Hasil untuk "Electronics"

Shihao Zhang, Yanhui Xiao, Huawei Tian et al.

Abstract Unlike single-image steganography, the scheme of payload distribution on different images plays a pivotal role in the security performance of multi-image steganography. In this paper, a novel multi-image steganography scheme: image stitching sender (ISS) is proposed, which achieves optimal payload distribution by optimizing the stitching scheme of multi-cover-images. In the ISS scheme, we employ peak signal-to-noise ratio as the similarity evaluation metric for the stitched cover image and stego image. Besides, genetic algorithm is used to find the local optimal solution for the similarity, corresponding to a locally optimal multi-image steganographic stitching scheme. The experiment demonstrates that ISS exhibits enhanced anti-detection capabilities in comparison to other multi-image steganography schemes. Furthermore, when combined with non-additive embedding methods, the ISS can achieve a more substantial improvement in security compared to additive embedding methods.

M.I. Sayyed, Abdelmoneim Saleh, Anjan Kumar et al.

Investigations were conducted on the addition of barium's impact on the radiation shielding and physical attributes of five different glasses, designated S1–S5, with varying BaO contents. Using two point sources namely Co60 and Cs137 along with a scintillation detector [NaI(TL)], experimental measurements were made of the shielding parameters of γ-rays, namely the effective atomic number (Zeff), electron density (Nel), half-value layer (HVL), linear attenuation coefficient (μ), mass attenuation coefficient (μm), mean free path (λ), and radiation protection effectiveness at the energies of 0.664, 1.177, and 1.334 MeV, and comparisons made with recently considered glasses as well as frequently employed materials for γ-ray shielding. The results show that the examined glasses' physical and radiation shielding qualities are improved by the addition of BaO. The μ values increased from 0.245 to 0.275 cm−1 (0.662 MeV), from 0.174 to 0.198 cm−1 (1.173 MeV), and from 0.161 to 0.189 (1.332 MeV). The observed values of HVL decreased from 2.83, 3.98, and 4.3 cm to 2.5, 3.5, and 3.62 cm at 0.662, 1.173, and 1.332 MeV, respectively, for the samples S1 and S5. In addition, the S5 glass sample was determined to have the best protection against photon among all the samples that were evaluated, as well as against recently considered glasses and those materials often utilized for gamma-ray shielding purposes.

Yuan Lv, Shuhao Zhang, Kai Zhang et al.

Abstract An improved model predictive control (MPC) with Luenberger state observer is proposed in this article for LC‐coupling hybrid active power filter (LC‐HAPF). Traditionally, the implementation of MPC for LC‐HAPF requires additional sensors to measure coupling capacitor voltage, thereby increases the system cost and reduces reliability. The existence of one‐step sampling delay in practice will also affect the final compensation performance. To relax these problems, both continuous and discrete models are deduced first. Then, the Luenberger observer is utilized based on the discrete model to mitigate the steady‐state error without additional sensors. In addition, the sampling delay compensation is provided by improving the prediction horizon. Finally, the effectiveness of the improved MPC for LC‐HAPF is verified by experiment results, indicating that the proposed method has fast dynamic response and low steady‐state error.

Francisco Cejas Rodríguez, Elizabeth Roig Villariño, Dayniel Hernández Mestre et al.

A partir de la información extraída de la Base de datos de fanerógamas (plantas con flores) de Cuba, depositada en el Instituto de geografía Tropical, la presente investigación conformó una tabla en Excel que recoge la información sistemática detallada en cuanto a: familia botánica, género, especie, autor de la especie y sinonimia, entre otros, junto al nombre común, cuyo empleo facilita el reconocimiento de la especie a nivel del público en general. Con diferentes Macros implementadas sobre Visual Basic for Applications (VBA), que automatizaron la revisión del entorno, se procedió a un análisis de la información compilada. Se obtuvo una  aproximación al estado de conocimiento sobre la composición y distribución de las especies arbóreas en las formaciones boscosas naturales cubanas, señalándose las principales dificultades para acometer esta tarea y recomendaciones para llevarla a término felizmente.

