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Publications related to Radio Frequency (10,000)
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In this paper, we report the recent progress in visible light positioning and communication systems using light-emitting diodes (LEDs). Due to the wide deployment of LEDs for indoor illumination, visible light positioning (VLP) and visible light communication (VLC) using existing LEDs fixtures have attracted great attention in recent years. Here, w...
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The Local Climate Zone (LCZ) classification is already widely used in urban heat island and other climate studies. The current classification method does not incorporate crucial urban auxiliary GIS data on building height and imperviousness that could significantly improve urban-type LCZ classification utility as well as accuracy. This study utiliz...
Article
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Online Social Network (OSN) is one of the biggest platforms that spread real and fake news. Many OSN users spread malicious data, fake news, and hoaxes using fake or social bot account for business, political and entertainment purposes. These accounts are also used to spread malicious URLs, viruses and malware. This paper proposes UCred (User Credi...
Article
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Background Recently, machine learning (ML) has become attractive in genomic prediction, but its superiority in genomic prediction over conventional (ss) GBLUP methods and the choice of optimal ML methods need to be investigated. Results In this study, 2566 Chinese Yorkshire pigs with reproduction trait records were genotyped with the GenoBaits Por...
Article
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Clinical risk prediction models powered by electronic health records (EHRs) are becoming increasingly widespread in clinical practice. With suicide-related mortality rates rising in recent years, it is becoming increasingly urgent to understand, predict, and prevent suicidal behavior. Here, we compare the predictive value of structured and unstruct...
Article
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Plasma production experiments in helium at Uragan-2M have been performed to investigate the role of the hydrogen minority in helium. The experiments presented here were carried on with a controlled minority hydrogen concentration. The hydrogen minority allowed one to increase plasma density more than three times as compared with pure helium. The ob...
Article
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Seeking to obtain a competitive advantage and manage the risk of injury, team sport organisations are investing in tracking systems that can quantify training and competition characteristics. It is expected that such information can support objective decision-making for the prescription and manipulation of training load. This narrative review aims...
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Acousto-optic devices that use radio frequency mechanical waves to manipulate light are critical components in many optical systems. Here, the researchers bring acousto-optic devices on-chip and make them more efficient for integrated photonic circuits.
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A microwave photonics‐based channelized receiver for broadband vector signals is proposed and experimentally demonstrated. A 4‐line optical frequency comb (OFC) generated by a dual‐parallel Mach‐Zehnder modulator (DPMZM) is used as local oscillator (LO) signal in the in‐phase/quadrature (I/Q) receiver for coherently down‐converting the broadband si...
Article
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This letter presents a compact tri‐band filter using a dual‐capacitively loaded (DCL) substrate integrated waveguide (SIW) triple‐mode resonator. The frequencies of TE101, TE102, and TE103 are shifted lower by the capacitive loading effect, which is achieved by the DCL structure. A compact tri‐band example filter is then built by using two DCL trip...
Article
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This article presents the impact of different radio frequency (RF) power during deposition on the ZnO thin films properties, deposited using RF sputtering deposition technique. The effect of these process parameters on the structural, morphological, electrical and optical properties are elaborated in detail. The crystalline quality and optical para...
Article
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In this paper, a novel and efficient photonic-assisted remote frequency measurement (RFM) system with a significantly simplified structure and flexible operation range is proposed. In this system, the remote antenna unit (RAU) and the the central station (CS) are separated to ensure the concealment and safety of the signal processing unit. At the R...
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This article presents an electronically beam‐switching conformal microstrip array antenna for 5G applications. The 1 × 2 array microstrip antenna is used as a radiating element. They are placed on a hexagonal shape‐holding structure to form the conformal geometry. The radiating elements are excited with a six‐faced feeding network. It consists of o...
Article
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The performance of a radiofrequency quadrupole (RFQ) is known to be sensitive to its geometric errors, as well as to the amplitude and phase errors of the input RF. Extensive statistical simulations are typically performed using the available computer codes, for assessing the effect of various errors, to fix the tolerances on these errors. Each of...
