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In-vehicle qi-compliant inductive wireless charging solutions: A review
No full textIn-vehicle wireless charging systems are becoming increasingly popular in modern vehicles, providing a convenient and efficient way to recharge electronic devices while on the move. This article aims to provide an overview of the standard applied for wireless chargers in these systems, as well as the various inductive wireless power transfer methods used. It covers the design of transmitter and receiver circuits, including key design topologies such as coil selection, compensation methods, and quality factor, and explores the importance of choosing the most optimal methods and parameters for efficient and safe wireless charger design. The paper also highlights the crucial role of the Qi standard in ensuring compatibility and interoperability between different wireless charging devices, as well as the importance of prioritizing efficiency and security in the design of in-vehicle wireless charging systems. In particular, it examines two security solutions that are commonly used in these systems: Near Field Communication (NFC) and Foreign Object Detection (FOD). NFC technology allows two electronic devices, such as a smartphone and an in-vehicle wireless charger, to communicate with each other when they are nearby. This can help ensure that only authorized devices can access the wireless charger, preventing unauthorized access and ensuring safe and secure wireless charging. FOD technology, on the other hand, detects foreign objects that may be in the proximity of the wireless charger, such as metal objects or coins, and prevents the charger from operating if it detects such objects. This helps to prevent damage to the charger, or the electronic device being charged. Overall, this paper emphasizes the necessity and importance of developing efficient and secure in-vehicle wireless charging systems that comply with the Qi standard and incorporate NFC and FOD technologies to ensure reliable and convenient charging for modern vehicles
Valorization of biomass ashes in the production of cementitious composites: A comprehensive review of properties and performance
No full textThe demand for cementitious composites as the most abundantly used construction material is increasing due to rapid urbanization and industrialization, resulting in the exploitation of natural resources. Parallel to this, the ever-increasing world population is raising the demand for agricultural products leading to various challenges in disposing of consequential agricultural waste. One of the popular methods of managing agricultural waste is incineration, resulting in the production of biomass ash, which is eventually landfilled leading to environmental pollution. The scarcity of natural resources and increasing degradation of the environment are instigating scientific investigations to explore the potential of reducing the dependence on energy- and carbon-intensive materials (such as cement) by replacing them with waste materials. Therefore, this study evaluates the influence of biomass ashes (such as rice husk ash (RHA), bamboo leaf ash (BLA), sugarcane bagasse ash (SCBA), wood waste ash (WWA), and palm oil fuel ash (POFA)) derived from five abundantly available agricultural waste on the performance of cementitious composites. Based on the previously published literature, the biomass ashes were characterized by analyzing their mineralogical, physiochemical, mechanical, and durability properties. According to the analysis, it can be concluded that 5–10% cement can be replaced with RHA, BLA, WWA, and POFA without any significant effect on cementitious composites’ workability, whereas the incorporation percentage for SCBA can be 5–20%. Moreover, the optimal incorporation percentage of RHA, BLA, SCBA, WWA, and POFA in cementitious composites without any negative influence on the mechanical properties is 5–15%, 5–10%, 5–30%, 5–10%, and 5–20%, respectively. It is worth noting that these replacement ratios can be further increased by subjecting biomass ashes to different pretreatment methods, such as controlled combustion and grounding. The promising findings of this study may encourage additional experimental investigations on this topic to achieve sustainable development goals in agriculture and construction industries
Armenians in 1920s Greece: Turkey’s unwanted minority, the league of nations’ Burden, Greece’s “Other” refugees
No full textThis article sheds light upon the history of an underresearched group of refugees who settled in Greece in the 1920s. It focuses on Armenians from Anatolia who fled to Greece in 1921-22, during and after the Greek-Turkish War of 1919-22. The article examines how the Greek government and international humanitarian organizations (Near East Relief, American Red Cross, etc.) approached the Armenian refugees, including orphans. The study further highlights practices such as transfers of Armenians within Greece, repatriation programs supported by Greece to send the Armenian refugees to Soviet Armenia, and citizenship policies regarding them
Gradient-based optimization of micro-scale pressurized volumetric receiver geometry and flow rate
