Homogeneous Blocks Research Articles

Harvesting fragmented boreal forest: system selection using a simulation-optimization approach

ABSTRACT Nordic forests, such as those found in Canada were known to offer opportunities for large and relatively homogeneous harvesting blocks. Increased fragmentation of forests makes operation planning more difficult and affects costs of road building and machinery relocation. Currently, the diversity of systems used for forest operations in eastern Canada represents only a fraction of existing alternatives. It might be that at least one alternative outperforms the systems currently used in the fragmented boreal forest. Hence, a subset of potential systems was identified in a preliminary evaluation of harvest systems in fragmented operations. From this sample, the objective is to develop a mathematical model to identify the harvest system with the lowest wood procurement cost in fragmented boreal forests. The candidate systems were simulated and optimized using a static deterministic approach. According to our results, the best systems in fragmented forests involve fewer machines, hence a lower relocation cost. Two CTL systems outperformed all others. The system using removable crane self-loading trucks for transport and the one using the forwarder for loading both resulted in 4 $/m3 (USD) advantage over the third least expensive system in the most fragmented harvest sites. The proposed model can be directly applied to assess harvest systems in other parts of the world with similar forest fragmentation challenges.

Unsupervised Change Detection Methods Applied to Landslide Mapping: Case Study in São Sebastião, Brazil

ABSTRACTLandslides represent a growing global geological hazard, further intensified by climate‐induced changes. Remote sensing data, through its capacity for repetitive collection and change detection techniques, that compare and quantify the spatio‐temporal alterations over time, plays a critical role in landslide detection. Considering the February 2023 São Sebastião event and Sentinel‐2 imagery, we assessed diverse unsupervised change detection techniques, encompassing both traditional and recent machine learning‐based approaches. Notably, the Floating References (FR) and Homogeneous Blocks Single‐class Classification (HBSC) methods outperform classic approaches and deliver the most accurate results with F1‐Score and kappa coefficient exceeding 0.96 and 0.92, respectively. These outcomes demonstrate the efficacy of machine learning in automating landslide delineation and underscore the necessity of meticulous data and parameter selection in achieving high‐accuracy automatic landslide mapping. Lastly, this study fills a significant gap in the existing literature by evaluating unsupervised change detection methods for landslide mapping within the Brazilian context.

Optimized manufacturing process of homogeneous microwave-sintered blocks of KLS-1 lunar regolith simulant

The use of materials from the Moon's surface based on In-Situ Resource Utilization (ISRU) is gaining considerable attention as a means of constructing infrastructure to sustain a human presence there. In particular, the sintering of lunar regolith appears a promising way to fabricate infrastructure on the lunar surface. This study presents a method to manufacture homogeneous blocks using a lunar regolith simulant. The tested simulant, KLS-1, was sintered under diverse conditions in a multi-mode microwave sintering furnace. Successful sintering requires the sample to be heated throughout, without generating a temperature gradient. This was achieved by testing various heating rates and sample sizes. X-ray computed tomography was used to assess the pore structure of sintered samples. While the optimized sintering conditions resulted in the formation of internal cracks by outgassing, preheating the KLS-1 in a vacuum oven at 250 °C effectively prevented the formation of internal cracks. The homogeneity of the blocks was confirmed by coring and measurements of true density, bulk density, porosity, and unconfined compressive strength. The robust reproducibility and similarity in physical and mechanical properties validate the viability of microwave sintering in manufacturing large and uniform blocks suitable for application as construction materials on the Moon.

MHD Natural Convection and Sensitivity Analysis of Ethylene Glycol Cu-Al2O3 Hybrid Nanofluids in a Chamber with Multiple Heaters: A Numerical Study of Lattice Boltzmann Method

