ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California / There is growing concern that the U.S. military can no longer meet its domestic and international spectrum needs. Demand for this resource is growing at an exponential pace, both within the Department of Defense (DoD) and in the commercial sector (partly due to rapid growth in broadband wireless electronics). A microcosm of these challenges is evident in flight test operations, where there is a growing need for advanced spectrum assignment, frequency deconfliction, and scheduling optimization decision support capabilities. This paper describes research aimed at investigating how to optimize frequency scheduling, dynamic assignment, and real-time metrics adjustment to promote assured access to the electronic spectrum, including emerging technology developments to support that need.

ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, Nevada / This paper describes research aimed at investigating how to help decision makers devise optimized frequency scheduling and management strategies, both for advanced planning and real-time metrics adjustment. Part of these investigations include research to (i) define the metrics, objectives, and constraints involved in optimal frequency allocation decision-making; (ii) harmonize competing, orthogonal goals when devising candidate solutions; and (iii) devise an architectural strategy for dynamic spectrum allocation and management.

ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / Current real-time data communications links supporting Major Range and Test Facility Base (MRTFB) operations are one-way, dedicated links based on the IRIG 106 standard. One of the goals of the iNET program is to provide for shared, two-way networked communications links enabling more flexible operation and more efficient use of spectrum. Central to this goal is the provision for a Spectrum Assignment Manager (SAM) as referred to in the iNET architecture. The SAM element of the Resource Management Facility (RMF) works in concert with the TmNS Network Manager to support dynamic frequency assignment and real-time metrics adjustment. This paper describes the potential role, key functions, and technology elements needed to support this important function.

The C͂¹B₂ ←　X͂¹A₁ electronic transition of SeO₂ has been investigated under high resolution, at a rotational temperature of around 10 K, using the technique of Laser Excitation Spectroscopy. The vibrationally-resolved survey spectrum contained around 100 new bands in addition to the bands which had been reported in a previous study of the same region (G.W. King and P.R. McLean, J. Mol. Spec. 51, 1974). In the light of this new spectrum a number of bands have been reassigned, most significantly the O⁰₀ band, and a number of progressions have been extended. This led to a revised determination of the vibrational constants of the excited state, and a more acceptable estimate of v'₃ than was suggested in the previous work. These reassignments and extensions of existing assignments accounted for only a small fraction of the newly observed bands; those remaining are thought to be due to a different electronic transition which lies in the same region as the C͂¹B₂ ←　X͂¹A₁ transition. The 1³₀, 1²₀ and 1¹₀ bands of the C͂¹B₂ ←　X͂¹A₁ transition were also recorded at rotational resolution and analysed using the method of ground state combination differences. The 1³₀ band was found to be perturbed, which was one of the major factors which prompted the survey study described above. From the analysis of these bands the rotational constants of the excited state were determined and hence the geometry of the SeO₂ molecule in the given vibrational levels of the ¹B₂ excited state was calculated. This in turn enabled the rotational constants and the geometry of the (00) vibrational level of the excited state to be estimated. This work confirms that the symmetry of the excited state is ¹B₂ and the transition studied is C͂¹B₂ ←　X͂¹A₁. An additional band around 31957 cm⁻¹ was also recorded at rotational resolution, which was initially though to be the O⁰₀ band, on the basis of King and McLean's assignments. However in the light of the reassignments the nature of this band is not known, and attempts to assign it as vibrationally cold band of the C͂¹B₂ ←　X͂¹A₁ transition were unsuccessful, implying that it is probably either a hot band of the C͂¹B₂ ←　X͂¹A₁ transition or a band belonging to different electronic transition.

