基于异构分类体系的书目数据库合并

将不同馆藏编码尤其是连分类系统都不相同的书库合并在一起,是一个综合性项目,涉及到很多因素。其中,选择一个好的书目数据合并算法十分重要。本文分析了书目数据合并时要处理的基本对象,建立了基于异构分类体系书目数据库合并的数学模型并讨论其解的情况,最后提出了解决这一问题需综合考虑的几个因素。     

Joint Initial Stocking and Transshipment—Asymptotics and Bounds

A common problem faced by many firms in their supply chains can be abstracted as follows. Periodically, or at the beginning of some selling season, the firm needs to distribute finished goods to a set of stocking locations, which, in turn, supply customer demands. Over the selling season, if and when there is a supply‐demand mismatch somewhere, a re‐distribution or transshipment will be needed. Hence, there are two decisions involved: the one‐time stocking decision at the beginning of the season and the supply/transshipment decision throughout the season. Applying a stochastic dynamic programming formulation to a two‐location model with compound Poisson demand processes, we identify the optimal supply/transshipment policy and show that the optimal initial stocking quantities can be obtained via maximizing a concave function whereas the contribution of transshipment is of order square‐root‐of T. Hence, in the context of high‐volume, fast‐moving products, the initial stocking quantity decision is a much more important contributor to the overall profit. The bounds also lead to a heuristic policy, which exhibits excellent performance in our numerical study; and we further prove both the bounds and the heuristic policy are asymptotically optimal when T approaches infinity. Extension to multiple locations is also discussed.     

基于建模理论的高校专业结构自主调控机制研究

新建本科高校转型发展是我国高等教育领域一次深刻的变革,探索建设应用技术类型高校发展道路,提高新建本科高校对经济社会发展的服务能力至关重要。优化和调控新建本科高校的学科专业结构,避免专业重复设置和同质化现象,是提高学校办学特色和应用型人才培养质量的有效途径。影响专业结构设置与调控的相关因素很多,应加以系统科学的研究。     

Managing stochastic demand in an Inventory Routing Problem with transportation procurement

We study an Inventory Routing Problem in which the supplier has a limited production capacity and the stochastic demand of the retailers is satisfied with procurement of transportation services. The aim is to minimize the total expected cost over a planning horizon, given by the sum of the inventory cost at the supplier, the inventory cost at the retailers, the penalty cost for stock-out at the retailers and the transportation cost. First, we show that a policy based just on the average demand can have a total expected cost infinitely worse than the one obtained by taking into account the overall probability distribution of the demand in the decision process. Therefore, we introduce a stochastic dynamic programming formulation of the problem that allows us to find an optimal policy in small size instances. Finally, we design and implement a matheuristic approach, integrating a rollout algorithm and an optimal solution of mixed-integer linear programming models, which is able to solve realistic size problem instances. Computational results allow us to provide managerial insights concerning the management of stochastic demand.     

A Bayesian estimate of the concordance correlation coefficient with skewed data

Concordance correlation coefficient (CCC) is one of the most popular scaled indices used to evaluate agreement. Most commonly, it is used under the assumption that data is normally distributed. This assumption, however, does not apply to skewed data sets. While methods for the estimation of the CCC of skewed data sets have been introduced and studied, the Bayesian approach and its comparison with the previous methods has been lacking. In this study, we propose a Bayesian method for the estimation of the CCC of skewed data sets and compare it with the best method previously investigated. The proposed method has certain advantages. It tends to outperform the best method studied before when the variation of the data is mainly from the random subject effect instead of error. Furthermore, it allows for greater flexibility in application by enabling incorporation of missing data, confounding covariates, and replications, which was not considered previously. The superiority of this new approach is demonstrated using simulation as well as real‐life biomarker data sets used in an electroencephalography clinical study. The implementation of the Bayesian method is accessible through the Comprehensive R Archive Network. Copyright © 2015 John Wiley & Sons, Ltd.     

提高黎族地区初中数学教育质量的探讨

通过对GX教材、教学原则进行教学实验研究,探讨了提高黎族地区初中数学教育质量问题,阐明了在黎族地区使用GX教材教法进行教学能解决海南黎族初中数学教学中存在的问题。     

有机硅产业群的形成及其启示

本文首先对产业集群研究的历史进行了回顾 ,列举了产业集群促进区域经济发展的若干实例。通过对江西星火工业园有机硅产业集群案例的实证分析揭示了产业集群的形成因素 ,探讨了地方政府在集群规划中的作用 ,并提出了地方政府应该采取的若干对策     

基于PBL教育理念的数学建模课程的教与学

为解决有限的学习时间与知识爆炸之间的矛盾,从教学本质出发,将PBL教育理念在数学建模课程的教与学方面进行了实践,并将实践结果与传统模式下的教学进行对照,发现以PBL教育理念为指导的教与学不仅能够激发学生的学习兴趣,而且有利于形成学生的创新思维与创新能力。     

C中易出错的若干问题

分析了C语言编程中存在的若干问题 ,并指明了原因 ,给出了解决方法。     

An Exposure‐Response Threshold for Lung Diseases and Lung Cancer Caused by Crystalline Silica

Whether crystalline silica (CS) exposure increases risk of lung cancer in humans without silicosis, and, if so, whether the exposure‐response relation has a threshold, have been much debated. Epidemiological evidence is ambiguous and conflicting. Experimental data show that high levels of CS cause lung cancer in rats, although not in other species, including mice, guinea pigs, or hamsters; but the relevance of such animal data to humans has been uncertain. This article applies recent insights into the toxicology of lung diseases caused by poorly soluble particles (PSPs), and by CS in particular, to model the exposure‐response relation between CS and risk of lung pathologies such as chronic inflammation, silicosis, fibrosis, and lung cancer. An inflammatory mode of action is described, having substantial empirical support, in which exposure increases alveolar macrophages and neutrophils in the alveolar epithelium, leading to increased reactive oxygen species (ROS) and nitrogen species (RNS), pro‐inflammatory mediators such as TNF‐alpha, and eventual damage to lung tissue and epithelial hyperplasia, resulting in fibrosis and increased lung cancer risk among silicotics. This mode of action involves several positive feedback loops. Exposures that increase the gain factors around such loops can create a disease state with elevated levels of ROS, TNF‐alpha, TGF‐beta, alveolar macrophages, and neutrophils. This mechanism implies a “tipping point” threshold for the exposure‐response relation. Applying this new model to epidemiological data, we conclude that current permissible exposure levels, on the order of 0.1 mg/m³, are probably below the threshold for triggering lung diseases in humans.