基于H∞//μ鲁棒控制原来和使用ATMD的高楼主动振动控制策略研究

对使用主动脉调频质量块ＡＴＭＤ（ＡｃｉｔｖｅＴｕｎｅｄＭａｓｓＤａｍｐｅｒ）的具有ｎ阶自由度的柔性大楼结构建立了全阶模型,并由此将得到的结构降价模型用于设计ＡＴＭＤ的控制器,通过分析,大楼结构的位置和速度可被列为控制器的输出反馈变量,将等效两端口模型应用于带ＡＴＭＤ的大楼结构上,使用Ｈ∞／μ频域定型综合理论,设计出ＡＴＭＤ的鲁棒控制器,通过模拟分析,可见该控制算法是非常有效的,ＡＴＭＤ中的小质量决     

Deletion of glutamate receptor-A (GluR-A) AMPA receptor subunits impairs one-trial spatial memory.

Genetically modified mice lacking the glutamate receptor A (GluR-A) subunit of the AMPA receptor (GluR-A-/- mice) display normal spatial reference memory but impaired spatial working memory (SWM). This study tested whether the SWM impairment in these mice could be explained by a greater sensitivity to within-session proactive interference. The SWM performance of GluR-A-/- and wild-type mice was assessed during nonmatching-to-place testing under conditions in which potential proactive interference from previous trials was reduced or eliminated. SWM was impaired in GluR-A-/- mice, both during testing with pseudotrial-unique arm presentations on the radial maze and when conducting each trial on a different 3-arm maze, each in a novel testing room. Experimentally naive GluR-A-/- mice also exhibited chance performance during a single trial of spontaneous alternation. This 1-trial spatial memory deficit was present irrespective of the delay between the sample information and the response choice (0 or 45 min) and the length of the sample phase (0.5 or 5 min). These results imply that the SWM deficit in GluR-A-/- mice is not due to increased susceptibility to proactive interference. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of combined lesions of the subicular complex and the entorhinal cortex on two forms of spatial navigation in the water maze.

The role of the subicular complex and entorhinal cortex (SUB–EC) in spatial learning was examined in 2 water maze experiments. In Experiment 1, rats had to locate a hidden platform that was always a fixed distance and direction from an intramaze landmark. Each day, the landmark and platform were moved to a new location. Both control and SUB–EC-lesioned rats learned to locate the platform equally readily during training. However, the control group was impaired in locating the platform when the visual extramaze cues were concealed, whereas the lesioned group was unaffected by this manipulation. In Experiment 2, the lesioned rats were impaired in finding a hidden platform that was in a fixed place in the water maze and showed no evidence of having learned its location in a probe test. These results suggest that damage to the SUB–EC impairs the integration of geometric information but spares a more general navigational-directional strategy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive Factors in Programming with Diagrams

Visual programming languages aim to broaden the use ofdiagrams within the software industry, to the extentthat they are integrated into the programming languageitself. As a result, they provide an ideal opportunityto study the benefits of diagrams as an externalrepresentation during problem solving: not only isprogramming a challenging problem-solving activity,but the effect of diagram usage can be directlyassessed by comparing performance while using a visualprogramming language to performance with a standardtextual language. There have been severalmisconceptions amongst visual language researchersregarding the role of diagrams in software design, butthese are being addressed by empirical studies and bynew theories of notation design derived from studiesof visual programming. Based on this research, theauthors are able to recommend several new directionsfor research into thinking with diagrams.     

The Hobetron-a high power vacuum electronic switch

This paper describes a new high-power, hollow electron beam, current-regulating switch tube that we call the Hobetron. Experimental data on the Litton L-6026 Hobetron, an engineering prototype designed to stand off 125 kV dc and switch 200 amps, has demonstrated that Hobetron performance is in excellent agreement with computer predictions over the range of test. Further, the data confirmed that L-6026 switch power loss is less than 20% that of standard magnetron injection gun (MIG) switch tubes (for similar currents through each). Various potential Hobetron applications are presented throughout the paper. It is possible to include an additional electrode in the basic Hobetron configuration for even higher voltage standoff and switch current capability, and the paper presents an arrangement capable of standing off 500 kV dc and switching 500 amps. Simulations of a superpower “Hobetron-Plus” are presented, and the potential of this device as an efficient, 50 MW peak, relatively compact, VHF power amplifier for advanced heavy-particle (e.g., muon) colliders, is evaluated     

Hypothesis validity of clinical research.

