Assurance of uniformity of measurements of spectral and dispersion characteristics in fiber-optic information transmission systems with wavelength-division multiplexing

The state and problems involved in achieving the uniformity of measurements in the field of fiber-optic information transmission systems and their components are considered. Possible approaches to the solution of these problems and the basic methods and techniques that have been developed in Russia up to this point are analyzed. __________ Translated from Izmeritel’naya Tekhnika, No. 5, pp. 30–34, May, 2006.     

An evolutionary approach to pattern-based time series segmentation

Time series data, due to their numerical and continuous nature, are difficult to process, analyze, and mine. However, these tasks become easier when the data can be transformed into meaningful symbols. Most recent works on time series only address how to identify a given pattern from a time series and do not consider the problem of identifying a suitable set of time points for segmenting the time series in accordance with a given set of pattern templates (e.g., a set of technical patterns for stock analysis). However, the use of fixed-length segmentation is an oversimplified approach to this problem; hence, a dynamic approach (with high controllability) is preferable so that the time series can be segmented flexibly and effectively according to the needs of the users and the applications. In view of the fact that this segmentation problem is an optimization problem and evolutionary computation is an appropriate tool to solve it, we propose an evolutionary time series segmentation algorithm. This approach allows a sizeable set of pattern templates to be generated for mining or query. In addition, defining similarity between time series (or time series segments) is of fundamental importance in fitness computation. By identifying the perceptually important points directly from the time domain, time series segments and templates of different lengths can be compared and intuitive pattern matching can be carried out in an effective and efficient manner. Encouraging experimental results are reported from tests that segment both artificial time series generated from the combinations of pattern templates and the time series of selected Hong Kong stocks.     

Using genetic algorithms to establish efficient walking gaits for an eight-legged robot

In the design and development of a legged robot, many factors need to be considered. As a consequence, creating a legged robot that can efficiently and autonomously negotiate a wide range of terrains is a challenging task. Many researchers working in the area of legged robotics have traditionally looked towards the natural world for inspiration and solutions, reasoning that these evolutionary solutions are appropriate and effective because they have passed the hard tests for survival over time and generations. This paper reports the use of genetically inspired learning strategies, commonly referred to as genetic algorithms, as an evolutionary design tool for improving the design and performance of an algorithm for controlling the leg stepping sequences of a walking robot. The paper presents a specific case of finding optimal walking gaits for an eightlegged robot called Robug IV and simulated results are provided.     

Using OR to adapt supply chain management best practices to humanitarian logistics

The demand for humanitarian aid is extraordinarily large and it is increasing. In contrast, the funding for humanitarian operations does not seem to be increasing at the same rate. Humanitarian logistics has the challenge of allocating scarce resources to complex operations in an efficient way. After acquiring sufficient contextual knowledge, academics can use operations research (OR) to adapt successful supply chain management best practices to humanitarian logistics. We present two cases of OR applications to field vehicle fleet management in humanitarian operations. Our research shows that by using OR to adapt supply chain best practices to humanitarian logistics, significant improvements can be achieved.     

Tribochemical transformations of glycerol

The friction process is considered in this work from the viewpoint of chemical transformations, which occur in liquid lubricating medium and on the friction surface during the friction interactions. The results of tribotechnical tests of a conventional latten brass–glycerol–steel tribosystem are given and an attempt has been made to rationalize the evolution of tribotechnical characteristics of the tribosystem in the context of tribochemistry. The results of tunneling and IR spectroscopies indicate the formation of complex organic and organometallic films on the friction surface, which differ in chemical composition from the initial lubricating medium, which proves its deep triboconversion upon friction engagement. Chromato-massspectrometry studies of the products of tribotransformations of the lubricating medium enabled its identification. Based on this identification, chemical reactions, and a general scheme according to which tribochemical transformations take place in the lubricating medium have been suggested.