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Dissertations / Theses on the topic 'Model Transferability'
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1
Skinner, Andrew John. "Transferability within the tight binding bond model." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47665.
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Hunukumbura, J. M. P. B. "Distributed hydrological model transferability across basins with different physio-climatic characteristics." 京都大学 (Kyoto University), 2009. http://hdl.handle.net/2433/126504.
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Kyoto University (京都大学)0048
新制・課程博士
博士(工学)
甲第14933号
工博第3160号
新制||工||1474(附属図書館)
27371
UT51-2009-M847
京都大学大学院工学研究科都市環境工学専攻
(主査)教授 椎葉 充晴, 教授 寶 馨, 准教授 立川 康人
学位規則第4条第1項該当
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Silva, Karla Cristina Rodrigues. "Assessing the transferability of crash prediction models for two lane highways in Brazil." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/18/18144/tde-10112017-215500/.
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The present study focused on evaluating some crash prediction models for two lane highways on Brazilian conditions. Also, the transferability of models was considered, specifically by means of a comparison between Brazil, HSM and Florida. The analysis of two lane highways crash prediction models was promising when the road characteristics were well known and there was not much difference from base conditions. This conclusion was attained regarding the comparison of results for all segments, non-curved segments and curved segments, confirming that a transferred model can be used with caution. In addition, two novel models for Brazilian two-lane highways segments were estimated. The model developed showed better results for non-curved segments in the calibration/validation sample. Thus, for a general analysis purpose of non-curved segments this model is recommended. Finally, there are many factors that could not be measured by these models and reflects road safety various condition. Even so, the study of crash predict models in Brazilian context could provide a better start point in safety road analysis.O foco desta pesquisa foi avaliar a aplicação de alguns modelos de previsão de acidentes em rodovias de pista simples de três estados brasileiros. Ainda, a transferabilidade destes modelos foi abordada, especificamente por meio de uma comparação entre características do Brasil, Florida e aquelas recomendadas pelo Highway Safety Manual. O uso dos distintos modelos se mostrou promissor para situações nas quais as características da via se mantiveram semelhantes às condições para as quais os modelos foram desenvolvidos. A avaliação foi empreendida para todos os segmentos homogêneos, separados posteriormente segundo a existência de curvas horizontais. Adicionalmente, dois novos modelos foram equacionados para a amostra brasileira. O modelo de previsão de acidentes desenvolvido apresentou melhores medidas de desempenho para segmentos sem curvas horizontais, sendo recomendável para previsão de acidentes em análises preliminares. Por fim, foi constatado que outros fatores não contemplados pelos modelos podem ter impactado as condições de segurança dos locais estudados. Ainda assim, essa pesquisa representa no contexto do Brasil um ponto de partida em análises relacionadas à segurança de rodovias de pista simples.
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Rosenberger, Amanda Elizabeth. "Multi-scale patterns of habitat use by Roanoke logperch (Percina rex) in Virginia rivers: a comparison among populations and life stages." Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/26015.
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The Roanoke logperch (Percina rex) is a federally endangered large darter that occurs only within the Roanoke and Chowan drainages of Virginia. This dissertation examines multi-scale habitat use patterns by logperch in three river systems in Virginia, including comparisons among rivers and life stages.
The first study in this dissertation compares microhabitat use patterns of logperch among the Roanoke, Pigg, and Nottoway rivers. My objectives are to: 1) compare available microhabitat and microhabitat use by logperch among these rivers; and 2) examine the transfer of habitat models among rivers. Habitat availability in the three rivers indicates that the Nottoway River is least impacted by human activity, while the Pigg River is most impacted. The Roanoke and Pigg rivers are found within the same region of Virginia and share many habitat characteristics. Logperch consistently use silt free, loosely embedded gravel in all rivers and can occupy a variety of depths and velocities to accommodate substrate requirements. Microhabitat models transfer better between the similar Pigg and Roanoke rivers.
The second study in this dissertation compares micro- and meso-habitat use patterns by Roanoke logperch in the Roanoke and Nottoway rivers. My objectives are to: 1) compare micro- and meso-habitat use patterns of logperch in the Roanoke and Nottoway rivers; and 2) examine transfer of habitat models at both scales. An increase in scale from micro- to meso- habitat did not improve model transfer. Habitat selectivity and transfer was strongest at the microhabitat scale. Logperch appear to be microhabitat substrate specialists and mesohabitat generalists.
The final study in this dissertation examines ontogenetic patterns of habitat use by Roanoke logperch in the Roanoke and Nottoway rivers. My goals are to: 1) examine habitat use by three age classes of logperch and 2) compare ontogenetic patterns of habitat use between the Roanoke and Nottoway rivers. In the Roanoke River, adult and subadult logperch primarily used run and riffle habitat, often over gravel substrate. Subadults were found in lower water velocities and more embedded microhabitats than adults. Young-of-year logperch were found in shallow, stagnant backwaters and secondary channels. In the Nottoway River, both adult and subadult logperch were found over sand and gravel in deep, low velocity pools and runs. Subadults were observed in slightly more silted, lower velocity habitat. Younger age classes of logperch appear to be more vulnerable to sedimentation caused by human activity.
Evidence in this dissertation strongly indicates that logperch have strict substrate requirements and the distribution of habitat types and pathways of dispersal will be critical for completion of the logperch life cycle. A watershed-level conservation approach that addresses sediment loading and preserves ecological processes that provide ephemeral, seasonal, and persistent types of habitat required over logperch ontogeny will be most effective for management geared towards the recovery of this endangered species.Ph. D.
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Venne, Simon. "Can Species Distribution Models Predict Colonizations and Extinctions?" Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/38465.
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Aim
MaxEnt, a very popular species distribution modelling technique, has been used extensively to relate species’ geographic distributions to environmental variables and to predict changes in species’ distributions in response to environmental change. Here, we test its predictive ability through time (rather than through space, as is commonly done) by modeling colonizations and extinctions.
Location
Continental U.S. and southern Canada.
Time period
1979-2009
Major taxa studied
Twenty-one species of passerine birds.
Methods
We used MaxEnt to relate species’ geographic distributions to the variation in environmental conditions across North America. We then modelled site-specific colonizations and extinctions between 1979 and 2009 as functions of MaxEnt-estimated previous habitat suitability and inter- annual change in habitat suitability and neighborhood occupancy. We evaluated whether the effects were in the expected direction, we partitioned model’s explained deviance, and we compared colonization and extinction model’s accuracy to MaxEnt’s AUC.
Results
IV
Colonization and extinction probabilities both varied as functions of previous habitat suitability, change in habitat suitability, and neighborhood occupancy, in the expected direction. Change in habitat suitability explained very little deviance compared to other predictors. Neighborhood occupancy accounted for more explained deviance in colonization models than in extinction models. MaxEnt AUC correlates with extinction models’ predictive ability, but not with that of colonization models.
Main conclusions
MaxEnt appears to sometime capture a real effect of the environment on species’ distributions since a statistical effect of habitat suitability is detected through both time and space. However, change in habitat suitability (which is much smaller through time than through space) is a poor predictor of change in occupancy. Over short time scales, proximity of sites occupied by conspecifics predicts changes in occupancy just as well as MaxEnt. The ability of MaxEnt models to predict spatial variation in occupancy (as measured by AUC) gives little indication of transferability through time. Thus, the predictive value of species distribution models may be overestimated when evaluated through space only. Future prediction of species’ responses to climate change should make a distinction between colonization and extinction, recognizing that the two processes are not equally well predicted by SDMs.
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Curós, i. Vilà Maria Pilar. "El model japonès de gestió dels recursos humans i las seva implantació a les filials japoneses de Catalunya." Doctoral thesis, Universitat de Girona, 2002. http://hdl.handle.net/10803/7950.
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L'objectiu d'aquesta tesi doctoral consisteix en determinar si el model de gestió dels recursos humans de les empreses matrius japoneses es transferible a les filials japoneses de Catalunya.Per tot això després d'un estudi teòric sobre la literatura existent del model de gestió dels recursos humans japonès i la internacionalització dels recursos humans, s'ha realitzat un treball empíric mitjançant una enquesta a les filials japoneses instal.lades a Catalunya. En el qüestionari s'analitzen diferents àmbits de la gestió dels recursos humans i que constitueixen les 7 hipòtesis del nostre treball de camp basades en el model de recursos humans japonès referides a: 1- Reclutament i selecció, 2- Promoció i Rotació, 3- Lideratge, comunicació i treball en equip, 4- Motivació, clima laboral i cultura empresrial, 5- Formació i desenvolupament, 6- Avaluació de l'acompliment, y 7- Retribució i beneficis socials. Tot això ens ha indicat quina es la tendència del model japonès de recursos humans a les filials catalanes tenint en compte que estem analitzant un contexte cultural diferent a la idiosincrasia dels treballadors japonesos. El treball ens ha permés de proposar dues línies d'investigació, una a determinar en el temps i una altre en l'espai. En el temps amb la nova generació s'està produint un canvi cultural en el qual els joves japonesos intenten importar part dels valors occidentals que es veurà reflectit al llarg de 10-20 anys. I en l'espai l'aplicació de l'estudi a altres països europeus, com Anglaterra, França i Alemanya que són els principals països on els japonesos prefereixen instal.lar-se.
