A Proportional Digital Controller to Monitor Load Variation in Wind Turbine Systems

Monitoring the variation of the loading blades is fundamental due to its importance in the behavior of the wind turbine system. Blade performance can be affected by different loads that alter energy conversion efficiency and cause potential safety hazards. An example of this is icing on the blades. Therefore, the main objective of this work is to propose a proportional digital controller capable of detecting load variations in wind turbine blades together with a fault detection method. An experimental platform is then built to experimentally validate the main contribution of the article. This platform employs an automotive throttle device as a blade system emulator of a wind turbine pitch system. In addition, a statistical fault detection algorithm is established based on the point change methodology. Experimental data support our approach.

FEATURES STUDIES OF TRANSITION LAYERS IN SEMICONDUCTOR HETEROSYSTEMS

Studies of spectral characteristics in Schottky's contact specimens showed that photemf generated by mono­chromatic light, according to the formation mechanism, has a predominantly lateral nature, that is, in a hetero­system there are at least two areas separated by a potential barrier along the interface, with different conductivity levels. The feature of the photoemf spectral characteristics is a variations its appearance when changing the thermal annealing temperature of the studied heterosystems. A significant characteristic and a small amplitude of the characteristic indicates the formation of a transition layer, relatively homogeneous and with insignificant, compared with the volume of GaAs, the doping concentration. If the spectral characteristic has one maximum and amplitude, which several times exceeds the amplitude of a significant characteristic, which means the formation of a transition layer in the Schottky contact depletion area with high conductivity, compared with a quasine-neutral region of a semiconductor. The distribution of lateral photoemf along the sample also has a significant character. In order to obtain the correct results relative to the heterosystem transition layer, it is necessary to measure spectral acute characteristics at a distance from the point change sign of the emf that several times the diffusion length of non-equilibrium charge carriers in GaAs. The problem of the formation of a metal-semiconductor contact and other heterosystems accompanied by the occurrence of heterogeneous transition layers, always paid attention. The use of the proposed photovoltaic method allows to establish the degree of homogeneity of semiconductor layers, components of the structure and predict the redistribution of current density flowing through the physical scope of the device.

Repeated, low-dose oral esketamine in patients with treatment-resistant depression: pilot study

Background Intravenous infusion of ketamine can produce rapid and large symptom reduction in patients with treatment-resistant depression (TRD) but presents major obstacles to clinical applicability, especially in community settings. Oral esketamine may be a promising addition to our TRD treatment armamentarium. Aims To explore the safety, tolerability and potential clinical effectiveness of a 3-week treatment with repeated, low-dose oral esketamine. Method Seven patients with chronic and severe TRD received 1.25 mg/kg generic oral esketamine daily, over 21 consecutive days. Scores on the Systematic Assessment for Treatment Emergent Events (SAFTEE), Community Assessment of Psychic Experiences (CAPE), Clinician Administered Dissociative States Scale (CADSS) and Hamilton Rating Scale for Depression (HRSD) instruments, as well as blood pressure and heart rate, were repeatedly assessed. Results Treatment with oral esketamine was well-tolerated. No serious side-effects occurred, and none of the participants discontinued treatment prematurely. Psychotomimetic effects were the most frequently reported adverse events. Mean HDRS score decreased by 16.5%, from 23.6 to 19.7. Three participants showed reductions in HDRS scores above the minimum clinically important difference (eight-point change), of whom two showed partial response. No participants showed full response or remission. Conclusions These results strengthen the idea that oral esketamine is a safe and well-tolerated treatment for patients with chronic and severe TRD, but therapeutic effects were modest. Results were used to design a randomised controlled trial that is currently in progress.

