Miracle-dz/UniFAR-FTUs huggingface dataset:
Optimization Strategy of Flow Table Storage Based on “Betweenness Centrality”

With the gradual progress of cloud computing, big data, network virtualization and other network technology. The traditional network architecture can no longer support this huge business. At this time, the clean slate team defined a new network architecture, SDN (Software Defined Network). It has brought about tremendous changes in the development of today's networks. The controller sends the flow table down to the switch, and the data flow is forwarded through matching flow table items. However, the current flow table resources of the SDN switch are very limited. Therefore, this paper studies the technology of the latest SDN Flow table optimization at home and abroad, proposes an efficient optimization scheme of Flow table item on the betweenness centrality through the main road selection algorithm, and realizes related applications by setting up experimental topology. Experiments show that this scheme can greatly reduce the number of flow table items of switches, especially the more hosts there are in the topology, the more obvious the experimental effect is. And the experiment proves that the optimization success rate is over 80%.
Adapting the number of replicas in the E-IRSA system using the power control

In this paper, we propose a new random access scheme to improve the throughput by using the easy power control. A slotted ALOHA type protocol with successive interference cancellations (SICs) is the promising scheme to meet the requirements of the Internet of things society which comes within the decades. Ones of the most effective methods are with SICs using the temporal diversity and the capture effect. We apply the easy power control to the system with those types of SICs. The distribution of the number of transmission considering the power control is also optimized to maximize the throughput property. The results of the computer simulation show that the proposed method can increase the number of nodes whose packet can be successfully decoded at the receiver without degrading the quality of service.
Design and Implementation of a Multiplier SEPIC Converter to Emulate a Photovoltaic System Using Power HIL

This paper presents the design and implementation of a multiplier Single-Ended Primary-Inductor Converter (SEPIC) for a Power-Hardware-in-the-Loop (Power HIL) emulator of a PV system. The emulation system has been developed in a dSPACE 1104, allowing to exchange the data from a voltage variable power supply and the SEPIC converter in order to extract the maximum power from a solar panel. This methodology is intended for the evaluation of supervision strategies using a Power Hardware-in-the-Loop approach. The proposed project would offer laboratory studies closer to the collection of raw data in a fieldwork, thus facilitating the development of new technologies by obtaining faster and more comfortable results.
Geocalibrating Millimeter-wave Spaceborne Radiometers for Global-scale Cloud Retrieval

The planned EUMETSAT Polar System-Second Generation (EPS-SG) Ice Cloud Imager (ICI) radiometer will provide quantitative estimates of ice clouds and snowfall from space. ICI has 11 channels in the millimeter and sub-millimeter wave range (from 183 up to 664 GHz). These wavelengths allow to detect ice clouds, whereas the emission signal from the surface is predominantly masked by high water vapor opacity. The latter is a problem for the geolocation assessment because current methods, comparing coastlines in imagery data with the known geographic locations, are not readily applicable to ICI channels. However, in very dry atmospheric conditions the geolocation validation technique could be still based on the observations at $183.3\pm 7\ \mathrm{GHz}$. This work proposes to evaluate geolocation error over the two biggest ice shelves (Ross and Filchner-Ronne) in the Antarctic region as surface natural targets, using as a coastline reference, data derived from Sentinel-1 synthetic aperture radar (SAR) imagery.
Fairness-Driven Energy Efficient Resource Allocation in Uplink MIMO Enabled HetNets

Heterogeneous network (HetNet) is a promising solution to meeting the unprecedented demand for higher data rate in the next generation mobile networks. Compared with the traditional single-layer cellular networks, the resource management (e.g., user association and power control problems) is more challenging in the multi-tier HetNets. In addition, due to the new application scenarios and battery-limited nature of the user equipment (UE), improving energy efficiency (EE) of individual while ensuring EE fairness among UEs is one of the key design issues in the uplink HetNets. In this paper, by considering the fairness for EE, joint user association and power control problems are studied in the uplink multiple input multiple output (MIMO) enabled HetNets. Under the quality of service (QoS) and transmit power constraints of UE, two kinds of fairness, namely, proportional fairness and max-min fairness, are investigated. The optimization problems of maximizing the EE are formulated by considering the fairness among UEs. Considering the non-convex characteristic of the problem, the formulated problem is divided into two subproblems, i.e., user association and power control subproblems, then an iterative algorithm is proposed to achieve the fair EE resource allocation for each fairness criterion until convergence. For the proportional fairness problem, the dual decomposition and Newton methods are applied. Then, by using successive convex approximation (SCA) and dual decomposition, the problem of max-min fairness is solved. Through both theoretical analysis and simulations, the convergence and the effectiveness of the proposed algorithms are proved and evaluated. Simulation results show that the proposed algorithms can significantly improve the average EE of users.
A Flying IoT Network to Help in Disaster Recovery

