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1.
Sensors (Basel) ; 17(1)2017 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-28075372

RESUMO

Provision of energy to wireless sensor networks is crucial for their sustainable operation. Sensor nodes are typically equipped with batteries as their operating energy sources. However, when the sensor nodes are sited in almost inaccessible locations, replacing their batteries incurs high maintenance cost. Under such conditions, wireless charging of sensor nodes by a mobile charger with an antenna can be an efficient solution. When charging distributed sensor nodes, a directional antenna, rather than an omnidirectional antenna, is more energy-efficient because of smaller proportion of off-target radiation. In addition, for densely distributed sensor nodes, it can be more effective for some undercharged sensor nodes to harvest energy from neighboring overcharged sensor nodes than from the remote mobile charger, because this reduces the pathloss of charging signal due to smaller distances. In this paper, we propose a hybrid charging scheme that combines charging by a mobile charger with a directional antenna, and energy trading, e.g., transferring and harvesting, between neighboring sensor nodes. The proposed scheme is compared with other charging scheme. Simulations demonstrate that the hybrid charging scheme with a directional antenna achieves a significant reduction in the total charging time required for all sensor nodes to reach a target energy level.

2.
Sci Rep ; 14(1): 8629, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38622228

RESUMO

One of the biggest problems with Internet of Things (IoT) applications in the real world is ensuring data integrity. This problem becomes increasingly significant as IoT expands quickly across a variety of industries. This study presents a brand-new data integrity methodology for Internet of Things applications. The "sequence sharing" and "data exchange" stages of the suggested protocol are divided into two parts. During the first phase, each pair of nodes uses a new chaotic model for securely exchanging their identity information to generate a common sequence. This phase's objectives include user authentication and timing calculations for the second phase of the recommended method's packet validation phase. The recommended approach was tested in numerous settings, and various analyses were taken into account to guarantee its effectiveness. Also, the results were compared with the conventional data integrity control protocol of IoT. According to the results, the proposed method is an efficient and cost-effective integrity-ensuring mechanism with eliminates the need for third-party auditors and leads to reducing energy consumption and packet overhead. The results also show that the suggested approach is safe against a variety of threats and may be used as a successful integrity control mechanism in practical applications.

3.
Sci Rep ; 14(1): 16701, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39030213

RESUMO

Due to their simplicity of implementation and compliance with the encryption issue, chaotic models are often utilized in picture encryption applications. Despite having many benefits, this approach still has a crucial space issue that makes encryption algorithms based on it susceptible to brute-force assaults. This research's proposed novel picture encryption technique has a vast key space and great key sensitivity. To achieve this goal, the proposed method combines two-way chaotic maps and reversible cellular automata (RCA). First, this approach uses a two-way chaotic model named spatiotemporal chaos for image confusion. This step includes permuting the image pixels using a chaotic map at the byte level. Then, the RCA model is utilized for image diffusion. In this step, the RCA model iterates over image pixels to modify them at the bit level. The method's performance in encrypting grayscale images was evaluated using various analysis methods. According to the results, the proposed method is a compelling image encryption algorithm with high robustness against brute-force, statistical, and differential attacks.

4.
Sci Rep ; 14(1): 2170, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38273051

RESUMO

As is known, having a reliable analysis of energy sources is an important task toward sustainable development. Solar energy is one of the most advantageous types of renewable energy. Compared to fossil fuels, it is cleaner, freely available, and can be directly exploited for electricity. Therefore, this study is concerned with suggesting novel hybrid models for improving the forecast of Solar Irradiance (IS). First, a predictive model, namely Feed-Forward Artificial Neural Network (FFANN) forms the non-linear contribution between the IS and dominant meteorological and temporal parameters (including humidity, temperature, pressure, cloud coverage, speed and direction of wind, month, day, and hour). Then, this framework is optimized using several metaheuristic algorithms to create hybrid models for predicting the IS. According to the accuracy assessments, metaheuristic algorithms attained satisfying training for the FFANN by using 80% of the data. Moreover, applying the trained models to the remaining 20% proved their high proficiency in forecasting the IS in unseen environmental circumstances. A comparison among the optimizers revealed that Equilibrium Optimization (EO) could achieve a higher accuracy than Wind-Driven Optimization (WDO), Optics Inspired Optimization (OIO), and Social Spider Algorithm (SOSA). In another phase of this study, Principal Component Analysis (PCA) is applied to identify the most contributive meteorological and temporal factors. The PCA results can be used to optimize the problem dimension, as well as to suggest effective real-world measures for improving solar energy production. Lastly, the EO-based solution is yielded in the form of an explicit formula for a more convenient estimation of the IS.

