Laboratory experiments were performed to study and improve longshore sediment transport rate predictions. Measured total longshore transport in the laboratory was approximately three times greater for plunging breakers than spilling breakers. Three distinct zones of longshore transport were observed across the surf zone: the incipient breaker zone, inner surf zone, and swash zone. Transport at incipient breaking was influenced by breaker type; inner surf zone transport was dominated by wave height, independent of wave period; and swash zone transport was dependent on wave period. Selected predictive formulas to compute total load and distributed load transport were compared to laboratory and field data. Equations by Kamphuis (1991) and Madsen et al. (2003) gave consistent total sediment transport estimates for both laboratory and field data. Additionally, the CERC formula predicted measurements well if calibrated and applied to similar breaker types. Each of the distributed load models had shortcomings. The energetics model of Bodge and Dean (1987) was sensitive to fluctuations in energy dissipation and often predicted transport peaks that were not present in the data. The Watanabe (1992) equation, based on time-averaged bottom stress, predicted no transport at most laboratory locations. The Van Rijn (1993) model was comprehensive and required hydrodynamic, bedform, and sediment data. The model estimated the laboratory cross-shore distribution well, but greatly overestimated field transport. Seven models were developed in this study based on the principle that transported sediment is mobilized by the total shear stress acting on the bottom and transported by the current at that location. Shear stress, including the turbulent component, was calculated from the wave orbital velocity. Models 1 through 3 gave good estimates of the transport distribution, but underpredicted the transport peak near the plunging wave breakpoint. A suspension term was included in Models 4 through 7, which improved estimates near breaking for plunging breakers. Models 4, 5 and 7 also compared well to the field measurements. It was concluded that breaker type is an important variable in determining the amount of transport that occurs at a location. Lastly, inclusion of the turbulent component of the orbital velocity is vital in predictive sediment transport equations.

This dissertation studies social incentives in pro-social behavior and its various implications, including but not limited to disclosure policies, fundraising strategies and geographic polarization. / Economics

No description available.

In dieser Arbeit werden nichtlineare Kopplungsmechanismen von akustischen Oszillatoren untersucht, die zu Synchronisation führen können. Aufbauend auf die Fragestellungen vorangegangener Arbeiten werden mit Hilfe theoretischer und experimenteller Studien sowie mit Hilfe numerischer Simulationen die Elemente der Tonentstehung in der Orgelpfeife und die Mechanismen der gegenseitigen Wechselwirkung von Orgelpfeifen identifiziert. Daraus wird erstmalig ein vollständig auf den aeroakustischen und fluiddynamischen Grundprinzipien basierendes nichtlinear gekoppeltes Modell selbst-erregter Oszillatoren für die Beschreibung des Verhaltens zweier wechselwirkender Orgelpfeifen entwickelt. Die durchgeführten Modellrechnungen werden mit den experimentellen Befunden verglichen. Es zeigt sich, dass die Tonentstehung und die Kopplungsmechanismen von Orgelpfeifen durch das entwickelte Oszillatormodell in weiten Teilen richtig beschrieben werden. Insbesondere kann damit die Ursache für den nichtlinearen Zusammenhang von Kopplungsstärke und Synchronisation des gekoppelten Zwei-Pfeifen Systems, welcher sich in einem nichtlinearen Verlauf der Arnoldzunge darstellt, geklärt werden. Mit den gewonnenen Erkenntnissen wird der Einfluss des Raumes auf die Tonentstehung bei Orgelpfeifen betrachtet. Dafür werden numerische Simulationen der Wechselwirkung einer Orgelpfeife mit verschiedenen Raumgeometrien, wie z. B. ebene, konvexe, konkave, und gezahnte Geometrien, exemplarisch untersucht. Auch der Einfluss von Schwellkästen auf die Tonentstehung und die Klangbildung der Orgelpfeife wird studiert. In weiteren, neuartigen Synchronisationsexperimenten mit identisch gestimmten Orgelpfeifen, sowie mit Mixturen wird die Synchronisation für verschiedene, horizontale und vertikale Pfeifenabstände in der Ebene der Schallabstrahlung, untersucht. Die dabei erstmalig beobachteten räumlich isotropen Unstetigkeiten im Schwingungsverhalten der gekoppelten Pfeifensysteme, deuten auf abstandsabhängige Wechsel zwischen gegen- und gleichphasigen Sychronisationsregimen hin. Abschließend wird die Möglichkeit dokumentiert, das Phänomen der Synchronisation zweier Orgelpfeifen durch numerische Simulationen, also der Behandlung der kompressiblen Navier-Stokes Gleichungen mit entsprechenden Rand- und Anfangsbedingungen, realitätsnah abzubilden. Auch dies stellt ein Novum dar. / In this work non-linear coupling mechanisms in acoustic oscillator systems are examined which can lead to synchronization phenomena. This mechanisms are investigated in particular on organ pipes. Building up on the questions of preceding works the elements of the sound generation are identified using detailed experimental and theoretical studies, as well as numerical simulations. Furthermore the organ pipes interaction mechanisms of the mutual coupling are developed. This leads to a non-linear coupled oscillator model which is developed on the aeroacoustical and fluiddynamical first principles. The carried out model calculations are compared to the experimental results from preceding works. It appears that the sound generation and the coupling mechanisms are properly described by the developed nonlinear coupled model of self-sustained oscillators. In particular the cause can be cleared with it for the non-linear edges of the Arnold tongue of the coupled two-pipe system. With the new knowledge the influence of various space geometries on the sound generation of organ pipes is investigated. With numerical simulations the interaction of an organ pipe and different space geometries, like plane, convex, concave, and ridged geometry is studied. Also the influence of so called swell boxes on the sound generation and the sound pattern of the organ pipe is studied. In further new synchronization experiments with precisely equally tuned pairs of organ pipes, as well as with mixtures the synchronization is examined for various grids of horizontal and vertical pipe distances in the 2D-plane of sound radiation. The spatial discontinuities observed in the oscillation behaviour of the coupled pipe systems, point to changes between anti-phase and in-phase regimes of sychronization depending on pipes distances. Finally the possibility is documented to describe the phenomenon of the synchronization of two organ pipes realisticaly by solving the compressible Navier-Stokes equations numerically.

