34 resultados para partial adjustment model
Resumo:
Objectives: To investigate the validity of a common depression metric in independent samples. Study Design and Setting: We applied a common metrics approach based on item-response theory for measuring depression to four German-speaking samples that completed the Patient Health Questionnaire (PHQ-9). We compared the PHQ item parameters reported for this common metric to reestimated item parameters that derived from fitting a generalized partial credit model solely to the PHQ-9 items. We calibrated the new model on the same scale as the common metric using two approaches (estimation with shifted prior and StockingeLord linking). By fitting a mixed-effects model and using BlandeAltman plots, we investigated the agreement between latent depression scores resulting from the different estimation models. Results: We found different item parameters across samples and estimation methods. Although differences in latent depression scores between different estimation methods were statistically significant, these were clinically irrelevant. Conclusion: Our findings provide evidence that it is possible to estimate latent depression scores by using the item parameters from a common metric instead of reestimating and linking a model. The use of common metric parameters is simple, for example, using a Web application (http://www.common-metrics.org) and offers a long-term perspective to improve the comparability of patient-reported outcome measures.
Resumo:
In this paper, we propose a model that estimates the speed of energy price adjustment to its target level. We also explain the source of price adjustment. Moreover, we extract energy price bubbles and show that bubbles help explain price adjustment. Since ours is the first paper that develops an energy price adjustment model and links it to bubbles, several avenues for future research have emerged from our analysis. The first is to provide a theoretical framework for the bubbles and price adjustment mechanism. The second direction of research will be to continue the search for other potential determinants of price adjustment.
Resumo:
This paper reports the results of a student survey of perceptions of classroom learning environment conducted as part of a major investigation into effective pedagogical practices in mathematics and science. All primary school project participants were surveyed, The 36 Likert-type items were subjected to a Partial Credit Model analysis, and response categories subjected to statistical requirements. The results are presented graphically, their meanings examined, and the implications of the findings for both researchers and practitioners are discussed.
Resumo:
This research adopts the Malmquist total factor productivity model with Lovell's decomposition and renovated partial factor model to evaluate changes of productivity levels in Australia's construction industry. Research results find that the average annual productivity levels for Australian states are slowly growing, except for Queensland's total factor and capital productivities.
Resumo:
AIMS:
To estimate the cost-effectiveness of training in flexible intensive insulin therapy [as provided in the Dose Adjustment for Normal Eating (DAFNE) structured education programme] compared with no training for adults with Type 1 diabetes mellitus in the UK using the Sheffield Type 1 Diabetes Policy Model.
METHODS:
The Sheffield Type 1 Diabetes Policy Model was used to simulate the development of long-term microvascular and macrovascular diabetes-related complications and the occurrence of diabetes-related adverse events in 5000 adults with Type 1 diabetes. Total costs and quality-adjusted life years were estimated from a National Health Service perspective over a lifetime horizon, discounted at a rate of 3.5%. The treatment effectiveness of DAFNE was modelled as a reduction in HbA1c that affected the risk of developing long-term diabetes-related complications. Probabilistic and structural sensitivity analyses were conducted.
RESULTS:
DAFNE resulted in greater life expectancy and reduced incidence of some diabetes-related complications compared with no DAFNE. DAFNE was found to generate an average of 0.0294 additional quality-adjusted life years for an additional cost of £426 per patient, leading to an incremental cost-effectiveness ratio of £14 400 compared with no DAFNE. There was a 54% probability that DAFNE would be cost-effective at a willingness-to-pay threshold of £20 000 per quality-adjusted life year.
CONCLUSIONS:
The results of this study suggest that DAFNE is a cost-effective structured education programme for people with Type 1 diabetes and support its provision by the National Health Service in the UK.
Resumo:
If one concedes that the Freudian unconscious is inseparable from a society attached to its past, for example, its phallocentric traditions, Guattari’s alternative model dealing with "the production of subjectivity" offers a new perspective (1995: 11). From this vantage point, it is possible to map the way "every individual and social group" models the creation of subjectivity, a subjectivity "composed of cognitive references as well as mythical, ritual and symptomatological references" (1995: 11).
