Multiple Interconnected Areas Research Articles

ARTIFICIAL INTELLIGENCE OPTIMIZED CONTROLLER DESIGN FOR AUTOMATIC GENERATION CONTROL IN RESTRUCTURED POWER SYSTEMS

This paper presents an investigation on automatic generation control (AGC) in restructured power systems with multiple interconnected areas and multiple machines. A particle swarm optimized combined optimal fuzzy controller has been proposed. The results obtained with the proposed controller have been compared with the conventional PI controller and optimal controller to exhibit its robust performance. Furthermore, the proposed controller aims to rapidly achieve zero deviations in frequency and tie line power, thereby maintaining system synchronism. The PSO-optimized combined optimal fuzzy controller demonstrates superior performance in terms of peak transient deviation, settling periods, and dynamic oscillations compared to other controllers.

Receptive language and receptive-expressive discrepancy in minimally verbal autistic children and adolescents.

Among the approximately one-third of autistic individuals who experience considerable challenges in acquiring spoken language and are minimally verbal (MV), relatively little is known about the range of their receptive language abilities. This study included 1579 MV autistic children and adolescents between 5 and 18 years of age drawn from the National Database for Autism Research and the SFARI Base data repository. MV autistic children and adolescents demonstrated significantly lower receptive language compared to the norms on standardized language assessment and parent report measures. Moreover, their receptive language gap widened with age. Overall, our sample demonstrated significantly better receptive than expressive language. However, at the individual level, only about 25% of MV autistic children and adolescents demonstrated significantly better receptive language relative to their minimal expressive levels. Social skills explained a significant proportion of the variance in parent-reported receptive language skills, while motor skills were the most significant predictor of greater receptive-expressive discrepancy. Findings from this study revealed the heterogeneous language profiles in MV autistic children and adolescents, underscoring the importance of individualizing interventions to match their different communication strengths and needs and integrating multiple interconnected areas to optimize their overall development of language comprehension, socialization, and general motor skills.

Enhancement the Frequency Stability and Protection of Interconnected Microgrid Systems Using Advanced Hybrid Fractional Order Controller

Substituting conventional energy sources with new renewable sources is crucial issue nowadays in energy generation systems to face climate changes and increased load demands. Due to the increased penetration levels of renewable sources in power systems, the benefits of the high-inertia of conventional sources are being insufficient. The resulting low-inertia power systems introduce several stability, reliability, and coordination problems for power system operation and control. Therefore, this paper tackles the coordination assessment and enhancement between digital frequency relays using a new fractional order load frequency controller equipped with superconducting magnetic energy storage (SMES) virtual inertia system. The improved coordination method is established using optimized fractional order controller based on slime mould optimization algorithm (SMA). The proposed SMA-based design method benefits the adaptive weights of SMA algorithm. The proposed design is generalized to be applied on single area and multi-area interconnected power systems as well. Compared to existing literature, this paper presents an advanced fractional order controller with coordinated operation with existing protection relays. The obtained results show the coordination shortcomings of renewable energy based microgrids with traditional control systems. However, improved design and coordination are obtained using the proposed SMA-optimized fractional order controllers. The superiority and feasibility of the proposed analysis and methods are verified on different case studies using single and multiple interconnected areas.

Controlling the Mitigating Impacts of Communication Delay on Load Frequency Control with an Adaptive Method

Abstract: Load Frequency Control is one of the most essential frequency management technologies in modern power systems (LFC). When employing LFC over a vast region, communication latency is unavoidable. A delay might not only affect system performance but also cause system instability. An alternate design strategy for constructing delay compensators for LFC in one or more control areas utilising an AFPI controller and ANFIS is proposed in this paper. For one-area LFC, a sufficient and required condition for designing a delay compensator is described. It is demonstrated that for multi-area LFC with Area Control Errors (ACEs), each control area can have its own delay controller designed as if it were a one-area system if the index of coupling among the areas is less than the small gain theorem's threshold value. The effectiveness of the proposed technique is validated by simulation experiments on LFCs with communication delays in one and multiple interconnected areas with and without time variable delays.

