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Leilões para publicidade na Internet; Auctions for Internet advertising

Oliveira, Atol Fortin de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 27/09/2012 PT
Relevância na Pesquisa
36.2%
Neste projeto apresentamos três modelos para publicidade na Internet, e mecanismos associados a cada modelo, analisando suas propriedades como estabilidade, otimalidade, prova de estratégia, e consumo de tempo. Primeiramente apresentamos um dos primeiros artigos publicados sobre o problema de leilões para publicidade na Internet, que descreve essencialmente o funcionamento dos atuais leilões para publidade na Internet. Em seguida, apresentamos outros dois modelos. O primeiro deles permite publicidade com exclusividade. O segundo modelo permite mais opções ao leiloeiro e aos anunciantes, ao permitir preços mínimos de venda e preços máximos de compra.; In this project we present three Internet sponsored search advertising models, and mechanisms related to each model, analyzing properties such as stability, optimality, strategy-proof, and time consumption. We start presenting one of the first articles on the problem of sponsored search advertising. Next, we present other two models. The first one allows exclusivity advertising. The second model allows a wider variety of options for both the auctioneer and the bidders, including minimum selling prices and maximum buying prices.

Representando o vendedor e a sociedade : mecanismos com dois critérios para leilões combinatórios com demandas unitárias; On Behalf the Seller and Society: a bicriteria mechanism for unit demand combinatorial auctions

Laber, Eduardo Sany
Fonte: Escola de Pós-Graduação em Economia da FGV Publicador: Escola de Pós-Graduação em Economia da FGV
Tipo: Trabalho em Andamento
EN_US
Relevância na Pesquisa
36.2%
This work focuses on obtaining truthful mechanisms that aim at maximizing both the revenue and the economic efficiency (social welfare) for the unitdemand combinatorial auction problem (UDCAP), in which a set of k items is auctioned to a set of n consumers. Although each consumer bids on all items, no consumer can purchase more than one item in the UDCAP. We present a framework for devising poly-time randomized competitive truthful mechanisms that can be used to either favor economic efficiency or revenue.

Um agente para leilões eletronicos simultaneos heterogeneos com bens inter-relacionados; An agent for electronic simultaneous heterogeneous auctions with inter-related goods

Cynthia Samara de Medeiros Gonzaga
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 11/05/2006 PT
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36.43%
Agentes computacionais têm um papel importante no comércio eletrônico, pois permitem um melhor aproveitamento de negociações e aumentam o grau de automação do mercado eletrônico. Agentes podem interagir entre si para atingir seus objetivos. Leilões fornecem mecanismos simples de interação e negociação entre agentes e, com o advento da Internet, estão se tomando um veículo eficaz para a realização de negociações eletrônicas intermediadas por agentes. Destaca-se nesse contexto o desenvolvimento de agentes para atuar em leilões eletrônicos simultâneos heterogêneos com bens inter-relacionados. Participar de múltiplos leilões simultaneamente traz a vantagem de permitir, por exemplo, que um agente possa monitorar preços de vários leilões e realizar o negócio naquele que se mostrar mais lucrativo. Além disso, muitas vezes a compra de bens individuais pode não fazer sentido. É o caso, por exemplo, de passagens aéreas e diárias de hotel em agências de viagem; a compra de um bem só se justifica diante da presença do outro. Com o intuito de promover e encorajar pesquisas na área de agentes atuando em leilões eletrônicos simultâneos heterogêneos com bens interrelacionados criou-se uma competição, o Trading Agent Competition-Classic (TAC-Classic). O TACClassic simula uma agência de viagem onde os agentes (participantes da competição) têm o objetivo de propor pacotes de viagem. Os bens são negociados em leilões simultâneos heterogêneos. Esta dissertação versa sobre o agente e-Agent...

Metodologia e simulação de leilão simultâneo-combinatório para novos empreendimentos de geração de energia elétrica; Methodology and simulation of simultaneous-combinatorial auctions for new power plants

