Discrete Domain Research Articles

Policy success and failure in Australia

AbstractThis paper introduces the seven articles in the symposium on policy success and failure together with a short introduction to the large literature on policy success and failure. The issue brings together an analysis of success and failure within seven discrete policy domains, including Indigenous policy; immigration; foreign policy; water; government roll‐outs; education; and foreign aid. Previous case studies have not looked as systematically at both success and failure within the same policy domain, and so the direct comparison in a most similar systems framework has not previously been adopted. Each paper sets its own criteria for what it considers success and failure, allowing for the forthcoming analyses to remain relevant to their specific context and parameters. However, despite their differences, the papers reflect on the importance of institutions, implementation processes—specifically their attentiveness to the on‐ground conditions and target groups—political dimensions, time, expectations, and memory. This suggests that while it may be difficult to compare across policy domains, our within‐policy domain comparison reveals that good governance, despite some failures, is not a lost art.Points for practitioners The criteria for success or failure of government policy is relative to time, perspective, ideology, and context. The criteria for success or failure of government policy might vary across policy domains; what is appropriate for some domains might not be for others. We can consider policy success and failure in terms of programme, outcome, or political agenda. Programmes can succeed in some aims and fail in others. Case studies are the appropriate means for examining success and failure, and capturing the narrative is important in how a policy is viewed.

A Thermo‐Mechanical Localizing Gradient Damage Model With Modified Mazars Strain

ABSTRACTThis work establishes a thermo‐mechanical coupling model for thermally induced cracks in quasi‐brittle materials within the framework of localizing gradient damage theory. The constitutive relation considering the thermal expansion effect, and the heat conduction equation integrating the volumetric strain and damage evolution, are formulated based on the Clausius–Duhem inequality to ensure thermodynamic consistency. In particular, to accommodate the tension‐compression strength asymmetry across different quasi‐brittle materials, a modified Mazars strain is proposed as the driving force for the micro equivalent strain, where the first invariant of strain tensor and an adjustable ratio of compressive strength to tensile strength () are introduced. The numerical implementation employs the generalized‐α method for time domain discretization and the staggered scheme for decoupling. Numerical simulations demonstrate a nice feasibility of the modified Mazars strain in capturing both tensile and mixed‐mode failures, and the proposed model proves capable of characterizing complex crack behaviors under thermal loading in both quasi‐static and dynamic scenarios. The quenching test simulations of ceramic plates highlight the bidirectional coupling effects on crack patterns. Unidirectional coupling models that ignore the influence of volumetric strain and damage evolution on the temperature field would underestimate the temperature gradient, resulting in larger crack spacing and fewer cracks. In the thermal shock tests of cylindrical specimens, the transition in crack patterns from spiral shear bands to an annular damage zone with increasing compression‐tension strength ratio () is precisely captured, demonstrating the generality of the proposed model for various quasi‐brittle materials with tension‐compression strength asymmetry.

A novel transgenic reporter of extracellular acidification in zebrafish elucidates skeletal muscle T-tubule pH regulation.

Disruption of extracellular pH and proton-sensing can profoundly impact cellular and protein functions, leading to developmental defects. To visualize changes in extracellular pH in the developing embryo, we generated a zebrafish transgenic line that ubiquitously expresses the ratiometric pH-sensitive fluorescent protein pHluorin2, tethered to the extracellular face of the plasma membrane using a glycosylphosphatidylinositol (GPI) anchor. Monitoring of pHluorin2 with ratiometric fluorescence revealed dynamic and discrete domains of extracellular acidification over the first 72 h of embryonic development. These included acidification of the notochord intercalations, transient acidification of the otic placode, and persistent acidification of the extracellular space of the myotome at distinctly different pH from that within the T-tubules. Knockdown of centronuclear myopathy genes Bin1b (OMIM: 255200) and MTM1 (OMIM: 310400), which disrupt T-tubule formation, also disrupted myotome acidification. In this study we visualize extracellular acidic microdomains in the tissues of whole live animals. This real-time reporter line for directly measuring changes in extracellular pH can be used to illuminate the role of extracellular pH in normal physiological development and disease states.

Irritability as a Transdiagnostic Construct Across Childhood and Adolescence: A Systematic Review and Meta-analysis.