Resumo:
Two alternate processes that may explain the relationship between child maltreatment, childhood family characteristics and adult adjustment (mediation and moderation) were tested using retrospective data from a community sample (N = 175). The levels of five different types of child maltreatment did not mediate the relationship between childhood family variables and adult adjustment. In contrast, family background played a mediating role in the relationship between maltreatment and adjustment. Evidence of moderation was found in the interactions between different maltreatment types in predicting adjustment. Partial support was found for the moderating influence of family factors on the relationship of maltreatment to adjustment.
Resumo:
This questionnaire study examined the adjustment of 245 lone-parenting women following marital separation. A composite model included intrapsychic variables as intervening between demographic and contextual variables and adjustment (life satisfaction). Regression analyses showed that the demographic and contextual variables were partially mediated by the intrapsychic variables. The path model indicated that the intrapsychic variables (sense of coherence, control, depression, and grief) had a direct impact on life satisfaction and that there was an indirect path for depression through sense of coherence (SOC) and control. It was concluded that the intrapsychic variables had a more powerful relationship with women's post-separation life satisfaction than did the demographic/contextual variables. Social implications and recommendations for future policy are considered.
Resumo:
This paper attempts to study the propagating characteristics of acoustic signals emitted from the breakdown of air using time domain numerical model. Acoustic emissions are produced by high voltage faults such as partial discharge and surface discharge. Study of such emissions has become popular among researchers because of the promising correlation between partial and surface discharges and its byproduct, acoustic signal emission. In this paper, propagation characteristics of acoustic signals are studied using finite difference time domain (FDTD) method. Multiple monitoring points are placed within a designated computation space at different distance away from a source.
Resumo:
In the neoclassical growth theory, higher saving rate gives rise to higher output per capita. However, in the Keynesian model, higher saving rate causes lower consumption, which may lead to a recession. Students may ask, “Should we save or should we consume?” In most of the macroeconomics textbooks, economic growth and Keynesian economics are in separate, sometimes unsequential, chapters. The connection between the short run and the long run is not apparent. The author builds a bridge between the neoclassical growth theory and the Keynesian model. He links the Solow diagram and the IS-LM curves and depicts the short-run to long-run transition of the economy after changes in saving and other macroeconomic policies.
Resumo:
A feasibility study for handling the partial recrystallisation in multi-pass hot deformation where the heterogeneity of microstructure of deformed austenite is inherently accompanied is presented. The proposed model is based on modification of the conventional model in which the microstructure of deformed austenite at each pass is simply taken as being homogeneous during the multi-pass deformation. The usefulness of the modified model has been demonstrated by applying it to a four-pass oval–round (or round–oval) rod rolling sequence. The recrystallised fraction, austenite grain size (AGS) and mean flow stress at each pass computed from the modified model has been compared with those from the conventional model. The result showed that the recrystallisation behaviour and evolution of AGS at a given pass were dependent on the modelling method of the partial recrystallisation in the multi-pass rolling for the case studied. As the rolling speed increased, the difference between the mean flow stresses calculated by the conventional model and the proposed model was gradually larger in accordance with the contribution of partial recrystallisation.
