基于灰色层次模型的机载电子对抗系统效能评估

机载电子对抗系统效能评估是航空电子对抗领域的一个重要课题,同时也一个涉及多指标多因素的复杂问题,且部分因素存在不完全和不确定。灰色系统理论是处理这类问题的有力工具。文章建立机载电子对抗系统效能评估指标体系,能够全面和客观地反映机载电子对抗系统能力。通过专家系统评价分值和设置权重,并构建灰色白化权函数统一量化专家给出的评价描述,运用灰色层次分析方法对其效能进行评估。最后实例分析验证了方法的有效性和可行性。     

基于距离信息的鱼雷攻击意图判别方法研究

编队作战是未来海上作战的基本样式,进行舰艇编队水声对抗研究具有十分重要的意义.如果舰艇编队能够通过数据融合等方式获取鱼雷距离和方位的报警信息,并根据这些信息判断出鱼雷对舰艇编队的攻击意图,即鱼雷攻击的具体目标舰艇,则有助于指挥员采取有效、合理的对抗方法,从而提高舰艇编队的生存能力.论文在建立声自导鱼雷攻击模型和舰艇编队运动模型的基础上,对鱼雷从不同区域来袭时的态势划分,提出了攻击意图的判断准则,并且通过仿真验证,分析了影响判断准确度的因素,为编队协同水声对抗指挥决策提供了必要参考.     

Putting our money to good use: Can we attract more passengers without increasing subsidies?

This paper evaluates the policy of Swedish public transport authorities, determining whether the number of trips on local public transport could have been increased without increasing subsidies. Based on annual data from Swedish counties, the evaluation found that between 1986 and 2001 public transport fares exceeded the passenger-maximising fare most of the time in all but two counties, the average deviation being 1-215%. Evaluating the alternative, passenger-maximising policy, including both fare and service changes for 2001, demonstrated that demand for local public transport in Swedish counties could have been increased by 0-178% without increasing subsidies. Aggregated, this represents a 2.3% increase in the number of trips on local public transport in Sweden.     

On the evaluation of a public transportation network quality: Criteria validation methodology

A public transportation network serves in adequate way a population if it evolves in time following the existent social reality. Changes made in order to improve service must be analyzed and evaluated. The introduction of modern technology to validate the fare card allowed a quick access to important, although incomplete, data. Databases with only the getting in validation information can be used to construct an origin–destination (OD) matrix, allowing a service quality analysis. Here it is presented a basic methodology to rigorously validate service quality criteria considering what might be interesting for the user. The quality analysis philosophy is the following. First, based on automatically gathered data, one reconstructs the origin–destination (OD) matrix, which contains information concerning the number of passengers traveling between zones of a certain region. The OD matrix is used to calculate some criteria characterizing the transportation network quality, such as traveling times, waiting times at a stop or transport occupation. The reconstructed OD matrix always contains errors, which cause errors in the criteria values. How significant are these errors? This question can be answered using our criteria validating methodology, which is based on statistical analysis. It has been implemented at the urban bus transport system of Porto, STCP, allowing the evaluation of the transportation network quality under a number of criteria and guaranteeing rigorous results.     

Optimal investment priority in container port development

The aim of this paper is to develop realistic and relevant investment planning models for inland container transportation systems. The models may be utilized to identify the most effective investment plan for inland transportation infrastructure development and to evaluate the inland container transportation system. The procedure enables determination of the optimal locations, sizes and time of container port developments as well as the optimal container cargo flows through transportation networks. A heuristic algorithm was developed for the purpose of evaluating alternative investment plans. Dynamic and linear programming methods are applied to each of the two planning problems: the former for the optimum container port capacity development problem and the latter for the optimal allocation of inland container traffic movements. The model has been applied to concrete inland container transportation system problems in Korea.     

Optimal investment priority in container port development

The aim of this paper is to develop realistic and relevant investment planning models for inland container transportation systems. The models may be utilized to identify the most effective investment plan for inland transportation infrastructure development and to evaluate the inland container transportation system. The procedure enables determination of the optimal locations, sizes and time of container port developments as well as the optimal container cargo flows through transportation networks. A heuristic algorithm was developed for the purpose of evaluating alternative investment plans. Dynamic and linear programming methods are applied to each of the two planning problems: the former for the optimum container port capacity development problem and the latter for the optimal allocation of inland container traffic movements. The model has been applied to concrete inland container transportation system problems in Korea.     

