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SMA actuators are a group of lightweight actuators that offer advantages over conventional technology and allow for simple and compact solutions to the increasing demand for electrical actuation. In particular, an increasing number of SMA torsional actuator applications have been published recently due to their ability to supply rotational motion under load, resulting in advantages such as module simplification and the reduction of overall product weight. This paper presents the conceptual design, operating principle, experimental characterization and working performance of torsional actuators applicable in active rudder in aeronautics. The proposed application comprises a pair of SMA torsion springs, which bi-directionally actuate the actuator by Joule heating and natural cooling. The experimental results confirm the functionality of the torsion springs actuated device and show the rotation angle of the developed active rudder was about 30° at a heating current of 5 A. After the design and experiment, one of their chief drawbacks is their relatively slow operating speed in rudder positioning, but this can be improved by control strategy and small modifications to the actuator mechanism described in this work.

Siri Jakobsson Støre,1 Maria Tillfors,1 Erik Wästlund,1 Charlotte Angelhoff,2,3 Gerhard Andersson,3– 5 Annika Norell6,7 1Department of Social and Psychological Studies, Karlstad University, Karlstad, Region Värmland, Sweden; 2Crown Princess Victoria’s Child and Youth Hospital, Linköping University Hospital, Linköping, Region Östergötland, Sweden; 3Department of Biomedical and Clinical Sciences (BKV), Linköping University, Linköping, Region Östergötland, Sweden; 4Department of Behavioural Sciences and Learning, Linköping University, Linköping, Region Östergötland, Sweden; 5Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Region Stockholm, Sweden; 6School of Behavioural, Social and Legal Sciences, Örebro University, Örebro, Region Örebro län, Sweden; 7Faculty of Health Sciences, Kristianstad University, Kristianstad, Region Skåne, SwedenCorrespondence: Siri Jakobsson Støre, Department of Social and Psychological Studies, Karlstad University, Karlstad, SE-651 88, Sweden, Email siri.store@kau.seIntroduction: The study aimed to explore characteristics of responders to a sleep robot intervention for adults with insomnia, and the likelihood that participants responded to the intervention.Methods: Data from the intervention and the control group in a randomized waitlist-controlled trial (n = 44) were pooled together after both had undergone the intervention. A repeated measures ANOVA and Friedman tests were used to explore changes over time. Differences in baseline characteristics between responders (n = 13), defined as a reduction of − 5 on the Insomnia Severity Index from pre- to post-intervention, and non-responders (n = 31) were analyzed with t-tests and chi-square tests. Finally, logistic regression models were estimated.Results: Baseline anxiety was the only statistically significant difference between responders and non-responders (p = 0.03). A logistic regression model with anxiety and sleep quality as predictors was statistically significant, correctly classifying 83.3% of cases.Discussion: The results imply that people with lower anxiety and higher sleep quality at baseline are more likely to report clinically significant improvements in insomnia from the sleep robot intervention.Keywords: anxiety, depression, insomnia, sleep, sleep diary, sleep robot, treatment response

SMA actuators are a group of lightweight actuators that offer advantages over conventional technology and allow for simple and compact solutions to the increasing demand for electrical actuation. In particular, an increasing number of SMA torsional actuator applications have been published recently due to their ability to supply rotational motion under load, resulting in advantages such as module simplification and the reduction of overall product weight. This paper presents the conceptual design, operating principle, experimental characterization and working performance of torsional actuators applicable in active rudder in aeronautics. The proposed application comprises a pair of SMA torsion springs, which bi-directionally actuate the actuator by Joule heating and natural cooling. The experimental results confirm the functionality of the torsion springs actuated device and show the rotation angle of the developed active rudder was about 30° at a heating current of 5 A. After the design and experiment, one of their chief drawbacks is their relatively slow operating speed in rudder positioning, but this can be improved by control strategy and small modifications to the actuator mechanism described in this work. [ABSTRACT FROM AUTHOR]

This paper is the first part of a two-part series in which we present results from one of the first worldwide experimental demonstrations of frequency regulation in a commercial building test facility. We demonstrate that commercial buildings can track a frequency regulation signal with high accuracy and minimal occupant discomfort in a realistic environment. In addition, we show that buildings can determine the reserve capacity and baseline power a priori, and identify the optimal tradeoff between frequency regulation and energy efficiency. In part I, we introduce the test facility and develop relevant building models. Furthermore, we design a hierarchical controller for the heating, ventilation, and air conditioning system that consists of three levels: 1) a reserve scheduler; 2) a building climate controller; and 3) a fan speed controller for frequency regulation. We formulate the reserve scheduler as a robust optimization problem and introduce several approximations to reduce its complexity. The building climate controller is comprised of a robust model predictive controller and a Kalman filter. The frequency regulation controller consists of a feedback and a feedforward loop, provides fast responses, and is stable. Part I presents building model identification and controller tuning results. Specifically, we find out that with an appropriate formulation of the model identification problem, a two-state model is accurate enough for use in a reserve scheduler that runs day-ahead. In part II, we report results from the operation of the hierarchical controller under frequency regulation.

