Miracle-dz/UniFAR-FTUs huggingface dataset:
Architecture Design and Evaluation of Hybrid AC/DC Power Grids Based on Power Electronic Transformer

This paper presents the architecture design and evaluation method of power electronic transformer (PET) based hybrid AC/DC power grids. The architecture design is carried out from two aspects: one is AC/DC hybrid substation wiring mode, and the other is PET based DC grid topology. Then the benefit evaluation of different architecture is established, including maximum power supply capacity, power supply reliability, and fault operation characteristics. Finally, all these operation performances of three typical architectures are compared and analyzed.
OpenFOAM Solver Based on Regularized Hydrodynamic Equations for High Performance Computing

In the paper we investigate scaling of parallel performance for an implementation of quasi-hydrodynamic (QHD) approach as an OpenFOAM solver. Time-dependent partial differential equations are discretized using Finite volume method (FVM). As a test hydrodynamical problem we take internal wave generation in a bounded tank of trapezoidal shape, and set of parameters, which allows internal wave attractors to evolve. Proper Orthogonal Decomposition was applied to analyze and compare 2D and full 3D simulations.
Design of a web service based prototype appointment system for improving the patient access to primary health care service

Research Aim and Questions: This research aims to develop a computer-based appointment system, which could integrate with the existing clinical information system and improve the patient access to the services offered by both General Practitioners (GPs) and Allied Health Professionals (AHPs) in a primary health care clinic Centre Health Complex (CHC). To achieve this requires the development of an understanding of the features and processes of patient booking in the primary health care environment; the identification of the gaps of the existing patient booking system; and a scheme of an improved system, which could fill these gaps. The output of this project is a prototype of patient appointment system built on web service technology. Research background: To acquire a routine appointment from a GP or an AHP, a patient may need to wait more than several weeks in CHC. Patient's long waiting time is always accompanied with some series access problems such as missed appointments in the practice. Consequently, some patients are driven from primary health care to Emergency Department (ED) and add pressure to the overburdened hospital system. The patient’s access problem is initiated by the traditional appointment system, which is based on a basic fixed schedule for booking patients. It does not record a patient request if the request is not met; therefore, it has missed the essential baseline data about the patient’s actual demands. Without this information, the practice could not plan effectively to fully meet the demands of the patients for primary care services. Research Methodology: This research followed a standard software development process – waterfall model. Three phases of study were carried out, including (1) requirement analysis, (2) system design, and (3) prototyping and unit testing. First, a filed study was conducted in the CHC to collect information about the features and processes of patient booking and the IT infrastructure in the clinic. The weakness of the practice workflow and the IT infrastructure were identified. Then the design of the new appointment system was proposed to plug these gaps. Finally, a prototype of the proposed appointment system was built.
Monitoring DXA Measurement in Clinical Practice

Osteoporosis is a worldwide major public health problem. Bone densitometry has become the “gold standard” in its diagnosis and treatment evaluation(El Maghraoui and Roux 2008). With its advantages of high precision, short scan times, low radiation dose, and stable calibration, dual-energy x-ray absorptiometry (DXA) has been established by the World Health Organization (WHO) as the technique of reference for assessing bone mineral density (BMD) in postmenopausal women and based the definitions of osteopenia and osteoporosis on its results. Recently, efficient therapeutic options for treatment of osteoporosis have been developed which create possibilities of effective intervention. Therefore, screening for and treatment of osteoporosis are widely practised in postmenopausal women and in people with an increased risk of osteoporosis because of underlying diseases (e.g. chronic rheumatic diseases especially when treated by corticosteroids)(Phillipov, Seaborn et al. 2001). Moreover, BMD measurement is needed to select patients for osteoporosis treatment, as there is no proof that drugs for osteoporosis (other than hormone replacement therapy [HRT]) are beneficial in women with clinical risk factors for fractures but normal BMD values.
On direct matching and efficiency improvements for integrated array antennas

The goal of this design study is to determine the insertion-loss associated with a sequence of impedance-matching networks. These results are compared to the performance of direct integration of PA/antenna. In high-frequency, ≥ 20GHz, co-design of PA/antenna has as an important goal to remove any matching networks between the antenna and power amplifier by e.g. antenna shaping both to reduce the physical size and to improve the power added efficiency of the radio-front end. We determine the insertion-loss for matching a 2W GaN RF Transistor TGF2942 working in Class-A to a given real-valued load. This type of reference can serve as a benchmark to compare co-designed antenna performance. We also determine changes in power added efficiency and insertion-loss associated with changes in the physical size of a sequence of differently sized matching-network. The results are examined with respect to the electrical size, choice of material (dielectric attenuation), and given $Z_{\mathbf{ant}}$ & $Z_{\mathbf{opt}}$. In the reference case, we observe that direct matching may improve the power added efficiency by 10% for a 5% frequency bandwidth and by 6% at the center frequency.
Spectral Norm Based Mean Matrix Estimation and Its Application to Radar Target CFAR Detection

