Capacity Development for Integrated Coastal Zone Management in Egypt

Since 1990 there has been a considerable increase in the number of developing countries undertaking Integrated Coastal Zone Management (ICZM) schemes at both the local and national levels. Unfortunately many of these ICZM schemes have failed to be implementated due to difficulties such as information and communication gaps and restricted technical and financial capacity. Common problems experienced across all developing countries. As a case in point, it is argued that developing countries suffer from capabilities at the local institutional level. Similarly, it is advocated that Mediterranean developing countries have not fully implemented ICZM as a result of lack of stakeholder capacity. Egypt provides a case study of this argument. Since the mid-1990s several attempts have been made to promote ICZM in Egypt, however none have achieved their goal of having an ICZM plan become operational. This paper reviews ICZM processes in Egypt focussing on the capacity of all instituions and key stakeholders to plan and implement ICZM based on interviews with key ICZM key stakeholders as well as documentary analysis and participant observation in ICZM meetings. It seeks through a critical evaluation to provide practical recommendations that serve to enhance the implementation of ICZM in Egypt and other developing countries.     

关于船舶UPS的容量估算

伴随着不间断电源(UPS)技术在船舶以及海洋工程项目中的使用日益广泛,人们对不间断电源技术的了解也日益增加。该文通过实船案例结合理论知识详细介绍UPS的工作方式以及UPS的容量确定、蓄电池容量确认等内容。     

大极差情况下载荷试验承载力取值计算

对于载荷试验的大极差,各种规范没有给出统一的规定,试验数据的处理比较随便,造成不经济或不安全。当极差大于30%平均值或最大值与最小值之比大于1.3时,承载力取值可采用离群值剔除法、变异系数折减法确定。案例计算分析表明,给出的计算公式合理、计算简单方便,可用于各种载荷试验确定承载力。     

不同土质下预制方桩沉桩承载力特性分析

对沿海地区某码头预制方桩沉桩过程进行监控。结果表明,打桩时由于桩周土扰动剧烈,桩的贯入阻力大幅减小,粉质土贯入阻力降低比例高于粉砂。复打测试表明:粉质土的恢复系数较粉砂高;桩侧摩阻力与土层性质密切相关。在沉桩时可根据土层情况选用合适的打桩锤击力,以减小或避免对桩的不利影响。     

考虑应变强化效应海底管道极限承载力研究

文章基于线性强化材料模型,推导了轴向拉力作用下海底管道极限弯矩承载力解析解,给出了海底管道在轴向拉力与弯矩载荷同时作用下的极限承载力的近似解,编制了海底管道极限承载力计算程序BCP。通过与实验结果的比对,验证了解析方法的正确性。结论表明考虑应变强化效应的海底管道极限承载力结算结果更为合理,该文可为海底管道的结构强度设计和安全性评价提供一定的参考依据。     

基于频域搜索的梳状谱信号检测方法

由于梳状谱信号多普勒容限较小,利用常规的匹配/相关检测方法进行检测时,需要较大数量的拷贝信号与计算量。针对这一问题,本文提出一种基于频域搜索的梳状谱信号检测算法。通过利用梳状谱信号频域多峰结构的特点,根据信号的先验信息计算出不同径向速度下回波信号的频点分布,对接收的信号在频域进行搜索累计的方法同时实现信号的检测与速度估计。仿真分析证明了本文算法的有效性。     

基于EMD的矢量水声器方位估计算法

对经验模态分解算法(EMD算法)进行深入研究,对其基本原理、基本性质以及存在的问题进行分析。为改善EMD算法在方位估计的精度,减少高频噪声、间断干扰的影响,本文采用Hilbert-Huang变换方法来消除模态混叠现象。实验结果表明,本文提出的基于EMD的矢量水声器方位估计算法,能够有效提高方位估计的精度。     

Quasi-dynamic estimation of o–d flows from traffic counts: Formulation,statistical validation and performance analysis on real data

The paper proposes a “quasi-dynamic” framework for estimation of origin–destination (o–d) flow from traffic counts, under the assumption that o–d shares are constant across a reference period, whilst total flows leaving each origin vary for each sub-period within the reference period. The advantage of this approach over conventional within-day dynamic estimators is that of reducing drastically the number of unknowns given the same set of observed time-varying traffic counts. Obviously, the gain in accuracy depends on how realistic is the underlying assumption that total demand levels vary more rapidly over time than o–d shares. Firstly, the paper proposes a theoretical specification of the quasi-dynamic estimator. Subsequently, it proposes empirical and statistical tests to check the quasi-dynamic assumption and then compares the performances of the quasi-dynamic estimator of o–d flows with both classical off-line simultaneous dynamic estimators and on-line recursive Kalman filter-based estimators. Experiments are carried out on the real test site of A4–A23 motorways in North-Eastern Italy. Results confirm the acceptability of the assumption of quasi-dynamic o–d flows, even under the hypothesis of constant distribution shares for the whole day and show that the quasi-dynamic estimator outperforms significantly the simultaneous estimator. Data also suggest that using the quasi-dynamic estimates instead of the simultaneous estimates as historical o–d flows improves significantly the performances of the Kalman filter, which strongly depends of the quality of the seed o–d flows. In addition, it is shown that the aggregation of quasi-dynamic o–d estimates across subsequent time slices represents also the most effective way to obtain o–d estimates for larger time horizons (e.g. hourly estimates). Finally, a validation based on an hold-out sample of link flows (i.e. counts not used as inputs in the o–d estimation/updating process) revealed the quasi-dynamic estimator to be overall more robust and effective with respect to the other tested estimators.     

A practical capacity model of a single track line

The paper presents a model for determining the practical capacity of a single track line, i.e. the maximum number of trains which can be run along it in a time unit under the condition that each train enters its bottleneck segment with a definite delay.

The input data used in the model are: geometrical characteristics of the bottleneck segment of the line under study, the intensity and structure of demand expressed by a number of trains which are run over the line in a given time unit, the scenario of traffic running over the line under study and the operational tactics of individual train categories processing on the bottleneck segment.

(Two tactics can be applied in the train processing on the line under study; first, the trains of individual categories are given different priorities in the processing, and second, all the trains have the same priority).

The output results of the model are average delays of trains of each category occurring within the train processing performed on the bottleneck segment of the line under study in a given time unit.     

浅谈公路工程估算编制的新规则

新的《公路工程基本建设项目投资估算编制办法》和《公路工程估算指标》自2012年1月1日正式实施。取代1996编办和指标,针对估算编制的新规则,分析总结新旧差异,为以后估算编制工作提供指导。