Bidirectional Control Research Articles

Human TNFR2 Exhibits Bi-Directional Control over Regulatory T Cells

Human TNFR2 Exhibits Bi-Directional Control over Regulatory T Cells

Matrix converter for static synchronous series compensator using cooperative bacteria foraging optimisation

Static synchronous series compensator (SSSC) is utilised for power flow control and reactive power compensation in transmission lines. In this paper, a new configuration of SSSC based on matrix converter is presented. The proposed SSSC has various advantages over traditional one. It is recognised by bi-directional power flow control capability, elimination of the DC-link, fast dynamic response and simple control system. Using the introduced switching algorithm for ac/ac matrix converter, an approximately sinusoidal series compensation voltage is injected to transmission line with low total harmonic distortion. The optimal parameters of power flow controller are achieved by using cooperative bacterial foraging optimisation. The proposed SSSC is tested at different operating condition by using MATLAB/Simulink software. Results show that the designed control strategy with the new SSSC topology is robust against sudden changes in active and reactive power flow. As well as, it copes significantly with symmetrical and asymmetrical faults conditions. Finally, measurements of system performance validate the proposed technique and emphasise its feasibility.

Two-sided wave-absorbing control of a heterogenous vehicular platoon

The paper tailors the so-called wave-absorbing control designed for a homogenous platoon of vehicles to a platoon where dynamics of vehicles differ. The proposed solution is based on the symmetric bidirectional control of the in-platoon vehicles and wave-absorbing control of the platoon ends. This type of control reduces oscillations of vehicle's velocities and significantly decrease the settling time of the platoon by absorbing waves on the platoon ends. The necessary transfer-function-based mathematical apparatus for description of the so-called soft boundary is also presented. Although the soft boundary is a virtual boundary located between the vehicles of different dynamics, it significantly alters the behaviour of the platoon. It is shown how to incorporate model of the soft boundary into the design of the wave-absorbing control such that its effect is minimized. The proposed control scheme is verified on numerous mathematical simulations.

HOLOGRAPHIC OPTICAL ELEMENTS FOR BEAUTIFICATION

In this research, holographic optical element appli ed for beautification recorded in holographic surfa ce relief photoresist. Various symmetric periodic structure with high diff raction efficiency in photosensitive material depen ds on various recording geometry parameters are explained. We used holograp hic dual beam multiple interference method for this pattern creation. A long range periodicity confirmed with the help of o ptical microscope, laser light diffraction and scan ning electron microscope. Combination of symmetric structured holographic opt ical elements, DPSS laser source and bi-directional RPM controller results the proto type HOLO-DRZZLER product. Our auspicious aim is to commercialize and our product is mainly meant for outdoor beautification application. Index Terms: Holography, photoresist, holographic decoration, l aser and holographic optical element

Stable Decentralized Control of a Platoon of Vehicles With Heterogeneous Information Feedback

The problem of controlling a string of vehicles moving in one dimension is considered so that they all follow a lead vehicle with constant spacing between successive vehicles. Due to practical design and implementation, the negative effect of the tracking lag parameter is taken into account. A hierarchical platoon controller design framework is established comprising a feedback linearization controller at the first layer and a decentralized bidirectional control controller at the second layer. The stability criterion is examined by using a partial differential equation approximation in the limit of the number of vehicles subjected to unequal asymmetry in position and velocity feedback. For disturbance attenuation, string stability analysis is also examined. At the end of the paper, simulations are given to show the efficiency of the proposed results.

The infralimbic cortex bidirectionally modulates mesolimbic dopamine neuron activity via distinct neural pathways.

The ventral tegmental area (VTA) has been implicated in a number of psychiatric disorders, including schizophrenia, depression, and bipolar disorder. One major regulator of the mesolimbic dopaminergic system is the medial prefrontal cortex (mPFC), which makes direct and indirect connections to the hippocampus and amygdala, as well as directly to the VTA. The mPFC is comprised of two subregions: the infralimbic and prelimbic cortices (ilPFC and plPFC). However, the specific roles of these subregions in regulating VTA dopamine activity have remained unclear. In this study, we aim to clarify this role and to examine the divergent neuranatomical circuits by which the mPFC regulates VTA activity. Using in vivo extracellular recordings in rats, we tested the effects of pharmacological activation (with NMDA) and inactivation (with TTX) of the ilPFC and plPFC on dopamine neuron activity, and tested the roles of the ventral subiculum (vSub) and basolateral amygdala in this process. We found that the ilPFC exerts a bidirectional control of VTA dopamine neurons, which are differentially modulated through the vSub and the basolateral amygdala. Specifically, activation or inactivation of the ilPFC attenuated or activated dopamine neuron population activity, respectively. Furthermore, dopamine activation depended on the ventral hippocampus and inactivation on the amygdala. In contrast, only inactivation of the plPFC altered dopamine neuron activity. These data indicate that the mPFC has the ability to uniquely fine-tune dopaminergic activity in the VTA. Furthermore, the data presented here suggest that the ilPFC may have a role in the pathophysiology of psychiatric disorders.

