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  • 1.
    Adolphson, Marcus
    KTH, Superseded Departments, Infrastructure.
    New urban settlements in a perspective of public and private interests2004Conference paper (Other academic)
  • 2. Ahmed, Niaz
    et al.
    Näsman, Per
    KTH, Superseded Departments, Infrastructure.
    Wahlgren, Nils Gunnar
    Effect of intravenous nimodipine on blood pressure and outcome after acute stroke2000In: Stroke, ISSN 0039-2499, E-ISSN 1524-4628, Vol. 31, no 6, 1250-1255 p.Article in journal (Refereed)
    Abstract [en]

    Background and Purpose-The Intravenous Nimodipine West European Stroke Trial (INWEST) found a correlation between nimodipine-induced reduction in blood pressure (BP) and an unfavorable outcome in acute stroke. We sought to confirm this correlation with and without adjustment for prognostic variables and to investigate outcome in subgroups with increasing levels of BP reduction. Methods-Patients with a clinical diagnosis of ischemic stroke (within 24 hours) were consecutively allocated to receive placebo (n=100), 1 mg/h (low-dose) nimodipine (n=101), or 2 mg/h (high-dose) nimodipine (n=94). The correlation between average BP change during the first 2 days and the outcome at day 21 was analysed. Results-Two hundred sixty-five patients were included in this analysis (n=92, 93, and 80 for placebo, low dose, and high dose. respectively). Nimodipine treatment resulted in a statistically significant reduction in systolic BP (SBP) and diastolic BP (DBP) from baseline compared with placebo during the first few days. In multivariate analysis, a significant correlation between DBP reduction and worsening of the neurological score was round for the high-close group (beta=0.49, P=0.048). Patients with a DBP reduction of greater than or equal to 20% in the high-dose group had a significantly increased adjusted OR for the compound outcome variable death or dependency (Barthel Index <60) (n/N=25/26, OR 10.16, 95% CI 1.02 to 101.74) and death alone (n/N=9/26, OR 4.3361 95% CI 1.131 16.619) compared with all placebo patients (n/N=62/92 and 14/92. respectively). There was no correlation between SEP change and outcome. Conclusions-DBP, but not SEP, reduction was associated with neurological worsening after the intravenous administration of high-dose nimodipine after acute stroke. For low-dose nimodipine, the results were not conclusive. These results do not confirm or exclude a neuroprotective property of nimodipine.

  • 3. Albertoni, Riccardo
    et al.
    Bertone, Alessio
    Demšar, Urška
    KTH, Superseded Departments, Infrastructure.
    De Martino, Monica
    Hauska, Hans
    KTH, Superseded Departments, Infrastructure.
    Knowledge Extraction by Visual Data Mining of Metadata in Site PlanningManuscript (Other academic)
    Abstract [en]

    The paper describes a tool designed within the first stage of the European project INVISIP in order to explore geographical metadata in the site planning process. A visual data mining approach is applied to a database of geographical metadata to help the user find an optimal subset of the existing geographical datasets for his particular planning task. It allows the user to perform both confirmative and explorative analysis. The approach is implemented in the Visual Data Mining tool, which integrates different types of visualisations with various interaction functionalities. It includes the interactive communication with the user and the brushing and linking process between different visualisations. The paper also presents an example of an application on a test metadatabase which was created for this purpose.

  • 4.
    Andersson, Mats B.
    KTH, Superseded Departments, Infrastructure.
    Hantering av osäkerhet i samband med investeringsbeslut – några metodansatser och exempel2004Licentiate thesis, monograph (Other scientific)
    Abstract [sv]

    Before you take a decision you can normally choose amongmany different alternatives. The alternatives can be rankeddepending on what net benefits they produce. The alternativewith the best net benefit is chosen. Within economicscost-benefit analysis may be used to decide which alternativeis likely to offer the best net benefit.

    Some time after the decision it may be found that theselected alternative turned out not to be as favourable asexpected. The reason is often that there are uncertainties inthe decision process. Sometimes this is not a major problemsince it is possible to change the decision or the costconsequences may be small.

    When the National Traffic Administrations make investmentslarge volumes of capital are involved. It is often difficult orvery expensive to change an investment when started. It istherefore essential to get an early knowledge about potentialuncertainties, which can affect the decision. Uncertainties canaccrue from incorrect input data. A reason for spreading ofuncertainties is the presence of dependencies among thevariables. The uncertainties are also usually dependent upontime.

    This thesis describes some methods to take uncertaintiesinto account in cost-benefit analysis before a decision istaken. The aim is both to identify the uncertainties and tooutline methods for coping with uncertainties.

    The methods rely on results in reliability theory and riskanalyses among others. Some statistical methods and discretedata models are also applied. The aim is to increase theprobability of selecting an alternative with high and stablenet benefits over a long time period.

    The cost-benefit estimates are divided into smaller parts tomake it possible to locate uncertainties. Descriptive andanalytical models are recommended for handling the cost-benefitstructure and the uncertainties found in its components.Dependencies among variables and, in particular, timedependencies are analysed.

