Design of adaptive controllers using partial certainty equivalence principle

Optimal stochastic control problem for general non‐linear dynamic system with unknown parameters is considered. An approximative assumption, which has been named partial certainty equivalence (PCE) principle, is suggested for design of adaptive controllers of non‐linear and linear stochastic systems. For derivation of a suboptimal controller with the PCE principle the certainty equivalence (CE) assumption is used only for the part of the system states and unknown parameters. The PCE control policy has a simple form for linear systems with unknown parameters. It is suggested in the present paper to design adaptive dual control using the PCE assumption and bicriterial optimization to derive the adaptive controller with the optimal persistent excitation. Simulated examples are used to demonstrate the potential of the suggested method and its superiority over the generally used CE‐controllers. Copyright © 2004 John Wiley & Sons, Ltd.     

Assessing statistical similarity in dietary intakes of women of reproductive age in Bangladesh

Women of reproductive age (WRA) need adequate nutrient intakes to sustain a healthy pregnancy, support fetal growth, and breastfeed after childbirth. However, data on women''s dietary intake in low‐ and middle‐income countries (LMICs) are limited, and assessment of differences between dietary intakes of pregnant or lactating women compared with that of nonpregnant, nonlactating (NPNL) women is untested. Using single, multiple‐pass 24‐h dietary recall data from a sample of WRA residing in rural Bangladesh, we examined women''s dietary intakes for energy, protein, calcium, iron, vitamin A, and dietary diversity for three groups: NPNL (n = 2,903), pregnant (n = 197), and lactating women (n = 944). We used equivalence testing to examine similarity in adjusted intakes for pregnant versus NPNL women and lactating versus NPNL women with a predetermined equivalence threshold based on recommendations specific for each reproductive stage. On average, both pregnant and lactating women had insufficient intakes for all dietary measures. Although statistically significant differences were observed between pregnant and NPNL women for energy intake and dietary diversity and between lactating and NPNL women for energy and protein intake, the magnitudes of these differences were too small to reject equivalence. Statistical similarity was also evident in all micronutrients and dietary diversity for both two‐group comparisons. Understanding statistical differences and similarities between dietary measures of women in distinct reproductive stages has important implications for the relevance, appropriateness, and evaluation of maternal diet‐enhancing interventions in LMICs, especially during pregnancy and lactation, when demand for macronutrients and micronutrients is elevated.     

The cross-cultural equivalence of participation instruments: a systematic review

Purpose: Concepts such as health-related quality of life, disability and participation may differ across cultures. Consequently, when assessing such a concept using a measure developed elsewhere, it is important to test its cultural equivalence. Previous research suggested a lack of cultural equivalence testing in several areas of measurement. This paper reviews the process of cross-cultural equivalence testing of instruments to measure participation in society. Methods: An existing cultural equivalence framework was adapted and used to assess participation instruments on five categories of equivalence: conceptual, item, semantic, measurement and operational equivalence. For each category, several aspects were rated, resulting in an overall category rating of ‘minimal/none’, ‘partial’ or ‘extensive’. The best possible overall study rating was five ‘extensive’ ratings. Articles were included if the instruments focussed explicitly on measuring ‘participation’ and were theoretically grounded in the ICIDH(-2) or ICF. Cross-validation articles were only included if it concerned an adaptation of an instrument developed in a high or middle-income country to a low-income country or vice versa. Results: Eight cross-cultural validation studies were included in which five participation instruments were tested (Impact on Participation and Autonomy, London Handicap Scale, Perceived Impact and Problem Profile, Craig Handicap Assessment Reporting Technique, Participation Scale). Of these eight studies, only three received at least two ‘extensive’ ratings for the different categories of equivalence. The majority of the cultural equivalence ratings given were ‘partial’ and ‘minimal/none’. The majority of the ‘none/minimal’ ratings were given for item and measurement equivalence. Conclusion: The cross-cultural equivalence testing of the participation instruments included leaves much to be desired. A detailed checklist is proposed for designing a cross-validation study. Once a study has been conducted, the checklist can be used to ensure comprehensive reporting of the validation (equivalence) testing process and its results.

Implications for Rehabilitation

• Participation instruments are often used in a different cultural setting than initial developed for.

• The conceptualization of participation may vary across cultures. Therefore, cultural equivalence – the extent to which an instrument is equally suitable for use in two or more cultures – is an important concept to address.

• This review showed that the process of cultural equivalence testing of the included participation instruments was often addressed insufficiently.

• Clinicians should be aware that application of participations instruments in a different culture than initially developed for needs prior testing of cultural validity in the next context.

     

Using functional equivalence training to reduce severe challenging behavior: A case study

A case study is described in which functional equivalence was used to reduce severe tantrums and property destruction by an 8-year-old boy with autism. Although data were collected on the frequency of these behaviors, no treatment was applied directly to them. Rather, the child and his mother were taught functional communication training and the mother was taught activity planning. As the boy gained communication skills, his tantruming and property damage were virtually eliminated. The value of case studies is also discussed.University of Judaism.     

Alternatives to mega-trials in cardiovascular disease

Summary This article considers the dominant role of trials involving thousands of patients-the mega-trials—in cardiovascular disease. Problems with large trials mean that alternative strategies must be developed to aid the introduction of new drugs. The limitations of meta-analysis, and of trials with combined and surrogate endpoints are discussed. Properly organized trials designed to establish whether or not two treatments have an equivalent effect seem to offer the best alternative to mega-trials.     

Comparison of Steady-State Blood Levels of Two Carbamazepine Formulations

The steady-state plasma level produced by brand-name carbamazepine (CBZ) (Tegretol, Ciba-Geigy) was compared with a generic formulation (Parke-Davis) in 10 subjects with partial epilepsy in a randomized, double-blind, cross-over clinical trial. In addition, seizure frequency and clinical and laboratory signs of toxicity were evaluated. Our results failed to show any difference in CBZ blood levels, seizure frequency, or clinical or laboratory signs of toxicity in patients receiving either the brand-name or generic formulation.     

英汉公示语及其语义信息的传递

作为一个全新的通用流行词语,公示语的语义信息异常丰富。英汉公示语之间偶有部分对应,完全对应的情况极少,其语义信息的传递方式可根据具体的题旨情境或直译、或意译、或借译、或仿译、或反译、或图示、或图示并辅以文字标识,以实现交际意图。