IoT platforms are considered the future of sensor networks. Its embedded nature facilitates the addition of mobility to these devices and dramatically broadens the possibility of using such systems. Especially when shipped on aerial vehicles, those networks can be quickly utilized to assess crises. During disaster recovery operations, instant communication is of the essence for the coordination of activities. However, those scenarios commonly are deprived of good communication infrastructure. This work proposes a system capable of deploying an instant network mounted on UAVs that connects all interested parties through an IPv6 mesh network made of IoT devices. The experiments showed that a small set of 50 UAVs equipped with a 50-meter range communication device is capable of connecting up to 24 elements spread over an area of 13,000 square meters. For a set of 150 UAVs, it was possible to serve an average of 68 agents in an area of 25,600 square meters.
Image Reconstruction Based on Compressive Sensing Using Total Variation Spatial Regulation for Microwave Imaging

Medical Imaging is an essential tool in supporting medical diagnosis as well as early detection of a number of diseases, e.g., tumor and cancer. Computed Tomography (CT) scan and Magnetic Resonance Imaging (MRI) are the modalities that are widely used for these purposes. Recently, Microwave Imaging has emerged as a modality that promotes tomography techniques with lower economical cost and smaller size than the previous technologies. For the sake of the image quality, however, this imaging system requires a large amount of data measurements in the reconstruction process. To overcome the drawback, this research proposes an algorithm to reconstruct the microwave images with lower number of measurements using Compressive Sensing (CS) approach. CS enables reconstructing a signal from a smaller number of measurements than which is required in the conventional sampling method. To meet this framework, in our proposed formulation, the acquisition scheme of scanning process is represented by a projection matrix for which a weight matrix of Discrete Radon Transform is used. In addition, in the data acquisition process, a number of translation and rotation positions are provided and varied in combinations to confirm the fewer measurement concept of CS. As the basic sparse reconstruction had been successfully proven for this task, this research contributes by adding spatial information using total variation (TV) and solving the proposed optimization problem using Alternating Direction Method of Multipliers (ADMM). As for the sparse dictionary matrix, Discrete Cosine Transform (DCT) is selected. The experiment shows that the proposed algorithm successfully outperforms the reconstruction which applied Filtered Back Projection (FBP), Simultaneous Algebraic Reconstruction Technique (SART) algorithm, and Basis Pursuit (BP) in terms of image quality and quantitative parameters.
A Compact UHF Planar Monopole Antenna Using Magnetodielectric Ferrite Substrate

In this paper, a compact planar monopole antenna (CPMA) using magnetodielectric ferrite substrate is proposed for applications of Ultra High Frequency (UHF). The presented antenna is fabricated on the magnetodielectric ferrite substrate, relative permittivity = 15 and relative permeability = 9. The size of the antenna is largely affected by a miniaturization factor n (n = (μ ‘ε ‘) 1/2, where μ ‘ is the real part of permeability and ε ‘ is the real part of permittivity). Because of its concomitant medium to high permeability and permittivity, the multifunctional magneto-dielectric information materials become an important means to reduce the size of the antenna. Firstly, a conventional microstrip antenna is designed and manufactured with the magnetodielectric ferrite substrate. The size of this microstrip antenna is 40 × 40 × 1.6 mm3 and its operating bandwidth is 840MHz-930MHz. On this basis, the proposed antenna in this paper is smaller than the conventional microstrip antenna. The proposed antenna consists of a feed line and an M-shape patch. The patch and ground plane make up the microstrip monopole antenna. The bandwidth and efficiency of the proposed antenna are enhanced by reduce the background copper plane. And the overall size of this antenna is 10 × 30 × 1 mm3 which achieves the requirement of compact antenna. Simulations and measurements are used to study and design the CPMA using magnetodielectric ferrite substrate. The measured results in the vector network analyzer show that the −10dB ($S$11 < −10dB) band of the antenna is 850 MHz-930 MHz (80 MHz, 8.8%). The proposed antenna is capable for wireless communications because of its simple structure and easy processing.
Assessment of the Urban Three-dimensional Structural Influence on the Satellite Thermal Infrared Measurement

