the resonator are utilised to achieve desired differential mode (DM) transmission and high common mode suppression. Two SIW cavities are properly coupled in the back-to-back form to realise a closed dual-passband-balanced response by virtue of singly one cruciform coupling aperture etched on the ground. Additionally, two pairs of perturbed slotlines are elaborately introduced on the top and bottom layers to perturb the resonant frequencies of TE102-mode and TE201-mode, realising both adjustable upper- and lower-DM passbands. For demonstration, a prototype dual-band-balanced SIW BPF operating at 12.7 and 15.5 GHz is designed, fabricated and tested. Measured and simulated results are in good agreement, verifying the feasibility of the design concept.

Three-Dimensional Beamsteering Low-Complexity Reconfigurable Multilevel Antenna

A low-complexity reconfigurable antenna (RA) capable of steering its beam into nine different directions corresponding to 0 = {-42°, 0°, 42°} in the φ = {25°, 0°, 155°} planes, and 0 = ±25° in the φ = 90° plane, using a reduced number of switches is presented. The RA operating at 3.4-3.8 GHz consists of a central dipole element excited by a coaxial probe, surrounded by four switchable parasitic dipoles located at different height levels above a ground plane, which acts as either a reflector for the elements located at an upper layer or a director for the ones at a lower layer, improving the radiation characteristics of the antenna. Each parasitic dipole is fed with a p-i-n diode as a switch, which enables the activation of these elements providing the desired modes of operation. The presented RA was manufactured and measured showing results with a good agreement with the theoretical and numerical simulation.

Evaluation on Filter Performance of Variational Mode Decomposition and Its Application in Separating Closely Spaced Modes

The equivalent filter characteristics of variational mode decomposition (VMD) are fully evaluated when applied to the fractional Gaussian noise (fGn) and the application in separating closely spaced modes of vibration system is performed in this paper. VMD is a newly proposed signal decomposition technique, which nonrecursively decomposes a signal into a given number of subsignals (modes), and each mode is mostly compact around a center pulsation. The filter performance of VMD is largely dependent on the constraint parameter and the initialization of center frequencies. In order to extract the desired modes, criteria for the determination of decomposition parameters are established. The initial center frequencies could be simply determined by prior estimated modal frequencies of the analyzed signal, while the constraint parameter is optimized utilizing a genetic algorithm (GA). A two-degree-of-freedom parametric system is considered to evaluate the capability of VMD in the separation of closely spaced modes. Compared with the noise-assisted versions of empirical mode decomposition (EMD) and wavelet packet transform (WPT), the parameter-optimized VMD can successfully separate the closely spaced modes while recovering the most modal information simultaneously. When introduced to the ground vibration test (GVT) of a horizontal tail, the proposed method successfully extracted the first five oscillation modes and identified the modal parameters accurately.

Stable generation of orbital angular momentum mode with an all-fiber laser

In this letter, an all-fiber laser that can generate stable OAM modes with topological charges of ±1 is demonstrated. A ring-core fiber designed in-house is used to reduce the crosstalk between OAM mode and other modes. A ring-core fiber-based long-period fiber grating (LPFG) and a fiber Bragg grating (FBG) are employed to select desired OAM mode. The coupling ratio of LPFG from HE11 mode to OAM mode exceeds 16 dB, and the mode purity of OAM mode is as high as 94.41%. This simple and compact fiber laser can be integrated into fiber-based OAM mode multiplexing optical communication system.

Design concept of an electromagnetic undulator to produce arbitrarily polarized light

An undulator magnet design is described consisting of four electromagnet arrays to produce arbitrarily polarized photon beams including a linear inclined mode. Polarization changes are effected by a current switch rather than mechanical longitudinal translations. The capability of choosing a variety of current excitations in each double coil of the structure can produce any desired polarization mode. This concept exhibits an advantage over mechanical designs especially for superconducting design versions of this undulator. In this paper, we will discuss the magnet structure concept, the current distribution in each double coil and magnetic field features for various polarizing modes. In addition, the concept of current switching will be discussed, which allows to reduce the number of individual current sources from eight to one.

Orifice enabled flow stabilization of natural circulation loop at lower inclinations

Abstract Natural circulation loop (NCL) is mainly used as passive cooling system in nuclear power plants to ensure safety during pump failure and station blackout. Stable operation without flow instability is the most desirable operational mode of natural circulation loop for passive cooling. The present work deals with numerical analysis on the effect of inclination of horizontal leg of a rectangular loop working in single phase and presence of orifice on the thermohydraulic behaviour of NCL, using commercial CFD code ANSYS FLUENT 19.0. The effect of temporal variation of loop mass flow rate and temperature difference across the cooler section is compared for inclined loop with and without orifice. It is observed that the flow stability attained in the loop at inclination h = 308 can be achieved at h = 108 with orifice, with a reduction in the loop mass flow rate of 28.57%. The reduction in loop mass flow rate is accompanied by an increase in temperature difference across the cooler of 46.67%.

