Radio Characteristics Research Articles

Evidence for radio and X-ray auroral emissions from the magnetic B-type star ρ Oph A

Abstract We present new ATCA multiwavelength radio measurements (range 2.1–21.2 GHz) of the early-type magnetic star ρ Oph A, performed in 2019 March during three different observing sessions. These new ATCA observations evidence a clear rotational modulation of the stellar radio emission and the detection of coherent auroral radio emission from ρ Oph A at 2.1 GHz. We collected high-resolution optical spectra of ρ Oph A acquired by several instruments over a time span of about 10 yr. We also report new magnetic field measurements of ρ Oph A that, together with the radio light curves and the temporal variation of the equivalent width of the He i line (λ = 5015 Å), were used to constrain the rotation period and the stellar magnetic field geometry. The above results have been used to model the stellar radio emission, modelling that allowed us to constrain the physical condition of ρ Oph A’s magnetosphere. Past XMM–Newton measurements showed periodic X-ray pulses from ρ Oph A. We correlate the X-ray light curve with the magnetic field geometry of ρ Oph A. The already published XMM–Newton data have been re-analysed showing that the X-ray spectra of ρ Oph A are compatible with the presence of a non-thermal X-ray component. We discuss a scenario where the emission phenomena occurring at the extremes of the electromagnetic spectrum, radio and X-ray, are directly induced by the same plasma process. We interpret the observed X-ray and radio features of ρ Oph A as having an auroral origin.

Collaborative SLAM Based on WiFi Fingerprint Similarity and Motion Information

Simultaneous localization and mapping (SLAM) has been extensively researched in past years particularly with regard to range-based or visual-based sensors. Instead of deploying dedicated devices that use visual features, it is more pragmatic to exploit the radio features to achieve this task, due to their ubiquitous nature and the widespread deployment of the Wi-Fi wireless network. This article presents a novel approach for collaborative simultaneous localization and radio fingerprint mapping (C-SLAM-RF) in large unknown indoor environments. The proposed system uses received signal strengths (RSS) from Wi-Fi access points (APs) in the existing infrastructure and pedestrian dead reckoning (PDR) from a smartphone, without a prior knowledge about map or distribution of AP in the environment. We claim a loop closure based on the similarity of the two radio fingerprints. To further improve the performance, we incorporate the turning motion and assign a small uncertainty value to a loop closure if a matched turning is identified. The experiment was done in an area of 130 m by 70 m and the results show that our proposed system is capable of estimating the tracks of four users with an accuracy of 0.6 m with Tango-based PDR and 4.76 m with a step counter-based PDR.

The Origins of Certain Lives: The Development, Reception and Influence of the ‘Inventions for Radio’ by Barry Bermange and Delia Derbyshire

This article explores the four ‘Inventions for Radio’, first broadcast on the BBC’s Third Programme across 1964 and 1965, created by the dramatist Barry Bermange in collaboration with the composer and sound designer Delia Derbyshire. The ‘Inventions’ combined a collage of interviews, on subjects such as the existence of God, the process of ageing and the dream condition, with electronic music and soundscapes by Derbyshire. The ‘Inventions’ have been described as pioneering a ‘poetic realism’ and established a distinctive form of radio feature. Yet, existing scholarship on the radio feature has made little if any reference to the ‘Inventions’ and their authorship has been contested with Derbyshire’s role often uncredited and their development unclear. The article addresses how the ‘Inventions’ came into being and their immediate reception and influence. In doing so, the article argues that the ‘Inventions’ were important not just for their formal achievement but for their socio-political significance as well, integrating the thoughts and experiences of people from different socio-economic backgrounds and providing an atypical outlet for working class voices in particular, on subjects they would not normally be heard discussing on British radio and television at that time.

On the Validation of Satellite Microwave Remote Sensing Data under Soil Salinity Conditions

The results of a comparative analysis of the underlying surface brightness temperature obtained from the SMOS satellite and calculated with the use of ground-based measurements of moisture and the laboratory measurements of dielectric characteristics of samples of saline soils and saline water from test sites of the Kulunda Steppe are presented. The values of the underlying surface brightness temperatures calculated with the use of ground investigations and the laboratory studies correlate satisfactorily with the values of brightness temperatures measured from the SMOS satellite. The deviations can be caused by the seasonal drying of highly mineralized shallow lakes, which results in a significant change in the areas occupied by lakes and the appearance (instead of a water surface) of wetlands with a high content of mineral salts, whose radio emission characteristics differ from the characteristics of the water surface and the soil cover.

