Miracle-dz/UniFAR-FTUs huggingface dataset:
Resource Allocation for IRS-Assisted Wireless-Powered FDMA IoT Networks

This article investigates intelligent reflecting surface (IRS)-assisted wireless-powered Internet of Things (IoT) networks. Specifically, multiple IoT devices first collect energy radiated from a power station (PS), then each device uses its harvested energy to support data transmission to an access point (AP) via frequency-division multiple access (FDMA). In addition, an IRS aims to improve wireless energy transfer (WET) and wireless information transfer (WIT) capabilities using passive reflection beamformers. The system sum throughput, as a performance metric, is maximized evaluate the overall performance of the considered model, which is subject to the constraints of IRS phase shifts, transmission time scheduling, and bandwidth allocation. This problem is not convex with respect to multiple coupled variables, and cannot be directly solved. To circumvent this nonconvexity, the transmission time scheduling and the bandwidth allocation are optimally designed in the closed form by the Lagrange dual method and the Karush–Kuhn–Tucker (KKT) conditions. Moreover, an alternating optimization (AO) algorithm is used to optimally design the IRS’s phase shifts during the WET and WIT phases in an alternating fashion. Specifically, we propose elementwise block coordinate decent (EBCD) and complex circle manifold (CCM) algorithms to iteratively derive the optimal phase shifts in the closed form. We also characterize the convergence behavior of the proposed algorithms. Finally, numerical results are presented to validate the performance of the proposed scheme, where the benefits of the IRS are highlighted in terms of sum throughput, transmission time scheduling, and energy harvesting, compared with the benchmark schemes.
Reducing unnecessary disconnection of renewable generation from the power system

Future power systems with large proportions of embedded generation could be severely affected if several loss of mains (LOM) protection systems maloperate in response to a non-islanding condition, potentially leading to generation shortfall and stability problems. Although many papers discuss methods of sensitively detecting islanded conditions (a short bibliographical survey is included), almost no papers in the literature address the problems associated with the stability of such protection methods during and after perturbations on the network to which they should not react. The aim is to highlight the shortcomings in existing power system protection practices relating to islanding detection with a view to identifying necessary areas of improvement to facilitate the ongoing proliferation of renewable sources in active distribution networks. Existing LOM techniques are described and stability-related shortcomings are demonstrated using the results of rigorous laboratory testing of several commercially available relays. The testing scenarios are developed using a UK Generic Distribution System repository, a public domain database representing typical distribution system architectures. Recommendations relating to the setting of existing LOM protection devices are provided, along with an overview of research and development activities relating to improvements in anti-islanding protection, including a discussion of both technical and economical viability.
Distributed MAC protocols for heavily loaded ad hoc networks

This thesis contributes to the domain of medium access control for wireless ad hoc networks. These networks are by definition created for the occasion, or for a specific purpose, and usually have to operate without any existing fixed infrastructure. In the first chapter of this thesis, a synthesis of the MAC protocols and algorithms is proposed. The contention-based and the conflict-free protocols are two well known families. IEEE 802.11 DCF is the heir of the first family. It is able to address both access point centric and ad hoc deployments, as well as single and multi-hop communications. The foremost objective of this dissertation is to find alternative schemes for improved MAC performance in highly loaded networks. Chapter 2 studies the capacity of IEEE 802.11b in case of AP centric networks with TCP and UDP traffic. A specific kind of near-far effect has been detected. The consequent performance degradation is highlighted and some solutions are proposed. A real world deployment is presented for outdoor provisioning of high speed Internet to low density areas. Advantage of using the multi-hop concept to extend the coverage range of an access point and the corresponding issues of degradation in throughput and fairness at high input loads have been analyzed in detail. In chapter 3, we propose a new slotted protocol, called CROMA, to overcome the weaknesses of IEEE 802.11 in highly loaded multi-hop ad hoc networks. We provide an analytical study of CROMA in a fully connected network. Extensive simulations considering a challenging network topology, a random network, and a mobile network show that CROMA clearly outperforms IEEE 802.11 in the targeted environments in terms of channel utilization and fairness. Chapter 4 explores three examples of cross-layer mechanisms estimated to be useful for further improvement in capacity of ad hoc networks and CROMA evolutions. Impressive performance improvements have been demonstrated through theoretical analysis and simulations in the following three cases: (i) A simplified version of CROMA and an associated scheduling policy can take advantage of node mobility for throughput improvement. (ii) Multi-user diversity considerably improves the CROMA reservation scheme based on slotted ALOHA. (iii) Multi-user detection can offer additional improvement for reservation too.
A boost DC-AC converter: operation, analysis, control and experimentation

