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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

A indústria de reciclagem e a questão ambiental / The recycling industry and environmental issues

Lino, Helio Francisco Corrêa 02 August 2011 (has links)
Esta tese pesquisou a questão da reciclagem no Brasil, destacando quatro dos mais significativos resíduos sólidos recicláveis: as latas de alumínio, o papel, as garrafas polipolietileno-tereftalato (PET) e o vidro. Busca oferecer maiores subsídios sobre um tema que só recentemente tem sido melhor estudado, dada a sua ligação com o meio ambiente e a polêmica sobre o desenvolvimento sustentável. / This thesis researched about recycling in Brazil highlighting four of the most significatives recyclily solid residues, e.g. tin (aluminium) cans, paper, bottles made of polyethylene terephthalate (PET) and the glass. Due to its liaison with the environment and the controversies about the sustainable development, this thesis offer great subsidies about a theme that only recently has been deeply studied.
102

營利與非營利機構的營運管理策略 / A Study on Operation Strategies of for-profit and non-profit Firms

宋豪漳, Sung, Hao Chang Unknown Date (has links)
本論文為關於營利與非營利機構之營運管理策略之兩篇理論性質的文章。 第一篇文章旨在探討營利機構之實質盈餘管理策略。本研究檢驗在產品市場競爭下,公司如何透過實質盈餘管理策略來滿足盈餘目標之要求以及公司之實質盈餘管理動機會如何影響市場競爭對手之行為。本文考慮一個兩期非合作之R&D競爭寡占模型。本文假設存在資訊不對稱;具有私人資訊的廠商為追求獲利最大亦或追求盈餘目標達成兩種類型。本文透過完美貝氏均衡 (perfect Bayesian equilibrium) 解出分離均衡 (separating equilibrium) 與混和均衡 (hybrid equilibrium)。 本研究指出追求獲利最大類型之廠商可以藉由影響競爭對手之猜測來進一步左右追求盈餘目標達成類型之目標達成之可能性。在分離均衡中,當外在成本衝擊未超過預期時,追求獲利最大類型之廠商無誘因藉由R&D 投資水準之提升來規避負向成本衝擊以影響市場對手猜測並且進一步提升其產品市場競爭力。因此,追求盈餘目標達成類型之盈餘目標無法達成。 在混和均衡中,當外在成本衝擊超過預期時,追求獲利最大類型之廠商有誘因採取混合策略以誤導市場對手之猜測;該類型之廠商可以藉由部分模仿盈餘目標達成類型之R&D 投資策略以混淆競爭對手之信念並且提升其產品產出、獲利水準。在此,追求盈餘目標達成類型之盈餘目標能夠達成。本研究之結果有別於傳統R&D盈餘管理實證文獻中,公司內部當局有誘因透過R&D支出的減少用以滿足公司短期之盈餘目標 (Barber et. al., 1991; Bushee, 1998; Graham, 2005) 。本研究指出公司可以藉由R&D 投資水準之提升,以創造“cookie jar” 並且有助於公司獲利提升與盈餘目標之達成。此外,本研究與盈餘奇異現象之實證研究 (earnings kinky) 結論一致: 公司可以藉由盈餘管理策略來達成盈餘目標,但是盈餘目標之達成不盡然是透過盈餘管理策略 (Dechow, Richardson and Tuna, 2003)。 第二篇文章旨在探討非營利機構提供非獲利性質服務之策略性之影響。本研究指出非獲利性質服務之提供不僅有助於非營利機構於獲利性質服務之競爭優勢的提升,相對於營利機構。當所有權與經營權分離時,若市場需求彈性為不具彈性時,非獲利性質服務之提供對非營利機構之經理人而言,可以做為一個策略工具藉以促使該機構之所有人提供一個於獲利部分過分補償之薪酬水準。此外,隨著非獲利性質服務之外生價格的提升,當非營利性質服務之外生價格的提升對於非營利機構之所有人與經理人利益衝突影響之間接效果大於對獲利性質服務價格影響之直接效果時,非營利機構之所有人仍然會提供一個獲利部分過分補償之薪酬水準。這會有助於非營利機構於獲利性質服務之競爭優勢的提升。 / This dissertation consists of two theoretical studies on the operation strategies of for-profit and non-profit firms. Chapter 1 addresses how firms use real earnings management to meet or beat their earnings targets, and how this influences sequential product market competition. We study this issue in a two-period non-cooperative R&D competition with one-sided asymmetric information in which the informed firm could be either the maximizing type or the target-meeting type (or target-beating). We show that the maximizing type of the informed firm’s R&D investment level could influence rival firm’s conjecture about the informed firm’s type which in term affects the success of meeting or beating the target for the target-meeting type of the informed firm. We find that the privately informed firm can increase its R&D investment in the first period to meet or beat the earnings target. This can help the firm increase profits in a sequential product market competition. More precisely, once the cost uncertainty realized is realized to exceed expectations, the maximizing type of the informed firm could hide its identity by adopting a mixed strategy and setting its R&D investment and output level higher than in the separating equilibrium. Contrary to popular claims that meeting or beating short earnings targets induces an R&D investment reduction (Barber et. al., 1991; Bushee, 1998; Graham, 2005), we show that R&D overinvestment can give an opportunity to create some reserves, i.e., a cookie jar, to be used later to earn a higher profit and reach later targets. Our result is also supporting the observation of firms meeting or beating the earnings target, but not necessarily using earnings management (Dechow, Richardson and Tuna, 2003). Chapter 2 shows that the provision of not-for profit service would not only give not-for-profit organizations a competitive advantage over for-profit organizations. Under the separation of control and ownership, we illustrate that once market demand is inelastic, the provision of not-for-profit service serves as a strategic device for the manager of a not-for-profit organization and thus induces the owner of a not-for-profit organization to overcompensate his manager regarding the margin of profit. Moreover, as the regulated price of not-for-profit service increases, a not-for-profit organization could still over-compensate his manager in regard to profit, when the indirect effect on increasing preference difference between the owner and manager of the not-for-profit organization dominates the direct effect on market price. Thus, a not-for-profit organization could charge more in for-profit service.
103

