Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.198
Filtrar
1.
Elife ; 102021 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-34739372

RESUMO

How fast the brain and muscles can respond to information about prey location constrains visual and echolocating predators in similar ways.


Assuntos
Ecolocação , Acústica , Animais , Encéfalo , Baleias
2.
Elife ; 102021 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-34696826

RESUMO

Visual predators rely on fast-acting optokinetic responses to track and capture agile prey. Most toothed whales, however, rely on echolocation for hunting and have converged on biosonar clicking rates reaching 500/s during prey pursuits. If echoes are processed on a click-by-click basis, as assumed, neural responses 100× faster than those in vision are required to keep pace with this information flow. Using high-resolution biologging of wild predator-prey interactions, we show that toothed whales adjust clicking rates to track prey movement within 50-200 ms of prey escape responses. Hypothesising that these stereotyped biosonar adjustments are elicited by sudden prey accelerations, we measured echo-kinetic responses from trained harbour porpoises to a moving target and found similar latencies. High biosonar sampling rates are, therefore, not supported by extreme speeds of neural processing and muscular responses. Instead, the neurokinetic response times in echolocation are similar to those of tracking responses in vision, suggesting a common neural underpinning.


Assuntos
Ecolocação , Comportamento Predatório , Baleias/fisiologia , Acústica , Animais , Fenômenos Biomecânicos , Cinética
3.
Anal Chem ; 93(37): 12733-12739, 2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34499489

RESUMO

Nanoscale secondary ion mass spectrometry (NanoSIMS) is a dynamic SIMS technique, which offers high spatial resolution allowing the mapping of chemical elements at the nanometer scale combined with high sensitivity. However, SIMS for mercury analysis is a challenging issue due to the low secondary ion yield and has never been done on NanoSIMS. The introduction of an rf plasma oxygen primary ion source on NanoSIMS enabled higher lateral resolution and higher sensitivity for electropositive elements such as most metals. In this paper, for the first time, mercury analysis by NanoSIMS was developed applying the new rf plasma O- ion source. All mercury isotopes could be detected as Hg+ secondary ions and the isotopic pattern corresponded to their natural isotopic abundances. Furthermore, Hg+ detection in HgSe nanocrystals has been investigated where polyatomic interferences from selenium clusters were identified and separated by high mass resolution (ΔM/M ≥ 3200). However, in the presence of selenium a strong matrix effect was observed, decreasing the Hg+ secondary ion yield. In addition, a detection of Se+ ions was possible, too. The newly developed method was successfully applied to nanoscale localization by chemical imaging of HgSe particles accumulated in the liver tissue of sperm whale (Physeter macrocephalus). This demonstrated the applicability of NanoSIMS not only for mercury detection in surface analysis but also for mercury mapping in biological samples.


Assuntos
Mercúrio , Selênio , Animais , Fígado , Espectrometria de Massa de Íon Secundário , Baleias
4.
J Acoust Soc Am ; 150(2): 1264, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34470309

RESUMO

We present a new method of detecting North Atlantic Right Whale (NARW) upcalls using a Multimodel Deep Learning (MMDL) algorithm. A MMDL detector is a classifier that embodies Convolutional Neural Networks (CNNs) and Stacked Auto Encoders (SAEs) and a fusion classifier to evaluate their output for a final decision. The MMDL detector aims for diversity in the choice of the classifier so that its architecture is learned to fit the data. Spectrograms and scalograms of signals from passive acoustic sensors are used to train the MMDL detector. Guided by previous applications, we trained CNNs with spectrograms and SAEs with scalograms. Outputs from individual models were evaluated by the fusion classifier. The results obtained from the MMDL algorithm were compared to those obtained from conventional machine learning algorithms trained with handcrafted features. It showed the superiority of the MMDL algorithm in terms of the upcall detection rate, non-upcall detection rate, and false alarm rate. The autonomy of the MMDL detector has immediate application to the effective monitoring and protection of one of the most endangered species in the world where accurate call detection of a low-density species is critical, especially in environments of high acoustic-masking.


