Semiconductor optical amplifier for CWDM operating over 1540-1620 nm

A semiconductor optical amplifier was developed for coarse wavelength-division-multiplexing (CWDM) operating over 1540-1620 nm (C-L band). A unique quantum-well structure was designed to meet the requirements for the CWDM operation such as wide bandwidth, low polarization-dependent gain, and high-saturation power at the short wavelength end of the band (1540 nm). Over the band, 24-dB maximum chip gain was obtained with less than 4.3-dB gain flatness and more than 14.6-dBm saturation power.     

Scaling System-Level Science: Scientific Exploration and IT Implications

The study and creation of the infrastructure required to enable system-level science--the integration of diverse sources of knowledge about the constituent parts of a complex system with the goal of obtaining an understanding of the system's properties as a whole--is becoming increasingly important, spawning new knowledge in variety of fields at a rapid pace.     

Determination of siphon operating regimes

Necessary and sufficient conditions are found for continuous and periodic liquid motion in systems containing siphons.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 52, No. 6, pp. 916–920, June, 1987.     

Reconstruction of the friction units of turbine guide vanes

Conclusions After the almost 2-yr operation of the gate apparatus since the start of reconstruction of friction units of the vanes, we can make a preliminary evaluation of the effectiveness of the works:There is practically no leakage of water through the gate vanes to the turbine cover, which led to a complete unloading of the drainage pumps on the turbine cover and the efficiency of operating the gate apparatus increased considerably.Repair of the gate apparatus is not required during maintenance.There is no vibration of the gate vanes, since the gaps in the friction units of the journals of the gate vanes are minimum and stable.The operating personnel objectively evaluate highly the work of the gate apparatus of the turbine after reconstruction and will continue this work on the remaining turbines.Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 9, pp. 12–14, September, 1985.     

Changing the hydrogen content of alloy steel in relation to the technology used to cool cast slabs

Results are reported from the production of two trial heats of alloy steel in which the cast slabs were cooled in a thermostatted chamber and in a dense stack. It is shown that cooling slabs in such a chamber makes it possible to reduce the hydrogen content of the steel 30% compared to slabs that are cooled while stacked.     

Time-series detection of perspiration as a liveness test in fingerprint devices

Fingerprint scanners may be susceptible to spoofing using artificial materials, or in the worst case, dismembered fingers. An anti-spoofing method based on liveness detection has been developed for use in fingerprint scanners. This method quantifies a specific temporal perspiration pattern present in fingerprints acquired from live claimants. The enhanced perspiration detection algorithm presented here improves our previous work by including other fingerprint scanner technologies; using a larger, more diverse data set; and a shorter time window. Several classification methods were tested in order to separate live and spoof fingerprint images. The dataset included fingerprint images from 33 live subjects, 33 spoofs created with dental material and Play-Doh, and fourteen cadaver fingers. Each method had a different performance with respect to each scanner and time window. However, all the classifiers achieved approximately 90% classification rate for all scanners, using the reduced time window and the more comprehensive training and test sets.