排序方式: 共有21条查询结果,搜索用时 15 毫秒
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We present in this paper BP-QL, a novel query language for querying business processes. The BP-QL language is based on an intuitive model of business processes, an abstraction of the emerging BPEL (business process execution language) standard. It allows users to query business processes visually, in a manner very analogous to how such processes are typically specified, and can be employed in a distributed setting, where process components may be provided by distinct providers. 相似文献
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In this paper we propose a new model for estimating the effective properties of regular hexagonal honeycombs. This model yields some new simple formulae which, in contrast to previous attempts, match the general invariant relations found by Vigdergauz in 1999. By comparing with numerical results, we also find some improved (but still simple) formulae which enable us to estimate the effective properties with an accuracy better than 1%, even for high density honeycombs. 相似文献
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Inheritance hierarchy design in object-oriented databases 总被引:2,自引:0,他引:2
Object-oriented database schema design is still mostly an art. One of the difficulties encountered during design is typing conflicts induced by multiple inheritance. In this paper, we propose a method for treating such a kind of conflicts. Our approach to inheritance conflict solving consists of several ingredients. First, we rely on branding, to introduce ‘type equivalence by name', thus allowing a designer to distinguish between structurally similar but semantically different types. However, we offer a heuristic that does not require a designer to explicitly state branding declarations. Second, we describe various kinds of conflicts, and we offer a set of procedures that analyze a schema to discover such conflicts, classify them, offering potential solutions, if possible. The procedures have been conceived for a design system that allows a designer maximum flexibility, while guiding him/her to a correct design. 相似文献
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R Beeri N Le Novère R Mervis T Huberman E Grauer JP Changeux H Soreq 《Canadian Metallurgical Quarterly》1997,69(6):2441-2451
In a search for behavioral, neuroanatomical, and metabolic characteristics of Alzheimer's disease that may result from cholinergic malfunction, we used transgenic mice overexpressing acetylcholinesterase (AChE) mRNA and active enzyme in brain neurons. Mapping by in situ hybridization revealed that transgenic and host AChE mRNAs were distributed similarly. In a Morris water maze working memory paradigm, adult transgenic mice did not display the characteristic improvement found in control mice either between or within test days and spent less time than control mice in the platform zone. In 5-week-old transgenic mice, the basilar dendritic trees of layer 5 pyramidal neurons from the frontoparietal cortex were essentially as developed as in age-matched controls. However, branching totally ceased after this age, whereas in control adults it continued up to at least 7 months. Therefore, dendritic arbors became smaller in adult transgenic mice than those of controls. Furthermore, the average number of spines was significantly lower on dendritic branches of 7-month-old but not 5-week-old transgenics as compared with controls. Binding of tritiated hemicholinium-3, a blocker of the high-affinity choline uptake characteristic of active cholinergic terminals, was over twofold enhanced in the brain of transgenic mice. In contrast, no differences were observed in the mRNA and ligand binding levels of several different subtypes of nicotinic and muscarinic acetylcholine receptors. These findings suggest that three different hallmarks associated with Alzheimer's disease--namely, progressive cognitive failure, cessation of dendrite branching and spine formation, and enhanced high-affinity choline uptake--are outcomes of cholinergic malfunction. 相似文献
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C Andres R Beeri A Friedman E Lev-Lehman S Henis R Timberg M Shani H Soreq 《Canadian Metallurgical Quarterly》1997,94(15):8173-8178
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Estimating forage quantity and quality using aerial hyperspectral imagery for northern mixed-grass prairie 总被引:3,自引:0,他引:3
Sustainable rangeland stewardship calls for synoptic estimates of rangeland biomass quantity (kg dry matter ha− 1) and quality [carbon:nitrogen (C:N) ratio]. These data are needed to support estimates of rangeland crude protein in forage, either by percent (CPc) or by mass (CPm). Biomass derived from remote sensing data is often compromised by the presence of both photosynthetically active (PV) and non-photosynthetically active (NPV) vegetation. Here, we explicitly quantify PV and NPV biomass using HyMap hyperspectral imagery. Biomass quality, defined as plant C:N ratio, was also estimated using a previously published algorithm. These independent algorithms for forage quantity and quality (both PV and NPV) were evaluated in two northern mixed-grass prairie ecoregions, one in the Northwestern Glaciated Plains (NGGP) and one in the Northwestern Great Plains (NGP). Total biomass (kg ha− 1) and C:N ratios were mapped with 18% and 8% relative error, respectively. Outputs from both models were combined to quantify crude protein (kg ha− 1) on a pasture scale. Results suggest synoptic maps of rangeland vegetation mass (both PV and NPV) and quality may be derived from hyperspectral aerial imagery with greater than 80% accuracy. 相似文献
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Catriel Beeri 《Data & Knowledge Engineering》1990,5(4):353-382
Object-oriented database systems are the focus of current research and development efforts. Yet, there is no commonly accepted object model, nor is it clear whether such a model can be developed. This paper reports on efforts to develop a formal framework that contains most features found in current object oriented database systems. The framework contains two parts. The first is a structural object model, including concepts such as structured objects, identity, and some form of inheritance. For this model, we explain the distinction between values and (abstract) objects, describe a system as a directed graph, and discuss declarative languages. The second part deals with higher-order concepts, such as classes and functions as data, methods, and inheritance. This part is a sketch, and leaves many issues unresolved. Throughout the paper, the emphasis is on logic-oriented modeling. 相似文献
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