The estimation of mean matrix for a set of Hermitian positive definite (HPD) matrices can be considered based on a geometric framework. This kind of estimator is closely related to geometric measures, which can be established to measure the dissimilarity between two matrices on the matrix manifold. In this paper, the matrix spectral norm is exploited to derive a new geometric measure on the matrix manifold consisting of all HPD matrices. Correspondingly, the mean matrix associated with the new geometric measure on the matrix manifold is considered via two effective solution techniques. More specifically, the first method transforms the mean matrix estimation into a semidefinite programming problem solved by the interior point method; the second method exploits joint approximate diagonalization to diagonalize the given covariance matrices and then recasts the mean matrix estimation into an optimization problem with linear inequality constraints. Furthermore, two matrix detectors employing the proposed mean matrix estimators are designed for target detection using pulse Doppler radar with a small bunch of pulses. At the analysis stage, we show that the proposed matrix detector can guarantee the bounded constant false alarm rate property in terms of the clutter covariance matrix. Finally, numerical experiments based on simulated clutter data and real sea clutter data are performed to verify the effectiveness and robustness of the proposed matrix detectors.
Design and Analysis of Nano-Optical Networks Consisting of Nanowires and Optimized Couplers

We present computational design and investigation of nano-optical systems involving nanowires and well-designed nano-couplers to effectively transmit electromagnetic power in nanometer scales. Different nano-couplers, which consist of optimal arrangements of nano-cubes, are carefully designed by considering various scenarios, e.g., nanowire lines with sharp corners and junctions. An efficient combination of genetic algorithms and the multilevel fast multipole algorithm is used to find suitable configurations of nano-cubes that provide desired electromagnetic responses. Combinations of multiple nano-couplers and nanowires allow us to build larger nano-optical systems with different shapes, inputs, and outputs. Initial results presented in this paper demonstrate the feasibility of complex networks based on nanowires and nano-couplers.
Boron Nitride Coated Three-Dimensional Graphene as an Electrically Insulating Electromagnetic Interference Shield

We demonstrate the potential of a novel hybrid nanostructure three-dimensional graphene (3D-C) coated with boron nitride (BN) as an electromagnetic interference (EMI) shield. BN, deposited by sputtering, encapsulates 3D-C to form a light-weight graphene based EM shield that has an electrically insulating exterior. The BN deposited on 3D-C was homogeneously distributed with even coverage on the struts of 3D-C. EMI shielding results have shown that the hybrid material has a total shielding effectiveness (SET) of 53dB and 58dB in the X band and Ku band respectively.
Traveling Maintenance System Design for Wide-Area Telecommunication Networks

This paper proposes a traveling maintenance method as a new network maintenance model. For failure recovery, the proposed method utilizes permissible time, which keeps high availability, ensured by shared backup resources. In the proposed method, even though a failure occurs in a communication facility, maintenance staff waits for occurrence of successive failures in other communication facilities during the permissible time instead of immediately tackling the failure. Then the maintenance staff successively go to the communication facilities that have faulty devices and repair them. By doing so, the proposed method can reduce the amount of time that the maintenance staff consumes for fault recovery. Furthermore, this paper provides a system design that aims at optimizing the proposed traveling maintenance according to system requirements determined by the design philosophy of telecommunication networks. Through simulation experiments, we show the effectiveness of the proposed method.
Design and Implementation of Droop Control Strategy for DC Microgrid Based on Multiple DC/DC Converters

Design and implementation of DC microgrid based on droop control in islanded mode are carried out in this paper. In this study, a parallel circuit including three DC/DC converters (two Boost and one Buck) was designed, which were connected to a resistive load and a constant power load respectively through the multi-pole switch. The power sharing under different conditions is achieved through droop control and the influence of the droop coefficient on the parallel system is verified by simulation results. In addition, detailed hardware circuit design schemes are provided. The characteristics of the droop control are confirmed through experiments and the effectiveness of the designed circuit is confirmed.
Application of Two-Stage Feature Selection Technique in Power Load Forecasting Considering Delayed Effect

