Miracle-dz/UniFAR-FTUs huggingface dataset:
Statistical mmWave Channel Modeling and Characterization in Indoor Airport Environments

With the extensive demand of higher data rate with advancement of mobile applications currently facing the need of unbounded bandwidth for everlasting mobile traffic. Recently, researchers showing great interest in improving wireless communication inside airports, as airports are very important spots that needs inexhaustible communication and tackles huge indoor mobile traffic. This has become a quite challenging issue in this regard. Despite of limitations, mmWave with latest technology 5G, along with its special features is expected to satisfy this huge demand of users. This article provides investigation of power delay profiles for statistical channel model for both line-of-sight (LOS) and non-line-of-sight (NLOS) conditions inside airport environments at mmWave bands 28, 60, and 73 GHz. The simulation outputs exhibit the channel response statistics in different frequencies and conditions. The results presented here may facilitate improvements in the future works related to inside airport or overall aviation communications.
Beyond First Impressions: Estimating Quality of Experience for Interactive Web Applications

The number of web applications for both personal and business use will continue to increase. The popularity of web applications has grown, increasing the need to estimate Quality of Experience for web applications (Web QoE). Web QoE helps providers to understand how their end-users perceive quality and point towards areas to improve. Waiting time has been proven to have a significant influence on user satisfaction. Most studies in the field of Web QoE have focused on modelling Web QoE for the user’s first interaction with the application, e.g., the waiting time for the first page load to complete. This does not include a user’s subsequent interactions with the application. Users keep interacting with the application beyond the first page load resulting in an experience that consists of a series of waiting times. In this study, we have chosen web maps as a use case to investigate how to measure waiting time for a user’s interactions across a web browsing session, and to measure the correlation between waiting time and user-reported perceived quality. We provide a short survey of existing Web QoE estimation metrics and models. We then propose two new measures: interactive Load Time (iLT) and Total Completed interactive Load (TCiL) to establish the waiting time associated with a web application user’s interactions. A subjective study confirms a logarithmic relationship for interactive web application sessions between iLT and perceived quality. We compare the correlation between QoE for iLT and the state of the art, non-interactive equivalent, Page Load Time (PLT)/Waiting Time. We demonstrate how the iLT/QoE fitting curve deviates from PLT/QoE. The number of clicks in completing tasks and TCiL are explored to explain the connections between user’s interactions behaviour and the perceived quality.
Adaptive Backstepping Sliding Mode Dynamic Positioning System for Pod Driven Unmanned Surface Vessel Based on Cerebellar Model Articulation Controller

The dynamic positioning system is a system that ships rely on their own propulsion devices to maintain position and course. Pod propulsion was more and more installed in dynamic positioning unmanned surface vessels because it can rotate 360 degrees freely. The maximum disturbance of unmanned surface vessel dynamic positioning comes from the forces and moments generated by the ocean wind, wave and current. In order to improve its accuracy of disturbance rejection, the mathematical model of the vessel was established according to the special structure of pod propulsion ship, and the calculations of the forces and moments of wind, wave and current are given. Then, the sliding mode controller based on approach law and adaptive backstepping were designed, and optimal controller based on cerebellar model articulation controller (CMAC) was further designed. The tracking differentiator was added to eliminate the large chattering in the initial stage of the system. Finally, the simulation verification was carried out. It can be seen from the results that the control law designed has better control effects than traditional sliding mode control and can realize dynamic positioning of pod driven unmanned surface vessel under certain disturbances.
Fibroblast-specific protein-1(FSP-1) expression and metabolic alteration in aortic valve calcification