The Design and Application of SVG for Low Voltage Distribution Networks

SVG can compensate reactive power deficiency, suppress harmonics, improve three-phase imbalance and power quality more flexibly. There are very few small volume SVG products available for low voltage distribution network in the past. The generic SVG products are very expansive, thus not suitable for low voltage distribution network. Therefore, it is an urgent task to design a new generation distribution network SVG product that offers good value for money. This paper studied a SVG digital controller based on TMS320F28335 DSP chip. The fast and powerful computing and parallel operation capability of TMS320F28335 can satisfy the real-time, multifunction and multiple objective coordination control of SVG. Applied the instantaneous reactive power theory and adopted current direct control mode, an enhanced filtering algorithm to filter instantaneous sampling value is proposed. Automatic bi-directional compensation control strategy effectively reduced voltage variation at the user side. Its effectiveness is verified by an engineering project.

Research on Remote Network Bidirectional Detect and Control Model

Remote network bidirectional detect and control technologies are the key factors to solve local network allopatry expansibility and management. With studying gateway integration technology, bidirectional VPN technology, identity authentication technology and dynamic host management technology can be integrated into gateway. Thus, bidirectional connect and control among allopatry local networks based on Internet can be solved. Whole area expansibility of local network is realized. With experiment, the model is proved to finish remote bidirectional interconnection of local network automatically and to obtain allopatry local users authority. The equipment detecting and controlling in remote local networks are realized. DOI: http://dx.doi.org/10.11591/telkomnika.v11i9.3243 Full Text: PDF

Bidirectional modulation of hippocampal gamma (20–80 Hz) frequency activity in vitro via alpha(α)- and beta(β)-adrenergic receptors (AR)

Noradrenaline (NA) in the hippocampus plays an important role in memory function and has been shown to modulate different forms of synaptic plasticity. Oscillations in the gamma frequency (20–80Hz) band in the hippocampus have also been proposed to play an important role in memory functions and, evidence from both in vitro and in vivo studies, has suggested this activity can be modulated by NA. However, the role of different NA receptor subtypes in the modulation of gamma frequency activity has not been fully elucidated. We have found that NA (30μM) exerts a bidirectional control on the magnitude of kainate-evoked (50–200nM) gamma frequency oscillations in the cornu Ammonis (CA3) region of the rat hippocampus in vitro via activation of different receptor subtypes. Activation of alpha-adrenergic receptors (α-AR) reduced the power of the gamma frequency oscillation. In contrast, activation of beta-adrenergic receptors (β-AR) caused an increase in the power of the gamma frequency oscillations. Using specific agonists and antagonists of AR receptor subtypes we demonstrated that these effects are mediated specifically via α1A-AR and β1-AR subtypes. NA activated both receptor subtypes, but the α1A-AR-mediated effect predominated, resulting in a reversible suppression of gamma frequency activity. These results suggest that NA is able to differentially modulate on-going gamma frequency oscillatory activity that could result in either increased or decreased information flow through the hippocampus.

A Bidirectional System for the Dynamic Small Molecule Control of Intracellular Fusion Proteins

Small molecule control of intracellular protein levels allows temporal and dose-dependent regulation of protein function. Recently, we developed a method to degrade proteins fused to a mutant dehalogenase (HaloTag2) using small molecule hydrophobic tags (HyTs). Here, we introduce a complementary method to stabilize the same HaloTag2 fusion proteins, resulting in a unified system allowing bidirectional control of cellular protein levels in a temporal and dose-dependent manner. From a small molecule screen, we identified N-(3,5-dichloro-2-ethoxybenzyl)-2H-tetrazol-5-amine as a nanomolar HALoTag2 Stabilizer (HALTS1) that reduces the Hsp70:HaloTag2 interaction, thereby preventing HaloTag2 ubiquitination. Finally, we demonstrate the utility of the HyT/HALTS system in probing the physiological role of therapeutic targets by modulating HaloTag2-fused oncogenic H-Ras, which resulted in either the cessation (HyT) or acceleration (HALTS) of cellular transformation. In sum, we present a general platform to study protein function, whereby any protein of interest fused to HaloTag2 can be either degraded 10-fold or stabilized 5-fold using two corresponding compounds.

