Shared Medium Research Articles

Mutual socialization during shared media moments: U.S. LGBTQ teens and their parents negotiate identity support

AbstractSocial relational theory proposes that children and parents socialize each other, particularly when knowledge, beliefs, and identities diverge. For families with lesbian, gay, bisexual, transgender, queer (LGBTQ) teens, identity-relevant media depictions may spark moments of mutual socialization, including attempts to mediate each other’s viewing and discussions of the teen’s identity. U.S. data from 200 LGBTQ teens (aged 13–18) and one of their parents indicated that 83% of dyads reported that media content had elicited identity-related conversations. Both teens and parents perceived teens to mediate more often than parents, though latent profile analyses suggested distinct dyadic profiles. Although all teens were out to their parent, those with more identity certainty engaged in and received more frequent mediation. For parents, the frequency and positivity of “media moments” were associated with greater support for their teen’s identity. For teens, positivity (but not frequency) of such moments was associated with perceptions of more parental support for their identity.

Shared Network Effects in Time- versus Event-Triggered Consensus of a Single-Integrator Multi-Agent System

Event-triggered control has the potential to provide a similar performance level as time-triggered (periodic) control while triggering events less frequently. It therefore appears intuitive that it is also a viable approach for distributed systems to save scarce shared network resources used for inter-agent communication. While this motivation is commonly used also for multi-agent systems, a theoretical analysis of the impact of network effects on the performance of event- and time-triggered control for such distributed systems is currently missing. With this paper, we contrast event- and time-triggered control performance for a single-integrator consensus problem under consideration of a shared communication medium. We therefore incorporate transmission delays and packet loss in our analysis and compare the triggering scheme performance under two simple medium access control protocols. We find that network effects can degrade the performance of event-triggered control beyond the performance level of time-triggered control for the same average triggering rate if the network is used intensively. Moreover, the performance advantage of event-triggered control shrinks with an increasing number of agents and is even lost for sufficiently large networks in the considered setup.

Optimization Logic and Paradigm Construction of Digital Transformation of Technical Skill Training Model under the Perspective of Social Media Communication and Intelligent Natural Language Integration

Research has shown that social media can help students learn. Through a variety of different social platforms, teachers can work with students to integrate social media into their daily instruction to make lessons more interesting and engaging and increase student engagement. With the rise of Metaverse, Artificial Intelligence, Blockchain, New generation communication technology, Brain interface and other intelligent technologies, especially the application of shared media communication and intelligent natural language system, human society has undergone profound changes in production and lifestyle. The digital economy will lead to systematic changes in the concept, mode and governance system of talent training, and the numerical transformation of education training mode, especially the training of technical skills, is imperative. Although some studies try to discuss the construction of intelligent ecology of vocational education, there is a lack of verified scientific theories and practical experience on the implementation path of digital transformation of vocational education. To address this theme, this paper follows the main line of the path of development background, realistic dilemma, hierarchical features, logical framework and paradigm construction of digital transformation of vocational education, and systematically elaborates the great differences between traditional economy and digital economy as the supply base of vocational education development on the basis of full research on the development of digital industry, digital technology and digital education at home and abroad, clarifies the development features including operation mode, strategic direction and value It also focuses on the logical framework of vocational education with industrial chain as the core, innovation chain as the leader, talent chain as the support and education chain as the foundation, analyzes the importance of social communication and natural language intelligent changes in the process of technical skills talents, and explores the practical path of building a vocational education talent training model that is compatible with the intelligent era.

Rural electrification subsidy estimation: a spatial model development and case study

A global push to achieve universal electricity access, paired with drastic reductions in the cost of decentralized electricity technologies, has led to significant research on how best to roll out access to rural communities in sub-Saharan Africa. Various geospatial electrification models have been developed to aid the decision-making process considering decentralized grid alternatives such as mini-grids and solar home systems. Despite these tools suggesting that in many cases, decentralized systems are a more cost-effective electricity access pathway, grid extension still predominates in practice. This is due, at least in part, to institutional structures in most countries that provide significant direct and indirect subsidies to grid extension projects, commonly through publicly-owned utilities. These sources of finance are generally not available to primarily privately operated off-grid energy service providers. However, the subsidy provided for grid extension projects is not well understood. In this paper, we employ utility grid extension costs and revenue data, and geospatial grid infrastructure data to estimate the size and distribution of subsidy implicitly provided to rural grid extension projects for 129 communities in Mombasa County, Kenya. We also estimate subsidies for hypothetical off-grid electricity systems in the same communities that would deliver equivalent services to the grid. We allocate the cost of shared medium voltage (MV) distribution infrastructure using a marginal and an average cost method for grid extension and compare these with subsidies for off-grid systems. We find that the average of average subsidy per customer across communities for grid extension is US$5,118 and US$5,330 for the two MV cost allocation methods respectively, while for the off-grid systems the corresponding average of average subsidies are US$3,380, using a real discount rate of 1.3% evaluated from a nominal discount rate of 8% and inflation rate of 6.7%. Our results show that in the communities in our case study, 40% and 37% of the communities would command less subsidy while served by minigrids over the grid, and the switch would save 50% and 54% of the total cost for average and marginal cost allocation methods respectively. We also show that by using a multi-model approach to electrification and by reallocation of implicit subsidies that have been exclusive to grid extension to other technology options utilities can cast the net wider, without an increase in budgets.