The present work investigates the magnetohydrodynamic (MHD) convective heat transport of hybrid nanofluids in a chamber with multiple heaters (such as hot microchips). The multiple-relaxation-time (MRT) lattice Boltzmann method (LBM) and graphics processing unit (GPU) computing are used here. The present study is important due to its relevance to real-world applications, the use of advanced simulation techniques, the consideration of hybrid nanofluids, the inclusion of magnetohydrodynamics, and the identification of critical parameters influencing heat transfer. Thermally homogeneous blocks are set at the bottom of a rectangular enclosure filled with ethylene glycol Cu-Al2O3 hybrid nanofluids with temperature-dependent viscosity. The cold temperature of the enclosure’s left and right walls and the bottom and top surfaces is kept at adiabatic conditions. The numerical outcomes for the various parameters Rayleigh number (104≤Ra≤106), volume fraction (0.00≤ϕ≤0.04), Hartmann number (0≤Ha≤60), and viscosity variation parameter (0≤ε∗≤5) are presented in terms of streamlines, isotherms, and the peripheral local and average Nusselt numbers for the heated chips. The results demonstrated that inside the chamber, the Rayleigh number (Ra), the Hartmann number (Ha), and the volume fraction of nanoparticles (ϕ) have the highest impact on the heat transfer rate for hybrid nanofluid. For increased Ha from 0 to 20, while ϕ=0.0 and Ra=106, average Nusselt number decreased with 13.65%. For the same case, if the volume fraction was increased to ϕ=0.04, then the average Nusselt number decreased 14%. Finally, a sensitivity analysis was done to analyze the system’s correctness and effectiveness to determine the significance of the specified parameters.

Meta-Analysis of Social Presence Effects on Stroop Task Performance.

In this paper, we conducted a meta-analytic review to examine the impact of social presence on individuals' performance on the Stroop task, shedding light on the cognitive processes underlying social facilitation. We followed PRISMA guidelines to identify and include 33 relevant studies in a multivariate random-effects meta-analysis. Our results show that social presence reliably modulates Stroop interference (a measure of cognitive control); specifically, participants exhibit lower Stroop interference when performing the task in the presence of others compared to performing it in isolation. We also found that the strength of the effect varies depending on the type of social presence: it is stronger with an attentive audience compared to an inattentive one, and null with an evaluative audience. Additionally, different features of the Stroop task itself moderate the effect; the effect is stronger for the classic version of the task compared to the semantic version, and for experiments that use mixed within-block trials compared to those with homogenous blocks. We also observed a negative relationship between the number of trials and the magnitude of the effect. Overall, these findings provide insights into the mechanisms by which the presence of others affects performance on the Stroop task, and how they align with social facilitation theories.

High-Capacity Reversible Data Hiding in Encrypted Images Based on Pixel Prediction and QuadTree Decomposition

Over the past few years, a considerable number of researchers have shown great interest in reversible data hiding for encrypted images (RDHEI). One popular category among various RDHEI methods is the reserving room before encryption (RRBE) approach, which leverages data redundancy in the original image before encryption to create space for data hiding and to achieve high embedding rates (ERs). This paper introduces an RRBE-based RDHEI method that employs pixel prediction, quadtree decomposition, and bit plane reordering to provide high embedding capacity and error-free reversibility. Initially, the content owner predicts the error image using a prediction method, followed by mapping it to a new error image with positive pixel values and a compressed binary label map is generated for overhead pixels. Subsequently, quadtree decomposition is applied to each bit plane of the mapped prediction error image to identify homogeneous blocks, which are then reordered to create room for data embedding. After generating the encrypted image with the encryption key, the data hider employs the data hiding key to embed the data based on the auxiliary information added to each embeddable bit plane’s beginning. Finally, the receiver is able to retrieve the secret message without any error, decrypt the image, and restore it without any loss or distortion. The experimental results demonstrate that the proposed RDHEI method achieves significantly higher ERs than previous competitors, with an average ER exceeding 3.6 bpp on the BOSSbase and BOWS-2 datasets.

FNRegion: A fast NAM‐based region extraction algorithm

AbstractRegion extraction is usually used by many computer vision tasks as a pre‐processing step to extract image features. However, how to efficiently extract effective regions remains a challenging problem. In this paper, inspired by the non‐symmetry and anti‐packing pattern representation model (NAM) and the FatRegion algorithm, a fast NAM‐based region extraction algorithm which is called FNRegion is proposed. A NAM‐based homogeneous block generation algorithm is first presented to represent an image as a combination of multiple homogeneous blocks, each of which is a square region with visually indistinguishable intra‐region colour difference. Then, these homogeneous blocks are merged into larger regions according to their colour and shape information. To group these regions into larger ones in order to progressively build a region tree, a distance function is defined using variety of regional information to measure the distance between adjacent regions. Also, a multi‐feature region merging algorithm with linear complexity both in time and space is presented.The proposed algorithm has been evaluated on multiple public datasets in comparison with the state‐of‐the‐art region extraction algorithms. The experimental results show that in the case of almost the same or even less running time as other fast region extraction algorithms, the proposed algorithm is able to extract higher‐quality regions.

