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排序方式: 共有107条查询结果,搜索用时 31 毫秒
1.
The evolution of the Internet of Things (IoT) has empowered modern industries with the capability to implement large-scale IoT ecosystems, such as the Industrial Internet of Things (IIoT). The IIoT is vulnerable to a diverse range of cyberattacks that can be exploited by intruders and cause substantial reputational and financial harm to organizations. To preserve the confidentiality, integrity, and availability of IIoT networks, an anomaly-based intrusion detection system (IDS) can be used to provide secure, reliable, and efficient IIoT ecosystems. In this paper, we propose an anomaly-based IDS for IIoT networks as an effective security solution to efficiently and effectively overcome several IIoT cyberattacks. The proposed anomaly-based IDS is divided into three phases: pre-processing, feature selection, and classification. In the pre-processing phase, data cleaning and normalization are performed. In the feature selection phase, the candidates’ feature vectors are computed using two feature reduction techniques, minimum redundancy maximum relevance and neighborhood components analysis. For the final step, the modeling phase, the following classifiers are used to perform the classification: support vector machine, decision tree, k-nearest neighbors, and linear discriminant analysis. The proposed work uses a new data-driven IIoT data set called X-IIoTID. The experimental evaluation demonstrates our proposed model achieved a high accuracy rate of 99.58%, a sensitivity rate of 99.59%, a specificity rate of 99.58%, and a low false positive rate of 0.4%.  相似文献   
2.
Microsystem Technologies - The dynamic performance of a micro-resonator depends on its energy loss mechanism which is quantified by Q-factor (Quality factor). This paper presents numerical...  相似文献   
3.
The tremendous development of cloud computing with related technologies is an unexpected one. However, centralized cloud storage faces few challenges such as latency, storage, and packet drop in the network. Cloud storage gets more attention due to its huge data storage and ensures the security of secret information. Most of the developments in cloud storage have been positive except better cost model and effectiveness, but still data leakage in security are billion-dollar questions to consumers. Traditional data security techniques are usually based on cryptographic methods, but these approaches may not be able to withstand an attack from the cloud server's interior. So, we suggest a model called multi-layer storage (MLS) based on security using elliptical curve cryptography (ECC). The suggested model focuses on the significance of cloud storage along with data protection and removing duplicates at the initial level. Based on divide and combine methodologies, the data are divided into three parts. Here, the first two portions of data are stored in the local system and fog nodes to secure the data using the encoding and decoding technique. The other part of the encrypted data is saved in the cloud. The viability of our model has been tested by research in terms of safety measures and test evaluation, and it is truly a powerful complement to existing methods in cloud storage.  相似文献   
4.
Universal access from a handheld device (such as a PDA, cell phone) at any time or anywhere is now a reality. Ubicomp Assistant (UA) (Sharmin et al. in Proceedings of the 21st annual ACM symposium on applied computing (ACM SAC 2006), Dijon, France, pp 1013–1017, 2006) is an integral service of MARKS (Sharmin et al. in Proceedings of the third international conference on information technology: new generations (ITNG 2006), Las Vegas, Nevada, USA, pp 306–313, 2006). It is a middleware developed for handheld devices, and has been designed to accommodate different types of users (e.g., education, healthcare, marketing, or business). This customizable service employs the ubiquitous nature of current short range, low-power wireless connectivity and readily available, low-cost lightweight mobile devices. These devices can reach other neighbouring devices using a free short-range ad hoc network. To the best of the authors’ knowledge, the UA service is the only service designed for these devices. This paper presents the details of Ubi-App, a ubiquitous application for universal access from any handheld device, which uses UA as a service. The results of a usability test and performance evaluation of the prototype show that Ubi-App is useful, easy to use, easy to install, and does not degrade the performance of the device.  相似文献   
5.
Relatively high purity of nitrogen atom encapsulated fullerene (N@C60) has been synthesized by an electron beam superimposed radio frequency (RF) discharge plasma method. Nitrogen species are characterized by an optical emission spectroscopy (OES); and a relationship between optical emission spectra and the purity of N@C60 has been examined. It is observed that the increased amount of nitrogen molecule ions impinging on the sublimated fullerenes enhance the synthesis of N@C60. Here, it is cleared that the efficient synthesis of N@C60 is possible by controlling the parameters of electron beam superimposed RF plasma. As a consequence, comparatively high purity of about 0.08% of N@C60 has been obtained.  相似文献   
6.