Assuntos
Aprendizado Profundo , Baleias , Acústica , Algoritmos , Animais , Redes Neurais de Computação
5.
J Acoust Soc Am ; 150(2): 1120, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34470263

RESUMO

Passive acoustic monitoring using a towed line array of hydrophones is a standard method for localizing cetaceans during line-transect cetacean abundance surveys. Perpendicular distances estimated between localized whales and the trackline are essential for abundance estimation using acoustic data. Uncertainties in the acoustic data from hydrophone movement, sound propagation effects, errors in the time of arrival differences, and whale depth are not accounted for by most two-dimensional localization methods. Consequently, location and distance estimates for deep-diving cetaceans may be biased, creating uncertainty in abundance estimates. Here, a model-based localization approach is applied to towed line array acoustic data that incorporates sound propagation effects, accounts for sources of error, and localizes in three dimensions. The whale's true distance, ship trajectory, and whale movement greatly affected localization results in simulations. The localization method was applied to real acoustic data from two separate sperm whales, resulting in three-dimensional distance and depth estimates with position bounds for each whale. By incorporating sources of error, this three-dimensional model-based approach provides a method to address and integrate the inherent uncertainties in towed array acoustic data for more robust localization.


Assuntos
Acústica , Vocalização Animal , Animais , Som , Cachalote , Baleias
6.
PLoS One ; 16(8): e0254393, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34449769

RESUMO

Narwhals (Monodon monoceros) are gregarious toothed whales that strictly reside in the high Arctic. They produce a broad range of signal types; however, studies of narwhal vocalizations have been mostly descriptive of the sounds available in the species' overall repertoire. Little is known regarding the functions of highly stereotyped mixed calls (i.e., biphonations with both sound elements produced simultaneously), although preliminary evidence has suggested that such vocalizations are individually distinctive and function as contact calls. Here we provide evidence that supports this notion in narwhal mother-calf communication. A female narwhal was tagged as part of larger studies on the life history and acoustic behavior of narwhals. At the time of tagging, it became apparent that the female had a calf, which remained close by during the tagging event. We found that the narwhal mother produced a distinct, highly stereotyped mixed call when separated from her calf and immediately after release from capture, which we interpret as preliminary evidence for contact call use between the mother and her calf. The mother's mixed call production occurred continually over the 4.2 day recording period in addition to a second prominent but different stereotyped mixed call which we believe belonged to the narwhal calf. Thus, narwhal mothers produce highly stereotyped contact calls when separated from their calves, and it appears that narwhal calves similarly produce distinct, stereotyped mixed calls which we hypothesize also contribute to maintaining mother-calf contact. We compared this behavior to the acoustic behavior of two other adult females without calves, but also each with a unique, stereotyped call type. While we provide additional support for individual distinctiveness across narwhal contact calls, more research is necessary to determine whether these calls are vocal signatures which broadcast identity.


Assuntos
Vocalização Animal/fisiologia , Baleias/fisiologia , Animais , Regiões Árticas , Feminino
7.
PLoS One ; 16(8): e0255368, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34343192

RESUMO

Most of our knowledge on reproductive biology of gray whales dates back to scientific research conducted during commercial whaling in the late 1950s and 1960s. The goal of the present study was to provide updated insights on reproductive physiology of gray whales, using progesterone and testosterone as biomarkers. We measured hormone concentrations using enzyme immunoassay (EIA) techniques in blubber biopsies collected from 106 individual whales from March to November over a span of 12 years (2004-2016) between California and Alaska. We found testosterone concentrations in males to increase significantly with age (P = 0.03). Adult males showed significantly elevated testosterone concentrations when sampled in the fall compared to the summer (P = 0.01), likely indicating physiological preparation for mating. We measured testosterone concentrations in females of different age classes, but no statistical differences were found. We found significantly higher progesterone concentrations in pregnant females compared to non-pregnant females and adult males (P< 0.001), indicating progesterone is a valid biomarker for pregnancy in gray whales. Both female and male calves had elevated progesterone concentrations, suggesting maternal transfer via lactation. We fit a mixture of two normal distributions to progesterone data from all non-calf females to identify clusters of high and low progesterone and estimated the probability of being pregnant for whales of unknown reproductive status. With this approach we identified likely pregnant and non-pregnant animals. This study represents an important milestone on reproductive profiles in this population, that can be used to estimate more accurate and precise reproductive parameters to be used for better understanding population dynamics of gray whales.


