Seismic design criteria have been heavily improved by the Federal Emergency Management Agency (FEMA) after the Northridge CA earthquake in 1994. Most of the damage observed was caused by brittle failure of moment frame connections. This failure was induced by the formation of the plastic hinge at undesirable locations in the beam and the column near the connection. Using welded flange plate (WFP) connections will force the formation of the plastic hinge away from the face of the column while preventing the brittle failure of the moment connection. FEMA-350 design criteria recommendations for WFP connections suggest that the plastic hinge will form away from the face of the column directly under the cover plate. The purpose of this research is to prove that the plastic hinge will form away from the face of the column, at a distance of approximately half the depth of the beam away from the cover plate. The further away the plastic hinge is from the face of the column the higher the connection demands. Therefore, underestimating the location of the plastic hinge could lead to under designed connections. The modeling and analysis of WFP connections was performed using finite element analysis software. A total of eight models with half beam half column configuration were considered in this study. Each selected section of beam and column was first designed, modeled and analyzed using WFP connections design recommendations from FEMA-350, with calculations modifications to account for the proposed plastic hinge location. Results were computed and comparisons were made in terms of plastic hinge location from the cover plates. Strength obtained for each model using finite element analysis software was also compared with hand calculations. This research also proves that increasing the thickness of the cover plates will generate an increase in the connection capacity and strength.

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This thesis deals with designing the construction of an active bonnet hinge, tuning the kinematics and appropriate proportioning of individual parts of the hinge. The thesis consists of two main parts – the first part is an analysis of the current state of knowledge and the second part presents a designing the construction. The active hinge should serve as a safety element in automobiles to minimize consequences of head injury suffered during the collision of a pedestrian with an automobile.

The design and maintenance of Marine Oil and LNG Terminals is governed by the Marine Oil Terminal Engineering and Maintenance Standards (MOTEMS) which is part of the 2010 Title 24 California Code of Regulations, Part 2, California Building Code, Chapter 31F: Marine Oil Terminals. The purpose of this thesis is to evaluate the current recommendations for the in-ground plastic hinge length and depth for piles in section 7 of MOTEMS for all typical soil properties and pile dimensions found in Marine Oil and LNG Terminals. The pile types considered in this analysis are 24-inch octagonal prestressed concrete piles and 24-, 36-, and 48-inch steel pipe piles in varying soil conditions. Existing recommendations for plastic hinges are incomplete and inadequate. MOTEMS does not have any recommendations for plastic hinge depth, only length, nor does it have any recommendations for in-ground plastic hinge for steel piles. Recommendations for steel piles are however found in the Port of Long Beach Wharf Design Criteria (POLB), but the recommendations in both MOTEMS and POLB have shown to be inadequate for both steel and prestressed concrete piles. MOTEMS also proves to be adequate for Level 2 earthquakes but not for Level 1. The plastic hinge length for Level 1 is much longer than that for Level 2. So the MOTEMS recommendations for Level 1 lead to conservatively small displacement capacity. POLB recommendations are also adequate for Level 2 but not Level 1 for concrete and are overly conservative for steal and therefore, not adequate for either level except in dense and medium sands during a Level 1earthquake. POLB does not take into account different soil characteristics and has one value for all soils, which is inadequate for most cases.

The following inquiry pursues two interlinked aims. The first is to understand Wittgenstein's idea of non-foundational certainty in the context of a reading of On Certainty that emphasizes its Pyrrhonian elements. The second is to read Wittgenstein's remarks on idealism/radical skepticism in On Certainty in parallel with the discussion of rule-following in Philosophical Investigations in order to demonstrate an underlying similarity of philosophical concerns and methods. I argue that for the later Wittgenstein, what is held certain in a given context of inquiry or action is a locally transcendental condition of the inquiry or action in question. In On Certainty, Wittgenstein's analysis of the difference between knowledge and certainty forms the basis of his critique of both Moore's "Proof" and radical skepticism. This critique takes the shape of rejection of a presupposition shared by both parties, and utilizes what I identify as a Pyrrhonian-style argument against opposed dogmatic views. Wittgenstein's method in this text involves describing epistemic language-games. I demonstrate that this is consistent with the rejection of epistemological theorizing, arguing that a Wittgensteinian "picture" is not a theory, but an impressionistic description that accomplishes two things: (i) throwing into relief problems with dogmatic theories and their presuppositions, and (ii) describing the provenance of linguistic and epistemic practices in terms of norms grounded in convention. Convention, in turn, is not arbitrary, but grounded in the biological and social natures of human beings--in what Wittgenstein calls forms of life. Thus there is a kind of naturalism in the work of the later Wittgenstein. It is a naturalism that comes neatly dovetailed with Pyrrhonism--a combination of strategies traceable to Hume's work in the Treatise. I read Hume as someone who develops the Pyrrhonian method to include philosophy done "in a careless manner," and argue that Wittgenstein adopts a similar method in his later works. Finally, I explain the deference to convention in the work of both Hume and Wittgenstein by reference to a passage in Sextus' Outlines, on which I provide a gloss in the final chapter of this work.

