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91.
N. Giri  M. Behara  P. Banerjee 《Metrika》1992,39(1):75-84
Summary LetX=(X ij )=(X 1, ...,X n )’,X i =(X i1, ...,X ip )’,i=1,2, ...,n be a matrix having a multivariate elliptical distribution depending on a convex functionq with parameters, 0,σ. Let ϱ22 -2 be the squared multiple correlation coefficient between the first and the remainingp 2+p 3=p−1 components of eachX i . We have considered here the problem of testingH 02=0 against the alternativesH 11 -2 =0, ϱ 2 -2 >0 on the basis ofX andn 1 additional observationsY 1 (n 1×1) on the first component,n 2 observationsY 2(n 2×p 2) on the followingp 2 components andn 3 additional observationsY 3(n 3×p 3) on the lastp 3 components and we have derived here the locally minimax test ofH 0 againstH 1 when ϱ 2 -2 →0 for a givenq. This test, in general, depends on the choice ofq of the familyQ of elliptically symmetrical distributions and it is not optimality robust forQ.  相似文献   
92.
ABSTRACT

The emergence of online social network invokes social actors to share their personal information digitally. Moreover, it provides the facility to maintain their links with people of same interest globally. Take advantage of these services; it has become a fascinating testbed to invite various threats like a spammer. Detection of spammer in OSN is one of the most critical tasks. Spammer not only spreads unwanted or bad advertisement but does certain malicious activity in others' profiles. By clearly understanding the activities of different threats, some incremental and accurate approaches are needed for detecting spammer content and profiles involved in these activities by using social network services. Therefore, the focus of this article is to detect spammer content and account, specifically on the leading microblogging platform called Twitter. We propose a hybrid approach which leverages the capabilities of various machine learning algorithms to separate spammer and nonspammer contents and account. Initially, the optimisation algorithm called genetic algorithm analyses the various features and selects the best suitable features that influence the behaviour of user account, and these features are then used to train classifiers. Our framework achieved to severalise spammer and nonspammer content in an effective way. Finally, to prove the efficiency of our proposed framework, a comparative analysis is conducted with some existing state-of-art techniques. The experimental analysis shows that our approach achieves a high detection rate of 99.6%, which is better than other state-of-art techniques.  相似文献   
93.
94.
    
The authors present a semester-long game to teach the role of economics in natural resources management. The game is framed within a fisheries context: multiple student fisheries harvest fish to maximize yield/profit, which is measured using a piecewise linear function. There are prizes for both the student and the group with the highest semester-long catch, which brings forth the social dilemma associated with dynamic stock externalities in fisheries. The game can be played in large classes, is robust to student attrition, and requires 5–10?minutes per class period. Given its features, it can be used to teach behavioral economic principles in resource management, incentives versus command-and-control regulations, role of cheap talk, social preferences, punishment, and community management as well as solutions such as aquaculture.  相似文献   
95.
A new approach to modelling equivalence scales and household demand systems is introduced and its usefulness empirically demonstrated. The empirical results suggest that price effects on the general equivalence scale are more important than utility effect.  相似文献   
96.
    
This study departs from the previous literature on purchasing power parity (PPP) by proposing a demand system based methodology for calculating the PPP that takes account of consumer preferences and allows for the substitution effect of price changes. The methodology is used to calculate the PPP between the Indian Rupee and the Vietnamese Dong. The study allows for regional variation in preferences and price changes both inside the country and between countries. It proposes and applies a methodology for constructing prices from unit values after adjusting them for quality and demographic effects. The adjusted unit values are used as prices in the demand estimations, and the demand parameter estimates are used to calculate both spatial prices within each country and the PPP between the two countries within a consistent framework. The study illustrates the usefulness of preference consistent methods to calculate the PPP by applying the PPPs to compare living standards between India and Vietnam. The significance of the results follows from the fact that the levels of living comparisons are quite sensitive to the PPP used in converting the Rupee expenditure into Vietnamese Dong. The present results on food PPPs question the relevance of the PPPs from the ICP project in cross‐country welfare comparisons especially in a period of high food inflation.  相似文献   
97.
    
It is widely accepted that the concepts and practices of management can only be of benefit when they are anchored to the contextual architecture of people, processes, structures, and technologies. The challenge of establishing a bridging program for providing managerial competencies to Australian Indigenous people has become a serious one for multinational mining companies. As the wings of globalization interact with the long-ignored reality of marginalized local milieu, a need for an innovative management education system has become a major imperative compelling multinational mining companies to work collaboratively with the government, educational institutions, and Indigenous communities. The article outlines a specific decision-making dilemma in an Indigenous context, while explaining the imperatives for educators, who have the challenging task of instructing potential graduates how to manage the unique contextuality of rural Australian Aboriginal communities. The article presents implications for large-scale modern multinationals as they move to geographically remote regions of the world where large number of marginalized local people need to be drawn into the workforce not only as an act of a social responsibility imperative, but also as sound business pragmatism.  相似文献   
98.
    
What is the impact of product certification on small‐scale farmers’ livelihoods? To what extent does the participation of Ethiopian small‐scale coffee farmers in certified local cooperative structures improve their socioeconomic situation? To answer these questions, this article employs household data of 249 coffee farmers from six different cooperatives collected in the Jimma zone of Southwestern Ethiopia in 2009. Findings show that the certification of coffee cooperatives has in total a low impact on small‐scale coffee producers’ livelihoods mainly due to (1) low productivity, (2) insignificant price premium, and (3) poor access to credit and information from the cooperative. Differences in production and organizational capacities between the local cooperatives are mirrored in the extent of the certification benefits for the smallholders. “Good” cooperatives have reaped the benefits of certification, whereas “bad” ones did not fare well. In this regard the “cooperative effect” overlies the “certification effect.”  相似文献   
99.
    
This empirical study uses 100 years of annual data on 11 agricultural commodities from Belgium to measure the impact of structural changes coinciding with economic development and changes in political institutions on agricultural protection. The analysis shows that changes in agricultural protection are caused by a combination of factors. Governments have increased protection and support to farmers when world market prices for their commodities fell, and vice versa, offsetting market effects on producer incomes. Other economic determinants were the share of the commodities in total consumer expenditures (negative effect) and in total output of the economy (positive effect). With Belgium a small economy, there was no impact of the trade position. Changes in political institutions have affected agricultural protection. Democratic reforms which induced a significant shift in the political balance towards agricultural interests, such as the introduction of the one‐man‐one‐vote system, led to an increase in agricultural protection. The integration of Belgian agricultural policies in the Common Agricultural Policy in 1968 coincided with an increase in protection, ceteris paribus. Both institutional factors, related to changes in access to and information about the decision‐making at the EU level, and structural changes in the agricultural and food economy may explain this effect.  相似文献   
100.
  总被引:1,自引:0,他引:1  
The paper tests a political economy theory of simultaneous government decision‐making on income redistribution through commodity policies and on public research investment in agriculture. We use data from 37 countries on agricultural protection and public agricultural research expenditures (PARI). The empirical results are consistent with the political economy hypotheses. The analysis suggest that structural changes in the economy have important effects on the political incentives for governments not only to subsidize or tax farmers, but also to invest in public agricultural research. Furthermore, the analysis supports the hypotheses that the impact of such structural changes on government decision‐making on PARI is non‐linear and conditional on other factors. Regarding the impact of political institutions, the results suggest that more democracy neither leads to more distortionary transfers (agricultural protection), nor to lower investment in public goods (PARI). ©2000 Elsevier Science B.V. All rights reserved.  相似文献   
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