Nesta Pain

The ‘cultural translator’ is an individual who expresses the essence of entanglement in their career choices, moving between genres, media, or nations. This article suggests that the BBC producer and writer, Nesta Pain, was such an individual. Over the course of her career, Pain not only wrote and produced radio features and radio dramas but was also a successful journalist and author. She translated her experience in radio production onto the stage and on television by exploiting the different possibilities offered by these visual media—all evidence of her transmedial cultural translation. Further adding to the transgressive nature of her career, was her place as a woman in male-dominated radio production arenas.

The Soft X-Ray Counterpart of Hanny’s Voorwerp Near IC 2497

Abstract We report the detection in Chandra Advanced CCD Imaging Spectrometer archival data of an elongated soft (<3 keV) X-ray feature to the south of the Compton-thick active galactic nucleus (AGN) galaxy IC 2497, coincident with the emission-line feature known as Hanny’s Voorwerp. The data are consistent with the spatial correspondence between X-ray, optical emission-line, and radio features detected in nearby obscured AGNs (e.g., ESO 428-G014). The X-ray luminosity of the (0.3–3.0 keV) soft feature is ∼1.2 × 1040 erg s−1. We infer an [O iii]/soft-X-ray ratio in the range of ∼200, consistent with the highest values measured in some of the clouds of NGC 4151. Overall, given the uncertainties, Hanny’s Voorwerp appears to be a feature consistent with the ionization cone emission of nearby AGNs. We estimate an X-ray recombination time of ∼2 × 107 yr, longer than the [O iii] recombination time (∼8000 yr). This suggests that extended soft X-ray components may be a better diagnostic of overall long-term activity, while detection of an [O iii] HV would point to a time-limited activity burst.

Mobility-Aware and Radio Characteristics Enabled Routing for Video Streaming over MANETs

Providing an adequate level of quality-of-experience (QoE) for multimedia applications in mobile ad-hoc networks (MANETs) is a challenging task due to its environmental characteristics, such as dynamic network topology, variable bit-rates of transmitting traffic, and fluctuating link conditions. In this paper, we propose a QoS provisioning mobility-aware and radio characteristics enabled routing for video streaming over MANETs (Q-RCNM) based routing protocol, and its multipath variant (i.e., Q-RCNMM). Our protocols ensure adequate QoE to the end users while receiving the multimedia traffic. Q-RCNM uses link-bandwidth, link-delay, and link-transmission efficiency ratio as QoS metrics along with the node mobility during its QoS-aware route discovery phase. We propose novel techniques for accurately estimating the aforementioned QoS metrics. Additionally, we design a joint analytical model that simultaneously considers the dynamic values of the aforementioned metrics to generate a single link-QoS value. Simulation results in terms of peak signal-to-noise ratio (PSNR), delay, route throughput, transmission efficiency, and route lifetime, shows the efficiency of our proposal when compared with similar state-of-the-art techniques.

Predicting uptake of aquaculture technologies among smallholder fish farmers in Kenya

In Africa, many governments and development agencies have promoted aquaculture as a panacea for household food security, rural development, and poverty reduction. However, aquaculture production in the continent remains low despite significant investments in research and technology development. While numerous initiatives have been directed at technological innovation and transfer, their present scale of uptake is very slow and therefore inadequate to achieve transformational change envisaged in the 2030 Agenda for sustainable development. In this paper, we aim to (1) critically analyze the factors that influence fish farmer’s perceptions, attitudes, and behaviors toward technology adoption; and (2) to determine the impacts of technology adoption on farmer’s livelihoods. Primary data were collected using a self-administered digitized questionnaire to 331 randomly selected farmers in Kenya. Multivariate logistic regression models were used to analyze data. Results revealed that variables including secondary education, diversified on-farm activities, farm size, production levels, attendance of extension training, ease of understanding, and ease of handling technologies were positive and significant predictors of aquaculture technology adoption. However, 30% of fish farmers were categorized as high adopters of novel aquaculture technologies, implying that there are gaps in technical skills hindering adoption of innovative technologies and best management practices. To facilitate learning and uptake of technologies and good practices by farmers, a range of aquaculture-related extension and communication materials, including posters, hard copy information leaflets and brochures of recipes in appropriate languages, short video presentations, and radio features, should be commissioned to support the smallholder farmers.

