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Toward an Integrated Assessment of Risk Perceptions: Development and Testing of The Berlin Risk Perception Inventory
Get PDFResearch across four decades in psychology has suggested that risk perceptions can often be multi-dimensional, reflecting psychological constructs such as dread (how severe the consequences tend to be) and unknown (knowledge about risks; Fischhoff et al., 1978). However, research has largely neglected the assessment and integration of these dimensions across different orientations of risk perceptions (i.e., general versus specific risk perceptions; societal versus personal risk perceptions; absolute versus relative risk perceptions). As such, the current set of studies aimed to distill a brief psychometric scale to robustly measure diverse, multi-dimensional perceptions of risk to society: The Berlin Risk Perception Inventory (BRPI). Study 1 used Item Response Theory to distill a brief, robust measure of individual differences in societal risk perceptions from previously established standards. Structural analyses revealed that the BRPI explained between 2-3 times more variance in specific risks across emerging domains of weather, cybersecurity and health/safety compared to the original form. Study 2 conducted a successful out of sample replication and validation of the BRPI and demonstrated novel evidence in explaining perceptions of personal risks (i.e., how risky is HIV for me, personally). Study 3 tested the brief scale amidst a truly novel and unprecedented risk: COVID-19. Results revealed that this 3-minute instrument robustly explained both societal and personal perceptions of COVID-19, and downstream consequences (i.e., knowledge and behavioral intentions). General discussion focuses on providing analytic frameworks for measuring general, specific, societal, and personal risk perceptions. Finally, some of the earliest evidence on the measurement of relative risk perceptions of COVID-19 is discussed, with findings suggesting that failure to use the BRPI may result in studies with biased estimates of risk perceptions
Light Matter Interaction in A Rydberg Blockaded Ensemble
Get PDFThis thesis presents a study of the interactions between two Rydberg atoms and Rydberg atomic ensemble with a monochromatic light field. The first part of the thesis covers the interaction between two Rydberg atoms. The result of this calculation for two Rydberg atoms is compared to an experiment and single atom Stark shift calculations. The pair-potential curves for interacting Rydberg atoms in a constant electric field are calculated. We use the pair-potentials to determine the effective dipole-dipole coefficient , and van der Waals coefficients . We compared the and coefficients to the experimental results. The experiment is performed for a quasi one dimensional trap at ultracold temperatures. In the experiment the angle of a polarizing electric field is varied with respect to the trap axis. The dipoles produced via polarization of the atoms have an angular dependent dipole-dipole interaction. We focused on two Rubidium Rydberg atoms in states interacting in the blockade regime. For internuclear distances close to the blockade radius m, molecular calculations are in much better agreement with experimental results compared to those based on the properties of single atoms. The calculation based on single and independent atoms for and was used to analyze the original experiment. Our result shows that the calculated coefficient is within of the experimental value while the coefficient is within of the experimental value.
The second part of the thesis is a theoretical study of the interaction between a few atoms in a Rydberg ensemble in a monochromatic light field. We presented the solution of the full many-body master equation for an ensemble of two-level atoms. For a few atoms, through a full many-body master equation, it is possible to capture the main features of the physics of the problem. Our results demonstrate the capability of a full many-body master equation with a few atoms to investigate the novel quantum phases in long-range interacting quantum systems. The system's response to the driving laser field was studied by calculating the susceptibility, the correlation between Rydberg excitations, and excitation statistics. We studied the time evolution and the medium's response to the applied optical field. We calculated the linear dispersive and absorptive parts ( and ) of the susceptibility of the medium for various densities of the atomic ensemble. The nature of interactions between the atoms follows the van der Waals behavior and is inversely proportional to the sixth power of the internuclear distance, , between two atoms . In our calculations, we randomly generate the atoms' positions in a three-dimensional experimental box. This results in shot-to-shot fluctuations of the observables, such as susceptibility, which depends on atoms' positions relative to each other. The fluctuation of the observables (susceptibility and Rydberg excitations) happens around the transition boundary between two phases of the system. These fluctuations are quantum fluctuations since the temperature is set to be zero in the calculations. The critical parameters at which the transition of the system happens, such as critical density , are presented. We found that the system of interacting Rydberg atoms experiences a phase transition (at resonance, ) from a classical individual interacting atoms in the weakly interacting regime into a many-body quantum interacting regime in the strongly interacting regime at critical density cm. We found the Rydberg blockade radius , through the pair correlation function by sweeping the parameter space ( and ). Defining the reduced control parameter and , we investigated the features of the second-order phase transition close to the transition critical point ( and ). We define the order parameter to be the Rydberg excitation fraction . The phases are separated by analyzing the behavior of this order parameter. shows a power-law behavior close to the critical point with critical exponent .
