--- _id: '11668' abstract: - lang: eng text: "We study multiple keyword sponsored search auctions with budgets. Each keyword has multiple ad slots with a click-through rate. The bidders have additive valuations, which are linear in the click-through rates, and budgets, which are restricting their overall payments. Additionally, the number of slots per keyword assigned to a bidder is bounded.\r\n\r\nWe show the following results: (1) We give the first mechanism for multiple keywords, where click-through rates differ among slots. Our mechanism is incentive compatible in expectation, individually rational in expectation, and Pareto optimal. (2) We study the combinatorial setting, where each bidder is only interested in a subset of the keywords. We give an incentive compatible, individually rational, Pareto-optimal, and deterministic mechanism for identical click-through rates. (3) We give an impossibility result for incentive compatible, individually rational, Pareto-optimal, and deterministic mechanisms for bidders with diminishing marginal valuations." article_number: '2' article_processing_charge: No article_type: original author: - first_name: Riccardo full_name: Colini-Baldeschi, Riccardo last_name: Colini-Baldeschi - first_name: Stefano full_name: Leonardi, Stefano last_name: Leonardi - first_name: Monika H full_name: Henzinger, Monika H id: 540c9bbd-f2de-11ec-812d-d04a5be85630 last_name: Henzinger orcid: 0000-0002-5008-6530 - first_name: Martin full_name: Starnberger, Martin last_name: Starnberger citation: ama: Colini-Baldeschi R, Leonardi S, Henzinger MH, Starnberger M. On multiple keyword sponsored search auctions with budgets. ACM Transactions on Economics and Computation. 2015;4(1). doi:10.1145/2818357 apa: Colini-Baldeschi, R., Leonardi, S., Henzinger, M. H., & Starnberger, M. (2015). On multiple keyword sponsored search auctions with budgets. ACM Transactions on Economics and Computation. Association for Computing Machinery. https://doi.org/10.1145/2818357 chicago: Colini-Baldeschi, Riccardo, Stefano Leonardi, Monika H Henzinger, and Martin Starnberger. “On Multiple Keyword Sponsored Search Auctions with Budgets.” ACM Transactions on Economics and Computation. Association for Computing Machinery, 2015. https://doi.org/10.1145/2818357. ieee: R. Colini-Baldeschi, S. Leonardi, M. H. Henzinger, and M. Starnberger, “On multiple keyword sponsored search auctions with budgets,” ACM Transactions on Economics and Computation, vol. 4, no. 1. Association for Computing Machinery, 2015. ista: Colini-Baldeschi R, Leonardi S, Henzinger MH, Starnberger M. 2015. On multiple keyword sponsored search auctions with budgets. ACM Transactions on Economics and Computation. 4(1), 2. mla: Colini-Baldeschi, Riccardo, et al. “On Multiple Keyword Sponsored Search Auctions with Budgets.” ACM Transactions on Economics and Computation, vol. 4, no. 1, 2, Association for Computing Machinery, 2015, doi:10.1145/2818357. short: R. Colini-Baldeschi, S. Leonardi, M.H. Henzinger, M. Starnberger, ACM Transactions on Economics and Computation 4 (2015). date_created: 2022-07-27T11:54:56Z date_published: 2015-12-05T00:00:00Z date_updated: 2023-02-09T10:03:35Z day: '05' doi: 10.1145/2818357 extern: '1' intvolume: ' 4' issue: '1' keyword: - Algorithms - Economics - Clinching ascending auction - auctions with budgets - Sponsored search auctions language: - iso: eng main_file_link: - open_access: '1' url: http://eprints.cs.univie.ac.at/3510/ month: '12' oa: 1 oa_version: Submitted Version publication: ACM Transactions on Economics and Computation publication_identifier: eissn: - 2167-8383 issn: - 2167-8375 publication_status: published publisher: Association for Computing Machinery quality_controlled: '1' scopus_import: '1' status: public title: On multiple keyword sponsored search auctions with budgets type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 4 year: '2015' ... --- _id: '11669' abstract: - lang: eng text: We study individual rational, Pareto-optimal, and incentive compatible mechanisms for auctions with heterogeneous items and budget limits. We consider settings with multiunit