The influence of relevant features on power load, such as rainfall, temperature, generation capacity and so on, often has delayed effect. For measuring this effect, the delay time is introduced into mutual information (MI) to form delayed mutual information (DMI), and the prediction reference point of the input set is reselected based on maximum DMI. By using feature selection technique based on MI for the reconstructed input set, we can obtain an optimal subset which not only contains several features that have the most significant impact on prediction accuracy, but also embodies the delayed effect between feature and load. It is helpful to reduce the prediction error and time.
Study of the Hierarchical Control System for DC Micro-grid

In order to better realize the plug and play function of various distributed energy sources (photovoltaic, storage batteries, etc.) in the DC micro-grid, improve energy conversion efficiency and improve DC side bus voltage performance. The layered control strategy introduced contains two layers: the new energy in the inner layer of the micro-grid is maximized by the maximum power tracking control, and the energy storage unit uses the voltage leveling control to ensure the stability of the DC side bus voltage; The bidirectional vector decoupling control includes voltage and current double closed loop control, and uses d-q coordinate axis transformation to control DC voltage and power factor to solve the problem of bidirectional flow of power during grid connection. This paper gives a detailed theoretical analysis and design method for each layer control. Simulation results demonstrate the feasibility and effectiveness of the proposed method.
Operating Overvoltage Simulation Research of ±800kV UHVDC Transmission Converter DC Yard Caused by Typical Grounding Fault

The simulation model of the power system is established according to the parameters of the main equipment of Xiangjiaba-Shanghai 800kV UHVDC transmission project. The operating overvoltage generating mechanism and distributing law caused by typical grounding fault at the top of high-voltage valve and the valve side of high-voltage transformer is analyzed. According to the simulation results, it is found that the absorb energy of the neutral bus arrester exceeds the designed maximum. Therefore, the measures by increasing the number of the neutral bus arresters to control the arrester absorb energy is presented and verified by simulation. This study is of guiding significance to the optimization design of arrester configuration scheme in UHVDC project.
Cloud-Supported Internet of Things Data Security and Access Control in Smart Grid

The cloud-supported Internet of Things (Cloud-IoT) has been widely used in smart grid. The amount of data related to the power grid is huge and sensitive. In order to improve the security of data storage and achieve fine-grained access control with flexibility, a multi-authorization center and fixed-length ciphertext policy attribute encryption access control scheme with attribute revocation is proposed in this paper. The multi-attribute authority is introduced to generate keys to defend against collusion attack, and partial decryption is delegated to the proxy server to reduce user’s computing cost. In addition, user revocation updates and attribute revocation updates are used to improve system flexibility. The security of the scheme is proved by Diffie-Hellman hypothesis, and comparative analysis is carried out. The results show that the scheme effectively improve the speed of encryption and decryption, as well as reduce time cost of the system.
Short-term Voltage Stability Mechanism Analysis Based on a Double-generator-one-load Model

This paper presents the mechanism analysis of short-term voltage stability based on a double-generator-one-load model. A double-generator-one-load (DGOL) model of power system is introduced. Compared with other existing simplified model, the DGOL model not only includes the dynamic of motor, but also takes the interactions of generators into consideration. Then, this paper analyses the mechanism of voltage stability based on DGOL model, and proposes a quantitative index (RAV ratio) to evaluate the influence of rotor angle variation on short-term voltage stability. At last, the simulation work is introduced to illustrate the advantage of the proposed simplified model and analysis method.
A Simplified Model Prediction Control Method for PV Grid-Connected Inverter

To optimize the control methods of PV grid-connected inverter, a simplified Model Prediction Control(MPC) method is proposed. Firstly, the second-order discretization mathematical model of grid-connected inverter control is established in the d-q coordinate system to find out the mathematical relationship between the controlled quantity and the input quantity and the related physical quantities involved in the calculation. Then, receding horizon optimization is performed according to the MPC method to obtain the physical quantity value. Since these physical quantities are approximately constant in a brief time, a batch update method can be adopted. The simulation experiments are carried out in the Simulink platform to verify the steady-state tracking effect of the method, the responses of slope function and step function. The simulation results show that the proposed method can achieve error- free tracking for steady-state function and slope function. The step function response has a fast response time and no overshoot, but there is A brief period of three-phase unbalanced time. Finally, a physical experiment platform is built, the method is solidified into a grid-connected inverter controller to be executed, and step function response verification is performed. The experiment results show that the proposed method can achieve steady- state error-free tracking, the dynamic corresponding speed is fast, and the overshoot is not obvious.
Integration of Microwave Components through Selective Laser Melting

This paper discusses on the potential application of the selective laser melting technology to the integration of microwave waveguide components in single monolithic parts. Three study cases working in Ku, K, or Ka bands are reported. For each study case, the correlation between the predicted and measured RF performance is significant. Benefits in terms of minimization of mass, envelope, interfaces and parts count are identified.
Effect of etching conditions of alumina nanotemplate for copper nanowires fabrication