The objective of this doctoral thesis is to consider if the Human Resource Management model of the Japanese head office is transferable to the Japanese subsidiaries settled in Catalonia.
After a theoretical study about the existent literature of the Japanese Human Resource Management model and the internationalization of Human Resources an empirical research has been carried out by means of a survey in the Japanese subsidiaries set up in Catalonia. In this survey different aspects of the Human Resource Management have been analysed and they constitute the seven hypotheses of our research based on the Japanese Human Resources model conerning:
1- Recruitment and Selection, 2- Promotion and Rotation, 3- Leardership, communication and Teamwork, 4- Motivation, labour atmosphere and Management culture, 5- Training and development, 6- Personnel Appraisal and 7- Retribution and Social Benefits. All this has shown us what the tendency of the Japanese Human Resources model in the Catalan subsidiaries is, taking into account that we are analysing a different cultural context to the idiosyncrasy of Japanese workers.
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Baštářová, Tereza. "Přenositelnost skandinávského modelu sociálního státu na základě makroekonomické analýzy." Master's thesis, Vysoká škola ekonomická v Praze, 2013. http://www.nusl.cz/ntk/nusl-193606.
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This thesis deals with question of Scandinavian social model's transferability on Baltic countries and Iceland. The aim of the thesis is to establish whether and to what extent Estonia, Latvia, Lithuania and Iceland are ready to adopt the system. Three main methods are used in the thesis, namely: analysis of macroeconomic indicators and competitiveness indices, synthesis using the magic pentagon and comparison via coefficient of variation. The thesis comprises three main parts. The first one deals with theory and methodology. The second part applies information gained from databases of world organisations and follows their development. The last part then compares these figures.
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Corvo, E. "Exploration of the effectiveness and transferability of an English model of health promotion based on participation in singing groups for older adults (Silver Song Clubs) in Italy." Thesis, Canterbury Christ Church University, 2013. http://create.canterbury.ac.uk/12993/.
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Background There is growing interest in the idea that arts and singing have effects on health, wellbeing and quality of life in older individuals. This study assesses the effectiveness and transferability to Italy of an English model of health promotion which promotes wellbeing and quality of life in older people through participation in singing groups (Silver Song Clubs). The model developed in the South East of England has proved to be successful. A recently completed randomized controlled trial (Coulton, et al. in press) demonstrated a significant improvement in mental health with a reduction in measured anxiety and depression for older people living independently. The current study adopted the same measures. Method A mixed method approach was adopted with research divided into two parts; Part A was focused on exploring the status of older people living in Rome, their interest in music and singing today and in the past and in taking part in a singing experience. It also explored how local politicians and social workers see the status of older people. Part B was focused on setting up and evaluating singing groups and gathering information from participants on their experiences of singing. The primary outcome measure was an Italian version of the York SF-12 which provides scores for physical and mental wellbeing. The Italian version of the EQ-5D-3L questionnaire was also employed. Results Results from Part A revealed a highly fragmented Italian family, with widespread poverty and social isolation and a need for emotional support and leisure activities among older people. In Part B, three singing groups were established in different areas of Rome with weekly sessions over a period of three months. Participants completed the standardized measures of health and wellbeing at baseline (n=62), after the singing experience (n=45) and three months later (n=41). After the singing experience, older people showed a statistically significant decrease in their levels of anxiety and depression, but this was not maintained over the three month follow up period. However, a significant improvement was found from baseline to follow up in reported performance of „usual activities‟. Conclusions Silver Song Clubs provide a health promotion model which was successfully transferred from England to the different cultural setting of Italy. Singing can be widely used because it is grounded in a fundamental human ability to engage with music. The present study had a number of limitations, primarily a lack of a control group and small sample size. However it provides a good foundation for the development of further research on singing and the wellbeing of older people in Italy.
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Cabrera, Delgado Jorge. "Quelle prise en compte des dynamiques urbaines dans la prévision de la demande de transport ?" Phd thesis, Université Lumière - Lyon II, 2013. http://tel.archives-ouvertes.fr/tel-00877044.
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Dans la pratique de la planification urbaine, la prévision de la demande de transport fait en général appel au modèle à quatre étapes (génération, distribution, répartition modale et affectation), malgré des avancées théoriques considérables dans le domaine.Cette persistance s'explique par une facilité relative de mise en œuvre, liée notamment à la forme des données disponibles et susceptibles d'alimenter les modèles. Cependant, la nature statique de l'approche pose des interrogations quant à sa pertinence pour faire des prévisions de moyen-long terme. Cette thèse étudie, la validité de l'hypothèse de stabilité temporelle des trois premières étapes du modèle de prévision. Pour ce faire, en prenant l'agglomération lyonnaise comme terrain d'étude, nous avons codifié des réseaux routiers et de transports en commun à différentes dates (1985, 1995 et 2006). Cette donne, généralement indisponible, combinée aux enquêtes ménages déplacements correspondantes,nous permet de calibrer les trois premières étapes du modèle traditionnel et de tester leur capacité prédictive. Pour les modèles de génération, on note des prévisions acceptables à un horizon de 10 ans. À 20 ans, certaines évolutions dans les styles de vie se sont traduites paru ne baisse du nombre moyen de sorties pour le motif travail, que les modèles traditionnels ne permettent pas de prévoir complètement. Au niveau de la distribution, l'allongement des distances entre lieux de réalisation de certaines activités et le lieu de domicile peut être relativement bien reproduit par des modèles gravitaires avec des paramètres stables dans le temps. Au niveau de la répartition modale, les paramètres ne sont pas stables et les modèles estimés n'auraient pas permis de prévoir le regain de parts de marché des transports en commun observé ces dernières années.
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Rulewski, Stenberg Louis. "High frequency rainfall data disaggregation with a random cascade model : Identifying regional differences in hyetographs in Sweden." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-434661.
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The field of urban hydrology is in need of high temporal resolution data series in order to effectively model and analyse existing and future trends in extreme precipitation. When high resolution data sets are, for any number of reasons, not available for a given location, the technique of disaggregation using a random cascade model can be applied. Previous studies have demonstrated the relevance of random cascades in the context of rainfall data disaggregation with temporal resolutions usually down to 1 hour. In this study, an attempt at disaggregation to a resolution of 1 minute was made. Using newly disaggregated rainfall data for different regions in Sweden, the possibility of clustering rain events into separate regional hyetographs was investigated. The random cascade model was calibrated using existing municipal rainfall data with a temporal resolution of 1 minute, in order to disaggregate continuous 15 minutes data series provided by the Swedish Meteorological and Hydrological Institute (SMHI). The disaggregation process was then performed in multiple stochastic realisations, in order to correct the uncertainties inherent to the random cascade model. The disaggregation results were assessed by comparing them with calibration data: two main rainfall parameters, EV and ED, were analysed by determining their behaviours and distribution. The possibility of transfering calibration parameters from one station to another was also assessed in a similar manner, again by studying EV & ED for different scenarios. Finally, hyetographs were clustered, compared and contrasted, in order to ascertain previously theorized differences between regions. This research showed the feasibility of applying a random cascade model to very high temporal resolutions in Sweden, while replicating rainfall characteristics from the calibration data quite well. The analysis of the spatial transferability of calibration parameters yielded inconclusive results, as rainfall characteristics were preserved in some cases but failed in others. Lastly, distinct regional differences in hyetographs were noted, but no clear conclusions could be drawn owing to the delimitations of this study.Inom småskalig hydrologisk modellering finns det idag ett behov av dataserier med hög tidsupplösning för att effektivt kunna modellera och analysera både aktuella och kommande trender hos extrema regnhändelser. När högupplösta dataserier är otillgängliga vid en önskad mätplats kan disaggregering med hjälp av en slumpmässig kaskadmodell tillämpas. Tidigare forskning har visat att kaskadmodeller är användbara för disaggregering av regndata med en tidsupplösning av 1 timme. I denna studie disaggregerades dataserier med syftet att uppnå en tidsupplösningav av 1 minut. För att kunna analysera eventuella skillnader mellan regioner klustrades även hyetografer med de framtagna dataserierna. Den slumpmässiga kaskadmodellen kalibrerades med befintlig kommunal data med en tidsupplösning på 1 minut, för att sedan kunna disaggregera 15 minuters data från SMHIs databaser. Disaggregeringen genomfördes i ett antal olika stokastiska realisationer för att kunna ta hänsyn till, och korrigera, de inneboende osäkerheterna i den slumpmässiga kaskadmodellen. Disaggregeringsresultaten bedömdes genom en jämförelse med kalibreringsdata: två regnegenskaper, regnvaraktighet (ED) och regnvolym (EV), analyserades för att kunna bestämma derasfördelningar och beteenden. Kalibreringsparametrarnas överförbarhet analyserades också med hjälp av ED & EV för olika scenarier. Slutligen klustrades hyetografer för att fastställa potentiella skillnader mellan regioner. Studien påvisade möjligheten att använda en slumpmässig kaskadmodell till höga tidsupplösningar i Sverige. Modellen lyckades återskapa regnegenskaper från kalibreringsdata vid disaggregeringen. Möjligheten att överföra kalibreringsparametrar från en station till en annan visade sig dock inte vara helt övertygande: regnegenskaper återskapades endast i vissa fall, men inte i samtliga. Slutligen konstaterades regionala skillnader i hyetografer, men tydliga slutsatser kunde inte dras på grund av underliggande begränsningar med studien.
