Synchronous Transmission Research Articles

Local storage meets local demand: a technical solution to future power distribution system

Future power systems are expected to integrate large-scale stochastic and intermittent generation and load due to reduced use of fossil fuel resources, including renewable energy sources and electric vehicles (EV). Inclusion of such resources poses challenges for the dynamic stability of synchronous transmission and distribution networks, not least in terms of generation where system inertia may not be wholly governed by large-scale generation but displaced by small-scale and localised generation. Energy storage systems (ESS) can limit the impact of dispersed and distributed generation by offering supporting reserve while accommodating large-scale EV connection; the latter (load) also participating in storage provision. In this study, a local energy storage system (LESS) is proposed. The structure, requirement and optimal sizing of the LESS are discussed. Three operating modes are detailed, including: (i) storage pack management; (ii) normal operation; and (iii) contingency operation. The proposed LESS scheme is evaluated using simulation studies based on data obtained from the Northern Ireland regional and residential network.

Dynamic response of a carbon nanotube-based rotary nano device with different carbon-hydrogen bonding layout

In a nano rotational transmission system (RTS) which consists of a single walled carbon nanotube (SWCNT) as the motor and a coaxially arranged double walled carbon nanotube (DWCNT) as a bearing, the interaction between the motor and the rotor in bearing, which has great effects on the response of the RTS, is determined by their adjacent edges. Using molecular dynamics (MD) simulation, the interaction is analyzed when the adjacent edges have different carbon-hydrogen (CH) bonding layouts. In the computational models, the rotor in bearing and the motor with a specific input rotational speed are made from the same armchair SWCNT. Simulation results demonstrate that a perfect rotational transmission could happen when the motor and rotor have the same CH bonding layout on their adjacent ends. If only half or less of the carbon atoms on the adjacent ends are bonded with hydrogen atoms, the strong attraction between the lower speed (100GHz) motor and rotor leads to a synchronous rotational transmission. If only the motor or the rotor has CH bonds on their adjacent ends, no rotational transmission happens due to weak interaction between the bonded hydrogen atoms on one end with the sp1 bonded carbon atoms on the other end.

Performance analysis and transmission strategies comparison for synchronous WDM passive star LANs

Two synchronous transmission strategies suitable for optical WDM networks of passive star topology are presented in this study. The fiber bandwidth is divided into parallel WDM channels: the control and the data channels, while the number of control channels is less than the number of data channels. In particular, the control channels are used for the control information exchange prior to the data packet transmission, aiming to avoid the data channel collisions. This is achieved by effectively exploiting the propagation delay latency as appropriate acknowledgment time. The first transmission strategy performs the data channel collisions avoidance by allowing only one station per cycle to transmit over a data channel, employing appropriate transmission rules, like in [12]. On the other hand, the second transmission strategy (Improved Protocol) assigns to each control channel a dedicated data channel to ensure that each successfully transmitted control packet corresponds to a successful data packet transmission. Thus, it requires less processing overhead as compared to the first one. The performance of both the WDMA strategies are analytically studied based on Markovian models for finite population, while the performance measures are derived by closed mathematical formulas. The protocol performance is extensively studied for various number of stations, control and data channels. Finally, the comparison of the two protocols proves that second one essentially improves the throughput, while this improvement is an increasing function of the number of control channels.

Enabling interference-aware and energy-efficient coexistence of multiple wireless body area networks with unknown dynamics

This paper presents an adaptive interference mitigation scheme for multiple coexisting wireless body area networks (WBANs) based on social interaction. The proposed scheme considers the mobility of nodes within each WBAN as well as the relative movement of WBANs with respect to each other. With respect to these mobile scenarios traffic load, signal strength, and the density of sensors in a WBAN are incorporated to optimize transmission time with synchronous and parallel transmissions to significantly reduce the radio interference and energy consumption of nodes. This approach leads to higher packet delivery ratio (PDR) and longer network lifetime even with nodes dynamically moving into and out of each others interference region. We make channel assignment more energy-efficient and further reduce power consumption using transmit power control with simple channel prediction. Simulation results show that our approach maintains optimum spatial reuse with a range of channel dynamics within, and between, coexisting BANs. This protocol based on social interaction is shown to mitigate interference and minimize power consumption, and increase the spatial reuse and PDR of each WBAN, while increasing network lifetime. In the context of the adaptive interference mitigation scheme proposed, this paper also reviews the state of the art in literature on mobility, MAC layer, and power control solutions for WBANs, as well as providing a summary of interference mitigation schemes previously applied for the coexistence of WBANs.

