This study aims to investigate the effect of elastic properties of viscoelastic polymer solutions on the microscopic sweep efficiency in enhanced oil recovery (EOR) operations. The effect of elasticity was studied as isolated from the shear viscosity effect using polymer blends with identical shear viscosity behavior but different elastic characteristics. Oil displacement results were compared and the individual effect of elasticity on the sweep efficiency was investigated. A detailed rheological characterization of the polymer solutions was done to measure their viscoelastic properties. A series of polymer flooding experiments were performed using a radial core holder. Results of the experiments indicated that the sweep efficiency of a polymeric fluid could be effectively improved by adjusting the molecular weight distribution (MWD) of the solution at constant shear viscosity and polymer concentration. An attempt was made to find a rheological parameter of polymer solutions that correlates better with the resultant oil recovery. / Petroleum Engineering

Financial analysts are considered inefficient when they do not fully incorporate relevant information into their forecasts. In this dissertation, I investigate differences in the observable efficiency of analysts' earnings forecasts between firms that consistently meet or exceed analysts' earnings expectations and those that do not. I then analyze the extent to which the market incorporates this (in)efficiency into its earnings expectations. Consistent with my hypotheses, I find that analysts are relatively less efficient with respect to prior returns for firms that do not consistently meet expectations than for firms that do follow such a strategy, especially when prior returns convey bad news. However, forecast errors for firms that consistently meet expectations do not appear to be serially correlated to a greater extent than those for firms that do not consistently meet expectations. It is not clear whether the market considers such inefficiency when setting its own expectations. While the evidence suggests they may do so in the context of a shorter historical pattern of realized forecast errors, other evidence suggests they may not distinguish between predictable and surprise components of forecast error when the historical forecast error pattern is more established.

To design a cyclone abatement system for particulate control, it is necessary to accurately estimate cyclone performance. In this cyclone study, new theoretical methods for computing travel distance, numbers of turns and cyclone pressure drop have been developed. The flow pattern and cyclone dimensions determine the travel distance in a cyclone. The number of turns was calculated based on this travel distance. The new theoretical analysis of cyclone pressure drop was tested against measured data at different inlet velocities and gave excellent agreement. The results show that cyclone pressure drop varies with the inlet velocity, but not with cyclone diameter. Particle motion in the cyclone outer vortex was analyzed to establish a force balance differential equation. Barth??s "static particle" theory, particle (with diameter of d50) collection probability is 50% when the forces acting on it are balanced, combined with the force balance equation was applied in the theoretical analyses for the models of cyclone cut-point and collection probability distribution in the cyclone outer vortex. Cyclone cut-points for different dusts were traced from measured cyclone overall collection efficiencies and the theoretical model for calculating cyclone overall efficiency. The cut-point correction models (K) for 1D3D and 2D2D cyclones were developed through regression fit from traced and theoretical cut-points. The regression results indicate that cut-points are more sensitive to mass median diameter (MMD) than to geometric standard deviation (GSD) of PSD. The theoretical overall efficiency model developed in this research can be used for cyclone total efficiency calculation with the corrected d50 and PSD. 1D3D and 2D2D cyclones were tested at Amarillo, Texas (an altitude of 1128 m / 3700 ft), to evaluate the effect of air density on cyclone performance. Two sets of inlet design velocities determined by the different air densities were used for the tests. Experimental results indicate that optimal cyclone design velocities, which are 16 m/s (3200 ft/min) for 1D3D cyclones and 15 m/s (3000 ft/min) for 2D2D cyclones, should be determined based on standard air density. It is important to consider the air density effect on cyclone performance in the design of cyclone abatement systems.

