International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / During shallow water exercises, the performance of acoustic tracking and telemetry systems is degraded by severe multipath interference. The feasibility of an optical source attached to the underwater vehicle (UV) and a tracking aircraft-based receiver was theoretically established. Supporting water absorption and surface interaction experiments were also performed. The limiting case was the tracking of an unmanned underwater vehicle (UUV). The requirements of daylight operation, atmospheric visibility, limited space and weight, self-contained power, exercise duration, sample rate, optimum search area, robustness in varying scattering and sea states, non-cooperating (except for low-data-rate communications of information such as depth) source and receiver, and relative simplicity, lead to two optimum candidate systems. One system uses a commercially available 5 megawatt q switched and double laser diode pumped YAG laser operating at 532 nm and 1 Hz rep rates. The second system uses a pulsed (2 μsec) zenon flash tube. Both systems satisfy the robustness constraint by intentional beam spreading. A performance constraint of 10:1 signal to noon solar upwelling shot noise ratio was imposed. This constraint can be met for water depths of 10 and 5 absorption lengths, respectively, for the laser and incoherent systems. An optimum search diameter of approximately 700 meters (m) at an optimum aircraft elevation of 3,000 meters is calculated for both systems. The 4-inch diameter F/1 wide-angle light pulse detection system gates a 4-inch diameter F/1 intensified charged coupled device (CCD) imaging system that locates the light surface penetration point. Another candidate receiver that performs both functions is a positive sensitive photomultiplier tube with crossed wire anodes. A supporting night-time experiment has been designed and is under construction.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / 1 ill. in back pocket. Vita. Abstract. Includes bibliographical references (leaves 224-228). Also available via the Internet.

Thesis (M. Phil.)--University of Hong Kong, 2000.

Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, December 2003. / Thesis advisor(s): David C. Jenn, Jeffrey B. Knorr. Includes bibliographical references (p. 85-87). Also available online.

M. Tech. Electrical Engineering. / This study is dedicated to the investigation of different methodologies used to determine the location of a beacon type active radio frequency identification device (RFID). Also included in the study is the hardware implementation of a system based on the angle of arrival location method, which makes use of array theory and angle of arrival techniques to identify the angle of the impinging tag transmission. In order to address the complex issues of array theory and linear array structures, a large part of the study is devoted to antennae, antenna arrays and the radiation patterns regarding the latter.

Thesis (M.S.)--Ohio University, August, 1981. / Title from PDF t.p.

The purpose of this research was to study the hybridization of molecular beacons under different conditions and designs. Data collected suggest that the inconsistency found in the emission intensity of several of these probes may be caused by 3 important factors: length of the probe, nucleotide sequence and, the formation of an alternative complex structure such as a dimer. Of all three factors, dimer formation is the most troublesome, since it reduces the emission of the reporter molecules. A new probe design was used to reduce dimer formation. The emission signal of the improved probe was several folds stronger than those probes with the early design. In this research, dimer formation is detected, furthermore a new probe with a different design was tested. If dimer formation can be reduced molecular beacons can be integrated into more complex hybridization systems providing an important tool in research and diagnosis of genetic disorders.

No description available.

