形成性评价在大学英语教学中的应用

大学英语教学评价研究是大学英语教学改革的内在需要。随着大学英语教学改革的进行,注重知识和运用能力培养的形成性评价在英语教学中受到了越来越多的关注。形成性评价的主要目的是支持高质量的学习,因此,形成性评价应该成为最重要的教学评价模式。形成性评价有助于教员了解学员的学习进展,以便不断调整教学,满足学员的需求,提高教学质量。     

基于马尔可夫更新过程的装甲装备使用可用度模型

针对在装甲装备使用可用度评估中,采用统计评估法存在统计周期长和不能用于研制阶段的缺点,利用马尔可夫更新过程,建立了考虑工作时间、修复性维修时间、延误时间和预防性维修时间的装甲装备的稳态可用度模型,并进行了示例应用。该模型可以在装备研制阶段,根据装备各项时间参数的分布,来估计装甲装备的使用可用度,可为装备设计、装备维修间隔期规划等提供理论和方法指导。     

论教学过程中的理性思维

教学过程本来是个理性的实践过程,但是,目前现实的情况确实存在一些非理性的现象和问题,影响教学过程的质量。本文从现实教学过程存在的非理性问题和现象,产生和形成的原因,以及如何进行理性思考和反思等方面进行分析,以提高教学的实效性、创新性。     

信息/求解 Petri 网系统

绝大多数 Petri 网在变迁发生后前集库所会失去标记,不便于表达一个条件一旦具备将永远具备的情形.针对该问题,基于0-1标识与变迁发生后其前集不失去标记的思想,提出了信息/求解扩展 Petri 网系统(I/S系统).给出了I/S系统的相关定义、部分基本性质、矩阵表示、求解发生权向量的求法和状态方程.最后,给出了以I/S系统表示的几种常见滑模变结构控制策略的设计过程,该例显示了I/S系统的模型表达能力.     

基于Petri网的维修过程建模仿真方法研究

通过引进老化令牌对随机Petri网进行理论扩展,提出了一种基于老化令牌的随机Petri网（SPNAT）的维修过程建模与仿真方法,有效地解决了传统维修性建模方法在多个失效率不同的部件系统所存在的建模复杂和求解困难等问题,并通过实例验证了该建模方法的有效性和优越性。     

基于灰色层次分析法的侦察装备效能评估

针对侦察系统性能参数的不确定性,本文把灰色理论与层次分析法相结合,运用灰色层次分析综合评估模型,对侦察系统的效能进行评估。用专家评估分析法确定侦察装备效能评价指标权重,用灰色评估理论建立侦察系统效能评估模型。以某常规侦察雷达为例,用建立的模型进行量化评估,充分利用决策者的判断信息,较为准确地反映实际情况,验证了评估模型的可靠性。该模型可为部队作战提供装备的效能数据,为发展新型装备提供依据。其方法和成果可供其它武器系统效能评估时借鉴参考。     

Simultaneous determination of production and maintenance schedules using in‐line equipment condition and yield information

In many manufacturing environments, equipment condition has a significant impact on product quality, or yield. This paper presents a semi‐Markov decision process model of a single‐stage production system with multiple products and multiple maintenance actions. The model simultaneously determines maintenance and production schedules, accounting for the fact that equipment condition affects the yield of each product differently. It extends earlier work by allowing the expected time between decision epochs to vary by both action and machine state, by allowing multiple maintenance actions, and by treating the outcome of maintenance as less than certain. Sufficient conditions are developed that ensure the monotonicity of both the optimal production and maintenance actions. While the maintenance conditions closely resemble previously studied conditions for this type of problem, the production conditions represent a significant departure from earlier results. The simultaneous solution method is compared to an approach commonly used in industry, where the maintenance and production problems are treated independently. Solving more than one thousand test problems confirms that the combination of both features of the model—accounting for product differences and solving the problems simultaneously—has a significant impact on performance. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

Level product form QSF processes and an analysis of queues with Coxian interarrival distribution

In this article, we study a class of Quasi‐Skipfree (QSF) processes where the transition rate submatrices in the skipfree direction have a column times row structure. Under homogeneity and irreducibility assumptions we show that the stationary distributions of these processes have a product form as a function of the level. For an application, we will discuss the ‐queue that can be modeled as a QSF process on a two‐dimensional state space. In addition, we study the properties of the stationary distribution and derive monotonicity of the mean number of the customers in the queue, their mean sojourn time and the variance as a function of for fixed mean arrival rate. © 2016 Wiley Periodicals, Inc. Naval Research Logisticsxs 66:57–72, 2019