遺傳演算法在演化賽局上之應用:策略生態之模擬、計算與分析

倪志琦 Unknown Date (has links)
本論文主要是在agent-based計算經濟體系下,利用Holland(1975)所提的遺傳演算法(genetic algorithms)作為計算工具,分別探討連鎖店賽局及寡占市場廠商價格策略的生態演化。 在連鎖店賽局的研究中,藉由agent-based計算經濟分析掠奪性定價的特性,並進一步探討參賽者價格策略的共演化(co-evolutionary)特性,及多元均衡賽局中均衡移轉的動態過程。針對賽局中不同的不確定性進行模擬,結果顯示廠商長期總合行為是否穩定,和賽局中的不確定程度有相當的關聯。另外,弱獨占者和潛在競爭者的價格策略存在著共演化特性。在此演化賽局中,Nash均衡雖非穩定均衡解,但卻最常浮現在長期總合行為中。因此,Nsah均衡對agent-based演化賽局的結果而言,相當具有參考價值。在特定的不確定程度下,長期總合行為似乎只在某些特定的Nash均衡中徘徊。這些移轉途徑並不具有對稱性,甚至移轉速度也非對稱。本研究所呈現的演化結果跳脫一般對均衡的觀念,展現出傳統理論所無法預知的共演化特性,並呈現出非對稱的吸引環。 此外,同樣在Agent-based計算經濟下探討寡占市場廠商策略生態。本研究首先闡明N參賽者囚犯兩難重複賽局和N廠商寡占賽局之間的異同,經由寡占賽局廠商償付矩陣(payoff matrix)的狀態相依馬可夫移轉矩陣( state-dependent Markov transition matrix)性質,說明N廠商寡占賽局和N參賽者囚犯兩難重複賽局的差異。其次,透過三家廠商寡占賽局的模擬實驗,以遺傳演算法建構參賽廠商的適應性行為,分別以寡占市場生態上的表現型(phenotypes)和基因型(genotype)進行分析。20次模擬結果所呈現的最終市場狀態相當分歧,有形成吸引環的三廠商寡占市場、有收斂到價格戰的三廠商寡占市場。另外也成功的模擬出三廠商寡占市場演化至雙佔市場、甚或獨占市場的過程。但是,在眾多模擬中並沒有發現持續的勾結定價狀態,反而掠奪性價格是較主要的價格策略。這些結果相對於實際經濟社會中的寡占市場,給予一個活潑生動的範例。 / Recently, genetic algorithms have been extensively applied to modeling evolution game in agent-based computational economic. While these applications advance our understanding of evolution game, they have generated some new phenomena that have not been well treated in conventional game theory. In the first topic, we shall systemize the study of one of these new phenomena, namely, coevolutionary instability. We exemplify the basic properties of coevolutionary instability by the chain store game, which is the game frequently used to study the role of reputation effects in economics. In addition, we point out that, while, due to uncertainty effects, Nash equilibria can no longer be stable, and they can still help us predict the dynamic process of the game. In particular, we can see that the dynamic process of the game is well captured by a few Nash equilibria and the transition among them. A careful study can uncover several interesting patterns and we show the impact of uncertainty on these patterns. In the second topic, the relation between the N-person IPD game and the N-person oligopoly game is rigorously addressed. Our analytical framework shows that due to the path-dependence of the payoff matrix of the oligopoly game, the two games in general are not close in spirit. We then further explore the significance of the path-dependence property to the rich ecology of oligopoly from an evolutionary perspective. More precisely, we simulated the evolution of a 3-person oligopoly game, and showed that the rich ecology of oligopoly can be exhibited by modeling the adaptive behavior of oligopolists with genetic algorithms. The emergent behavior of oligopolists are presented and analyzed. We indicate how the path-dependence nature may shed light on the phenotypes and genotypes coming into existence.
104

Radio resource sharing with edge caching for multi-operator in large cellular networks

