A bintree energy approach for colour image segmentation using adaptive channel selection

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.     

A new channel allocation scheme for hierarchical wireless networks

A channel allocation scheme for hierarchical wireless networks was proposed in terms of the connection-level quality of service. The channel allocation scheme was analyzed using both horizontal channel borrowing and vertical traffic overflowing. Pre-emptive priority strategies are used to classify real-time services and non-real-time services, real-time service is given higher priority for it is allowed to pre-empt channels used by non-real-time service. Some channel borrowing thresholds and acceptance ratios are used to avoid channel locking or dynamic power control, which can also be dynamically adjusted according to network load. Simula-tion results show that the proposed schemes can improve the system performance.     

基于层次分析法的渤海海峡跨海通道项目投资风险分析

为了评估渤海海峡跨海通道项目的投资风险,利用层次分析法进行了投资风险分析,分解了影响渤海海峡跨海通道项目的各项因素,按各因素对项目总风险影响大小进行排序,分析了在项目进展过程中最应该把握的关键因素。分析结果表明:各子项目的影响程度从大到小依次是地理条件、技术水平、意外事件、资金、资源利用和政策法规;按风险由大到小将风险划分为4个级别,海底地质情况风险最大,防灾救援系统、照明系统等隧道项目中的基础功能设施风险较大,洞口防洪设施、隧道监控系统等设施风险较小,规划预留功能风险最小;最后对结果进行了解释,项目规划者与投资者可以参考分析结果进行风险管理。     

钢筋混凝土连续箱梁剪力滞效应研究

利用空间有限元法分析了单箱双室钢筋混凝土连续箱梁剪力滞效应,分别计算了自重作用及活载作用下跨中截面与支座处截面的正应力分布规律及剪力滞系数,并将采用有限元分析得到的翼缘有效宽度与规范中的有效宽度规定进行了比较,以期为同类桥梁设计提供参考。     

三峡水库蓄水后坝上下游航道条件变化分析

分析三峡水库蓄水后进出库水沙特性;库尾、葛洲坝下游河道、永久船闸引航道、两坝间河道冲淤特点;变动回水区回水末端范围、葛洲坝下游宜昌、沙市枯水水位变化;库区航道条件和葛洲坝下游河段航道尺度变化。     

焊接规范对单组分活性剂A-TIG焊焊缝成形的影响

采用Cr2O3活性剂对1Cr18Ni9Ti不锈钢实施A-TIG焊，改变焊接规范研究焊接电流、焊接速度以及弧长对活性剂作用下的熔深熔宽的影响．结果表明，在弧长为1mm的条件下，焊接电流大于80A时活性剂能显著的提高熔深降低熔宽，焊接弧长小于1．5mm时，活性剂能显著的提高熔深降低熔宽，活性剂的作用使熔深熔宽随焊速的变化缓慢．     

温州石化基地30万吨级航道选线研究

采用水动力泥沙条件分析、冲淤演变分析、航道轴线平均水深与开挖深度统计、基建工程量计算、二维潮流数学模型计算、航道年淤积强度与淤积量计算、航道骤淤计算、三维潮流数学模型计算、通航安全分析等多种手段对温州石化基地30万吨级航道多条轴线方案进行了比选研究。根据航道轴线自然淤积厚度、航道天然平均水深、航道平均开挖深度、航道首次开挖量、航道长度，大潮最大流速与航道轴线交角、最大横流速度、航道年平均淤积强度、航道年淤积量、航道平均骤淤强度、航道段最大骤淤强度及通航安全（航道拐点、附近有无岛礁）等多项指标对航道轴线方案进行了选择。研究结果认为与涨落潮流方向基本一致的直线方案为最佳航道轴线方案。     

双电源监控装置在长大干线上的应用

双电源监控系统通过远程监视、协调、控制能将故障定位、隔离、自动恢复供电,减少自闭、贯通线路故障停电范围,提高信号供电的可靠性,确保供电质量,节约大量的人力和物力,使电力调度管理走向自动化、信息化。     

航道边线与桥墩之间安全距离的研究

合理地确定通航桥梁的最小净空宽度,保证船队航行和桥梁安全,是桥梁建设和航道建设均应重视的问题。文章提出了计算通航桥孔宽度的计算公式。当桥梁轴线的法线方向与水流方向的偏角超过5°时,通航桥孔净空宽度应在一般航道宽度的基础上增加考虑水流产生的船舶横向漂移,并在桥墩和航道边线之间留有足够的安全距离。利用PIV技术,获得桥墩周围流场的准确信息,从水流紊动的角度,提出了安全距离的确定方法。     

基于可拓方法的连续配筋混凝土路面裂缝宽度评价

在简述可拓评判方法的基本原理和评价步骤的基础上,根据京珠高速湖南段耒宜高速公路CRCP 3个路段的裂缝宽度检测结果,进行了用可拓方法评价CRCP裂缝宽度的研究,确定了相应的评价步骤,并将其评价结果与统计方法进行了对比分析,从而提出了运用可拓方法评价CRCP裂缝宽度的方法。结果表明,可拓方法不仅能合理评价裂缝宽度的现时状况,而且其关联度可以反映裂缝宽度等级的动态发展趋势;而统计方法的评价结果受个别较宽裂缝的影响较大,且为静态结果,只能反映CRCP裂缝宽度的现时状况。因此,可拓方法比统计方法更可靠、更准确,更能满足CRCP裂缝宽度检测的要求,从而为CRCP路面养护维修提供参考依据。