The growth of internet communication has affected deliberative democracy by introducing new public spheres. One emerging public sphere is the discussion forum linked to online news sources. By analyzing 1,768 comments posted to a regional online news website, I discuss five key frameworks that commenters used to simplify the debate over immigration. I also find that extreme comments decreased in frequency over a two-year period while more moderate comments increased. In light of group polarization theory, this finding suggests that the forum is more like a single community with a fairly moderate average position to which people with differing opinions converge, rather than a divided community consisting of two distinct groups, each polarizing toward more extreme positions. The forum appears to have moderated itself in response to triggers of discourse change by means of temporary reframing of arguments. I develop a theoretical framework for understanding how group interactions produce self-regulatory behavior that can prevent polarized discourse.

Leakages from seals are one of the important factors that are taken into consideration while designing any machining element. This is because leakages can affect the performance of any component and can also turn into a catastrophe. If looked into it, many parameters can be pointed out that can enhance leakages within the system, some of them may be pressure, temperature, clamping force and bolt distance etc. But the main parameter is the surface roughness, higher the roughness more the leakage and vice-versa. Thus, in this thesis an attempt has been made how the surface roughness can affect the performance of the sealing concept for metal bounded gasket with above four mentioned parameters. Also how leak proof surface can be defined using standard tribological parameters is the aim of this thesis. This report includes the results for methodologies implemented during the thesis and track down the leakages. The leaked surfaces were carefully studied and analyzed using different standards compared with the non leaked surfaces’ roughness parameters. / Läckagerisk från tätande förband är en av de viktigaste faktorerna som beaktas vid utformning av konstruktionsartiklar. Detta på grund av att konsekvenserna kan bli förödande. Det tätande förbandet påverkas av många olika parametrar såsom till exempel tryck, temperatur, klämkraft, skruvavstånd och val av packning. En viktig faktor är ytans beskaffenhet; Generellt läcker en grov yta och vågig yta mer än en fin och plan yta. Således har i denna avhandling ytans beskaffenhet studerats tillsammans med en packning av typen metallburen gummipackning för att påvisa täthetfunktionen som en funktion av tryck, temperatur, klämkraft och skruvavstånd. Denna rapport innehåller resultat och analys av olika standardmetoder för de ytor som ingick i utredningen.

This study was developed to provide information about the relationship of principals' use of Bolman and Deal's (1991) four frame model of leadership to student achievement. The collection and analysis of student Florida Comprehensive Assessment Testing (FCAT) data over a 2 year period served as a measure to indicate whether or not an increase in reading mean scale score occurred from 2004 to 2005. Comparative analysis of both sets of data using multiple regressions was used to determine if there was a relationship between the self-reported leadership orientations of the principals and student achievement. In addition, the study was intended to contribute to the quantitative data produced concerning the use of the four frames, multi-framing and reframing by elementary and secondary leadership. Principals in this study were surveyed concerning their use of the structural, human resource, political and symbolic frames of leadership using the Leadership Orientations (Self) instrument constructed by Bolman and Deal (1990). The only restriction concerning usability of the returned survey was that the principal had to be at the same school during the 2004 and 2005 school years. Of the 52 surveys returned, 42 (73%) formed the population for this study. This study found that the human resource frame was used most often but that 59% of the elementary teachers and 93% of the secondary teachers multi-framed on a regular basis. The study also found that that the use of the political frame and symbolic frame has increased. The self-reported data indicated no difference in effectiveness as a leader or as a manager, unlike previous data which indicated that leaders and managers worked from different frames to effect organizational policies. The analysis of data also indicated that there was no difference in frame use between elementary and secondary principals. The data indicated no relationship between the principals' frame usage and student achievement as measured by increases in FCAT Reading mean scale scores for the years 2004 and 2005. The implications of this finding are that there are other variables than use of the four frame model that contribute to an increase in FCAT mean scale scores. These emergent factors within and without the organization that is the public school system transcend what the data show in this case. Based on the findings of this study and supported by the literature review, it appears that school organizations could benefit leadership practice and possibly student achievement by providing training in the political and symbolic frames. It might also be perceived from the data, which indicated no relationship between principals' frame usage and student achievement, that leadership might begin to foster awareness of how successful principals' identify emergent patterns in the system. This ability to guide the diverse and constantly changing educational landscape toward positive adjustments in the system may be best served by those who are most adept at multi-framing and reframing to ensure student achievement.