Elisa Bastos Silva
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 15/02/2011 PT
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36.48%
Os mecanismos de comercialização de energia elétrica foram modificados pelo Governo por meio do novo modelo do setor elétrico instituído em 2004. Esse procedimento foi definido, elegendo-se os leilões como forma de licitação para o ambiente de contratação regulada, objetivando minimizar os preços de venda (aproximando-os do custo de produção) e introduzir a competição de mercado. O mecanismo de leilões, no âmbito do setor elétrico, foi adotado por diversos países, que nem sempre obtiveram níveis elevados de. Entretanto, apesar das experiências de insucesso, verifica-se a necessidade de se comercializar energia elétrica através de contratos de longo prazo; logo a formatação dos leilões deve prever diversos aspectos com vista a evitar tais insucessos. Por isso, para o setor elétrico brasileiro, anualmente, são descritas pelo MME uma série de diretrizes em que constam os procedimentos para habilitação técnica, prazos e sistemática adotada para esses leilões. Em esfera nacional, os leilões são classificados como: leilão de linha de transmissão, leilão de energia existente, leilão de energia de ajuste, leilões de reserva e leilão de energia nova. Os leilões de novos empreendimentos tendem à expansão da oferta; são constituídos por aqueles que não sejam detentores de concessão...

Accounting for Cognitive Costs in On-Line Auction Design

Parkes, David C.; Ungar, Lyle H.; Foster, Dean P.
Fonte: Springer Verlag Publicador: Springer Verlag
Tipo: Monograph or Book
EN_US
Relevância na Pesquisa
26.57%
Many auction mechanisms, including first and second price ascending and sealed bid auctions, have been proposed and analyzed in the economics literature. We compare the usefulness of different mechanisms for on-line auctions, focusing on the cognitive costs placed on users (e.g. the cost of determining the value of a good), the possibilities for agent mediation, and the trust properties of the auction. Different auction formats prove to be attractive for agent mediated on-line auctions than for traditional off-line auctions. For example, second price sealed bid auctions are attractive in traditional auctions because they avoid the communication cost of multiple bids in first price ascending auctions, and the “gaming” required to estimate the second highest bid in first price sealed bid auctions. However, when bidding agents are cheap, communication costs cease to be important, and a progressive auction mechanism is preferred over a closed bid auction mechanism, since users with semi-autonomous agents can avoid the cognitive cost of placing an accurate value on a good. As another example, when an on-line auction is being conducted by an untrusted auctioneer (e.g. the auctioneer is selling its own items), rational participants will build bidding agents that transform second price auctions into first price auctions.; Engineering and Applied Sciences

Revenue in Truly Combinatorial Auctions and Adversarial Mechanism Design

Micali, Silvio; Valiant, Paul
Fonte: MIT - Massachusetts Institute of Technology Publicador: MIT - Massachusetts Institute of Technology
Formato: 30 p.
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Little is known about generating revenue in UNRESTRICTED combinatorial auctions. (In particular, the VCG mechanism has no revenue guarantees.) In this paper we determine how much revenue can be guaranteed in such auctions. Our analysis holds both in the standard model, when all players are independent and rational, as well as in a most adversarial model, where some players may bid collusively or even totally irrationally.

New Resiliency in Truly Combinatorial Auctions (and Implementation in Surviving Strategies)

Chen, Jing; Micali, Silvio
Fonte: MIT - Massachusetts Institute of Technology Publicador: MIT - Massachusetts Institute of Technology
Formato: 32 p.
Relevância na Pesquisa
36.3%
Following Micali and Valiant [MV07.a], a mechanism is resilient if it achieves its objective without any problem of (1) equilibrium selection and (2) player collusion. To advance resilient mechanism design,We put forward a new meaningful benchmark for the COMBINED social welfare-revenue performance of any mechanism in truly combinatorial auctions.We put forward a NEW notion of implementation, much more general than the ones used so far, which we believe to be of independent interest.We put forward a new RESILIENT mechanism that, by leveraging the knowledge that the players have about each other, guarantees at least one half of our benchmark under a very general collusion model.

Resilient Provision of a Public and/or Private Good, or: Resilient Auctions of One Good in Unlimited Supply

Chen, Jing; Micali, Silvio
Fonte: MIT - Massachusetts Institute of Technology Publicador: MIT - Massachusetts Institute of Technology
Formato: 3 p.
Relevância na Pesquisa
36.2%
We present two resilient mechanisms: the first for the provision of a public good, and the second for the provision of a private good. Both mechanisms adopt a knowledge-based benchmark.

