To investigate the relationship between the structural characteristics of rough single fracturesand the electrical properties of the rock. In this study, a series of physical models of roughand smooth single fractures were established using the finite element method and Ohm's lawto test the electrical conductivity. By varying the distance between the fracture surfaces, arange of individual fractures with different surface roughness characterized by the relativestandard deviation (RSD) was generated using COMSOL Multiphysics software.Subsequently, the intensity of current passing through the fractures and the influence of roughsurfaces on rock electrical properties were monitored. Numerical simulations demonstrated anon-linear relationship between the current intensity through the models and the RSDroughness, with the equivalent resistivity of the fractured rock increasing with higher RSDvalues. As the RSD roughness increased, the difference in equivalent resistivity betweenrough and smooth fractures also increased, indicating a greater impact of rough surfaces onelectrical properties. The equivalent resistivity of the rock model was 1.05-1.45 times that ofthe parallel plate model with same average aperture. The novelty of this study lies in directlyinvestigating the relationship between roughness of single fractures and rock electricalproperties in three-dimensional, providing insights for understanding the electrical behaviorof rock fractures. / För att undersöka sambandet mellan strukturella egenskaper hos ojämna enkelstrålar och deelektriska egenskaperna hos bergarten. I denna studie etablerades en serie fysiska modeller avojämna och jämna enkelstrålar genom att använda finita elementmetoden och Ohms lag föratt testa elektrisk ledningsförmåga. Genom att variera avståndet mellan strålytornagenererades en rad individuella strålar med olika ytjämnhet som karakteriseras av relativstandardavvikelse (RSD) med hjälp av COMSOL Multiphysics-programvara. Därefterövervakades intensiteten av ström som passerade genom strålarna och inflytandet av ojämnaytor på bergens elektriska egenskaper. Numeriska simuleringar visade på ett icke-linjärtsamband mellan strömintensiteten genom modellerna och RSD-ytjämnheten, där denekvivalenta resistiviteten hos den spruckna bergarten ökade med högre RSD-värden. NärRSD-ytjämnheten ökade, ökade även skillnaden i ekvivalent resistivitet mellan ojämna ochjämna strålar, vilket indikerar en större påverkan av ojämna ytor på de elektriskaegenskaperna. Den ekvivalenta resistiviteten hos bergmodellen var 1,05–1,45 gånger högreän den hos parallellplattanmodellen med samma genomsnittliga apertur. Nyheten i dennastudie ligger i att direkt undersöka sambandet mellan ytjämnheten hos enkelstrålar ochbergens elektriska egenskaper på en tredimensionell skala, vilket ger värdefulla insikter föratt förstå det elektriska beteendet hos bergstrålar och ytterligare förbättra modeller.

To stay competitive in today's market, organizations focus on efficiency to reduce costs. Since there are still processes that are manually handled, there is a risk of affecting workers health during streamlining. Volvo CE Braås are currently working with a takt time of 35 minutes throughout their facility. They are looking to implement a takt flow system on their Pallet breakdown disassembly line to unify the systems within the company. The current situation of the pallet breakdown consists of variation, ergonomic issues, inconsistencies, disturbances and lay-out problems. Main problems have remained unidentified. The goal of the thesis has been to determine how optimization as well as, takt time implementation affects the workers. The aim of the thesis has been to analyze their current situation, present relevant changes to be made and to improve the ergonomics of the employees. Methods such as flow mapping, surveys, gemba walks and interviews have contributed to a basis of understanding. The methods have, together with selected theory, contributed to important knowledge and understanding of the disassembly system, that has led to conclusions and recommendations regarding the impact of optimization and takt time implementation on ergonomics. By using ergonomic guidelines together with discrete event simulation, an identification of human factors when optimizing has been detected. For Volvo CE to successfully implement takt time, several optimizations are needed together with relevant investments to ensure that the ergonomic values are kept on an appropriate level when the frequency of tasks increases. As a conclusion, to optimize a system which has a direct impact on the employees, there is a need to investigate the ergonomic values of today together with values after optimization. Optimization can not occur without investing in tools.

