Providing personalized system optimum traveler information in a congested traffic network with mixed users

The advancement of information and communication technology allows the use of more sophisticated information provision strategies for real-time traffic management in a congested network. This article proposes a personalized system optimum traveler information (PSOI) system under ubiquitous communication, which allows traffic system operators to fully optimize and coordinate individuals' trip plans according to the personal attributes, such as real-time location, value of time, allowable budgets for congestion tolling, and willingness to take detours. We also developed an efficient queue-based evaluation and solution heuristic algorithm using mesoscopic simulation models to solve for near-optimal PSOI strategies—route suggestions for each individual traveler. The simulation optimization algorithm can account for different information users and provide predictive information that robustly accounts for potential decisions of other travelers in real time. Case studies were carried out on a test network and a real-world network, and the proposed heuristic algorithm is proven effective. Also, sensitivity analyses show that PSOI not only is an effective traffic management method in reducing average system travel time, but also potentially provides travelers with reasonable or even shorter travel times compared with other information users. Further, simulation results showed that even in mixed traffic, PSOI is able to shorten travel times for both users without information and users of other information types. Thus, PSOI is recommended by this article as an advantageous way for next-generation advanced information systems and dynamic traffic management.     

车轮前束手动测量方法解析

四轮定位作为底盘调整与维护的重要手段之一,相关维修人员能够真正认识到四轮定位的作用和目的,并能正确、规范的对车轮定位参数进行调整,其意义不言而喻。本文针对目前各品牌4S服务站定位操作费用较高的现象,提出了简单易行的手动测量方法,主要用于测量前束值和外倾值,目前先就前束值的测量方法展开了详细陈述。该方法最大的优点在于简单、方便、可行、高效,操作人员不需要很系统的专业知识,所以非常便于车辆改装爱好者以及动手能力较强的广大车主使用,同时,相关售后市场的人员在车辆检修时,可作为进一步正确认识四轮定位尤其是前束参数的重要参考信息;也可以作为部分需要定期校准的四轮定位仪校准方法之一;同时亦可用于汽车相关专业在四轮定位内容教学环节有效的参考和实践方法,具有较好的推广、实用价值。     

MSP3再考船级社--欧盟第三套海上安全一揽子措施获EC通过

虽然国际海事组织（IMO）及国际劳工组织（ILO）都已经制定了非常完善的旨在促进海上安全和环境保护的国际公约框架，但世界各国对公约的执行力度参差不齐，再加上许多公约很多时候只适用于国际航行船舶，这些都促使欧盟开始制定地区性海上安全法令和措施，这些法令和措施的目的是通过切实统一地执行国际公约来取缔低标准航运。     

多级增压控制管路节流气穴噪声的试验研究

在试验研究的基础上，论述了多级节流增压模拟水泵实际运行背压具有的低噪声特性，并在此基础上对管路系统的低噪声设计提出了几点建议。     

船用液控蝶阀节流调速系统的数字仿真(英文)

Hydraulic butterfly valves have been widely applied in marine engineering because of their large switching torque, low pressure loss and suitability for large and medium diameter pipelines. Due to control problems resulting from switching angular speeds of the hydraulic butterfly valve, a throttle-governing control mode has been widely adopted, and detailed analysis has been carried out worldwide on the structural principle concerning speed-regulation and the load torque on the shaft while opening or closing a hydraulic butterfly valve. However relevant reports have yet been published on the change law, the error and the influencing factors of the rotational angular velocity of the hydraulic butterfly valve while opening and closing. In this article, research was based on some common specifications of a hydraulic butterfly valve with a symmetrical valve flap existing in a marine environment. The throttle governing system supplied by the accumulator to achieve the switching of the hydraulic control valve was adopted, and the mathematical models of the system were established in the actual conditions while the numerical simulations took place. The simulation results and analysis show that the rotational angular velocity and the error of the hydraulic butterfly valve while switching is influenced greatly by the drainage amount of the accumulator, resulting in pressure loss in the pipeline, the temperature of hydraulic medium and the load of the hydraulic butterfly valve. The simulation results and analysis provide a theoretical basis for the choice of the total capacity of the accumulator and pipeline diameters in a throttle governing system with a hydraulic butterfly valve. It also determines the type and specification of the hydraulic butterfly valve and the design of motion parameters of the transported fluid.     

沥青路面早期破坏的防治措施

通过对沥青混凝土路面出现早期破坏的机理分析,从路面设计、施工工艺、材料选用诸方面提出了解决的对策。     

船用水泥罐结构分析与选型

为提高工作船的空间利用率和装卸物料的效率进而提高运营效率,通过对国内外各种水泥罐的结构形式和尺寸进行比较分析得出其中较为经济实用的水泥罐结构形式及适宜的长径比,供设计者选用时参考。     

船舶在能见度不良时的近距离避让

简述船舶在能见度不良时近距离避让的产生与后果，归纳了能见度不良时近距离避让行为的问卷调查情况和结论，提出了一些关于能见度不良时近距离避碰的措施与方法。     

FastICA算法对非高斯混合信号分离的性能分析

基于独立分量分析的盲源分离方法,采用快速独立分量分析(Fast Independent ComponentAnalysis,FastICA)的算法对混合的非高斯信号进行分离.通过对仿真信号的分离比较,使用峭度值和信噪比对分离函数tanh和gauss函数的性能进行了分析,研究分离函数的选择对于分离效果的影响。     

近水平软硬互层围岩公路隧道初期支护内力分析

将近水平软硬互层围岩等效为横观各向同性岩层,推导其密度、弹性模量、泊松比等材料参数。以广南高速公路文家垭隧道为分析对象,根据横观各向同性围岩参数建立平面应变有限元模型,结合现场测试数据分析近水平软弱围岩台阶法施工过程中初期支护的受力状态。研究表明:上台阶开挖后初期支护受轴向压力,拱顶和拱墙腰向内弯,而拱腰向外弯;下台阶开挖后,初期支护继续受轴向压力,拱顶和仰拱向内弯,拱腰和拱墙腰向外弯。研究结论与拱顶沉降和拱底隆起现象相符合。