Analysis of improved pulse-shaped RPRCC for synchronous and asynchronous MC-CDMA system under multi-user CFO estimation techniques

Long-term evolution (LTE) is one of the emerging fourth-generation (4G) standards for high-speed wireless networks. Due to the high spectral efficiency, large system capacity and robustness to multi-path fading, multi-carrier code division multiple access (MC-CDMA) system is a highly apt standard for 4G. However, MC-CDMA systems are more susceptible to carrier frequency offset (CFO) due to the discrepancy between the carrier frequencies of transmitter and receiver local oscillators. CFO effects loss of orthogonality among the subcarriers and introduces intercarrier interference (ICI). To reduce ICI and to confine the interference only to a limited number of neighbouring subcarriers, an improved pulse shaping with receiver phase rotated conjugate cancellation (RPRCC) scheme is proposed in this paper. Simulation results are provided to validate the performance of the proposed method using different spreading codes such as Walsh-Hadamard code, m-sequence and gold code in both synchronous and asynchronous transmissions.

Synchronous transmission of a Gong-Che notation musical score and its MIDI information

We present a watermarking algorithm to synchronously transmit Gong-Che notation musical scores and their musical instrument digital interface (MIDI) information. Our algorithm transforms the MIDI information into a binary sequence, which is used to form watermarking data. This watermark is embedded into the Gong-Che notation musical score image, using an inward clockwise rotation. The algorithm then uses optical music recognition to judge whether the musical information in the image is loss. Experiments have validated the effectiveness of our watermarking and expansion algorithms. The expansion process increases transmission accuracy, and the added processing time is minimal. Furthermore, our methodology can be applied to other musical notations such as conventional musical notation or numbered musical notation.

Efficient Mobile Fronthaul via DSP-Based Channel Aggregation

Mobile fronthaul is an important network segment that bridges wireless baseband units and remote radio units to support cloud radio access network. We review recent progresses on the use of frequency-division multiplexing to achieve highly bandwidth-efficient mobile fronthaul with low latency. We present digital signal processing (DSP) techniques for channel aggregation and deaggregation, frequency-domain windowing, adjacent channel leak age ratio reduction, and synchronous transmission of both the I/Q waveforms of wireless signals and the control words (CWs) used for control and management purposes. In a proof-of-concept experiment, we demonstrate the transmission of 48 20-MHz LTE signals with a common public radio interface (CPRI) equivalent data rate of 59 Gb/s, achieving a low round-trip DSP latency of <2 μs and a low mean error-vector magnitude (EVM) of ∼2.5% after fiber transmission. In a follow-up experiment, we further demonstrate the transmission of 32 20-MHz LTE signals together with CPRI-compliant CWs, corresponding to a CPRI-equivalent data rate of 39.32 Gb/s, in single optical wavelength channel that requires an RF bandwidth of only ∼1.6 GHz. After transmission over 5-km standard single-mode fiber, the CWs are recovered without error, while the LTE signals are recovered with an EVM of lower than 3%. Applying this technique to future 5G wireless networks with massive multiple-input multiple-output is also discussed. This efficient mobile fronthaul technique may find promising applications in future integrated fiber/wireless access networks to provide ultrabroadband access services.