As the world faces unprecedented environmental challenges, there is an urgent need for largescale investments in green infrastructure and technologies. If we are going to achieve carbon neutrality, significant investments are necessary, and therefore must the entire financial system unite and endorse sustainable investment activities in a market-oriented manner.   A green bond is a relatively new type of bond. It was first introduced in 2007 by the European Investment Bank (EIB). This was followed up by a collaboration between Skandinaviska Enskilda Banken (SEB) and the World Bank, a group of Swedish investors, pension funds, and SRI-focused investors. They issued their first green bond in 2008 intending to attract more investors. However, this attempt to increase the interest did not work, green bonds were almost nonexistent until 2013. One explanation for the slow development of the green bond market was the financial crisis in 2008. Further, the reason for the low interest in green bonds during this period was that traditional investors deemed these risky and non-profitable.  Using a deductive approach, this thesis investigates how green bonds perform compared to conventional bonds and stocks from the issuing company. The authors sampled green and conventional bonds from 33 companies that matured from 2018 to 2023. The sample data set contains bonds from Asia, Europe, South America, North America, and Australia. The data was tested using multiple hypotheses.  This thesis sets out to answer the research question: How do green bonds perform compared to conventional bonds and stocks?   The results indicated there is a significant difference between the three asset types. First, the stocks yield higher returns and higher standard deviations than green and conventional bonds. Second, the authors found no evidence for a difference in return thus a significant difference in standard deviation. The results also suggest there is a difference in modified duration, convexity, maturity, and yield to maturity. These findings indicate that green bonds performed better than conventional bonds, especially regarding risk and volatility. Therefore, could green bonds be useful when diversifying a portfolio.  The findings suggested that a portfolio composition that combines the three assets could be in line with both shareholder theory and stakeholder theory. The portfolio theory also provides interesting insights into the potential portfolio optimizations since there are differences between green and conventional bonds. Since no difference in the return was found for green and conventional bonds the authors find no reason to support the idea of herding behavior in the trading of green bonds.  However, the difference in standard deviation is interesting from a behavioral perspective, a lower standard deviation indicates that the green bond experiences lower volatility compared to conventional bonds.

This dissertation is based on the hypothesis that a third dimension, namely investment time horizon, can add value to the more conventional two-dimensional methodology of assessing the relative risk and return attributes of various assets and portfolios in order to enhance investment decisions. This study shows that time horizons should be considered in the investment decision making process and provides concrete evidence that a methodology that is not cognizant of investment time horizon is prone to extensive long-term opportunity cost risk. In addition to providing evidence of investment time horizon relevance, the study makes suggestions as to how time horizons could be incorporated into the risk return assessments of various asset classes and also presents a framework for the more holistic assessment of asset class properties while incorporating time horizons. / Business Management / Thesis (M. Com. (Business Management))

Long-term omni-directional ambient noise was collected at several sites in the Gulf of Mexico during 2004 and 2005. The Naval Oceanographic Office deployed bottom moored Environmental Acoustic Recording System (EARS) buoys approximately 159 nautical miles south of Panama City, Florida, in water depths of 3200 meters. The hydrophone of each buoy was 265 meters above the bottom. The data duration ranged from 10-14 months. The buoys were located near a major shipping lane, with an estimated 1.5 to 4.5 ships per day passing nearby. The data were sampled at 2500 Hz and have a bandwidth of 10-1000 Hz. Data are processed in eight 1/3-octave frequency bands, centered from 25 to 950 Hz, and monthly values of the following statistical quantities are computed from the resulting eight time series of noise spectral level: mean, median, standard deviation, skewness, kurtosis and coherence time. Four hurricanes were recorded during the summer of 2004 and they have a major impact on all of the noise statistics. Noise levels at higher frequencies (400-950 Hz) peak during extremely windy months (summer hurricanes and winter storms). Standard deviation is least in the region 100-200 Hz but increases at higher frequencies, especially during periods of high wind variability (summer hurricanes). Skewness is positive from 25-400 Hz and negative from 630-950 Hz. Skewness and kurtosis are greatest near 100 Hz. Coherence time is low in shipping bands and high in weather bands, and it peaks during hurricanes. The noise coherence is also analyzed. The 14-month time series in each 1/3- octave band is highly correlated with other 1/3-octave band time series ranging from 2 octaves below to 2 octaves above the band's center frequency. Spatial coherence between hydrophones is also analyzed for hydrophone separations of 2.29, 2.56 and 4.84 km over a 10-month period. The noise field is highly coherent out to the maximum distance studied, 4.84 km. Additionally, fluctuations of each time series are analyzed to determine time scales of greatest variability. The 14-month data show clearly that variability occurs primarily over three time scales: 7-22 hours (shipping-related), 56-282 hours (2-12 days, weather-related) and over an 8-12 month period.

