首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   300篇
  免费   18篇
  国内免费   1篇
  2024年   1篇
  2023年   3篇
  2022年   14篇
  2021年   11篇
  2020年   16篇
  2019年   18篇
  2018年   16篇
  2017年   13篇
  2016年   13篇
  2015年   21篇
  2014年   13篇
  2013年   45篇
  2012年   6篇
  2011年   18篇
  2010年   10篇
  2009年   24篇
  2008年   26篇
  2007年   10篇
  2006年   8篇
  2005年   9篇
  2004年   5篇
  2003年   5篇
  2002年   3篇
  2001年   1篇
  1999年   1篇
  1997年   1篇
  1994年   1篇
  1992年   3篇
  1989年   1篇
  1988年   1篇
  1984年   1篇
  1978年   1篇
排序方式: 共有319条查询结果,搜索用时 15 毫秒
101.
A data integration system provides the user with a unified view, called global schema, of the data residing at different sources. Users issue their queries against the global schema, and the system computes answers to queries by suitably accessing the sources, through the mapping, i.e., the specification of the relationship between the global schema and the sources. Since sources are in general autonomous subsystems, the information provided by the data at the sources and the mapping is likely not to be consistent with the knowledge expressed by the global schema. Therefore, the question arises of how to interpret user queries in such a situation, i.e., in the presence of data contradicting the global schema and the mapping. In this paper, we provide an in-depth analysis of the problem of dealing with inconsistencies in data integration systems. In this respect, we highlight the central role played by the mapping, and propose a general “mapping-centered” semantics that allows for computing significant answers to user queries even in the presence of inconsistent information. Based on such a semantic analysis, we define a general formal framework for data integration. Then, we argue that our semantic approach formalizes a very reasonable way of handling inconsistency in such systems, since practically all the existing proposals in the literature can be reconstructed in our framework. This allows for comparing and evaluating the different existing proposals.  相似文献   
102.
Logic-based XML data integration: a semi-materializing approach   总被引:1,自引:0,他引:1  
We first describe the approach to XML data integration in the XPathLog/LoPiX project that uses a warehouse strategy. We show that the DOM model and the XML Query Data Model are not suitable for this task since the integrated database is not necessarily a tree, but a set of overlapping (original and integrated) trees. The problem is solved by using a node-labeled graph-based data model, called XTreeGraph, for the internal XML database that represents multiple, overlapping XML trees, or tree views.In the second part, we return to the standard XML data model—by still keeping the overlapping tree idea by “simulating” it: The data is internally represented by XML where the “overlayed” resulting tree is represented by XLink elements that refer to the original sources. By using a logical, transparent data model for XLinks as investigated in [May, in: 11th WWW Conference, 2002], all queries behave as stated against the XTreeGraph. The use of links for partial materialization also turns the approach from a warehouse approach into a mixed approach that combines the advantages of the warehouse approach and of the virtual approach. The approach is again illustrated by using XPathLog as data integration language.  相似文献   
103.
This paper uses a narrative approach to examine some of the dilemmas that counselling trainers face when designing and running personal development activities as part of a Diploma in Counselling training programme. The research emerges from a focus group discussion by the tutors involved in piloting and evaluating an experimental personal development training programme. The themes examined include: the strengths and weaknesses of unstructured group work; whether structured activities helped quieter members to participate and learn more; how trainers can evaluate and assess students learning in relation to personal development in order to maximize student learning potential. The aim is to invite debate and further re‐tellings from other counselling trainers and practitioners in the field.  相似文献   
104.
We studied 2 groups of workers from Oaxaca (Mexico) with different levels of income and education to investigate the role that the affective‐based psychological mechanism of personal trust, as evolutionarily acquired, plays on group cooperation. We measured trust levels through some questionnaires and cooperative behaviour through an iterated prisoner's dilemma under different conditions and analysed trust networks of group members. While these groups did not differ in trust levels or cooperation among trustees, they did differ in terms of cooperation with other group members. Such differences are related to dissimilarities in the trust network topology—as a measure of group cohesion. These results suggest that some personal trust networks extend cooperation within a group beyond trustees in a way that complements the role of the reputation for indirect reciprocity.  相似文献   
105.
Research with infants is often slow and time-consuming, so infant researchers face great pressure to use the available participants in an efficient way. One strategy that researchers sometimes use to optimize efficiency is data peeking (or “optional stopping”), that is, doing a preliminary analysis (whether a formal significance test or informal eyeballing) of collected data. Data peeking helps researchers decide whether to abandon or tweak a study, decide that a sample is complete, or decide to continue adding data points. Unfortunately, data peeking can have negative consequences such as increased rates of false positives (wrongly concluding that an effect is present when it is not). We argue that, with simple corrections, the benefits of data peeking can be harnessed to use participants more efficiently. We review two corrections that can be transparently reported: one can be applied at the beginning of a study to lay out a plan for data peeking, and a second can be applied after data collection has already started. These corrections are easy to implement in the current framework of infancy research. The use of these corrections, together with transparent reporting, can increase the replicability of infant research.  相似文献   
106.