Multiphase Zero-Current Switching Bidirectional Converters and Battery Energy Storage Application

A multiphase quasi-resonant (QR) zero-current switching (ZCS) switched capacitor (SC) bidirectional dc-dc converter structure is proposed to reduce current ripple and switching loss, and significantly increase converter efficiency and power density. This approach provides a more precise output voltage to obtain voltage conversion ratios from the double-mode versus half-mode to <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> -mode versus 1/ <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> mode. This is accomplished by adding a different number of switched capacitors and power MOSFET switches with a small series connected resonant inductor for forward and reverse schemes. The size and cost can be reduced when the proposed converter is designed with coupled inductors. Simulation and experimental results demonstrate four-phase with and without coupled inductor interleaved QR ZCS SC converter performance for bidirectional power flow control applications. A battery energy storage system for a bidirectional power flow control application is demonstrated.

Direct-pathway striatal neurons regulate the retention of decision-making strategies.

The dorsal striatum has been implicated in reward-based decision making, but the role played by specific striatal circuits in these processes is essentially unknown. Using cell phenotype-specific viral vectors to express engineered G-protein-coupled DREADD (designer receptors exclusively activated by designer drugs) receptors, we enhanced Gi/o- or Gs-protein-mediated signaling selectively in direct-pathway (striatonigral) neurons of the dorsomedial striatum in Long-Evans rats during discrete periods of training of a high versus low reward-discrimination task. Surprisingly, these perturbations had no impact on reward preference, task performance, or improvement of performance during training. However, we found that transiently increasing Gi/o signaling during training significantly impaired the retention of task strategies used to maximize reward obtainment during subsequent preference testing, whereas increasing Gs signaling produced the opposite effect and significantly enhanced the encoding of a high-reward preference in this decision-making task. Thus, the fact that the endurance of this improved performance was significantly altered over time-long after these neurons were manipulated-indicates that it is under bidirectional control of canonical G-protein-mediated signaling in striatonigral neurons during training. These data demonstrate that cAMP-dependent signaling in direct-pathway neurons play a well-defined role in reward-related behavior; that is, they modulate the plasticity required for the retention of task-specific information that is used to improve performance on future renditions of the task.

Optimal design of wireless monitoring system in mountain citrus orchard and improvement monitoring

In order to monitor in real time the growth environment of a mountain citrus orchard and its variation with spatio-temporal and weather status, the optimal design and evaluation of a wireless monitoring system in a mountain citrus orchard was introduced in this paper. The wireless monitoring system is comprised of end nodes used for obtaining citrus growth environment information including air temperature, air humidity, soil moisture and light; router nodes used to relay citrus growth environment information; and a network coordinator, which performs functions such as managing the nodes, collecting and analyzing the data received from the end nodes, and connecting as a gateway for remote data access. CC2530 is adopted as the core processor of the monitoring system; it has the capability of wireless communication and central processing. The optimal design was introduced in this system including information frame structure suitable for a mountain orchard environment, bidirectional instruction control function, topology discovery, routing monitoring mechanism and node information diversification collection mechanism, so as to effectively enhance the robustness and controllability of monitoring the citrus orchard environment. In this paper, the citrus orchard in the subtropical garden of SCAU (South China Agriculture University) was selected for the test. The orchard hill has sloping terrain; citrus trees are planted by terraced distribution. The average slope is 20 degrees, the citrus trees have a height of 2.8m, their shrub diameters are 3m, and the average spacing of citrus plants is 2.8m. The citrus orchard wireless channel was measured in citrus orchard, and the wireless channel model was established through blocking factor and rain attenuation factor, it was used to guide the evaluation of the wireless monitoring network. Experimental results of RSSI (Receiver Signal Strength Index) and communication quality under different distances and climates show that reliable collection and transmission were available in the mountain citrus orchard when the wireless system was deployed with an antenna height of 1.5m and a maximum single-hop communications distance of 30m. Continuous 744h online test results show that the optimized wireless monitoring system improved the transmission success rate; it has a success rate of at least 99.12% for data transmission within the 30m distance. The system ran well, worked stably, and was suitable for the remote, real-time monitoring of the citrus growth environment in a mountainous orchard.

