炮射投掷式雷达干扰机作战辅助决策研究

根据炮射投掷式雷达干扰机的作战运用特点,建立了干扰机空间排布模型、射击时机和用弹量计算模型,并结合干扰机的工作方法建立了风飘修正模型。经过计算机仿真检验,达到预期的效果,对投掷式雷达干扰机作战运用有一定的指导意义。     

炮射投掷式通信干扰机作战效能评估

针对炮射投掷式通信干扰机的作战对象,结合工作波段分别计算了单部悬浮式和落地式干扰机的压制区域,并对干扰机的空域覆盖进行了计算机仿真和分析,对投掷式通信干扰机作战运用有一定的指导意义。     

投掷式干扰的压制概率分析

根据实际作战环境下地面投掷式通信干扰机所需压制的通信电台的地域分布特点，将通信电台分为点目标、线目标和面目标，探讨了地面投掷式通信干扰机对不同目标的压制概率，并给出了相应的计算公式。     

基于悲观准则的投掷式雷达干扰战术计算研究

针对战场活动目标侦察雷达的相控阵天线,提出在雷达搜索空域内每个波束宽度中部署一部投掷式雷达干扰机的干扰方式,以掩护圆形等效区域内的活动目标为战术背景,采用悲观准则进行投掷式雷达干扰机的排布方式、投掷位置、投掷时机和使用数量等战术要素的定量计算.结果表明该方法可行有效,能快速计算投掷式雷达干扰机作战运用的战术要素.     

浮标型干扰机对机载塔康设备干扰效能评估与仿真

在随机海浪模型的基础上对影响浮标型干扰机的横摇运动进行分析,建立浮标型干扰机对机载塔康设备的干扰模型.通过仿真分析,给出了不同波浪等级、波浪方向、投掷偏角条件下浮标型干扰机的干扰效能.对结果进行了分析,为浮标型干扰机作战运用提供一定的参考依据.     

投掷式干扰机对炮位侦校雷达的干扰决策建模

投掷式电子对抗装备是近几年发展起来的,本文根据炮射投掷式雷达干扰机的工作特点,针对炮位侦校雷达的特殊体制进行了干扰效能的分析,建立了相关决策模型,并进行了实例仿真和结果分析,对投掷式干扰机的战术运用具有一定的实用价值。     

炮射通信干扰机投掷数量估算系统设计

在实施投掷阻塞式干扰时,能否完成干扰使命并发挥其作用效能,根据不同的干扰对象,投掷多少部干扰机才能达到战术使用有效干扰的目的,需要进行投掷密度的估算和有效干扰所需干扰机数目的估算研究.从投掷数量的计算原理出发,分析了干扰机投掷密度和数量的影响参数,建立了估算数学模型并提出了理论计算方法,给出投掷数量估算系统的设计方案和估算实例,对炮射通信干扰机的应用研究具有参考作用.     

远距离支援干扰机阵位设计方法研究

由于远距离支援干扰机技术性能的不同,不同的干扰阵位对敌方防空系统产生的干扰效果也不尽相同。基于支援式干扰下的雷达探测模型,分别从距离、方位和高度3个方面对干扰机阵位选择对雷达最大探测距离的影响进行了研究,总结提出了干扰机阵位设计和作战应用的原则,可为干扰飞机掩护作战编队执行任务时的航迹规划提供依据。     

通信系统抗干扰能力对作战指挥效率的影响评估研究

从复杂电磁环境下陆军合成作战的实际需要出发,运用概率论和作战指挥运筹理论,建立了通信系统抗干扰能力和作战指挥效率的评估模型,根据作战中可能使用的作战指挥方式,进行了通信系统抗干扰能力和作战指挥效率相关性的数学分析,结合实例说明了所建模型的具体应用,得出了基于量化的可供作战指挥决策的有关结论。     

干扰压制系数在通信对抗态势构建中的应用

作战距离是对抗态势构建的关键因素,为进一步提高通信部队基地训练的科学性与合理性,运用战术计算的思想,提出了一种基于通信装备干扰压制系数计算通信距离和干扰距离的方法。设计了通信装备干扰压制系数测试方法,以某型微波接力通信系统为例,测试有效干扰时的通信信号和干扰信号功率,计算其干扰压制系数。利用Egli传播模型和视线距离公式,计算微波接力通信系统的通信距离,及干扰机的干扰距离,为通信部队基地训练中的阵地开设和兵力部署提供技术支撑。     

电磁兼容性通用测量模型研究

以电磁兼容性测量标准为研究对象,建立了具体项电磁兼容性测量模型,据此总结出了硬件类模型和属性模型.在这两个模型基础上,建立了基于类的电磁兼容通用测量模型,该模型是最终建立电磁兼容性测量系统计算机辅助优化设计的基础.     

The modelling of semiconductor laser diodes

This paper presents a number of models for semiconductor laser diodes. The models are divided into different categories, according to the independent variables they include. The use of these different models is critically investigated and the advantages of these models are compared and discussed. A number of models are elaborated into mathematical detail and some examples are discussed.     

自然语言处理中的模型

本文简单介绍了自然语言处理发展的现状,讨论了自然语言处理模型,将其分为三大类:分析模型、统计模型及混合模型.具体介绍了分析模型原理及存在的问题,重点讨论了各种统计模型的特点及局限性,最后简单介绍了混合模型,并指出目前自然语言处理技术中存在的问题.     