Article
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In this article, a new general and effective design method of miniaturized quasi‐lumped‐element wideband filtering phase shifters for integrated RF front‐end is proposed, which is promising in both industrial and academic fields. This wideband filtering phase shifter is built by exploring the multiple different kinds of lumped resonators and arrang...
Article
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We present an estimation of the heating rate due to Joule heating in the F region of the ionosphere as a result of its interaction with high-power HF O-mode radio waves transmitted by a ground-based antenna. We refer to experiments conducted at Platteville, Colorado in the 70’s, i.e., at a mid-latitude ionosphere, as the ionospheric conditions and...
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In this work, we study the effect of vacuum annealing and position of metal Cu on structural, optical, electrical and thermoelectrical properties of ITO/Cu/ITO multilayers prepared on glass substrates, at room temperature by Radio Frequency (RF) sputtering. ITO (80 nm)/Cu(5 nm)/ITO (80 nm) ICI(a) and ITO (150 nm)/Cu(5 nm)/ITO (10 nm) ICI(b) multila...
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The data science has developed into an effective approach for predicting wear behaviour of solid materials. This contemporary work has mainly focused on the prediction of wear rate for the hypereutectoid steel which are tested under different operating conditions (sliding speed, normal pressure and sliding distance). To train and forecast the wear...
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Introduction: Post-coronavirus disease (post-COVID) symptoms arise mostly from impaired function of respiratory tract although in many patients, the dysfunction of gastrointestinal tract and liver among other organ systems may persist. Methods: Primary data collection was based on a short gastrointestinal symptom questionnaire at the initial scr...
Article
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In this article, a miniaturized reconfigurable 4‐element ultra‐wideband (UWB) multiple‐input‐multiple‐output (MIMO) antenna is proposed to operate from 2.52 to 24 GHz, and studied using characteristics mode analysis (CMA). Initially, a 1‐element antenna is designed and then extended to 4‐element MIMO configuration. The MIMO antenna achieves design...
Article
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This article explores the feasibility of utilizing an interdigitated capacitor (IDC) based RF sensor for studying nanoparticle properties. The parameters include their size, shape, thickness, and relative arrangement in aqueous media. The analysis is carried out using the CAD tool high frequency structure simulator (HFSS). We study the variation in...
Conference Paper
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Multiple rectifiers (rectennas or arrays) have been widely adopted in nowadays wireless power transfer (WPT) and wireless energy harvesting (WEH) systems to receive/harvest as much power as possible from multiple power sources. However, few studies focused on the overall RF-to-dc efficiency when combining the DC outputs together under nonuniform RF...
Article
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In dealing with RF-Q2, one of the central themes that arises is the one of translating teacher resource use from one cultural context to another. In fact, two of the three papers of this RF session deal with the difficulties that researchers have found in translating the ideas of the DAD into other languages. Before I comment on the challenges of t...
Chapter
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Today's communication systems are concentrated majorly in wireless networks that depend upon the density in the radio frequency (RF) spectrum. This density means a shortage of space for new services or technologies to be created in the RF spectrum. The main reason for this density in the frequency spectrum is the inefficient use of the RF spectrum...
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Screen-printed carbon electrode (SPCE) has been extensively used in electrochemical (EC) detections due to its excellent EC characteristics and low cost. However, SPCE is not sensitive to a small amount of reagents, which severely limits its application in trace detection. Herein, an effective method, radio frequency plasma-assisted polypyrrole (PP...
Preprint
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Pulsed SRF linacs with high accelerating gradients experience large frequency shifts caused by Lorentz force detuning (LFD). A piezoelectric actuator with a resonance control algorithm can maintain the cavity frequency at the nominal level, thus reducing the RF power. This study uses a double lever tuner with a piezoelectric actuator for compensati...
Article
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Background: Patients with Major Depressive Disorder (MDD) have been found to have restricted capacity for mentalization, and it is possible that this constitutes a vulnerability factor for developing depression. Due to its focus on linking depressive symptomatology to emotions and interpersonal relations, it was hypothesized that Interpersonal Psy...
