Use Of Multi-scale Approach Research Articles

Multiscale entropy analysis of monthly rainfall time series in Paraíba, Brazil

In this work we study the complexity of monthly rainfall temporal series recorded from 1962 to 2012, at 69 meteorological stations in Paraiba state, northeastern Brazil. We use the Modified Multiscale Entropy Method (MMSE) suitable for short time series and analyze rainfall regularity over a wide range of temporal scales from 1 month to 1 year. By comparing the results for stations across Paraiba state and performing a statistical significance test, we distinguish rainfall regime in the inland semiarid Sertão and Borborema regions from the transition inland Agreste, and coastal, tropical humid Mata regions. Our work represents a contribution to establishing the use of multiscale approach with methods from information theory in climatological studies.

Ceco Environmental Corp, USA

In this work we study the complexity of monthly rainfall temporal series recorded from 1962 to 2012, at 69 meteorological stations in Paraiba state, northeastern Brazil. We use the Modified Multiscale Entropy Method (MMSE) suitable for short time series and analyze rainfall regularity over a wide range of temporal scales from 1 month to 1 year. By comparing the results for stations across Paraiba state and performing a statistical significance test, we distinguish rainfall regime in the inland semiarid Sertão and Borborema regions from the transition inland Agreste, and coastal, tropical humid Mata regions. Our work represents a contribution to establishing the use of multiscale approach with methods from information theory in climatological studies.

Asahi Kasei Corp, Japan

In this work we study the complexity of monthly rainfall temporal series recorded from 1962 to 2012, at 69 meteorological stations in Paraiba state, northeastern Brazil. We use the Modified Multiscale Entropy Method (MMSE) suitable for short time series and analyze rainfall regularity over a wide range of temporal scales from 1 month to 1 year. By comparing the results for stations across Paraiba state and performing a statistical significance test, we distinguish rainfall regime in the inland semiarid Sertão and Borborema regions from the transition inland Agreste, and coastal, tropical humid Mata regions. Our work represents a contribution to establishing the use of multiscale approach with methods from information theory in climatological studies.

Multi-Scale Self-Guided Attention for Medical Image Segmentation.

Even though convolutional neural networks (CNNs) are driving progress in medical image segmentation, standard models still have some drawbacks. First, the use of multi-scale approaches, i.e., encoder-decoder architectures, leads to a redundant use of information, where similar low-level features are extracted multiple times at multiple scales. Second, long-range feature dependencies are not efficiently modeled, resulting in non-optimal discriminative feature representations associated with each semantic class. In this paper we attempt to overcome these limitations with the proposed architecture, by capturing richer contextual dependencies based on the use of guided self-attention mechanisms. This approach is able to integrate local features with their corresponding global dependencies, as well as highlight interdependent channel maps in an adaptive manner. Further, the additional loss between different modules guides the attention mechanisms to neglect irrelevant information and focus on more discriminant regions of the image by emphasizing relevant feature associations. We evaluate the proposed model in the context of semantic segmentation on three different datasets: abdominal organs, cardiovascular structures and brain tumors. A series of ablation experiments support the importance of these attention modules in the proposed architecture. In addition, compared to other state-of-the-art segmentation networks our model yields better segmentation performance, increasing the accuracy of the predictions while reducing the standard deviation. This demonstrates the efficiency of our approach to generate precise and reliable automatic segmentations of medical images. Our code is made publicly available at: https://github.com/sinAshish/Multi-Scale-Attention.

Material testing of magnesium alloy AZ31B using a finite element polycrystal method based on a rate independent crystal plasticity model

Magnesium and its alloys are attractive structural light materials because they have a high spe-cific strength and high specific stiffness. That is why their usage in high performance automotive and aerospace applications has been increased. However, their high anisotropy and low ductility could bring to forming failure, to avoid these a better accuracy for metal forming simulation is re-quired. The identification of macroscopic parameters is expensive due to the experiments needed to find them, the use of multi-scale approach allows to find parameters for the model through easier experiments. A finite element polycrystal method, based on a rate independent polycrystal plasticity model, is implemented in order to perform the material testing of a cast magnesium alloy AZ31B. The parameters of the model are adjusted to better fit the experimental data through a trial and error process.

