Semi Varying Coefficient Zero-Inflated Generalized Poisson Regression Model

In this paper, the semi varying coefficient zero-inflated generalized Poisson model is discussed based on penalized log-likelihood. All the coefficient functions are fitted by penalized spline (P-spline), and Expectation-maximization algorithm is used to drive these estimators. The estimation approach is rapid and computationally stable. Under some mild conditions, the consistency and the asymptotic normality of these resulting estimators are given. The score test statistics about dispersion parameter is discussed based on the P-spline estimation. Both simulated and real data example are used to illustrate our proposed methods.     

A generalized score confidence interval for a binomial proportion

Constructing a confidence interval for a binomial proportion is one of the most basic problems in statistics. The score interval as well as the Wilson interval with some modified forms have been broadly investigated and suggested by many statisticians. In this paper, a generalized score interval CI_G(a) is proposed by replacing the coefficient 1/4 in the score interval with parameter a. Based on analyzing and comparing various confidence intervals, we recommend the generalized score interval CI_G(0.3) for the nominal confidence levels 0.90, 0.95 and 0.99, which improves the spike phenomenon of the score interval and behaves better and computes more easily than most of other approximate intervals such as the Agresti-Coull interval and the Jeffreys interval to estimate a binomial proportion.     

能源化工产业高级化与经济增长——兼论能源化工产业最优匹配

能源化工产业是重要的基础性产业，现阶段对能源化工产业高级化及其对经济增长影响研究的成果还较少。文章首先将能源化工产业分为能源开采业、能源加工业和化工产业三大产业，测算能源化工产业高级化水平，结果表明能源资源禀赋导致了能源化工高级化水平的“低端锁定”，能源富集区能源产业高级化水平远远低于非能源富集省份，能源化工产业空间错配现象突出。其次，实证检验能源化工产业高级化对经济增长的影响，结果表明提高能源化工高级化水平能够显著促进经济增长，且不同产业规模的能源化工产业高级化对经济增长的影响存在差异性。再次，采用滚动回归方法检验随着能源化工产业高级化水平和产业结构变动，能源化工产业高级化水平对经济增长影响的变动状况，探讨能源化工产业内部最优匹配问题，结果表明能源化工产业高级化水平在1.05-1.15之间、能源开采业占能源化工产业比重在0.20-0.40之间，能源化工产业高级化对经济增长的促进效应最大。最后提出优化能源富集区能源化工产业匹配度、促进化工产业富集区新产品和新技术研发以及缓解能源化工产业空间错配等方面的政策建议。     

微机选配机床挂轮

利用微机选配挂轮,可以快速、准确地选配出在机床备用挂轮限制下的传动比精度最高的挂轮组合,并进行齿轮啮合性校核,实现机床挂轮的优化组合。     

Generalized exchange and propensity for military service: The moderating effect of prior military exposure

The propensity for military service (PMS) of young Americans is an important issue for our Armed Forces. Since the 1990s, the PMS of young Americans has steadily declined. Overtime, a declining PMS may cause military mission degradation, lowering of military recruitment standards, base closures, and reinstatement of the unpopular military draft system. This paper investigates the moderator effect of prior military service on the Generalized Exchange-PMS relationship. Generalized exchange is when indirect benefits such as preserving freedom and the American way of life accrue to the larger society because of an individual's military service. This paper uses a structural equation modelling approach to analyse the moderating effect of prior military exposure on prospective recruits regarding their PMS. Findings indicate that the group of prospective recruits with prior military exposure had higher levels of PMS than the group without such exposure, that is, the young people with prior military exposure are more likely to enlist in the military than the young Americans with no prior military exposure.     

Finding the best treatment under heavy censoring and hidden bias

Summary.  We analyse male survival duration after hospitalization following an acute myocardial infarction with a large ( N =11024) Finnish data set to find the best performing hospital district (and to disseminate its treatment protocol). This is a multiple-treatment problem with 21 treatments (i.e. 21 hospital districts). The task of choosing the best treatment is difficult owing to heavy right censoring (73%), which makes the usual location measures (the mean and median) unidentified; instead, only lower quantiles are identified. There is also a sample selection issue that only those who made it to a hospital alive are observed (54%); this becomes a problem if we wish to know their potential survival duration after hospitalization, if they had survived to a hospital contrary to the fact. The data set is limited in its covariates—only age is available—but includes the distance to the hospital, which plays an interesting role. Given that only age and distance are observed, it is likely that there are unobserved confounders. To account for them, a sensitivity analysis is conducted following pair matching. All estimators employed point to a clear winner and the sensitivity analysis indicates that the finding is fairly robust.     

新经济时代企业采购战略研究

21世纪是新经济时代,新经济与传统经济不同,以经济全球化、竞争链条化和技术网络化为特征。新经济导致企业的竞争环境发生了变化,由过去企业间的竞争转变为供应链间的竞争,企业生存环境越加复杂和多变。为此,企业已不能单纯依靠降低内部运营成本来获取更大的利润。企业如何与供应商合作,如何选择正确的采购战略尤为重要。新经济时代的采购战略主要有：供应商整合战略、供应商的全面质量管理战略、全球采购战略、供应商的长期合作关系战略、供应商提早参与战略、供应商发展战略、在线逆向拍卖战略、集中采购战略、联合采购战略和电子采购战略。企业应根据自身的发展目标和资源以及本企业总的发展战略合理选择适宜的采购战略,这样才能有效地提高自身的竞争力,实现可持续发展。     

Large Matching Markets as Two‐Sided Demand Systems

This paper studies two‐sided matching markets with non‐transferable utility when the number of market participants grows large. We consider a model in which each agent has a random preference ordering over individual potential matching partners, and agents' types are only partially observed by the econometrician. We show that in a large market, the inclusive value is a sufficient statistic for an agent's endogenous choice set with respect to the probability of being matched to a spouse of a given observable type. Furthermore, while the number of pairwise stable matchings for a typical realization of random utilities grows at a fast rate as the number of market participants increases, the inclusive values resulting from any stable matching converge to a unique deterministic limit. We can therefore characterize the limiting distribution of the matching market as the unique solution to a fixed‐point condition on the inclusive values. Finally we analyze identification and estimation of payoff parameters from the asymptotic distribution of observable characteristics at the level of pairs resulting from a stable matching.     

企业家社会资本与企业成长阶段的匹配性研究

企业家社会资本是企业获得持续成长所需的不可或缺的资源。企业家社会资本可以从微观、中观和宏观进行层次界定,企业家社会资本与企业成长各阶段具有非常高的匹配关系,企业成长的不同阶段通过构建相应类型的社会关系网络,获取相应类型的社会关系网络关键资源,保证了企业的持续经营和健康发展。