The purpose with this study is to show how the subjective uncertainty analysis can be applied to the cost estimates and examine how the attitudes towards risk budgeting of construction projects works. Biogas Mellannorrland is based on a case study and focuses on four location options for the biogas plant. For each option, a cost estimate in form of a fixed cost and variable cost elements, where the latter are uncertain. Pearson-Tukey method have been applied as a method to estimating subjective probabilities. An assumption is made so that the uncertain costs are normally distributed, where the parameters’ mean and standard deviation collected from respondents indicating percentiles at 5% and 95% for doubtful cost elements. In order to identify the project managers risk attitude, the risk premium method will be used to calculate where the expected value is produced by Pearson-Tukey method. The expected value is subtracted with certainty equivalent, which consist of the budgeted amount. The study was conducted through interviews in order to obtain the costs and the subjective probabilities. The study results show that it is difficult to determine which option is the best, or the worst, by just looking at the expected value. The risk premium shows that each option is a risk averse choice for the project managers, since the risk premium was greater than zero. / Denna studie syftar till att visa hur subjektiv osäkerhetsanalys kan tillämpas vid kostnadskalkyler samt undersöka riskattityder vid budgetering av byggprojekt. Undersökningen är en fallstudie vid Biogas Mellannorrland och fokuserar på fyra lokaliseringsalternativ för biogasanläggning. För varje alternativ görs en kostnadskalkyl i form av ett antal fasta och rörliga delkostnader, där de senare är osäkra. Som metod för att skatta subjektiva sannolikheter har Pearson-Tukey-metoden tillämpats. Ett antagande görs att osäkra kostnader är normalfördelade, där parametrarna väntevärde och standardavvikelse hämtas från respondenter som anger percentilerna vid 5 % och 95 % för osäkra delkostnader. För att identifiera projektledarnas riskattityd, kommer riskpremium att beräknas, där det förväntade värdet tas fram med Pearson-Tukey- metoden. Det förväntade värdet subtraheras med säkerhetsekvivalensen, vilket utgörs av det budgeterade beloppet. Studien har genomförts med hjälp av intervjuer för att få fram kostnader och subjektiva sannolikheter. Studiens resultat visar att det är svårt att avgöra vilka alternativ som är bäst eller sämst genom att bara titta på väntevärdet. Med riskpremium visar alla alternativ att projektledarna gör ett riskaversivt val, eftersom riskpremium blev större än noll.

Under detta arbete studeras en av Europas mest moderna cementfabriker med kapacitet att producera runt 2,6 miljoner ton cement per år. Syftet med examensarbetet är att beskriva variationen i utfallen av råmjöl och identifiera vilka orsaker till variation som är möjliga att minska. Oavsiktliga variationer av kvalitet i råmjölet kan resultera i bristande klinkerkvalitet, som i sin tur kan medföra en betydande intäktsförlust. Arbetet utgår från teorier om offensiv kvalitetsutveckling, Six sigma, processledning och cementproduktion. En metodkombination av kvantitativa och kvalitativa metoder har tillämpats för datainsamling och dataanalys, där den kvantitativa datainsamlingen baserats på historiska data från referensorganisationen. De slutsatser som redogörs för, är att processen som studeras har möjlighet till att prestera i världsklass. Huvudsakliga bidragande orsaken är metoden för styrning där systemet saknar styrgränser som leder till överstyrning. Även materialvariation vid byten av råmaterialslimpor är en betydande orsak till variansen i råmjölet. Förutsatt att styrsystemet kopplas på för tidigt efter ett genomfört limpbyte kan effekten av ett limpbyte förvärras. Vidare tyder resultaten på att 80% av den totala variationen i råmjölets kalkmättnad skapas av limpbyten. / During this work, one of Europe's most modern cement factories is studied, with the capacity to produce around 2.6 million tons of cement per year. The purpose of the thesis is to describe the variation in the outcome of raw meal and identify which causes of variation are possible to reduce. Involuntary variations in the quality of the input raw meal can result in a lack of clinker quality, which in turn can result in a significant loss of revenue. The work is based on theories relating to Total Quality Management, process management and cement production. A method combination of quantitative and qualitative methods has been applied for data collection and data analysis, where the quantitative data collection is based on historical data gathered from the reference organization. The conclusions outlined are that the process being studied has the opportunity to perform world-class. The main contributing factor is the method for control where the system lacks control limits that lead to over compensation. Also, material variation in the case of changes of raw material piles is a significant cause of the variance in the raw meal. Provided that the control system is switched on prematurely after a raw material pile change has been carried out, the effect of the change can be worsened. Furthermore, the results indicate that 80% of the total variation in the raw meal’s lime saturation is created by raw material pile changes.