This meta-analytic review examined irritability across childhood and adolescence as it relates to symptoms of common mental health disorders in these periods. Of key interest was whether the relationship between irritability and symptom severity varies according to symptom domain. This was tested at the level ofbroad symptom dimensions (internalizing versus externalizing problems) as well as discrete diagnostic domains (e.g., anxiety, depression, oppositional defiant disorder, conduct disorder, attention deficit hyperactivity disorder; autism spectrum disorder). Following PRISMA guidelines, a systematic search of five databases was conducted to identify studies reporting on associations between irritability and mental health symptoms in samples of children aged 2-18years. Meta-analytic tests based on random effects models examined concurrent and longitudinal associations between irritability and symptom severity. Meta-regression tested potential moderators including symptom domain, child age, sex, informant type, and study quality. 119 studies met inclusion criteria with a total of 122,456 participants. A significant and positive association was found between irritability and severity of concurrent overall psychopathology in the order of a moderate effect size, while small to moderate effect sizes characterized the association between irritability and later mental health outcomes in prospective data. Further variation in this association was seen across specific diagnostic domains and methodological moderators. Findings support the conceptualization of irritability as a transdiagnostic construct reflecting emotion dysregulation across diverse forms of psychopathology in childhood and adolescence. Further research into the risk mechanisms underlying irritability is needed, in addition to translational approaches to early intervention.

Highly Robust Active Damping Approach for Grid-Connected Current Feedback Using Phase-Lead Compensation

The grid-current-feedback active damping (GCFAD) strategy has been widely utilized in LCL-type cascaded H-bridge static var generator (SVG) systems. Although digital control in GCFAD enhances sampling accuracy, it introduces delays in the subsequent calculation and execution processes, thereby reducing the effective damping region and weakening the robustness of the LCL-type cascaded H-bridge SVG system under a broad domain of grid impedance changes. This paper expands the effective damping area from (0, fR) (fR ∈ (fs/6, fs/3)) to (0, 0.45fs) by introducing a phase-lead compensator into the active damping feedback loop to reduce the delay. This reduces the negative effect of the digital control on the system’s effective damping region and significantly enhances its robustness under an extensive domain of grid impedance variations. The improved GCFAD is employed to establish the system’s discrete domain model and the controller parameters are adjusted in conjunction with the mentioned model. Simulation outcomes indicate the efficiency of the presented approach.

Evidence of High‐Pressure Metamorphism Along the Mahanadi Shear Zone in the Eastern Ghats Province, Eastern India: Implications on Tectonics and Continental Assembly Involving India and East Antarctica

ABSTRACTA suite of mafic granulite enclaves within mylonitised felsic gneiss occurring along the E‐W trending Mahanadi Shear Zone of the Eastern Ghats Province preserves evidence of high‐pressure metamorphism. Garnet‐clinopyroxene‐bearing mafic granulite contains a mineral assemblage of garnet + clinopyroxene + plagioclase + quartz + rutile which was formed after dehydration melting of a hornblende‐bearing protolith during M1 metamorphism that peaked at 1.1–1.4 GPa, 760°C–840°C. The retrograde stage (M1R) is marked by the formation of hornblende and symplectic intergrowth of clinopyroxene + plagioclase + orthopyroxene after garnet at 0.8–0.9 GPa, 760°C–810°C, suggesting an isothermal decompression type P–T path. The whole rock trace element and REE characteristics suggest a MORB‐OIB protolith for the mafic granulites. The host felsic gneiss has a granitic protolith which was emplaced in an arc setting. The rocks exposed south of the Mahanadi Shear Zone in the Phulbani domain are represented by granulites with contrasting metamorphic characteristics. The garnet‐orthopyroxene‐bearing mafic granulite within coarse‐grained charnockite and the aluminous granulite within felsic gneiss show evidence of biotite dehydration melting. The peak M1 assemblage in the aluminous granulite is represented by the assemblage spinel + garnet + quartz + plagioclase + K‐feldspar which was stable at 0.70–0.74 GPa, 904°C–935°C. M1R in this rock is characterised by coronas of garnet and sillimanite over spinel and the formation of matrix biotite at 707°C–806°C by near‐isobaric cooling. Similar isobaric cooling has been documented from the formation of garnet, clinopyroxene and quartz coronas on orthopyroxene in mafic granulite and garnet and quartz coronas on clinopyroxene, wollastonite and calcite in calc‐silicate granulite. The juxtaposition of lower crustal rocks showing clockwise and counterclockwise P–T paths across the Mahanadi Shear Zone implies a paired metamorphic character in a subduction–collision setting. Zircon U‐Pb and monazite U‐Th‐total Pb data show a complex history of the rock suite. The enclave suite of rocks within the Mahanadi Shear Zone underwent peak M1 metamorphism at ca. 980–960 Ma which was followed by decompression to a shallower level by ca. 960 Ma when the host granitic magma crystallised. Rocks occurring in the Phulbani domain (southernly placed crustal domain), on the other hand, underwent ultrahigh temperature metamorphism at shallower crustal levels broadly at the same time. We argue that the southern Phulbani domain of the Eastern Ghats Province, India, collided with the Angul‐Prydz domain of the Rayner Province, East Antarctica which eventually caused underthrusting of the former below the latter across the Mahanadi Shear Zone. In the context of the Eastern Ghats‐Rayner reconstruction, this indicates the closure of the intervening Mawson Sea. A second metamorphic event (M2) reworked the exhumed deep crustal rocks at ca. 900 Ma during the final docking of the Eastern Ghats‐Rayner belt against cratonic India. Our results clearly show that the Angul domain is an exotic block, and the Mahanadi Shear Zone is a terrane boundary shear zone suturing discrete domains of the Rayner‐Eastern Ghats orogen.

