Multiple Boundaries Research Articles

Low Temperature Thermal Properties of Nanodiamond Ceramics

The temperature dependence of thermal conductivity and specific heat for detonated nanodiamond ceramics is investigated on specially designed experimental setups, implementing the uniaxial stationary heat flow method and the thermal relaxation method, respectively. Additionally, complementary studies with a commercial setup (Physical Property Measurement System from Quantum Design operating either in Thermal Transport or Heat Capacity Option) were performed. Two types of samples are under consideration. Both ceramics were sintered at high pressures (6–7 GPa) for 11–25 s but at different sintering temperatures, namely 1000 °C and 1600 °C. The effect of changing the sintering conditions on thermal transport is examined. In thermal conductivity κ(T), it provides an improvement up to a factor of 3 of heat flow at room temperature. The temperature dependence of κ(T) exhibits a typical polycrystalline character due to hindered thermal transport stemming from the microstructure of ceramic material but with values around 1–2 W/mK. At the lowest temperatures, the thermal conductivity is very low and increases only slightly faster than linear with temperature, proving the significant contribution of the scattering due to multiple grain boundaries. The specific heat data did not show a substantial difference between detonated nanodiamond ceramics obtained at different temperatures unlike for κ(T) results. For both samples, an unexpected upturn at the lowest temperatures is observed—most likely reminiscent of a low-T Schottky anomaly. A linear contribution to the specific heat is also present, with a value one order of magnitude higher than in canonical glasses. The determined Debye temperature is 482 (±6) K. The results are supported by phonon mean free path calculations.

Development of a Technique for the Spectral Description of Curves of Complex Shape for Problems of Object Classification

Vascular pathology symptoms can be determined by retinal image segmentation and classification. However, the retinal images from non-invasive diagnostics have a complex structure containing tree-like vascular beds, multiple segment boundaries, false segments, and various distortions. It should be noted that complex structure images’ segmentation does not always provide a single solution. Thus, the goal is to increase the efficiency of vascular diagnostics. This study aims to develop a technique for describing the geometric properties of complexly structured image segments used for classifying vascular pathologies based on retinal images. The advantages and disadvantages of the existing methods and algorithms of segmentation were considered. The most effective use areas of the mentioned methods and algorithms are revealed. Through detecting retinal thrombosis, the algorithm's efficiency for constructing a mathematical model of an arbitrary shape segment based on the morphological processing of binary and halftone images was justified. A modified variant of this algorithm based on the spectral analysis procedure of arbitrary shape boundary curves was used for the spectral description of complex shape curves for classifying vascular pathologies based on retinal images. Two approaches have been developed. The first one allows obtaining a closing segment of the curve from a symmetric mapping of the initial parametric curves. The second involves intelligent data processing and obtaining contours of minimum thickness, forming convex sets. The results of experiments confirm the possibility of practical use of the developed technique to solve problems of vascular pathology classification based on retinal images, showing the correct forecast probability was 0.93 with all associated risk factors. Doi: 10.28991/ESJ-2022-06-06-015 Full Text: PDF

Water-Linked Heritage as a Vector of Ecosystemic Change in Cities and Regions

Water and water-linked heritage play a very important role for many cities and regions. They are at the center of many places’ identities and key activities. Consider historic waterfronts and infrastructures such as bridges, port facilities, sluices, dams, water towers, mills and specific water-related landscapes, both in the city and in the countryside. Consider also intangible aspects of water-linked heritage, from traditional water management practices to values and local stories. These all have the potential to galvanize the interests of diverse stakeholders and provide a foundation for an ecosystemic approach to sustainable urban and regional development. This is not only because of positive values associated with water, but also because water-linked heritage valorization can effectively connect environmental, economic and social dimensions of sustainability. By working with water-linked heritage as a vector of the ecosystemic transformation of cities and regions, one can span multiple boundaries. First, doing so can attract a diverse set of stakeholders representing different disciplines and policy sectors, engaging them in place-making and the co-creation of transition strategies and tactical activities. Second, water allows for defining functional geographies and strategically linking diverse places connected by water bodies, cutting across administrative boundaries. By drawing upon five international case studies involved in the Interreg WaVE project, the authors have elaborated a typology to classify and compare different approaches to heritage valorization.

