舰载C4ISR软件质量指标体系和度量方法的研究

分析了传统度量模型的使用范围,根据舰载C4ISR软件的功能要求和工作环境的特点,提出了舰载C4ISR软件质量的层次指标体系.在该指标体系的基础上,分析了各个层次之间的关系,给出了每个层次指标权重的确定方法和判定矩阵的计算方法,采用基于二次模糊判定的软件质量度量方法来度量舰载C4ISR软件质量,从而为复杂系统软件质量的度量探讨了一种可行的度量方法.     

A new rule-based integrated decision making approach to container transshipment terminal selection

The choice of the port or terminal to perform transshipment operations is a critical decision for container transportation companies (i.e. shipping line companies). This choice is not only affected by transshipment costs but also by the location, infrastructure, equipment, and technologies of the alternative terminals. In this study, a rule-based integrated multi-criteria group decision making approach is proposed in order to support such complex decision processes which involve substantial uncertainties and subjectivities. The proposed approach involves simple mathematics and provides a flexible modeling approach close to human reasoning that is able to consider uncertain information and relationships of arbitrary complexity. To prioritize the sub-criteria affecting the choice of the most appropriate terminal and to assess alternatives with respect to these sub-criteria, the Analytic Hierarchy Process (AHP) based on absolute measurement is used. Then, to determine the most appropriate terminal, a Fuzzy Rule-Based System is developed, which adopts the scores of criteria (i.e. the total scores of sub-criteria) obtained by AHP as input. In order to demonstrate the applicability and effectiveness of the proposed approach, an application is presented for the choice of the most appropriate container transshipment port in Turkey for a shipping line company.     

一种面向水下无人航行器的实效图像增强算法

针对水下图像存在严重模糊、对比度低、噪声多等问题,根据小波的时频特性及多分辨率特点,提出一种基于小波变换的水下模糊图像增强算法。利用小波变换对RGB图像进行二层小波分解,把原图分解为高、低频子带,利用导向滤波算法估计低频子带上的照射分量并进行去除;利用软阈值算法对高频子带上的图像边轮廓信息进行去噪和增强处理;对水下图像进行小波逆构,并进行伽玛校正;最后利用改进的灰度世界算法对水下图像进行颜色校正。试验结果表明,使用文章中算法处理所得到图像的对比度及信噪比都较高,且清晰度较高,满足水下无人航行器的要求。     

基于被动式PD控制策略的“双水舱”减摇系统研究

被动可控式U型减摇水舱利用气阀开关控制水舱内液体运动,使之与船舶横摇运动保持π/2相位差。文章针对在随机海浪下水舱被动控制中存在的问题,提出了由两个被动可控式减摇水舱组成的被动可控式双水舱减摇系统,文中对双水舱系统的数学模型及系统设计方法进行了研究,并提出利用不同的船舶横摇信号分别控制两个水舱内液体流动的被控式PD控制策略。以高速滚装船为例,对双水舱系统进行了计算机仿真,仿真结果表明被动可控式双水舱系统在更宽的海浪干扰频率范围内具有更好的减摇效果。     

低水头航运枢纽工程施工导流方案风险决策方法

根据低水头航运枢纽工程施工导流的特点,分析了影响低水头航运枢纽工程施工导流方案优选的6个主要指标,建立了导流方案风险决策模型。模型中以区间数的形式来表示决策信息,运用了区间数相离度概念来计算各指标的权重大小,并采用多属性决策模型的投影排序方法进行优选。株洲航电枢纽实例验证了该方法的可行性,分析结果可以为导流方案选择提供决策支持。     

基于VLCC的液货智能管理系统设计技术

基于超大型油船(VLCC),针对液货相关系统展开分析,完成以液货智能管理系统框架设计、液货和货舱监测报警系统集成设计、液货保护系统监测报警系统集成设计、辅助决策设计为四大关键技术的液货智能管理系统的设计研究。在智能船舶1.0的研究背景下,依托招商局能源公司VLCC实船安装的液货智能管理系统,通过对关键数据进行采集和监测分析,实现液货系统的预报警和报警功能,同时为船员提供对应辅助决策。该系统突破了常规油船液货控制及监测系统独立显示和报警的模式,实现了对液货系统状态的集成监测报警、智能管理及辅助决策功能,很大程度地提高了液货系统操作的安全性和便利性。     

基于变权TOPSIS法的舰艇对空防御威胁评估模型

威胁评估是舰艇对空防御指挥控制的关键环节之一。针对传统威胁评估方法在确定指标权重时采用常权重加权求和所带来的评估不合理的问题,将变权理论引入到舰艇对空防御的威胁评估中,构造状态变权向量表达式,使得权重随态势变化而做出相应调整。综合考虑目标属性与本舰防空武器性能,给出威胁评估指标体系,并结合“逼近于理想排序法”(TOPSIS)构建舰艇对空防御威胁评估模型。实例分析表明,该模型得到的评估结果较为科学合理,为舰艇对空防御威胁评估提供了理论与方法的参考。

     

Evaluating Boating Safety Risk in Intracoastal Waterways

Growth in the number of recreational vessels that use inland and coastal waterways, coupled with the diversity of boating activities, results in increased boating-related conflicts, accidents, and fatalities. This situation has led to numerous requests from boaters, shorefront property owners, waterfront businesses, and local governments for the imposition and enforcement of boating safety speed zones within Florida's Intracoastal Waterways. A decision-support framework that incorporates Geographic Information Systems (GIS)–based risk assessment was developed to assist the Florida Fish and Wildlife Conservation Commission's Division of Law Enforcement evaluate requests and applications for the establishment of boating safety zones, pursuant to the Florida Administrative Code Rule 68-D-23.105 “Criteria for Approval of Regulatory Markers.” The risk assessment uses geospatial data compiled from multiple government agencies, survey data from subject matter experts, and public input from participatory workshops. Relevant spatial data includes waterway features and marine infrastructure from field surveys, vessel traffic patterns observed and mapped from aerial reconnaissance, and indicators of boater behaviors extracted from accident and citation reports. The outcome is a characterization of waterway segments according to perceived risk to boating safety. The application was tested in two Florida counties and it helped guide the establishment of new, and the revision of existing, boating regulatory zones within their Intracoastal Waterways. The application design is such that it is adaptable to waterways beyond those in Florida.     

HTS磁体的失超判别

高温超导磁体的失超过程比较缓慢,失超判别很困难。本文提出定性的失超判别方法：在电流恒定的前提下,若磁体电压持续上升,则认为磁体失超。对试验数据进行线性拟合,提出失超判别的数学表示形式：磁体电压的变化率dV／dt〉0。     

Terminal investment timing decisions in a competitive setting with uncertainty using a real option approach

This paper uses a real option approach to analyze terminal investment timing decisions for situations in which a port faces competition from its rivals in an uncertain market. We propose a network model to describe carriers’ cargo routing decisions and competition among rival ports. We then transform this model into a multicommodity flow problem and use the column generation algorithm to solve it. After obtaining a port’s possible future annual revenues and the potential net present value (NPV) for its terminal construction project through the network model, we adopt the expanded NPV rule and transform the investment timing decision into an optimal stopping problem. A least squares Monte Carlo simulation algorithm is proposed to find the investing probabilities for future years. The proposed models are applied to a steel cargo terminal investment case in the Port of Bengbu in Anhui province of China. The impacts on the investing probability and the expanded NPV of changes in the demand volatility, the initial investment and the port discharging rate are analyzed to provide managerial insights for port managers.