Robust adaptive backstepping sliding mode control for motion mode decoupling of two‐axle vehicles with active kinetic dynamic suspension systems

SummaryA mode decoupling control strategy is proposed for the active Kinetic Dynamic Suspension Systems (KDSS) with electrohydrostatic actuator (EHA) to improve the roll and warp mode performances. A matrix transfer method is employed to derive the modes of body and wheel station motions for full vehicle with active KDSS. The additional mode stiffness produced by the active KDSS is obtained and quantitatively described with the typical physical parameters. A new hierarchical feedback control strategy is proposed for the active KDSS to improve the roll and warp motion performances and simultaneously accounting for nonlinear dynamics of the actuators with hydraulic uncertainties. H∞ static output‐feedback control is employed to obtain the desirable mode forces, and a new projection‐based adaptive backstepping sliding mode tracking controller is designed for EHA to deal with address the nonlinearity and parameters uncertainty. This controller is used to realize the desirable pressure difference of EHA required from the target mode forces. Numerical simulations are presented to compare the roll and warp performances between the active KDSS, conventional spring‐damper suspension, and suspension with antiroll bar under typical excitation conditions. The evaluation indices are normalized and compared with radar chart. The obtained results illustrate that the proposed active KDSS with proposed controller does not produce additional warp motion for vehicle body, and has achieved more reasonable tire force distribution among wheel stations, the roll stability, road holding, and significantly improved ride comfort simultaneously.

Order reduction mechanism for large-scale continuous-time systems using substructure preservation with dominant mode

This work is about a balanced truncation type order reduction method which is developed for stable and unstable large-scale continuous-time systems. In this method, a quantitative measure criterion for choosing the dominant eigenvalues helps in determining the steady-state and transient information of the dynamical system. These dominant eigenvalues are used to form a new substructure matrix that retains the dominant modes (or may desirable mode) of the original system. Retaining the dominant eigenvalues in the reduced mode assures stability and results in greater accuracy as the retained eigenvalues provides a physical link to the real system. In the quest to preserve the dominant eigenvalue of the real system, the proposed technique uses Sylvester equation for system transformation. Having obtained transformed model, the reduced model has been achieved by truncating the non-dominant eigenvalues using the singular perturbation approximation method. The efficiency and accuracy of the proposed method has been demonstrated by the benchmark test systems which were from the state-of-the-art models.

The Influence of Feed Probes on the Modes of Circular Sector Microstrip Antennas: An investigation

In this article, the key influence of the feed-probe position for the excitation of desired modes in a circular sector microstrip antenna (CSMA) is thoroughly investigated via physical analysis comprising simulations and measurements. The approximate feed location used to excite a particular mode is also empirically determined to facilitate further exploration of CSMAs. Based on the proposed analysis and simulations, CSMAs with a wide range of sector angles are studied, and good agreements are revealed when compare with the measurements.

Understanding Better the Influential Factors of Commuters’ Multi-Day Travel Behavior: Evidence from Shanghai, China

Alleviating traffic congestion and developing sustainable transportation systems in a city can be assisted by promoting environmentally friendly transportation modes such as walking, cycling, and public transport. Strategies for promoting these desirable transportation modes can be identified based on a sound understanding of how commuters choose travel modes. In this study, multi-day commuting travel mode data was used to explore factors that influenced commute mode choice. A multinomial logit model and a binary logit model were proposed to study commuter travel behavior. The results showed the following. (1) Age, gender, and marriage indirectly influence the commute mode choice; (2) The cost of travel mode has little effect on commute mode choice; (3) The probability of commute mode change mainly influences the car mode choice; (4) The number of transfer times and the distance to the nearest public transport stations are main factors that restrict commuters from choosing public transport; (5) The number of bicycles in the family and commute distance are main factors that restrict commuters from choosing cycling for commuting. Based on these findings, several potential measures are demonstrated to policymakers and transportation planners to alleviate traffic congestion and develop sustainable transportation systems.

Quantum algorithm for simulating molecular vibrational excitations.

The excitation of vibrational modes in molecules affects the outcome of chemical reactions, for example by providing molecules with sufficient energy to overcome activation barriers. In this work, we introduce a quantum algorithm for simulating molecular vibrational excitations during vibronic transitions. We discuss how a special-purpose quantum computer can be programmed with molecular data to optimize a vibronic process such that desired modes get excited during the transition. We investigate the effect of such excitations on selective bond dissociation in pyrrole and butane during photochemical and mechanochemical vibronic transitions. The results are discussed with respect to experimental observations and classical simulations. We also introduce quantum-inspired classical algorithms for simulating molecular vibrational excitations in special cases where only a limited number of modes are of interest.

Designing Transformation-Induced Plasticity and Twinning-Induced Plasticity Cr-Co-Ni Medium Entropy Alloys: Theory and Experiment

In order to efficiently explore the nearly infinite composition space in multicomponent solid solution alloys, it is important to establish predictive design strategies and use computation-aided methods. In the present work, we demonstrated the density functional theory calculations informed design routes for realizing transformation-induced plasticity (TRIP) and twinning-induced plasticity (TWIP) in Cr-Co-Ni medium entropy alloys (MEAs). We systematically studied the effects of magnetism and chemical composition on the generalized stacking fault energy surface (γ-surface) and showed that both chemistry and the coupled magnetic state strongly affect the γ-surface, consequently, the primary deformation modes. Based on the calculated effective energy barriers for the competing deformation modes, we constructed composition and magnetism dependent deformation maps at both room and cryogenic temperatures. Accordingly, we proposed various design routes for achieving desired primary deformation modes in the ternary Cr-Co-Ni alloys. The deformation mechanisms predicted by our theoretical models are in nice agreement with available experimental observations in literature. Furthermore, we fabricated two non-equiatomic Cr-Co-Ni MEAs possessing the designed TWIP and TRIP effects, showing excellent combinations of tensile strength and ductility.