Gradient consistency strategy cooperative meta-feature learning for mixed domain generalized machine fault diagnosis

Recently, fault diagnosis methods based on domain generalization (DG) have been developed to improve the diagnostic performance of unseen target domains by multi-source domain knowledge transfer. However, existing methods assume that the source domains are discrete and that domain labels are known a priori, which is difficult to satisfy in complex and changing industrial systems. In addition, the gradient update conflict caused by the specific information of source domains leads to the degradation of the DG performance. Therefore, in this study, we relax the discrete domain assumption to the mixed domain setting and propose a novel gradient-consistency strategy cooperative meta-feature learning for mixed-domain generalized machine fault diagnosis. First, a domain feature-guided adaptive normalization module is proposed to normalize the underlying distribution of multi-source domains, and the mixed-source domains are divided into potential domain clusters. Then, a novel meta-feature encoding method is proposed to explicitly encode the overall fault feature structure, which is used to learn the generalized fault feature representation. Finally, a novel gradient consistency update strategy is designed to reduce the impact of domain-specific differences on model generalization. The effectiveness and superiority of the proposed method are verified on many DG diagnostic tasks on two public bearing datasets and the nuclear circulating water pump planetary gearbox dataset.

Uncovering the hidden architecture of the Rengali Province, eastern Indian shield using high-resolution aero-geophysics, ground-gravity, structure: Insights towards geology and tectonics

The Rengali Province is a shear zone bounded discrete domain of amalgamation among two Archean Cratons viz. the Singhbhum and Bastar cratons and a mobile belt namely Eastern Ghat Mobile belt. Based on geological evidences, it also displays an India-Antarctica connection in the past geological time-slice and supports supercontinental reconstruction. Although, the tectonothermal evolution of this province has been largely probed based on lithological, structural and metamorphic accounts, however, correlative geophysical-geology integration is absent. Hence, we analyze and interpret newly acquired high-resolution aero-geophysical data for the first time. The interpretations of high-resolution aero-geophysics, ground gravity and radiometric anomaly have been connected with geology to provide insights into tectonic evolution. Multi-scale geological-geophysical-structuralanalysis has been employed for understanding the subsurface architecture and contact relationship with the nearby cratons-mobile belt. Based on the aero-magnetic signature, three different zones have been delineated viz. northern, central and southern zones within the Rengali Province. The three zones are characterized by their distinct geophysical fabric and further are correlated with the geology. The gravity anomaly and modeling suggest the presence of a high-density body at mid-upper crustal depth (∼5–10 km). Three major shear zones, viz. the Barakot, Riamal and Kerajang delineate the bounding surfaces of the Rengali Province. However, the current geophysical signature indicate that the western part of the Kerajang Fault zone (KFZ) shares an inter-domain status between the Rengali Province and the Bastar Craton while the eastern part showcases an intra-domain character. Based on the complex series of magnetic fabric and anastomosing geophysical (particularly, magnetic) signature, the Rengali Province (RP) displays a classical signature of multiple accretionary histories supported by various episodic tectono-thermal activities at different time-slices.

