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Imaging of gases is a major challenge for any modality including MRI. NMR and MRI signals are directly proportional to the nuclear spin density and the degree of alignment of nuclear spins with applied static magnetic field, which is called nuclear spin polarization. The level of nuclear spin polarization is typically very low, i.e., one hundred thousandth of the potential maximum at 1.5 T and a physiologically relevant temperature. As a result, MRI typically focusses on imaging highly concentrated tissue water. Hyperpolarization methods transiently increases nuclear spin polarizations up to unity, yielding corresponding gains in MRI signal level of several orders of magnitude that enable the 3D imaging of dilute biomolecules including gases. Parahydrogen-induced polarization is a fast, highly scalable, and low-cost hyperpolarization technique. The focus of this Minireview is to highlight selected advances in the field of parahydrogen-induced polarization for the production of hyperpolarized compounds, which can be potentially employed as inhalable contrast agents.

The paper considers typical designs of surveillance devices for acousto-optic leakage channels. To assess the quality of the channel, it is proposed to use the criterion of the minimum permissible power of the information signal at the input. To analyze the processes that occur while the probe signal propagates to the pick-up point and back to the surveillance device, the authors propose a detailed model of the information leakage channel with the indication of the main transformations of the intercepted signal. The paper presents the main criteria for the correct reception of an optical signal and for the extraction of acoustic information from it. A number of assumptions are formulated regarding the practical implementation of the optoelectric converter of the receiving device, and a simplified equivalent functional model of the optical information transmission channel is developed. The authors also propose a method for calculating the voltage at the load of the photodiode depending on the distance to the vibrating surface, power and the coefficient of directional action of the transmitter emitter. The numerical dependences of the voltage at the load of the photodiode on the distance are obtained for specific numerical values of the load resistance, supply voltage, directional coefficient of the emitter and receiver, as well as the geometric dimensions of the information interception zone. A simplified technique is developed that allows determining the signal level at the input of the sensitive element of a photodetector under idealized conditions, if the minimum permissible optical signal power condition is met and there is no background illumination of the photodetector of the surveillance device.

This paper proposes for the development of a path-loss model to improve the accuracy in predicting the signal level in office locations for the reception of FM broadcast. Identifying the factors that affect the signal level and eventually developing a model to predict the signal inside buildings will guide engineers in designing a broadcast system. A properly designed broadcast system will ensure optimum signal penetration in these listening areas. Further, the developed model can find applications in policy-making on the regulation of FM broadcast stations, both for analog and digital radio systems. Signal level measurements from three FM broadcast stations have been made inside eight office rooms in De La Salle University-Manila. With the three stations utilizing circularly polarized transmitting antennas, the measurements aim to determine the signal levels of the horizontal and vertical components of the received signal. These measured levels are used to determine the effects on the magnitude of the received signal of some factors, such as signal frequency and polarization, receiving antenna height, walls, transmitter-receiver distance, etc. Since the developed model is based on the measured signal levels in the actual office environment, its accuracy is then better than any of the existing models earlier developed.

Graphene-based biosensors can be produced in a scalable manner at reasonable cost, and they show significant promise for sensitive detection of small molecules and biomarkers such as proteins, single strand nucleic acids, and drug targets. Here, we describe an approach that enables a limit of detection of ~1 aM for a ssDNA target without amplification. We also show that a sensor based on a short (20mer) probe complementary to a portion of a longer (100mer) target provides enhanced sensitivity and saturation signal level. Finally, we show that graphene-based DNA biosensors can be repeatedly recycled with consistent sensor responses by melting off bound target strands. These results show the potential utility of this technology in nucleic acid detection for disease diagnostics.

Under consideration is the inverse problem of controlling the deposition of a multilayer coating using optical monitoring. Some new nonlocal algorithm is introduced for data analysis. Using the simulation of deposition process, the errors are compared of the proposed nonlocal algorithm and the traditional local algorithm. Some scheme of correction of the levels of the deposition process termination is considered that allows us to improve the accuracy of deposition monitoring. We show that the nonlocal algorithm is more efficient both for the deposition without correction of the signal level for the deposition interruption and with correction of this level.

