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31.
The oil supply chain is facing new challenges due to emerging issues such as new alternative energy sources, oil sources scarcity, and price variability with high impact on demand and production and profit margins reduction. Additionally, the existence of large, complex and world wide spread businesses implies a complex system to be managed where distribution can be seen as one of the key areas that needs to be efficiently and effectively managed. Different types of distribution modes characterize the oil supply chain where the pipeline mode is one of the most complex to operate when having multiproduct characteristics. This paper addresses the planning of a generic oil derivatives transportation system characterized by a multiproduct pipeline that connects a single refinery to a storage tank farm. Two alternative mixed integer linear programming models (MILP) that aim to attain a set of planning objectives such as fulfilling costumers’ demands (which is mandatory) while minimizing the medium flow rate are developed. Additionally, final inventory levels are avoided to be excessively low. A real world scenario of a Portuguese company is used to validate and compare the two alternative MILP models developed in this paper.  相似文献   
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This paper investigates the effect of linguistic diversity on redistribution in a broad cross‐section of countries. We use the notion of “linguistic distances” and show that the commonly used fractionalization index, which ignores linguistic distances, yields insignificant results. However, once distances between languages are accounted for, linguistic diversity has both a statistically and economically significant effect on redistribution. With an average level of redistribution of 9.5% of GDP in our data set, an increase byone standard deviation in the degree of diversity lowers redistribution by approximately one percentage point. We also demonstrate that other measures, such as polarization and peripheral heterogeneity, provide similar results when linguistic distances are incorporated. (JEL: D6, D74, H5, Z10)  相似文献   
34.
This article addresses the problem of the multiscale importance of road networks, with the aim of helping to establish a more resilient network in the event of a road disruption scenario. A new model for identifying the most important roads is described and applied on a local and regional scale. The work presented here represents a step forward, since it focuses on the interaction between identifying the most important roads in a network that connect people and health services, the specificity of the natural hazards that threaten the normal functioning of the network, and an assessment of the consequences of three real‐world interruptions from a multiscale perspective. The case studies concern three different past events: road interruptions due to a flood, a forest fire, and a mass movement. On the basis of the results obtained, it is possible to establish the roads for which risk management should be a priority. The multiscale perspective shows that in a road interruption the regional system may have the capacity to reorganize itself, although the interruption may have consequences for local dynamics. Coordination between local and regional scales is therefore important. The model proposed here allows for the scaling of emergency response facilities and human and physical resources. It represents an innovative approach to defining priorities, not only in the prevention phase but also in terms of the response to natural disasters, such as awareness of the consequences of road disruption for the rescue services sent out to local communities.  相似文献   
35.

Multiprocessor open shop makes a generalization to classical open shop by allowing parallel machines for the same task. Scheduling of this shop environment to minimize the makespan is a strongly NP-Hard problem. Despite its wide application areas in industry, the research in the field is still limited. In this paper, the proportionate case is considered where a task requires a fixed processing time independent of the job identity. A novel highly efficient solution representation is developed for the problem. An ant colony optimization model based on this representation is proposed with makespan minimization objective. It carries out a random exploration of the solution space and allows to search for good solution characteristics in a less time-consuming way. The algorithm performs full exploitation of search knowledge, and it successfully incorporates problem knowledge. To increase solution quality, a local exploration approach analogous to a local search, is further employed on the solution constructed. The proposed algorithm is tested over 100 benchmark instances from the literature. It outperforms the current state-of-the-art algorithm both in terms of solution quality and computational time.

  相似文献   
36.
In the past few years, the field of dam safety has approached risk informed methodologies throughout the world and several methodologies and programs are appearing to aid in the systematization of the calculations. The most common way of implementing these calculations is through the use of event trees, computing event probabilities, and incremental consequences. This methodology is flexible enough for several situations, but its generalization to the case of systems of several dams is complex and its implementation in a completely general calculation methodology presents some problems. Retaining the event tree framework, a new methodology is proposed to calculate incremental risks. The main advantage of this proposed methodology is the ease with which it can be applied to systems of several dams: with a single risk model that describes the complete system and with a single calculation the incremental risks of the system can be obtained, being able to allocate the risk of each dam and of each failure mode. The article shows how both methodologies are equivalent and also applies them to a case study.  相似文献   
37.
This paper looks at the media in Germany and Australia in order to focus on the question of how Islam is accepted in both countries, and the extent to which Islamophobia exists. It was discovered that, for the most part, the media in both countries present a somewhat biased view of Muslims and Islam. However, there were some significant differences: (1) a higher acceptance of multiculturalism in the Australian media, which is revealed in the greater number of articles on ordinary, everyday multicultural life; (2) differences in the portrayal of migrants’ roles; and (3) the terminology used to refer to migrants. The paper concludes by outlining the ways in which multicultural education could contribute to a reduction of Islamophobia.  相似文献   
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Three separate issues concerning the relation between age and satisfaction with sex life are addressed in this article. The first issue was concerned with the age generalizability of the factor structure produced by responses to the Satisfaction with Sex Life Scale (SWSLS). The second issue was to examine whether there were differences in the satisfaction with sex life according to certain background characteristics, namely age. Finally, the relationship between scores on the SWSLS with those on other relational constructs was explored. Data collection involved completion of a questionnaire. The sample consisted of 1,144 participants. The mean ages of the sample were 38.99 years in (SD = 16.91); ages ranged from 20 to 80. The data indicated that the factor structure of responses to the SWSLS were highly similar through adult life. Religious involvement, marital status, and love status influenced satisfaction with sex life. Expected correlations with measures of other relationship constructs were found. The strongest predictor of satisfaction with sex live across the adult life span was love satisfaction. Suggestions concerning the use of the SWSLS for research and clinical purposes are offered.  相似文献   
40.
Word clouds constitute one of the most popular statistical tools for the visual analysis of text documents because they provide users with a quick and intuitive understanding of the content. Despite their popularity for visualizing single documents, word clouds are not appropriate to compare different text documents. Independently generating word clouds for each document leads to configurations where the same word is typically located in widely different positions. This makes it very difficult to compare two or more word clouds. This paper introduces COWORDS, a new stochastic algorithm to create multiple word clouds, including one for each document. The shared words in multiple documents are placed in the same position in all clouds. Similar documents produce similar and compact clouds, making it easier to simultaneously compare and interpret several word clouds. The algorithm is based on a probability distribution in which the most probable configurations are those with a desirable visual aspect, such as a low value for the total distance between the words in all clouds. The algorithm output is a set of word clouds that are randomly selected from this probability distribution. The selection procedure uses a Markov chain Monte Carlo simulation method. We present several examples that illustrate the performance and visual results that can be obtained by our algorithm.  相似文献   
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