Worst-case efficiency ratio in false-name-proof combinatorial auction mechanisms

Iwasaki, A.; Conitzer, V.; Omori, Y.; Sakurai, Y.; Todo, T.; Guo, M.; Yokoo, M.
Fonte: International Foundation for Autonomous Agents and Multiagent Systems; USA Publicador: International Foundation for Autonomous Agents and Multiagent Systems; USA
Tipo: Conference paper
Publicado em //2010 EN
Relevância na Pesquisa
36.28%
This paper analyzes the worst-case efficiency ratio of false-name-proof combinatorial auction mechanisms. False-name-proofness generalizes strategy-proofness by assuming that a bidder can submit multiple bids under fictitious identifiers. Even the well-known Vickrey-Clarke-Groves mechanism is not false-name-proof. It has previously been shown that there is no false-name-proof mechanism that always achieves a Pareto efficient allocation. Consequently, if false-name bids are possible, we need to sacrifice efficiency to some extent. This leaves the natural question of how much surplus must be sacrificed. To answer this question, this paper focuses on worst-case analysis. Specifically, we consider the fraction of the Pareto efficient surplus that we obtain and try to maximize this fraction in the worst-case, under the constraint of false-name-proofness. As far as we are aware, this is the first attempt to examine the worst-case efficiency of false-name-proof mechanisms. We show that the worst-case efficiency ratio of any false-name-proof mechanism that satisfies some apparently minor assumptions is at most 2/(m + 1) for auctions with m different goods. We also observe that the worst-case efficiency ratio of existing false-name-proof mechanisms is generally 1/m or 0. Finally...

A genetic algorithm for solving the first price sealed bid auction in communication networks

Portilla Figueras, José Antonio; Salcedo Sanz, Sancho; García Díaz, Pilar; Hackbarth Planeta, Klaus Dietrich
Fonte: World Scientific and Engineering Academy and Society (WSEAS) Publicador: World Scientific and Engineering Academy and Society (WSEAS)
Tipo: info:eu-repo/semantics/conferenceObject; publishedVersion
ENG
Relevância na Pesquisa
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This paper shows the first result obtained in the application of economic mechanisms for the efficient assignment of resources in communication networks. The final objective is to determine which Service Provider will carry their traffic over the network of a Network Provider, which will be the most profitable route and which price the ISPs will pay for it to the Network provider. As the price is a key driver a good approach to select the ISP may be an auction mechanism. The implementation of these kind of auction mechanisms becomes a NP complete problem which is solved in this paper using novel metaheuristics, specifically a genetic algorithm.

Exploring pricing rules in combinatorial sealed-bid auctions

Mochón, Asunción; Sáez, Yago; Gómez-Barroso, J.L.; Isasi, Pedro
Fonte: Elsevier Publicador: Elsevier
Tipo: info:eu-repo/semantics/draft; info:eu-repo/semantics/article Formato: application/pdf
Publicado em /05/2012 ENG
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36.3%
The allocation of public goods such as the radio spectrum is a difficult task that the government must face. Currently, auctions are becoming an important tool to deal with this duty. In this context, the rules that the auctioneer establishes are particularly relevant, as the final outcome depends on them. When auctioning many related items, such as spectrum licenses, the bidders’ values for one item may depend on the number of items already obtained (complements and substitutes items). In such circumstances, combinatorial auctions are the most appropriate alternative for allocating lots. This paper analyzes the implications of selecting a particular pricing mechanism on the final result in a combinatorial sealed-bid auction. The following pricing rules are selected: the first-price mechanism, the Vickrey–Clarke–Groves (VCG) mechanism, and the bidder–Pareto–optimal (BPO) core mechanism, a core-selecting auction. To test these pricing rules, a simulator of the auction model has been developed. Then, to tackle the complex problem of simulating bidders’ behavior, a co-evolutionary system has been designed to identify improved strategies. The results revealed that the first-price mechanism yields inefficient outcomes and a notable reduction in the seller's revenues. Both the VCG and BPO mechanisms yield outcomes that are closer to the efficient allocation...

Design of Auctions for Short-Term Allocation in Gas Markets Based on Virtual Hubs

VAZQUEZ, Miguel; HALLACK, Michelle
Fonte: Instituto Universitário Europeu Publicador: Instituto Universitário Europeu
Tipo: Trabalho em Andamento Formato: application/pdf
EN
Relevância na Pesquisa
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Gas markets based on virtual hubs has been the preferred EU design. Such market designs are based on socializing network flexibility services. Nonetheless, shippers have different preferences about the network flexibility, which are not reflected in current allocation models. We propose the introduction of auction mechanisms to deal with network service allocation in the short term. The auction aims to represent simultaneously the diversity of players' preferences and the trade-offs implied by network constraints. Two sealed-bid auctions are proposed. On the one hand, an auction with one product allocates network services through the minimization of gas price differences. On the other, a multi-product (gas and line-pack storage) auction is designed to facilitate the revelation of preferences on line-pack storage.

