变压器铁芯柱截面优化模型与设计

本文建立了变压器铁芯柱截面形状和油道位置的普遍性、通用性优化模型,该模型考虑了铁芯柱截面阶梯的初级最小厚度和末级最小宽度,可允许一定的圆形线圈半径误差,并且非常有利于数学优化软件开展规范化求解。文中给出了优化算例,设计并绘制了各类铁芯柱截面图。     

Handling multi-lean measures with simulation and simulated annealing

This paper describes a simulation-based approach for developing a lean production system of multi-lean measures. Three lean measures are defined to characterize the leanness of the underlying production system: productivity, cycle time, and work-in-process inventory. An optimized setting to certain operational parameters is determined so that a best tradeoff of the three lean measures is reached. The problem formulation results in a multi-objective optimization problem with no closed-form definition of problem objective functions and constraints. The solution approach utilizes Discrete Event Simulation (DES) to deploy lean techniques and model lean measures under process variability and plant constraints and dynamics. A direct search method (i.e., Simulated Annealing (SA)) is used to search of problem domain. A model-based Value Mapping (VM) is used for combining the conflicting multi-lean measures and guiding the SA search for optima. The DES model is also used to develop a future state dynamic Value Stream Map (VSM) of the optimized production process. The approach is applied to an example production system where the capacity of material handling conveyors and the size of maintenance crew are optimized to develop a lean system in terms of three lean measures. Little’s formula is used to verify the simulation assessment of lean measures. Optimization results are also used to demonstrate the conflict among lean measures, the impact of process variability on lean measures, and the role of VM in reaching an efficient tradeoff of multi-lean measures.     

基于ISM模型的大学生就业系统构建与分析

大学生就业难一直是社会关注的热点问题,尤其是在当前的经济背景下,就业形势更为严峻。从系统工程的角度来分析大学生就业问题,构建了大学生就业系统,在对系统各要素进行描述分析的基础上,利用解释结构模型对大学生就业影响因素之间的相互关系作了详细研究,得到了大学生就业系统多级递阶结构模型图。对模型的进一步分析指出,大学生自身状况是影响就业最直接的因素。针对模型结果提出了促进大学生就业的若干政策和建议。     

实例探究SketchUp在动画场景制作中的应用

随着动漫产业的日益发展和网络技术的迅速普及,小团队短周期动画制作越来越具有影响力。SketchUp作为一款计算机辅助构思软件可以很好地实现与动画制作者的人机交互,改变以往动画场景制作的复杂、枯燥过程,降低动画制作的难度。     

利用函数思想培养学生的创新意识和创新能力

数学教学中创新意识、创新能力的培养是极其重要的。函数思想的渗透与应用在初中阶段是薄弱的。这一点又恰恰是培养学生创新思维意识的很好契机。在数学教学中,教师要积极探索,不断提供学生探究的素材,给学生正确的引导,达到培养学生创新思维能力的目的。     

健身俱乐部利用者感知服务质量对利用满意和行为意向影响的实证研究

以位于上海市和广东省的3家健身俱乐部的利用者为研究对象,采用从调查中得到的376个样本数据探讨健身俱乐部利用者感知服务质量、利用满意和行为意向之间的关系为主要目的.基于相关文献构建了有关服务质量、利用满意和行为意向之间的关系的4个假设模型,借助结构方程模型分析,从中筛选出最佳模型,采用该最佳模型讨论构成概念间的关系.结果揭示了在服务质量对行为意向施加影响的过程中,利用满意起着完全中介作用的模型与数据的拟合程度最佳.这表明了服务质量通过利用满意对行为意向起着间接的作用.此外,对有关服务质量、利用满意和行为意向之间的关系及其对管理实践的启示也进行了探讨.     

Fifty years of information management research: A conceptual structure analysis using structural topic modeling

Information management is the management of organizational processes, technologies, and people which collectively create, acquire, integrate, organize, process, store, disseminate, access, and dispose of the information. Information management is a vast, multi-disciplinary domain that syndicates various subdomains and perfectly intermingles with other domains. This study aims to provide a comprehensive overview of the information management domain from 1970 to 2019. Drawing upon the methodology from statistical text analysis research, this study summarizes the evolution of knowledge in this domain by examining the publication trends as per authors, institutions, countries, etc. Further, this study proposes a probabilistic generative model based on structural topic modeling to understand and extract the latent themes from the research articles related to information management. Furthermore, this study graphically visualizes the variations in the topic prevalences over the period of 1970 to 2019. The results highlight that the most common themes are data management, knowledge management, environmental management, project management, service management, and mobile and web management. The findings also identify themes such as knowledge management, environmental management, project management, and social communication as academic hotspots for future research.     

Therapeutic radionuclides in nuclear medicine: current and future prospects

The potential use of radionuclides in therapy has been recognized for many decades. A number of radionuclides, such as iodine-131 (¹³¹I), phosphorous-32 (³²P), strontium-90 (⁹⁰Sr), and yttrium-90 (⁹⁰Y), have been used successfully for the treatment of many benign and malignant disorders. Recently, the rapid growth of this branch of nuclear medicine has been stimulated by the introduction of a number of new radionuclides and radiopharmaceuticals for the treatment of metastatic bone pain and neuroendocrine and other malignant or non-malignant tumours. Today, the field of radionuclide therapy is enjoying an exciting phase and is poised for greater growth and development in the coming years. For example, in Asia, the high prevalence of thyroid and liver diseases has prompted many novel developments and clinical trials using targeted radionuclide therapy. This paper reviews the characteristics and clinical applications of the commonly available therapeutic radionuclides, as well as the problems and issues involved in translating novel radionuclides into clinical therapies.     

言语行为研究的另一个界面：现场即席话语视角

作为语用学的经典课题,言语行为研究受到前贤时哲的持续关注,涌现了诸多成果．逐步形成了具有不同特征和方向的研究态势,形式逻辑研究传统是其中之一。从研究对象、研究方法、对言语行为的本质认识、实际言语行为范畴等方面梳理形式化研究之特点,可以认清该研究态势背后的成因。包括言语行为理论建立的历史渊源,语力研究的侧重及其性质的认知．以及研究材料和方法等。随着语用学自身的发展、研究者对话语认识的深入以及研究手段的提升,言语行为研究呈现了新的界面,即面向现场即席话语。秉承这一思路,研究者可以在分析现场即席话语中施事行为／语力的性质与特征基础上,运用多模态语言研究手段．借助仿真建模的核心步骤。这种研究在内容、材料、方法与路径上拓展了言语行为理论及相关研究的维度。     

基于SOLIDWORKS电加热器三维建模与数值分析

分析了电加热器的结构特点与SolidWorks软件的三维建模步骤。在几何模型上直接定义了载荷和边界条件,对电加热器温度场与速度场进行了模拟,模拟结果与工程实际吻合较好。探索了有无折流板对电加热器换热的影响,结果显示无折流板的出口温度高于有折流板情况,这对电加热管不利,局部温度过高,长时间工作,容易导致电加热管烧坏。可见利用SolidWorks软件可为电加热器的结构优化与换热等性能的研究提供新的设计手段。