MOSFET集约模型的发展

MOSFET集约模型作为连接半导体生产商与电路设计者之间的桥梁,是半导体行业不可或缺的一环。随着对器件物理效应的不断深入了解,以及不断满足电路设计新要求,MOSFET集约模型经历了长时间的发展。从模型的基础出发,介绍了基于阈值电压Vth、反型层电荷Qi和表面势Φs这三类MOSFET集约模型的发展历程及其主要特征。     

Dimensioning of the LTE access network

This paper proposes efficient analytical models to dimension the necessary transport bandwidths for the Long Term Evolution (LTE) access network satisfying the QoS targets required by different services. In this paper, we consider two major traffic types: elastic traffic and real time traffic. For each type of traffic, individual dimensioning models are proposed for both the S1 interface and the X2 interface. For elastic traffic the dimensioning models are based on the Processor Sharing models; while for real time traffic the dimensioning models are based on the fundamental queuing models. For validating these analytical dimensioning models, a developed LTE system simulation model is used. Extensive simulations are performed for various traffic and network scenarios. The analytical results derived from the proposed dimensioning models are compared with the simulation results. The presented results demonstrate that the proposed analytical models can appropriately estimate the required performances for different service classes and priorities. Hence they are suitable to be used for dimensioning of the LTE access network with different traffic and network conditions.     

Modern approaches in modeling of mobile radio systems propagation environment

In this article a review of popular propagation models for wireless communication channels is given. Macrocell, microcell, and indoor prediction methods are considered separately. Advantages and disadvantages of these models are discussed. Also, some practical improvements of the existing models as well as some new models are given.     

HOG特征混合模型结合隐SVM的感兴趣目标检测定位算法

针对传统基于梯度方向直方图特征检测算法对解决目标模型单一、发生形变、存在遮挡及目标受干扰下定位困难的问题,提出一种基于HOG特征混合模型结合隐SVM的感兴趣目标检测算法。首先利用用训练图像的HOG特征金字塔表示得到包含感兴趣目标根模型、部件模型和对应可变形部件特征表示,该模型不仅描述目标的整体轮廓,而且能够捕捉到更为精细的目标部件轮廓,在一定程度上提高了检测算法在目标姿态复杂情况下的鲁棒性。然后利用HOG特征混合特征训练部件检测分类器LSVM(Latent Support Vector Machine)。最后通过动态规划和距离转换算法在测试图上扫描出与可变形部件模型相匹配的区域,实现感兴趣目标的检测定位。经过多组实验结果表明,所提出的算法能较好地解决目标在发生较大形变和存在遮挡等复杂姿态下的定位问题。      

Estimation and choice of neighbors in spatial-interaction models of images

Some aspects of statistical inference for a class of spatial-interaction models for finite images are presented: primarily the simultaneous autoregressive (SAR) models and conditional Markov (CM) models. Each of these models is characterized by a set of neighbors, a set of coefficients, and a noise sequence of specified characteristics. We are concerned with two problems: the estimation of the unknown parameters in both SAR and CM models and the choice of an appropriate model from a class of such competing models. Assuming Gaussian-distributed variables, we discuss maximum likelihood (ML) estimation methods. In general, the ML scheme leads to nonlinear optimization problems. To avoid excessive computation, an iterative scheme is given for SAR models, which gives approximate ML estimates in the Gaussian case and reasonably good estimates in some non-Gaussian situations as well. Likewise, for CM models, an easily computable consistent estimate is given. The asymptotic mean-squared error (mse) of this estimate for a four-neighbor CM model is shown tn be substantially less than the mse of the popular coding estimate. Asymptotically consistent decision rules are given for choosing an appropriate SAR or CM model. The usefulness of the estimation scheme and the decision rule for the choice of neighbors is illustrated by using synthetic patterns. Synthetic patterns obeying known SAR and CM models are generated, and the models corresponding to true and several competing neighbor sets are fitted. The estimation scheme yields estimates close to the parameters of the true models, and the decision rule for the choice of neighbors picks up the true model from the class of competing models.     

Effect of interseed spacing, tissue perfusion, thermoseedtemperatures and catheters in ferromagnetic hyperthermia: results fromsimulations using finite element models of thermoseeds andcatheters

Finite element heat-transfer models of ferromagnetic thermoseeds and catheters are developed for simulating ferromagnetic hyperthermia, These models are implemented into a general purpose, finite element computer program to solve the bioheat transfer equation. The seed and catheter models are unique in that they have fewer modeling constraints than other previously developed thermal models. Simulations are conducted with a 4×4 array of seeds in a multicompartment tissue model. The heat transfer model predicts that fractions of tumor greater than 43°C are between 8 and 40% lower when seed temperatures depend on power versus models which assume a constant seed temperature. Fractions of tumor greater than 42°C, in simulations using seed and catheter models, are between 3.3 and 25% lower than in simulations with bare seeds. It is demonstrated that an array of seeds with Curie points of 62.6°C heats the tumor very well over nearly all blood perfusion cases studied. In summary, results herein suggest that thermal models simulating ferromagnetic hyperthermia should consider the power-temperature dependence of seeds and include explicit models of catheters     

振荡器时变相位噪声分析技术研究进展

介绍了两种射频振荡器的时变相位噪声模型:Demir&Mehrotra的非线性扰动模型和Hajimiri&Lee的时变相位噪声模型。对一个简单的非线性电导LC振荡器,分别建立了这两种模型,并指出了两种模型的联系和区别。讨论了两种模型的计算方法,介绍了在EDA软件HSpice和SpectreRF下,以及频域中相位噪声的计算问题。最后,进一步讨论了时变相位噪声,指出相位噪声分析的难点和未来的发展方向。