Fast Desynchronization Algorithms for Decentralized Medium Access Control Based on Iterative Linear Equation Solvers

We tackle the problem of having multiple transmitters cooperating to be desynchronized using a distributed algorithm. Although this problem can also be found in surveillance, it has the most impact in achieving a fair access to a wireless shared communication medium at the medium access control layer in the context of wireless sensor networks. In this article, we first theoretically investigate the convergence rate of various optimization algorithms, giving closed-form expressions for the parameters achieving the best worst-case convergence rate. We then show that a recently proposed time-varying parameters Nesterov algorithm applied to this problem has worse performance assuming one can determine the number of sensors in the network. In order to remove such an assumption, the problem is seen as the solution of a linear equation corresponding to the first optimality condition. Both theoretically and in simulation, we show that using the Gauss–Seidel method improves the speed of convergence, although its performance degrades for large network sizes. In simulations, it is shown the behavior for various number of wireless devices, emphasizing how the algorithms actually perform in comparison with their worst-case theoretical rates for different network sizes.

A Model-Free Cognitive Anti-Jamming Strategy Using Adversarial Learning Algorithm

Abstract Modern networking systems can benefit from Cognitive Radio (CR) because it mitigates spectrum scarcity. CR is prone to jamming attacks due to shared communication medium that results in a drop of spectrum usage. Existing solutions to jamming attacks are frequently based on Q-learning and deep Q-learning networks. Such solutions have a reputation for slow convergence and learning, particularly when states and action spaces are continuous. This paper introduces a unique reinforcement learning driven anti-jamming scheme that uses adversarial learning mechanism to counter hostile jammers. A mathematical model is employed in the formulation of jamming and anti-jamming strategies based on deep deterministic policy gradients to improve their policies against each other. An open-AI gym-oriented customized environment is used to evaluate proposed solution concerning power-factor and signal-to-noise-ratio. The simulation outcome shows that the proposed anti-jamming solution allows the transmitter to learn more about the jammer and devise the optimal countermeasures than conventional algorithms.

Mobile Ad-Hoc Wireless Networks In Medium Access Control Protocol

Nodes in an ad hoc wireless network share a common broadcast radio channel. The radio spectrum is limited, the bandwidth available for communication in such networks is also limited. Access to this shared medium should be controlled in such manner that all nodes receive a fair share of the available bandwidth, and that the bandwidth is utilized efficiently. Since the characteristics of the wireless medium are completely different from those of the wired medium ,and since ad hoc wireless networks need to address unique issues such as node mobility, limited bandwidth availability ,error-prone broadcast channel hidden and exposed terminals problems and power constraints that are not applicable to wired networks ,a different set of protocols is required for controlling access to the shared medium in such networks, This paper focuses on media access protocols for ad hoc wireless networks

Supervisory Event-Triggered Control of Uncertain Process Networks: Balancing Stability and Performance

This work presents a methodological framework for the design of a resource-aware supervisory control system for process networks with model uncertainty and communication resource constraints. The developed framework aims to balance the objective of closed-loop stabilization of the overall network with that of meeting the local performance requirements of the component subsystems while keeping the rate of data transfer between the local control systems to a minimum. First, a quasi-decentralized networked control structure, with a set of local model-based controllers communicating with one another over a shared communication medium at discrete times, is designed. A Lyapunov stability analysis of the closed-loop system is then carried out, and the results are used to derive appropriate bounds on the local model state estimation errors as well as the dissipation rates of the local control Lyapunov functions. These bounds are used as stability and performance thresholds to trigger communication between the local control systems and a higher-level supervisor that coordinates the transfer of state measurements between the distributed control systems. A breach of the local stability and performance thresholds generates alarm signals which are transmitted to the supervisor to determine which subsystems should communicate with one another. The supervisor employs a composite Lyapunov function to assess the impact of the local threshold breaches on the stability of the overall closed-loop system. The supervisory communication logic takes account of the evolution of the local and composite Lyapunov functions in order to balance the stability and local performance requirements. Finally, the developed framework is demonstrated using a representative chemical process network and compared with other unsupervised event-based control approaches. It is shown that the supervisory event-based control approach leads to a more judicious utilization of network resources that helps improve closed-loop process performance in the presence of unexpected disturbances and input rate constraints.