Made available in DSpace on 2016-04-27T16:58:16Z (GMT). No. of bitstreams: 1 Claudia Borim da Silva.pdf: 1181639 bytes, checksum: a1c349e009d97a59b67411221aef0c9a (MD5) Previous issue date: 2007-05-30 / Due to student difficulty with understanding standard deviation, this work aimed to identify the reasoning about variation and variability in all parts of the investigation cycle of the statistical thinking. Nine middle and high school Mathematics teachers and two mathematics students of University of São Paulo participated in an action research, 3 hr meetings, lasting in total for 48 hrs. The contents were simple and grouping data frequency distribution, graphics, center and spread measures. The reasoning levels were classified using the general model developed by Garfield (2002). The teachers showed no variaton reasoning during the first week, except for a teacher with idiosyncratic reasoning. During the action research sensibility phase and planning of investigative cycle phase, the teachers developed variability reasoning naturally, but not about variation. However, this experience promoted an upgrade of teachers statistical thinking, that used three (between four) dimensions created by Wild e Pfannkuch (1999). Nevertheless, the statistical thinking upgrade did not implicate a gain in variation reasoning level, observed during the data analysis phase. To compare three discret variable frequency distribution were done using the perception of mode, minimum and maximum values and minimum frequency and use of the distribution chunk with range was organized with existence of the frequency in all groups, understood like verbal until procedural reasoning, respectively. The center measures discussion showed the misconception of mean, which was understood as the mode, and this inhibited necessity perception of a spread measure. The use of correct mean of arithmetic mean induced the teachers use complement measures as the mode and minimum and maximum values, but not the standard deviation. The mean fo standard deviation was predominantely a measure of number of differents observations, signal of homogeneous sample, as many Mathematics textbooks introduced the concept of variation. The comprehension of one standard deviation interval towards mean didn´t develop naturally and the teachers who understood this mean of standard deviation had difficulty to understand what was in the interval, which suposed to develop this integrated reasoning process with the educational softwares created for this intention. In conclusion, the term more variation can cause wastly differing results due to personal interpretation of the phrase ´more variation´ and idiosyncratic reasoning process involved in analysing complex mathematical data: more variation between frequency in only the variable category or variable value in comparing frequency distributions and more variation between sample different observations, both without use of variation from mean / Devido à dificuldade encontrada por alunos de graduação para a compreensão do desvio padrão, este trabalho teve como objetivo verificar o raciocínio sobre variação e variabilidade nas etapas do ciclo investigativo do pensamento estatístico. Foram participantes da pesquisa nove professores de Matemática da escola básica e dois alunos de Matemática da Universidade de São Paulo. O trabalho seguiu os pressupostos de uma pesquisa-ação e a fase de implementação teve duração de quarenta e oito horas, divididas em dezesseis encontros de três horas cada. Foram discutidos os conteúdos estatísticos: distribuição de freqüência simples e com dados agrupados, representações gráficas, medidas de tendência central e dispersão. Os níveis de raciocínio sobre variação foram classificados de acordo com o modelo proposto por Garfield (2002). O diagnóstico identificou a ausência de raciocínio sobre variação, exceção feita a um professor que apresentava raciocínio idiossincrático. Durante a fase de sensibilização da pesquisa-ação e planejamento do ciclo investigativo, os professores apresentaram naturalmente o raciocínio sobre variabilidade, mas não sobre variação. Entretanto, a experiência com a elaboração de uma pesquisa, desde a definição dos objetivos até a coleta e montagem do banco de dados permitiu um avanço no desenvolvimento do pensamento estatístico dos professores, que já transitavam em três das quatro dimensões de sua estrutura elaborada por Wild e Pfannkuch (1999). Não obstante, o desenvolvimento do pensamento estatístico não implicou diretamente em um nível mais avançado do raciocínio de variação, observado durante a fase de análise dos resultados da pesquisa. Para a comparação de três distribuições de freqüências simples de variável discreta foram utilizadas a percepção da moda, a observação dos valores máximo e mínimo e da menor freqüência e a elaboração de um intervalo de variação composto pelos valores da variável que tinham freqüência nas três distribuições, conjuntamente, que foram categorizados como raciocínio verbal de variação até raciocínio de procedimento, respectivamente. A discussão sobre as medidas de tendência central permitiu observar a interpretação equivocada de média como maioria, que se refere à moda, que foi um fator impeditivo para a percepção da necessidade de uma medida de variação. A utilização do correto significado de média motivou os professores a utilizarem medidas complementares como a moda e os valores máximo e mínimo, mas não o desvio padrão. O significado atribuído ao desvio padrão foi, predominantemente, uma medida da variação entre as observações indicando homogeneidade da amostra, aspecto reforçado pelos livros didáticos de Matemática do ensino médio e categorizado como raciocínio verbal de variação. A composição do intervalo de um desvio padrão da média não surgiu naturalmente e mesmo os participantes que compreenderam esta interpretação do desvio padrão, apresentaram dificuldade para identificar o que tinha no intervalo. Acredita-se que o desenvolvimento de aplicativos computacionais para trabalhar o conceito de intervalo em torno da média possa auxiliar na aquisição deste raciocínio, considerado um raciocínio completo de variação. Conclui-se que a linguagem maior variação pode induzir dois diferentes raciocínios idiossincráticos: a maior variação das freqüências em alguma categoria ou valor da variável de uma distribuição de freqüências e a maior variação de observações diferentes na amostra, ambas não relacionadas com a medida de tendência central

