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In resonant inductive coupling wireless power transfer systems, a repeater resonator is crucial in expanding the charging area, enabling efficient power supply to receivers, such as small Internet of Things (IoT) devices sparsely distributed in a wide area. However, the repeater current is highly susceptible to deviations in resonance frequency due to manufacturing tolerance and aging, as well as to the magnetic coupling between the transmitter and repeater coils, potentially leading to insufficient amplitude. Consequently, the magnetic field generated by the repeater decreases and the receiver may be difficult to obtain sufficient power from the transmitter via the repeater. To address this problem, this paper proposes a wireless power transfer system with active reactance compensators incorporated in the repeater and the transmitter. The proposed system can equivalently adjust the resonant frequencies of the transmitter and repeater to stably maximize the repeater coil current regardless of the variations in the resonant frequency and the magnetic coupling intensity. Experiments successfully verify that the proposed system can provide a more stable and larger repeater current and output power than the conventional system against the variations in the magnetic field intensity and the resonant frequency of the repeater, validating the feasibility of the proposed system for practical utilization of the repeater in expanding the charging area.

Natural activities such as mountain climbing are activities that require a good communication system, whether it is for the purposes of knowing the position or communication to fellow climbers in a small or large group. Cases of missing climbers often occur in the mountains, so communication in search in mountainous areas becomes one of the difficult things when searching. The purpose of designing LoRa RFM95 repeaters with a frequency of 915 MHz based on ESP32 is to improve the range and stability of communication in LoRa networks. International scale research on LoRa performance testing implies that the LoRa coverage distance is strongly influenced by the conditions of the tested area. Therefore, a repeater is needed for LoRa RFM95 to increase the range distance which refers to the System Development Life Cycle (SDLC) method. The results of tests conducted for transmitters and receivers can communicate as far as 80 meters with line of sight (LoS) conditions and 60meters with non-line of sight (NLOS) conditions. The results of trials conducted by repeaters can extend communication range as far as 60 meters with line of sight conditions and 40 meters with non-line of sight (NLOS) conditions. [ABSTRACT FROM AUTHOR]

Differential participation in violent protests has been explained in terms of protesters' personal values, biographical availability, and network embeddedness. However, the form of mass protest may be influenced less by the microstructure of protesters and more by their collective past experiences of resistance. Through the South Korean candlelight protests of 2008 and 2016–2017, this article examines novices' and repeaters' perceptions of nonviolent protest. Onsite survey and interview data show that previous frustrating protest experiences in 2008 made repeater protesters more perseverant, even when violence was expected. Repeaters had little faith in "disciplined" protests, whereas novices hoped for change through "peaceful" protests. I argue that previous experiences of resistance and their outcomes influenced protesters' perceptions on the efficiency and legitimacy of violent protest. By examining protesters' varying perseverance, which mediates the condition of violence, this article advances the relationship between violence and civic participation. [ABSTRACT FROM AUTHOR]