An alternative method for mitigating impacts of communication delay on load frequency control

Load frequency control (LFC) has been considered as one of the most important frequency regulation mechanisms in modern power system. One of the inevitable problems involved in LFC over a wide area is communication delay. Not only can the delay deteriorate the system performance but also cause system instability. In this paper, an alternative design method is proposed to devise delay compensators for LFC in one or multiple control areas. For one-area LFC, a sufficient and necessary condition is given for designing a delay compensator. For multi-area LFC with area control errors (ACEs), it is demonstrated that each control area can have its delay controller designed as that in a one-area system if the index of coupling among the areas is below the threshold value determined by the small gain theorem. Effectiveness of the proposed method is verified by simulation studies on LFCs with communication delays in one and multiple interconnected areas with and without time-varying delays, respectively.

A simple, inexpensive method for subcortical stereotactic targeting in nonhuman primates

BackgroundMany current neuroscience studies in large animal models have focused on recordings from cortical structures. While sufficient for analyzing sensorimotor systems, many processes are modulated by subcortical nuclei. Large animal models, such as nonhuman primates (NHP), provide an optimal model for studying these circuits, but the ability to target subcortical structures has been hampered by lack of a straightforward approach to targeting. New MethodHere we present a method of subcortical targeting in NHP that uses MRI-compatible titanium screws as fiducials. The in vivo study used a cellular marker for histologic confirmation of accuracy. ResultsHistologic results are presented showing a cellular stem cell marker within targeted structures, with mean errors ± standard deviations (SD) of 1.40 ± 1.19 mm in the X-axis and 0.9 ± 0.97 mm in the Z-axis. The Y-axis errors ± SD ranged from 1.5 ± 0.43 to 4.2 ± 1.72 mm. Comparison with existing methodsThis method is easy and inexpensive, and requires no fabrication of equipment, keeping in mind the goal of optimizing a technique for implantation or injection into multiple interconnected areas. ConclusionThis procedure will enable primate researchers to target deep, subcortical structures more precisely in animals of varying ages and weights.

High field imaging of large-scale neurotransmitter networks: Proof of concept and initial application to epilepsy.

The brain can be considered a network, existing of multiple interconnected areas with various functions. MRI provides opportunities to map the large-scale network organization of the brain. We tap into the neurobiochemical dimension of these networks, as neuronal functioning and signal trafficking across distributed brain regions relies on the release and presence of neurotransmitters. Using high-field MR spectroscopic imaging at 7.0 T, we obtained a non-invasive snapshot of the spatial distribution of the neurotransmitters GABA and glutamate, and investigated interregional associations of these neurotransmitters. We demonstrate that interregional correlations of glutamate and GABA concentrations can be conceptualized as networks. Furthermore, patients with epilepsy display an increased number of glutamate and GABA connections and increased average strength of the GABA network. The increased glutamate and GABA connectivity in epilepsy might indicate a disrupted neurotransmitter balance. In addition to epilepsy, the ‘neurotransmitter networks’ concept might also provide new insights for other neurological diseases.

Evidence for face pareidolia in rhesus monkeys.

In everyday life we have a tendency to see faces in non-face objects; a famous example is the face of a nondescript man on the surface of mars. Although these misperceptions are often very compelling, it is not known whether "face pareidolia" is unique to humans or whether it is an experience shared with other animals. Like humans, rhesus monkeys have a functionally defined face-processing system, comprised of multiple interconnected areas distributed along the ventral visual pathway. In this study, we reasoned that the potential analogy between this system and our own made it likely that rhesus monkeys also experience face pareidolia. To test this hypothesis, we first collected 15 examples of face pareidolia from the public domain together with objects matched for object-content. An additional 15 photographs were taken of unfamiliar rhesus monkey faces. All possible pairs of these 45 images were shown to 5 male rhesus monkeys, one at a time for 4 seconds, in a visual paired comparison task. We collected two dependent variables (the total amount of time spent looking at each image; first fixation in each trial). In addition to replicating the common observation that rhesus monkeys look longer at face stimuli than other kinds of objects, we also found clear evidence that monkeys look for longer periods of time (and first) at examples of face pareidolia than at object-matched control images. We repeated this experiment with the images inverted and collected independent data from human participants (N = 10) who were asked to rate how face-like each image was on a 200-point scale. Overall, our results indicate that monkeys also see face configurations in non-face objects and, as such, provide the first compelling evidence of face pareidolia in any species other than our own. Meeting abstract presented at VSS 2017

