隧道二次衬砌病害通用处治方法研究

通过对隧道病害形成的环境条件和结构条件进行分析,研究病害产生的原因。提出隧道病害按不同荷载形式、病害表现和发展程度划分为4个补强等级。给出隧道病害的三种主要处治方法及不同等级病害相应的通用处治方法。对垂直荷载引起的病害进行数值模拟计算,其结果与现场实测结果相互吻合。     

大学英语分级教学的探索与实践

根据新《大纲》“分类指导,因材施教”的原则,探索构建与时代发展同步的教学模式,已成为高等院校大学外语教学改革面临的紧迫任务。大学英语要求分级教学,是改革传统大学英语教学模式、适应时代发展要求的需要。本文结合大学英语教学现状及分级教学的理论依据,提出了大学英语教学改革——分级教学的必要性和科学性,以及如何有效实施分级教学。     

Discussion on retaining structure limit state classificationEI北大核心

Research purposes: Retaining structure belongs to the geotechnical engineering structure, the limit state classification of geotechnical engineering is more difficult than the structure projects. Based on the limit state concept at home and abroad, this paper makes a comparison and analysis of the common and difference of geotechnical engineering and structural engineering limit state, teases the retaining structure limit state and focuses on limit state of open-cut foundation and pile foundation, proposes the recommendation of limit state classification of retaining structure. Research conclusions: (1) The generalized limit state can be considered as a function which can achieve the expected requirements, the limit state is not limited to the concept of damage and failure, and its extension has been expanded to the requirements of that the goal of expected design cannot be achieved-a prescribed limit. (2) Retaining structure belongs to the category of geotechnical engineering, its limit state includes structure overall stability limit states and the structural stability limit state which includes the bearing capacity limit state and serviceability limit state and limit state between them, the state needs to be studied further. (3) In general area, the compressive stress limit state of open-cut foundation and lateral pressure limit state of rock foundation anchor pile foundation can be considered as the serviceability limit state. (4) The research conclusion is useful for guiding the design research of retaining structure limit state.     

Rigor and Representativeness in Marine Protected Area Design

Virtually all marine conservation planning and management models in place or proposed have in common the need for improved scientific rigor in identifying and characterizing the marine habitats and processes encompassed. An emerging central theme in the last few years has been the concept of representativeness, or representative systems of marine protected areas (MPAs). Representativeness and similar terms are used in two distinct senses in current literature, leading to considerable confusion. Definitions of these terms as they are currently used are provided. The habitat classification and mapping needed to incorporate considerations of representativeness into MPA planning must logically be carried out at the same scale at which management occurs. Management of highly protected areas is found to occur almost exclusively at local scales or finer, independent of the reservation model or philosophy employed. Current techniques for cost-effective surveying of marine areas are discussed. The emerging field of remote videography, in some cases linked with acoustic discrimination sensors, can provide quantitative data on real biological distributions. Such data lend themselves well to robust multivariate analysis in deriving habitat maps at scales relevant to managers, as a basis for assessing and planning for representation in MPA design.     

城市客运交通枢纽预警分级阈值简析

交通枢纽作为服务于公共交通之间以及公共交通与其它交通方式之间客流转换的场所,是改善整个交通系统,提高居民出行效率、解决出行换乘等问题的重要影响因素。本文结合东直门综合运输枢纽信息服务平台工程,采集枢纽客流进出量,总结客流统计规律,对东直门交通枢纽预警分级阈值进行简析,相关研究成果可为交通枢纽预警分级阈值分析提供参考。     

Improved Classification Approach via GEPSVM

A modified multisurface "proximal support vector machine classifier via generalized eigenvalues (GEPSVM for short)" was proposed. By defining a new principle, we designed a new classification approach via GEPSVM, namely, maximum or minimum plane distance GEPSVM (MPDGEPSVM). Unlike GEPSVM, our approach obtains two planes by solving two simple eigenvalue problems, such that it can avoid occurrence of singular problems. Our approach, compared with GEPSVM, has better classification performance. Moreover, MPDGEPSVM is over one order of magnitude faster than GEPSVM, and almost two orders of magnitude faster than SVM. Computational results on public datasets from UCI database illustrated the efficiency of MPDGEPSVM.     

城市埋地钢质管道外覆盖层安全质量状况分级问题的探讨

对目前城市埋地钢质管道外覆盖层安全质量状况分级评价现状、分级等级以及分级评价指标进行了探讨和总结,提出了分级级别划分的方法,给出了用电流衰减法对石油沥青进行分级的参数和部分具体数值,并对分级尚存的问题进行了讨论。     

森林防火SUPOTRBO数字无线调度系统案例分析

为解决北京林业森林防火基础设施和装备建设严重落后问题,定制开发森林防火SUPO-TRBO数字无线调度系统,建立一个功能实用、操作简单、高效可靠的防火信息指挥系统体系。介绍方案采用的技术,系统组成和功能特点。