P.152 Efficacy of Dorsal Root Ganglion Stimulation for Post Surgical Neuropathic Pain

Background: The dorsal root ganglion (DRG) has been established as an important structure in the development and modulation of chonic neuropathic pain and has demonstrated superiority over spinal cord stimulation in the management of challenging neuropathic pain conditions, including complex regional pain syndrome and chronic post-spine surgery neuropathic pain. DRG has only been available in Canada for patient application since January 2020. The St Pauls Hospital Neuromodulation Program was one of the first Canadian centers to offer this procedure. Methods: We reviewed our early experience with DRG therapy in 10 patients. Patient-reported outcome measures were collected pre-trial, post-trial, and post-device implantation, to determine the efficacy of DRG. We hypothesized that DRG stimulation would demonstrate a meaningful change in PROMIS-29 domains and at least 50% improvement in pain intensity at 8 wks. Results: All patients demonstrated a > 5 point change in T scores in PROMIS-29 domains suggesting a meaningful benefit. Patients also demonstrated a percentage pain improvement at 8 wks of 64 % based on a numerical rating scale. No major complications were observed. Conclusions: DRG stimulation is a safe and effective treatment option for neuropathic pain.

Adaptive Predictive Functional Control of X-Y Pedestal for LEO Satellite Tracking Using Laguerre Functions

In this paper, Predictive Functional Control (PFC) is used for X-Y pedestal control for LEO satellite tracking. According to the nonlinear characteristics of the X-Y pedestal and pedestal model variation caused by its operating point change, the use of system identification algorithm, which is based on special types of orthonormal functions known as Laguerre functions, is presented. This algorithm is combined with PFC to obtain a novel adaptive control algorithm entitled Adaptive Predictive Functional Control (APFC). In this combination, Laguerre functions are utilized for system identification, while the PFC is the control law. An interesting feature of the proposed algorithm is its desirable performance against the interference effect of channel X and channel Y. The proposed APFC algorithm is compared with Proportional Integral Derivative (PID) controller using simulation results. The results confirm that the proposed controller improves the performance in terms of the pedestal model variations; that is, the controller is capable of adapting to the model changes desirably.

Impact of Pharmacist Education on Incoming Medical Residents

Introduction: The graduating medical student transitioning to the role of a first-year medical resident is expected to know the proper medications and dosages for routine patient conditions. Pharmacists on an interdisciplinary health care team can be effective teachers of medical residents. Given the small amount of pharmacy-based education included in medical school curricula, it is important that medical residents have a basic foundation of pharmacotherapeutic knowledge. The purpose of this study was to assess the effectiveness of a pharmacist-led education session in improving medical resident pharmacotherapy knowledge. Methods: During orientation in 2016 to 2019, first-year medical residents completed an 8-item pre-test assessing their choices of medications and dosages on 8 patient conditions. A post-test assessing these same items was taken after a 50-minute lecture from a pharmacist experienced in resident education. First-year medical residents at a separate institution within the university system completed the pre-test only. Results: Overall, 243 medical residents received the lecture and took both tests and 170 medical residents at the other institution completed the pre-test only (100% response rate). Using descriptive statistics, the 2 groups of medical residents were comparable in age, gender, and scores on the pre-test. Medical residents receiving the lecture showed an average 32% point change improvement in performance on the post-test. The pharmacist-led lecture consistently received the highest ratings (4.7 ± 0.5 out of 5) from residents of all the orientation topics presented. Conclusions: A pharmacist-led education session increased the pharmacotherapy knowledge of first-year medical residents at their resident orientation. Medical residents value reinforcement of basic pharmacotherapy knowledge to start their training.

Establishing the Minimal Clinically Important Differences for Sagittal Hip Range of Motion in Chronic Stroke Patients

Many researchers have pointed out that decreased sagittal range of motion (ROM) in the affected hip joint is a common consequence of stroke, and it adversely affects walking performance and walking speed. Nevertheless, the minimal clinically important differences (MCID) in hip-related kinematic gait parameters post-stroke have not yet been determined. The present study aimed to define MCID values for hip ROM in the sagittal plane i.e., flexion–extension (FE), for the affected and unaffected sides at a chronic stage post-stroke. Fifty participants with hemiparesis due to stroke were enrolled for the study. Four statistical methods were used to calculate MCID. According to the anchor-based approach, the mean change in hip FE ROM achieved by the MCID group on the affected/unaffected side amounted to 5.81°/2.86° (the first MCID estimate). The distribution-based analyses established that the standard error of measurement in the no-change group amounted to 1.56°/1.04° (the second MCID estimate). Measurements based on the third method established that a change of 4.09°/0.61° in the hip ROM corresponded to a 1.85-point change in the Barthel Index. The optimum cutoff value, based on ROC curve analysis, corresponded to 2.9/2.6° of change in the hip sagittal ROM for the affected/unaffected side (the fourth MCID estimate). To our knowledge, this is the first study to use a comprehensive set of statistical methods to determine the MCID for hip sagittal ROM for the affected and unaffected sides at a chronic stage post-stroke. According to our findings, the MCID of the hip FE ROM for the affected side amounts to 5.81° and for the unaffected side to 2.86°, in patients with chronic stroke. This indicator is extremely important because it allows clinical practitioners to assess the effects of interventions administered to patients, and to interpret the significance of improvements in sagittal kinematic parameters of the hip; ultimately, it may facilitate the process of designing effective gait reeducation programs.

