33 research outputs found

    Tour-based Travel Mode Choice Estimation based on Data Mining and Fuzzy Techniques

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    This paper extends tour-based mode choice model, which mainly includes individual trip level interactions, to include linked travel modes of consecutive trips of an individual. Travel modes of consecutive trip made by an individual in a household have strong dependency or co-relation because individuals try to maintain their travel modes or use a few combinations of modes for current and subsequent trips. Traditionally, tour based mode choice models involved nested logit models derived from expert knowledge. There are limitations associated with this approach. Logit models assumes i) specific model structure (linear utility model) in advance; and, ii) it holds across an entire historical observations. These assumptions about the predefined model may be representative of reality, however these rules or heuristics for tour based mode choice should ideally be derived from the survey data rather than based on expert knowledge/ judgment. Therefore, in this paper, we propose a novel data-driven methodology to address the issues identified in tour based mode choice. The proposed methodology is tested using the Household Travel Survey (HTS) data of Sydney metropolitan area and its performances are compared with the state-of-the-art approaches in this area

    An Agent Based Model for the Simulation of Transport Demand and Land Use

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    Agent based modelling has emerged as a promising tool to provide planners with insights on social behaviour and the interdependencies characterising urban system, particularly with respect to transport and infrastructure planning. This paper presents an agent based model for the simulation of land use and transport demand of an urban area of Sydney, Australia. Each individual in the model has a travel diary which comprises a sequence of trips the person makes in a representative day as well as trip attributes such as travel mode, trip purpose, and departure time. Individuals are associated with each other by their household relationship, which helps define the interdependencies of their travel diary and constrains their mode choice. This allows the model to not only realistically reproduce how the current population uses existing transport infrastructure but more importantly provide comprehensive insight into future transport demands. The router of the traffic micro-simulator TRANSIMS is incorporated in the model to inform the actual travel time of each trip and changes of traffic density on the road network. Simulation results show very good agreement with survey data in terms of the distribution of trips done by transport modes and by trip purposes, as well as the traffic density along the main road in the study area

    Evaluation of the undergraduate family medicine programme of Faculty of Medicine, University of Kelaniya : quantitative and qualitative student feedback

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    Background: Worldwide there is an increasing emphasis on the importance of primary care. The ministry of health Sri Lanka issued a directive in 2016 that training of doctors in primary care should be strengthened. Medical students of the Faculty of Medicine, University of Kelaniya follow a 1 month long clinical appointment in family medicine in their fourth year of study. Methods: Feedback is taken from students on completion of the appointment. Half the students from each group complete a pre tested structured feedback questionnaire that consists of answers to questions based on a likert scale with a space for free comments. The other half provide qualitative feedback. In this evaluation data were gathered from 185 (98%) students from all eight clinical groups throughout the year 2016. Quantitative data were analysed using SPSS version 22. Inductive thematic analysis was used to analyse the qualitative data from the Round Robin activity and free comments from the questionnaire. Results: The qualitative feedback provided a richer indepth overview of student ideas on the appointment compared to the quantitative data. In reflection of a desire for learning to be of relevance students wanted clinically oriented teaching focused on management. They preferred active teaching learning methods such as the opportunity to conduct consultations and receive immediate feedback. Students had a high regard for the teaching sessions by general practitioners at their clinics. The appointment had created an interest in the discipline of family medicine which could have an impact on future choice of career. There were indications to suggest that student attitudes towards patients may have evolved to be more patient centred. Students appreciated the inclusive and low stress ambience of the learning environment. Conclusions and recommendations: Regular evaluation of teaching programmes helps maintain accountability of faculty and paves the way for more student centred teaching through the incorporation of studentsā€™ views in devising teaching methods. This evaluation found that qualitative feedback provided more descriptive material to reflect on and therefore improve teaching on the programme. It is recommended that more use should be made of qualitative methodologies in programme evaluations

    Frequency Domain Measurements for Diagnosis of Power Transformers: Experiences from Australia, Malaysia, Sri Lanka and UK

