二值图像边缘检测的动态数学形态运算方法

应用基本形态运算,定义了动态形态学运算,并将动态膨胀运算应用到图像对象的边缘检测,运算方法只对图像中的对象进行运算,在每一步运算中,动态地选择结构元素的下一个原点位置。运算方法减少了运算量,执行速度快、效率高,在MATLAB6.5上得到了满意的仿真效果。

基于动态数学形态运算的二值图像边界提取

应用基本形态运算,定义了动态形态学运算,并将动态腐蚀运算和小结构元素应用到图像对象的边界提取,这种方法只对图像中的对象进行运算并得到对象的边界;在每一步运算中,动态地选择结构元素的下一个原点位置。这种方法减少了运算量,执行速度快、效率高,在MATLAB6.5上得到了满意的仿真效果。

早期周围型肺癌孤立性多结节聚合HRCT征的动态形态变化研究

目的探讨早期周围型肺癌孤立性多结节聚合HRCT征动态变化规律，提高对早期周围型肺癌的认识。方法搜集46例经手术、穿刺、痰细胞学病理证实的孤立性多结节聚合征，首次发现癌灶直径为0．5—2．0cm，所有病例均进行了4周的前后两次动态追踪观察，检查技术包括采用5mm层厚HRCT扫描，然后对“兴趣区”采用1mm重组，其中包括纵隔窗、肺窗及增强扫描检查，重点研究前后两次多结节聚合征的形态学变化，将多结节聚合HRCT征分为“花瓣”状、“桑椹”状、“宝塔”状，通过前后两次多结节聚合HRCT征形态的变化，揭示早期周围型肺癌孤立性多结节聚合征各种形态的演变规律。结果46例中首次形态分类为：“花瓣”状30／46（65．2％）；“桑椹”状7／46（15．2％）；“宝塔”状9／46（19．5％）。动态追踪后其形态特征发生明显变化：“花瓣”状8／46（17．3％）；“桑椹”状15／46（32．6％）；“宝塔”状20／46（43．4％）。3例直径〉3cm呈不规则肿块，其中来自“桑椹”状2例，“宝塔”状1例。“花瓣”状转化“桑葚”型8例（8／30，26．6％），“花瓣”状转化“宝塔”型11例（11／30，36．6％），增强扫描所有病例均有不同程度强化，强化后多结节聚合征更加明显。结论多结节聚合征是早期周围型肺癌征象之一，其形态具有动态变化，花瓣状多结节聚合征是桑葚状及宝塔状多结节聚合征的早期征象。

动态数学形态学轮廓提取算法在ARM上的实现

提出一种新的基于动态数学形态学的动态腐蚀轮廓提取算法。该算法以动态数学形态学中的约束条件为判断准则,通过定义评价函数来动态确定结构元素的移动方向,直接对感兴趣的目标进行轮廓提取。该算法引入自适应滤波门限,进一步增强了其抗噪处理能力。通过在ARM上对算法进行实现,得到了清晰的人体轮廓图像。该算法对实时目标的轮廓提取具有快速性和准确性的特点。

前房形态动态裂隙摄像测量系统的研制

目的 :设计制作一种前房形态动态裂隙摄像测量系统,对其精密度及可重复性进行检测 ,并应用其定量分析浅前房者在暗室俯卧试验过程中前房形态的变化。方法 :自行设计制作了前房形态动态裂隙摄像测量系统 ,然后用同一摄像系统拍摄标准米尺1张 ,测量计算其精密度。通过同一人对同一眼连续摄像测量10次及同一人对同一前房图像连续测量10次计算其可重复性。选取浅前房22例22只眼在暗室俯卧试验前后用本前房形态动态摄像测量系统摄像 ,并测量计算试验前后的前房深度及虹膜曲率半径。结果 :本摄像测量系统的精密度为0.035mm。变异系数为1.21%～3.69 %。22只浅前房眼在暗室俯卧后的前房深度小于暗室俯卧前 ,有统计学显著性差异 (P<0.01) ,试验后虹膜曲率半径小于试验前 ,差异有统计学显著性 (P<0.01)。结论 :本装置具备检测暗卧过程中晶体虹膜隔前移量及瞳孔阻滞力增加引起的虹膜膨隆程度改变量的能力 。

1985-2005年中南地区土家、壮、瑶、黎学生身体形态发育状况的动态分析

利用中南地区2005年和1985年少数民族学生体质健康调研所获得的数据,对该地区土家、壮、瑶、黎学生的身体形态发育状况作20年的动态观察、对比分析。结合环境因素探讨该地区少数民族学生身体形态发育变化的特点、规律、趋势及存在的差异和原因。为提高中南地区少数民族学生体质健康水平,改善少数民族地区学校体育卫生工作提供科学依据。

基于电压最小原理的脉冲微束等离子弧焊电弧形态的动态平衡研究

脉冲参数对脉冲微束等离子弧形态及其动态变化有直接影响,电弧形态是焊接电弧内部物理过程变化的直接反映。针对不同脉冲参数下电弧形态及其动态变化的特征进行了研究,将电弧最小电压原理和电弧内部洛伦兹力与气体内压力之间的平衡过程相结合,揭示了电弧形态变化的本质原因。研究分析表明,电弧半径随电流增加而增加,随电流减小而减小。只有在洛伦兹力与气体内压力达到平衡后,电弧才处于稳定状态,此时电弧半径相对稳定并使弧柱沿长度方向的电场强度具有最小值。