Objectives: Study the effect of hyperleptinaemia (systemically and locally) and hyperglyceamia on Fibroblast-specific protein-1 gene expression, atrial natriuretic peptide (ANP) level, and extent of calcification in stenotic aortic valves, the role of FSP1 as a marker of valve calcification, the role of aortic valve repair in ameliorating the metabolic alterations and study the sensitivity, specificity of ANP, leptin and NO as diagnostic and prognostic markers in valve diseases. Design and Methods: FSP-1(by qRT-PCR and western blotting), atrial natriuretic peptide, glucose, insulin and leptin (by ELISA), nitric oxide and calcium (colorimetrically) were studied in 20 aortic stenosis patients and 10 controls. Results: In valve tissues, high leptin was significantly associated with increased FSP1 and calcium deposition, 66% of patients had glucose intolerance with increase in the studied parameters and decreased to 36% after surgery. Conclusion: FSP-1 is a useful marker for valve calcification. Valve surgery, by decreasing leptin, ANP and NO had a beneficial role in improving insulin resistance, Elevated leptin and ANP levels, not insulin resistance, were associated with poor survival.
A Broadband Circularly Polarization AMC-based Antenna for S-Band Satellite Applications

This paper proposes a right-handed circularly polarization (RHCP) antenna by using a single-fed planar oval shape antenna on a finite artificial magnetic conductor (AMC) surface. The proposed antenna is designed to improve the performance and dimension of the existing conventional RHCP satellite antennas for modern use. To validate the antenna prototype design by simulation, the prototype of the proposed antenna were fabricated and measurement were conducted and measured results are in good agreement with simulated results. Compared with other RHCP antennas, the proposed antenna has broad impedance bandwidth (IBW) of 69.3% and axial ratio bandwidth (ARBW) of 25.4% from 1885 MHz to 2550MHz and the total size is 82mm × 82mm × 16.2mm (0.48 λo × 0.48 λ0 × 0.065 λ0at the lowest operating frequency). The compact size and low cost are demonstrated and the proposed antenna is suitable for S-band micro satellite applications.
Finite-Time Backstepping of a Nonlinear System in Strict-Feedback Form: Proved by Bernoulli Inequality

In this paper, we propose a novel state-feedback backstepping control design approach for a single-input single-output (SISO) nonlinear system in strict-feedback form. Rational-exponent Lyapunov functions (ReLFs) are employed in the backstepping design, and the Bernoulli inequality is primarily adopted in the stability proof. Semiglobal practical finite-time stability, or global asymptotically stability, is guaranteed by a continuous control law using a commonly used recursive backstepping-like approach. Unlike the inductive design of typical finite-time backstepping controllers, the proposed method has the advantage of reduced design complexity. The virtual control laws are designed by directly canceling the nonlinear terms in the derivative of the specific Lyapunov functions. The terms with exponents are transformed into linear forms as their bases. The stability proof is simplified by applying several inequalities in the final proof, instead of in each step. Furthermore, the singularity problem no longer exists. The weakness of the concept of practical finite-time stability is discussed. The method can be applied to smoothly extend numerous design methodologies with asymptotic stability with a higher convergence rate near the equilibrium. Two numerical case studies are provided to present the performance of the proposed control.
Trimming the Tail for Deterministic Read Performance in SSDs

With SSDs becoming commonplace in several customer-facing datacenter applications, there is a critical need for optimizing for tail latencies (particularly reads). In this paper, we conduct a systematic analysis, removing one bottleneck after another, to study the root causes behind long tail latencies on a state-of-the-art high-end SSD. Contrary to a lot of prior observations, we find that Garbage Collection (GC) is not a key contributor, and it is more the variances in queue lengths across the flash chips that is the culprit. Particularly, reads waiting for long latency writes, which has been the target for much study, is at the root of this problem. While write pausing/preemption has been proposed as a remedy, in this paper we explore a more simple and alternate solution that leverages existing RAID groups into which flash chips are organized. While a long latency operation is ongoing, rather than waiting, the read could get its data by reconstructing it from the remaining chips of that group (including parity). However, this introduces additional reads, and we propose an adaptive scheduler called ATLAS that dynamically figures out whether to wait or to reconstruct the data from other chips. The resulting ATLAS optimization cuts the 99.99th percentile read latency by as much as 10X, with a reduction of 4X on the average across a wide spectrum of workloads.
A N260 Band 64 Channel Millimeter Wave Full-Digital Multi-Beam Array for 5G Massive MIMO Applications

