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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

OPTIMIZATION OF STEEL MOMENT FRAME USING HARMONY SEARCH ALGORITHM

Marafi, Abdulmohsen January 2020 (has links)
Design optimization of structures has become an important method to study and develop these days. Due to the fact that the world's population is increasing, and the worlds' resources are decreasing. An optimum design algorithm is a useful tool that can help to minimize the weight of a structure. Over the last four decades, several number of algorithms have been developed to solve engineering optimization problems, for example, metaheuristic algorithms. An example of metaheuristic algorithms is the Harmony Search algorithm (HS). HS algorithms make use of the analogy between the performance process of natural music and searching for solutions to optimization problems. In this research, the HS was applied on the College of Engineering Building at Temple University Main Campus in Philadelphia, PA. The HS algorithm searches for minimum cross-sectional areas that leads to find optimal steel sizes considering design constrains such as: stress, deflection, and lateral displacement limitations. The HS algorithm obtained lighter weight of steel frames by selecting a suitable steel section from the American Institute of Steel Construction (AISC) and by following the specification of Allowable Stress Design method (ASD). The results show that HS yielded lighter steel moment frames with approximately 20% weight reduction. Keywords: Harmony Search Algorithm, Steel Moment Frame, Optimization. / Civil Engineering
212

Psychiatry and Resentment: A Philosophical Examination of the Psychiatric Survivors' Movement

Cuk, Christine 07 1900 (has links)
In this thesis I set out to show that the ethical literature dealing with psychiatry contains a serious omission: it does not discuss the issue of humiliation in the psychiatric context. I claim that the reason for this lies in the "objective attitude" that typifies both discourse on psychiatric ethics and actual clinical practice. Psychiatrists and psychiatric ethicists tend to view patients as things to be "controlled, studied, cured or trained," an attitude inimical to the "participant attitude" that sees others as responsible members of the moral community. This leads not only to a distorted view of the patient, but it also prevents doctors and ethicists from addressing the normative content of patient grievances. On the other hand, Axel Honneth and Charles Taylor's theories of "recognition" emphasize the subjective experience of humiliation and show how feelings of wounded dignity can motivate social struggles --including, I claim, the psychiatric survivors' movement. I argue further that psychiatric ethics must take account of what the patients themselves say about their experience of psychiatry; to this end I juxtapose some of the main ideas found in psychiatric ethics with quotations from psychiatric survivors about their experience of humiliation at the hands of psychiatry. / Thesis / Master of Arts (MA)
213

Moment resistance and rotation capacity of semi-rigid composite connections with precast hollowcore slabs.

Fu, F., Lam, Dennis, Ye, J. January 2010 (has links)
Semi-rigid composite connections with precast hollowcore slabs are a newly developed technique with few applications in current construction practice. The research on the structural behaviour of this new type of connection is limited, with no existing method available to predict its important characteristics such as moment and rotation capacities. In this paper, based on the parametric studies of the three-dimensional finite element model and full-scale tests, analytical methods to calculate the moment and rotation capacity of this type of composite joint are proposed. A comparison between the proposed calculation method and the full-scale test results was made, and good agreement was obtained.
214

Behaviour of composite steel beams with precast hollow core slabs in hogging moment regions

Lam, Dennis, Fu, F. January 2005 (has links)
No / The chapter discusses the behavior of composite steel beams with precast hollow core slabs in hogging moment regions. Full-scale composite beams to column semi-rigid connections with precast hollow core slabs are tested in the chapter. The chapter presents a steelwork connection consists of a flush end plate bolted to column flanges. The main variables studied are shear stud's spacing and degree of shear connection. Comprehensive instrumentations are used for all the tests, based on the experimental data, and equations to predict the rotation and the moment capacity for this type of composite connection are proposed in the chapter. A precast composite hollow core floor is a newly developed composite system for building that use precast hollow core slabs as the structural flooring. However, research on composite construction incorporating steel beams with precast hollow core slabs is still relatively new in comparison to the more traditional composite metal deck flooring.
215