Need and design of short-term auctions in the EU gas markets

VAZQUEZ, Miguel; HALLACK, Michelle
Fonte: Elsevier Sci Ltd Publicador: Elsevier Sci Ltd
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.22%
In the EU, gas markets are based on socializing network flexibility services. However, shippers have different preferences on network flexibility, which are not reflected in current allocation models. We propose the introduction of auction mechanisms to allocate network services in the short run. The auction aims to represent simultaneously the diversity of players' preferences and the trade-offs implied by network constraints. Two sealed-bid auctions are proposed: (a) an auction based on bids for gas, which allocates network services through the minimization of gas price differences; (b) an auction with explicit bids for line-pack, which allows shippers' valuation of line-pack storage.

Promoting Renewable Energy through Auctions

Elizondo Azuela, Gabriela; Barroso, Luiz
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Journal Article; Publications & Research :: Brief; Publications & Research
ENGLISH; EN_US
Relevância na Pesquisa
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This knowledge note singles out auctions as an important mechanism that has been implemented in a growing number of countries in recent decades. It features case studies of auctions designed to promote the generation of electricity from renewable sources in Brazil, China, and India. Auctions in various forms are being used to promote the generation of electricity from renewable sources. Properly structured auctions can avoid the disadvantages of feed-in tariffs and renewable purchase obligations. Moreover, they offer the best of both of these early mechanisms, providing stable revenue guarantees for investors while also avoiding the risk of overbuilding. They do this by determining both price and quantity in advance. Promoting renewable energy through auctions is important, because experience with the use of auctions can guide future efforts. Among the examples of the benefits to be obtained from generating electricity from renewable sources are (i) increasing countries' energy security by reducing their dependency on fossil fuel imports...

Court Auctions : Effective Processes and Enforcement Agents

Gramckow, Heike
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Publications & Research :: Working Paper; Publications & Research
ENGLISH; EN_US
Relevância na Pesquisa
36.35%
This paper considers the historical origins and efficacy of enforcement of civil court judgments, with a special focus on court auctions. It reviews the procedural and practical options available to courts and associated agencies for the identification of assets that may be used to satisfy a judgment debt and the processes for court-supervised asset seizure and sale by public auction. The efficiencies of public court auction processes are considered, including the elements of enforcement systems that can produce sub-optimal returns on sold assets and higher incentives for corrupt practices. Also considered is the trend in some systems for greater use of private agents as a means by which the cost of court enforcement processes can be reduced and for overcoming sometimes lengthy delays in enforcement. The paper concludes by identifying alternatives to public auction that in some cases can offer better prospects of assuring full payment of a judgment debt.

Performance of Renewable Energy Auctions : Experience in Brazil, China and India

Elizondo Azuela, Gabriela; Barroso, Luiz; Khanna, Ashish; Wang, Xiaodong; Wu, Yun; Cunha, Gabriel
Fonte: World Bank Group, Washington, DC Publicador: World Bank Group, Washington, DC
Tipo: Publications & Research :: Policy Research Working Paper; Publications & Research
ENGLISH; EN_US
Relevância na Pesquisa
36.32%
This paper considers the design and performance of auction mechanisms used to deploy renewable energy in three emerging economies: Brazil, China, and India. The analysis focuses on the countries' experience in various dimensions, including price reductions, bidding dynamics, coordination with transmission planning, risk allocation strategies, and the issue of domestic content. Several countries have turned to public competitive bidding as a mechanism for developing the renewable generation sector in recent years, with the number of countries implementing some sort of auction procedure rising from nine in 2009 to 36 by the end of 2011 and about 43 in 2013. In general, the use of auctions makes sense when the contracting authority expects a large volume of potentially suitable bids, so that the gains from competition can offset the costs of implementation. A study of the successes and failures of the particular auction design schemes described in this paper can be instrumental in informing future policy making.

Electricity Auctions : An Overview of Efficient Practices

Maurer, Luiz T. A.; Barroso, Luiz A.
Fonte: World Bank Publicador: World Bank
Tipo: Publications & Research :: Publication; Publications & Research :: Publication
ENGLISH
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This report assesses the potential of electricity contract auctions as a procurement option for the World Bank's client countries. It focuses on the role of auctions of electricity contracts designed to expand and retain existing generation capacity. It is not meant to be a 'how-to' manual. Rather, it highlights some major issues and options that need to be taken into account when a country considers moving towards competitive electricity procurement through the introduction of electricity auctions. Auctions have played an important role in the effort to match supply and demand. Ever since the 1990s, the use of long-term contract auctions to procure new generation capacity, notably from private sector suppliers, has garnered increased affection from investors, governments, and multilateral agencies in general, as a means to achieve a competitive and transparent procurement process while providing certainty of supply for the medium to long term. However, the liberalization of electricity markets and the move from single-buyer procurement models increased the nature of the challenge facing system planners in their efforts to ensure an adequate and secure supply of electricity in the future at the best price. While auctions as general propositions are a means to match supply with demand in a cost-effective manner...