LNG罐式集装箱水运安全性探讨

LNG公路运输成本高,交通事故频发,为此有关专家提出LNG罐式集装箱水路运输的模式。该模式将会使运输成本显著降低,但如何保障运输安全就成为关键问题。该文就LNG罐式集装箱水路运输涉及的各个环节——LNG罐式集装箱、码头装卸和水路运输的安全性要求进行探讨,分析LNG罐式集装箱的积载和隔离方式,并提出一些建议,为中国开展LNG罐式集装箱水路运输业务提供参考。     

一型磁场仿真模拟器的设计

简要论述了磁场半实物仿真模拟器在水雷反水雷武器仿真系统中的重要作用;介绍了磁场半实物仿真模拟器的结构组成和工作原理,针对磁场产生器和磁场驱动器2个核心装置,分别作了理论推导和调试结果的分析,验证了模拟器的合理性。磁场半实物仿真模拟器根据仿真数学模型来计算空间某一点磁场的时间历程,模拟舰船通过环境干扰或两者复合作用时,水雷磁传感器所接收到的真实磁场信号,可以用来验证水雷反水雷武器性能、评估水雷反水雷作战效果等。     

潜艇极限承载力计算与分析

潜艇承载力是指抵抗静力载荷的能力,同时也是其动力抗沉能力大小的一个侧面。采用潜艇垂直面操纵性运动方程,考虑潜艇纵向水动力的平衡,将螺旋桨推力分解成系泊状态的推力和相对系泊状态减少的推力,导出潜艇承载力计算的动力学方程和承载力平衡方程。然后基于承载力平衡方程,提出潜艇极限承载力的4个衡准,并导出衡准参数的计算解析表达式。计算分析表明：螺旋桨是衡量潜艇承载力的重要因素,衡准参数能清晰地表征潜艇极限承载能力的大小,衡准参数的解析表达式可为承载力设计提供依据。     

Examining the linkages between electronic roadway tolling technologies and road pricing policy objectives

The surge of road pricing projects in the U.S. and around the globe over the past 15 years has been enabled by a variety of new communication and transportation technologies. While all of these technologies increase the efficiency of roadway tolling vis-à-vis manual collection, no “best” configuration has emerged. Rather, optimal configurations depend on the objectives of the tolling effort, such as facility type, geographic scope, desire to price externalities, integration with other operations, and so on. While such policy objectives for road pricing have been examined extensively, little has been written on the explicit links between tolling technology configurations and policy objectives. This paper addresses this gap in the literature through an examination of eight road pricing programs. For each program we evaluate the conduct of the three technical tasks via the nine technology sets in light of six principal policy objectives of road pricing.     

高桩码头完好状态的模糊综合评估

根据高桩码头结构特点和功能特征,建立了包括指标层、准则层和目标层的多层评估模型。利用模糊综合评估将影响高桩码头安全运行的各个因素有机地结合起来,再根据经验所得到的判断矩阵,利用matlab软件编制出的层次分析法计算程序确定各个部分的权重,经过模糊运算得出高桩码头的状态评估结果。以天津港高桩码头为研究背景进行实用分析,结果表明这种方法具有一定的实际应用价值。     

宁夏交通数据中心技术架构研究

建设交通运输数据中心是宁夏云计算产业高地发展的重要组成部分,科学合理地设计交通数据中心总体技术架构有助于交通运输行业数据资源的汇集、整合、挖掘和共享.从交通数据中心逻辑框架出发,分析不同逻辑层面的应用需求.在此基础上,结合技术架构框架模型,搭建宁夏数据中心总体技术架构,具体分析基础设施架构、系统集成架构和技术标准架构的详细组成.     

智能交通系统与通信技术

高新技术的智能交通系统 (Intelligent Transport Systems)是改善世界性交通难题的希望所在。本文基于交通信息系统的智能化水平和通信技术的发展趋势 ,综述了 ITS的功能及其相关的通信问题 ,对提高我国高速公路交通监控系统的智能化水平具有参考意义     

Inland transportation system planning by life-cycle impact assessment: a case study. 2nd report: single comparison index

A model to estimate and compare the ecological impact and economic feasibility of a land transportation system (trucks) and a marine transportation system (cargo ships) was developed and presented in a previous report.¹ Three different comparison indices—environmental, economic, and customer service—were used to evaluate and compare their ecological impacts and determine their economic superiority. In this article, a single comparison index is proposed and assessed for the two transportation systems. The estimates were made for nine different routes in Japan. A simple mathematical model of the whole methodology is given. The sensitivity of the weighting factors used in the comparison method was analyzed. The social cost saving in monetary terms through a modal shift is also presented. Received: February 15, 2001 / Accepted: September 19, 2001     

日照港石臼港区公路对外集疏运研究

日照港石臼港区位于日照市主城区的东南部,港区最终规模将建设成74个泊位,年吞吐总量将达到3.5亿t.解决好其公路集疏运问题,是日照市和日照港达到"港城共赢"最为关键的因素之一.通过分析石臼港区营运货物及其集疏运构成,计算其各流向的公路集疏运交通量,研究确定石臼港区对外集疏运公路建设标准和建设时序.     

