bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prefrontal cortical activation measured by fNIRS during walking: effects of age, disease and secondary task
Authors: Pelicioni Paulo H.S. , Tijsma Mylou , Lord Stephen R. , Menant Jasmine 
Published: May 2019

Background
Cognitive processes are required during walking to appropriately respond to environmental and task demands. There are now many studies that have used functional Near-Infrared Spectroscopy (fNIRS) to record brain activation to investigate neural bases of cognitive contributions in gait. The aim of this systematic review was to summarize the published research regarding Prefrontal cortical (PFC) activation patterns during simple and complex walking tasks in young adults, older adults and clinical groups with balance disorders using fNIRS. Our secondary aim was to evaluate each included study based on methodological reporting criteria important for good data quality.

Methods
We conducted searches in June 2018 using four databases: Embase, PubMed, Scopus and PsycINFO. The strategy search used was: (((((near infrared spectroscopy) OR functional near infrared spectroscopy) OR nirs) OR fnirs) AND (((gait) OR walking) OR locomotion) AND (((((young) OR adult) OR older) OR elderly) NOT children)) AND (((Brain) OR cortex) OR cortical) for our search. The papers included met the specific review criteria: (i) used fNIRS to measure PFC activation patterns; (ii) included walking tasks (simple and complex) and; (iii) assessed young people, older people and/or clinical groups with balance disorders.

Results
Thirty five (describing 75 brain activation comparisons) of the 308 studies retrieved through our search met the inclusion criteria. Based on 6 methodological reporting considerations, 20 were of high quality, 10 were of medium quality and 5 were of low quality. Eleven/20 comparisons in young people, 23/37 comparisons in older people and 15/18 comparisons in clinical groups reported increased PFC activation with increased walking task complexity. The majority of comparisons that used verbal fluency, counting backwards or secondary motor tasks reported increases in PFC activation (83%, 64% and 58% of these studies, respectively). In contrast, no studies found secondary visual tasks increased PFC activation.

Conclusion
Increased PFC activation was most common in studies that involved walks comprising secondary verbal fluency and arithmetic tasks. Clinical groups generally showed increased PFC activation irrespective of type of secondary task performed during walking which suggests these groups require more attentional resources for safe walking. Systematic review registration number: PROSPERO 2017 - CRD42017059501.
Pharmacy Students’ Perception and Evaluation of Objective Structured Clinical Examination: Near East University Experience
Authors: Basgut Bilgen , Abdi Abdikarim Mohamed 
Published: May 2019

Background: Pharmacy educators have always been desirous of the best methods for formative and summative evaluation of trainees. The Objective Structured Clinical Examination (OSCE) is an approach for student assessment in which aspects of clinical competence are evaluated in a comprehensive, consistent, and structured manner. Though recently become popular in pharmacy schools globally, its use in North Cyprus and Turkey pharmacy schools appears limited.
Objectives: To assess pharmacy students’ evaluation and overall perception of OSCE.
Methods: A cross-sectional survey was conducted on pharmacy students, who participated in the final OSCE examination in 2015-2016.The study sample consisted of fifth-year Pharmacy students who took the OSCE assessment during their studies. A24-item self-administered structured questionnaire was employed to obtain relevant data on OSCE evaluation in terms of content reliability and structure of the examination. Students’ responses were based on a 4-point Likert scales ranging from disagree to no comment. The data were analyzed using SPSS, version 22.
Results: Of 81 eligible students, 74 completed self- administered questionnaire representing 91.35% response rate. A total of 68(90.7%) students agreed that wide knowledge area and clinical skills were covered in the exam. Over 80% of the students saw that OSCE besides it provided them with an opportunity to learn real life scenario, it was well administered and run in the faculty and better organized compared to a previous pilot OSCE (68%). Around 77% of the students saw that 7 minutes time allocated per station was adequate, while a close percentage also agreed that standardized patients were competent in their role playing. Majority of students though they identify that OSCEs highlighted areas of weakness in their skills and knowledge but still disagree with incorporating OSCEs marks into final marks and thus prefer it as an formative assessment.
Conclusions: Students highly perceived the exam feeling that it is more resembles actual practice providing them with self-confidence, and more clearly their defects and what they need to improve regarding both skills and knowledge. They saw OSCEs as being a beneficial formative assessment that should not be included as marks into finals.
Gratings and Grating Antennas
Authors: Rodenbeck Christopher T. , Chang Kai 
Published: November 2024