SammanfattningTitel: Om individer får förberedande information om att arbeta i grupp, kan detta då ses kunna förändra deras upplevelse av att arbeta i grupp?Författare: Hayat Ashkar och Görgen Jansson Handledare: Ilkka Henrik Mäkinen Examinator: Hedvig EkerwaldLärosäte: Uppsala Universitet Datum: 5/1 2015Bakgrunden till den här studien bygger på tidigare forskning som visat att om en vårdsökande i väntan på sin läkartid får hjälp till självhjälp får denna patient ut mer av behandlingen, jämfört med en patient som endast fått vänta på sitt läkarbesök. Det kan då tolkas som att någon form av självhjälp, förberedelse, innan behandlingen är gynnsamt.Detta ledde till en tanke om samma princip kan gälla för grupparbeten. Om individer som ska genomföra ett grupparbete får information om att arbeta i grupp, en förberedelse, kan det då förbättra deras upplevelse av att arbeta i grupp? Syftet med uppsatsen är att undersöka om kunskap om socialpsykologiska begrepp kan ge någon inverkan på elevers upplevelser till att arbeta i grupp. För att undersöka om så var fallet genomfördes ett experiment med tre olika gymnasieklasser. Deltagarna fick genomföra ett grupparbete och därefter svara på en enkät som mätte deras upplevelse av arbetet. I nästa steg fick en grupp, experimentgruppen, lyssna på en föreläsning om socialpsykologiska begrepp för att därefter återigen genomföra ett grupparbete och besvara samma enkät igen. En annan grupp, kontrollgruppen, fick inte lyssna på föreläsningen men göra allt övrigt experimentgruppen gjorde, ett grupparbete med enkät samt ett grupparbete till med enkät.De teoretiska begrepp som använts för att analysera resultatet är bland annat, definition av situationen, priming och Hawthorneeffekten. Resultatet tyder på att en förändring i upplevelsen av grupparbete skett hos både experimentgruppen och kontrollgruppen, dock var den större hos experimentgruppen. / AbstractTitle: If individuals get an information about how to work in a group, could that change their experience about cooperation?Authors: Hayat Ashkar and Görgen JanssonMentor: Ilkka Henrik MäkinenSeat of learning: Uppsala UniversityDate: 5/1 2014The background to this study is based on studies that have shown that if a patient while waiting for a doctor's appointment gets help to self-help, the patient will assimilate more of the treatment than a patient who only has to wait for their doctor’s appointment. That can then be interpreted as any kind of stimuli (self-help) before treatment is favourable.That led to a wonder if the same principle might apply to work in groups. If individuals who are going to do cooperation receive information about working in groups, in terms of social psychology concepts, could that improve their ability to work in a group? The purpose of this paper is to examine whether knowledge in social psychological concepts can be seen to give any impact on students' experiences and attitudes towards working in groups. To examine this, an experiment with different high school classes was conducted. In the experimental group the students implemented a group project and then answered a questionnaire that measured the students' experience of the work. In the next step they had to listen to a lecture about social psychological concepts. After that they did another group project and answered the same questionnaire again. In the control group the students did just the same except listening to the lecture about social psychological concepts.The theoretical concepts used include social negotiation, definition of the situation and priming. The results of this study show that the experimental group showed a consistently higher average current experience of group work. That indicates that a process of change begins in the participants. It can be explained by priming.