During seismic events, inefficient steel moment frame building systems may exhibit soft-story failures. This thesis focuses on development and validation of a seismic retrofit strategy for avoiding soft-story failures in low-rise and mid-rise steel moment frame buildings. The considered retrofit strategy consists of a sufficiently stiff Rocking Core (RC) pinned to the foundation and pin connected to the existing frame. For demonstration purposes, two representative benchmark steel moment frames, which are modified from the three- and nine-story pre-Northridge steel moment frames designed for Los Angeles in the SAC Steel Project, are considered. Finite Element (FE) models of the benchmark buildings are developed with consideration of member yielding, connection rupture, and P-Delta effect, and validated using published results. Eigenvalue analyses are conducted to investigate the effect of the RC on system modal properties. It is found that in general the added RC with practical stiffness value does not significantly change the fundamental period and therefore does not attract excessive earthquake force to the system. In addition, nonlinear static pushover analyses are performed to address the beneficial contribution of the RC to the system under the performance objectives including immediate occupancy, life safety, and collapse prevention. The Monte-Carlo simulation technique is used to generate the random lateral force distribution required in the nonlinear static pushover analysis. It is found that RC works as expected in all considered scenarios and creates more uniform inter-story distribution along the vertical direction when it is sufficiently stiff. Furthermore, nonlinear dynamic analyses are conducted using three different ground motion suites (including two suites with ground motions having probabilities of exceedance of 2% and 10% in 50 years, and one suite with near-fault ground motions). It is shown that the systems with properly selected RC can achieve the Best Safety Objective defined in FEMA 356 and exhibit collapse prevention performance under near-fault earthquakes.

Difficulties in characterizing the dynamic behavior of wood structures have hindered investigations into their performance under dynamic loading. Because of this, wood structures are treated unfavorably in seismic design codes, even though past damage assessment surveys after seismic events indicated generally satisfactory performance. To allow investigations into their performance and safety under dynamic loading, the energy dissipation mechanisms of wood joints and structural systems must be known and the hysteretic behavior modeled properly. This dissertation presents a general hysteresis model for wood joints and structural systems, based on a modification of the Bouc-Wen-Baber-Noori (BWBN) model. The hysteretic constitutive law, based on the endochronic theory of plastidty and characterized by a single mathematical form, produces a versatile, smoothly varying hysteresis that models previously observed behavior of wood joints and structural systems, namely, (1) nonlinear, inelastic behavior, (2) stiffness degradation, (3) strength degradation, (4) pinching, and (5) memory. The constitutive law takes into account the experimentally observed dependence of wood joints' response to their past history (i.e., the input and response at earlier times, or memory). Practical guidelines to estimate the hysteresis parameters of any wood joint or structural system are given. Hysteresis shapes produced by the proposed model are shown to compare favorably with experimental hysteresis of wood joints with; (1) yielding plates, (2) yielding nails, and (3) yielding bolts. To verify its behavior under arbitrary dynamic loadings, the proposed model is implemented in a nonlinear dynamic analysis program for single-degree-of-freedom (SDF) systems. Three SDF wood systems are subjected to the Lama Prieta accelerogram to obtain their response time histories. Advantages of using the proposed model over currently available models in nonlinear dynamic analysis of more complex systems are identified. A multi-degree-of-freedom shear building model incorporating the proposed hysteresis model is formulated but not implemented on a computer. For more realistic loadings, the random characteristics of earthquakes are modeled as a stochastic or random process. Nonlinear response statistics of SDF wood systems are obtained by Monte Carlo simulation and statistical linearization The statistical linearization solutions are shown to give reasonably good estimates of mean-square response, for a range of practical system and model parameter values. An example verification procedure that can be used in applying the method to practical engineering problems is presented. The response analysis technique is general and can be applied not only in random vibration analysis of wood structural systems but also in the analysis of a wide variety of hysteretic systems with general pinching behavior, including reinforced concrete structures, braced steel frames and laterally loaded piles. Potential practical applications of the analysis method and of the response statistics obtained from the analysis are presented. The present work is the first known attempt to use random vibration techniques in studying the response of wood structures under natural hazard loadings. / Ph. D.

The effect of panel zone (PZ) flexibility and yielding on the stiffness and strength of steel moment resisting frames (SMRF) has been the topic of numerous papers over the past thirty years. When properly detailed, the PZ is an excellent source of energy dissipation, even under large inelastic deformations. Due to these large inelastic deformations, the PZ region may also be a weak link in steel moment frame behavior. Because of the importance of PZ deformation in the behavior of steel frames, accurate modeling of this region is critical. Two of the most commonly used mathematical models for representing PZ behavior are investigated. They are referred to herein as the Krawinkler model and the Scissors model. From the literature review conducted at the beginning of this study, it was determined that there were no PZ models available that accounted for the elastic drift associated with PZ flexure which could be used in computer representations using commercial software that is currently available. This thesis details the analytical work used to establish the estimated elastic drift associated with PZ flexure and a method to include this estimated drift and the contribution of continuity plates in the Krawinkler and Scissors models. This study is initially focused on elastic deformations of individual structural subassemblages. First, formulas are derived to account for each major elastic component of drift in an individual subassemblage. The results from these derivations were implemented into a computer program named PANELS to allow for rapid calculation of the estimated drifts. Then, the properties (elastic and inelastic) for the Krawinkler and Scissors models are derived in their entirety. The Krawinkler model's results are compared to the results from PANELS, neglecting the PZ flexural component in PANELS and any inelastic contributions in the Krawinkler model. Since the Krawinkler model does not include PZ flexure, this established that the derived formulas accounted for all the remaining sources of elastic strain energy, assuming that the Krawinkler model is accurate. The results from PANELS are compared to those from finite element models developed using ABAQUS. Using the ABAQUS results, a method for determining the elastic drift associated with PZ flexure in PANELS is presented. A detailed inelastic study of the Krawinkler and Scissors models is then conducted both on the subassemblage level and on full structural frames to determine any differences associated with them. First, the two models are compared to each other on a subassemblage level to ensure that they both give the same results. Then, both PZ models are included in multiple full structural frames using various design configurations and loading conditions to ascertain their differences. Initially it was believed that there would be a large disparity between the two models. This study shows that there is actually little difference between the two models, although the kinematics of the Scissors model is still questionable. Elastic and inelastic comparisons between the PANELS formulas (elastic) and the ABAQUS models (elastic and inelastic) and data collected from tests performed at Lehigh University by Dr. James Ricles are then presented. This was done to show that the ABAQUS models and the PANELS formulas (including the PZ flexural component) give an accurate estimation of the drift of a subassemblage. The results from these comparisons show that the modeling techniques used are accurate and not including PZ flexural component of drift will cause the overall drift estimate to be unconservative. Finally, a method of including the elastic component of drift attributed to PZ flexure and continuity plates in both models is presented. The Ricles' Lehigh test data is again used in an inelastic comparison between the original Krawinkler and Scissors models and their updated counterparts. These comparisons show that including this component enables both the Krawinkler and Scissors models to more accurately estimate the total drift of an individual subassemblage. / Master of Science