Georg Winkens, Alexander Kauffmann, Johannes Herrmann et al.

Abstract Mo-Ti alloys form solid solutions over a wide range of compositions, with lattice misfit parameters increasing significantly with titanium content. This indicates a strong increase in the critical stress for edge dislocation motion. Here, we probe the transition from screw to edge dislocation-dominated strengthening in Mo-Ti solid solutions with titanium content up to 80 at%. The alloys were scale-bridging characterized to isolate the impact of substitutional solid solution strengthening. Mechanical testing yielded no significant influence of grain boundaries or grain orientation. The results were corrected for the strengthening by unavoidable interstitial oxygen. Modelling of screw and edge dislocation-controlled solid solution strengthening was applied to the results to evaluate the contributions of both dislocation types. The analysis reveals that screw dislocation motion controls the strength in allows with less than 40 at% titanium, while edge dislocation motion provides comparable strength for 60–80 at% titanium. These results in a system of reduced chemical complexity support the recent investigations of edge dislocation-controlled strengthening found in high-entropy alloys.

Robert T. Woodward, Alexander Bismarck

editorial

P. Antony Seba, J. V. Bibal Benifa

This article performs a detailed data scrutiny on a chronic kidney disease (CKD) dataset to select efficient instances and relevant features. Data relevancy is investigated using feature extraction, hybrid outlier detection, and handling of missing values. Data instances that do not influence the target are removed using data envelopment analysis to enable reduction of rows. Column reduction is achieved by ranking the attributes through feature selection methodologies, namely, extra-trees classifier, recursive feature elimination, chi-squared test, analysis of variance, and mutual information. These methodologies are ranked via Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) using weight optimization to identify the optimal features for model building from the CKD dataset to facilitate better prediction while diagnosing the severity of the disease. An efficient hybrid ensemble and novel similarity-based classifiers are built using the pruned dataset, and the results are thereafter compared with random forest, AdaBoost, naive Bayes, k-nearest neighbors, and support vector machines. The hybrid ensemble classifier yields a better prediction accuracy of 98.31% for the features selected by extra tree classifier (ETC), which is ranked as the best by TOPSIS.

António J. Arsénio, Francisco Ferreira da Silva, João F. P. Fernandes et al.

This document presents a study on the optimization of the 3D geometry of a horizontal axis radial levitation bearing with zero-field cooled (ZFC) high-temperature superconductor (HTS) bulks in the stator, and radially magnetized permanent magnet (PM) rings in the rotor. The optimization of component dimensions and spacing to minimize the volume or cost concerning only the maximization of the levitation force was previously studied. The guidance force and guiding stability depend on the spacing between PM rings in the rotor and between the rings of HTS bulks in the stator. This new optimization study aims to find the optimum spacing that maximize the guidance force with given HTS bulk and PM ring dimensions while maintaining the minimum required levitation force. Decisions are taken using the non-dominated sorting genetic algorithm (NSGA-II) over 3D finite element analysis (FEA). A simplified electromagnetic model of equivalent relative permeability is used on 3D FEA to reduce numerical processing and optimization time. Experimental prototypes were built to measure magnetic forces and validate appropriate values of equivalent magnetic permeability. An analysis of stable and unstable geometry domains depending on the spacing between rings of HTS bulks and PM rings is also done for two HTS bulk sizes.

Suxia Li, Gunasekaran Manogaran

Brain stroke is one of the three most deadly diseases in humans, especially since the time window from onset to treatment is very short, and this time determines whether the patient can get effective treatment. In addition, although individuals store a large amount of historical medical information in various medical organizations, the information is isolated and does not play its value. In response to the above-mentioned problems, the business needs of the Brain stroke prevention and emergency services have analyzed, and a networked collaborative service system for brain stroke prevention and first aid has been designed and implemented. The services of the brain stroke prevention and first aid networked collaborative service system discover and select candidate services, design service interfaces, and promote the collaborative work of medical organizations. Because the system involves the patient's medical data, it has related to personal privacy. In the following work, this paper needs to further improve the security aspects of the system to ensure the safety and reliability of the patient health information data.