    Throughout the thesis the various methods are applied to anexample referring to a road investment.

  • 5.
    Arousell, Patrik
    KTH, Superseded Departments, Infrastructure.
    Interregional freight flows: model system and estimation2002Licentiate thesis, monograph (Other scientific)
  • 6.
    Assefa, Getachew
    KTH, Superseded Departments, Infrastructure.
    Towards a systematic approach for technology assessment by combining material flow analysis, life cycle assessment and life cycle costing2002Licentiate thesis, comprehensive summary (Other scientific)
  • 7.
    Atterhög, Mikael
    KTH, Superseded Departments, Infrastructure.
    Vilka effekter har ökad kondurrens på bostadshyresmarknaden?2003Licentiate thesis, comprehensive summary (Other scientific)
  • 8.
    Azasu, Samuel
    KTH, Superseded Departments, Infrastructure.
    Using pay and benefits in real estate firms: an initial look at the Swedish experience2004Licentiate thesis, monograph (Other scientific)
  • 9. Ben-Akiva, M.
    et al.
    McFadden, D.
    Train, K.
    Walker, J.
    Bhat, C.
    Bierlaire, M.
    Bolduc, D.
    Boersch-Supan, A.
    Brownstone, D.
    Bunch, D. S.
    Daly, A.
    De Palma, A.
    Gopinath, D.
    Karlström, Anders
    KTH, Superseded Departments, Infrastructure.
    Munizaga, M. A.
    Hybrid choice models: Progress and challenges2002In: Marketing letters, ISSN 0923-0645, E-ISSN 1573-059X, Vol. 13, no 3, 163-175 p.Article in journal (Refereed)
  • 10.
    Berdica, Katja
    KTH, Superseded Departments, Infrastructure.
    TraVIS for Roads - Examples of Road Transport Vulnerability Impact Studies2002Doctoral thesis, comprehensive summary (Other scientific)
  • 11.
    Berggren, Björn
    et al.
    Uppsala University.
    Lundahl, Nicolaus
    KTH, Superseded Departments, Infrastructure.
    Silver, Lars
    Uppsala University.
    Vegholm, Fatima
    KTH, Superseded Departments, Infrastructure.
    Norrtäljeprojektet - En lägesrapport2004Report (Other academic)
  • 12.
    Berggren, Kersti
    KTH, Superseded Departments, Infrastructure.
    Varsam ombyggnad i ett riksintressant område2002Licentiate thesis, monograph (Other scientific)
  • 13.
    Berglund, Svante
    et al.
    KTH, Superseded Departments, Infrastructure.
    Karlström, Anders
    KTH, Superseded Departments, Infrastructure and Planning.
    Identifying local spatial association in flow data1999In: Journal of Geographical Systems, ISSN 1435-5930, E-ISSN 1435-5949, Vol. 1, no 3, 219-236 p.Article in journal (Refereed)
    Abstract [en]

    In this paper we develop a spatial association statistic for flow data by generalizing the statistic of Getis-Ord, Gi (and Gi*). This local measure of spatial association, Gij, is associated with each origin-destination pair. We define spatial weight matrices with different metrics in flow space. These spatial weight matrices focus on different aspects of local spatial association. We also define measures which control for generation or attraction nonstationarity. The measures are implemented to examine the spatial association of residuals from two different models. Using the permutation approach, significance bounds are computed for each statistic. In contrast to the Gi statistic, the normal approximation is often appropriate, but the statistics are still correlated. Small sample properties are also briefly discussed.

  • 14.
    Beser Hugosson, Muriel
    KTH, Superseded Departments, Infrastructure.
    Issues in Estimation and Application of Long Distance Travel Demand Models2003Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Forecasts of the demand for long distance travel areessential for many decisions, such as infrastructureinvestments, operators´management policies etc. Manyresearch issues are related to this field, and the purpose ofthis thesis is to contribute to some of them. Paper I Modellingchoice of flight and booking class–a study using Stated Preference and Revealed Preference data goes into theinteresting issue of modelling departure time and ticket typechoices. The data used in the estimation process were acombination of revealed preference (RP) data and statedpreference (SP) data. A model was developed to estimaterecapture and buyup to improve the SAS (Scandinavian AirlinesSystem) yield management system. Paper II Endogenoussegmentation applied to long distance business trips in Swedenis related to the possibilities of identifying market segmentsthat differ in travel behaviour. The procedure of endogenoussegmentation has been explored to identify different tastesegments in a population. The results indicate that the methodis an efficient way of identifying market segments andoutperforms the traditional manual segmentation when modelefficiency is the objective.