Three-dimensional dust mapping of 12 supernovae remnants in the Galactic anticentre

ABSTRACT We present three-dimensional (3D) dust mapping of 12 supernova remnants (SNRs) in the Galactic anticentre (Galactic longitude l between 150○ and 210○) based on a recent 3D interstellar extinction map. The dust distribution of the regions, which cover the full extents in the radio continuum for the individual SNRs, is discussed. Four SNRs show significant spatial coincidences between molecular clouds (MCs) revealed from the 3D extinction mapping and the corresponding radio features. The results confirm the interactions between these SNRs and their surrounding MCs. Based on these correlations, we provide new distance estimates of the four SNRs, G189.1+3.0 (IC443, $d=1729^{+116}_{-94} \rm \, pc$), G190.9–2.2 ($d=1036^{+17}_{-81} \rm \, pc$), G205.5+0.5 ($d=941^{+96}_{-94}$ or $1257^{+92}_{-101} \rm \, pc$), and G213.0–0.6 ($d=1146^{+79}_{-80} \rm \, pc$). In addition, we find indirect evidences of potential interactions between SNRs and MCs for three other SNRs. New distance constraints are also given for these three SNRs.

Development of a new reproductive tissue cryopreservation clinical service for children: the Oxford programme

PurposeThis article describes the development of a new reproductive tissue cryopreservation clinical service for children at high risk of infertility in the NHS during times of severe financial constraints in the health service.MethodA development plan with two phases was drawn up. Phase 1 restricted the service to childhood cancer patients referred to the Oxford Paediatric Oncology and Haematology Principle Treatment Centre. It was estimated that there would be 10 patients/year and used existing staff and facilities from paediatric oncology, surgery, anaesthetics radiology, pathology, psychology, teenage–young adult gynaecology, and an existing Human Tissue Authority tissue bank with a licence for storage of tissue under a Human Sector Licence. Phase 2 extended the service to include children and young adults across England, Wales and Ireland—patients from Scotland having access to a research programme in Edinburgh. The main challenge in phase 2 being resources and the need for patients to be able to be treated as close to home as safely as possible.ResultsThe Oxford team developed information resources and eligibility criteria based on published best practice, referral and treatment pathways, multidisciplinary team meetings, a network of third party sites, and a dedicated case management and database. As the programme expanded, the Oxford team was able to justify to management the need for a dedicated theatre list. Patient feedback through questionnaires, qualitative work conducted as part of a Ph.D. thesis as well as direct patient stories and interviews in TV, and radio features underpins the positive impact the programme has on patients and their families.ConclusionThe Oxford Reproductive Cryopreservation programme delivers fertility preservation treatment to children and young adults at high risk of infertility safely, effectively and as close to home as possible. The onward view is to apply for national funding for this programme for recognition and sustainability.

Normalization of Radio Feature for Online Learning for Identification in Cognitive Radio

The identification of the radio access technology (RAT) of the primary user by secondary users is important to avoid interference for spectrum-sharing techniques using cognitive radio (CR). RATs ha...

Measurements at 2.4, 3.4, 5.2, 28 and 60 GHz for Device-to-Device Wireless Communications

Wireless communication networks with increased demand for higher speed in data transfer have paved way for device-to-device (D2D) wireless communications. This paper, investigates the radio link characteristics of D2D communication network in an indoor environment utilizing radio frequency experiments and ray-tracing based simulations at frequencies of 2.4, 3.4, 5.2, 28 and 60 GHz. The path loss exponent and standard deviation are estimated and compared with free space path loss, log normal shadowing, International Telecommunication Union model and compared with other research works. This work also studied the impact of indoor environments on D2D communications.