In this paper, a 37-42.5GHz (N260 Band) 64 channel full-digital multi-beam array for 5G massive multiple input multiple output (MIMO) applications is developed. The multi-beam array is built on a time division duplexing (TDD) architecture in which the transmitter and receivers are independent and working separately to enable more flexible channel configuration and hardware distribution. The 64 antenna elements of the array are aligned in a way that 16 elements lie in the horizontal and 4 in the vertical direction to deliver higher beam resolution in the horizontal plane. By using cables of unequal lengths, the $16\times 4$ antenna elements are connected to a cluster of $8\times 8$ transmitters/receivers. The hardware design of the transmitters, receivers, antennas and other circuits is demonstrated, with excellent measured RF performance achieved. Furthermore, the calibration of the massive MIMO array is presented, and the influence of inequality of array feedlines on calibration accuracy in a wide bandwidth is analyzed and experimentally verified. Finally, experimental studies on single beam scanning, multiple concurrent beam generation and over-the-air (OTA) performance of the transmitting and receiving array have been done. Simulation and measurement results suggest that the array has an excellent beam-forming capability that supports beam steering and generation of multiple concurrent beams. The OTA test reveals that the array can provide high modulation and demodulation accuracy for communication.
Evaluation of Performance Index Methodology for Power Network Contingency Ranking

Line outage contingency ranking and analyses using various Performance Index (PI) approaches are investigated in this study. Independent contingency rankings based on voltage, real power, reactive power, voltage fused with reactive power and real power amalgamated with voltage fused reactive power PI are the ranking methods used. Analyses of most severe contingencies resulting from different ranking methods are carried out and the behavioural patterns of the affected transmission lines investigated and validated. Newton Raphson power flow equations developed in Matlab environment are used for these analyses while IEEE 30 bus network is the test system. Line 28–27 outage which is the most severe contingency based on voltage PI ranking resulted into both line overloads and bus voltage limits violations, while outage of line 2–5 which is the most severe contingency consequent of real power PI ranking only resulted into line thermal limits violations.
Comparison of State Feedback Controllers for the Magnetic Levitation System

The paper studies state feedback control design for the laboratory magnetic levitation system (MLS) with two coils from InTeCo [1]. Pole-placement and LQ based PI controllers are designed and compared for both SISO and MISO configurations. Controllers designed for the linearized MLS model are verified on the nonlinear simulation model and by experiments in the real plant.
Energy Function based Approach for Online Inertia Estimation Utilizing Synchrophasor Measurements

System inertia plays a crucial role in maintaining transient stability in a Power System (PS) network during a disturbance. Increased penetration of Renewable Energy Sources (RESs) into the system, makes the system inertia a variable quantity. Hence, the estimation of the system inertia under such scenarios is becoming more pertinent. In this paper, an energy function based approach is proposed for online inertia estimation using measurements from Phasor Measurement Units (PMUs). The synchronous machine's swing equation is used to emulate the system dynamics. The Potential Energy (PE) at a bus is calculated from the PMU measurement. A novel analogy is established between the inertia constant and the rate of change of PE. Real-Time Digital Simulator (RTDS) is used to illustrate the performance of the proposed approach on the WSCC 9 bus system. The superiority of the proposed approach is investigated by comparing the results with an existing method in the literature.
Deep Reinforcement Learning for Topology-Aware VNF Resource Prediction in NFV Environments

