Bluetooth has emerged as a viable COTS alternative for military applications involving low power wireless networks, including wireless sensor networks and personal area networks for the foot soldier. However, the reac...
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Bluetooth has emerged as a viable COTS alternative for military applications involving low power wireless networks, including wireless sensor networks and personal area networks for the foot soldier. However, the reachability of Bluetooth networks is limited by the weak error control coding used by the predefined packets. In this paper, we propose a method for improving the performance of Bluetooth by using custom error control coding in general, and turbo codes in particular. An important aspect of the proposed technique is that it is comp.iant with the Bluetooth standard, and therefore requires no hardware modifications. More specifically, the AUX1 user-defined packet is used to transport rate comp.tible punctured turbo codes (RCPT). The result, as shown by a combination of analytical/simulation results, is a dramatic increase in throughput and decrease in latency at low signal to noise ratios.
"Looking human through a camera" is a potentially powerful technique to facilitate human-comp.ter interaction. Many 2D/3D visual human tracking techniques have been introduced in area of comp.ter vision, and...
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ISBN:
(纸本)7506255715
"Looking human through a camera" is a potentially powerful technique to facilitate human-comp.ter interaction. Many 2D/3D visual human tracking techniques have been introduced in area of comp.ter vision, and applied to smart surveillance, motion analysis, interactive comp.ter graphics and virtual reality applications. For applications emphasizing real time interactivity, the visual tracking techniques need to be fast, robust, and preferably run on an inexpensive hardware system. In this paper, we present a relatively inexpensive (e.g. run on a high-end PC) but reasonably robust real time motion-tracking system based on a simple 2D color object segmentation and recognition algorithm. Users grasp color objects for achieving more exact tracking performance on their hands and make predefined motion gestures continuously. Through object segmentation processing based on color information, 2D positions of the objects are comp.ted. And then, a motion gesture corresponding on these 2D position trajectories is found by a simple correlation-based matching algorithm. Also, we demonstrate this system by applying it to a popular interactive entertainment (e.g. TETRIS).
The magnetic properties of dot arrays prepared by block copolymer lithography were investigated. The coercivity measured by alternating force magnetometry, was found to be 90 Oe at room temperature and increased on in...
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ISBN:
(纸本)0780373650
The magnetic properties of dot arrays prepared by block copolymer lithography were investigated. The coercivity measured by alternating force magnetometry, was found to be 90 Oe at room temperature and increased on increasing the scan rate, characteristic of thermally-assisted reversal. The change in the net anisotropy was due to the increased aspect ratio and crystallographic texture of the dots.
The effect of two-dimensional photonic crystal (PC) on the emission properties of a quantum well was examined. Photoluminescence was observed using a continuous wave Ti:Al2O3 emission wavelength of 785 nm. Enhanced ex...
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The effect of two-dimensional photonic crystal (PC) on the emission properties of a quantum well was examined. Photoluminescence was observed using a continuous wave Ti:Al2O3 emission wavelength of 785 nm. Enhanced extraction of light into vertical direction was obtained and this was attributed to the presence of leaky resonant states created by coherent scattering from the periodicity of PC. Scattering along high-symmetry directions provided sufficient distributed feedback for lasing to occur.
The quantum-limited timing jitter in an active, harmonically modelocked fiber laser was discused. The phase noise spectrum for the case where the modulation type was set for mostly AM was presented. The effect of AM a...
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The quantum-limited timing jitter in an active, harmonically modelocked fiber laser was discused. The phase noise spectrum for the case where the modulation type was set for mostly AM was presented. The effect of AM and PM on the jitter spectrum were studied and their result were comp.red to the noise theory.
We investigated the light-soaked behaviors of hydrogen diluted amorphous silicon films and solar cells using the films as active layers. The films were fabricated at various hydrogen dilution ratios by using a mercury...
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We investigated the light-soaked behaviors of hydrogen diluted amorphous silicon films and solar cells using the films as active layers. The films were fabricated at various hydrogen dilution ratios by using a mercury-sensitized photo-chemical vapor deposition system. We found a moderate hydrogen dilution ratio where the stable phase protocrystalline silicon, a transient material prepared just before onset of microcrystalline regime, can be obtained. We observed that the films prepared at the onset of microcrystalline regime is unstable in spite of the facts that the films have i) more blue-shifted amorphous TO phonon bands;ii) nano-sized crystalline silicon grains;and iii) lower broadening parameters (C) in comp.rison with protocrystalline silicon. We claim two new facts from our experiments: i) the relatively high stability of the protocystalline silicon is attributed to the densest amorphous silicon network structure;ii) the decreased stability at the onset of microcrystallization is due to clustered hydrogen bonds accomp.nied by high atomic hydrogen content.
In this paper we propose a method for creating animation and animation-like video sequences from about any ordinary video recorded by any means available. The method is based on the Paintbrush Transformation earlier i...
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The emergence of silicon carbide- (SiC-) based power semiconductor switches, with their superior features comp.red with silicon- (Si-) based switches, has resulted in substantial improvement in the performance of powe...
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The emergence of silicon carbide- (SiC-) based power semiconductor switches, with their superior features comp.red with silicon- (Si-) based switches, has resulted in substantial improvement in the performance of power electronics converter systems. These systems with SiC power devices have the qualities of being more comp.ct, lighter, and more efficient;thus, they are ideal for high-voltage power electronics applications such as a hybrid electric vehicle (HEV) traction drive. More research is required to show the impact of SiC devices in power conversion systems. In this study, findings of SiC research at Oak Ridge National Laboratory (ORNL), including SiC device design and system modeling studies, will be discussed.
Purpose: Electrophysiological investigations of the short-wavelength sensitive pathway of the human eye require the use of a suitable light source as a S-cone stimulator. Different light sources with their spectral di...
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Purpose: Electrophysiological investigations of the short-wavelength sensitive pathway of the human eye require the use of a suitable light source as a S-cone stimulator. Different light sources with their spectral distribution properties were investigated and comp.red with the ideal S-cone stimulator. Methods: First, the theoretical background of the calculation of relative cone energy absorption from the spectral distribution function of the light source is summarized. From the results of the calculation, the photometric properties of the ideal S-cone stimulator will be derived. The calculation procedure was applied to virtual light sources (comp.ter generated spectral distribution functions with different medium wavelengths and spectrum widths) and to real light sources (blue and green light emitting diodes, blue phosphor of CRT-monitor, multimedia projector, LCD monitor and notebook display). The calculated relative cone absorbencies are comp.red to the conditions of an ideal S-cone stimulator. Results: Monochromatic light sources with wavelengths of less than 456 nm are close to the conditions of an ideal S-cone stimulator. Spectrum widths up to 21 nm do not affect the S-cone activation significantly (S-cone activation change < 0.2%). Blue light emitting diodes with peak wavelength at 448 nm and spectrum bandwidth of 25 nm are very useful for S-cone stimulation (S-cone activation ≈95%). A suitable display for S-cone stimulation is the Trinitron comp.ter monitor (S-cone activation ≈87%). The multimedia projector has a S-cone activation up to 91%, but their spectral distribution properties depends on the selected intensity. LCD monitor and notebook displays have a lower S-cone activation (≤ 74%). Conclusion: Carefully selecting the blue light source for S-cone stimulation can reduce the unwanted L- and M-cone activation down to 4% for M-cones and 1.5% for L-cones.
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