基于TMS320DM642的车载视频记录仪设计

针对传统视频记录仪图像质量低、稳定性和抗干扰能力差的缺点,设计了基于TMS320DM642的车载视频记录仪。将改进的H.264视频压缩算法嵌入到DM642中,提高了视频压缩的质量。利用ARM将压缩后的视频方便地存入SD卡,通过对异常驾驶信息的识别,实现在危险状态下视频信息的自动记录。运用改良的电源设计,提高了在车载环境下的稳定性。能够为车辆异常偏离车道检测、驾驶员异常驾驶行为监控和交通事故的责任认定证等提供可靠的事实依据。实验结果表明该系统在车载环境中工作稳定,存储的视频图像清晰。     

Population ageing,gender and the transportation system

Across the globe population structures are ageing and how older men and women interact with the transport system is increasingly important in maintaining a good quality of life and inclusion in society. The paper reviews three issues: the nature of older people’s interaction with the transport system by gender; older people’s attitude to travel; and the involvement of older people as road traffic casualties. Patterns of travel in the UK show that older people are heavily dependent on car use, but in the form of more frequent but shorter journeys than younger people. This is especially so for women over 70 years old who, as passengers, are very reliant on males to drive them. Attitudes suggest that there are few obstacles to public transport use, and most agree that bus travel is good, but convenience means many prefer cars. Involvement of older men and women in serious road traffic accidents show that they have lower killed and seriously injured (KSI) rates than 17–24 year old drivers. However, those aged over 70 years exhibit a trend of increasing KSI rates. Analysis of casualty rates of drivers by type of junction, manoeuvre and environmental conditions found that some gender-age groups are overrepresented in certain accident types, including higher serious accidents rates for men, and over representation of older women when driving in poor conditions and turning right and negotiating roundabouts, crossroads and T, Y and staggered junctions. Improvement in engineering design and driver training are suggested together with the need for a greater understanding of the transportation system needs of old and very old people.     

智能水下机器人的建模和控制策略研究(英文)

To provide a suitable model for AUV simulation and control purposes, a general nonlinear dynamic model including a novel thruster hydrodynamics model was derived. Based on the modeling method, the “AUV-XX” simulation platform was established to carry out fundamental tests on its motion characteristics, stability, and controllability. A motion control strategy consisting of both position and speed control in a horizontal plane was designed for different task assignments of underwater vehicles. Combined control of heave and pitch was adopted to compensate for the reduction of vertical tunnel thrusters when the vehicle is moving at a high speed. An improved S-surface controller based on the capacitor plate model was developed with flexible gain selections made possible by different forms of restricting the error and changing the rate of the error. Simulation results show that the derived general mathematical model together with simulation platform can provide a test bed for fundamental tests of motion control. Additionally, the capacitor plate model S-surface control shows a good performance in guiding the vehicle to achieve the desired position and speed with sufficient accuracy.     

水域交通危险度的模糊综合评判法

长期的事故统计数据，是交通环境、水域特征、航道特点、水文气象等各种因素的综合反映，而这些因素正是评判水域交通危险度的主要指标。而且，利用事故统计数据得到的评价结果也包含了操船者在这一水域的行为因素。为此，本文提出基于事故统计数据的水域交通危险度的多层次模糊综合评判法，并给出评判模型及评判实例。     

A review of recent theoretical and empirical analyses of asymmetric information in road safety and automobile insurance

Road safety policies and automobile insurance contracts often use incentive mechanisms based on traffic violations and accidents to promote safe driving. Can these mechanisms improve road safety efficiently? Do they reduce asymmetric information between drivers and insurers and regulators? In other words, is there residual asymmetric information in observed distributions of accidents and infractions? We answer these questions in this article by reviewing recent theoretical and empirical results that rest on various data and methodologies. We present recent tests related to the identification of residual asymmetric information in road safety management and in automobile insurance contracting. We also propose a theoretical analysis of the foundations of point-record driver's licenses observed around the world.     