demand and additive valuations. For single-dimensional valuations we prove a positive result for randomized mechanisms, and a negative result for deterministic mechanisms. While the positive result allows for private budgets, the negative result is for public budgets. For multidimensional valuations and public budgets we prove an impossibility result that applies to deterministic and randomized mechanisms. Taken together this shows the power of randomization in certain settings with heterogeneous items, but it also shows its limitations. article_number: '4' article_processing_charge: No article_type: original author: - first_name: Paul full_name: Dütting, Paul last_name: Dütting - first_name: Monika H full_name: Henzinger, Monika H id: 540c9bbd-f2de-11ec-812d-d04a5be85630 last_name: Henzinger orcid: 0000-0002-5008-6530 - first_name: Martin full_name: Starnberger, Martin last_name: Starnberger citation: ama: Dütting P, Henzinger MH, Starnberger M. Auctions for heterogeneous items and budget limits. ACM Transactions on Economics and Computation. 2015;4(1). doi:10.1145/2818351 apa: Dütting, P., Henzinger, M. H., & Starnberger, M. (2015). Auctions for heterogeneous items and budget limits. ACM Transactions on Economics and Computation. Association for Computing Machinery. https://doi.org/10.1145/2818351 chicago: Dütting, Paul, Monika H Henzinger, and Martin Starnberger. “Auctions for Heterogeneous Items and Budget Limits.” ACM Transactions on Economics and Computation. Association for Computing Machinery, 2015. https://doi.org/10.1145/2818351. ieee: P. Dütting, M. H. Henzinger, and M. Starnberger, “Auctions for heterogeneous items and budget limits,” ACM Transactions on Economics and Computation, vol. 4, no. 1. Association for Computing Machinery, 2015. ista: Dütting P, Henzinger MH, Starnberger M. 2015. Auctions for heterogeneous items and budget limits. ACM Transactions on Economics and Computation. 4(1), 4. mla: Dütting, Paul, et al. “Auctions for Heterogeneous Items and Budget Limits.” ACM Transactions on Economics and Computation, vol. 4, no. 1, 4, Association for Computing Machinery, 2015, doi:10.1145/2818351. short: P. Dütting, M.H. Henzinger, M. Starnberger, ACM Transactions on Economics and Computation 4 (2015). date_created: 2022-07-27T12:09:15Z date_published: 2015-12-05T00:00:00Z date_updated: 2022-09-09T12:08:37Z day: '05' doi: 10.1145/2818351 extern: '1' external_id: arxiv: - '1209.6448' intvolume: ' 4' issue: '1' keyword: - Algorithmic game theory - auction theory - Clinching auction - Pareto optimality - Budget limits language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1209.6448 month: '12' oa: 1 oa_version: Preprint publication: ACM Transactions on Economics and Computation publication_identifier: eissn: - 2167-8383 issn: - 2167-8375 publication_status: published publisher: Association for Computing Machinery quality_controlled: '1' scopus_import: '1' status: public title: Auctions for heterogeneous items and budget limits type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 4 year: '2015' ... --- _id: '11670' abstract: - lang: eng text: Auctions are widely used on the Web. Applications range from sponsored search to platforms such as eBay. In these and in many other applications the auctions in use are single-/multi-item auctions with unit demand. The main drawback of standard mechanisms for this type of auctions, such as VCG and GSP, is the limited expressiveness that they offer to the bidders. The General Auction Mechanism (GAM) of Aggarwal et al. [2009] takes a first step toward addressing the problem of limited expressiveness by computing a bidder optimal, envy-free outcome for linear utility functions with identical slopes and a single discontinuity per bidder-item pair. We show that in many practical situations this does not suffice to adequately model the preferences of the bidders, and we overcome this problem by presenting the first mechanism for piecewise linear utility functions with nonidentical slopes and multiple discontinuities. Our mechanism runs in polynomial time. Like GAM it is incentive compatible for inputs