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With the advancement in smart grid and smart energy devices, demand response becomes one of the most economic and feasible solutions to ease the load stress of the power grids during peak hours. In this work, we propose a fully decentralized ensemble control framework with consensus for demand response (DR) events and compatible control methods based on random policies. We show that under the consensus that is tailored to DR, our proposed decentralized control method yields the same optimality as the centralized control method in both myopic and multistage settings.

В статті розглянута можливість суттєвого покращення будівельно-технічних властивостей золовмісних бетонів з використанням полікарбоксилатних суперпластифікаторів. Досліджено комплекс технологічних аспектів пов’язаних з отриманням високотехнологічних бетонів High Performance Concrete (НРС), та отримано комплекс експериментально-статистичних моделей, які дозволять оцінити кількісний вплив основних технологічних факторів на їх властивості.

Objective: To evaluate the feasibility and effectiveness of a wearable robotic device in guiding isometric torque generation and passive-active movement training for ankle motor recovery in children with acute brain injury. Participants/setting: Ten inpatient children with acute brain injury being treated in a rehabilitation hospital. Design: Daily robot-guided ankle passive-active movement therapy for 15 sessions, including isometric torque generation under real-time feedback, stretch-ing, and active movement training with motivating games using a wearable ankle rehabilitation robot. Main measures: Ankle biomechanical improvements induced by each training session including ankle range of motion (ROM), muscle strength, and clinical (Fugl-Meyer Lower-Extremity (FMLE), Pediatric Balance Scale (PBS)) and biomechanical (ankle ROM and muscle strength) outcomes over 15 training sessions. Results: As training progressed, improvements in biomechanical performance measures followed logarithmic curves. Each training session increased median dorsiflexion active range of motion (AROM) 2.73° (standard deviation (SD) 1.14), dorsiflexion strength 0.87 Nm (SD 0.90), and plantarflexion strength 0.60 Nm (SD 1.19). After 15 training sessions the median FMLE score had increased from 14.0 (SD 10.11) to 23.0 (SD 11.4), PBS had increased from 33.0 (SD 19.99) to 50.0 (SD 23.13) (p

Background Recent advancement in the technology of virtual reality (VR) has allowed improved applications for cognitive rehabilitation. Objectives The aim of this review is to facilitate comparisons of therapeutic efficacy of different VR interventions. Methods A systematic approach for the review of VR cognitive rehabilitation outcome research addressed the nature of each sample, treatment apparatus, experimental treatment protocol, control treatment protocol, statistical analysis and results. Using this approach, studies that provide valid evidence of efficacy of VR applications are summarized. Applications that have not yet undergone controlled outcome study but which have promise are introduced. Results Seventeen studies conducted over the past eight years are reviewed. The few randomized controlled trials that have been completed show that some applications are effective in treating cognitive deficits in people with neurological diagnoses although further study is needed. Conclusion Innovations requiring further study include the use of enriched virtual environments that provide haptic sensory input in addition to visual and auditory inputs and the use of commercially available gaming systems to provide tele-rehabilitation services. Recommendations are offered to improve efficacy of rehabilitation, to improve scientific rigor of rehabilitation research and to broaden access to the evidence-based treatments that this research has identified.

Objective: To evaluate the feasibility of applying virtual reality and robotics technology to improve attention in patients with severe traumatic brain injury (TBI) in the early stages of recovery. Methods: A sample of TBI patients (n ¼ 18, aged 19–73) who were receiving acute inpatient rehabilitation completed threedimensional cancellation exercises over two consecutive days in an interactive virtual environment that minimized distractions and that integrated both visual and haptic (tactile) stimuli. Observations of behaviour during the intervention and of the instructions needed to encourage compliance were recorded. Performance data were compiled to assess improvement across three different treatment conditions. Outcomes: Fifteen of the 18 patients demonstrated tolerance of the virtual environment by completing the entire treatment protocol. Within-subjects comparisons of target acquisition time during treatment showed that a treatment condition that included haptic cues produced improved performance compared to a condition in which such cues were not provided. Separating out participants who were in post-traumatic amnesia showed that this group also demonstrated improvement in performance across trials despite their memory impairment. Conclusions: It is proposed that attention exercises using virtual environments are well-tolerated and engaging and that they could be beneficial for inpatients with severe TBI.

