Operations research and queue theory have many different applications, providing tremendous value for different organizations. With the rise of fast computers and better data, stochastic processes can be better modeled into simulations to provide results of higher quality. The application of Operations Research is a very interesting intersection of mathematics, statistics, computer science and management science. In this project, the benefits of using point wise stationary approximations and stationary independent period by period approximationsto simulate staffing requirements at LAX (Los Angeles International Airport) in conjuction are examined with the motivation of reducing arrival processing times. This paper then examines the performance of different airport layouts, utilizing a discrete event simulation.

While modeling stochastic systems it is very important results to be examined using reliable statistics analysis. Estimation methods that can allow user to make statistic conclusions about model from simulation results are needed. These methods are also used while determining relation between simulation time and precision of estimations. To complete the task regeneration method was chosen. This method is successfully used in various practical problems solving. The usage of regeneration method is based on the fact that many stochastic systems renovate in a probability sense. Besides regeneration method easily solves such “tactical” problems like: • How to start simulation? • Which moment to start to gather data at? • What to do with strongly correlated data? Received results are confidential intervals of the queue forming in two and three – channel system characteristics (medium waiting time in queue and maximal length of queue). From these results we can judge about effectiveness of system work and relation between results’ precision and simulation time.

O presente estudo tem por objetivo fornecer uma maior compreensão acerca do consumo e das comunidades de consumo formadas nas filas de espera que antecedem a apresentação de bandas internacionais. A questão central de pesquisa pode ser assim definida: como são formadas as comunidades de consumo nas filas de espera que antecedem apresentações musicais de bandas internacionais? E a espera nas filas, é compreendida como sendo parte do consumo? A importância do estudo se justifica devido à existência de lacunas na literatura que tratem as filas de espera formadas por consumidores como comunidades de consumo. Para suportar a pesquisa, foi realizada uma análise teórica acerca de comunidade de consumo, fanatismo, consumo experiencial e a fila de espera como um sistema social. O método utilizado teve inspiração etnográfica, para que houvesse a imersão da pesquisadora no universo do fenômeno a ser estudado. Foi verificado que a busca dos fileiros para chegar cedo nas filas de espera que antecedem a apresentação musical de bandas internacionais se deve ao fato de procurarem garantir o melhor lugar para assistir ao show, que seja o mais próximo possível dos seus artistas, além de ser uma forma de homenagear seus ídolos. A fila também é uma forma encontrada de expandir a duração da experiência, pois para eles o evento já começa na fila de espera. Foi observado que na fila ocorre a formação de comunidades de consumo, à medida que há um encontro de pessoas com gostos semelhantes, reunidas em torno de um interesse único em comum, que procuram enfrentar os desafios da fila de espera através de um cuidado e colaboração mútua entre seus membros. / The present study aims to provide a greater understanding about the consumption and consumption communities formed in the queues that precede the presentation of international bands. The central question of research can be defined as: how are consumer communities formed in the queues that precede musical performances of international bands? And the wait in queues is understood as being part of consumption? The importance of the study is justified due to the existence of gaps in the literature that deal with waiting lines formed by consumers as communities of consumption. To support the research, a bibliographical search about the consumption community, fanaticism, experiential consumption and the queue as a social system was carried out. The method used had ethnographic inspiration, so that the researcher could immerse herself in the universe of the phenomenon to be studied. It was verified that the search of the ranks to arrive early in the queues that precede the musical presentation of international bands of must to the fact to look for guarantee the best place to watch the show, that is as near as possible of its artists, besides being a way to honor their idols. Queuing is also a way to extend the duration of the experiment because for them the event already starts in the queue. It has been observed that in the queue occurs the formation of communities of consumption, as there is a meeting of people with similar tastes, gathered around a unique interest in common, that seek to face the challenges of the queue through a care and collaboration between its members.