Xiantao Zeng, Baoguo Yu, Lifang Liu et al.

Dynamic cluster network localization requires taking the following factors into consideration: 1) the localization time of network nodes; 2) the communication load among all cluster nodes, and; 3) the presence of the abnormal distance measurement data. However, most of the existing network localization algorithms only focus on localization accuracy. To solve the localization problem of the dynamic cluster network nodes, an improved combined trilateral localization algorithm is proposed. This proposed algorithm not only inherits the advantages of trilateration but also addresses the error propagation and accumulation problem with the strategies of anchor nodes selection in combined trilateral localization. Furthermore, by filtering the candidate positions, this algorithm can deal with some abnormal distance measurement data existing in the localization process. Finally, the extensive simulation of the algorithm is performed considering the actual unmanned aerial vehicle (UAV) cluster network, and the experimental results demonstrate the proposed algorithm can achieve high localization accuracy and have robustness as well as good adaptability to the dynamic network.

Gediminas Bačkys, Renata Černeckienė, Birutė Dalmantienė

The adoption of energy efficiency measures is shifting the building installation industry towards green technologies, such as smart metering and home automation, bringing significant changes on workplace requirements and training. Electricians, apart from technical proficiency, require a combination of digital and environmental skills to respond to the installation, maintenance, and programming of smart metering and energy efficiency home automation systems. Although the adoption of energy measures for building installation is promoted under national and EU initiatives, the provision of relevant vocational education and training (VET) is insufficient in quality and quantity, fragmented and infrequent, not adequately addressing the needs of the sector. There is, thus, a clear challenge to increase the quality of VET provision for electricians to match their competences and skills with smart metering and home automation needs of a fast-changing market and to promote employability within the sector. The aim of the research - to analyse the opinion of employers of the energy sector in different European countries on the need for the employees‘ competence in smart metering and home automation. Respondents in different European countries have been fairly ambiguous about the importance of employees‘ competences in implementing smart metering technologies and home automation systems. This could be influenced by the different experiences of the countries and the level of implementation of smart metering. The results of the research show that knowledge of the network infrastructure and a wide range of smart devices including Internet systems, the impact of smart meters and home automation systems on the environment are among the key knowledge and competences of the EU labor market in the field of smart measurement and home automation. The most desired technical skills of employees are related to the implementation of smart devices and automatic systems in new buildings and the modification of housing automation technologies in the existing buildings, the technical skills of incorporating smart metering technologies into automated housing infrastructure. Sufficiently important respondents consider skills such as customer consultation about the right choice of automation systems, the use of systems and their environmental and economic impacts, and a deeper knowledge of home automation systems and smart devices. Having summarized the results of the research, the working group of Electrical and Electronics Study lecturers of Panevezys University of Applied Science together with partners from the SMARTEL project, suggested a solution to the problem: to create an open virtual training course on smart metering and home automation systems employed electricians and vocational training providers. After defining the outcomes the training course on smart metering and home automation based on survey results from five European countries, European employers and vocational training providers are offered an open training course "Smart Metering and Home Automation Skills for Electricians", consisting of 6 parts: building engineering systems automation, energy management, intelligent control systems networks, sensors, intelligent device programming and installation, programming of user interface for automated devices.

Kuldeep Randhawa, Chu Kiong Loo, Manjeevan Seera et al.

Credit card fraud is a serious problem in financial services. Billions of dollars are lost due to credit card fraud every year. There is a lack of research studies on analyzing real-world credit card data owing to confidentiality issues. In this paper, machine learning algorithms are used to detect credit card fraud. Standard models are first used. Then, hybrid methods which use AdaBoost and majority voting methods are applied. To evaluate the model efficacy, a publicly available credit card data set is used. Then, a real-world credit card data set from a financial institution is analyzed. In addition, noise is added to the data samples to further assess the robustness of the algorithms. The experimental results positively indicate that the majority voting method achieves good accuracy rates in detecting fraud cases in credit cards.

