An experimental study on the dynamic response of a hull girder subjected to near field underwater explosion

An experiment of hull girder model subjected to near field underwater explosion at midship is implemented. High-speed photography is applied to achieve the time history of hog displacement of the hull girder model subjected to shock wave of undex. The determination method of hog distortion using these show-motion pictures is presented. The experiment also achieves the local plate distortion of the hull girder model. Based on these works, the damage mechanism and mode of hull girder subjected to near field undex at midship are discovered. Finally, the coupling effect between whole motion of hull girder and distortion of local structure is discussed.     

海损散货船艏部舱室型线测量

海损船舶修理是修船企业重要的产值及利润增长点,而船舶首部是易海损区域,修复海损重要依据是型线图及型值表,由于很多海损船没有保存型线图或型值表,给修理工作带来不便.针对这种情况,文章结合散货船的艏部货舱特点,介绍艏部货舱型线测量的方法.     

耙吸挖泥船DR68完整稳性及破舱稳性研究

DR68规范对挖泥船完整稳性、破舱稳性的要求与CCS规范具有较大差别,因此对泥舱设置、船体设计也提出不同的要求。文章通过对入级BV及CCS的耙吸挖泥船项目进行对比,简述了该船型稳性计算在满足DR68时需要注意的一些问题。     

水面舰船破损稳性的概率评估方法

水面舰船生命力的主要影响因素之一是舰船遭遇不同武器破坏下的薄弱性,而薄弱性主要由破损稳性决定。目前,舰船破损稳性评估主要运用确定性方法,但该方法不能全面评估舰船破损稳性。为了更加客观、全面地评估舰船破损稳性,探讨水面舰船破损稳性评估的概率方法,提出变区间线性插值计算残存概率S_i的新方法并开发计算程序。以某水面舰船为例,计算各种破损情况的进水概率P_i以及残存概率S_i,并累加所有破损情况P_i和S_i的乘积,得到分舱指数A。研究表明：通过将分舱指数A作为评估指标并考虑不同武器和碰撞的综合破坏效应,概率方法可以实现水面舰船破损稳性定量且整体的评估,能为舰船初步设计阶段主船体的分舱优化以致提高舰船生命力提供一种解决途径。     

高职学生人格现状调查及对策分析

通过采用卡特尔16PF人格调查问卷对重庆市4所高等职业技术学院学生人格特征进行调查研究,分析了不同类型高职学生人格特征的差异性,并提出了矫正建议。     

海底管线调查方法和资料处理

从海底管线的铺设方法和灾害类型入手,阐述了目前海管调查的基本方法和实施思路,对工程物探和潜水检测资料的处理过程进行了描述。     

Risk Management in Motorway PPP Projects: Empirical-based Guidelines

Abstract

This paper deals with the topic of risk management in Public Private Partnership (PPP). The analysis of the related literature reveals that risks must be analyzed and managed on a context-specific approach, and that there is a lack of a comprehensive study on the appropriate risk mitigation strategies for each risk embedded in PPP projects. Focusing on the transport sector, based on the results of a Delphi survey, the paper provides guidelines for both public and private parties in defining a list of significant risks in PPP motorway projects, and identifying for them both the effective allocation and the suitable mitigation strategies. Results of the Delphi survey have been compared with the common practices on risk management applied in eight real motorway PPP projects.     

Integrated imputation of activity-travel diaries incorporating the measurement of uncertainty

Procedures to transform GPS tracks into activity-travel diaries have been increasingly addressed due to their potential benefit to replace traditional methods used in travel surveys. Existing approaches for data annotation however are not sufficiently accurate, which normally involves a prompted recall survey for data validation. Imputation algorithms for transportation mode detection seem to be largely dependent on speed-related features, which may blur the quality of classification results, especially with transportation modes having similar speeds. Therefore, in this paper we propose an enhanced integrated imputation approach by incorporating the critical indicators related to trip patterns, reflecting the effects of uncertain travel environments, including bus stops and speed percentiles. A two-step procedure which embeds a segmentation model and a transportation mode inference model is designed and examined based on purified prompted recall data collected in a large-scale travel survey. Results show the superior performance of the proposed approach, where the overall accuracy at trip level reaches 93.2% and 88.1% for training and surveyed data, respectively.     

基于车联网的用户汽车使用测量与应用

用户实际用车数据是汽车产品设计的重要基础,同时也是制定汽车系统、零部件设计标准,产品验证规范开发和评价指标的基础.汽车在联网环境中的大量信息,对于挖掘和分析汽车用户驾驶的特征,具有不可替换的意义和价值.通过对车辆加减速、油耗等行驶数据的挖掘,有助于分析用户的驾驶风格、行为和车辆工作情况,为整车厂设计和研发提供了客观用户...     

Auction-based tolling systems in a connected and automated vehicles environment: Public opinion and implications for toll revenue and capacity utilization

Autonomous and connected vehicles are expected to enable new tolling mechanisms, such as auction-based tolls, for allocating the limited roadway capacity. This research examines the public perception of futuristic auction-based tolling systems, with a focus on the public acceptance of such systems over current tolling practices on highways (e.g., dynamic and fixed tolling methodologies). Through a stated-preference survey, responses from 159 road-users residing in Virginia are elicited to understand route choice behavior under a descending price auction implemented on a hypothetical two-route network. Analysis of the survey data shows that there is no outright rejection of the presented auction-based tolling among those who are familiar with the current tolling methods. While males strongly support the new method, no clear pattern emerges among other demographic variables such as income and education level, and age. While high income respondents and regular commuters are more likely to pay higher tolls, no statistical significance between different genders, age groups, household sizes, and education levels is found. Based on the modeling results and the hypothetical road network, it is found that descending price tolling method yields higher average toll rates, and generates at least 70% more revenue when travel time saving is 30 min, and improves capacity utilization of the toll road significantly compared to fixed tolls.