Miracle-dz/UniFAR-FTUs huggingface dataset:
An On-Chip Noise Canceller with High Voltage Supply Lines for Nanosecond-Range Power Supply Noise

An on-chip noise canceller with high voltage supply lines for the nanosecond-range power supply noise is proposed. The canceller fabricated with 90-nm CMOS achieves 68% noise reduction with 2.0% power increase. Under the same noise reduction conditions, the area penalty for the canceller is 1/77 and 1/45 of those for the additional on-chip decoupling capacitors and the power supply lines respectively.
Diagnostic accuracy of imaging examinations for peri-implant bone defects around titanium and zirconium dioxide implants: A systematic review and meta-analysis

Purpose This systematic review and meta-analysis assessed the diagnostic accuracy of imaging examinations for the detection of peri-implant bone defects and compared the diagnostic accuracy between titanium (Ti) and zirconium dioxide (ZrO2) implants. Materials and Methods Six online databases were searched, and studies were selected based on eligibility criteria. The studies included in the systematic review underwent bias and applicability assessment using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool and a random-effect meta-analysis. Summary receiver operating characteristic (sROC) curves were constructed to compare the effect of methodological differences in relation to the variables of each group. Results The search strategy yielded 719 articles. Titles and abstracts were read and 61 studies were selected for full-text reading. Among them, 24 studies were included in this systematic review. Most included studies had a low risk of bias (QUADAS-2). Cone-beam computed tomography (CBCT) presented sufficient data for quantitative analysis in ZrO2 and Ti implants. The meta-analysis revealed high levels of inconsistency in the latter group. Regarding sROC curves, the area under the curve (AUC) was larger for the overall Ti group (AUC=0.79) than for the overall ZrO2 group (AUC=0.69), but without a statistically significant difference between them. In Ti implants, the AUCs for dehiscence defects (0.73) and fenestration defects (0.87) showed a statistically significant difference. Conclusion The diagnostic accuracy of CBCT imaging in the assessment of peri-implant bone defects was similar between Ti and ZrO2 implants, and fenestration was more accurately diagnosed than dehiscence in Ti implants.
A Generic Theory for Design of Efficient Three-Stage Doherty Power Amplifiers

An analytical load—pull-based design methodology for three-stage Doherty power amplifiers (PAs) is presented and demonstrated. A compact output combiner network, together with the input phase delays, is derived directly from transistor load—pull data and the design requirements. The technique opens up a new design space for three-stage Doherty PAs with reconfigurable high-efficiency power back-off levels. The method is designed to enable high transistor power utilization by maintaining full voltage and current swings of the main and auxiliary amplifier cells. Therefore, a wide efficiency enhancement range can be achieved also with symmetrical devices. As a proof of concept, a 2.14-GHz 30-W three-stage Doherty PA with identical gallium nitride (GaN) HEMT active devices is designed, fabricated, and characterized. The prototype PA is able to linearly reproduce 20-MHz long-term evolution signals with 8.5- and 11.5-dB peak-to-average power-ratio (PAPR), providing average efficiencies of 56.6% and 46.8% at an average output power level of 36.8 and 33.8 dBm, respectively. Moreover, an average efficiency as high as 54.5% and an average output power of 36.3 dBm have been measured at an adjacent power leakage ratio of −45.7 dBc for a 100-MHz signal with 8.5 dB of PAPR, after applying digital predistortion linearization.
Mechanical considerations and design skills.

The purpose of the report is to provide experienced-based insights into design processes that will benefit designers beginning their employment at Sandia National Laboratories or those assuming new design responsibilities. The main purpose of this document is to provide engineers with the practical aspects of system design. The material discussed here may not be new to some readers, but some of it was to me. Transforming an idea to a design to solve a problem is a skill, and skills are similar to history lessons. We gain these skills from experience, and many of us have not been fortunate enough to grow in an environment that provided the skills that we now need. I was fortunate to grow up on a farm where we had to learn how to maintain and operate several different kinds of engines and machines. If you are like me, my formal experience is partially based upon the two universities from which I graduated, where few practical applications of the technologies were taught. What was taught was mainly theoretical, and few instructors had practical experience to offer the students. I understand this, as students have their hands full just to learn the theoretical. The practical partmore » was mainly left up to 'on the job experience'. However, I believe it is better to learn the practical applications early and apply them quickly 'on the job'. System design engineers need to know several technical things, both in and out of their field of expertise. An engineer is not expected to know everything, but he should know when to ask an expert for assistance. This 'expert' can be in any field, whether it is in analyses, drafting, machining, material properties, testing, etc. The best expert is a person who has practical experience in the area of needed information, and consulting with that individual can be the best and quickest way for one to learn. If the information provided here can improve your design skills and save one design from having a problem, save cost of development, or reduce difficulty in manufacturing, then my writing effort will have been worthwhile. It is also my hope that you will freely provide others with design information that you have found beneficial to the less-experienced engineers. The result will be that as a whole, the designs will improve, and the development time will be shortened from start of the design to full system operation or deployment. « less
Traveling-wave microwave power divider composed of reflectionless dividing units

