Including Signal Strength Research Articles

A novel artificial intelligence‐based antenna designing model for optimizing 5G mobile communication

AbstractAntenna designing involves the creation of devices to transmit or receive electromagnetic signals for various applications. It encompasses optimizing parameters such as size, shape, and frequency response to achieve desired performance characteristics, including signal strength, bandwidth, and efficiency, across diverse communication systems and frequencies. In this research, we intend to establish a novel artificial intelligence (AI)‐based antenna designing model for optimizing 5th generation (5G) mobile communication. We proposed Multi‐Objective Zebra Optimization (MOZO) to enhance 5G antenna design, aiming to minimize return loss () and maximize gain (G) concurrently. MOZO efficiently explores design space, offering Pareto‐optimal solutions that balance objectives. This approach ensures optimal antenna performance across the desired frequency range, advancing 5G communication efficiency. Our model enhances the functionality of a small, rectangular patch antenna designed for the 5G band, specifically operating at 30 GHz. Additionally, we conducted a comparative analysis between the performance of our optimized rectangular 5G antenna and several recently employed 5G‐millimeter wave (mmWave) antennas. This comparison sheds light on the efficacy and competitiveness of our optimized design within the 5G‐mmWave antenna landscape.

ПРОБЛЕМАТИКА ВИКОРИСТАННЯ БЕЗПРОВІДНИХ СЕНСОРНИХ МЕРЕЖ У ВІЙСЬКОВИХ ЦІЛЯХ

The article analyzes wireless sensor networks and identifies their advantages and disadvantages when used for military purposes. It is proposed to consider the architecture of the network based on a four-level model, which consists of the level of sensors, data channels, data processing and applications for creating various types of services. This creates a versatile and effective set of instruments for solving various tasks of special purpose for military purposes. The structure of a wireless sensor network for military use is considered in detail, taking into account the variety of sensors and their purpose. It also emphasizes the importance of compact and efficient sensors for military purposes, which contain means of digital information processing, receiver and transmitter, including measurements of electromagnetic waves, light, pressure, sound. The possibility of creating sensor fields based on unmanned aerial vehicles and their use for security and information gathering is noted. Data link parameters are detailed, including signal strength and signal level at the receiving end. The importance of space scanning radars for ensuring the safety of unmanned aerial vehicles in the conditions of wind speed and obstacles is noted. The article points out the problems of energy and computing resources when using sensors, in particular, the limitation of energy consumption and the length of the information transmission channel. Methods of rationalizing energy consumption by aggregating data and using clustering protocols are proposed. The main idea of the article is that the use of wireless sensor networks for military purposes requires attention to architectural details, sensor selection and power consumption optimization to ensure effective and reliable use of this system for its intended purpose, which will lead to the successful completion of the task by the unit. Therefore, the main advantages include the simplicity and flexibility of deploying sensor fields and the prompt receipt of information directly from the contact line, which is the key to a quick response to the enemy's actions.

MRI Applications and Research in Materials Science

Magnetic resonance imaging (MRI) has emerged as an indispensable noninvasive technique in materials research, offering comprehensive insights into the interior composition of diverse materials while preserving their integrity. The primary objective of this study is to investigate the utilization of magnetic resonance imaging to examine porous materials, biomaterials, polymers, and composites. This research aims to emphasize the benefits of MRI in the context of non-destructive testing and analysis. Magnetic resonance imaging (MRI) is advantageous due to its capacity to provide exceptional spatial resolution, facilitating the observation of minute structures inside porous materials. This capability significantly contributes to comprehending fluid dynamics and the distribution of pores within such materials. Within the field of biomaterials, magnetic resonance imaging plays a pivotal role in the examination of tissue interactions and drug delivery systems. This imaging technique provides high-resolution visualizations essential for the meticulous research of cellular-level phenomena. The significance of technology in the realm of polymers and composite materials is noteworthy, as it plays a crucial role in facilitating the identification of heterogeneities and the analysis of phase distribution. Nevertheless, various issues need improvement, including signal strength, resolution, and the reaction of materials to magnetic fields. It is advisable to employ advanced imaging techniques, implement signal improvements, and make material-specific adjustments to address these constraints.