that fulfill a certain nondegeneracy assumption, but our requirement is more general than the requirement of GAM. For discontinuous utility functions that are nondegenerate as well as for continuous utility functions the outcome of our mechanism is a competitive equilibrium. We also show how our mechanism can be used to compute approximately bidder optimal, envy-free outcomes for a general class of continuous utility functions via piecewise linear approximation. Finally, we prove hardness results for even more expressive settings. acknowledgement: We would like to thank Veronika Loitzenbauer and the anonymous referees for their valuable feedback. article_number: '1' article_processing_charge: No article_type: original author: - first_name: Paul full_name: Dütting, Paul last_name: Dütting - first_name: Monika H full_name: Henzinger, Monika H id: 540c9bbd-f2de-11ec-812d-d04a5be85630 last_name: Henzinger orcid: 0000-0002-5008-6530 - first_name: Ingmar full_name: Weber, Ingmar last_name: Weber citation: ama: Dütting P, Henzinger MH, Weber I. An expressive mechanism for auctions on the web. ACM Transactions on Economics and Computation. 2015;4(1). doi:10.1145/2716312 apa: Dütting, P., Henzinger, M. H., & Weber, I. (2015). An expressive mechanism for auctions on the web. ACM Transactions on Economics and Computation. Association for Computing Machinery. https://doi.org/10.1145/2716312 chicago: Dütting, Paul, Monika H Henzinger, and Ingmar Weber. “An Expressive Mechanism for Auctions on the Web.” ACM Transactions on Economics and Computation. Association for Computing Machinery, 2015. https://doi.org/10.1145/2716312. ieee: P. Dütting, M. H. Henzinger, and I. Weber, “An expressive mechanism for auctions on the web,” ACM Transactions on Economics and Computation, vol. 4, no. 1. Association for Computing Machinery, 2015. ista: Dütting P, Henzinger MH, Weber I. 2015. An expressive mechanism for auctions on the web. ACM Transactions on Economics and Computation. 4(1), 1. mla: Dütting, Paul, et al. “An Expressive Mechanism for Auctions on the Web.” ACM Transactions on Economics and Computation, vol. 4, no. 1, 1, Association for Computing Machinery, 2015, doi:10.1145/2716312. short: P. Dütting, M.H. Henzinger, I. Weber, ACM Transactions on Economics and Computation 4 (2015). date_created: 2022-07-27T12:43:18Z date_published: 2015-12-02T00:00:00Z date_updated: 2023-02-09T10:08:41Z day: '02' doi: 10.1145/2716312 extern: '1' intvolume: ' 4' issue: '1' keyword: - Computational Mathematics - Marketing - Economics and Econometrics - Statistics and Probability - Computer Science (miscellaneous) language: - iso: eng month: '12' oa_version: None publication: ACM Transactions on Economics and Computation publication_identifier: eissn: - 2167-8383 issn: - 2167-8375 publication_status: published publisher: Association for Computing Machinery quality_controlled: '1' scopus_import: '1' status: public title: An expressive mechanism for auctions on the web type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 4 year: '2015' ... --- _id: '11774' abstract: - lang: eng text: "Combinatorial auctions (CA) are a well-studied area in algorithmic mechanism design. However, contrary to the standard model, empirical studies suggest that a bidder’s valuation often does not depend solely on the goods assigned to him. For instance, in adwords auctions an advertiser might not want his ads to be displayed next to his competitors’ ads. In this paper, we propose and analyze several natural graph-theoretic models that incorporate such negative externalities, in which bidders form a directed conflict graph with maximum out-degree Δ. We design algorithms and truthful mechanisms for social welfare maximization that attain approximation ratios depending on Δ.\r\n\r\nFor CA, our results are twofold: (1) A lottery that eliminates conflicts by discarding bidders/items independent of the bids. It allows to apply any truthful \U0001D6FC-approximation mechanism for conflict-free valuations and yields an \U0001D4AA(\U0001D6FCΔ)-approximation mechanism. (2) For fractionally sub-additive valuations, we design a rounding algorithm via a novel combination of a semi-definite program and a linear program, resulting in a cone program; the approximation ratio is \U0001D4AA((ΔloglogΔ)/logΔ). The ratios are almost optimal given existing hardness results.