Triruthenium alkylidyne cluster complexes [H2Ru3(CO)9(μ3-CX)] (X=pyridine, 4-ethylpyridine)

Crystal structure analyses of nonacarbonyl-1K3C, - 2K3 C,3 K3 C-di-#-hydrido - l :2x2 H;2:3 K'-H-# 3-(pyrid-1- ylmethylidyne)-triangulo-triruthenium, [Ru3(#-H)2- (#3-C6HsN)(CO)9], (I), and nonacarbonyl-lK3C,- 2 K3C,3 K3C-# 3-[(4-ethylpyrid- 1 -yl)met hylidyne]-di- #-hydrido- l :2K2 H;2:3 x2 H-triangulo-triruthenium, [Ru3(#-H)2(#3-CsHgN)(CO)9], (II), reveal that both compounds consist of a triruthenium alkylidyne core with the nucleophiles [pyridine in (I) and 4-ethylpyridine in (II)] bonded to the #3-bridging alkylidyne C atom.published_or_final_versio

A cell-based logit-opportunity taxi customer-search model

This paper proposes a cell-based model to predict local customer-search movements of vacant taxi drivers, which incorporates the modeling principles of the logit-based search model and the intervening opportunity model. The local customer-search movements were extracted from the global positioning system data of 460 Hong Kong urban taxis and inputted into a cell-based taxi operating network to calibrate the model and validate the modeling concepts. The model results reveal that the taxi drivers’ local search decisions are significantly affected by the (cumulative) probability of successfully picking up a customer along the search route, and that the drivers do not search their customers under the random walk principle. The proposed model helps predict the effects of the implementation of the policies in adjusting the taxi fleet size and the changes in passenger demand on the customer-search distance and time of taxi drivers

Sequential Logit Approach to Modeling Customer-searching Decisions of Taxi Drivers

Fulltext link: http://easts.info/on-line/proceedings/vol9/PDF/P137.pdfThis paper develops an enhanced sequential logit model to depict the customer-search behavior of vacant-taxi drivers. This model considers that vacant-taxi drivers can change the choices they make on their way to a designated district. Trip data from the global positioning systems (GPSs) of 460 urban taxis were extracted to calibrate the model and verify the factors underlying the drivers’ search decisions. The findings reveal that the proposed sequential logit model is capable of predicting the search paths of vacant-taxi drivers. This model form is considered more informative for policymakers who aim to study search paths and the associated traffic congestion contributed by taxis in each district

Bi-level decisions of vacant taxi drivers traveling towards taxi stands in customer-search: Modeling methodology and policy implications

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Cantonese consonantal development: towards a nonlinear account

Descriptions of the development of prosodic and segmental tiers of children's phonological systems have been derived from investigations of the development of English. This paper provides a preliminary description of phonological tier development in Cantonese-speaking children. Eight children, (two each at 1;7, 2;6, 3;5, and 4;2 years) named 95 pictures. The data were analysed for word, syllable, onset-rime, skeletal, and segmental tiers. The results suggested a developmental order in the acquisition of hierarchical features. Decreasing order of accuracy of the tiers was word = syllable > onset-rime = skeletal > segmental. A model of feature geometry was adopted to describe the acquisition of features. An interesting finding is the way the laryngeal feature (aspiration) was combined with place contrasts one at a time rather than all at once.published_or_final_versio

Dynamic traffic assignment: model classifications and recent advances in travel choice principles

Dynamic Traffic Assignment (DTA) has been studied for more than four decades and numerous reviews of this research area have been conducted. This review focuses on the travel choice principle and the classification of DTA models, and is supplementary to the existing reviews. The implications of the travel choice principle for the existence and uniqueness of DTA solutions are discussed, and the interrelation between the travel choice principle and the traffic flow component is explained using the nonlinear complementarity problem, the variational inequality problem, the mathematical programming problem, and the fixed point problem formulations. This paper also points out that all of the reviewed travel choice principles are extended from those used in static traffic assignment. There are also many classifications of DTA models, in which each classification addresses one aspect of DTA modeling. Finally, some future research directions are identified.postprin

Mixed logit approach to modelling arrival time choice behaviour of cemetery and columbarium visitors during grave-sweeping festivals

Special events attract extraordinarily high travel demands over a relatively short time. Managing the travel demand for special events is more difficult than for normal commuting trips. Grave-sweeping is a special event that is popular in Asia, especially in Chinese societies. In Hong Kong, many people visit cemeteries and columbaria around the two traditional festivals, causing overcrowding at the sites and congestion on the access roads. To mitigate the adverse traffic effects, the police usually implement temporary traffic management measures to control the number of visitors accessing the sites. However, these measures often ignore visitors’ arrival time preferences and hence their effectiveness is questionable. This study models and analyses the arrival time preferences of cemetery and columbarium visitors under various transport mode scenarios. The model development is based on 3128 choice decisions collected from 782 respondents. A mixed logit model is calibrated to investigate the potential taste heterogeneity of the respondents, and a likelihood ratio test demonstrates that the model is superior to a standard multinomial logit model and provides a better fit to the survey data. The model results indicate that in-vehicle travel time, total waiting and walking time, and the provision and travel fare of feeder services are significant factors influencing cemetery and columbarium visitors’ arrival time choices. The effects of socio-economic factors are also examined and discussed. Based on the model results, recommendations are provided for managing the travel demand to cemeteries and columbaria at peak and off-peak hours on or around festival days.postprin

Cross-cultural validation of models of approaches to learning: An application of confirmatory factor analysis

Six structural equation models were tested by analysing responses to the Learning Process Questionnaire of 10 samples of primary and secondary school students from Nigeria, Zimbabwe, Malaysia, Beijing, Hong Kong and Canada. Confirmatory factor analyses provided general support for the cross-cultural within-construct validity of the questionnaire. As predicted, the dimensions of deep and surface approaches to learning received cross-cultural support, but the positioning of the achieving dimension varied across cultures. This is in line with the notion that students who adopt an achieving approach will adopt different strategies which will be likely to maximise their achievement according to particular course and teacher characteristics.published_or_final_versio

The chemical reaction optimization approach to solving the environmentally sustainable network design problem

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