Cooperative behavior arises from the interactions of single units that globally produce a complex dynamics in which the system acts as a whole. As an archetype I refer to a flock of birds. As a result of cooperation the whole flock gets special abilities that the single individuals would not have if they were alone. This research work led to the discovery that the function of a flock, and more in general, that of cooperative systems, surprisingly rests on the occurrence of organizational collapses. In this study, I used cooperative systems based on self-propelled particle models (the flock models) which have been proved to be virtually equivalent to sociological network models mimicking the decision making processes (the decision making model). The critical region is an intermediate condition between a highly disordered state and a strong ordered one. At criticality the waiting times distribution density between two consecutive collapses shows an inverse power law form with an anomalous statistical behavior. The scientific evidences are based on measures of information theory, correlation in time and space, and fluctuation statistical analysis. In order to prove the benefit for a system to live at criticality, I made a flock system interact with another similar …

It was hypothesized that the variations in time to solution are driven by the competing mechanisms of exploration and exploitation.This thesis explores this hypothesis by examining two contrasting problems that embody the hypothesized tradeoff between exploration and exploitation. Plus one recall store (PORS) is an optimization problem based on the idea of a simple calculator with four buttons: plus, one, store, and recall. Integer addition and store are classified as operations, and one and memory recall are classified as terminals. The goal is to arrange a fixed number of keystrokes in a way that maximizes the numerical result. PORS 15 (15 keystrokes) represents the subset of difficult PORS problems and PORS 16 (16 keystrokes) represents the subset of PORS problems that are easiest to optimize. The goal of this work is to examine the tradeoff between exploitation and exploration in graph based evolutionary algorithm (GBEA) optimization. To do this, computational experiments are used to examine how solutions evolve in PORS 15 and 16 problems when solved using GBEAs. The experiment is comprised of three components; the graphs and the population, the evolutionary algorithm rule set, and the example problems. The complete, hypercube, and cycle graphs were used for this experiment. …

Deuteron photodisintegration is a benchmark process for the investigation of the role of quarks and gluons in nuclei. Existing theoretical models of this process describe the available cross sections with the same degree of success. Therefore, spin-dependent observables are crucial for a better understanding of the underlying dynamical mechanisms. However, data on the induced polarization (P{sub y}), along with the polarization transfers (C{sub x'} and C{sub z'} ), have been shown to be insensitive to differences between theoretical models. On the other hand, the beam-spin asymmetry {Sigma} is predicted to have a large sensitivity and is expected to help in identifying the energy at which the transition from the hadronic to the quark-gluon picture of the deuteron takes place. Here, the work done to determine the experimental values of the beam-spin asymmetry in deuteron photodisintegration for photon energies between 1.1 – 2.3 GeV is presented. The data were taken with the CLAS at the Thomas Jefferson National Accelerator Facility during the g13 experiment. Photons with linear polarization of ~80% were produced using the coherent bremsstrahlung facility in Hall B. The work done by the author to calibrate a specific detector system, select deuteron photodisintegration events, study the degree of photon …

This thesis reports on two experiments conducted by the HAPPEx (Hall A Proton Parity Experiment) collaboration at the Thomas Je#11;erson National Accelerator Facil- ity. For both, the weak neutral current interaction (WNC, mediated by the Z{sup 0} boson) is used to probe novel properties of hadronic targets. The WNC interaction amplitude is extracted by measuring the parity-violating asymmetry in the elastic scattering of longitudinally polarized electrons o#11; unpolarized target hadrons. HAPPEx-III, con- ducted in the Fall of 2009, used a liquid hydrogen target at a momentum transfer of Q{sup 2} = 0.62 GeV{sup 2}. The measured asymmetry was used to set new constraints on the contribution of strange quark form factors (G{sup s}{sub E,M} ) to the nucleon electromagnetic form factors. A value of A{sub PV} = -23.803{+-}#6; 0.778 (stat){+-}#6; 0.359 (syst) ppm resulted in G{sup s}{sub E} + 0:517G{sup s}{sub M} = 0.003{+-} 0.010 (stat){+-} #6;0.004 (syst){+-}#6; #6;0.009 (FF). PREx, conducted in the Spring of 2010, used a polarized electron beam on a 208Pb target at a momentum transfer of Q{sup 2} = 0.009 GeV{sup 2}. This parity-violating asymmetry can be used to obtain a clean measurement of the root-mean-square radius of the neutrons in the {sup 208}Pb nucleus. …

