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Global Navigation Satellite Systems (GNSS) has become an essential component in modern times for positioning, navigation, and timing. A fast-growing economic region in Malaysia required a GNSS-based augmentation positioning and navigation service. To improve navigation solution, several augmentation techniques exist, such as a differential Global Positioning System (DGPS) assisted by reference station, or augmentation service provided by commercial communication satellite. The DGPS correction is applied through a real-time communication medium and can be received at the user side by several communication methods including internet-based, and this method is favourable for land and near-coast areas. This case study aims to investigate the reliability of internet-based DGPS and SBAS along the Peninsular Malaysia. A test was conducted and data were collected over 15 hours at a rate of 1 Hz from the available GNSS satellite using a geodetic-grade receiver mounted on a moving vehicle. The obtained results showed that DGPS and SBAS perform better than the navigation solution with an accuracy of 1.536 m and 0.955 m respectively, compared to the navigation solution with an accuracy of 3.159 m. The limitations of both augmentation techniques were also analysed and discussed in this study. [ABSTRACT FROM AUTHOR]

Nowadays, with the advancement of technology, the use of news sources has also undergone a great evolution. News sources have constantly evolved from past to present, ranging from magazines to radios, from newspapers to televisions. The fact that it has become so easy to access news has caused society to pay more attention to fake news. Fake news has the ability to influence society through news sources such as social media, which can reach wider audiences with the development of technology. The difficulties of users in accessing accurate and reliable sources in this information flow that shapes their daily lives increases the potential for the spread of fake news, and it becomes increasingly difficult to distinguish between real and fake news. In this study, classification models for fake news detection were designed using machine learning algorithms. The dataset, which includes fake and real news examples, contains 42,000 examples. Each class, including fake and real samples, contains 22,000 sample data. In order to increase data quality, accuracy and usability, preprocessing methods were applied to the data set. The removal of numbers, stop words, and html tags was done in the pre-processing step to remove unnecessary information from the text. Models were created for fake news detection with singular and ensemble classification algorithms. Performance evaluation of the models was performed using 5-fold cross-validation. In the performance comparisons of the models, values such as accuracy, sensitivity, specificity, tp rate and fp rate were calculated. The highest performance results were observed in the random forest classification algorithm with an accuracy rate of 76%. [ABSTRACT FROM AUTHOR]

This article explores the role of the radio as an artistic instrument. It discusses both contemporary and historical art experiments, namely those where the sound of the radio or the form of radio reception is an important aspect of the final work. We examine the question, 'What does it mean for a radio to be an instrument?' And to clarify, we mean any kind of instrument, not just a musical one. To answer this question, this article focuses on the concepts and theory of those Polish artists who have used radio in their artwork, either as the source of a particular type of sound or as a medium that collects and transmits the sound of its surroundings. [ABSTRACT FROM AUTHOR]

As a medium for information, entertainment and communication, radio had taken precedence over television for decades, at least in terms of its accessibility in all households. Television and later the internet never completely annulled its aural condition, while its form altered to keep up with developments in terms of asynchrony or subject areas. Today it is considered the predominantly 'cool medium'. Recent developments in television and the internet's ways of operating render it a more detached medium than the alternative, given that a medium can change 'temperature' over time depending on the use (Levinson 2001: 108). But what about its accessibility to d/Deaf and Hard-of-hearing groups? Are these communities excluded by default from radio programmes and artistic creation through radiophonic media? In this article I analyse a case study, 'Tangible Radio – Class on Air' workshop, as part of B-AIR Creative Europe programme, as well as the convergences of sound art and the deaf experience in terms of co-creation, participation and educational processes. I will argue that radio as a medium can very successfully include the d/Deaf and Hard-of-hearing communities if relevant methodologies and technologies are encompassed to its processes. [ABSTRACT FROM AUTHOR]

This article traces the history of the use and reception of field recordings on radio, in France and Britain, outside the categories considered as art or music such as hörspiel or musique concrète. It shows that radio producers had diverse reactions to the use of sonic ambiences recorded in the field. There was an opposition between a 'Pure Sound School', which promoted the use of field recordings instead of voice to depict the environment where the reporter was, and a school that privileged voice. If the use of recordings of sonic ambiences was not new, their utilisation on radio as elements autonomous in themselves was. They were falling between categories: they were not reports (because of the absence of voice), they were not musique concrète (because sounds were not modified and were presented within their context, that is, not as sound objects), they were not sound effects (because they lasted several minutes and could be composed through editing), and they were not wildlife recordings (because wildlife could be absent). Sonic ambiences were new sonic objects that took time to digest. This time also represented a listening mutation, and this will be analysed through the beginnings of radio documentaries and the works of sound hunters. [ABSTRACT FROM AUTHOR]