A simple numerical model that describes the altitude effect of solar UV flux under cloud-free conditions was developed and tested. The model computes the direct and diffuse UV irradiances for the wavelength range 290–385 nm, at any sub-polar location and time (restricted to arid areas). The input parameters include extraterrestrial solar irradiance, ozone content and vertical distribution, aerosol amounts and size distribution, SO 2 and NO 2 contents, surface albedo and solar zenith angle. Model results were compared with measurements made in the tropical Chilean Andes for altitudes up to 5500 m above sea level. The model and data show good agreement. For the measured direct component a linear increase with altitude was assumed, whereas model results, computed up to 15 km altitude, exhibit a non-linear behavior. However, in the lowest few kilometers a linear regression was adequate for both model and measurements. As for the diffuse component, the variation with altitude strongly depends on wavelength and solar zenith angle. At short wavelengths and large solar zenith angles, a pronounced maximum occurs at a level which depends on these parameters. The maximum cannot be observed when integrating over the UV-A range. This behavior can be understood by taking into account the sources of the diffuse flux at any given level in the atmosphere.

Attention deficits are a highly prevalent result of traumatic brain injury (TBI) that has a profound effect on an individual's functional abilities. However, studies that test the severely impaired inpatient population are scarce. 21 severe TBI inpatients completed 2-week intervention (either visuo-haptic environment training or standard attention training). Results indicate that patients who received the VR intervention may exhibit greater improvement in clinical attention scores compared to those in the control group. Performance during the VR intervention was retained from one day to the next, (even when patients were in post-traumatic amnesia). Visuo-haptic environments could be beneficial for this population.

Severe behavioural disturbances exhibited during the earliest stages of recovery from severe traumatic brain injury often limit the ability to provide standard care. Studies that focus on treatment options for inpatients with such behaviours are scarce. There is limited guidance on how to approach therapy that will maximize the patient's tolerance and participation and how to measure meaningful progress.This case study describes how the use of an innovative treatment approach to improve attention was beneficial in rehabilitation of a patient with severe traumatic brain injury whose profound behaviour disturbances substantially precluded participation in traditional therapies. The study shows how rehabilitation utilizing an interactive virtual reality-robotics environment that minimized distractions was associated with improved engagement in therapy, decreased disruptive behaviour during treatment and more sensitive measurement of progress.These results may be instructive in how technology can be used to modify therapy sessions to make them accessible to patients with profound behaviour disturbance and how meaningful progress can be measured even in the absence of gains in traditional metrics.

Background. Spatial neglect affects perception along different dimensions. However, there is limited availability of 3-dimensional (3D) methods that fully map out a patient’s volume of deficit, although this could guide clinical management. Objective. To test whether patients with neglect exhibit simple contralesional versus complex perceptual deficits and whether deficits are best described using Cartesian (rectangular) or polar coordinates. Methods. Seventeen right-hemisphere persons with stroke (8 with a history of neglect) and 9 healthy controls were exposed to a 3D virtual environment. Targets placed in a dense array appeared one at a time in various locations. Results. When tested using rectangular array of targets, subjects in the neglect group exhibited complex asymmetries across several dimensions in both reaction time and target detection rates. Paper-and-pencil tests only detected neglect in 4 of 8 of these patients. When tested using polar array of targets, 2 patients who initially appeared to perform poorly in both left and near space only showed a simple left-side asymmetry that depended almost entirely on the angle from the sagittal plane. A third patient exhibited left neglect irrespective of the arrangements of targets used. An idealized model with pure dependence on the polar angle demonstrated how such deficits could be misconstrued as near neglect if one uses a rectangular array. Conclusions. Such deficits may be poorly detected by paper-and-pencil tests and even by computerized tests that use regular screens. Assessments that incorporate 3D arrangements of targets enable precise mapping of deficient areas and detect subtle forms of neglect whose identification may be relevant to treatment strategies.