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Fox, James Barnaby. "Temporal transferability of mode-destination choice models." Thesis, University of Leeds, 2015. http://etheses.whiterose.ac.uk/10479/.
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Transport planning relies extensively on forecasts of traveller behaviour over horizons of 20 years and more. Implicit in such forecasts is the assumption that travellers tastes, as represented by the behavioural model parameters, are constant over time. This assumption is referred to as the temporal transferability of the models. This thesis presents four main contributions in this area. First, a comprehensive review of the transferability literature in the context of the temporal transferability of mode-destination models. This review demonstrated that there is little evidence about the transferability of mode-destination models over typical forecasting horizons, and further that most evidence is from models of commuter mode choice. Second, further empirical evidence on the temporal transferability of mode destination models using data from Toronto and Sydney for transfer periods of up to 20 years in duration. The transferability of commuter and non-commuter travel has been compared, and models of non-commute travel were found to be less temporally transferable. Improving model specification through fixed socio-economic parameters was found to improve model transferability, and the travel time and socio-economic parameters were found to be more transferability than the cost parameters and the model constants. Third, and most novel, what is believed to be the first empirical evidence on the impact of taking account of heterogeneity in cost and in-vehicle time sensitivity on the temporal transferability of mode-destination models. This analysis demonstrated that while accounting for taste heterogeneity led to a better fit to the base data, there was no evidence that these models were more transferable than models without random heterogeneity. This may be due to the taste heterogeneity specification over-fitting the base data. Fourth, practical recommendations are presented for model developers on how to maximise the transferability of mode-destination models used for assessing policy.
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Kratzert, Ludvig. "Adversarial Example Transferabilty to Quantized Models." Thesis, Linköpings universitet, Medie- och Informationsteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-177590.
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Deep learning has proven to be a major leap in machine learning, allowing completely new problems to be solved. While flexible and powerful, neural networks have the disadvantage of being large and demanding high performance from the devices on which they are run. In order to deploy neural networks on more, and simpler, devices, techniques such as quantization, sparsification and tensor decomposition have been developed. These techniques have shown promising results, but their effects on model robustness against attacks remain largely unexplored. In this thesis, Universal Adversarial Perturbations (UAP) and the Fast Gradient Sign Method (FGSM) are tested against VGG-19 as well as versions of it compressed using 8-bit quantization, TensorFlows float16 quantization, and 8-bit and 4-bit single layer quantization as introduced in this thesis. The results show that UAP transfers well to all quantized models, while the transferability of FGSM is high to the float16 quantized model, lower to the 8-bit models, and high to the 4-bit SLQ model. We suggest that this disparity arises from the universal adversarial perturbations having been trained on multiple examples rather than just one, which has previously been shown to increase transferability. The results also show that quantizing a single layer, the first layer in this case, can have a disproportionate impact on transferability.Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet
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Sikder, Sujan. "Spatial Transferability of Activity-Based Travel Forecasting Models." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4771.
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Spatial transferability of travel forecasting models, or the ability to transfer models from one geographical region to another, can potentially help in significant cost and time savings for regions that cannot invest in extensive data-collection and model-development procedures. This issue is particularly important in the context of tour-based/activity-based models whose development typically involves significant data inputs, skilled staff, and long production times. However, most literature on model transferability has been in the context of traditionally used trip-based models, particularly for linear regression-based trip generation and logit-based mode choice models, with little evidence on the transferability of activity-based models and that of emerging model structures.
The overarching goal of this dissertation is to assess the spatial transferability of activity-based travel demand models. To this end, the specific objectives are to:
1. Survey the literature to synthesize: (a) the approaches used to transfer models, (b) the metrics used to assess model transferability, (c) the available evidence on spatial transferability of travel models, and (d) notable gaps in literature;
2. Lay out a framework for assessing the spatial transferability of activity-based travel forecasting model systems, and evaluate alternative methods/metrics used for assessing the transferability of specific model components and their parameters;
3. Conduct empirical assessments of spatial transferability of the following two model components used in today's activity-based model systems: (a) daily activity participation and time-use models, and (b) tour-based time-of-day choice models. Data from the 2009 National Household Travel Survey (NHTS) and the 2000 San Francisco Bay Area Travel Survey (BATS) were used for these empirical assessments;
4. Conduct empirical assessments of model transferability using emerging model structures that have begun to be used in activity-based model systems - specifically the multiple discrete-continuous extreme value (MDCEV) model;
5. Investigate alternate ways of enhancing model transferability; specifically: (a) pooling data from different geographical regions, and (b) improvements to the model structure.
The dissertation provides a framework for assessing the transferability of activity-based models systems, along with empirical evidence on the pros and cons of alternative methods and metrics of transferability assessment. The results suggest the need to consider model sensitivity to changes in explanatory variables as opposed to relying solely on the ability to predict aggregate distributions. Updating the constants of a transferred model using local data (a widely used method to transfer models) was found to help in increasing the model's ability to predict aggregate patterns but not necessarily in enhancing its sensitivity to changes in explanatory variables. Also, transferability assessments ought to consider sampling variance in parameter estimates as opposed to only the point estimates.
Empirical analysis with the daily activity participation and time-use model shed new light on the prediction properties of the MDCEV model structure that have implications for model transferability. This led to the development of a new model structure called the multiple discrete continuous heteroscedastic extreme value (MDCHEV) model that incorporates heteroscedasticity in the model's stochastic distributions and helps in enhancing model transferability. Transferability assessment of the time-of-day choice models show encouraging evidence of transferability of a large proportion of the model coefficients, albeit except important parameters such as the travel time coefficients. Collectively, there is evidence that pooling data from multiple regions may help in building better transferable models than those transferred from a single region.
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Gbobaniyi, Emiola Olabode. "Transferability of regional climate models over different climatic domains." Doctoral thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/4854.
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Includes abstract.Includes bibliographical references (p. 119-144).
In the continuing quest to improve climate model predictions to meet the increasing demand for knowledge on the regional effects of global climate change, it is pertinent to increase our understanding of how the underlying processes of climate are represented in the models we use to make these predictions. Concerted efforts in model evaluations and intercomparison have provided numerous insights into various model biases which plague current state-of-the-art regional climate models (RCMs). Model evaluation and assessment is crucial to model development and understanding how physical processes are represented in models is necessary for improving model parameterizations. This thesis explored model transferability as a new approach for systematic process-based intercomparison of RCMs. It investigated an untested transferability hypothesis which states that “for non-monsoon regions experiencing weak synoptic scale forcing, the height of the cloud base is correlated with the daytime surface fluxes”. An initial transferability experiment was conducted over Cabauw, the Netherlands (51.97°N, 4.93°E) to assess the models’ skill in resolving the diurnal and seasonal cycles and to investigate the simulated connections between surface and hydrometeorological variables over a non-monsoon station. The ability of models to resolve these cycles correctly is a good metric of their predictive capabilities. The data used for the study comprises three-hourly surface observations for the period October 2002 – December 2004 from the Coordinated Enhanced Observing Period (CEOP) measuring campaigns of the Global Energy and Water Cycle Experiment (GEWEX) and three-year simulations (2002 -2004) from five RCMs (CLM, GEMLAM, MRCC, RCA3 and RSM). In simulating seasonal and diurnal cycles of CBH and surface variables, the European models (CLM and RCA3) demonstrate a clear home advantage over the North American models (GEMLAM, MRCC and RSM). Principal component analysis revealed that the models couple the cloud base height with surface fluxes as in observations and that this coupling is not sensitive to changes in wind speed. This study found that summer daytime loadings gave the strongest couplings of variables. Three major processes were identified over Cabauw. First and most dominant is the surface energy process which couples sensible and latent heat with net radiation. The second process is thermodynamic, coupling temperature and surface moisture (specific humidity), and the third is a dynamic process which couples pressure and wind speed. A model intercomparison was then carried out across the six midlatitude domains to test the validity of the Cabauw findings. In observations, CBH is well coupled with the surface fluxes over Cabauw, Bondville, Lamont and BERMS, but coupled only with temperature over Lindenberg and Tongyu. All the models (except GEMLAM) simulated a good coupling with surface fluxes at all stations. In GEMLAM, there is no coupling between CBH and surface fluxes at any station. In less homogenous domains of the study, a very slight decrease in the strength of coupling is seen in most of the models, under strong large scale forcing. This would suggest that the coupling between cloud base height and surface fluxes in the models is possibly more influenced by radiative forcing than by synoptic controls. This second study confirmed the findings at Cabauw that the simulated cloud base is correlated with surface energy fluxes and the sign of the correlations in the models is as in observations. This finding is important for the modeling community as it establishes the fact that the models are actually simulating the direction of influence of surface fluxes and possibly, soil water variability, on cloud processes.
