基于D-S理论及Einstain算子的ISM模型分析

在评价相控阵天线质量的传统方法中,往往依据指标主要属性分类成层,容易忽视指标间的复杂联系。针对该问题,从研究指标间的内部关系出发,搭建了反映相控阵天线质量特性的解释结构模型。并着重探讨如何分析该模型,将模型分为"一对多"和"多对一"两种基本结构,利用D-S理论、模糊分配及Einstain算子详细叙述了这两种结构的求解过程。最后,以该方法在某型远海机动水文监测雷达天线中的具体应用,验证了ISM模型从建立到分析整个过程的可行性和准确性。     

军事办公建筑被动式节能设计策略

军事办公建筑的节能设计与使用,对推动节能减排、促进军营建设具有重要意义。通过对被动式节能设计策略的研究,从建筑设计的视角,以军事办公建筑设计为突破口,分析能耗现状,明确设计目标和思路,从空间设计布局、围护结构热工性能、遮阳系统设置、自然通风与自然采光等方面,探讨被动式节能设计策略在军事办公建筑设计中的应用。结合特定环境,寻求贯穿节能设计始终的适宜技术,充分发挥被动式节能技术集成的优势。通过多项节能技术的协同作用,可以强化和扩大节能措施带来的节能效应,在降低能耗的同时创造出健康、舒适、高效的办公环境。     

基于Ansofl的PMLS发电机纵向边端效应仿真

永磁直线同步发电机特殊的结构使其存在一种特殊现象——纵向边端效应,从而严重影响了永磁直线同步发电机的性能。利用有限元电磁场分析软件Ansoft建立了永磁直线同步发电机的二维模型,分析了纵向边端效应产生的原因,以及纵向边端效应对永磁直线同步发电机初级磁场的影响。利用磁阻相等的原理,通过增加发电机端部齿宽度和极数两种方法来改善永磁直线发电机性能。经Ansoft软件仿真,结果表明增加端部齿宽度和极数可以有效抑制纵向边端效应,提高永磁直线同步发电机的性能。     

空间飞行器主动段的轨道估计与误差分析

为了对无源探测卫星系统的定轨方式和精度进行定量分析,通过坐标转换、受力分析、拟合、最小二乘法、微分方程数值解法与误差分析等方法,建立了基于卫星无源探测的空间飞行器在主动段的交汇定位优化模型和运动方程模型。基于模拟数据和模型,给出了卫星和空间飞行器的轨道曲线以及卫星的系统误差。经过系统误差修正,空间飞行器的估计轨道误差仅为7.582 1 m。     

Inventory financing under Risk-Adjusted-Return-On-Capital criterion

Risk-Adjusted-Return-On-Capital (RAROC) is a loan-pricing criterion under which a bank sets the loan term such that a certain rate of return is achieved on the regulatory capital required by the Basel regulation. Some banks calculate the amount of regulatory capital for each loan under the standardized approach (“standardized banks,” the regulatory capital is proportional to the loan amount), and others under the internal rating-based (IRB) approach (“IRB banks,” the regulatory capital is related to the Value-at-Risk of the loan). This article examines the impact of the RAROC criterion on the bank's loan-pricing decision and the retailer's inventory decision. We find that among the loan terms that satisfy the bank's RAROC criterion, the one that benefits the retailer the most requires the bank to specify an inventory advance rate in addition to the interest rate. Under this loan term, the retailer's inventory level is more sensitive to his asset level when facing an IRB bank compared to a standardized bank. An IRB (standardized) loan leads to higher profit and inventory level for retailers with high (low) asset. For retailers with medium asset, an IRB loan results in a higher retailer profit but a lower consumer welfare. Calibrated numerical study reveals that the benefit of choosing standardized banks (relative to IRB banks) can be as high as 30% for industries with severe capital constraints, volatile demands, and low profit margins, highlighting the importance for retailers to carefully choose the type of banks to borrow from. When the interest rate is capped by regulation, retailers borrowing from a standardized bank are more likely to be influenced by the interest rate cap than those borrowing from an IRB bank. Under strong empire-building incentives (the bank will offer loan terms to maximize the size of the loan), retailers with medium initial asset level shift their preference from IRB banks to standardized banks.     

Coping with shortages caused by disruptive events in automobile supply chains

Unpredictable disruptive events significantly increase the difficulty of the management of automobile supply chains. In this paper, we propose an automobile production planning problem with component chips substitution in a finite planning horizon. The shortage of one chip can be compensated by another chip of the same type with a higher-end feature at an additional cost. Therefore, the automobile manufacturer can divert the on-hand inventory of chips to product lines that are more profitable in the event of shortages caused by supply chain disruptions. To cope with this, we propose a max-min robust optimization model that captures the uncertain supplies of chips. We show that the robust model has a mixed-integer programming equivalence that can be solved by a commercial IP solver directly. We compare the max-min robust model with the corresponding deterministic and two-stage stochastic models for the same problem through extensive numerical experiments. The computational results show that the max-min robust model outperforms the other two models in terms of the average and worst-case profits.     

排液槽对折板捕雾器性能影响数值模拟

为研究气液分离器内使用的折板式捕雾器的流场特性及排液槽对其性能的影响,利用流体动力学计算软件Fluent,采用Low-Re Stress-Omega模型和DPM两相流模型,对捕雾器气液两相流流场进行了数值模拟。通过对比安装排液槽前后捕雾器内流场,分析了排液槽对捕雾器流场速度、液滴运动轨迹的影响;发现排液槽能大幅提高捕雾器的除雾效率,10μm以上液滴基本能够全部去除,但是也会使除雾器压降急剧增大。最后研究了排液槽主要结构参数——折弯直径和长度对捕雾器性能的影响,发现增大排液槽折弯直径和长度均能增加除雾效率,但同时也会增大进出口压降。     

交流杂散电流对埋地钢质管道腐蚀危害实验

为探究交流杂散电流的影响因素及其对阴极保护系统的影响,搭建交流干扰腐蚀实验平台研究了土壤电阻率、干扰电压大小、涂层电阻率和通断时间比对交流杂散电流密度的影响;采用腐蚀试片失重法研究了交流杂散电流密度对腐蚀速率的影响以及阴极保护电位分别为-850 mV和-1 000 mV时对阴极保护系统的影响。实验结果表明:土壤电阻率、干扰电压大小、涂层电阻率和通断时间比对交流杂散电流密度具有较为显著的影响;阴极保护电位为-1 000 mV时,即使交流电流密度为20 mA/cm2,腐蚀试片也能得到有效保护。因此,埋地管道应采用绝缘性能好的防腐涂层,规划合理的铺设路线,并在运行过程中采取强制电流阴极保护系统,设置合理的阴极保护电位。     

分布式态势感知一致性分析与度量方法研究

一致的态势感知,是现代武器、火力系统以及部队紧耦合协同作战的基础。本文以分布式态势感知理论为依据,从系统的角度,构建了团队达成一致态势感知过程的动力学模型;以系统内部一致性、外部一致性和一致所需最短时间为指标,给出了团队态势感知一致性的度量方法。仿真结果表明,适当地提高团队内沟通的广泛度和相互作用强度,选择合适的沟通网络,对提高一致性能力有积极的作用。