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-09-04T14:24:54Z No. of bitstreams: 1 rodrigofragadealmeida.pdf: 7192674 bytes, checksum: 6ae959161ccde060e031fade5c149253 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-09-04T15:52:10Z (GMT) No. of bitstreams: 1 rodrigofragadealmeida.pdf: 7192674 bytes, checksum: 6ae959161ccde060e031fade5c149253 (MD5) / Made available in DSpace on 2018-09-04T15:52:10Z (GMT). No. of bitstreams: 1 rodrigofragadealmeida.pdf: 7192674 bytes, checksum: 6ae959161ccde060e031fade5c149253 (MD5) Previous issue date: 2018-07-30 / A busca por fontes renováveis de energia cresce cada vez mais em diversas regiões do mundo devido a demanda crescente e pela poluição gerada pelo uso de combustíveis fósseis. A energia solar é uma fonte renovável e inesgotável de energia que pode ser aproveitada diretamente por diversos tipos de células solares. Entre estes variadostipos, as células solares sensibilizadas por corante (DSSCs em inglês) se mostram promissoras devido à sua alta eficiência. Das variadas moléculas usadas como sensibilizador neste tipo de célula, as mais eficientes são os complexos polipiridínicos de rutênio(II). Diversas propriedades são importantes para que uma molécula seja aplicável em uma DSSC como um sensibilizador eficiente, entre elas uma larga e intensa absorção na região visível e infravermelho próximo do espectro eletromagnético e um potencial redox que permita que o sensibilizador seja regenerado pelo par redox,que também faz parte da célula. Neste trabalhofoi construída uma metodologia computacional baseada em dados experimentais que leva a resultados com pequenos desviospara o cálculo de potenciais redox e espectros eletrônicosde complexos cis-[Ru(R2-phen)(dcbpy)(NCS)2], sendo dcbpy a 4,4’-dicarboxi-2,2’-bipiridina e R2-phen a 1,10-fenantrolina com substituintes R nas posições 4 e 7.Parao cálculo de potenciais redox foi aplicadaa teoria do funcional da densidade (DFT) e paraasimulação dosespectroseletrônicosa DFT dependente do tempo (TDDFT). Com esta metodologia, novos complexos foram avaliados e suas propriedades estudadas visando estimar as suas eficiências se aplicados a DSSCs. Os novos complexos que apresentaram melhores resultados,em ordem do menos para o mais promissor,são aqueles com substituintes R = 2-piridil, 2-(5-etilfuril), 2-benzotiazolil. / The search for renewable energy sources grows increasingly in many regions of the world due to the crescent demand and pollution generated by the use of fossil fuels.The solar energy is a renewable and endless source of energy, which may be harnessed directly with different types of solar cells. Among thesevaried types, the dye-sensitized solar cells (DSSCs) present themselves to be promising owing to their high efficiency. Fromthe many molecules used as sensitizers in this kind of cell, the most efficient are thepolypyridinicruthenium(II) complexes. Different properties are important for a molecule to be applicable in a DSSC as an efficient sensitizer, among them a broad and intense absorption in the visible and near infrared region of the electromagnetic spectrum and a redox potential that allows the sensitizer to be regenerated by the redox couple,that is also part of the cell. In this work wasbuilt a computational methodologybased on experimental datawhich gives results with small deviations, for the calculation of redox potentials and electronic spectra of complexes cis-[Ru(R2-phen)(dcbpy)(NCS)2], where dcbpy is the4,4’-dicarboxylic acid 2,2’-bipyridineandR2-phenthe1,10-phenanthrolinewith R substituents on the positions 4 and 7. For the calculation of redox potentials, was applied the density functional theory (DFT) and for the electronic spectra simulations, the time-dependent DFT (TDDFT). With this methodology, new complexes where evaluated and their properties studied intending to estimate their efficiencies if applied to DSSCs. The new complexes that presented better results, in order from the less to the most promising, were those with substituents R = 2-pyridyl, 2-(5-ethylfuryl) and 2-benzothiazolyl.

<p>Space-based global navigation and precision timing systems are critical for modern infrastructure. Atomic clock technology has increased the precision of these systems so that they are viable for military operations, navigation, telecommunications, and finance. Advances in optical atomic clocks, based on optical frequencies, provide an opportunity for even more precise timing. Therefore, developments in chip-scale optical atomic clock technologies could lead to increased and more wide-spread application of this precision timing. One component of the optical atomic clock is the optical frequency comb which serves as an interface between optical and microwave frequencies. This thesis will cover experiments related to these optical frequency combs. A 2$\mu$m fiber laser was developed in order to test second harmonic devices required to stabilize an optical frequency comb. The laser was then employed to measure the operating wavelengths and efficiencies of non-linear devices. In addition, an analysis of the radio frequency instruments used to evaluate microwave outputs was conducted to determine whether a digital signal analyzer (oscilloscope) or an analog electronic spectrum analyzer provides more accurate results for optical frequency comb based experiments.</p>