Assuntos
Biomarcadores/metabolismo , Progesterona/metabolismo , Comportamento Sexual Animal/fisiologia , Testosterona/metabolismo , Baleias/fisiologia , Fatores Etários , Alaska , Animais , California , Feminino , Lactação/metabolismo , Masculino , Gravidez
8.
PLoS One ; 16(8): e0254380, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34347780

RESUMO

Emergence of new technologies in remote sensing give scientists a new way to detect and monitor wildlife populations. In this study we assess the ability to detect and classify two emblematic Arctic cetaceans, the narwhal (Monodon monoceros) and beluga whale (Delphinapterus leucas), using very high-resolution (VHR) satellite imagery. We analyzed 12 VHR images acquired in August 2017 and 2019, collected by the WorldView-3 satellite, which has a maximum resolution of 0.31 m per pixel. The images covered Clearwater Fiord (138.8 km2), an area on eastern Baffin Island, Canada where belugas spend a large part of the summer, and Tremblay Sound (127.0 km2), a narrow water body located on the north shore of Baffin Island that is used by narwhals during the open water season. A total of 292 beluga whales and 109 narwhals were detected in the images. This study contributes to our understanding of Arctic cetacean distribution and highlights the capabilities of using satellite imagery to detect marine mammals.


Assuntos
Migração Animal/fisiologia , Beluga/fisiologia , Baleias/fisiologia , Animais , Regiões Árticas , Canadá , Astronave
9.
Comput Intell Neurosci ; 2021: 9931521, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34335729

RESUMO

E-commerce has become a crucial business model through the Internet around the world. Therefore, its transaction trend forecast can provide important information for the market planning and development in advance. For this purpose, the integrated model of enhanced whale optimization algorithm (EWOA) with support vector machine (SVM) is proposed for forecast of E-commerce transaction trend in this study. First, the global optimization ability of the whale optimization algorithm (WOA) is enhanced by the search updating strategy. Second, multiple factors that may affect the E-commerce transaction trend are analyzed and determined using the gray correlation mechanism. Third, the EWOA algorithm is employed to optimize the SVM random parameters. Finally, the EWOA-SVM model is established for forecasting E-commerce transaction trend. Two representative cases tests confirm that the EWOA-SVM model is superior to other existing methods in terms of fast convergence speed and high prediction accuracy.


Assuntos
Máquina de Vetores de Suporte , Baleias , Algoritmos , Animais , Comércio , Previsões
10.
Sci Rep ; 11(1): 15986, 2021 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-34373473

RESUMO

Cetacean morbillivirus (CeMV) is a global threat to cetaceans. We report a novel morbillivirus from a Fraser's dolphin (Lagenodelphis hosei) that stranded in Maui, Hawaii in 2018 that is dissimilar to the beaked whale morbillivirus previously identified from Hawaii and to other CeMV strains. Histopathological findings included intranuclear inclusions in bile duct epithelium, lymphoid depletion, rare syncytial cells and non-suppurative meningitis. Cerebellum and lung tissue homogenates were inoculated onto Vero.DogSLAMtag cells for virus isolation and cytopathic effects were observed, resulting in the formation of multinucleated giant cells (i.e., syncytia). Transmission electron microscopy of infected cell cultures also revealed syncytial cells with intracytoplasmic and intranuclear inclusions of viral nucleocapsids, consistent with the ultrastructure of a morbillivirus. Samples of the cerebellum, lung, liver, spleen and lymph nodes were positive for morbillivirus using a reverse transcription-polymerase chain reaction. The resulting 559 bp L gene sequence had the highest nucleotide identity (77.3%) to porpoise morbillivirus from Northern Ireland and the Netherlands. The resulting 248 bp P gene had the highest nucleotide identity to porpoise morbillivirus in Northern Ireland and the Netherlands and to a stranded Guiana dolphin (Sotalia guianensis) in Brazil (66.9%). As Fraser's dolphins are a pelagic species that infrequently strand, a novel strain of CeMV may be circulating in the central Pacific that could have additional population impacts through transmission to other small island-associated cetacean species.


