没变，还是那个VDO——VDO天骄DN4300便携导航测试

DN4300有个显著的变化就是“SIEMENS”（西门子）的LOGO被拿掉了，只剩下VDO的独家招牌。是的，就在2007年VDO汽车电子集团被西门子以114亿欧元的高价卖给了德国大陆集团，而大陆集团对我们来说，最熟悉的就是旗下有个赫赫有名的马牌轮胎。     

On the fundamental diagram and supply curves for congested urban networks

Macroscopic fundamental diagrams (MFD) of traffic for some networks have been shown to have similar shape to those for single links. They have erroneously been used to help estimate the level of travel in congested networks. We argue that supply curves, which track vehicles in their passage through congested networks, are needed for this purpose, and that they differ from the performance curves generated from MFD. We use a microsimulation model, DRACULA and two networks, one synthesizing the network for Cambridge, England, and one of the city of York, England, to explore the nature of performance curves and supply curves under differing patterns of demand.We show that supply curves differ from performance curves once the onset of congestion is reached, and that the incorrect use of performance curves to estimate demand can thus seriously underestimate traffic levels, the costs of congestion, and the value of congestion relief measures. We also show that network aggregated supply curves are sensitive to the temporal distribution of demand and, potentially, to the spatial distribution of demand. The shape of the supply curve also differs between origin–destination movements within a given network.We argue that supply curves for higher levels of demand cannot be observed in normal traffic conditions, and specify ways in which they can be determined from microsimulation and, potentially, by extrapolating observed data. We discuss the implications of these findings for conventional modelling of network management policies, and for these policies themselves.     

功能诱惑：GARMIN 760便携导航仪测试

GARMIN在中国市场推出的机型并不多,而且价格又屹立在不胜寒的高处。不过,因其硬件品质的优越,加上菜单操作的简洁,我对GARMIN的产品有种偏爱。尤其是经典机型310让人赞不绝口,拿到加宽屏幕的760当然要狠狠地把玩一番!     

Quantifying erosion rates and stability of bottom sediments at mussel aquaculture sites in Prince Edward Island,Canada

Downward fluxes of organic biodeposits under suspended mussel culture cause benthic impacts such as microbial mat production. Quantifying sediment erosion in these coastal ecosystems is important for understanding how fluxes of organic matter and particulates contribute to benthic–pelagic coupling. Critical shear velocity (u?), erosion rates and particle size distributions of resuspended sediment were measured at two sites; an impacted muddy site with extensive mussel culture (site 1), and a coarser sandier site with less mussel influence (site 2), using a new method for assessing sediment erosion at Tracadie Bay, Prince Edward Island in August 2003. Shear forces were generated by vertically oscillating a perforated disc at controlled frequencies. These forces correspond to shear velocity, using a re-designed and calibrated Particle Erosion Simulator. Undisturbed sediment cores obtained by divers and grab (sub-cored using a Plexiglas? cores) were exposed to shear stress to compare differences between collection methods. Microbial mats were present at site 1 which initially biostabilized sediment against erosion due to ‘armoring’ of the sediment, but onset of erosion was abrupt once these mats failed. Erosion sequences at site 2 (without mat cover) were smoother resulting in less material being eroded. Mean mass of material eroded was 47 and 23 g m^? 2 min^? 1 at sites 1 and 2 respectively. Mat area cover and shear velocity was strongly related. Critical shear velocities varied between 1.70 and 1.77 cm s^? 1, with no obvious differences between location or collection method, so sediments from these two contrasting sites had identical mean critical shear velocities. Significant differences existed in the concentrations of chlorophyll a, colloidal and bulk carbohydrates, between mats and bare sediment from site 1. Particle sizes measured by videography of resuspended sediment at different shear velocities ranged from 100 μm (the minimum diameter capable of being detected by the system), to large mat fragments of 1700 μm for both sites. These results provide evidence of the relevance of using a portable erosion device to indicate how sediment erodability is affected by mussel–microbial relationships.     

Improving port effectiveness through determinance/performance gap analysis

Port managers, governments, and stakeholders bring different perspectives to the challenges of port management. One of the greatest of these challenges is identifying and prioritizing investments to take advantage of the opportunities for future growth and to meet the needs of customers and users seeking value in the supply chains served by the port. Importance–performance gap analysis, based on discrepancies between performance effectiveness and user expectations, has been illustrated to be one means of guiding these decisions while determinance scores offer another. However, user perceptions of satisfaction and effectiveness often lead to conflicting signals between these two methods when port managers seek to allocate resources for performance improvements. The authors develop a mapping process based on determinant/performance gap analysis to address conflicting signals between the methodologies for evaluating performance effectiveness and thereby assist port managers in making appropriate performance investment decisions that will address users’ requirements.     

专注产生力量——GARMIN任我游255W导航测试

相对于目前便携式导航仪多功能化的趋势，加泊车系统、电子书、MP4等等眼花缭乱功能，GARMIN却只专注于“导航功能”的本身，它“不变应万变”的固执让人觉得值得尊敬。     

用飞轮作动力的Mk 3客车

虽然对Mk 3客车前景的争论还在继续,使用飞轮供应所储能作为驱动手段的长期冠军PPM(Parry People Movers)建议创新使用Mk 3.图1所示PPM建议如何在Mk 3或Mk 2客车前、后使用一对动力车编组成一列车,可在英国的社区铁路使用或提供出口.Parry的PPM80和PPM170转向架车辆的开发方案可到公司的网站上查看.动力车为自推进式,采用飞轮与用液化石油气(LPG)作燃料的小型内燃机,或环保柴油机相结合的方式,甚至氢燃料电池也可作为一种选择方案.     

Road pricing: An international perspective

This paper reviews experience with road pricing in Europe and Asia. It considers the objectives of road pricing, and demonstrates that differences in objectives lead to differences in scheme design and performance. It reviews the criteria for design of road pricing systems, and the development of charging structures and technologies to meet those criteria. In particular it discusses the relative merits of pre-determined and congestion-dependent charging structures, and of off-vehicle and on-vehicle charging systems. It assesses the performance of road pricing systems to date, discusses objections to road pricing and demonstrates that the role of road pricing within a wider transport strategy and the use made of the revenue generated, will be important determinants of public acceptability. Finally it assesses the relative merits of alternative approaches to implementation and argues that these will need to pay as much regard to public acceptability as to technical performance.