Gender and Overconfidence

Do males differ from females in terms of self-confidence? The structure of the Economics I exam at Stockholm University provides an opportunity to shed some light on this question. By answering an extra, optional question, the students can aim for a higher mark. We find a clear gender difference in that male students are more inclined than female students to take this opportunity. This difference in selfassessment is more pronounced among younger than among older students.Overconfidence; gender differences; exam behavior; exam results

Reduction in ground vibrations by the use of wave obstacles

The increasing size of the population results in that unbuilt spaces needing to be used for the construction of new facilities. Large construction sites can generate disturbing vibrations to nearby buildings, both while construction is underway and afterwards through the operation of subways, for example. The establishment of new areas close to, for example, motorways and railways increases the risk of disturbing vibrations being propagated to the new buildings. It is important that efficient methods for reducing ground vibrations be available when densely built areas are being planned. Reduction in ground vibrations by use of wave obstacles is investigated here by use of numerical simulations, trenches and shaped landscapes being considered as wave obstacles. The effects of geometric parameters on open trenches, material parameters of filled trenches, and of infiltrated water in open trenches, were examined in appended Paper A. The finite element method involving use of both finite and infinite elements in the frequency domain was employed. In investigating the effects of the infiltrated water, account was taken of fluid-structure interaction. The finite element model, in which plane strain conditions were assumed, was applied to a road, the bedrock, two layers of soil and a trench. The depth of the trench and the elastic modulus of the solid material that was inserted into it were found to be the most important parameters to consider. The results concerning the infiltration of water into an open trench indicated the presence of water there to increase the vibration levels. Reduction in traffic-induced ground vibrations by use of shaped landscapes is investigated in appended Paper B, the effects of shaping the landscape surrounding a high-tech facility and using the landscape as a wave obstacle being studied. The effects of the geometric parameters of a shaped landscape were examined in parametric studies. An architectural landscape design was also investigated in terms of its effectiveness in reducing trac-induced ground vibrations. The finite element method involving use of both finite and infinite elements in the frequency domain was employed, the finite element models employed concerning a layer of soil and the underlying bedrock. It was found that anywhere from an appreciable reduction to an appreciable amplification of the vibrations can occur, depending upon the geometric parameters of the shaped landscape. Both types of ground modifications that were investigated were shown to be able to achieve an appreciable reduction in the level of vibration. Both the use of a trench filled with a solid material and use of a shaped landscape were found to result in a reduction in the level of vibrations of approximately 35 %. Both these types of methods can thus be regarded as being suitable for making it possible in this respect for buildings to be constructed close to vibration sources

An investigation of abnormal returns in distress exchange : a Norwegian case

The main objective of this research is to investigate whether distress firm creditors get better or worse recoveries during the financial restructuring process in Norwegian Bond market. To investigate that question we have created a sample using Norsk Tillitsmann database. For the criterion we needed firms in the data sample that went through financial restructuring due to financial distress or financial. We managed to get hold of ninety seven bonds using the above criterion. The sample was composed of different classes of bonds according to their seniority, but majority was senior secured and senior unsecured bonds. We have also divided the sample into five broader industry classifications and the majority of the sample firms were oil and gas related. During the literature review process we came up with a few hypotheses and tried to find evidence of them in the sample. For this purpose we conducted a layman analysis, i.e. descriptive analysis in which we came to conclusion that creditors are better off if the borrower is in oil and gas industry and if they hold senior secured or senior unsecured securities. We also found descriptive evidence that debt exchange produce higher “abnormal” return for distress firm’s creditors than debt to equity swap. Finally we conducted statistical tests on the sample to find the evidence of stated hypotheses to see if the results are statistical significant or not. The results were not significant to the hypothesis that seniority and collateral leads to higher abnormal returns; however there are strong indications that the industry as well as debt exchange or equity swap are relevant factors for higher abnormal returns. Also examined was if bondholders recoveries are being affected by the gearing (leverage) of the distress firm and also by the time to maturity (settlement date) of the bonds. In regression analysis we did not find both of these to be significant affecting bondholders’ returns however we did notice that almost all of the firms had 66% to 80% debt in their capital structure. As well we believed that high leverage is the reason for them to be in distress. In our sample of there is one financial restructuring (Sevan Marine ASA) that stands out with the clear violation of Absolute Priority Rule (APR), and there were other minor APR violation in not so strict sense. The final conclusion we drew from analyzing the sample is that a creditor’s or investor’s in the Norwegian bond market should place themselves in the Oil & Gas industry and negotiate for debt exchanges during restructurings process to get higher abnormal returns

