Time substitution and network effects with an application to nanobiotechnology policy for US universities

We present a dynamic network model of the knowledge production process for nanobiotechnology research at 25 US universities during 1990–2005. Universities produce knowledge outputs in nanobiotechnology consisting of Ph.D. graduates, research publications, and patents. Inputs include the university’s spending on R&D in engineering and the life sciences, and the university’s own stock of knowledge measured by past publications in nanobiotechnology. In addition, universities take advantage of the stock of knowledge produced by other universities in previous periods. We simulate the effect of the National Science Foundation being able to optimally allocate research funds for nanobiotechnology research between universities and across time so as to maximize the aggregate amounts of the three knowledge outputs produced by the universities.     

《红楼梦》二书合成过程中被隐藏的叙述--由薛蟠、秦钟、秦可卿三人的关系谈起

《红楼梦》的成书,有“一稿多改”和“二书合成”两说。在对现存诸版本《红楼梦》内容情节进行细读的时候发现的许多问题,如用“二书合成”的观点进行分析,则会得到较为合理的解释。在“二书合成”过程中,有一些情节被删去或隐藏起来,薛蟠、秦钟、秦可卿三人之间的关系,便是其中之一。     

Bootstrap Procedures for Online Monitoring of Changes in Autoregressive Models

We compare the behavior of several bootstrap procedures for monitoring changes in the error distribution of autoregressive time series. The proposed procedures are designed to control the overall significance level and include classical tests based on the empirical distribution function as well as Fourier-type methods that utilize the empirical characteristic function, both functions being computed on the basis of properly estimated residuals. The Monte Carlo study incorporates different estimators and a variety of sampling situations with and without outliers.     

Curve of Correlation for Time Series

The curve of correlation is a measure of local correlation between two random variables X and Y at the point X = x of the support of this variable. This article studies this local measure using the theory of time series for bivariate and univariate stationary stochastic process. We suggest local polynomial estimators for time series observing their consistency both theoretically and through simulations. For this, different sizes of series, bandwidths, and kernels, besides lags and models’ configurations were used. Applications have also been made using the daily returns of two financial series.     

Manufacturing bill-of-material planning

The bill-of-material BOM in the machine tool industry takes two different forms in design and manufacturing functions: Engineering BOM E BOM , which is used by the design engineer to represent designed product structure; and manufacturing BOM M BOM , which is used by MRPII system for MRP explosion. The designer constructs the E BOM after the product has been designed. Next, the E BOM is transformed into the M BOM by considering assembly sequence and constraints. Constructing a M BOM simply involves compressing the E BOM into a three-level M BOM. Planning of a M BOM still depends primarily on the experience input of a manufacturing engineer and is performed manually. This trial and error and time consuming approach creates an inconsistent method for planning the M BOM. Therefore, in this study, a three-stage M BOM planning method is developed. Stage one plans the initial M BOM, stage two improves the M BOM and stage three tunes the M BOM. Concepts and algorithms of each stage are highlighted in this study. Moreover, an illustration is presented to demonstrate the feasibility of M BOM planning.     

An Evaluation of the NERJIT Priority Rule in a Kanban‐Controlled Flowshop

Significant progress in production and information technologies and innovations in management of operations during the last couple of decades have made the production of small lots and deployment of Just‐In‐Time (JIT) concepts in flowshops possible. As a result, some researchers and practitioners have been seeking to improve the performance of non‐repetitive systems using JIT concepts. In this process, the JIT concepts that were originally designed for mass production have been modified to adapt JIT to non‐repetitive systems. This article uses a priority rule that is based on real‐time demand and production information for sequencing jobs in a kanban‐controlled flowshop. The analysis of the effect of this priority rule; the number of kanbans; the length of the withdrawal cycle; First‐Come, First‐Served (FCFS); and Shortest Processing Time (SPT) on four performance measures—customer wait time, total inventory, input stock‐point inventory, and output stock‐point inventory, shows that the use of this priority rule results in a significant reduction of customer wait time and a slight decrease in inventory.     

Dose-response assessment for influenza A virus based on data sets of infection with its live attenuated reassortants

Reported data sets on infection of volunteers challenged with wild-type influenza A virus at graded doses are few. Alternatively, we aimed at developing a dose-response assessment for this virus based on the data sets for its live attenuated reassortants. Eleven data sets for live attenuated reassortants that were fit to beta-Poisson and exponential dose-response models. Dose-response relationships for those reassortants were characterized by pooling analysis of the data sets with respect to virus subtype (H1N1 or H3N2), attenuation method (cold-adapted or avian-human gene reassortment), and human age (adults or children). Furthermore, by comparing the above data sets to a limited number of reported data sets for wild-type virus, we quantified the degree of attenuation of wild-type virus with gene reassortment and estimated its infectivity. As a result, dose-response relationships of all reassortants were best described by a beta-Poisson model. Virus subtype and human age were significant factors determining the dose-response relationship, whereas attenuation method affected only the relationship of H1N1 virus infection to adults. The data sets for H3N2 wild-type virus could be pooled with those for its reassortants on the assumption that the gene reassortment attenuates wild-type virus by at least 63 times and most likely 1,070 times. Considering this most likely degree of attenuation, 10% infectious dose of H3N2 wild-type virus for adults was estimated at 18 TCID50 (95% CI = 8.8-35 TCID50). The infectivity of wild-type H1N1 virus remains unknown as the data set pooling was unsuccessful.     

上市公司协议收购的法律分析

上市公司协议收购是我国目前证券市场上盛行的做法。协议收购的法律制度既被决定于和体现了经济因素,同时又通过所形成的制度约束,使立法者、监管者和收购方与被收购方之间进行着反复博弈,不断地强化着协议收购制度的合理性。但应加强上市公司协议收购中的信息披露,建立异议股东股份回购请求制度,加强和完善小股东的诉讼机制。     

《列车正点到达》中的时间关系

在亨利希.伯尔的《列车正点到达》中,既存在空间时间,也存在心理时间,这两种时间既尖锐地相悖,有悖反的张力,又惊人地统一,有极端的巧合。在这两种时间关系上,伯尔选择性地吸收了柏格森的直觉主义,又赋予它新的涵义,表达了他对二战的明确的态度。     

基于无穷状态转换模型的中国股票市场收益率分析

本文建立一个状态数目由数据决定的马尔可夫转换向量自回归模型,用贝叶斯方法推断模型参数,并利用基于Gibbs分块采样的MCMC方法做逼近。然后本文用此模型和估计方法分析上海A股市场周收益率,结果发现,我国股票市场最可能存在5个不同的状态,状态间的区分首以波动性大小不同为标准,股市除了在初期波动性极小外,从1992年4月开始可以分为两个阶段,在各阶段股市均在三个状态之间转换。