Enhanced ferroelectric, piezoelectric, and dielectric properties in potassium sodium niobate lead-free piezoelectric ceramics by constructing of multiple phase boundaries

In this work, we report excellent ferroelectric, piezoelectric, and dielectric properties in 0.95(K0.5−x/2Na0.5−x/2Lix)NbO3-0.04BaZrO3-0.01BiFeO3, ((KN)1−xLxN-BZ-BF) lead-free piezoelectric ceramics system by constructing a coexistence of orthorhombic-tetragonal phase boundary near the room temperature, and increasing of grain size as well through the conventional sintering process. The addition of Li+ ions, in ((KN)1−xLxN-BZ-BF) composition, increased the grain size, and shifted the orthorhombic-tetragonal phase transition to near room temperature, and shifted the tetragonal-cubic phase transition toward higher temperatures, since both large electrical properties, and moderate Curie temperature was achieved simultaneously. The sample with x = 0.03 showed large average grain size of (9 µm), and possess coexisting of orthorhombic-tetragonal phases, since the sample showed excellent physical properties, such as d33 = 330 pC/N, kp = 0.5, Pr = 25 µC/cm2, and εr = 1740. The origin of these decent combinations of physical properties owes to the coexistence of orthorhombic-tetragonal phase transition to near room temperature, large grain size, and hybridization between Bi 6p, and O 2p as well.

Making drug supply chain secure traceable and efficient: a Blockchain and smart contract based implementation.

The healthcare supply chain involves obtaining resources, managing supplies, and delivering goods and services to patients across multiple teams, stakeholders, and geographical boundaries. With such a complex structure, the healthcare supply chain is vulnerable to fraud, inaccurate data, and lack of transparency. These misdeeds cost businesses money and harm health. To address these issues, the health care supply chain needs an end-to-end decentralized track-and-trace system. Most centralized systems risk drug and data safety. This paper presents an Ethereum blockchain-based solution for a health care supply chain track-and-trace mechanism that uses smart contracts and data immutability. Hash functions store data in a public distributed ledger. This protects and discloses data. Smart contracts automate agreement execution so all parties know the outcome instantly, without an intermediary or time loss. It also outlined decentralized healthcare supply chain application architecture and algorithms. This paper proposes a system to address the lack of transparency and tracking in traditional supply chains. The blockchain-based method proposed in this paper runs on Solidity smart contracts. The system's algorithms and methods are tested against a variety of inputs, and the results are presented as an average gas cost for specific functionality. The proposed system tracks goods' histories (medicine). The average gas cost for all accounts is 18,027.2. Overall, log gas costs 48,118.6 to buy medicine, gas costs 229,607.5, and to log out 14,275.The results of the proposed system are compared to state-of-the-art methods. Thus, the presented work allows a seamless flow of medicines via blockchain and smart contracts without intermediaries. Finally, it addresses building a secure pharma supply chain application for blockchain 4.0.

PENGARUH MODAL USAHA, LOKASI USAHA DAN PENGGUNAAN ECOMMERCETERHADAP PENJUALAN UMKM BIDANG FASHION DI DENPASAR

This study aims to analyze the influence of business capital, business location, and E-commerce simultaneously and partially on the sales of MSMEs in the fashion sector in Denpasar City. Research sampling was carried out using the accidental proportional sampling method. Based on the calculation results, the number of samples used in this study totals a total of 100 samples that will be included in the business category that is in the selected regional cluster and the business category that is outside the cluster. The analysis techniques used are simultaneous multiple linear boundary tests and partial regression coefficient significance tests tested using the SPSS 25.0 program. The results showed that business capital, business location, and the use of E-commerce simultaneously had a positive effect on the sales of MSMEs in the fashion sector in Denpasar City. The results of this study also show that business capital, business location, and the use of E-commerce partially have a positive effect on the sales of MSMEs in the fashion sector in Denpasar City. Keywords: Venture capital; business location; E-commerce; sales; Fashion