A 10-kW Two-Stage Isolated/Bidirectional DC/DC Converter With Hybrid-Switching Technique

This paper suggests a two-stage isolated/bidirectional dc/dc converter with hybrid-switching technique. High-frequency bidirectional resonant converter with a fixed gain can reduce the bulky transformer size by minimizing Insulated Gate Bipolar Junction Transistor (IGBT) turn-off loss due to tail current, and it forms bidirectional power flow without any control operation. Pulsewidth-modulation nonisolated converter takes in charge of bidirectional control, and its serious turn-off switching loss is alleviated using MOSFET-assisted hybrid-switching structure. The proposed scheme provides low switching loss and removes snubber circuitry so a high efficiency and a high power density can be obtained in high-voltage/high-power bidirectional applications.

역보행 제어 형태의 궤환 선형화를 이용한 양방향 플래툰 제어

This paper proposes a bidirectional platoon control law using a coupled distance error based on the backstepping-like feedback linearization control method for an interconnected mobile agent system with a string structure. Unlike the previous results where the single agent was controlled using the only own information without other agents, the proposed control law cannot show the only distance error convergence of each agent, but also the string stability of the whole system. Also, the control performances are improved by the proposed control law in spite of low performance of bidirectional control strategy in the previous results. The proposed bidirectional platoon control algorithm is based on the backstepping-like feedback linearization control method. The position errors between each agent and the preceding and the behind agents are coupled by weighted summation. By the proposed control law, the distance error of each agent can converge to zero while the string stability is guaranteed when the coupled errors can converge to zero. To this end, the back-stepping control method is employed. The pseudo velocity input is determined considering the kinematic relationship between agents and the string stability. Then, the actual dynamic control input is determined to make the actual velocity converge to the pseudo velocity input. The stability analysis and the simulation results of the proposed method are included in order to demonstrate the practical application of the proposed algorithm.

Plating pulse switching power based on a CPLD

This paper presents a method of using a CPLD to generate a PWM trigger pulse to a full bridge inverter and a chopper circuit. This method results in a very good high power and low voltage large current pulse plating power supply. A single-chip microcomputer is the core of the feedback control system. A fuzzy PID algorithm with SCM and CPLD complexes precisely controls the output voltage, allowing it to maintain a constant value. The system contains a protection circuit that detects output current and output voltage and can correct the system if it enters an over-current abnormal state, ensuring that the driving circuit can effectively drive the IGBT. The circuit is also protected by setting the inverter frequency and dead time of a digital PWM chip. This method for bidirectional pulse plating power supply digital control was verified to be correct and practicable by a Matlab software simulation.

Lateral hypothalamus as a sensor-regulator in respiratory and metabolic control

Physiological fluctuations in the levels of hormones, nutrients, and gasses are sensed in parallel by interacting control systems distributed throughout the brain and body. We discuss the logic of this arrangement and the definitions of “sensing”; and then focus on lateral hypothalamic (LH) control of energy balance and respiration. LH neurons control diverse behavioral and autonomic processes by projecting throughout the neuraxis. Three recently characterized types of LH cells are discussed here. LH orexin/hypocretin (ORX) neurons fire predominantly during wakefulness and are thought to promote reward-seeking, arousal, obesity resistance, and adaptive thermogenesis. Bidirectional control of ORX cells by extracellular macronutrients may add a new regulatory loop to these processes. ORX neurons also stimulate breathing and are activated by acid/CO2in vivo and in vitro. LH melanin-concentrating hormone (MCH) neurons fire mostly during sleep, promote physical inactivity, weight gain, and may impair glucose tolerance. Reported stimulation of MCH neurons by glucose may thus modulate energy homeostasis. Leptin receptor (LepR) neurons of the LH are distinct from ORX and MCH neurons, and may suppress feeding and locomotion by signaling to the mesolimbic dopamine system and local ORX neurons. Integration within the ORX–MCH–LepR microcircuit is suggested by anatomical and behavioral data, but requires clarification with direct assays of functional connectivity. Further studies of how LH circuits counteract evolutionarily-relevant environmental fluctuations will provide key information about the logic and fragilities of brain controllers of healthy homeostasis.