Following laboratory experiments and friction theory, slow slip events and seismicity rate accelerations observed before mainshocks are sometimes interpreted as evidence of a nucleation phase. However, such precursory observations still remain scarce and are associated with different time and length scales, raising doubts about their actual preparatory nature. We study the 2017 Valparaiso Mw = 6.9 earthquake, which was preceded by aseismic slip accompanied by an intense seismicity, suspected to reflect its nucleation phase. We complement previous observations, which have focused only on precursory activity, with a continuous investigation of seismic and aseismic processes from the foreshock sequence to the post‐mainshock phase. By building a high‐resolution earthquake catalog and searching for anomalous seismicity rate increases compared to aftershock triggering models, we highlight an over‐productive seismicity starting within the foreshock sequence and persisting several days after the mainshock. Using repeating earthquakes and high‐rate GPS observations, we highlight a transient aseismic perturbation starting 1‐day before the first foreshock and continuing after the mainshock. The estimated slip rate over time is lightly impacted by large magnitude earthquakes and does not accelerate toward the mainshock. Therefore, the unusual seismic and aseismic activity observed during the 2017 Valparaiso sequence might be interpreted as the result of a slow slip event starting before the mainshock and continuing beyond it. Rather than pointing to a possible nucleation phase of the 2017 Valparaiso mainshock, the identified slow slip event acts as an aseismic loading of nearby faults, increasing the seismic activity, and thus the likelihood of a large rupture. Plain Language Summary: Both laboratory experiments and friction theory show that earthquakes do not begin abruptly but are preceded by an accelerating slip associated with a seismicity increase. On the field, however, such precursory observations still remain scarce and are associated with different characteristic time and length scales, raising doubts that they actually reflect the same nucleation phenomena. We study the 2017 Valparaiso M = 6.9 earthquake, which was preceded by both a slow slip and an intense seismicity suspected to reflect such nucleation phase. We complement previous studies, that have focused only on precursory activity, with a continuous investigation of seismic and slow slip before and after the mainshock. Using refined earthquake detection tools, we highlight a seismicity excess starting before and persisting several days after the mainshock. Using repeating earthquakes and high‐resolution GPS, we show that the slow slip does not accelerate toward the mainshock, but continues after it. Therefore, rather than pointing to a possible accelerating nucleation phase of the Valparaiso mainshock, we suggest that the slow slip drives an enhanced seismic activity that is not mainshock‐directed. Within such slow‐slip driven seismicity, the probability of triggering a large earthquake (subsequently considered as the mainshock) is increased. Key Points: We use a high resolution seismic catalog and GPS to investigate seismic and aseismic process before and after the Valparaiso mainshockAn unusually high seismicity and a slow slip event is continuously observed from the foreshock sequence up to days after the mainshockRather than a nucleation phase of the mainshock, the slow slip event acts as an aseismic loading of nearby faults during the entire sequence [ABSTRACT FROM AUTHOR]

Synthetic aperture radar (SAR) is an established technique for high-resolution radar imaging relying on the ego-motion of the radar. The long coherent integration time of the radar in conjunction with a linear or circular trajectory enables the illumination of targets under different observation angles leading to robustness against short-time interference signals. The use of a bistatic setup to simultaneously acquire multiple observation angles further increases the aforementioned benefits. In this work, a bistatic SAR system using an active repeater is proposed, in the following called Bistatic Repeater-SAR (BR-SAR). In BR-SAR the repeater acts as a second observer providing a bistatic path with low system cost and hardware effort. This article discusses the BR-SAR approach with all signal processing and hardware considerations necessary to build the bistatic radar system. This includes a description of the full system and signal chain with a focus on the signal separation and evaluation of both monostatic and bistatic signals and the subsequent SAR processing. The approach is verified via simulations and measurements, in which conventional SAR is compared to the proposed BR-SAR system. Hardware effects leading to a deteriorated system performance of the bistatic system are analyzed and countermeasures are discussed and implemented. Finally, the benefits of the bistatic system are demonstrated based on a realistic measurement scenario.

Summary: In this paper, a capacitive wireless power transfer link with two repeaters between the transmitter and receiver is analyzed. The performance of the system is optimized by maximizing the different gains. Two approaches of practical interest are analytically studied and solved. First, the couplings between different resonators is considered fixed and the optimal load and source of the system are determined as function of the network characteristics. Second, the performance is optimized by varying the couplings between resonators for a configuration with a given (nonideal) source and load. The analytical results are verified through circuital simulations. It is demonstrated that, under certain conditions, both approaches allow for the maximization of the different gains, resulting in more optimization options than a single repeater configuration. [ABSTRACT FROM AUTHOR]

For ten years Polish distribution companies have implemented several AMR and AMI pilot projects. In Poland, the Distribution System Operator (DSO) equips households with smart energy meters (e.g. in the United Kingdom - the energy supplier, which can be changed by the customer). Over these years the operators collected a lot of experience with these pilot projects. The author of this publication describes his personal experience in the research projects in which he was involved, directly or indirectly, as well ones of which he has received information about from the DSOs. This article does not present the experiences from all major AMI system projects in Poland, but only from few projects in which the author of this article participated. The author participated in projects in which the smart meters utilize a variety of different technologies: PLC, GPRS, HSCSD, RS-232, etc. In this article, however, he focuses only on his experience in working with PLC technology. This paper presents the requirements, considerations and experience gained in the development and pilot implementation of AMI systems in Poland. [ABSTRACT FROM AUTHOR]