Muhammad Muneer Umar, Shafiullah Khan, Rashid Ahmad et al.

Selfish or non-cooperative behavior of nodes can degrade the performance of a wireless sensor network in many ways. These nodes can cause increased end-to-end delays and unfair energy consumption among the nodes due to higher packet loss ratio and non-utilization of optimal routes. Various nodes' stimulation techniques have been proposed. Credit-based incentives with game theoretic approaches are said to be more effective in such experiments. This paper introduces a game theoretic reward-based mechanism to balance the work load among network nodes by stimulating them to equally cooperate in data forwarding toward the base station. Various possible parameters associated with a network and its nodes are considered. In addition, a card-based punishment system is introduced, which is rationally applied on the nodes according to their individual importance in the network. A new technique for finding nodes' individual importance in the network is designed for better manipulation of nodes.

Yu Miao

With the continuous development of network communication technology, the development of simulation training system based on the power of the Internet has been studied. Chemical enterprises themselves have high risks, so the issue of safe production is more and more serious. In this paper, a simulation training system suitable for chemical production is developed according to the particularity of chemical enterprises, based on the cloud computation technology and combined with mathematical modelling. The system can be used for student simulation training or to deal with the failure through the data mining technology in computer network, in order to achieve safe production. In addition, the research on simulation training system for chemical production based on cloud computation technology is conducive to pre-employment training of chemical workers and can improve the quality of operators and managers and the operating conditions of production facilities.

Jianmin ZHANG, Weiliang XIE, Fengyi YANG

Ultra dense network（UDN）is referred to as the most efficient technique for meeting the challenges of 1 000 times higher trafficvolume and 10～100 times higher user data rate，which can improve the network capacity dramatically through network densification.However，due to the limited coverage and higher density of small cell，the problems of frequent handover and inter-cell interference become intractable，which degrade the system capacity and user experience.Therefore，in order to satisfy the challenges of coverage and capacity simultaneously，the architecture of 5G ultra dense network was proposed，which was characterized as the separation of control and user planes and cluster-based centralized control.Besides，regarding to the UDN scenarios of macro-micro and micro-micro，different solutions were presented，respectively.In addition，the problems and challenges of the architecture of 5G ultra dense network were also discussed in detail，providing reference for future research and development.

Vahid Dehghanian, John Nielsen

Capacity of a wireless link can be enhanced by increasing the number of receive antennas. However, imposed receiver physical size constraints necessitate that the antenna elements be in close proximity, which typically reduces the overall link capacity of the wireless channel. Counterintuitively, under certain conditions the capacity of the overall link can be enhanced by decreasing antenna spacings. The focus of this paper is that of identifying the fundamental mechanisms and the conditions that give rise to this excess capacity. Closed-form expressions that directly quantify this capacity gain are derived based on a representative circuit theoretic model. Interesting insights are developed about the impact of different noise and interference sources and the limiting effect of heat losses in the antenna system. The capacity analysis is subsequently generalized to encompass the effect of antenna current deformation and load mismatch due to mutual coupling, based on the standard Method of Moments (MoM) analysis, demonstrating similar capacity enhancement behavior as predicted by the closed-form expressions.

S. Coco, F. Di Maggio, A. Laudani et al.

This paper describes the design and fabrication of a Ka Band PLL DRO having a fundamental oscillation frequency of 19.250 GHz, used as local oscillator in the low-noise block of a down converter (LNB) for an EHF band receiver. Apposite circuital models have been created to describe the behaviour of the dielectric resonator and of the active component used in the oscillator core. The DRO characterization and measurements have shown very good agreement with simulation results. A good phase noise performance is obtained by using a very high Q dielectric resonator.

А.V. LYULKO, B.B. JMAJLOV

Results of research of properties of the polycomponental powder materials formed of separate components in factorial space of "mixing - property" on the flat simplex diagram are submitted. Thus on the basis of the general principles of construction of information-analytical system (IAS) the decision of individual problems of designing and the analysis of properties of composite materials of systems , , for mechanical engineering is submitted.