Microscopic scales of linear tearing modes: a tutorial on boundary layer theory for magnetic reconnection

We revise in detail and in a pedagogical way the analysis of the boundary layer theory of warm tearing modes in slab, reduced magnetohydrodynamics (MHD), when magnetic reconnection is driven by electron inertia and/or resistivity, and ion-sound Larmor radius effects are included. By comparison with the numerical solution of the corresponding eigenvalue problem, we interpret these results by means of a heuristic approach, which in the warm-electron regime, we show to be in general not feasible without knowledge of the scaling of the gradient of the magnetic flux function, differently from what happens in the cold-electron regimes. We put in evidence for a non-trivial relation between the first derivative of the magnetic flux function and of the velocity parallel to the neutral line, evaluated in its proximity, by thus providing insight to the multiple boundary layer analysis that Pegoraro & Schep (Plasma Phys. Control. Fusion, vol. 28, 1986, p. 647) first showed to be required in warm-tearing regimes. In this way, we also suggest and justify a general operational definition of the reconnecting layer width and we discuss the linear appearance of microscopic scales related to the gradients of the eigenfunctions of the tearing modes.

Intracrystalline deformation microstructures in natural olivine with implications for stress estimation

Constraining the stress related to lithospheric deformation in natural rocks is key to develop and test a geodynamic model. However, the cautions of extrapolating piezometers that are established on experimental samples to natural rocks are less addressed. In this study, we investigated the microstructures of a natural harzburgite sample using the electron backscatter diffraction (EBSD) technique. Subgrain boundary (SGB) geometries suggest large percentages of (010)[100] and {0kl}[100] dislocation slip systems in olivines. More importantly, multiple low-angle misorientation boundaries (LAMBs) variants are recognized for the first time in olivine based on their distinctive characteristics with the change of EBSD mapping step size. The LAMBs that exist at a small step size (≤ 1 μm) are mostly equivalent to real SGBs, while other LAMBs that appear only when the step size is larger (> 1 μm) are artificial SGBs. Besides, the former develop mainly in the high LAMB density grains, whereas the latter are mostly found in the low LAMB density grains. This result reinforces the previous knowledge that the stress calculated using subgrain-related piezometers is meaningful only when real SGBs are captured at sufficiently small step size. Furthermore, we provide a proof of concept that SGB density and kernel average misorientation (KAM) are two viable metrics to estimate stress. These two alternative piezometers, which still need calibrations using the experimentally deformed samples, are anticipated to have wide applications in natural rocks.

A computationally efficient hydrologic modeling framework to simulate surface-subsurface hydrological processes at the hillslope scale

Considering surface and subsurface interactions is imperative to predict water movement, water quantity and quality in the environment. However, substantial execution time and over-parameterization presently limit the applicability of integrated hydrologic models at larger scales. Herein, a new efficient coupling routine for one-dimensional (1D) surface–subsurface modeling was developed by externally coupling two widely used open-source codes. KINEROS2 (K2) solves the 1D kinematic wave equation for overland flow, and HYDRUS-1D (H1D) solves the Richards equation for subsurface flow. A novel approach, combined with water balance and boundary condition switching, is used to account for surface ponding and water exchange between the two model domains. A weighting factor related to the surface water depth is used to assign the time series of exchange fluxes in one H1D profile to multiple surface nodes in the K2 calculation. This novel approach enables us to represent the entire subsurface below each overland-flow plane by one vertical soil column with different soil layering. When soil properties vary horizontally, multiple soil columns can represent spatial heterogeneities. The performance of the coupled H1D-K2 model is examined by comparing simulation results with the HYDRUS-2D (H2D) model for six benchmark problems. The solution's robustness, stability, and accuracy are assessed for a wide variety of cases, including multiple rainstorms, different slopes, heterogeneous subsurface, and different bottom boundary conditions resulting in 41 cases. The simulated hydrographs, surface water levels, and water balance components are all in good agreement. Relative mass balance errors are very small, typically not exceeding 4.0% for the coupled H1D-K2 model. Compared with the H2D model, the coupled model achieves a factor of 1.3–10 speedup by applying one H1D soil profile to an entire overland flow plane rather than to individual surface nodes.