Sanguanpuak, T. (Tachporn) 04 January 2019 (has links)
Abstract The aim of this thesis is to devise new paradigms on radio resource sharing including cache-enabled virtualized large cellular networks for mobile network operators (MNOs). Also, self-organizing resource allocation for small cell networks is considered. In such networks, the MNOs rent radio resources from the infrastructure provider (InP) to support their subscribers. In order to reduce the operational costs, while at the same time to significantly increase the usage of the existing network resources, it leads to a paradigm where the MNOs share their infrastructure, i.e., base stations (BSs), antennas, spectrum and edge cache among themselves. In this regard, we integrate the theoretical insights provided by stochastic geometrical approaches to model the spectrum and infrastructure sharing for large cellular networks. In the first part of the thesis, we study the non-orthogonal multi-MNO spectrum allocation problem for small cell networks with the goal of maximizing the overall network throughput, defined as the expected weighted sum rate of the MNOs. Each MNO is assumed to serve multiple small cell BSs (SBSs). We adopt the many-to-one stable matching game framework to tackle this problem. We also investigate the role of power allocation schemes for SBSs using Q-learning. In the second part, we model and analyze the infrastructure sharing system considering a single buyer MNO and multiple seller MNOs. The MNOs are assumed to operate over their own licensed spectrum bands while sharing BSs. We assume that multiple seller MNOs compete with each other to sell their infrastructure to a potential buyer MNO. The optimal strategy for the seller MNOs in terms of the fraction of infrastructure to be shared and the price of the infrastructure, is obtained by computing the equilibrium of a Cournot-Nash oligopoly game. Finally, we develop a game-theoretic framework to model and analyze a cache-enabled virtualized cellular networks where the network infrastructure, e.g., BSs and cache storage, owned by an InP, is rented and shared among multiple MNOs. We formulate a Stackelberg game model with the InP as the leader and the MNOs as the followers. The InP tries to maximize its profit by optimizing its infrastructure rental fee. The MNO aims to minimize the cost of infrastructure by minimizing the cache intensity under probabilistic delay constraint of the user (UE). Since the MNOs share their rented infrastructure, we apply a cooperative game concept, namely, the Shapley value, to divide the cost among the MNOs. / Tiivistelmä Tämän väitöskirjan tavoitteena on tuottaa uusia paradigmoja radioresurssien jakoon, mukaan lukien virtualisoidut välimuisti-kykenevät suuret matkapuhelinverkot matkapuhelinoperaattoreille. Näiden kaltaisissa verkoissa operaattorit vuokraavat radioresursseja infrastruktuuritoimittajalta (InP, infrastructure provider) asiakkaiden tarpeisiin. Toimintakulujen karsiminen ja samanaikainen olemassa olevien verkkoresurssien hyötykäytön huomattava kasvattaminen johtaa paradigmaan, jossa operaattorit jakavat infrastruktuurinsa keskenään. Tämän vuoksi työssä tutkitaan teoreettisia stokastiseen geometriaan perustuvia malleja spektrin ja infrastruktuurin jakamiseksi suurissa soluverkoissa. Työn ensimmäisessä osassa tutkitaan ei-ortogonaalista monioperaattori-allokaatioongelmaa pienissä soluverkoissa tavoitteena maksimoida verkon yleistä läpisyöttöä, joka määritellään operaattoreiden painotettuna summaläpisyötön odotusarvona. Jokaisen operaattorin oletetaan palvelevan useampaa piensolutukiasemaa (SBS, small cell base station). Työssä käytetään monelta yhdelle -vakaata sovituspeli-viitekehystä SBS:lle käyttäen Q-oppimista. Työn toisessa osassa mallinnetaan ja analysoidaan infrastruktuurin jakamista yhden ostaja-operaattorin ja monen myyjä-operaattorin tapauksessa. Operaattorien oletetaan toimivan omilla lisensoiduilla taajuuksillaan jakaen tukiasemat keskenään. Myyjän optimaalinen strategia infrastruktuurin myytävän osan suuruuden ja hinnan suhteen saavutetaan laskemalla Cournot-Nash -olipologipelin tasapainotila. Lopuksi, työssä kehitetään peli-teoreettinen viitekehys virtualisoitujen välimuistikykenevien soluverkkojen mallintamiseen ja analysointiin, missä InP:n omistama verkkoinfrastruktuuri vuokrataan ja jaetaan monen operaattorin kesken. Työssä muodostetaan Stackelberg-pelimalli, jossa InP toimii johtajana ja operaattorit seuraajina. InP pyrkii maksimoimaan voittonsa optimoimalla infrastruktuurin vuokrahintaa. Operaattori pyrkii minimoimaan infrastruktuurin hinnan minimoimalla välimuistin tiheyttä satunnaisen käyttäjän viive-ehtojen mukaisesti. Koska operaattorit jakavat vuokratun infrastruktuurin, työssä käytetään yhteistyöpeli-ajatusta, nimellisesti, Shapleyn arvoa, jakamaan kustannuksia operaatoreiden kesken.
105

A indústria de reciclagem e a questão ambiental / The recycling industry and environmental issues

Helio Francisco Corrêa Lino 02 August 2011 (has links)
Esta tese pesquisou a questão da reciclagem no Brasil, destacando quatro dos mais significativos resíduos sólidos recicláveis: as latas de alumínio, o papel, as garrafas polipolietileno-tereftalato (PET) e o vidro. Busca oferecer maiores subsídios sobre um tema que só recentemente tem sido melhor estudado, dada a sua ligação com o meio ambiente e a polêmica sobre o desenvolvimento sustentável. / This thesis researched about recycling in Brazil highlighting four of the most significatives recyclily solid residues, e.g. tin (aluminium) cans, paper, bottles made of polyethylene terephthalate (PET) and the glass. Due to its liaison with the environment and the controversies about the sustainable development, this thesis offer great subsidies about a theme that only recently has been deeply studied.
106

Economic analysis of wireless sensor-based services in the framework of the Internet of Things. A game-theoretical approach