We propose a new waveguide type traveling-wave microwave power divider that is adequate for high power applications. The divider is composed of multiple stages of reflectionless dividing units, each having two output ports. Design formulas for reflectionless equal-power dividing are first derived. Structural parameters for wideband design of two- to six-stage dividers are then obtained by means of numerical analyses based on an equivalent circuit. Comparison of experiments at X-band shows good qualitative agreement with the analyses. Typical measured bandwidth for relative divided powers deviation of less than /spl plusmn/0.5 dB was 2.7 GHz, and that for -20 dB return loss was more than 3.2 GHz for the four-stage (eight-way) divider. The divider presented here has excellent features; the bandwidth for equal-power dividing decreases very little and the bandwidth for low return loss increases with increasing number of the dividing stages. It also has advantages of low insertion loss and flexibility over the number of the dividing stages. >
Modelling the pressure die casting process with the boundary element method: Die deformation model for flash prevention

Abstract In pressure die casting, the thermal loads, injection pressure and clamping forces cause the individual blocks of a die to deform. This deformation results in gaps between the interface surfaces which, if big enough and in the vicinity of the cavity, permit material to seep into the gaps, causing flash. This paper describes a thermoelastic model to predict the deformation of the die so that it can be machined to prevent flash. The model is based on the boundary element method and allows the use of linear isoparametric or quadratic subparametric elements. Each die block is analysed as a separate problem. To avoid the occurrence of flash, the model suggests the amounts that should be machined from each die block. The predicted deformation has been experimentally verified by measuring the profile of a test die using displacement transducers and die impressions. It is shown that there is good agreement between the predicted and experimental results for different operating conditions. By machining the amounts suggested by the model, the test die was run without flash at operating conditions that had previously resulted in flash.
A novel compact electromagnetic-bandgap (EBG) structure and its applications for microwave circuits

A novel electromagnetic-bandgap (EBG) structure in a fork-like shape is investigated. This structure has an extremely compact size. A comparison has been carried out between the new structure and the conventional mushroom-like EBG structure. Simulations and experimental results have verified that the area of the fork-like structure is less than 40% of the latter. The presented structure also provides an additional degree of freedom to adjust the bandgap position, which is applied to design a novel reconfigurable multiband EBG structure. Several application examples have been demonstrated, including a double-element microstrip antenna array with low mutual coupling, notch-type antenna duplexer, and steerable array with a linearly discrete beamsteering of 20/spl deg/ in steps of 10/spl deg/ at 2.468 GHz.
Trajectory tracking control of underactuated tendon‐driven truss‐like manipulator based on type‐1 and interval type‐2 fuzzy logic approach

This paper deals with the trajectory tracking control problem of a planar underactuated tendon‐driven truss‐like manipulator (UTTM) by using fuzzy logic control methods, including type‐1 fuzzy and interval type‐2 fuzzy approaches. The UTTM is a novel designed underactuated robot that excels in manipulating in harsh environments due to its tendon‐driven parallelogram structure. This unique structure, however, poses challenges for UTTM's trajectory tracking controller design, including underactuation, excessive nonlinearity, parameter uncertainty, and so on. To solve these problems, a fuzzy logic‐based approach is proposed. First, the dynamic model of UTTM is transformed into a partially linearized form. Then a type‐1 fuzzy controller is designed according to a linear quadratic regulator controller for the linearized system. Then by blurring the membership functions of type‐1 fuzzy controllers, an interval type‐2 fuzzy logic controller is designed, aiming at dealing with uncertainties. The proposed type‐1 and interval type‐2 fuzzy logic controllers are validated through simulations, and made comparisons with each other, especially when the system is involved with uncertainties. Simulation results show that the interval type‐2 fuzzy‐based trajectory tracking controller provides better performance than the type‐1 counterpart in terms of tracking accuracy and capacity against uncertainties.
Challenges and Opportunities for Practical and Effective Dynamic Information Flow Tracking

