Fuzzy logic based algorithms for maximum covering location problems

This paper concerns a class of maximum covering location problems in networks in uncertain environments. It is assumed that (a) relative weights of demand nodes are either deterministic or imprecise, described by linguistic expressions and (b) potential facility site locations are limited to network nodes. The concept of coverage is extended to include a degree of node coverage which means that the borders between the subset of covered demand nodes and the subset of uncovered demand nodes are inexact. The acceptable service distance/travelling times from a facility site to demand nodes are modelled by fuzzy sets. Three new algorithms for choosing the best facility locations are developed which assume that (1) demands at all nodes are equally important, (2) relative weights of demand at nodes are deterministic and (3) weights of demand at nodes are imprecise and described by linguistic terms, respectively. The algorithms are based on searching among potential facility nodes by applying comparison operations on discrete fuzzy sets. It is shown how to extend the proposed algorithms from one-site to multi-site covering problems. Illustrative examples of selecting locations for logistics centres in a distribution company are given.     

The serotonin uptake-enhancing drug tianeptine suppresses asthmatic symptoms in children: a double-blind, crossover, placebo-controlled study

Studies have shown that levels of free serotonin in plasma are increased in symptomatic patients with asthma. In addition, the concentration of free serotonin in symptomatic patients with asthma correlates positively with clinical status and negatively with pulmonary function. Thus, reducing the concentration of free serotonin in plasma might be useful in treating patients with asthma. We studied the effectiveness of tianeptine in treating patients with asthma. Tianeptine is the only drug known to be able to reduce levels of free serotonin in plasma and to enhance uptake by platelets. In this study, 69 children with asthma were assigned in randomized fashion to receive tianeptine and/or placebo in a double-blind crossover trial that lasted 52 weeks. Tianeptine provoked a dramatic and sudden decrease in both clinical rating and free serotonin plasma levels and an increase in pulmonary function.     

Characteristics of optical recording on thin films of quaternary glasses Cu-As-Se-I

The characteristics of optical recording and changes in the hologram parameters of the amorphous quaternary system Cu-As-Se-I are described. The dependence of the relative contrast of recording on the exposure and transparency properties of the film before and after erasure is the basis for discussion of these processes. Investigation into the dependence of diffraction efficiency of the holograms indicates that these quantities are determined by the thin film composition.     

Formation of scawtite from mixtures of CaO,magnesite and quartz under hydrothermal conditions

The phase composition of samples prepared under hydrothermal conditions at 200°C from a suspension of mixtures of CaO, quartz and magnesite has been studied. When 10, 20, 30 and 50 wt % of CaO were substituted by magnesite, the mole ratio CaO/SiO₂ being 0,83 and 1,20 - chiefly tobermorite, gyrolite and calcite or scawtite and tobermorite were formed, and the strength of the tested materials was observed to decrease.     

Power spectrum of the balanced digital signal generated by Markov source

A class of balanced digital signals generated by 2N-state Markov source defined. It is shown that the power spectrum of this class of signals can be determined by the same algorithm as for the ordinary digital signal generated by Markov source, but with a benefit that the calculation procedure requires a matrix algebra in which the vectors and matrices have size N instead of 2N.     

Representation of IF-probability on MV-algebras

A probability theory on IF-events has been constructed by Grzegorzewski and Mrówka in [2] and axiomatically characterized by B. Riečan in [6]. More general situation was studied by B. Riečan in [5]. He introduced the IF-probability, which is decomposed onto two probabilities on Lukasiewicz tribe. The aim of this paper is to define the IF-probability and IF-observable on MV-algebras. We show that some known results of [7] can be applied also for these IF-events.     

Controller order reduction for robust control of parallel operating dc/dc converters

 A useful straightforward controller order reduction procedure for multivariable robust control is presented. Reduced controllers regarding robust stability criterion and robust performance criterion are developed. Weighted Balanced Truncation is used as the concept for the real reduction work. The procedure is applied to Loop Shaping Design Procedure, Internal Model Control and Decentralized robust controllers of parallel operating dc/dc converters. Uncertainty robustness and performance of the closed-loop systems with reduced controllers are investigated. The reduction procedure efficiently decreases high controller orders, from which robust theory suffers, preserving at the same time closed-loop robust stability and robust performance at a desired level.