\r\n\r\nFor adwords auctions, we present several algorithms for the most relevant scenario when the number of items is small. In particular, we design a truthful mechanism with approximation ratio \U0001D45C(Δ) when the number of items is only logarithmic in the number of bidders." alternative_title: - LNCS article_processing_charge: No author: - first_name: Yun Kuen full_name: Cheung, Yun Kuen last_name: Cheung - first_name: Monika H full_name: Henzinger, Monika H id: 540c9bbd-f2de-11ec-812d-d04a5be85630 last_name: Henzinger orcid: 0000-0002-5008-6530 - first_name: Martin full_name: Hoefer, Martin last_name: Hoefer - first_name: Martin full_name: Starnberger, Martin last_name: Starnberger citation: ama: 'Cheung YK, Henzinger MH, Hoefer M, Starnberger M. Combinatorial auctions with conflict-based externalities. In: 11th International Conference on Web and Internet Economics. Vol 9470. Springer Nature; 2015:230–243. doi:10.1007/978-3-662-48995-6_17' apa: 'Cheung, Y. K., Henzinger, M. H., Hoefer, M., & Starnberger, M. (2015). Combinatorial auctions with conflict-based externalities. In 11th International Conference on Web and Internet Economics (Vol. 9470, pp. 230–243). Amsterdam, Netherlands: Springer Nature. https://doi.org/10.1007/978-3-662-48995-6_17' chicago: Cheung, Yun Kuen, Monika H Henzinger, Martin Hoefer, and Martin Starnberger. “Combinatorial Auctions with Conflict-Based Externalities.” In 11th International Conference on Web and Internet Economics, 9470:230–243. Springer Nature, 2015. https://doi.org/10.1007/978-3-662-48995-6_17. ieee: Y. K. Cheung, M. H. Henzinger, M. Hoefer, and M. Starnberger, “Combinatorial auctions with conflict-based externalities,” in 11th International Conference on Web and Internet Economics, Amsterdam, Netherlands, 2015, vol. 9470, pp. 230–243. ista: 'Cheung YK, Henzinger MH, Hoefer M, Starnberger M. 2015. Combinatorial auctions with conflict-based externalities. 11th International Conference on Web and Internet Economics. WINE: International Conference on Web and Internet Economics, LNCS, vol. 9470, 230–243.' mla: Cheung, Yun Kuen, et al. “Combinatorial Auctions with Conflict-Based Externalities.” 11th International Conference on Web and Internet Economics, vol. 9470, Springer Nature, 2015, pp. 230–243, doi:10.1007/978-3-662-48995-6_17. short: Y.K. Cheung, M.H. Henzinger, M. Hoefer, M. Starnberger, in:, 11th International Conference on Web and Internet Economics, Springer Nature, 2015, pp. 230–243. conference: end_date: 2015-12-12 location: Amsterdam, Netherlands name: 'WINE: International Conference on Web and Internet Economics' start_date: 2015-12-09 date_created: 2022-08-08T13:54:32Z date_published: 2015-12-09T00:00:00Z date_updated: 2023-02-10T09:08:30Z day: '09' doi: 10.1007/978-3-662-48995-6_17 extern: '1' external_id: arxiv: - '1509.09147' intvolume: ' 9470' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.1509.09147 month: '12' oa: 1 oa_version: Preprint page: 230–243 publication: 11th International Conference on Web and Internet Economics publication_identifier: eisbn: - '9783662489956' isbn: - '9783662489949' issn: - 0302-9743 publication_status: published publisher: Springer Nature quality_controlled: '1' scopus_import: '1' status: public title: Combinatorial auctions with conflict-based externalities type: conference user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 9470 year: '2015' ... --- _id: '11773' abstract: - lang: eng text: "Ad exchanges are an emerging platform for trading advertisement slots on the web with billions of dollars revenue per year. Every time a user visits a web page, the publisher of that web page can ask an ad exchange to auction off the ad slots on this page to determine which advertisements are shown at which price. Due to the high volume of traffic, ad networks typically act as mediators for individual advertisers at ad exchanges. If multiple advertisers in an ad network are interested in the ad slots of the same auction, the ad network might use a “local” auction to resell the obtained ad slots among its advertisers.