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1.
Routing and wavelength assignment of scheduled lightpath demands 总被引:4,自引:0,他引:4
Kuri J. Puech N. Gagnaire M. Dotaro E. Douville R. 《Selected Areas in Communications, IEEE Journal on》2003,21(8):1231-1240
We present algorithms that compute the routing and wavelength assignment (RWA) for scheduled lightpath demands in a wavelength-switching mesh network without wavelength conversion functionality. Scheduled lightpath demands are connection demands for which the setup and teardown times are known in advance. We formulate separately the routing problem and the wavelength assignment problem as spatio-temporal combinatorial optimization problems. For the former, we propose a branch and bound algorithm for exact resolution and an alternative tabu search algorithm for approximate resolution. A generalized graph coloring approach is used to solve the wavelength assignment problem. We compared the proposed algorithms to an RWA algorithm that sequentially computes the route and wavelength assignment for the scheduled lightpath demands. 相似文献
2.
Adalberto Llarena Jesus Savage Angel Kuri Boris Escalante-Ramírez 《Journal of Intelligent and Robotic Systems》2012,66(1-2):75-109
This paper proposes an approach that solves the Robot Localization problem by using a conditional state-transition Hidden Markov Model (HMM). Through the use of Self Organized Maps (SOMs) a Tolerant Observation Model (TOM) is built, while odometer-dependent transition probabilities are used for building an Odometer-Dependent Motion Model (ODMM). By using the Viterbi Algorithm and establishing a trigger value when evaluating the state-transition updates, the presented approach can easily take care of Position Tracking (PT), Global Localization (GL) and Robot Kidnapping (RK) with an ease of implementation difficult to achieve in most of the state-of-the-art localization algorithms. Also, an optimization is presented to allow the algorithm to run in standard microprocessors in real time, without the need of huge probability gridmaps. 相似文献
3.
Thermoelectric Detection of Multi‐Subband Density of States in Semiconducting and Metallic Single‐Walled Carbon Nanotubes 下载免费PDF全文
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Genichi Shigesato Taishi Fujishiro Takuya Hara 《Metallurgical and Materials Transactions A》2014,45(4):1876-1882
The boron concentration profiles around prior austenite grain boundaries in Fe-0.05C-0.5Mo-0.001B (mass pct) are examined using aberration-corrected STEM-EELS. In order to obtain the precise distribution of boron around the boundaries, tilt series measurements with thin specimens (<30 nm) are performed and the EEL spectra are analyzed by principal component analysis (PCA) and multivariate curve resolution (MCR). The boron concentration profile changes with the cooling rate from the solid solution temperature. The concentration at grain boundaries is maximized at a medium rate (30 °C/s), where the concentration reaches 8 at. pct, and it decreases at a larger (250 °C/s) or smaller (5 °C/s) rate. On the other hand, the boron distribution becomes wider as the cooling rate becomes smaller. The current results suggest that the boron segregation in the alloy is formed by the “non-equilibrium segregation mechanism.” 相似文献
7.
Takayuki Sasaki Takayuki Koukami Taishi Kobayashi Akira Kirishima Hiroaki Murakami Yuki Amano 《Journal of Nuclear Science and Technology》2017,54(3):373-381
At two underground research laboratories situated at Horonobe and Mizunami, Japan, trace amounts of natural thorium and uranium dissolved in deep groundwater were investigated with the help of chemical pre-concentration method. The groundwater was sampled from underground boreholes under the geochemical condition of no atmospheric exposure, and the colloid contribution was checked by in situ two size-fractionated ultrafiltration systems. A rough decrease by half in the concentration after in situ filtration suggested the presence of natural colloids and suspended matter that were carriers of a portion of the elements. The Th and U concentrations in groundwater after 10 kDa filtration was evaluated as dissolved species, and was identified thermodynamically using existing hydrogeological and geochemical data, such as the mineral components in the groundwater at a given pH, ionic strength, concentration of co-existing ions, redox potential, and a hypothetical solubility-limiting solid phase. The crystalline solid phase of tetravalent thorium and uranium dioxides made the solubility very low compared with that of the amorphous phase. 相似文献
8.
A large amount of bandwidth has been achieved with advanced construction methods developed for ultra-high bandwidth distributed amplifiers. A 66 GHz-bandwidth GaAs device with more than 6 Vpp of voltage swing has been manufactured 相似文献
9.
Ceramics display superior properties of hardness, chemical stability and refractoriness. However, their brittleness often limits their application as engineering components. The addition of second‐phase inclusions that influence crack propagation has been exhaustively studied. One of the main toughness enhancement theories proposes it is caused by the plastic deformation of ductile inclusions during crack propagation. This article proposes a model to explain the oxidation mechanisms of niobium particles embedded in an Al2O3 matrix, based on a thermogravimetric analysis. Two types of oxidation kinetics are identified here: linear and parabolic kinetics, with activation energies of 12.4 kJ/mol and 24.9 kJ/mol, respectively. Based on our results, a kinetic model is proposed to describe the oxidation of niobium particles embedded in alumina ceramic composite matrix. 相似文献
10.
In this paper, a 60-GHz-band millimeter-wave (mm-wave) signal generation using a new 60-GHz mode-locked laser diode (MLLD) module stabilized by an optical injection will be presented. To modularize the MLLD, the precise position alignments and the fine tuning for the repetition rate is released; moreover, the output optical power of more than 6.0 dBm and the stability over nearly 1500 h are obtained. It is experimentally confirmed that the frequency and power stabilities are several tens of hertz and less than 1 dBm, respectively. The generated 60-GHz-band mm-wave signal with the 3-dB linewidth of less than 300 Hz over a 100-km-long optical fiber link is also successfully demonstrated 相似文献