This paper is the second part of a two-part series presenting the results from an experimental demonstration of frequency regulation in a commercial building test facility. In part I, we developed relevant building models and designed a hierarchical controller for reserve scheduling, building climate control, and frequency regulation. In part II, we introduce the communication architecture and experiment settings, and present extensive experimental results under frequency regulation. More specifically, we compute the day-ahead reserve capacity of the test facility under different assumptions and conditions. Furthermore, we demonstrate the ability of model predictive control to satisfy comfort constraints under frequency regulation, and show that fan speed control can track the fast-moving RegD signal of the Pennsylvania, Jersey, and Maryland power market very accurately. In addition, we discuss potential effects of frequency regulation on building operation (e.g., increase in energy consumption, oscillations in supply air temperature, and effect on chiller cycling), and provide suggestions for real-world implementation projects. Our results show that hierarchical control is appropriate for frequency regulation from commercial buildings.

Gunilla Westman Andersson,1,2 Nanna Gillberg,3 Carmela Miniscalco4 1Department of Education and Special Education, Faculty of Education, University of Gothenburg, Gothenburg, Sweden; 2Gillberg Neuropsychiatry Centre, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; 3Department of Business Administration, School of Business, Economics and Law at the University of Gothenburg, Gothenburg, Sweden; 4Neuropsychiatric Department and Pediatric Speech and Language Pathology Department, Queen Silvia Children’s Hospital & Gillberg Neuropsychiatry Centre, University of Gothenburg, Gothenburg, SwedenCorrespondence: Gunilla Westman AnderssonDepartment of Education and Special Education, Box 300, Gothenburg, 40530, SwedenTel +46 31 342 5970Email gunilla.andersson@gu.seBackground: In Sweden, children diagnosed with autism spectrum disorders (ASD) as well as other children in need of special support, according to the law should be provided stimulation and support for their development in their preschools. Parents of children diagnosed with ASD have been shown to struggle to ensure the right to support for their child from society, including in preschool. This study reports parent expectations and experiences when having a child diagnosed with ASD in preschool.Methods: A questionnaire with 12 open-ended and 9 multiple-choice questions was completed by parents of 26 children (3 girls, 23 boys, mean age 4:3 years). The children had been diagnosed with ASD within the last year. The data were analyzed using a qualitative inductive approach with a content analysis of the open-ended questions.Findings and Conclusions: This study shows that parents expect competence and knowledge about ASD among preschool staff, including the principal. They need continuous dialogue between parents and the preschool staff and expect individualized support for their child. Concerns about their child in preschool frequently occurred.Keywords: autism spectrum disorder, children, parents, preschool

This work presents an experimental study related to the mechanical performance of a special design spring fabricated with a superelastic shape memory alloy (SMA-SE). For the experimental testing, the spring was coupled in a rotor machine, aiming to attenuate the mechanical vibration when the system went through a natural frequency without any external power source. It was verified that the reduction in instabilities stemmed from the better distribution of vibration force in the proposed device, as well as the damping capacity of the spring material. These findings showed that the application of the M-Shape device of SMA-SE for three different cases could reduce vibration up to 23 dB when compared to the situations without, and with, 1.5 mm of preload. The M-Shape device was shown to be efficient in reducing the mechanical vibration in a rotor system. This was due to the damping capacity of the SMA-SE material, and because the application did not require any external source of energy to generate phase transformation.

Nina Bendelin,1 Björn Gerdle,1 Gerhard Andersson2,3 1Pain and Rehabilitation Centre and Department of Medical and Health Sciences, Linköping University, Linköping, Sweden; 2Department of Behavioural Sciences and Learning, Linköping University, Linköping, Sweden; 3Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden Purpose: Methods for delivering aftercare to help chronic pain patients to continue practice self-management skills after rehabilitation are needed. Internet-delivered cognitive behavioral therapy (ICBT) has the potential to partly fill this gap given its accessibility and emphasis on self-care. Methods for engaging and motivating patients to persist throughout the full length of treatment are needed. The aim of this study was to describe how chronic pain patients work in an ICBT program, through their descriptions of what is important when they initiate behavior change in aftercare and their descriptions of what is important for ongoing practice of self-management skills in aftercare. Patients and methods: Following a multimodal rehabilitation program, 29 chronic pain patients participated in a 20-week-long Internet-delivered aftercare program (ACP) based on acceptance-based cognitive behavioral therapy. Latent content analysis was made on 138 chapters of diary-like texts written by participants in aftercare. Results: Attitudes regarding pain and body changed during ACP, as did attitudes toward self and the future for some participants. How participants practiced self-management skills was influenced by how they expressed motivation behind treatment goals. Whether they practiced acceptance strategies influenced their continuous self-management practice. Defusion techniques seemed to be helpful in the process of goal setting. Mindfulness strategies seemed to be helpful when setbacks occurred. Conclusion: Self-motivating goals are described as important both to initiate and in the ongoing practice of self-management skills. Experiencing a helpful effect of acceptance strategies seems to encourage participants to handle obstacles in new ways and to persist throughout treatment. Research on whether tailored therapist guidance might be helpful in stating self-motivating goals and contribute to ongoing practice of self-management skills is needed. Keywords: Internet-delivered cognitive-behavioral therapy, chronic pain, acceptance and commitment therapy, qualitative analysis, self-management