En kunskapsgraf lagrar information från webben i form av relationer mellan olika entiteter. En kunskapsgrafs kvalité bestäms av hur komplett den är och dess noggrannhet. Dessvärre har många nuvarande kunskapsgrafer brister i form av saknad fakta och inkorrekt information. Nuvarande lösningar av länkförutsägelser mellan entiteter har problem med skalbarhet och hög arbetskostnad. Denna uppsats föreslår ett deklarativt regelbaserat probabilistiskt ramverk för att utföra länkförutsägelse. Systemet involverar en regelutvinnande modell till ett “hinge-loss Markov random fields” för att föreslå länkar. Vidare utvecklades tre strategier för regeloptimering för att förbättra reglernas kvalité. Jämfört med tidigare lösningar så bidrar detta arbete till att drastiskt reducera arbetskostnader och en mer spårbar modell. Varje metod har utvärderas med precision och F-värde på NELL och Freebase15k. Det visar sig att strategin för regeloptimering presterade bäst. MAP-uppskattningen för den bästa modellen på NELL är 0.754, vilket är bättre än en nuvarande spjutspetsteknologi graphical model(0.306). F-värdet för den bästa modellen på Freebase15k är 0.709. / The knowledge graph stores factual information from the web in form of relationships between entities. The quality of a knowledge graph is determined by its completeness and accuracy. However, most current knowledge graphs often miss facts or have incorrect information. Current link prediction solutions have problems of scalability and high labor costs. This thesis proposed a declarative rule-based probabilistic framework to perform link prediction. The system incorporates a rule-mining model into a hingeloss Markov random fields to infer links. Moreover, three rule optimization strategies were developed to improve the quality of rules. Compared with previous solutions, this work dramatically reduces manual costs and provides a more tractable model. Each proposed method has been evaluated with Average Precision or F-score on NELL and Freebase15k. It turns out that the rule optimization strategy performs the best. The MAP of the best model on NELL is 0.754, better than a state-of-the-art graphical model (0.306). The F-score of the best model on Freebase15k is 0.709.

Elongation of the vertebrate rostrocaudal axis depends on localised populations of axial progenitors. Previous work has demonstrated the presence of Neuromesodermal (NM) progenitors that behave as multipotent stem cells, which contribute to the neurectoderm and mesoderm throughout axis elongation. They have been localised to the Node-­‐Streak Border (NSB) in the primitive streak region, and the Chordoneural Hinge (CNH) in its descendant, the tail bud. At primitive streak stages, the Caudal Lateral Ectoderm (CLE) on either side of the primitive streak itself is also fated for neurectoderm and mesoderm. However, fate mapping studies in mouse and chick have suggested that these progenitors are more transitory than those in the NSB and CNH, leading to the idea that two different types of progenitor cell exist in the primitive streak region; long-­‐term (stem cell-­‐like) and transient progenitors. In this thesis, I have examined the potency of the CLE cells by heterotopically grafting them into the NSB. Anterior CLE cells are exquisitely sensitive to their position and differentiate predominantly as neurectoderm, mesoderm, or both, depending on their exact location in the NSB. Most significantly, their descendants are retained in the CNH, indicating that CLE cells show equal potential to NSB progenitors on transplantation to the border environment. The relationship between fate and potency within the streak stage embryo suggest a mechanism by which stem cells are maintained not only by their intrinsic stem cell program, but are also influenced by their location. Furthermore, I have investigated the expression of candidate markers of NM-­‐progenitors, and have found that the combined expression of Sox2 and T genes in the progenitor area coincides with observed NM-­‐potency, and could serve as a marker for this stem cell population. Over time, axial elongation comes to a halt and NM-­‐progenitors are thereafter not longer active. It is still unclear how exactly this process occurs and specifically whether axial elongation ceases because NM progenitors are eliminated. I have investigated the events occurring immediately before the end of axial elongation. Morphological and gene expression analysis shows that apoptosis reaches a peak only after the complete axis has been laid down, and is not dramatically elevated in the progenitors themselves before that. In order to test signalling pathways that lead to progenitor maintenance, I have developed an in vitro tail growth assay that recapitulates in vivo development, as measured by several morphometric criteria. I show that, even though FGF signalling is critical for most cells in the tail bud including NM-­‐progenitors, it is not sufficient for NM-­‐ progenitor maintenance. In contrast, exposing tail buds to elevated Wnt/β-­‐catenin signalling does prolong the lifetime of NM-­‐progenitors in the ageing tail bud, as judged by the presence of Sox2-­‐T double-­‐positive cells. In this regard we have found that the time of cessation coincides with the disappearance of Sox2-­‐T double-­‐positive cells, the disappearance of Wnt3a and concomitant neuralisation of the progenitor region. This data suggest an important governing role for Wnt signalling in both maintenance and fate decision of NM progenitors. Thus the disappearance of Wnt signalling in the tail bud over time could well be the main reason for triggering the halt of caudal elongation.