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Hongsrisuk, Nathaporn. "Transferability of near-infrared quantitative calibration models between different instruments." Thesis, University College London (University of London), 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.517948.
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Elmi, Abdishakor Mohamoud. "Analysis of the temporal transferability of work trip distribution gravity models." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0012/MQ32396.pdf.
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Khondaker, Bidoura. "Transferability of community-based macro-level collision prediction models for use in road safety planning applications." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/2867.
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This thesis proposes the methodology and guidelines for community-based macro-level CPM
transferability to do road safety planning applications, with models developed in one spatial-temporal
region being capable of used in a
different spatial-temporal region. In doing this.
the macro-level CPMs developed for the Greater Vancouver Regional District (GVRD) by
Lovegrove and Sayed (2006, 2007) was used in a model transferability study. Using those
models from GVRD and data from Central Okanagan Regional District (CORD), in the
Province of British Columbia. Canada. a transferability test has been conducted that involved
recalibration of the 1996 GVRD models to Kelowna, in 2003 context. The case study was
carried out in three parts. First, macro-level CPMs for the City of Kelowna were developed
using 2003 data following the research by GVRD CPM development and use. Next, the 1996
GVRD models were recalibrated to see whether they could yield reliable prediction of the
safety estimates for Kelowna, in 2003 context. Finally, a
comparison between the results of
Kelowna’s own developed models and the transferred models was conducted to determine
which models yielded better results.
The results of the transferability study revealed that macro-level CPM transferability was
possible and no more complicated than micro-level CPM transferability. To facilitate the
development of reliable community-based, macro-level collision prediction models, it was
recommended that CPMs be transferred rather than developed from scratch whenever and
wherever communities lack sufficient data of adequate quality. Therefore, the transferability
guidelines in this research, together with their application in the case studies, have been
offered as a contribution towards model transferability to do road safety planning
applications, with models developed in one spatial-temporal region being capable of used in
a different spatial-temporal region.
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Han, Yafei. "Temporal transferability assessments of vehicle ownership models and trip generation models for Boston Metropolitan Area." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/99566.
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Thesis: M.C.P., Massachusetts Institute of Technology, Department of Urban Studies and Planning, 2015.Thesis: S.M. in Transportation, Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 158-162).
In the last few decades, travel demand models have undergone tremendous development and, today, are routinely used to support planning and policy decisions. But uncertainty in forecasting with such models is often overlooked, and its impact on forecast accuracy is rarely evaluated. My thesis is motivated to understand behavior uncertainty and model uncertainty in travel demand modeling. In particular, I assess the temporal transferability of vehicle ownership models and trip generation models for Boston metropolitan area from 1990 to 2010. Through statistical tests, I find significantly changed preferences in household vehicle ownership choice and trip production. For vehicle ownership choice, the effects of most socio-economic and demographic factors, and regional location factor have evolved; while the effects of local built environment factors and transit access are stable. Trip rates have changed over time, with decreased home-based work, home-based shopping, home-based bank and personal business, home-based social, home-based eating and non-home-based work trips; and increased home-based recreational and home-based work-related trips. The prediction tests suggest that failing to consider preference changes cause significant bias in forecasts. The transferred vehicle ownership model of 1991 under-predicts 0- vehicle households by 42.5%, and over-predicts 2-vehicle households by 14.8% in 2010. The transferred trip rates from 1991 overestimate total trips in 2010 by 7% to 9%. Homebased work-related, home-based pick-up and drop-off, and home-based recreational trips are significantly unpredicted by 34%, 12% and 27%; while home-based work, home-based shopping, home-based social, and non-home-based work trips are significantly overpredicted by 9%, 20%, 31%, and 69%. Different model specifications have shown a modest range of variability in prediction outcomes, suggesting model specification uncertainty has less influence on forecasts than behavior uncertainty. In vehicle ownership modeling, children, seniors, and local built environment variables improve the prediction accuracy for 0-vehicle group. But all model specifications cannot well distinguish between 0- and 1-vehicle households, and between 2- and 3-vehicle households. Household characterization affects the prediction accuracy for certain trip purposes. Including more detailed household information may lead to worse forecasts because of large sampling variance. Future works are suggested to incorporate behavior uncertainty in forecast, explore uncertainty in model structure, and evaluate the practical implications of the lack of model transferability.
by Yafei Han.
M.C.P.
S.M. in Transportation
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Shew, Cameron Hunter. "TRANSFERABILITY AND ROBUSTNESS OF PREDICTIVE MODELS TO PROACTIVELY ASSESS REAL-TIME FREEWAY CRASH RISK." DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/863.
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This thesis describes the development and evaluation of real-time crash risk assessment models for four freeway corridors, US-101 NB (northbound) and SB (southbound) as well as I-880 NB and SB. Crash data for these freeway segments for the 16-month period from January 2010 through April 2011 are used to link historical crash occurrences with real-time traffic patterns observed through loop detector data.
The analysis techniques adopted for this study are logistic regression and classification trees, which are one of the most common data mining tools. The crash risk assessment models are developed based on a binary classification approach (crash and non-crash outcomes), with traffic parameters measured at surrounding vehicle detection station (VDS) locations as the independent variables. The classification performance assessment methodology accounts for rarity of crashes compared to non-crash cases in the sample instead of the more common pre-specified threshold-based classification.
Prior to development of the models, some of the data-related issues such as data cleaning and aggregation were addressed. Based on the modeling efforts, it was found that the turbulence in terms of speed variation is significantly associated with crash risk on the US-101 NB corridor. The models estimated with data from US-101 NB were evaluated based on their classification performance, not only on US-101 NB, but also on the other three freeways for transferability assessment. It was found that the predictive model derived from one freeway can be readily applied to other freeways, although the classification performance decreases. The models which transfer best to other roadways were found to be those that use the least number of VDSs–that is, using one upstream and downstream station rather than two or three.
The classification accuracy of the models is discussed in terms of how the models can be used for real-time crash risk assessment, which may be helpful to authorities for freeway segments with newly installed traffic surveillance apparatuses, since the real-time crash risk assessment models from nearby freeways with existing infrastructure would be able to provide a reasonable estimate of crash risk. These models can also be applied for developing and testing variable speed limits (VSLs) and ramp metering strategies that proactively attempt to reduce crash risk.
The robustness of the model output is assessed by location, time of day and day of week. The analysis shows that on some locations the models may require further learning due to higher than expected false positive (e.g., the I-680/I-280 interchange on US-101 NB) or false negative rates. The approach for post-processing the results from the model provides ideas to refine the model prior to or during the implementation.
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Elleuch, Fatma. "Transférabilité d'une modélisation-simulation multi-agents : le comportement inter-gares des voyageurs de la SNCF lors des échanges quai-train." Thesis, Paris, CNAM, 2019. http://www.theses.fr/2019CNAM1227/document.