Multiscale patterns of rarity in fungi, inferred from fruiting records

AbstractAimIt is unknown whether fungi show similar trends to other organisms in their macroecological patterns of abundance and spatial distribution. Here, we investigated fungal abundance–occupancy relationships to determine whether fungi that are common at a local scale tend to be more widely distributed.LocationUK and Switzerland.Time period1950–2014.Major taxa studiedFungi.MethodsWe used a local data set of fruiting records of 2,319 species in the UK, accumulated over 65 years, and one from Switzerland of 319 species, spanning 32 years. Using the number of records and occurrence as proxies for abundance, in each case we examined the form of species and rank abundance distributions and compared these with distributions of records in the national databases over the same time. We plotted relationships of the local number of records and regional occupancy and calculated multiscale indices of rarity for all fungal species.ResultsThere was a remarkable congruence in the patterns found in the UK and Switzerland. Regional assemblages are characterized by many rare species, whereas few are common (fitting the lognormal distribution). However, at local scales, distributions best fitted a power law, suggesting that habitat availability or dispersal processes might play important roles. Fungi with a high number of local records are densely distributed nationally, but unlike other organisms, locally rare fungi may also be densely distributed at a wider scale.Main conclusionsFungal fruiting records can be used to infer patterns in fungal distributions. Abundances in local assemblages may be determined by the position of the assemblage in the overall geographical range of each species, dispersal ability and environmental filtering. We advocate the use of multiscale approaches to rarity in future fungal sampling programmes, to provide more reliable information for future conservation policy decisions and fungal biogeography.

Diversity patterns of alien and native plant species in Trieste port area: exploring the role of urban habitats in biodiversity conservation

Nowadays, urban areas play a crucial role in biodiversity conservation and habitat protection despite the constant pressures on which these habitats are subjected. They may even host relatively new plant communities due to the peculiar ecosystem where they vegetate. The port of Trieste (NE Italy) is characterized by a mixed mosaic of intensely human impacted areas (where commercial activities are still ongoing) flanked by abandoned areas where vegetation persists or has spontaneously recovered. In this study, we sampled the whole port area through a stratified random sampling by placing multiscalar nested plots in four different habitats (strata) previously identified by photo-interpretation. Plant species richness and abundance were assessed in each plot. Each species was then classified as native or alien and patterns of species richness and complementarity were compared among habitats. Results show that there is a significant difference in species richness patterns among habitats, while observed patterns are likely to vary at different spatial scales. As expected, urban plots account for most of the alien species in the sampling, while wooded plots cope better with invasion, accounting for a lower alien/native ratio. These results highlight how habitat diversity enhances biodiversity in urban areas and how it could provide an effective filtering effect able to reduce the spread of alien species. In addition, we provide further evidence for the use of multi-scale approaches in order to study the complex relationships between spatial heterogeneity and plant species richness.

Multiscale approach for modeling electron spectra induced by photons from solids

Physical and chemical phenomena reflected in electron spectra excited by photons from solids take place on very wide scales of space, time, and excitation energy, covering sometimes differences of many orders of magnitude. Therefore, the use of multiscale approaches seems to be promising when extracting information on electronic structure or chemical composition from such electron spectra. Following a summary of phenomena reflected in electron spectra induced from solids by photons and different type of models available for their interpretation, the challenges of characterization of advanced materials and the need for multiscale materials analysis and modeling will be discussed. Copyright © 2015 John Wiley & Sons, Ltd.

Use of Multi-scale Approach for Vehicle Weight Reduction Study

This paper presents the use of the multi-scale approach developed by Nexter, to study the weight reduction of military armored vehicles. The fatigue design of such mechanical system is often complex due to the gap between the scale of the system and the scale at which the fatigue phenomenon occurs. The multi-scale approach developed by Nexter involves first simulating the dynamic behavior of the mechanical system, then a dynamic finite element model coupled with a global fatigue criterion identifies the weak points location of the structure for different combination of loads. By focusing on these hot spots, local modeling including geometric singularities are done to assess fatigue life. This process is illustrated on a vehicle structure to study different concepts of weight reduction.

Verification of a Two-Way Coupled Multiscale Finite Element Code for Dynamic/Impact Problems

Engineering applications are increasingly facing structural challenges. Restrictive economic constraints and more complex geometric design have led to the use of advanced materials, such as fiber-reinforced composites. The behavior of such materials is governed by their microstructure, thus demanding the use of multiscale approaches. The present article aims at the verification of a two-way coupled multiscale finite element code previously developed by the authors. A two-scale analytical solution for a functionally graded elastic material subject to dynamic loads is herein derived in order to verify the multiscale code. Comparisons to overkilled single scale finite element solutions are also presented.

Monitoring effects of GM crops on butterflies: the use of multiscale approaches for general surveillance

According to EU Directive 2001/18/EC, a general surveillance monitoring must be implemented to detect possible unexpected effects of genetically modified (GM) crops on the environment. Butterflies have been proposed to be suitable indicators for monitoring environmental changes in agricultural landscapes. Using such mobile organisms as indicators for general surveillance is a challenge as their populations vary according to many environmental factors acting at the field, landscape and regional scales. They might thus not be appropriate to detect unexpected effects of GM crops, unless the sources of variation in their populations can be identified and accounted for. In the present study we use a multiscale approach to describe the interactions between butterfly populations, the environment and farming activities. We analysed existing butterfly data from several Swiss agricultural landscapes in order to identify the sources of variation in butterfly populations and to give guidelines for the design of general surveillance protocols for butterflies.