Ograniczanie wyników
Czasopisma help
Autorzy help
Lata help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 117

Liczba wyników na stronie
first rewind previous Strona / 6 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  game theory
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 6 next fast forward last
EN
We consider a communication network routing problem wherein a number of users need to efficiently transmit their throughput demand in the form of data packets (incurring less cost and less delay) through one or more links. Using the game theoretic perspective, we propose a dynamic model which ensures unhindered transmission of data even in the case where the capacity of the link is exceeded. The model incorporates a mechanism in which users are appropriately punished (with additional cost) when the total data to be transmitted exceeds the capacity of the link. The model has multiple Nash equilibrium points. To arrive at rational strategies, we introduce the concept of focal points and get what is termed focal Nash equilibrium (FNE) points for the model. We further introduce the concept of preferred focal Nash equilibrium (PFNE) points and find their relation with the Pareto optimal solution for the model.
EN
Purpose: The purpose of the paper is to illustrate the usage of techniques known from chaos theory to analyze the risk Design/methodology/approach: In this case the objects of application are winnings graphs of different poker players. Two types of players are presented; winning players (those with positive expected value) and breaking even players (expected value close to zero). Findings: Charts were analyzed with a fractal dimension calculated with the box method. Originality/value: Relation between fractal dimension and Hurst exponent is shown. Relation between risk in sense of chaos theory and players’ long-term winning is also described. Further applications of chaos theory to analyze the risk in games of chance are also proposed.
EN
Nowadays, the container shipping industry in Indonesia has a tendency to oligopoly, even in one shipping route. Two big shipping liners in Indonesia, PT. X and PT. Y, have been dominating sales on the Surabaya-Banjarmasin route. The aim of this study is to know how the liners behave in an oligopoly, making decisions that are profitable for both parties. The agreement on challenge, competition, and cooperation between PT. X and PT. Y in serving shipping services is the main focus in this study. The methodology used is a game theory approach to show the possible strategies in rates and supply competition. The result shows that the agreement between PT. X and PT. Y consisted of price decision and supply quantity. The price decision is rated at a lower price of USD 300/TEU where P = MC which has no incentive. While the agreement on supply quantity is 26.000 TEUs in total. Moreover, the cooperative agreement between the shipping liners is a joint allience which not depend on each capacity ratio.
EN
The paper presents a mathematical model of a positional game of the safe control of a vessel in collision situations at sea, containing a description of control, state variables and state constraints as well as sets of acceptable ship strategies, as a multi-criteria optimisation task. The three possible tasks of multi-criteria optimisation were formulated in the form of non-cooperative and cooperative multi-stage positional games as well as optimal non-game controls. The multicriteria control algorithms corresponding to these tasks were subjected to computer simulation in Matlab/Simulink software based on the example of the real navigational situation of the passing of one’s own vessel with eighteen objects encountered in the North Sea.
EN
A method of the finite approximation of continuous non-cooperative two-person games is presented. The method is based on sampling the functional spaces, which serve as the sets of pure strategies of the players. The pure strategy is a linear function of time, in which the trend-defining coefficient is variable. The spaces of the players’ pure strategies are sampled uniformly so that the resulting finite game is a bimatrix gamewhose payoff matrices are square. The approximation procedure starts with not a great number of intervals. Then this number is gradually increased, and new, bigger, bimatrix games are solved until an acceptable solution of the bimatrix game becomes sufficiently close to the same-type solutions at the preceding iterations. The closeness is expressed as theabsolute difference between the trend-defining coefficients of the strategies from the neighboring solutions. These distances should be decreasing once they are smoothed with respective polynomials of degree 2.
EN
The peculiarity of the transit freight transportation by rail in international traffic is the fact that while performing transportation, the railway administrations are in competition among themselves. At the same time, the routes of cargo traffic volumes significantly depend on the conditions of transportation by railways of individual states. The mathematical model for the distribution of transit freight traffic volumes on the railway network, based on the methods of graph theory and game theory, was proposed in this article. The developed model enables the evaluation of the possibilities of attracting transit freight traffic volumes by individual railway administrations by changing the tariff value and transportation conditions.