Numerical solution and analysis of extended Fisher–Kolmogorov equation using an improved collocation algorithm

The paper investigated the approximate solution of the extended Fisher–Kolmogorov. For this, an advanced approach: the improved quintic B-spline collocation technique has been employed, which is an enhancement over the conventional B-spline collocation method. The B-spline interpolant of degree five has been refined through the posteriori corrections, leading to the development of the improved B-spline solution. This proposed technique demonstrates superior convergence compared to the standard B-spline method, as assessed both theoretically and numerically. In tackling the extended Fisher–Kolmogorov equation, the space discretization is conducted using the improved quintic B-spline collocation methodology (IQSCM), and for the temporal domain discretization, the Crank-Nicolson scheme is applied. The error bounds and convergence analysis is established using the Green's functions. Von-Neumann stability analysis is carried out to discuss the stability of the technique. A few examples are solved and are represented graphically which helps in determining the nature of the solution. Also, L 2 , L ∞ error norms, and order of convergence are calculated to demonstrate the contribution of the new improved technique over the standard spline collocation technique.

A Review of the Basic Principles and Methods of Signal Sampling Technology

In modern life, communication is an essential human activity. In the process of communication, various information spreads around the world in the form of signals. In order to optimize the communication, the reasonable processing of the signal becomes an important research problem. Signal processing is an important step during signal processing. It is one of two processes that convert an analog signal into a digital equivalent signal. It can be considered that signal sampling transforms the time axis of the signal into a set of discrete time moments, that is, the process of converting a signal in a continuous time domain to a discrete time domain through a series of methods. It is used to convert continuous time signals into digital signals for relevant processing and storage of digital signals in subsequent operations. This paper will summarize the basic principles and methods of signal sampling technology, introduce the sampling theorem, sampling frequency, sampling depth, sampling method and sampling error, and finally discuss the future development of signal adoption technology.

Numerical computation of cut off wave number in polygonal wave guide by eight node finite element mesh generation approach

This study proposes a two-dimensional, eight-noded automated mesh generator for precise and efficient finite element analysis (FEA) in microwave applications. The suggested method for solving the Helmholtz problem employs an optimal domain discretization procedure. MAPLE-13 software's advanced automatic mesh generator was developed specifically for this work. To demonstrate the effectiveness of the approach, three distinct waveguide structures are analyzed, with the results compared to the best available analytical or numerical solutions. The findings indicate that the proposed method yields highly accurate and efficient finite element results, particularly for waveguide structures containing singularities. In microwave applications, this method can significantly enhance energy transmission efficiency.

Free vibration and buckling characteristics of temperature dependent FGCNT reinforced plates in finite element framework of a non-polynomial axiomatic approach

In the present work, a generalized finite element formulation is established and implemented for the free vibration and buckling characteristics for temperature dependent carbon nanotube (CNT) reinforced plate. The uniform and functionally graded distribution of CNT is assumed in the plate and the plate is modeled in non-polynomial axiomatic framework. The extended rule of mixture is employed for computing the equivalent material parameters which are temperature dependent. Further, an eight-noded C0 continuous element with seven degree of freedom is adopted for discretization of the plate domain. The convergence and comparison studies are carried out to ensure the accuracy and effectiveness of the proposed formulation. As temperature conditions significantly influence structures integrity, on that account, thorough parametric studies are performed to examine the influence of volume fraction (VCNT ), span to thickness ratio ( a / h ), CNT distribution and boundary conditions on the FG-CNTR plate for the different temperature conditions. The results demonstrate that the efficient use of CNT distribution and boundary conditions can consequently improve free vibration and buckling characteristics of the temperature dependent FG-CNTR plates.