This paper proposes a new voltage source inverter referred to as a boost inverter or boost DC-AC converter. The main attribute of the new inverter topology is the fact that it generates an AC output voltage larger than the DC input one, depending on the instantaneous duty-cycle. This property is not found in the classical voltage source inverter which produces an AC output instantaneous voltage always lower than the DC input voltage. Operation, analysis, modulation, control strategy and experimental results are included in this paper. The new inverter is intended to be used in UPS design, whenever an AC voltage larger than the DC link voltage is needed, with no need of a second power conversion stage.
Numerical Modeling and Inverse Scattering in Nondestructive Testing: Recent Applications and Advances

This paper presents recent advances and future challenges of the application of different numerical modeling tools and linear and nonlinear inversion algorithms in ultrasonics and electromagnetics applied in NDE. The inversion methods considered in the presented work vary from linear schemes, e.g. SAFT/InASAFT and Diffraction Tomography/FT‐SAFT, to nonlinear schemes, e.g. the Contrast Source Inversion. Inversion results are presented and compared for modeled and measured ultrasonic and electromagnetic data to locate voids and cracks as well as to locate aluminum tendon ducts in concrete, which is a typical GPR problem. Finite Integration Technique (FIT) and Domain Integral Equation (DIE) solvers are used as modeling tools.
Forming Spaces with Colour and Light: Trends in Architectural Practice and Swedish Colour Research

Architecture is space built for human life, and colour in architecture means colouring this space, or spaces. To choose colour for rooms within a building is profoundly different from two-dimensional artwork or colour design, as the spatial preconditions themselves interact with the chosen colours to form a three-dimensional totality. On the other hand, the experience of space is always present in our visual perceptions, even when we look at surfaces that physically have only two dimensions. Colour presupposes light, and the understanding of light and shadow is decisive for our spatial understanding. The purpose of this article is to discuss the issues of colour, light and space, mainly with reference to current Swedish research results and the experiences of practicing architects and interior designers.
Smooth light extraction in lighting optical fibre

Recent advances in LED technology have relegated the use of optical fibre for general lighting, but there are several applications where it can be used as scanners lighting systems, daylight, cultural heritage lighting, sensors, explosion risky spaces, etc. Nowadays the use of high intensity LED to inject light in optical fibre increases the possibility of conjugate fibre + LED for lighting applications. New optical fibres of plastic materials, high core diameter up to 12.6 mm transmit light with little attenuation in the visible spectrum but there is no an efficient and controlled way to extract the light during the fibre path. Side extracting fibres extracts all the light on 2π angle so is not well suited for controlled lighting. In this paper we present an extraction system for mono-filament optical fibre which provides efficient and controlled light distribution. These lighting parameters can be controlled with an algorithm that set the position, depth and shape of the optical extraction system. The extraction system works by total internal reflection in the core of the fibre with high efficiency and low cost. A 10 m length prototype is made with 45° sectional cuts in the fibre core as extraction system. The system is tested with a 1W white LED illuminator in one side.
Engineering Fundamentals of the Internal Combustion Engine

Notation. 1. Introduction. 2. Operating Characteristics. 3. Engine Cycles. 4. Thermochemistry and Fuels. 5. Air and Fuel Induction. 6. Fluid Motion Within Combustion Chamber. 7. Combustion. 8. Exhaust Flow. 9. Emissions and Air Pollution. 10. Heat Transfer in Engines. 11. Friction and Lubrication. Appendix. References. Answers to Selected Review Problems. Index.
The Study on the Cathodic Protection Effect of the ICCP Anodes with Exposed Conditions

This paper presents the results of the effects of anodes for impressed current cathodic protection (ICCP) system on reinforced concrete. Experimental tests were carried out on reinforced concrete specimens with 3 different kinds of commercial anodes that are used for ICCP in order for comparative study. Results have shown that the type of anodes is irrelevant to the effectiveness of cathodic protection. CP current similarly flowed to the anodes regardless of anode types in seawater condition. In addition, current was much higher in seawater condition than freshwater and air condition. The results show that titanium rod anode was slightly more effective in fresh water, and titanium mesh anode showed a better performance in atmospheric condition. The potential drop caused by concrete resistance in atmospheric condition should be considered at depolarization potential measurement.
Distraction Detection and Mitigation Through Driver Feedback

Despite government efforts to regulate distracted driving, distraction-related fatalities and injuries continue to increase. Manufacturers are introducing real-time driver monitoring systems that detect risk from distracted driving and warn drivers; however, little is known about these systems. This report identifies evaluation techniques to characterize and assess these emerging technologies, presents results of their application, develops a framework for estimating systems’ safety benefits, and provides safety relevant information to guide technology development. A standardized language for describing and differentiating systems was created, and its application revealed key trends in the design landscape. A novel approach to detection that provides prospective indications of safety-critical vehicle state changes is described. Two evaluation protocols were developed and to provide empirical assessments of (1) detection algorithm performance and (2) the effect of mitigations on driver performance and acceptance. The protocol included driving on different types of roadways and performing secondary tasks in the high-fidelity NADS-1 driving simulator. Four progressively complex distraction detection algorithms were compared to evaluate the ability of vehicle-based systems to distinguish between distracted and non-distracted drivers. Algorithm performance varied across road types and distraction tasks. A safety benefits framework appropriate for distraction mitigation systems is proposed that expands on past benefit analyses.
Dispersive Wave Analysis Using the Chirplet Transform

