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Privacy paradox or bargained-for-exchange : capturing the relationships among privacy concerns, privacy management, self-disclosure, and social capital
textThe dissertation seeks to bridge the gap between privacy and social capital on SNS use by bringing the essential elements of social networking, privacy concerns, privacy management, self-disclosure, and social capital together to examine their complex relationships and the daily challenges every SNS user faces. The major purposes of this dissertation were to revisit the privacy paradox phenomenon, update the current relationships among privacy concerns, self-disclosure, and social capital on Facebook, integrate these relationships into a quantitative model, and explore the role of privacy management in these relationships. The goal was realized by using Amazon.com’s Mechanical Turk to test a theoretical model that used survey data from 522 respondents. The findings from the dissertation show the impact of the structural factor—Facebook social network intensity and diversity—and the impact of individuals’ self-disclosure on Facebook on their perceived bridging and bonding social capital. This dissertation employed various measurements of key variables to update the current status of the privacy paradox phenomenon—the disconnection between privacy concerns and self- disclosure on social media—and found the break of the traditional privacy paradox and the existence of the social privacy paradox. Findings also show that private information about personal information, thoughts, and ideas shared on Facebook become assets in using Facebook and accumulating social capital. Meanwhile, higher privacy concerns reduce the level of self-disclosure on Facebook. Therefore, privacy concerns become a barrier in Facebook use and in accumulating social capital within these networks. This dissertation further examined the mediating role of privacy management to solve the dilemma. Findings confirmed that privacy management is important in redirecting the relationships among privacy concerns, self-disclosure, and social capital. People who have higher privacy concerns tend to disclose fewer personal thoughts and ideas on Facebook and miss the opportunity to accumulate social capital. However, when they employ more privacy management strategies, they are more willing to self-disclose and thus accumulate more social capital on Facebook networks. Lastly, the proposed integrated model examined through SEM analysis confirms the delicate relationships among the social networking characteristics, privacy concerns, privacy management, self-disclosure, and social capital.Journalis
Non-Standard Search for Dark Matter with CRESST
Dunkler Materie ist eines der großen Rätsel unserer Zeit. CRESST ist ein Experiment, das darauf abzielt, den von dunkler Materie induzierten Kernrückstoß und damit ihre Existenz nachzuweisen und Rückschlüsse auf ihre Eigenschaften ziehen zu können. Da dieser Nachweis bis heute weder CRESST noch anderen Experimenten gelungen ist, geraten zunehmend Theorien in den Fokus, die von der Standardannahme eines etwa 100 GeV/c2schweren sogenannten WIMPs abweichen, das über einen relativ zum Energieübertrag schweren Mediator und spin-, isospin-, geschwindigkeits- und impulsunabhängig mit Nukleonen interagieren soll. Insbesondere ist der Schwerpunkt des CRESST-Experiments aufgrund der kleinen, aber genauen Detektoren leichte dunkle Materie mit einer Masse weit unter 10 GeV/c^2. In dieser Arbeit werden die Messdaten des Experi-ments im Rahmen einer effektiven Feldtheorie untersucht, bei der die Wechselwirkung zu Nukleonen mit 28 verschiedenen Operatoren (je nach Darstellung je 14 Operatoren für Protonen und Neutronen bzw. für Isoskalar- und Isovektor-Wechselwirkung) beschrieben wird und so mögliche Abhängigkeiten vom Isospin, den Spins der Nukleonen und der dunklen Materie, vom Impulsübertrag, sowie von der relativen transversalen Geschwindigkeit, mit in Betracht gezogen werden. Die theoretischen Rückstoßspektra für zwei der Hauptbestandteile der CRESST-Detektoren, Sauerstoff-16 und Calcium-40, für sieben verschiedene dieser Operatoren werden in dieser Arbeit berechnet, mit den aufgenommenen Spektra verglichen und somit massen abhängige obere Grenzen auf die Kopplungsstärke gesetzt. Alle diese Limits überschreiten die Sensitivität von bisher publizierten Ergebnissen im Bereich niedriger Dunklen-Materie-Massen unter 3 GeV/c^2.Dark Matter is one of the large puzzles of our time. CRESST is an experiment trying to prove nuclear recoils induced by dark matter and thus its existence, and to deduce some of its properties. Up until know, no such signal has been proven by CRESST or other experiments. Therefore, a growing emphasis is on dark matter theories that differ from the standard assumption of so-called WIMPs with a mass of around 100 GeV/c^2 that interact with nucleons via a heavy mediator (compared to the energy transfer) and independently of involved spins, isospins, velocities and momenta. Especially, the focus of the CRESST experiment with its small, but sensitive detectors is light dark matter with a mass of way below 10 GeV/c^2. In this work, experimental data from the experiment is investigated in the context of an effective field theory, where the interaction to nucleons is described with 28 different operators (depending on the reprensentation 14 operators each for protons and neutrons, or for isoscalar and isovector interaction). Possible dependencies on the isospin, spins of the nucleons and of the darkmatter, the momentum transfer, as well as the relative transverse velocitiesare taken into account by these operators.Theoretical recoil spectra for two of the main components of the CRESST detectors, oxygen-16 and calcium-40, for seven of these operators are calculated in this work and compared to the measured experimental spectra. Mass-dependent upper limits are set on the interaction strength. All of these limits surpass the sensitivity of previously published results for masses below 3 GeV/c^
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