Full-duplex (FD) transceivers suffer from inevitable self-interference (SI) from the transceiver’s own transmitted signal which is 60–100 dB stronger than the desired signal of interest. A major FD transceiver design challenge is the SI cancellation. The techniques used for SI cancellation should be able to mitigate the SI signal below the desired signal level at the receiver and ideally below the receiver’s sensitivity level. In this letter, an SI cancellation technique using extended Kalman filter is presented. Performance evaluation of the proposed techniques is carried out on the basis of SINR at the receiver. The proposed technique provides an attractive analogue/RF SI cancellation and an SINR improvement in 90 dB.

Subject and Purpose. Answering the need for powerful high-frequency signal generation and desired radar range provision, pulsed magnetrons hold the current lead as part of radar transmitters. Yet there are some disadvantages, such as significant noise level and technological difficulties concerning the frequency tuning implementation. In this connection, a direct control of the pulsed magnetron frequency with the use of the Automatic Frequency Control (AFC) causes problems. And in the receiver, the AFC of the heterodyne rather than of the magnetron is more frequently used. The heterodyne frequency is maintained at such a level that the receiver is always tuned to the frequency of signal to receive. For various signal generation arrangements, the existing methods of frequency tuning with a frequency discriminator will be analyzed towards the following development of a principal electrical schematic diagram with gaining the operating characteristics of the frequency discriminator prototype on that diagram basis. Methods and methodology. The electrical schematic diagram is developed in terms of intuitive approach and analyzed by the mathematical modeling method. Results. The functional scheme of a frequency discriminator combining advantages of both single-cycle circuit (design simplicity and ease of tuning) and two-cycle circuit (null output voltage at a given frequency of the input signal and compensation possibilities as to the input voltage amplitude varying and interference) has been developed. The principal electrical schematic diagram of this new frequency discriminator has been reported together with the measured amplitude and frequency characteristics, dynamical figures, etc. Conclusions. The novelty of the proposed concept of a heterodyne AFC system built around a frequency discriminator has been confirmed. Its advantages over the known solutions have been shown.

Recent computing and hardware advances have resulted in the proliferation of autonomous embedded networked devices in modern homes and industrial production systems which comprises several IoT devices in different physical environments. In this work, we take the first step towards investigating the feasibility of IoT devices fingerprinting by analyzing their WiFi packet signal level information along with MAC level information. We consider a scenario where a commodity WiFi Access Point is configured to passively listen to the WiFi packets and extract not only their MAC layer information but also the signal level information. Using such information, our results demonstrate that the adversary can successfully build fingerprinting profiles for different IoT devices.

Recent years have witnessed an unexpected and astonishing rise of AI-synthesized fake media (GAN synthesized faces, face-swap videos, and style transferred audios, commonly known as the DeepFakes), thanks to the rapid advancement of technology and the omnipresence of social media. Together with other forms of online disinformation, the AI-synthesized fake media are eroding our trust in online information and have already caused real damage. It is thus important to develop countermeasures to limit the negative impacts of AI-synthesized fake media. In this presentation, I will first provide a high level overview of the AI-synthesized fake media and their potential negative social impacts. I will then highlight recent technical developments to fight AI-synthesized fake media, including the signal level methods [1], and physical/physiological based methods [2,3], as well as our effort of making large datasets [4] and open-platforms for DeepFake detection [5]. I will also point out some current challenges, and discuss the future of AI-synthesized fake media and their counter technology.

In the research community of Internet of underground things (IOUT) and smart farming, soil properties estimation presents a challenging task, especially the moisture content. Here, a small printed antenna, as a version of inverted F monopole modeled in a form of letters, is proposed for soil sensing. It is shown that a simple tuning of the proposed antenna underground can provide higher signal level and its difference between dry and moistened soil antenna environment.

At suprathreshold sound levels, interactions between masking noise and sound signals are liable to compressive nonlinearity in the auditory system. The compressive nonlinearity is a property of the "active" cochlear mechanism. It is not known whether this mechanism is capable to function at frequencies close to or above 100 kHz that are available to odontocetes (toothed whales, dolphins, and porpoises). This question may be answered by the use of the frequency-specific masking. Auditory evoked potentials to sound stimuli in a bottlenose dolphin, Tursiops truncatus, were recorded in the presence of simultaneous maskers. Stimulus frequencies were 45, 64, or 90 kHz. Maskers were on-frequency bandlimited noise or low-frequency noise of frequencies 0.25-1 oct below the stimulus frequency. The stimuli provoked responses as a series of brain-potential waves following the pip-train rate. For the on-frequency masker, the masker level at threshold dependence on the signal level was 1.1 dB/dB. For maskers of 1 oct below the stimulus, the dependence was 0.53-0.57 dB/dB. The data considered evidence for the compressive nonlinearity of responses to stimuli, and therefore, are indicative of the functioning of the active mechanism at frequencies up to 90 kHz.