Time‐frequency representations (TFR) are a widely used tool to analyze signals of guided waves such as Lamb waves. As a consequence of the uncertainty principle, however, the resolution in time and frequency is limited for all existing TFR methods. Due to the multi‐modal and dispersive character of Lamb waves, displacement or energy related quantities can only be allocated to individual modes when they are well‐separated in the time‐frequency plane.The chirplet transform (CT) has been introduced as a generalization of both the wavelet and Short‐time Fourier transform (STFT). It offers additional degrees of freedom to adjust time‐frequency atoms which can be exploited in a model‐based approach to match the group delay of individual modes. Thus, more exact allocation of quantities of interest is possible.The objective of this research is to use a previously developed adaptive algorithm based on the CT for nondestructive evaluation. Both numerically and experimentally generated data for a single aluminum pla.
Structural diagnostics of CFRP composite aircraft components by ultrasonic guided waves and built-in piezoelectric transducers

To monitor in-flight damage and reduce life-cycle costs associated with CFRP composite aircraft, an autonomous built-in structural health monitoring (SHM) system is preferred over conventional maintenance routines and schedules. This thesis investigates the use of ultrasonic guided waves and piezoelectric transducers for the identification and localization of damage/defects occurring within critical components of CFRP composite aircraft wings, mainly the wing skin-to-spar joints. The guided wave approach for structural diagnostics was demonstrated by the dual application of active and passive monitoring techniques. For active interrogation, the guided wave propagation problem was initially studied numerically by a semi-analytical finite element method, which accounts for viscoelastic damping, in order to identify ideal mode-frequency combinations sensitive to damage occurring within CFRP bonded joints. Active guided wave tests across three representative wing skin-to-spar joints at ambient temperature were then conducted using attached Macro Fiber Composite (MFC) transducers. Results from these experiments demonstrate the importance of intelligent feature extraction for improving the sensitivity to damage. To address the widely neglected effects of temperature on guided wave base damage identification, analytical and experimental analyses were performed to characterize the influence of temperature on guided wave signal features. In addition, statistically-robust detection of simulated damage in a CFRPmore » bonded joint was successfully achieved under changing temperature conditions through a dimensionally-low, multivariate statistical outlier analysis. The response of piezoceramic patches and MFC transducers to ultrasonic Rayleigh and Lamb wave fields was analytically derived and experimentally validated. This theory is useful for designing sensors which possess optimal sensitivity toward a given mode-frequency combination or for predicting the frequency dependent directivity patterns in a transducer's response. Based upon this theory, a novel approach was developed for passive damage and impact location in anisotropic or geometrically complex systems. The detection and location of simulated ''active'' damage or impacts was experimentally demonstrated on a scaled CFRP honeycomb sandwich wing skin using this technique. « less
Fruizione digitale di reperti archeologici. L’esperienza del Museo Civico Archeologico di Bologna

This contribution presents a series of investigations undertaken thanks to the collaboration between the Department of Architecture and Territorial Planning of the University of Bologna and the Archaeological Museum of Bologna , aimed at finding a procedure for the 3d digital survey and exploration of archaeological finds. In particular, this paper shows how users can benefit from the use of digital technologies for the fruition of historical-artistic heritage. As a matter of fact, digital communication tools stimulate multisensory perception mechanisms and therefore allow to actively involve users in the exploration of contents presented through collections. Immersive visualizations, augmented reality and both tactile and visual exploration of findings can ease the establishment of a more immediate and direct communication channel with users that generally communicate and access information using digital technologies and mediums.
Radiated microwave power transmission system efficiency measurements

The measured and calculated results from determining the operating efficiencies of a laboratory version of a system for transporting electric power from one point to another via a wireless free space radiated microwave beam are reported. The system's overall end-to-end efficiency as well as intermediated conversion efficiencies were measured. The maximum achieved end-to-end dc-to-ac system efficiency was 54.18% with a probable error of + or - 0.94%. The dc-to-RF conversion efficiency was measured to be 68.87% + or - 1.0% and the RF-to-dc conversion efficiency was 78.67 + or - 1.1%. Under these conditions a dc power of 495.62 + or - 3.57 W was received with a free space transmitter antenna receiver antenna separation of 170.2 cm (67 in).
Computer aided optimisation of an agro-industrial complex consisting of processes and inventories by means of a custom-developed hybrid genetic algorithm