The multiple phonological activation in Chinese spoken word production: An ERP study supporting cascaded model

A central issue in spoken word production concerns how activation is transmitted from semantic to phonological levels. The current study investigated the issue of seriality and cascadedness in Chinese spoken word production, via the combined semantic blocked paradigm (with homogeneous and heterogeneous blocks) and picture-word interference paradigm (with phonologically related, mediated and unrelated distractors). Naming latencies data showed a mediated effect via comparing mediated and unrelated distractors in homogeneous blocks, a phonological facilitation effect via comparing phonologically related and unrelated distractors in homogeneous and heterogeneous blocks, and a semantic interference effect via comparing homogeneous and heterogeneous blocks. Critically, cluster-based permutation test of ERP data demonstrated a mediated effect around 266-326ms and an overlapped pattern of semantic interference effect around 264-418ms and phonological facilitation effect around 210-310ms in homogeneous or around 236-316ms in heterogeneous blocks. These findings indicated that speakers activate phonological nodes of non-targets, and present a cascadedness pattern of the transmission from semantics to phonology in Chinese spoken production. The present study sheds new insight on the neural correlates of semantic and phonological effects, and provides behavioral and electrophysiological evidences for the cascaded model within a theoretical framework of lexical competition in speech production.

Methodology of stem water potential measurement on hedgerow olive orchards

Aim of study:To evaluate the effect of leaf covering, leaf position, leaf age, time and sample size in measurements of stem water potential (Ψstem) in olive hedgerow orchards. Area of study: The experimental orchards were located in the Centre of Spain (Toledo) Material and methods: Midday Ψstem was measured using a pressure chamber in two super-intensive olive hedgerow orchards subjected to various water status. Main results: Measurements were taken at solar noon on shaded leaves at mid canopy height following at least 1 hour of covering. Such measurements on 5 trees were sufficient to define the water status of individual homogeneous irrigation blocks. This combination of techniques is essential for repeatable measurements of Ψstem required to establish critical irrigation points and manage deficit irrigation strategies seeking to control vegetative growth and reduce water use with minimal effect on oil yield in olive hedgerow orchards and maximum oil quality. Part of our results weren’t previously reported: 1) Covering leaves with aluminium doesn’t completely stop transpiration and leaves must be covered and located in the shaded part of the canopy. 2) Ψstem depends on leaf height on olive hedgerow. 3) Ψstem of young leaves was less variable than in older ones. 4) Ψstem at solar noon presented larger differences with previous hours than later. Research highlights: Leaves for measurements of stem water potential must be previously covered and located in the middle height of the shaded part of the canopy.

Tectonic Earthquake Source Mechanism Model Based on Moment Theory

During the construction of strategic facilities, micro zoning is required to determine the peak values of terrain acceleration due to possible earthquakes. The acceleration of the soil in this case strongly depends not only on the power of the earthquake, but also on the earthquake source mechanism and the geodynamic state of the terrain. The known dislocation models of a single dipole with a moment and a pair of dipoles without a moment of the earthquake source mechanism satisfactorily describe the observed effects of the quadrant stress distribution on the Earth’s surface during earthquakes. When carrying out calculations within the framework of the theory of elasticity, the actions of the dipoles are expressed through volumetric forces. There are two known models of replacing the moments with equivalent forces: one of them is based on the equilibrium equations for an infinitely elastic space (Landau and Lifshitz,1965; Maruyama,1963), and the other is based on the representation theorem for elastic bodies, by introducing a singular internal volume, at the boundary of which there are dislocations (Vvedenskaya, 1969; Aki and Richards, 1983). Although these models involve moment effects, they themselves are derived from the momentless theory of elasticity. In our work, we propose a double dipole effect without a moment based on the moment theory of elasticity. The proposed model of the earthquake source mechanism is applied to solve the problem of stress variations in the Earth’s crust in Central Asia using the example of a particular earthquake with a simplified orientation of the rupture plane. Stress variation is understood as the difference in stresses in problems with and without an earthquake mechanism. Static stresses are obtained by solving the inverse elasticity problem with partially unknown boundary conditions. The lithosphere is a prismatic body consisting of several homogeneous blocks, the upper surfaces of which correspond to the relief of Central Asia. Verification of the results of the numerical solution is carried out by comparing the obtained stresses with previously established empirical values. As a priori stresses for solving the inverse problem, we used the solution of the elastic plane problem, the boundary conditions in which correspond to the lateral compression of the lithosphere of the region of the Indian and Arabian plates on the one hand, and the Eurasian plate on the other hand. The obtained solutions of the problem were used to analyze the geodynamic state of Central Asia. Based on the results of laboratory experiments, the unambiguity of the conclusions about the geodynamic state of the Earth’s crust (compression, extension) according to the Lode-Nadai coefficient, which are currently used by many researchers, is questioned. It is shown, contrary to earlier statements, that the values μσ = +1 and μσ = –1 can correspond simultaneously to both tension and compression cases, depending on the spatial form (ellipsoid) of the stress state. Geodynamic analysis of the Earth’s crust is carried out according to the Anderson method.