This essay discusses different opinions about experimental archaeology. To start with literature was examined and a questionnaire was sent out to students and working archaeologists. The possibility for experiments to mediate archaeology to people without an education in archaeology is lifted and is also mentioned in the questionnaire. In the discussion part of the essay the results from the questionnaire and the literature are used to see what opinions are the strongest. The mediating is also discussed and the result is compiled in the conclusion. There are different opinions about experimental archaeology, but no prominent difference between what students and archaeologists answered. It is possible to see different opinions in the literature, but concerning the mediating most of the writers agree that the experimental archaeology is a good method to communicate with the laymen.

Zugl.: Regensburg, Univ., Diss., 2006

Univ., Diss.--Mannheim, 2002. / Literaturverz. S. 189 - 212.

This dissertation explores what factors and institutions influence individual decision making and their economic impacts on the society, using approaches of laboratory and field experiments. The first essay addresses the effect of communication on cooperation. The second essay explores various types of public recognition, and their impacts on individual donation. The third essay studies how principals use their time in K-12 schools and the potential impact on student and school outcomes. The first essay employs a laboratory experiment including three factors in human interactions, a noisy environment, indefinite length of interactions, and various levels of communication, to study what factors make individuals more cooperative. Results show that subjects are less cooperative in a noisy environment, and communication via fixed messages is not a remedy for the low cooperation rate in this noisy environment. However, communication via free messages leads to more cooperations, and it maintains cooperation rate at a high level over time. The second essay is a joint work with Yefeng Chen, Haoran He, and Jun Luo. We conduct a field experiment to investigate how public recognition influences individual charitable giving. We design five treatments with distinct public recognition schemes and vary the timing when we offer opportunities of public recognition. Results show that both donation amount and participation rate are significantly higher when we mandate recognition. However, public recognition offered before donation crowds out small donations and thus lowers the participation rate. We claim that public recognition is a “double-edged sword” on individual charitable giving. The third essay is a joint work with Mary Mira. We conduct a principal motion study in Fulton County, Georgia and shadow 30 school principals from all levels of public K-12 schools for two work days. We link our observational data with student performance data from state-wide standard scores. Results show that principals’ time spend on building and maintaining school culture and school climate, as well as evaluating teachers and school staff are most positively related to student performance.

The Daya Bay experiment is designed to precisely measure short-baseline disappearance of reactor antineutrinos from reactor cores at the Daya Bay nuclear power plant complex in the Guangdong Province of China. It pre- sented the most precise measurements of oscillation parameters sin2 2θ13 = 0.084 ± 0.005 and |∆m2 ee| = (2.42 ± 0.11) × 10−3 eV2 . Background to the antineutrino signals is mainly created by cosmic muons and is effectively suppressed by use of water Cherenkov and RPC muon detectors. This thesis describe testing of RPC detectors prior to their installation at the experi- mental site. Part of the cosmic muons stop in the experiment's antineutrino detectors, and they decay or are captured by 12 C producing 12 B. Isotope 12 B contribute to accidental background. Rates of muon decays in the detectors are estimated in the thesis. The experiment can register electron antineutri- nos from supernova with expected signals around 20 MeV. Energy scale of the detectors at 53 MeV is determined.