Article
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To better develop and protect the pelagic fishery in the northwest Indian Ocean, China’s fishing enterprises have been producing pelagic fisheries in the said area for a long time. Based on the fishing log data of light falling gear in the northwest Indian Ocean from 2016 to 2020, this study analyzed the impact of different time scales on the catch...
Article
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In this paper, a dual-band implantable rectenna is proposed for recharging and operating biomedical implantable devices at 0.915 and 2.45 GHz. The rectenna system consists of a compact dual-band antenna based on a meandered-resonator as well as efficient dual-band rectifier circuit. Both components (antenna and rectifier) are integrated inside a ca...
Technical Report
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Radio over fiber (RoF) is a technique that uses optical fiber to transmit radio frequencies. In this process, light is modulated by a radio frequency (RF) signal and then this RF signal is transmitted with the help of optical fiber (Singh & Singh, 2016). Previously, in wireless communication, RF links are used to transfer data but there are some li...
Article
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The dependency of RF performance on the local oscillator (LO) drive amplitude and DC bias is an important topic for RF mixers, especially as carrier frequency increases and generation of RF power thus becomes more complex. The prediction of mixer performance, without initial reliance on full circuit simulations, can provide important insights. In t...
Experiment Findings
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The first spectrum is a cross-relaxation. The (sharp) low frequency lines are from the 14N (V+ and V-). These are low because the nitrogen is protonated. The broad peak(s) are from the chlorine isotopes 35Cl and 37Cl. the 37 isotope has a smaller quadrupole moment so appears first and the 35Cl line is hopelessly broadened. the second spectrum is sc...
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Purpose To construct an automatic machine-learning derived algorithm discriminating between normal corneas and suspect irregular or keratoconic corneas. Methods A total of 8526 corneal tomography images of 4904 eyes obtained between November 2010 and July 2017 using a combined Scheimpflug/Placido tomographer were retrospectively evaluated. Each im...
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The popularity of peer-to-peer (P2P) network can be attributed to their inherent advantages such as resource utilization, scalability and better response. At the same time modern networks have become highly complex and need better approaches for management and monitoring of traffic. The use of machine learning (ML) techniques is inevitable due to t...
Preprint
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Hybrid beamforming is a promising technology to improve the energy efficiency of massive MIMO systems. In particular, subarray hybrid beamforming can further decrease power consumption by reducing the number of phase-shifters. However, designing the hybrid beamforming vectors is a complex task due to the discrete nature of the subarray connections...
Article
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Two modeling approaches for the estimation of durum wheat yield based on Sentinel-2 data are presented for 66 fields across three growing periods. In the first approach, a previously developed multiple linear regression model (VI-MLR) based on vegetation indices (EVI, NMDI) was used. In the second approach, the reflectance data of all Sentinel-2 ba...
Article
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Network Intrusion Detection (NID) is an important domain of research and as the network traffic is growing enormously, new challenges are emerging forth in terms of quality of service and security thus a reliable and robust network intrusion detection system (NIDS) has become an inevitable requirement. Researchers have developed and implemented man...
Article
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Particle colliders remain indispensable scientific instruments to discover and study new elementary particles and fundamental forces of nature. Whether the collider is a factory (used to improve precision of measuring properties of already discovered particles or to enable studies of rare decay channels), an energy frontier machine (aimed at discov...
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Continuous urbanization and industrialization lead to plenty of rural residents migrating to cities for a living, which seriously accelerated the population hollowing issues. This generated series of social issues, including residential estate idle and numerous vigorous laborers migrating from undeveloped rural areas to wealthy cities and towns. Qu...
Article
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The timely and accurate estimation of grassland aboveground biomass (AGB) is important. Machine learning (ML) has been widely used in the past few decades to deal with complex relationships. In this study, based on an 11-year period (2005–2015) of AGB data (1620 valid AGB measurements) on the Three-River Headwaters Region (TRHR), combined with remo...
Article
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An accurate classification of the precipitation type is important for forecasters, particularly in the winter season. We explored the capability of three supervised machine learning (ML) methods (decision tree, random forest, and support vector machine) to determine ground precipitation types (no precipitation, rain, mixed, and snow) for winter pre...
