Telecommunications Research Articles

The Seven-State RF MEMS Miniaturized Broadband Reconfigurable Step Attenuator.

This paper presents a three-channel reconfigurable step attenuator based on radio frequency (RF) microelectromechanical system (MEMS) switches, in response to the current issues of high insertion loss and low attenuation accuracy of attenuators. The coplanar waveguide (CPW), cross-shaped power dividers, RF MEMS switches, and π-type attenuation resistor networks are designed as a basic unit of the attenuator. The attenuator implemented attenuation of 0~30 dB at 5 dB intervals in the frequency range of 1~25 GHz through two basic units. The results show that the insertion loss is less than 1.41 dB, the attenuation accuracy is better than 2.48 dB, and the geometric size is 2.4 mm × 4.0 mm × 0.7 mm. The attenuator can be applied to numerous fields such as radar, satellites, aerospace, electronic communication, and so on.

Tailoring iron hexadecafluorophthalocyanine/GO nanocomposite separators for polysulfide adsorption and enabling fast electrochemical kinetics of Li-S batteries

The cycling stability of lithium-sulfur batteries is significantly compromised by the shuttle effect. Herein, we employed a preformed process to successfully load spherical nanoparticles of Iron hexadecafluorophthalocyanine (FePcF16) with sizes between 10 and 20 nm onto oxidized graphene sheets. The FePcF16 spherical particles with lithium and sulfur-affinitive sites maximally expose catalytically active sites, facilitating effective adsorption and catalysis of polysulfides (LiPSs). Density-functional theory (DFT) calculations suggest that the electron-rich fluorine substituents enhance the conjugation effect of FePcF16, facilitating electronic communication between the catalyst and graphene oxide (GO), achieving precise modulation of the electronic structure of Fe-N4 active centers. The electrochemical analysis demonstrates that the nanostructured and Fe-N4 site-containing FePcF16 integrated with the robust two-dimensional graphene structure synergistically facilitates both redox reactions and lithium affinity effects. Consequently, in extended cycling tests at 2 C, the initial discharge-specific capacity reached 857.7 mAh g−1. After 500 cycles, the capacity remained at 737.7 mAh g−1, with a minimal capacity decay rate of only 0.028 % per cycle.

Review on techno-socio-economic studies of electric vehicles in electrical energy systems

Transportation electrification is a practical solution for the world's environmental, economic, and technical challenges. During the last decades, numerous studies have focused on electric vehicles (EVs) as one of the essential energy fields due to the growth rate of EV penetration into energy systems. Researchers have investigated different operation and long-term planning models of EV charging infrastructure and prediction and uncertainty-handling approaches for EV drivers’ behavior (i.e., the arrival/departure time to/from charging stations and the associated state-of-charge) as well as fixed and mobile charging stations (MCSs) and social equity access to EV charging infrastructure. This study provides a detailed analysis and discussion of the daily operation and long-term planning of EV charging stations with economic and technical aspects. Also, the prediction of EV drivers’ behavior and approaches to dealing with uncertain EV parameters are studied. Furthermore, the role of MCSs and social equity access in planning EVs’ charging station placement is investigated. The authors also assess the applications of permanent and MCSs and the social equity access to EV infrastructure. Finally, the current study discusses EVs future trends and their effect on electrical systems as future subjects of research studies.

Floor-Level Occupancy Estimation of a Multi-Story Building Using Coarse Wi-Fi Data

In recent years, there has been an extraordinary increase in wireless capable devices and network infrastructure, which spawned a corresponding rise in data produced from the interactions of these technologies. Mobile devices constantly roam, leading to a perpetual dialog between a mobile device and wireless access points. This dialogue generates a continuous stream of device-specific data, including but not limited to a device’s media access control address, time of access, and received signal strength. Given the knowledge of the access point’s location and received signal strength, it is possible to infer the position of user devices and estimate their mobility and occupancy. This article presents two methods for accurately measuring floor-level occupancy in a multi-story building at Texas State University using coarse Wi-Fi log data. The first method employs a static filter, while the second incorporates user-role data and user location to create a dynamic filter. Quantitative methods are used to evaluate these filters against field-collected reference data and existing internal people-counting sensors. Our results demonstrate that the dynamic filter, leveraging variable thresholds, provides a more accurate estimation of occupancy compared to the fixed 5-min static filter which consistently overestimated occupancy. This research sheds light on the potential of dynamic filters derived from user-role data for precise floor-level occupancy estimations, with implications for various applications.

