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Summary A quasi‐proportional resonant (QPR) composite control strategy based on disturbance observer (DOB) is proposed to improve the power quality and dynamic performance of the high‐frequency AC ... distribution system source side. The load DOB normalizes the controlled object while suppressing the load disturbance and improving the system's robustness and dynamic performance of the system. The QPR control strategy is proposed based on the internal mode principle, which improves the tracking capability of the system for the operating frequency band signal, reduces the system output steady‐state error, and suppresses the inverter output voltage harmonics. To adapt to the high bandwidth requirement of the controller for high‐frequency AC inverters, the proposed control strategy based on analogy devices implementation circuit is designed, and the corresponding controller parameters design method is given. Compared with the traditional control strategy, the proposed control strategy can reduce the inverter output voltage harmonics, effectively suppress the load disturbance, and improve the dynamic performance and steady‐state performance of the system. Finally, the experimental platform verifies the feasibility and effectiveness of the proposed control strategy and the designed circuit. more

为了提高并网逆变器在电网电压不平衡及谐波状态下的适应能力，使其能够输出高质量的并网电流，需对传统并网逆变器控制策略进行改进。以卵坐标系下LCL型并网逆变器模型为研究对象，提出一种基于准比例谐振（QPR）和电网电压前馈的控制策略。首先，分析了并网电流与其给定值和电网电压之间的关系，得出稳态误差及扰动分量产生的原因。然后，通过QPR控制策略来实现并网电流的无静差控制，引入电网电压前馈控制来抑制电网扰动对并网电流的直接影响。同时，为了提高传统锁相环在电网电压非理想情况下锁相精度及谐波抑制能力，对传统锁相环做进一步改进，以提高锁相环抗扰能力。最后，在Matlab／Simulink中进行仿真验证，仿真结果表明该控制策略能够在电网电压不平衡及谐波状态下得到高质量的并网电流，使逆变器能高效稳定运行，验证了该控制方法的有效性和正确性。

According to the inherent characteristics of the hydraulic power take-off (PTO) system, the output power of a generator tends to be intermittent when the wave is random. Therefore, this paper aims to ... improve the effective utilization of wave energy and reduce power intermittency by constructing a topology with two branches to transmit electrical energy. Firstly, the wave-to-wire (W2W) model of the system is constructed. Secondly, the W2W model is simulated by using synovial and quasi-proportional resonance (QPR) control with regular and irregular incident waves, and the results of PI control are compared. Then, the control strategy in simulation is verified by experiments. The simulation and experimental results show that the control strategy has better performance, and the stability of the system output power is greatly improved. more

Recovery from substance use disorders (SUD) has traditionally been equated with abstinence. “Personal recovery” however emphasizes recovery as a unique and personal process, supported by changes in ... connectedness, hope, identity, meaning and empowerment. This study aimed to examine personal recovery in people receiving extended-release naltrexone (XR-NTX); specifically investigate changes in personal recovery during treatment, identify groups of participants following distinct trajectories of recovery, and characteristics predicting group-belonging. Overall change in recovery (Questionnaire about the Process of Recovery, QPR) score was assessed by linear mixed model in a subsample of 135 people with opioid use disorder (OUD) participating in a 24 + 28-week trial of XR-NTX. Growth mixture model was used to identify potential groups of people following distinct trajectories of personal recovery. Overall, there was a significant change in QPR score during treatment. Four groups with distinct recovery trajectories were identified: “initially low– increase” (G1), “initially average– no change” (G2), “initially high– no change” (G3) and “initially high– increase” (G4). The groups were different with regards to level of psychological distress, social support, and the use of benzodiazepines. In addition, previous participation in opioid agonist treatment programs, current pain, life satisfaction, employment, heroin craving and previous use of heroin also differed between groups. Personal recovery among people receiving XR-NTX follows different trajectories, and various factors are associated with personal recovery. Particular attention regarding psychological distress, social support and heroin use among patients commencing XR-NTX treatment is important to facilitate successful recovery trajectories. •People with OUD in XR-NTX treatment experienced an increase in personal recovery.•Different recovery-trajectories were identified.•Psychological distress, social support and heroin use at baseline predicted subsequent recovery trajectory.•Patients with both initially poor and good outsets had much to gain in XR-NTX treatment, in terms of personal recovery.•Findings offer important implications regarding the overall understanding of individual needs and required measures in XR-NTX treatment more

Background: Research on models of implementation that enable widespread dissemination of suicide prevention to young adults is needed to address the critical public health issue of suicide among ... young adults. A peer-to-peer implementation approach may increase widespread dissemination of suicide prevention on college campuses. Aims: The current study involved the evaluation of a peer-led implementation of the evidence-based program Question, Persuade, and Refer Gatekeeper Training for Suicide Prevention (QPR). Method: A total of 161 college students attended one of eight QPR implementations conducted by student peer educators certified as QPR trainers. Questionnaires were administered at pretest and posttest to assess knowledge of suicide, likelihood of intervening with someone suicidal, and self-efficacy to intervene with someone suicidal. Results: Results from a series of paired-samples t tests showed significant increases from pretest to posttest on the three outcomes of interest - knowledge of suicide, self-efficacy to intervene with someone suicidal, and likelihood to intervene with someone suicidal. Limitations: The short time frame of the current study is a limitation. Conclusion: Support for a peer-led model of implementation for college students has critical implications in terms of increasing the capacity for widespread dissemination of suicide prevention efforts on college campuses. more