\r\n\r\nIn this work we want to deepen the theoretical understanding of these new markets by analyzing them from the viewpoint of combinatorial auctions. Prior work studied mostly single-item auctions, while we allow the advertisers to express richer preferences over multiple items. We develop a game-theoretic model for the entanglement of the central auction at the ad exchange with the local auctions at the ad networks. We consider the incentives of all three involved parties and suggest a three-party competitive equilibrium, an extension of the Walrasian equilibrium that ensures envy-freeness for all participants. We show the existence of a three-party competitive equilibrium and a polynomial-time algorithm to find one for gross-substitute bidder valuations." alternative_title: - LNCS article_processing_charge: No author: - first_name: Oren full_name: Ben-Zwi, Oren last_name: Ben-Zwi - first_name: Monika H full_name: Henzinger, Monika H id: 540c9bbd-f2de-11ec-812d-d04a5be85630 last_name: Henzinger orcid: 0000-0002-5008-6530 - first_name: Veronika full_name: Loitzenbauer, Veronika last_name: Loitzenbauer citation: ama: 'Ben-Zwi O, Henzinger MH, Loitzenbauer V. Ad exchange: Envy-free auctions with mediators. In: 11th International Conference on Web and Internet Economics. Vol 9470. Springer Nature; 2015:104–117. doi:10.1007/978-3-662-48995-6_8' apa: 'Ben-Zwi, O., Henzinger, M. H., & Loitzenbauer, V. (2015). Ad exchange: Envy-free auctions with mediators. In 11th International Conference on Web and Internet Economics (Vol. 9470, pp. 104–117). Amsterdam, Netherlands: Springer Nature. https://doi.org/10.1007/978-3-662-48995-6_8' chicago: 'Ben-Zwi, Oren, Monika H Henzinger, and Veronika Loitzenbauer. “Ad Exchange: Envy-Free Auctions with Mediators.” In 11th International Conference on Web and Internet Economics, 9470:104–117. Springer Nature, 2015. https://doi.org/10.1007/978-3-662-48995-6_8.' ieee: 'O. Ben-Zwi, M. H. Henzinger, and V. Loitzenbauer, “Ad exchange: Envy-free auctions with mediators,” in 11th International Conference on Web and Internet Economics, Amsterdam, Netherlands, 2015, vol. 9470, pp. 104–117.' ista: 'Ben-Zwi O, Henzinger MH, Loitzenbauer V. 2015. Ad exchange: Envy-free auctions with mediators. 11th International Conference on Web and Internet Economics. WINE: International Conference on Web and Internet Economics, LNCS, vol. 9470, 104–117.' mla: 'Ben-Zwi, Oren, et al. “Ad Exchange: Envy-Free Auctions with Mediators.” 11th International Conference on Web and Internet Economics, vol. 9470, Springer Nature, 2015, pp. 104–117, doi:10.1007/978-3-662-48995-6_8.' short: O. Ben-Zwi, M.H. Henzinger, V. Loitzenbauer, in:, 11th International Conference on Web and Internet Economics, Springer Nature, 2015, pp. 104–117. conference: end_date: 2015-09-12 location: Amsterdam, Netherlands name: 'WINE: International Conference on Web and Internet Economics' start_date: 2015-09-09 date_created: 2022-08-08T13:33:56Z date_published: 2015-12-09T00:00:00Z date_updated: 2023-02-10T09:06:23Z day: '09' doi: 10.1007/978-3-662-48995-6_8 extern: '1' external_id: arxiv: - '1604.05562' intvolume: ' 9470' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.1604.05562 month: '12' oa: 1 oa_version: Preprint page: 104–117 publication: 11th International Conference on Web and Internet Economics publication_identifier: eisbn: - '9783662489956' isbn: - '9783662489949' issn: - 0302-9743 publication_status: published publisher: Springer Nature quality_controlled: '1' scopus_import: '1' status: public title: 'Ad exchange: Envy-free auctions with mediators' type: conference user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 9470 year: '2015' ... --- _id: '11785' abstract: - lang: eng text: "Recently we presented the first algorithm for maintaining the set of nodes reachable from a source node in a directed graph that is modified by edge deletions with \U0001D45C(\U0001D45A\U0001D45B) total