Fraunhofer Chalmers Research Centre for Industrial Mathematics
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Förskjutning av döden kring födelsedagen
No full textIn this thesis we adress a hypothesis that suggests that people can postpone their imminent
death (given natural causes). The so-called "Postponement hypothesis" assumes that a
meaningful occasion can act as a motivator to prolong life for a short amount of time. We
consider a persons birthday as that meaningful occasion and analyze the hypothesis around
this date by using tools from a statistical discipline known as Survival analysis. If the hypothesis
is true it can be expected that the mortality rate should be lower a period before
a person's birthday and, perhaps, higher shortly afterwards. We choose to set this period
to a limit of 14 days. This would indicate that there is a force which postpones death for
the population concerned. The datasets used in analysis are mortality data over people who
lived to be Supercentenarian and Italian people who became older than 105 years, and also
primarily a dataset for South African people who died in the year 2015. The mortality rate
is summarised by hazard functions, which at each age expressed in days describes the dying
rate of people who survived to this day. We thereafter apply various parametric models to
the hazard, in order to discover any discrepancy around the birthdays. For this a t-test is
conducted on the mean of the residuals mortality in the birthday period, to see if the mean is
non-zero. This should be the case if the days around the birthdays are no different in terms
of mortality rate compared to other days of the year. The results of our analysis show that
no postponement of death can be seen for the examined dataset. Instead the data suggest
that the mortality rate is actually higher both before and after the birthday. Speculations as
to why this is the case might be a higher risk associated with the stress of preparing for the
birthday
Understanding driver planning behaviour when overtaking a bicyclist: Time to collision estimations from naturalistic driving data
No full textIn Europe, bicyclist road fatalities have increased for the last ten years. Active safety systems such as Automated Emergency Braking can give a considerable benefit in reducing bicyclist road fatalities, but knowledge on when they should intervene is still limited. Estimation of Time to Collision (TTC) when the driver starts planning to overtake (planning point) could help in improving active safety systems, since TTC is a good estimate of the available mitigation time for the algorithms to intervene. This thesis, carried out using naturalistic driving data from the UDRIVE project, mainly consisted in extracting data from bicyclist overtaking scenarios on rural road and modelling TTC and longitudinal distance to quantify how they are influenced by different factors. The result of the estimation is that the presence of oncoming traffic and an increase in bicyclist lateral distance caused a decrease of both TTC and longitudinal distance at the planning point. Moreover, male drivers showed higher TTC at the planning point than female drivers. Interestingly, the planning point was not affected by the overtaking strategy
Reducing Lead Times for Organizations Handling Multiple Projects in an Engineer to Order Environment - A Case Study at Jensen Sweden
No full text
Validation of a Damage Accumulation Model of Replicative Ageing in S.cerevisiae.
No full textAge-related diseases and conditions give rise to societal challenges and pose a threat
to healthy ageing. At the same time, the more recent evolutionary theories of
ageing hypothesise that the process of ageing is a consequence of living rather than
an evolutionary strategy. Consequently, it is implied that ageing is not as inevitable
as many might believe and, as a consequence, it is of interest to study this biological
process and its underlying mechanisms.
On a cellular level, accumulation of damage is often regarded as the main cause
of ageing. Since the basic properties of ageing between unicellular and multicellular
organisms are similar on this level, it is common to use the unicellular yeast
Saccharomyces cerevisiae as a model organism in the field of ageing research.
The aim of this project is to validate a mathematical damage accumulation model
of replicative ageing in yeast. The model represents a cell by intact protein and
damage and describes how these quantities change as the cell grows. In addition
to cell growth, the model takes asymmetric division, retention and cell death into
account.
For the purpose of validating the model of replicative ageing, structural and numerical
identifiability methods are applied and continuous optimisation is performed
using single-cell area data. The model is fit to experimental data obtained for wildtype
yeast and the two deletion strains sir2 and fob1. Moreover, replicative
lifespan data of 4,698 single-gene deletion strains is analysed and, in conjunction to
this, it is investigated how the model parameters affect the replicative lifespan of
the simulations.
The results show that the parameters in the model of replicative ageing that
describes the rate of change of intact protein and damage in the cell, are structurally
identifiable. In spite of this, they are not numerically identifiable based on the
experimental data available; the parameter estimates obtained have high variances
and are moderately or highly correlated with each other. Likewise, it is possible to
generate parameter sets that make the mathematical model reproduce the replicative
lifespans of the investigated strains, if a replicative lifespan constraint is inferred on
the optimisation.