Beacons are small devices that can broadcast messages using Bluetooth and other communication technologies using low power consumption. Beacons technology started to emerge lately and many companies has started to see opportunities. One usage of beacons is improving online advertising by using localized information. The most common way to consume beacons today, is by using a native application. This solution is viable in many cases, but not for online advertising. The reason for this is that users do not want to download a native application only for advertising. In this study, solutions for online advertising using beacons, are examined. The study is focused around a case study on implementing a plugin for Android applications. The plugin consists of a background service that listens for beacon messages, converts the beacon messages to geographic information and gathers user information. All that information is sent to a web service to later perform retargeting. This improves online advertisement, since localized advertisement can be displayed to the user. The results of the case study showed that the plugin is a viable solution for online advertising using beacons. The plugin could be integrated and launched from different Android applications in a simple way. Measurements of the RAM usage and battery consumption indicates that the plugin can run with no huge impact on the performance or battery of the phone. The purpose of the study is to present different ways of using beacons for online advertising. / Beacons är små enheter som kan sända ut meddelanden genom att använda Bluetooth eller andra kommunikationstekniker med låg energiförbrukning. Teknologin bakom Beacons började framträda nyligen och många företag har redan sett de möjligheter som finns med teknologin. Beacons kan bland annat användas till att förbättra digital reklam genom att använda lokaliserad information. Det vanligaste sättet att konsumera beacons är att använda en lokal applikation. Det sättet är användbart i många fall, men inte för digital reklam. Anledningen till det är att användare tenderar att inte vilja ladda ner applikationer endast för att få reklam. I den här studien undersöks lösningar för att använda beacons för digital reklam. Studien fokuserar kring en fallstudie om ett insticksprogram till applikationer för Android. Insticksprogrammet består av en bakgrundstjänst som lyssnar efter meddelande från beacons, konverterar meddelandet till geografisk information, samlar information om användaren och skickar informationen till en web service, som senare använder informationen för att ge användare anpassad reklam. Detta förbättrar reklamen, eftersom användarens position kan användas för att ge bättre anpassad reklam. Resultaten från fallstudien visar att insticksprogrammet är en genomförbar lösning för att använda beacons för digital reklam. Insticksprogrammet kan integreras och startas från en applikation i Android på ett enkelt sätt. Mätningar av insticksprogrammets RAM-användning och batterianvändning visar på att det kan köras utan att märkbart påverka telefonens prestanda eller batteri. Syftet med den här studien är att visa olika sätt som beacons kan användas för digital reklam.

Thesis advisor: Torsten Fiebig / Thesis advisor: Mary Roberts / Understanding the electronic nature of DNA is profound and has been attempted for decades. Photoexcitation of DNA with UV light deposits electronic energy in the base stack and prepares highly reactive excited states. These states are precursors for photoinduced damage reactions which can lead to mutations and ultimately to cell death. While many DNA photo products have been isolated and characterized, the primary events immediately after photon absorption are not yet understood. Recent studies with ultrafast lasers have revealed that the majority of excess energy gained by DNA with light absorbance is dissipated on the femtosecond and picosecond time scales. In this study double-stranded oligonucleotides with different base sequences, content and lengths were systematically examined using femtosecond pump-probe spectroscopy. The results indicate that excitations in DNA are delocalized over more than two bases and the extent of the delocalization depends strongly on the structure of the investigated systems. Exciton delocalization domains in the longer duplexes are larger than in the shorter ones. Also, single-stranded oligonucleotides show smaller extent of exciton delocalization than duplexes with the same length. In addition to the fundamental studies on DNA photophysics, the properties and the structure of new molecular beacons based on thiazole orange dimers were studied. A full account of the optical and structural properties of the dimers in different base environments and orientations is presented here. Currently, the development of efficient ways to utilizing solar energy is at the forefront of the scientific community due to the ever rising demand for energy. Both, colloidal semiconductor nanocrystals and single-walled carbon nanotubes are potential alternatives to conventional inorganic and organic materials in photovoltaic devices Thorough understanding of the charge transfer and related photophysical phenomena in these systems will answer the question whether these nanomaterials can be applied in future generations of solar cells. The photoinduced electron transfer in donor-acceptor CdSe/CdTe heterostructured nanorods, in which CdTe is grown on top of CdSe in a single rod structure, was studied. The electron transfer between the two nanocrystals occurs on the subpicosecond time scale, competing with the ultrafast relaxation mechanisms in the quantum confined nanocrystals. Furthermore, investigations on how quantum confinement influences the phonon wavepackets in semiconductor nanocrystals were carried out. Quantum beats corresponding to longitudinal optical phonon modes were observed in the femtosecond pump-probe spectra of colloidal CdTe nanocrystals. Size-dependent experiments revealed that the optical phonon frequencies and the exciton-phonon coupling strength do not depend on the crystal's size. Only the wavepacket dephasing time was influenced by the diameter of the particles which was correlated with the hole relaxation to the exciton band edge. Electron donor-acceptor constructs, based on single-walled carbon nanotubes (SWNT), can be attained by noncovalent functionalization of the nanotubes with pyrene derivatives. However, charge transfer does not take place in the simplest pyrene-SWNT constructs. For the first time the pure SWNT-pyrene construct was isolated and investigated. Our results revealed that the optical properties of pyrene are drastically altered due to strong electronic interactions with the SWNT surface. In other words, aromatic molecules lose their electronic (and chemical) signature when non-covalently attached to carbon nanotubes. / Thesis (PhD) — Boston College, 2010. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.