Relationships between occupational physical exposures and risks of contracting musculoskeletal disorders are still not well understood; exposure-response relationships are scarce in the musculoskeletal epidemiology literature, and many epidemiological studies, including intervention studies, fail to reach conclusive results. Insufficient exposure assessment has been pointed out as a possible explanation for this deficiency. One important aspect of assessing exposure is the selected measurement strategy; this includes issues related to the necessary number of data required to give sufficient information, and to allocation of measurement efforts, both over time and between subjects in order to achieve precise and accurate exposure estimates. These issues have been discussed mainly in the occupational hygiene literature considering chemical exposures, while the corresponding literature on biomechanical exposure is sparse. The overall aim of the present thesis was to increase knowledge on the relationship between data collection design and the resulting precision and accuracy of biomechanical exposure assessments, represented in this thesis by upper arm postures during work, data which have been shown to be relevant to disorder risk. Four papers are included in the thesis. In papers I and II, non-parametric bootstrapping was used to investigate the statistical efficiency of different strategies for distributing upper arm elevation measurements between and within working days into different numbers of measurement periods of differing durations. Paper I compared the different measurement strategies with respect to the eventual precision of estimated mean exposure level. The results showed that it was more efficient to use a higher number of shorter measurement periods spread across a working day than to use a smaller number for longer uninterrupted measurement periods, in particular if the total sample covered only a small part of the working day. Paper II evaluated sampling strategies for the purpose of determining posture variance components with respect to the accuracy and precision of the eventual variance component estimators. The paper showed that variance component estimators may be both biased and imprecise when based on sampling from small parts of working days, and that errors were larger with continuous sampling periods. The results suggest that larger posture samples than are conventionally used in ergonomics research and practice may be needed to achieve trustworthy estimates of variance components. Papers III and IV focused on method development. Paper III examined procedures for estimating statistical power when testing for a group difference in postures assessed by observation. Power determination was based either on a traditional analytical power analysis or on parametric bootstrapping, both of which accounted for methodological variance introduced by the observers to the exposure data. The study showed that repeated observations of the same video recordings may be an efficient way of increasing the power in an observation-based study, and that observations can be distributed between several observers without loss in power, provided that all observers contribute data to both of the compared groups, and that the statistical analysis model acknowledges observer variability. Paper IV discussed calibration of an inferior exposure assessment method against a superior “golden standard” method, with a particular emphasis on calibration of observed posture data against postures determined by inclinometry. The paper developed equations for bias correction of results obtained using the inferior instrument through calibration, as well as for determining the additional uncertainty of the eventual exposure value introduced through calibration. In conclusion, the results of the present thesis emphasize the importance of carefully selecting a measurement strategy on the basis of statistically well informed decisions. It is common in the literature that postural exposure is assessed from one continuous measurement collected over only a small part of a working day. In paper I, this was shown to be highly inefficient compared to spreading out the corresponding sample time across the entire working day, and the inefficiency was also obvious when assessing variance components, as shown in paper II. The thesis also shows how a well thought-out strategy for observation-based exposure assessment can reduce the effects of measurement error, both for random methodological variance (paper III) and systematic observation errors (bias) (paper IV).

Evolutionary biology is dependent on accurate phylogenies. In this thesis two branch support methods, Bayesian posterior probablities and bootstrap frequencies, were evaluated with simulated data and empirical data from the chloroplast genome. Bayesian inference was found to be more powerful and less conservative than maximum likelihood bootstrapping, but considerably more sensitive to choice of parameters. Bayesian inference increased in power when data were underparameterized, but the associated increase in type I error was comparatively larger. The chloroplast DNA phylogeny of the tribe Sileneae (Caryophyllaceae) was inferred by analysis of 33,149 aligned nucleotide bases representing 24 taxa. The position of the SW Anatolian taxa Silene cryptoneura and S. sordida strongly disagreed with previous studies on nuclear DNA sequence data, and indicate a possible case of homoploid hybrid origin. Silene atocioides and S. aegyptiaca formed a sister group to Lychnis and remaining Silene, thus suggesting that Silene may be paraphyletic, despite recent revisions based on molecular data. Several nodes in the phylogeny remained poorly supported, despite large amounts of data. Additional sequence sampling is not expected to solve this problem. The main reason for poor resolution is probably a combination of rapid radiation and substitution rate hererogeneity. Apparent incongruent patterns between different regions of the chloroplast genome are evaluated with ancient interspecific chloroplast recombination as explanatory model. Extremely elevated substitution rates in the exons of the plastid clpP gene was documented in Oenothera and three separate lineages of Sileneae. Introns have been lost in some of the lineages, but where present, intron sequences have a markedly slower substitution rate, similar to the rates found in other introns of their genomes. Three branches in the phylogeny show significant whole gene positive selection. In two of the lineages multiple partial copies of the gene were found.