Grid-Interface Bidirectional Converter for Residential DC Distribution Systems—Part One: High-Density Two-Stage Topology

With the emerging installations of multitype renewable energy sources and energy storage elements, the dc electronic distribution systems in residential buildings (dc nanogrid) are becoming an alternative future system solution, achieving a zero net-energy consumption and optimized power management. The concept of the energy control center (ECC), which interconnects the dc system to the traditional ac utility grid, is introduced, and the operation function of ECC converter suitable for dc nanogrid application is defined. This paper investigates a two-stage topology using a full bridge in series with a bidirectional synchronous rectifier dc–dc converter as a single-phase ECC for dc nanogrid, with a significant reduction of the dc-link capacitor value. The operation analysis and the design of passive components are provided. A bidirectional control system and the design process are also presented in terms of the system requirement and the small dc-link capacitor.

A Calcineurin Docking Motif (LXVP) in Dynamin-related Protein 1 Contributes to Mitochondrial Fragmentation and Ischemic Neuronal Injury

Fission and fusion events dynamically control the shape and function of mitochondria. The activity of the mitochondrial fission enzyme dynamin-related protein 1 (Drp1) is finely tuned by several post-translational modifications. Phosphorylation of Ser-656 by cAMP-dependent protein kinase (PKA) inhibits Drp1, whereas dephosphorylation by a mitochondrial protein phosphatase 2A isoform and the calcium-calmodulin-dependent phosphatase calcineurin (CaN) activates Drp1. Here, we identify a conserved CaN docking site on Drp1, an LXVP motif, which mediates the interaction between the phosphatase and mechanoenzyme. We mutated the LXVP motif in Drp1 to either increase or decrease similarity to the prototypical LXVP motif in the transcription factor NFAT, and assessed stability of the mutant Drp1-CaN complexes by affinity precipitation and isothermal titration calorimetry. Furthermore, we quantified effects of LXVP mutations on Drp1 dephosphorylation kinetics in vitro and in intact cells. With tools for bidirectional control of the CaN-Drp1 signaling axis in hand, we demonstrate that the Drp1 LXVP motif shapes mitochondria in neuronal and non-neuronal cells, and that CaN-mediated Drp1 dephosphorylation promotes neuronal death following oxygen-glucose deprivation. These results point to the CaN-Drp1 complex as a potential target for neuroprotective therapy of ischemic stroke.

Coordination between the fore- and hindlimbs is bidirectional, asymmetrically organized, and flexible during quadrupedal locomotion in the intact adult cat

Despite the obvious importance of inter-girdle coordination for quadrupedal locomotion in terrestrial mammals, its organization remains poorly understood. Here, we evaluated cycle and phase durations, as well as footfall patterns of four intact adult cats trained to walk on a transverse split-belt treadmill that could independently control fore- and hindlimb speed. When the hindlimbs walked at faster speeds than the forelimbs, an equal rhythm was always maintained between the fore- and hindlimbs, even at the highest fore–hindlimb speed ratio of 1:3 (0.4:1.2m/s). The locomotor pattern adjusted through changes in both hindlimb stance and swing phase durations, whereas only the forelimb stance phase was affected. In such conditions, when fore- and hindlimb values were compared to those obtained at matched speeds during tied-belt walking (i.e. predicted values based on treadmill speed), hindlimb cycle, stance and swing durations were consistently longer than predicted. On the other hand, forelimb cycle and stance durations were shorter than predicted but only at the highest split-belt speed ratios. Forelimb swing durations were as predicted based on front-belt speed. The sequence of footfall pattern when hindlimb speed was faster was identical to tied-belt walking. In stark contrast, when the forelimbs walked at slightly faster speeds than the hindlimbs, the rhythm between the fore- and hindlimbs broke down. In such conditions, the locomotor pattern was adjusted through changes in stance and swing phase durations in both the fore- and hindlimbs. When the rhythm between the fore- and hindlimbs broke down, hindlimb cycle and phase durations were similar to predicted values, whereas forelimb values were shorter than predicted. Moreover, several additional sequences of footfall patterns were observed. Therefore, the results clearly demonstrate the existence of a bidirectional, asymmetric, and flexible control of inter-girdle coordination during quadrupedal locomotion in the intact adult cat.