Dynamically shaping protein assemblies into desired nanostructures is a grand challenge. Here we present a new strategy that exploits protein allosteric effect to flexibly manipulate protein amphiphilic self-assembly. This allosteric regulation emphasizes that a huge deformation of protein assemblies is stemmed from a tiny protein conformational switch. Using adenylate kinase as an allosteric protein, adenylate kinase (AKe)-based protein amphiphiles can transform their assembling architectures between 1D nanofilament and 2D crystalline nanosheet due to AKe conformation folding and unfolding. Control over the allosteric degree by tuning the allosteric signal level allows us to mold protein nanostructures in various morphologies and dimensionalities. This method is universal and would open a new avenue to construct dynamic protein structural materials.

The effects of adapting sounds (pip trains or pure tones) on auditory evoked potentials (the rate following response, RFR) were investigated in a beluga whale. During RFR acquisition, adapting signals lasting 128 ms each were alternated with test signals lasting 16 ms each; the test signal levels varied randomly. Adapting signals were trains of cosine-enveloped tone pips or pure tones. Pip rate varied with the envelope cosine cycle maintained at 0.125 of pip intervals and the cosine rise-fall time maintained at 0.0625 of pip intervals. Adapting signals shifted the amplitude-level function upward compared to the baseline (no adapting signal) function. The higher the adapting signal level was, the bigger the shift in the amplitude-level function was. The slower the pips were in the adapting signal, the smaller the adaptation effect was. A train of pips with a 0.0625-ms rise-fall time and 125 dB SPL shifted the function by 35-40 dB, whereas a train of pips with a 1-ms rise-fall time or a pure tone with the same SPL shifted the function by approximately 15 dB. The difference between the "fast" and "slow" adapting signals is supposed to be associated with their abilities to stimulate the auditory system in odontocetes.

In this paper, we propose an improved closed form large injection perturbation analytical model for accurately studying the phase-locking dynamics and frequency pulling phenomenon in optoelectronic oscillator (OEO) for radio frequency (RF) signal injection. We provide formulas for the lock-range, and the beat frequency, which are general and accurate in estimating the degree of phase perturbation in unlocked-driven OEO under weak as well as strong injection signal level. We also give closed form expressions for the spectral components of the unlocked-driven oscillator. It is shown that our model is capable of predicting the phase-locking and estimating the frequency pulling of RF driven OEO under weak and strong injection signal level. The accuracy of the proposed model is verified by the simulations.

Global Navigation Satellite Systems (GNSSs) are ubiquitously relied upon for positioning and timing. Detection and prevention of attacks against GNSS have been researched over the last decades, but many of these attacks and countermeasures were evaluated based on simulation. This work contributes to the experimental investigation of GNSS vulnerabilities, implementing a relay/replay attack with off-the-shelf hardware. Operating at the signal level, this attack type is not hindered by cryptographically protected transmissions, such as Galileo's Open Service Navigation Message Authentication (OS-NMA). The attack we investigate involves two colluding adversaries, relaying signals over large distances, to effectively spoof a GNSS receiver. We demonstrate the attack using off-the-shelf hardware, we investigate the requirements for such successful colluding attacks, and how they can be enhanced, e.g., allowing for finer adversarial control over the victim receiver.

