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.     

公路隧道衬砌背后空洞成因及规律研究

衬砌背后空洞是常见的公路隧道质量缺陷之一。衬砌背后空洞不但会恶化支护与围岩间的相互作用关系,还会给隧道结构带来巨大的安全隐患,是导致隧道衬砌结构产生病害主要原因。本文首先从设计、施工和养护3个方面系统地分析了衬砌背后空洞产生的主要原因,然后结合宁波地区11座公路隧道的无损检测数据对公路隧道衬砌背后空洞的变换规律进行了深入研究,研究成果可为国内外相关工程提供借鉴。     

电站装备虚拟维修训练系统开发

利用3D模型、3KO虚拟交互操作、动画、音视频等技术手段,开发了一种电站装备虚拟维修训练系统。     

某核电厂取水明渠平面布置优化设计

核电厂取水多采用取水明渠的形式,取水明渠的设计中,拦污能力是一项关系到取水安全的重要设计项目。本文基于国内某核电厂取水明渠改造项目,通过各优化方案的对比,介绍了提升取水明渠拦污能力的设计优化过程,可为今后同类工程提供有价值的参考。     

深圳华强北综合商业中心区交通改善探索

为改善深圳华强北综合商业中心区在步行街及城市轨道开通运营后面临的复杂交通问题,充分应用大数据、无人机等新型技术和设备对片区道路、公交、慢行及静态交通系统存在的问题进行高效精准分析,从道路空间重分配、公交线站位优化、慢行品质提升、挖潜停车供给等方面制定有针对性且实施性强的改善措施,持续跟踪措施落实情况并进行评估,多项已落实措施有效改善了华强北片区的交通运行状况.     

Lesion segmentation and identification of breast tumor on dynamic contrast-enhanced magnetic resonance imaging

Dynamic contrast-enhanced magnetic resonance imaging （DCE-MRI） can show subtle lesion morphol- ogy, improve the display of lesion definitions, and objectively reflect the blood supply of breast tumors; it can also reflect different strengthening patterns of normal tissues and lesion areas after medical tracer injection. DCE-MRI has become an important basis for the clinical diagnosis of breast cancer. To DCE-MRI data acquired from several hospitals across multiple provinces, a series of in-silico computational methods were applied for lesion segmentation and identification of breast tumor in this paper. The image segmentation methods include Otsu segmentation of subtraction images, signal-interference-ratio segmentation method and an improved variational level set method, each has its own application scope. After that, the distribution of benign and malignant in lesion region is iden- tified based on three-time-point theory. From the experiment, the analysis of DCE-MRI data of breast tumor can show the distribution of benign and malignant in lesion region, provide a great help for clinicians to diagnose breast cancer more expediently and lay a basis for medical diagnosis and treatment planning.     

秦岭终南山公路隧道初期运营通风研究

秦岭终南山隧道通风设计采用三竖井送排式纵向通风。目前,隧道通风系统中的竖井尚未正式投入使用,隧道内射流风机所构成的全纵向通风系统,能否满足当前交通流量状况的供风要求,以及火灾状况下提供的风速是否大于临界风速,是我们所关心的焦点。为此,本文通过计算,着重分析在现有通风条件下,在正常运营和火灾工况下,洞内可容纳的最大车辆数。据此,就秦岭终南山公路隧道初期运营通风状态作出评价或建议。     

氮氧化物对隧道需风量影响研究

为研究隧道环境中氮氧化物对隧道通风的影响,根据不同国家隧道通风环境标准,综合考虑车型、汽车质量、海拔、车龄等影响因素,结合PIARC的相关标准和计算模型,以港珠澳大桥海底隧道工程为例,得出稀释氮氧化物的需风量,并与稀释一氧化碳及烟雾需风量进行对比分析。研究结果表明,氮氧化物中转化为二氧化氮的部分对隧道需风量影响较大,与稀释一氧化碳及烟雾需风量比较,稀释氮氧化物的需风量为控制值。     

复合式连拱隧道曲中墙施工力学行为时空演化规律

为解决连拱隧道开挖过程中曲中墙安全承载问题，依托浙江省某在建复合式曲中墙连拱隧道，采用数值计算及现场监测手段对施工阶段曲中墙力学演化规律及偏压机制进行分析，并从设计、施工层面分别就曲中墙厚度及主洞施工步距对曲中墙应力及偏压影响规律进行研究。研究结果表明： 1）连拱隧道主洞上台阶开挖对曲中墙应力分布影响显著，此阶段应力增量约占应力终值的50%，曲中墙以承受竖向应力为主，横断面最小截面为受力最不利位置。2）连拱隧道非对称开挖造成曲中墙承受偏压荷载，导致曲中墙发生向先行洞一侧偏转，偏转现象在先行洞开挖过渡至后行洞开挖阶段尤为显著。3）曲中墙厚度对其应力分布、偏转效应影响显著，曲中墙厚度的减小降低了结构承载能力； 当曲中墙厚度为1.3 m时，曲中墙墙身应力急剧增大，曲中墙可能发生压溃失稳。4）主洞施工步距对曲中墙应力分布影响较大，但不改变曲中墙应力终值； 随着主洞施工步距增大，曲中墙偏压弯矩越大，偏转效应持续时间越长。