Assuntos
Golfinhos/virologia , Infecções por Morbillivirus/virologia , Morbillivirus/isolamento & purificação , Animais , Brasil/epidemiologia , Hawaii/epidemiologia , Infecções por Morbillivirus/epidemiologia , Países Baixos/epidemiologia , Irlanda do Norte/epidemiologia , Baleias/virologia
11.
Proc Biol Sci ; 288(1957): 20211368, 2021 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-34428967

RESUMO

Over about 10 million years, the ancestors of whales transformed from herbivorous, deer-like, terrestrial mammals into carnivorous and fully aquatic cetaceans. Protocetids are Eocene whales that represent a unique semiaquatic stage in that dramatic evolutionary transformation. Here, we report on a new medium-sized protocetid, Phiomicetus anubis gen. et sp. nov., consisting of a partial skeleton from the middle Eocene (Lutetian) of the Fayum Depression in Egypt. The new species differs from other protocetids in having large, elongated temporal fossae, anteriorly placed pterygoids, elongated parietals, an unfused mandibular symphysis that terminates at the level of P3, and a relatively enlarged I3. Unique features of the skull and mandible suggest a capacity for more efficient oral mechanical processing than the typical protocetid condition, thereby allowing for a strong raptorial feeding style. Phylogenetic analysis nests Phiomicetus within the paraphyletic Protocetidae, as the most basal protocetid known from Africa. Recovery of Phiomicetus from the same bed that yielded the remingtonocetid Rayanistes afer provides the first clear evidence for the co-occurrence of the basal cetacean families Remingtonocetidae and Protocetidae in Africa. The discovery of Phiomicetus further augments our understanding of the biogeography and feeding ecology of early whales.


Assuntos
Cervos , Baleias , Animais , Evolução Biológica , Fósseis , Filogenia , Crânio/anatomia & histologia
12.
J Morphol ; 282(9): 1415-1431, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34228354

RESUMO

The cetacean vertebral canal houses the spinal cord and arterial supply to and venous drainage from the entire central nervous system (CNS). Thus, unlike terrestrial mammals, the cetacean spinal cord lies within a highly vascularized space. We compared spinal cord size and vascular volumes within the vertebral canal across a sample of shallow and deep diving odontocetes. We predicted that the (a) spinal cord, a metabolically expensive tissue, would be relatively small, while (b) volumes of vascular structures would be relatively large, in deep versus shallow divers. Our sample included the shallow diving Tursiops truncatus (n = 2) and Delphinus delphis (n = 3), and deep diving Kogia breviceps (n = 2), Mesoplodon europaeus (n = 2), and Ziphius cavirostris (n = 1). Whole, frozen vertebral columns were cross-sectioned at each intervertebral disc, scaled photographs of vertebral canal contents acquired, and cross-sectional areas of structures digitally measured. Areas were multiplied by vertebral body lengths and summed to calculated volumes of neural and vascular structures. Allometric analyses revealed that the spinal cord scaled with negative allometry (b = 0.51 ± 0.13) with total body mass (TBM), and at a rate significantly lower than that of terrestrial mammals. As predicted, the spinal cord represented a smaller percentage of the total vertebral canal volume in the deep divers relative to shallow divers studied, as low as 2.8% in Z. cavirostris. Vascular volume scaled with positive allometry (b = 1.2 ± 0.22) with TBM and represented up to 96.1% (Z. cavirostris) of the total vertebral canal volume. The extreme deep diving beaked whales possessed 22-35 times more vascular volume than spinal cord volume within the vertebral canal, compared with the 6-10 ratio in the shallow diving delphinids. These data offer new insights into morphological specializations of neural and vascular structures that may contribute to differential diving capabilities across odontocete cetaceans.


Assuntos
Golfinho Nariz-de-Garrafa , Baleias , Animais , Medula Espinal , Coluna Vertebral
13.
Comput Intell Neurosci ; 2021: 5546758, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34211547