Article
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For reducing the switching frequency between the radio frequency (RF) chain and transmit antennas, a class of new sparse space shift keying modulation (SSSK) schemes are presented. This new class is proposed to simplify hardware implementation, through carefully designing the spatial constellation mapping pattern. Specifically, different from tradi...
Article
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RF Controlled Robotic Vehicle with Metal Detection Project. Our project proposes a Metal detection robotic vehicle operated using RF remote control wirelessly. The project demonstrates real life robotic vehicles used to detect land mines or other metal base objects on its path. The vehicle is fitted with a metal detection system that senses metals...
Article
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This article presents a four-element multiple-input multiple-output (MIMO) antenna design for next-generation millimeter-wave (mmWave) communication systems. The single antenna element of the MIMO systems consists of a T-shaped and plow-shaped patch radiator designed on an ultra-thin Rogers RT/Duroid 5880 substrate. The dimensions of the single ant...
Article
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Continuous respiration monitoring is significant for real-life healthcare applications, but realizing it is extremely hard as wearable sensors are cumbersome and contact-free sensors largely fail to tolerate user movements. Meanwhile, tracking users indoors mostly demands user-held devices, while device-free localization can barely tell what and wh...
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The effective pattern recognition of cable partial discharges (PDs) enables prompt corresponding measures to ensure cable safety. Traditional PD monitoring methods have limitations in online monitoring and accurate positioning, and the feature extraction of the monitored electrical signals requires significant prior knowledge. Therefore, this paper...
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To obtain a high-power radiation source in the terahertz band, this paper proposes a multi-gap extended interaction oscillator (EIO) circuit that works in TM31 mode. The simulated results show that, compared with the fundamental mode extended interaction oscillation circuit, the central electric field strength of the high-order mode circuit is grea...
Preprint
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Background: Confusion of information has also colored the course of the Covid-19 pandemic in Indonesia. The study analyzes the relationship between media exposure and information clarity about Covid-19 in Indonesia. Methods: The study collected extensive data (n=5,397). The study determines information clarity about Covid-19 based on respondents' a...
Article
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Global warming mitigation via terrestrial albedo increase has been widely investigated in literature; the proposed methodologies relate CO2 compensation to albedo increase generally via the concept of Radiative Forcing (RF). However, literature methods calculate RF by averaged input data, without considering RF variation due to many local and tempo...
Preprint
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Estimating the importance of variables is an essential task in modern machine learning. This help to evaluate the goodness of a feature in a given model. Several techniques for estimating the importance of variables have been developed during the last decade. In this paper, we proposed a computational and theoretical exploration of the emerging met...
Article
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A convergent gas feeding method is proposed to alleviate neutral gas depletion near the central plasma region in typical electrodeless radio-frequency (RF)/helicon plasma thrusters. To achieve further performance improvement, the SuperSonic Gas Puffing (SSGP) system is one of the methods that is expected to overcome the above-mentioned depletion an...
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The main objective of this study is to predict groundwater levels (GWLs) using modified hybrid algorithms with two levels of improvement. The observed GWLs, precipitation, and temperature were used as input variables in the prediction algorithms. Two widely used machine learning algorithms, namely support vector machine (SVM) and random forest (RF)...
Article
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Ambient RF energy harvesting (RF-EH) is a particular case of wireless power transfer (WPT), which is characterized by ultra-low power operation. This work points out theoretical and practical aspects that should be considered in the design of RF rectifiers for ambient RF energy harvesting systems. The most common RF rectifier circuits are compared...
Article
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In the present study, a silicon on insulator metal–semiconductor FET (SOI MESFET) with embedded metal and L-shaped oxide layers (EMLO) is introduced. This structure consists of two-part oxide section (stepped) in the channel area and a nickel-metal layer in the upper part of the buried oxide, where the dimensions have been optimized to achieve the...
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Low-valent aluminium compounds are very reactive main-group species and have therefore been widely investigated. Since the isolation of a stable molecular Al(I) compound in 1991, [(AlCp*)4] (Cp* = [C5Me5]–), a variety of highly reactive neutral or anionic low-valent aluminium complexes have been developed. By contrast, their cationic counterparts h...