Efficiency evaluation for pooling resources in health care

Hospitals traditionally segregate resources into centralized functional departments such as diagnostic departments, ambulatory care centers, and nursing wards. In recent years this organizational model has been challenged by the idea that higher quality of care and efficiency in service delivery can be achieved when services are organized around patient groups. Examples include specialized clinics for breast cancer patients and clinical pathways for diabetes patients. Hospitals are struggling with the question of whether to become more centralized to achieve economies of scale or more decentralized to achieve economies of focus. In this paper we examine service and patient group characteristics to study the conditions where a centralized model is more efficient, and conversely, where a decentralized model is more efficient. This relationship is examined analytically with a queuing model to determine the most influential factors and then with simulation to fine-tune the results. The tradeoffs between economies of scale and economies of focus measured by these models are used to derive general management guidelines.     

做好输油处安全管理的思考

输油处作为输油管道中的关键节点,安全形势十分严峻,安全管理工作尤其重要.分析了输油处面临的主要危险因素,并提出了改善输油处安全管理的具体措施,为输油处的安全可靠运行提供参考.     

A characterization of independence for competing Markov chains withapplications to stochastic Petri nets

This paper shows that some of the recently obtained product form results for stochastic Petri nets can be obtained as a special case of a simple exclusion mechanism for the product process of a collection of Markov chains     

ITS—90温标在83.8058—273.16K温区内温标的非唯一性研究

对ＩＴＳ＿９０温标在８３．８０５８－２７３．１６Ｋ温区内的温标的非唯一性进行了研究。在高精度低温恒温槽内对九支套管铂电阻温度计进行分度,分析其非唯一性,并研究此温区与１３．１８－２７３．１６Ｋ温区的非一致性。     

Analytical models to determine room requirements in outpatient clinics

Outpatient clinics traditionally organize processes such that the doctor remains in a consultation room while patients visit for consultation, we call this the Patient-to-Doctor policy (PtD-policy). A different approach is the Doctor-to-Patient policy (DtP-policy), whereby the doctor travels between multiple consultation rooms, in which patients prepare for their consultation. In the latter approach, the doctor saves time by consulting fully prepared patients. We use a queueing theoretic and a discrete-event simulation approach to provide generic models that enable performance evaluations of the two policies for different parameter settings. These models can be used by managers of outpatient clinics to compare the two policies and choose a particular policy when redesigning the patient process. We use the models to analytically show that the DtP-policy is superior to the PtD-policy under the condition that the doctor’s travel time between rooms is lower than the patient’s preparation time. In addition, to calculate the required number of consultation rooms in the DtP-policy, we provide an expression for the fraction of consultations that are in immediate succession; or, in other words, the fraction of time the next patient is prepared and ready, immediately after a doctor finishes a consultation. We apply our methods for a range of distributions and parameters and to a case study in a medium-sized general hospital that inspired this research.     

氟、硅改性聚氨酯材料的研究进展

聚氨酯(PU)是一类用途广泛的工程材料,但用传统原料和方法制备的聚氨酯也存在诸多缺点,如耐热性、耐侯型不好,从而限制了它在工程技术领域的进一步应用。为此,聚氨酯的化学改性成为该领域的研究热点之一。作者综述了近年来氟、硅化学改性聚氨酯方面的研究进展,并对今后的研究发展进行展望。     

汽-液两相反应精馏过程的反应-扩散模型与模拟计算——(Ⅰ)反应-扩散模型

本文根据汽-液两相的反应和传质、传热特征,结合两相界面的平衡性质建立了描述反应精馏过程实际板的反应-扩散(非平衡级)模型。从而避免了板效率取值问题和由此带来的计算不确定性。模型方程由汽-液两相质量衡算方程、焓衡算方程、汽-液相界面平衡关系式和组分浓度归一化方程等基础方程以及诸如有关的求算相间传质通量的特征方程组成。利用所提出的两组方程对汽-液两相反应精馏过程的实际板进行了模拟计算。     

汞三相点的研究

叙述了汞三相点密封容器的设计和制作程序，并介绍了具体的复现装置和实验方法。实验结果表明，复现性为±０．１ｍＫ，平均熔化温度与平均凝固温度的差为０．１ｍＫ，不同密封容器间的差小于０．２ｍＫ。     

Transient product from distributions in queueing networks

In this paper it is shown that a necessary and sufficient condition for a Markovian queueing network to have a particular type of closed form transient distribution which is a natural extension of an equilibrium produc-form distribution is that all queues have infinitely many servers.     

一步法成型保温管聚氨酯泡沫层力学性能研究

文章对采用"一步法"成型工艺生产的保温管取其聚氨酯泡沫保温层剖面不同位置的试样进行密度和力学性能研究,探讨了保温层试样性能的差异。采用扫描电子显微镜观察了初始泡孔结构,发现低密度聚氨酯泡沫的泡孔结构为多面体,泡孔之间以薄膜相隔离;高密度泡沫的泡孔结构呈球形,气泡之间相互孤立;中密度泡沫的泡孔以球形和多面体形状混合存在。