Concepts of strategic commercial location: the case of container ports

A World that shrinks with progressive improvements in transportation and communications is a fact of 20th century life. The shrinking process can produce new patterns and perceptions of strategic location. In this paper we are looking specifically at nodes in transportaion system. In the ligth of transportation progress, we re-consider some of the time-worn ideas about centrality, accessibility, gateway locaations, junction, transit points, and the like. Do some of these notions become irrelevant in the modern transport age? Is it a questions f shifting geographical scale? Do we need more sophisticated concepts of strategic location? We suggest the answer 'yes' to all three questions. Our illustrations come from an examination of the world's top-ranked container ports. We give primary emphasis to the external geographical relationships of the ports, that is to situational aspects (not to say, however, that sitefeatures are inconsequetial). We are interested in the seaports users' —i.e., carriers and shippers—perceptions of strategic location. Readily available container throughput data provide and initial platform for empirical research but also give proof that some commercial interests find these ports strategically important to their system.     

The role of geomatics engineering in establishing the marine information system for maritime management

Maritime management encompasses the employment and manipulation of human resources, financial resources, technological resources and natural resources that relate to the sea, maritime navigation, shipping, port development and coastal protection. It contributes to the economic growth, price stability, transportation of cargoes and passengers, and business activities of shipping organizations. The efficient management of resources, operations and activities relies on a modern marine information system (MIS) whose information is provided by geomatics engineers and IT professionals, among others. This paper first introduces the role of the geomatics engineer as geodesist, engineering surveyor, land boundary surveyor, cartographer, hydrographer, photogrammetrist and geographic information system (GIS) engineer since all these fields are related to maritime trade, supply chains and development of ports and airports. It then describes the principal components of a web-based MIS and the important role of geomatics engineers in surveying data. This includes collecting data from electronic nautical charts (ENC) and raster nautical charts (RNC), by applying high resolution light detection and ranging (LIDAR), satellite platform sensors and GIS.     

Crucial factors influencing international logistics operations for African landlocked countries – A case study of Burkina Faso

ABSTRACT

This study aims to evaluate the crucial factors influencing international logistics operations for African landlocked countries. To this end, a case study and a questionnaire survey were conducted. A total of 147 usable responses from container shipping firms were obtained as a result of the questionnaire survey. The results of factor analysis revealed that transportation capability, external risks, information integration, logistics infrastructure, local agents’ logistics capability, and national law and policy were crucial factors influencing the logistics operations of African landlocked countries. Specifically, local agents’ logistics capability was perceived by respondents to be the most important factor. Moreover, the results of the study also indicated that the highest factor mean values of small shipping companies were related to transportation capability, external risks and the local agents’ logistics capability, whereas container shipping companies that arranged trucks for inland transportation paid more attention to the external risks, logistics infrastructure, the local agents’ logistics capability, and national law and policy.     

The role of geomatics engineering in establishing the marine information system for maritime management

Maritime management encompasses the employment and manipulation of human resources, financial resources, technological resources and natural resources that relate to the sea, maritime navigation, shipping, port development and coastal protection. It contributes to the economic growth, price stability, transportation of cargoes and passengers, and business activities of shipping organizations. The efficient management of resources, operations and activities relies on a modern marine information system (MIS) whose information is provided by geomatics engineers and IT professionals, among others. This paper first introduces the role of the geomatics engineer as geodesist, engineering surveyor, land boundary surveyor, cartographer, hydrographer, photogrammetrist and geographic information system (GIS) engineer since all these fields are related to maritime trade, supply chains and development of ports and airports. It then describes the principal components of a web-based MIS and the important role of geomatics engineers in surveying data. This includes collecting data from electronic nautical charts (ENC) and raster nautical charts (RNC), by applying high resolution light detection and ranging (LIDAR), satellite platform sensors and GIS.     

国外海底管道局部屈曲研究综述

海底管道是海洋油气集输系统中最重要的组成部分之一,从铺设到服役都将承受多种载荷的作用,并可能发生局部屈曲且沿管道传播开来,由此造成严重的后果。海底管道的局部屈曲在管道安全性方面具有重要意义,已成为海底管道设计与评估中重要的内容。详细阐述了国外关于海底管道受外压、弯矩和轴力作用下的局部屈曲研究成果,论述了在单个载荷和多个载荷联合作用下的局部屈曲破坏机理,并提出了未来研究的建议。