EN
Most of real-life problems, including design, optimization, scheduling and control, etc., are inherently characterized by multiple conflicting objectives, and thus multi-objective linear programming (MOLP) problems are frequently encountered in the literature. One of the biggest difficulties in solving MOLP problems lies in the trade-off among objectives. Since the optimal solution of one objective may lead other objective(s) to bad results, all objectives must be optimized simultaneously. Additionally, the obtained solution will not satisfy all the objectives in the same satisfaction degree. Thus, it will be useful to generate a set of compromise solutions in order to present it to the decision maker (DM). With this motivation, after determining a modified payoff matrix for MOLP, all possible ratios are formed between all rows. These ratio matrices are considered a two person zero-sum game and solved by linear programming (LP) approach. Taking into consideration the results of the related game, the original MOLP problem is converted to a single objective LP problem. Since there exist numerous ratio matrices, a set of compromise solutions is obtained for MOLP problem. Numerical examples are used to demonstrate this approach.
EN
A problem of simultaneously reducing a group of interval uncertainties is considered. The intervals are positively normalized. There is a constraint, by which the sum of any point estimates taken from those intervals is equal to 1. Hence, the last interval is suspended. For mapping the interval uncertainties into point estimates, a minimax decision-making method is suggested. The last interval’s point estimate is then tacitly found. Minimax is applied to a maximal disbalance between a real unknown amount and a guessed amount. These amounts are interpreted as aftermaths of the point estimation. According to this model, the decision-maker is granted a pure strategy, whose components are the most appropriate point estimates. Such strategy is always single. Its components are always less than the right endpoints. The best mapping case is when we obtain a totally regular strategy whose components are greater than the left endpoints. The irregular strategy’s components admitting many left endpoints are computed by special formulae. The worst strategy exists, whose single component is greater than the corresponding left endpoint. Apart from the point estimation, irregularities in the decision-maker’s optimal strategy may serve as an evidence of the intervals’ incorrectness. The irregularity of higher ranks is a criterion for correcting the intervals.
9
Content available remote Best response dynamics for VLSI physical design placement
EN
The physical design placement problem is one of the hardest and most important problems in micro chips production. The placement defines how to place the electrical components on the chip. We consider the problem as a combinatorial optimization problem, whose instance is defined by a set of $2$-dimensional rectangles, with various sizes and wire connectivity requirements. We focus on minimizing the placement area and the total wire length.
EN
In this paper, resource allocation technique for LTE femtocell network in licensed and unlicensed bands is proposed. Additionally, allocation of wireless resources to each mobile user in the Wi-Fi band occurs in parallel with the bandwidth allocation between competing users in LTE. To improve the performance of femtocells, a heuristic algorithm based on Kalai-Smorodinsky solution of bargaining problem is presented. The numerical simulation conf rms the correctness of the adopted mode.
PL
W artykule zaproponowano technike przydzielania zasobów dla sieci femtokomórkowej w licencjonowanych i nielicencjonowanych pasmach. Ponadto przydzielanie zasobów bezprzewodowych każdemu użzytkownikowi mobilnemu w paśmie Wi-Fi odbywa się równolegle z alokacją szerokości pasma pomiędzy konkurującymi użytkownikami w LTE. W artykule przedstawiono heurystyczny algorytm oparty na schemacie arbitrażowym Kalai-Smorodinsky'ego dla przetargu. Symulacja numeryczna potwierdza poprawność przyjętej metody alokacji zasobów.
EN
Heterogeneous wireless networks is a term referring to networks combining different radio access technologies with the aim of establishing the best connection possible. In this case, users with multi-mode terminals can connect via different wireless technologies, such as 802.16, 802.11, UMTS, HSPA and LTE, all at the same time. The problem consists in the selection of the most suitable from all radio access technologies available. The decision process is called network selection, and depends on several parameters, such as quality of service, mobility, cost, energy, battery life, etc. Several methods and approaches have been proposed in this context, with their objective being to offer the best QoS to the users, and/or to maximize re-usability of the networks. This paper represents a survey of the network selection methods used. Multiple attribute-dependent decision-making methods are presented. Furthermore, the game theory concept is illustrated, the use of the fuzzy logic is presented, and the utility functions defining the network selection process are discussed.
