Miracle-dz/UniFAR-FTUs huggingface dataset:
Design and optimization of millimeter-wave IMPATT oscillators

An efficient frequency-domain nonlinear circuit analysis for the design of IMPATT oscillators is presented. A nonlinear circuit model for the active device which is valid up to millimeter-wave frequencies is combined with the load impedance function of a radial-line resonator waveguide mount calculated by mode-matching. Results for a 140 GHz GaAs IMPATT diode oscillator demonstrate that the method is well suited to investigate the influence of resonator dimensions and parasitic elements on the oscillator performance systematically.
29.3L: Late‐News Paper: Eye‐Trace Integration Effect on The Perception of Moving Pictures and A New Possibility for Reducing Blur on Hold‐Type Displays

A detailed analysis on “eye‐trace integration” which causes the degradation of moving pictures is made. Some intrinsic characteristics and questions are found and the visual results that show the effects of the overdrive and the intraframe blanking are obtained. Also a new possibility is found, that could produce a better view without using blanking.
Analysis of electromechanical boundary effects on the pull-in of micromachined fixed–fixed beams

Using a commercial finite-element simulation tool, this work considers some of the electromechanical effects commonly neglected during the analysis of electrostatically actuated fixed–fixed beams. These structures are used in many applications of micromechanical systems, from relay switches and RF resonators to thin film characterization tests, but much of the analytical modelling of the device behaviour disregards the effects of electrostatic field fringing, plane-strain conditions and anchor compliance. It is shown that the cumulative total of these errors can be substantial, and may lead to large discrepancies in the expected operational characteristics of the device. We quantify the influence of these effects on the electrostatic pull-in of fixed–fixed beams, and illustrate some of the limitations of ideal pull-in theory. In order to more accurately predict the pull-in voltage for a real structure, a model is developed that combines ideal case theory with anchor compliance correction factors extracted using finite-element analysis. Three common anchor types (ideal, step-up and cup-style) are characterized. The final model takes account of the compliance of the beam anchors, electrostatic field fringing and plane-strain effects, and agrees well with simulated results.
Accounting for the Needs of Blind and Visually Impaired People in Public Realm Design

Public realm schemes are being introduced in urban areas without the usual delineation between the footway and carriageway provided by kerb edges. Concern has been expressed about the resulting spaces on behalf of the approximately two million people in the UK who are blind or visually impaired. This paper questions these concerns and presents the results from a questionnaire and in-depth interviews, and observational studies of blind and visually impaired people navigating in urban streets and spaces with and without shared surfaces. They show that blind and visually impaired people can identify many different surface types and delineators, and they use these, along with other features of the urban environment, in creative ways to identify their location and guide themselves. Shared Space schemes need to preserve a safe area for pedestrians, they need to provide a rich physical environment of contrasts in terms of surface tactility, colour contrast, and the enhancement of sound and other sensory clues.
Conductor requirements for high-temperature superconducting utility power transformers

High-temperature superconducting (HTS) coated conductors in utility power transformers must satisfy a set of operating requirements that are driven by two major considerations—HTS transformers must be economically competitive with conventional units, and the conductor must be robust enough to be used in a commercial manufacturing environment. The transformer design and manufacturing process will be described in order to highlight the various requirements that it imposes on the HTS conductor. Spreadsheet estimates of HTS transformer costs allow estimates of the conductor cost required for an HTS transformer to be competitive with a similarly performing conventional unit.
Solutions for Impact over Aerospace Protection

New ballistic protection systems based on alternative materials have been recently developed. One of the industry’s objectives is to develop lighter and stronger defensive systems, which allow higher mobility and safety for both vehicles and humans. This work studies the behavior of an aerospace protection against a projectile impact, seeking an optimized construction. The Al-Qureshi et al. model suggests a ceramic-metal layer system and describes its behavior. The literature shows, due to the considered parameters, the erosion tax and the loss of velocity. The phenomenon is described in steps, presenting particular effects for each. The equations are not equal between the stages showing different properties. The present work searches for a solution that can show the expression for mass and velocity, for each stage of the phenomenon. The results from the numerical method used were plotted and analyzed. The treatment was performed using Maplesoft Maple software. As a result, graphs were generated, which allow a deeper analysis of the model. Finally, advance in the knowledge of fracture processes in materials by high velocity impact can be concluded. This fact permits developments in materials that can perform shock absorption.
Aerodynamics of the Tacoma Narrows Bridge - 60 Years Later