Metastasis is the primary reason for treatment failure and cancer-related deaths. Hence forecasting the disease in its primary state can advance the prognosis. However, existing techniques fail to reveal the tumor heterogeneity or its evolutionary cascades; hence they are not feasible to predict the onset of metastatic cancer. The key to metastasis originates from the primary tumor cells, evolving by inheriting multistep sequential cue signals. We have identified this specific population, termed metastatic cancer stem-like cells (MCSCs), to foresee cancer's ability to metastasize. An invasive property renders MCSCs nonadherent, summoning a powerful technique to forecast metastasis. Thus, we have generated an ultrasensitive 3D-metasensor to efficiently capture and investigate MCSCs and magnify the vital premetastatic signals from a single cell. We developed 3D-metasensor by an ultrafast laser ionization technique, consisting of self-assembled three-dimensionally organized nanoprobes incorporated with dopant functionalities. This distinct methodology establishes attachment with nonadherent MCSCs, elevates Raman activity, and enables probing of consequent signals (metabolic, proliferation, and metastatic) specifically altered in MCSCs. Extensive analysis using prediction tools-the area under the curve (AUC) and principal component analysis (PCA)-revealed high sensitivity (100%) and specificity (80%) to differentiate the MCSCs from other populations. Further, investigation reveals that the cue signal level from MCSCs of primary cancer is analogous to MCSCs from higher-level tumors, disclosing the relative dependence to estimate the primary tumor's capacity to metastasize. Multiple spectrum evaluation using the metasensor pinpoint the dynamic cues in MCSCs predict the onset of metastasis; thus, exploring these metastasis hallmarks can enhance prognosis and revolutionize therapy strategies.

The well-known thermoluminescent material LiF:Mg,Cu,P (MCP) was previously shown to emit significant optically stimulated luminescence (OSL). In this paper, we investigate the rate of OSL recombination processes in MCP, expressed as effective lifetimes, using time-correlated single photon counting, in this context often referred to as time-resolved pulsed OSL. The recombination luminescence fell into two categories: (i) a dominant fast decaying luminescence described by the two lifetimes τ 1 = 22.8 ( 1.7 ) μs and τ 2 = 60 ( 5 ) μs and (ii) a slowly decaying part with indeterminate decay profile at a comparatively low signal level (we denote this as “offset luminescence”). The fast recombination channels corresponding to τ 1 and τ 2 are responsible for 71 % of the total luminescence observed during test measurements. The luminescence associated with τ 1 dominate the beginning of an experiment, but is depleted much quicker than the luminescence associated with τ 2 . We show that all recombination channels show similar response to preheating of the sample, which suggests that they are associated with the same trapping centers.

Об’єктом дослідження є процеси формування електромагнітної обстановки приміщень з радіоелектронною апаратурою різного призначення. Предмет дослідження: математичні моделі для визначення електромагнітної обстановки. Метою роботи є забезпечення електромагнітної сумісності, тобто штатне функціонування апаратури розумного будинку . Методом дослідження є аналіз характеристик обладнання розумних будинків та використання програми для досягнення сприйнятливої електромагнітної обстановки у приміщенні. У результаті виконання дипломної роботи проаналізовано проблеми з обладнанням та забезпеченням електромагнітної сумісності в Інтернеті речей. Описані SaaS платформи, безпроводові технології. Розглянута рекомендована програма для досягнення ЕМО. Галузь застосування: компанії, що надають послуги Інтернет та налаштування маршрутизаторів. The object of study are mathematical models of the electromagnetic environment of the premises. The aim of the work is to achieve EMO in a brick house with an office. The research method is a theoretical study of the construction of smart homes and the use of the program to achieve EMO indoors. As a result of the thesis work, problems with equipment and EMC in the Internet of Things were analyzed, SaaS platforms and wireless technologies were considered. In addition, the program for achieving EMO was reviewed. Field of application: companies that provide Internet services and router settings.

In recent years, the evolvement of mobile devices which perform sophisticated functions have been on the rise. Mobile applications which solved engineering challenges are now available due to the high computational capabilities, large random access memory and storage location of the mobile devices. An Android application called signal detect, which measures network signal strength value from 2G-4G received on an android mobile device has been developed using android app development environment called Android studio. Validation becomes necessary because different readings were obtained on smartphones with different specifications. Two validation techniques were used to validate the data obtained. To know the efficiency of the application; a field strength meter was used to compare the readings received on the mobile device with the meter. It was observed that there is a time lag on the received values of the mobile device to the field strength meter. Therefore, a moving average technique was used to correlate the two data which increased the correlation coefficient to about 0.85.