Resumo:
This thesis examines the nature, extent and impact of multiple forms of maltreatment (multi-type maltreatment) from within a developmental victimological framework. The interrelationships between sexual abuse, physical abuse, psychological maltreatment, neglect, and witnessing family violence are assessed. The role of family variables in predicting maltreatment and the relative contribution of child maltreatment and family variables to adjustment are evaluated. Risk factors for multi-type maltreatment, and the relationship between multi-type maltreatment and adjustment are explored. The major theories of child development are reviewed. As well as exploring the relevance of developmental theories to understanding the impact of child maltreatment, factors influencing the emergence of child psychopathology are reviewed from a developmental psychopathology perspective. Ecological and developmental perspectives on how child maltreatment translates into the behavioural and emotional adjustment problems of children are integrated in the Child Maltreatment: Risk and Protection Model. After exploring some of the relevant conceptual issues, the literature on the prevalence and impact of each maltreatment type is reviewed, and the literature on multi-type maltreatment critiqued. Methodological and ethical concerns with the conduct of research in the field of child maltreatment using direct assessment of children led to the need for an instrument to assess parent perceptions of each of the types of abuse and neglect, as well as adult retrospective reports. Data are presented from two cross-sectional questionnaire-based studies using the Parent and Adult versions of the Family and Life Experiences Questionnaire which was designed to assess perceptions of children's experiences of sexual abuse, physical abuse, psychological maltreatment, neglect and witnessing family violence. Problems with the isolated focus of research on single forms of child maltreatment are addressed by the inclusion of each of these forms of child maltreatment within a single research design. Respondents for both studies were volunteers recruited from counselling agencies, medical, community health, child care and fitness centres and a first year psychology course. Parents (N=50) described their perceptions of primary school children's family characteristics, experiences of maltreatment and adjustment. Children's behavioural adjustment (internalising and externalising), sexual behaviours, emotions, self-esteem, gender identity, family adaptability and cohesion, parental traditionality, parental sexual punitiveness, interparental relationship satisfaction, and demographic characteristics are assessed in the study of Parents' perceptions. A large degree of overlap between the different types of abuse and neglect was found, with a high proportion of parents describing children's experiences of multiple forms of child maltreatment. Using both maltreatment and family characteristics to predict internalising behaviour problems, neglect and family cohesion were the only unique predictors. Family adaptability and cohesion were the only unique predictors of externalising behaviour problems. Physical and sexual abuse were not predicted from family characteristics; neglect was predicted, but no variables provided unique prediction. Unique predictors of psychological maltreatment were family cohesion, parental sexual punitiveness and divorce. Divorce was the only variable with significant unique prediction of the child witnessing family violence. Family background and family functioning were found to predict some forms of maltreatment, but to also be important factors mediating the adjustment of children, independent of maltreatment. The results are interpreted within an ecological framework, integrating risk factors for maltreatment with experiences of abuse and neglect and subsequent adjustment in childhood. Retrospective reports of adults' (N=175) own childhood family characteristics, experiences of maltreatment, and reports of their current adjustment are also studied. Included with the adult version of the FLEQ were the Trauma Symptom Checklist-40, Rosenberg's Self-esteem Scale, and the Family and Adaptability and Cohesion Evaluation Scale-II. Similar results were found in the in the Adult Study. As hypothesised, adult retrospective reports of the five different types of child maltreatment were found to be highly intercorrelated. Family characteristics predicted maltreatment and adjustment scores and discriminated between single and multi-type maltreatment. Maltreatment scores also predicted adult adjustment. As the number of maltreatment types increased, there was an increase in the number of adjustment problems reported. Alternate hypotheses regarding the possible operation of mediating and moderating processes in the relationships between family characteristics, maltreatment and the adjustment of adults were assessed. Finally, the results of these investigations are discussed and interpreted in the light of extant findings previously reviewed. Data from the two major empirical studies are used to demonstrate the overlap between different child maltreatment categories, and the extent and impact of multi-type maltreatment. The results show that children are vulnerable to more than one type of maltreatment. Individuals who experience a number of different forms of maltreatment had greater adjustment problems than those experiencing only one or two different types of abuse or neglect. Dysfunctional families place children at risk of child maltreatment. Negative family characteristics lead to adjustment problems in children and adults. The type of maltreatment having the most damaging effect on children was neglect, and in the long-term, sexual abuse. A multi-dimensional approach to prevention and intervention needs to be adopted, based on the co-morbidity of maltreatment types, and the likelihood of children experiencing further abuse or neglect of a different type. Dysfunctional family dynamics which place children at risk of multi-type maltreatment, and mediate the effects of maltreatment on adjustment, need to be specifically targeted with support and family intervention strategies. Risk-assessment measures used by Child Protection workers must include adequate knowledge of the inter-relationships between maltreatment types, and the particularly negative impact on adjustment of experiencing many forms of abuse or neglect. Suggestions for future clinical and research work in the area of child maltreatment are developed. The importance of assessing all forms of maltreatment when examining the relationships of maltreatment to adjustment is emphasised. It is recommended that prevention and intervention strategies acknowledge the interrelationships between maltreatment types.