Gyro-Chirality Effect of Bianisotropic Substrate On the operational of Rectangular Microstrip Patch Antenna

Zebiri, Chemseddine, Daoudi, S., Benabdelaziz, F., Lashab, Mohamed, Sayad, D., Ali, N.T., Abd-Alhameed, Raed 08 July 2016 (has links)
Yes / In this paper, the gyrotropic bi-anisotropy of the chiral medium in substrate constitutive parameters (ξc and ηc) of a rectangular microstrip patch antenna is introduced in order to observe its effects on the complex resonant frequency, half-power bandwidth and input impedance. Numerical calculations and analysis based on the dominant mode are carried out to show that the latter is directly related to the former. This paper is based on the Moment Method as full-wave spectral domain approach using sinusoidal basis functions. Two new results, namely the appearance of the difference (ξc-ηc) and sum (ξc+ηc) of the two magneto-electric elements are obtained in the electric transverse components and Green tensor expressions, respectively. These new results can be considered as a generalisation form of the previously published work.
216

Phenomenological Consequences of Heavy Right Handed Neutrinos

Rayyan, Saifuddin Ramadan 30 May 2007 (has links)
The discovery of neutrino mixing provides the possibility of a non vanishing CP violating phase in the neutrino mixing matrix. CP violation in the leptonic sector can be large enough to explain the matter-antimatter asymmetry in the universe. An indirect probe of CP violation is the experimental measurement of Electric Dipole Moment (EDM). CP violation has been discovered in the quark sector,but it contributes to lepton EDM at the 3-loop level. Neutrino masses can be generated in the standard model via the see-saw mechanism where heavy right-handed neutrinos mix with the weak-basis states. The Majorana nature of the seesaw type neutrinos generates new 2-loop diagrams that lead to a non-vanishing lepton EDM. Only estimates of the resulting EDM have been done in the literature. A full calculation of the 2-loop diagrams and the exact result is presented. / Ph. D.
217

What do Master Clinical (Experiential) Teachers do When Teaching Clinically?

Schultz, Karen Kennedy 22 April 2002 (has links)
An urgent need exists for balance between students learning the theory of clinical practice and becoming an expert. While theory is taught in the didactic setting, it is the experiential setting where the mastery of the clinical teacher is demonstrated. What does the master clinical teacher do that makes the student's learning experience so significant? One must recognize the moment, capture the learning opportunity, and draw the student in so that learning can occur. Effective clinical teaching is paramount in creating empowered students and practitioners. This qualitative case study of a doctoral pharmacy program identified two master clinical preceptors and shadowed one in a hospital and the other in a retail pharmacy. Interactions between clinical preceptors and students were captured through direct observation, audio-tape, and complemented with in-depth interviews. Content analysis identified emerging themes yielding an emerging model of master clinical teaching, illuminating teachable moments between student and clinical preceptor, and the manner in which they interacted with each other and the clinical environment. The model highlights an approach for making the critical time on clinical rotations as effective as possible and offers a practical means to study interactions between students and preceptors, discerning those that lead to teachable moments. Features of the teachable moments are identified. Although expertise cannot be taught, current and future clinical teachers can use this study to improve their teaching and effectiveness in clinical teaching practice. The methodology of this study can be applied to future studies in the same discipline, other rotations, or other disciplines. This study augmented the literature in qualitative research in pharmacy education for clinical practice by 1) utilizing a methodology that could be used in future studies 2) identifying features of teachable moments in the interactions of clinical preceptors and students 3) exploring how the clinical preceptors dealt with the changing environment of their clinical teaching 4) offering an emerging model to guide clinical preceptors for making the critical clinical teaching time as effective as possible. Future studies could utilize this emerging model to gain further insight on clinical teaching practices thus increasing the expertise of clinical teaching. / Ph. D.
218