Comet 2I/Borisov in Comparison with Comets of the Solar System

The brief review summarizes data on the chemical and mineral composition, as well as on the phys ical properties, of the first extrasolar comet 2I/Borisov, obtained from observations that were carried out from September 2019 to the end of March 2020. It is noted that the qualitative chemical composition of the volatile and mineral components comet 2I/Borisov is similar to the composition of comets in the Solar System, but there are differences that indicate the specific conditions for the formation of its nucleus in a circumstellar gas and dust disk. Different release rates of CO and H2O molecules in the vicinity of perihelion indicate the pos sible heterogeneity of the comet’s nucleus, which was formed from more homogeneous ice blocks, but differ ing in composition. These constituent blocks could have formed over a wide range of radial distances: from the snow line of H2O to the CO snow line. Their accumulation in the comet’s nucleus indicates large-scale mixing of protocometary bodies in the circumstellar disk. No spectra of finely crystalline magnesium silicates were found in cometary coma of 2I/Borisov, which can be interpreted as the absence of a significant amount of gas and dust transfer from the inner hot regions of the disk to the outside, into the zone of formation of protocometary bodies.

AE localization issues in heavy reinforced post-tensioned concrete beams

Damage localization is a relevant issue in structural health monitoring (SHM) of concrete structures. A greater level of insight into the structure can be so reached enabling more informed maintenance decisions and reducing operation and maintenance costs. The basic approach to acoustic emission localization, which is often referred to as the Time of Arrival (TOA) method, is based on detecting an AE source at a number of spatially-distributed sensors. However, in anisotropic media such as reinforced concrete, the basic assumptions for the TOA method become largely invalid. Different robust methods suitable to anisotropic media, incorporating an angular-dependent velocity term into the minimization process have been developed in the past. However, the wave-velocity profile is not always known. More recently a number of other authors have adopted various Bayesian approaches as part of AE localization strategies, including the use of a Markov chain Monte Carlo inference scheme as well as nonlinear Kalman filters. The use of a probabilistic approach in source location has become increasingly applied for AE source localization in complex large structures. In heavy reinforced post-tensioned concrete structures acoustic wave path can be significantly influenced by rebars as well as metallic post-tensioning ducts. Cracks opening can further influence acoustic propagation paths and greatly influence the reliability of AE source localization algorithms. In the present paper, different localization procedures have been developed and tested on post-tensioned concrete beams during loading and unloading cycles as well as on small homogeneous concrete blocks. In a highly emissive environment, significant difficulties have been reported also in event identification thus further reducing localization procedure reliability. EWGAE 35, Ljubljana, Slovenia, 13th – 16th Sep. www.ewg

Engineering Silk Protein to Modulate Polymorphic Transitions for Green Lithography Resists

Silk protein is being increasingly introduced as a prospective material for biomedical devices. However, a limited locus to intervene in nature-oriented silk protein makes it challenging to implement on-demand functions to silk. Here, we report how polymorphic transitions are related with molecular structures of artificially synthesized silk protein and design principles to construct a green-lithographic and high-performative protein resist. The repetition number and ratio of two major building blocks in synthesized silk protein are essential to determine the size and content of β-sheet crystallites, and radicals resulting from tyrosine cleavages by the 193 nm laser irradiation induce the β-sheet to α-helix transition. Synthesized silk is designed to exclusively comprise homogeneous building blocks and exhibit high crystallization and tyrosine-richness, thus constituting an excellent basis for developing a high-performance deep-UV photoresist. Additionally, our findings can be conjugated to design an electron-beam resist governed by the different irradiation-protein interaction mechanisms. All synthesis and lithography processes are fully water-based, promising green lithography. Using the engineered silk, a nanopatterned planar color filter showing the reduced angle dependence can be obtained. Our study provides insights into the industrial scale production of silk protein with on-demand functions.

Effect of Cooking Methods on Amphenicols and Metabolites Residues in Livestock and Poultry Meat Spiked Tissues.