Enhancing moisture-resistance in polyimide aerogels: A novel hydrophobic modification approach with ortho-positioned long-chain barriers

Polyimide (PI) aerogels possess significant potential for various applications due to their outstanding mechanics and thermal insulation. However, a major drawback of these aerogels is their susceptibility to moisture, which not only compromises their insulative performance but also leads to an increase in weight. To address this issue, we have developed a moisture-resistance technique by incorporating a long-chain hydrophobic barrier at the ortho position relative to the imide groups to enhance the moisture-resistance of the PI aerogels. This approach involved using a series of diamines with hydroxyl groups strategically located at the ortho position of imide groups as reactants. The resulting PI aerogels demonstrated a significant improvement in water resistance, reducing water-uptake to merely one-tenth of that recorded in unmodified samples. Furthermore, the effectiveness of this hydrophobic modification was validated through molecular dynamics simulations, which indicated a diffusion coefficient of 4.41 × 10−11 m2/s after modification. These findings represent a considerable advancement in developing effective methods for hydrophobic modification of PI aerogels, with potential applications in aerospace, electronic communications, and environmental protection.

Remote Exercise Engagement Among Individuals With Cardiovascular Disease

Purpose: To systematically review the literature regarding barriers and facilitators to remote exercise among individuals with cardiovascular diseases (CVD). Review Methods: Six databases were searched (inception—December 2023). Studies including barriers and facilitators for remote exercise reported by individuals living with CVD were considered. Quality was rated using the Mixed Methods Assessment Tool (MMAT). Results were synthesized following a thematic analysis approach. Characteristics of interventions were reported using the Template for Intervention Description and Replication (TIDieR). Summary: From an initial pool of 8543 records, 18 studies met the inclusion criteria. Among these, 13 were qualitative studies, with individual interviews being the most frequent data extraction method. Nine studies received 5/5 MMAT scores (ie, high quality). Twelve studies reported remote exercise interventions, mostly delivered within cardiac rehabilitation, by physiotherapists, nurses, and dietitians, predominantly via telephone calls or videoconferences, with only one study incorporating text messages. Five key themes influencing remote exercise interventions were identified: technology (encompassing access and literacy, self-monitoring/motivation, and security concerns), individual health considerations (health/personal aspects and coronavirus disease-2019), social factors (support from health care team and family/social support), environment (facilities), and logistical factors (time and displacement). Several themes served as both facilitators and barriers. Key insights for remote exercise interventions included mobile accessibility, interactive chat sessions, minimal click interactions, short sessions, personalized feedback, and flexible timing. Results emphasize the importance of promoting social interaction and support between participants and health care teams to mitigate barriers and enhance facilitators in remote exercise interventions for individuals with CVD.

E-Counseling : Mobile-Based Specialization System in Vocational Schools

Many students who will continue their studies to the high school level are confused about choosing a major. This is because most students do not understand the majors at the vocational level, making it difficult for students to enter majors according to the talents and interests of each student. This research is a continuation of previous research that has developed web-based applications. With a majors specialization system using the Inventory Personal Survey Test model system which was built as a majors selection system at the SMK level, mobile access is needed to make it easier for students to access this service via an application on a smartphone.This system is designed using Android Studio and the database creation using MYSQL. The results of the specialization that has been carried out show that the system can be used to conduct online counseling and makes it easier for counselors to collect and analyze counseling results.

Strong dipole-dipole interactions via enhanced light-matter coupling in composite nanofiber waveguides

We study the interaction of emitters with a composite waveguide formed from two parallel optical nanofibers in regimes of experimental importance for atomic gases or solid-state emitters. Using the exact dyadic Green's function we comprehensively investigate the coupling efficiency and the fiber-induced Lamb shift accounting for variations in emitter positions and fiber configurations. This reveals coupling efficiencies and Purcell factors that are enhanced considerably beyond those using a single fiber waveguide, and robustness in the figures of merit. We finally investigate resonant dipole-dipole interactions and the generation of entanglement between two emitters mediated through the composite waveguide under excitation. We show that the concurrence can be enhanced for two fiber systems, such that entanglement may be present even in cases where it is zero for a single fiber. All-fiber systems are simple in construction and benefit from a wealth of existing telecommunications technologies, while enjoying strong couplings to emitters and offering interesting light-matter functionalities specific to slot waveguides. Published by the American Physical Society 2024

A Multi-step Integrative Workflow Implementation to Improve Documentation of Point of Care Ultrasound in Medical Intensive Care Unit.