Method of intelligent support of decision-making at dispatching the geospatial processes

ABSTRACTState-of-the-art means of intelligent support of decision-making at dispatching the geospatial processes that use the digital cartographic data sets do not allow for an operative and adequate enough consideration of the rapidly varying natural environment’s characteristics influencing upon the dispatching decisions being made when controlling the complexly distributed geospatial processes’ totalities. At that dispatching is an overall manifestation of a versatile process of geospatial processes’ management. As a rule, the task of managing the objects realising geospatial processes is solved in isolation from the current state of their natural environment, and does not consider the environment radio, physical and other characteristics’ variability. The issues of changes in navigational and meteorological conditions, as well as the issues related to ensuring spatial security, are exclusively subjected to the consideration. Under current conditions becomes meaningful a more complex version of the spatial processes dispatching problem, when the environment variability determines the unique conditions for dispatching at each point of the coordinated geographical space. This statement of a problem is especially relevant under an introduction of modern adaptive means intended for monitoring and sensing the natural environment, like subsystems for monitoring the corresponding systems of spatial processes dispatching. The novelty both of this formulation and the method of this version problem-solving consists in the data fusion from the representation of spatial processes subject domain and those corresponding to the standard models of digital data sets, the integration of software mechanisms for working with information on geospatial processes and programmes for working with cartographic data sets. Development of a reasonable problem statement and a method for this problem’s version solving is the essence of this article.

Application of Bluetooth in Mine Gas Information Transmission

In order to solve the problem of information transmission, such as underground gas concentration, etc. Using Bluetooth Multi-hop Communication Technology based on VoWPAN, the feasibility of using Bluetooth multi-hop communication system to transmit data on aircraft is analyzed from three aspects: the transmission characteristics of radio in mine roadway, the construction of Bluetooth communication system and the Bluetooth multi-hop communication system mounted on aircraft. The most advanced detection vehicle is responsible for collecting data, and Bluetooth in the middle of the vehicle acts as a relay system. Theoretical research shows that this communication system has a good guiding effect on the downhole detection and rescue of aircraft.

Detection of Nonthermal Hard X-Ray Emission from the “Fermi Bubble” in an External Galaxy

Abstract We report new Chandra hard X-ray (>2 keV) and Jansky Very Large Array C-band observations of the nuclear superbubble of NGC 3079, an analog of the “Fermi bubble” in our Milky Way. We detect extended hard X-ray emission on the southwest (SW) side of the galactic nucleus with coherent multiwavelength features in radio, Hα, and soft X-ray. The hard X-ray feature has a cone shape with possibly a weak cap, forming a bubble-like structure with a diameter of ∼1.1 kpc. A similar extended feature, however, is not detected on the northeast (NE) side, which is brighter in all other wavelengths such as radio, Hα, and soft X-ray. Scattered photons from the nuclear region or other nearby point-like X-ray bright sources, inverse Compton emission from cosmic-ray (CR) electrons via interaction with the cosmic microwave background, or any individually faint stellar X-ray source populations, cannot explain the extended hard X-ray emission on the SW side and the strongly NE/SW asymmetry. A synchrotron emission model, plus a thermal component accounting for the excess at ∼1 keV, can well characterize the broadband radio/hard X-ray spectra. The broadband synchrotron spectra do not show any significant cutoff, and even possibly slightly flatten at higher energy. This rules out a loss-limited scenario in the acceleration of the CR electrons in or around this superbubble. As the first detection of kiloparsec-scale extended hard X-ray emission associated with a galactic nuclear superbubble, the spatial and spectral properties of the multiwavelength emissions indicate that the CR leptons responsible for the broadband synchrotron emission from the SW bubble must be accelerated in situ, instead of transported from the nuclear region of the galaxy.

A Picture of Abanded Children in Padang, A Human Interest Radio Feature

Abandoned children is one of the problems faced by Padang city. Many reasons make the number of abanded children still high. Although, the news about abandoned children have been posted in newspaper, magazine even online and social media, but seen that they just inform in partially. Therefore the researchers conducted a project on presenting the data on the picture of abanded children in padang in form of radio feature. It is expected that this radio feature can give useful information about the reason why they “work on the street”, the life that they run everyday. Hence it is hope that it can touch the human care of people and government to find the best solution for them. The data was gotten from the result of interview by using recorder tools. Then Cool Edit Pro 2.1 application was used to edit and mix the voice . Moreover this project applied the stages of making radio feature likes pre-production, production and post-production. The result of thisl project were in form of audio, radio feature with 15 minutes duration, and the English script with 756 word.

