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631.
A new hierarchical approach called bintree energy segmentation was presented for color image segmentation. The image features are extracted by adaptive clustering on multi-channel data at each level and used as the criteria to dynamically select the best chromatic channel, where the segmentation is carried out. In this approach, an extended direct energy computation method based on the Chan-Vese model was proposed to segment the selected channel, and the segmentation outputs are then fused with other channels into new images, from which a new channel with better features is selected for the second round segmentation. This procedure is repeated until the preset condition is met. Finally, a binary segmentation tree is formed, in which each leaf represents a class of objects with a distinctive color. To facilitate the data organization, image background is employed in segmentation and channels fusion. The bintree energy segmentation exploits color information involved in all channels data and tries to optimize the global segmentation result by choosing the "best" channel for segmentation at each level. The experiments show that the method is effective in speed, accuracy and flexibility. 相似文献
632.
阐明了石油沥青是一种燃烧不产生致癌物质、能燃尽的特殊液体燃料,替代柴油作燃料经济效益明显,且管理方便。深入讨论了双重内击式雾化喷咀的特点和设计中的问题及特种燃料沥青使用中的一些工程问题。 相似文献
633.
高速列车司机室内气动噪声预测 总被引:3,自引:0,他引:3
为了降低司机室内的噪声,采用大涡模拟法计算了高速列车车头曲面的脉动压力,将脉动压力作为头车司机室有限元分析的激励载荷,通过谐响应分析求得司机室壁板的振动速度,将振动速度作为司机室声场边界元模型的激励条件,求出了司机室内的气动噪声在不同频率点的声压分布。计算结果表明:司机室内的声压级在52·3~58·8dB(A)之间变化,声压级较大点位于司机室前窗玻璃向车顶过渡处及纵向中截面型线附近,且在50~315Hz之间,声压幅值较大;司机室内的气动噪声主要是低频噪声,对纵向中截面型线采取更平滑的过渡形式,可降低司机室内的气动噪声。 相似文献
634.
Jinchuan ZHANG Hao YANG Yuguang WEI 《Journal of Transportation Systems Engineering and Information Technology》2008,8(2):96-102
The transportation organization of heavy haul railway is complex in China, especially, the feedback of empty cars. On the basis of reference to the existing research results, and deep analysis of the characteristics of empty cars distribution of heavy haul railway, the authors construct the feedback schematic model of empty cars in unloading end of heavy haul railway. The minimum quantity of the combined trains and the time for combination is taken as the model goal and solution algorithm on the basis of minimum cost and maximum flow is formulated. Daqin railway is taken as an example and relevant conclusions of feedback scheme of empty cars of heavy haul railway, through an analysis of calculation results, are drawn. 相似文献
635.
轨道交通系统目前已经在许多城市形成了线网结构,在运营范围扩大的同时也增加了票务管理的难度。系统投资高、回收期长的特点决定了轨道交通系统必须设置具有吸引力的票种和探讨线网条件下的票务规则。在根据系统客流时空特性的基础上,设置了单程类和储值类2大类13种轨道交通车票,并根据系统运营的实际情况把轨道交通运营状态分成正常、降级和紧急3大类工作模式,探讨了不同工作模式下各类车票的票务规则,有利于提高轨道交通系统的经济和社会效益。 相似文献
636.
直达列车多点装卸取送顺序直接关系到铁路货车运用效率;文章考虑车辆行驶时间及装卸时间的不确定性,假设它们为服从正态分布的随机变量,经过分析,在给定置信水平下,提出了调车机车作业中断时间的计算方法,并结合算法设计建立了极小化调车机车作业中断时间的最佳取送模型;利用遗传算法的原理及方法对取送顺序方案进行了研究,构造了解决该问题的单亲遗传算法;通过从遗传算法对算例的计算过程和结果可见,该算法求解直达列车多点装卸取送问题取得了较好的效果。 相似文献
637.
Huailong Shi Jianbin Wang Chunyuan Song Wanxiu Teng 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2018,56(8):1187-1206
This investigation demonstrates the wheel wear evolution and related vehicle dynamics of high-speed trains with an operating distance (OD) of around two million kilometres. A long-term experimental test lasting two years was conducted to record the wheel profiles and structural vibrations of various trainsets. The wheel wear, namely the profile shape, worn distribution and wheelset conicity, is investigated for several continuous reprofiling cycles. Typical results are illustrated for the stability analysis, and the ride quality is examined with increasing OD. In addition, the vibration transition characteristics between suspensions are investigated in both the time and frequency domains. The experiments show that the dominant wear concentrates on the nominal rolling radius, and the wear rate increases with OD because of the surface softening resulting from the loss of wheel material. The vibration of structural components is aggravated by the increase of the equivalent conicity of the wheelset, which rises approximately linearly with the wheel wear and OD. High-frequency vibrations arise in the bogie and car body related to the track arrangement and wheel out-of-roundness, causing the ride comfort to worsen significantly. Additionally, the system vibration characteristics are strongly dependent on the atmospheric temperature. Summaries and conclusions are obtained regarding the wheel wear and related vehicle dynamics of high-speed trains over long operating times and distances. 相似文献
638.
639.
简要介绍一种新型混联式混合动力客车动力系统的结构;重点介绍系统结构、控制策略方面的设计;详细分析系统在多种控制策略下的运行模式及主要技术特点。 相似文献
640.
为了实现方便调试基于MST785芯片的车载主机,提出了一种基于MST785芯片和WINCE6.0系统的新型实用调试工具。该工具基于MST785芯片和WINCE6.0嵌入式系统,能够实现自动插卡运行调试工具,规律性操作调试开关和操作模式,并自动记录打印log。实际应用表明,该工具特别适用于分析导航电子产品显示异常和触摸异常的问题,并具有操作简便、节约成本、提高导航产品研发和售后的效率,达到了设计要求。 相似文献