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351.
针对具有类矩形双肢钝体断面拱肋的大跨度拱桥在风洞试验过程易出现大幅涡激振动问题,沿拱肋模型表面进行动态风压同步测量及基于POD算法的本征气动力荷载分布模式分解,获得了涡振发生时对于周期性涡激力具有最大贡献的气动力荷载作用位置,初步揭示出此类断面涡激动发生时的局部气动力荷载作用机制。以上海卢浦大桥和肇庆西江特大桥此类具有双肢钝体断面拱桥为工程实例,结合涡激气动力沿拱肋周向时空气分布特征,提出并以二维悬吊节段模型风洞试验验证了拱肋断面多种有针对性的气动控制措施;结合实际桥梁拱肋的三维空间效应,利用全桥气弹模型 相似文献
352.
Using data from 7272 adolescent US girls, we explore how girls’ race/ethnic group status affects their bodyweight, perceptions of overweight, and weight control practices. We hypothesize that a girl’s race/ethnic status influences her basic identity which in turn prompts her to adopt or reject a “drive for thinness.” After controlling for family and peer support, school engagement, family SES, maturation, and family structure, we find that girls’ race/ethnic status influences their susceptibility to the thinness ideals of mainstream culture. African American girls weigh more than Asian, Hispanic, or White girls, but at any given weight they perceive themselves as overweight and attempt to control their weight less. Asian American and White girls invest most in thinness dynamics. Some evidence also suggests girls from lower SES families are less driven to be thin. Our results affirm the utility of viewing material bodies as “situations” that are experienced and interpreted in accord with identity group relations and dynamics. 相似文献
353.
The Hispanic population is now the largest and fastest growing minority in the United States, so it is not surprising that ethnic threat linked to Hispanics has been associated with harsher crime control. While minority threat research has found that individuals who associate blacks with crime are more likely to support harsh criminal policies, the possibility that this relationship exists for those who typify Hispanics as criminal has yet to be examined. Using a national random sample, this study is the first to use HLM to find that perceptions of Hispanics as criminals do increase support for punitive crime control measures, controlling for various individual and state influences. Moderated and contextual analyses indicate this relationship is most applicable for individuals who are less apt to typify criminals as black, less prejudiced, less fearful of victimization, politically liberal or moderate, not parents, and living in states with relatively fewer Latin American immigrants. 相似文献
354.
The manufacturing industry is currently facing unprecedented challenges from changes and disturbances. The sources of these changes and disturbances are of different scope and magnitude. They can be of a commercial nature, or linked to fast product development and design, or purely operational (e.g. rush order, machine breakdown, material shortage etc.). In order to meet these requirements it is increasingly important that a production operation be flexible and is able to adapt to new and more suitable ways of operating. This paper focuses on a new strategy for enabling manufacturing control systems to adapt to changing conditions both in terms of product variation and production system upgrades. The approach proposed is based on two key concepts: (1) An autonomous and distributed approach to manufacturing control based on multi-agent methods in which so called operational agents represent the key physical and logical elements in the production environment to be controlled – for example, products and machines and the control strategies that drive them and (2) An adaptation mechanism based around the evolutionary concept of replicator dynamics which updates the behaviour of newly formed operational agents based on historical performance records in order to be better suited to the production environment. An application of this approach for route selection of similar products in manufacturing flow shops is developed and is illustrated in this paper using an example based on the control of an automobile paint shop. 相似文献
355.
《Journal of Child Custody》2013,10(4):1-8
Abstract It is important for judges to accurately convey what they intend when speaking to litigants involved in domestic violence. Language has idiosyncratic meaning to perpetrators and to victims. Therefore, it is imperative that judges know and understand the language of domestic violence and use it properly. This editorial comments on some of the pitfalls of improper use of language, its impact, and suggests some solutions. 相似文献
356.
A generalized negative binomial distribution is derived from the Markov Bernoulli sequence of successes and failures. We study the properties and applications of this distribution. The properties are illustrated by two examples of discrete time queueing systems. The distribution is then fitted to two data sets, the eruption record of Mt. Sangay, and a record of computer disk failure accesses. In the first case there is a strong serial dependence in the data and the generalized negative binomial provides a good fit, while in the second case, although there is a significant serial dependence, it is insufficient to justify the additional parameter of the distribution. We conclude by demonstrating the usefulness of the distribution in the field of statistical quality control. 相似文献
357.
Jon E. Grant JD MD MPH Brian L. Odlaug MPH Katherine Derbyshire BS Liana R. N. Schreiber BA Katherine Lust PhD MPH Gary Christenson MD 《Journal of American college health : J of ACH》2013,61(1):75-78
Abstract Objective: This study examined the prevalence of mental health disorders and their clinical correlates in a university sample of lesbian, gay, bisexual, and queer (LGBQ) students. Participants: College students at a large public university. Methods: An anonymous, voluntary survey was distributed via random e-mail generation to university students during April and May of 2011. LGBQ students were compared with their heterosexual counterparts on psychological and physical status as well as academic performance. Results: LGBQ students reported worse depressive symptoms, higher levels of perceived stress, considered themselves less attractive, and were more likely to be overweight. LGBQ students were significantly more likely to report histories of affective, substance use, and certain anxiety disorders as well as compulsive sexual behavior and compulsive buying. Conclusions: The higher rates of many psychiatric conditions among LGBQ students underscore the need for universities to provide LGBQ students a nonjudgmental environment to discuss sexual orientation and health issues. 相似文献
358.
《Journal of American college health : J of ACH》2013,61(6):635-642
Objective: The authors' aim in this study was to determine, after adjustment for the effects of body mass index and sociodemographic measures, whether sex-specific weight control norms would have significant independent relationships with the weight control behavior of college women and men. Participants: The authors used an anonymous questionnaire to assess a sample of 470 college students, aged 18 to 26 years, attending either a 2- year community college or a 4-year public university. Methods: To calculate body mass index, the authors objectively measured the height and weight of each participant. They conducted separate discriminant function analyses for women and men. Results: The discriminant function analyses clearly indicated that weight control norms of same-sex, close friends were the best discriminators of involvement in weight control. Conclusions: The findings indicate that perceived peer norms may be important but overlooked risk factors for engaging in unhealthy weight control practices. The authors discuss the implications of these findings in the context of student health promotion. 相似文献
359.
采用汇文系统实现统编工作的探索 总被引:1,自引:0,他引:1
谢东 《江南大学学报(人文社会科学版)》2001,2(4):439-441
统一编目工作是促进图书馆业务工作自动化与标准化的重要技术,笔者从采用汇文系统进行统编工作的实践尝试中,探讨了统编工作中存在的一些实际问题,并提出了解决方案. 相似文献
360.
白伟 《吉林工程技术师范学院学报》2010,26(2):71-74
介绍了聚合釜聚酯聚合反应温度过程控制系统及其设计方法。控制系统以高性能单片机系统为直控机(DDC),PC机为上位机(MIS),直控机负责聚合釜釜温及夹套温度采集、分析、控制,并将参数送上位机。上位机负责控制过程的时间及温度值设定、温度监测、工作过程监控。 相似文献