某型发动机离心通风器故障模式分析及预防措施

通过三起离心通风器的故障实例，分析了离心通风器的故障模式和对滑油系统及整个发动机可靠性的影响，并根据故障产生的原因及外场维护条件，提出了设计改进意见和外场预防故障的具体措施。     

SAR图像识别提取与选择特征

阐述了SAR图像在模式识别中特征提取与选择的概念、任务和基本原则,结合国内外图像特征提取与选择的最新研究动态,介绍了在SAR图像目标识别中普遍采用的一些特征提取与选择方法,并对提取纹理特征采用的灰值共生矩阵及其统计量进行了研究。     

鸭翼双三角翼流态及气动力特性研究

本文给出了鸭翼对双三角翼气动特性及涡的发展和破裂过程的影响，进而分析了鸭翼位置、平面形状对全机气动特性影响的机理，并提出了合理的鸭翼双三角翼布局形式。     

降压法抑制自然对流的数值模拟

具有强迫流动的航天器密封舱在地面模拟试验时常用降压法来抑制自然对流的影响，但降压比的确定往往取决于一些未知参数，这些参数的不确定使得自然对流的抑制效果难以保证，该文提出了一种通过数值模拟验证来确定降压比的方法，以某航天器密封舱为原型，通过直接对在轨飞行和不同舱压地面状态进行数值模拟，得出了最佳降压比。     

IMF effect on ionospheric trough occurrence at equinoxes

Previous observations have shown that there is a relationship between the F region trough and both B_z and B_y components of the interplanetary magnetic field (IMF). Since IMF governs the polar cap convection, we investigate here if this relationship can be explained by means of polar cap convection. The study is limited to equinox seasons. The poleward and equatorward edges of the trough are determined from satellite tomographic observations and their locations are plotted in magnetic coordinates together with the convection pattern given by Papitashvili and Rich [Papitashvili, V.O., Rich, F.J. High-latitude ionospheric convection models derived from DMSP ion drift observations and parameterized by the IMF strength and direction. J. Geophys. Res. 107, 2002, doi:10.1029/2001JA000264] using IMF measurements coincident with trough observations. The results indicate a close relationship between the troughs and convection. Most of the troughs are seen within the dusk cell and the pattern of trough observations rotates with the convection pattern, when B_y changes its sign. More dayside troughs are observed when B_z is negative than in the opposite case, i.e. fast convective flow favours the dayside trough occurrence. Nightside troughs are observed more frequently when B_y is negative. In both evening and morning sectors the trough is situated close to the edges of convection cells, which partly contradicts previous results showing that the troughs are associated with the convection reversal. It is concluded that plasma convection has an important role in trough generation, although the effect of a strong electric field and other mechanisms like precipitation certainly have a role of their own.     

一种实用的景象匹配区选择方法

从分析影响配准概率和定位精度的景象匹配区的景象信息量、稳定性和重复模式等各项特征参数出发，研究了一种简洁实用的匹配区选择方法，并给出了快速算法。仿真试验结果表明，该方法的选择速度及所选匹配区配准概率和定位精度都能令人满意。     

Spatial understanding and temporal correlation for a mobile robot

In this article we discuss a network model, which simulates functionallysome of the features intrinsic to human navigation and the merits ofincorporating such features on a behavior-based robot. Specifically thepaper deals with implementing a memory based reasoning strategy duringreal-time navigation of a mobile robot. For the purpose ofimplementation, memory has been identified with an ability to cognizethe local environment or scenario, classify such scenarios in terms ofpreviously learned primitives or landmarks, remember and recollect suchprimitives at later instants and correlate over time similar experiencesof scenarios. Such memory based reasoning enhances the robot'snavigation capabilities through intelligent decisions due to spatialunderstanding, scene recollection abilities by remembrance and detectinglocal minimum traps through place recognition. A double layeredspatio-temporal classification scheme consisting of a fuzzy rule-basedspatial classifier and a temporal classifier based on self-organizingmap and ART networks are adopted for this purpose. The classifiernetwork reduces the robot's experience of its environment consisting ofa stream of sensor patterns into weight vectors that signify aparticular landmark. An extension of the network architecture is alsointroduced to cognize the presence of dynamic obstacles amidststationary ones.     

一种改善水槽尾部流态的新型斜拉孔板尾门

为了改善水槽尾门对水槽尾部流态的影响 ,从几种常用水槽尾门对流态影响的分析入手 ,结合明渠流速分布对数公式和小孔口自由出流公式 ,并根据分层来流量与孔口出流量相等的原则 ,推导出一种新型斜拉孔板尾门开设孔径的计算公式。经验证 ,用该公式设计的新型斜拉孔板尾门对水槽尾部的流态影响较小 ,在水槽总长度不变的前提下 ,可增加水槽的有效工作长度     

数字图象条纹细化——逐层削取方法

本文提出一种新方法来解决一般性的条纹细化问题,该方法可以广泛地应用于数字图象处理、模式识别、图象测量等技术领域。算法设计中采用了详尽的模块分析方法,所产生的条纹细化计算法非常有效,已经成功应用于激光全息测量——一种图象测量技术。     

一种不规则封闭形状的轮廓跟踪算法

论述了一种对不规则封闭形状的快速轮廓跟踪算法，提出了一种用于确定轮廓下一搜索点及判断轮廓走向的二维坐标算子，使得轮廓跟踪的搜索时间大为减少，提高了图象处理的实时性。用该算法编制的程序能适应各种形状的跟踪要求。