Adaptive Limited-Supply Online Auctions

Hajiaghayi, Mohammad T.; Kleinberg, Robert; Parkes, David C.
Fonte: Association for Computing Machinery Publicador: Association for Computing Machinery
Tipo: Monograph or Book
EN_US
Relevância na Pesquisa
36.1%
We study a limited-supply online auction problem, in which an auctioneer has k goods to sell and bidders arrive and depart dynamically. We suppose that agent valuations are drawn independently from some unknown distribution and construct an adaptive auction that is nevertheless value- andtime-strategy proof. For the k=1 problem we have a strategyproof variant on the classic secretary problem. We present a 4-competitive (e-competitive) strategyproof online algorithm with respect to offline Vickrey for revenue (efficiency). We also show (in a model that slightly generalizes the assumption of independent valuations) that no mechanism can be better than 3/2-competitive (2-competitive) for revenue (efficiency). Our general approach considers a learning phase followed by an accepting phase, and is careful to handle incentive issues for agents that span the two phases. We extend to the k›1 case, by deriving strategyproof mechanisms which are constant-competitive for revenue and efficiency. Finally, we present some strategyproof competitive algorithms for the case in which adversary uses a distribution known to the mechanism.; Engineering and Applied Sciences

Truthful Learning Mechanisms for Multi-Slot Sponsored Search Auctions with Externalities

Gatti, Nicola; Lazaric, Alessandro; Rocco, Marco; Trovò, Francesco
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 10/05/2014
Relevância na Pesquisa
26.59%
Sponsored search auctions constitute one of the most successful applications of microeconomic mechanisms. In mechanism design, auctions are usually designed to incentivize advertisers to bid their truthful valuations and to assure both the advertisers and the auctioneer a non-negative utility. Nonetheless, in sponsored search auctions, the click-through-rates (CTRs) of the advertisers are often unknown to the auctioneer and thus standard truthful mechanisms cannot be directly applied and must be paired with an effective learning algorithm for the estimation of the CTRs. This introduces the critical problem of designing a learning mechanism able to estimate the CTRs at the same time as implementing a truthful mechanism with a revenue loss as small as possible compared to an optimal mechanism designed with the true CTRs. Previous work showed that, when dominant-strategy truthfulness is adopted, in single-slot auctions the problem can be solved using suitable exploration-exploitation mechanisms able to achieve a per-step regret (over the auctioneer's revenue) of order $O(T^{-1/3})$ (where T is the number of times the auction is repeated). It is also known that, when truthfulness in expectation is adopted, a per-step regret (over the social welfare) of order $O(T^{-1/2})$ can be obtained. In this paper we extend the results known in the literature to the case of multi-slot auctions. In this case...

Auctions, mechanisms and uncertainty

Ferenc, Veszteg Róbert
Fonte: Bellaterra : Universitat Autònoma de Barcelona, Publicador: Bellaterra : Universitat Autònoma de Barcelona,
Tipo: Tesis i dissertacions electròniques; info:eu-repo/semantics/doctoralThesis Formato: application/pdf
Publicado em //2005 ENG; ENG
Relevância na Pesquisa
36.2%
Consultables des del TDX; Títol obtingut de la portada digitalitzada; Los mecanismos que permiten la interacción de los individuos tienen un gran impacto sobre los resultados de esta interacción. La teoría económica de diseño de mecanismos estudia el diseño de procedimientos de decisión social en situaciones en la cuales los agentes económicos guardan información privada y se comportan, la utilizan, de forma estratégica. Como ejemplo, considérese el caso en el cual la autoridad central de un país está considerando la posibilidad de declarar como «reserva nacional» una determinada área geográfica. Para poder tomar la decisión óptima, por ejemplo la que maximiza el bienestar social, ésta se tiene que basar en la información individual de las ciudades, estados, o agentes, cuya opinión sobre el problema que se considera se puede preguntar directamente, pero la verdad no se expresará sin los incentivos adecuados. Estos pueden aparecen como transferencias monetarias u otros instrumentos controlados por la autoridad. Con otras palabras, la teoría de diseño de mecanismos estudia la harmonización de los incentivos que se tienen que aplicar cuando un conjunto de agentes interactúa para que estos muestren un comportamiento deseado...