update time, where \U0001D45A is the number of edges and \U0001D45B is the number of nodes in the graph [Henzinger et al. STOC 2014]. The algorithm is a combination of several different algorithms, each for a different \U0001D45A vs. \U0001D45B trade-off. For the case of \U0001D45A=Θ(\U0001D45B1.5) the running time is \U0001D442(\U0001D45B2.47), just barely below \U0001D45A\U0001D45B=Θ(\U0001D45B2.5). In this paper we simplify the previous algorithm using new algorithmic ideas and achieve an improved running time of \U0001D442̃ (min(\U0001D45A7/6\U0001D45B2/3,\U0001D45A3/4\U0001D45B5/4+\U0001D45C(1),\U0001D45A2/3\U0001D45B4/3+\U0001D45C(1)+\U0001D45A3/7\U0001D45B12/7+\U0001D45C(1))). This gives, e.g., \U0001D442(\U0001D45B2.36) for the notorious case \U0001D45A=Θ(\U0001D45B1.5). We obtain the same upper bounds for the problem of maintaining the strongly connected components of a directed graph undergoing edge deletions. Our algorithms are correct with high probabililty against an oblivious adversary." alternative_title: - LNCS article_processing_charge: No author: - first_name: Monika H full_name: Henzinger, Monika H id: 540c9bbd-f2de-11ec-812d-d04a5be85630 last_name: Henzinger orcid: 0000-0002-5008-6530 - first_name: Sebastian full_name: Krinninger, Sebastian last_name: Krinninger - first_name: Danupon full_name: Nanongkai, Danupon last_name: Nanongkai citation: ama: 'Henzinger MH, Krinninger S, Nanongkai D. Improved algorithms for decremental single-source reachability on directed graphs. In: 42nd International Colloquium on Automata, Languages and Programming. Vol 9134. Springer Nature; 2015:725-736. doi:10.1007/978-3-662-47672-7_59' apa: 'Henzinger, M. H., Krinninger, S., & Nanongkai, D. (2015). Improved algorithms for decremental single-source reachability on directed graphs. In 42nd International Colloquium on Automata, Languages and Programming (Vol. 9134, pp. 725–736). Kyoto, Japan: Springer Nature. https://doi.org/10.1007/978-3-662-47672-7_59' chicago: Henzinger, Monika H, Sebastian Krinninger, and Danupon Nanongkai. “Improved Algorithms for Decremental Single-Source Reachability on Directed Graphs.” In 42nd International Colloquium on Automata, Languages and Programming, 9134:725–36. Springer Nature, 2015. https://doi.org/10.1007/978-3-662-47672-7_59. ieee: M. H. Henzinger, S. Krinninger, and D. Nanongkai, “Improved algorithms for decremental single-source reachability on directed graphs,” in 42nd International Colloquium on Automata, Languages and Programming, Kyoto, Japan, 2015, vol. 9134, pp. 725–736. ista: 'Henzinger MH, Krinninger S, Nanongkai D. 2015. Improved algorithms for decremental single-source reachability on directed graphs. 42nd International Colloquium on Automata, Languages and Programming. ICALP: International Colloquium on Automata, Languages, and Programming, LNCS, vol. 9134, 725–736.' mla: Henzinger, Monika H., et al. “Improved Algorithms for Decremental Single-Source Reachability on Directed Graphs.” 42nd International Colloquium on Automata, Languages and Programming, vol. 9134, Springer Nature, 2015, pp. 725–36, doi:10.1007/978-3-662-47672-7_59. short: M.H. Henzinger, S. Krinninger, D. Nanongkai, in:, 42nd International Colloquium on Automata, Languages and Programming, Springer Nature, 2015, pp. 725–736. conference: end_date: 2015-07-10 location: Kyoto, Japan name: 'ICALP: International Colloquium on Automata, Languages, and Programming' start_date: 2015-07-06 date_created: 2022-08-11T08:51:32Z date_published: 2015-01-01T00:00:00Z date_updated: 2023-02-10T09:10:26Z day: '01' doi: 10.1007/978-3-662-47672-7_59 extern: '1' external_id: arxiv: - '1612.03856' intvolume: ' 9134' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1612.03856 month: '01' oa: 1 oa_version: Preprint page: 725 - 736 publication: 42nd International Colloquium on Automata, Languages and Programming publication_identifier: isbn: - '9783662476710' issn: - 0302-9743 publication_status: published publisher: Springer Nature quality_controlled: '1' scopus_import: '1' status: public title: Improved algorithms for decremental single-source reachability on