    The restrictive assumption of independent distributed randomcomponents in the logit model utility function can be relaxedby finding a suitable nesting structure. The task ofestablishing such structures, another crucial issue in traveldemand model development, is further analysed in papers IIIExploring the HEV model to improve nesting structures of modelsfor Swedish long distance private trips and paper IV Enhancingmodel structure and treatment of incomplete geocodes in SAMPERSlong distance models. In paper III a technique to identifyscale parameters for separate alternatives is used. Based onthis, different nesting structures are tested and the resultsare compared with the old mode choice model for long distancetrips in Sweden. This paper leads to paper IV, where similarnesting structures were tested on the long distance mode anddestination choice model in the SAMPERS system. Paper IV alsodeals with data problems, as the destination coding wasincomplete. A final model formulation, related to these issuesis suggested. To turn the view a bit beside the pure estimationtechniques and structures used in the estimation of differentmodels, paper V Quantifying uncertainties in the SAMPERS longdistance forecasting model system considers uncertaintiesrelated to the fact that models are estimated on a sample of apopulation. The bootstrap method, a computer intensivestatistical method, can be used to compute statistical measuresfor very complex systems, without being bound to an analyticalapproach. The bootstrap method is applied on the SAMPERSsystem, and numerical results are presented on different modelsystem output levels.

  • 15.
    Brokking, Peter
    et al.
    KTH, Superseded Departments, Infrastructure.
    Schmidtbauer Crona, Jan
    KTH, Superseded Departments, Land and Water Resources Engineering.
    Eriksson, Inga-Maj
    Swedish National Road Administration.
    Balfors, Berit
    KTH, Superseded Departments, Land and Water Resources Engineering.
    SEA in Swedish Transportation Policy-making and Planning: Political Ambitions and Practice2004In: European Environment, ISSN 0961-0405, E-ISSN 1099-0976, Vol. 14, no 2, 94-104 p.Article in journal (Refereed)
    Abstract [en]

    Since the mid-1990s, the aim to incorporate SEA into Swedish strategic transportation planning has been repeatedly expressed in government documents and directives. To support a successful implementation, efforts have been made to develop tools and methods for the integration of SEA into strategic transportation planning. These efforts concern, for example, the application of SEA in corridor development and long-term transportation planning. The practical experiences of SEA in strategic transportation planning have been influenced by the ambiguity of the scope and structure of SEA. In this paper the process of implementing the SEA in Swedish transportation planning will be reviewed. The review relates to political ambitions and practice, and highlights the methodological development of SEA applications in the Swedish transport sector.

  • 16.
    Brunes, Fredrik
    KTH, Superseded Departments, Infrastructure.
    Do investors behave myopically whendeciding to invest in office buildings? Anempirical study using Tobins Q.Manuscript (preprint) (Other academic)
    Abstract [en]

    The purpose of this paper is to build a regression model using the investment rule “Tobins Q”(TQ). TQ is the quota of the market price and the replacement cost of a good. TQ indicatewhen there is potential in the market to build and sell office buildings. We have used data formarket price, construction cost and production for a period of 22 years for a suburban officemarket in Stockholm. TQ has been regressed on newly produced offices with different timelags. The result indicates that, with our model, we can with TQ decision rule explain theproduction of office space better with a three-year lag on TQ than with no lag. The resultmight indicate that investors have myopic view.

  • 17.
    Brunes, Fredrik
    KTH, Superseded Departments, Infrastructure.
    Overbuilding in office markets, a behaviouralapproach to investigate possible explanations.Manuscript (preprint) (Other academic)
    Abstract [en]

    The purpose of this paper is to apply behavioural theories on the decision-makers in theoffice-building sector. The market has a well-known feature of cycles of production. This cansometimes lead to overbuilding. This paper tries to illuminate the problem with overbuildingby using economic behavioural theory developed the last 25 years. We have formulated sixpossible behavioural explanations for overbuilding. The method we have used is partly byinterviewing investors about specific projects and partly by a survey, which was sent out toindependent persons that has followed the office market for a long time. Our results indicatethat myopic behaviour and sunk cost fallacy have influenced decision makers.

  • 18.
    Burghout, Wilco
    KTH, Superseded Departments, Infrastructure.
    Hybrid microscopic-mesoscopic traffic simulation2004Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    Traffic simulation is an important tool for modelling the operations of dynamic traffic systems and helps analyse the causes and potential solutions of traffic problems such as congestion and traffic safety. Microscopic simulation models provide a detailed representation of the traffic process, which makes them most suitable for evaluation of complicated traffic facilities and Intelligent Transportation Systems that often consist of complex traffic management, safety and information systems. Macroscopic and mesoscopic models on the other hand, capture traffic dynamics in lesser detail, but are faster and easier to apply and calibrate than microscopic models. Therefore they are most suitable for modelling large networks, while microscopic models are usually applied to smaller areas.

    The objective of this thesis is to combine the strengths of both modelling approaches and diminish their individual weaknesses by constructing a hybrid mesoscopic-microscopic model that applies microscopic simulation to areas of specific interest, while simulating a surrounding network in lesser detail with a mesoscopic model.

    Earlier attempts at hybrid modelling have concentrated on integrating macroscopic and microscopic models and have proved difficult due to the large difference between the continuous-flow representation of traffic in macroscopic models and the detailed vehicle-and driver-behaviour represented in microscopic models. These problems are solved in this thesis by developing a mesoscopic vehicle-based and event-based model that avoids the (dis)aggregation problems of traffic flows at the inter-model boundaries. In addition, this thesis focuses on the general problems of consistency across the entire hybrid model.

