Coverage in a Wireless Sensor Network reflects how well a sensor network monitors an area. Many times it is impossible to provide full coverage. The key challenges are to prolong the lifetime and ensure connectivity to provide a stable network. In this thesis we first define p-percent coverage problem in which we require only p% of the whole area to be monitored. We propose two algorithms, Connected P-Percent Coverage Depth First Search (CpPCA-DFS) and Connected P-Percent Connected Dominating Set (CpPCA-CDS). Through simulations we then compare and analyze them for their efficiency and lifetime. Finally in conclusion we prove that CpPCA-CDS provides 5 to 20 percent better active node ratio at low density. At high node density it achieves better distribution of covered area however the lifetime is only 5 to10 percent shorter then CpPCA-DFS. Overall CpPCA-CDS provides up to 30 percent better distribution of covered area.

When foundations are designed on weak clay layers, it is a common practice to modify the subgrade by installing stone columns. Currently used methods for determining the level of ground modification, represented by the percentage of soil replaced (replacement ratio), assume a rigid foundation. These analytical methods provide the designer with the potential settlement reduction based on the compressibility parameters of the subgrade and the replacement ratio. The deficiencies of these methods are the assumption of rigidity of the foundation and the consideration of the settlement reduction as the only design criterion. Furthermore, they do not consider the effects that ground modification has on differential settlement, moments, and shear forces within the slab. In order to determine the effects of ground modification on the overall performance of a flexible foundation, a computer program was formulated which compares a multitude of design parameters of the modified subgrade to those of the unmodified subgrade to determine the impact of ground modification. By performing this investigation, correlations were found between the replacement ratio and the settlement reduction factors. Similarly, correlations were also found between the ratio of the length of the foundation to the radius of relative stiffness, and the moments and shear forces generated within the slab. The use of the findings of this thesis would allow the design to make more informed decisions when designing foundations on modified subgrade resulting in safer and more economical designs.

The mean residual life (MRL) function is an important function in survival analysis, actuarial science, economics and other social sciences and reliability for characterizing lifetime. Different methods have been proposed for doing inference on the MRL but their coverage probabilities for small sample sizes are not good enough. In this thesis we apply the empirical likelihood method and carry out a simulation study of the MRL function using different statistical distributions. The simulation study does a comparison of the empirical likelihood method and the normal approximation method. The comparisons are based on the average lengths of confidence intervals and coverage probabilities. We also did comparisons based on median lengths of confidence intervals for the MRL. We found that the empirical likelihood method gives better coverage probability and shorter confidence intervals than the normal approximation method for almost all the distributions that we considered. Applying the two methods to real data we also found that the empirical likelihood method gives thinner pointwise confidence bands.

One of the most important, but often ignored, factors affecting the transport and the seismic properties of hydrocarbon reservoir is pore shape. Transport properties depend on the dimensions, geometry, and distribution of pores and cracks. Knowledge of pore shape distribution is needed to explain the often-encountered complex interrelationship between seismic parameters (e.g. seismic velocity) and the independent physical properties (e.g. porosity) of hydrocarbon reservoirs. However, our knowledge of reservoir pore shape distribution is very limited. This dissertation employs a pore structure parameter via a rock physics model to characterize mean reservoir pore shape. The parameter was used to develop a new physical concept of critical clay content in the context of pore compressibility as a function of pore aspect ratio for a better understanding of seismic velocity as a function of porosity. This study makes use of well log dataset from offshore Norway and from North Viking Graben in the North Sea. In the studied North Sea reservoir, porosity and measured horizontal permeability was found to increase with increasing pore aspect ratio (PAR). PAR is relatively constant at 0.23 for volumes of clay (V_cl) less than 32% with a significant decrease to 0.04 for V_cl above 32%. The point of inflexion at 32% in the PAR –V_cl plane is defined as the critical clay volume. Much of the scatters in the compressional velocity-porosity cross-plots are observed where V_cl is above this critical value. For clay content higher than the critical value, Hertz-Mindlin (HM) contact theory over-predicts compressional velocity (V_p) by about 69%. This was reduced to 4% when PAR distribution was accounted for in the original HM formulation. The pore structure parameter was also used to study a fractured carbonate reservoir in the Sichuan basin, China. Using the parameter, the reservoir interval can be distinguished from those with no fracture. The former has a pore structure parameter value that is ≥ 3.8 whereas it was < 3.8 for the latter. This finding was consistent with the result of fracture analysis, which was based on FMI image. The results from this dissertation will find application in reservoir characterization as the industry target more complex, deeper, and unconventional reservoirs.

This work aims to integrate Byrne’s theory of visual salience computation (2006) with Salvucci’s model of eye movements (2001) by testing participants on a visual search task similar to Findlay (1997). By manipulating the number, salience, and spacing of targets, participants exhibited the global effect averaging phenomena during the first recorded saccade, whereby short‐latency saccades land in between adjacent objects. Previous work has argued that the saccadic targeting system causing the averaging is influenced both by the salience and arrangement of objects displayed (Rao, Zelinsky, Hayho, & Ballard, 2002). However, to accurately account for these results, we did not have to couple the salience system with the saccadic targeting system. Instead, the systems work sequentially and in isolation, whereby the salience system simply hands off the next object to examine to the targeting system, whose accuracy depends only on saccadic latency and the location of the targeted and non‐targeted items.