Multi-layered heterostructured CoCrFeMnNi high-entropy alloy processed using direct energy deposition and ultrasonic nanocrystalline surface modification

The advantages of heterostructured materials as structural materials include superior mechanical properties and the ability to tailor the strength-ductility combination via microstructure customization. To maximize heterostructure effects, this study combined direct energy deposition and ultrasonic nanocrystalline surface modification processes to create a CoCrFeMnNi equiatomic high-entropy alloy with multi-layered microstructures. The fabricated CoCrFeMnNi high-entropy alloy has a novel microstructure composed of multiple layers of repetitive microstructures with heterogeneity and demonstrates a remarkable synergetic strengthening effect in comparison to conventional heterogeneous materials. The outstanding mechanical properties derived from various hard and soft layer interfaces, as well as the effects of each layer and interface, were quantitatively analyzed using grain-scale digital image correlation technology. By combining the direct energy deposition and ultrasonic nanocrystalline surface modification processes, this study presents a method for fabricating a new class of heterostructured materials with multi-layered microstructure that exhibit deformation heterogeneity and grain size heterogeneity. The multi-layered microstructure with multiple heterogeneous boundaries breaks the conventional wisdom regarding heterostructured materials having only one or two heterogeneous interfaces.

The case for the angrite parent body as the archetypal first-generation planetesimal: Large, reduced and Mg-enriched

Angrites are silica-undersaturated achondrites formed very early in the history of the Solar System, and the most volatile-depleted known meteorites. As such, the study of angrites can provide critical insights into the early stages of planetary formation, melting and differentiation. Yet, understanding the origins of angrites and the nature of their parent body has long been hindered by the initially small number of specimens available. Here, we leverage (i) the rapidly growing number of known angrites, and (ii) equilibrium crystallization experiments at various pressure, temperature and oxygen fugacity conditions (P-T-fO2), to revisit the petrogenesis of angrites and constrain key features of the angrite parent body (APB), such as its composition and size.We observe that quenched (i.e., volcanic) angrites define two compositional groups, which we show are readily related by fractional crystallization. This crystallization trend converges on an olivine-clinopyroxene-plagioclase (Ol + Cpx + Plag) multiple saturation boundary, whose composition is sampled by D’Orbigny, Sahara 99555 and NWA 1296. Using the observation that some quenched specimens represent primitive angritic melts, we derive a self-consistent bulk composition for the APB. We find that this composition matches the proposed Mg/Si ratio of 1.3 derived from the angrite δ30Si values, and yields a core size (18 ± 6 wt%) in agreement with the siderophile elements depletion in the APB mantle. Our results support a primary control of nebular fractionation (i.e., partial condensation) on the composition of the APB. To establish the liquid phase equilibria of angrites, a series of 1 atmosphere and high-pressure crystallization experiments (piston cylinder and internally heated pressure vessel) were performed on a synthetic powder of D’Orbigny. The results suggest that the APB was a large (possibly Moon-sized) body, formed from materials condensed at relatively high-temperature (∼1300–1400 K), and whose fO2 changed from mildly reducing (∼IW-1.5) to relatively oxidizing (∼IW+1 ± 1) in the ∼ 3 Myr between its core formation and the crystallization of D’Orbigny-like (Group 2) angrites. Based on its timing of accretion and differentiation, its composition, redox, and size, we argue that the APB represents the archetype of the first-generation of refractory-enriched planetesimals and embryos formed in the innermost part of the inner Solar System (<1 AU), and which accreted in the telluric planets.