A-118 Efficacy of Computerized Cognitive Rehabilitation Programs in Treating Warfighters with a History of Mild Traumatic Brain Injury

Background Computerized cognitive rehabilitation programs (CCRP) have gained popularity in recent years. The objective of this study was to investigate the efficacy of CCRP in military personnel with a prior mTBI. Methods 21 active-duty service members with a history of mTBI were enrolled in the randomized clinical trial. Participants completed one of two CCRPs (Lumosity or the University of California Riverside Brain Game Center). Primary dependent variable was the Key Behavioral Change Inventory (KBCI) with eight scales: Inattention, Impulsivity, Unawareness of problems, Apathy, Interpersonal difficulty, Communication problems, Somatic difficulties, and Emotional adjustment. Other variables included age, education, number of mTBIs, years since last mTBI, total lifetime years of repetitive head injury (RHI). Results There was a significant reduction in Somatic Difficulties post-treatment (p = 0.029) with trends towards reductions on Inattention (p = 0.077) and Apathy (p = 0.064). 19/21 (90%) of participants had improvement in at least one KBCI scale (i.e., at least one point change), 14/21 (66%) had 3 or more scales improved, and 7/21 (67%) had 5 or more scales improved. Total number of scales improved was correlated with years since TBI (rho = 0.38, p = 0.044) and years of RHI (rho = 0.459, p = 0.018). Conclusions CCRP had modest efficacy in improving persistent symptoms following a mTBI. Fewer years since mTBI and fewer number of years of RHI were associated with better treatment response.

The Hidden Role of Contract Terms: The Case of Credit Card Minimum Payments in Mexico

This paper argues that thresholds in financial contracts act as implicit nudges in consumers’ decisions. Exploiting a regulatory change to credit card minimum payments in Mexico, we find that a 1-percentage point change in minimum payments leads to a 0.87-percentage point change in actual payments, both expressed as a percentage of total balances. We decompose the effect of minimum payments into a constraining effect and a reference effect. The former captures the effect of minimum payments as a binding constraint and accounts for 59% of its total effect. The latter captures any remaining impact of changes in minimum payments beyond their constraining effect and represents 41% of the total. In turn, 67% of the reference effect is explained by the multiple heuristic: the tendency of consumers to pay whole-number multiples of the minimum payment. This paper was accepted by Kay Giesecke, finance.

Methods of Pre-Identification of TITO Systems

The content of this article is the presentation of methods used to identify systems before actual control, namely decentralized control of systems with Two Inputs, Two Outputs (TITO) and with two interactions. First, theoretical assumptions and reasons for using these methods are given. Subsequently, two methods for systems identification are described. At the end of this article, these specific methods are presented as the pre-identification of the chosen example. The Introduction part of the paper deals with the description of decentralized control, adaptive control, decentralized control in robotics and problem formulation (fixing the identification time at the existing decentralized self-tuning controller at the beginning of control and at the beginning of any set-point change) with the goal of a new method of identification. The Materials and methods section describes the used decentralized control method, recursive identification using approximation polynomials and least-squares with directional forgetting, recursive instrumental variable, self-tuning controller and suboptimal quadratic tracking controller, so all methods described in the section are those ones that already exist. Another section, named Assumptions, newly formulates the necessary background information, such as decentralized controllability and the system model, for the new identification method formulated in Pre-identification section. This section is followed by a section showing the results obtained by simulations and in real-time on a Coupled Drives model in the laboratory.