This article takes a new approach to understanding the aerodynamics failure mechanism responsible for the collapse of the Tacoma Narrows Bridge 60 years ago. It is demonstrated that the instability mechanism is associated with the formation and drift of large vortices from the upwind edge of the bridge girder cross section. An empirical model of the vortex formation and drift process is formulated that allows critical wind speed for onset of the instability to be estimated. The model is supported by numerical simulations and experimental results. It is shown that a structural modification of the Tacoma Narrows Bridge cross section would have suppressed the vortex formation or counteracted the aerodynamic actions and thus rendered the bridge more aerodynamically stable.
Comparison of thin-film resistance heat-transfer gages with thin-skin transient calorimeter gages in conventional hypersonic wind tunnels

Thin film gages deposited at the stagnation region of small (8.1-mm-diameter) hemispheres and gages mounted flush with the surface of a sharp-leading-edge flat plate were tested in the Langley continuous-flow hypersonic tunnel and in the Langley hypersonic CF4 tunnel. Two substrate materials were tested, quartz and a machinable glass-ceramic. Small hemispheres were also tested utilizing the thin-skin transient calorimeter technique usually employed in conventional tunnels. One transient calorimeter model was a thin shell of stainless steel, and the other was a thin-skin insert of stainless steel mounted into a hemisphere fabricated from a machinable-glass-ceramic. Measured heat-transfer rates from the various hemispheres were compared with one another and with predicted rates. The results demonstrate the feasibility and advantages of using-film resistance heat-transfer gages in conventional hypersonic wind tunnels over a wide range of conditions.
Integrated-circuit test structure which uses a vernier to electrically measure mask misalignment

A test structure consisting of a vernier implemented in MOS technology which may be used to electrically measure the amount of misalignment between two mask levels is described. It is ideally suited to characterise and monitor the performance of high resolution aligners such as 10:1 wafer steppers. The resolution of the vernier is limited only by the minimum grid unit permitted by the CAD system or mask resolution. The vernier is also designed to automatically compensate for any over etching which may occur during processing.
Elements of a Supportive Learning Environment for Mathematics Learners

South Africa is witnessing an education crisis of significant proportions and universities are suffering the consequences of under preparation of learners for tertiary studies especially in mathematics. It has become common practice for universities to deploy augmented programmes in mathematics for secondary school learners in the surrounding areas. This article reports on an intervention in the Eastern Cape of South Africa, called the Incubator School Project (ISP) an initiative of the Nelson Mandela Metropolitan University. The defining feature of the ISP is that it incorporates DVD technology that offers an affordable and accessible option for the particular group of learners and the schools they attend. The article considers the research question: What elements present in this intervention support the teaching and learning of mathematics? This case study within an action research project explores the particular blended approach and reports qualitatively based firstly on a questionnaire completed by learners, secondly on interviews of learners, and thirdly on the facilitators reports. This research revealed that using the DVD approach within a blended learning environment provided learners with a supportive environment in which to learn mathematics. The elements which supported learning in this approach are presented.
Total Cost Minimization of a High-Pressure Natural Gas Network

This paper deals with a high-pressure gas pipeline optimization, where the problem is to find the design properties of the pipelines and necessary compressor stations to satisfy customer requirements, using available supply gas and storage capacities. The considered objective function is the total annualized cost, including the investment and operating costs. The binary variables used to represent the flow direction of pipelines lead to a mixed integer nonlinear programming problem, solved by using the standard branch and bound solver in GAMS. The optimization strategy provides the main design parameters of the pipelines (diameters, pressures, and flow rates) and the characteristics of compressor stations (location, suction pressure, pressure ratio, station throughput, fuel consumption, and station power consumption) to satisfy customer requirements.
Risk Assessment in Construction Schedules

Construction projects are initiated in complex and dynamic environments resulting in circumstances of high uncertainty and risk, which are compounded by demanding time constraints. This paper describes a systematic way to consider and quantify uncertainty in construction schedules. The system incorporates knowledge and experience acquired from many experts, project-specific information, decision analysis techniques, and a mathematical model to estimate the amount of risk in a construction schedule at the initiation of a project. The model provides the means for sensitivity analyses for different outcomes wherein the effect of critical and significant risk factors can be evaluated. The paper focuses on lessons learned from past projects and describes a risk assessment process involving typical inputs and expected outputs. The paper also briefly reviews the information technology of HyperCard and Excel, which were used to develop the system.
Effect of Cell Geometry on the Freezing and Melting Processes inside a Thermal Energy Storage Cell