Design and analysis of intrusion detection systems for wireless mesh networks

Intrusion is any unwanted activity that can disrupt the normal functions of wired or wireless networks. Wireless mesh networking technology has been pivotal in providing an affordable means to deploy a network and allow omnipresent access to users on the Internet. A multitude of emerging public services rely on the widespread, high-speed, and inexpensive connectivity provided by such networks. The absence of a centralized network infrastructure and open shared medium makes WMNs particularly susceptible to malevolent attacks, especially in multihop networks. Hence, it is becoming increasingly important to ensure privacy, security, and resilience when designing such networks. An effective method to detect possible internal and external attack vectors is to use an intrusion detection system. Although many Intrusion Detection Systems (IDSs) were proposed for Wireless Mesh Networks (WMNs), they can only detect intrusions in a particular layer. Because WMNs are vulnerable to multilayer security attacks, a cross-layer IDS are required to detect and respond to such attacks. In this study, we analyzed cross-layer IDS options in WMN environments. The main objective was to understand how such schemes detect security attacks at several OSI layers. The suggested IDS is verified in many scenarios, and the experimental results show its efficiency.

Effect of micro/nano-sheet array structures on the osteo-immunomodulation of macrophages.

The immune response induced by surface topography crucially determines the implant success. However, how the immune response is mediated by the size of surface topography remains unclear. Hence, various biocompatible Mg-Al layered double hydroxides sheet-array films with different sizes (nano, micro and nano/micro mixture) were constructed on the biomedical titanium, and their osteo-immunomodulation effects on the macrophages were explored. The nano-sheet array structures significantly promoted the polarization of M2 macrophages by activating the PI3K-AKT-mTOR signaling pathway with high gene expressions of integrin β2 and FAK. While the micro-sheet array structures enhanced osteogenic differentiation of mouse bone marrow mesenchymal stem cells (mBMSCs) via ROCK-YAP/TAZ-mediated mechanotransduction. Moreover, the nano-sheet array structures promoted the osteogenic differentiation of mBMSCs with a high proportion of M2 macrophages through a shared medium. This study gave further information concerning integrin-induced focal adhesions in cells of different sheet array structures and their role in macrophage polarization and osteogenic differentiation of mBMSCs, which might help to design biomaterial surfaces with optimal geometry for a desired immunemodulation.

Doing participatory fandom through trans‑scripting

Abstract This article examines trans-scripting in transnational, multilingual fandom on Sina Weibo, the largest Chinese microblogging site. Taking one of the most popular Korean pop music (K-pop) bands named BTS as a case study, 741 instances of trans-scripting were manually selected from a total of 18,243 comments under the official Weibo account of the largest BTS fan club in China. Combining online observation and corpus-based analysis, our study draws on the notions of engaged audience and affinity space to reveal how multiple patterns of trans-scripting are heavily mobilized by K-pop fans in translingual idol naming, the transcultural maintenance of fan-idol kinship, and the intertextual confirmation of shared media consumption experiences. We argue that trans-scripting is an under-explored linguistic strategy used by transnational pop-culture fans, providing an analytical lens for research on fan identity and fan-communal membership. Theoretically, trans-scripting can serve as a useful lens to analyze networked multilingual fandom.

Convergence of Federated Learning Over a Noisy Downlink

We study federated learning (FL), where power-limited wireless devices utilize their local datasets to collaboratively train a global model with the help of a remote parameter server (PS). The PS has access to the global model and shares it with the devices for local training using their datasets, and the devices return the result of their local updates to the PS to update the global model. The algorithm continues until the convergence of the global model. This framework requires downlink transmission from the PS to the devices and uplink transmission from the devices to the PS. The goal of this study is to investigate the impact of the bandwidth-limited shared wireless medium on the performance of FL with a focus on the downlink. To this end, the downlink and uplink channels are modeled as fading broadcast and multiple access channels, respectively, both with limited bandwidth. For downlink transmission, we first introduce a digital approach, where a quantization technique is employed at the PS followed by a capacity-achieving channel code to transmit the global model update over the wireless broadcast channel at a common rate such that all the devices can decode it. Next, we propose analog downlink transmission, where the global model is broadcast by the PS in an uncoded manner. We consider analog transmission over the uplink in both cases, since its superiority over digital transmission for uplink has been well studied in the literature. We further analyze the convergence behavior of the proposed analog transmission approach over the downlink assuming that the uplink transmission is error-free. Numerical experiments show that the analog downlink approach provides significant improvement over the digital one with a more notable improvement when the data distribution across the devices is not independent and identically distributed. The experimental results corroborate the convergence analysis, and show that a smaller number of local iterations should be used when the data distribution is more biased, and also when the devices have a better estimate of the global model in the analog downlink approach.