The experiment SANE (Spin Asymmetries of the Nucleon Experiment) measured inclusive double polarization electron asymmetries on a proton target at the Continuous Electron Beam Accelerator Facility at the Thomas Jefferson National Laboratory in Newport News Virgina. Polarized electrons were scattered from a solid {sup 14}NH{sub 3} polarized target provided by the University of Virginia target group. Measurements were taken with the target polarization oriented at 80 degrees and 180 degrees relative to the beam direction, and beam energies of 4.7 and 5.9 GeV were used. Scattered electrons were detected by a multi-component novel non-magnetic detector package constructed for this experiment. Asymmetries measured at the two target orientations allow for the extraction of the virtual Compton asymmetries A{sub 1}{sup p} and A{sub 2}{sup p} as well as the spin structure functions g{sub 1}{sup p} and g{sub 2}{sup p}. This work addresses the extraction of the virtual Compton asymmetry A{sub 1}{sup p} in the deep inelastic regime. The analysis uses data in the kinematic range from Bjorken x of 0.30 to 0.55, separated into four Q{sup 2} bins from 1.9 to 4.7 GeV{sup 2}.

The aim of the present thesis is to investigate the local magnetic properties of homometallic Cr{sub 8} antiferromagnetic (AFM) ring and the changes occurring by replacing one Cr{sup 3+} ion with diamagnetic Cd{sup 2+} (Cr{sub 7}Cd) and with Ni{sup 2+} (Cr{sub 7}Ni). In the heterometallic ring a redistribution of the local magnetic moment is expected in the low temperature ground state. We have investigated those changes by both {sup 53}Cr-NMR and {sup 19}F-NMR. We have determined the order of magnitude of the transferred hyperfine coupling constant {sup 19}F - M{sup +} where M{sup +} = Cr{sup 3+}, Ni{sup 2+} in the different rings. This latter result gives useful information about the overlapping of the electronic wavefunctions involved in the coordinative bond.

The goal of the Q-weak experiment is to make a measurement of the proton's weak charge Q{sub W}{sup p} = 1 - 4 sin{sup 2}({theta}{sub W}) to an accuracy of {approx} 4%. This would represent a {approx} 0.3% determination of the weak mixing angle sin{sup 2}({theta}{sub W}) at low energy. The measurement may be used for a precision test of the Standard Model (SM) prediction on the running of sin{sup 2}({theta}{sub W}) with energy scale. The Q-weak experiment operates at Thomas Jefferson National Accelerator Facility (Jefferson Lab). The experiment determines Q{sub W}{sup p} by measuring the parity violating asymmetry in elastic electron-proton scattering at low momentum transfer Q{sup 2} = 0.026 (GeV/c){sup 2} and forward angles (?8 degrees). The anticipated size of the asymmetry, based on the SM, is about 230 parts per billion (ppb). With the proposed accuracy, the experiment may probe new physics beyond Standard Model at the TeV scale. This thesis focuses on my contributions to the experiment, including track reconstruction for momentum transfer determination of the scattering process, and the focal plane scanner, a detector I designed and built to measure the flux profile of scattered electrons on the focal plane of the Q-weak spectrometer to …

A laser offers a unique set of opportunities for precise delivery of high quality coherent energy. This energy can be tailored to alter the properties of material allowing a very flexible adjustment of the interaction that can lead to melting, vaporization, or just surface modification. Nowadays laser systems can be found in nearly all branches of research and industry for numerous applications. Sufficient evidence exists in the literature to suggest that further advancements in the field of laser material processing will rely significantly on the development of new process schemes. As a result they can be applied in various applications starting from fundamental research on systems, materials and processes performed on a scientific and technical basis for the industrial needs. The interaction of intense laser radiation with solid surfaces has extensively been studied for many years, in part, for development of possible applications. In this thesis, I present several applications of laser processing of metals and polymers including polishing niobium surface, producing a superconducting phase niobium nitride and depositing thin films of niobium nitride and organic material (cyclic olefin copolymer). The treated materials were examined by scanning electron microscopy (SEM), electron probe microanalysis (EPMA), atomic force microscopy (AFM), high resolution …