O presente estudo tem por objetivo fornecer uma maior compreensão acerca do consumo e das comunidades de consumo formadas nas filas de espera que antecedem a apresentação de bandas internacionais. A questão central de pesquisa pode ser assim definida: como são formadas as comunidades de consumo nas filas de espera que antecedem apresentações musicais de bandas internacionais? E a espera nas filas, é compreendida como sendo parte do consumo? A importância do estudo se justifica devido à existência de lacunas na literatura que tratem as filas de espera formadas por consumidores como comunidades de consumo. Para suportar a pesquisa, foi realizada uma análise teórica acerca de comunidade de consumo, fanatismo, consumo experiencial e a fila de espera como um sistema social. O método utilizado teve inspiração etnográfica, para que houvesse a imersão da pesquisadora no universo do fenômeno a ser estudado. Foi verificado que a busca dos fileiros para chegar cedo nas filas de espera que antecedem a apresentação musical de bandas internacionais se deve ao fato de procurarem garantir o melhor lugar para assistir ao show, que seja o mais próximo possível dos seus artistas, além de ser uma forma de homenagear seus ídolos. A fila também é uma forma encontrada de expandir a duração da experiência, pois para eles o evento já começa na fila de espera. Foi observado que na fila ocorre a formação de comunidades de consumo, à medida que há um encontro de pessoas com gostos semelhantes, reunidas em torno de um interesse único em comum, que procuram enfrentar os desafios da fila de espera através de um cuidado e colaboração mútua entre seus membros. / The present study aims to provide a greater understanding about the consumption and consumption communities formed in the queues that precede the presentation of international bands. The central question of research can be defined as: how are consumer communities formed in the queues that precede musical performances of international bands? And the wait in queues is understood as being part of consumption? The importance of the study is justified due to the existence of gaps in the literature that deal with waiting lines formed by consumers as communities of consumption. To support the research, a bibliographical search about the consumption community, fanaticism, experiential consumption and the queue as a social system was carried out. The method used had ethnographic inspiration, so that the researcher could immerse herself in the universe of the phenomenon to be studied. It was verified that the search of the ranks to arrive early in the queues that precede the musical presentation of international bands of must to the fact to look for guarantee the best place to watch the show, that is as near as possible of its artists, besides being a way to honor their idols. Queuing is also a way to extend the duration of the experiment because for them the event already starts in the queue. It has been observed that in the queue occurs the formation of communities of consumption, as there is a meeting of people with similar tastes, gathered around a unique interest in common, that seek to face the challenges of the queue through a care and collaboration between its members.

Arterial performance measurement is an essential tool for both researchers and practitioners, guiding decisions on traffic management, future improvements, and public information. Link travel time and intersection control delay are two primary performance measures that are used to evaluate arterial level of service. Despite recent technological advancements, collecting travel time and intersection delay data can be a time-consuming and complicated process. Limited budgets, numerous available technologies, a rapidly changing field, and other challenges make performance measurement and comparison of data sources difficult. Three common data collection sources (probe vehicles, Bluetooth media access control readers, and manual queue length counts) are often used for performance measurement and validation of new data methods. Comparing these and other data sources is important as agencies and researchers collect arterial performance data. This study provides a methodology for comparing data sources, using statistical tests and linear correlation to compare methods and identify strengths and weaknesses. Additionally, this study examines data normality as an issue that is seldom considered, yet can affect the performance of statistical tests. These comparisons can provide insight into the selection of a particular data source for use in the field or for research. Data collected along Grant Road in Tucson, Arizona, was used as a case study to evaluate the methodology and the data sources. For evaluating travel time, GPS probe vehicle and Bluetooth sources produced similar results. Bluetooth can provide a greater volume of data more easily in addition to samples large enough for more rigorous statistical evaluation, but probe vehicles are more versatile and provide higher resolution data. For evaluating intersection delay, probe vehicle and queue count methods did not always produce similar results.

The aim of this thesis was to modify an existing order queue application which was unable to execute orders in a queue in parallel which in turn could lead to a bad user experience due to the increased queue delay. The thesis proposes two queue structures to allow parallel execution within a queue. One of the two is selected for implemented in the modified order queue application. The implementation was carried out in Java EE and used different types of frameworks such as JPQL. Some parts of the order queue application had to be modified to be able to handle the new queue structure. New attributes that defines dependencies of the orders are used to find a suitable parent for each order in the queue. The queue structure was visualized making it possible to see the execution in real time, and a test server was implemented to test the queue structure. This resulted in a working prototype able to handle dependencies and parallel orders. The modified order queue application was performance measured and compared to the original order queue application. The measurement showed that the modified order queue application performed better than the original order queue application in terms of execution time below a certain number of queues. Future work includes optimizing the methods and queries in the implementation to increase the performance and to handle parallelism within the orders.