With radar networks, the resolution of critical radar parameters such as Doppler and angle can be improved compared to a single radar sensor. As the network’s aperture is considerably larger than that of a single radar, a much higher angular resolution is achieved. However, with a large aperture, range-dependent phase deviations, that is, near-field effects, occur and affect the angle estimation. In this work, these near-field effects are evaluated exemplarily for a coherent network. Furthermore, a new strategy to compensate for those network near-field effects is proposed and demonstrated based on measurements. The benefits of the near-field compensation are emphasized by comparing the network’s angle-estimation capabilities with and without compensated near-field effects. [ABSTRACT FROM AUTHOR]

The traditional Optical Time Domain Reflectometry (OTDR) technology uses back Rayleigh scattering power for fiber detection. In transmission lines with optical amplifier, Erbium-Doped Fiber Amplifiers (EDFA) are mostly used to compensate for the loss of signal light and extend the transmission distance of the signal light. Since the EDFA amplifies the signal, it will generate spontaneous radiation noise, and the continuous accumulation of noise will rapidly decrease the signal-to-noise ratio measured by the OTDR. The paper mainly expounds the principle of Coherent Optical Time Domain Reflectometry (C-OTDR) technology. The detected signal optical power is concentrated to the intermediate frequency by the coherent detection method, and most of the noise can be filtered out by band-pass filtering the frequency signal. It can continuously extend the detection distance through the EDFA. We also propose to use the frequency shift keying method to eliminate the optical surge problem caused by the cascade of multi-stage repeaters in long-distance transmission of submarine cables. Through the development of self-developed coherent optical time domain reflectmeter, the actual test of C-OTDR technology in the simulated submarine cable multi-span transmission system has reached 3 000 km, which fully meets practical conditions.

The traditional Optical Time Domain Reflectometry (OTDR) technology uses back Rayleigh scattering power for fiber detection. In transmission lines with optical amplifier, Erbium-Doped Fiber Amplifiers (EDFA) are mostly used to compensate for the loss of signal light and extend the transmission distance of the signal light. Since the EDFA amplifies the signal, it will generate spontaneous radiation noise, and the continuous accumulation of noise will rapidly decrease the signal-to-noise ratio measured by the OTDR. The paper mainly expounds the principle of Coherent Optical Time Domain Reflectometry (C-OTDR) technology. The detected signal optical power is concentrated to the intermediate frequency by the coherent detection method, and most of the noise can be filtered out by band-pass filtering the frequency signal. It can continuously extend the detection distance through the EDFA. We also propose to use the frequency shift keying method to eliminate the optical surge problem caused by the cascade of multi-stage repeaters in long-distance transmission of submarine cables. Through the development of self-developed coherent optical time domain reflectmeter, the actual test of C-OTDR technology in the simulated submarine cable multi-span transmission system has reached 3 000 km, which fully meets practical conditions.

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Copyright of Railway Signalling & Communication Engineering is the property of Railway Signalling & Communication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

At least two decades ago, various applications have been proposed for the implementation of ultra-wideband (UWB) technology, but only a few of them are being realised such as radar detection, home networking, and indoor positioning. Although UWB positioning offers precise locality tracking, the accuracy of the estimation is greatly affected by the non-line-of-sight (NLOS) path effect. In this paper, we propose a hybrid indoor UWB positioning and networking system that utilises the existing repeater of the data network to eliminate the NLOS paths. A switching algorithm is written to identify the existence of NLOS paths based on received signal strength (RSS) and unique channel characteristics such as mean excess delay (MED) and root mean square (RMS). From the simulation results, the NLOS paths have been successfully identified under the NLOS environment. Hence, a higher probability of accuracy across the entire tested area can be achieved for the UWB positioning system by mitigating the NLOS path effect using the proposed algorithm. Besides that, the transmission of the line-of-sight (LOS) signal attains a data rate of around 15 times higher than the NLOS signal at a bit-error-rate (BER) of 10-5 in the indoor networking system. In this case, the minimum-bit-errorrate (MBER) receiver is again shown to outperform the minimum-mean-square error (MMSE) and the performance gain drops around 5 dB to 6 dB at a BER of 10-5 when the repeaters increase to a maximum number of 10 units. In conclusion, the proposed method is capable of mitigating the NLOS path effect on both indoor positioning and data networking systems. [ABSTRACT FROM AUTHOR]

