The relations between dry port characteristics and regional port-hinterland settings: findings for a global sample of dry ports

This paper aims at defining generic characteristics of dry ports by carrying out an analysis using a large sample of dry ports from around the world. The dataset includes details on 107 inland terminals worldwide. All dry ports in the database have been selected from studies in the extant literature before being shortlisted to fit our research scope. Data collected include terminologies used, actors driving the development, terminal throughput, total area, services provided and the relation with the corresponding seaport(s). Using statistical analysis, the paper examines how dry port parameters are influenced by (1) a different terminal set up, like sea-driven and land-driven development, developed and developing system, dry port functions; (2) specifications of the seaport with which the dry port is connected, i.e. seaport traffic, connectivity, utilization, etc. and (3) the transport leg linking dry ports and seaports. The findings could be applied to the planning and development of inland nodes from the perspectives of different stakeholders.     

Market based framework for multiple AUVs cooperation

A“Market” based framework for multiple AUVs team is introduced in this paper. It is a distributed meta-level task allocation framwork. The formulation and the basic concepts of the “Market” such as “goods” and “price” are discussed first, then the basic algorithm of the “auction”. The loosely coupled v-MDTSP tasks are considered as an example of the task allocation mission. A multiple AUV team controller and a detailed algorithm are developed for such applications. The simulation results show that the controller has the advantages such as robustness and low complexity and it can achieve better optimization results than the classical central controller （ such as GA） in some tasks. And the comparison of two different local solvers also implies that we should get the reasonable task allocation even not using the high quality algorithm, which can considerably decrease the cooperation computation.     

动态环境下基于FFT实现伪码快速捕获

无线电导航系统中，载体动态性引入的多普勒频移对扩频信号捕获造成了很大困难。针对全数字化实现的扩频接收机，提出了一种新的捕获方案，即基于FFT算法实现对多普勒进行一定程度的补偿，解决了高动态环境下伪码序列的快速捕获问题。理论分析和计算机仿真结果表明，该方法简单有效。     

沿海交通水域测绘行业管理研究

文中在东海海区三个测量案例分析的基础上,指出了沿海交通水域测绘市场中存在的主要问题和原因,并提出了进一步加强海事测绘部门和通航部门合作,规范行业管理的对策建议。     

声阵测量中校核声传感器相位失配量的新方法

在声学测量中，测量通道间的相位失配引起的误差有时候至关重要，以致必须进行相位失配量的校核试验。如果使用传统的自由场行波法，由于存在安装误差，高频时无法得到高精度数据。本文提出了一种新的在驻波场条件下校核两路测量通道间相位失配量的方法。通过对形成驻波场的反射界面的不同情况的讨论，和对使用这种校核方法引起的误差分析，可以发现：在驻波场的波峰附近，两传感器的测量相位差的变化对安装位置的偏差最不敏感，该测量相位差本身就是两测量通道间相位失配的反映。通常，驻波效应的加剧有助于校核结果精度的提高。在硬边界／软边界条件下，当|R|＝ξ→1时，驻波效应很强烈，所得数据精度最高，能容许的声传感器安装偏差也最大。通过与行波场条件下计算结果的比较，发现驻小场条件下所得结果精度更高，适用的频率范围更宽。考虑到校核试验中所显示的操作的可靠性和成本的低廉性，该方法具有较高的工程应用价值。     

Large eddy simulations for quasi-2D turbulence in shallow flows: A comparison between different subgrid scale models

In this study, the performance of the horizontal large eddy simulation module, developed at the University of Leuven (HLES-KULeuven module) is assessed. A comparison between different subgrid scale models has been carried out. The study is concerned with the non-rotating and unstratified flows. The results of the simulation for an oscillatory backward facing (BFS) flow are presented in case of an expanding flume based on a one-length scale approach and a two-length scale approach. Three subgrid scale (SGS) models have been tested: Smagorinsky SGS model (Smagorinsky, J., (1963). General circulation experiments with the primitive equations, I. the basic experiments. Monthly Weather Review, 91(3), 99–164), Uittenbogaard SGS model (Uittenbogaard, R.E., and van Vossen, B., (2004). Subgrid-scale model for quasi-2D turbulence in shallow water. Shallow Flows. Jirka and Uijttewaal (Eds.), Taylor & Francis Group, London, ISBN 90 5809 700 5) and a proposed two-length scale approach. The first two models are considered to be a one-length scale models. A simulation without a subgrid scale model for the horizontal mixing has also been conducted. In all simulations, a quadratic friction model parameterizes the dissipation produced by the 3D-subdepth scale turbulence. The two-length scale concept uses a newly mixing length formulation for the quasi-2D turbulence and doesn't depend on the filter width in contrast to the one-length scale approach, in which the mixing length is function of the filter width. The outputs of the HLES-KULeuven module have been compared with the experimental data taken from Stelling, G.S., and Wang, L.X., (1984). Experiments and computations on separating flow in an expanding flume. Dept. Civil Engineering, Delft University of Technology, Report 2–84.). The two-length scale approach has been validated with experimental data from SERC Flood Channel Facility at HR Wallingford. In general, there is a qualitative agreement with the experimental data. It has also been found that the two-length scale approach produces more elongated and less isotropic vortex than the one-length scale models.