Estimating accurately the signal levels that a user equipment experiences along a movement route is a key step in the process of providing and guaranteeing the required service quality. Obtaining accurate location-specific estimations of the signal level is challenging due to its random variations. In this paper we investigate the use of aggregated measurements from multiple User Equipments (UE) to estimate the serving Reference Signal Received Power (RSRP) that the user will experience along a route. We use LTE measurements obtained in rural and urban areas from drive tests and analyze the dependence of data variability. Results show that the accuracy of data-driven estimation is impacted significantly by the variability in the underlying data due to UE orientation, UE characteristics and their immediate environment. With compensation for a subset of these effects the standard deviation of the estimation error can be lowered from an overall approximately 8 dB down to 4dB.

The requirements for a wide range of electroacoustic devices: telephones, microphones, loudspeakers, sound recorders and repeaters, as well as amplifiers, radio and television programs are largely determined by the human hearing organ. The first feature of the hearing organ is the presence of a sound hearing limit at different pitches

A structure that consists of a λ/4 stepped-impedance microstrip resonator is proposed as an instrument for the investigation of nonlinear effects in thin magnetic films and also can be used as a microwave frequency doubler. A conversion efficiency of 0.65% is observed at a one-layer 100 nm Ni80Fe20 thin film at an input signal level of 4.6 W for a 1 GHz probe signal. The maximum measured conversion efficiency (1% at 1 GHz) was achieved for the 9-layer Ni80Fe20 film where 150 nm magnetic layers were separated by SiO2 layers.

This article examines the issues and problems of building and organizing a wireless network with a high density of clients. Nowadays, when the number of devices that one person has with him at a time is constantly growing, the load on the network equipment used by the Wi-Fi network also increases. Already at the design stage, it is important to take into account the fact that the projected network will have a segment where a large share of traffic will be concentrated. The article describes the process of calculating a network at the design stage, which helps to calculate the optimal distance to the access point at which the loss of signal power from the point will be minimal. For the calculation, the network was presented as a system of clusters, where an access point to a wireless network was taken as the center of attraction (cluster), and user devices were taken as objects of attraction that form a group around the cluster. The article shows graphs of the dependence: delay time on the number of subscribers at the access point, signal level depending on the distance to the cluster. And also, a graph of the distribution of the free loss factor in space and a graph of the optimal ratio of gain and free loss factor.

The services of Telkomsel celullar have not evenly spread throughout the entire region of Lembata Regency. Furthermore the quality of the coverage area of the service that has not maximized results in frequent failed calls or disconnected communications. This research aims to determine location of signal ditribution and quality in each Telkomsel BTS in order to improve and expand the quality of service. This measurement used the drive test method with the G-Net Track application to measure receive signal level (Rxlev). The drive test based on four directions of each BTS with 3 km distance in each direction. The result then analyzed and mapped with Google Earth. The result is not absolute because the antenna sensitivity of the receiver signal varies based on the type of handphone. The result of 800 measurement points for RxLev in Lembata county region show that 327 points or 40.875% is very good category, 170 points or 21.25% is good category, 147 point or 18.375% is medium category, 110 point or 13.75% is bad category, and 46 point or 5.75% is very bad category. It is only ± 36,98% of the total area of Lembata Regency has coverage by Telkomsel services.

Accurate and timely precipitation forecasts are crucial for early warning. Rainfall nowcasting, the process of statistically extrapolating recent rainfall observations, is increasingly used for short-term forecasting. Nowcasts are generally constructed with high-resolution radar observations. As a proof of concept, we construct nowcasts with country-wide rainfall maps estimated from signal level data of commercial microwave links (CMLs) for 12 summer days in the Netherlands. CML nowcasts compare well to radar rainfall nowcasts. Provided well-calibrated CML rainfall estimates are employed, CML nowcasts can outperform unadjusted real-time radar nowcasts for high rainfall rates, which are underestimated as compared to a reference. Care should be taken with the sensitivity of the advection field derivation to areas with low CML coverage and the inherent measurement scale of CML data, which can be larger than the application scale. We see potential for rainfall nowcasting with CML data, for example, in regions where weather radars are absent.