No full textThis study focuses on the design optimization of a micro-scale pressurized volumetric receiver by changing geometry and flow rate constrained by the volume, outlet air temperature, and outer surface temperature. The pressurized volumetric receiver model is replicated from an existing model, which assumes constant air pressure and neglects the convection loss from the cavity. The existing model is revised from a solver to a design optimizer. The replicated model is restructured using OpenMDAO (Open-source MultiDisciplinary Analysis and Optimization) framework, and analytical derivatives are implemented for efficient derivative calculation to increase optimization performance. The replicated model is verified, and the maximum outlet air temperature difference is less than 0.05%. Optimization performance, selection of optimizers, the effect of the domain size, and radiative methods are discussed. The combined impact of the design variables is observed by selecting SLSQP (Sequential Least SQuares Programming) and trust-region optimizers. Optimization performance is tested in different domain sizes and compared with a design of experiments analysis. For testing the impact of radiative heat transfer methods to design optimization, the Rosseland approximation, and P1 method are selected. Depending on the design domain, a solution methodology is suggested for future receiver design optimizations applicable for macro-scale pressurized volumetric receivers
Improved LNB power circuit design for enhanced reliability by current limiting control
No full textLow Noise Block (LNB) circuits are an essential component of satellite receiving systems in televisions. LNB converts high-frequency satellite signals into a lower frequency range for transmission to the receiver. Also, LNB ensures low-noise signal reception, enables polarization control, supports multiple frequency bands, and amplifies signals. The LNB power circuits provide power to the LNB. Voltage-controlled boost converters are commonly used in these circuits; the current limiting feature used in these circuits can be insufficient to handle sudden current spikes, leading to feedback from end users. They are not immune to short circuits because of installation problems with satellite cables, which are a common failure mode that potentially damages the LNB power or other components in the television, resulting in a loss of satellite signal. Hence, leading to a poor user experience and harming the manufacturer's reputation. Replacing a damaged LNB power circuit is also difficult b ecause i t i s o ften i ntegrated i nto t he T V's d esign and is not easily replaceable. To mitigate this problem, a parallel resonant converter approach is introduced that limits the output current up to a pre-defined l evel b y f requency c ontrol, which provides an alternative to voltage-controlled boost converters. Parallel resonant converter circuits operate as current sources so maximum current cannot exceed this defined operation frequency point under any circumstances. In this study, the mathematical equations of the proposed circuit were obtained, and then the operating conditions were determined. The operation frequency ranges were interpreted graphically using Matlab, and the parallel resonant converter design was evaluated using simulation model by using MATLAB's Simulink Toolbox. These results show that the parallel resonant converter approach maintaining a stable current and reducing the risk of short circuit damage. The proposed design is expected to reduce repair costs due to LNB power circuits for TV manufacturers
Can you see me at my worst? A latent Profile analysis of students and teachers’ perceptions of student behavior problems
No full textThere is renewed interest in multi-informant and person-centered approaches to comprehending the nature of students’ behavior problems. However, most previous studies utilized single-informant or variable-based approaches. To address this gap, we aspired to identify profiles of student behavior problems, consequently comparing student-reported profiles and teacher-reported profiles. We recruited 904 students (68.3% Males) across ten schools. Students’ age ranged from 9 to 16 years (M = 11.87, SD = 1.21). Teachers and students reported students’ emotional problems, conduct problems, hyperactivity, and peer problems using the Strengths and Difficulties Questionnaire (SDQ; Goodman 2001). Results from latent profile analysis (LPA) supported a 3-profile solution as optimal for student reports (Low Behavior Problem [BP] (67.4%), High BP (17.4%), and Social-Emotional BP (15.1%) and a 4-profile solution for teacher reports (Low BP (34.3%), High BP (13.4%)Social-Emotional BP (15.4%), and Externalizing BP (37%). Results from both LPA and bivariate correlation analyses showed some discrepancies between teachers’ and students’ perceptions. These discrepancies are discussed in the context of a multi-informant approach
Explain to me: Towards understanding privacy decisions