Sanchis Cano, Ángel 25 May 2018 (has links)
El mundo de las telecomunicaciones está cambiando de un escenario donde únicamente las personas estaban conectadas a un modelo donde prácticamente todos los dispositivos y sensores se encuentran conectados, también conocido como Internet de las cosas (IoT), donde miles de millones de dispositivos se conectarán a Internet a través de conexiones móviles y redes fijas. En este contexto, hay muchos retos que superar, desde el desarrollo de nuevos estándares de comunicación al estudio de la viabilidad económica de los posibles escenarios futuros. En esta tesis nos hemos centrado en el estudio de la viabilidad económica de diferentes escenarios mediante el uso de conceptos de microeconomía, teoría de juegos, optimización no lineal, economía de redes y redes inalámbricas. La tesis analiza la transición desde redes centradas en el servicio de tráfico HTC a redes centradas en tráfico MTC desde un punto de vista económico. El primer escenario ha sido diseñado para centrarse en las primeras etapas de la transición, en la que ambos tipos de tráfico son servidos bajo la misma infraestructura de red. En el segundo escenario analizamos la siguiente etapa, en la que el servicio a los usuarios MTC se realiza mediante una infraestructura dedicada. Finalmente, el tercer escenario analiza la provisión de servicios basados en MTC a usuarios finales, mediante la infraestructura analizada en el escenario anterior. Gracias al análisis de todos los escenarios, hemos observado que la transición de redes centradas en usuarios HTC a redes MTC es posible y que la provisión de servicios en tales escenarios es viable. Además, hemos observado que el comportamiento de los usuarios es esencial para determinar la viabilidad de los diferentes modelos de negocio, y por tanto, es necesario estudiar el comportamiento y las preferencias de los usuarios en profundidad en estudios futuros. Específicamente, los factores más relevantes son la sensibilidad de los usuarios al retardo en los datos recopilados por los sensores y la cantidad de los mismos. También hemos observado que la diferenciación del tráfico en categorías mejora el uso de las redes y permite crear nuevos servicios empleando datos que, de otro modo, no se aprovecharían, lo cual nos permite mejorar la monetización de la infraestructura. También hemos demostrado que la provisión de capacidad es un mecanismo válido, alternativo a la fijación de precios, para la optimización de los beneficios de los proveedores de servicio. Finalmente, se ha demostrado que es posible crear roles específicos para ofrecer servicios IoT en el mercado de las telecomunicaciones, específicamente, los IoT-SPs, que proporcionan servicios basados en sensores inalámbricos utilizando infraestructuras de acceso de terceros y sus propias redes de sensores. En resumen, en esta tesis hemos intentado demostrar la viabilidad económica de modelos de negocio basados en redes futuras IoT, así como la aparición de nuevas oportunidades y roles de negocio, lo cual nos permite justificar económicamente el desarrollo y la implementación de las tecnologías necesarias para ofrecer servicios de acceso inalámbrico masivo a dispositivos MTC. / The communications world is moving from a standalone devices scenario to a all-connected scenario known as Internet of Things (IoT), where billions of devices will be connected to the Internet through mobile and fixed networks. In this context, there are several challenges to face, from the development of new standards to the study of the economical viability of the different future scenarios. In this dissertation we have focused on the study of the economic viability of different scenarios using concepts of microeconomics, game theory, non-linear optimization, network economics and wireless networks. The dissertation analyzes the transition from a Human Type Communications (HTC) to a Machine Type Communications (MTC) centered network from an economic point of view. The first scenario is designed to focus on the first stages of the transition, where HTC and MTC traffic are served on a common network infrastructure. The second scenario analyzes the provision of connectivity service to MTC users using a dedicated network infrastructure, while the third stage is centered in the analysis of the provision of services based on the MTC data over the infrastructure studied in the previous scenario. Thanks to the analysis of all the scenarios we have observed that the transition from HTC users-centered networks to MTC networks is possible and that the provision of services in such scenarios is viable. In addition, we have observed that the behavior of the users is essential