Scheduling policies adopted for statistical multiplexing should provide delay differentiation between different traffic classes, where each class represents an aggregate traffic of individual applications having same target-queueing-delay requirements. We propose scheduling to optimally balance weighted mean instanteneous queue lengths and later weighted mean cumulative queue lengths as an approach to delay differentiation, where the class weights are set inversely proportional to the respective products of target delays and packet arrival rates. In particular, we assume a discrete-time, two-class, single-server queueing model with unit service time per packet and provide mathematical frame-work throughout our work. For iid Bernoulli packet arrivals, using a step-wise cost-dominance analytical approach using instantaneous queue lengths alone, for a class of one-stage cost functions not necessarily convex, we find the structure of the total-cost optimal policies for a part of the state space. We then consider two particular one-stage cost functions for finding two scheduling policies that are total-cost optimal for the whole state-space. The policy for the absolute weighted difference cost function minimizes the stationary mean, and the policy for the weighted sum-of-square cost function minimizes the stationary second-order moment, of the absolute value of the weighted difference of queue lengths. For the case of weighted sum-of-square cost function, the ‘iid Bernoulli arrivals’ assumption can be relaxed to either ‘iid arrivals with general batch sizes’ or to ‘Markovian zero-one arrivals’ for all of the state space, but for the linear switching curve. We then show that the average cost, starting from any initial state, exists, and is finite for every stationary work-conserving policy for our choices of the one-stage cost-function. This is shown for arbitrary number of class queues and for any i.i.d. batch arrival processes with finite appropriate moments. We then use cumulative queue lengths information in the one-step cost function of the optimization formulation and obtain an optimal myopic policy with 3 stages to go for iid arrivals with general batch sizes. We show analytically that this policy achieves the given target delay ratio in the long run under finite buffer assumption, given that feasibility conditions are satisfied. We take recourse to numerical value iteration to show the existence of average-cost for this policy. Simulations with varied class-weights for Bernoulli arrivals and batch arrivals with Poisson batch sizes show that this policy achieves mean queueing delays closer to the respective target delays than the policy obtained earlier. We also note that the coefficients of variation of the queueing delays of both the classes using cumulative queue lengths are of the same order as those using instantaneous queue lengths. Moreover, the short-term behaviour of the optimal myopic policy using cumulative queue lengths is superior to the existing standard policy reported by Coffman and Mitrani by a factor in the range of 3 to 8. Though our policy performs marginally poorer compared to the value-iterated, sampled, and then stationarily employed policy, the later lacks any closed-form structure. We then modify the definition of the third state variable and look to directly balance weighted mean delays. We come up with another optimal myopic policy with 3 stages to go, following which the error in the ratio of mean delays decreases as the window-size, as opposed to the policy mentioned in the last paragraph, wherein the error decreases as the square-root of the window-size. We perform numerical value-iteration to show the existence of average-cost and study the performance by simulation. Performance of our policy is comparable with the value-iterated, sampled, and then stationarily employed policy, reported by Mallesh. We have then studied general inter-arrival time processes and obtained the optimal myopic policy for the Pareto inter-arrival process, in particular. We have supported with simulation that our policy fares similarly to the PAD policy, reported by Dovrolis et. al., which is primarily heuristic in nature. We then model the possible packet errors in the multiplexed channel by either a Bernoulli process, or a Markov modulated Bernoulli process with two possible channel states. We also consider two possible round-trip-time values for control information, namely zero and one-slot. The policies that are next-stage optimal (for zero round-trip-time), and two-stage optimal (for one-slot round-trip-time) are obtained. Simulations with varied class-weights for Bernoulli arrivals and batch arrivals with Poisson batch sizes show that these policies indeed achieve mean queueing delays very close to the respective target delays. We also obtain the structure for optimal policies with N = 2 + ⌈rtt⌉ stages-to-go for generic values of rtt, and which need not be multiple of time-slots.

Master’s thesis is dedicated to the issue of network element. In the first part are described technological aspects as the internal structure of network elements and control mechanisms that provide differentiaton of services and support their quality requirements. In the first chapter are listed control mechanisms from most simple like FIFO to the more sophisticated like CBWFQ. Active queue managements are not missing and they are described in the section Riadiaci člen. Significant role in the differentiation of services have processes marking and pakets classification. The second chapter is devoted most promising standard DiffServ. Contains section devoted to architecture, paket marking, code point DSCP and the final part is devoted to the types of per-hop behavior and it is expedited forwarding EF and technique assured forwarding AF. The third chapter gives an overview common models of neural networks, their properties and assess their suitability for deployment in network elements. The routher design itself and its structure in programming environment Matlab/Simulink is the subject of the fourth chapter. Except used bloks from Simulink library is described their setting and function in the wiring. Consequently results are reviewied and conclusions drawn.

This master’s thesis deals with architecture of the IMS network and analysis of the affects when loading the network. Architecture of IMS is a network of new generation. It convergates fixed and mobile networks and it enables quick installation of new multimedia services. The first chapter is focused on the description of the IMS architecture, its components and their function. The next chapter is devoted to the main protocols in the IMS system. It is mainly about signalization protocol SIP. The third chapter focuses on the queueing theory. For simulation of the IMS network, Open IMS Core enviroment was chosen, described in the fourth chapter. Next chapter is dedicated to the IMS Bench SIPp tool used for generating and testing the SIP protocol with focus on the IMS. The final chapter dedicates to the realization of an IMS network. The begining of this chapter deals with the description of individual conections generated by the IMS Bench SIPp tool. In the next part load tests focused on the created IMS network are created and analyzed in detail. The end of the chapter describes the implementation of the real finished call between devices and the Android operating system.

CPU schedulers are an integral part of all operating systems used in modern systems, as they enable efficient task execution. In recent years the demand for interactive tasks such as video playback, streaming and gaming has increased rapidly. This combined with new ideas and design for CPU scheduling has led to the development of the BitMap Queue scheduler(BMQ) by Alfred Chen. Which aims to be efficient and scalable for interactive tasks, in hopes of becoming an alternative scheduler for Linux. This paper evaluates the performance of BMQ compared to the current default scheduler, the Completely Fair Scheduler(CFS). The methodology in the paper focuses on two key aspects latency and interactivity. The results display BMQ outperforming CFS in latency while maintaining similar performance in interactivity. However during heavier loads in the interactivity test BMQ outperformed CFS significantly. Thus the results suggest that BMQ provides reduced latency while providing at least similar and in some cases better interactive performance when compared to CFS.