利用“有效风能”预报航道淤积

提出了"有效风能"概念;导出了"有效风能"与浪、沙、航道淤积之间的相关关系;得出了利用"有效风能"计算航道淤积的计算公式,并与黄骅港海区现场资料进行了验证和校核,效果良好。     

公路工程不同报价评标办法结果的经济合理性分析

根据交通部颁布的“公路工程施工招标投标办法”及有关文件,采用3种不同标底对某项工程的投标报价进行评定,并对评定结果进行分析,研究探讨最适合市场经济特点的科学评标办法。     

让压预应力锚索在软岩隧道大变形控制中的作用机制研究

为解决高地压、高流变条件下软岩隧道围岩及支护结构大变形控制难题，通过理论和数值分析，研究让压预应力锚索在隧道大变形控制中的作用机制。研究内容包括2个方面，一是研究新型让压锚垫板在低预紧力及低围压下的力学性能，满足支护结构先柔让压的要求； 二是让压结束后，预应力锚索在高预紧力条件下改善支护结构受力性能，实现后刚强支的作用。结果表明： 1）预应力锚索通过施加预紧力，增大洞壁径向阻力，提高围岩稳定性； 2）预应力锚索在让压结束后对支护结构的主要作用是减跨，由此提高支护结构刚度和承载能力； 3）围岩、支护结构和让压预应力锚索变形协调，力学上相互耦合，构成“先柔后刚”的支护体系。     

大型充泥袋结构在黄骅港一期工程引堤工程中的应用

重点介绍黄骅港引堤工程采用大型充泥袋结构方案的研究应用情况,并对设计、施工中的某些技术问题进行探讨并提出建议。     

深基坑土钉墙支护现场测试及优化设计

以成都市锦贸大厦深基坑土钉支护为实例,对土钉应变测试,地表土体变形破裂观测,位移监测三项成果进行分析,对土钉支护作用机制作了初步探讨,并提出了土钉墙的优化设计。     

Optimization models for differentiating quality of service levels in probabilistic network capacity design problems

This paper develops various chance-constrained models for optimizing the probabilistic network design problem (PNDP), where we differentiate the quality of service (QoS) and measure the related network performance under uncertain demand. The upper level problem of PNDP designs continuous/discrete link capacities shared by multi-commodity flows, and the lower level problem differentiates the corresponding QoS for demand satisfaction, to prioritize customers and/or commodities. We consider PNDP variants that have either fixed flows (formulated at the upper level) or recourse flows (at the lower level) according to different applications. We transform each probabilistic model into a mixed-integer program, and derive polynomial-time algorithms for special cases with single-row chance constraints. The paper formulates benchmark stochastic programming models by either enforcing to meet all demand or penalizing unmet demand via a linear penalty function. We compare different models and approaches by testing randomly generated network instances and an instance built on the Sioux–Falls network. Numerical results demonstrate the computational efficacy of the solution approaches and derive managerial insights.     

Driver fatigue: a vision-based approach to automatic diagnosis

In this paper, we describe a system that locates and tracks the eyes of a driver. The purpose of such a system is to perform detection of driver fatigue. By mounting a small camera inside the car, we can monitor the face of the driver and look for eye movements which indicate that the driver is no longer in condition to drive. In such a case, a warning signal should be issued. This paper describes how to find and track the eyes. We also describe a method that can determine if the eyes are open or closed. The primary criterion for this system is that it must be highly non-intrusive. The system must also operate regardless of the texture and the color of the face. It must also be able to handle changing conditions such as changes in light, shadows, reflections, etc. Initial experimental results are very promising even when the driver moves his/her head in a way such that the camera does not have a frontal view of the driver’s face.     

牵引定数不统一的港口后方腹地车流组织优化

线路区段牵引定数不统一是影响列车编组计划制定的重要因素,导致了列车在部分区段欠轴运行,在换重站或技术站进行补减轴作业.本文重点论述了减重方向列车编组方案的优化问题,提出了按充分条件将各种方案归类的方法,从而减少方案成本的对比次数,能快速获得最优的运送方案.在方案成本构成的分析过程中,充分考虑了各影响因素,将牵引机车费用看作与里程相关的可变成本,将欠轴列车浪费的机车和线路能力转化为惩罚费用,并考虑列车开行频率对方案费用的影响,最后从全网络的角度建立减重方向减轴列车编组优化模型.该模型既可获得合理的减重站,又能依据车流量关系选择优化的减轴编组方式,实例验证了模型的有效性.     

Economic Valuation of Coastal and Marine Resources: Bohol Marine Triangle,Philippines

This article provides results on the net benefits generated from the natural resources in the Bohol Marine Triangle (BMT) in the Philippines. The BMT spans over 112,000 ha and its coastal ecosystems are rich in biodiversity and provide economic opportunities to the coastal communities. With a 10% discount rate, the accumulated total net benefits for the BMT resources over a 10-year period is US$11.54 million. Tourism and the municipal fisheries are the most important direct use values of the coastal and marine resources of the BMT accounting for 44% and 39% of the total net benefits. Annual revenues attributed to ecosystems were as follows: coral reefs, US$1.26 million; beach/intertidal area, US$1.12 million; marine waters, US$646,501; mangrove, US$239,561; and seagrass, US$105,990. The large market values indicate the dependence of the local community on the BMT coastal and marine resources. In the same way, non-market values show the important life-support functions of coastal and marine ecosystems. The net benefits reflect the magnitude of potential losses due to improper management of coastal and marine resources in the BMT. This valuation highlights the importance of the coastal services to the BMT economy and draws attention to the benefits the local stakeholders derive from BMT coastal resources. Policy measures can now take into account these values to justify a sufficient investment in coastal management efforts to sustain the flow of coastal services in the interest of current and future generations.     

铁路小半径曲线刚构-连续梁桥设计研究

为研究小半径曲线刚构-连续梁桥的受力特点,以某(36+60+36)m铁路刚构-连续梁桥为背景进行分析。采用BSAS、MIDAS、ANSYS建立有限元模型,针对该桥小半径、施工复杂等特点,从弯扭耦合效应、刚度、变形、稳定性等方面进行详细分析,结果表明:该桥具有足够的强度、刚度和稳定性。