State of the Art in Quorum-Based Sleep/Wakeup Scheduling MAC Protocols for Ad Hoc and Wireless Sensor Networks

In energy-constrained networks, designing an energy-efficient MAC protocol is crucial since the MAC protocol controls the access of the nodes to the shared wireless medium. Indeed, an efficient MAC protocol should reduce or even mitigate the consumption of the main sources of energy wastage, namely, overhearing, collision, and idle listening, and hence the network lifetime will be improved. One of the most efficient solutions is designing a MAC protocol that utilizes the quorum concept to increase energy efficiency by reducing idle listening and overhearing. Researchers have proposed several quorum-based MAC protocols to conserve energy. This paper presents a detailed overview and classification of several existing quorum-based sleep/wakeup scheduling MAC protocols. We classify these quorum-based MAC protocols into homogeneous and heterogeneous based on their quorum system characteristics. Moreover, we further classify these protocols according to the guaranteed intersection between any two quorums into fixed and limited. Furthermore, we compare these protocols in terms of their quorum system characteristics, limitations, and performance. Finally, a guide for future research directions is presented.

How Right-Wing Populists Engage with Cross-Cutting News on Online Message Boards: The Case of ForoCoches and Vox in Spain

Anecdotal evidence suggests a link between online message boards and the rise of far-right movements, which have achieved growing electoral success globally. Press accounts and scholarship have suggested these message boards help to radicalize like-minded users through exposure to shared media insulated from cross-cutting viewpoints (e.g., Hine et al. 2017 ; Palmer 2019). To better understand what role online message boards might play for supporters of right-wing populist movements, we focus on the Spanish political party Vox and its supporters’ use of the message board ForoCoches, a fan site for car enthusiasts, which became an important platform for the party. Using more than 120,000 messages collected from threads mentioning the party between 2013–2019, we examine the URLs shared to show how mainstream news media events shape the conversation online and how users not only were exposed but deeply engaged with cross-cutting news sources. We argue that the use of sites such as ForoCoches should be viewed in the context of a broader increasingly hybrid political and media landscape where activity online and offline cannot be understood separate from one another. Moreover, our findings suggest that the online political discussions that take place in Vox-related threads on ForoCoches resemble normatively positive deliberative spaces—albeit in this case in support of illiberal political positions. In other words, our findings complicate conventional notions about the benefits of political talk, especially online, as a democratically desirable end in and of itself.

The Use of English Language Vocabulary Learning Strategies through Social Media by Pakistani EFL Students

The study aims to explore the effect of using social media on University students' vocabulary achievement, To motivate EFL learners to use latest effective vocabulary learning strategies through social media, .and to formulate useful recommendations for the development of English language vocabulary items by the routine of interesting shared media and the influence of social media on educating scholars' English dialectal skills, i.e., speaking with BS level EFL students at The Islamic University of Bahawalpur. Social media technologies include wikis, social networks, podcasts, pictures, magazines, internet forums, weblogs, social blogs, videos, and more. It works in many different ways, including. Still, rare research has focused precisely on the role of social media in learning foreign languages. .Findings reveal social media as an operative tool for the development of English dialectal vocabulary and motivate the learners to use social media positively for the enhancement of vocabulary.

An energy‐efficient priority‐based packet scheduling mechanism for enhancing quality of service in mobile ad hoc network

AbstractIn today's world, a mobile ad hoc network plays a predominant role for numerous applications such as education, entertainment, emergency services, tactical services, and home applications. The performance of IEEE 802.11 based wireless ad hoc networks degrades due to high contention for the shared medium among multiple ad hoc nodes. However, the shared medium can be accessed by multiple nodes, which causes link collisions and packet drop at the link level. These kinds of packet drops have a direct impact on the overall performance of the transmission control protocol (TCP). In this article, a new robust prioritized packet scheduling with adaptive backoff window (PPSAB) mechanism has been proposed to enhance the quality of service of TCP in the wireless scenario. In order to determine the congestion in the network, the proposed PPSAB mechanism anticipates the cross‐layer parameters instead of transport layer parameters. The proposed access scheme assures minimized collisions and energy by setting the node level access to prevailing network parameters. The performance of the proposed PPSAB has been evaluated using an NS‐2 environment and the results manifest that the normalized overhead is reduced by 20% and network throughput is increased by 17% than the existing methods.