Electromagnetic production of neutral pions near threshold is the most basic, lowest energy reaction in which a new hadron is created. The electromagnetic interaction is well understood so measurements of this reaction can yield direct insight into the hadronic production mechanism. During the past three decades there have been many developments in both the measurement and theory of threshold pion production, starting with measurements of photo-production at Saclay in 1986 and at Mainz in 1990. These measurements indicated a surprising discrepancy with so-called Low Energy Theorems (LETs) which are based on quite fundamental symmetries and considerations. Chiral Perturbation Theory (ChPT) is an e#11;ective #12;eld theoretic description of the nuclear force which contains the underlying symmetries of the force but deals with nucleons and pions rather than quarks and gluons. It has the advantage of being applicable at low energies but requires tuning some parameters to experimental data. Once these parameters have been determined ChPT predicts how the reaction should behave as a function of the kinematic variable. When applied to the reaction, p({gamma},{pi}{sup 0})p, near threshold it explained the discrepancy with the LETs and made predictions for electroproduction, p(e,e'p){pi}#25;{sup 0}. Electroproduction measurements at Mainz in the 1990's showed a clear …

The push to provide ever brighter coherent radiation sources has led to the creation of correspondingly bright electron beams. With billions of electrons packed into normalized emittances (phase space) below one micron, collective effects may dominate both the preservation and use of such ultra-bright beams. An important class of collective effects is due to density modulations within the bunch, or microbunching. Microbunching may be deleterious, as in the case of the Microbunching Instability (MBI), or it may drive radiation sources of unprecedented intensity, as in the case of Free Electron Lasers (FELs). In this work we begin by describing models of microbunching due to inherent beam shot noise, which sparks both the MBI as well as SLAC's Linac Coherent Light Source, the world's first hard X-ray laser. We first use this model to propose a mechanism for reducing the inherent beam shot noise as well as for predicting MBI effects. We then describe experimental measurements of the resulting microbunching at LCLS, including optical radiation from the MBI, as well as the first gain length and harmonic measurements from a hard X-ray FEL. In the final chapters, we describe schemes that use external laser modulations to microbunch light sources of the …

The purpose of this study was to better predict how a first semester college freshman becomes prepared for college. the theoretical framework guiding this study is Vrooms’ expectancy theory, motivation plays a key role in success. This study used a hierarchical multiple regression model. the independent variables of interest included high school percentile class rank, composite ACT scores, composite SAT scores, and the 10 themes as measured by the Student Readiness Inventory (SRI) to address two research questions: What are the psychosocial factors identified by the SRI are most relevant in predicting college success? What conventional academic indicators are most relevant in predicting college success? the sample size for this study was 5279 (n), including a stratified random sample of first semester college freshman enrolled in credit bearing courses; these participants were deemed college ready by the university. Academic Discipline accounted for 4.2% of the variance in first semester college GPA, General Determination accounted for 1.7% of the variance, and the remaining psychosocial factors of the SRI accounted for less than 1% of the variance. High school percentile class rank accounted for 10.7% of the variance, composite ACT accounted for 5.9% of the variance, and composite SAT accounted for 5.6% …

This collection of short stories attempts to examine the role of a changing and often indifferent world has in the way various characters achieve maturity. Though the past is not always obvious in each story, each protagonist is characterized as holding onto some aspect of his or her past life in a way that is detrimental to their growing as human beings. the stories attempt to portray the indifference of the world as it moves forward to the plight of these characters, and to portray the manner in which they each come to terms with such a world and with their own lives.

Research has shown that health promotion programs (HPP) that incorporate education about physical activity (PA) are one mode of rehabilitation that can improve the health of individuals with disabilities. However, education-based PA curriculum is not included in the rehabilitation program for individuals with a brain injury, indicating a gap in services provided. Consequently, the purpose of this study was to create and deliver a physical activity centered education (PACE) program that supplemented the existing rehabilitation program for brain injury. PACE consists of an 8-week (16 session) program aimed to (1) increase self-efficacy for being physically active of PACE program participants, (2) increase PA stage of change in PACE program participants or the maintenance of adequate level of PA, and (3) improve the rehabilitation outcomes (i.e., abilities, participation, adjustment) of PACE program participants. Based on previous research, it is hypothesized that participation in PACE will result in (1A) increased self-efficacy for PA, (1B) greater self-efficacy for PA than the standard of care group, (2A) increased readiness to be physically active, (2B) greater readiness to change their PA behavior than the standard of care group, (3A) improved rehabilitation outcomes, and (3B) greater rehabilitation outcomes than the standard of care group. the PACE …