Purpose To overcome methodology limitations for studying auditory development in young children, we have recently developed an observer-based procedure that uses a conditioned, play-based, motor response (see Bonino & Leibold, 2017). The purpose of this article was to examine interrater reliability for the method. Method Video recordings of test sessions of 2- to 4-year-old children ( n = 17) were examined. Detection of a 1000-Hz warble tone was measured with the Play Observer-Based, Two-Interval (PlayO2I) method in each of two conditions: for a fixed intensity level (30 dB SPL) or for a variable intensity level signal (0–30 dB SPL). All test sessions were scored independently by three observers (one real-time, two offline). Observer consensus was evaluated with Fleiss' kappa statistic. To determine if summary data were similar across the observers of each test session, the proportion of correct trials (fixed-level condition) or threshold (variable-level condition) were computed. Results The strength of observer consensus was classified as “almost perfect” and “substantial” for the fixed-level and variable-level conditions, respectively. Follow-up analysis of the variable-level data indicated that differences in observer consensus were seen based on the signal level, the type of response behavior provided by the child, and the confidence level of the real-time observer. Resulting summary data were similar across the three observers of each test session: no significant differences for estimates of the proportion of correct trials or threshold. Conclusions Results from this study confirm strong interrater reliability for the method. The PlayO2I method is a powerful tool for measuring detection and discrimination abilities in young children. Supplemental Material https://doi.org/10.23641/asha.12978197

A dominant impediment in magnetic recording is pattern-dependent media noise, and its impact will only grow more severe as areal densities increase. The pattern-dependent noise prediction (PDNP) algorithm [1] [2], widely used as an effective strategy for mitigating pattern-dependent media noise in single-track detection, has recently been extended to the multitrack scenario [3]; it uses 2D patterns (spanning multiple tracks) to mitigate both downtrack and crosstrack pattern-dependent noise, based on the architecture shown in Fig. 1. The sampled readback waveforms are filtered by a $2 \times 2$ MIMO equalizer with coefficients $\mathbf{C}$, whose output $\mathbf{y}_{k}=\left[y_{k}^{(1)}, y_{k}^{(2)}\right]^{T}$ is passed to a 2D -PDNP multitrack detector. Associated with each 2D bit pattern is a signal level vector $\mathbf{s}$, a standard deviation diagonal matrix $\Lambda$, and a set of matrix-valued predictor coefficients $\mathbf{P}_{0}, \mathbf{P}_{1}, \ldots, \mathbf{P}_{N_{p}-1} $. The branch metric of edge e for the 2D -PDNP Viterbi detector is [3]

In most cases, the cellphone signal level is found weak inside a building than outside due to signal dropping caused by penetration. Because of penetration loss, the indoor cellular network signal shows poor performance, and imperfect reception occurs. Penetration loss is influenced by the building material types used in construction, the building structure, and orientation. In this work, the penetration loss was measured subject to construction materials and different network bands, i.e. UMTS and LTE on 3G and 4G network. The measurements were taken from a multi-storied building and a multi-storied mud house located in a rural area in Chattogram district of Bangladesh. This work was done in respect of Bangladesh, where most of the areas are rural; therefore, the rural area was taken as standard. Android mobile with an installed application named "Network Signal Info" and LTE/4G/3G network supported SIM of a primary cellular network service provider in Bangladesh named 'Robi Axiata' was used to measure the data. Penetration loss fluctuation on the variation of the receiver height (floor to floor) and the Base station (BS)-Rx distance (room to room) was accounted as evaluation metrics to measure and study the signal strength performance. It is observed from the resultant data that; the increment of receiver height reduces the penetration loss where the increment of BS-Rx distance exacerbates this loss. By comparison, it is also found that penetration loss is always higher in 4G networks than 3G network band from all aspects. Besides, the mud constructed house gives higher penetration loss compared to the brick constructed building for each parameter.

For ever-increasing demand for communication capacity, carrier frequencies are increasing, but this brings greater shadowing which compromises the radio coverage. For example, mmWave signals are severely attenuated in the simplest of non-line-of-sight scenarios - around the corner of a building. We present a simple corner modification comprising a fixed scattering dipole to improve the coverage in the shadow region of the corner diffraction. Simulations are used to thoroughly investigate the scenario, and our numerical experiments are validated with physical experiments. For the vertical polarization, a signal level increase of well over ten dB in the shadow region is demonstrated using a single half-wavelength dipole scatterer.

