调距桨桨毂机构水动力负荷加载方式仿真研究

本文首先对某调距桨进行了CFD仿真分析,然后将CFD计算得到的桨叶分布式压力负荷加载至调距桨桨毂有限元模型的桨叶上进行有限元静强度仿真计算,并与多点约束集中(MPC)加载方式的计算结果进行比较。因分布式压力加载方式更接近真实加载情况,更适应于精度要求较高的高负载调距桨桨毂设计,与分布式压强加载相比,虽然MPC加载方式精度较低,但因其载荷加载处理与仿真计算时间大为缩短,得到的结果偏安全,因此适用于一般的工程强度估算校核。     

加注LNG燃料的船舶安全管理措施研究

为给液化天然气(LNG)动力船舶的安全管理体系建立提供参考,文章从LNG燃料加注5种模式比较及加注注意事项、LNG翻滚和间歇泉的原因及措施、LNG泄漏及火灾的对策等方面进行研究。结果表明:不同气源的LNG分开储存并采取合适的进料方式可预防LNG翻滚;需预置接液盘、水幕和护板等预防LNG泄漏,若泄漏发生,可视情采用贴堵法或塞堵法,同时配合使用水幕系统;LNG着火时,可综合运用水幕隔离、消防冷却、泡沫覆盖和干粉灭火。此外,向上实心锥形水幕控制LNG扩散效果最好,且水幕高度需高于云团2倍以上;高倍泡沫可明显降低LNG的挥发,但对最小有效淹没深度有要求;干粉降低池火最高温度明显,使用时需喷洒到火焰根部。     

面向生产管理信息化的涂装智能设计系统

研究分析涂装设计工艺流程、涂装生产管理流程及涂装机器人工艺参数，整理分析涂装工艺数据、生产管理信息和涂装机器人的工艺特征，对这些数据进行整理归纳，理清他们之间的逻辑关系，形成数据接口，通过数据库系统完成涂装规范化设计和生产管理以及涂装机器人的对接。     

新高等学校会计制度实施对策研究

随着《高等学校会计制度》的实施,高等学校财务制度得以落实,学校的财务管理工作产生重大的改变,高校的会计制度将更加客观合理.本文通过对高校新旧会计制度的比较,分析新会计制度变化要点,针对性地提出实施新制度的对策措施.     

Compromising system and user interests in shelter location and evacuation planning

Traffic management during an evacuation and the decision of where to locate the shelters are of critical importance to the performance of an evacuation plan. From the evacuation management authority’s point of view, the desirable goal is to minimize the total evacuation time by computing a system optimum (SO). However, evacuees may not be willing to take long routes enforced on them by a SO solution; but they may consent to taking routes with lengths not longer than the shortest path to the nearest shelter site by more than a tolerable factor. We develop a model that optimally locates shelters and assigns evacuees to the nearest shelter sites by assigning them to shortest paths, shortest and nearest with a given degree of tolerance, so that the total evacuation time is minimized. As the travel time on a road segment is often modeled as a nonlinear function of the flow on the segment, the resulting model is a nonlinear mixed integer programming model. We develop a solution method that can handle practical size problems using second order cone programming techniques. Using our model, we investigate the importance of the number and locations of shelter sites and the trade-off between efficiency and fairness.     

重大铁路工程标准化开工组织清单化管理研究

随着铁路建设的发展,标准化管理水平越来越高,对工程质量的提升效果也越来越明显。但目前铁路工程开工标准化在操作过程上缺少科学管理方法和管理手段,开工标准化流于形式,影响后续主体工程施工。对此,文章创新性地提出重大铁路工程标准化开工组织清单化管理的思路,提出工作流程,设计管理实施方案,并在某重大铁路工程进行运用,取得良好效果。标准化开工组织清单化管理对于重大铁路工程的高质量、快速开工具有重要的指导意义。     

轨道交通科研项目管理平台功能应用分析

将科研管理项目按研发内容分类、分级、逐层分解,并将其中的主要数据录入数据平台后,可以形成可用的科研管理项目平台的数据分析模型。轨道交通科研项目的主要数据具有大量、高速、多样、高价值的特点,完全符合数据分析的工作要求。结合轨道交通科研项目开发体系管理工作的特点,通过各项目数据的快速查询调用、分解及比对分析,可以取得更直观、更有效、更简洁的管理效果,提高对科研项目的执行的保障效率,增强对预算投入等的监督力度。以实际科研项目的数据应用为例,分析了科研项目管理平台的功能。     

A carbon footprint-based closed-loop supply chain model under uncertainty with risk analysis: A case study

The management of products’ end-of-life and the recovery of used products has gained significant importance in recent years. In this paper, we address the carbon footprint-based problem that arises in a closed-loop supply chain where returned products are collected from customers. These returned products can either be disposed of or be remanufactured to be resold as new ones. Given this environment, an optimization model for a closed-loop supply chain (CLSC) in which carbon emission is expressed in terms of environmental constraints, i.e., carbon emission constraints, is developed. These constraints aim to limit the carbon emission per unit of product supplied with different transportation modes. Here, we design a closed-loop network where capacity limits, single-item management and uncertainty on product demands and returns are considered. First, fuzzy mathematical programming is introduced for uncertain modeling. Then, the statistical approach to the possibility to synthesize fuzzy information is utilized. Therefore, using a defined possibilistic mean and variance, we transform the proposed fuzzy mathematical model into a crisp form to facilitate efficient computation and analysis. Finally, the risk caused by violating the estimated resource constraints is analyzed so that decision makers (DMs) can trade off between the expected cost savings and the expected risk. We utilize data from a company located in Iran.     

Evaluating sustainability of supply chains by two-stage range directional measure in the presence of negative data

Assessing sustainability of supply chains is a critical and increasingly complex problem. In recent years sustainability has received more attention in supply chain management (SCM) literature with triple bottom lines including social, environmental, and economic factors. Conventional data envelopment analysis (DEA) models consider decision making units (DMUs) as black boxes that consume a set of inputs to produce a set of outputs and do not take into consideration internal interactions of DMUs. Two-stage DEA models deal with such DMUs. However, existing two-stage DEA models are applicable only in technologies characterized by positive inputs/outputs. This paper aims to build and present a new two-stage DEA model considering negative input-intermediate-output data. Some numerical examples along with some theorems and properties are given to show capability of proposed method. The proposed ideas are used in a case study where 29 Iranian supply chains producing equipment of expendable medical devices are evaluated in terms of sustainability.     

基于规范方法的小水线面双体船疲劳强度研究

论文介绍了船舶结构疲劳强度评估基本原理,并对一条2200t级小水线面双体船进行规范法疲劳强度评估。针对小水线面双体船结构特点,采用规范进行疲劳载荷计算；结合全船有限元计算结果进行疲劳部位筛选；采用有限元法提取疲劳部位的热点应力,并计算疲劳部位的累积损伤度。分析计算结果,提出疲劳部位优化方案。