Maintaining constant power transfer while keeping near-unity transfer efficiency at varying transfer distances is a major challenge for existing wireless power transfer (WPT) system with multiple repeaters. In order to overcome the problem, this article proposes a novel WPT mechanism with multiple repeaters based on the concept of parity-time symmetry. First, the coupled-mode model of this WPT relay system is established. Then, the steady-state transfer characteristics of the proposed WPT system with an odd and even number of repeaters are analyzed. The theoretical analysis shows that whether an odd or even number of repeaters are inserted between the transmitting and receiving coils, the proposed system automatically achieves constant output power and transfer efficiency against the variation of the transfer distance without any tuning or feedback within a certain distance. The prototype with one repeater and two repeaters is implemented to verify the validity of the theoretical analysis. Experimental results show that the prototype with one repeater can transfer power with an invariant transfer efficiency of 91% and a constant output power of 15 W within a transfer distance of 420 mm. Similarly, the prototype with two repeaters transfers constant power of 15 W over a transfer distance ranging from 420 to 500 mm, and the transfer efficiency is constant near 89%. [ABSTRACT FROM AUTHOR]

In this paper, we have investigated the delay optimization using repeater insertion in folded graphene nanoribbon (FGNR) interconnect systems for different nanometer technology nodes. The mean free path is modeled as a function of GNR width and Fermi energy. The RLC equivalent circuit is modeled for analyzing delay and power for global interconnects. The performance of FGNR is compared to that of multi‐layer horizontal graphene nanoribbon (ML‐HGNR) and multi‐layer vertical graphene nanoribbon (ML‐VGNR) interconnects. Our analysis shows that proposed FGNR interconnect with fully diffusive edges can outperform both the ML‐HGNR and ML‐VGNR interconnects as well as the traditional Cu interconnects by reducing the number of repeaters. [ABSTRACT FROM AUTHOR]

Next-generation radar sensors require imaging capabilities with high angular resolution. As for a single sensor, the aperture, and thus the achievable resolution, is limited due to the constraints of the front end, radar networks consisting of multiple sensors are a possible solution. However, their incoherency usually makes joint angle estimation impossible. This article presents a network concept consisting of an orthogonal frequency-division multiplexing (OFDM) radar and repeater elements, which receive the reflections from targets and retransmit them back to the radar. Thereby, any frequency conversion from radio frequency to baseband and vice versa is omitted such that the signal remains coherent to the initial transmit signal. To distinguish the bistatic signal transmitted by the repeater from the monostatic one of the OFDM radar, the orthogonal subcarrier structure of OFDM waveforms is exploited by combining a sparse radar transmit signal with a low-frequency modulation in the repeater. This allows to evaluate the bistatic signals at the radar with standard multiple-input–multiple-output (MIMO)-OFDM signal processing, leading to separate range–Doppler images for each virtual channel. Finally, it is shown that this method offers a coherent angular estimation based on the extended aperture of the network. For this purpose, a method to establish phase coherency by a reconstruction of the modulation phase is presented. The network concept is proved with measurements at 77 GHz. [ABSTRACT FROM AUTHOR]

In all Hard IP (HIP) designs, there is a need for signals to travel from its source to destination module. To meet timing, they are flop repeated based on the floorplan of the design. Different signals have unique repetition requirements based on their functionality/timing criticality. Also signals may have single destination or multiple destinations. The flop repeater structure for each signal should be optimized so that it has minimum number of flops and timing is also met, to achieve desired targets for timing, area and power. This paper will show how we are creating optimized treestructure based on mathematical techniques and generating automated RTL for such repeater flop module. This submission presents a new tool ART (Auto Repeater Tool) that completely eliminates the manual effort/time required to generate functional, ready to plug-in RTL.

