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Network Dimensioning with Maximum Revenue Efficiency for the Fairness Index

100%

Zalewski G. , Ogryczak W.

2016

tom nr 4

15--21

Network dimensioning is a specific kind of the resource allocation problem. One of the tasks in the network optimization is to maximize the total flow on given pairs of nodes (so-called demands or paths between source and target). The task can be more complicated when different revenue/profit gained from each unit of traffic stream allocated on each demand is taken into account. When the total revenue is maximized the problem of starvation of less attractive paths can appear. Therefore, it is important to include some fairness criteria to preserve connections between all the demands on a given degree of quality, also for the least attractive paths. In this paper, a new bicriteria ratio optimization method which takes into account both, the revenue and the fairness is proposed. Mathematical model is built in a form of linear programming. The solutions are analyzed with some statistical measures to evaluate their quality, with respect to fairness and efficiency. In particular, the Gini’s coefficient is used for this purpose.

Comparison of Selected Fair-optimization Methods for Flow Maximization between Given Pairs of Nodes in Telecommunications Network

100%

Zalewski G. , Ogryczak W.

tom nr 3

18--24

Dimensioning of telecommunications networks requires the allocation of the ows (bandwidth) to given trac demands for the source-destination pairs of nodes. Unit ow allocated to the given demand is associated with revenue that may vary for dierent demands. Problem the decision-making basic algorithms to maximize the total revenue may lead to the solutions that are unacceptable, due to "starvation" or "locking" of some demand paths less attractive with respect to the total revenue. Therefore, the fair optimization approaches must be applied. In this paper, two fair optimization methods are analyzed: the method of ordered weighted average (OWA) and the reference point method (RPM). The study assumes that ows can be bifurcated thus realized in multiple path schemes. To implement optimization model the AMPL was used with general-purpose linear programming solvers. As an example of the data, the Polish backbone network was used.

The airway obstruction - important abrupt condition for pediatrics

51%

Tomaszewski M. , Banakiewicz K. , Jajko K. , Szypowski R. , Zielinski P. , Zalewski G. , Spisacka S. , Olchowik G.

nr 1

The ability of fast response in case of increasing health problems of a child which lead directly to life-threatening situations is a necessary condition for creating opportunity of child’s survival until it will be transported to intensive care unit, where it will be provided with care by a specialist. In case of healthy children the most common cause of acute respiratory failure is obstruction of upper respiratory tract. There is an enormous variety of causes of upper airway obstruction, but the most important are the result of congenital defects, acute inflammation, anaphylactic reactions, foreign body aspiration and injuries. Consequence of the hypoventilation resulting from significant impediment of airflow through the obstructed airways is impaired gas exchange in the lungs. This leads to the increasing hypoxemia (PaO 2 <60 mmHg) and hypercapnia (PaCO2> 45 mmHg). This condition is called the total respiratory failure. The persistence of hypoventilation leads to hypoxia of vital organs (heart muscle, brain), increased anaerobic metabolism, acidosis, and inevitably to cardiac arrest as a result of homeostasis disorders. Respiratory failure is defined as acute when developing suddenly and is potentially reversible. We can find such a situation in the fast-increasing stenosis of the larynx. Symptoms of severe dyspnoea occur in a short time, but can be interrupted by an effective airway patency. Acute respiratory failure is a state of direct threat to life, which is why it is crucial to give a prompt aid to the sick child. The aim of this paper is to discuss the signs and symptoms, knowledge of which is essential for rapid identification and initial differentiation of the causes of acute upper airway obstruction in children. The principles of first-aid for children with acute respiratory failure and above all the description of life-saving procedures will be presented.