Cloud cover based solar radiation models are relatively simple and convenient as the models require the input of cloud cover data which are mostly available from the meteorological stations. In this study, the performance of a cloud cover based solar radiation model (Kasten–Czeplak model) with original or locally fitted coefficients was evaluated for estimating the hourly global solar radiation for four different locations in Western Canada. The average value of R2, mean bias error, and root mean square error are 0.69, ?61.6, and 157.9?W?m?2, respectively, for the model with original coefficients, whereas 0.82, 4.4, 107.1?W?m?2 with locally fitted coefficients. Results show that the Kasten–Czeplak model with locally fitted coefficients satisfactorily estimated the hourly solar radiation of four different locations in Western Canada. Also, the results indicate that the model with original coefficients has very limited accuracy under intermediate cloud cover conditions.  相似文献   
7.
The influences of annealing effects have been explored on the crystallinity, morphology, optical and magnetic properties of Ag–ZnO nanostructures prepared by a simple sol–gel method. X-ray powder diffraction, scanning electron microscope, high resolution transmission electron microscope (HRTEM), vibrating sample magnetometer and photoluminescence spectroscopy (PL) have been used to characterize the crystal structures, surface morphology, magnetic and optical properties of the pure ZnO and Ag–ZnO nanostructures respectively. The synthesized Ag–ZnO nanostructures are found to have hexagonal wurtzite crystal structures and their grain size increases while lattice strain decreases on annealing. From HRTEM observation, it is found that the annealed samples show nanorod like structures with Ag nanoparticles (NPs) embedded on the surface. Due to annealing effect, Ag–ZnO shows higher saturation magnetization at room temperature.  相似文献   
8.
Novel flexible dielectric composites composed of polyvinyl alcohol (PVA), polyethylene glycol (PEG), and graphene oxide (GO) with high dielectric constant and low dielectric loss have been developed using facile and eco-friendly colloidal processing technique. The structure and morphology of the PVA/PEG/GO composites were evaluated using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, UV-vis spectroscopy (UV-vis), X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The dielectric behavior of PVA/PEG/GO composites was investigated in the wide range of frequencies from 50 Hz to 20 MHz and temperature in the range 40 to 150 °C using impedance spectroscopy. The dielectric constant for PVA and PVA/PEG (50/50) blend film was found to be 10.71 (50 Hz, 150 °C) and 31.22 (50 Hz, 150 °C), respectively. The dielectric constant for PVA/PEG/GO composite with 3 wt% GO was found to be 644.39 (50 Hz, 150 °C) which is 60 times greater than the dielectric constant of PVA and 20 times greater than the dielectric constant of PVA/PEG (50/50) blend film. The PVA/PEG/GO composites not only show high dielectric constant but also show low dielectric loss which is highly attractive for practical applications. These findings underline the possibilities of using PVA/PEG/GO composites as a flexible dielectric material for high-performance energy storage applications such as embedded capacitors.  相似文献   
9.
Greenhouses in northern climates require a large amount of supplemental heating for growing crops in winter seasons, so energy‐efficient design of greenhouses based on local climate is important to minimize the heating demand. In this study, greenhouse design parameters including shape, orientation, the angle of the roof, and width of the span have been studied for the conceptual design of conventional greenhouses for Canadian Prairies using a heating simulation model. Five different shapes of greenhouses including even‐span, uneven‐span, modified arch, vinery, and quonset shape have been selected for the study. The simulation results proved that the uneven‐span gable roof shape receives the highest solar radiation, whereas the quonset shape receives the lowest solar radiation. However, the quonset shape greenhouse requires about 7.6% less annual heating as compared to the gable roof greenhouse, but the quonset would not be adopted as multispan greenhouses. Therefore, the gable roof greenhouse is considered as energy efficient for the multispan gutter connected greenhouses whereas quonset shape as a free‐standing single‐span greenhouses. In high northern latitudes, the greenhouse with east‐west orientation is more energy efficient from heating and cooling point of view when the length‐width ratio of the greenhouse is more than 1. The heating energy saving potential of the large span width in single‐span greenhouses is relatively higher as compared to the multispan greenhouses.  相似文献   
10.
The use of non-equilibrium models for integrated processes involving liquid-liquid systems has increased in recent years. These processes often exhibit complex dynamic behavior. These dynamical systems still pose many open questions, e.g. with regard to the sources of multiple steady states (MSS). This article analyzes the effect of mass transfer on the MSS of these systems. A generalized non-equilibrium modeling approach based on linear thermodynamics of irreversible processes (LTIP) is presented, and the dynamics of the system is studied systematically. It is shown that the non-linearity present in even the simplest non-ideal activity model acts as a source for MSS. The parameters that affect the solubility, e.g. temperature, can play a critical role on the existence of MSS in the system. A geometrical visualization of the MSS is also illustrated.  相似文献   
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