AbstractAgratingis an array of parallel obstructions separated from one another at a distance comparable to a wavelength. When an electromagnetic wave is incident up on a grating, it scatters to one or more specific angles determined by the spacing of the grating and the frequency of the wave. Since this effect is a diffraction phenomenon, gratings are often also referred to asdiffraction gratings.One of the most important uses of the diffraction grating is as an antenna for millimeter‐wave through optical frequencies. This type of diffraction grating is the primary focus of this article. In integrated optics, grating antennas are used to couple power into and out of dielectric waveguides. For millimeter‐wave systems, grating antennas have received attention for several key advantages that they have in comparison with other conventional microwave antennas. They have low radiation losses, they are inexpensive and easy to fabricate, and they are planar. There is also considerable interest in using grating antennas to implement low‐cost beam steering at millimeter‐wave frequencies.This article examines gratings and grating antennas in a series of five sections. Each of these sections is presented in such a way that it may be read independently from the others. An overview of the historical development of diffraction gratings is presented. The fundamental principles behind grating diffraction are explained in a manner suitable for those with an RF/microwave background. A clear design procedure for grating antennas is offered, along with an extensive reference list for those interested in further study. Some of the latest and most impressive applications of millimeter‐wave gratings are described. The article then concludes with a brief discussion of the future of this field.
Microstrip Antenna Arrays
Authors: Hall Peter S. 
Published: November 2024

AbstractMicrostrip antenna arrays offer low‐profile solutions to many antenna applications with potentially low cost. Their low profile comes about from the use of microstrip patch radiators fed by microstrip circuit‐based feed networks, or by using the naturally occurring radiation from the feed networks to form a beam. Both patches and microstrip feeds consist of metallic strips or shapes photoetched on one side of a grounded substrate and can be made using conventional photolithographic processes. The use of the microstrip transmission‐line medium, widely used in both hybrid and monolithic radiofrequency circuits, also gives rise to a unique potential for integration with active devices and radio front ends.This article gives an overview of microstrip array architectures. These include parallel‐ and series‐fed arrays and also arrays formed by discontinuities in a microstrip line, such as the serpent and rampart lines. Other forms such as ultrawideband arrays, leaky‐wave arrays, multilayer arrays, sequentially rotated arrays, multibeam arrays, reflect arrays, and active integrated arrays are also described. The article concludes by describing the impact on array design of important factors such as accuracy in pattern synthesis, feed loss and radiation, and mutual coupling.
Notch Antennas
Authors: Lee Richard Q. 
Published: November 2024

AbstractNotch antennas, also known as the tapered slot antennas (TSA), have been the topics of research for decades. TSA has demonstrated multioctave bandwidth, moderate gain (7–10 dB), and symmetricE‐ andH‐plane beam patterns and can be used for many different applications. This article summarizes the research activities on notch antennas over the since the early 1990s with emphasis on their most recent advances and applications. The article begins with some discussions on the design of single TSA, then follows with detailed discussions of issues associated with TSA designs and performance characteristics. To conclude the article, some recent developments in TSA arrays and their applications are highlighted.
Wavelet Transforms
Authors: Deans Stanley R. , Heine John J. , Gangadharan Deepak , Qian Wei , Kallergi Maria , Clarke Laurence P. 
Published: November 2024

AbstractFunctions that oscillate over time are often called waves. If the function is such that it oscillates only in a localized region and goes to zero outside the region it may be called a wavelet. Thus we say wavelets are localized waves.The fundamental role of the wavelet transform is to facilitate the analysis of signals or images according to scale. Wavelets are functions with some special mathematical properties that serve as a tool for efficiently dividing data into a sequence of frequency components without losing all information about position.
High‐Temperature Superconductors
Authors: Mansour Raafat R. 
Published: November 2024

AbstractThis article provides an overview of the microwave applications of high‐temperature superconductor (HTS) technology. The main characteristics of HTS materials are outlined, highlighting the differences between superconductors and normal conductors. The article also presents the most recent progress in the development of HTS filters, multiplexers, cryogenic receivers, delay lines, and antennas. A brief summary of cryocooler technology and cryopackaging requirements is presented. The benefits of using HTS technology in wireless and satellite systems are also discussed. Newcomers to the field are encouraged to continue reading about the subject to understand more about the potential challenges and limitations of this revolutionary technology.
Superconducting Filters and Passive Components
Authors: O’Callaghan Juan M. , Collado Carlos , Talisa Salvador H. , Mateu Jordi 
Published: November 2024

AbstractThis article gives an overview of the applications of high‐temperature superconductors for passive microwave devices, with an emphasis on planar filters. It includes a description of the basic characteristics of these superconducting materials and relates these characteristics to device performance. In the case of filters, the low loss of superconducting films allows the development of small, planar filters with superior performance. One important application of these filters is preselector filters for receiver front‐ends, because they combine high‐frequency selectivity with low insertion loss and low noise figure because of the low temperatures of operation.The article also gives a short overview of applications of high‐temperature superconducting materials in planar delay lines, cryocoolers, and cryogenic packaging.
Frequency Synthesizers
Authors: Goldberg Bar-Giora 
Published: November 2024