The original works of copyright holders included tangible creations, as music written on a page, thereby, extending copyright protection to songwriters and music publishers. Until 1995, absent from U.S. copyright law was protection for copyright owners of intangible sound recordings. the Performance Rights Act (PRA) seeks to amend the US copyright law in order to grant copyright holders of sound recordings the right to performance royalties from terrestrial broadcast radio. If passed, the legislation would be unprecedented in the United States. the PRA has implications for broadcast radio, record labels, and performing artists. This study includes historical and legal perspective of previous attempts at legislation of this nature and predicts outcomes of current legislation.

This dissertation investigates three questions: First, what conditions make dissident collective action such as protest, revolt, rebellion, or civil war more likely to happen in a country? Second, what conditions make citizens more likely to join in dissident collective action? Third, does Internet use play a role in dissident collective action, and if so, why? I argue that motives and resources are necessary rather than sufficient conditions for dissident collective action. I develop an analytical framework integrating motives and resources. Specifically, I theorize that state repression is an important motive, and that civil society is critical in providing resources. Four statistical analyses are conducted to test the hypotheses. Using aggregate level data on countries over time, I find that civil war is more likely to occur in countries where both state repression and civil society are strong. Moreover, the effect of civil society on civil war onset increases as the repression level rises. at the individual level using 2008 Latin American Public Opinion Project surveys from 23 Latin American and Caribbean countries, I find individuals more likely to join in protest when they experience both more repression and greater civic engagement. Moreover, civic engagement’s effect on protest participation increases as …

My Land, My Life is a documentary film about the woman, Jo Angela Lamb, who lives and works on Frying Pan Ranch in Texas Panhandle. the film explores the complexity of a ranch woman's experience that breaks the spell of the stereotyped image of American cowgirls. It also reflects on women ranchers’ relationship with their family members and their relationship with the land.

This dissertation is a qualitative study of racially ambiguous people and their life experiences. Racially ambiguous people are individuals who are frequently misidentified racially by others because they do not resemble the phenotype associated with the racial group to which they belong or because they belong to racial/ethnic groups originating in different parts of the world that resemble each other. the racial/ethnic population of the United States is constantly changing because of variations in the birth rates among the racial/ethnic groups that comprise those populations and immigration from around the world. Although much research has been done that documents the existence of racial/ethnic mixing in the history of the United States and the world, this multiracial history is seldom acknowledged in the social, work, and other spheres of interaction among people in the U.S., instead a racialized system based on the perception of individuals as mono-racial thus easily identified through (skin tone, hair texture, facial features, etc.). This is research was done using life experience interviews with 24 racially ambiguous individuals to determine how race/ethnicity has affected their lives and how they negotiate the minefield of race.

Jiggs is a documentary that explores how Jiggs Gaffney serves despite his mental disability. By observing Jiggs’ involvement at Pine Cove Christian Camps, and revealing his past, the documentary shows how anyone can be used for a greater good, and reveals how God can be served and glorified by anyone, no matter the individual circumstances.

This dissertation provides the first biographical overview and annotated catalog of the organ music of Alsatian-American organist and composer René Louis Becker. Born and educated in Strasbourg, Alsace, Becker emigrated to the United States in 1904 and remained active as a composer and church musician for the next 50 years. in addition to providing sources for his biographical information, documentation of the specific organs with which Becker was professionally associated is included for the purpose of evaluating possible dates of composition of his undated organ works as well as for consideration of organ registrations when performing his works. Primary sources include newspaper clippings, personal correspondence, family scrapbooks, organ archives, and both published and unpublished manuscripts. Study of these manuscripts, including rediscovery of more than fifty works of Becker’s which were previously published in the early 1900s, present an opportunity to introduce a large new body of sophisticated repertoire from a distinguished and accomplished musician to the field of organ music. Becker composed more than 180 individual works for the organ, over half of which remain in manuscript and which were completely unknown since even before his death in 1956. Becker’s complete known oeuvre for organ includes 34 marches, 15 toccatas, …