This study examined the writing score and writing feature changes of 562 repeat test takers who took the Canadian English Language Proficiency Index Program–General (CELPIP–General) test at least three times, with a short (30–40 day) interval between the first and second attempts and a longer (90–180 day) interval between the first and third attempts. Analysis was conducted to uncover whether changes occurred at different testing durations (short vs. long) and whether the observed changes varied across repeater's initial proficiency groups (low, mid, high). The writing scores measured by CELPIP bands showed great stability over the 6-month period, but the trends of development differed by proficiency group. Low proficiency test takers were more likely to have faster observable score gains, compared to the medium proficiency group, whereas high proficiency repeaters may not maintain their score levels at later attempts. Writing quality was analyzed using natural language processing (NLP) tools. Results suggested that for all proficiency groups, lexical features were more likely to improve over the 6-month period, with some measures showing improvement at 1 month; features in cohesion and syntactic sophistication, however, did not change significantly. [ABSTRACT FROM AUTHOR]

Broadband over Power Lines (BPL) is considered a promising communication technology in the concept of Smart Grids. This paper evaluates networks based on BPL, with a focus on the impact of repeaters in the linear topology of distribution substations. In large-scale Smart Grids network planning, positions of repeaters have to be carefully chosen. This article should help to determine such positions and limitations of BPL linear topology networks. Laboratory and on-field measurements and their results are presented in this article. Results show the impact of repeater's deployment for different testing methodologies also with regard to other already presented studies. Measured values and the determined impacts of repeaters are later used as input data for simulation of the linear BPL topology in terms of network throughput with multiple streams and bottlenecks. These occur especially on lines shared by multiple communicating nodes. Furthermore, the simulation investigates the balancing time of multiple data streams throughput. The simulation shows that the throughput balancing can occupy a significant time slot, up to tens of seconds before the throughput of different streams balances. Also, the more data is generated, the more time the balancing time takes. Additionally, the throughput drop caused by a repeater is determined into the range of 35–60%. Based on the measurement and simulation results, lessons learned are presented, and possible performance improvements are discussed. [ABSTRACT FROM AUTHOR]

This work concentrates the analysis of the system of automatic control of the directive diagram of the moving active electronically scanned array with a limited number of transceiver modules. The analysis revealed a number of shortcomings that lead to a significant increase in standard deviations, quadratic integral estimates, and an increase in transient time. The identified disadvantages lead to a decrease in the efficiency of the antenna system, an increase in the error rate at the reception, the inability of the system to react to disturbances applied to any point of the system in the event of a mismatch of a given signal/noise level. In accordance with the analysis, the mathematical model of the automatic control system of the directional diagram of the moving active electronically scanned array was considered, considering this a new method of estimating the quality indicators of the automatic control diagram of the directional diagram of the active electronically scanned array in a random setting and disturbing action was developed. The difference between the proposed method and the existing method is in the construction of an automatic control system with differential coupling equivalent to the combination due to the introduction of derivatives of the random setting action of the open compensation connection. [ABSTRACT FROM AUTHOR]

As citizen report systems are introduced in municipalities worldwide, research on extracting knowledge useful for resolving local issues from accumulated citizen report data is being actively promoted. However, to utilize this knowledge in practice, clarifying the characteristics of the participating reporters and the bias caused by them is necessary. This study focuses on repeat reporters who play an important role and extracts knowledge regarding their behavioral characteristics from citizen report data. [ABSTRACT FROM AUTHOR]

A wearable stripline-fed circularly polarized dual-patch antenna structure that exhibits enhanced into-body gain is presented. The antenna is designed for body-surface repeater solutions and it addresses the problem of marginal into-body deep tissue communication links, where power consumption is of the utmost importance and system link efficiency is critical. Under realistic operation conditions, the antenna’s circular polarization (CP) successfully mitigates implant orientation and polarization mismatch. Polarization loss for linear antennas can be up to 16 dB in anechoic environments and as much as 12.5 dB in a realistic multipath environment, as demonstrated by measured co- and cross-polar forward path gain between implanted and linearly polarized surface antennas. To overcome the body-isolating effect of an antenna ground plane and to produce an effective off-body mode, a novel dual-aperture stripline feed was developed which also improves the body-mounted antenna radiation efficiency. The antenna provides a 0 dBi off-body gain while still maintaining excellent into-body performance. The into-body link was shown to exhibit CP with a maximum isolation of only 1.5 dB between co- and cross-polar measurements in the 2.36–2.4 GHz band. All measurements were carried out using an accurate, next-generation layered phantom tested representative of a wide range of the population. [ABSTRACT FROM AUTHOR]