Teismo precedento kaip teisės šaltinio problematika Lietuvoje Santrauka Konstituciniam Teismui paskelbus 2006 m. kovo 28 d. ir 2007 m. spalio 24 d. nutarimus, Lietuvoje precedentas pirmą kartą oficialiai pripažintas privalomu teisės šaltiniu. Lietuvos teisininkų bendruomenėje buvo ir vis dar yra svarstoma, kokos priežastys lėmė, kad bendrosios teisės institutas tapo Lietuvos teisės sistemos dalimi. Darbe, remiantis statutinės teisės normomis, Lietuvos teisės mokslo atstovų darbais, bei konkrečiais pavyzdžiais iš Lietuvos Aukščiausiojo Teismo ir Lietuvos apeliacinio teismo praktikos, stengiamasi ištirti ir atskleisti prielaidas bei aplinkybes, lėmusias precedento susiformavimą dabartinėje Lietuvos teisės sistemoje. Precedento instituto užuomazgų būta jau tarpukario Lietuvoje, tačiau pasireiškus tarybinės teisės intervencijai, jis taip ir liko nesusiformavęs. Vėliau, Lietuvai atkūrus nepriklausomybę, teismų vaidmuo ir jų formuojamos praktikos reikšmė palaipsniui didėjo, kol galiausiai Konstitucinis Teismas konstatavo, jog teismai, spręsdami analogiškas bylas, privalo vadovautis jau sukurtais precedentais, o ne kurti naujus. Tai buvo precedento doktrinos formavimosi Lietuvoje pradžia. / A Precedent as a Source of Law Issues in Lithuania Summary A judicial precedent was established as a binding source of law in the Lithuanian law system by the resolution of the Constitutional Court of the Republic Lithuania, dated 28h March 2006, and the resolution of the Constitutional Court of the Republic of Lithuania, dated 24th October 2007. The question whether the institute of the common law tradition should have had to become a part of Lithuanian law system is still considered and discussed among the Lithuanian lawyers. This paper, which is based on the analysis of legal acts, works of Lithuanian law scientists and decisions of the Supreme Court of Lithuania and the Court of Appeals of Lithuania, seeks to analyse the background and circumstances under which the precedent institute was established in Lithuanian law system. A germ of the precedent already existed in the interwar Lithuania. However, due to the historical reasons and an intervention of the Soviet law, the precedent institute was not further developed. Later, after Lithuania announced independence, the role of Lithuanian courts and their jurisprudence has become important again. Finally, the Constitutional Court of the Republic of Lithuania has stated that the same cases must be decided in the same way, i.e. they have to be decided not by creating new court precedents, competing with the existing ones, but by taking account of the already consolidated ones.

No description available.

In this paper, I evaluate the out-of-sample performance of the portfolio optimizer relative to the naïve and market strategy on the Swedish stock market from January 1998 to December 2012. Recent studies suggest that simpler strategies, such as the naïve strategy, outperforms optimized strategies and that they should be implemented in the absence of better estimation models. Of the 12 strategies I evaluate, 11 of them significantly outperform both benchmark strategies in terms of Sharpe ratio. I find that the no-short-sales constrained minimum-variance strategy is preferred over the mean-variance strategy, and that the historical sample estimator creates better minimum-variance portfolios than the single-factor model and the three-factor model. My results suggest that there are considerable gains to optimization in terms of risk reduction and return in the context of portfolio selection.

No description available.

This research attempts to quantify the complex interactions between HVDC transmission schemes in a multi-infeed configuration, particularly with regard to the voltage interactions and the commutation failure phenomena. The in-depth analysis of multi-infeed HVDC systems discussed in this research shows the application of several indices such as the MIIF, MIESCR, and CFII, that can provide researchers and planning engineers in the area of HVDC transmission with the necessary tools for their system studies. It shows that these indices are applicable in a multi-infeed system comprising HVDC schemes with different ratings. The Multi-Infeed Interaction Factor (MIIF) quantifies the level of voltage interactions between converter ac buses. The Multi-Infeed Effective Short Circuit Ratio (MIESCR) index is an indicator of ac system strengths with regard to the assessment of the transient overvoltage (TOV) and the power-voltage stability of multi-infeed HVDC systems. The Commutation Failure Immunity Index (CFII) utilizes electromagnetic transient simulation programs to evaluate the immunity of an HVDC converter to commutation failures. The CFII takes into account the ac system strength and the HVDC controls and evaluates their impact on the commutation process. The immunity of both single-infeed and multi-infeed systems to commutation failure phenomena are accurately evaluated and quantified by the CFII. Using the CFII, it is shown that the current commutation in multi-infeed HVDC schemes could fail under circumstances in which the probability of failure had been perceived to be low. The causes of, the effects of, and the remedial actions needed to deal with such anomalous commutation failures are discussed in this thesis. The capability of the new indices to provide an insight into the interactions phenomena in multi-infeed systems are clearly demonstrated by examples that show their application in the analysis of an actual multi-infeed HVDC system that is in the planning phase in the province of Alberta in Canada.