Abstract
Traditionally, frequency synthesis (FS) generated a single tone with variable frequency or amplitude. There are new applications, especially for testing and simulation, that require multitone generation and even arbitrary wave generation, which relate to digital frequency synthesis. Since the late 1970s, FS has evolved from mainly analog to a mix of analog, radiofrequency (RF), digital, and digital signal processing (DSP) technologies.
Multiresolution Techniques
Authors: Chen Yinchao , Cao Qunsheng , Mittra Raj 
Published: November 2024

AbstractWe begin by reviewing the foundation of the MRTD scheme—the multiresolution analysis (MRA ), and then exploring the properties of the scaling functions and wavelets. Also, we demonstrate the applications of the MRTD technique by analyzing a transverse electromagnetic (TEM ) wave propagation in a dielectric layered stratified space and an integrated microwave circuit, which can be extended to solve electromagnetic engineering problems of a general nature.
Klystron
Authors: Tallerico Paul J. 
Published: November 2024

AbstractThe klystron is a vacuum electron device for transforming DC energy into RF energy, and it may be either an oscillator or an amplifier. In the past, small reflex klystron oscillators were used as local oscillators in microwave receivers, but these oscillators are not used in modern equipment. Therefore the amplifier klystron is emphasized in this article.
Microwave Resonance Plasma Source
Authors: Taube Alexander L. , Demyashev Gregory M. 
Published: November 2024

AbstractThis article summarizes important aspects of a microwave resonance plasma source (MRPS ) based on the resonance phenomenon and running at atmospheric pressure. The novel MRPS using the high‐efficiency tunable cylindrical resonant cavity of TM013mode and operating at 2.45 GHz, was designed and manufactured. The MRPS was successfully approved with different carrier gases (N2, Ar, He) and precursor (gases, liquids, and powders) for creation of thermal plasma torch.Some examples of technological applications are highlighted. The feasibility of using the MRPS for nitriding/oxinitriding of Ti, 304 and 316 stainless steel, and 5140 steel by pure N2and with air (the mixture of N278 vol% +O221 vol%) was confirmed. For the purpose of plasma chemistry applications, two gaseous systems were chosen. The first one is CO2–H2O–N2, which imitates exhaust/flue gases. The second one is CO2–N2, which is of interest for deposition of superhard nanocrystalline carbon nitride (C3N4), the hardness of which is comparable to that of diamond. The MRPS commercially applicable in industry is practical for plasma chemistry, materials processing, coating deposition, surface treatment, and other applications.
Tunnel Devices
Authors: Sargent Edward H. , Xu J. M. 
Published: November 2024

AbstractTunnel devices take advantage of the wave‐like properties of charge carriers in implementing a desired function. The term tunneling refers to the movement of matter from one side of an energetic barrier to the other even though it does not possess sufficient energy to overcome the potential barrier according to the laws of classical mechanics. Instead, the quantum‐mechanical wave function of the particle penetrates inside the barrier and extends into the medium on the far side. Tunnel devices typically possess nonlinear, nonmonotonic current‐voltage characteristics and are characterized by very rapid fundamental propagation times. They find application in such diverse areas as microwave oscillators; multiple‐level logic, switches, memory elements; and lasers.
Electromagnetic Subsurface Remote Sensing
Authors: Chen S. Y. , Chew W. C. 
Published: November 2024

AbstractSubsurface electromagnetic (EM) methods are applied to obtain underground information that is not available from surface observations. Subsurface EM methods include a variety of techniques depending on the application, surveying method, system, and interpretation procedure, and thus a “best” method simply does not exist. One of the most challenging parts of subsurface EM methods is interpretation of the data. Data interpretation is also a critical factor in evaluating the effectiveness of the system. In the following sections, we will use several typical applications to outline the basic principles of subsurface EM methods. Physical insight is emphasized rather than rigorous mathematical analysis.
Antenna Reverberation Chamber
Authors: Kouveliotis N.K. , Trakadas P.T. , Heretakis I.I. , Capsalis C.N. 
Published: November 2024

AbstractThe use of the reverberation chamber for performing electromagnetic compatibility (EMC) tests and antenna measurements is examined in this article. This kind of chamber exhibits a significant number of advantages compared to the other commonly used test sites. Its low cost, compact, and easily built structure simultaneously appears to host a very “convenient” electromagnetic environment inside the enclosure, with regard to the requirements that are posted by the standard that is followed during the EMC or any other type of test such as antenna measurements. More specifically, antenna radiation efficiency measurements prove to be satisfactorily performed through the use of a reverberating enclosure, as well as other antenna parameters (e.g., input impedance) tests. The basic characteristics of such a structure are presented with regard to the recently introduced IEC 61000‐4‐21 specification and studies available in the literature. The field uniformity requirements are being extensively described, as well as ways of improving the achieved uniformity. The field inside a reverberating enclosure is statistically characterized with the use of the models proposed in the literature, which are experimentally verified. The use of the reverberation chamber at relatively low frequencies is presented, together with its ability to store large amounts of energy. Finally, the different ways of operating a reverberation chamber are described with regard to which of its features is (are) needed for each instance. The whole presentation marks out the usefulness of the reverberation chamber for performing electromagnetic compatibility tests as well as antenna measurements.
Microwave Integrated Circuits
Authors: Das Nirod K. , Bolle Donald M. 
Published: November 2024