Solar Thermal Energy In Thimphu, Bhutan - A feasibility study using TRNSYS modeling

Bhutan is one of the highest per capita users of firewood in the world. Firewood and electricity are the most common methods for heating in Bhutan and both methods suffer from drawbacks. Bhutan’s capitol, Thimphu, lies some 2500 meters above sea level and has cold winters with clear skies. These facts are the base for this report’s investigation of the potential to use solar thermal energy to mitigate the use of firewood and electricity for heating. Fieldwork and interviews were carried out in areas in and around Thimphu. Two models were made; one for a typical rural house, heated with firewood, and one for a typical urban apartment complex, heated with electricity. The rural house was modeled as a two story building with one family living on each floor. The urban apartment complex was modeled as a four story building with four apartments on each floor for a total of 16 families living in the building. These models were input into the simulation program TRNSYS. A solar thermal system was optimized for each house based on performance while trying to keep the system as small as possible. The effects of this system on the comfort and energy consumption in the rural and urban model were noted. In the rural case a solar thermal system with a solar collector area of 15 m2 and a tank volume of 0.65 m3 decreased the firewood usage over a year with 50 % while increasing the comfort level. In the urban case a solar thermal system with a solar collector area of 20 m2 and 0.8 m3 per floor, i.e. 5 m2 and 0.2 m3 per apartment, decreased the use of the electric heater with 44 % while increasing the comfort. Several variations to the system and mode of heating were tested and are detailed in the report. It was found that a solar thermal system has a high potential of heating houses in the Thimphu area. The main obstacle for implementing a solar thermal system is its cost

Effect of structural design on traffic-induced building vibrations

Population growth and urbanization results in densified cities, where new buildings are being built closer to existing vibration sources, and new transportation systems are constructed closer to existing buildings. Potential disturbing vibrations are one issue to consider in planning urban environments and densification of cities. Vibrations can be annoying for humans but also for sensitive equipment in, for example, hospitals. In determining the risk for disturbing vibrations, the distance between the source and the receiver, the ground properties, and type and size of the building are governing factors. In the paper, a study is presented aiming at investigating the influence of various parameters of the building’s structural design on vibration levels in the structure caused by ground surface loads, e.g. traffic. Parameters studied are related to the type of construction material (if it would be a light or heavy structure), and to the slab thickness. The study is limited to the structural response at frequencies near the first resonance frequency of the soil. The finite element method is employed for discretizing the building structure that is coupled to a semi-analytical model considering a layered ground

Variation in models for simple dynamic structure–soil–structure interaction problems

To account for dynamic cross-coupling of structures via the soil, a computational model must be accurate enough to provide the correct overall behaviour of the scattered wave field. However, simplicity is also important when a model should be used for design purposes, especially in the early design stages and feasibility studies. The paper addresses the accuracy of simple models in which an array of structures is simplified into blocks placed on the ground surface or embedded within the soil. Comparisons are made between models that account or do not account, in a proper manner, for the inertia and embedment of the structures. Especially, the limitations of simplified models are discussed regarding their capability to quantify the insertion loss accurately

POD GENERATED BY MONTE CARLO SIMULATION USING A META-MODEL BASED ON THE simSUNDT SOFTWARE

A recent developed numerical procedure for simulation of POD is used to identify the most influential parameters and test the effect of their interaction and variability with different statistical distributions. With a multi-parameter prediction model, based on the NDT simulation software simSUNDT, a qualified ultrasonic procedure of personnel within Swedish nuclear power plants is investigated. The stochastical computations are compared to experimentally based POD and conclusions are drawn for both fatigue and stress corrosion cracks

Bodily mimesisas “the missing link” in human cognitive evolution

It is fairly uncontroversial that there is a large gap between the communicative and cognitive systems of non-human animals and those of human beings. There is much less consensus, however, on what the nature of this gap is, and even less on how it was bridged in evolution