Land surface temperature (LST) is one of the key parameters to study the global warming, evaporation, urban heat island, among many others. After decades of development, numerous LST retrieval algorithms have been developed, by using which, the LST could be retrieved at high accuracy of about 1.0 K for most flat natural surfaces. But for rugged terrain such as urban areas, the satellite observed radiance, especially for high spatial resolution thermal infrared images, is influenced by the surface three-dimensional (3-D) structure, which deteriorates the LST retrieval accuracy. Therefore, only the 3-D structural influence is well corrected, can the urban LST retrieval accuracy be improved. However, only a few forward radiative transfer models are available to explore the urban 3-D structural influence nowadays. In this study, a modification is attempted to take the urban 3-D structural influence into the traditional thermal infrared radiation transfer model, and then the resulted effect on the satellite observed brightness temperature is evaluated. To be more specific, viewing factors between target pixel and surrounded buildings are introduced to calculate the energy exchange inside the urban 3-D structure, based on which, the environmental radiance arriving at the target pixel can then be determined. As to the required atmospheric parameters, they were obtained from the MODerate resolution atmospheric TRANsmission (MODTRAN) model. After specifying different atmospheric profiles and simulated scenario parameters, the urban 3-D structural influence on the satellite measurement under different circumstances can be quantitively assessed. Results showed that the satellite observed target radiance is greatly affected by the radiation from 3-D surroundings. Besides, as the land surface emissivity (LSE) of the target decreases and the LST of the adjacent buildings increases, more environmental radiance is reflected into the sensor from the target, indicating that the 3-D structure contributes more to the satellite measurement. For example, given a normal urban landscape with the target LSE of 0.97 and the building LST of 290.0 K, the influence of the 3-D structure on the satellite observed brightness temperature at 10 µm was about 0.42 K, compared with the observation under flat surface assumption. When the target LSE decreases to 0.91 and the building LST increases to 310.0 K, the 3-D structural influence can be up to 2.06 K, quite large. Overall, the urban 3-D structure significantly influences the satellite measurement. Numerical results show that using the method proposed in this study, the 3-D structural influence can be well calibrated out. Field campaigns are under planned to experimentally validate the proposed method.
Attitude and Position Estimation of Quad-rotor UAVs Through Computer-based Visualization

This paper presents a method that employs computer-visualization techniques for attitude and position estimation of quad-rotor unmanned aerial vehicles (UAVs). The proposed method employs minimal equipment–two digital cameras installed at the ground station and targets marked on the UAV body in the form of colored dots. An algorithm has been developed in the proposed study to recognize target dots in the images obtained from the two cameras, and hence, provide a match between them. The 3-D position of the target UAV and its attitude are then computed based on results of the matching exercise performed by the proposed algorithm. Different methods are employed to eliminate any incorrectly matched pair of images. Results of the experiment performed on the author’s test bed demonstrate that the proposed method for attitude and position estimation attains high precision with translational and rotational errors of 5 cm and 3 degs, respectively, which are acceptable in most applications.
Localization of Nodes in Underwater Wireless Sensor Networks

Localization refers to the estimated position of each sensor node within a network. It's necessary since underwater sensor nodes depend on this information for reliable communication. The main challenge over here would be that the environment underwater is naturally quite different from land, posing uncertainty in sound speed variations and hence more noise in the channel. Here, the Kalman filter and extended Kalman filtering methods are explored to minimize the localization errors. This is validated by simulating the shallow water experiment and further the localization results are compared.
Toroidal and reverse flux of light in the sharp focus

We obtain a set of explicit analytical expressions that completely describe a light field with a double higher-order singularity (phase and polarization), as well as distributions of its intensity and energy flux near the focus.There is a reverse energy flux on the optical axis near the focus, which is comparable in magnitude with the forward flux. There is a toroidal energy flux in the focal area near the dark rings in the distribution of the longitudinal component of the Poynting vector.
Substrate Integrated Coaxial Line Based Continuous Transverse Stub (SICL-CTS) Array Antenna for 5G Base Station Applications

In this paper, a coaxial continuous transverse stub (CTS) array antenna using substrate integrated coaxial line (SICL) is proposed, to address the antenna design requirements of low loss, high performance, and compact size for millimeterwave applications. Different from conventional CTS antennas, the proposed SICL-CTS array antenna consists of SICL for transmitting TEM waves and parallel metal plates for radiation. A SICL-CTS array antenna with four elements is designed to verify the concept. From the simulated results, it can be seen that the reflection coefficient is below -10 dB from 19.64 GHz to 24.17 GHz, and the peak gain is about 6.8 dB at 20 GHz with the radiation efficiency of 94.34%. Moreover, the proposed array can maintain a ominidirectional pattern within a broadband performance. Due to the wide bandwidth and ominidirectional coverage ability, the presented SICL-CTS array antenna is a good candidate for 5G base stations.
An Improved Observer-Based State Feedback Controller for Grid-Tied Inverters with LCL filters

LCL-filters are typically employed in renewable energy systems between voltage source inverters and the power grid for their high harmonic attenuation capability. However, because of the LCL-filter resonance, the control design of such systems is very challenging particularly under parameter uncertainties and grid disturbances. This work aims at developing a new solution based on linear matrix inequality (LMI) for robust observer-based current control of grid-tied inverters with LCL-filters. The application of the state observer will eliminate the need of additional sensor for active damping. Moreover, a sufficient stability condition is proposed in terms of LMIs based on the Lyapunov theory, which guarantee effective suppression of the LCL-filter resonance under parameter uncertainties with a predefined grid disturbance attenuation level. The general formulation of the control design leads to an LMI optimization problem that can be easily solved using LMI solvers. The obtained results illustrate the performance and robustness of the proposed control method under parameters uncertainties and grid disturbances.
Numerical modeling of active microcavities with piercing holes using the Muller boundary integral equations and the Galerkin method