    The requirements are identified that are important for a hybrid model to be consistent across the models at different levels of detail. These requirements vary from network and route-choice consistency to consistency of traffic dynamics across the boundaries of the micro- and mesoscopic submodels. An integration framework is proposed that satisfies these requirements. This integration framework has been implemented in a prototype hybrid model, MiMe, which is used to demonstrate the correctness of the solutions to the various integration issues. The hybrid model integrates MITSIMLab, a microscopic traffic simulation model, and Mezzo, the newly developed mesoscopic model. Both the hybrid model and the new Mezzo model are applied in a number of case studies, including a network in the North of Stockholm, which show their validity and applicability. The results are promising and support both the proposed integration architecture and the importance of integrating microscopic and mesoscopic models.

  • 19.
    Burghout, Wilco
    et al.
    KTH, Superseded Departments, Infrastructure.
    Koutsopoulos, Haris
    Andreasson, Ingmar
    KTH, Superseded Departments, Infrastructure.
    Hybrid mesoscopic-microscopic traffic simulation2004Conference paper (Refereed)
  • 20.
    Bäckman, Johan
    KTH, Superseded Departments, Infrastructure.
    Railway Safety - Risks and Economics2002Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    Safety analysis is a process involving several techniques.The purpose of this thesis is to test and develop methodssuitable for the safety analysis of railway risks and railwaysafety measures. Safety analysis is a process comprisingproblem identification, risk estimation, valuation of safetyand economic analysis. The main steps are described in separatechapters, each of which includes a discussion of the methodsand a review of previous research, followed by the contributionof this author. Although the safety analysis proceduredescribed can be used for analysing railway safety, it has suchgeneral foundations that it can be used wherever safety isimportant and wherever safety measures are evaluated. Itcombines cost benefit analysis with criteria for thedistribution and the absolute levels of risk.

    Risks are estimated with both statistical and risk analysismethods. Historical data on railway accidents are analysed andstatistical models fitted to describe trends in accident ratesand consequences. A risk analysis model is developed usingfault tree and event tree techniques, together with Monte Carlosimulation, to calculate risks for passenger train derailments.The results are compared with the statistical analysis ofhistorical data.

    People's valuation of safety in different contexts isanalysed, with relative values estimated in awillingness-to-pay study. A combination of focus groups andindividual questionnaires is used. Two different methods areused to estimate the value of safety and the results arecompared. Comparisons are also made with other studies.

    Different approaches for safety analysis and methods foreconomic analysis of safety are reviewed. Cost-benefit analysisas a decision criterion is discussed and a study on theeconomic effectsof a traffic control system is presented.

    There are several results of the work. Historical data showsa decrease in the accident rate. The average consequence ofeach accident has not changed over time. The risk analysismodel produces comparable results and enables analysis ofvarious safety measures. The valuation study shows that peopleprefer the prevention of small-scale accidents over theprevention of larger, catastrophic accidents. There are onlysmall differences in the valuation of safety in differentcontexts.

  • 21.
    Börjesson, Maria
    KTH, Superseded Departments, Infrastructure.
    A Communication Choice Model2003Article in journal (Other academic)
  • 22.
    Börjesson, Maria
    KTH, Superseded Departments, Infrastructure.
    Communication technology and travel demand models2003Licentiate thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Transportation planners have traditionally focused onphysical travel only, and disregarded the fact that other modesof communication may influence travel demand. However, moderntelecommunications are rapidly increasing the accessibility toactivities that previously only could be reached by physicaltransportation. This development calls for methods to analyseinteractions between telecommunications and transport systems.The objective of this thesis is to accomplish a betterunderstanding of if and how impacts of information technologycould be implemented in travel demand models. An important partof this issue is to investigate what kind of data that isneeded.

    This thesis also aims at investigating whether theCommunication Survey, KOM, collected by Swedish Institute forTransport and Communications, SIKA, can be used to improvetransport modelling with respect to how moderntelecommunications influence travel demand. KOM is a one-daytravel and communication diary survey, including information onthe respondents telecommuting habits as well as socio-economicstatus. One problem was the small sample size in KOM, whichmade the analyses uncertain. Since KOM is collected on a yearlybasis, it is still possible to apply similar analysis methodswithin a few years, using a larger data set, which might enableextended analyses. The small sample in KOM available to date isbest suited for general descriptive analyses of communicationpatterns in Sweden. The main conclusions of the paper aretherefore connected to the methods and future datacollection.

