Global ETD Search

21	Development and Testing of A Space-borne GPS Signal Strength Sensor Lu, Dianhong 13 October 2003 (has links) The Global Positioning System (GPS) satellite signals provide not only traditional radionavigation service but inexpensive and convenient radio beacons for signal propagation studies on ionosphere and atmosphere. This thesis describes the development and testing of a specialized GPS sensor which measures, plots and records real-time high-resolution L1 (1575.42MHz) GPS signal strength at a data rate of up to 10Hz. The instrument is based on an open architecture GPS receiver development kit that can be modified and rebuilt. The signal strength is defined as mean-square signal strength in the thesis. The coarse/acquisition code (C/A-code) correlation is applied and the raw correlation data from a GPS correlator chip is obtained to calculate the signal strength. The gain variation of the automatic gain control (AGC) in the GPS signal link is considered, and a model is designed and implemented in data post-processing to reduce the AGC distortion to GPS signal strength measurements. Speed limitation of 1,000 knots and height limitation of 60,000 feet are removed so that it can track spacecraft such as low earth orbit (LEO) satellite. Four testing plans are developed and conducted to test the GPS signal strength sensor. A GPS simulator is used and the testing results prove that the space-borne sensor is fully operational and the signal strength resolution can be smaller than 0.05dB. Additionally, a COM-port-to-TCP/IP GPS simulation remote control gateway is designed and implemented for the senor and the GPS simulator to conduct formation flying. A graphic user interface (GUI) program is also built to retrieve data from a commercial high-performance space-borne GPS receiver for comparison. A Red Hat Linux signal strength sensor based on the National Aeronautics and Space Administration (NASA) PiVoT GPS receiver is achieved by modifications. The NASA PiVoT sensor, working together with the former signal strength sensor and the commercial space-borne GPS receiver, will strengthen our academic research strength in the studies on the ionospheric and atmospheric effects and irregularities which cause GPS signal degradation and scintillations. / Master of Science Linux PiVoT DS-CDMA GPS Builder GP2021 GPS simulator GP2015 Spacecraft tracking Ashtech G12 Remote control task COMPORT GPS signal strength sensor
22	Market reaction to seasoned offerings in China Liu, J., Akbar, Saeed, Shah, S.Z.A., Zhang, D., Pang, D. 12 June 2019 (has links) Yes / This study examines stock market reaction to the announcement of various forms of seasoned issues in China. Our empirical evidence demonstrates that market reactions differ in ways that suggest a difference between management's internal assessment and the market's assessment of the stock price. The market responds unfavourably to the announcement, notably in the case of rights issues and also with regard to open offers. Private placements experience an unfavourable pre‐announcement reaction, which contrasts with the favourable reaction after the event. Convertible bond issues generate positive excess returns consistent with the market's confidence that they can help to align management and shareholders’ interests. Further investigation shows that market reaction is related to factors specific to the issuer and issue by reference to the period immediately surrounding the issue. Specifically, ownership concentration, agency matters connected with equity offerings, investor protection connected with fund allocation and security pricing, and the influence of powerful moneyed interests together provide an instructive insight into market reaction. Institutional inefficiency pertaining to underwriting, auditing, analysts’ forecasts and credit ratings are found to have a weak association with market price, consistent with due public scepticism concerning management and their gatekeepers. Seasoned issues Seasoned equity offerings Convertible bond issues Market reaction Information Information asymmetry Agency costs Market infrastructure China G12 G14 G32 G30
23	Molecular Mechanisms of Serotonergic Signaling: Role in Neuronal Outgrowth and Receptor Oligomerization / Molekulare Mechanismen des serotonergen Systems: Rolle bei neuronalem Wachstum und Rezeptoroligomerisierung Kobe, Fritz 30 April 2010 (has links) No description available. 570 Biowissenschaften, Biologie Biology (incl. Psychology) Serotonin 5-HT7 Rezeptor 5-HT1A Rezeptor G12 Protein Synaptogenese Oligomerisierung Palmitoylierung FRET serotonin 5-HT7 receptor 5-HT1A receptor G12 Protein Synaptogenesis Oligomerization FRET palmitoylation 42.15
24	An Investigation of Dividend Signalling on the New Zealand Stock Exchange in the 1990s and of Several New Tools Employable in such an Investigation Anderson, Warwick Wyndham January 2006 (has links) This thesis investigates the nature of joint dividend-and-earnings signalling in announcements to the New Zealand Stock Exchange in the 1990s. Initially the Market Model is used to compute expected returns, and the abnormal returns derived from these are subjected to restricted least squares regressions to separate out a putative dividend signal from the concurrent earnings signal. But with the Market Model, the zero-value company returns associated with an absence of trading in thinly traded stocks are over-represented in returns distributions leading to problems of bias. New models are developed that explicitly exploit zero returns. The first alternative methodology entails friction modelling, which uses a maximum likelihood estimation procedure to find the relationship coefficients and the range of returns that should be considered as zero, and then proceeds to treat them as a separate category. The second alternative methodology is that of state asset models, which take a fresh new look at investor perceptions of the connection between movements in company returns and those of the concurrent underlying market. Zero-value company returns cease to be zero in value, where a state model is rotated, or alternatively they can be modelled as an extra state. All three methodologies furnish some evidence of dividend signalling; but this evidence is highly dependent on small changes within the given methodology. G14 Event Studies G14 Market Efficiency G12 Asset Pricing C22 Time Series Models Dividend Signalling Friction Models State Asset Pricing Models Market Model Thin Market
25	First Time Measurements of Polarization Observables for the Charged Cascade Hyperon in Photoproduction Bono, Jason S 06 June 2014 (has links) The parity violating weak decay of hyperons offers a valuable means of measuring their polarization, providing insight into the production of strange quarks and the matter they compose. Jefferson Lab’s CLAS collaboration has utilized this property of hyperons, publishing the most precise polarization measurements for the Λ and Σ in both photoproduction and electroproduction to date. In contrast, cascades, which contain two strange quarks, can only be produced through indirect processes and as a result, exhibit low cross sections thus remaining experimentally elusive. At present, there are two aspects in cascade physics where progress has been minimal: characterizing their production mechanism, which lacks theoretical and experimental developments, and observation of the numerous excited cascade resonances that are required to exist by flavor SU(3)F symmetry. However, CLAS data were collected in 2008 with a luminosity of 68 pb−1 using a circularly polarized photon beam with energies up to 5.45 GeV, incident on a liquid hydrogen target. This dataset is, at present, the world’s largest for meson photoproduction in its energy range and provides a unique opportunity to study cascade physics with polarization measurements. The current analysis explores hyperon production through the γp → K+K+Ξ− reaction by providing the first ever determination of spin observables P, Cx and Cz for the cascade. Three of our primary goals are to test the only cascade photoproduction model in existence, examine the underlying processes that give rise to hyperon polarization, and to stimulate future theoretical developments while providing constraints for their parameters. Our research is part of a broader program to understand the production of strange quarks and hadrons with strangeness. The remainder of this document discusses the motivation behind such research, the method of data collection, details of their analysis, and the significance of our results. Physics Weak Nuclear Polarization Hyperon Particle Baryon Meson Strange Quark Kaon Photoproduction Jlab Jefferson Lab Photon Lambda Production Gamma K P Xi Cascade Jason Bono Experimental Accelerator g12 CLAS Jason Bono Jason S. Bono Nuclear Physics Particle Physics Hyperon Polarization Weak Decay Cascade Polarization Xi Polarization Induced Transfered Cx Cz Induced Polarization Transfered Polarization FIU Jlab Jefferson Lab Hall b

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