The association between personality and personal relationships is mostly studied within dyadic relationships. We examined these variables within the context of personal network types. We used Latent Class Analysis to identify groups of students with similar role relationships with three focal figures. We performed Latent Class Logistic Regression to explore the relationships of the latent classes with the Big Five personality factors. Personality was assessed with the Five Factor Personality Inventory. We found three personal network types: a primarily family oriented network, a primarily peer oriented network, and a mixed family/peer oriented network. We found significant associations between personality and personal network type. Extraverted students were more likely to have a primarily peer oriented network relative to a primarily family oriented network. Autonomous students were more likely to have a primarily family oriented network relative to a primarily peer oriented network. Autonomous students were also more likely to have a mixed family/peer oriented network relative to a primarily peer oriented network. Conscientious students were more likely to have a primarily family oriented network relative to a mixed family/peer oriented network.  相似文献   
107.
Daniel Kolak 《Synthese》2008,162(3):341-372
Sydney Shoemaker leads today’s “neo-Lockean” liberation of persons from the conservative animalist charge of “neo-Aristotelians” such as Eric Olson, according to whom persons are biological entities and who challenge all neo-Lockean views on grounds that abstracting from strictly physical, or bodily, criteria plays fast and loose with our identities. There is a fundamental mistake on both sides: a false dichotomy between bodily continuity versus psychological continuity theories of personal identity. Neo-Lockeans, like everyone else today who relies on Locke’s analysis of personal identity, including Derek Parfit, have either completely distorted or not understood Locke’s actual view. Shoemaker’s defense, which uses a “package deal” definition that relies on internal relations of synchronic and diachronic unity and employs the Ramsey–Lewis account to define personal identity, leaves far less room for psychological continuity views than for my own view, which, independently of its radical implications, is that (a) consciousness makes personal identity, and (b) in consciousness alone personal identity consists—which happens to be also Locke’s actual view. Moreover, the ubiquitous Fregean conception of borders and the so-called “ambiguity of is” collapse in the light of what Hintikka has called the “Frege trichotomy.” The Ramsey–Lewis account, due to the problematic way Shoemaker tries to bind the variables, makes it impossible for the neo-Lockean ala Shoemaker to fulfill the uniqueness clause required by all such Lewis style definitions; such attempts avoid circularity only at the expense of mistaking isomorphism with identity. Contrary to what virtually all philosophers writing on the topic assume, fission does not destroy personal identity. A proper analysis of public versus perspectival identification, derived using actual case studies from neuropsychiatry, provides the scientific, mathematical and logical frameworks for a new theory of self-reference, wherein “consciousness,” “self-consciousness,” and the “I,” can be precisely defined in terms of the subject and the subject-in-itself.  相似文献   
108.
Troy Catterson 《Synthese》2008,162(3):385-404
In this paper I shall attempt to argue for the simple view of personal identity. I shall first argue that we often do have warrant for our beliefs that we exist as continuing subjects of experience, and that these beliefs are justified independently of any reductionist analysis of what it means to be a person. This has two important implications that are relevant to the ongoing debate concerning the number of persons that are in existence throughout any duration in time: (1) the lack of logically or metaphysically necessary and sufficient conditions for distinguishing one person from another should imply neither that there is only one person nor that personhood is not individuative; and (2) the lack of such universally applicable identity criteria should not imply that the term ‘person’ is a folk term with no real application. In other words, lack of reductionist analysis does not entail lack of existence.  相似文献   
109.
Marya Schechtman 《Synthese》2008,162(3):405-423
In the spirit of the discussion in Daniel Kolak’s I Am You: The Metaphysical Foundation for Global Ethics, I consider the way in which divisions that we usually think of as borders between distinct people occur within a single life. Starting with the dispute between constructionist and non-constructionist views of persons, I argue for a view that places the unity of persons in the dynamic generated by simultaneously taking a constructionist and non-constructionist view of oneself. In order to unify ourselves as agents we need to treat past and future selves as others, but to motivate this endeavor we need to think of ourselves as temporally extended agents, and so identify with past and future selves. Understanding this dynamic illuminates the structure of our agency and the unity of the self.  相似文献   
110.
There has been a vast amount of research on the changes experienced by immigrants, but little is known about the changes experienced by host individuals. This article focuses on the role of host individuals in the networks of relations between immigrant populations and the communities from the dominant culture, as well as the changes experienced by host individuals because of their continuous contact with immigrants. This research applied a network approach to the study of the acculturation of host individuals. Two independent studies were carried out: a systematic analysis of the personal networks of Argentinean (n = 67), Ecuadorian (n = 59), Italian (n = 37) and German (n = 37) residents in Seville and Cadiz (Spain) (Study 1); and an ethnographic study with human service workers for Latin American immigrants in Boston (USA) (Study 2). With two different strategies, the role of host individuals in personal networks of foreigners in the United States and Spain was analyzed. The results show that host individuals tend to have less centrality than compatriots, showing an overall secondary role in the personal networks of immigrants. The lowest average centrality was observed in recent and temporal migrants, whereas the highest corresponded to the individuals with more time of residence in Spain. The personal networks of human service providers in the United States vary in ethnic composition and in their structural properties, and therefore shape different types of integrative bridges for immigrants.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号