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Lei Sun Evor L. Hines Roger J. Green Mark S. Leeson D. Daciana Iliescu 《国际射频与微波计算机辅助工程杂志》2007,17(5):493-504
This article illustrates a microwave dielectric lens design using genetic programming (GP), which, to the best knowledge of the authors, is the first time GP has been applied to design a microwave dielectric lens. A phase‐compensating single layer lens and a quarter‐wave phase‐compensating multilayer dielectric lens, which uses four types of materials and a zoned structure, was designed using GP. The dielectric lens shape was designed using GP strategy, with a random initial shape, to compensate for the phase error of the multilayer dielectric lens and to achieve the required performance. Standard GP (SGP) and hierarchical fair competition genetic programming (HFC‐GP) was applied to obtain the solution. The results show that this novel method of microwave lens shape design using GP is both accurate and stable. In addition, the simulation results of using high frequency simulation software (HFSS) are illustrated and compared. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007. 相似文献
73.
The simplicity principle—an updating of Ockham's razor to take into account modern information theory—states that the preferred theory for a set of data is the one that allows for the most efficient encoding of the data. We consider this in the context of classification, or clustering, as a data reduction technique that helps describe a set of objects by dividing the objects into groups. The simplicity model we present favors clusters such that the similarity of the items in the clusters is maximal, while the similarity of items between clusters is minimal. Several novel features of our clustering criterion make it especially appropriate for clustering of data derived from, psychological procedures (e.g., similarity ratings): It is non-parametric, and may be applied in situations where the metric axioms are violated without requiring (information-forgetting) transformation procedures. We illustrate the use of the criterion with a selection of data sets. A distinctive aspect of this research is that it motivates a clustering algorithm from psychological principles. 相似文献
74.
Experiences with adult conspecifics can influence the ontogeny of species-typical behaviours in naive young of many species. Two processes of influence, direct and indirect, are proposed to describe the effect of adult behaviours on juvenile development. In Belding's ground squirrels, Spermophilus beldingiexposure to adults experienced with responding to alarm calls may affect how juveniles respond to calls and/or the rate at which juveniles acquire adult-like responses to calls. Because dams and their juvenile offspring interact extensively during early development, the influence of dams on the ontogeny of juvenile alarm-call responses was investigated by conducting playbacks of alarm calls and non-alarm calls to captive ground squirrels. Juveniles were more likely to respond to auditory stimuli if their dam responded, but the responses of unrelated adult females did not influence juveniles. A dam's presence at the time of a playback had no consistent effect, however, on the type of initial response made by her juvenile, its response duration or the vigilance of its postures. The permanent absence of adult models (dams) after weaning appeared to delay the rate at which juveniles developed a discrimination between alarm calls and non-alarm calls, but had no long-term influence on juveniles' expression of responses. Thus, dams indirectly influenced juvenile response development by acting as models of species-typical responses. The outcome of dams' influence was facilitative rather than inductive, because exposure to dams affected the rate of response development but was not necessary for juveniles to acquire alarm-call responses.1997The Association for the Study of Animal Behaviour 相似文献
75.
Stephen C. Hines 《The Journal of communication》2001,51(3):498-513
This essay extends problematic integration theory and related theories of uncertainty management to communication about serious illness and death. These extensions (a) note that theorizing must focus on multiple, interrelated uncertainties rather than a single such uncertainty; (b) explain how communication with others often problematizes efforts to cope with illness-related uncertainties; and (c) identify specific factors that may influence how persons choose to cope with these uncertainties. The essay describes implications for ongoing efforts to improve communication with persons nearing death. Specifically, they point to 5 incorrect assumptions that limit the effectiveness of current efforts to encourage persons to talk about their end-of-life preferences with others in a process referred to as advance care planning and then suggest concrete changes derived from this framework that can improve the advance care planning process and enhance the quality of end-of- life care. 相似文献
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Stephen P. Hines 《Journal of the Society for Information Display》1999,7(3):187-192
Abstract— A multi-viewer autostereoscopic display that provides motion parallax without encumbering the observer with special equipment is described. The display is built around a single liquid-crystal panel, from which multiple images are projected to a screen where they form the 3-D image. The display can be produced economically because it uses a single display panel and conventional optics. The primary advantage of this technique is its simplicity. Computer-generated images are supplied to the liquid-crystal panel with a single video board. 3-D television can be broadcast by a single unmodified television station (NTSC, PAL, SECAM, HDTV, etc.), and recorded and replayed in 3-D with a VCR. Applications include 3-D video arcade games, avionics, engineering workstations, scientific visualization, video phones, and 3-D television. 相似文献
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79.
SE Hiscox MB Hallett MC Puntis T Nakamura WG Jiang 《Canadian Metallurgical Quarterly》1997,15(6):513-521
To characterize the clinical features of childhood tuberculosis, we analyzed the symptoms, signs, and laboratory findings of the 89 children with tuberculosis admitted to the Yokohama City University Hospital from 1975 to 1994. Compared with the numbers of patients admitted from 1975 to 1979, those of patients of the past 5 years (from 1990 to 1994) were reduced by half. Of the 89 subjects, 56.2% were below 3 years of age and 24.7% were under 1 year of age. 51.7% had primary complex and 20.2% had serious tuberculosis (tuberculous meningitis 14.6%, miliary tuberculosis 3.4%, and bone and joint tuberculosis 2.2%). Tuberculous children below 3 years of age consisted of primary complex (60.0%) and serious tuberculosis (32.0%). The majority (86.0%) of tuberculous children below 3 years of age had not received BCG vaccination. In 55 (61.8%) of 89 subjects, the sources of tuberculosis were clarified. Of these subjects, 83.6% were infected in the family. The rate of BCG inocluation tended to decrease with decreasing age, especially that of children below 3 years of age was 14.0%. Of the 89 subjects, only 16.9% proved to be smear-positive. Taken together, in order to eliminate tuberculous children below 3 years of age, the following is necessary; (1) BCG inoculation in early infancy, (2) early diagnosis of index cases with adult tuberculosis, and (3) prompt and appropriate family contact examination. 相似文献
80.