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    This is the author accepted manuscript. The final version is available from CIGRE via the link in this recordPower transformers and their performance and reliability in electric power networks are important research issues of power systems. Much information has already been collected and reported; however, it is rare to report comparisons of transformer service performance under different geographical locations and working conditions. CIGRE Working Group A2.37 collected information on 964 transformer failures from 58 utilities and 21 countries covering the period from 1996 to 2009. The main failure modes included failures in windings, tap changers, bushings, insulation, and core. As estimated, based on available literature, nearly 50% of the failures could be related to transformer windings and insulation. This collective paper summarizes experiences from the use of diagnostic tools based on frequency domain measurements at different geographical regions of the world. It starts with a short introduction to response measurements in frequency domain for condition assessment of transformers; then theoretical backgrounds of the two widely used response measurements, namely Frequency Dielectric Spectroscopy (FDS) and Frequency Response Analysis (FRA), are presented. Afterward details of tested transformers and measurement procedures are described for which selected set of FDS and FRA measurement results are analysed for respectively elucidating their potential in assessment of moisture content, ageing degree and fault identi cation

    The epidemiology of postpartum malaria: a systematic review

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    Pregnant women are more susceptible to malaria than their non-pregnant counterparts. Less is known about the risk of malaria in the postpartum period. The epidemiology of postpartum malaria was systematically reviewed. Eleven articles fitted the inclusion criteria. Of the 10 studies that compared malaria data from the postpartum period with pregnancy data, nine studies suggested that the risk for malaria infection decreased after delivery. All three studies that compared postpartum data with non-pregnant non-postpartum women concluded that the risk did not return to pre-pregnancy levels immediately after delivery. The results of this review have to be carefully interpreted, as the majority of studies were not designed to study postpartum malaria, and there was large variability in study designs and reported outcomes. Current evidence suggests an effort should be made to detect and radically cure malaria during pregnancy so that women do not enter the postpartum period with residual parasites

    IDENTIFICATION OF INTERNAL ORGANIZATIONAL FACTORS CAUSING RESISTANCE TO CHANGE

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    The external environment is subjected to frequent changes. Therefore, organizations must continuously change in order to remain competitive. But often changes are obstructed by internal resistance. The objective of this study was to identify internal organizational factors causing resistance to change and to research on their nature of relationship with the level of resistance. The study involved four independent variables and one dependent variable. Data was gathered by way of a questionnaire and from discussions held with the respective management personnel. The analysis proved that thereā€™s a strong positive relationship between negative employee attitudes and the level of resistance. Lack of employee knowledge too showed a strong positive relationship with the level of resistance. But both communication barriers and cultural barriers demonstrated a weak relationship with the level of resistance. This study has contributed in bridging the research gap in terms of change and resistance in Sri Lankan context. Keywords: Resistance, Attitudes, Knowledge, Communication, CultureFor full paper: [email protected]

    The price of a view: Estimating the impact of view on house prices

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    Ā© 2019 Pacific Rim Real Estate Society. Houses with desired aesthetic views have a price premium over similar houses without such views. This article raises the following questions in relation to view as a location-specific amenity: How can we calculate a reliable indicator for view using available information? Are dwellings with a view sold for a premium compared to otherwise similar properties? Using more than 5,000 house transactions in the Illawarra region in Australia, and applying hedonic price method, the study analyses the price effects of key aesthetic views. Due to unavailability of view as a housing characteristic within historical records, spatial analysis tools were used to estimate views for housing locations. The results confirm the significance of aesthetic views in explaining house prices. Beach view is the most important aesthetic view. An increase of 1% of beach view drives house prices up by nearly 2ā€“3%. Significant positive contributions to prices are also evident from sea, conservation area and inland water views. In addition to the views, other location-specific attributes also influence house prices. Methods developed in this study to quantify the value of aesthetic views and location-specific characteristics associated with residential locations form an important contribution to urban planning and policy development

    Modelling mode choice of individual in linked trips with artificial neural networks and fuzzy representation

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    Traditional mode choice models consider travel modes of an individual in a consecutive trip to be independent. However, a persons choice of the travel mode of a trip is likely to be affected by the mode choice of the previous trips, particularly when it comes to car driving. Furthermore, traditional travel mode choice models involve discrete choice models, which are largely derived from expert knowledge, to build rules or heuristics. Their approach relies heavily on a predefined specific model structure (utility model) and constraining it to hold across an entire series of historical observations. These studies also assumed that the travel diaries of individuals in travel survey data is complete, which seldom occurs. Therefore, in this chapter, we propose a data-driven methodology with artificial neural networks (ANNs) and fuzzy sets (to better represent historical knowledge in an intuitive way) to model travel mode choices. The proposed methodology models and analyses travel mode choice of an individual trip and its influence on consecutive trips of individuals. The methodology is tested using the Household Travel Survey (HTS) data of Sydney metropolitan area and its performance is compared with the state-of-the-art approaches such as decision trees. Experimental results indicate that the proposed methodology with ANN and fuzzy sets can effectively improve the accuracy of travel mode choice prediction
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