The current paper proposes a Galerkin method for calculating spectral characteristics of microcavity lasers with piercing holes. If boundaries of the cavity and holes are circles, then entries of the matrix have explicit expressions computed in the present work. Using the proposed algorithm, we calculate directivities, spectra, and thresholds of laser modes. Numerical experiments demonstrate that, by varying the location of the hole, we can increase the directivity, while the threshold gain stays low.
Intrusion Detection System using Naive Bayes algorithm

The growth of internet usage increased the need of security in network which is monitored by Intrusion Detection System (IDS). Using machine learning algorithms is common for implementing any IDS to detect network traffic weather it is normal or attack. Naive Bayes algorithm is one of the popular supervised classification algorithm for categorical dataset which is built on conditional independence of feature assumption. Our experimental research focused on comparison of traditional Naive Bayes algorithm and PCA based implementation using with(sklearn) and without built in python library. Experimental results using PCA based NSL-KDD intrusion detection system indicate better accuracy compared to traditional Naive Bayes in both with and without built in sklearn python library.
Adaptive Power Control using Reinforcement Learning in 5G Mobile Networks

With increasing data transmission requirements, radio remote heads (RRH) are densely deployed and device-to-device (D2D) communication is developed. D2D communication can decrease device energy consumption by reducing transmission power. In addition, D2D communication reuses cellular resources, and it can maximize system spectral efficiency. However, inter-cell interference from densely deployed RRHs can be critical to D2D communication. To mitigate the inter-cell interference problem, RRH switching method has been studied with D2D communication. In this paper, an adaptive power control algorithm using reinforcement learning in 5G mobile networks is proposed. To maximize system energy efficiency, we utilize Q-learning in the baseband unit (BBU) pool to decide the optimal number of active RRH. To maximize device energy efficiency, we utilize Q-learning in each device to decide transmission power. Further, to take account of changing channel quality, we adjust target SINR according to outage probability. Simulations and performance evaluations are presented to compare the system energy efficiency and device energy efficiency as well as average SINR.
Target Detection Using Space Time Adaptive Processing

The radar system uses space time adaptive processing as a type of signal processing technique. STAP uses antenna array with multiple channels to obtain two dimensional filtering. In ground moving target indicator system(GMTI),the echo is received by the radar from the target, these signals received not only contains the reflected echo from the target but also contains the ground returned signals, the ground returns are called as clutter. The total returned clutter is stronger in amplitude than the returned echo from the target, this poses a challenge for target detection in the presence of clutter and jammer interference, as this clutter signal's energy fills all range bins, clutter filtering is a critical part of ground moving target indicator (GMTI) system. Jamming signal is also a significant interference source to radar. STAP, filter the signal received in angular and Doppler domains to suppress both the clutter and jammer returns. The main goal of STAP is to reduce clutter and null the jammer interference.
6-DOF Formation Keeping Control for Three-Craft Electromagnetic Formation with Triangular Invariant Shape*

Spacecraft relative motion control with inter-craft electromagnetic force has distinct advantages, and its invariant shapes which are convenient for formation keeping ensure some significant potential applications. However, the electromagnetic actuators affect both the relative trajectory and attitude motion, complicating related studies on issues of invariant shape design and formation control. This paper mainly focuses on the formation keeping control for three-craft electromagnetic formation with triangular invariant shape on the basis of a 6-DOF full nonlinear dynamic model. Considering the high nonlinearity, strong coupling, model uncertainties and external disturbances, a combined control scheme involving feed-forward and feedback control components is proposed. The feed-forward component is obtained through desired invariant shape design which is complicated by the superposition and coupling effects of any two distinct magnetic dipoles. The feedback component is realized utilizing linear feedback controller based on the LQR method and active disturbance rejection control based on the extended state observer. Finally, the numerical simulation is presented to verify the feasibility and validity of the proposed 6-DOF control scheme.
Investigations of Non-uniform Pollution Impact on Electric Field Distribution in a Point-Barrier-Plane Arrangement under AC Voltage

This research work presents the influence of the polluting layers deposited on the surface of an insulating barrier on the electric field distribution under AC voltage, in a pointbarrier-plane electrode system. A numerical simulation using COMSOL Multiphysics based on the finite element method was carried out. The influence of a polluted barrier with different volumes conductivities and different diameters of the pollution layer on the electric field is studied. A comparison between a part and a completely polluted insulating barrier is performed. The difference between polluted and conductive barriers in also presented. The obtained results are in good agreement.