For future work, it is suggested that new experimental data is generated as to
fit the model of replicative ageing to growth curves belonging to cells of later life
stages. Ultimately, the data should be sufficient enough for the optimisation to
generate parameter sets that make the model adapt to the characteristics of the
investigated strains, without having additional constraints added to the objective
function
The assessment of small wastewater treatment plants in Cochabamba, Bolivia - A framework for using sustainable development indicators
No full textHow bridges and pedestrian subways can be more than means for transportation A study on how to raise social aspects in planning processes
No full textThe strive for building sustainable denser cities requires a knowledge for what sustainability is and how to apply it to our planning processes to achieve a sustainable built environment. Areas around and under bridges and in pedestrian subways can be utilised for creating social values and thus adding additional values rather than being structures for transportation means. This report seeks to find why social aspects should be raised in such environments, exemplify what social sustainability could be and finally how to raise social aspects in parity to ecological, economic and technical aspects. The discussion is based on previous research about social sustainability within urban planning and infrastructure and on interviews. Findings suggests that social sustainability is fundamental in built environment. Simply because there is a need to create attractive, usable, safe places where can interact with other, learn or perform activities. Further, adapting a new way of working, collaborating across disciplines and organisational boundaries is essential. In this report, social sustainability is regarded as a perspective that needs to characterise the other elements and there are different tools and methods for raising social aspects in planning processes
Successiv kalkylering i tidigt skede
No full textInom byggprocessen genomför man olika kalkyler som grundar sig i modeller och handlingar som utarbetas under olika faser utav en rad olika discipliner. Parallellt med projekteringsfasen upprättar en anbudsingenjör succesivt kalkyler. Detta sätt man arbetar på i det företaget som undersöktes kan innebära att funderingar och frågor uppkommer hos både projekteringsgruppen och anbudsingenjören. Syftet med detta examensarbete är att undersöka hur kalkylprocessen samverkar med projekteringsprocessen. En litteraturstudie genomfördes för att ligga till grund för de kvalitativa intervjuer och observationer som genomfördes för att utreda studiens frågeställningar. Det var ett bostadsprojekt som följdes och som under utförandet av arbetet befann sig i sitt projekteringsskede. Resultatet visade att man i tidiga skeden på företaget genomför tre olika kalkyler vid tre olika faser i byggprocessen. I första fasen användes nyckeltal för att sedan övergå till att man kalkylerar succesivt. Samverkan mellan processerna sker framförallt genom att projektörerna gör iordning handlingar som skall användas vid kalkylering av en anbudingenjör. Vissa personer som intervjuades efterfrågade en förbättring i samverkan mellan kalkyler och projekteringsprocesserna medan andra inte såg nyttan av den. En slutsats är att kalkylprocessen behöver bli mer identifierad och bör integreras i projekteringsprocessen istället för att vara en osammanhängande parallell process till projekteringen. Man behöver även tillämpa NCC Projektstudion på rätt sätt så att man finner rätt förutsättningar för att delta i den
Feasibility study of structural batteries for electrical vehicles
No full textThe recent growth in the electric vehicle industry and the fast development of electrical vehicle transportation lead the investigation to new technologies as structural batteries for the electrical vehicle industry. To fulfil the emission agreements, the electric vehicle becomes a promising technology, reducing the emission and CO2 footprint. However, the relatively low specific energy of this actual lithium-ion technology results in an increase of the vehicle weight. By a combination of a high specific stiffness and energy-storage capabilities within a multifunctional material, the structural power technology, undertakes the duty to bring a solution for this problem. So, this technology endorses weight savings for future vehicle models. In this current study the feasibility analysis was driven to verify the potential of structural power technology. The energy available in the three structural batteries connected in series is analysed. The voltage imbalance between cells was analysed and a technology to minimize this problem was evaluated. The strategy to overcome the cell imbalance was selected and the energy efficiency provided by the battery managements system (BMS). The impact of the selected BMS was assessed in a comparative study between two different BMS technologies. Target energy losses and efficiencies were calculated for both passive and active BMS methods. Significant benefits with an active BMS technology are revelled for structural batteries composites