On the micro-foundations of corporate social responsibility: a perspective based on dynamic managerial capabilities

PurposeThis study proposes that the three core underpinnings of dynamic managerial capabilities (DMCs) – managerial cognition, managerial human capital and managerial social capital – represent individual-level micro-foundations that influence corporate social responsibility (CSR). It further explores the interaction mechanism between the three underpinnings in influencing CSR, and their influence depends on the technological turbulence caused by big-data-related technologies.Design/methodology/approachThis study uses a quantitative research method and partial least squares structural equation modelling (PLS-SEM) to test the relationship between latent factors based on a sample of 270 Chinese top managers.FindingsThe three core underpinnings of DMCs are positively related to CSR. Managerial human capital and managerial social capital mediate the relationship between managerial cognition and CSR. Technological turbulence's moderating effects are also tested. Specifically, technological turbulence amplifies the positive relationship between managerial cognition, managerial human capital and CSR but negatively moderates the relationship between managerial social capital and CSR.Originality/valueWhy are some firms more willing to participate in CSR than others mainly depend on the fact that the actual participants of CSR are the top managers who formulate strategies and implement CSR plans. This study, grounded in the DMCs framework and the upper echelons perspective, is arguably the first to link DMCs' three core underpinnings and CSR, and further explore the multiple drivers' mechanisms and boundary conditions. This study contributes to individual micro-foundation of CSR literature, and advances the understanding of whether and how top managers influence CSR engagement.

Effects of non-Darcy mixed convection over a horizontal cone with different convective boundary conditions incorporating gyrotactic microorganisms on dispersion

This paper investigates the influence of dispersion impact on mixed convection flow over a horizontal cone within a non-Darcy porous medium. Multiple convective boundary conditions are applied to address the heat, mass and motile microorganism transfer phenomena. This paper incorporates the dispersion effect for gyrotactic microorganisms due to biological and environmental applications. By imposing appropriate similarity transformations, the nonlinear partial differential equations governing flow, temperature, concentration, and microbe fields are reduced to a system of ordinary differential equations & then solved using the MATLAB BVP4C function. The computation of grid independence test is analyzed for different flow profiles to show the precision of the points. In a few instances, our present numerical data is compared with previously published works, leading to excellent agreement. The non-Darcy effect, as well as mixed convection values from 0.1 to 0.9 and buoyancy parameters from 0.2 to 0.8, all significantly affects the velocity profile. The reduction in the microorganism profile is brought on by the increase in the bioconvection Lewis parameter and bio convection peclet number between 0.3 and 1. In the absence of dispersion, the variation of Biot numbers between 0.5 and 2, favor heat, mass, and motile microorganism transfer the most in the range of mixed convection parameter 0.5 to pure forced convection 1. Thermal, solutal and microorganism dispersion coefficients a, b, c that lie between frac{1}{7} and frac{1}{3} and higher values of modified peclet number ranges from 2 to 10 cause increased dispersion effects which lower flow transfer rates mostly in forced convection regime.

Perovskite-Surface-Confined Grain Growth for High-Performance Perovskite Solar Cells.

The conventional post-annealing (CPA) process is frequently employed and regarded a crucial step for high-quality perovskite thin-films. However, most researchers end up with unwanted characteristics because controlling the evaporation rate of perovskite precursor solvents during heat treatment is difficult. Most perovskite thin-films result in rough surfaces with pinholes and small grains with multiple boundaries, if the evaporation of precursor solvents is not controlled in a timely manner, which negatively affects the performance of perovskite solar cells (PSCs). Here, we present a surface-confined post-annealing (SCPA) approach for controlling the evaporation of perovskite precursor solvents and promoting crystallinity, homogeneity, and surface morphology of the resulting perovskites. The SCPA method not only modulates the evaporation of residual solvents, resulting in pinhole-free thin-films with large grains and fewer grain boundaries, but it also reduces recombination sites and facilitates the transport of charges in the resulting perovskite thin-films. When the method is changed from CPA to SCPA, the power conversion efficiency of PSC improves from 18.94% to 21.59%. Furthermore, as compared to their CPA-based counterparts, SCPA-based PSCs have less hysteresis and increased long-term stability. The SCPA is a potentially universal method for improving the performance and stability of PSCs by modulating the quality of perovskite thin-films.