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Les travaux de cette thèse portent sur la définition et la validation d’une méthode de modélisation-simulation de foule permettant le transfert des principes et des mesures établis dans un contexte source d'observations vers des contextes cibles, non observables a priori. A partir de l'observation de comportements de piétons d’un contexte environnemental, social et urbain, nous inférons les règles et des motivations, rendant possible la modélisation et la simulation du comportement individuel de piétons dans ce contexte source, puis à évaluer la transférabilité du modèle dans un autre contexte cible. Nous appuyons nos travaux sur un cas réel. Il s’agit de la simulation du comportement des voyageurs entrants et sortants des trains dans une gare à fort trafic. Après une revue des théories, de modèles de simulation, nous retenons une approche basée sur la simulation microscopique d’agents sociaux, situés, basée sur les motivations. Nous argumentons le choix par le fait que, par rapport à une simulation de foule classique elle, a priori, l’avantage de favoriser la transférabilité. L’objectif de cette simulation est d’étudier, entre autres, les évolutions architecturales des stations permettant de raccourcir les temps d’arrêt des trainsThis thesis focuses on the definition and the validation of a crowd-simulation modeling method. This method allows transferring principles and measurements established in a source observation context to a target one. From the observation of pedestrian behavior in a social and urban context, our approach infers rules and motivations in order to model and simulate the individual pedestrian behavior in this source context. This allows, in a second step, to evaluate the transferability of the model to a given target context. Our work is based on a real case: the simulation of the passenger’s behavior while boarding and alighting trains (platform-train exchange) in a high-traffic station (dense situation). Starting from the state of the art of theories, models and types of simulation, we choose an approach based on the microscopic simulation of social agent’s motivation. This choice relies mainly on the fact that, compared to a classic crowd simulation, it has, a priori, a better transferability potential. The goal of this type of simulation is to study the architectural evolutions of the stations that could allow to control or shorten train dwell times
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Huang, Yingchun [Verfasser], and András [Akademischer Betreuer] Bárdossy. "Study on the spatial and temporal transferability of conceptual hydrological models / Yingchun Huang ; Betreuer: András Bárdossy." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2016. http://d-nb.info/1135185255/34.
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Huang, Jian. "Assessing predictive performance and transferability of species distribution models for freshwater fish in the United States." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/73477.
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Rigorous modeling of the spatial species distributions is critical in biogeography, conservation, resource management, and assessment of climate change. The goal of chapter 2 of this dissertation was to evaluate the potential of using historical samples to develop high-resolution species distribution models (SDMs) of stream fishes of the United States. I explored the spatial transferability and temporal transferability of stream–fish distribution models in chapter 3 and chapter 4 respectively. Chapter 2 showed that the discrimination power of SDMs for 76 non-game fish species depended on data quality, species' rarity, statistical modeling technique, and incorporation of spatial autocorrelation. The area under the Receiver-Operating-Characteristic curve (AUC) in the cross validation tended to be higher in the logistic regression and boosted regression trees (BRT) than the presence-only MaxEnt models. AUC in the cross validation was also higher for species with large geographic ranges and small local populations. Species prevalence affected discrimination power in the model training but not in the validation. In chapter 3, spatial transferability of SDMs was low for over 70% of the 21 species examined. Only 24% of logistic regression, 12% of BRT, and 16% of MaxEnt had AUC > 0.6 in the spatial transfers. Friedman's rank sum test showed that there was no significant difference in the performance of the three modeling techniques. Spatial transferability could be improved by using spatial logistic regression under Lasso regularization in the training of SDMs and by matching the range and location of predictor variables between training and transfer regions. In chapter 4, testing of temporal SDM transfer on independent samples resulted in discrimination power of the moderate to good range, with AUC > 0.6 for 80% of species in all three types of models. Most cool water species had good temporal transferability. However, biases and misspecified spread occurred frequently in the temporal model transfers. To reduce under- or over-estimation bias, I suggest rescaling the predicted probability of species presence to ordinal ranks. To mitigate inappropriate spread of predictions in the climate change scenarios, I recommended to use large training datasets with good coverage of environmental gradients, and fine-tune predictor variables with regularization and cross validation.Ph. D.
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Wittwer, Rico. "Raumstrukturelle Einflüsse auf das Verkehrsverhalten - Nutzbarkeit der Ergebnisse großräumiger und lokaler Haushaltsbefragungen für makroskopische Verkehrsplanungsmodelle." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2008. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1201084936499-97472.
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Für die Verkehrsnachfragemodellierung stehen dem Planer sehr differenzierte Modellansätze zur Verfügung. Ein wesentliches Unterscheidungskriterium stellt dabei der Modellierungsgegenstand dar. Der Fokus der vorliegenden Arbeit ist auf makroskopische Verkehrsplanungsmodelle gerichtet. Es wird der Frage nachgegangen, in welcher Form die Ergebnisse großräumiger und lokaler Haushaltsbefragungen effizient bzw. sich gegenseitig ergänzend in Modellierungsaufgaben Einsatz finden können. Im Mittelpunkt der empirischen Datenanalyse steht die Frage, ob ein Unterschied in der Ausprägung zentraler modellierungsrelevanter Kenngrößen differenziert nach Raumtypen statistisch belegbar und planungspraktisch bedeutsam ist. Vor diesem Hintergrund wird auch die Auswirkung der komplexen Stichprobenpläne von MiD 2002 und SrV 2003 auf die Varianz der Parameterschätzung berücksichtigt. Ein in dieser Arbeit entwickelter, mehrstufiger Bewertungsalgorithmus, der dem Signifikanz-Relevanz-Problem hinreichend Rechnung trägt, bildet die Grundlage der Hypothesenprüfung. Er verbindet das Standardvorgehen (Signifikanztest) mit normativ gesetzten Effektgrößen und dem schätzerbasierten Vorgehen (Konfidenzintervalle). Eine besonders hohe Transparenz und Entscheidungskonsistenz erlangt der Ansatz dadurch, dass die Hypothesenprüfung auf Basis zweier voneinander unabhängig erhobener Untersuchungsgruppen (MiD, SrV) erfolgt. Die intensive Arbeit mit den Datengrundlagen MiD und SrV liefert eine Vielzahl von Erkenntnissen zur weiteren Qualifizierung des Erhebungsinstrumentes „Mobilität in Städten – SrV“. In Vorbereitung der im Jahre 2008 anstehenden Neuauflage der Erhebungsreihe wird nach Ansicht des Autors mit der Arbeit ein wesentlicher Impuls zur Weiterentwicklung der Methodik gegeben.
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Soret, Clément. "Dimensionnement de canalisations sur des critères en déformation dans des environnements extrêmes." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEM044/document.
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Les standards consacrés à la conception des oléoducs se concentrent principalement sur les chargements opérationnels, tels que les pressions internes et externes, et les procédures d'analyse de défauts actuelles n'exploitent pas les capacités d'écrouissage du matériau. Pourtant, dans des conditions extrêmes, les oléoducs peuvent être soumis à des contraintes au-delà de la limite d'élasticité jusqu'à atteindre 2.5% de déformations plastiques. Ici, les procédures proposées par ExxonMobil et PRCI basées sur des critères en déformation sont présentées, et l'utilisation de l'éprouvette SENT (Single Edge Notched Tension) pour caractériser la ténacité est étudiée, en comparant les différentes procédures d'essais recommandées. Puis, une importante campagne expérimentale a été réalisée pour caractériser deux aciers pour oléoducs à température ambiante et à basses températures. Les comportements mécaniques des matériaux de base et d'apport ont été identifiés grâce à l'utilisation de l'analyse inverse, et il est montré que le modèle d'endommagement GTN permet de modéliser finement les essais sur éprouvettes de laboratoire. Enfin, deux essais sur structures (pression et flexion, puis pression et traction) ont été réalisés de manière à comparer les approches globales et le modèle d'endommagement GTN. Ce dernier démontre une bonne transférabilité de l'éprouvette vers la structurePipeline design codes and standards traditionally focus on the operational loadings such as internal and external pressures that are likely to exist over the entire lifetime of the pipeline. Existing Engineering Critical Assessments are mostly based on stress considerations, where the design margin is given as a percentage of the yield strength. In extrem environments, pipelines may experience stresses beyond the yield and plastic deformations up to 2.5 %. In such conditions, strain-based design procedures apply. In this work, a literature review of the existing strain based methods is proposed, including ExxonMobil and PRCI multi-tier approaches. The use of the Single Edge Notched Tension (SENT) specimen to measure the material toughness is then studied, benchmarking the recommended testing procedures from literature. A comprehensive experimental campaign was carried out to fully characterize two actual line pipes at room and low temperatures. The mechanical behavior of parent and weld materials are identified using an inverse analysis, and GTN damage model is shown to allow accurate modeling of the laboratory testings. Finally, two full scale tests (pressure + bending or pressure + tension) were carried out to benchmark the global approaches and GTN damage model. The latter showed a very good transferability from specimens to the structure
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Wittwer, Rico. "Raumstrukturelle Einflüsse auf das Verkehrsverhalten - Nutzbarkeit der Ergebnisse großräumiger und lokaler Haushaltsbefragungen für makroskopische Verkehrsplanungsmodelle." Doctoral thesis, Technische Universität Dresden, 2007. https://tud.qucosa.de/id/qucosa%3A24043.