基于动态结构元的药柱表面图像边缘检测

以某产品药柱表面图像边缘检测为例,提出了一种基于动态形态学结构元和SUSAN算子相结合的图像边缘检测算法。该算法采用动态形态学结构元得到梯度图像,根据梯度图像利用SUSAN算子进行边缘检测。采用动态形态学结构元得到的梯度图像服从统一分布,有利于边缘提取,克服了采用固定形态学结构元不能适应不同的梯度图像的不足。通过与So-bel和固定形态学结构元的边缘检测算子进行对比实验,实验结果表明,该方法具有较好的边缘提取能力,抗噪性能好,对药柱表面图像处理具有很好的实际应用价值。

一种基于无线网络的动态主动防御系统设计方法

随着无线网络的应用程度的深入,随之引起的安全问题已经成为现代网络安全研究的一个重要领域。本文从无线网络应用的特点入手,提出主动防御的"动态形态"的陷阱网络体系结构,并设计了原型系统的主要算法。通过仿真实验证明,应用该动态主动防御体系,大大提高了无线网络主动防御能力和安全性。

虫形飞机的研究动态

文章介绍了虫形飞机的概念和用途、类型、基本结构、设计与制造难点等方面 。

论室内空间形态的时空关系

新时期,人们对室内空间形态提出了新的挑战,"时空"概念的产生,四维空间设计理论的提出都对传统的室内设计思维模式带来了一定的冲击,也为室内设计师带来了新的创作灵感,开辟了一条新的设计思路。当代室内设计,在继承传统室内空间的优良传统的同时,还应该看到"时空"的概念所带来的创造性设计思维。本文从空间形态的角度,阐述了时间和空间的关系,详细阐述了时空关系的表现形式,并以历史的视角阐明了传统空间的时空关系的营造手法对我们的启示。

浅谈城市形态

探讨了城市形态是构成城市发展变化的空间形态特征,这种变化是城市这个“有机体”内外矛盾导致的结果,从不同的生产力水平、不同的经济结构,以及人们生活方式等,分析了城市是一种动态性形态的表征。

基于条件笔画密度提取的文本定位方法

为了解决视频检索中文本定位精确度不高的问题,提出一种基于条件笔画密度提取的文本定位方法。根据文本笔画的特征对视频图像中的文本进行初步定位,用基于条件密度的方法滤去一部分非文本区域,再利用动态形态学对提取的文本区域精确定位并对其优化得到最终的文本区域。实验结果表明,该方法能滤去大部分非文本信息,得到相对精确的文本区域,并且定位效果较好。

扁弯口吸虫Clinostomum complanatum(Rud.)的生物学(I.生活史)

本文研究一种鸮形吸虫—扁弯口吸虫—的生活史。这种吸虫在广东顺德和南海县一些渔场曾引起流行性疾病,给幼鱼培育带来严重的损失。本文对吸虫生活史各个时期的描述以动态形态学的观点追踪从一个时期到另一时期的连续变化,并探讨吸虫各个时期的形态对特殊生活方式的适应。研究着重探索螺体内雷蚴的繁殖力,雷蚴在生长过程中焰细胞数目的增长,尾蚴尾干肌肉系统的结构与雌雄生殖系统的发育。讨论涉及下列各问题:扁变口吸虫种群的建立和环境的关系;雷蚴在螺体内的繁殖策略和种群的延续性;生活史的研究与分类学、行为学及种系发生学的关系。

Dynamic recovery and dynamic recrystallization of NiTi shape memory alloy under hot compression deformation

Mechanical behavior of nickel？titanium shape memory alloy（NiTi SMA） under hot deformation was investigated according to the true stress—strain curves of NiTi samples under compression at the strain rates of 0.001-1 s-1 and at the temperatures of 600？1000℃.Dynamic recovery and dynamic recrystallization of NiTi SMA were systematically investigated by microstructural evolution.The influence of the strain rates,the deformation temperatures and the deformation degree on the dynamic recovery and dynamic recrystallization of NiTi SMA was obtained as well.NiTi SMA was characterized by the combination of dynamic recovery and dynamic recrystallization at 600℃ and 700℃,but the complete dynamic recrystallization occurred at other deformation temperatures.Increasing the deformation temperatures or decreasing the stain rates leads to larger equiaxed grains.The deformation degree has an important influence on the dynamic recrystallization of NiTi SMA.There exists the critical deformation degree during the dynamic recrystallization of NiTi SMA,beyond which the larger deformation degree contributes to obtaining the finer equiaxed grains.

