Adaptive Channel Recommendation For Opportunistic Spectrum Access

We propose a dynamic spectrum access scheme where secondary users recommend "good" channels to each other and access accordingly. We formulate the problem as an average reward based Markov decision process. We show the existence of the optimal stationary spectrum access policy, and explore its structure properties in two asymptotic cases. Since the action space of the Markov decision process is continuous, it is difficult to find the optimal policy by simply discretizing the action space and use the policy iteration, value iteration, or Q-learning methods. Instead, we propose a new algorithm based on the Model Reference Adaptive Search method, and prove its convergence to the optimal policy. Numerical results show that the proposed algorithms achieve up to 18% and 100% performance improvement than the static channel recommendation scheme in homogeneous and heterogeneous channel environments, respectively, and is more robust to channel dynamics

A Two-Player Resource-Sharing Game with Asymmetric Information

This paper considers a two-player game where each player chooses a resource from a finite collection of options. Each resource brings a random reward. Both players have statistical information regarding the rewards of each resource. Additionally, there exists an information asymmetry where each player has knowledge of the reward realizations of different subsets of the resources. If both players choose the same resource, the reward is divided equally between them, whereas if they choose different resources, each player gains the full reward of the resource. We first implement the iterative best response algorithm to find an $\epsilon$-approximate Nash equilibrium for this game. This method of finding a Nash equilibrium may not be desirable when players do not trust each other and place no assumptions on the incentives of the opponent. To handle this case, we solve the problem of maximizing the worst-case expected utility of the first player. The solution leads to counter-intuitive insights in certain special cases. To solve the general version of the problem, we develop an efficient algorithmic solution that combines online-convex optimization and the drift-plus penalty technique

Підвищення рівня енергозабезпечення офісно-складського приміщення

Актуальність теми. Міністерство енергетики затвердило на 2021 рік програму забезпечення надійності роботи електричних мереж, роботи такі як ремонт 46,76 тис. км повітряних ліній та 20,6 тис. трансформаторних підстанцій. У міністерстві наголошують, що 61% основного обладнання електропідстанцій та 4,95% від загальної довжини повітряних ліній електропередач в Україні повністю спрацювали свій ресурс[17]. Неналежний стан електромереж через які зазвичай розподіляють електроенергію обумовлює відсутність стабільного та надійного електрозабезпечення. Така ситуація вимушує кінцевого споживача переходити на автономну систему електрозабезпечення. Серед різних варіантів найбільш розповсюдженим є АСЕ з використання відновлювальних джерел енергії. Вибір на ВДЕ припадає завдяки зручності використання таких систем на відстані від основних магістралей електропостачання, відсутність викидів у навколишнє середовище, тобто вони є екологічно чистими, та при малому власному споживанні дозволяє отримувати додатковий прибуток. Метою магicтерcької диcертацiї є підвищення рівня енергоефективності за рахунок вибору і встановлення автономних систем енергозабезпечення на основі відновлюваних джерел енергії. Для досягнення цієї мети вирішувалися наступні завдання: • Провести аналіз напрямків застосування сучасних технологій в системах енергозабезпечення; • Визначити технології та підходи реалізації інтелектуальних систем енергозабезпечення; • Сформувати систему безперебійного забезпечення електроенергією офісно-складського приміщення. Об’єкт дослідження. Системи автономного енергозабезпечення з використанням відновлюваних джерел енергії Предмет дослідження. Методи та засоби підвищення рівня енергозабезпечення офісно- складського приміщення Наукова новизна одержаних результатів. Одержали подальший розвиток підходу щодо забезпечення надійного і автономного електропостачання за рахунок інтергації ВДЕ і СНЕ , що дозволяє підвищення рівня енергоефективності підприємства. Практичне значення роботи. Полягає у підвищенні енергоефективності офісно-складського приміщення шляхом інтергації ВДЕ та СНЕ до системи енергозабезпеченняActuality of theme. The Ministry of Energy approved for 2021 the program for ensuring the reliability of electrical networks, works such as the repair of 46.76 thousand km of overhead lines and 20.6 thousand transformer substations. The ministry emphasizes that 61% of the main equipment of electrical substations and 4.95% of the total length of overhead power lines in Ukraine have fully worked their resource [17]. The improper condition of the power grids through which electricity is usually distributed causes the lack of a stable and reliable power supply. Such a situation forces the final consumer to switch to an autonomous power supply system. Among the various options, the most widespread is ACE for the use of renewable energy sources. The choice of RES is due to the convenience of using such systems at a distance from the main electricity supply lines, the absence of emissions into the environment, i.e. they are environmentally friendly, and with low own consumption, it allows you to earn additional income. The goal of the master's thesis is to increase the level of energy efficiency due to the selection and installation of autonomous energy supply systems based on renewable energy sources. To achieve this goal, the following tasks were solved: • To analyze directions of application of modern technologies in energy supply systems; • Decide on the technologies and approaches to the implementation of intelligent energy supply systems; • To create a system of uninterrupted supply of electricity to the office and warehouse premises. Object of study. Autonomous energy supply systems using renewable energy sources Subject of study. Methods and means of increasing the level of energy supply of office and warehouse premises Scientific novelty of the obtained results. We received further development of approaches to ensure reliable and autonomous power supply due to the integration of RES and SNE, which allows increasing the level of energy efficiency of the enterprise. Practical meaning of work. It consists in increasing the energy efficiency of the office and warehouse space by integrating RES and SNE into the energy supply syste