Full textAbstract:
Für die Verkehrsnachfragemodellierung stehen dem Planer sehr differenzierte Modellansätze zur Verfügung. Ein wesentliches Unterscheidungskriterium stellt dabei der Modellierungsgegenstand dar. Der Fokus der vorliegenden Arbeit ist auf makroskopische Verkehrsplanungsmodelle gerichtet. Es wird der Frage nachgegangen, in welcher Form die Ergebnisse großräumiger und lokaler Haushaltsbefragungen effizient bzw. sich gegenseitig ergänzend in Modellierungsaufgaben Einsatz finden können. Im Mittelpunkt der empirischen Datenanalyse steht die Frage, ob ein Unterschied in der Ausprägung zentraler modellierungsrelevanter Kenngrößen differenziert nach Raumtypen statistisch belegbar und planungspraktisch bedeutsam ist. Vor diesem Hintergrund wird auch die Auswirkung der komplexen Stichprobenpläne von MiD 2002 und SrV 2003 auf die Varianz der Parameterschätzung berücksichtigt. Ein in dieser Arbeit entwickelter, mehrstufiger Bewertungsalgorithmus, der dem Signifikanz-Relevanz-Problem hinreichend Rechnung trägt, bildet die Grundlage der Hypothesenprüfung. Er verbindet das Standardvorgehen (Signifikanztest) mit normativ gesetzten Effektgrößen und dem schätzerbasierten Vorgehen (Konfidenzintervalle). Eine besonders hohe Transparenz und Entscheidungskonsistenz erlangt der Ansatz dadurch, dass die Hypothesenprüfung auf Basis zweier voneinander unabhängig erhobener Untersuchungsgruppen (MiD, SrV) erfolgt. Die intensive Arbeit mit den Datengrundlagen MiD und SrV liefert eine Vielzahl von Erkenntnissen zur weiteren Qualifizierung des Erhebungsinstrumentes „Mobilität in Städten – SrV“. In Vorbereitung der im Jahre 2008 anstehenden Neuauflage der Erhebungsreihe wird nach Ansicht des Autors mit der Arbeit ein wesentlicher Impuls zur Weiterentwicklung der Methodik gegeben.
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Mpofana, Mziwonke Milton. "Transferability of Policies and Organisational Practices across Public and Private Health Service Delivery Systems: A Case Study of Selected Hospitals in the Eastern Cape: Exploring Lessons, Ambiguities and Contradictions." University of the Western Cape, 2016. http://hdl.handle.net/11394/5638.
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Philosophiae Doctor - PhDSince the advent of South Africa's democracy in 1994 there have been several changes in the policy and legislative arena specifically promoting public-private-partnerships in the health sector. These initiatives have given rise to opportunities for inter-sectoral policy transfer under the rubric of ―best practices‖. This exploratory study examines the character, obstacles and contested nature of a selection of policy transfers between private and public health institutions in a single province of South Africa. The study looks at the dynamics at play around envisaged, current and past transfers of policies and organisational practices in relation to administrative systems and technologies used in four different hospital settings – two public and two private hospitals in the Eastern Cape Province of South Africa. This thesis explores the views of managers and labour organisations about policy transfer focusing on local contexts, and how various parties construct policy transfer, hence providing a perspective of policy at the ―plant‖ level. In this research, special focus is placed on different agents' role and understandings of their contexts and how and why policies move and contradictions of these developments. In-depth interviews were conducted at four major Eastern Cape hospitals. The thesis argues that in practice, policy transfer is messy, politicized and traversed by power and vested interests and that organised labour plays a key role in policy transfer process. The thesis focuses on the different philosophical/ideological underpinnings, socio-political values and operational environments in each sector. This study is designed to contribute to existing knowledge on practices particularly between the public and private sectors in order to widen the understanding of the complexity of transferability.
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Abeere-Inga, Emmanuel. "The Transferability of Land Use and Transport Systems Planning and Policy : Models within an integrated Framework: A Case Study of Cape Town and the Millennium Cities." Thesis, University of Manchester, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.516429.
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Deichmann, Gregor [Verfasser], der Vegt Nico [Akademischer Betreuer] Van, and Florian [Akademischer Betreuer] Müller-Plathe. "Coarse-Graining Based on Pair Interactions - Studies on Transferability and Dynamic Consistency in Coarse-Grained Models of Soft Matter / Gregor Deichmann ; Nico Van der Vegt, Florian Müller-Plathe." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2020. http://d-nb.info/1203301367/34.
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Deichmann, Gregor [Verfasser], Nico van der [Akademischer Betreuer] Vegt, and Florian [Akademischer Betreuer] Müller-Plathe. "Coarse-Graining Based on Pair Interactions - Studies on Transferability and Dynamic Consistency in Coarse-Grained Models of Soft Matter / Gregor Deichmann ; Nico Van der Vegt, Florian Müller-Plathe." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2020. http://d-nb.info/1203301367/34.
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Neuser, Hannah. "Source Language of Lexical Transfer in Multilingual Learners : A Mixed Methods Approach." Doctoral thesis, Stockholms universitet, Engelska institutionen, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-142050.
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The study reported in this thesis investigates the source language of lexical transfer in multilingual learners using a mixed methods approach. Previous research has shown that the source language of crosslinguistic influence can be related to factors such as proficiency, recency/exposure, psychotypology, the L2 status, and item-specific transferability. The present study employed a mixed methods approach in order to best serve the particularities of each of the five factors under investigation. Multinomial logistic regression was emloyed to test the predictive power of the first four factors, thereby addressing the issue of confounding variables found in previous studies. A more exploratory qualitative analysis was used to investigate item-specific transferability due to the lack of prior empirical studies focusing on this aspect. Both oral and written data were collected, offering an analysis of modal differences in direct comparison. The results show a significant effect of proficiency and exposure, but inconsistent patterns for psychotypology. Most importantly, in this study of lexical transfer, a significant L1 status effect was found, rather than an L2 status effect. In addition, the statistical model predicted the source language of transfer better in the spoken than in the written mode. Finally, learners were found to assess, as well as actively improve, an item’s transferability in relation to target language norms and constraints. All of these findings contribute to our understanding of lexical organization, activation, and access in the multilingual mind.
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Hliwa, Mohamed. "Traitement simplifie des interactions moleculaires en chimie quantique." Toulouse 3, 1988. http://www.theses.fr/1988TOU30038.
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Calculs ab initio sur le systeme hautement degenere cr h: mise en evidence d'un fort couplage entre etats ioniques et neutres et analyse des fonctions d'onde dans une description diabatique. Proposition d'une methode perturbative pour calcul des energies de dispersion entre un systeme versatil a (decrit dans une grande base) et un systeme quasi passif b (traite a l'approximation en coeur gele et caracterise par sa polarisabilite); calcul scf + ci de (a + b gele), du champ electrique exerce par a sur b, et de ses fluctuations, a l'aide d'un hamiltonien effectif; application a l'etude des courbes de potentiel des premiers etats excites des molecules diatomiques de ar avec na, k ou mg. Emploi de la theorie des pseudopotentiels et des potentiels modeles pour le calcul de potentiels impulsifs d'atomes inertes transferables a des systemes moleculaires; a partir de ces potentiels, calcul d'energies de dispersion applicable a la spectroscopie d'atomes alcalins en matiere de gaz rare
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Lu, Kai-Pin, and 劉凱平. "A Study on The Urban Disaggregate Modal Switching Behavior and Transferability of Mode Choice Model." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/74202007533227859606.
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碩士淡江大學
土木工程研究所
83
In the process of evaluating the transportation plans and policies, we often have to use a lot of resources in the data collection. In order to improve the efficiency, we can develop a method of transferability of mode choice model. Thus this study ， explores the urban dissaggregate modal switching (DMS) behavior and transferability of dissaggregate mode choice model before untroducting a rapid transit system. The DMS model adopts revealed preference (PR) model , stated preference (SP) model and the RP-SP combined model. Employ the revealed preference data and the stated preference data before analyzing the impact of brown line and red line rapid transits while introducing them to Taipei Metropolitan area. Based on the trip purpose, we can divided all-trip data into two parts ： the work-trip and non-work-trip. The spatial transferability DMS model is compared with three procedures in order to get the best fit. The results of empirical study indicate that the performance of the " Reference Model " is superior to the other models. On the other hand, RP-SP combined model can explains the essentials of both RP and SP models. In addition, the transferability evaluation is based on both statistical test and naive aggregation procedure. The transferability method of " Adjustment of Alternative-Specific Constants and Scale Parameters " is the best according to statistical tests. The transferability method of "Adjustmen of Alternative - Specific Constant " posses transfer value in naive aggregation procedure.Transferability of " Combined Transfer Estimators and Bayesian Estimators " are well either from statistical test or naive aggregation procedure. The results of the study can be also applied to other lines of rapid transit.
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Hadayeghi, Alireza. "Use of Advanced Techniques to Estimate Zonal Level Safety Planning Models and Examine their Temporal Transferability." Thesis, 2009. http://hdl.handle.net/1807/17768.
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Historically, the traditional planning process has not given much attention to the road safety evaluation of development plans. To make an informed, defensible, and proactive choice between alternative plans and their safety implications, it is necessary to have a procedure for estimating and evaluating safety performance. A procedure is required for examining the influence of the urban network development on road safety, and in particular, determining the effects of the many variables that affect safety in urban planning.