This paper presents an analysis of the charge and discharge processes in a latent thermal energy storage cell. An individual cell is analyzed to study how its behavior affects the performance of a thermal energy storage system. The analysis considers the exchange of thermal energy between a thermal energy storage cell and a source or sink of thermal energy. Two cases are considered, (i) a process in which the phase change material melts and freezes when a constant and uniform temperature is imposed at the lower surface of the cell, and (ii) a process in which the phase change material melts and freezes when a fluid with a constant inlet temperature flows under the cell. The effect of the aspect ratio of the energy storage cell is analyzed in detail as a possible method to enhance heat transfer and improve performance of the thermal energy storage system. The results include, for different aspect ratios of the storage cell, the evolution of the solid-liquid interface, the rates of melting and solidification, the rate of energy storage and the total amount of energy storage.
Design Guideline of Si-Based L-Shaped Tunneling Field-Effect Transistors

In this work, novel L-shaped tunneling field-effect transistors (TFETs) have been proposed. The proposed L-shaped TFETs feature higher on-current (Ion) and lower subthreshold swing (SS) than conventional TFETs. It is because L-shaped TFETs have large cross-sectional area of band-to-band tunneling junction which is perpendicular to the channel direction and their tunneling barrier width (Wt) is defined by the length of an intrinsic silicon region. As the devices are based on the Si without any other material, it can be fabricated with well-established Si process technology. In addition, it can moderate some issues come from scaling down and enlarging tunneling area due to its mesa structure. Simulation results have confirmed the superiority of L-shaped TFETs over conventional TFETs. Additionally, the effect of some device parameters on device performance has been investigated for the clear verification of its operation mechanism and the optimization.
Applying transformer concept to nonisolated voltage regulators significantly improves the efficiency and transient response

A voltage regulator (VR) is a DC-DC converter dedicated to powering the microprocessors in today's computers. The multiphase buck converter, as the current solution, faces great challenges for future use in VRs. This paper applies the transformer concept to generate several families of new converters, therefore providing opportunities to improve the efficiency while maintaining good transient response. Topology derivation, analysis and experimental results are presented. Test results verify the theoretical prediction.
Exploring the Factors Influencing Big Data Technology Acceptance

Big Data has received great attention in academic literature and industry papers. Most of the experiments and studies focused on publishing results of big data technologies development, machine learning algorithms, and data analytics. To the best of our knowledge, there is not yet any comprehensive empirical study in the academic literature on big data technology acceptance. The statistical results of this model provide a compelling explanation of the relationships among the antecedent variables and the dependent variables. The analysis of the structural model reveals that the hypothesis tests are significant for 8 out of 12 path relationships.
Influence of hydrodynamic effects on iceberg collisions

This paper examines various hydrodynamic effects which should be considered when analyzing iceberg collisions with a fixed structure. Iceberg added mass is among the hydrodynamic parameters that must be known to evaluate collision severity. Effective added mass is shown to vary with collision duration and recommendations are made for the selection of added masses to be used in iceberg collision design. Iceberg impact velocities are influenced by waves and currents, which can both be significantly influenced by the presence of a large structure. Wave-driven iceberg drift motions are shown to be more sensitive than current-driven motions to the presence of a structure. The contribution of wave-induced oscillatory motions to impact velocity is also discussed. Key words: added mass, hydrodynamics, ice impact, icebergs, ocean engineering, offshore structures.
Impact of Forward Substrate Bias on Threshold Voltage Fluctuation in Metal–Oxide–Semiconductor Field-Effect Transistors

The effect of forward substrate (body) bias on threshold voltage (Vth) fluctuation in metal–oxide–semiconductor field-effect transistors (MOSFET) and its device parameter [e.g., gate length, substrate impurity concentration, gate oxide thickness (effective oxide thickness), etc.] dependence are investigated using a charge-sharing model. It is predicted that, through the application of a forward substrate bias of 0.5 V, Vth fluctuation is suppressed by up to 20% and the device parameter sensitivity of Vth is reduced in sub-100-nm devices. An experimental result demonstrating the effect of forward substrate bias on Vth fluctuation suppression is also presented.
Deformation Characteristic of Thin Stainless Gasket Material

Previous studies on corrugated metal gaskets have established that the contact width, contact stress, and surface roughness are important design parameters for optimizing gasket performance. However, the metal gaskets studied previously required a high axial force for the tightening process; in addition that metal gaskets tend to corrode easily. In this study, we examined the deformation mode of a thin stainless gasket using a finite element method (FEM) analysis. A final evaluation was made using a compression examination. The analysis based on the dimension of flat and convex portion. The load, deformation mode, and contact stress were obtained through a simulation. Based on the deformation of the flat and convex portions, the deformation modes were divided into three types. The deformation mode of the thin stainless gasket material has a higher probability of deformation in mode I when the aspect ratio of the length of the flat portion to the length of the convex portion, L/D, increases.
Optimal and Coherence Zone Comparison Within and Between Flight Simulators

