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- Nord, Catharina, 1956-
(författare)
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The visible patient. Hybridity and inpatient ward design in a Namibian context.
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Even if one is confident that the staff provide the bestpossible treatment, being admitted into hospital is still astressful situation. In recent decades, architecturalresearchers have elaborated on aspects of the patient'sperspective where the design of the physical environment maypositively enhance the healing experience. The emergingunderstanding reveals that this is not an issue to be solvedsimply by decorative design, for it entails the spatialinterpretation and integration of broader and deeper facets ofhuman response, within which suffering, empathy andprofessional care are embraced.This thesis elucidates the patients' use of space accordingto their cultural perceptions in two inpatient wards in aregional hospital in northwestern Namibia. The study appliescase study methodology with the focus on the interactionbetween patients, visitors and nursing staff in relation to thephysical environment.The theoretical basis within medical anthropologyconceptualises sickness as a cultural event in the dual notionillness and disease, signifying two ways of understandingsickness, the individual and the professional interpretations.The Foucauldian theory on discipline and space suggests thatthe biomedical discipline is spatially represented by themodern hospital, from which aspects of illness areexcluded.The results show that circumstances in the physicalenvironment highly influence the patients' illness experienceby possessing certain qualities or by the activities renderedpossible by spatial conditions. The two wards possess manymodern qualities adding to an enclosed and restrictingenvironment. Patients come from a culturally dynamic andchanging context where new approaches to healthcare andhospital physical space are generated. Whereas patients haveintegrated hospital-based biomedicine as a medical alternative,modern hospital space cannot accommodate certain patient needs.Patients, visitors and nursing staff negotiate space in orderto overcome spatial weaknesses. Family members' overnightaccommodation in the hospital, as well as their voluntarycontribution to patient care, are two important aspects whichare not spatially incorporated.An alternative ward design is suggested in which patients'and family members' active participation in the healing processis encouraged, with support from the nursing staff. The higherflexibility the design offers caters for the spatialintegration of future hybrid processes.
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| 2. |
- Andersson, Mats B.
(författare)
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Hantering av osäkerhet i samband med investeringsbeslut – några metodansatser och exempel
- 2004
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 3. |
- Archer, Jeffery, 1961-
(författare)
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Indicators for traffic safety assessment and prediction and their application in micro-simulation modelling : a study of urban and suburban intersections
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In order to achieve sustainable long-term transport infrastructure development, there is a growing need for fast, reliable and effective methods to evaluate and predict the impact of traffic safety measures. Recognising this need, and the need for an active traffic safety approach, this thesis focuses on traffic safety assessment and prediction based on the use of safety indicators that measure the spatial and/or temporal proximity of safety critical events. The main advantage of such measures is that they occur more frequently than accidents, and therefore require relatively short periods of study to establish values that can later be used for comparison, or for accident prediction purposes. There are a number of more generally accepted safety indicators including: Time-to-Accident, Time-to-Collision, and Post-Encroachment Time. These are based on different underlying principles and measurement techniques, including both on-site subjective estimation, and objective photometric measures. A major part of the work presented in this thesis, concerns identifying the potential and limitations of the different safety indicators with regard to their validity and reliability, and practical use for safety assessment and prediction purposes. This is done in conjunction with field studies in the urban and suburban environment, at both signalised and unsignalised intersections. Results from these studies indicate that on-site observation methods provide useful quantitative and qualitative information relatively quickly and efficiently, provided that they are used correctly. On the other hand, the methods based on photometric measurement (video-analysis) proved arduous and time-consuming. Furthermore, there are questions regarding the abilities of the Time-to-Collision and Post-Encroachment Time safety indicators to adequately represent interaction severity, suggesting possible flaws in fundamental concepts related to construct validity. Importantly, results showed that the relationship between safety indicators and traffic accidents is complex and equivocal, where many different factors and processes can impose a significant influence on safety. This makes generalised predictive modelling a particularly difficult task for safety analysts. The potential of micro-simulation for traffic safety and performance estimation based on the use of safety indicators was investigated in the second part of this thesis. Microscopic traffic simulation has become increasingly popular among transport planners, due to the fact that it serves as a safe and flexible off-line test environment for the estimation of dynamic and complex traffic system effects. It is useful and cost-effective in relation to the evaluation of issues concerning roadway design, and technological systems that influence road-user behaviour and vehicle performance. For reasons related to modelling fidelity and data quality, simulation has seldom been used for traffic safety estimation. Simulation model development is however, undergoing rapid development and the area of ‘safety-simulation’ and is recognised as having a high potential in the field of transport planning and traffic engineering. As part of the work in this thesis, practical simulation experiments were carried out to investigate this potential, and identify limitations. Based on the data from one of the earlier studies, and knowledge regarding important safety-influencing factors and behavioural processes, one of the simulation experiments showed evidence to suggest that realistic safety critical events could be generated and measured using safety indicators in a simulation environment, without making unnecessary and unrealistic behavioural assumptions. Furthermore, a second application of this methodology revealed the safety potential of a rear-end incident-reduction function used in standard vehicle actuated signalling. While both of these simulation studies highlighted the potential of this type of approach, the need for more flexible and realistic models of interactive behavioural processes could be identified in addition to the general need for greater active research into the field of safety simulation.