In 2003, a new radio programme called Radioatelier was launched as part of the Czech Radio 3 – Vltava broadcast, the national public service art channel. It was aimed at presenting experimental radio forms, something completely unprecedented at that time. With 213 new commissions by December 2022, the programme entered its third decade of existence, having won a number of major radio art awards, while facing threats of impending programme cancellation in 2023. The present article is quite personal, offering generational insights of the producer, who was privileged enough to set goals and scope of the programme in its initial stages and who went on to co-exist with it for the following two decades. It also presents the complete list of sound compositions commissioned by Radioatelier between 2003 and 2022. [ABSTRACT FROM AUTHOR]

This article attends to the emergence of musique concrète as a theoretical object in Pierre Schaeffer's writing between 1941 and 1952, seeing it as the logical endpoint of Schaeffer's quest for an art proper to the radio. In this strong sense of the word, art is here positioned in opposition to entertainment, and as such Schaeffer seeks to separate the properly radiophonic from the impure, mercenary forms that radio had hitherto adopted. Schaeffer's account of musique concrète follows this logic, seeking to cast off the vestiges of radio drama that remain audible in such works as Symphonie pour un homme seul. By way of conclusion, I suggest that grasping the entanglement of musique concrète with mass-cultural forms such as radio requires a mode of reading oriented not towards formalism or sonic ontology but towards the figure of the text. [ABSTRACT FROM AUTHOR]

This study examines radio as a pedagogical approach and students' academic performance in Nigerian universities. The objective of the study aims to ascertain the effectiveness of radio as a pedagogical tool in education at the tertiary level, among others. The quantitative (survey) method was adopted for the study. Data were collected with questionnaire. The data collected were analyzed with the simple percentage method while the result of the analysis revealed that radio is very effective as a pedagogical tool in education at the tertiary level. Based on the findings, it was concluded that though there are other educational policies and programmes aimed at improving students' academic performance in the university, students can also improve to a high extent on their academic performance in the university through active radio listenership. [ABSTRACT FROM AUTHOR]

Course books are the most popular way to learn foreign languages. However, in the 21st century, there are other ways to learn languages, such as multimedia tools. The use of the Internet, newspapers, radio, or television can be an alternative to traditional language learning methods. The rapid advancement of science and technology, such as multimedia technology, has made it possible to explore this new teaching method more effectively. In reality, multimedia technology plays a vital role in the teaching of English language, particularly in the context of non-native speaking English. It also helps non-native English speakers of language teachers to understand how to use it effectively. The use of multimedia in foreign language teaching has grown steadily, and it has greatly improved the quality of teaching and learning. To effectively teach a foreign language, the traditional method is insufficient. We ought to reconsider the way we teach and accept their impersonal quality as a type of instruction. Thus, we can legitimately use contemporary educational technology to achieve the goal of teaching languages. Nowadays, almost everyone uses multimedia tools to help them with daily tasks. For example, some people get ready to leave the house to the beat of the radio's music, while others can't imagine having breakfast without reading the newspaper and so on. [ABSTRACT FROM AUTHOR]

Terrestrial radio navigation systems are an important data source for increasing the integrity of position, navigation, and timing information and for strengthening the immunity to the spoofing and jamming of satellite-based systems. A possible solution for maritime use is the medium frequency R-Mode. Here, the first real results were presented in the Baltic Sea within the R-Mode Baltic project. For the development of receivers and future signal evolution of R-Mode, there is a great need to provide simulated signals to the receiver hardware. For our laboratory work, we developed different hardware in the loop test systems which enable the simulation of each of the three components and the entire medium frequency R-Mode signal. With this setup, we are able to conduct reproducible tests of the R-Mode receiver's ranging and positioning performance without the necessity of field tests. Furthermore, the impact of R-Mode signal modifications can be initially analyzed without the need of an implementation in the real-world test bed. Firstly, we describe the usage of arbitrary wave generators that can be used to replay received or simulated signals. Due to their wide distribution in electronic laboratories, there are cost-efficient ways to build up test capabilities. For this work, we tested the Tektronix AFG 3022 and the Rigol DG1032. For further tests, we utilize software-defined radios that are capable of streaming continuous signals. We utilize the ETTUS N210 to directly output the simulated signals. Additionally, we test the LimeSDR with an external down-converter. To generate these signals, we utilize software packages that were created to support the development of the digital signal processing. This approach allows us to test our receiver with a continuous integration from pure software to hardware in the loop test. A comprehensive summary gives an overview of the pros and cons for the different suggested systems. [ABSTRACT FROM AUTHOR]