Modeling and simulation of defense game model for jamming attack in wireless sensor networks using evolutionary game theory

AbstractThe open and shared communication medium of wireless sensor networks creates vulnerability to various types of attacks. In particular, jamming is a kind of attack that is difficult to defend. When the jammer transmits the jamming signal, the nodes covered by the jamming signal will suffer for their transmission. The interactions between the jammer and the source nodes are complex. Thus this article models the interactions between the jammer and the source node as an evolutionary game‐theoretical model. The game model of jamming is formulated, and then the evolutionary analysis of the game model is done. The game model is solved using replicator dynamics, and also the solution is verified by conducting various simulations. It can also be verified by using a stability diagram of replicator dynamics. The equilibrium points are analyzed to check whether that is an evolutionarily stable strategy. Extensive numerical simulation experiments have been carried out to analyze the evolution of strategies for source nodes and jammer nodes.

Negotiations of Power: The Persistence of Indigenous Meanings of Space in Mission-era Alta California

Across all cultures, there is one shared medium through which humans exist: space.Space can be defined as the natural land that people live on, it is also constituted of the artificialstructures that we build on it. Interpretations of writings by the humanist geographer, Yi Fu Tuan,have described space as, “...a multiplicity of mental constructions which all rely on theinteraction between the human body and its environment” (Mahoudeau, 2016). It is the physicalrealm through which individuals live their lives in and through. It is through this exchange thatpeople are able to develop particular meanings of space including religious ideologies,sentiments of belonging, or even domination. Each of these examples are commonly displayedand dictates how and why people treat spaces differently and in turn, one another. As peoplebuild their emotional ties with an environment, they feel a sense of entitlement towards it andstrive to project their personal desires onto it. This tendency has been magnified by groups ofpeople to maintain or create ownership of land (Mahoudeau, 2016).

Data Collision and Interference Minimization in Wireless Sensor Network using Node Data Addressing with Random Access Time

A wireless sensor network (WSN) refers to a spatially dispersed network of sensors that monitor and collect environmental data and forward the collected data to the central station. WSN has been widely used in daily life and industrial applications, ranging from surveillance, military, healthcare, habitat monitoring, and agriculture application. However, WSN that uses radiofrequency (RF) communication may suffer from noise and interference caused by two or more radios that uses the same frequency. Data collision is also expected within the wireless network especially when numerous sensor nodes are transmitting their data to the base station (BS) through a shared medium. Hence, this research contributes in mitigating the RF interference and data collision in the network to increase the network’s data reliability by using the concept of Time Division Multiple Access (TDMA) protocol where each sensor node will be transmitting their data at a different time to avoid collision and interference in the shared medium. However, in this research, each sensor node will access the channel or the transmission medium at a random time. To prove the concept of the proposed method on data collision and interference minimization, an Internet of Things (IoT) based wireless sensor network for alerting application will be designed and implemented in the fire station. It has been found from the experimental result that RF interference and data reliability in the network can be reduced by 90% with the proposed algorithm by allowing the sensor node to access the RF channel and transmit the data at a random time.

A survey on recent contention-free MAC protocols for static and mobile wireless decentralized networks in IoT

Medium Access Control (MAC) protocols for wireless decentralized networks in IoT have attracted a lot of attention in both academic and industrial fields. They aim to coordinate access among IoT devices to the shared wireless medium. More specifically, contention-free MAC protocols are known to be more efficient than contention-based ones in the case of high traffic load and dense networks. To face the main communication challenges between IoT devices such as collisions and conflicts as well as mobility, it is crucial to design an efficient MAC protocol. To do so, several solutions have been proposed in the literature. Among recent proposed solutions, Machine Learning (ML) algorithms and game theory models were used to revolutionize the communication in IoT networks, especially for devices with high mobility degree. In our survey, we first start by studying the challenges and requirements of communication in wireless networks. Then, we provide a comprehensive survey on recent contention-free MAC protocols existing in the literature. Next, we compare these solutions based on important metrics such as QoS, robustness, fairness etc., and discuss the relationship between MAC protocols, network type and network mobility. Finally, we investigate a future research direction to solve a major problem, which is the network disruption and delay tolerance in IoT wireless mobile networks.