A Unified Prediction Framework for Signal Maps: Not All Measurements are Created Equal

Signal maps are essential for the planning and operation of cellular networks. However, the measurements needed to create such maps are expensive, often biased, not always reflecting the performance metrics of interest, and posing privacy risks. In this paper, we develop a unified framework for predicting cellular performance maps from limited available measurements. Our framework builds on a state-of-the-art random-forest predictor, or any other base predictor. We propose and combine three mechanisms that deal with the fact that not all measurements are equally important for a particular prediction task. First, we design <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">quality-of-service functions (<inline-formula><tex-math notation="LaTeX">$Q$</tex-math></inline-formula>)</i> , including signal strength (RSRP) but also other metrics of interest to operators, such as number of bars, coverage (improving recall by 76%-92%) and call drop probability (reducing error by as much as 32%). By implicitly altering the loss function employed in learning, quality functions can also improve prediction for RSRP itself where it matters ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">e.g.</i> MSE reduction up to 27% in the low signal strength regime, where high accuracy is critical). Second, we introduce <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">weight functions</i> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$W$</tex-math></inline-formula> ) to specify the relative importance of prediction at different locations and other parts of the feature space. We propose re-weighting based on importance sampling to obtain unbiased estimators when the sampling and target distributions are different. This yields improvements up to 20% for targets based on spatially uniform loss or losses based on user population density. Third, we apply the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Data Shapley</i> framework for the first time in this context: to assign values ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\phi$</tex-math></inline-formula> ) to individual measurement points, which capture the importance of their contribution to the prediction task. This can improve prediction ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">e.g.</i> from 64% to 94% in recall for coverage loss) by removing points with negative values and storing only the remaining data points ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i.e.</i> as low as 30%), which also has the side-benefit of helping privacy. We evaluate our methods and demonstrate significant improvement in prediction performance, using several real-world datasets.

Ascending with ultrasound: telementored eFAST in flight—a feasibility study

PurposeTeleultrasound uses telecommunication technologies to transmit ultrasound images from a remote location to an expert who guides the acquisition of images and interprets them in real time. Multiple studies have demonstrated the feasibility of teleultrasound. However, its application during helicopter flight using long-term evolution (LTE) for streaming has not been studied. Therefore, we conducted a study to examine the feasibility of teleultrasound in an Airbus H145 helicopter.MethodsFour anesthesiologists and one military physician were recruited to perform telementored extended Focused Assessment with Sonography in Trauma (eFAST) during nine helicopter flights, each with a unique healthy volunteer. A radiologist was recruited as a remote expert, guiding the physicians in their examinations. The examining physicians reported the user experience of telementored eFAST on a questionnaire, while the remote expert rated the diagnostic quality of the images on a 1–5 Likert scale. In addition, we measured the duration of the examinations and key LTE network parameters including signal strength, quality, and continuity.ResultsThe images were rated to an average of 4.9 by the remote expert, corresponding to good diagnostic quality. The average duration of telementored eFAST was 05:54 min. LTE coverage was negatively affected by proximity to urban areas and ceased above 2000 ft altitude. Occasional audio problems were addressed by using the Voice over LTE network for communication. The examining physicians unanimously reported on the questionnaire that they would use telementored eFAST on patients.ConclusionTelementored eFAST is feasible in ambulance helicopters and can produce images of good diagnostic quality. However, it relies on stable LTE coverage, which is influenced by many factors, including the helicopter’s altitude and flight path. Furthermore, its benefit on patient outcomes remains to be proven.Graphical abstract

Transience of the Retinal Output Is Determined by a Great Variety of Circuit Elements.

Retinal ganglion cells (RGCs) encrypt stimulus features of the visual scene in action potentials and convey them toward higher visual centers in the brain. Although there are many visual features to encode, our recent understanding is that the ~46 different functional subtypes of RGCs in the retina share this task. In this scheme, each RGC subtype establishes a separate, parallel signaling route for a specific visual feature (e.g., contrast, the direction of motion, luminosity), through which information is conveyed. The efficiency of encoding depends on several factors, including signal strength, adaptational levels, and the actual efficacy of the underlying retinal microcircuits. Upon collecting inputs across their respective receptive field, RGCs perform further analysis (e.g., summation, subtraction, weighting) before they generate the final output spike train, which itself is characterized by multiple different features, such as the number of spikes, the inter-spike intervals, response delay, and the rundown time (transience) of the response. These specific kinetic features are essential for target postsynaptic neurons in the brain in order to effectively decode and interpret signals, thereby forming visual perception. We review recent knowledge regarding circuit elements of the mammalian retina that participate in shaping RGC response transience for optimal visual signaling.

High-Performance Sample Substrate of Gold Nanoparticle Multilayers for Surface-Assisted Laser Desorption/Ionization Mass Spectrometry.