No full textPrivacy assistants help users manage their privacy online. Their tasks could vary from detecting privacy violations to recommending sharing actions for content that the user intends to share. Recent work on these tasks are promising and show that privacy assistants can successfully tackle them. However, for such privacy assistants to be employed by users, it is important that these assistants can explain their decisions to users. Accordingly, this work develops a methodology to create explanations of privacy. The methodology is based on identifying important topics in a domain of interest, providing explanation schemes for decisions, and generating them automatically. We apply our proposed methodology on a real-world privacy data set, which contains images labeled as private or public to explain the labels.Ministerie van Onderwijs, Cultuur en Wetenschap ; Nederlandse Organisatie voor Wetenschappelijk Onderzoek ; TÜBİTA
A two-phase heuristic algorithm for the label printing problem
No full textIn this paper, we study the label printing problem (LPP) which has applications in the printing industry. In LPP, the demand for a set of labels is satisfied by printing the labels using templates with multiple slots. Given a fixed number of templates, the decisions in LPP are determining (i) the assignment of labels to the slots of the templates (which we call template designs), and (ii) the number of prints made using each template design. The objective is to satisfy the demand with minimum waste. We consider two variants of LPP where (i) each label can be assigned to the slot(s) of a single template, and (ii) each label can be assigned to the slot(s) of multiple templates. To address LPP, we propose a novel sampling-based construct-improve heuristic where we first generate "good" template designs and then choose the ones to be used and determine the number of prints made through a set covering-type mathematical model. Then, we improve the solution using some improvement ideas that utilize a strengthened linear integer model for the problem. Using the instances from the literature, we show that the proposed heuristic provides better results compared to the benchmark algorithm. We also find optimal solutions for some of the instances from the literature using the strengthened linear integer model. With the help of the optimal solutions found we identify some problems in the previously reported results in a related study. Finally, we observe that the proposed heuristic approach not only provides better solutions but also runs in less amount of time compared to the benchmark algorithm on the large instances
Classification of hundreds of classes: A case study in a bank internal control department
No full textThe main function of the internal control department of a bank is to inspect the banking operations to see if they are performed in accordance with the regulations and bank policies. To accomplish this, they pick up a number of operations that are selected randomly or by some rule and, inspect those operations according to some predetermined check lists. If they find any discrepancies where the number of such discrepancies are in the magnitude of several hundreds, they inform the corresponding department (usually bank branches) and ask them for a correction (if it can be done) or an explanation. In this study, we take up a real-life project carried out under our supervisory where the aim was to develop a set of predictive models that would highlight which operations of the credit department are more likely to bear some problems. This multi-classification problem was very challenging since the number of classes were enormous and some class values were observed only a few times. After providing a detailed description of the problem we attacked, we describe the detailed discussions which in the end made us to develop six different models. For the modeling, we used the logistic regression algorithm as it was preferred by our partner bank. We show that these models have Gini values of 51 per cent on the average which is quite satisfactory as compared to sector practices. We also show that the average lift of the models is 3.32 if the inspectors were to inspect as many credits as the number of actual problematic credits
A comparison study between 1D and 2D site response analyses based on observed earthquake acceleration records
No full textThe objective of the present work is to evaluate the necessity of 2D site response analysis based on the comparison among the peak ground and spectral accelerations recorded by Istanbul Rapid Response Network and Istanbul vertical array stations during the Mw = 6.5 24/5/2014 Gökçeada and Mw = 5.9 19/5/2011 Kütahya earthquakes with the calculated accelerations by 1D and 2D site response analyses. The shear wave velocity profiles determined based on in-situ geophysical and geotechnical measurements and laboratory tests within the Istanbul Microzonation Project are revaluated adopting a revision scheme to obtain the best fits between the recorded and calculated spectral accelerations by 1D site response analysis. These modified shear wave velocity profiles are later used for 1D and 2D site response analyses performed in North–South and East–West directions to model peak ground and spectral accelerations on the ground surface. Finally, by modelling different distances around boreholes the influence of variation of the soil profile in horizontal direction is investigated by 2D analyses.TÜBİTA