In the last part, the full many-body master equation for an ensemble of three-level atoms inside a cavity is presented. We investigated the result of the cavity quantum electrodynamics (CQED) experiment in our group. We calculated the susceptibility through a full many-body density matrix calculations and used its result to study the transmitted light from the cavity. In the experimental analysis, the effect of the interaction between atoms is not considered. However, this can affect the result obtained through the many-body master equation calculations where these effects are considered. The future goal for the CQED experiment is to observe single-photon source by means of Rydberg blockade in the cavity. For this reason, the interactions between atoms need to be considered in the calculation and experimental analysis. To examine the effect of adsorbates on the surfaces of the mirrors of the cavity, we performed a pair-potential calculation in the background electric field of 1.6 V/cm created by the absorbates
Analysis of Mutual Coupling Models for Phased Array Calibration
Get PDFThere is a demand for more effective phased array calibration both in initial and in
situ setups, including but not limited to airborne and spaceborne radars. Mutual coupling is a method of calibration which involves gathering amplitude and phase components. However, obtaining mutual coupling information from a phased array is complicated due to array geometry, patch modeling, nulls in coupling, edge effects, and
changes in time and temperature. As such, simulating these phased arrays becomes difficult with larger array sizes in electromagnetic solvers as the demand for computational
memory increases.
This thesis introduces an array model meant to quickly provide mutual coupling
data which can in turn be used to help in the implementation of future mutual coupling
calibration algorithms. This accuracy of this model is verified using full wave simulations. Additionally, the parameters of this model are adjusted to the parameters of a
real life patch array and observed for similar mutual coupling behavior
The Stranger in the Architectural Project on the City
Get PDFThis paper was presented at the 2020 Schools of Thought Conference hosted by the Christopher C. Gibbs College of Architecture at the University of Oklahoma.This paper presents the project “Two Strangers Meet in a Parking Lot” and associated research studios as a case study of decolonized architecture pedagogy. The project conceptualizes the stranger as an alternative architectural user, creating a dialectical conversation with the users and architectural visions from architectural history. This dialogue encourages new pedagogical research methodologies related to the topic of city design. The case study uses these methodologies to recuperate lost cultural histories of Tennessee Town, an overlooked neighborhood in Topeka, Kansas, with an important connection to the Harlem Renaissance. According to Kwame Anthony Appiah, strangers transgress and challenge cultural boundaries by creating conversations at the edges of these borders, yet strangers counterintuitively utilize the environments in the city that are initially foreign to them to produce alternative cultural knowledge. This interaction between stranger and entities in the city provides a model for how disciplines can communicate across their own boundaries. The strangers’ conversation, when transferred to the architectural studio setting, becomes what Mark Linder calls “transdisciplinary” discourse, which occurs at the borders of adjacent disciplines. The resulting knowledge intentionally highlights overlooked and misinterpreted cultural moments in the city while creating an alternative to traditional interdisciplinary modes of working, which the philosopher Homi Bhabha says is essential if disciplinary fields are to progress with the global city. The “Two Strangers” case study consists of built structures that were designed, first, to transform people into strangers and, then, to instigate conversations between them. As a result, strangers become acquaintances and exchange new knowledge. The architectural studio course explored this idea further by taking students outside of the classroom where they engaged with the community through conversations with city archivists, community leaders, city council persons, urban planners, and museum directors.Support for the project “Two Strangers Meet in a Parking Lot” was provided by a Rocket Grants project award, a program of the Charlotte Street Foundation and the University of Kansas Spencer Museum of Art. Funding was provided by the Andy Warhol Foundation for the Visual Arts.Ye