RESUMO

An important challenge facing cloud computing is how to correctly and effectively handle and serve millions of users' requests. Efficient task scheduling in cloud computing can intuitively affect the resource configuration and operating cost of the entire system. However, task and resource scheduling in a cloud computing environment is an NP-hard problem. In this paper, we propose a three-layer scheduling model based on whale-Gaussian cloud. In the second layer of the model, a whale optimization strategy based on the Gaussian cloud model (GCWOAS2) is used for multiobjective task scheduling in a cloud computing which is to minimize the completion time of the task via effectively utilizing the virtual machine resources and to keep the load balancing of each virtual machine, reducing the operating cost of the system. In the GCWOAS2 strategy, an opposition-based learning mechanism is first used to initialize the scheduling strategy to generate the optimal scheduling scheme. Then, an adaptive mobility factor is proposed to dynamically expand the search range. The whale optimization algorithm based on the Gaussian cloud model is proposed to enhance the randomness of search. Finally, a multiobjective task scheduling algorithm based on Gaussian whale-cloud optimization (GCWOA) is presented, so that the entire scheduling strategy can not only expand the search range but also jump out of the local maximum and obtain the global optimal scheduling strategy. Experimental results show that compared with other existing metaheuristic algorithms, our strategy can not only shorten the task completion time but also balance the load of virtual machine resources, and at the same time, it also has a better performance in resource utilization.


Assuntos
Computação em Nuvem , Baleias , Algoritmos , Animais , Distribuição Normal
14.
Proc Biol Sci ; 288(1954): 20211156, 2021 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-34229495

RESUMO

Animals use varied acoustic signals that play critical roles in their lives. Understanding the function of these signals may inform about key life-history processes relevant for conservation. In the case of fin whales (Balaenoptera physalus), that produce different call types associated with different behaviours, several hypotheses have emerged regarding call function, but the topic still remains in its infancy. Here, we investigate the potential function of two fin whale vocalizations, the song-forming 20-Hz call and the 40-Hz call, by examining their production in relation to season, year and prey biomass. Our results showed that the production of 20-Hz calls was strongly influenced by season, with a clear peak during the breeding months, and secondarily by year, likely due to changes in whale abundance. These results support the reproductive function of the 20-Hz song used as an acoustic display. Conversely, season and year had no effect on variation in 40-Hz calling rates, but prey biomass did. This is the first study linking 40-Hz call activity to prey biomass, supporting the previously suggested food-associated function of this call. Understanding the functions of animal signals can help identifying functional habitats and predict the negative effects of human activities with important implications for conservation.


Assuntos
Baleia Comum , Acústica , Animais , Biomassa , Vocalização Animal , Baleias
15.
J Acoust Soc Am ; 149(5): 2950, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34241117

RESUMO

Mitigation of threats posed to marine mammals by human activities can be greatly improved with a better understanding of animal occurrence in real time. Recent advancements have enabled low-power passive acoustic systems to be integrated into long-endurance autonomous platforms for persistent near real-time monitoring of marine mammals via the sounds they produce. Here, the integration of a passive acoustic instrument capable of real-time detection and classification of low-frequency (LF) tonal sounds with a Liquid Robotics wave glider is reported. The goal of the integration was to enable monitoring of LF calls produced by baleen whales over periods of several months. Mechanical noises produced by the platform were significantly reduced by lubricating moving parts with polytetrafluoroethylene, incorporating rubber and springs to decelerate moving parts and shock mounting hydrophones. Flow noise was reduced with the development of a 21-element hydrophone array. Surface noise produced by breaking waves was not mitigated despite experimentation with baffles. Compared to a well-characterized moored passive acoustic monitoring buoy, the system greatly underestimated the occurrence of sei, fin, and North Atlantic right whales during a 37-d deployment, and therefore is not suitable in its current configuration for use in scientific or management applications for these species at this time.


Assuntos
Vocalização Animal , Baleias , Acústica , Animais , Ruído
16.
Can Vet J ; 62(7): 765-766, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34219789

Assuntos
Baleias , Animais
17.
J Acoust Soc Am ; 149(6): 4264, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34241431

RESUMO

Fin whale 20 Hz calls were detected, localized, and tracked using a 10 km aperture network of three acoustic receivers deployed for 11 months in a Pacific Canadian fjord system. The area has been historically important for fin whales and is located along a route that tankers will begin using in 2024. A total of 6712 calls were localized, and trajectories were fitted for 55 acoustic tracks. Fin whale tracks occurred throughout the monitoring site. Call activity peaked in September and was low during winter months. Swimming characteristics varied significantly between day- and nighttime: at night, whales swam faster (7.1 vs 4.0 km/h median, +75.2%), which resulted in longer (+34.7%), less predictable (-70.6%) tracks as compared to daylight hours. Call frequencies varied between 16 and 32 Hz. Beside stereotypical song frequencies, fin whales also used irregular frequency components, which contributed the majority of calls in the summer but did not occur in the winter. The results suggest that the area is primarily used as a summer feeding ground, where fin whales follow a diel behavioral cycle. The observed activity patterns will aid in the assessment of strike risk and harassment mitigation and provide a baseline to document behavioral change.