Dynamic caustics experimental study on interaction between propagating crack and deformity inclusions in primary structure

The approach combining the dynamic caustics method with high-speed photography technology is used to study the interaction between propagating cracks and three kinds of deformity inclusions（ cylinder inclusion, quadruple inclusion and triangular inclusion） under lowvelocity impact loading. By recording the caustic spots of crack tips at different moments during the crack propagation, the variation regulations of dynamic stress intensity factors（ DSIF） and crack growth velocity with respect to time are obtained. The experimental results showthat the resistance effects to crack growth are varied with different shapes of inclusions in specimens, and the quadruple inclusion＇s effect is more apparent. The distortion degree of caustic spots is affected by the shapes of inclusions as well, and the situation is more serious for cylinder and quadruple inclusions. The overall values of DSIFs of triangular inclusion specimen are greater than the others, and the crack growth velocities, characteristic sizes and DSIFs showprocesses of fluctuations because of the disturbance of reflection waves in specimens. The results provide an experimental basis for the analysis of strength and impact-resistance ability in structures with deformity inclusions.

Effect of hot deformation conditions on grain structure and properties of 7085 aluminum alloy

The influences of deformation conditions on grain structure and properties of 7085 aluminum alloy were investigated by optical microscopy and transmission electron microscopy in combination with tensile and fracture toughness tests. The results show that the volume fraction of dynamic recrystallization increased with the decrease of Zener-Hollomon （Z） parameter, and the volume fraction of static recrystallization increased with the increasing of Z parameter. The strength and fracture toughness of the alloy after solution and aging treatment first increased and then decreased with the increase of Z parameter. The microstructure map was established on the basis of microstructure evolution during deformation and solution heat treatment. The optimization deformation conditions were acquired under Z parameters of 1.2×10^10-9.1×10^12.

Hot deformation behavior of Al-Zn-Mg-Cu-Zr aluminum alloys during compression at elevated temperature

The hot compression tests of Al-Zn-Mg-Cu-Zr aluminum alloys （7056 alloy and 7150 alloy） were performed in a temperature range from 300 to 450 °C and at strain rate range from 0.01 to 10 s-1. The results show that the true stress-true strain curves exhibit a peak stress at a critical strain, then the flow stresses decrease monotonically until high strains, showing a dynamic flow softening. The peak stresses depend on the temperature compensated strain rate, which can be represented by the Zener-Hollomon parameter Z in the hyperbolic-sine equation with hot deformation activation energy of 244.64 kJ/mol for 7056 alloy and 229.75 kJ/mol for 7150 alloy, respectively, while the peak stresses for the former are lower than those for the latter under the similar compression condition. The deformed microstructures consist of a great amount of precipitates within subgrains in the elongated grains at high Z value and exhibit well formed subgrains in the recrystallized grains at low Z value. The smaller subgrains and greater density of fine precipitates in 7150 alloy are responsible for the high peak stresses because of the substructural strengthening and precipitating hardening compared with 7056 alloy.

Characterization of dynamic microstructure evolution during hot deformation of Al-4.10Cu-1.42Mg-0.57Mn-0.12Zr alloy

The Al?4.10Cu?1.42Mg?0.57Mn?0.12Zr alloy was compressed to different strains at deformation temperature of 300 oC and strain rate of 10 s?1 on Gleeble?1500 system. The dynamic complex microstructures evolutions were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The true stress?true strain curves exhibited a peak stress at critical strain, after which the flow stresses decreased monotonically, showing a dynamic flow softening. As the strain increased, the dislocation tangled to cell structure and sub-grain structure, which indicated the occurrence of dynamic recovery during deformation. Dynamic precipitations ofS (Al2CuMg),θ (Al2Cu) and Al3Zr phase were accelerated and coarsened by deformation. ContinuousS phases precipitated in the Al matrix and discontinuousS phases were found to be nucleated near the Al3Zr phase and at the sub-grain boundary. The flow softening mechanism was resulted from the reduction of dislocation density which attributed to dynamic recovery and precipitates coarsening.

Dynamics of Nitrogen Speciation in Horticultural Soils in Suburbs of Shanghai,China

Dissolved organic nitrogen （DON） represents a significant pool of soluble nitrogen （N） in soil ecosystems. Soil samples under three different horticultural management practices were collected from the Xiaxiyang Organic Vegetable and Fruit Farm, Shanghai, China, to investigate the dynamics of N speciation during 2 months of aerobic incubation, to compare the effects of different soils on the mineralization of ^14C-labeled amino acids and peptides, and to determine which of the pathways in the decomposition and subsequent ammonification and nitrification of organic N represented a significant blockage in soil N supply. The dynamics of N speciation was found to be significantly affected by mineralization and immobilization. DON, total free amino acids, and NH^＋-N were maintained at very low levels and did not accumulate, whereas NO3^--N gradually accumulated in these soils. The conversion of insoluble organic N to low-molecular-weight （LMW） DON represented a main constraint to N supply, while conversions of LMW DON to NH4^＋-N and NH4^＋-N to NO3^--N did not. Free amino acids and peptides were rapidly mineralized in the soils by the microbial community and consequently did not accumulate in soil. Turnover rates of the additional amino acids and peptides were soil-dependent and generally followed the order of organic soil 〉 transitional soil 〉 conventional soil. The turnover of high-molecular-weight DON was very slow and represented the major DON loss. Further studies are needed to investigate the pathways and bottlenecks of organic N degradation.