This work presents the results showing the improvement of the performance of a Galileo receiver processing the new I/NAV words 16–20 and SSP in comparison to the performance using the previous legacy I/NAV configuration. The results were obtained by replaying GNSS signals recorded in Urban and Open Sky mobile environments when at least four satellites broadcasting the new words were visible. The results show an improvement of Time to First Fix values using RedCED (word 16) and FEC2 (words 17–20) in cold start conditions and a reduction in time needed to converge using SSP when coarse time (within 3 s error) is available. [ABSTRACT FROM AUTHOR]

This paper addresses cooperative navigation using range radios to enable absolute positioning of low-flying UAS (LF) while operating in GNSS-denied environments. High-flying UAS (HF) are positioned above the denied area and broadcast position reports. These reports, in combination with range measurements from the LF to the HF, enable absolute positioning of the LF. (1) Methods: As the navigation performance is directly influenced by the geometry of both LF and HF's relative positions, HF positions shall be optimized such that the Dilution of Precision (DOP) becomes minimal. The authors derive optimal azimuth angle combinations, which guarantee a minimal Horizontal Dilution of Precision (HDOP), and show the error characteristic for sub-optimal configurations, which enables the formulation of multi-vehicle-constrained optimization problems for specific combinations of numbers of HF and LF. (2) Results: An optimization problem is derived and solved for two HF aiding three LF as an example application for the derived rules. (3) Conclusions: The resulting geometry has yielded promising HDOP values, improving navigation performance in GNSS-denied environments. [ABSTRACT FROM AUTHOR]

High-accuracy (HA) positioning services allow users to achieve sub-decimeter-level positioning accuracy. Although these kinds of services are not new, the market is showing great interest in exploiting them for new applications within the mass-market domain. This growing interest is causing a change in the paradigm of HA services, moving from niche sectors to applications targeting billions of users. Considering this framework, the Galileo High Accuracy Service (HAS) provides an open-access service based on the provision of high-accuracy corrections transmitted through the Galileo E6-B signal (E6, data component). The data retrieved by the end-user, which includes orbit, clock, and bias corrections, is reconstructed to allow the computation of Precise Point Positioning (PPP) solutions. This paper is focused on the description and results of GMV's HAS Positioning Engine (HAS-PE) software library which, implements a PPP solution using the HAS corrections transmitted through Galileo Signal-in-Space. A high-level overview of the integration of the HAS in the Positioning Engine software is presented together with user performance assessments based on static and kinematic tests executed to process real data from GNSS receivers in real time. The static tests are performed using the GMV Global station network, which consists of geodetic grade receivers tracking the signal in open-sky locations around the globe. The kinematic tests are performed with a setup consisting of a mass-market receiver and a high-end receiver for obtaining the E6 pages. The PPP solutions are configured to process both Galileo and GPS corrections transmitted through the Galileo satellites. The assessment performed includes the computation of a set of performance indicators aimed at the analysis of high-accuracy positioning performances. The results of this assessment show that a PPP user taking advantage of this Galileo HAS initial service may easily achieve decimeter-level accuracy on the horizontal and vertical components. [ABSTRACT FROM AUTHOR]

The delivery of emergency services is often contingent on social processes launched when someone calls to request help. While initial encounters between civilian callers and institutional call-takers have been extensively studied, little is known about subsequent encounters between dispatchers and first responders. This paper examines police radio dispatch calls and the language practices enacting the dispatcher's operational role. It sketches the technological constraints and communicative challenges of the two-way radio medium, and the overall activity structure of radio dispatch. It then focuses on the design of dispatchers' instructions to officers. The instruction has a recurrent base form but may be expanded with optional material addressing atypical or specialized circumstances. Accordingly, dispatchers are not passive conduits of information transfer; working within the constraints of the radio medium, they elaborate and reframe the available information in ways that triage the problem and aid in its downstream management. [ABSTRACT FROM AUTHOR]