Assuntos
Baleia Comum , Acústica , Animais , Canadá , Ecossistema , Estuários , Vocalização Animal , Baleias
18.
J Acoust Soc Am ; 149(6): 3797, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34241455

RESUMO

This paper proposes a robust system for detecting North Atlantic right whales by using deep learning methods to denoise noisy recordings. Passive acoustic recordings of right whale vocalisations are subject to noise contamination from many sources, such as shipping and offshore activities. When such data are applied to uncompensated classifiers, accuracy falls substantially. To build robustness into the detection process, two separate approaches that have proved successful for image denoising are considered. Specifically, a denoising convolutional neural network and a denoising autoencoder, each of which is applied to spectrogram representations of the noisy audio signal, are developed. Performance is improved further by matching the classifier training to include the vestigial signal that remains in clean estimates after the denoising process. Evaluations are performed first by adding white, tanker, trawler, and shot noises at signal-to-noise ratios from -10 to +5 dB to clean recordings to simulate noisy conditions. Experiments show that denoising gives substantial improvements to accuracy, particularly when using the vestigial-trained classifier. A final test applies the proposed methods to previously unseen noisy right whale recordings and finds that denoising is able to improve performance over the baseline clean-trained model in this new noise environment.


Assuntos
Aprendizado Profundo , Baleias , Animais , Redes Neurais de Computação , Ruído/efeitos adversos , Razão Sinal-Ruído
19.
J Acoust Soc Am ; 149(6): 3830, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34241458

RESUMO

Acoustic point-transect distance-sampling surveys have recently been used to estimate the density of beaked whales. Typically, the fraction of short time "snapshots" with detected beaked whales is used in this calculation. Beaked whale echolocation pulses are only intermittently available, which may affect the best choice of snapshot length. The effect of snapshot length on density estimation for Cuvier's beaked whale (Ziphius cavirostris) is investigated by sub-setting continuous recordings from drifting hydrophones deployed off southern and central California. Snapshot lengths from 20 s to 20 min are superimposed on the time series of detected beaked whale echolocation pulses, and the components of the density estimation equation are estimated for each snapshot length. The fraction of snapshots with detections, the effective area surveyed, and the snapshot detection probability all increase with snapshot length. Due to compensatory changes in these three components, density estimates show very little dependence on snapshot length. Within the range we examined, 1-2 min snapshots are recommended to avoid the potential bias caused by animal movement during the snapshot period and to maximize the sample size for estimating the effective area surveyed.


Assuntos
Ecolocação , Baleias , Acústica , Animais
20.
Sensors (Basel) ; 21(13)2021 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-34283139

RESUMO

There is a crucial need to process patient's data immediately to make a sound decision rapidly; this data has a very large size and excessive features. Recently, many cloud-based IoT healthcare systems are proposed in the literature. However, there are still several challenges associated with the processing time and overall system efficiency concerning big healthcare data. This paper introduces a novel approach for processing healthcare data and predicts useful information with the support of the use of minimum computational cost. The main objective is to accept several types of data and improve accuracy and reduce the processing time. The proposed approach uses a hybrid algorithm which will consist of two phases. The first phase aims to minimize the number of features for big data by using the Whale Optimization Algorithm as a feature selection technique. After that, the second phase performs real-time data classification by using Naïve Bayes Classifier. The proposed approach is based on fog Computing for better business agility, better security, deeper insights with privacy, and reduced operation cost. The experimental results demonstrate that the proposed approach can reduce the number of datasets features, improve the accuracy and reduce the processing time. Accuracy enhanced by average rate: 3.6% (3.34 for Diabetes, 2.94 for Heart disease, 3.77 for Heart attack prediction, and 4.15 for Sonar). Besides, it enhances the processing speed by reducing the processing time by an average rate: 8.7% (28.96 for Diabetes, 1.07 for Heart disease, 3.31 for Heart attack prediction, and 1.4 for Sonar).


Assuntos
Algoritmos , Baleias , Animais , Teorema de Bayes , Big Data , Atenção à Saúde
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...