Syfte: Syftet med denna undersökning är att göra en komparativ studie mellan Sverige-och global aktiefonder för att vidare analysera vilka aktiefonder som ger högst avkastning. Metod: Uppsatsen bygger på en statistisk analys vilket sekundärdata ligger till grund för våra beräkningar. Genom tillämpning av kvantifierbar hård data där bland annat historiska aktiekurser ingår, så har en kvantitativ studie använts. Befintliga teorier och modeller har tillämpats. Slutsats: Studien visar i stort sett att högre risk ger en högre avkastning. Under period 1 presterade Latin Amerika fonderna bäst varefter Sverige fonder presterade bättre under period 2. Dessa marknader kan vara väldigt oberoende av varandra och tenderar därmed inte att följa varandras kursutveckingen. Slutsatsen är då att en investering i olika geografiska placeringar diversifierar risken mer. Exempelvis en investering i en svensk fond och en latin amerika fond.

Background: In 1999 the Swedish pension system was reformed with an aim to create a stable and high return on pension assets. First, Second, Third and Fourth general pension funds, hereby referred to as AP1-AP4, had an important part in the reform. AP1-AP4, also called the buffer funds, was assigned to secure long-term, big parts of the pension capital. The funds objective is by law, to manage the fund's assets in a manner that provides maximum benefit for the state pension. The funds will also invest pension assets with an overall low level of risk while achieving a sustainable high return. Aim: The purpose of this study is to investigate whether the First-Fourth AP-Funds is meeting its objectives regarding risk and return according to Swedish law. The aim is also to see how AP1-AP4 risk-adjusted returns compare to the four Sweden funds risk-adjusted returns according to modern portfolio theory. Theory: Morningstar Rating, Treynor ratio, Sharpe ratio, Jensen's Alpha, Standard Deviation, Beta. Conclusion: The risk-adjusted performance measures used in this study shows that there are clear differences between the two fund groups, where the AP-funds performed worse than the Sweden funds in every measurement. The study shows that the pension funds do not reach their goals over the five-year period, in four of the five time intervals listed in the study. In summary, the study shows that pension funds have a lower risk-adjusted return than the four bank Sweden funds and that the pension funds have not achieved their goals.