The Study of Synchronous Belt Transmission Stability with the Influence of Rotation Speed and Tension

The vibration of belt affects the transmission stability, products noise and the life of automotive synchronous belt. The mathematical model of longitudinal vibration was established through analyzing the longitudinal vibration of automotive synchronous belt. The vibration dynamic measurement device was developed based on the laser displacement triangulation measurement principle, aiming at RU style arc teethed synchronous belt transmission process, measured the variety of amplitude over time at the middle of the belt span when rotation speed was 600r/min, 1200r/min, 1800r/min and tensile force was 320N, 480N, 640N, obtained the rules of amplitude and frequency change along with the variation of rotation speed and tensile force. It has significance on improving the transmission stability of arc teeth synchronous belt, reducing the transmission noise and prolonging the service life of belt.

Synchronization of an uncertain small-world neuronal network based on modified sliding mode control technique

In this paper, we propose a novel sliding mode control technique for synchronization transmission of information in a small-world neuronal network with uncertainty. First, we introduce the structure of small-world neuronal network. Then, we modified the sliding mode control technique to make it suitable for network synchronization. The control input of the small-world neuronal network and the adaptive law of the uncertain configuration coefficient can be effectively determined by using this modified technique. Finally, we compare our analytic results with numerical simulations through a few examples.

Remote videolaryngoscopy skills training for pre-hospital personnel.

Videolaryngoscopy (VL) is a novel technology that can facilitate rapid acquisition of intubation skills with simultaneous teacher and learner visualization of laryngeal structures. Videolaryngoscopy improves laryngeal visualization, and improves intubation success in difficult airway management compared to standard direct laryngoscopy. First responders need enhanced airway management tools to improve intubation success rates in civilian pre-hospital and military battlefield settings. We evaluated feasibility and efficacy of a remote first responder videolaryngoscopy skills training paradigm using distance learning by VTC (256kb ISDN) with synchronous transmission of laryngoscopy images to a remotely located trainer. Airway visualization, intubation success rates, and intubation times documented feasibility and comparability of remote and face-to-face introductory familiarization and intubation training with the Storz-Berci videolaryngoscopy system. User acceptance was good. Remote training paradigms for advanced technology solutions such as videolaryngoscopy can accelerate the diffusion of life-saving new technologies, especially when there is limited access to specialized training. Videolaryngoscopy visualization and difficult airway intubation success rates were better than direct laryngoscopy.

Study on the dynamics responses of a transmission system made from carbon nanotubes

A rotational transmission system from coaxial carbon nanotubes (CNTs) is investigated using a computational molecular dynamics approach. The system consists of a motor from a single-walled carbon nanotube and a bearing from a double-walled carbon nanotube. The motor has a high fixed rotational frequency and the two ends of the outer tube in the bearing are fixed. The inner tube in the bearing works as a rotor. Because of the interlayer friction in the bearing, configurations of the joint between the adjacent ends of motor and rotor have significant effects on rotational transmission properties. Four factors are considered in simulation, i.e., the bonding types of atoms (sp1 and sp2) on the ends of motor and rotor, the difference between motor and rotor radii, the rotational speed of motor, and the environmental temperature. It is found that the synchronous transmission happens if the sp1 atoms on the jointed ends of motor and rotor are bonded each other and become new sp2 atoms. Therefore, the lower difference between radii of motor and rotor, higher temperature of environment leads to synchronous rotational transmission easily. If the environmental temperature is too low (e.g., &amp;lt;150 K), the end of motor adjacent to rotor is easily under buckling and new sp2 atoms appear, too. With capped CNTs or higher radii difference between rotor and motor at an appropriate temperature, a stable asynchronous rotation of rotor can be generated, and the rotor's frequency varying linearly with motor's frequency between 230 and 270 GHz. A multi-signal transmission device combined with oscillating and rotational motion is proposed for motor and stator shares a same size in radius.