This article investigates the influence of planet mounting position on axle loads in double planet planetary gear trains. The study includes basic information about the type of geartrain used, theoretical data, finite element analysis simulations, and empirical experiments to provide more detailed data on the impact of planet pin position on bearing loads in different scenarios. A test model with six different setups is designed for the studies. Finite element simulations were then conducted to examine the model and to give more comprehensive information on the effect of pin location. Empirical experiments were conducted on a test rig to verify the theoretical and simulation results. The results indicate that the position of the planet pins has an impact on the distribution of load between the bearings of the outer and inner planets of the gear train. This study aims to provide more insights into the design and optimization of planetary gear trains when evaluating the loads on the bearings of the planet gears. [ABSTRACT FROM AUTHOR]

The rapid emergence of the 5G networks has posed a number of new planning problems, which should be carefully analyzed to optimize the installation of the new technologies and to integrate them into the existing mobile network. The main planning objectives are to build up a network satisfying the expected traffic demands in its various sections, in compliance with the performance quality targets suggested by international committees International Telecommunication Union (ITU), Comité Consultatif International pour la Radio (CCIR), etc. The following paper discusses some of the main aspects which should be evaluated in the planning stage of 5G radio relay transmission, such as traffic capacity, propagation problems, and interference problems. [ABSTRACT FROM AUTHOR]

Rain attenuation prediction models are inevitably deployed to provide rough estimates of the actual measured attenuation due to severe scarcity in most of the tropical and equatorial climates. The results of rain attenuation measurements over a 14.8 GHz terrestrial microwave link and slant-path attenuation in vertically polarized signals propagating at 10.982 GHz in a tropical Malaysian climate were reported in this study. The experimental results including the path adjustment factors were compared with the predictions of some selected rain attenuation models. The relative errors in the path length adjustment factors (PLAFs) are in the range -0.3370 - 2.6272, while those of the slant path adjustment factors (SPAFs) are -0.9252 - +0.2923. Moreso, the charts of PLAFs and SPAFs at 0.01% of the time were also presented because they are the most commonly used availability by the telecommunications service providers. This study will allow the radio engineer to select the most suitable prediction models for the particular region under study, thereby ensuring adequate radio planning for improved service delivery especially in the tropical climates due to their peculiarity. [ABSTRACT FROM AUTHOR]

The analysis of phenyl isocyanide (C6H5NC, μa = 4.0 D) in its ground vibrational state and two lowest-energy excited vibrational states, ν22 (141 cm−1) and ν33 (155 cm−1), in the 130–370 GHz frequency region has been completed. Over 4500 new rotational transitions have been measured in the ground vibrational state for the most abundant isotopologue, resulting in the determination of the spectroscopic constants for a partial octic Hamiltonian with low error. The Coriolis-coupled ν22-ν33 dyad reported herein, containing over 3500 new transitions for each vibrational state, has been analyzed for the first time. The coupled-state least-squares fit utilizes seven coupling terms (Ga, G a J , G a K , G a J J , G a J K , Fbc, and F b c K ) to address perturbation between the two vibrational states, including resonances and several nominal interstate transitions. This work results in precise determination of the energy separation between the two states, ΔE22,33 = 9.682 248(3) cm−1, and the Coriolis coupling coefficient, | ζ 22,33 a | = 0.858(9). The precise rotational and distortion constants determined in this work provide the foundation for an astronomical search for phenyl isocyanide across the radio band. [ABSTRACT FROM AUTHOR]

Mass media can play a key role in bringing out desirable changes in women's life by empowering them through creating awareness about their rights and help raise their status even in traditionally-rooted tribal society. Unlike in other conservative societies, women in tribal society in Arunachal Pradesh, though patriarchal in nature, enjoy a sense of freedom of speech and expression. However, they are deprived of various rights such as the rights to claim inheritance of their parental property as their customary law does not provide for it. In such a situation the mass media in general and radio in particular have been creating awareness about women issues and rights through women-specific programmes thereby promoting women empowerment in the society. While the level of importance given to women issues has been directly or indirectly decided by the kind of mass media, the All India Radio Itanagar and All India Radio Pasighat have been playing a key role in women empowerment in tribal areas of Arunachal Pradesh since their inceptions. Along with changes in media exposure and usage patterns, the status of tribal women in rural areas of Arunachal Pradesh has been undergoing transformations enabling them to contribute to the overall development of the society. Based on a recent study, this paper explores the role of radio broadcasting particularly the All India Radio Itanagar and All India Radio Pasighat in promoting women empowerment in tribal society particularly the Adi women of East Siang district of Arunachal Pradesh. [ABSTRACT FROM AUTHOR]