The development of a sample substrate with superior performance for desorption and ionization of analyte is the key issue to ameliorate the quality of mass spectra for measurements of small molecules in surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). Herein, the homogeneous sample substrate of gold nanoparticle multilayers (AuNPs-ML) with hexagonal lattice was successfully prepared by self-assembly technique. With strong surface plasmon resonance absorption and superior photothermal effect, the sample substrate of AuNPs-ML exhibited high signal sensitivity and low background noise for the detection of model analyte of glucose without additional matrixes in SALDI-MS. Furthermore, compared to merchant matrixes of α-cyano-4-hydroxycinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB), the sample substrate of AuNPs-ML was demonstrated to ameliorate the quality of mass spectra, including signal strength, background interference and signal/noise (S/N) ratio. The sucrose and tryptophan were also measured to show the extensive applications of AuNPs-ML sample substrate for the detections of small molecules in SALDI-MS. Most importantly, the remarkable reproducibility of glucose mass spectra with relative signal of 7.3% was obtained by the use of AuNPs-ML sample substrate for SALDI-MS. The homogeneous sample substrate of AuNPs-ML greatly improved the quality of mass spectra because of its strong absorption of laser energy, low specific heat, high heat conductivity and extraordinary homogeneity. We believe that AuNPs-ML could be a practical sample substrate for small molecule detection in SALDI-MS.

A fast-responding semi-transparent pressure-sensitive paint based on through-hole anodized aluminum oxide membrane

A novel pressure-sensitive paint (PSP) has been developed which uses through-hole anodized aluminum oxide (AAO) membrane as the binder to achieve fast response (up to 80 kHz) and sufficient transparency in visible wavelength. The AAO membrane has well-organized nanostructure with through holes, which are prepared from typical AAO by first chemically removing the aluminum substrate and then applying a pore opening procedure by chemical etching. The geometry of AAO membrane, including thickness, pore size and porosity can be precisely defined by controlling the parameters of the anodization process. The pressure-sensitive paint was prepared by dipping the AAO membrane into the solution of a ruthenium-based luminophore. The sensing performance of PSP samples, including signal strength, pressure sensitivity and response time, was evaluated based on static and dynamic calibrations. The effects of pore size and porosity on PSP performance were investigated and their relations with the binder’s optical properties were discussed in detail. Unlike the conventional AA-PSP, the application of this semi-transparent membrane PSP (STM-PSP) is not limited to aluminum models. In addition, its high transparency allows back-illumination and back-imaging during applications if necessary, and makes it very suitable for developing multi-layer paint systems.

Fuzzy extended Kalman filter for dynamic mobile localization in urban area using wireless network

The problem of accurate mobile positioning in cellular network is very challenging and still subject to intensive research, especially given the uncertainty pervading the signal strength measurements. This paper advocates the use of fuzzy based reasoning in conjunction with Kalman filtering like approach in order to enhance the localization accuracy. The methodology uses TEMS Investigation software to retrieve network information including signal strength and cell-identities of various base transmitter stations (BTS). The distances from the mobile station (MS) to each BTS are therefore generated using Walfish-Ikigami radio propagation model. The performances of the established hybrid estimator −fuzzy extended Kalman filter (FEKF)- are compared with extended Kalman filter approach and fuzzy-control based approach. Both simulation and real-time testing results demonstrate the feasibility and superiority of the FEKF localization based approach.

Spectrum monitoring with unmanned aerial vehicle carrying a receiver based on the core technology of cognitive radio – A software-defined radio design

In this paper, we design and make a prototype of an aerial spectrum monitoring system that consists of a ground control station and a four-rotor unmanned aerial vehicle (UAV). This UAV carries a software-defined radio (SDR) receiver to perform spectrum monitoring tasks, including signal strength, frequency occupancy, and signal analysis. A light and low-cost SDR-based dongle consisting of RTL2832U chip and R820T tuner is employed as the monitoring receiver. A global positioning system and an electronic compass system are built on board to report the UAV’s position and direction. The open-source development platform GNU Radio is employed to design the radio monitoring system through the use of software-defined blocks. The proposed aerial monitoring system can detect radio signals in the frequency range of 25–1700 MHz that in practice covers the FM and DVB bands. With the prototype monitoring system, we have performed a few measurement tasks, including signal strength, waterfall display, and demodulation for identifying FM stations. Our proposed aerial monitoring system is more cost-effective than land-vehicle monitoring stations because of its much more flexible implementation.