Point of care ultrasound (POCUS) provides quick bedside assessment for diagnosing and managing life-threatening conditions in critical care medicine. There has been increasing interest in developing infrastructure to archive images, record clinical interpretation, assess quality, and recoup revenue for POCUS. We present a simple workflow by systems integration of electronic medical record, ultrasound machines, picture archiving, and communication system to facilitate POCUS documentation and billing. We recorded a trend on the number of POCUS performed before and after introduction of the structured integration. We observed and recorded a linear increase over time post-intervention. Our innovative and integrated POCUS workflow is an effective way to document and bill POCUS.

A Framework for 5G Network Slicing Optimization using 2-Edge-Connected Subgraphs for Path Protection

Emerging telecommunications technologies require robust frameworks for efficient network slicing. We propose a network-slicing model that aims to optimize the deployment of virtual networks on a physical network topology. Our model ensures compliance with 5G requirements, incorporating latency and capacity constraints on virtual links. Selecting slices with cost and resource requirements on the computing nodes is optimized using a Knapsack problem with revenue maximization. We propose a path protection algorithm to deal with link failures by constructing a 2-edge-connected subgraph (or two link-disjoint Steiner trees) for each slice to provide both primary and backup paths. Simulation results include comparison with existing solutions by metrics such as latency, revenue, resource utilization, number of protected slices, and computation time, providing valuable insights for network planners operating in diverse and dynamic environments. Key contributions include efficient resource allocation using the Knapsack problem, enhanced network resilience via 2-edge-connected subgraphs for path protection, and realistic simulation experiments on SNDlib dataset topologies. The simulation results show that the proposed framework improves computational efficiency compared to the recent related solutions, particularly in large network topologies where k-connected function slicing (KC- FS) subgraph embeddings take approximately 3.5 times more computation time.

Electrobiofabrication of antibody sensor interfaces within a 3D printed device yield rapid and robust electrochemical measurements of titer and glycan structure.

We report the integration of 3D printing, electrobiofabrication, and protein engineering to create a device that enables near real-time analysis of monoclonal antibody (mAb) titer and quality. 3D printing was used to create the macroscale architecture that can control fluidic contact of a sample with multiple electrodes for replicate measurements. An analysis "chip" was configured as a "snap-in" module for connecting to a 3D printed housing containing fluidic and electronic communication systems. Electrobiofabrication was used to functionalize each electrode by the assembly of a hydrogel interface containing biomolecular recognition and capture proteins. Specifically, an electrochemical thiol oxidation is used to assemble a thiolated polyethylene glycol hydrogel, that in turn is covalently coupled to either a cysteine-tagged protein G that binds the antibody's Fc region or a lectin that binds the glycans of target mAb analytes. We first show the design, assembly, and testing of the hardware device. Then, we show the transition of a step-by-step sensing methodology (e.g., mix, incubate, wash, mix, incubate, wash, measure) into the current method where functionalization, antibody capture, and assessment are performed in situ and in parallel channels. Both titer and glycan analyses were found to be linear with antibody concentration (to 0.2 mg/L). We further found the interfaces could be reused with remarkably similar results. Because the interface assembly and use are simple, rapid, and robust, we suggest this assessment methodology will be widely applicable, including for other biomolecular process development and manufacturing environments.

Truthful mechanism for joint resource allocation and task offloading in mobile edge computing

In the context of mobile edge computing (MEC), the delay-sensitive tasks can achieve real-time data processing and analysis by offloading to the MEC servers. The objective is maximizing social welfare in an auction-based model. However, the distances between mobile devices and access points lead to differences in energy consumption. Unfortunately, existing works have not considered both maximizing social welfare and minimizing energy consumption. Motivated by this, we address the problem of joint resource allocation and task offloading in MEC, with heterogeneous MEC servers providing multiple types of resources for mobile devices (MDs) to perform tasks remotely. We split the problem into two sub-problems: winner determination and offloading decision. The first sub-problem determines winners granted the ability to offload tasks to maximize social welfare. The second sub-problem determines how to offload tasks among the MEC servers to minimize energy consumption. In the winner determination problem, we propose a truthful algorithm that drives the system into equilibrium. We then show the approximate ratios for single and multiple MEC servers. In the offloading decision problem, we propose an approximation algorithm. We then show it is a polynomial-time approximation scheme for a single MEC server. Experiment results show that our proposed mechanism finds high-quality solutions in changing mobile environments.