The current study was designed to evaluate the utility of progressing sequentially from multiple-respondent anecdotal assessments through test-control treatment analysis as an effective and efficient method of identifying the environmental determinants of problem behavior. the goal of the study was to evaluate overall agreement among multiple respondents on the primary function of aberrant behavior using the Motivation Assessment Scale (MAS) and Questions About Behavioral Function (QABF) and, if agreement was obtained, conduct a test-control evaluation to confirm anecdotal assessment findings while simultaneously evaluating the effects of function-based treatment. for 4 individuals, at least 4 of 5 respondents to the anecdotal assessments agreed (both within and across assessments) on the probable maintaining consequence for their problem behaviors. Test-control multielement evaluations were then conducted in which baseline sessions, corresponding to the suspected operant function of each individual’s problem behavior, were alternated with sessions in which the identified contingency was arranged for alternative behavior. Each evaluation showed substantial decreases in problem behavior and maintenance of alternative responses.

Aggression has traditionally been subdivided into two correlated, but distinct, subtypes: reactive and instrumental. Reactive aggression (RA) is considered impulsive, emotionally driven behavior, whereas instrumental aggression (IA) is planned and incentive-motivated. This thesis examines the relationships between RA, IA, psychopathy, and antisocial personality disorder (APD) symptoms in male and female offenders recruited from a jail in north Texas. Contrary to predictions, psychopathic traits did not account for more variance in aggression than did APD symptoms. Impulsivity demonstrated slight incremental validity over psychopathy for RA, and to a lesser degree, IA. the continued utility of the reactive-instrumental distinction and implications for professional practice in relation to the current study are examined. Study limitations and directions for future research are discussed.

This project traces the wide and varied uses of patriotic (and, at times, jingoistic and xenophobic) humor within the Victorian novel. a culture’s humor, perhaps more than any other cultural markers (food, dress, etc.), provides invaluable insight into that nation’s values and perceptions—not only how they view others, but also how they view themselves. in fact, humor provides such a unique cultural thumbprint as to make most jokes notoriously untranslatable. Victorian humor is certainly not a new topic of critical discussion; neither is English ethno-cultural identity during this era lacking scholarly attention. However, the intersection of these concerns has been seemingly ignored; thus, my research investigates the enmeshed relationship between these two areas of study. Not only do patriotic sentiment and humor frequently overlap, they often form a causational relationship wherein a writer’s rhetorical invocation of shared cultural experiences creates humorous self-awareness while “inside” jokes which reference unique Anglo-specific behaviors or collective memories promote a positive identity with the culture in question. Drawing on and extending the work of James Kincaid’s Dickens and the Rhetoric of Laughter, Harold Nicolson’s “The English Sense of Humor,” and Bergson’s and Freud’s theories of humor as a social construct, I question how this reciprocated …

Cyclic voltammetry experiments were performed to compare the electrodeposition characteristics of bismuth on ruthenium. Two types of electrodes were used for comparison: a Ru shot electrode (polycrystalline) and a thin film of radio-frequency sputtered Ru on a Ti/Si(100) support. Experiments were performed in 1mM Bi(NO3)3/0.5M H2SO4 with switching potentials between -0.25 and 0.55V (vs. KCl sat. Ag/AgCl) and a 20mV/s scan rate. Grazing incidence x-ray diffraction (GIXRD) determined the freshly prepared thin film electrode was hexagonally close-packed. After thermally oxidizing at 600°C for 20 minutes, the thin film adopts the tetragonal structure consistent with RuO2. a hydrated oxide film (RuOx?(H2O)y) was made by holding 1.3V on the surface of the film in H2SO4 for 60 seconds and was determined to be amorphous. Underpotential deposition of Bi was observed on the metallic surfaces and the electrochemically oxidized surface; it was not observed on the thermal oxide.

Behavior analysts form parent-professional relationships with families of many different backgrounds. the study evaluated the effectiveness of a training program to teach behavior analysts to utilize an open family interview format. the study was conducted at an autism treatment program. a pre-post treatment design with in vivo simulation probes before and after training was used to assess the effects of the workshop on the participants and parents’ verbal behavior. Results showed that rate of questions per minute and number of closed-ended questions decreased after training, the duration of interviews decreased after training, the number of closed-ended questions significantly decreased after training, and frequency of the discussion topic of child goals increased after training. in general, interviewer responses varied. Preliminary data and parent questionnaire responses suggested parents were comfortable with the new interview format and felt the behavior analyst understood cultural and family needs.