Simplified method based on an intelligent model to obtain the extinction angle of the current for a single-phase half wave controlled rectifier with resistive and inductive load

With the aim of calculating the extinction angle of the current of a single-phase half wave controlled rectifier with resistive and inductive load, present work shows a method to obtain a regression model based on intelligent methods. This type of circuit is a typical non-linear case of study that requires a hard work to solve it by hand. To create the intelligent model, a dataset has been obtained with a computational method for the working range of the circuit. Then, with the dataset, to achieve the final solution, several methods of regression were tested from traditional to intelligent types. The model was verified empirically with electronic circuit software simulation, analytical methods and with a practical implementation. The advantage of the proposed method is its low computational cost. Then, the final solution is very appropriate for applications where high computational requirements are not possible, like low-performance microcontrollers or web applications.     

Selecting the Right Tool For the Job

There are competing ethical concerns when it comes to designing any clinical research study. Clinical trials of possible treatments for Ebola virus are no exception. If anything, the competing ethical concerns are exacerbated in trying to find answers to a deadly, rapidly spreading, infectious disease. The primary goal of current research is to identify experimental therapies that can cure Ebola or cure it with reasonable probability in infected individuals. Pursuit of that goal must be methodologically sound, practical and consistent with prevailing norms governing human subjects research. Some maintain that only randomized controlled trials (RCTs) with a placebo or standard-of-care arm can meet these conditions. We maintain that there are alternative trial designs that can do so as well and that sometimes these are preferable to RCTs.     

Examining patterns suggestive of acquisition during functional analyses: A consecutive controlled series of 116 cases

The functional analysis approach described by Iwata et al. (1982/1994) has been used widely to determine the variables evoking and maintaining challenging behavior. However, one potential concern with conducting functional analyses is that repeated exposure to contingencies may induce a novel functional relation. To examine the likelihood of these potential iatrogenic effects, we evaluated social test conditions of the functional analysis for 116 participants and searched for patterns of responding indicative of acquisition. Patterns suggestive of acquisition occurred in 13.70% of tangible reinforcement conditions; however, the prevalence was only slightly lower in the attention condition (8.75%). Much lower prevalence was observed for the escape condition (2.13%). When grouped by quotient score, a pattern of acquisition was just as likely to be observed in the attention condition as in the tangible condition. Additionally, patterns indicative of acquisition were no more likely to be observed with participants who emitted automatically reinforced challenging behavior.     

Handling Missing Covariates in Conditional Mixture Models Under Missing at Random Assumptions

Mixture modeling is a popular method that accounts for unobserved population heterogeneity using multiple latent classes that differ in response patterns. Psychologists use conditional mixture models to incorporate covariates into between-class and/or within-class regressions. Although psychologists often have missing covariate data, conditional mixtures are currently fit with a conditional likelihood, treating covariates as fixed and fully observed. Under this exogenous-x approach, missing covariates are handled primarily via listwise deletion. This sacrifices efficiency and does not allow missingness to depend on observed outcomes. Here we describe a modified joint likelihood approach that (a) allows inference about parameters of the exogenous-x conditional mixture even with nonnormal covariates, unlike a conventional multivariate mixture; (b) retains all cases under missing at random assumptions; (c) yields lower bias and higher efficiency than the exogenous-x approach under a variety of conditions with missing covariates; and (d) is straightforward to implement in available commercial software. The proposed approach is illustrated with an empirical analysis predicting membership in latent classes of conduct problems. Recommendations for practice are discussed.     

Long-Term Effects of an Internet-Based Treatment for Posttraumatic Stress

Abstract

Advances in communication technology offer additional strategies for providing psychological treatment. Previous trials of Internet-based treatment approaches reported significant reductions in posttraumatic stress and related symptoms in response to Internet-based treatments relative to control groups. However, empirical data on the long-term effects of those approaches are sparse. In order to evaluate the long-term effect of an Internet-based intervention, the authors conducted an 18-month follow-up of an Internet-based cognitive behavioural therapy for posttraumatic stress. Severity of posttraumatic stress symptoms was the primary outcome. Additional measures were depression, anxiety, mental and physical health, and health care utilization during the follow-up period. Treatment group participants (n = 34) were assessed 1.5 years after completing treatment. Results indicated that reductions in symptoms of posttraumatic stress symptoms, depression, and anxiety found at posttreatment were sustained during the 18-month follow-up period. Preliminary evidence on long-term effects of Internet-based health care as shown in this study is promising. However, research with larger and clinically more diverse samples is needed to fully assess the clinical impact and potential of Internet-based health care provision.     

针灸治疗周围性面瘫随机对照研究的文献分析

遵循循证医学评价文献的原则,在中国生物医学文献数据库、CNKI等数据库全面检索2002—2006年间的相关文献并进行计量学评价分析。共检索出文献1284篇,其中RCT文献共有169篇,按照循证医学评价文献的原则及方法,从研究对象、随机分配方法、对照措施、盲法采用情况等多个方面进行分析评价。2002—2006五年间报道的RCT数量比从建国到2000年报道的RCT数量多,但仍需进一步改善文献质量。     

药物临床试验设计的伦理思考

目前广泛采用的药物临床试验设计中,由于不能使受试者最大限度的受益而在伦理学方面存在弊端。自适应设计方法的出现,为克服这一弊端提供了现实途径,可使药物临床试验的受试者能够最大程度的受益。本文从传统临床试验引发的伦理问题入手,阐述了自适应设计以人为本的特点,探讨了其在解决伦理与疗效冲突问题中的重要作用。     

Evaluation of a Peer-Led Mutual Support Group for Chinese Families of People with Schizophrenia

Family interventions in schizophrenia have shown positive effects on patients but little attention has been paid to their effects on family members, particularly those in non-Western countries. This randomized controlled trial evaluated the effectiveness of a bi-weekly, 12-session, family-led mutual support group for Chinese caregivers of schizophrenia sufferers over 6 months compared with standard psychiatric care. It was conducted with 76 families of outpatients with schizophrenia in Hong Kong of whom 38 were assigned randomly to either a mutual support group or standard care. Families' psychosocial health status and patients' symptom severity and length of re-hospitalizations at recruitment, one-week and 12-month post-intervention were compared between groups. Results of repeated-measures mixed model indicated that the mutual support group experienced significantly greater improvements in families' burden, functioning and number of support persons and length of patients' re-hospitalizations at two post-tests. The findings provide evidence that mutual support groups can be an effective family-initiated, community-based intervention for Chinese schizophrenia sufferers.     

The relationship between psychoanalysis and schizophrenia-A response to the commentary by Robert Michels

In this section, the author responds to Dr Michels's commentary. In contrast to the situation in the United States, there are far fewer psychoanalysts in the UK and very few indeed working in general psychiatry to influence its practice. It is argued that psychoanalysis differs from all other psychological approaches with its recognition of the inner world and its unconscious influence on the individual's everyday life. Michels invites one to focus on outcome studies to judge the effectiveness of psychoanalysis in schizophrenia. There is a danger of throwing the baby out with the bathwater in that psychoanalysis helps in understanding presenting clinical material and in risk assessment in everyday general psychiatry.