Improving Energy Adaptivity of Constructive Interference-Based Flooding for WSN-AF

Constructive interference (CI) is a synchronous transmission technique for multiple senders transmitting the same packet simultaneously in wireless sensor networks (WSNs). CI enables fast and reliable network flooding in order to reduce the scheduling overhead of MAC protocols, to achieve accurate time synchronization, to improve link quality of lossy links, and to realize efficient data collection. By achieving microsecond level time synchronization, Glossy realizes millisecond level CI-based flooding and 99% reliability. However, Glossy produces substantial unnecessary data forwarding, which significantly reduces the network lifetime. This is a very critical problem, especially in energy-limited large-scale wireless sensor networks for agriculture and forestry (WSN-AF) system. In this paper, we present an energy adaptive CI-based flooding protocol (EACIF) by exploiting CI in WSN-AF. EACIF proposes a distributed active nodes selection algorithm (ANSA) to reduce redundant transmissions, thereby significantly reducing energy consumption and flooding latency. We estimate the performance of EACIF both with real data traces and with uniformly distributed topology. Simulation results show that EACIF achieves almost the same packet reception ratio (PRR) as Glossy (e.g., 99%), while reducing 63.96% energy consumption. EACIF also reduces 25% flooding latency. When the packet interval is 30 seconds, EACIF achieves 0.11% duty cycle.

A Novel Watermarking Method for Synchronous Transmission of Gong-Che Notation Score and its MIDI Information

In this paper, a new watermarking algorithm to realize synchronous transmission of Gong-Che Notation musical score image and its MIDI information was been present. Firstly, it transforms the MIDI information to a sequence of 0 1 codes which is the watermarking data, then it embeds the watermarking data into the Gong-Che Notation musical score image by clockwise inward rotating order, finally, it judges whether the Gong-Che Notation musical score image need expand to avoid loss musical information by computing number of connected component labeling. Experiments shows that the expanded times are no more than Len(M(2))/(2H*W).

Reduced endogenous Ca2+ buffering speeds active zone Ca2+ signaling

Fast synchronous neurotransmitter release at the presynaptic active zone is triggered by local Ca(2+) signals, which are confined in their spatiotemporal extent by endogenous Ca(2+) buffers. However, it remains elusive how rapid and reliable Ca(2+) signaling can be sustained during repetitive release. Here, we established quantitative two-photon Ca(2+) imaging in cerebellar mossy fiber boutons, which fire at exceptionally high rates. We show that endogenous fixed buffers have a surprisingly low Ca(2+)-binding ratio (∼ 15) and low affinity, whereas mobile buffers have high affinity. Experimentally constrained modeling revealed that the low endogenous buffering promotes fast clearance of Ca(2+) from the active zone during repetitive firing. Measuring Ca(2+) signals at different distances from active zones with ultra-high-resolution confirmed our model predictions. Our results lead to the concept that reduced Ca(2+) buffering enables fast active zone Ca(2+) signaling, suggesting that the strength of endogenous Ca(2+) buffering limits the rate of synchronous synaptic transmission.

Synchronization Sequence Generated by Modified Park Algorithm for NC-OFDM Transmission

The traditional schemes for the synchronization in the OFDM transmission, such as the Schmidl&Cox, Minn and Park algorithms, utilize the only every second or fourth subcarriers of the preamble symbol. This regular subcarrier occupation pattern does not meet the requirement of Non-Continuous OFDM (NC-OFDM) with the arbitrary spectrum holes free from the interference with the primary users. In this letter, a special synchronization sequence with non-continuous spectrum is constructed and can be evaluated at the receiver with a modified version of the Park algorithm. Our new synchronization concept not only complies with the traditional Park algorithm, but also has the considerable smaller sidelobes in the correlation function evaluated for the time synchronization, so that a higher synchronization detection probability is obtained.

Investigation of manual transmission synchronizer failure mechanism induced by interface material/lubricant combinations

To better understand the effects of interface material/lubricant combinations on the failure mechanism of a certain type of manual transmission synchronizer, a gear shift experiment was performed on the custom-built apparatus. After the experiment which ran for thousands of simulated shifts, the surfaces of friction material were analyzed by a non-contact surface profiler, and the Fe content contained in gear oil was measured by atomic emission spectrometry. The results show that with an increase of the number of shifts the surfaces became smoother, which in turn caused a decrease in the contact temperature and local asperity pressure. The increment of Fe content in the gear oil decreased gradually, which signified that a thick oil film had formed between the contact surfaces. Therefore, the oil film became very much stable. The contribution of solid/solid interactions on the friction coefficient continued to reduce as the liquid gradually dominated performance. Due to the low friction coefficient, quick synchronization became unavailable and when any gear shocks occurred, it meant that the synchronizer was not performing as intended.