In all Hard IP (HIP) designs, there is a need for signals to travel from its source to destination module. To meet timing, they are flop repeated based on the floorplan of the design. Different signals have unique repetition requirements based on their functionality/timing criticality. Also signals may have single destination or multiple destinations. The flop repeater structure for each signal should be optimized so that it has minimum number of flops and timing is also met, to achieve desired targets for timing, area and power. This paper will show how we are creating optimized tree structure based on mathematical techniques and generating automated RTL for such repeater flop module. This submission presents a new tool ART (Auto Repeater Tool) that completely eliminates the manual effort/time required to generate functional, ready to plug-in RTL. [ABSTRACT FROM AUTHOR]

Yasuyuki Okumura,1 Daisuke Nishi21Research Department, Institute for Health Economics and Policy, Association for Health Economics Research and Social Insurance and Welfare, Tokyo, 2Department of Mental Health Policy and Evaluation, National Institute of Mental Health, National Center of Neurology and Psychiatry, Kodaira, JapanObjective: We aimed to estimate risk of recurrent overdose associated with psychosocial assessment by psychiatrists during hospitalization for nonfatal overdose and prescribing patterns of psychotropic medications after discharge. Methods: A retrospective cohort study was conducted using a nationwide claims database in Japan. We classified patients aged 19–64 years hospitalized for nonfatal overdose between October 2012 and September 2013 into two cohorts: 1) those who had consulted a psychiatrist prior to overdose (n=6,790) and 2) those who had not (n=4,950). All patients were followed up from 90 days before overdose until 365 days after discharge. Results: Overall, 15.3% of patients with recent psychiatric treatment had a recurrent overdose within 365 days, compared with 6.0% of those without psychiatric treatment. Psychosocial assessment during hospital admission had no significant effect on subsequent overdose, irrespective of treatment by psychiatrists before overdose. There was a dose–response relationship for the association of benzodiazepine prescription after overdose with subsequent overdose in either cohort, even after accounting for average daily dosage of benzodiazepines before overdose and other confounders. In patients with recent psychiatric treatment, the cumulative proportion of recurrent overdose at 365 days was 27.7% for patients receiving excessive dosages of benzodiazepines, 22.0% for those receiving high dosages, 15.3% for those receiving normal dosages, and 7.6% for those receiving no benzodiazepines. In patients without psychiatric treatment, the cumulative proportion of recurrent overdose at 365 days was 24.3% for patients receiving excessive dosages of benzodiazepines, 18.0% for those receiving high dosages, 9.0% for those receiving normal dosages, and 4.1% for those receiving no benzodiazepines.Conclusion: Lower dose of benzodiazepines after overdose is associated with lower risk of subsequent overdose.Keywords: drug poisoning, self-harm, suicide attempt, repeater, consultation–liaison service, administrative database

In this paper, a coherent multistatic radar network with a novel system architecture is presented, which circumvents the general problems of clock distribution and phase noise-related signal-to-noise ratio (SNR) issues. The proposed network consists of a variable number of multiple-input multiple-output (MIMO) radar sensors and a variable number of repeater tags, all of which operate incoherently on the hardware level. In a minimum configuration, the network only consists of one MIMO radar sensor and a repeater tag. The theory behind such a multistatic network is mathematically derived, and simulations are presented to show key aspects of the network, i.e., multistatic range and Doppler measurements, as well as high-resolution angle estimation, exploiting a very large virtual aperture spanning the whole network. Measurements with one sensor and one repeater tag at 77 GHz are carried out to verify the simulations. The measurements show that the bistatic path between the sensor and the repeater tag retains coherency. [ABSTRACT FROM AUTHOR]

We propose a strategy to reduce the propagation delay of microprocessors' digital bus lines at very low costs in terms of area overhead, power consumption and power-delay product. Likewise some solutions adopted in industry nowadays, our strategy inserts in the bus lines repeaters implemented as a chain of inverters with increasing size. In this paper, we derive new expressions to determine the optimum number of inverters to be used within each repeater, and the optimum number of repeaters to insert in the bus lines. Our derived expressions yield to bus implementations with significant lower cost in terms of area overhead and power consumption than alternative solutions in literature. Considering a 32 nm technology as a significant example, we show that, compared to the traditional solution that inserts repeaters implemented as a single inverter, our strategy enables reductions up to 84% in terms of area overhead, up to 65% in power consumption, and up to 66% in power-delay product. Compared to three recent alternative solutions in the literature, our strategy enables reductions up to 88% in terms of area overhead, up to 48% in power consumption, and up to 43% in power-delay product. Therefore, our approach is particularly suitable to the growing market of mobile applications that require low cost in terms of power consumption and chip area. [ABSTRACT FROM AUTHOR]