EN
The study here presented pertains to the analysis of mutual interactions of the monetary and fiscal policies in the case of Poland. The historical policies carried out during different periods of time and their economic effects are compared with the possible strategies, obtained from the analysis of the proposed monetaryfiscal game. In the study, the methods of non-cooperative game theory are combined with macroeconomic modeling. The respective game is formulated for monetary and fiscal authorities as players. Strategies of these players refer to the respective instruments of their policies: the real interest rate and the budget deficit in relation to GDP. Payoffs include inflation and GDP growth, respectively. The payoffs are calculated using a recursive macroeconomic model estimated for the Polish economy. The model describes influences of the instruments of the monetary and fiscal policies on the state of the economy. The best response strategies, the Nash equilibria and Pareto optimality are analyzed. Changes of the policies towards the more restrictive or more expansive ones and their effects in comparison to the historically applied are discussed. This is performed for two different time periods – the time of recovery after 2004 and the time of the global financial crisis after 2008.
PL
Założenie, że każdy uczestnik ruchu drogowego przestrzega przepisów, idealnie dostosowuje swoje zachowanie do warunków panujących na drodze, jest nierealistyczne, a jako podstawa podejmowania działań może doprowadzić do kolizji i wypadku. W artykule przedstawiono modele teoriogrowe pozwalające zrozumieć zachowania kierowców, którzy umyślnie wymuszają pierwszeństwo przejazdu, a ich jedyną motywacją jest jak najkrótszy czas przejazdu przez skrzyżowanie. Rozważane są dwa rodzaje sytuacji na skrzyżowaniach: z ruchem kierowanym i niekierowanym ze znakiem STOP. Przedstawione modele matematyczne zilustrowano dostępnymi w Internecie nagraniami rzeczywistych zachowań kierowców.
EN
The assumption that each road participant adheres to the rules, ideally adapts his behavior to the prevailing road conditions, is unrealistic, and as the basis for taking action can lead to collisions and accidents. The article presents the theoretical models allowing to understand the behavior of drivers who deliberately enforce the priority of passing, and their only motivation is the shortest travel time through the intersection. Two types of situations at crossroads are considered: with guided and non-guided traffic with the STOP sign. The presented mathematical models are illustrated by the real-life recordings of drivers available on the Internet.
14
PL
W artykule podjęto problem opracowania koncepcji rozproszonego zarzą- dzania popytem energii elektrycznej w mikrosieciach niskiego napięcia z użyciem algorytmu wykorzystującego elementy teorii gier. Takie rozwiązanie może być stosowane jako podstawowy sposób bilansowania mocy czynnej oraz jako system awaryjny w przypadku przejścia sieci w tryb pracy izolowanej lub w inteligentnych sieciach elektroenergetycznych w sytuacji utraty komunikacji pomiędzy sterownikami.
EN
The article discusses the problem of developing a concept of fully distributed Demand Side Management in a low-voltage microgrid, using an algorithm based on game theory. The following solution can be used as a primary method to maintain the balance of active power and as a backup system in a case of switching the microgrid to isolated mode, and also in Smart Power Grid in a situation where there is a loss of communication between the controllers.
EN
In this paper, a new power control scheme for cognitive LTE-femtocell networks based on game theory is proposed. The problem is formulated as a coalition graph game problem to maximise throughput and system fairness. Then, a heuristic low-complexity algorithm to solving so presented problem is given. Simulation results have validated that the proposed scheme is effective in managing the cognitive femtocell network.
PL
W tym artykule proponuje się nowy schemat kontroli mocy dla sieci kognitywnych femtokomórek LTE oparty o teorię gier. Problem jest sformułowany jako gra koalicyjna, maksymalizująca przepustowość i sprawiedliwość systemu. Następnie, przedstawiono heurystyczny algorytm o małej złożoności dla rozwiązanie tego problemu. Wyniki symulacji potwierdziły, że proponowany schemat jest efektywny dla zarządzanie femtokomórką kognitywną LTE.