Health Analytics for Decision Making in Healthcare Spatial Access

Appropriate access to healthcare services is important for preventing the spread of disease, reducing hospitalizations and emergency department use, and increasing quality of life. However, within the United States healthcare system, there exist many disparities in access to care. In this dissertation, we aim to quantify and assess disparities in healthcare access, for informed decision making towards improving access. Compared to existing methods, our approach allows for local-level estimates, is data-rich, and is statistically rigorous. In Chapter 2 of this dissertation, we focus on access to pediatric primary care services in seven states. We design an optimization model to match primary care need with supply while taking into consideration system constraints such as health insurance acceptance and maximum travel distance. We perform statistical inference, both between and within states, to determine whether there are significant disparities in travel distance and congestion. In Chapter 3, we focus on primary care for non-elderly adults in Georgia and how it may be impacted by the Affordable Care Act. We additionally evaluate the impact of two other policies intended to improve access: increasing the number of residency positions in Georgia and implementing a parity program so that more providers accept Medicaid insurance. In Chapter 4, we begin analysis of psychosocial services for Medicaid-insured children. Using Medicaid claims data for 34 states, we identify which providers are likely to treat Medicaid-insured children and their practice settings, comparing across states, urbanicity, and provider specialties. Finally, in Chapter 5, we develop a modeling framework for one potential intervention to increase access to psychosocial services: collaboration between mental health providers and primary care providers. We create this framework by extending congestion games into a setting in which players have their own private cost function for each resource and resources have their own capacities and preferences over the players. We construct a polynomial-time algorithm to find a Nash equilibrium for singleton games with non-decreasing cost functions under this setting and demonstrate our model for services to Medicaid-insured children in New York.Ph.D

Game theoretic models for resource sharing in wireless networks

Wireless communications have been recently characterized by rapid proliferation of wireless networks, impressive growth of standard and technologies, evolution of the end-user terminals, and increasing demand in the wireless spectrum. New, more flexible schemes for the management of the available resources, from both the user and the network side, are necessary in order to improve the efficiency in the usage of the available resources.This work aims at shedding light on the performance modeling of radio resource sharing/allocation situations. Since, in general, the quality of service perceived by a system (e.g., user, network) strictly depends on the behavior of the other entities, and the involved interactions are mainly competitive, this work introduces a framework based on non–cooperative game theoretic tools. Furthermore, non–cooperative game theory is suitable in distributed networks, where control and management are inherently decentralized.First, we consider the case in which many users have to make decisions on which wireless access point to connect to. In this scenario, the quality perceived by the users mainly depends on the number of other users choosing the very same accessing opportunity. In this context, we also consider two–stage games where network make decisions on how to use the available resources, and users react to this selecting the network that maximizes their satisfaction. Then, we refer to the problem of spectrum sharing, where users directly compete for portions of the available spectrum. Finally, we provide a more complex model where the users utility function is based on the Shannon rate. The aim of this second part is to provide a better representation of the satisfaction perceived by the users, i.e., in terms of achievable throughput. Due to the complexity of the game model, we first provide a complete analytical analysis of the two–user case. Then, we extend the model to the N–user case. We mainly analyze this game through simulations. Finally, inspired by the results obtained numerically, we introduce stochastic geometry in the analysis of spectrum games in order to predict the performance of the game in large networks.Ph.D., Electrical Engineering -- Drexel University, 201