Network Function Virtualisation (NFV) has emerged as a key paradigm in network softwarisation, enabling virtualisation in future generation networks. Once deployed, the Virtual Network Functions (VNFs) in an NFV application’s Service Function Chain (SFC) experience dynamic fluctuations in network traffic and requests, which necessitates dynamic scaling of resource instances. Dynamic resource management is a critical challenge in virtualised environments, specifically while balancing the trade-off between efficiency and reliability. Since provisioning of virtual infrastructures is time-consuming, this negates the Quality of Service (QoS) requirements and reliability criterion in latency-critical applications such as autonomous driving. This calls for predictive scaling decisions to balance the provisioning time sink, with a methodology that preserves the topological dependencies between the nodes in an SFC for effective resource forecasting. To address this, we propose the model for an Asynchronous Deep Reinforcement Learning (DRL) enhanced Graph Neural Networks (GNN) for topology-aware VNF resource prediction in dynamic NFV environments.
A Self-Sustained Sensor Node through Far-Field Wireless Powering

In this work, a wireless sensor node technology is developed in which the sensor nodes are powered wirelessly to ensure battery-less operation. A planar inverted-F antenna is designed at 860 MHz for rectenna implementation that is capable of harvesting $48\ \mu \mathrm{W}$ power at 4 m transmission distance. Low power BLE transceiver is used to data communication between the sensor node and the base station. All functional blocks including the antenna are implemented in a limited board area of $6\times 4\ \mathrm{cm}^{2}$. The BLE data protocol is optimized to ensure energy efficient operation, and it helped to achieve continuous and self-sustain operation of the sensor node.
Study of Distributed Phased Array Antenna Array Spacing for 5G User Equipment

This paper focuses on the design of a distributed phased array (DPA) based on microstrip antennas for user equipment. First, an optimized microstrip antenna is designed to operate at 28 GHz with a maximum gain of 6.45 dBi. Followed by introducing characteristics of antenna arrays, array spacing (AS) is investigated as an important design parameter in DPA. A hybrid far-field radiation model is developed to study AS-induced impacts on overall DPA performance indexed by coverage efficiency (CE). Through the analysis, we find that certain ranges of AS lead to better performance. CE of the 2-layer DPA is studied and 95% or higher CE can be achieved when the minimum required gain is less than or equal to 8 dBi.
Context-Aware Action with a Small Mobile Robot

Simultaneous advances in mobile GPU computing and real-time object recognition now enable machines to make decisions and take actions based on the detection of objects of interest in the environment. An implementation of a mobile robot system that combines autonomous exploration and mapping capabilities with a real-time object recognition method based on a deep neural network running on a mobile GPU, is described. The system is able to detect objects of interest and then take real-time actions to interact with the objects, in this case, by moving to acquire inspection-style images of the object, from multiple angles. The robot system is small, self-contained and runs on battery power. The system shows the potential for the development of robotic systems with context awareness, permitting advanced autonomy.
Conformal Leaky-Wave Antenna Based on Partially Filled Rectangular Waveguide

The present paper is devoted to the development of a conformal leaky-wave antenna based on a curved rectangular waveguide. The process of obtaining the required beam position is about longitudinal tailoring the phase velocity. This is achieved with choosing the thickness of dielectric, which partially fills the slotted waveguide. The difference between wavelengths in curved and straight waveguides is taken into account. An amplitude distribution function is realized by means of traditional adjusting the each particular slot parameters. The results of computer simulation validate the proposed design technique.
Checking Diagnosability on Centralized Model of the System

In this work, the problem of checking diagnosability on Discrete Event System (DES) is considered especially in centralized architecture. Many approaches in literature deals with diagnosability using one or more intermediate models. In this paper, we present a new model based diagnosability algorithms in the framework of set theory for deciding diagnosability, without any intermediate constructions or models and considering several faults at the same time.
Reproducing the bifidogenic effect of human milk in formula‐fed infants: Why and how?