集装箱岸边起重机吊具防过倾安全保护系统的研制

随着新的集装箱码头不断建成,大量新培养桥吊司机上岗作业。由于技术不熟练导致操作失误、安全事故频发。针对该问题,从事故的预防出发,研制了监测吊具倾斜和桥吊起升安全保护系统,保障码头关键设备处于良好安全的运行状态。     

Culture in maritime safety

Many accidents, resulting in a larger number of fatalities during the last few years, have focused attention on issues of maritime safety. Accident registration reveals that a large proportion have human related causes, and indicates that, by looking at cultural aspects, one's understanding of the underlying mechanisms leading to accidents might increase. Several constructs of culture and climate have appeared on national, organizational and safety levels. Those constructs are discussed together with problems that occur when interpreting accidental data, and recording accidental causes. The papers reviewed indicate the existence of a ‘chain of evidence’ from accidents/safety to attitudes, communications, conflict-solving, etc. and further to safety culture. To be able to reduce the risk for accidents, there seems to be a need for coordination and the cultural perspective seems to be one that integrates and takes the many disciplines and multi-level nature of accidents and safety into account.     

航行气垫船激励均匀水深浮冰层位移响应的数值模拟

在均匀水深条件下,基于 ALE算法对匀速航行气垫船激励浮冰层的位移响应问题进行数值模拟。计算不同气垫船速度和河道岸壁宽度条件下的冰层位移响应,获得对应于冰层最大垂向位移变形情况下的气垫船临界速度。计算结果与理论解和试验结果符合良好,验证计算方法的有效性。计算结果表明：在临界速度时冰层下陷位移达到最大,而河道岸壁的存在将会使临界速度减小。     

The influence of oceanographic scenarios on the population dynamics of demersal resources in the western Mediterranean: Hypothesis for hake and red shrimp off Balearic Islands

The aim of the present paper is to study the relationships between some climatic indices and parental stock, recruitment and accessibility to trawl fishery of hake (Merluccius merluccius) and red shrimp (Aristeus antennatus) off Balearic Islands (western Mediterranean). Available annual catch per unit effort, recruitment and spawning stock biomass have been used as biological data. As environmental data, the meso-scale IDEA index and the large-scale North Atlantic Oscillation (NAO) and Mediterranean Oscillation (MO) indices have been used. To analyze possible links between these indices with the population dynamics of demersal resources, two non-linear approaches have been applied: (i) stock–recruitment relationships from Ricker and Beverton–Holt models, by sequentially incorporating environment factors; (ii) generalized additive modelling, both classical general and threshold non-additive models were considered. The latter simulate an abrupt change in explicative variables across different phases (time periods or climatic index values). The results have shown that two oceanographic scenarios around the Balearic Islands, associated with macro and meso-scale climate regimes, can influence the population dynamics of hake and red shrimp. This is especially true for recruitment, which seems to be enhanced during low NAO and IDEA indices periods. During these periods, colder-than-normal winters generate high amounts of cold Western Mediterranean Intermediate Waters (WIW) in the Gulf of Lions, which flow southwards and reach the Balearic Islands channels in spring, increasing the productivity in the area. This oceanographic scenario could also be favourable to the distribution of hake on the fishing grounds where the trawl fleet targets this species, increasing its accessibility to the fishery. Both spawning stock and abundance of red shrimp seems to be also enhanced by high MO index periods, which could reflect the increased presence of the saline and warm Levantine Intermediate Waters (LIW) in the study area, extending over the fishing grounds of this species. The proposed interactions can be useful to assess and manage these important demersal resources.     