Предложена вероятностная модель работы автономного обнаружителя на этапе ожидания сигнала, когда момент появления сигнала неизвестен и по этой причине решающая статистика, сравниваемая с порогом, формируется непрерывно во времени в режиме скользящего окна . Ложная тревога в этом случае эквивалентна появлению хотя бы одного выброса помехового индикаторного процесса выше порога на максимально возможном интервале ожидания сигнала. Высота порога такова, что ложные выбросы являются редкими событиями, подчиняющимися закону Пуассона. На основе такой вероятностной модели показано, что вероятность ложной тревоги равна среднему числу ложных выбросов на максимально возможном интервале ожидания сигнала. Для обнаружителей с нормализованным индикаторным процессом получены соотношения, определяющие порог селекции сигнала по заданной вероятности ложной тревоги на заданном максимально возможном интервале ожидания сигнала. Показано, что в определении порога важную роль играет средняя квадратичная частота флюктуаций помехового индикаторного процесса. Дана численная оценка увеличения порога по сравнению с его значением, определенным по вероятности ложной тревоги в точке . Показано, что определение порога по предложенной методике особенно актуально для обнаружителей, работающих в длительном автономном режиме.This article proposes a probabilistic model of the autonomous detector in standby mode, when the moment of the signal appearance is unknown and for this reason the decisive statistics is generated continuously in time in the sliding window mode and compared with the threshold value. In this case, false alarm is equivalent to the appearance of at least one outlier of the jamming indicator process above the threshold at the maximum possible signal waiting interval. The threshold level match case when the false alarm are rare events and obey the Poisson law of distribution. Based on such a probabilistic model, we show that the probability of a false alarm is equal to the average number of false emissions at the maximum possible interval for a signal waiting. For detectors with a normalized indicator process, are obtained relations that determine the threshold for signal selection by a given probability of false alarm at a given maximum possible signal waiting interval. It is shown that in determining the threshold, the mean square frequency of fluctuations of the interference indicator process plays an important role. Also, a numerical estimate of the increase in the threshold is given compared with its value determined by the probability of false alarm at a point . It is shown that the determination of the threshold by the proposed method is especially relevant for detectors operating in a long autonomous mode.

Technology in sector communication is growth rapidly, which is marked by the increasing number of facilities offered, for example the growth of data, voice and video communication. The technology that can answer these communication demands is Long Term Evolution Adavanced (LTE-A) technology. To optimize the quality by using a combination of frequencies on LTE-A. This research comparing results of non-Carrier Aggregation (Non-CA) and Carrier Aggregation (CA). The frequency band that use existing frequency one of cellular operator in Surakarta 1800 MHz and the additional frequency for CA 2100 MHz. The result shows signal level value is above th threshold -80 dB increase from 89.51 to 96.04%. The percentage of reviewed RSRP if the value is above threshold -105 dBm increased from 83% to 95.44%. the parameter of distribution SINR in percentage values are above threshold above 5dB increased from 47.22% to 69.67%. The value of the mean throughput increase from 25.41 Mbps be 37.31 Mbps, with target KPI 12 Mbps. The number of rejected user in the network decreased from 2.2% to 0.6%. Parameters that are reviewed in this research can meet the target KPI.

Better-ear glimpsing (BEG) utilizes interaural level differences (ILDs) to improve speech intelligibility in noise. This spatial benefit is reduced in most hearing-impaired (HI) listeners due to their increased hearing loss at high frequencies. Even though this benefit can be improved by providing increased amplification, the improvement is limited by loudness discomfort. An alternative solution therefore extends ILDs to low frequencies, which has been shown to provide a substantial benefit from BEG. In contrast to previous studies, which only applied linear stimulus manipulations, wide dynamic range compression was applied here to improve the audibility of soft sounds while ensuring loudness comfort for loud sounds. Performance in both speech intelligibility and BEG was measured in 13 HI listeners at three different masker levels and for different interaural stimulus manipulations. The results revealed that at low signal levels, performance substantially improved with increasing masker level, but this improvement was reduced by the compressive behaviour at higher levels. Moreover, artificially extending ILDs by applying infinite (broadband) ILDs provided an extra spatial benefit in speech reception thresholds of up to 5 dB on top of that already provided by natural ILDs and interaural time differences, which increased with increasing signal level.

