As an important part of image processing, image demosaicking has been widely researched. It is especiallynecessary to propose an efficient interpolation algorithm with good visual quality and ...performance. To improvethe limitations of residual interpolation (RI), based on RI algorithm, minimalized-Laplacian RI (MLRI), anditerative RI (IRI), this paper focuses on adaptive RI (ARI) and proposes an improved ARI (IARI) algorithmwhich obtains more distinct R, G, and B colors in the images. The proposed scheme fully considers thebrightness information and edge information of the image. Since the ARI algorithm is not completely adaptive,IARI algorithm executes ARI algorithm twice on R and B components according to the directional difference,which surely achieves an adaptive algorithm for all color components. Experimental results show that theimproved method has better performance than other four existing methods both in subjective assessment andobjective assessment, especially in the complex edge area and color brightness recovery. KCI Citation Count: 0
As an important part of image processing, image demosaicking has been widely researched. It is especially necessary to propose an efficient interpolation algorithm with good visual quality and ...performance. To improve the limitations of residual interpolation (RI), based on RI algorithm, minimalized-Laplacian RI (MLRI), and iterative RI (IRI), this paper focuses on adaptive RI (ARI) and proposes an improved ARI (IARI) algorithm which obtains more distinct R, G, and B colors in the images. The proposed scheme fully considers the brightness information and edge information of the image. Since the ARI algorithm is not completely adaptive, IARI algorithm executes ARI algorithm twice on R and B components according to the directional difference, which surely achieves an adaptive algorithm for all color components. Experimental results show that the improved method has better performance than other four existing methods both in subjective assessment and objective assessment, especially in the complex edge area and color brightness recovery.
This paper formulates a mathematical framework to describe the dynamics of SIS-type infectious diseases with resource constraints. We first define the basic reproduction number that determines ...disease prevalence and analyze the existence and local stability of the equilibria. Subsequently, we analyze the global dynamics of the model, excluding periodic solutions and heteroclinic orbits, using the compound matrix approach. The analysis implies that the model can undergo forward and backward bifurcations depending on critical parameters. In the former scenario, the disease persists when the basic reproduction number under resource constraints exceeds one. In the latter scenario, the backward bifurcation creates bistability dynamics in which the disease may persist or become extinct depending on the initial level of infected individuals and the resource abundance.
Airborne LiDAR bathymetry (ALB) has shown great potential in shallow water and coastal mapping. However, due to the variability of the waveforms, it is hard to detect the signals from the received ...waveforms with a single algorithm. This study proposed a depth-adaptive waveform decomposition method to fit the waveforms of different depths with different models. In the proposed method, waveforms are divided into two categories based on the water depth, labeled as "shallow water (SW)" and "deep water (DW)". An empirical waveform model (EW) based on the calibration waveform is constructed for SW waveform decomposition which is more suitable than classical models, and an exponential function with second-order polynomial model (EFSP) is proposed for DW waveform decomposition which performs better than the quadrilateral model. In solving the model's parameters, a trust region algorithm is introduced to improve the probability of convergence. The proposed method is tested on two field datasets and two simulated datasets to assess the accuracy of the water surface detected in the shallow water and water bottom detected in the deep water. The experimental results show that, compared with the traditional methods, the proposed method performs best, with a high signal detection rate (99.11% in shallow water and 74.64% in deep water), low RMSE (0.09 m for water surface and 0.11 m for water bottom) and wide bathymetric range (0.22 m to 40.49 m).
Hot dry rock geothermal energy is deep geological energy. Its ability to resist fracture is an important basis for effective reconstruction and scientific evaluation of the stability of geothermal ...reservoirs. Hot dry rock is typically buried deeply, and the reservoir is often in a high-temperature and high stress environment. There have been limited studies conducted on the effect of different three-dimensional stress and temperature on granite fracture toughness. Thereby, herein an experimental study is conducted on the heat treatment of granite under different external loads and temperatures. The variation in fracture toughness of granite with temperature and pressure is studied using a three-point bending fracture mechanics experiment, scanning electron microscope (SEM) observation, and acoustic wave velocity measurement. The results show that under the joint influence of 25 MPa deviator stress and 200°C temperature, the Mode I, Mixed mode (I + II), and Mode II fracture toughness of granite show a nonlinear change trend of decreasing and increasing. Among the three modes, the change range of Mode I fracture toughness is not more than 10% which is not significant. Contrarily, the degradation effect of rock mechanical properties caused by the joint action of stress and temperature in Mode II and Mixed mode (I + II) is predominant. The maximum range of Mode II fracture toughness is reduced by 22%, whereas the maximum range of Mixed mode (I + II) fracture toughness is reduced by 18%. However, the compression action of three-dimensional stress causes a slight enhancement in granite mechanical properties, wherein the maximum range of Mixed mode (I + II) fracture toughness is increased by 12%. Furthermore, the change of granite's ability to resist tensile, shear, and composite (tensile + shear) fracture is not coordinated under the joint action of different temperatures and external loads. This may be due to the small deviator stress effect, which is similar to the early loading stage of uniaxial compression. External loads and thermal stress damage occur in the rock along with the compaction of pore cracks. These mechanisms have different dominant positions under varied temperature and three-dimensional stress coupling conditions, resulting in either the enhancement or weakening of the mechanical properties of granite. The results of this experimental study are conducive to gaining an in-depth understanding of the change law of deep rock mechanical properties and the exploration of hot dry rock reservoir reconstruction.
