Current Issue : July - September Volume : 2016 Issue Number : 3 Articles : 4 Articles
The key technology and main difficulty for optical fiber intrusion pre-warning systems\n(OFIPS) is the extraction of harmful-intrusion signals. After being processed by a phase-sensitive\noptical time-domain reflectometer (-OTDR), vibration signals can be preliminarily extracted.\nGenerally, these include noises and intrusions. Here, intrusions can be divided into harmful and\nharmless intrusions. With respect to the close study of signal characteristics, an effective extraction\nmethod of harmful intrusion is proposed in the paper. Firstly, in the part of the background\nreconstruction, all intrusion signals are first detected by a constant false alarm rate (CFAR). We then\nreconstruct the backgrounds by extracting two-part information of alarm points, time and amplitude.\nThis ensures that the detection background consists of intrusion signals. Secondly, in the part of the\ntwo-dimensional Kolmogorov-Smirnov (K-S) test, in order to extract harmful ones from all extracted\nintrusions, we design a separation method. It is based on the signal characteristics of harmful\nintrusion, which are shorter time interval and higher amplitude. In the actual OFIPS, the detection\nmethod is used in some typical scenes, which includes a lot of harmless intrusions, for example\nconstruction sites and busy roads. Results show that we can effectively extract harmful intrusions....
A 3D point cloud object encryption method was proposed with this study. With the method, a mapping relationship between 3D\ncoordinates was formulated and ...
This work describes various performance trade-offs that arise from the use of a technique for optical switching under various\nnetwork topologies. Such switching operation can be summarized as follows: (a) user data are divided into fixed-length fragments,\n(b) each fragment is assigned to a different wavelength, and (c) all wavelengths are simultaneously switched to the egress links. This\nconcept of dividing user data into several wavelengths to be simultaneously switched is called wavelength striping and its purpose\nis to reduce latency and increase throughput for short distance interconnects. We depart from previous work where a building\nblock implementing this basic switching function has been built around semiconductor optical amplifiers (SOAs). In this paper, we\ninvestigate diverse trade-offs that arise from the use of this switching approach in different network topologies. One of the main\nissues addressed in this paper is the relation between cascadability and bit error rate (BER). In this case, our results indicate that\na switch fabric can cascade up to five stages without exceeding a BER of 10âË?â??9 and without incurring in power budget problems.\nWe also show that the performance degradation, introduced by cascading SOAs, can be compensated with a star interconnect\narchitecture that is introduced. Other issues addressed in this paper are the effect of scalability on cost and the effect of latency on\nTCP performance and reliability....
A multichannel heterodyne fiber optic vibrometer is demonstrated which can be operated\nat ranges in excess of 50 m. The system is designed to measure periodic signals, impacts, rotation, 3D\nstrain, and vibration mapping. The displacement resolution of each channel exceeds 1 nm. The\noutputs from all channels are simultaneous, and the number of channels can be increased by using\noptical switches....
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