Broadband over Power Lines (BPL) is considered a promising communication technology in the concept of Smart Grids. This paper evaluates networks based on BPL, with a focus on the impact of repeaters in the linear topology of distribution substations. In large-scale Smart Grids network planning, positions of repeaters have to be carefully chosen. This article should help to determine such positions and limitations of BPL linear topology networks. Laboratory and on-field measurements and their results are presented in this article. Results show the impact of repeater’s deployment for different testing methodologies also with regard to other already presented studies. Measured values and the determined impacts of repeaters are later used as input data for simulation of the linear BPL topology in terms of network throughput with multiple streams and bottlenecks. These occur especially on lines shared by multiple communicating nodes. Furthermore, the simulation investigates the balancing time of multiple data streams throughput. The simulation shows that the throughput balancing can occupy a significant time slot, up to tens of seconds before the throughput of different streams balances. Also, the more data is generated, the more time the balancing time takes. Additionally, the throughput drop caused by a repeater is determined into the range of 35–60%. Based on the measurement and simulation results, lessons learned are presented, and possible performance improvements are discussed.

A temperature-dependent delay optimization model for a multilayered graphene nanoribbon (MLGNR) with top contact (TC-GNR), side contact (SC-GNR), and Cu-based nano-interconnects using a wire sizing method was applied to determine the delay for different interconnects widths (11 nm, 16 nm, and 22 nm) and lengths (10 μm, 50 μm, and 100 μm), being the first such model for TC-GNR, SC-GNR, and Cu interconnects applied at three different chip operating temperatures (233 K, 300 K, and 378 K). The results reveal that the SC-GNR requires ~ 3-6× and ~ 2-3× fewer repeaters w.r.t. the TC-GNR or Cu interconnect, and that the SC-GNR and Cu interconnects can achieve ~ 4-5× and ~ 2-2.5× reduction in repeater dimension compared with the TC-GNR interconnect. Meanwhile, the SC-GNR interconnect can achieve 73× less propagation delay w.r.t. the TC-GNR interconnect for interconnect width of 22 nm, interconnect length of 10 μm, and two different chip operating temperatures of 233 K and 300 K. Similarly, the Cu interconnect can achieve 6× less propagation delay w.r.t. the TC-GNR interconnect at interconnect width of 22 nm and 16 nm, interconnect length of 10 μm, and 300 K. [ABSTRACT FROM AUTHOR]

Past research conducted on visitors' behavior has highlighted the differences between first-time and repeat visitors in urban and natural settings. To determine whether these differences also exist in a monumental city, we have studied visitor behavior in the historic city of Girona (Spain). Data from 1288 GPS tracking were recorded. Of these, 928 were first-time visitors, and the remaining 360 corresponded to repeat visitors. Findings show that there is very little difference in how first-time and repeat visitors act, compared to visitor behavior in other types of tourist destinations. Nevertheless, the results do demonstrate differences between low frequency visitors (between 1 and 4 visits) and high frequency visitors (more than 4 visits). These results suggest that sightseeing creates very homogeneous behavior pattern between first-time and repeat visitors, and highlight the need to differentiate repeat visitors according to the number of visits done in the monumental city. [ABSTRACT FROM AUTHOR]

Dual-band coil modules facilitate efficient access to distinct-band, high-power, or rapid-charging wireless power transfer (WPT) systems. However, they do not function efficiently when the frequency ratio between two operating frequencies is large. To overcome this problem, we propose enhanced dual-band coil modules that adopt repeaters in the WPT system. We present a circuit-based analysis of repeaters in various dual-band coil modules compared with those in a single-band WPT system. The analytical results provide a design methodology applicable to diverse types of dual-band coil modules with a repeater in the WPT system. Our experimental results are consistent with the circuit-based analysis: coil power transfer efficiencies of 55% at 200 kHz and 74% at 6.78 MHz were obtained concurrently in the dual-band WPT system with a dual-band repeater. This paper reduced the application constraint of dual-band coil modules and facilitated the realization and application of multiband WPT systems. [ABSTRACT FROM PUBLISHER]