油耗监控系统的介绍和应用

为加强对港口机械燃油管理,降低燃油损耗,介绍了一种车辆油耗监测系统。该系统可以实时记录油量的剩余值,并通过PC软件可以看出油量变化情况,以确定每辆车燃油的使用情况是否正常。能有效控制司机及其车辆的油耗变化及其管理,可在港口行业内推广。     

疏水表面流体流动特性的格子Boltzmann方法模拟

采用格子Boltzmann方法研究了微形貌对固体表面润湿性的影响,在此基础上进一步模拟了具有微形貌的疏水表面通道内的流体流动,从法向速度、剪应力、滑移速度等角度分析了疏水表面的流场特性,揭示了疏水表面滑移流动的产生机制。结果表明,疏水表面的滑移流动是由低表面能作用和微形貌共同引起的。具有微形貌的疏水表面比光滑疏水表面具有更好的减阻效果,原因在于微形貌能够驻留气体,形成的气液自由剪切面加剧了疏水表面的滑移流动,最大滑移速度可以达到主流平均速度的50%左右。     

Culture in maritime safety

Many accidents, resulting in a larger number of fatalities during the last few years, have focused attention on issues of maritime safety. Accident registration reveals that a large proportion have human related causes, and indicates that, by looking at cultural aspects, one's understanding of the underlying mechanisms leading to accidents might increase. Several constructs of culture and climate have appeared on national, organizational and safety levels. Those constructs are discussed together with problems that occur when interpreting accidental data, and recording accidental causes. The papers reviewed indicate the existence of a 'chain of evidence' from accidents/safety to attitudes, communications, conflict-solving, etc. and further to safety culture. To be able to reduce the risk for accidents, there seems to be a need for coordination and the cultural perspective seems to be one that integrates and takes the many disciplines and multi-level nature of accidents and safety into account.     

A cross-section analysis of stock returns: The case of shipping firms

This paper undertakes an analysis of the determinants of the cross-section of expected stock returns of 19 shipping companies listed in the US, Norway, Stockholm and London. Various factors, including company stock market beta, divided yield, and financial leverage have been identified in the finance literature as determinants of share price performance. We capitalize on these findings and add one more industry specific factor, the average age of the company's fleet, to quantitatively analyse the determinants of the performance of shipping shock returns. We use the Fama-MacBeth methodology to empirically test whether the five factors above have a significant effect on shipping stocks' performance. Our results indicate that the industry specific factor (the average age of the fleet) plus financial leverage, are significant in explaining shipping stocks' returns, wheras the stock market beta and the dividend yield are far less significant.     

通气超空泡形态及视景仿真研究

超高速航行器在水下运动时,其大部分表面被超空泡包裹,构成了一种新的流体动力布局,运动模式和运动特性完全不同于常规水下航行器。为了分析超高速水下航行器运动的稳定性,本文对超空泡生成机理进行研究,给出描述超空泡形态的数学模型,得到不同影响因素作用下超空泡形态的变化规律。为验证超空泡实时生成效果和超高速水下航行器运动过程各种动作功能,采用Vega Prime构建三维虚拟环境,在此基础上设计超空泡视景演示系统,通过ADI仿真系统实时解算超空泡和水下航行器运动数据来驱动超空泡视景系统,逼真地演示超空泡动态生成过程以及水下航行器高速运行轨迹和“空泡+航行器”的相对运动关系等关键技术。     

新型爪式水泵应用于水下航行器喷水推进上的性能分析

为研究新型爪式水泵应用在水下航行器喷水推进上的性能,对该新型爪式水泵的流场特性、不同转动角度下内泄对扬程的影响等性能进行分析。建立水泵喷水推进数学模型,并进行推力模拟试验及其影响因素分析。结果表明:新型爪式水泵在角度0°时的泄漏量最低,在角度40°时的泄漏量最高,在不同尺寸间隙下,随着角度改变,泄漏量变化趋势一致,而随着间隙的增大,内泄量增多。推力随喷嘴尺寸变化的试验结果与理论模型预测值的变化趋势一致,推力与喷嘴直径呈负相关关系。随着航行器航行速度的增加,喷水速度增大,且增大的幅度会比航行器航行速度的增加量大。     

