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Rozwój symulacji jako narzędzia w logistyce miejskiej za pomocą sztucznej inteligencji na przykładzie gry Cities: Skylines

Pajka A., Gera G.

Journal of TransLogistics

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2018

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Vol. 4, nr 1

101--108

PL

Artykuł prezentuje możliwość zastosowania sztucznej inteligencji w symulacjach jako nowego rozwiązania w celu poprawienia przepływu dóbr i osób w mieście. Pokazuje też zależność i kooperacyjność rozwoju sztucznej inteligencji z grami komputerowymi jako możliwy fundament rozwoju jej algorytmów. Omówiono także elementy gry Cities: Skylines odzwierciedlające rzeczywistość, które mogłyby pomóc w rozwoju sztucznej inteligencji. Dodatkowo omówiono temat użycia gry jako narzędzia badawczego podnoszącego świadomość problemów logistyki miejskiej wśród zwykłych uczestników ruchu codziennego w miastach zarówno tych poruszających się pieszo jak i środkami transportu publicznego bądź prywatnego.

EN

The article presents the possibility of using artificial intelligence in simulations as a new solution to improve the flow of goods and people in the city. It also shows the dependence and interaction of the development of artificial intelligence with computer games in order to develop its algorithms. The parts of the Cities: Skylines game reflecting reality these could help in the development of artificial intelligence was presented. Additionally, the topic of using game as a research instrument which improves awareness of urban logistics’ problem for common people using public or private transport was also presented.

2

Two queues with random time-limited polling

Saxena M., Boxma O., Kapodistria S., Núñez-Queija R.

Probability and Mathematical Statistics

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2017

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Vol. 37, Fasc. 2

257--289

EN

In this paper, we analyse a single server polling model with two queues. Customers arrive at the two queues according to two independent Poisson processes. There is a single server that serves both queues with generally distributed service times. The server spends an exponentially distributed amount of time in each queue. After the completion of this residing time, the server instantaneously switches to the other queue, i.e., there is no switch-over time. For this polling model we derive the steady-state marginal workload distribution, as well as heavy traffic and heavy tail asymptotic results. Furthermore, we also calculate the joint queue length distribution for the special case of exponentially distributed service times using singular perturbation analysis.

3

Heavy-traffic approximations for a layered network with limited resources

Aveklouris A., Vlasiou M., Zhang J., Zwart B.

Probability and Mathematical Statistics

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2017

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Vol. 37, Fasc. 2

497--532

EN

Motivated by a web-server model, we present a queueing network consisting of two layers. The first layer incorporates the arrival of customers at a network of two single-server nodes. We assume that the interarrival and the service times have general distributions. Customers are served according to their arrival order at each node and after finishing their service they can re-enter at nodes several times for another service. At the second layer, active servers act as jobs that are served by a single server working at speed one in a processor-sharing fashion. We further assume that the degree of resource sharing is limited by choice, leading to a limited processor-sharing discipline. Our main result is a diffusion approximation for the process describing the number of customers in the system. Assuming a single bottleneck node and studying the system as it approaches heavy traffic, we prove a state-space collapse property.

4

GI/GI/1 queues with infinite means of service time and interarrival time

Szczotka W.

Probability and Mathematical Statistics

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2016

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Vol. 36, Fasc. 2

279--293

EN

The main results deal with the GI/GI/1 queues with Infinite means of the service times and interarrival times. Theorem 3.1 gives an asymptotic, in a heavy traffic situation, of the sequence of waiting times of the consecutive customers. Theorem 4.1 gives an asymptotic of stationary waiting times in a heavy traffic situation. In a special case, the asymptotic stationary waiting times have an exponential distribution (Corollary 4.1).

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Tightness of stationary waiting times in heavy traffic for G1/G1/1 queues with thick tails

Czystołowski M., Szczotka W.

Probability and Mathematical Statistics

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2007

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Vol. 27, Fasc. 1

109--123

EN

Recently, a Heavy Traffic Invariance Principle was proposed by Szczotka and Woyczyński to characterize the heavy traffie limiting distribution of normalized stationary waiting times of G/G/X queues in terms of an appropriate convergence to a Levy process. It has two important assumptions. The first of them deals with a convergence to a Levy process of appropriate processes which is well investigated in the literature. The second one states that the sequence of appropriate normalized stationary waiting times is tight. In the present paper we characterize the tightness condition for the case of GI/GI/1 queues in terms of the first condition.

6

On global maxima in multiphase queues

Minkevicius S., Steisunas S.

Control and Cybernetics

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2005

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Vol. 34, no 2

575-588

EN

The target of this research in the queueing theory is to prove the law of the iterated logarithm (LIL) under the conditions of heavy traffic in multiphase queueing systems. In this paper, the LIL for global maxima is proved in the phases of a queueing system studied for an important probability characteristic of the system (total waiting time of a customer and waiting time of a customer).

7

Heavy-tailed dependent queues in heavy traffic

Szczotka W., Woyczyński W. A.

Probability and Mathematical Statistics

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2004

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Vol. 24, Fasc. 1

67--96

EN

The paper studies G/G/1 queues with heavy-tailed probability distributions of the service times and/or the interarrival times. It relies on the fact that the heavy traffic limiting distribution of the normalized stationary waiting times for such queues is equal to the distribution of the supremum M = sup0 ≤ t < ∞ (X(t)−βt), where X is a Lévy process. This distribution turns out to be exponential if the tail of the distribution of interarrival times is heavier than that of the service times, and it has a more complicated non-exponential shape in the opposite case; if the service times have heavy-tailed distribution in the domain of attraction of a one-sided α-stable distribution, then the limit distribution is Mittag-Leffler’s. In the case of a symmetric α-stable process X, the Laplace transform of the distribution of the supremum M is also given. Taking into account the known relationship between the heavy-traffic-regime distribution of queue length and its waiting time, asymptotic results for the former are also provided. Statistical dependence between the sequence of service times and the sequence of interarrival times, as well as between random variables within each of these two sequences, is allowed. Several examples are provided.

8

Distributions of suprema of Lévy processes via the Heavy Traffic Invariance Principle

Szczotka W., Woyczyński W. A.

Probability and Mathematical Statistics

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2003

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Vol. 23, Fasc. 2

251--272

EN

We study the relationship between the distribution of the supremum functional MX = sup0 ≤ t < ∞ (X(t) − βt) for a process X with stationary, but not necessarily independent increments, and the limiting distribution of an appropriately normalized stationary waiting time for G/G/l queues in heavy traffic. As a by-product we obtain explicit expressions for the distribution of MX in several special cases of Lévy processes.

9

Modelowanie rozprzestrzeniania się tlenku węgla w obszarze drogi o dużym natężeniu ruchu

Kamiński W., Tomczak E., Kucharski M.

Inżynieria Chemiczna i Procesowa

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2001

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T. 22, z. 3C

615--620

PL

Celem pracy było wykonanie symulacji komputerowej rozprzestrzeniania się tlenku węgla w powietrzu atmosferycznym w pobliżu ciągów komunikacyjnych aglomeracji miejskich. Pod uwagę wzięto rzeczywisty prostoliniowy odcinek drogi o dużym natężeniu ruchu (droga wylotowa z Łodzi). Wykonano obliczenia dwoma metodami i porównano uzyskane wyniki z własnymi danymi pomiarowymi.

EN

A computer simulation of carbon monoxide dispersion in the air near traffic roads was a subject of the paper. A linear real segment of the road with heavy traffic was considered (outlet road from the city of Lodz). Two methods were applied and the results obtained were compared to our experimental data.