The use of mobile technology in higher education: implications for students and instructors

Mobile learning has become a prominent topic in educational settings today due to its significant developments in information and communication technology (ICT). This flexibility not only benefits student-teachers who can learn at their own pace and convenience but also empowers instructors to engage with their student-teachers more dynamically. Literature indicates that mobile learning encourages collaboration and active participation, fostering critical thinking skills and creating a more engaging learning experience. Despite the many advantages of integrating technology into the classroom, research indicates that most faculties higher education are resistant to incorporating technology into their activities since there are no institutional norms. The study aims at evaluating the use of mobile learning in higher education in Lesotho and the implications it has on both instructors and student-teachers when using mobile learning. The study adopted a systematic literature review to review the available research using an integrative method of studies conducted on mobile learning in higher education between 2013 and 2023. The study found that some instructors ban the use of mobile devices because they distract from teaching and learning. In addition, not all devices can handle the demands of remote learning. Student-teachers believe that mobile technology enhances communication with peers and instructors. Among other factors, limited Internet connectivity and funding are the most common inhibiting factors for instructors to adopt technology into the teaching and learning process. Other inhibiting factors are the high costs of mobile data access and smart mobile devices. The study recommends that ICT policy must be in place to manage and control mobile learning for effective adoption.

Role of Telemedicine and Telehealth in Public Healthcare Sector: A Narrative Review.

Clinicians, researchers in health services, and other experts have been investigating how to improve healthcare using advanced computer and telecommunication technology for more than 30 years. Adequate medical facilities are still lacking in many places of the world. In these kinds of situations, technology can be quite helpful in expanding healthcare access to rural locations and offering better care at a lower cost. The delivery of healthcare is changing dramatically because of telemedicine and telehealth, particularly in terms of improving access to care. This paper aims to provide an update on the history, background, applications, benefits, barriers, and challenges of these recent technologies. This review article also covers the healthcare conditions of rural as well as urban communities. Furthermore, the implications of technologies used and improvement in the health status of an individual are also discussed. During the COVID-19 epidemic, telehealth quickly gained popularity, bringing to light a number of issues. Effective primary medical networks are crucial, as the COVID-19 pandemichighlighted the need for improving public health responses during crises and revealed the existing fragmentation in healthcare delivery systems.

The Influence of Personal Selling and E-Marketing Marketing Communications of Dapurnya Ami UMKM on Consumer Brand Awareness in Banuhampu District, Agam Regency

This study aims to analyze the impact of marketing communication through personal selling on consumer brand awareness in Banuhampu District, Agam Regency. Additionally, this study evaluates the effect of electronic marketing communication (e-marketing) by the micro, small, and medium enterprises (MSME) Dapurnya Ami on consumer brand awareness in the area. The research method used is a quantitative approach conducted in Banuhampu District, which consists of seven villages. The sample was selected using proportionate stratified random sampling, purposive sampling, and accidental sampling techniques, with a total of 400 respondents. Data was collected through questionnaires distributed to consumers who are the target market of the MSME Dapurnya Ami. Data analysis was performed using various techniques, including single table analysis, cross-tabulation analysis, and hypothesis testing using Spearman's rho rank. The results show a positive correlation between the personal selling marketing communication of Dapurnya Ami and consumer brand awareness, indicated by r=0.001 and p=0.718. This suggests that the first hypothesis is accepted with a significance level of less than 0.05. Furthermore, the correlation between electronic marketing communication (e-marketing) of Dapurnya Ami and consumer brand awareness is also positive, with r=0.001 and p=0.836, indicating that the second hypothesis is accepted at the same significance level

Implementing geographic information systems in academic paper search: A framework and case study: GISAPS

The Geographic Information Systems Academic Publication Search (GISAPS) project pioneers the integration of spatial data into academic research through a novel online platform. Utilizing Web Map Service (WMS) and advanced search functionalities, GISAPS enables efficient access and analysis of georeferenced academic publications. This paper outlines the development and capabilities of GISAPS, including experimental WMS layer integration for enhanced data visualization. Key contributions include facilitating interdisciplinary research, improving spatial data accessibility, and promoting open science through its open-source framework. GISAPS's implications for academia and the research community are significant, offering new avenues for data-driven research and education. Future enhancements aim to incorporate real-time data feeds, advanced spatial analysis tools, and mobile accessibility, ensuring GISAPS remains at the forefront of GIS technology in academic settings.