Radio Link Power Density and Antenna Factor

Generally antenna characteristics have been defined always in the transmitting case. In free space radio link identical antennas characteristics show that they have exactly the same gain, area, and factor. Contrary to current usage and practices transmitting and receiving antenna characteristics are not the same, since the surface of the earth acts as a reflecting plane. This investigation was conducted to show the difference in gain, area, and factor of two identical antennas in the transmitting and receiving role, through calculations, simulation, and measurements necessary for electromagnetic compatibility.

The Impact of the Environment on the Early Stages of Radio Source Evolution

Abstract Compact symmetric objects (CSOs) show radio features such as jets, lobes, and hot spots that are contained within the central 1 kpc region of their host galaxy. Thus, they are thought to be among the progenitors of large-scale radio galaxies. A debate regarding whether the CSOs are compact primarily because they are young or because they are surrounded by a dense medium impacting their expansion is ongoing. Until now, attempts to discriminate between the environmental and genuine youthfulness scenarios have been inconclusive. We present a study of three CSOs selected on the basis of their puzzling X-ray absorbing properties in prior Beppo-SAX and/or Chandra X-ray Observatory data. Our new XMM-Newton observations unambiguously confirm the nature of their X-ray absorbers. Furthermore, for the first time, our X-ray data reveal the existence of a population of CSOs with intrinsic hydrogen column density N H > 1023 cm−2 that is different from the population of X-ray unabsorbed CSOs. The two groups appear to be separated in the linear size versus radio power plane. This finding suggests that a dense medium in X-ray obscured CSOs may be able to confine the radio jets. Alternatively, X-ray obscured CSOs could be seen as radio brighter than their unobscured counterparts either because they reside in a dense environment or because they have larger jet powers. Our results help constrain the origin of the X-ray emission and the location and size of the X-ray obscurer in CSOs, and indicate that the environment may play a key role during the initial expansion of a radio source.

Gemini IFU, VLA, and HST observations of the OH Megamaser Galaxy IRAS17526 + 3253★

AbstractWe present a multiwavelength study of the OH megamaser galaxy IRAS17526 + 3253, based on new Gemini multi-object spectrograph integral field unit (GMOS/IFU) observations, Hubble Space Telescope F814W, and H α + [N ii] images, and archival 2MASS and 1.49 GHz VLA data. The Hubble Space Telescope(HST) images clearly reveal a mid-to-advanced stage major merger whose northwestern and southeastern nuclei have a projected separation of ∼8.5 kpc. Our HST/H α + [N ii] image shows regions of ongoing star formation across the envelope on ∼10 kpc scales, which are aligned with radio features, supporting the interpretation that the radio emission originates from star-forming regions. The measured H α luminosities imply that the unobscured star formation rate (SFR) is ∼10–30 M⊙ yr−1. The GMOS/IFU data reveal two structures in northwestern separated by 850 pc and by a discontinuity in the velocity field of ∼ 200 km s−1. We associate the blueshifted and redshifted components with, respectively, the distorted disc of northwestern and tidal debris, possibly a tail originating in southeastern. Star formation is the main ionization source in both components, which have SFRs of ∼2.6–7.9 M⊙ yr−1 and ∼1.5–4.5 M⊙ yr−1, respectively. Fainter line emission bordering these main components is consistent with shock ionization at a velocity ∼200 km s−1 and may be the result of an interaction between the tidal tail and the northwestern galaxy’s disc. IRAS17526 + 3253 is one of only a few systems known to host both luminous OH and H2O masers. The velocities of the OH and H2O maser lines suggest that they are associated with the northwestern and southeastern galaxies, respectively (Martin et al.; Wagner).

Signs of the Times – A Historical Radio Feature

Abstract The article discusses ZeitZeichen, an immensely successful 15-minute radio feature that focuses on a certain date in history and is aired daily on German public radio. Using a concrete example, the authors show how ZeitZeichen can be used as a model for productions by local radio stations or as a student assignment in public history programs.