Awareness of the key role of the intestinal microflora in the generation of the immunophysiological regulation and in the defence against pathogenic agents has attracted our interest in ways of manipulating the microbiota to improve health. Dietary modulation of the intestinal microflora is today one of the main topics of interest in the nutritional sciences. Performing this modulation in the neonatal or early infancy period, when immunological programming takes place, is a relatively new concept. Fructo‐oligosaccharides (FOS) and galacto‐oligosaccharides (GOS) are prebiotics whose bifidogenic activity has been proven in adults. However, only recently have they been combined in infant formulas to reproduce the prebiotic effect of human milk oligosaccharides. In two consecutive trials, it has been demonstrated that supplementation of infant formulas with a mixture of GOS and FOS modified the fecal flora of term and preterm infants, stimulating the growth of Bifidobacteria. In the trial with term infants, the bifidogenic effect of the prebiotic mixture was dose dependent and there was also a significant increase in the number of Lactobacilli in the supplemented group. These findings offer a promising horizon for the early prevention of allergy and infections in infants.
Detailed Voxel-Based Implicit Modeling With Local Boolean Composition of Discrete Level Sets

Compared with the functionally-based implicit models, the level set models are usually defined by discretely sampling the implicit function values over the volume grid to represent the shapes, which are suitable for scientific computing and engineering. However, the voxel-based level set methods usually lose some features and details to represent the solids due to the finite grid resolutions. In this paper, we propose a more accurate voxel-based implicit modeling method based on discrete level sets. Compared with the traditional level set methods, more than one level set function can be defined in an implicit model with our approach by classifying the cells of the volume grid. The local Boolean compositions conducted over the compound cells are used to depict the interactions of different implicit surfaces represented by corresponding level set functions, and the sharp and thin details caused by Boolean operations are preserved owing to the definition of the compound cells. We show in our experiments that our method is robust to provide the more detailed implicit description of the shapes with less loss of the features than the conventional voxel-based level set methods.
Wideband and Bandwidth-Controllable Hybrid-Cylindrical Glass Dielectric Resonator Antenna for Indoor Communication

In this paper, a wideband and bandwidth-controllable hybrid-glass dielectric resonator antenna (DRA) excited by a probe platform is proposed. The proposed hybrid-glass DRA simply consists of a probe platform and a solid cylindrical glass DRA unit, making the fabrication easier. The probe mode and the TM $_{01 \delta }$ mode of the cylindrical glass DRA are employed to design the wideband antenna. It is found that the impedance bandwidth of this hybrid-DRA can be controlled by the height of the glass DRA in a wide range of ~23%-70%, without changing the size of the feeding. Engineering formula considering the bandwidth has been given to facilitate the design. To demonstrate the idea, three wideband hybrid-glass DRAs with their measured impedance bandwidths of 39.5%, 56.6% and 74% have been designed. To upgrade the three hybrid-glass DRAs as the artistic antennas, laser-engraving patterned glass is employed to do the fabrication again. The measured results show that the performance of the hybrid-glass DRAs with and without patterns are basically the same.
Wireless Communication For A Modular Heliostat Field

The global demand for affordable renewable energy has driven Stellenbosch University's Solar Thermal Energy Research Group, STERG, to design and construct a modular heliostat field for a central receiver concentrating solar thermal (CST) plant. The heliostat field requires a robust wireless communication network with sufficient range, bandwidth and low latencies to enable a high level of control over each heliostat. Currently several wireless communication technologies are available on the market such as LoRa and LoRaWAN, NB-IoT, ZigBee, Bluetooth low energy (BLE) and Wi-Fi and its variants. In this article these different wireless communication standards are investigated within the scope of a modular heliostat field. The advantages and disadvantages of each is discussed with regards to range, bandwidth, energy consumption, ease of implementation and latencies. Furthermore, different architectural designs for wireless networks are analysed. The Wi-Fi 6 standard (IEEE 802.11ax) operating in a star network topology is proposed for the modular heliostat field. This technology is able to operate with sufficient range, throughput and minimal latencies in a dense network such as the proposed CST plant. This work is part of the H2020 PREMA project, aiming to advance novel energy systems in the drying and pre-heating of furnace materials.