Nonlinear radio is sometimes perceived as being less enjoyable than traditional radio as elements like jokes, breaks, moderation, and the value-add of editors and radio hosts are often omitted. We start thinking about the design of nonlinear digital radio services with a focus on the traditional "radio-listening experience" from a consumer value perspective and the transformation of its characteristics to a digital context. We catalog the characteristics that make classic radio worth listening to from the perspective of a younger audience by conducting a qualitative study. Further, we identify implications for digital radio services based on the characteristics we elicited. [ABSTRACT FROM AUTHOR]

This study presents an ultra-low-voltage Operational Transconductance Amplifier (OTA) and Gm-C filter, both operating with a single supply voltage of 0.3 V. Using the pseudo-differential structure, the common mode rejection is the main challenge in the low-voltage condition and it is resolved by a new common mode feedback circuit. OTA can be tuned through the gate terminal of body-driven PMOS input transistors. Postlayout simulation showed 23.4 dB differential gain and 47.4 dB CMRR at low frequencies. By changing the tune voltage from 50 mV to 0 V, the transconductance of OTA could be tuned from 7.9 to 17.4 -A/V. By applying input voltages up to 0.36 Vpp, the Total Harmonic Distortion (THD) of the output current remained less than -60 dB. The proposed OTA was employed to implement a tunable low-pass Gm-C filter. The cut-off frequency of Gm-C filter could be tuned from 1.13 to 1.9 MHz, making it applicable to multi-standard direct conversion receivers as the channel selection filter. According to the results of postlayout simulations, the power consumption of the filter and its input-referred voltage noise were 111.3 -W and 168.7 nV/pHz, respectively. The post-layout simulation showed the IIP3 with 8.5 dBm at a cutoff frequency of 1.9 MHz. [ABSTRACT FROM AUTHOR]

As the primary multiplatform business of ESPN, Inc., espnW claims to engage and inspire women through sports with inside access to female athletes, sports leagues, important events, and trends in sports 'life/style' through content on digital, television, radio, in films, at events, on educational platforms, and in social media. The purpose of this analysis is to present longitudinal data on 1,881 photographs and 1,966 articles from the espnW website for four time periods in the first 8 years of espnW's existence to show how espnW shapes the media narrative of female athletes. espnW consistently presents female athletes as serious competitors. [ABSTRACT FROM AUTHOR]

From warning sirens to loud booms in the sky; from tweaked radio playlists to the silence of a military funeral, sound is central to the civilian experience of wartime in Israel. Drawing upon public discourse among Jewish-Israelis during periods of armed conflict with Hamas militants in Gaza during 2012 and 2014, this article explores practices of civilian listening and sounding during times of national emergency. More than just making the ears prick, wartime sounds are implicated in an assemblage of bodily action: stimulating the body to move, prompting vocal responses and serving as a focal point for conversation. Recent work in ethnomusicology has sought to theorise soundscapes and listening practices during wartime – yet most work to date has focused on combatants. Building on previous literature in sound studies and on civil preparedness, in this article I focus on wartime regimes of civilian listening, arguing that embodied listening and sounding practices index a reconfiguration of the relationship between the state and its citizens, characterised by mutually co-constructed vigilance, and articulating consensual models of disciplined citizenship that help to sustain collective resilience, yet which also reinforce ethnonational divisions in society and bolster neoliberal practices of securitisation. [ABSTRACT FROM AUTHOR]

The 2017 West Bank Municipal elections were framed by locally based non-governmental organisations and the Palestinian Authorities – albeit to a lesser extent – in terms of the desirability of increasing female participation in them in two particular ways: participation as representatives and participation as voters. Both aspects of participation were supported by extensive radio campaigns conducted by locally based non-governmental organisations. The effectiveness of these campaigns and the approaches used form the basis of this article. Using a mixed-methods approach consisting of both quantitative and qualitative data, it concludes that radio has endemic socio-technical advantages for reaching women, particularly in conflict-affected areas, and that broadcasting content aimed at women by women is essential in terms of increasing their representation and voting. [ABSTRACT FROM AUTHOR]

The article presents the discussion on "Downunder" refering to the islands of Australia and New Zealand. Topics include radio being a key technology for both societies shaping the coverage of the islands with radio networks; revealing about the challenges facing musicians in the digital age and generally as workers in the contemporary cultural economy; and exploring the experiences of independent podcasters highlighting the diversity and relevancy of radio and audio media.