    The thesis includes three papers. The first paper tested amodel approach that assumes substitution between travel andnon-travel based communication, using the KOM database. Traveldemand models are in general constructed as nested logit modelswith frequency, mode and destination choice levels. In thepaper, non-travel based modes of communication were included inthe choice set of such a model. The non-travel based modes ofcommunication considered were Internet (and e-mail), ordinarymail and telephone contacts. The model was developed for postand bank activities only, since that was the only activity forwhich the numbers of contacts and trips were large enough toallow model estimation. Several conclusions could be drawn.Describing the utility of the non-travel based alternatives isdifficult and needs more research. The analysisis also verysensitive to how activities are defined. It is furtheressential that the data collection is more process orientedthan traditional cross-sectional data is when analysing traveland telecommunications interactions. That is, habits ofperforming particular activities, including both trips anddifferent types of contacts, must be studied. The second andthird papers investigate telecommuting. As a first step toreach the goal of forecasting telecommuting, the second paperexamined the characteristics of current telecommuters by use ofKOM. This was mainly accomplished by estimating a telecommutingadoption model of logit type. However, only 122 employees outof 7578 actually telecommutes full days at home. Thesetelecommuters work primarily in information- and service-basedindustrial sectors concerned with computers, finance orcommunication. The difficulties in describing the utility ofthe telecommunications based alternatives (representing”no travel”) concerned also the telecommutingadoption model. Also impacts on travel from telecommuting wereinvestigated. Comparing the average commuting distance showedthat employees who exclusively telecommute full days havelonger commuting distances than others, but that othertelecommuters do not have longer average commuting distances.Telecommuting in general does not seem to be influenced by lowaccessibility to the labour market.

    The third paper used data collected from a working sitewithin the company Ericsson, located in the office district ofNacka Strand in Stockholm during the autumn 2002. Thetelecommuting frequency was substantially higher at Ericssonthan in the workforce as a whole. The propensity to adopttelecommuting was modelled as a function of socio-economicvariables and access to technical equipment, work tasksuitability and management attitudes, as perceived by theemployees. The focuswas to identify tools that the company canuse to promote telecommuting, and to find incentives for thecompany to promote telecommuting. Technical equipment, suitablework tasks and managers attitude were identified as constraintsfor telecommuting. The employees also perceived that theybecame more efficient and saved time when telecommuting.

  • 23.
    Börjesson, Maria
    KTH, Superseded Departments, Infrastructure.
    Telecommuting and work travel demand modelling in Sweden2003Article in journal (Other academic)
  • 24.
    Ceccato, Vania
    KTH, Superseded Departments, Infrastructure.
    Assessing the Impact of Modernization on Fertilty: The Case of Mozambique2000Report (Other academic)
    Abstract [en]

    Mozambique is one of the poorest countries in the world. It also has one of the world’shighest birth rates. Until recently there has been virtually no way to studyMozambique’s high fertility because of the civil war. This paper uses a very recentsurvey of Mozambican women from 1997. The objective of this paper is to assess theimpact of modernization on fertility in Mozambique, using as a background the“supply-demand theory” presented by Easterlin and Crimmins (1985). The first part ofthis paper describes the indicators of modernization for Mozambique by using maps,and indicates eventual correlations. The second part deals with the estimation ofequations for demand for children, the supply of children and the use of contraception.The third part shows how the modernization variables visualized in the first part of thepaper influence all these equations. The results show that the country has one of thehighest demands for children in the world, but also one of the largest supply of children,followed by high infant and child mortality. In many provinces, the regulation costs arestill high. Those who deliberately use contraceptives already have many children.Among the modernization variables, education is the factor that most affects supply,demand and also regulation costs in Mozambique.

  • 25.
    Ceccato, Vania
    KTH, Superseded Departments, Infrastructure.
    Banco de dados geo-relacinal aplicado a qualidade de vida urbana1994In: Symposium of quantification in Geo-sciences, Rio Claro, SP: UNESP , 1994Conference paper (Other academic)
  • 26.
    Ceccato, Vania
    KTH, Superseded Departments, Infrastructure.
    GIS, rumslig dimension och livskvalitet1999In: PLAN, Vol. 3, 151-158 p.Article in journal (Other academic)
  • 27.
    Ceccato, Vania
    KTH, Superseded Departments, Infrastructure.
    Objective and subjective indicators of quality of life in two districts in Stockholm County1998In: Urban Ecology, Springer Publishing Company, 1998, 283-287 p.Chapter in book (Refereed)
  • 28.
    Ceccato, Vania
    KTH, Superseded Departments, Infrastructure.
    Quality of life and social cohesion: a methodological discussion and their implications in planning2002In: Reshaping regional planning: a Northern perspective / [ed] F Snickars, B Olerup and L O Persson, Hampshire,: Ashgate, 2002, 135-165 p.Chapter in book (Refereed)
  • 29.
    Ceccato, Vania
    KTH, Superseded Departments, Infrastructure.
    Quality of life: concepts and some methodologies of study1996In: Design methodologies in urban context / [ed] Reza Kazemian, Stockholm: Architecture, KTH , 1996, 183-193 p.Chapter in book (Other academic)
  • 30.
    Ceccato, Vania
    et al.
    KTH, Superseded Departments, Infrastructure.
    Foresti, Celina
    INPE, BRAZIL.
    Kurkdjian, Maria
    INPE, BRAZIL.
    Gerenciamento urbano e qualidade de vida usando dados de sensoriamneto remoto1995In: Analise Ambiental: estrategias e acoes / [ed] Tauk-Tornisielo, S, Rio Claro, SP, Brazil: Centre of Environmental Studies, Rio Claro, UNESP , 1995Chapter in book (Other academic)
  • 31.
    Ceccato, Vania
    et al.
    KTH, Superseded Departments, Infrastructure.
    Persson, Lars Olof
    KTH, Superseded Departments, Infrastructure.
    Differential Economic Performance (DEP) in the periphery: evidence from Swedish rural areas2003In: European Journal of Spatial Development, ISSN 1650-9544, E-ISSN 1650-9544, Vol. 7Article in journal (Refereed)
    Abstract [en]