Mixing is a very common industrial process; the resulting mixture may be either a final or an intermediate product, of predetermined content for each constituent, according to certain quality specifications. During the production process within an agro-industrial complex, raw materials (usually highly inhomogeneous and sensitive by nature) from external inventories, distributed in the time/space domain, should cater for the internal ones that feed the mixer. The aim of the present work is the computer-aided optimisation of such a combined industrial process by (a) continuously locating transhipment points, (b) determining the optimal routing of raw materials, (c) reshuffling the external inventory list and (d) obtaining the minimal operating cost provided through a custom-developed module, namely the external inventory cost optimiser which is fed with real-time data obtained by the coupled use of a geographical information system (GIS) with a Global Positioning System (GPS). To accomplish such tasks, a hybrid genetic algorithm (GA) is employed featuring specific myopic rules. A case study is also presented referring to the design of an ethanol production unit located in the Thessaly plane of Central Greece where the number of inventories varies. In addition, the impacts of certain unpredictable events on raw material concentration (e.g. deterioration of residues quality, etc) are discussed.
Clinical and radiographic classification of implant supported prosthesis for edentulous patients

Relevance. In domestic and foreign professional literature there is a lack of aggregated consolidated data about immediate long span implant supported prosthesis which could be fundamental in making decision making process during the treatment planning stage, as well as at the estimation of quality of implant supported prosthetics. The aim of this study – the creation of a conceptual model of the standard implant prosthetics for edentulous patients.Materials and methods. A comprehensive examination and implantation prosthetics 382 patients aged 38 to 84 years (211 women, 171 men) with 582 implant supported prosthesis of various types, supporting on implants "Nobel Replace Select / Groove», «Nobel Parallel CC», «Nobel Speedy Groove», «Nobel Trefoil CC» (3775 implants). We have created a new clinical and radiographic classifcation of implant-supported prosthesis for edentulous patients.Result. As a result of the classifcation in the I (1-2 implants) class rallied 6.2% of implant supported prosthesis, to II class (3-4 implant, «TREFOIL» included) was assigned 19.2% of prostheses, to III class (5-6 implants) – 30.2% of replacement structures IV- to (7-10 implants) – 44%, and V – 0,3%. Meanwhile II, III, IV classes and I statistically revealed age diﬀerences. Conclusions: We have sorted out fve main classes, 8 subclasses and 18 groups with 34 subgroups of implant supported prosthesis based on the number of abutments, type of prosthesis, retention method and the presence of unilateral or bilateral cantilever.
School Experiences and Postschool Pathways in the Republic of Ireland

This chapter draws on a mixed methods longitudinal study of a cohort of young adults in Ireland who were followed from their entry to secondary education to their outcomes three to four years after completing upper secondary education. In keeping with previous international research, the study findings show that the main pathways taken by young people reflect their gender, social class background, and academic performance. However, the analyses go further than previous work by indicating the way in which the nature of postschool transitions are firmly embedded in earlier school experiences. In particular, the chapter contributes to the ongoing debate on the effects of school composition to show that school social mix has a very significant impact on postschool outcomes, with those who attended middle-class schools having particularly high levels of participation in higher education. This is consistent with higher education assuming a ‘taken for granted’ quality in middle-class schools. In contrast, young people who had attended working-class schools are much more likely than those in middle-class or socially mixed schools to enter the labor market directly upon leaving school, even taking account of their exam grades. School climate plays an important role, with negative relations with teachers serving to discourage young people from remaining on in any form of education/training. The chapter concludes by highlighting the implications of the findings for our understanding of youth transitions and for policy designed to improve equity of outcomes.
Design, Analysis of Solar Operated Hybrid (Water Heater Plus Cooking) System

The energy obtains from the solar radiation by the Concentrating system. Here design and analysis is carried out for combined hybrid system of solar cooker and water heater. Hybrid system develops and fabricate for three research objectives ENERGY, ECOLOGY & ECONOMY. Study the effects of the solar cooker on its performance with wrapping water circulating copper tube for heat recovery system. More than 85% of the incoming solar energy is either reflected or absorbed as heat energy.The hybrid concentrating collector technology using water as the heat recover has been seen as a solution for improving the energy performance. The study was carried out to evaluate the combined effect of solar cooker with water heating system. Our observation is that very few studies and design appropriate recommendations are made which will aid solar cooker with water heating systems to improve their overall and thermal efficiency and reducing their cost and utilize energy for making combination of solar cooker with water heating system. With this type of hybrid system saving increased and return on investment is faster so payback period of investment is reduced. System is utilized for more hours/day for cooking as well as water heating. that the model is verified for wide range of load.