Question, Persuade, and Refer (QPR) training also known as gatekeeper training, is a short and effective method for spreading awareness and preparing community members to actively engage in ... preventing suicide, through appropriate knowledge and actions. This study's purpose was to explore differences in QPR gatekeeper training in educational and religious settings. Outcomes of focus were changes in participants' self-rated readiness, willingness, and ability to help a person at risk of suicide. Measures were administered at baseline and after the training for participants in educational settings (N = 747) and in religious settings (N = 698). Findings: Results were statistically significant for educational settings λ = .37, F (1,776) = 1297.69, p = <.001 and for religious settings λ = .30, F (1,724) = 1690.23, p = <.001. Strong training effects were noted in both settings. Application: Suicide prevention gatekeeper training is a ripe opportunity for meso and macro practice in social work. Gatekeeper training can enable social workers to extend their reach far beyond direct practice through empowering community members with awareness of suicide risk factors as well as with confidence to actively intervene with those who may be at risk of suicide. In this way, social workers can enhance connectedness in communities to help prevent death by suicide. more

Background: Despite wide usage of the Questionnaire about the Process of Recovery (QPR), the minimum important difference (MID) for the measure has not been identified. Establishing the MID for the ... QPR is required in order to facilitate the interpretation of outcomes in clinical practice and the use of this scale in research, to measure meaningful change in people with psychosis. Methods: Using an anchor-based method, data from four existing trials of interventions for people with psychosis (N = 681) were used to identify the MID for the QPR. Changes in QPR total scores between baseline and end of treatment were assessed for correspondence with several anchor measures which had established MIDs or face-value clinical meaning. A range of MID values were calculated. Results: Based on anchor measures that were orientated towards service-user priorities, a within-person MID of 5 points and a between-group MID of 4 points are suggested. Results also indicated that the reliability and validity of the 15-item version of the QPR was high, which provides support for its use in clinical practice and research. Conclusions: Implications for future research and clinical practice are discussed. more

Suicide in Missouri is a significant public health issue that has taken the lives of 8351 individuals over the last decade. The recognition of suicide as an imminent concern has led to the ... development of evidence-based prevention programs to decrease suicide-related mortality. One program, question, persuade, refer (QPR), has become the most widely-distributed gatekeeper training program in the world. This article presents both immediate and 2-year follow-up analyses of QPR trainees who work with youth, specifically examining changes in knowledge, self-efficacy, and help-giving behaviors. Results indicate both short- and long-term positive outcomes in knowledge and self-efficacy, supporting use of QPR. more

Despite the rising recognition of personal recovery, there is a lack of research on personal recovery in individuals with psychosis in Singapore. This study aims to evaluate the psychometric ... properties of the QPR-15 using the CHIME personal recovery framework and to examine its associations with clinical recovery factors. Sixty-six stable outpatients were recruited and assessed at two time points approximately 2 weeks apart. Convergent validity was examined through Spearman correlations with scores on CHIME-related psychological factors: connectedness (Ryff subscale- positive relations with others), hope (Herth Hope Index- abbreviated), identity (Ryff subscale- self-acceptance, Internalized Stigma of Mental Illness- Brief), meaning (World Health Organization Quality of Life Assessment-Brief Form), empowerment (Empowerment Scale). Pearson's correlation was used to examine the test-retest reliability, while Cronbach's alpha was used to examine internal consistency. The initial factor structure was evaluated via principal component analysis, Velicer's minimum average partial (MAP) criteria, parallel analysis, and a scree plot. Spearman correlations and hierarchical multiple linear regression (controlling for age and gender) were employed to examine the association of clinical (symptoms and functioning) and psychological factors with the QPR-15. The QPR-15 demonstrated convergent validity with all CHIME-related psychological factors (r ranged from 0.472 to 0.687). Internal consistency was excellent (Cronbach's alpha = 0.934), and test-retest reliability was adequate (r = 0.708). Initial factor structure evaluations revealed a one-factor model. Correlations of clinical factors with the QPR-15 were mostly low (r ranged from - 0.105 to - 0.544) but significant, except for depressive symptoms (CDSS: r  = - 0.529 to - 0.544), while correlations were moderate for psychological factors. Clinical factors significantly explained 28.3-31.8% of the variance of the QPR-15. Adding psychological factors significantly increased the model variance at baseline (∆ adjusted R  = 0.369, F change < 0.001) and at time point 2 (∆ adjusted R  = 0.208, F change < 0.001). Our results provide preliminary evidence that the QPR-15 has adequate psychometric properties in Singapore and encompasses the CHIME personal recovery framework. In addition, our results suggest that clinical recovery and personal recovery are not substitutes for each other but rather are complementary, thereby promoting a more holistic evaluation of recovery in people with psychosis. Implications are discussed. more

The grid current of a Vienna rectifier will change from the continuous conduction mode (CCM) to the discontinuous conduction mode (DCM) when the load current or the inductance decreases. This ... deteriorates the grid current. Therefore, a strategy based on the variable duty ratio feed‐forward and quasi‐proportional‐resonant (QPR) combined control is put forward, by introducing the needed duty ratio to the original output of current inner loop, whereby the pressure of the inner loop is effectively reduced. The working mechanism of the Vienna rectifier is first analyzed. The transfer functions of CCM and DCM between duty ratio and grid current are then built. At the same time, the parallel multi‐QPR harmonic compensators are adopted in the current inner loop to effectively eliminate the specific harmonic pollution. To verify the correctness and effectiveness of the proposed strategy, a 5.3‐kW prototype under digital control is established. The simulation and experimental results show that both the steady and transient performance of the proposed strategy are better under the fixed current inner loop parameters, the current zero crossing distortion can be eliminated, and the current quality acquired under the transformation between CCM to DCM can be further improved. more