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| 4. |
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| 5. |
- Atterhög, Mikael, 1962-
(författare)
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The effect of competition and ownership policies on the housing market
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation consists of five studies presented in seven essays. The overall objectives are to investigate the extent and consequences of competition on the rental housing market as well as the importance of national government policies for the substitute good, i.e. owner-occupied housing. However, each essay also has specific objectives. Due to the characteristics of the housing market, one should not expect competition to be very fierce. The market characteristics are, for instance, capital-intensive, complicated and time-consuming construction processes as well as a limited supply of land in many areas. In fact, firms have a lot to gain from colluding and to avoid e.g. price wars. It is therefore theoretically more likely that housing companies will engage in “functional” or “strategic” competition such as the quality of housing services. Essay I and IV analyze the unique municipal housing market in Sweden where apartment rents are determined by negotiations between the local municipal company and the local Union of Tenants. A regression analysis is applied on data from 30 municipalities. There was a strong correlation between apartment rents at local municipal markets and the level of “external” competition (measured by the price level on the market for single-family owner occupied housing), but not with “internal” competition (measured by the market share of the municipal housing company) or the capital expenditure of the municipal housing company (presumed to reflect historical construction and renovation costs for the apartments). The dissertation also investigates the consequences on rents (essay II) and on the quality of housing services (essay III) from a local Swedish municipal housing company selling a substantial part of its apartment stock (15-40 percent) and thereby theoretically creating more competition. These essays use a quasi-experimental methodology whereby the development of the housing market in a privatization town is compared with the development in a very similar comparison town. It is found that privatization has lead to lower rents in the short- and medium-term in six out of seven privatization towns. The development of the quality of housing services was more related to the performance of each individual company and not a specific category of companies. In essay V, these results are merged and developed further. Essay VI presents a wide range of policies available for governments wishing to increase access to home ownership for low-income households and thereby increasing the pressure on rental housing companies to reduce rents. A systematic overview of policies is provided based on the four distinct time periods of a typical ‘housing career’ of a household; i.e. down payment accumulation stage, transaction stage, ownership stage and selling stage. It is found that many policies are required to meet the specific and differing needs of households for governments wishing to encourage home ownership. Essay VII describes that home ownership rates have increased in almost all industrialized countries during the period from World War II until mid-1990s. The essay analyses the implications of government policies and some other factors (e.g. national wealth, income distribution) on home ownership rates in 13 industrialized countries during the period 19702000. A fixed-effect model is applied on a panel data set. The most important result is that a statistically significant and positive correlation between government support and home ownership rates was found although this is only a preliminary conclusion since data was scarce.
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| 9. |
- Beser Hugosson, Muriel, 1968-
(författare)
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Issues in Estimation and Application of Long Distance Travel Demand Models
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 10. |
- Burghout, Wilco, 1975-
(författare)
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Hybrid microscopic-mesoscopic traffic simulation
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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