The thesis consists of five papers: three deal with the efficiency of higher education institutions (HEI) and two with entrepreneurship among university graduates. The efficiency of HEIs is analyzed at three different levels: units of one university, universities of one country and universities of a group of European countries. Using data envelopment analysis (DEA) the first paper compares technical efficiency among university units at the Royal Institute of Technology (Stockholm). An interesting result is that there seems to be a complementary relationship between efficiency of resource utilization in teaching and in research. The second paper applies stochastic frontier analysis (SFA) to estimate the cost efficiency of Swedish higher education institutions. According to the estimates, half of the Swedish HEIs have an above average efficiency of 85 percent. The efficiency differences are mainly influenced by the source of funding, HEI size, the number of students per faculty as well as faculty and student compositions. The third paper analyses the cost efficiency of universities among a set of public higher education institutions from six European countries by means of stochastic frontier techniques. The results suggest small variation in the mean economic efficiency of higher education institutions from UK, Norway, Sweden, Finland and Switzerland, implying that the efficiency differences are not explained by country effects. Instead the variations in efficiency are related to organizational differences. The two essays on entrepreneurship among university graduates are based on a unique dataset encompassing individual level data on all employees registered in the Swedish labor market. The first paper explores the differences in entrepreneurial choice of graduates from different universities. The main finding from this paper is that the entrepreneurial choice of graduates from internationally ranked Swedish universities systematically differs from others with the difference varying by the area of education. The second paper on entrepreneurship aims at explaining the high interest in entrepreneurship among arts graduates and finds that the need for self-expression is among the main motivations for their high interest in entrepreneurship. / <p>QC 20130107</p>

The most prevailing feature that led to the massive success of current Wireless Mobile Tele-Communication systems, is mobility. Being able to communicate on the go, anywhere and anytime has revolutionized modern day communication. In recent times the focus has not been only on simply being reachable while on the move but at the same time to use a variety of rich media content services over a variety of available network technologies, termed as 4G networks. The telecommunication development from the very beginning took two different tracks. One was the Internet which provided a fixed means of communication delivering rich media content taking full advantage of its packet switched nature. The second track was that of the cellular systems taking advantage of their circuit switched nature providing mainly voice and short messaging services to wireless and mobile users. In time both these technologies made major advances following their own respective tracks and it became evident that the convergence of both these technologies would be of even greater value. The driving force for this convergence was that a great need was felt for the support of mobility in the Internet. But since the Internet was not designed keeping mobility in mind, it did not support mobility by design. On the other hand in cellular systems in addition to circuit switching, packet switching was needed for flexibility, to make better use of network resources, and to deliver rich media content to the user at cheaper prices. For non-mobile user’s, packet switched networks performed really well in providing the required Quality of Service (QoS). However such networks faced considerable problems to achieve similar QoS for mobile users. With no support for mobility in the Internet from scratch, new components and functionalities were needed to be incorporated into the Internet for mobility support. Examples of such functionality include location tracking, network discovery, packet re-routing to the current point of attachment of the Mobile Node (MN), accounting, authorization and authentication. Special mobility management protocols to provide the required new functionalities were needed. For this purpose the Internet Engineering Task Force (IETF) proposed Mobile IP version 4 (MIPv4) and Mobile IP version 6 (MIPv6) to support mobility for a single IP host and Network Mobility (NEMO) protocol to support mobility for a whole network in motion. These protocols have the ability to maintain data connections for mobile IP enabled devices when they roam across different subnets or networks. When a mobile user moves across network boundaries, it has to perform handover to maintain its connections. When performing a handover a MN may not be able to send or receive data packets therefore the handover duration becomes a critical factor in guaranteeing real time applications (e.g. Voice over IP (VoIP)) their QoS. The purpose of this research work is to deal with handover issues in packets switched networks. A stepwise approach was followed during this study. Starting at layer-2 of the TCP/IP protocol stack and after identifying major problems at this layer for 802.11 networks, solutions were devised for seamless handovers by utilizing the Media Independent Information Service (MIIS) of the Media Independent Handover (MIH). After dealing with major handover issues at the MAC layer of 802.11 networks, the work moved one layer up in the TCP/IP protocol stack to layer three or the IP layer. The MIH framework which was originally proposed for vertical handovers is proposed to be utilized for improving the efficiency of horizontal handovers. Keeping the research work focused on horizontal handovers in 802.11 networks only, an Access Point (AP) selection scheme is proposed and an investigation was carried out regarding the implications of proposed solutions at the MAC layer, on MIPv6 handover delays. In the next step, the study is extended to vertical or heterogeneous handovers. This part proposes to break up a heterogeneous handover algorithm in a Wi-Fi/WiMAX integrated environment, into two parts. The handover algorithm parts are proposed to be executed separately from each other distributed among multiple network components, resulting in intelligent resource utilization and good scalability, without sacrificing handover efficiency. For proof of concept and the effectiveness of the proposed schemes simulations were performed in Network Simulator-2 (ns-2) for a scenario in which a MN moves linearly in the topology, performs handovers and makes use of MIH facilities for improved handovers. An important portion of this research also deals with the analysis of a variety of NEMO route optimization schemes proposed in the literature and their implications on handovers in NEMO networks. The goal of this part is to overview the handover signaling complexity of the various proposed NEMO route optimization schemes.