    Understanding Differential Economic Performance (DEP) at the local andregional level is a key element in devising practical strategies and programmes forsustainable regional development in different contexts. This paper contributes to theunderstanding of the factors underlying persistent differences in DEP between rurallocalities. The basic hypothesis is that the DEP of rural areas can be explained by acombination of ‘tangible’ and ‘less tangible’ factors and the way in which these interactin specific national, regional and local contexts. Natural and human resources,infrastructure, economic structure and investments are together with institutions,networks and community values the most decisive factors that help to characterise DEPfor the Swedish case studies. Findings show that such factors not only define the differentopportunities and constraints for local development, but also illustrate how effective thelocal and regional system is in tapping into resources and opportunities and inameliorating constraints. This sheds light on the importance of taking a broaderperspective regarding policies towards regional development, making them much morefocused on contextual and environmental aspects than uni-faceted, sectoral measures. Thepaper also provides a discussion of the implications of the results for policy and gives anaccount of new research questions for future studies.

  • 32.
    Ceccato, Vania
    et al.
    KTH, Superseded Departments, Infrastructure.
    Persson, Lars Olof
    KTH, Superseded Departments, Infrastructure.
    DORA - Dynamics of rural areas: National Report - Sweden2001Report (Other academic)
    Abstract [en]

    The aim of this study is to investigate the reasons for good and bad economic performance indifferent rural areas and, in particular, to investigate the role of tangible and less tangiblefactors in influencing development outcomes1. The core research question can be stated as:Why do rural areas in apparently similar economic, social and environmental circumstanceshave markedly different performance over relatively long periods of time? The basicresearch hypothesis is that the differential development of rural areas can be explained by acombination of ‘tangible’ and ‘less tangible’ factors and the way in which these interact inspecific national, regional and local contexts. Such factors not only define differentopportunities and constraints for local development, but also illustrate how effective the localand regional system is in tapping resources and opportunities and ameliorating constraints.

  • 33.
    Ceccato, Vania
    et al.
    KTH, Superseded Departments, Infrastructure.
    Persson, Lars Olof
    KTH, Superseded Departments, Infrastructure.
    Dynamics of Rural Areas (DORA)1: The Swedish case studies2000In: ERSA, Barcelona, 2000Conference paper (Other academic)
    Abstract [en]

    Understanding differential economic performance at local and regional levels is akey element in devising practical strategies and programmes for sustainable rural and regionaldevelopment in different contexts. The project DORA – Dynamics of Rural Areas deals withregional and local differences in rural Europe. The DORA project seeks to improve ourunderstanding of the factors underlying and explaining persistent differences in economicperformance between rural localities. The basic hypothesis is that the differential development ofrural areas can be explained by a combination of ‘tangible’ and ‘less tangible’ factors and theway in which these interact in specific national, regional and local contexts. Such factors notonly define different opportunities and constraints for local development, but also illustrate howeffective the local and regional system is in tapping resources and opportunities and amelioratingconstraints. This paper provides a discussion of the preliminary results for the Swedish casestudy areas based on the analysis of ten factors as well as the interrelationships between them toexplain differential economic performance and gives an account of methodological challengeswhen combining qualitative and quantitative methods.

  • 34.
    Ceccato, Vania
    et al.
    KTH, Superseded Departments, Infrastructure.
    Persson, Lars Olof
    KTH, Superseded Departments, Infrastructure.
    Forskning för regional utveckling svensk FoU med Europeiska Utblickar1999Report (Other academic)
  • 35.
    Ceccato, Vania
    et al.
    KTH, Superseded Departments, Infrastructure.
    Persson, Lars Olof
    KTH, Superseded Departments, Infrastructure.
    Transport och kommunikation vid sekelskiften1998Report (Other academic)
  • 36.
    Ceccato, Vania
    et al.
    KTH, Superseded Departments, Infrastructure.
    Persson, Lars Olof
    KTH, Superseded Departments, Infrastructure.
    Westholm, Erik
    Forskning om och för landsbygds- och glesbygdsutveckling2000In: Kungl. Skogs- och Lantbruksakademiens Tidskrift, ISSN 0023-5350, Vol. 139, no 11Article in journal (Other academic)
  • 37.
    Churie Kallhauge, Angela
    KTH, Superseded Departments, Infrastructure.
    Managing complexity in multiateral environmental negotiations2004Licentiate thesis, comprehensive summary (Other scientific)
  • 38.
    Demšar, Urška
    KTH, Superseded Departments, Infrastructure.
    A Visualisation of a Hierarchical Structure in Geographical Metadata2004In: Proceedings of the 7 th AGILE Conference on Geographical Information Science, 2004Conference paper (Refereed)
    Abstract [en]

    The paper presents a visualisation of a hierarchical structure discovered in a repository of geographical metadata by clustering. The hierarchical structure is visualised as a radial tree. The clusters at different levels of detail are represented by the vertices and the subset relationship between the clusters by the edges of the tree. The similarity between elements in different clusters is shown using a colour scheme for the vertices and the edges. The visualisation is integrated in a visual data mining tool for the exploration of the geographical metadata.