The fracture network of a deep geothermal reservoir forms the place for heat exchange between injected fluid and rock mass with high temperature. The fracture resistance ability of reservoir rocks ...will affect the formation of fracture-network structure, heat exchange and transmission characteristics, and reservoir mechanical stability. However, there are few reports on the fracture toughness and trajectory prediction of geothermal reservoirs with different depths. In this paper, the modified maximum tangential stress criterion (MMTS) is analyzed. The results show that the experimental data are significantly different from the theoretical estimate of MMTS under the influence of different occurrence depths. It is found that the fracture process zone (FPZ) seriously affects the accuracy of predicting fracture initiation angle and mixed-mode (I+II) fracture toughness by MMTS. The FPZ value, considering the influence of different occurrence depths, is modified, and the accuracy of MMTS in predicting the fracture mechanical characteristics of granite is improved. In addition, the mechanical test results show that the Brazilian splitting strength (σt) of granite fluctuates increase with the increase in temperature. With the increase in deviatoric stress, the Brazilian splitting strength and the Brazilian splitting modulus of rock show a trend of first increasing, then decreasing, and then increasing.
The collective foraging behavior of ant colonies is a central focus in behavioral ecology. This paper enhances the classical model of foraging dynamics in harvester ant colonies by introducing a ...nonlinear recruitment rate and considering environmental variability. Initially, we analyze the existence and stability of steady states in the deterministic model. The results suggest that an increase in mean recruitment time can reduce the foraging threshold, leading to both forward and backward bifurcations. Furthermore, both average recruitment time and the interference intensity of recruiters impact the number of workers in each subgroup. Subsequently, we conduct an analysis of the long-term and transient dynamics of collective foraging in random environments, providing sufficient conditions for the colony to sustain foraging activity. The findings emphasize the scene-dependent impact of environmental stochasticity on foraging dynamics. When ant colonies deterministically cease foraging, environmental stochasticity may unexpectedly prolong the foraging state. Conversely, when colonies deterministically persist in foraging, environmental stochasticity may disrupt this continuity. Additionally, the effect of environmental stochasticity on foraging status varies with the initial worker size. Sizes near the boundary of the basin of attraction between non-foraging and foraging states exhibit greater sensitivity to environmental stochasticity, and sufficiently large stochasticity can impact foraging dynamics across a broader range of initial worker sizes. These findings underscore the intricate interplay between intrinsic factors (e.g., recruitment efficiency and interference intensity) and extrinsic factors (e.g., environmental stochasticity) in shaping the collective foraging dynamics of ant colonies.
•The study improves the classic ant colony foraging model with nonlinear recruitment and environmental variability.•Increased recruitment time alters foraging thresholds, causing forward or backward bifurcations.•Environmental variability can extend or disrupt foraging, with sensitivity related to worker size, showcasing the interplay of intrinsic and extrinsic factors in colony behavior.
All-perovskite tandem solar cells have great potential to realize the efficiency beyond the Shockley-Queisser efficiency limitation of single junction solar cells. Here we investigate the photon ...redistribution effect induced by introduction of the optical coupling layer in two terminal (2 T) tandem solar cells. In this work, it is shown that the introduction of the optical coupling layer could not only reduce the reflection loss, but also would affect the redistribution of the absorbed photons in the tandem device due to the optical interference effect, which will disturb the previous balance and complicate the optical modulation. This photon redistribution phenomenon is systemically investigated by combining the optical and electrical aspects. By considering the coupling effect beyond the antireflection function after introducing the optical coupling layer, the new current match could be achieved, which would obviously improve the device performance further. Various materials such as LiF, MgF 2 , Al 2 O 3 , ZnO have been adopted as the optical coupling layer and it is demonstrated that this phenomenon is universal for all the cases. The improvement brought by photon redistribution effect may be even more obvious than antireflection function. Through analyzing the inner optical mechanism and modulating the structure, a higher performance can be achieved by carefully considering the optical coupling effect.
Understanding collective behavior is integral to disciplines including developmental biology, behavioral ecology, and sociology. In this investigation, we construct deterministic and stochastic ...models for exploring how internal factors (i.e., task demand) and external factors (i.e., dynamic environment) drive the collective foraging behavior of social insect colonies. Through theoretical analysis, we demonstrate the global stability of an interior equilibrium for the deterministic case, and study the existence of a unique stationary distribution for the stochastic case. Surprisingly, the global stability of the interior equilibrium and the existence of a unique stationary distribution of the proposed models do not depend on additional conditions. The main contribution of this work is to construct a new mathematical framework to explore the influence of internal stimulus and external fluctuation on the dynamics of social insect colonies, and to provide corresponding theoretical analysis methods.
Wide-bandgap all-inorganic CsPbIBr 2 solar cells with MoO x /Ag/TeO 2 composite transparent electrode have been firstly used to construct a 4T perovskite/Si-heterojunction tandem cells. The ...calculation results showed that the long wavelength transmission (600 to 1100 nm) of MoO x /Ag film can be enhanced remarkably by adding a TeO 2 optical capping layer. This resulted in an obviously increase of the PCE (J SC ) from 10.70% (17.56 mA/cm 2 ) to 14.76% (24.67 mA/cm 2 ) for corresponding bottom Si cell in CsPbIBr 2 /Si devices, although the PCE of top CsPbIBr 2 cell decreased from 17.52% to 16.58%, the overall PCE of tandem device has increased from 28.22% to 31.34%. This J SC -dependent PCE improvement mainly came from the more balanced light absorption, which can be understood by the optical interference induced light field redistributions in CsPbIBr 2 /Si devices. Specially, comparing with the original Si cell, the J SC and PCE losses in bottom Si cell have been suppressed to about 33% and 32%, which are superior to most the reported pervoskite/Si tandem cells. Therefore, the tandem of Si cell and CsPbIBr 2 cell with optimized MoO x (20 nm)/Ag(8 nm)/TeO 2 (50 nm) transparent electrode could be the promising cost-effective photovoltaic in the future. This work is instructive to the fabrication of pervoskite/Si tandem solar cells.
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