基于一个二维修正水弹性方法的集装箱船体梁动态前极限强度评估研究

海上极端波因其巨大的波高常常导致船体的极限破坏。该文提出了一个二维的修正水弹性方法来研究一个集装箱船船体梁在极端波中的动态前极限强度。传统的极限强度评估基于准静态方法,没有动态效应被考虑。而船体在波浪下的动态结构响应是基于水弹性方法,传统的水弹性方法并不能计算船体梁的动态非线性强度。该二维修正的水弹性方法考虑时域波浪和非线性船体梁之间的耦合,将水弹性方法和Smith方法结合,用Smith方法计算船体梁的刚度,而其刚度与船体梁的强度和变形曲率有关。所以该时域的非线性刚度被用于修改水弹性方法里的常数项的结构梁刚度。几组极端波模型被用以产生船体梁的大变形和非线性动态垂向弯矩。文中分别采用修正水弹性方法和普通水弹性方法,通过改变四个重要的极端波参数如极端波最大波高、规则波的波高、波速和波长等来研究其对船体梁船中处的大变形转角和非线性垂向弯矩的影响,通过采用修正的水弹性方法计算得来的结果与水弹性方法计算得来的结果相比较,得到了一些差异和结论。     

长江南京以下深水航道生态建设与保护技术及措施

为探索长江生态航道的建设,依托长江南京以下12.5 m深水航道建设工程,针对工程河段生态环境特点及保护需求,研发多种生态型整治建筑物结构。在工程受影响区域,探索人工鱼巢、生态浮床等生态修复尝试。计算与分析潮汐河段施工引起的水体悬浮物浓度对取水口及水源地影响,提出防护方案。在研究噪声对江豚影响的基础上,提出声学驱赶与声学诱导技术。提出全过程的生态环境保护措施与管理办法。成果均已应用于长江南京以下深水航道工程,结果表明生态效果良好,无生态环境事故发生。     

The analysis of life safety and economic loss in marine accidents occurring in the Turkish Straits

The increase in the world's trading capacity, which has been spurred by globalization, has caused problems in marine transportation, namely congestion. Despite the safety measures currently in place, marine accidents are still not being prevented. This study focuses on marine accidents in the Turkish Straits that have done serious harm to humans, the natural environment, and the economy. To reduce the negative impacts mentioned above, this study considered the most common types of accidents, their causes, and their results. For this purpose, 850 serious marine accidents, which took place in the Turkish Straits between the years of 2001 and 2010 (as recorded by the Undersecretaries for Maritime Affairs), have been analyzed and the data obtained have been systematically tabulated using analytic hierarchy process (AHP) methodology. According to the data, the most significant cause of marine accidents in the Turkish Straits is human error. This study proposes measures to ensure that ship personnel are competent, mentally and physically, to navigate narrow and dangerous waterways in order to minimize the amount of accidents caused by human error.     

Analyzing the structure of informal transit: The evening commute problem

Through the use of a profit-maximizing continuum approximation model, this paper systematically analyzes the development and structure of informal transit systems as a function of the network, user, and modal characteristics. This study examines the evening commute problem along a linear corridor where passengers originate uniformly from a central business district and have destinations uniformly distributed along the corridor. Informal transit drivers who are profit-maximizing will be compared against the traditional case of coordinated, government service that aims to maximize the total welfare. Policies, such as fare regulation and vehicle licensing schemes, will be presented to help rationalize informal transit service using a government-operated service as the baseline.     

902冲翼试验艇设计

冲翼艇是一种利用机翼的地面效应离开水面又十分贴近水面飞行的高速运载工具。它具有速度高、长时间超低空飞行、适航性和经济性好等优点,有广阔的发展前途。902冲翼试验艇是中国船舶科学研究中心设计的单座冲翼性能试验艇。试航证明它具有良好的稳定性、操纵性和适航性。本文主要介绍该艇的总体布局、气动设计、水动设计、结构设计以及试飞结果。