Linn Karlsson,1 Björn Gerdle,1 Esa-Pekka Takala,2 Gerhard Andersson,3,4 Britt Larsson1 1Pain and Rehabilitation Centre, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden; 2Work-related Diseases, Finnish Institute of Occupational Health, Helsinki, Finland; 3Department of Behavioural Sciences and Learning, Swedish Institute for Disability Research, Linköping University, Linköping, Sweden; 4Department of Clinical Neuroscience, Psychiatry Section, Karolinska Institute, Stockholm, Sweden Purpose: The purpose of this study was to describe how patients with chronic pain experience physical activity and exercise (PA&E).Method: This qualitative interview study included 16 women and two men suffering from chronic pain and referred to a multimodal pain rehabilitation program. Semi-structured interviews were conducted and qualitative content analysis was used to analyze the interviews.Results: One main theme emerged: “To overcome obstacles and to seize opportunities to be physically active despite chronic pain.” This main theme was abstracted from five themes: “Valuing a life with physical activity,” “Physical activity and exercise – before and after pain,” “A struggle – difficulties and challenges,” “The enabling of physical activity,” and “In need of continuous and active support.” Conclusion: Although these participants valued PA&E, they seldom achieved desirable levels, and performance of PA&E was undermined by difficulties and failure. The discrepancy between the intention to perform physical activity and the physical activity accomplished could be related to motivation, self-efficacy, and action control. The participants desired high-quality interaction with healthcare providers. The findings can be applied to chronic pain rehabilitation that uses PA&E as treatment. Keywords: chronic pain, experiences, physical activity, rehabilitation, qualitative content analysis

Gunilla Westman Andersson, Carmela Miniscalco, Nanna Gillberg Gillberg Neuropsychiatry Centre, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden Background: Early support and interventions are suggested to be important for children with autism spectrum disorder (ASD) and other developmental problems and their families. Parents are described to have a burdensome life situation where the child’s problems have a great impact on the family’s well-being. Aim: To obtain increased knowledge of parents’ experiences of support and interventions 6 years after their child was assessed for ASD. Methods and procedures: A semi-structured questionnaire was sent to all parents (n=101) whose preschool children (

Andrea Pozza,1,2 Gerhad Andersson,3 Davide Dèttore2,41Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy; 2Miller Institute of Behavioural and Cognitive Psychotherapy, Genoa, Italy; 3Department of Behavioural Sciences and Learning, Linköping University, Linköping, Sweden; 4Department of Health Sciences, University of Florence, Florence, Italy Abstract: Group cognitive–behavioral therapy (GCBT) may be a cost-effective alternative modality for the treatment of obsessive–compulsive disorder (OCD). In the last decade, a great deal of research has been conducted to evaluate the efficacy of GCBT for OCD. Despite promising results, studies have produced inconclusive evidence. The current paper will present a protocol for a systematic review and meta-analysis of randomized controlled trials assessing the efficacy of GCBT compared with control conditions or individual CBT at post-treatment and follow-up on OCD symptoms, anxiety, depression, obsessive beliefs, quality of life, and functioning. Another aim will be to compare the levels of early drop out from GCBT relative to control conditions or individual CBT. Finally, the study will investigate potential outcome moderators (age, sex, OCD severity, severity of concurrent depression, comorbid personality disorders, duration of OCD symptom onset, duration of treatment, intensity of treatment, generation cohort, methodological quality, and publication date). A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines will be conducted using random-effects meta-analyses. Online databases and trial registries will be searched, the corresponding authors will be contacted, and conference proceedings and relevant journals will be hand-searched to locate published and unpublished studies. Risk of bias will be assessed using the Cochrane Collaboration’s tool. Keywords: obsessive–compulsive disorder, cognitive–behavioral therapy, meta-analysis, group therapy