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41.
42.
Penta is the configuration shown in figure 1(a), where continuous lines represent edges and dotted lines represent non-edges. The vertex u in figure 1(a) is called the center of Penta. A graph G is called a pentagraph if every induced subgraph H of G has a vertex v which is not a center of induced Penta in H. The class of pentagraphs is a common generalization of chordal [triangulated] graphs and Mahadev graphs. We construct a polynomial-time algorithm that either find a maximum stable set of G or concludes that G is not a pentagraph. We propose a method for extending α-polynomial hereditary classes based on induced Pentas.  相似文献   
43.
Much of the increased risk for atherosclerosis progression with age may be a result of age-related declines in the capacity of precursor cells to repair damage in the arterial endothelium. To estimate the impact of progenitor cell therapy for atherosclerosis on cardiovascular disease (CVD) mortality, life expectancy, and survival, as compared with the lifetime control of conventional risk factors, we modeled the health effects of bone marrow-derived endothelial progenitor cell therapy using data from the 1950 to 1996 follow-up of the Framingham Heart Study. To model cardiovascular disease mortality, we assumed that progenitor cell therapy was applied at age 30, with the effect assumed to be a 10-year delay in atherosclerosis progression. Age projections were constructed analytically using the stochastic process model for risk factor dynamics and mortality and microsimulation techniques. We considered three types of interventions: (i) keeping risk factors within selected limits to model current clinical recommendations; (ii) an age shift of 10 years to model the effects of progenitor cell therapy; and (iii) elimination of a competing risk (such as cancer). Our study suggests that progenitor cell therapy might increase life expectancy in the population as much as the complete elimination of cancer (in females, an additional 3.67 versus 3.37 years; in males, an additional 5.94 versus 2.86 years, respectively).  相似文献   
44.
Limiting distributions play an important role in approximating the exact distributions, especially when they have a rather cumbersome analytic form, or simply when they do not have a closed from. The question that naturally arises is how good the approximation is. In this article, we propose a procedure for the numerical assessment of the “goodness” of some easy-to-calculate limiting distributions, originally proposed in Bar-Lev and Enis, in various cases of the underlying distributions, some of which are inherently computationally challenging. The details of the procedure are provided in three examples. The first example deals with the gamma distributions; the second deals with Bessel distributions related to a symmetric random walk, and the third example deals with positive stable distributions. The details of two additional variations of these examples are also discussed. These examples illustrate the ease with which the limiting approximations could be applied in the various cases, well-demonstrating their computational simplicity and attractiveness.  相似文献   
45.
Within the microelectronics industry, there is a growing concern regarding the introduction of counterfeit electronic parts into the supply chain. Even though this problem is widespread, there have been limited attempts to implement risk‐based approaches for testing and supply chain management. Supply chain risk management tends to focus on the highly visible disruptions of the supply chain instead of the covert entrance of counterfeits; thus counterfeit risk is difficult to mitigate. This article provides an overview of the complexities of the electronics supply chain, and highlights some gaps in risk assessment practices. In particular, this article calls for enhanced traceability capabilities to track and trace parts at risk through various stages of the supply chain. Placing the focus on risk‐informed decision making through the following strategies is needed, including prioritization of high‐risk parts, moving beyond certificates of conformance, incentivizing best supply chain management practices, adoption of industry standards, and design and management for supply chain resilience.  相似文献   
46.
Completely random measures (CRM) represent the key building block of a wide variety of popular stochastic models and play a pivotal role in modern Bayesian Nonparametrics. The popular Ferguson & Klass representation of CRMs as a random series with decreasing jumps can immediately be turned into an algorithm for sampling realizations of CRMs or more elaborate models involving transformed CRMs. However, concrete implementation requires to truncate the random series at some threshold resulting in an approximation error. The goal of this paper is to quantify the quality of the approximation by a moment-matching criterion, which consists in evaluating a measure of discrepancy between actual moments and moments based on the simulation output. Seen as a function of the truncation level, the methodology can be used to determine the truncation level needed to reach a certain level of precision. The resulting moment-matching Ferguson & Klass algorithm is then implemented and illustrated on several popular Bayesian nonparametric models.  相似文献   
47.
We analyze the concept of correlated equilibrium in the framework of two-player two-strategy games. This simple framework makes it possible to clearly demonstrate the characteristic features of this concept. We develop an intuitive and easily memorizable test for equilibrium conditions and provide a complete classification of symmetric correlated equilibria in symmetric games.  相似文献   
48.
Numerous studies suggest that our society is stratified not only by race and class, but also by phenotypic characteristics. The main objective of the present investigation was, using the National Longitudinal Study of Adolescent Health, to elucidate the link between phenotype and violence involvement. Two outcomes were examined: being a perpetrator of violence and criminal justice system contact. Cross-sectional and longitudinal analyses were conducted on Asian, black and Hispanic respondents and as well as on the subsample of siblings. Independent variables included phenotype, socioeconomic status, other family, peer and neighborhood effects. Notwithstanding a certain degree of heterogeneity of outcomes across race–ethnicity, the results indicate a negative relationship between proximity to the European phenotype and the likelihood of violence involvement. In other words, the darker one’s complexion, eye and hair color, the higher the likelihood of violence involvement.  相似文献   
49.
Until recent times, psychology and the social sciences have paid only limited attention to the positive aspects of human life. The present article aims to review psychological and epidemiological studies about the occurrence of happy and traumatic events in the life of common people, critically discussing their findings and suggesting new research directions. Overall, it has emerged that most people report having experienced at least one traumatic event in their lives; on the other hand, moderate happy experiences may occur with a daily frequency. Unfortunately, the studies conducted thus far suffer from methodological limitations as they did not consider extremely happy events and collected data about happy and traumatic events separately. The author emphasizes the necessity to jointly investigate the prevalence of both happy and traumatic events. Hopefully, this will permit to achieve more reliable indicators of quality of life, thus contributing to increase researchers’ understanding of what makes human existence joyful and sorrowful.  相似文献   
50.
Risk assessors and managers face many difficult challenges related to novel cyber systems. Among these challenges are the constantly changing nature of cyber systems caused by technical advances, their distribution across the physical, information, and sociocognitive domains, and the complex network structures often including thousands of nodes. Here, we review probabilistic and risk-based decision-making techniques applied to cyber systems and conclude that existing approaches typically do not address all components of the risk assessment triplet (threat, vulnerability, consequence) and lack the ability to integrate across multiple domains of cyber systems to provide guidance for enhancing cybersecurity. We present a decision-analysis-based approach that quantifies threat, vulnerability, and consequences through a set of criteria designed to assess the overall utility of cybersecurity management alternatives. The proposed framework bridges the gap between risk assessment and risk management, allowing an analyst to ensure a structured and transparent process of selecting risk management alternatives. The use of this technique is illustrated for a hypothetical, but realistic, case study exemplifying the process of evaluating and ranking five cybersecurity enhancement strategies. The approach presented does not necessarily eliminate biases and subjectivity necessary for selecting countermeasures, but provides justifiable methods for selecting risk management actions consistent with stakeholder and decisionmaker values and technical data.  相似文献   
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