Problem: Recent articles argue that the new accounting standard regarding abandonment of depreciation of goodwill will cause a rise in share prices. According to the Efficient Market Hypothesis, a rise in profits due to accounting changes should not cause an increase in share prices. Therefore we ask the following main question in our thesis: Do investors on the Stockholm Stock Exchange act semi-strong efficient in relation to the abandonment of linear depreciation of goodwill? Purpose: The purpose of this study is to test the semi-strong form of market efficiency on the Stockholm Stock Exchange by studying if companies show positive abnormal returns caused by the removal of linear depreciation of goodwill. Method: Both a qualitative and quantitative approach was used to investigate semi-strong market efficiency. We conducted an event study to measure if companies with a high degree of goodwill showed abnormal returns. To be able to see if the abnormal returns were caused by the new accounting standards, a qualitative research was made. Conclusion: The empirical investigation indicates that investors acted semistrong efficient in relation to the abandonment of linear depreciation of goodwill.

Adaptive modulation has been actively researched as a means to increase spectral efficiency of wireless communications systems. In general, analytic closed form models have been derived for the performance of the communications system as a function of the control parameters. However, in systems where general error correction coding is employed, it may be difficult to derive closed form performance functions of the communications systems. In addition, in closed form optimization, real time adaptation is not possible. Systems designed with deterministic state optimization are developed offline for a certain set of parameters and hardwired into mobile devices. In this thesis we present stochastic learning algorithms for adaptive modulation design. The algorithms presented allow for adaptive modulation system design in-dependent of error correction coding and modulation constellation requirements. In real time, the performance of the system is measured and stochastic approximation techniques are used to learn the optimal transmission parameters of the system. The technique is applied to Software Defined Radio (SDR) platforms, an emerging wireless technology which is currently being researched as a means of designing intelligent communications devices. The fundamental property that sets SDR apart from traditional radios is that the communications parameters are controlled in software, allowing for real-time control of physical layer communications. Our treatment begins by modeling the time evolution of the adaptive modulation process as a general state space Markov chain. We show the existence and uniqueness of the invariant measure and model performance functions as expectations with respect to the invariant measure. We consider constrained and unconstrained throughput optimization. We show that the cost functions considered are convex. Next we present stochastic approximation algorithms that are used to estimate the gradient of the cost function given only noisy estimates. We conclude by presenting simulation results obtained by the presented method. The learning based method is able to achieve the maximum throughput as dictated by exhaustive Monte Carlo simulation of the communications system, which provide an upper bound on performance. In addition, the learning algorithm is able to optimize communications under various error correction schemes. The tracking abilities of the algorithm are also demonstrated. We see that the proposed method is able to track optimal throughput settings as constraints are changed in time.