5.
Heliyon ; 9(11): e20890, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37928024

RESUMO

The health-care industry is in a state of constant flux, with new challenges and opportunities emerging regularly. Hospitals, as the cornerstone of health-care delivery, must adapt and embrace change to provide optimal patient care. One crucial aspect that plays a significant role in the success of hospitals is sustainable learning. Sustainable learning refers to acquiring knowledge, skills, and competencies that enable health-care professionals to adapt to changes, implement best practices, and deliver high-quality care. Sustainable learning, a concept gaining prominence, emphasizes the ability of hospitals to learn from experiences and adapt to changing circumstances while maintaining quality health-care delivery. This article aims to investigate the role of hospital capabilities in sustainable learning and explore how hospitals can foster an environment that promotes continuous learning and development. Another goal of the paper is to test the relationships between cultural capabilities, structural capabilities, knowledge management capabilities, Information Technology (IT) infrastructure, top management support, application capabilities, and sustainable learning. The Partial Least-Squares (PLS) algorithm was performed using SmartPLS 3.0 to attain this goal. The results successfully support the study goals. This study verified that cultural capability, structural capabilities, knowledge management capabilities, IT infrastructure, top management support, and application capabilities positively affected sustainable learning. This investigation contributes to hospital, management, and education research by developing an integrated paradigm for sustainable learning. In conclusion, the new conceptual model presented here provides a robust framework for investigating the role of hospital capabilities in sustainable learning. By understanding and improving their capabilities, hospitals can not only adapt to change but also thrive in an ever-changing health-care landscape.

6.
Sci Rep ; 13(1): 19377, 2023 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-37938553

RESUMO

Skin Cancer (SC) is one of the most dangerous types of cancer and if not treated in time, it can threaten the patient's life. With early diagnosis of this disease, treatment methods can be used more effectively and the progression of the disease can be prevented. Machine Learning (ML) techniques can be utilized as a useful and efficient tool for SCD. So far, various methods for automatic SCD based on ML techniques have been presented; However, this research field still requires the application of optimal and efficient models to increase the accuracy of SCD. Therefore, in this article, a new method for SCD using a combination of optimization techniques and Artificial Neural Networks (ANNs) is presented. The proposed method includes four steps: pre-processing, segmentation, feature extraction, and classification. Image segmentation for identifying the lesion region is performed using a Kohonen neural network, where the identified region of interest (ROI) is enhanced using the Greedy Search Algorithm (GSA). The proposed method, uses a Convolutional Neural Network (CNN) for extracting features from ROIs. Also, to classify features, an ANN is used, and by the Improved Gray Wolf Optimization (IGWO) algorithm, the number of neurons and weight vector are adjusted. In this method, a probabilistic model is used to improve the convergence speed of the GWO algorithm. Based on the evaluation results, using the IGWO model to optimize the structure and weight vector of the ANN can be effective in increasing the diagnosis accuracy by at least 5%. The results of implementing the proposed method and comparing its performance with previous methods also show that this method can diagnose SC in the ISIC-2016 and ISIC-2017 databases with an average accuracy of 97.09 and 95.17%, respectively; which improves accuracy by at least 0.5% compared to other methods.


Assuntos
Neoplasias Cutâneas , Humanos , Neoplasias Cutâneas/diagnóstico , Pele , Redes Neurais de Computação , Algoritmos , Bases de Dados Factuais
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