in order to determine the viability of a business model, and therefore, it is needed to study their behavior and preferences in depth in future studios. Specifically, the most relevant factors are the sensitivity of the users to the delay and to the amount of data gathered by the sensors. We also have observed that the differentiation of the traffic in categories improves the usage of the networks and allows to create new services thanks to the data that otherwise would not be used, improving the monetization of the infrastructure and the data. In addition, we have shown that the capacity provision is a valid mechanism for providers' profit optimization, as an alternative to the pricing mechanisms. Finally, it has been demonstrated that it is possible to create dedicated roles to offer IoT services in the telecommunications market, specifically, the IoT-SPs, which provide wireless-sensor-based services to the final users using a third party infrastructure. Summarizing, this dissertation tries to demonstrate the economic viability of the future IoT networks business models as well as the emergence of new business opportunities and roles in order to justify economically the development and implementation of the new technologies required to offer massive wireless access to machine devices. / El món de les telecomunicacions està canviant d'un escenari on únicament les persones estaven connectades a un model on pràcticament tots els dispositius i sensors es troben connectats, també conegut com a Internet de les Coses (IoT) , on milers de milions de dispositius es connectaran a Internet a través de connexions mòbils i xarxes fixes. En aquest context, hi ha molts reptes que superar, des del desenrotllament de nous estàndards de comunicació a l'estudi de la viabilitat econòmica dels possibles escenaris futurs. En aquesta tesi ens hem centrat en l'estudi de la viabilitat econòmica de diferents escenaris per mitjà de l'ús de conceptes de microeconomia, teoria de jocs, optimització no lineal, economia de xarxes i xarxes inalàmbriques. La tesi analitza la transició des de xarxes centrades en el servici de tràfic HTC a xarxes centrades en tràfic MTC des d'un punt de vista econòmic. El primer escenari ha sigut dissenyat per a centrar-se en les primeres etapes de la transició, en la que ambdós tipus de tràfic són servits davall la mateixa infraestructura de xarxa. En el segon escenari analitzem la següent etapa, en la que el servici als usuaris MTC es realitza per mitjà d'una infraestructura dedicada. Finalment, el tercer escenari analitza la provisió de servicis basats en MTC a usuaris finals, per mitjà de la infraestructura analitzada en l'escenari anterior. Als paràgrafs següents es descriu amb més detall cada escenari. Gràcies a l'anàlisi de tots els escenaris, hem observat que la transició de xarxes centrades en usuaris HTC a xarxes MTC és possible i que la provisió de servicis en tals escenaris és viable. A més a més, hem observat que el comportament dels usuaris és essencial per a determinar la viabilitat dels diferents models de negoci, i per tant, és necessari estudiar el comportament i les preferències dels usuaris en profunditat en estudis futurs. Específicament, els factors més rellevants són la sensibilitat dels usuaris al retard en les dades recopilats pels sensors i la quantitat dels mateixos. També hem observat que la diferenciació del tràfic en categories millora l'ús de les xarxes i permet crear nous servicis emprant dades que, d'una altra manera, no s'aprofitarien, la qual cosa ens permet millorar la monetització de la infraestructura. També hem demostrat que la provisió de capacitat és un mecanisme vàlid, alternatiu a la fixació de preus, per a l'optimització dels beneficis dels proveïdors de servici. Finalment, s'ha demostrat que és possible crear rols específics per a oferir servicis IoT en el mercat de les telecomunicacions, específicament, els IoT-SPs, que proporcionen servicis basats en sensors inalàmbrics utilitzant infraestructures d'accés de tercers i les seues pròpies xarxes de sensors. En resum, en aquesta tesi hem intentat demostrar la viabilitat econòmica de models de negoci basats en xarxes futures IoT, així com l'aparició de noves oportunitats i rols de negoci, la qual cosa ens permet justificar econòmicament el desenrotllament i la implementació de les tecnologies necessàries per a oferir servicis d'accés inalàmbric massiu a dispositius MTC. / Sanchis Cano, Á. (2018). Economic analysis of wireless sensor-based services in the framework of the Internet of Things. A game-theoretical approach [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/102642

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