Recently, small businesses have attracted much attention from scholars and businessmen, since the significance of these businesses estimated essential in rapid changing business environment from the perspective of wealth and job creation. Simultaneously, it is well known that most infant entrepreneurs are constrained by shortage of financial resource for development and growth of their business. Some entrepreneurs carry out the need for resources by applying the particular methods of financial bootstrapping. Therefore, a number of researches have been conducted in order to define characteristics of bootstrapping and to analysis how it effects to financial decision making process of entrepreneurs. Under specific constrains and difficulties, the majority of the start-ups gain financial capital for business establishment from family funds and other informal sources based on personal contacts. Being directly connected with bootstrapping, financial decision making also must be implemented efficiently in the start-up phase of the company. Practically, the majority of nascent entrepreneurs face the lack knowledge about financing of small business frequently. Thus, the study of bootstrapping methods and the exploration of the factors, that effect decision making process, is important for both researchers and entrepreneurs. The regarding thesis, in turn, examines bootstrapping behavior and financial decision making processes of four different companies in the Create Business Incubator. First of all, it investigates financing, financial choice, network and learning in order to conceptualize appropriate frame for conducting the thesis work. Then, necessary hands-on information obtained by conducting certain interviews and analyzing the networking and coaching circumstances of the Incubator. Consequently, after analyzing the characteristics of business and entrepreneurs, a priori conclusion and recommendations are proposed which help to increase the financial awareness of nascent entrepreneurs in the Incubator in terms of financing small business.

Här kommer sammanfattning av vår uppsatts "Småföretagare och deras finansiering" Sammanfattning Det finns många faktorer, både yttre och inre, som påverkar en småföretagare vid dennes val av finansieringsform. Det finns även många olika former av finansiering att välja bland t ex banklån, leasing och riskkapital och de olika finansiärerna ställer skiftande krav på småföretagen och företagarna. Ett problem som nämns i teorin är det finansiella gapet som bygger på en asymmetrisk information mellan företagaren och finansiären. Småföretagare föredrar enligt pecking order modellen eget genererat kapital och är negativt inställda till att förlora kontroll över företaget samt självständighet. Den form av finansiering som företagarna enligt denna teori undviker därav så långt som möjligt är riskkapital då detta kortfattat innebär att företaget ”betalar” genom att ge bort ägande. Dock kan inte alla småföretag överleva samt finansiera sin verksamhet med egna vinster, speciellt inte i början och det kan vara svårt att erhålla extern finansiering då företagen kanske inte har så mycket att lämna i säkerhet för t ex ett banklån. Denna uppsats är en fallstudie över hur olika faktorer påverkat/påverkar tre företags kapitalförsörjning. En form av finansiering som de undersökta företagen alla anser vara bra är leasing och anledningen till detta är att räntorna idag är så låga. Företagen är inte helt negativt inställda till riskkapital som teorin framhåller, trots att de helst försörjer sig på eget kapital. De undersökta företagen har haft olika förutsättningar vad gäller anskaffning av kapital och de har även till viss del valt olika former. Trots detta kan deras agerande i stora drag sägas följa de teorier som finns angående små företags kapitalförsörjning.

This thesis identifies the attractors of Detroit’s growth and divulges into the cultural, federal, socio-economic and urban deterrents that have afflicted Detroit for the past fifty years. It probes the city of Detroit and exposes a hyper-segregated city that has been destroyed by a self-feeding cycle of nomadic behaviour and a speculative culture of endless opportunities. To initiate change this thesis examines real alternatives that are not defined for the citizens of Detroit, but are created by them. It is a self-organizing grassroots approach that applies pressure on the city to rethink its conventional methods of urban revitalization. Utilizing the city’s large inventory of vacant land, abandoned buildings and neighbourhood schools, an alternative design methodology is logically applied to atomize, consolidate, fortify and envisage a new Detroit; one where residents can remain sufficiently abreast of the social and economic problems that consistently challenge them.

