Aboard current ships, such as the DDG 51, engineering control and damage control activities are manpower intensive. It is anticipated that, for future combatants, the workload demand arising from operation of systems ...
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Aboard current ships, such as the DDG 51, engineering control and damage control activities are manpower intensive. It is anticipated that, for future combatants, the workload demand arising from operation of systems under conditions of normal steaming and during casualty response will need to be markedly reduced via automated monitoring, autonomous control, and other technology initiatives. Current DDG 51 class ships can be considered as a manpower baseline and under Condition III typical engineering control involves seven to eight watchstanders at manned stations in the Central Control Station, the engine rooms and other machinery spaces. In contrast to this manning level, initiatives such as DD 21 and the integrated engineering plant (IEP) envision a partnership between the operator and the automation system, with more and more of the operator's functions being shifted to the automation system as manning levels decrease. This paper describes some human systems integration studies of workload demand reduction and, consequently, manning reduction that can be achieved due to application of several advanced technology concepts. Advanced system concept studies in relation to workload demand are described and reviewed including. Piecemeal applications of diverse automation and remote control technology concepts to selected high driver tasks in current DDG 51 activities. Development of the reduced ship's crew by virtual presence system that will provide automated monitoring and display to operators of machinery health, compartment conditions, and personnel health. The IEP envisions the machinery control system as a provider of resources that are used by various consumers around the ship. Resource needs and consumer priorities are at all times dependent upon the ship's current mission and the availability of equipment pawnbrokers.
Recombination dynamics of localized excitons in strained cubic (c-)InxGa1−xN/GaN multiple quantum wells (MQWs) grown on 3C–SiC (001) were summarized in terms of well thickness L, InN molar fraction x, and temperature...
Recombination dynamics of localized excitons in strained cubic (c-)InxGa1−xN/GaN multiple quantum wells (MQWs) grown on 3C–SiC (001) were summarized in terms of well thickness L, InN molar fraction x, and temperature T. Photoluminescence (PL) peak energy of c-In0.1Ga0.9N/GaN MQWs showed a moderate blueshift as L decreased, and the low-temperature PL lifetime did not change remarkably by changing L. These results proved that the quantum-confined Stark effect due either to spontaneous or piezoelectric polarization was inactive in cubic polytypes. Consequently, time-resolved PL (TRPL) data of c-InGaN MQWs reflect the intrinsic exciton dynamics. The TRPL signal showed stretched exponential decay and spectral redshift with time after excitation up to 300 K. The results are fingerprints that the spontaneous emission is due to the radiative recombination of excitons localized in disordered quantum nanostructures forming extended and localized states. Effective localization depth increased with the increase in x, which gave rise to fast exciton localization. However, nonradiative lifetime in the free or extended states decreased more rapidly with the increase in x and T, giving the emission efficiency maximum at particular x around 0.1.
Bragg gratings fabricated on top of ion exchanged glass waveguides using PECVD-deposited silicon overlays are reported. The resulting Bragg gratings are characterized and transmission dips at 1536 nm in excess of 18 d...
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Infrared reflection experiments were performed on wurtzite InN films with a range of free-electron concentrations grown by molecular-beam epitaxy. Measurements of the plasma edge frequencies were used to determine ele...
Infrared reflection experiments were performed on wurtzite InN films with a range of free-electron concentrations grown by molecular-beam epitaxy. Measurements of the plasma edge frequencies were used to determine electron effective masses. The results show a pronounced increase in the electron effective mass with increasing electron concentration, indicating a nonparabolic conduction band in InN. We have also found a large Burstein-Moss shift of the fundamental band gap. The observed effects are quantitatively described by the k⋅p interaction within the two-band Kane model of narrow-gap semiconductors.
The optical properties of GaP1−xNx alloys (0.7%<~x<~2.3%) grown by gas-source molecular-beam epitaxy have been studied using photoluminescence spectroscopy under hydrostatic pressures up to 133 kbar at 30 K. The...
The optical properties of GaP1−xNx alloys (0.7%<~x<~2.3%) grown by gas-source molecular-beam epitaxy have been studied using photoluminescence spectroscopy under hydrostatic pressures up to 133 kbar at 30 K. The peak energy of the band-edge photoluminescence spectrum shows an unusual, nonmonotonic dependence on the hydrostatic pressure. The anomalous results are explained in terms of an anticrossing interaction of localized nitrogen states with the Γ band edge at low pressures and with the X band edge at large hydrostatic pressures.
Spatial coherence properties of 3 different kinds of coherent sources in extreme ultraviolet/soft x‐ray wavelength region, namely undulator, x‐ray laser and high harmonic generation source, are introduced. Advantage...
Spatial coherence properties of 3 different kinds of coherent sources in extreme ultraviolet/soft x‐ray wavelength region, namely undulator, x‐ray laser and high harmonic generation source, are introduced. Advantages of each source type and their potential applications are also discussed.
作者：
Vieira, Luis CarlosPrograma de Pós-Graduação em Engenharia Elétrica e Informática Industrial
Departamento de Eletrônica e Telecomunicações (Graduate Program in Electrical Engineering and Industrial Computer Science Department of Electronics and Telecommunications) Centro Federal de Educação Tecnológica do Paraná (Federal Center of Technological Education of Paraná) Curitiba Brazil
Photoyield changing reactions at the surface and within the gold film were characterized. It was shown that Au/Ti/sapphire provides a photocathode that is microstructurally stable to 700°C. Work on such photocath...
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Photoyield changing reactions at the surface and within the gold film were characterized. It was shown that Au/Ti/sapphire provides a photocathode that is microstructurally stable to 700°C. Work on such photocathodes demonstrated techniques that can provide further improvements for these cathodes and those made from other more reactive materials with lower work functions such as Mg and CsTe.
We report an observation of essentially full spatial coherence in a high average power soft-x-ray laser. Rapid coherence buildup due to strong refractive antiguiding in a long plasma column is experimentally demonstra...
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We report an observation of essentially full spatial coherence in a high average power soft-x-ray laser. Rapid coherence buildup due to strong refractive antiguiding in a long plasma column is experimentally demonstrated. This allows the generation of fully coherent, milliwatt-level average power soft-x-ray radiation by a tabletop device. The peak brightness of this laser reaches 2×1025photonss−1mm−2mrad−2 within 0.01% spectral bandwidth, making it one of the brightest soft-x-ray sources available.
Interband transitions in GaAs1−xNx/GaAs multiple quantum wells were studied at room temperature by photomodulated reflectance spectroscopy as a function of well width (3–9 nm), the nitrogen concentration (0.012<x&...
Interband transitions in GaAs1−xNx/GaAs multiple quantum wells were studied at room temperature by photomodulated reflectance spectroscopy as a function of well width (3–9 nm), the nitrogen concentration (0.012
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