A survey of the maps found in the social studies classrooms of the secondary schools of central Massachusetts

Thesis (Ed.M.)--Boston Universit

Smoothed Analysis of the Minimum-Mean Cycle Canceling Algorithm and the Network Simplex Algorithm

The minimum-cost flow (MCF) problem is a fundamental optimization problem with many applications and seems to be well understood. Over the last half century many algorithms have been developed to solve the MCF problem and these algorithms have varying worst-case bounds on their running time. However, these worst-case bounds are not always a good indication of the algorithms' performance in practice. The Network Simplex (NS) algorithm needs an exponential number of iterations for some instances, but it is considered the best algorithm in practice and performs best in experimental studies. On the other hand, the Minimum-Mean Cycle Canceling (MMCC) algorithm is strongly polynomial, but performs badly in experimental studies. To explain these differences in performance in practice we apply the framework of smoothed analysis. We show an upper bound of $O(mn^2\log(n)\log(\phi))$ for the number of iterations of the MMCC algorithm. Here $n$ is the number of nodes, $m$ is the number of edges, and $\phi$ is a parameter limiting the degree to which the edge costs are perturbed. We also show a lower bound of $\Omega(m\log(\phi))$ for the number of iterations of the MMCC algorithm, which can be strengthened to $\Omega(mn)$ when $\phi=\Theta(n^2)$. For the number of iterations of the NS algorithm we show a smoothed lower bound of $\Omega(m \cdot \min \{ n, \phi \} \cdot \phi)$.Comment: Extended abstract to appear in the proceedings of COCOON 201

Nonzero-sum Stochastic Games

This paper treats of stochastic games. We focus on nonzero-sum games and provide a detailed survey of selected recent results. In Section 1, we consider stochastic Markov games. A correlation of strategies of the players, involving ``public signals'', is described, and a correlated equilibrium theorem proved recently by Nowak and Raghavan for discounted stochastic games with general state space is presented. We also report an extension of this result to a class of undiscounted stochastic games, satisfying some uniform ergodicity condition. Stopping games are related to stochastic Markov games. In Section 2, we describe a version of Dynkin's game related to observation of a Markov process with random assignment mechanism of states to the players. Some recent contributions of the second author in this area are reported. The paper also contains a brief overview of the theory of nonzero-sum stochastic games and stopping games which is very far from being complete

Belarusian as an endangered language: can the mother tongue of an independent state be made to die?

Jerzy J. Smolicz and Ryszard Radzi

On a book Game Theory and Its Applications by Akio Matsumoto and Ferenc Szidarovszky

Prezentowana książka to wykład z teorii gier i jej zastosowań napisany przystępnie, z pokazaniem wykorzystania nowych narzędzi informatycznych do rozwiązywania szerokiej rozumianych problemów powstających przy modelowaniu metodami teorii gier. Zawiera szeroki wachlarz aplikacji do modelowania gier w wielu różnych dziedzinach. Autorzy skupili się na integracji podstaw, metodologii i głównych dziedzin zastosowań gier kooperacyjnych i niekooperacyjnych, w tym  antagonistycznych. Tematy omawiane w książce to gry dyskretne i ciągłe, w tym gry w postaci rozwiniętej, gry macierzowe i dwumacierzowe, koncepcje rozwiązań kooperacyjnych, gry w warunkach niepewności, gry dynamiczne i antagonistyczne. Metodologię ilustrują starannie wyselekcjonowane przykłady zastosowań modeli teorii gier, wybrane zagadnienia z ekonomii, nauk społecznych, inżynierii, bezpieczeństwa oraz modele militarne. Można książkę polecić czytelnikom, którzy są zainteresowani pogłębieniem metodologii oraz matematycznej teorii modelowania konfliktów i koncepcji rozwiązań dla takich zagadnień. Jest skierowany do uczestników studiów interdyscyplinarnych na poziomie magisterskim i doktorów prowadzących badania interdyscyplinarne. The book under review presents the serious theoretical development of the game models in an easy-to-follow style and provides computer methodology to solve a broad class of problems. It includes a wide range of game modeling applications in many different areas. The authors have focused on integration the fundamentals, methodology, and major application fields of non-cooperative and cooperative games including conflict resolution. The topics addressed in the book are discrete and continuous games including games represented by finite trees; matrix and bimatrix games as well as oligopolies; cooperative solution concepts; games under uncertainty; dynamic games and conflict resolution. The methodology is illustrated by carefully chosen examples, applications and case studies which are selected from economics, social sciences, engineering, the military and homeland security. This book is highly recommended to readers who are interested in the in-depth and up-to-date integration of the theory and ever-expanding application areas of game theory. It is addressed to interdisciplinary graduate/ undergraduate students and to interdisciplinary young researchers

Algorithm of steady-state direct determination for synchronous machines accounting for motion equation by harmonic balance method

The paper presents an iterative algorithm for direct determination of steady-state solutions in AC machines for performances when the equation of mechanical motion can of be neglected. In such cases electromagnetic and mechanic phenomena are strongly related what reflects as perturbances of angular velocity of a rotor. It happened when mechanical or electromagnetic torques have an alternating component. Nonlinear character of equations describing such performances leads to essential difficulties of finding the steady-state solutions. The algorithm is presented by a case study of a synchronous motor loaded by a torque with an alternating component. It is assumed that in steady-state a motor run synchronously but in the angular velocity appears periodic perturbations. In that case the steady-state can be found by the harmonic balance method. The paper shows how to do it

Improved algorithm for periodic steady-state analysis in nonlinear electromagnetic devices

This paper presents the improved methodology for the direct calculation of steady-state periodic solutions for electromagnetic devices, as described by nonlinear differential equations, in the time domain. A novel differential operator is developed for periodic functions and the iterative algorithm determining periodic steady-state solutions in a selected set of time instants is identified. Its application to steady-state analysis is verified by an elementary example. The modified algorithm reduces the complexity of steady-state analysis, particularly for electromagnetic devices described by high-dimensional nonlinear differential equations

Analysis of synchronous machine at load torque perturbations bound up with angle of rotation

This paper presents an algorithm for direct determination of steady-state solutions of synchronous machine equations when some perturbations occur in a mechanical load and bound up with angle of rotation. Algorithm allows to determine directly, precisely and clearly the Fourier spectra of machine currents and angular velocity. Exemplary computations are done for a synchronous motor running synchronously and loaded by a mechanical torque with a periodic ac component