In this work the possibility for free copper nanowires production by etching of anodic aluminum oxide (AAO) template in two different solutions was studied. It was found that the removal of the AAO template in alkaline solution cause the formation of a gelled substance with low solubility which caused conglomeration of nanowires. In acid solution the dissolving products of AAO were completely soluble and the copper nanowires were obtained free.
Fault Model of Inverter Interfaced Distributed Generator Adopting PQ Control Strategy Considering Current Tracking Capability of Converter

As the scale of inverter interfaced distributed generator (IIDG) in low-voltage grid expanding, the changes of distribution network’s fault characteristics are drawing great attention. The fault modeling method of IIDG gradually becomes an important part of the fault analysis of distribution network with IIDGs. This paper proposed an IIDG fault model considering the current tracking capability of the converter based on the analysis of the dynamic model, control system and parameter design of IIDG. In the proposed model, IIDG was equivalent to a voltage-controlled current source and a voltage- controlled voltage source according to whether the converter current tracks the reference exactly, which reflects the control characteristics of IIDG under different fault conditions. The case studies show that the calculation results based on proposed model are more consistent with electromagnetic transient simulation than that of existing model and have verified the high calculation accuracy as well as simplicity of the proposed model.
Multi-machine Power System Stabilizers Optimal Design Considering Multiple Operating Modes

This paper studies the problem of coordination and optimization of multi-machine PSS parameters under multiple operating modes. Firstly, there employs principal component analysis method based on trajectory sensitivity to select the optimal feedback input signals of PSS. Secondly, this paper proposes multi-objective optimization constraints including stability objective function and robust objective function. Then a special simplified method is proposed to filter partial oscillation curves into the objective function with larger correlation factors. Finally, employ the above optimization methods to design multi-machine PSS with EPRI-36 test system. Test and analysis results indicate that the proposed methods improve the positive damping of test system more effectively and implement better robust control effects for unknown operating modes and faults.
Embedded Suspended Stripline Substrate Technology (ESSS) as a Catalyst for Low-loss PCB Structures in the Ka-Band

A novel PCB embedded suspended stripline arrangement is proposed in order to improve the RF performance compared to classical planar technologies. The advantages are demonstrated through the design and characterization of a 2nd-order filter at Ka-band having 4.5% fractional bandwidth (FBW). The simulated Q-factor is around 455 which is significantly higher compared to what is achievable in microstrip. The manufactured sample shows deviations in the expected range given by the manufacturing tolerances from the simulated results. However, a similar high Q-factor of 410 in Ka-band was obtained.
Parameter Value Selection of Wind Turbines Frequency Controller

Frequency control of the power system with high penetration level of converter connected renewable power generation has become a challenge to system operators. In order for reliable operation of power system, variable speed wind turbines(WT) are required to provide frequency control to power system. This paper focuses on the frequency controller parameter value selection of the variable speed WTs. The WTs are controlled to have both the inertial response and primary frequency control capability which is similar to the synchronous generators. The de-load level of the WT is discussed, according to the operation curves, the value for the frequency controller gains is discussed. Matlab/Simulink is adopted to demonstrate the frequency control performances with different controller parameter values, the results show the variable speed WTs can be controlled to have similar frequency response as the synchronous generators, through proper controller value selection the WTs can have a better frequency control performance, which is helpful for the safe operation of the power system.
Video Analytics in Train Cabin Using Deep Learning

The motivation behind our work is to improve commuters overall train ride experience by providing crowd density information of incoming trains. Given the incoming train information, commuters can make an informed decision about which train cabin to board preferring those cabins with lower crowd density. Our proposed solution is to process extracted images from train cabin security footages using Convolutional Denoising Autoencoder-Convolutional Neural Network (CDAE-CNN) to predict crowd density in image frames. Experiment results show that adding the CDAE processing to the framework improves the performance in reconstructing noisy images before feeding the images as input data to CNN, thus overall improving the classification accuracy. Experimental results show that CDAE-CNN consistently outperforms CNN in labeling the train cabin image frames in various image datasets.
Modeling and Optimization of the Shape of an Opening Guide

The opening and closing procedure of baking tongs is governed by the shape of the opening guide and is an essential part of the baking process at automatic baking lines to guarantee for high-quality wafer products. To study the dynamic properties of the system related to the shape of the opening guide, a mechanical model is presented in this paper. Considering both procedural requirements and mechanical design to allow for reliable, long-lasting operation of the system, an approach to optimize the shape of the opening guide is introduced. Measurements on a reference system demonstrate the capabilities of the derived framework.