Pension funds play a large role in the UK pension system since the returns of the funds determine how large the total pension will be. The future retirees can choose between active and passive fund management where the active management often is more expensive. In this study 102 actively managed UK equity pension funds are analyzed in order to see if managers have sufficient skill to generate risk adjusted return to cover the cost imposed on the investors. The result implies that the active pension funds in aggregate, before expenses, hold a portfolio that imitates market returns during 2000 to 2012. Bootstrap simulations suggest that only eight funds out of the sample of 102 have skilled managers and six of these managers are skilled enough to produce risk adjusted excess return large enough to cover the expenses imposed on the investor.

The focus of this paper is to evaluate if forecast produced by the Central Bank of Sweden (Riksbanken) for the 12 month change in the consumer price index is unbiased? Results shows that for shorter horizons (h < 12) the mean forecast error is unbiased but for longer horizons its negatively biased when inference is done by Maximum entropy bootstrap technique. Can the unbiasedness be improved by strict ap- pliance to econometric methodology? Forecasting with a linear univariate model (seasonal ARIMA) and a multivariate model Vector Error Correction model (VECM) shows that when controlling for the presence of structural breaks VECM outperforms both prediction produced Riksbanken and ARIMA. However Riksbanken had the best precision in their forecast, estimated as MSFE

This thesis identifies the attractors of Detroit’s growth and divulges into the cultural, federal, socio-economic and urban deterrents that have afflicted Detroit for the past fifty years. It probes the city of Detroit and exposes a hyper-segregated city that has been destroyed by a self-feeding cycle of nomadic behaviour and a speculative culture of endless opportunities. To initiate change this thesis examines real alternatives that are not defined for the citizens of Detroit, but are created by them. It is a self-organizing grassroots approach that applies pressure on the city to rethink its conventional methods of urban revitalization. Utilizing the city’s large inventory of vacant land, abandoned buildings and neighbourhood schools, an alternative design methodology is logically applied to atomize, consolidate, fortify and envisage a new Detroit; one where residents can remain sufficiently abreast of the social and economic problems that consistently challenge them.

Bootstrapping is a resampling technique which treats the original data set as a population and draws samples from it with replacement. This technique is widely used, especially, in mathematically intractable problems. In this study, it is used to obtain the empirical distributions of the parameters to determine whether they are statistically significant or not in a special case of nonparametric regression, Conic Multivariate Adaptive Regression Splines (CMARS). Here, the CMARS method, which uses conic quadratic optimization, is a modified version of a well-known nonparametric regression model, Multivariate Adaptive Regression Splines (MARS). Although performing better with respect to several criteria, the CMARS model is more complex than that of MARS. To overcome this problem, and to improve the CMARS performance further, three different bootstrapping regression methods, namely, Random-X, Fixed-X and Wild Bootstrap are applied on four data sets with different size and scale. Then, the performances of the models are compared using various criteria including accuracy, precision, complexity, stability, robustness and efficiency. Random-X yields more precise, accurate and less complex models particularly for medium size and medium scale data even though it is the least efficient method.

[Truncated abstract] This thesis examines and compares the performance of three classes of stock trading strategies in the Australian stock market from 1980 to 2002. ... The first segment of this thesis examines some simple technical trading rules with a twostep methodology ... Our standard test results show that technical trading rules generate excess returns higher than that of the buy-and-hold portfolio equivalent prior to 1991, but generate lower returns in the period post-1991. Bootstrap test results also show that addressing nonnormality, time-dependence and conditional heteroskedasticity in the data reverses the standard test outcome of predictability ... In addition, our sub-sample results also show technical trading rules becoming less profitable over time ... The second segment of this thesis examines trading rules based on the forecasts of four time-series models: the AR(1), AR(1)-GARCH(1,1), AR(1)-GARCH(1,1)-M and AR(1)- EGARCH(1,1) models. These time-series trading rules were examined with standard t-tests and found to be significantly less profitable compared to technical trading rules. Subsample results also show the time-series trading rules losing profitability over time, which supports the conjecture that the Australian stock market became increasingly efficient over time. The third segment of this thesis examines trading strategies based on various combinations of technical trading rules and time-series models ... Due to the weak performance of the time-series trading rules, our results show that combining technical rules with time-series models do not lead to improved forecast accuracy. Sub-sample results again show a strong decline in profitability post-1991, suggesting that technological advancements in the ASX since 1991 enhance market efficiency such that the above simple stock trading strategies are no longer profitable.