Widening the Panama Canal and U.S. ports: historical and economic impact analyses

ABSTRACT

The economic history of the U.S. illustrates how the role of many cities has been changed by being seaports or located on navigable rivers or lakes. Based on the widening of the Panama Canal in 2016, the West Coast ports that include the west coast seaports of California, Oregon, and Washington were expected to become less important, while the freight shares of the East Coast and Gulf ports would increase. By how much it has been not easy to measure or predict so far, but this study attempted to define some of the key parameters in the measurement. As well as several relevant background topics, both the demand- and supply-side versions of the National Interstate Economic Model, have been applied for the measurement of economic impacts. U.S. port authorities and policy makers at the local and national levels who respond and develop plans for coping with the new realities of the Panama Canal are able to understand the extent to which changes in shippers’ and land-mode transporters’ behaviors would undermine the logistics and the costs of their activities. Therefore, this study is important for a diverse spectrum of port development strategies in the U.S. to respond to the Canal expansion.     

基于光流法的舰船运动要素测定原理研究

对基于光流法的舰船运动要素测定原理进行了研究，主要包括光流法测定舰船运动要素的思想、光流场解算、三维运动参数解算和舰船运动要素解算。该方法的提出，提高了运动要素测定的自主性，而且满足新型全封闭舰船的测定要求。     

从广州“海军一条巷”看文化遗产保护之迫切

广州＂海军一条巷＂在清末及民国时期走出了一批声名显赫的海军将士,因而被誉为＂中国海军之家＂.如今的＂海军一条巷＂在城市化进程中岌岌可危,其所在的古村落珠村也面临着巨大的挑战,承载着我们文化基因和密码的古村落的文化遗产保护刻不容缓.     

An analysis of trends in passenger and freight transport energy consumption in India

This primary objective of this paper is to examine the causes for the change in energy consumption in the transport sector in India. The pattern of energy consumption and their causes for change are benchmarked against select countries. A mathematical model that decomposes changes in energy consumption to various factors has been used. The changes in the energy consumption are attributed to growth in transport volume, structural change or modal shift, and energy intensity. The analysis is conducted for passenger and freight transport separately. Results indicate that the growth in transport volume has been the main cause for increase in energy consumption for both passenger and freight transport in India despite the decline in energy intensity of various transport modes. Though not surprising for a growing economy like India, this poses a challenge for the future. Currently, India is a low carbon economy.     

Extent and correlates of walking in the USA

This paper examines data about walking trips in the US Department of Transportation’s 2001 National Household Travel Survey. The paper describes and critiques the methods used in the survey to collect data on walking. Using these data, we summarize the extent of walking, the duration and distance of walk trips, and variations in walking behavior according to geographic and socio-demographic factors. The results show that most Americans do not walk at all, but those who do average close to thirty minutes of walking a day. Walk trips averaged about a half-mile, but the median trip distance was a quarter of a mile. A significant percentage of the time Americans’ walk was spent traveling to and from transit trips. Binary logit models are used for examining utility and recreational walk trips and show a positive relationship between walking and population density for both. For recreational trips, this effect shows up at the extreme low and high ends of density. For utility trips, the odds of reporting a walk trip increase with each density category, but the effect is most pronounced at the highest density categories. At the highest densities, a large portion of the effect of density occurs via the intermediary of car ownership. Educational attainment has a strong effect on propensity to take walk trips, for both for utility and recreation. Higher income was associated with fewer utility walk trips but more recreational trips. Asians, Latinos, and blacks were less likely to take utility walk trips than whites, after controlling for income, education, density, and car ownership. The ethnic differences in walking are even larger for recreational trips.     

Exchange rate and transport cost sensitivities of bilateral freight flows between the US and China

This paper explores the long-run impacts of gross domestic product, exchange rate, and transport costs on bilateral air and ocean freight flows between the US and China. The study employs a cointegration framework by using export and import data over the period of 2003:Q1-2014:Q2. Results show that gross domestic product is the key determinant of bilateral freight flows, indicating that real income of a trading partner is a driving force of the bilateral freight flows between the US and China. In examining the sensitivities of the bilateral trade flows, air freight flows are found to be more responsive to a real income change than ocean freight flows. The bilateral exchange rate is a significant factor affecting the freight flows from China to the US, suggesting that a US dollar appreciation against the Chinese yuan increases the inflows of Chinese commodities to the US. The impacts of the bilateral exchange rate and transport cost are found to vary at industry and commodity levels. These findings support the importance of employing disaggregate data in the bilateral freight flow analysis.     

拖船操纵运动与水下拖曳列阵的耦合运动分析

建立了拖船操纵运动与水下拖曳列阵的三维非线性数学模型,求解了在脐带非线性缆力作用下的运动方程,模拟了拖曳系统在几种典型状态下其缆索的形态变化,以及列阵张力变化。     

船用光纤陀螺随机漂移分析与研究

随机漂移是影响船用光纤陀螺精度的主要因素。对随机漂移进行建模并在系统中加以补偿是提高船用光纤陀螺及其导航系统精度的关键。本文对可用于精密仪器随机漂移研究的Allan方差法加以改进,将数字信号处理中加窗函数的方法应用于计算Allan方差,解决了某些频段内由于频混造成的随机漂移表征不唯一的问题。通过对光纤陀螺实测数据进行计算,得出各种随机漂移的系数,实验证明这是对光纤陀螺随机漂移进行研究的有效方法。     

美军综合电子信息系统发展概述

介绍了美军综合电子信息系统的发展历程,以及其未来发展概述;重点阐述了美军综合电子信息系统的几个典型计划和系统,包括全球信息栅格(GIG)、网络中心战(NCW)、建立C4KISR系统和部署联合指挥控制系统(JC2);对于美军综合电子信息系统的发展措施,概括为强调联合作战、从传感器到射手的综合一体化、加强基础设施的建设、发展空间优势和重视软件开发、采用商用流行技术;最后对我国综合电子信息系统的发展进行了简单评述.     

Analysis of the capabilities of a two-stage turbocharging system to fulfil the US2007 anti-pollution directive for heavy duty diesel engines

This article presents a two-stage turbocharged heavy-duty diesel (HDD) engine designed to fulfil the US2007 anti-pollution directive. This directive imposes very restrictive limits on the NOx and particle emissions of HDD engines. In this work, the possibility of combining particle traps in the exhaust line to reduce soot emissions with very high EGR rates to reduce NOx emissions is considered. This new generation engine implements two-stage turbocharging in order to improve the bsfc when the engine is working on steady conditions as well as to optimize the engine transient response. After carrying out the tests, the results were analyzed and the engine settings were adjusted to maximise its behaviour and minimise pollutant emissions. NOx and soot emission peaks were also analyzed at engine transient conditions in order to keep them under certain levels, and thus maintain the overall pollutant emissions to a level that is as low as possible. In summary, a double-stage turbocharging configuration can greatly improve engine driveability (between 23% and 36% depending on engine speed), while reducing NOx emissions during transient evolution without increasing opacity peaks beyond the stated limits.