The signal synchronization transmission among uncertain discrete networks with different nodes

This paper investigates the signal synchronization transmission among uncertain discrete networks with different nodes based on Lyapunov theorem. A novel synchronization technique and an identification law of adjustment parameter are designed. In order to testify the effectiveness of synchronization technique, laser phase-conjugate wave, Gibbs electro-optical system and Bragg acousto-optical system are taken as the nodes of the complex networks to make a simulation. It shows the synchronization technique can be applied to any network connected arbitrarily, and the network number and the number of network nodes can be selected freely.

Multiuser-Interference-Free Space–Time Spreading MIMO Systems Based on Three-Dimensional Complementary Codes

This paper proposes a new type of complementary code, i.e., 3-D complementary code (3DCC), which integrates space-time coding and code division multiple access under a unified framework for multiple-input-multiple-output (MIMO) system implementation. Owing to its ideal correlation properties, the 3DCC ensures orthogonal transmissions among users and antennas. Analytical studies given in this paper will show that the proposed 3DCC-MIMO system is able to support both transmit diversity and multiplex at the same time, with its unique agility to switch between them according to different channel environments and system configurations. Additionally, multiuser interference (MUI) is eliminated in a 3DCC-MIMO system for both synchronous and asynchronous transmissions over a flat-fading channel with a relatively low complexity. Simulation results are also provided to verify the correctness of analysis and demonstrate the superiority of the proposed MIMO system in terms of its MUI-free performance.

The MOA Live Detection System Based on Wireless Synchronization

The MOA is the main lightning protection equipment in power system, The status is generally monitored by online monitoring and offline test in routine maintenance. Traditional MOA live detection requires a lot of wiring, and has operation problems and safety risks. A new distributed MOA online monitoring wireless measurement is presented in this paper, that is, 433M wireless transmission and GPS clock synchronization technology fulfill distributed wireless synchronization measurement in MOA online monitoring device. Focusing on the design principles, implementation methods and the device composition, it is indicated that the wireless synchronization testing result is same with wired synchronization testing result, which can meet the requirements of MOA online monitoring.

Role for electrical synapses in shaping the output of coupled peptidergic neurons from Lymnaea

Electrically coupled neurons communicate through channel assemblies called gap junctions, which mediate the transfer of current from one cell to another. Electrical synapses ensure spike synchronization and reliable transmission, which influences bursting patterns and firing frequency. The present study concerns an electrically coupled two-neuron network in the gastropod mollusc, Lymnaea stagnalis. The neurons, designated Visceral Dorsal 1 (VD1) and Right Parietal Dorsal 2 (RPD2), are peptidergic, innervate aspects of the cardio-respiratory system, and show strong coupling, such that they fire synchronously. Using dual sharp-electrode current-clamp recording and morphological staining in isolated brain preparations, the hypothesis that the electrical synapse is necessary for accurate network output was tested. We found that both cells make extensive projections within and out of the brain, including across the visceral–parietal connective, which links VD1 and RPD2. Cutting this connective uncoupled the neurons and disrupted the firing rate and pattern of RPD2 more than VD1, consistent with VD1 being the master and RPD2 the follower. The electrical synapse was inhibited by select gap junction blockers, with niflumic acid and 5-nitro-2-(3-phenylpropylamino) benzoic acid decreasing the VD1→RPD2 and RPD2→VD1 coupling coefficients, whereas carbenoxolone, α-glycyrrhetinic acid, meclofenamic acid, and quinine were ineffective. There was little-to-no impact on VD1↔RPD2 firing synchrony or frequency when coupling was reduced pharmacologically. However, in the presence of gap junction blockers, suppressing the activity of VD1 by prolonged hyperpolarization revealed a distinct, low-frequency firing pattern in RPD2. This suggests that strong electrical coupling is key to maintaining a synchronous output and proper firing rate.