Safety planning models can provide a decision-support tool that facilitates the assessment of the safety implications of alternative network plans. The first objective of this research study is to develop safety planning models that are consistent with the regional models commonly used for urban transportation planning. Geographically weighted Poisson regression (GWPR), full-Bayesian semiparametric additive (FBSA), and traditional generalized linear modelling (GLM) techniques are used to develop the models. The study evaluates how well each model is able to handle spatial variations in the relationship between collision explanatory variables and the number of collisions in a zone. The evaluation uses measures of goodness of fit (GOF) and finds that the GWPR and FBSA models perform much better than the conventional GLM approach. There is little difference between the GOF values for the FBSA and GWPR models.
The second objective of this research study is to examine the temporal transferability of the safety planning models and alternative updating methods. The updating procedures examine the Bayesian approach and application of calibration factors. The results show that the models are not temporally transferable in a strict statistical sense. However, relative measures of transferability indicate that the transferred models yield useful information in the application context. The results also show that the updated safety planning models using the Bayesian approach predict the number of collisions better than the calibration factor procedure.
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Wafa, Zeina. "A latent-segmentation based approach to investigating the spatial transferability of activity-travel models." Thesis, 2014. http://hdl.handle.net/2152/28098.
Full textAbstract:
Spatial transferability of travel demand models has been an issue of considerable interest, particularly for small and medium sized planning areas that often do not have the resources and staff time to collect large scale travel survey data and estimate model components native to the region. With the advent of more sophisticated microsimulation-based activity-travel demand models, the interest in spatial transferability has surged in the recent past as smaller metropolitan planning organizations seek to take advantage of emerging modeling methods within the limited resources they can marshal. Traditional approaches to identifying geographical contexts that may borrow and transfer models between one another involve the exogenous a priori identification of a set of variables that are used to characterize the similarity between geographic regions. However, this ad hoc procedure presents considerable challenges as it is difficult to identify the most appropriate criteria a priori. To address this issue, this thesis proposes a latent segmentation approach whereby the most appropriate criteria for identifying areas with similar profiles are determined endogenously within the model estimation phase, customized for every model type. The end products are a set of optimal similarity measures that link regions to one another as well as a fully transferred model, segmented to account for heterogeneity in the population. The methodology is demonstrated and its efficacy established through a case study that utilizes the National Household Travel Survey (NHTS) dataset for information on weekday activities unemployed individuals within 9 regions in the states of California and Florida engage in. A multiple discrete continuous extreme value (MDCEV) model is developed that simulates the discrete nature of activity selection as well as the continuous nature of activity participation. The estimated model is then applied onto the Austin–San Marcos MSA, a context withheld from the original estimation in order to assess its performance. The performance of the segmented model was then examined vis-à-vis that of other models that are similar to the local region in only one dimension. It is found that the methodology offers a robust mechanism for identifying latent segments and establishing criteria for transferring models between areas.text
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Hsieh, Iuan Jiun, and 謝淵鈞. "The temporal transferability of intercity disaggregate mode choice models." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/79872019096249016851.
Full textAbstract:
碩士國立成功大學
交通管理(科學)學系
85
ABSTRACT This research discussed the temporal transferability of intercity disaggregate mode choice models by the updating techniques and model fitness. The intercity travel data were collected in the Taipei-Tainan corridor between 1994 to 1997 for the empirical study. Beside provides comparison of four updating techniques within different model specification, this research using combined transfer estimation to compare the model transferability within different utility models. At the end, the sensitivity analysis is applied to discuss model transfer performance. The empirical results showed:1.Model specification affects the perfomance of updating techniques and updating effect.2.Among the four updatings techniques, joint context estimation and combined transfer estimation have a better performance than others. For further measurement, it indicate that joint context estimation is the most effective updating method.3.There''s no difference in transfer effectiveness between earlier and later updating models.4.The indifference threshold models and the tradtional multinomial logit models are transferable when using combined transfer estimation. Every measures indicate the former models are better than the latter ones.5.The sensitivity analysis indicate all updating models can correctly reflect the changes of the market share. By the percentage of aggregate prediction error measure, the combinded transfer estimation and joint context estimation are superior to others. Some models such as Bayesian updating model which have bad performance in statistics may become better in aggregate forecasting.
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Weaver, Jennifer Elisabeth. "Invasive Species Distribution Models: An Analysis of Scale, Sample Selection Bias, Transferability and Prediction." Thesis, 2012. http://hdl.handle.net/1807/43940.
Full textAbstract:
Species distribution models must balance the need for model generality with that for precision and accuracy. This is critical when modelling range-expanding species such as invasive species. Given the increased use of species distribution models to study invasive species-landscape relationships, a better understanding of the effect of spatial scales, sampling biases, model transferability and discrepancies between different models’ future predictions is necessary. This dissertation addresses these knowledge gaps using mute swans (Cygnus olor) as a case study species. I specifically examine mute swan’s distributions in parts of their native range of Britain and their non-native range of Ontario, Canada. I first investigate which environmental variables at which spatial scales best explain mute swan’s distribution in its non-native range. Second, I perform a sample selection bias study to examine predictive accuracy when species distribution models are built using varying ranges of environmental variables and applied to broader spatial extents. Third, I examine the potential for, and limitations of model transferability between native and non-native regions. Finally, I use two different modelling approaches and three different climate change and land use change scenarios to predict future mute swan habitat suitability. The results indicate that (1) models with better predictive accuracy include environmental variables from multiple ecologically-meaningful scales and measured at spatial extents that include a broad range of environmental variable values; (2) models can exhibit asymmetrical transferability; (3) climate change will facilitate mute swan range expansion in the future more than land use change; and (4) mute swans are often found near urban waterbodies. When modelling invasive species distributions, I suggest that ecologists consider: (I) spatial scale of the underlying landscape processes and species’ use of the landscape; (II) variability and range of each environmental variable used for building models; and (III) stage of establishment of the invasive species.
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Silveira, Luís Filipe Oliveira. "Validating the transferability of ecological models under global change scenarios with Holocene rock-art." Dissertação, 2019. https://hdl.handle.net/10216/124797.
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Silveira, Luís Filipe Oliveira. "Validating the transferability of ecological models under global change scenarios with Holocene rock-art." Master's thesis, 2019. https://hdl.handle.net/10216/124797.
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Chang, Yu-Min, and 張鈺敏. "Transferability of 10 Tree Species' Distribution Models by MaxEnt from the Mountain Forest, Northeast Taiwan." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/65443590089337031572.
Full textAbstract:
碩士國立東華大學
自然資源管理研究所
97
The explicabilities of Species Distribution Models are count on their transfer abilities. There are many different factors with potential to affect transferability of SDM, including species’ characteristics themselves, environmental layers employed, and the nature of modelling method. All of these processes work under an ecological hierarchy system with highly complexity. As a relative young island in geology, Taiwan is a subtropical island with hilly landscape and complex climate. To apply SDM on this island, the representatives of environmental layers on the meanings of ecological processes affect species’ distribution are the key. Meanwhile, hilly landscape limits the resolution of environmental layers as well. Among various models, MaxEnt is recognized as one approach of SDM with good performance on transferability since it’s developed based on the maximum-entropy principle such that approximation can be on unknown distribution subject to given environmental constraints. As a preliminary study, terrain layers in resolution 40 m × 40 m were employed in this study. Ten tree species were chosen as modeled species to prevent the uncertainty of animal species’ nature to affect transferability of models. At the present time, the available environmental variables obtained from the Taiwan Information Vegetation System species distribution are far from adequate to ensure a plausible outcome of the species distribution modeling. MaxEnt and its associated Jackknife analysis were used to evaluate the contribution (training gain) of 14 environmental variables. Elevation stands out as the most important variable to the estimated distribution. As a result, most transferred models showed good transferability. Since all the environmental variables used here are just terrain variables, as application the SDM on assessment of climate change impacts is questionable. Other direct limiting factors as environmental layers on species distribution model are suggested.
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Everett, Jerry Don. "An Investigation of the Transferability of Trip Generation Models and the Utilization of aSpatial Context Variable." 2009. http://trace.tennessee.edu/utk_graddiss/47.
Full textAbstract:
The cost of collecting data for travel demand modeling is high and increasing each year. Data collection costs could easily exceed the annual budget of a metropolitan planning organization (MPO) in small or medium-sized area. Many of these agencies borrow or transfer data and/or models from other areas since they cannot afford the cost of collecting local data. This study included two primary research objectives. The first was to test the appropriateness of transferring commonly used trip generation models from one urban area to another under specific circumstances. The second was to improve the transferability of models by including a variable reflecting the spatial context of households, the basic unit of trip generation used in most MPO models. The data utilized for this research were drawn from four separate travel surveys and included data for 11 metropolitan planning areas in two states.