Telecommunications Performance During Entry, Descent, and Landing of the Mars Science Laboratory

This paper discusses the Mars Science Laboratory telecommunications configuration for ultrahigh-frequency relay data and direct-to-Earth X-band semaphore tones during entry, descent, and landing, as well as the configuration of the Mars Reconnaissance orbiter, Mars Odyssey orbiter, and the Deep Space Network. Actual link performance will be compared with a priori predictions, including signal strength, Doppler shift, plasma blackout, and the range and angles between the Mars Science Laboratory and orbiting relay assets. Predictions were generated using telecom link budgets and models developed at the Jet Propulsion Laboratory. These data were also integrated into the mission’s primary end-to-end entry, descent, and landing performance simulation, Program to Optimize Simulated Trajectories II, which enabled telecom predictions based on Monte Carlo results of entry, descent, and landing simulations.

Inkjet printed colloidal photonic crystal microdot with fast response induced by hydrophobic transition of poly(N-isopropyl acrylamide)

This paper presents rapid response colloidal photonic crystal (PC) microdots fabricated by inkjet printing, which demonstrate a fastest response of ca. 1.2 s to water vapor. This remarkable improvement of response rate could be attributed to the combined effects of the intrinsic small size of the inkjet microdots and the hydrophobic transition of poly(N-isopropyl acrylamide) (PNIPAm) above its lower critical solution temperature (LCST). The reversible phase transition of PNIPAm modifies the hydrophilic–hydrophobic balance of the polymer interface, which leads to the modulation of wetting states/adhesion properties of adsorbed water on the polymer segments, resulting in the remarkable improvement of response rate. Moreover, the optimal response performance (including signal strength and response sensitivity) of the printed PC microdot is achieved by the coordination of a well-ordered latex assembly and full infiltration of the responsive polymer in the latex interstices. This simple fabrication of functional colloidal PC microdots opens new avenues for the construction of advanced microanalysis and microsensing devices. In addition, improving the response rate by the phase transition of the polymer segments is promising for the creation of high-performance sensors.

Signal strength based link sensing for mobile ad-hoc networks

Mobility causes frequent link failures in ad-hoc networks. This results in a severe degradation of performance specially in case of high mobility of nodes. This is because the routing protocols for ad-hoc networks are not equipped to handle high mobility. In this paper, we have presented a new link management algorithm to locally manage links. This new mechanism is based on signal strength measurements. Researchers over the years have presented approaches which use signal strength measurements but their focus has been on re-active protocols while our algorithm is aimed at pro-active protocols. Pro-active protocols are used since they provide greater flexibility to take advantage of the mesh configuration. We develop the hysteresis mechanism provided by OLSR, based on hello packets, to include signal strength measurements. The mechanism in OLSR uses Hello packets received/lost to decide to establish link or not. The problem with this approach arises when there is high mobility in which case the time to break the link and use a new path becomes significant. To overcome this, we propose to use signal strength to determine if the link-quality is improving or deteriorating. This combination of the two mechanisms, makes the link management more robust and also helps in anticipating link breakages thereby greatly improving performance.

MO‐D‐304A‐04: Cone‐Beam CT Lag Correction Models: Effect of Optimized Parameter Selection

Purpose: Image lag degrades image quality in cone‐beam CT (CBCT). This work investigates the magnitude of lag artifacts and develops an optimized lag coefficient model to correct lag artifacts in CBCT images to improve guidance of radiotherapy(Elekta Synergy XVI). Method and Materials: Image lag and its relationship with various parameters including signal strength and frame number was investigated for a PerkinElmer (RID1640) flat‐panel imager. A new lag correction model referred to as the “average‐optimized lag coefficients model” (ALCM) is developed to correct CBCT images. The optimization of lag coefficients was purely based on quantitative improvement in lag corrected CBCT images. Each projection was corrected for lag effects by subtracting previous projections weighted by the magnitude of image lag. The quantification/measurement of lag coefficients for four different techniques including RESF(Rising‐Edge‐Step‐Response‐Function), IRF(Impulse‐Response‐Function), FESF(Rising‐Edge‐Step‐Response‐Function) and ALCM(Average‐Optimized‐Lag‐Coefficient‐Model) for the same detector. These models are applied/tested in correcting CBCT images of two customs made phantoms referred to as Ellipse_Lucite (MTF and skinline) and Irregular_Lucite (CNR). Results: Experimental results illustrate that the nth frame lag of the imager for all four model shows different behavior with frame number. The RCTN at 5 mm depth after lag correction was measured in CT♯ as 4.38±1.01, 10.51±1.35, 8.35±1.31 and 2.121±0.81 for RESF, IRF, FESF and ALCM, respectively. Similarly, the spatial frequency/cm for MTF(50%) before and after lag correction for RESF, IRF, FESF and ALCM was measured as 6.3±0.24, 5.7±0.23, 5.8±0.22 and 6.5±0.24, respectively. CNR for ALCMwas almost two times higher than nominal. Conclusion: Lag artifacts can be reduced by correction of the projection images using the ALCM model. Lag correction is most important for high contrast and irregularly shaped objects. The performance metrics suggest a significant improvement for RESF and ALCM and strongly support their use for lag correction in cone‐beam CT.Research sponsored by Elekta.