Long Term Evolution (LTE) merupakan teknologi generasi ke empat (4G) yang dikembangkan oleh 3rd Generation Partnership Project (3GPP). LTE mampu memberikan kecepatan downlink sampai dengan 100 Mbps dan uplink 50 Mbps. Penelitian ini mempunyai tujuan untuk melakukan perancangan jaringan 4G LTE pada wilayah kota Balikpapan dengan target khusus untuk mengetahui kualitas perancangan jaringan 4G LTE di kota Balikpapan melalui parameter best signal level, nilai C/ (N+I), throughput, RSRP dan BLER dari perancangan yang telah dilakukan. Metode penelitian dilakukan melaui survey ke lokasi site-site e Node yag diperlukan untuk memperoleh gambaran langsung kodisi sekitar e Node B dilanjutkan proses plotting 126 site-site e Node B di wilayah kota Balikpapan kemudian yang dilanjutkan dengan proses simulasi perancangan jaringan menggunakan software Atoll. Dari hasil simulasi ini dapat diketahui kualitas perancangan jaringan 4G LTE kota Balikpapan dengan nilai-nilai parameter yang diinginkan seperti best signal level sebesar -69,72 dBm, nilai C / (N+I) sebesar 5,08. Untuk perfomansi throughput sebesar 11.8034 kbps, sedangkan nilai RSRP sebesar -115, 88 dBm serta nilai BLER sebesar 0,03 .

In Indonesia, LTE technology is appropriately to be applied by telecommunication operators in improving cellular communication services. In 2018, the number of LTE network users in Pekanbaru continues to increase. Increasing number of customers need increasing service capacity. To fulfill the capacity needs of LTE network services with better signal level in 2018, then in this study has been analyzed the simulation of LTE network capacity in Pekanbaru City. In this research, we use Monte Carlo simulation for analyze capacity. Frequency Division Duplex method with 1800 MHz frequency and COST- 231 Hata propagation model were used in the simulation. The results of simulation capacity in Pekanbaru show that the urban area needs 143 number of BTSs for 20MHz bandwidth, BTSs coverage reaches 84.4% of covered area and highest focus zone covered at -100 dbm signal, and for 5MHz Bandwidth, the total number of subscribers is 47.375, with 39.158 connected subscribers and 8.216 unsuccessful subscribers.

We report a new correlation-based direct sequence spread-spectrum technique that estimates low-pass-equivalent Volterra coefficients for weakly nonlinear RF systems. The methodology provides robust coefficient estimates at test signal amplitudes well below the operating signal level during normal system operation, demonstrating that the technique can be used for “background” nonlinearity measurement. We demonstrate the methodology by measuring third-order Volterra kernels for a power amplifier chain operated in compression with a 10 MHz bandwidth signal at 1960 MHz.

This article involves the site specific determination of an outdoor path loss model and Signal penetration level in some selected modern residential and office apartments in Ogbomosho, Oyo State. Measurements of signal strength and its associated location parameters referenced globally were carried out. Propagation path loss characteristics of Ogbomosho were investigated using three different locations with distinctively different yet modern building materials. Consequently, received signal strength (RSS) was measured at a distance d in meters, from appropriate base stations for various environments investigated. The data were analyzed to determine the propagation path loss exponent, signal penetration level and path loss characteristics. From calculations, the average building penetration losses were, 5.93dBm, 6.40dBm and 6.1dBm outside the hollow blocks B1, solid blocks B2 and hollow blocks mixed with pre cast asbestos B3, buildings respectively with a corresponding path loss exponent values of, 3.77, 3.80 and 3.63. Models were developed and validated, and used to predict the received power inside specific buildings. Moreover, the propagation models developed for the different building types can be used to predict the respective signal level within the building types, once the transmitter – receiver distance is known. The readings obtained from the developed models were compared with both the measured values and values computed using some existing models with satisfactory results obtained.

This paper investigates the use of resonance-enhanced coupling to increase the received signal level in a six-degree-of-freedom electromagnetic tracking system. Resonant coupling is found to increase the efficiency of the transmitter and increase the gain of the sensing coil, resulting in improved range. However, the measurement update rate is reduced due to the settling time of the transmitter circuit and the limited bandwidth of the sensing circuit. A resistive tuning approach is proposed to balance the tradeoff between a decreased measurement bandwidth and an improved signal level.