Distribution of Decision Power among the Parties and Coalitions in the 44th Bulgarian Parliament as a Weighted Voting Game

Weighted voting games are a class of cooperative games that model group decision making systems in various domains, such as parliaments. One of the main challenges in a weighted voting game is to measure of player influence in decision making. This problem is fundamental in game theory and political science. In this paper we consider the 2017 Bulgarian Election and the distribution of decision power among the parties and coalitions in the 44th Bulgarian Parliament

The Basic Concepts On Distribution of Decision Power Between The Players and Manipulation in Weighted Voting Games

It is known that voting is a widely used method in social choice theory. In the present paper we consider some concepts of distribution of voting powers between the player and the process of manipulation in weighted voting games. The aim is to show some basic problems in social choice theory by studying the decision powers of players and the three processes of manipulation in weighted voting games: by merging of two players into a single player, by players splitting into a number of smaller units, and by annexation of a part or all of the voting weights of another player

Manipulation by Merging and Annexation in Weighted Voting Games

The problem of manipulation in voting is fundamental and has received attention in recent research in game theory. In this paper, we consider two cases of manipulation in weighted voting games done by merging of coalitions into single players and by annexation of a part or all of the voting weights of another player viewed from two perspectives: of the effect of swings of players and of the role of the Banzhaf power index. We prove two theorems for manipulation by merging and annexation, and show several attractive properties in these two processes. ACM Computing Classification System (1998): J.4, I.2.1

Serum lipid anomalies in adult patients with acute ischemic stroke

Introduction: There is rising evidence of the role of hyperlipidemia and dyslipidemia in the development of acute ischemic stroke (AIS). There is a considerable risk for AIS in adult individuals with these abnormalities. Our purpose was to reveal the incidence rate of the disorders of lipid metabolism in adult AIS patients.Material and methods: We examined 129 male and 129 female patients with AIS at a mean age of 70.59±7.22 years hospitalized in the First Clinic of Neurology, St. Marina University Hospital of Varna in 2007-2013. The serum levels of total cholesterol, triglycerides, HDL- and LDL-cholesterol at admission were examined. Statistical data processing was performed by ANOVA as t-criterion was considered significant if p<0.05.Results: The mean values of total cholesterol and LDL-cholesterol were slightly elevated while those of triglycerides were slightly reduced. The mean values of total cholesterol and triglycerides were higher in males than in females. Total cholesterol values were considerably more commonly higher in females than in males as the mean total cholesterol concentrations were higher in the female patients with normal, decreased and increased levels of this parameter. LDL-cholesterol was more commonly elevated as its mean values were higher in the female patients with its normal, decreased and increased levels.Conclusion: A regular control of the parameters of lipid metabolism and keeping-up the healthy life-style in adult individuals and in patients with cardiovascular diseases could ensure a successful prevention of ischemic stroke

Age-related metabolic disturbances in adult patients with acute ischemic stroke

INTRODUCTION. There is rising evidence of the role of hyperglycemia, hyperlipidemia and dyslipidemia in the etiopathogenesis of acute ischemic stroke (AIS). There is a considerable risk for AIS in adult individuals in advanced and senile age with these abnormalities. Our purpose was to reveal the incidence rate of the disorders of glucose and lipid metabolism in the adult patients with AIS.Material and methods. We examined 129 male and 129 female AIS patients at a mean age of 71 years hospitalized in the First Clinic of Neurology, St. Marina University Hospital of Varna, in 2007-2013. The levels of blood glucose and of serum total cholesterol, triglycerides, HDL- and LDL-cholesterol at admission were examined. Statistical data processing was performed by variation (ANOVA as t-criterion was considered significant if p<0.05) and correlation (Pearson`s coefficient) analyses.Results. Males aged ≤65 years and females aged 71-75 years presented with the highest mean blood glucose values. There are much more males with higher blood glucose concentrations than females aged ≤70 and 76-80 years. Both mean and maximal concentrations of total cholesterol were highest at the age 71-75 years, those of HDL-cholesterol - in males aged 66-70 years and those of LDL-cholesterol - in females aged 71-75 years. The differences between the mean levels of total cholesterol in males and females aged ≤65 years as well as those of LDL-cholesterol in males and females aged ≥81 years were statistically significant (p<0.01).Conclusion. A regular control of the parameters of glucose and lipid metabolism in adults is necessary. Keeping-up individual`s healthy life-style could ensure a more effective AIS prevention

Disorders of blood glucose levels in adult patients with acute Ischemic stroke

Introduction: Effective and timely prevention of acute ischemic stroke (AIS) is characterized by a rising socio-medical importance as this is the most common cerebrovascular disease worldwide and in Bulgaria as well. Our purpose was to reveal the incidence rate of the disorders of glucose metabolism in AIS development among adult patients.Material and methods: We examined 129 male and 129 female patients with AIS at a mean age of 70.59±7.22 years hospitalized in the First Clinic of Neurology, St. Marina University Hospital of Varna in 2007-2013. Blood glucose concentrations at admission were examined. Statistical data processing was performed by variation (ANOVA as t-criterion was considered significant if p<0.05) and correlation (Pearson`s coefficient) analyses.Results: Mean fasting blood glucose levels were most commonly elevated and total ones were higher in males than in females except for the minimal value. The males with abnormally elevated blood glucose values present with higher mean and maximal values than the females. The number and relative share of the patients with increased blood glucose values at admission considerably prevailed. The difference between the number of the males with increased values and that of those with normal values was statistically significant (t=3.33; p<0.01). There was moderate correlation between the level of blood glucose and the preceding diabetes mellitus (r=0.431) and a strong one between this level and the newly-diagnosed diabetes mellitus (r=0.733) among our AIS patients.Conclusion: The regular control of blood glucose by the general practitioners and the promotion of the healthy life-style in cardiovascular disease patients could successfully prevent AIS in Bulgaria

Върху паретовските множества в многокритериалната оптимизация

Здравко Д. Славов - В тази работа се разглеждат Паретовските решения в непрекъсната многокритериална оптимизация. Обсъжда се ролята на някои предположения, които влияят на характеристиките на Паретовските множества. Авторът се е опитал да премахне предположенията за вдлъбнатост на целевите функции и изпъкналост на допустимата област, които обикновено се използват в многокритериалната оптимизация. Резултатите са на базата на конструирането на ретракция от допустимата област върху Парето-оптималното множество.In this work we consider the Pareto solutions in continuous multi-criteria optimization problem. We discuss the role of some assumptions that affect the characteristics of Pareto sets. We have tried to remove the assumptions for concavity of the objective functions and convexity of the feasible domain which are usually used in multi-criteria optimization problems. The results are based on the construction of a retraction from the feasible domain onto the Pareto-optimal set. *2000 Mathematics Subject Classification: 90C29

Върху оптимално разпределените дялове в икономика с фиксирани общи ресурси

Здравко Д. Славов - В тази статия се разглежда математически модел на икономика с фиксирани общи ресурси, както и краен брой агенти и блага. Обсъжда се ролята на някои предположения за отношенията на предпочитание на икономическите агенти, които влияят на характеристиките на оптимално разпределените дялове. Доказва се, че множеството на оптимално разпределените дялове е свиваемо и притежава свойството на неподвижната точка.In this paper we consider a mathematical model of economy with fixed total resources when the numbers of agents and goods are finite. We discuss the role of some assumptions for preference relation of the economical agents that affect the characteristics of the optimal allocations. It is proved that a set of optimal allocations is contractible and has the fixed point property. *2000 Mathematics Subject Classification: 91B16

50 години Катедра „Социална медицина и организация на здравеопазването`

22 Май 201