Attention deficits are one of the most profound problems facing the traumatic brain injured individual. The Traumatic Brain Injury (TBI) inpatient population in the rehabilitation unit is difficult to study with new technology because it is often very difficult to render and evaluate such interventions in the short time span when a patient is still in the hospital, even though that is precisely the time when clinical attentional therapy is considered most critical. We developed and performed a preliminary test of a haptic/graphic paradigm for improving attention and concentration in early stages of recovery in the TBI inpatient population. Six TBI patients and three healthy controls were exposed to a minimal distraction/minimal interaction environment while reaching for a visual target. Our initial results showed (1) the subjects tolerated the experience, (2) the number of targets acquired in successive one-minute intervals indicated a sustained attention for the task, and (3) haptic interaction in such an environment was well tolerated, engaging, and enjoyable -- often considered a game. These findings have provided the foundation for a larger, intensive, protracted study with repeated treatment.

Spatial neglect has proven to be a significant factor limiting the success of the rehabilitation process following stroke. Current tests for neglect however have several substantial drawbacks, which often lead to a misdiagnosis of less severe cases. Further, while asymmetries of performance have been reported in the past along independent spatial dimensions, current tests are mostly limited to the horizontal dimension and do not reflect the reality of a three-dimensional world. We have previously demonstrated the feasibility of virtual reality tools for detailed assessments of attentional deficits [1]. We now provide further evidence for the sensitivity of our Virtual Environment for Spatial Neglect Assessment (VESNA) application for assessment of neglect as well as for monitoring recovery of patients. Seven stroke patients with neglect, nine stroke patients without neglect and nine age-matched healthy controls were tested on a target-detection task. Subjects were exposed to a three-dimensional virtual scene and were instructed to press a response button when they detected a target appearing within the scene. Percent of correct detection and reaction time to initiate a button press were calculated. Our results indicated significant differences between neglect patients and control subjects. All neglect patients exhibited asymmetries of performance, where their mean reaction time and detection accuracy systematically varied across space. This asymmetry was not a harsh transition but instead showed a gradual reduction of attention across the space. Importantly, while these results indicated an obvious spatial neglect for all seven neglect patients, their performance on the standard paper-and-pencil tests, administered at the day of testing, was less conclusive. A follow-up study with two of the neglect patients (10 months following the initial testing) revealed an obvious recovery pattern, showing a reduction of the spatial bias over time. By contrast, the paper-and-pencil tests showed no obvious change. Thus, we demonstrated that our paradigm provided a quantitative and more sensitive assessment and monitoring of recovery of neglect. This might provide clinicians with a more precise description of a patientpsilas deficit which will help direct training.

Spatial neglect is commonly assessed using batteries of "paper-and-pencil" tests (e.g., line bisection). However, these tests have several drawbacks due to their fixed and repetitive nature. Although neglect has been most commonly assessed and studied in the horizontal spatial dimension, recent studies have shown neglect along the radial and vertical axes of space as well. We have developed and tested a virtual reality based assessment tool for visual spatial neglect in multiple spatial dimensions. The performance of two stroke patients with neglect, during a target detection task, was compared to that of six healthy control subjects and a stroke patient without neglect. Our initial results indicated a significant difference between the neglect patients and the control subjects in all three dimensions, for both the reaction time and detection accuracy. Moreover, the neglect patients exhibited an obvious left as well as near neglect, mostly in pripersonal space. These findings demonstrate the feasibility of using virtual reality based assessment tool for characterizing multidimensional visual neglect.

Reaching toward a visual target involves the transformation of visual information into appropriate motor commands. Complex movements often occur either while we are moving or when objects in the world move around us, thus changing the spatial relationship between our hand and the space in which we plan to reach. This study investigated whether rotation of a wide field-of-view immersive scene produced by a virtual environment affected online visuomotor control during a double-step reaching task. A total of 20 seated healthy subjects reached for a visual target that remained stationary in space or unpredictably shifted to a second position (either to the right or left of its initial position) with different inter-stimulus intervals. Eleven subjects completed two experiments which were similar except for the duration of the target's appearance. The final target was either visible throughout the entire trial or only for a period of 200 ms. Movements were performed under two visual field conditions: the virtual scene was matched to the subject's head motion or rolled about the line of sight counterclockwise at 130 degrees/s. Nine additional subjects completed a third experiment in which the direction of the rolling scene was manipulated (i.e., clockwise and counterclockwise). Our results showed that while all subjects were able to modify their hand trajectory in response to the target shift with both visual scenes, some of the double-step movements contained a pause prior to modifying trajectory direction. Furthermore, our findings indicated that both the timing and kinematic adjustments of the reach were affected by roll motion of the scene. Both planning and execution of the reach were affected by roll motion. Changes in proportion of trajectory types, and significantly longer pauses that occurred during the reach in the presence of roll motion suggest that background roll motion mainly interfered with the ability to update the visuomotor response to the target displacement. Furthermore, the reaching movement was affected differentially by the direction of roll motion. Subjects demonstrated a stronger effect of visual motion on movements taking place in the direction of visual roll (e.g., leftward movements during counterclockwise roll). Further investigation of the hand path revealed significant changes during roll motion for both the area and shape of the 95% tolerance ellipses that were constructed from the hand position following the main movement termination. These changes corresponded with a hand drift that would suggest that subjects were relying more on proprioceptive information to estimate the arm position in space during roll motion of the visual field. We conclude that both the spatial and temporal kinematics of the reach movement were affected by the motion of the visual field, suggesting interference with the ability to simultaneously process two consecutive stimuli.