  • 39.
    Demšar, Urška
    KTH, Superseded Departments, Infrastructure.
    Exploring geographical metadata by automatic and visual data mining2004Licentiate thesis, monograph (Other scientific)
    Abstract [en]

    Metadata are data about data. They describe characteristicsand content of an original piece of data. Geographical metadatadescribe geospatial data: maps, satellite images and othergeographically referenced material. Such metadata have twocharacteristics, high dimensionality and diversity of attributedata types, which present a problem for traditional data miningalgorithms.

    Other problems that arise during the exploration ofgeographical metadata are linked to the expertise of the userperforming the analysis. The large amounts of metadata andhundreds of possible attributes limit the exploration for anon-expert user, which results in a potential loss ofinformation that is hidden in metadata.

    In order to solve some of these problems, this thesispresents an approach for exploration of geographical metadataby a combination of automatic and visual data mining.

    Visual data mining is a principle that involves the human inthe data exploration by presenting the data in some visualform, allowing the human to get insight into the data and torecognise patterns. The main advantages of visual dataexploration over automatic data mining are that the visualexploration allows a direct interaction with the user, that itis intuitive and does not require complex understanding ofmathematical or statistical algorithms. As a result the userhas a higher confidence in the resulting patterns than if theywere produced by computer only.

    In the thesis we present the Visual data mining tool (VDMtool), which was developed for exploration of geographicalmetadata for site planning. The tool provides five differentvisualisations: a histogram, a table, a pie chart, a parallelcoordinates visualisation and a clustering visualisation. Thevisualisations are connected using the interactive selectionprinciple called brushing and linking.

    In the VDM tool the visual data mining concept is integratedwith an automatic data mining method, clustering, which finds ahierarchical structure in the metadata, based on similarity ofmetadata items. In the thesis we present a visualisation of thehierarchical structure in the form of a snowflake graph.

    Keywords:visualisation, data mining, clustering, treedrawing, geographical metadata.

  • 40.
    Dovlén, Sylvia
    KTH, Superseded Departments, Infrastructure.
    Conditions for the integration of ecological knowledge in land-use planning: the local government ecologist perspective2002In: Planning in a Global Era / [ed] Andy Thornley, Yvonne Rydin, Ashgate , 2002Chapter in book (Other academic)
  • 41.
    Dovlén, Sylvia
    KTH, Superseded Departments, Infrastructure.
    Discursive power in professional interaction: a critique of the consensus approach in planning2004In: Planning Theory, ISSN 1473-0952, E-ISSN 1741-3052Article in journal (Other academic)
  • 42.
    Dovlén, Sylvia
    KTH, Superseded Departments, Infrastructure.
    Environmental issues in comprehensive land-use planning: a case study in four municipalities in Sweden1997In: Society, Environment and sustainability: the Nordic perspective, 1997Conference paper (Other academic)
  • 43.
    Dovlén, Sylvia
    KTH, Superseded Departments, Infrastructure.
    Local government planning for sustainability: the perspective of economic development professionals2004In: Sustainable Development, ISSN 0968-0802, E-ISSN 1099-1719Article in journal (Other academic)
  • 44.
    Dovlén, Sylvia
    et al.
    KTH, Superseded Departments, Infrastructure.
    Håkansson, Maria
    KTH, Superseded Departments, Infrastructure.
    The role of professions in environmental planning2002In: Reshaping Regional Planning: A Northern Perspective / [ed] Folke Snickars, Brita Olerup, Lars Olof Persson, Ashgate , 2002Chapter in book (Other academic)
  • 45.
    Dovlén, Sylvia
    et al.
    KTH, Superseded Departments, Infrastructure.
    Skantze, Ann
    KTH, Superseded Departments, Infrastructure.
    The role of metaphors in the interaction of perspectives: planning for sustainability in practise2004In: Planning Theory & Practice, ISSN 1464-9357, E-ISSN 1470-000XArticle in journal (Other academic)
  • 46.
    Dreborg, Karl Henrik
    KTH, Superseded Departments, Infrastructure.
    Scenarios and structural uncertainty2004Doctoral thesis, comprehensive summary (Other scientific)
  • 47.
    Dunkars, Mats
    KTH, Superseded Departments, Infrastructure.
    Multiple representation databases for topographic information2004Doctoral thesis, monograph (Other scientific)
  • 48.
    Ellmann, Artu
    KTH, Superseded Departments, Infrastructure.
    Effect of the GRACE satellite mission on gravity field studies in Fennoscandia and the Baltic Sea region2004In: Proceedings of the Estonian Academy of Sciences: Geology, ISSN 1406-0132, Vol. 53, no 2, 67-93 p.Article in journal (Refereed)
    Abstract [en]