The key finding of this research was that a meaningful consistent measure of spatial context can be included in trip generation models, and it can make these models more generic and transferable. This finding that the transferability of trip production models can be improved by including an additional variable called “Area Type” should be helpful to many MPOs, which have to borrow models or survey data from other areas. The data needed for developing this variable should not pose any difficulty since it is based on population data, which is readily available from the US Census Bureau. Further, the algorithm needed to stratify grid cells and the households located in them into different categories of Area Type is available in many geographic information system software packages including TransCAD, which is widely used by MPOs of all sizes.
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Abrantes, Bruno Tadeu Fernandes. "The internationalization paradigm and dynamic capabilities of Portuguese firms: contributions from case studies in the metallurgical and metal-mechanic sectors." Doctoral thesis, 2017. http://hdl.handle.net/10071/16556.
Full textAbstract:
Esta pesquisa mergulha na esfera microeconómica do setor secundário, visando iluminar os paradigmas de internacionalização das empresas Portuguesas. Um estudo de caso é conduzido nas empresas focais centrado no vértice estratégico. Uma revisão da literatura é realizada nos campos interdisciplinares das ciências económicas e da gestão, com uma focagem dualística no modelo processual de internacionalização de Uppsala e, comitantemente, na teoria das capacidades dinâmicas.
No contexto da indústria, o estudo centra-se no setor da metalurgia e metalomecânica. É seguido um
design comparativo, com uma configuração de caso múltiplo e unidades de análise incorporadas. Este
enquadra-se numa abordagem qualitativa e posição filosófica interpretativista, com uma orientação
dedutiva. A análise de dados está enraizada num quadro metodológico triádico: o procedimento
analítico geral de Miles e Huberman (1984), o protocolo de Weber (1990) e o quadro de referência
de Gioia (2009).
Os casos exibem uma realidade de internacionalização multiparadigmática, com heterogeneidade
entre si e sobreposição dimensional de alguns fenómenos, aderindo de forma distinta ao modelo de
Uppsala e à teoria das capacidades dinâmicas. Em segundo lugar, os construtos seminais abordados
na problemática de partida revelam efeitos distintos. Verificou-se uma relação positiva entre os
paradigmas de internacionalização observados e os fatores de distância psíquica. Os fatores de
distância geográfica, observam um efeito ambidexteriano (relação positiva e de espúrio). A última é
causada pelo fenómeno contingencial de perificidade económica (com raízes nas teorias Ricardiana
e Smithiana da competividade nacional e absoluta) revelando uma necessidade latente de políticas
públicas para restaurar o equilíbrio de forças com os outros mercados da UE e estimular os fluxos de
investimento para o exterior. Terceiro, as capacidades dinâmicas (CDs tipo 1 e 2) revelam processos
de reconfiguração orientados para a ambidexteridade internacional, porquanto as CD globais
demonstram sinais de mutabilidade e transferabilidade bidireccional para múltiplos pontos de destino.This research plunges into the microeconomic orb of the Portuguese economy of the secondary sector, aiming to illuminate the internationalization paradigms of these firms. A case research is conducted upon the focal firms focused on their strategic apex. A literature review is performed in the interdisciplinary fields of economics and managerial sciences, dualistically centered on the internationalization process model of Uppsala, and commitantly, at the dynamic capabilities theory. In the context of the manufacturing industries, this study focusses on the sector of metallurgy and metal-mechanic. A comparative design is followed, with a multiple case setting and embedded hermeneutic units of analysis. It fits a qualitative approach within an interpretative philosophical stance with a deductive orientation. The qualitative data analysis process is rooted in a triadic methodological framework: the general analytical procedure of Miles and Huberman (1984), the Weber protocol (1990) and the framework of Gioia (2009). The cases exhibited a multiparadigmatic internationalization reality, with heterogeneity among them although with some overlapping phenomena adhering differently to the U-model and to the dynamic capabilities doctrine. Second, seminal constructs addressed in the initial problematization revealed distintive relations. The psychic distance factors of the U-model were positively perceived as a true relation. The geographical distance factors observe an ambidexterian effect - true and spurious. The latter caused by the contingency phenomenon of economic periphery uncovers a latent need for public policies to retrieve the equilibrium of competitive forces with other EU markets and stimulate the outward flow of investment of the firms. Third, the DCs, both type 1 and type 2, exhibit processes of reconfiguration oriented towards international ambidexterity, while the GDCs evidence of DC mutability and indiscriminate bidirectional transferability.
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Everett, Jerry Don. "An investigation of the transferability of trip generation models and the utilization of a spatial context variable." 2009. http://trace.tennessee.edu/utk_graddiss/47.
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Deichmann, Gregor. "Coarse-Graining Based on Pair Interactions - Studies on Transferability and Dynamic Consistency in Coarse-Grained Models of Soft Matter." Phd thesis, 2020. https://tuprints.ulb.tu-darmstadt.de/9260/1/published_final_pdfa.pdf.
Full textAbstract:
Computer simulations of molecules and atoms are useful tools in soft matter research. Physical chemistry has profited significantly from the insight provided by the use of classical molecular dynamics simulations. In these simulations, atoms are modeled as point masses and their propagation in time and space is described by iterative solving of Newton’s equations of motion. A major challenge lies in the fact that the computational resources required to simulate systems at this resolution render atomistical simulations prohibitively expensive already at comparatively small time and length scales.
One approach to make simulations of given systems more efficient in computational terms is to coarse-grain the model, i.e., to reduce the spatial resolution by merging atoms into larger interaction sites. The procedure of coarse-graining consists of two steps: the definition of a mapping between the scales of resolution and the determination of suitable potentials for the interactions between the sites of the coarse-grained model.
Especially the second step is challenging because coarse-grained model needs to reproduce the physical behavior of the underlying (fine-grained) reference model as close as possible to retain its predictive quality. Several methods which share an approach described as systematic, bottom-up coarse-graining, have been published in the literature to determine interactions in the coarse-grained model from interactions in fine-grained (mostly atomistic) reference models of the systems of interest.
The transferability of a coarse-grained model, i.e, the capability of accurately reproducing predictions of the reference model at varying state points is especially dependent on the method chosen for the parameterization of the coarse-grained model. Among the existing systematic coarse-graining methods, the conditional reversible work (CRW) method achieves a high degree of transferability, while being conceptually simple, straightforward to implement and computationally efficient.
In this thesis, studies are presented which aim at an extension of the applications and systems of CRW-parameterized models. In a comparative study, the CRW method is used, among others, for the study of vapor-liquid equilibria and the thermodynamics of mixing with coarse-grained models of hexane and perfluorohexane. Results confirm the strong dependence of model transferability on the coarse-graining method chosen for its parameterization and show that the CRW models are transferable with respect to temperature, transfer from the interface to the bulk, transfer from the vapor to the liquid phase, and composition of a binary mixture.
In the existing literature, the CRW method has only been applied to systems of apolar hydrocarbons. This thesis presents studies in which CRW models are parameterized for systems of weakly polar organic molecules and ionic liquids. The resulting CRW models are transferable to the same degree as those of apolar systems.
Another major challenge in the simulation with coarse-grained models is the reproduction of dynamic properties in accordance with fine-grained reference models. In general, the time scales of relaxation are smaller in coarser models and this leads to an effective ‘speed-up’ of these simulations, a behavior which is related to a loss of dissipative degrees of freedom in the coarser model. The effective impact of these degrees of freedom on the dynamics of the system can be simulated through the insertion of dissipative pair interactions into the coarse-grained model. These interactions can be parameterized, like the interaction potential energy, in a bottom-up manner from simulations with the fine-grained model. This approach, which is based on the Mori-Zwanzig projection operator formalism, has been successfully utilized in several recent publications to parameterize coarse-grained models that consistently model the dynamics of model systems at low density. However, the approach relies on assumptions on the nature of the system which are not fully satisfied at the higher density typical for soft matter systems. Most importantly, it is assumed that the degrees of freedom removed from the model upon coarse-graining relax infinitely fast in comparison with those retained in the coarse-grained model (complete time scale separation).
In this thesis, an application of such a procedure for a dynamically consistent coarse-grained model is presented for realistic model systems of soft matter. The aim of this study is to evaluate whether Mori-Zwanzig-based coarse-grained models can be used for the simulation of realistic soft matter systems, in which time scale separation is not complete.
To this end, coarse-grained models are parameterized for model systems of different chain length and the predictions of the dynamics produced by the coarse-grained system are compared to those of an atomistic reference model. The self-diffusion coefficients of these systems can be reproduced to a good degree, whereas dynamics properties with a smaller characteristic time scale are less well reproduced with the Mori-Zwanzig coarse-grained model, a finding that can be related to the increasing deviation of the system’s state from the assumed complete time scale separation.