SU‐FF‐I‐21: An Empirical Method for Lag Correction in Cone‐Beam CT

Purpose: Image lag degrades image quality in cone‐beam CT (CBCT), resulting in contrast reduction, lack of CT number accuracy and uniformity, and skin‐line artifacts. This work investigates the magnitude of such degradation and demonstrates a lag correction method based on measured data from a system for CBCT guidance of radiotherapy (Elekta Synergy XVI). Method and Materials: Image lag and its relationship with various parameters including signal strength, photon energy and frame number was investigated for a PerkinElmer (RID1640) flat‐panel imager. An empirical lag correction based on measurements of image lag was developed to manage lag artifacts. The CatPhan phantom within an irregular body annulus was used to demonstrate the magnitude of artifacts before and after correction. Each projection was corrected for lag effects by subtracting previous projections weighted by the magnitude of image lag. The subtraction of previous projections was limited up to 51 frames due to uncorrelated noise. The reconstructed images before and after correction were analyzed for skin‐line and radar type artifacts, CT♯ accuracy, uniformity and contrast of several inserts. Reconstructed images were transformed into polar coordinates for analysis. Results: Experimental results illustrate that the first frame lag of the imager is less than 2.3%, and is independent of the kVp value (70–120 kV) and pixel saturation (20–80%). Lag correction improves the skin‐line artifact and reduces radar artifact by 40%. Contrast enhances by 20% and improves the CT♯ accuracy for water by 2.5%. It improves water uniformity by 5% compared to the nominal images. Conclusion: Lag artifacts can be reduced by correction of the projection images. Lag correction is most important for high contrast and irregularly shaped objects. For a circularly shaped object, lag correction does not improve the skin‐line artifact but can be useful for soft‐tissue visibility adjacent to bony anatomy.This research is sponsored by Elekta.

Target visibility measurements: Three‐dimensional laser vibrometer

A three‐dimensional laser vibrometer has been constructed, tested, and used for simultaneous measurements of three components of induced transient motion of target surfaces. Such target surfaces need to satisfy a wider range of optical scatter requirements than those for one‐dimensional motion measurement. This presentation outlines some of these requirements for high signal visibility and describes several interesting target surfaces under test, including stainless steel, paints, polymer, and retroreflecting preparations. Data presented for these surfaces include signal strength (visibility), repeatability, stability, and effects of surface roughening and a water environment. Results are interpreted in terms of simple physical models where possible to better understand potential specialized target fabrication for improving future vibrometer measurement system performance.

MR evaluation of renal space-occupying lesions: Diagnostic criteria

In order to assess the ability of magnetic resonance (MR) imaging to distinguish simple renal cysts from renal tumors, images from 53 patients with 74 lesions were reviewed. MR image characteristics, including signal strength and homogeneity for each lesion, were evaluated and compared with the final diagnoses. There were 53 cysts and 21 tumors. For 56 lesions (76%), MR allowed accurate diagnosis; on T1-weighted images, homogeneous low-intensity lesions were always cysts and inhomogeneous medium- or high-intensity lesions were always tumors. The remaining 18 lesions (24%) could not be distinguished, and T2-weighted images failed to improve differential diagnostic ability. In our experience, MR imaging allows differentiation of renal cysts and tumors less frequently than does computed tomography (CT) or ultrasound (US). MR criteria for simple renal cysts and tumors are offered, with the understanding that modification may be necessary as experience with these lesions increases.

MR EVALUATION OF RENAL SPACE-OCCUPYING LESIONS: DIAGNOSTIC CRITERIA

In order to assess the ability of magnetic resonance (MR) imaging to distinguish simple renal cysts from renal tumors, images from 53 patients with 74 lesions were reviewed. MR image characteristics, including signal strength and homogeneity for each lesion, were evaluated and compared with the final diagnoses. There were 53 cysts and 21 tumors. For 56 lesions (76%), MR allowed accurate diagnosis; on T1-weighted images, homogeneous low-intensity lesions were always cysts and inhomogeneous medium- or high-intensity lesions were always tumors. The remaining 18 lesions (24%) could not be distinguished, and T2-weighted images failed to improve differential diagnostic ability. In our experience, MR imaging allows differentiation of renal cysts and tumors less frequently than does computed tomography (CT) or ultrasound (US). MR criteria for simple renal cysts and tumors are offered, with the understanding that modification may be necessary as experience with these lesions increases.