Information flow tracking was proposed more than 40 years ago to address the limitations of access control mechanisms to guarantee the confidentiality and integrity of information flowing within a system, but has not yet been widely applied in practice for security solutions. Here, we survey and systematize literature on dynamic information flow tracking (DIFT) to discover challenges and opportunities to make it practical and effective for security solutions. We focus on common knowledge in the literature and lingering research gaps from two dimensions— (i) the layer of abstraction where DIFT is implemented (software, software/hardware, or hardware) and (ii) the security goal (confidentiality and/or integrity). We observe that two major limitations hinder the practical application of DIFT for on-the-fly security applications: (i) high implementation overhead and (ii) incomplete information flow tracking (low accuracy). We posit, after review of the literature, that addressing these major impedances via hardware parallelism can potentially unleash DIFT’s great potential for systems security, as it can allow security policies to be implemented in a built-in and standardized fashion. Furthermore, we provide recommendations for the next generation of practical and efficient DIFT systems with an eye towards hardware-supported implementations.
Improvement of the input power dynamic range for wavelength converters based on cross-gain modulation employing a probe power control loop

A technique for improving the input power dynamic range of wavelength converters based on cross-gain modulation in a semiconductor optical amplifier is presented. By experimentally investigating the effect of pump and probe powers on the operating performance in terms of power penalty for a conventional wavelength converter, we show that the optimal performance depends on the ratio of pump and probe powers coupled into the semiconductor optical amplifier in a certain input power range. Based upon the experimental result, a wavelength converter with a wide dynamic range has been proposed, in which the probe power is automatically adjusted to have the power proportional to the pump power. We show that a dynamic range of >20 dB is achievable for a 2.5 Gbit/s signal at a 2-dB penalty.
Improving the range/time sidelobes of large bandwidth discontinuous spectra HF radar waveforms

Due to heavy user congestion, many over-the-horizon (OTH) HF radars are restricted to operating within narrow frequency bands. As a result the achievable range resolution with such radars is poor. In order to operate a wideband HF radar, the signal spectrum must be made discontinuous, which gives rise to high range sidelobes and thus a low signal dynamic range. We introduce a new signal processing technique to lower the range sidelobes associated with discontinuous spectra signals. Results are presented for a repeated linear FM test case and show significant range sidelobe reduction using the new algorithm.
Application Research on the Medical imaging testing of Novel Coronavirus Pneumonia  COVID-19 based on Transfer Learning

Novel coronavirus pneumonia (COVID-19) is a highly infectious and fatal pneumonia-type disease that poses a great threat to the public safety of society. A fast and efficient method for screening COVID19-positive patients is essential. At present, the main detection methods are nucleic acid detection of manual diagnosis and medical imaging (CT image/X-ray image), both of which take a long time to obtain the diagnosis result. This paper discusses the common processing methods for the problem of insufficient medical image data. Then, transfer learning and convolutional neural network were used to construct the screening and diagnosis model of COVID-19, and different migration models were analyzed and compared to select a better pre-training model, which was trained and analyzed under small data sets. Finally, it analyzes and discusses how to train a highly reliable model to quickly help doctors provide advice in the critical moment of epidemic prevention and control when only a small sample data set is available.
Workforce Development Challenges in the Natural Gas Industry

Summary Thousands of short and long-term jobs will be created as natural gas drilling and hydrofracturing takes place in the Marcellus Shale, presenting both employment opportunities and workforce development challenges. These jobs – found primarily on crews needed during the drilling and completion process – are not for everyone and require a diverse skill set and a rigorous work ethic. In Pennsylvania, the industry has thus far relied on “out-of-town” workers to fill many of these hard-to-fill roles, but over time will replace a portion of these workers with local employees if they are available. A similar pattern is likely to be repeated in New York if shale gas drilling is approved. The number of workers needed will depend greatly upon the pace and scale of drilling – which has proven highly unpredictable in other areas. In general, local residents will find relatively fewer opportunities for accessible and stable employment in the short term, although opportunities may grow over time.
New technique for frequency and amplitude estimation of power system signals

This paper describes the design, analysis and computational aspects of a technique for the measurement of power system voltage, current and frequency. This technique can be used in a digital AVR for the state estimation of turbine-generator terminal quantities or in a digital relay for protection of a power system. This technique provides fast and accurate estimation of power system frequency, and is used in a Kalman-filtering algorithm to estimate power system voltage and current signals. Practical considerations such as the effect of power system harmonics, noise, frequency changes, mechanical and electrical load changes are taken into account during implementation of this technique. Several computer simulation tests are presented to highlight the usefulness of the technique. Simulation results show that the technique can simultaneously estimate the amplitude and frequency of a sinusoidal signal, even in the case that the signal is distorted by harmonics or noise or encounters frequency changes.
A Review Paper On Radio Over Fibre Technology)

Radio over Fibre technology (RoF), an integration of wireless and fibre optic networks, is an essential technology for the provision of untethered access to broadband wireless communications in a range of applications including last mile solutions, extension of existing radio coverage and capacity, and backhaul. This paper gives the brief introduction of radio over fibre technology used in communication system. In this paper applications and limitation of the radio over fibre technology are discussed. Some technologies which are used to transfer radio signal over fibre are also explained in this review paper. Some ideas of using radio over fibre technology in wireless technology are also introduced in this paper
An Experimental Investigation of Roll Motions of an FPSO