Hypothesis validity refers to the extent to which research results reflect theoretically derived predictions about the relations between or among constructs. The role of hypotheses in theory testing is discussed. Four threats to hypothesis validity are presented: (a) inconsequential research hypotheses, (b) ambiguous research hypotheses, (c) noncongruence of research hypotheses and statistical hypotheses, and (d) diffuse statistical hypotheses and tests. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Osteoporosis for the allergist

OBJECTIVE: This review is intended to be an authoritative summary of the pathogenesis of osteoporosis, a problem that may be encountered in allergy practice. It also provides an outline for identification of subjects at high risk and directions for their appropriate evaluation, management, and prevention of the disease. DATA SOURCES: References were obtained through a MEDLINE literature search as well as from previous reviews. Relevant articles were critically reviewed and their conclusions were included. RESULTS: Osteoporosis is a relatively common disease that is associated with significant morbidity and mortality. The management and prevention of osteoporosis have been improved by an increased awareness of the magnitude of the problem, a better understanding of the pathogenesis, development of a better technique for assessment of bone mineral density, and the availability of specific medications. With the increase in human life-span and the increasing use of glucocorticosteroids for a wide variety of diseases, the incidence of osteoporosis has been on the rise. CONCLUSION: Glucocorticosteroids are the most common medications that cause or contribute to the pathogenesis of osteoporosis and have been widely used in allergy practice. It is important for physicians to appreciate the current basic understanding of osteoporosis and to be able to identify patients at high risk for this serious disorder, and to initiate appropriate intervention at a sufficiently early time to be effective. Medications for treatment and prevention of osteoporosis include: calcium, vitamin D, estrogen, bisphosphonates, calcitonin, and others are reviewed in this article.     

A design system for RFIC: challenges and solutions

The expansion of the market for portable wireless communication devices has given a tremendous push to the development of a new generation of low-power radio frequency integrated circuit (RFIC) products. In this fast-growing environment where time-to-market constraints force tight schedules, having a good design methodology, innovation computer-aided design (CAD) tools, and a well-integrated design system are key factors for success. In this paper, we describe a design system developed to provide the designer with everything necessary to accurately predict the behavior of RFIC devices, including layout and package parasitic effects. We show how important a well-defined and integrated system is to manufacturing a design that meets specifications at the minimum cost, in the minimum time. A close link between schematic, models, and layout is of paramount importance to ensure the accuracy need for low-power RF design. We give an overview of the advanced methods and tools currently available for simulation and noise analysis of RF devices. Finally, we show a design example that obtained first-silicon success     

The "Swedish" mutation of the amyloid precursor protein (APPswe) dissociates components of object-location memory in aged Tg2576 mice.

Aged Tg2576 mice show abnormalities in hippocampal morphology and physiology and display behavioral deficits in spatial navigation tasks consonant with a deficit in the functional properties of the hippocampus. However, the nature of the spatial representations disrupted by the "Swedish" mutation of the amyloid precursor protein (APPswe) is unclear. In an effort to characterize the memory deficits in Tg2576 mice, the spontaneous object exploration paradigm was used to interrogate spatial and object memory in mice. With object arrays of comparable size, 16-month-old Tg2576 mice showed a normal object familiarity/novelty effect but impaired memory for the location of objects when 2 objects exchanged locations (topological transformation; Experiment 1). In contrast, Tg2576 mice showed preferential exploration of familiar objects when they were moved to previously unoccupied locations (Experiment 2), irrespective of whether the transformation altered the metric properties of the object array (Experiments 3). These results suggest that Tg2576 mice are able to form representations of the identity of objects and a memory of the spatial organization of objects in an arena. In contrast, conjunctive memory for specific object-location associations is severely impaired in aged Tg2576 mice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Wyes and wye nots of three-phase distribution transformerconnections

The advantages and disadvantages of various three-phase transformer connections are summarized. Recommendations are provided regarding the standard types of connections a utility should offer for various service requirements. Warehousing costs, ferroresonance, neutral grounding, core construction, overvoltages, unbalanced loading, zero sequence source, and through faults are considered. Emphasis is placed on the exchange of information between customer and utility. An Application for Three-Phase Service form is provided. It can be used to determine service requirements including voltage, grounded, ungrounded, three-phase load, single-phase load, motor characteristics, and fault current interruption rating of secondary breakers and switchgear. Suggestions on utility-supplied information such as maximum available three-phase and line-to-ground fault currents and a discussion of the operation of ungrounded systems are also provided