No abstract

We demonstrate an optical fiber fault location method based on the frequency response of the modulated fiber optical backscattered signal in a steady state low-frequency step regime. Careful calibration and measurement allows for the reconstruction of the fiber transfer function, which, associated to its mathematical model, is capable of extracting the fiber characteristics. The technique is capable of identifying non-reflective fault events in an optical fiber link and is perfectly compatible with previous methods that focus on the reflective events. The fact that the recuperation of the complex signal is performed in the frequency domain and not via a Fourier Transform enables the measurements to overcome the spatial resolution limitation of Fourier Transform incoherent-OFDR measurements even with frequency sweep ranges down to 100-100000 Hz. This result is backed up by a less than 10 meters difference in fault location when compared to standard OTDR measurements.

No abstract

Purpose -Recent surveys indicate that transportation companies are not utilizing technology in decision making despite growing complexity of transportation systems. This paper aims to present a discrete simulation approach to benchmarking performance measures of terminal operations of less-than-truckload (LTL) freight carriers. Design/methodology/approach -The methodology involves design of heuristics for the dock assignment problem and uses discrete event simulation to evaluate performance of the various heuristics. Findings -Intelligent dock assignment for incoming trailers can greatly improve performance of LTL terminals and simulation is an effective tool to determine the effects of various assignments on terminal performance. Originality/value -The paper introduces a dock assignment heuristic and integrates the tactical level decision-making process and operational aspects in LTL terminals to evaluate the performance of the system. A case study is used to demonstrate the use of the heuristic and performance improvements.

No abstract