Role congruence and study engagement in mature-age students: a serial indirect effects model

ABSTRACT We examined how mature-aged, non-traditional students (studying part-time, working full-time) managed their multiple roles by testing a serial, indirect effects model, in which student role congruence (i.e., extent to which students structure role boundaries to meet their own and others’ preferences) was related to study engagement, and where work-study conflict/facilitation and exhaustion, in sequence, were underlying mechanisms that explained this relationship. We also untangled congruence between different role boundaries (i.e., work, study, family, leisure) to assess which were more important to facilitate engagement. We found, (N = 211; M = 37 years; 65% women), study engagement was predicted by study (direct and indirect) and leisure congruence (indirect), but not work and family congruence, with these relationships explained by reduced conflict (not facilitation) and, in turn, less exhaustion. The study suggests that how students manage their multiple role boundaries is important as this potentially affects their study engagement.

Pushing the boundaries: Erotic romance and the symbolic boundary nexus

How do contested emerging subgenres become legitimated and institutionalized? This case illustrates the meso-level negotiation of community sense (Wohl, 2015) as stakeholders of a genre (romance fiction) debate whether genre boundaries include a new subgenre (erotic romance). Erotic romance upended conventions by introducing explicit and sometimes unconventional sex into the traditionally heteronormative romance genre. However, opposition to subgenre inclusion involved more than sexual content. Drawing on interviews (n = 40) and text data from Romantic Times (n = 360) and Romance Writers Report (n = 180), I find that mainstream incorporation of erotic romance involved community negotiation of multiple symbolic boundary debates: (1) What is acceptable sexuality? (2) What is a real book? (3) Who is a professional author? Erotic romance was fully institutionalized after best-selling Fifty Shades of Grey forced the community to confront all three boundary debates at once. Each debate represents a different symbolic boundary around the mainstream romance genre, but the case can only be fully understood by examining how they intersect. I conceptualize that intersection as the symbolic boundary nexus and argue that analyzing genre classifications as a set of intersecting boundaries is a productive approach for understanding how cultural communities negotiate contested classification processes.

Comparative Study on Rosseland’s Heat Flux on Three-Dimensional MHD Stagnation-Point Multiple Slip Flow of Ternary Hybrid Nanofluid over a Stretchable Rotating Disk

This article investigates the three-dimensional magneto stagnation-point flow of ternary hybrid nanofluid caused by a radially extended infinite gyrating disk with multiple slip effects. The main concern is to analyze the characteristics of heat transport when linear thermal radiation (LTR), quadratic thermal radiation (QTR), and full nonlinear thermal radiation (FNTR) are significant. Ternary fluid is a composition of water, spherical-shaped silver, cylindrical-shaped aluminum oxide, and platelet-shaped aluminum nanoparticles. Non-uniform heat source effects are taken into account. The governing equations are constructed using a single-phase nanofluid model using boundary layer theory and von Karman variables. The consequent nonlinear problem is solved with an efficient finite element method and the results are verified with the available data. The Nusselt number and friction factors are computed for both clean fluid and ternary nanofluid subjected to three different forms of Rosseland’s thermal radiation. Our results demonstrate that the rate of heat transport (Nusselt number) is higher in the FNTR case than in QTR and LTR, and it is even higher for ternary nanofluid compared to clean fluid. Further, the heat transport rate gets reduced for a higher heat source parameter. The rotation of the disk escalates the shear stress along both the radial and axial directions. The multiple slip boundary conditions lead to condensed boundary layers over a disk surface.

Computational fluid dynamics using finite volume method: A numerical model for Double Skin Façades with renewable energy source in cold climates