Рoint for autonomous access to information in the electronic communications network

The article is devoted to the problem of determination of concept of “point for autonomous access to information in the electronic communications network”, introduced in everyday life by the Law of Ukraine “On electronic communications”. The specified point for such access is determined by the provider of electronic communications services and/or networks. It provides the possibility at the point for autonomous access to information to connect the technical means of a united system that is used by all statutory authorities to intercept/obtain information from electronic communications networks.

Biomimetic Electronic Communication of Iodine Doped Single-Atom Fe Site for Highly Active and Stable Dopamine Oxidation.

Rational design of highly active and stable catalysts for dopamine oxidation is still a great challenge. Herein, inspired by the catalytic pocket of natural enzymes, an iodine (I)-doped single Fe-site catalyst (I/FeSANC) is synthesized to mimic the catalytic center of heme enzymes in both geometrical and electronic structures, aiming to enhance dopamine (DA) oxidation. Experimental studies and theoretical calculations show that electronic communication between I and FeN5 effectively modulates the electronic structure of the active site, greatly optimizing the overlap of Fe 3d and O 2p orbitals, thereby enhancing OH adsorption. In addition, the electronic communication induced by iodine doping attenuates the attack of proton hydrogen on the active center, thereby enhancing the stability of I/FeSANC. This work provides new insights into the design of highly active and stable single-atom catalysts and enhances the understanding of catalytic mechanisms for DA oxidation at the atomic scale.

Near‐IR Emissive B–N Lewis Pair‐Functionalized Anthracenes via Selective LUMO Extension in Conjugated Dimer and Polymer

AbstractAcenes are attractive as building blocks for low gap organic materials with applications, for example, in organic light emitting diodes, solar cells, bioimaging and diagnostics. Previously, we have shown that modification of dipyridylanthracene via B–N Lewis pair fusion (BDPA) strongly redshifts the emission, while facilitating self‐sensitized reactivity toward O2 to reversibly generate the corresponding endoperoxides. Herein, we report on the further expansion of the π‐system of BDPA to a vinyl‐substituted monomer, vinylene‐bridged dimer, and a polymer with an average of 20 chromophores. The extension of π‐conjugation results in largely reduced band gaps of 1.8 eV for the dimer and 1.7 eV for the polymer, the latter giving rise to NIR emission with a maximum at 731 nm and an appreciable quantum yield of 7 %. Electrochemical and computational studies reveal efficient delocalization of the lowest unoccupied molecular orbital (LUMO) along the pyridyl‐anthracene‐pyridyl axis, which results in effective electronic communication between BDPA units, selectively lowers the LUMO, and ultimately narrows the band gap. Time‐resolved emission and transient absorption (TA) measurements offer insights into the pertinent photophysical processes. Extension of π‐conjugation also slows down the self‐sensitized formation of endoperoxides, while significantly accelerating the thermal release of singlet oxygen to regenerate the parent acenes.

The Impact of Technology on Testate Succession in South Africa

One advantage of the Fourth Industrial Revolution (4IR) era is the expedient exchange of goods and services via the Internet. The Electronic Communications and Transactions Act 25 of 2002 (ECTA) plays a critical role in regulating transactions and communications. However, ECTA excludes the provisions of the Wills Act 7 of 1953 from its ambit. Inevitably, this creates difficulties for the recognition and/or validity of electronic wills in South Africa. If technology is not acknowledged and applied in the space of testate succession, enhanced 4IR innovations threaten the Wills Act with obsolescence. We argue in this contribution that the rapid changes brought about by the 4IR and the exclusion of the Wills Act from the ambit of ECTA mean that testate succession is not responding to the current impact of technology on people. In this contribution we seek to create a synergy between the two statutes with a view to ensuring the relevance of the Wills Act in the 4IR. Ultimately we propose that both statutes be amended to cater for electronic wills. This can be achieved by combining the use of digital signatures and Public Key Infrastructure (PKI) technology. In reaching this conclusion we draw some lessons from the statutory changes in the United States of America (USA).