No description available.

<p> The focus of this thesis is the importance of metaphor to an understanding of Isa 1:2-9. The argument depends on an understanding of metaphor as an imaginative structuring mechanism of cognitive linguistic behaviour, and a concrete mediator of meaning. The work proceeds from the observation that within contemporary scholarship readings of Isa 1 have failed to give sufficient attention to the occasion of its metaphors. The thesis argues that metaphor is essential to the text, and therefore a critical analysis of metaphor is central to its understanding. Using a Frame Semantic approach to contemporary Metaphor Theory, the interpretation of metaphors in Isa 1:2-9 is informed by insight offered from the historical and literary frames of the Ancient Near East and Hebrew Bible. Root metaphors of kinship, body, and land and their conceptual integration are discussed, and rich layers of meaning are revealed.</p> / Thesis / Master of Theological Studies (MTS)

<p> The optimization study of space frames has been considered in two aspects in this project work. The first was to develop a suitable optimization technique for a nonlinear programming problem including equality constraints, without any particular reference to structural optimization. The necessacity for the above requirement was due to the fact that almost all existing methods on optimization have some limitation. The second object of this study was to set up the necessary equations for the constraints on stress and on frequency for the structural model used, and then to use the developed technique to optimize the structural model for minimum weight. </p> <p> A simple and effective strategy, which is a combination of direct search and linear approximate programming is believed to have been developed for optimization of simple nonlinear type equations. </p> <p> The analysis of the space structure and the study of structural optimization revealed several difficulties inherent in the evaluation of constraining equations for the stresses and frequencies, which makes the optimization very difficult. </p> / Thesis / Master of Engineering (ME)

There is increasing demand, from both engineers and their clients, for structures that can be rapidly returned to occupancy following an earthquake, while also maintaining or reducing initial costs. One possible way towards this goal is to ensure that seismic damage occurs only within elements that can be removed and replaced following a damaging earthquake. For concentrically braced frames that use hollow structural sections, the current design practice requires field welding of the brace to the gusset in a way that causes the brace to buckle out-of-plane. In the event of a damaging earthquake, the out-of-plane brace buckling may damage both the gusset plate and also any adjacent exterior cladding. The plate cannot be easily replaced, resulting in expensive and time-consuming repairs, and the damaged cladding could endanger the lives of people evacuating the building and of other pedestrians. Through multiple design iterations, a new steel concentrically braced frame connection type was developed that can be bolted into place and that confines damage to replaceable components. The proposed connection is expected to result in reduced erection costs and be easier to repair following a major earthquake. Moreover, the new connection causes buckling to occur in-plane, preventing dangerous damage to the cladding. Large scale experimental testing on two variations of the new connection was performed. The cyclic, uniaxial testing of a brace with the new connection demonstrated the connection’s ability to behave in a desirable manner, with tensile yielding, brace buckling and connection rotation occurring during the expected drift levels associated with earthquake loading. A nonlinear finite element model of a brace with the new connection was developed and discussed. The finite element model was able to replicate the results of the experiment and will allow for further research and development of the new connection. The new connection shows promise as a replaceable connection for the seismic design of concentrically braced frames. / Thesis / Master of Applied Science (MASc) / Earthquakes can cause major, devastating damage to city structures. The cost of repairs and the time needed to make those repairs can be crippling, to the point where it is easier to tear down the structures than properly repair them. Designers and engineers need improved ways to design these structures to be more easily repaired, without driving up the initial cost of the structure. This research developed, tested and modelled a new, replaceable connection for earthquake resistant braces. The new connection is easier to install, easier to replace and provides added safety when compared to traditional designs.