Panama Canal And Maritime Industry：An International Perspective

2007年6月13日，巴拿马运河管理局在上海浦东香格里拉大酒店举办“巴拿马海运日”，巴拿马运河管理局国际顾问委员会主席、国际海事组织（IMO）前秘书长威廉·A·奥尼尔先生在开幕仪式上发表了演讲。奥尼尔先生的讲话着重强调海运在当代经济和社会发展中不可替代的巨大作用，集装箱化又是影响最大的因素之一，而且在可持续发展大趋势下，     

防撞轴承承受冲击

货车滚动轴承的开发和研究在很大程度上是由现场出现的各种轴承缺陷所驱使的.随着货车变得越来越重-车辆标准总重为286 000磅(110t),而315KGRL(即125t)的车辆刚面世-轴承供应商们正致力于解决这些大轴重所引起的轴承寿命短的问题,例如轴承疲劳、润滑和磨损(随之引起轴承在轴颈上失去夹持力).     

A traffic flow simulator for network reliability assessment

This paper investigates the transportation network reliability based on the information provided by detectors installed on some links. A traffic flow simulator (TFS) model is formulated for assessing the network reliability (in terms of travel time reliability), in which the variation of perceived travel time error and the fluctuations of origin-destination (OD) demand are explicitly considered. On the basis of prior OD demand and partial updated detector data, the TFS can estimate the link flows for the whole network together with link/path travel times, and their variance and covariance. The travel time reliability by OD pair can also be assessed and the OD matrix can be updated simultaneously. A Monte Carlo based algorithm is developed to solve the TFS model. The application of the proposed TFS model is illustrated by a numerical example.     

Abyssal seafloor waste isolation: the concept

The Naval Research Laboratory (NRL), with industry and university participation, conducted an assessment of the concept of isolating certain wastes (i.e., sewage sludge, fly ash from municipal incinerators, and contaminated dredged material) on the oceans' abyssal seafloor. In this assessment the advantages, disadvantages, and economic and environmental viability of potential engineering methods for achieving abyssal waste isolation were identified and compared. This paper presents background to the Abyssal Plains Waste Isolation (APWI) Project, describes the characteristics of the waste streams and quantities potentially available for disposal via the abyssal isolation concept, summarizes regulations affecting use of the abyssal seafloor for disposal of wastes, and introduces the technical and scientific premises underlying implementation of the concept.     

Short‐term travel time forecasts for transport information system in hong kong

In this paper, a case study is carried out in Hong Kong for demonstration of the Transport Information System (TIS) prototype. A traffic flow simulator (TFS) is presented to forecast the short‐term travel times that can be served as a predicted travel time database for the TIS in Hong Kong. In the TFS, a stochastic deviation coefficient is incorporated to simulate the minute‐by‐minute fluctuation of traffic flows within the peak hour period. The purposes of the case study are: 1) to show the applicability of the TFS for larger‐scale road network; and 2) to illustrate the short‐term forecasting of path travel times in practice. The results of the case study show that the TFS can be applied to real network effectively. The predicted travel times are compared with the observed travel times on the selected paths for an OD pair. The results show that the observed path travel times fall in the 90% confidence interval of the predicted path travel times.     

Lights, camera and acoustics: Assessing macrobenthic communities at a dredged material disposal site off the North East coast of the UK

This study presents the results of a trial assessment based on a combination of sampling techniques at a dredged material disposal site located off the North East coast of the UK, over 2001 to 2004. The site was surveyed with a high-resolution sidescan sonar system producing a mosaic with 100% coverage of the survey area. Benthic communities and sediments were ground-truthed using a Hamon grab with a video camera. Additionally, the area was also sampled in 2003 with a Sediment Profile Imaging (SPI) camera, which complemented other techniques by providing in situ information on sediment quality, and biogenic activities. An assessment is made of the benefits of combining the results from conventional methods, principally using grab samples, with those from acoustic techniques and optical imaging devices to determine seafloor and macrobenthic conditions. This information has the potential to contribute to the enhancement of routine monitoring programmes within UK waters.     

An Internal State Variable Model for the Low Temperature Tempering of Low Alloy Steels

QuanitativelyaccuratePredictionsofquenchinduceddistOnionandresidualstressrelyontheabilitytopredictthemicrosthectUralevolUtionthroughOutthequenchProcess.InlowaIloysteels,cUrrenresearchMshavefOcusedontheformationldneticsoffetrite,pearlite,bainiteandmartensite.However,temPeringcanhavealargeinfluenceondistOnionandresidualstrCss,andeffortstoaccountforthislagbehindthemodelingofthePrimnyphasetransihons.AsafirststeptowardsaccountingfortemPerillg,wehavedevelOpedanintemalstatevariablemodelthatuses…     

Estimation of AADT from short period counts in hong kong — A comparison between neural network method and regression analysis

The average annual daily traffic (AADT) volumes can be estimated by using a short period count of less than twenty‐four hour duration. In this paper, the neural network method is adopted for the estimation of AADT from short period counts and for the determination of the most appropriate length of counts. A case study is carried out by analysing data at thirteen locations on trunk roads and primary roads in urban area of Hong Kong. The estimation accuracy is also compared with the one obtained by regression analysis approach. The results show that the neural network approach consistently performed better than the regression analysis approach.     

Simulating pedestrian movements at signalized crosswalks in Hong Kong

This paper presents a new pedestrian simulation (PS) model for signalized crosswalks in Hong Kong. This PS model is capable of estimating the variations of walking speed particularly on the effects of bi-directional pedestrian flows so as to determine the minimum required duration of pedestrian crossing time. Video records taken from the observational surveys at the selected crosswalk in urban area were used to extract the required data for model calibration. It was found that the design walking speed for signalized crosswalks should be varied by the effects of the bi-directional pedestrian flows. It was also interesting to note that the negative impact of the bi-directional flow effects (ranging from uni-directional to bi-directional pedestrian flows) on the chance of pedestrian crossing the crosswalk is increasing from free-flow to at-capacity flow conditions. The new PS model is also validated using an independent data set so as to examine the reliability of the simulation results. The validation results show that the new PS model can provide an accurate evaluation on the changes of walking speed and its standard deviation under different scenarios with particular emphasis on the effects of the bi-directional pedestrian flows. The advancement of this PS model can be applied to assess the effects of each improvement measure and to evaluate the benefits of each scenario in practice.