    It is customary to utilize the Earth's artificial satellites for detecting long-wavelength components of the Earth's gravity field. The tracking data of the GRACE twin-satellites are the basis of the new geopotential model GGM01, released by the Centre for Space Research at the University of Texas in July 2003. The present paper assesses the quality of the GGM01 model through comparisons with an earlier geopotential model (EGM96). The method of spherical harmonic expansions is used in numerical investigations. The results of evaluation in Fennoscandia and the Baltic Sea region illuminate the discrepancies between the long-wavelength contributions of the models, which may reach several decimetres in the geoidal heights. Thus, even in the gravimetrically well studied area like the Baltic Sea region, the new satellite gravity missions may improve the gravity data significantly. Tests with high-precision GPS-levelling data indicate the offsets between global geoid models and national vertical datums in the Baltic Sea region. The gravity anomaly grid and the GGM01 model are utilized in the computation of the Estonian gravimetric geoid model by the least squares modification of Stokes' formula. The new model EST-03 is fitted to a set of 26 high-precision GPS-levelling points, yielding a root mean square error of 3 cm for the post-fitting residuals. This order of discrepancies is sufficient for many practical and scientific applications.

  • 49.
    Ellmann, Artu
    KTH, Superseded Departments, Infrastructure.
    The geoid for the Baltic countries determined by the least squares modification of Stokes´formula2004Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Precise knowledge of the geoid contributes to the studies ofthe Earth’s interior, the long-term geophysical processesand to oceanography. An accurate regional geoid model, inparticular, enables the user in many cases to replace thetraditional height determination techniques by faster and morecost-effective GPS-levelling.

    In regional gravimetric geoid determination, it has becomecustomary to utilize the modified Stokes formula, whichcombines local terrestrial data with a global geopotentialmodel. The Dissertation is devoted to the determination of ahighresolution geoid model for the three Baltic countries–Estonia, Latvia and Lithuania. Six differentdeterministic and stochastic modification methods are tested.These are: Wong and Gore (1969), Vincent and Marsh (1974),Vaníèek and Kleusberg (1987) and the biased, unbiasedand optimum least squares modifications by Sjöberg (1984b,1991, 2003d). Three former methods employ originally theresidual anomaly in Stokes’integral. For the sake ofcomparison these methods are expressed such that the fullgravity anomaly is utilised in all the six methods.

    The contribution of different error sources for geoidmodelling is studied by means of the expected global meansquare error (MSE). The least squares methods attempt tominimise all relevant error sources in geoid modelling byspecially determined modification parameters. Part of thepresent study contributes to some important computationalaspects of the least squares parameters sn.

    This study employs the new geopotential model GGM01s, whichis compiled from data of the GRACE twin-satellites. Three sets(one from each country) of GPSlevelling points were used for anindependent evaluation of computed geoid models. Generally, thepost-fit residuals from the least squares modifications areslightly smaller (up to 1 cm) than the respective values ofdeterministic methods. This could indicate that the efforts putinto minimization of the global MSE have been advantageous.

    The geoid model computed by the unbiased LS modificationprovides the“best”post-fit statistics and it isthus preferred as the final representation of the joint Balticgeoid. The modification parameters of this model are calculatedfrom the following initial conditions: (1) upper limit of theGGM01s and the modification degree of Stokes’function areboth set to 67, (2) terrestrial anomaly error variance andcorrelation length are set to 1 mGal2 and 0.1°,respectively, (3) integration cap size is 2°. Thisapproximate geoid model is supplemented by separately computedadditive corrections (the combined topographic and atmosphericeffects and ellipsoidal correction), which completes the geoidmodelling procedures. The new geoid model for the Balticcountries is named BALTgeoid-04. The RMS of the GPS-levellingpost-fit residuals are as follows: 5.3 cm for the joint Balticgeoid model and 2.8, 5.6 and 4.2 cm for Estonia, Latvia andLithuania, respectively. This fit indicates the suitability ofthe new geoid model for many practical applications.

    Key words: geoid:Stokes’formula, deterministicand stochastic modifications, least squares, additivecorrections, GRACE, Baltic.

  • 50.
    Engelson, Leonid
    KTH, Superseded Departments, Infrastructure.
    On dynamics of traffic queues in a road network with route choice based on real time traffic information2003In: Transportation Research Part C: Emerging Technologies, ISSN 0968-090X, E-ISSN 1879-2359, Vol. 11, no 2, 161-183 p.Article in journal (Refereed)
    Abstract [en]

    Introducing real time traffic information into transportation network makes it necessary to consider development of queues and traffic flows as a dynamic process. This paper initiates a theoretical study of conditions under which this process is stable. A model is presented that describes within-one-day development of queues when drivers affected by real-time traffic information choose their paths en route. The model is reduced to a system of differential equations with delay. Equilibrium points of the system correspond to constant queue lengths. Stability of the system is investigated using characteristic values of the linearised minimal face flow. A traffic network example illustrating the method is provided.

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