The purpose of this study was to use an x–y digitizer to collect handwriting samples typical of those written by the child in his or her natural environment, to analyze these samples with novel segmentation algorithms, and to present them visually in ways that illuminate spatial and temporal dynamic features amongst children with dysgraphic and proficient handwriting. While using the POET software (Penmanship Objective Evaluation Tool), a paragraph was copied onto paper affixed to an x–y digitizer by third-grade students, 14 with proficient and 14 with poor handwriting. A segmentation algorithm was developed to automatically isolate writing segments. Results yielded significant differences between the groups in various measures, including the number of the raw segments (i.e., the number of segments before combined with letters), the number of reverse segments (i.e., when the participant returned to correct or complete a previously written segment), the number of letters per minute, and the mean “In-Air” time between letters. Variability in both the spatial and temporal domains of instances of the same letter throughout the text was greater among the dysgraphic handwriters in comparison to the variability among the proficient. These results demonstrated the potential of using automated analytic techniques and visual display to achieve a more comprehensive understanding of handwriting difficulties.

Background Planning and execution of reaching requires a series of computational processes that involve localization of both the target and initial arm position, and the translation of this spatial information into appropriate motor commands that bring the hand to the target. We have investigated the effects of shifting the visual field on visuomotor control using a virtual visual environment in order to determine how changes in visuo-spatial relations alter motor planning during a reach. Methods Five healthy subjects were seated in front of an immersive, stereo virtual scene while reaching for a visual target that remained stationary in space or unpredictably shifted to a second position (either to the right or left of the first target) with different inter-stimulus intervals. Motion of the scene either matched the motion of their head or was rotated counter clockwise at 130 deg/s in the roll plane. Results Initial results suggested that both the temporal and spatial aspects of reaching were affected by a rolling visual field. Subjects were able to amend ongoing motion to match target position regardless of scene motion, but the presence of visual field motion produced significantly longer pauses during the reach movement when the target was shifted in space. In addition, terminal arm posture exhibited a drift in the direction opposite to the roll motion. Conclusion These findings suggest that roll motion of the visual field of view interfered with the ability to imultaneously process two consecutive stimuli. Observed changes in arm position following the termination of the reach suggest that subjects were compensating for a perceived change in their visual reference frame.

[1] The Dead Sea is a hypersaline terminal lake experiencing a water level drop of about 1 m/yr over the last decade. The existing estimations for the water balance of the lake are widely variable, reflecting the unknown subsurface water inflow, the rate of evaporation, and the rate of salt accumulation at the lake bottom. To estimate these we calculate the energy and mass balances for the Dead Sea utilizing measured meteorological and hydrographical data from 1996 to 2001, taking into account the impact of lowered surface water activity on the evaporation rate. Salt precipitation during this period was about 0.1 m/yr. The average annual inflow is 265–325 × 106 m3/yr, corresponding to an evaporation rate of 1.1–1.2 m/yr. Higher inflows, suggested in previous studies, call for increased evaporation rate and are therefore not in line with the energy balance.

Based on an analysis of monitoring data from coastal polar stations, the character of sea-level oscillations in the Laptev Sea is analysed. In addition, sea-level variability and regions displaying a similar character of sea-level oscillations are identified. The synoptic situations typically related to significant negative and positive storm surges along southern coast of the Laptev Sea are described.