Double-skin façades often rely on proper cavity design, which unleashes a significant potential for inhabitation and renewable energy integration in cold climates. A co-model between Matlab and Ansys Fluent was developed to investigate the performance of a new typology for such façades. The steady-state energy balance equations for heat transfer were introduced with governing non-isothermal turbulent flow such that energy was conserved at each element of the assembly. Internal and mixed-mode ventilation schemes were utilized with multiple cavity widths and boundary conditions. The numerical model was validated against experimental measurements where the average temperature deviation was 1.9 °C. For the renewable energy source, the system utilized photovoltaics and microalgae modules which were brought in contact with the occupied space in order to counter the heat loss to the cold ambient. Results showed that double-skin façades were more energy efficient than an insulated double-glazed assembly regardless of the cavity ventilation scheme. The flow of heat transfer was reversed from 82.1 W/m2 loss to the surrounding to 35.7 W/m2 gain into the occupied space. Microalgae photobioreactors were found to have higher heating potential by generating 8.1% more than that of photovoltaics. Introducing ventilation into the cavity led to enhanced photovoltaics efficiency by 7.5% associated with a minimum drop in the cavity's temperature from 16.3 °C to −6.8 °C. Photobioreactors' functionability was enhanced by feeding water at a mean flow of 0.26 kg/s. The study recommended utilizing adjustable external air vents that can be regulated depending on the ambient temperature and the personal occupancy level in the cavity whenever its size fits.

Three-dimensional coupling between Boussinesq (FEM) and Navier–Stokes (particle based) models for wave structure interaction

The paper presents coupling between a mesh-based finite-element model for Boussinesq equations (FEBOUSS Agarwal et al., 2022) with a meshless local Petrov–Galerkin model for the Navier–Stokes equations (MLPG_R Agarwal et al., 2021) in 3D. Boussinesq equation models are widely used for simulating wave-propagation over large domains with uneven topography using a 2D surface mesh. Mesh-less models inherently capture large free-surface deformations and have shown promise in simulating wave-structure interaction, run-up and breaking phenomenon. The hybrid approach in this paper assumes a 3D MLPG_R sub-domain surrounded by the 2D mesh of FEBOUSS. The coupling interface in MLPG_R consists of relaxation zones that can be placed along multiple boundaries of the sub-domain for exchanging particle velocity from FEBOUSS. This hybrid model is therefore capable of simulating directional waves, that has not been reported previously.The paper first presents the procedure for calculating the depth-resolved velocities in 3D from the Boussinesq model. The resultant velocities are compared against theory, experiments and other models. The following sections present the coupling algorithm along a single and multiple coupling interfaces in MLPG_R. Validation results for this hybrid model are provided using surface elevation and velocity measurements for regular waves, including directional cases. In general, the results from the hybrid model are reported to have marginal over-prediction of peaks compared to purely MLPG_R simulation. Finally, the interaction of a vertical cylinder with direction regular wave is simulated using the 3D hybrid model.

Accurate Bounding Box Prediction for Single-Shot Object Detection

Accurate single-shot object detection is an extremely challenging task in real environments because of complex scenes, occlusion, ambiguities, blur, and shadow, i.e., these factors are called uncertainty problem. It leads to unreliable labeling of bounding box annotation and makes detectors arduous to learn bounding box localization. Previous methods viewed the ground truth box coordinates as a rigid distribution omitting localization uncertainty in real datasets. This article proposes a novel bounding box encoding algorithm integrated into the single-shot detector (BBENet) to consider the flexible distribution of bounding box localization. First, discretized ground truth labels are generated by decomposing each object’s boundary into multiple boundaries. The new representation of ground truth boxes is more arbitrary and flexible to cover any case of complex scenes. During training, the detector directly learns discretized box locations instead of continuous domain. Second, the bounding box encoding algorithm reorganizes bounding box predictions to be more accurate. Furthermore, another problem in existing methods is inconsistency in estimating detection quality. The single-shot detection consists of classification and localization tasks, but the popular detectors consider the classification score as the final detection quality. Thus, it lacks localization quality and hinders the overall performance because both tasks have a positive correlation. To overcome this problem, BBENet introduces detection quality by combining the localization and classification quality to rank detection during nonmaximum suppression. The localization quality is computed based on how uncertain the predicted boxes are, which is a new perspective in detection literature. The proposed BBENet is evaluated on three benchmark datasets, i.e., MS-COCO, Pascal VOC, and CrowdHuman. Without bells and whistles, BBENet outperforms the existing methods by a large margin with comparable speed, achieving the state-of-the-art single-shot detector.