对墨西哥湾溢油事故钻井平台申请责任限制的思考

墨西哥湾溢油事故造成重大损失,钻井平台责任限制问题日显突出.移动式钻井平台属于海商法意义的船舶,依据责任限制的立法宗旨,应赋予移动式钻井平台享有油污损害赔偿责任限制的权利,且以"事故制"的计算方法解决责任限额问题.     

The costs and benefits of reducing SO2 emissions from ships in the US West Coastal waters

Potential costs and benefits of policy options for reducing offshore ship pollution are examined using a meta-analysis of studies synthesized regionally for the US West Coast. Net benefits of reducing SO₂ emissions from cargo ships in the US West Coast waters are found to range between $98 million and $284 million, annually; the benefit–cost ratio varies between 1.8 and 3.36, depending on the size of the control area and the sulfur content limit. The results show that about 21,000 tons of on-land equivalent SO₂ emissions or about 33% of SO₂ emissions from all mobile sources in California in 2005 can be reduced annually if the US West Coast exclusive economic zone is designated as an International Maritime Organization-compliant SO_x emission control area (SECA) with fuel-sulfur content not exceeding 1.5%. The analysis demonstrates that designating this area reduces more emissions than establishing a smaller zone at a lower but favorable benefit-cost ratio. Control measures that require 0.5% low-sulfur fuels reduce more SO₂ emissions, and also may have higher net benefits. Technological alternatives may achieve benefits of emissions reductions on the US West Coast across higher ranges of potential fuel prices. Combinations of fuel switching and control technology strategies provide the most cost-effective benefits from SECAs on the US West Coast and other world regions.     

Decomposing travel times measured by probe-based traffic monitoring systems to individual road segments

In probe-based traffic monitoring systems, traffic conditions can be inferred based on the position data of a set of periodically polled probe vehicles. In such systems, the two consecutive polled positions do not necessarily correspond to the end points of individual links. Obtaining estimates of travel time at the individual link level requires the total traversal time (which is equal to the polling interval duration) be decomposed. This paper presents an algorithm for solving the problem of decomposing the traversal time to times taken to traverse individual road segments on the route. The proposed algorithm assumes minimal information about the network, namely network topography (i.e. links and nodes) and the free flow speed of each link. Unlike existing deterministic methods, the proposed solution algorithm defines a likelihood function that is maximized to solve for the most likely travel time for each road segment on the traversed route. The proposed scheme is evaluated using simulated data and compared to a benchmark deterministic method. The evaluation results suggest that the proposed method outperforms the bench mark method and on average improves the accuracy of the estimated link travel times by up to 90%.     

数字与模拟对讲系统的对比分析

无线电对讲系统具有其他通信系统不可替代的实际作用,因而具有重要的研究和应用价值。随着通信技术的进步,数字化对讲系统受到越来越广泛的关注。为此,针对ETSI数字对讲标准DMR和现有模拟对讲系统进行详细分析,阐述数字化对讲系统的优势和所面临的问题。     

基于移动协同的智能客户端研究

支持移动的智能客户端的研究是移动协同研究领域的又一新课题,本文描述了移动环境下的网络自适应、协作数据传输、移动终端的人机界面、异步协作整合等关键技术,探讨了.NET智能客户端技术的特点及其优越性.在此基础上,提出了基于移动CSCW的智能客户端的系统应用架构,并分析了这种架构的特点以及实现.     

长途跨线高速列车直达与中转选择问题

我国快速客运网基本形成,长途跨线列车直达与中转选择对于高速列车开行方案设计至关重要。为提升长途跨线高速列车开行效益和服务品质,按长途跨线列车直达与中转方式对比的思路,以旅客出行需求、基础设施能力、移动设备能力等多方面因素对长途跨线列车开行方式的影响为约束条件,研究长途跨线列车直达与中转选择模型及求解方法。选取2025年15个长途跨线起讫点为对象进行案例研究,提出D站—E站、F站—D站等9个起迄点之间开行长途跨线直达列车的建议方案,研究表明直达与中转换乘选择模型能够解决长途跨线列车开行方案编制问题。     

Effects of income inequality on evacuation,reentry and segregation after disasters

Large-scale disasters often trigger mass evacuation due to significant damages to urban systems. Understanding the evacuation and reentry (return) process of affected individuals is crucial for disaster management. Moreover, measuring the heterogeneity in the individuals' post-disaster behavior with respect to their socio-economic characteristics is essential for policy making. Recent studies have used large-scale location datasets collected from mobile devices to analyze post-disaster mobility patterns. Despite the availability of such data and the societal importance of the problem, no studies have focused on how income inequality affects the equity in post-disaster mobility. To overcome these research gaps, we overlay mobility data with income information from census to quantify the effects of income inequality on evacuation and reentry behavior after disasters, and the resulting spatial income segregation. Spatio-temporal analysis using location data of more than 1.7 million mobile phone users from Florida affected by Hurricane Irma reveal significant effects of income inequality on evacuation behavior. Evacuees with higher income were more likely to evacuate from affected areas and reach safer locations with less damage on housing and infrastructure. These differences were common among evacuees from both inside and outside mandatory evacuation zones. As a result of such effects of inequality, significant spatial income segregation was observed in the affected areas. Insights on the effects of income inequality on post-disaster mobility and spatial segregation could contribute to policies that better address social equity in pre-disaster preparation and post-disaster relief.     

船载AIS设备信号异常原因分析及对策

近期,水上无线电管理秩序专项整治行动正在全国范围内开展,如何鉴别船舶自动识别系统(AIS)设备相关问题成了摆在海事现场执法人员面前的一道难题。文中通过典型案例介绍AIS工作原理和法规要求,逐一分析船载AIS设备信号异常的原因,为基层海事执法人员快速甄别AIS信号异常并打击船员恶意关闭AIS设备或修改其静态信息等违法行为提供建议。     

移动互联网技术在高速公路的应用展望

随着移动互联网技术的发展和用户数量的快速增长,其应用领域也在不断深化拓展,催生了很多新的应用模式.对于高速公路这一传统领域,移动互联网技术一方面可以作为高速企业和行业主管单位业务推广的手段,另一方面也重构了其业务模式,在移动信息发布、交通流量分析、移动数据传输以及车路联网等方面形成了全新的应用方式,深刻地影响和改变了高速公路的管理模式.     

大学生课堂使用手机情况调查与对策研究

文章从大学生课堂上使用手机的现状出发,调查研究大学生课堂使用手机的行为,并进行原因剖析,提出了针对性的对策与建议。