URBAN DISTRIBUTION NETWORK PLANNING MODEL IN TRANSITION THROUGH A SMART NETWORK

Ovaj disertacijski rad se sastoji od tri osnovna dijela kojima je cilj ostvariti opći model distribucijske mreže i njegovu optimalizaciju prema postizanju uvjeta ostvarenja pametne mreže. U prvom dijelu disertacije je napravljena temeljita energetska analiza i optimiranje tokova snage distribucijske mreže sa ciljem njenog unaprijeđenja i otklanjanja svih postojećih i potencijalnih poteškoća u njenom radu. Za primjer i podlogu promatranja je odabrana 10(20) kV distribucijska mreža grada Osijek. Analiziran je rad distribucijske mreže za trenutke najvećih registriranih strujnih opterečenja, te raznim situacijama (n-1) stanja visokonaponskih dalekovoda, ali također i energetskih situacija (n-1) stanja visokonaponskih distribucijskih trafostanica, te su predočena konkretna rješenja za unapređenje postojeće distribucijske mreže, te planiranje i razvoj njenog modela. U drugom dijelu disertacije, napravljen je teorijski model integracije obnovljivih izvora energije s obzirom na: optimalizaciju tehničkog stanja, optimalizaciju troškova investicije, te optimalizaciju troškova poslovanja. Ovaj opći model postiže očekivano stanje nulte potrošnje - „zero energy“ i prijelaz sa distribucijskog rada mikro mreže na otočni režim rada. Za usporedbu, sa iskustvom iz prakse distribucije HEP-d.d. opisan je model integracije obnovljivih izvora energije u postojeću urbanu distribucijsku mrežu sa prikazom različitih situacija NN mreže u odnosu na različite vrijednosti snage integracije obnovljivih izvora energije. U trećem dijelu disertacije, napravljena je primjena i potvrda općeg modela urbane distribucijske mreže, odnosno njena optimalizacija sa stvarnim parametrima iz postojeće distribucijske mreže. Model se promatrao u različitim vremenskim razdobljima koja se bitno razlikuju sa svojim udjelom instalirane snage obnovljivih izvora energije. Ovi rezultati pokazuju uspješno postizanje stanja nulte potrošnje-„zero energy“ i uspješni prijelaz razvijene urbane distribucijske mreže u virtualnu pametnu mrežu.This dissertation consists of three main parts which have the aim to achieve the universal model of distribution network which will fullfill the conditions of the advanced smart grid. In the first part of these science paper, it is done a complete energy analysis and optimization of power flow through the distribution network. The aim is to improve the present distribution network and elimination of all existing and potential difficulties which can occur in it's functioning. For observation example and as a groundwork concept this work has chosen high voltage 10(20) kV distribution network of city Osijek. It has been analyzed the operation of distribution network for the special moments of the greatest registered currents in the network and the others special situations (n-1) of high voltage power lines and special situations (n-1) of high voltage substations. As a result, following labour offers enhancement of existing distribution network and planning and developing of it's model in the future. In the second part of this dissertation, it is made theoretical model of integrated renewable energy sources from the different point of view: optimal tehnical states, optimal investment costs, optimal business costs. This theoretical model achieves the state of zero energy comsumption, and it is turn on from working in distribution mode to insular mode. For the purpose of comparison with the experience in practice of distribution company HEP d.d., it is presented the universal model of urban distribution network with integration of renewable energy sources, which is created for all different power values from integrated renewable energy sources. In the third part of this dissertation, it is done the optimalization of the universal model of distribution network with the true parameters from the present distribution network, which result with the approvement of the implementation and confirmation of universal model. After that, this work presents the analysis of working model of low voltage distribution network for the several time period which distinguish with it's share of installed renewable energy sources. On the base of this observations, and successfully reaching the state of zero energy comsumption, obtained results determine direction and course of development urban distribution network toward the future smart grid