FPSO roll motions can be major contributor to riser fatigue. This is especially true in regions where wind, waves and currents are non-collinear. Roll motions as high as 23 degrees have been reported in the Campos Basin. The most common roll mitigation strategy consists of adding bilge keels to the FPSO. Motivation for this work came from a need to develop a better understanding of roll motions as a function of bilge keel width. In addition to roll motions, the hydrodynamic forces on the bilge keels were measured. A series of tests were conducted at the LabOceano offshore basin. This new facility has a length of 4 0 m, a width of 30 m, a depth of 15 m and is equipped with a multi-flap wave generator on one side. A ship-shaped FPSO design with sponsons for a deepwater offshore development in Brazil was tested. It has a length of 316 m, a breadth of 57.2 m and a draft of 28.3 m. A 1:70 scale model was constructed. A horizontal soft mooring system consisting of four lines with springs was used. Regular waves of different amplitudes as well as random waves were generated in the basin. Two different loading conditions, ballast (draft = 6.7 m) and loaded (draft = 21.7 m), as well as three wave headings, beam seas (90°), and quartering seas (22.5°, 45°) were considered. Tests were undertaken for four bilge keel configurations, corresponding to a case without bilge keels, as well as bilge keels of 3 different widths (1 m, 2 m and 3 m). In all cases, the bilge keels had a length of 200 m. An optical system was used to measure ship motions in all six degrees of freedom. The hydrodynamic loads on the bilge keels were measured using strain gages. © 2008 ASME
Low loss mode converter based on adiabatically tapered hollow optical fibre

A new mode converter based on tapered hollow optical fibre is proposed and experimentally demonstrated. Two segments of a singlemode fibre and a tapered hollow ring core fibre were concatenated serially to convert a fundamental mode to a ring-shaped mode. The fabrication, far field pattern and insertion loss of the proposed mode converter were measured and discussed.
Phytochemical composition and pharmacological activities of Teucrium polium L. collected from eastern Turkey

Teucrium species that belong to the family Lamiaceae have been traditionally used for their medicinal properties. T. polium is one the most widespread members of the genus for its use in the treatment of several diseases. In this study, the essential oil and phenolic composition of the aerial parts from T. polium were assessed by GC-FID, GC/MS, and LC-MS/MS as well as for its total phenolic content. Several extracts such as n-hexane, chloroform, methanol, and infusion were prepared and their antimicrobial, antioxidant, and also acetylcholinesterase activities were studied. According to GC/MS results, β -caryophyllene (8.8%), t-cadinol (6.2%), (E)-nerolidol (5%), α -cadinol (5.4%), and α-pinene (4.7%) were identified as main constituents of the essential oil. LC MS/MS analysis of the infusion and the methanol extract showed the presence of 15 phenolic compounds. Moreover, the total phenolic content of each sample was also determined and the infusion had the highest percentage of phenolics. To evaluate the antioxidant properties, the samples were tested by using DPPH” free radical scavenging, FRAP, and CUPRAC activity methods. The infusion showed the strongest radical scavenging activity, whereas n-hexane and chloroform extracts exhibited considerable reducing power effects. The MIC values for all of the examined microorganisms ranged from 15 to 2000 μg/mL with respect to antimicrobial activities.
Comparison of healing assessments of periapical endodontic surgery using conventional radiography and cone-beam computed tomography: A systematic review

Purpose This systematic review aimed to compare assessments of the healing of periapical endodontic surgery using conventional radiography and cone-beam computed tomography (CBCT). Materials and Methods This review of clinical studies was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. All articles published from 1990 to March 2020 pertaining to clinical and radiographic healing assessments after endodontic surgery using conventional radiography and CBCT were included. The question was “healing assessment of endodontic surgery using cone-beam computed tomography. ” The review was conducted by manual searching, as well as undertaking a review of electronic literature databases, including PubMed and Scopus. The studies included compared radiographic and CBCT assessments of periapical healing after periapical endodontic surgery. Results The initial search retrieved 372 articles. The titles and abstracts of these articles were read, leading to the selection of 73 articles for full-text analysis. After the eligibility criteria were applied, 11 articles were selected for data extraction and qualitative analysis. The majority of studies found that CBCT enabled better assessments of healing than conventional radiography, suggesting higher efficacy of CBCT for correct diagnosis and treatment planning. A risk of bias assessment was done for 10 studies, which fell into the low to moderate risk categories. Conclusion Three-dimensional radiography provides an overall better assessment of healing, which is imperative for correct diagnosis and treatment planning.