EN
In Mobile Ad-hoc Networks, nodes exchange packets with each other using intermediate nodes as relays. Since nodes in MANETs are battery powered, energy conservation is a crucial issue. Accepting relay all request may not be in the best interest of a node. But if many nodes prefer not to consume energy in relaying packets on behalf of others, the overall performance of routing in network will be influenced. In this paper we address the energyefficient routing problem in MANETs with selfish nodes. We modeled this problem as a game-theoretic constraint optimization; we defined the utility of each node as a weighted difference between a performance metric and some transmission costs. A motivate mechanism is proposed in order to induce nodes to forwarding cooperation. Each node independently implements the optimal equilibrium strategy under the given constraints. Simulation results by NS3 simulator show that our proposed approach can improve system performance in network lifetime and packet delivery ratio.
17
PL
W artykule przedstawiono uproszczony model procesu rozgrywającego sterowania statkiem w sytuacjach kolizyjnych na morzu w postaci wielokrokowej gry macierzowej j obiektów sterowania. Sformułowano macierz gry zawierającą wartości ryzyka kolizji obliczone na podstawie informacji z systemu antykolizyjnego ARPA, dla dopuszczalnych strategii własnego statku i poszczególnych j spotkanych statków. Do rozwiązania zadania bezpiecznego i optymalnego sterowania statkiem wykorzystano metodę dualnego programowania liniowego. Rozważania zilustrowano komputerową symulacją wyznaczania bezpiecznej trajektorii własnego statku w rzeczywistej sytuacji nawigacyjnej na morzu podczas mijania się z wieloma spotkanymi statkami.
EN
The paper describes an approximated model of the process game ship control in collision situations at sea as the model of multi-step matrix game of j control objects. Formulated game matrix containing a collision risk calculated on the basis of information from the ARPA anti-collision system, for permissible strategies of own ship and individual j met ships. To solve the task safe and optimal control of the ship used method of dual linear programming. These considerations have been illustrated with a computer simulation of determining own safe ship trajectory in situation at sea during passing many ships.
18
Content available remote Model symulacyjny procesu bezpiecznego sterowania ruchem statku
PL
W artykule przedstawiono dokładny model ruchu statków na morzu, w postaci modelu gry różniczkowej j obiektów sterowania, uwzględniający ich kinematykę i dynamikę oraz warunki nieokreśloności i konfliktu, przy nie ścisłym współdziałaniu według zasad międzynarodowego prawa drogi morskiej MPDM. Podano nieliniowe równania stanu procesu, nieliniowe i zmienne w czasie ograniczenia stanu i sterowania oraz kryterium jakości sterowania rozgrywającego w postaci wypłaty całkowej i końcowej. W części końcowej przedstawiono wyniki komputerowej symulacji modelu dla manewru antykolizyjnego zmiany kursu własnego statku.
EN
The paper presents an accurate model of ships traffic, in the form of differential game model of j control objects, in view of their kinematics and dynamics and conditions of uncertainty and conflict, with no close cooperation according to the principles of international collision regulations COLREG. Given the non-linear equations of state of the process, non-linear and time varying constraints the state and control variables and the index of quality control in the form of integral and final payment. The final section presents the results of a computer simulation model for anti-collision maneuver to change the own ship course.
EN
This paper addresses the problem of navigating an autonomous vehicle using environmental dynamics prediction. The usefulness of the Game Against Nature formalism adapted to modelling environmental prediction uncertainty is discussed. The possibility of the control law synthesis on the basis of strategies against Nature is presented. The properties and effectiveness of the approach presented are verified by simulations carried out in MATLAB.
PL
W pracy przedyskutowano przydatność modelu gier przeciwko naturze do modelowania niepewności predykcji stanu otoczenia sterowanego pojazdu. Pokazano możliwość syntezy prawa sterowania realizującego bezkolizyjny ruch pojazdu w dynamicznym środowisku na bazie strategii gry przeciwko naturze. Działanie oraz efektywność proponowanego podejścia zweryfikowano za pomocą symulacji przeprowadzonych w środowisku MATLAB.
EN
This paper addresses the problem of collision free motion planning of a vehicle in a dynamical environment. The usefulness of the game against nature for modeling environmental prediction uncertainty was discussed. The possibility of the control law synthesis on the basis of strategies against nature was presented. The properties and effectiveness of the approach presented were verified by simulations carried out in MATLAB.
first rewind previous Strona / 6 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.