Because of their high strength to weight ratio, stiffened steel plates are often used in light structures where plates are placed into compression. The stability of steel plates stiffened with longitudinal tee-shaped stiffeners and subjected to uniaxial compression or combined axial compression and out-of-plane bending formed the basis for this research project. The research was conducted to develop a simple approach to assess the post-buckling behaviour of stiffened steel plates and provide a limit states design procedure that accounts for the post-buckling stability in the assessment of the resistance factor. The behaviour of stiffened plates was investigated using a finite element model that had been validated through comparison with test results. An exhaustive parametric study, including 1440 finite element analyses, was conducted to investigate the strength and behaviour of stiffened steel plates. A virtual work model was developed to explain the effect of the formation of a plastic hinge mechanism on the post-buckling strength and behaviour. Combined with the numerical results, the theoretical model confirms that the plastic hinge mechanism can cause a sudden loss of capacity. The required lateral deflection for a plastic hinge development can be calculated using the virtual work model for prediction of the unstable behaviour. Based on a better understanding of the behaviour of stiffened steel plates, a set of design equations were developed to calculate the strength of stiffened steel plate subjected to compression in the direction of the stiffener and out-of-plane bending. The proposed design equations were compared with current design guidelines through a comparison of the design approaches with the finite element analysis results. The proposed method showed much better accuracy than the current design approaches. A reliability analysis was conducted to provide appropriate resistance factors for limit states design. Due to the complexity of the design formulas, the Monte Carlo simulation technique was used to generate the statistical distributions of the predicted strength. The second-moment method was used to calculate the resistance factors for different values of safety index. The resistance factor varied from 0.90 to 0.65 for values of safety index from 2.5 to 4.5, respectively. / Structural Engineering

This thesis examines polarization and polarization mode dispersion (PMD) dynamics in optical fibers as well as the evaluation of probability density functions and bit error rates in a realistic wavelength division multiplexed (WDM) optical communication systems. In the first part of the thesis, experimental studies of the dynamics of polarization in a dispersion compensation module (DCM) are performed in which mechanical shocks are imparted to several different DCMs by dropping a steel ball on the outer casing at different locations and from different heights and the resulting rapid polarization fluctuations are measured. We provide a theoretical model that accounts for the dynamic birefringence generated due to the impact. Next, an experimental technique is proposed to detect the location of temporal polarization activity in WDM systems. It is demonstrated theoretically and in simulations that measurement of both the PMD vector and the Stokes parameters at the WDM frequencies enables the detection of the location of such activity. Different linear prediction procedures are applied to the differential group delay of an optical fiber link assumed to obey the hinge model. The hinges are modeled as polarization rotators with fixed rotation axes and sinusoidally varying rotation angles. Three prediction methods are investigated and consequently compared: an autoregressive model (AR) with Kalman filter, a pattern imitation method and a Taylor expansion technique. The effect of measurement noise on the prediction horizon is also investigated for each prediction method. Using a physically reasonable stochastic model for the hinges, we derive analytical expressions for the temporal autocorrelation functions of the state of polarization (SOP) and the PMD vector. The obtained analytical results are compared to simulations. Finally, we apply the multicanonical method to the probability density function of received symbols and the symbol error ratio (SER) in a dual polarization quadrature phase shift keyed (DP-QPSK) WDM system. We simulate five co propagating channels at a symbol rate of 10.7 GBaud/s and account for PMD and nonlinear effects. We evaluate the performance of the system for two different cases: single mode fibers with full dispersion compensation at the end of the link, effective large area fibers (LEAF) with full dispersion compensation at the end of the link.

Native heart valves that have limited functionality due to cardiovascular disease or congenital birth defects are commonly replaced by prosthetic heart valves. Bileaflet mechanical heart valves (BMHV) are the most commonly implanted valve design due to their long-term durability. However, their unnatural hemodynamics promote thrombosis and thromboembolic events. Clinical reports and in vitro experiments suggest that the thrombogenic complications in bileaflet valves are related to the stress imposed on blood by the valves during the closing phase. Additionally, animal and clinical studies have shown that BMHV in the aortic position demonstrate reduced failure rates compared to identical valves in the mitral position. The present study aimed to investigate the leakage, hinge, and near hinge flow fields of two BMHV under simulated physiologic aortic flow conditions and to compare these results with previous findings in the mitral position to better understand how the implant location influences the valve performance and the subsequent risk of blood damage. Two and three-component Laser Doppler Velocimetry techniques were used to quantify the velocity and turbulent shear stress fields in both the hinge and the upstream leakage flow regions. The study focused on the 23 mm St. Jude Medical Regent (SJM) and the 23 mm CarboMedics (CM) valves. Although they were tested under similar physiologic conditions, shape and location of the leakage jets were dependent on valve design. Nevertheless, turbulent shear stress levels recorded within all jets were well above the threshold shear stress for the onset of blood cell damage. Within the hinge region, the flow fields were complex and unsteady. The angulated hinge recess of the CM valve appeared to promote blood damage while the streamlined geometry of the SJM valve contributed to better washout of the hinge region. Animations of the velocity flow fields are given in QuickTime or MPEG format. Comparison of the present findings with previously published results for the mitral position suggests that the superior clinical results of the mechanical valves in the aortic position may be due to less severe leakage flow upon valve closure as well as to enhanced hinge washout during the forward flow phase.