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251.
One of the concerns often voiced by critics of the precautionary principle is that a widespread regulatory application of the principle will lead to a large number of false positives (i.e., over-regulation of minor risks and regulation of nonexisting risks). The present article proposes a general definition of a regulatory false positive, and seeks to identify case studies that can be considered authentic regulatory false positives. Through a comprehensive review of the science policy literature for proclaimed false positives and interviews with authorities on regulation and the precautionary principle we identified 88 cases. Following a detailed analysis of these cases, we found that few of the cases mentioned in the literature can be considered to be authentic false positives. As a result, we have developed a number of different categories for these cases of "mistaken false positives," including: real risks, "The jury is still out," nonregulated proclaimed risks, "Too narrow a definition of risk," and risk-risk tradeoffs. These categories are defined and examples are presented in order to illustrate their key characteristics. On the basis of our analysis, we were able to identify only four cases that could be defined as regulatory false positives in the light of today's knowledge and recognized uncertainty: the Southern Corn Leaf Blight, the Swine Flu, Saccharin, and Food Irradiation in relation to consumer health. We conclude that concerns about false positives do not represent a reasonable argument against future application of the precautionary principle.  相似文献   
252.
In the random-design non-parametric regression model, the locations of particular values of the regression function or its derivatives are estimated. This paper investigates several stochastic modes of convergence and finds their rate of convergence under regularity assumptions, for a wide class of non-parametric estimators. The approach finds two natural fields of application: estimation of zeros/extrema and non-parametric absolute calibration.  相似文献   
253.
Survival models assume that fates of individuals are independent, yet the robustness of this assumption has been poorly quantified. We examine how empirically derived estimates of the variance of survival rates are affected by dependency in survival probability among individuals. We used Monte Carlo simulations to generate known amounts of dependency among pairs of individuals and analyzed these data with Kaplan-Meier and Cormack-Jolly-Seber models. Dependency significantly increased these empirical variances as compared to theoretically derived estimates of variance from the same populations. Using resighting data from 168 pairs of black brant ( Branta bernicla nigricans ), we used a resampling procedure and program RELEASE to estimate empirical and mean theoretical variances. We estimated that the relationship between paired individuals caused the empirical variance of the survival rate to be 155% larger than the empirical variance for unpaired individuals. Monte Carlo simulations and use of this resampling strategy can provide investigators with information on how robust their data are to this common assumption of independent survival probabilities.  相似文献   
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256.
This article focuses on defining and discussing the concept of critical success factors as input into the environment analysis, resource analysis, and strategy evaluation steps in the strategic planning/strategy development process. The reader is provided with eight possible sources of critical success factors including environmental analysis, analysis of industry structure, industry/business experts, analysis of competition, analysis of dominant firm in the industry, company assessment, temporal/intuitive factors and PIMS results. Examples of CSF's from various sources are provided and a scheme by which the reader can assess the relative importance of identified CSF's is presented.  相似文献   
257.
Joel M Stern 《Omega》1974,2(1):11-32
One of the greatest dangers in corporate financial planning is failing to separate investment decision making from financial policy, because poor quality investments can appear to be desirable as a result of the particular financing vehicle employed. Management's focus of attention should not be rates of growth and earnings per share or return on net worth. Rather, the most important measure of corporate performance is the rate of return on total capital employed. The paper identifies the dangers of employing an earnings per share criterion for evaluating corporate performance, and suggests an alternative: focusing on a company's free cash flow, net operating profits after taxes minus the amount of new capital investment required in order to generate future profits. The author presents an analytical framework employing his free cash flow concept which can be applied to pricing and financing acquisitions.  相似文献   
258.
Improved Bounds on Relaxations of a Parallel Machine Scheduling Problem   总被引:4,自引:0,他引:4  
We consider the problem of scheduling n jobs withrelease dates on m identical parallel machines to minimize the average completion time of the jobs. We prove that the ratio of the average completion time of the optimal nonpreemptive schedule to that of the optimal preemptive schedule is at most 7/3, improving a bound of Shmoys and Wein.  相似文献   
259.
Social scientists generally presume that a good reputation has advantages. Yet the Walt Disney Corporation, a firm that has long benefited from a reputation for producing wholesome popular culture, attracts more than its share of efforts to link it to various social problems. In particular, conservative moralists argue that Disney in fact produces morally questionable products, progressive critics claim that Disney's messages help preserve social inequities, and social scientists criticize Disney for fostering inauthentic and alienating entertainment. These claims are a form of blowback—negative reactions to the firm's positive reputation. While blowback makes it easier to construct social problems claims, a good reputation remains a significant resource in deflecting these criticisms.  相似文献   
260.
Taylor's law, which originated in ecology, states that, in sets of measurements of population density, the sample variance is approximately proportional to a power of the sample mean. Taylor's law has been verified for many species ranging from bacterial to human. Here, we show that the variance V(x) and the mean M(x) of the primes not exceeding a real number x obey Taylor's law asymptotically for large x. Specifically, V(x) ~ (1/3)(M(x))2 as x → ∞. This apparently new fact about primes shows that Taylor's law may arise in the absence of biological processes, and that patterns discovered in biological data can suggest novel questions in number theory. If the Hardy-Littlewood twin primes conjecture is true, then the identical Taylor's law holds also for twin primes. Taylor's law holds in both instances because the primes (and the twin primes, given the conjecture) not exceeding x are asymptotically uniformly distributed on the integers in [2, x]. Hence, asymptotically M(x) ~ x/2, V(x) ~ x2/12. Higher-order moments of the primes (twin primes) not exceeding x satisfy a generalized Taylor's law. The 11,078,937 primes and 813,371 twin primes not exceeding 2 × 108 illustrate these results.  相似文献   
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