The article presents the discussion on approaching the peopled place through music and radio while tuning in to cars and trucks, frogs, bush hens, and the scratchy sounds of smart phone speakers.

The article examines the development of utility-expanding fair use and the concept's overall place in the U.S. copyright system, both doctrinally and normatively. Topics include development of compulsory licensing regimes; model of the historic approach to digital radio to argue that when a technology is utility-expanding but too market-harming to warrant a fair use finding; and the U.S. Supreme Court case Campbell v. Acuff-Rose Music, Inc on same.

The world governing body for cycling proscribed the use of two-way radio communication in road cycling races, with the ban set to become fully effective in 2012. The ban was instituted because radio use was perceived to have altered the cycling competitions by making outcomes more predictable and of less interest to sport’s consumers. This empirical analysis of the policy rationale considers the uncertainty of outcome hypothesis (UOH) as it applies to professional cycling races and creates a novel measure, the likelihood of breakaway success (LBS). The LBS is analyzed in 1436 bicycle races between 1985–2010 to examine potential changes in outcomes associated with the use of two-way radio technology by competitors and team directors. The data suggests that radio technology has had a significant association with event outcome types. The relevance of the findings to intraorganizational communication, management, and hierarchies of sports teams are also discussed. [ABSTRACT FROM AUTHOR]

We present observations of a region of the Galactic plane taken during the Early Science Program of the Australian Square Kilometre Array Pathfinder (ASKAP). In this context, we observed the scorpio field at 912 MHz with an uncompleted array consisting of 15 commissioned antennas. The resulting map covers a square region of ∼40 deg2, centred on (l, b)  = (343.5°, 0.75°), with a synthesized beam of 24 × 21 arcsec2 and a background rms noise of 150–200  μ Jy beam−1, increasing to 500–600  μ Jy beam−1 close to the Galactic plane. A total of 3963 radio sources were detected and characterized in the field using the caesar source finder. We obtained differential source counts in agreement with previously published data after correction for source extraction and characterization uncertainties, estimated from simulated data. The ASKAP positional and flux density scale accuracy were also investigated through comparison with previous surveys (MGPS, NVSS) and additional observations of the scorpio field, carried out with ATCA at 2.1 GHz and 10 arcsec spatial resolution. These allowed us to obtain a measurement of the spectral index for a subset of the catalogued sources and an estimated fraction of (at least) 8 per cent of resolved sources in the reported catalogue. We cross-matched our catalogued sources with different astronomical data bases to search for possible counterparts, finding ∼150 associations to known Galactic objects. Finally, we explored a multiparametric approach for classifying previously unreported Galactic sources based on their radio-infrared colours. [ABSTRACT FROM AUTHOR]

Synchrotron radiation from supernova remnants is caused by electrons accelerated through diffusive shock acceleration (DSA). The standard DSA theory predicts an electron spectral index of p  = 2, corresponding to a radio spectral index of α = −0.5. An extension of DSA theory predicts that the accelerated particles change the shock structure, resulting in a spectrum that is steeper than p > 2 (α < −0.5) at low energies and flattens with energy. For Cassiopeia A, a synchrotron spectral flattening was previously reported for a small part of the remnant in the mid-infrared regime. Here, we present new measurements for spectral flattening using archival radio (4.72 GHz) and mid-infrared (3.6  μ m) data, and we produce a complete spectral index map to investigate the spatial variations within the remnant. We compare this to measurements of the radio spectral index from L -band (1.285 GHz) and C -band (4.64 GHz) maps. Our result shows overall spectral flattening across the remnant (αR-IR ∼ −0.5 to −0.7), to be compared with the radio spectral index of αR = −0.77. The flattest values coincide with the locations of most recent particle acceleration. In addition to overall flattening, we detect a relatively steeper region in the south-east of the remnant (αR-IR ∼ −0.67). We explore whether these locally steeper spectra could be the result of synchrotron cooling, which provides constraints on the local magnetic field strengths and the age of the plasma, suggesting B ≲ 2 mG for an age of 100 yr, and even B ≲ 1 mG using the age of Cas A, in agreement with other estimates. [ABSTRACT FROM AUTHOR]