A Semi‐Analytical Method for Simulating Near‐Field Antiplane Wave Propagation in Layered Fluid‐Saturated Porous Media

ABSTRACTA semi‐analytical method for the near‐field antiplane wave propagation analysis in the layered fluid‐saturated porous media (FSPM) is proposed based on the Biot u–U dynamic formulation. The wave propagation equations of the FSPM are decoupled by the variable‐separating method. The thin‐layer element method (TLEM) is applied to discretize the infinite domain and construct the consistent artificial boundary condition. The finite element method (FEM) is adopted for the space discretization of the finite domain and the numerical solution of the dynamic response. The proposed method is validated by the comparison of the numerical results of this method with those in the published references and acquired from the remote artificial boundary. Subsequently, this method is applied to investigate typical near‐field antiplane wave propagation problems in the FSPM. Parametric sensitivity investigations are also executed to explore the impact of mechanical parameters, including permeability coefficients, porosity, and shear modulus of the solid phase, on the dynamic response of the FSPM. The study results confirm the efficacy and efficiency of the proposed method in the near‐field antiplane wave propagation analysis in the FSPM.

Anisotropic error analysis of weak Galerkin finite element method for singularly perturbed biharmonic problems

We consider the weak Galerkin finite element approximation of the singularly perturbed biharmonic elliptic problem on a unit square domain with clamped boundary conditions. Shishkin mesh is used for domain discretization as the solution exhibits boundary layers near the domain boundary. Error estimates in the equivalent H2− norm have been established and the uniform convergence of the proposed method has been proved. Numerical examples are presented corroborating our theoretical findings.

An analytic approach for nonlinear collisional fragmentation model arising in bubble column

The phenomenon of coagulation and breakage of particles plays a pivotal role in diverse fields. It aids in tracking the development of aerosols and granules in the pharmaceutical sector, coagulation or breakage of droplets in chemical engineering, understanding blood clotting mechanisms in biology, and facilitating cheese production through the action of enzymes within the dairy industry. A significant portion of research in this direction concentrates on coagulation or linear breakage processes. In the case of linear case, bubble particles break down due to inherent stresses or specific conditions of the breakage event. However, in many practical situations, particle division is primarily due to forces exerted during collisions between particles, necessitating an approach that accounts for nonlinear collisional breakage. Despite its critical role in a wide array of engineering and physical operations, the study of this nonlinear fragmentation phenomenon has not been extensively pursued. This article introduces an innovative semi-analytical method that leverages the beyond linear use of equation superposition function to address the nonlinear integro-partial differential model of collisional breakage population balance. This approach is versatile, allowing for the resolution of both linear/nonlinear equations while sidestepping the complexities associated with discretization of domain. To assess the precision of this method, we conduct a thorough convergence analysis. This process utilizes the principle of contractive mapping in the Banach space, a globally recognized strategy for verifying convergence. We explore a variety of kernel parameters associated with collisional kernels, alongside breakage and initial distribution functions, to derive novel iterative solutions. Comparing our findings with those obtained through the finite volume method regarding number density functions and their integral moments, we demonstrate the reliability and accuracy of our approach. The consistency and correctness of our method are further validated by depicting the errors between the exact and approximated solutions in graphical and tabular formats.

Long-range conformational changes in the nucleotide-bound states of the DEAD-box helicase Vasa

DEAD-box helicases use ATP to unwind short double-stranded RNA (dsRNA). The helicase core consists of two discrete domains, termed RecA_N and RecA_C. The nucleotide binding site is harbored in RecA_N, while both RecA_N and RecA_C are involved in RNA recognition and ATP hydrolysis. In the absence of nucleotides or RNA, RecA_N and RecA_C do not interact (“open” form of the enzyme). In the presence of both RNA and ATP the two domains come together (“closed” form), building the composite RNA binding site and stimulating ATP hydrolysis. Because of the different roles and thermodynamic properties of the ADP-bound and ATP-bound states in the catalytic cycle, the conformations of DEAD-box helicases in complex with ATP and ADP are assumed to be different. However, the available crystal structures do not recapitulate these supposed differences and show identical conformations of DEAD-box helicases independent of the identity of the bound nucleotide. Here, we use NMR to demonstrate that the conformations of the ATP- and ADP-bound forms of the DEAD-box helicase Vasa are indeed different, contrary to the results from x-ray crystallography. These differences do not relate to the populations of the open and closed forms, but are intrinsic to the RecA_N domain. NMR chemical shift analysis reveals the regions of RecA_N where the average conformations of Vasa-ADP and Vasa-ATP are most different and indicates that these differences may contribute to modulating the affinity of the two nucleotide-bound complexes for RNA substrates.

