Aspects of family and kinship in a North Carolina coastal community: a comparative study

The almost total absence of social-science data on North Carolina coastal fishing communities has provoked this preliminary study of the role played by family and kinship ties among fishermen and boat builders in such a community, with a view to developing new fisheries management strategies from an assessment of the social and economic impacts of those which already exist.     

3D Nonlinear Numerical Simulation of Intact and Debonded Reinforced Concrete Beams

To study the behaviour of reinforced concrete (RC) structures with sections of concrete removed and the reinforcement exposed, 3D nonlinear numerical analysis was performed upon both intact and debonded RC beams by using finite element techniques. The deformational characteristics and the ultimate loads were obtained through numerical models, as well as crack and stress distributions. The failure modes can also be deduced from computational results. Compared with intact beams, the normal assumptions of plane section behaviour is not hold true and the patterns of stress and strain are different in debonded RC beams. The numerical results show good consistency with experimental data. This kind of numerical simulation is a supplement to existing codes.     

Railway station choice modelling: a review of methods and evidence

Since the first railway station choice studies of the 1970s, a substantial body of research on the topic has been completed, primarily in North America, the U.K. and the Netherlands. With many countries seeing sustained growth in rail passenger numbers, which is forecast to continue, station choice models have an important role to play in assessing proposals for new stations or service changes. This paper reviews the modelling approaches adopted, the factors found to influence station choice and the application of models to real-world demand forecasting scenarios. A consensus has formed around using the closed-form multinomial logit and nested logit models, with limited use of more advanced simulation-based models, and the direction effects of a range of factors have been consistently reported. However, there are questions over the validity of applying non-spatial discrete choice models to a context where spatial correlation will be present, in particular with regard to the models’ ability to adequately represent the abstraction behaviours resulting from competition between stations. Furthermore, there has been limited progress towards developing a methodology to integrate a station choice element into the aggregate models typically used to forecast passenger demand for new stations.     

Improving the validity and reliability of authentic assessment in seafarer education and training: a conceptual and practical framework to enhance resulting assessment outcomes

Past literature on authentic assessment suggests that it provides a far more reliable and valid indicator of outcomes such as higher student engagement, ability to transfer skills to different contexts, multiple evidence of competence, and student performance. This has appeal in seafarer education and training where both students and employers increasingly perceive traditional assessment methods as failing to consistently generate these outcomes. However, this paper argues that improving different aspects of assessment validity and reliability is essentially required to enhance the outcomes identified above. The paper builds on and extends previous work to investigate and develop a conceptual and practical framework that promotes a holistic approach to authentic assessment that provides greater assurances of validity and reliability throughout all stages of assessment within seafarer programs. It also lays the path to future research directions by establishing the agenda to test the practicality of the framework in the authentic assessment of seafarer students and also investigate the impact of students’ perception of increasing authenticity on performance scores in assessment tasks.     

供应商关系

<正>供应商关系指数已经成为北美汽车制造公司的一个重要运营的指标,今天的汽车科技复杂,已经不再是任何一家汽车公司能够掌握的。菲亚特-克莱斯勒的一把手,Mr.Marchionne,最近发表的谈话:"供应商两位数字的利润率让我血压升高,我们要来研究一下如何分享他们的成功",引发北美汽车业界很多议论。因此,笔者想介绍一个测量汽车公司与供应商之间关系的指数。     

Developing travel time estimation methods using sparse GPS data

Existing methods of estimating travel time from GPS data are not able to simultaneously take account of the issues related to uncertainties associated with GPS and spatial road network data. Moreover, they typically depend upon high-frequency data sources from specialist data providers, which can be expensive and are not always readily available. The study reported here therefore sought to better estimate travel time using “readily available” vehicle trajectory data from moving sensors such as buses, taxis, and logistical vehicles equipped with GPS in “near” real time. To do this, accurate locations of vehicles on a link were first map-matched to reduce the positioning errors associated with GPS and digital road maps. Two mathematical methods were then developed to estimate link travel times from map-matched GPS fixes, vehicle speeds, and network connectivity information with a special focus on sampling frequencies, vehicle penetration rates, and time window lengths. Global positioning system (GPS) data from Interstate I-880 (California) for a total of 73 vehicles over 6 h were obtained from the University of California Berkeley's Mobile Century Project, and these were used to evaluate several travel time estimation methods, the results of which were then validated against reference travel time data collected from high resolution video cameras. The results indicate that vehicle penetration rates, data sampling frequencies, vehicle coverage on the links, and time window lengths all influence the accuracy of link travel time estimation. The performance was found to be best in the 5-min time window length and for a GPS sampling frequency of 60 s.