Nowadays, the strategy of improving the energy conserving situations of existing buildingshas been playing a more and more important role of further promoting the worldwide sustainabledevelopment paths, especially in China. This thesis presents the results of a case study based researchwhere several different building Energy Conservation and Efficiency Refurbishment (ECER) options toimprove the energy performance of two representative Chinese Residential Multi-Family Buildings(RMFBs) of two very different climate conditions are evaluated and compared, which have been seenas the typical case buildings of existing and aging less energy efficient urban residential building inthat regions (i.e. one in Urumqi belongs to north cold winter region; and other one in Shanghai belongsto south cold winter and hot summer region). In order to provide a scientific base to present the detailenergy conserving improvements in a quantity and quality way, the research methods are including: therelevant literature reviews; the real case data based interview data collections from the professionalworkers in building ECER field; the simulation and analysis processes are based on the building energysimulation computer program – VIP-Energy (Version 2.0.7). The study results are presented in acomprehensive yet straightforward way, and allow for later interesting comparisons between thedifferent building ECER measures for improvement. In a broader perspective, this research will help toexplore a comparative long-term perspective point of view on the existed and most commonly usedresidential building envelope refurbishment measures in a more comprehensive way, and identify thepotential opportunities for further promoting the building energy consumption reductions to meet thefuture increasingly restrict national building energy conservation standards. In addition, the researchalso suggested the optimal RMFB envelope refurbishment strategy based on the case buildings’ statusquo and subject ECER measures, which is introducing an advancing system thinking pattern to theexisting conventional ECER measures, implementing the combined building ECER options to the casebuildings are put forward. And the separate considerations of environmental and economic benefits thatobtained by the subject ECER measures are both presenting simultaneously in the end.

This research paper will, based on the frame of references and through a quantitative study, describe how Generation Y prefers to communicate with customer service departments. The purpose is to help companies lower their expenses by focusing on one of the two traditional communication tools, telephone or e-mail. Since more knowledge can arouse new questions this study was executed with an abductive approach. After studying theories regarding Generation Y a hypothesis was created: Customers from Generation Y will choose e-mail rather than telephone, when they are in need of personal customer service from a company. A simulation is used to get a better understanding of social behaviour. In this case two scenarios was simulated to test the research hypothesis. In the first scenario, the customer needs to contact customer service because of an error the company had made. However, in the second scenario is the contact necessary because of a mistake done by the customer. In these scenarios the participants had to make a choice between telephone and e-mail. The reasons for two scenarios are founded on the hypothesis that Generation Y prefers e-mail as communication tool, regardless of the situation. In this quantitative study with Facebook as survey platform, two hundred fifty-nine answers were gathered. Out of these, two hundred twenty-five were respondents belonging to Generation Y. The data collected from this research was analysed and the result showed we could reject our hypothesis in scenario one. In this case it was significantly proved that members from Generation Y prefer telephone instead of e-mail when the company has made an error. In scenario two where the customer had made a mistake there was a slight tendency to choose telephone. However, this could not be significantly proved and therefore we could not reject our hypothesis. To further explore the respondents’ choices a comparison between scenario one and two was made. A cross-tabulation showed that more than fifty per cent of the respondents that chose telephone in scenario one changed their preferred communication tool in scenario two. Our research led to a conclusion that members of Generation Y do not have one communication tool they always prefer to use and their choice of communication tool is not based on the fact that they were brought up during the digital revolution.

Biomass cogeneration systems can generate power and process heat simultaneously from a single energy resource efficiently. In this thesis, three biomass cogeneration systems are examined. Parametric analysis of back pressure steam turbine cogeneration system, condensing steam turbine cogeneration system and double back pressure steam turbine cogeneration system is conducted. Energy and exergy analyses are performed for three biomass based cogeneration configurations. The parametric analysis demonstrates the effects of varying operating conditions (temperature: 340 oCto 520 oCand pressure: 21bar to 81bar). A higher steam inlet temperature and pressure to the turbine yields better energy and exergy efficiencies and performance. Steam inlet conditions to the turbines and process heater requirements influence the power output and cogeneration system efficiencies. Greenhouse gases reduction is achieved by cooperating cogeneration systems with biomass to reduce CO2 emissions and global warming potential in the power industrial sectors. / UOIT