AbstractIn this article a general overview and basic principles of operation of a class of highly integrated analog devices and circuits, used for applications in the microwave and millimeter‐wave frequency range, are presented. Although there are subgroups of sister technologies that evolved over the years, having different acronyms such as MIC (microwave integrated circuits in hybrid form), MMIC (monolithic microwave integrated circuits), and MCMs (multichip modules), their basic principles of operation are similar, with their objectives and scopes rapidly overlapping. The discussions in this article may be directed to a broad class of such integrated circuits, referred to in general as microwave and millimeter‐wave integrated circuits, with “MMIC” as a generic acronym.
Microwave Photonics: Technological Evolution and Its Applications
Authors: Daryoush Afshin S. 
Published: November 2024

AbstractSince the late 1980s, novel microwave photonics techniques have been developed that lead to a performance superior to that obtained with the purely electronic systems. This discipline originated from the concept of light interaction with semiconductor devices and circuits, and has now branched to a number of applications dealing primarily with antenna technology and remote and signal processing. This article reviews the previously established optically controlled devices and circuits, followed by discussions of both directly and externally modulated fiberoptic links. Fiberoptic link performance is discussed in terms of system‐level figures of merit. A multifunction optoelectronic circuit is also discussed. Design innovations are introduced in low‐cost source packaging and system architectures of optically fed large phased‐array antennas. One important advantage of photonics in microwave systems is the optical signal processing based on low‐loss optical fibers. Examples of memory loops, narrowband notch filters, and transversal filters are introduced. All‐optical analog‐to‐digital conversion and diffuse photon near‐IR imaging are two new application areas that are currently under development. The GSPS optical ADC concepts are presented using mode‐locked lasers for optical sampling. Quantization could be achieved in both electrical and optical domains. Finally, an approach based on the diffused photon near‐infrared imaging technique is discussed, leading to medical monitoring and biomedical imaging systems. As the modulation frequency expands to microwave frequencies, a higher spatial resolution is observed.
Microwave Power Transmission
Authors: Strassner Berndie H. , Chang Kai 
Published: November 2024

AbstractMicrowave power transmission (MPT ) is the wireless transfer of large amounts of power at microwave frequencies from one location to another. MPT is often referred to in the literature as wireless power transmission (WPT ) at microwave frequencies. MPT research has been driven primarily by the desire to remotely power unmanned aerial vehicles (UAV s) and by the concept of space solar power (SSP ) first conceived by Dr. Peter Glaser of the Arthur D. Little Company in 1968. SSP is an MPT system with the addition of solar cells and magnetrons for microwave power generation. The SSP idea calls for a constellation of solar power satellites (SPS s) to capture the energy from the sun using arrays of solar cells. The solar cell panels output large DC voltages to awaiting cavity magnetrons positioned on various subarrays within each SPS phased‐array aperture. These magnetrons convert the high‐voltage DC outputs of the solar panel arrays to microwave power. The microwave energy is then beamed to Earth to farms of rectifying antenna (rectenna) arrays that convert the incoming microwave energy back to DC power. Since its inception, SSP has gained considerable attention since it has the potential of providing clean, renewable, and continuous power for generations to come. MPT has been shown experimentally as a way for people on Earth to remotely power unmanned high‐altitude platforms such as UAV s. Additional uses for MPT include powering space probes from future space stations into deep space and powering robots to enter dangerous environments such as nuclear‐contaminated areas.
Millimeter‐Wave Integrated Circuits
Authors: Wang Huei , Lin Kun-You , Liu Ren-Chieh , Chang Hong-Yeh 
Published: November 2024

AbstractMillimeter‐wave (MMW) components are becoming more available and affordable because of advances in design, processing, testing, and packaging technology. MMW circuits have become smaller, highly integrated, and low‐cost, and are being applied in instrumentation, electronic warfare, satellite communications and other applications. As a result, many MMW systems are being developed and deployed that provide new and unique capabilities such as more information transfer (wider bandwidth), enhanced precision (higher resolution), and all‐weather operation (through fog, dust, and smoke), for both military and commercial applications. Monolithic MMW integrated circuits (MMICs) are crucial to meet the requirements for the MMW systems and play an important role in the MMW components. This article describes the current status of MMW monolithic integrated circuits, including the MMIC technologies, representative designs, and performance for various integrated circuits.