Foods of animal origin, as nutritional supplements, are usually consumed after cooking, but residues of amphenicols in fresh raw meat threaten human health. Therefore, this study was designed to evaluate the effects of boiling, deep-frying and microwave processing under different time conditions on the residue levels of amphenicols and metabolites in livestock and poultry meat. Antibiotic-free pork, beef, lamb and chicken samples were spiked with chloramphenicol (CAP), thiamphenicol (TAP), florfenicol (FF) and florfenicol amine (FFA) standard solutions and made into homogeneous meat blocks. These positive mock meat blocks were processed using three different cooking methods, and the analyses were performed by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The results showed that cooking methods, time and food matrices were the main factors influencing the changes in amphenicols and metabolites residues in livestock and poultry meat. With the increase in cooking time, boiling processing was the most effective in reducing the four drug residues in livestock and poultry meat matrices, followed by deep-frying, while microwaving caused an increase in drug residue concentrations. Although boiling and frying processes are effective strategies to reduce amphenicols and metabolites residues in meat, it cannot be assumed that these residues can always decrease to levels that are safe for consumer health, especially when the drug residue concentrations in raw meat are above the maximum residue limits (MRLs). Therefore, it is not reliable to remove residues of amphenicols and metabolites from food by cooking. The solution to the food safety problem of veterinary drug residues must start from the breeding source and accelerate the implementation of antibiotic reduction, antibiotic substitution and antibiotic-free farming.

An Approximation Algorithm for Blocking of an Experimental Design

AbstractBlocked randomized designs are used to improve the precision of treatment effect estimates compared to a completely randomized design. A block is a set of units that are relatively homogeneous and consequently would tend to produce relatively similar outcomes if the treatment had no effect. The problem of finding the optimal blocking of the units into equal sized blocks of any given size larger than two is known to be a difficult problem—there is no polynomial time method guaranteed to find the optimal blocking. All available methods to solve the problem are heuristic methods. We propose methods that run in polynomial time and guarantee a blocking that is provably close to the optimal blocking. In all our simulation studies, the proposed methods perform better, create better homogeneous blocks, compared with the existing methods. Our blocking method aims to minimize the maximum of all pairwise differences of units in the same block. We show that bounding this maximum difference ensures that the error in the average treatment effect estimate is similarly bounded for all treatment assignments. In contrast, if the blocking bounds the average or sum of these differences, the error in the average treatment effect estimate can still be large in several treatment assignments.

Combating Communalism through Correct Narratives

Communalism is an ideology which negates the concept of pluralism and assumes that not only the interests of a religious community are common, but these are necessarily opposed to the interests of other religious communities. In India, communalism has spread mainly due to false historical narratives. The British historians, with an aim to create Hindu-Muslim dissension, divided the Indian history into Hindu, Muslim and British periods. It was projected that Hindus and Muslims had been two homogenous blocks who have always been antagonistic to each other and the subject of history is mainly a narration of the confrontation of Hindus and Muslims. It was also propagated that the religion of Islam spread mainly by sword and there was vast desecration of temples by Muslim rulers. But this communal version of history is not supported by historical research. All religions preach love and compassion and no religion teaches hatred for any class of persons. Responsible citizens of all religions need to become vocal and give an ideological challenge to communalism. Religious fanaticism needs to be strongly condemned and the common moral values of religions be emphasized. Highlighting the correct historical narratives and emphasizing the composite Indian culture will be helpful in engendering an environment of harmony and brotherhood. If the forces of Peace and Harmony become vocal, communalism will itself take a back seat.

Orthography influences spoken word production in blocked cyclic naming.

Does the way a word is written influence its spoken production? Previous studies suggest that orthography is involved only when the orthographic representation is highly relevant during speaking (e.g., in reading-aloud tasks). To address this issue, we carried out two experiments using the blocked cyclic picture-naming paradigm. In both experiments, participants were asked to name pictures repeatedly in orthographically homogeneous or heterogeneous blocks. In the naming task, the written form was not shown; however, the radical of the first character overlapped between the four pictures in this block type. A facilitative orthographic effect was found when picture names shared part of their written forms, compared with the heterogeneous condition. This facilitative effect was independent of the position of orthographic overlap (i.e., the left, the lower, or the outer part of the character). These findings strongly suggest that orthography can influence speaking even when it is not highly relevant (i.e., during picture naming) and the orthographic effect is less likely to be attributed to strategic preparation.

Experimental helium-beam radiography with a high-energy beam: Water-equivalent thickness calibration and first image-quality results.