Summary: The need for fifth generation (5G) wireless technology to meet stringent demands on high throughput, ultra low latency, high reliability, massive connectivity, and fairness among users has seriously constrained the limited radio spectrum. Non‐orthogonal multiple access (NOMA) has been identified as one of the promising enabling radio access techniques to solve this problem. The basic principle of NOMA is the ability to serve multiple users in the same time and frequency resources but differentiated by their power domains. However, the inherent power‐domain multiplexing requires channel gain disparity between the strong and weak users, thereby reducing the sum‐rate gain of the network. In this paper, we propose NOMA scheme, integrated with carrier aggregation (CA) to further increase the bandwidth and data rate of users. Simulation results show considerable improvement in terms of throughput, energy efficiency, and fairness among users. [ABSTRACT FROM AUTHOR]

We present the results of a weekly monitoring of the new black hole candidate X-ray binary MAXI J1631-472 carried out with the MeerKAT radio interferometer, the Neil Gehrels Swift Observatory , and the Monitor of All-sky X-ray Image (MAXI) instrument, during its 2018–2019 outburst. The source exhibits a number of X-ray states, in particular both high- and low-luminosity hard states bracketed by extended soft states. Radio flaring is observed shortly after a transition from hard/intermediate states to the soft state. This is broadly in agreement with existing empirical models, but its extended duration hints at multiple unresolved flares and/or jet–ISM interactions. In the hard state radio:X-ray plane, the source is revealed to be 'radio quiet' at high luminosities, but to rejoin the 'standard' track at lower luminosities, an increasingly common observed pattern of behaviour. [ABSTRACT FROM AUTHOR]

Some recent studies have examined the gamma-ray flux profile of our Galaxy to determine the signal of dark matter annihilation. However, the results are controversial and no confirmation is obtained. In this article, we study the radio flux density profile of the M31 galaxy and show that it could manifest a possible signal of dark matter annihilation. By comparing the likelihoods between the archival observed radio flux density profile data and the predicted radio flux density profile contributed by dark matter and stellar emission, we can constrain the relevant dark matter parameters. Specifically, for the thermal annihilation cross-section via the |$b\bar{b}$| channel, the best-fitting value of dark matter mass is ∼30 GeV, which is consistent with the results of many recent studies. We expect that this method would become another useful way to constrain dark matter, which is complementary to the traditional radio analyses and the other indirect detections. [ABSTRACT FROM AUTHOR]

Spectral variability of radio sources encodes information about the conditions of intervening media, source structure, and emission processes. With new low-frequency radio interferometers observing over wide fractional bandwidths, studies of spectral variability for a large population of extragalactic radio sources are now possible. Using two epochs of observations from the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey that were taken one year apart, we search for spectral variability across 100–230 MHz for 21 558 sources. We present methodologies for detecting variability in the spectrum between epochs and for classifying the type of variability: either as a change in spectral shape or as a uniform change in flux density across the bandwidth. We identify 323 sources with significant spectral variability over a year-long time-scale. Of the 323 variable sources, we classify 51 of these as showing a significant change in spectral shape. Variability is more prevalent in peaked-spectrum sources, analogous to gigahertz-peaked spectrum and compact steep-spectrum sources, compared to typical radio galaxies. We discuss the viability of several potential explanations of the observed spectral variability, such as interstellar scintillation and jet evolution. Our results suggest that the radio sky in the megahertz regime is more dynamic than previously suggested. [ABSTRACT FROM AUTHOR]

Mali's first nonstate radio went on air during the authoritarian rule of Moussa Traoré in 1988, challenging the common narrative that ties political and media liberalization together. Negotiations were conducted by Italian NGOs at a time when such organizations had become key political actors in Sahelian countries. The implementation of Radio Rurale de Kayes was part of a wider infrastructural project that notably included a road. This historical account follows the metaphorical and literal association between the radio and the road in order to reflect on mobility and its constraints. Tracing the radio's trajectory from space-making to community-building, it shows how the station managed to sustain itself thanks to its position within an emerging network of associations led by return migrants and because of how it fitted into local infrastructures of mobility, thus calling for a stronger attention to the relation between radio, the audiences it convenes, and space. [ABSTRACT FROM AUTHOR]