Tail Bounds on the Runtime of Categorical Compact Genetic Algorithm.

The majority of theoretical analyses of evolutionary algorithms in the discrete domain focus on binary optimization algorithms, even though black-box optimization on the categorical domain has a lot of practical applications. In this paper, we consider a probabilistic model-based algorithm using the family of categorical distributions as its underlying distribution and set the sample size as two. We term this specific algorithm the categorical compact genetic algorithm (ccGA). The ccGA can be considered as an extension of the compact genetic algorithm (cGA), which is an efficient binary optimization algorithm. We theoretically analyze the dependency of the number of possible categories K, the number of dimensions D, and the learning rate η on the runtime. We investigate the tail bound of the runtime on two typical linear functions on the categorical domain: categorical OneMax (COM) and KVAL. We derive that the runtimes on COM and KVAL are O(Dln(DK)/η) and Θ(DlnK/η) with high probability, respectively. Our analysis is a generalization for that of the cGA on the binary domain.

Контактная задача для трансверсально изотропного слоя с трением

It is investigated the spatial contact problem of asymmetric interaction of two punches on a transversally isotropic layer with friction forces taken into account in an unknown contact domain. The planes of isotropy are parallel to the layer faces. The friction forces are taken into account along one coordinate axis. The lower layer face is subjected to sliding support. The layer material is characterized by five independent elastic parameters. The problem is reduced to an integral equation with respect to the contact pressure with the help of a double Fourier transformation together with the Coulomb law. The anisotropy degree is characterized be three dimensionless parameters arising in the kernel of the integral equation, two of which satisfy characteristic equation. In particular cases, the integral equation coincides with those well-known for the corresponding contact problems with friction for the isotropic layer and half-space. The B.A. Galanov method is used for numerical solutions. A system of the integral equation and integral inequality is considered. A rectangle is taken which a priori contains the unknown contact domain. By introducing special nonlinear operators, the system is reduced to only one nonlinear equation of the Hammerstein type which can be solved by the successive approximations method. The contact domain is determined by nodes at which the function required is positive. The punches are taken in the form of asymmetric elliptic paraboloids. The method allows us to investigate percolation, i.e. the process of junction of the discrete contact domains due to increasing the forces applied and settlements of the punches. Calculations are made for different friction coefficients, materials and relative thicknesses of the transversally isotropic layer.

Effect of random variation in input parameter on cracked orthotropic plate using extended isogeometric analysis (XIGA) under thermomechanical loading

Abstract This research introduces the Stochastic Extended Isogeometric Analysis (XIGA) method to investigate fracture behavior of isotropic and orthotropic materials under mechanical, thermal, and thermomechanical loads. Employing knot spans from Isogeometric Analysis (IGA) for domain discretization, the study utilizes identical basis functions for geometry construction and solution discretization. Utilizing Extended Finite Element Method (XFEM) enrichment functions, accurate crack face displacement discontinuity and tip singularity within the stress field are characterized. Additionally, employing a second-order perturbation technique within XIGA framework, the research derives mean and coefficient of variance values for mixed-mode Stress Intensity Factors (SIF). Stochastic variations in material elastic properties, crack length, and crack angle are considered in this computation. Credibility and robustness of the study are confirmed through comparative analyses against available literatures and Monte Carlo Simulations (MCS). The observed exceptional agreement validates the precision and reliability of the proposed stochastic XIGA method for fracture analysis in orthotropic material systems under thermomechanical loading conditions.

Formability prediction of perforated sheet metal by representative volume element and homogenized sheet models

Perforated sheet metal (PSM) can be formed with plastic deformation. Modeling a perforated model in finite element analysis requires domain discretization with many small elements, which can lead to significant computation time and cost. This study introduces a novel approach using representative volume elements (RVE) and homogenized sheet (HS) models as an efficient alternative for PSM analysis. The forming limit of the PSM was established by analyzing localized necking in RVE. The HS model in simulations of the limit dome height and Swift cup tests results were in good agreement with those from the computational intensive perforated sheet models.