In flight simulation, motion-cueing algorithms are used to transform aircraft motion into motion within the simulator limits. When looking for the best match between visual and inertial amplitude in a simulator, researchers have found that there is a range of inertial amplitudes, rather than a single inertial value, that is perceived by subjects as optimal. This zone, hereafter referred to as the optimal zone, seems to correlate to the perceptual coherence zones measured in flight simulators. However, no studies were found in which these two zones were compared. This study investigates the relation between the optimal and the coherence-zone measurements within and between different simulators. An experiment was conducted at NASA Langley Research Center, where two simulators were used to measure the optimal and the coherence zone in the sway axis. Results show that the optimal zone lies within the coherence zone. The center of the optimal zone is significantly lower than the center of the coherence zone. I.
Novel combined standard hydromechanical sheet hydroforming process

Abstract Sheet hydroforming techniques are widely used in industries for the production of different components with specific characteristics. Despite the advantages of the conventional sheet hydroforming techniques, they have their own limitations. In this paper, to increase the application and to overcome the limitations of conventional deep drawing, a new sheet hydroforming technique is proposed that is a combination of the standard and the hydromechanical sheet hydroforming processes. The proposed method has the advantages of conventional processes but eliminates their limitations. This technique is used in forming a cylindrical cup and a complex industrial part. After applying the appropriate pressure path, the products are formed successfully in one stage without any defects. It is also shown that the required forming pressure in the proposed process is low compared with other sheet hydroforming processes. It is demonstrated that because of the low internal pressure required in the present method, pre-bulging does not have any significant effect on the thickness distribution of the product. It is concluded that in this process increasing the friction coefficient between punch and blank can reduce the sheet thinning.
Machine vision assisted characterization of machined surfaces

This paper demonstrates the feasibility of using an inexpensive machine vision system to compute non-contact, optical parameters for the characterization of surface roughness of machined surfaces. Two parameters were selected for online analysis, where surface roughness is measured during the rotation of a specimen on a lathe. The sensitivity of the vision-based optical parameters to differences in surface roughness, ambient light and spindle speed of a lathe during measurement was evaluated. Statistical analysis of data collected through experimentation revealed that the vision parameters can discriminate different surface roughness heights and are insensitive to changes in ambient lighting and speed of rotation during measurement. The results of the experimental analysis were used to conclude the feasibility of using machine vision for the evaluation of surfaces.
Food Preparation

Many foods are not safe to be eaten raw or untreated so they are prepared in different ways. Food can be prepared in many ways. Fire is used often to cook meats and fish, seeds and nuts were ground or roasted on the coals and shellfish, vegetables and meats are also steamed and boiled. Washing To remove poisons and bitter tastes from some vegetables, they were sliced or ground into a paste and put into a dilly bag and hung in running water in a stream.
Exosomes miR-184 and miR-3913-5p are involved in Osimertinib resistance in non-small cell lung cancer patients with exon 21 L858R mutation

Background The third-generation of EGFR-TKI Osimertinib has become an important treatment option for patients with EGFR-mutant advanced NSCLC. In recent years, more and more studies have begun to pay attention to the ability of miRNAs in exosomes secreted by tumor cells to transmit resistance information. The mechanisms of exosomal miRNAs involved in Osimertinib resistance need to be studied. Methods We constructed an Osimertinib-resistant cell line H1975-OR, and collected the exosomes from the cells of the drug-resistant strain and the sensitive strain, and extracted respective RNA for sequencing. We also compared miRNAs in serum exosomes of three patients before and after resistance to Osimertinib. Enlarged samples were then validated in 64 NSCLC patients. Results Cluster analysis of target genes revealed that miRNAs in exosomes participate in Osimertinib resistance mechanisms through the activation of bypass pathways (RAS-MAPK pathway abnormality, PI3K pathway activation). MiR-184 and miR-3913-5p increased significantly in serum exosomes of patients with later Osimertinib resistance. These two miRNAs mainly cause EGFR resistance in two types of NSCLC patients, EGFR exon 21 L858R mutation and T790M positive. Conclusions Exosomes miR-184 and miR-3913-5p mainly cause Osimertinib resistance in lung cancer patients containing EGFR exon 21 L858R+ and T790M+. They are regarded as important biomarkers of third-generation EGFR-TKI resistance. This not only enriches the application of liquid biopsy in lung cancer drug resistance, but also provides a direction for future targeted drug research.