Modulation of auditory processing by cortico-cortical feed-forward and feedback projections

The auditory center in the cerebrum, the auditory cortex, consists of multiple interconnected areas. The functional role of these interconnections is poorly understood. The auditory cortex of the mustached bat consists of at least nine areas, including the frequency modulation-frequency modulation (FF) and dorsal fringe (DF) areas. The FF and DF areas consist of neurons tuned to specific echo delays carrying target-distance information. The DF area is hierarchically at a higher level than the FF area. Here, we show that the feedback projection from the DF area to the FF area shifts the delay-tuning of FF neurons toward that of the stimulated DF neurons. In contrast, the feed-forward projection from the FF area to the DF area shifts the delay-tuning of DF neurons away from that of the stimulated FF neurons. The lateral projection within the DF area shifts the delay-tuning of DF neurons toward that of the stimulated DF neurons. In contrast, the lateral projection within the FF area shifts the delay-tuning of FF neurons away from that of the stimulated FF neurons. The delay-tuning shift evoked by the DF stimulation was 2.5 times larger than that evoked by the FF stimulation. Our data indicate that the FF-DF feed-forward and FF-FF lateral projections shape the highly selective neural representation of the tuning of the excited DF neurons, whereas the DF-FF feedback and DF-DF lateral projections enhance the representation of the selected tuning, perhaps, for focal processing of information carried by the excited FF neurons.

Functional MRI of galvanic vestibular stimulation.

The cortical processing of vestibular information is not hierarchically organized as the processing of signals in the visual and auditory modalities. Anatomic and electrophysiological studies in the monkey revealed the existence of multiple interconnected areas in which vestibular signals converge with visual and/or somatosensory inputs. Although recent functional imaging studies using caloric vestibular stimulation (CVS) suggest that vestibular signals in the human cerebral cortex may be similarly distributed, some areas that apparently form essential constituents of the monkey cortical vestibular system have not yet been identified in humans. Galvanic vestibular stimulation (GVS) has been used for almost 200 years for the exploration of the vestibular system. By contrast with CVS, which mediates its effects mainly via the semicircular canals (SCC), GVS has been shown to act equally on SCC and otolith afferents. Because galvanic stimuli can be controlled precisely, GVS is suited ideally for the investigation of the vestibular cortex by means of functional imaging techniques. We studied the brain areas activated by sinusoidal GVS using functional magnetic resonance imaging (fMRI). An adapted set-up including LC filters tuned for resonance at the Larmor frequency protected the volunteers against burns through radio-frequency pickup by the stimulation electrodes. Control experiments ensured that potentially harmful effects or degradation of the functional images did not occur. Six male, right-handed volunteers participated in the study. In all of them, GVS induced clear perceptions of body movement and moderate cutaneous sensations at the electrode sites. Comparison with anatomic data on the primate cortical vestibular system and with imaging studies using somatosensory stimulation indicated that most activation foci could be related to the vestibular component of the stimulus. Activation appeared in the region of the temporo-parietal junction, the central sulcus, and the intraparietal sulcus. These areas may be analogous to areas PIVC, 3aV, and 2v, respectively, which form in the monkey brain, the "inner vestibular circle". Activation also occurred in premotor regions of the frontal lobe. Although undetected in previous imaging-studies using CVS, involvement of these areas could be predicted from anatomic data showing projections from the anterior ventral part of area 6 to the inner vestibular circle and the vestibular nuclei. Using a simple paradigm, we showed that GVS can be implemented safely in the fMRI environment. Manipulating stimulus waveforms and thus the GVS-induced subjective vestibular sensations in future imaging studies may yield further insights into the cortical processing of vestibular signals.