An Analytical Motion Filter for Humanoid Robots

Muecke, Karl James 24 April 2009 (has links)
Mimicking human motion with a humanoid robot can prove to be useful for studying gaits, designing better prostheses, or assisting the elderly or disabled. Directly mimicking and implementing a motion of a human on a humanoid robot may not be successful because of the different dynamic characteristics between them, which may cause the robot to fall down due to instability. Using the Zero Moment Point as the stability criteria, this work proposes an Analytical Motion Filter (AMF), which stabilizes a reference motion that can come from human motion capture data, gait synthesis using kinematics, or animation software, while satisfying common constraints. In order to determine how the AMF stabilized a motion, the different kinds of instabilities were identified and classified when examining the reference motions. The different cases of instability gave more insight as to why a particular motion was unstable: the motion was too fast, too slow, or inherently unstable. In order to stabilize the gait two primary methods were utilized: time and spatial scaling. Spatial scaling scaled the COM trajectory down towards a known stable trajectory. Time scaling worked similarly by changing the speed of the motion, but was limited in effectiveness based on the types of instabilities in the motion and the coupling of the spatial directions. Other constraints applied to the AMF and combinations of the different methods produced interesting results that gave more insight into the stability of the gait. The AMF was tested using both simulations and physical experiments using the DARwIn miniature humanoid robot developed by RoMeLa at Virginia Tech as the test platform. The simulations proved successful and provided more insight to understanding instabilities that can occur for different gait generation methods. The physical experiments worked well for non-walking motions, but because of insufficient controllability in the joint actuators of the humanoid robot used for the experiment, the high loads during walking motions prevented them from proper testing. The algorithms used in this work could also be expanded to legged robots or entirely different platforms that depend on stability and can use the ZMP as a stability criterion. One of the primary contributions of this work was showing that an entire reference motion could be stabilized using a single set of closed form solutions and equations. Previous work by others considered optimization functions and numeric schemes to stabilize all or a portion of a gait. Instead, the Analytical Motion Filter gives a direct relationship between the input reference motion and the resulting filtered output motion. / Ph. D.
219

Moment sequences and their applications

Li, Xiaoguang 20 October 2005 (has links)
In this dissertation, we first present a unified treatment of compact moment problems, both the truncated and full moment cases. Second, we define the lower and upper functions V±(ð₁,... ð <sub>n</sub>) on the convex hull of the curve Γ<sub>n</sub> = {(t,.·.,t<sup>n</sup>): t ∈ [0,1] } for each positive integer n. Explicit formulas of these functions are derived and applied to the study of the subnormal completion problem in operator theory. Last, we show that certain power functions are the building blocks of completely positive functions; by our definition, these functions are the continuous functions on the interval [0, 1] that map each Hausdorff moment sequence of a probability measure into another one. / Ph. D.
220

A Study of Mine-Related Seismicity in a Deep Longwall Coal Mine

Warren, Justin Cable 16 June 2011 (has links)
This study involves seismic monitoring of a deep coal mine. The purpose is to examine the processes responsible for induced seismicity. A seismic network consisting of five three-component short-period seismometers located above the mine recorded the seismic data. The events discussed here occurred from March 1, 2009 until April 7, 2011 during the mining of three longwall panels and the data was telemetered to Blacksburg, Virginia. A correlation equation was developed to relate local magnitude estimated by automatic data processing software in near real-time to seismic moment for well-recorded events. Local magnitude is a relative measure of relative size for a suite of earthquakes, while seismic moment is an objective measure of the actual physical size. Using the calculated seismic moments, we calculated "moment magnitudes" (Mw) for all events, which allowed us to do further studies in terms of their absolute size as a function of both time and space. The results indicate that there are two distinct classes of seismic events at the mine. The first class consists of small (M<=0) earthquakes recorded near the moving mine face. The second class of seismicity occurs in the mined-out "gob" area of the longwall panel at a greater distance behind the moving face. Their occurrence and relation to the mining history, depth of overburden and geology of the roof rocks is a significant interest. Results show that thick overburden due to elevated topography has a positive correlation with the number of seismic events but is not the only controlling factor; other factors include gob size and geological variability. Another important observation is the high seismic attenuation of the rock mass above the mine. This appears to be the result of the fracturing and caving processes associated with the creation of the gob and the resulting subsidence of the ground surface. / Master of Science

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