A clinical implementation of ion-beam radiography (iRad) is envisaged to provide a method for on-couch verification of ion-beam treatment plans. The aim of this work is to introduce and evaluate a method for quantitative water-equivalent thickness (WET) measurements for a specific helium-ion imaging system for WETs that are relevant for imaging thicker body parts in the future. Helium-beam radiographs (αRads) are measured at the Heidelberg Ion-beam Therapy Center with an initial beam energy of 239.5 MeV/u. An imaging system based on three pairs of thin silicon pixel detectors is used for ion path reconstruction and measuring the energy deposition (dE) of each particle behind the object to be imaged. The dE behind homogeneous plastic blocks is related to their well-known WETs between 280.6 and 312.6 mm with a calibration curve that is created by a fit to measured data points. The quality of the quantitative WET measurements is determined by the uncertainty of the measured WET of a single ion (single-ion WET precision) and the deviation of a measured WET value to the well-known WET (WET accuracy). Subsequently, the fitted calibration curve is applied to an energy deposition radiograph of a phantom with a complex geometry. The spatial resolution (modulation transfer function at 10 % -MTF10% ) and WET accuracy (mean absolute percentage difference-MAPD) of the WET map are determined. In the optimal imaging WET-range from ∼280 to 300 mm, the fitted calibration curve reached a mean single-ion WET precision of 1.55 0.00%. Applying the calibration to an ion radiograph (iRad) of a more complex WET distribution, the spatial resolution was determined to be MTF10% = 0.49 0.03 lp/mm and the WET accuracy was assessed as MAPD to 0.21 %. Using a beam energy of 239.5 MeV/u and the proposed calibration procedure, quantitative αRads of WETs between ∼280 and 300 mm can be measured and show high potential for clinical use. The proposed approach with the resulting image qualities encourages further investigation toward the clinical application of helium-beamradiography.

Identifying the coal seams and their sedimentary environments in the Nui Beo mine, Quang Ninh province using K-means and regression methods

The Nui Beo mine is located in the southern part of the Quang Ninh province. It belongs to the Hon Gai-Cam Pha coal zone, where many coal resources have been estimated in Vietnam. Based on synthesizing and processing data of the coal seam parameters and coal quality by using K-means and regression methods, results allow dividing the Nui Beo mine into three areas, the area 1 bearing coal thickness greater than or equal to 18.5m, the area 2 containing coal thickness less than 18.5m, and coal seam dipping angle less than 32.0 degrees; and the area 3 obtaining coal thickness less than 18.5m, and coal seam dipping angle greater than or equal to 32.0 degrees, combining with five interlayers as the scared boundary. Identifying results using K-means and regression methods for 2 or 3 coal seam parameters is very low; only coal seams of V4, V12, and V14 are higher (over 50%). After dividing the mining area, the identifying rate is higher, especially the coal seams of V5, V7, V11, V12, and V14 reach 30.38% on average compared to 16.83% for the whole mining area. Identifying coal seams based on six analyzed parameters shows 16.64% on average; the nine analyzed parameters show 25.93% on average. Generally, each environment has increased significantly after dividing the identifying rates of coal seams according to seam parameters and coal quality. Using the seam characteristics as thickness, dip angle, the number of interlayers, and coal quality, they help divide the Nui Beo mine into 07 relatively homogenous blocks, namely A1, A2, A3, B, C, D, and E, respectively. In which block A1 is formed in a swamp environment; blocks A2 and A3 are characterized by a mudflat environment; block B is suggested a flow environment; block C is characterized by mudflat; block D features a swampy and block E in the periphery. The results confirm that applied mathematical methods in geological science are effective, especially in identifying coal seams and sedimentary environments.

Fast Fourier transform for fingerprint enhancement and features extraction with adaptive block size using orientation fields

Extracting minutiae from a digital fingerprint is a crucial step in a fingerprint-based recognition systems. This work deals with poor-quality fingerprint images containing broken ridges. The enhancement stage connects broken ridges and is essential for extracting correct minutiae. We use a FFT variant [8] for this stage, but, to truly benefit from FFT in a block, it is essential to determine a suitable block size, depending on ridges orientation field. We propose to use a quadtree to partition the ridges orientation field into homogeneous blocks. A block is homogeneous when at least seventy percent of its ridges orientations are within ten degrees. Another issue addressed in this article is the choice of a suitable neighborhood window size W for computing orientation field image, depending on the fingerprint image quality. The performance improvements of our algorithm are evaluated and compared with standard measures MSE, PSNR and GI, on databases DB1 to DB4 of FVC2004 and NIST special database SD302d.