A decomposition approach to suboptimal control of discrete-time systems

A suboptimal controller for a class of discrete-time systems is presented. The controller is derived by first solving ‘off-line’ a simplified optimal control problem obtained by neglecting part of the system state and by considering a larger time step, then by solving ‘on-line’ at each time step an optimization problem based on the results of the previously solved ‘off-line’ problem. A simple numerical example is presented to illustrate the control scheme.     

传染病流行的社会因素及社会控制策略刍议

传染病与社会文化因素的关系密切。应重视社会因素对传染病的发生发展影响，从社会根源上探究其发病原理，包括经济因素、科学技术、文化、人口、卫生服务和其它社会因素。人类要有与传染病长期斗争的思想准备，并制定包括大卫生观和技术合作等相应的社会策略。     

Effects of self-management training in Type 2 diabetes: a randomized, prospective trial.

AIMS: The efficacy of three education programmes for Type 2 diabetic patients was tested in a randomized trial. A didactic-oriented training programme (treatment A) was compared with a self-management-oriented programme delivered in group sessions (treatment B). The latter programme was compared with a more individualized approach (treatment C). METHODS: One hundred and eighty-one Type 2 diabetic patients (age 55.6 +/- 6.3 years, diabetes duration 6.6 +/- 6.2 years, HbA(1c) 7.8 +/- 1.6%, female 49.7%) took part. Efficacy was assessed 3 months (t1) after baseline (t0) and at a follow-up 15 months (t2) after baseline. RESULTS: The fall in HbA(1c) in treatment B at t1 was sustained at t2 (t0 8.1 +/- 1.8%, t1 7.3 +/- 1.7%, t2 7.4 +/- 1.9%). In treatment A, HbA(1c) was unchanged throughout (t0 7.6 +/- 1.5%, t1 7.5 +/- 1.3%, t2 7.7 +/- 1.7%; treatment A vs. treatment B; P < 0.05). With the more individualized approach of treatment C, there was a fall in HbA(1c) at t1, but this was not sustained at t2 (t0 7.8 +/- 1.6%, t1 7.1 +/- 1.3%, t2 7.6 +/- 1.6%; treatment B vs. treatment C; P = 0.73). There were also significant benefits in treatment B subjects compared with treatment A in further medical (body mass index and fasting blood glucose), psychological (control, irritability and hunger dependency of eating behaviour, and trait anxiety) and behavioural (exercise) variables. There were no significant benefits of the more individualized treatment C compared with group treatment B. No significant differences were found regarding triglyceride levels, high-density lipoprotein, diabetes-related knowledge, negative well-being, urine or blood glucose levels or foot care. CONCLUSION: Self-management training had a significantly higher medium-term efficacy than didactic diabetes education. The group sessions were more effective than a more individualized approach.     

Family Stress and Functioning in Children: the Moderating Effects of Children''s Beliefs About Their Control Over Parental Conflict

While factors such as gender and SES have been studied as moderators of stress for children, their perceptions of control have received little attention. In the current study, children's domain-specific perceptions of their control during marital conflict were investigated as potential moderators of the impact of family stress on children's behavior problems, and perceptions of competence. Ninety-four children aged 6-12 years and mothers from families ranging in level of parental conflict from nondiscordant to discordant to physically violent were interviewed. Multiple regression analyses revealed that higher levels of conflict control beliefs acted as compensatory moderators of stress, being associated with lower levels of problem behaviors across stress levels. However, higher conflict control beliefs acted as vulnerability moderators with regard to children's perceptions of competence.     

同济医科大学控烟活动及效果评价

我校自1993年开展控烟工作，1995年9月开始创办无吸烟大学校园，采取了卫生宣教和行政干预等综合措施，并进行了效果评价。高强度干预措施实施前期（1995年3月）和中期（1996年10月）相比，男医学生和男女学生平均吸烟率分别从16.3％和11．4％下降到9．6％和5．94％；男教工和男女教工平均吸烟率分别从28．6％和13．8％下降到13．9％和8．86％。     

The Fort McMurray demonstration project in social marketing: health- and safety-related behaviour among oil sands workers

This is the first round in a series of surveys conducted inFort McMurray as part of the Fort McMurray Demonstration Projectin social marketing. This component of the survey was intendedto focus on the most prominent group of employed workers inthe community and to compare their patterns of response withthe community as a whole. Respondents to the survey were overwhelminglymale (96%), married (72.9%) and living in households of twoto five persons (87.9%). They were predominantly aged 30–44(55%) and graduates of high school (53.5%). Younger male workers(below age 30) were more likely to have a high school diploma(78.3%) or some additional technical or vocational training(21.7% compared to 12.5% overall) and to be unmarried or separated.Attitudes toward safety-related behaviours were stronger thanfor respondents from the community as a whole. Approximately70–100% of all age groups and both sexes showed strongagreement with attitudes involving child car seats and the unacceptabilityof drinking and driving. These attitudes include strong advocacyof vigorous enforcement of occupational health and safety standards.However, they showed a variability similar to the communityas a whole in behaviour at home compared to work, generallyreporting more consistent use of personal protection on thejob than in their own homes, particularly hearing protection.Even so, they were much less likely to perform stretching andwarm-up exercises prior to exertion than community residentsin general. The potential may exist to transfer the technologyand attitudes from workplace health and safety to communitysafety. One possible strategy to accomplish this is to involveworkers in this industry directly in community initiatives.This strategy may be generalizable to any community in whichthere are major employers who place a heavy emphasis on riskcontrol and occupational health and safety.     

Biomonitoring of aromatic amines and alkylating agents by measuring hemoglobin adducts

Summary Analysis of hemoglobin adducts in blood samples is suitable for the biological monitoring of genotoxic chemicals. The method is specific because the compound to which the individual was exposed is identified. The sensitivity of the method depends on the analytical procedure applied, but is hardly limiting since large amounts of the protein can be obtained. The method provides not only information about the internal exposure to the environmental chemical, but also about the individual's capacity to generate ultimate genotoxic metabolites from it. Since macromolecular damage in blood cells is correlated to that in potential target tissues, this information is relevant to risk assessment, insofar as macromolecular damage produced by a specific chemical can be correlated with the development of tumors.     

基于系统输出分布的智能控制

提出了文题所述的控制策略,依据输出分布曲线的特征变量选取方法和依据该项信息的规则控制系统。仿真研究得到了满意的结果。在一个实验性二元精馏塔上用IBM-PC进行试验亦获成功。本法对具有非线性特性的分布参数对象,较常规控制策略有明显的优越性。