directed graphs type: conference user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 9134 year: '2015' ... --- _id: '11787' abstract: - lang: eng text: "We present faster algorithms for computing the 2-edge and 2-vertex strongly connected components of a directed graph. While in undirected graphs the 2-edge and 2-vertex connected components can be found in linear time, in directed graphs with m edges and n vertices only rather simple O(m n)-time algorithms were known. We use a hierarchical sparsification technique to obtain algorithms that run in time \U0001D442(\U0001D45B2). For 2-edge strongly connected components our algorithm gives the first running time improvement in 20 years. Additionally we present an \U0001D442(\U0001D45A2/log\U0001D45B)-time algorithm for 2-edge strongly connected components, and thus improve over the O(m n) running time also when \U0001D45A=\U0001D442(\U0001D45B). Our approach extends to k-edge and k-vertex strongly connected components for any constant k with a running time of \U0001D442(\U0001D45B2log\U0001D45B) for k-edge-connectivity and \U0001D442(\U0001D45B3) for k-vertex-connectivity." alternative_title: - LNCS article_processing_charge: No author: - first_name: Monika H full_name: Henzinger, Monika H id: 540c9bbd-f2de-11ec-812d-d04a5be85630 last_name: Henzinger orcid: 0000-0002-5008-6530 - first_name: Sebastian full_name: Krinninger, Sebastian last_name: Krinninger - first_name: Veronika full_name: Loitzenbauer, Veronika last_name: Loitzenbauer citation: ama: 'Henzinger MH, Krinninger S, Loitzenbauer V. Finding 2-edge and 2-vertex strongly connected components in quadratic time. In: 2nd International Colloquium on Automata, Languages and Programming. Vol 9134. Springer Nature; 2015:713-724. doi:10.1007/978-3-662-47672-7_58' apa: 'Henzinger, M. H., Krinninger, S., & Loitzenbauer, V. (2015). Finding 2-edge and 2-vertex strongly connected components in quadratic time. In 2nd International Colloquium on Automata, Languages and Programming (Vol. 9134, pp. 713–724). Kyoto, Japan: Springer Nature. https://doi.org/10.1007/978-3-662-47672-7_58' chicago: Henzinger, Monika H, Sebastian Krinninger, and Veronika Loitzenbauer. “Finding 2-Edge and 2-Vertex Strongly Connected Components in Quadratic Time.” In 2nd International Colloquium on Automata, Languages and Programming, 9134:713–24. Springer Nature, 2015. https://doi.org/10.1007/978-3-662-47672-7_58. ieee: M. H. Henzinger, S. Krinninger, and V. Loitzenbauer, “Finding 2-edge and 2-vertex strongly connected components in quadratic time,” in 2nd International Colloquium on Automata, Languages and Programming, Kyoto, Japan, 2015, vol. 9134, pp. 713–724. ista: 'Henzinger MH, Krinninger S, Loitzenbauer V. 2015. Finding 2-edge and 2-vertex strongly connected components in quadratic time. 2nd International Colloquium on Automata, Languages and Programming. ICALP: International Colloquium on Automata, Languages, and Programming, LNCS, vol. 9134, 713–724.' mla: Henzinger, Monika H., et al. “Finding 2-Edge and 2-Vertex Strongly Connected Components in Quadratic Time.” 2nd International Colloquium on Automata, Languages and Programming, vol. 9134, Springer Nature, 2015, pp. 713–24, doi:10.1007/978-3-662-47672-7_58. short: M.H. Henzinger, S. Krinninger, V. Loitzenbauer, in:, 2nd International Colloquium on Automata, Languages and Programming, Springer Nature, 2015, pp. 713–724. conference: end_date: 2015-07-10 location: Kyoto, Japan name: 'ICALP: International Colloquium on Automata, Languages, and Programming' start_date: 2015-07-06 date_created: 2022-08-11T09:38:34Z date_published: 2015-07-06T00:00:00Z date_updated: 2023-02-10T09:21:47Z day: '06' doi: 10.1007/978-3-662-47672-7_58 extern: '1' external_id: arxiv: - '1412.6466' intvolume: ' 9134' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1412.6466 month: '07' oa: 1 oa_version: Preprint page: 713 - 724 publication: 2nd International Colloquium on Automata, Languages and Programming publication_identifier: isbn: - '9783662476710' issn: - 0302-9743 publication_status: published publisher: Springer Nature quality_controlled: '1' scopus_import: '1' status: public title: Finding 2-edge and 2-vertex strongly connected components in quadratic time type: conference user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 9134 year: '2015' ... --- _id: '11788' abstract: - lang: eng text: "Ad exchanges are becoming an increasingly popular way to sell advertisement slots on the internet. An ad exchange is basically a spot market for ad impressions. A publisher who has already signed contracts reserving advertisement impressions on his pages can choose between assigning a new ad impression for a new page view to a contracted advertiser or to sell it at an ad exchange. This leads to an online revenue maximization problem for the publisher. Given a new impression to sell decide whether (a) to assign it to a contracted advertiser and if so to which one or (b) to sell it at the ad exchange and if so at which reserve price. We make no assumptions about the distribution of the advertiser valuations that participate in the ad exchange and show that there exists a simple primal-dual based online algorithm, whose lower bound for the revenue converges to \U0001D445\U0001D434\U0001D437\U0001D44B+\U0001D445\U0001D434(1−1/\U0001D452), where \U0001D445\U0001D434\U0001D437\U0001D44B is the revenue that the optimum algorithm achieves from the ad exchange and \U0001D445\U0001D434 is the revenue that the optimum algorithm achieves from the contracted advertisers." alternative_title: - LNCS article_processing_charge: No author: - first_name: Wolfgang full_name: Dvořák, Wolfgang last_name: Dvořák - first_name: Monika H full_name: Henzinger, Monika H id: 540c9bbd-f2de-11ec-812d-d04a5be85630 last_name: Henzinger orcid: 0000-0002-5008-6530 citation: ama: 'Dvořák W, Henzinger MH. Online ad assignment with an ad exchange. In: 12th International Workshop of Approximation and Online Algorithms. Vol 8952. Springer Nature; 2015:156–167. doi:10.1007/978-3-319-18263-6_14' apa: 'Dvořák, W., & Henzinger, M. H. (2015). Online ad assignment with an ad exchange. In 12th International Workshop of Approximation and Online Algorithms (Vol. 8952, pp. 156–167). Wroclaw, Poland: Springer Nature. https://doi.org/10.1007/978-3-319-18263-6_14' chicago: Dvořák, Wolfgang, and Monika H Henzinger. “Online Ad Assignment with an Ad Exchange.” In 12th International Workshop of Approximation and Online Algorithms, 8952:156–167. Springer Nature, 2015. https://doi.org/10.1007/978-3-319-18263-6_14. ieee: W. Dvořák and M. H. Henzinger, “Online ad assignment with an ad exchange,” in 12th International Workshop of Approximation and Online Algorithms, Wroclaw, Poland, 2015, vol. 8952, pp. 156–167. ista: 'Dvořák W, Henzinger MH. 2015. Online ad assignment with an ad exchange. 12th International Workshop of Approximation and Online Algorithms. WAOA: International Workshop on Approximation and Online Algorithms, LNCS, vol. 8952, 156–167.' mla: Dvořák, Wolfgang, and Monika H. Henzinger. “Online Ad Assignment with an Ad Exchange.” 12th International Workshop of Approximation and Online Algorithms, vol. 8952, Springer Nature, 2015, pp. 156–167, doi:10.1007/978-3-319-18263-6_14. short: W. Dvořák, M.H. Henzinger, in:, 12th International Workshop of Approximation and Online Algorithms, Springer Nature, 2015, pp. 156–167. conference: end_date: 2014-09-12 location: Wroclaw, Poland name: 'WAOA: International Workshop on Approximation and Online Algorithms' start_date: 2014-09-11 date_created: 2022-08-11T09:43:32Z date_published: 2015-01-01T00:00:00Z date_updated: 2023-02-10T09:26:06Z day: '01' doi: 10.1007/978-3-319-18263-6_14 extern: '1' external_id: arxiv: - '1604.05603' intvolume: ' 8952' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1604.05603 month: '01' oa: 1 oa_version: Preprint page: 156–167 publication: 12th International Workshop of Approximation and Online Algorithms publication_identifier: issn: - 0302-9743 publication_status: published publisher: Springer Nature quality_controlled: '1' scopus_import: '1' status: public title: Online ad assignment with an ad exchange type: conference user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 8952 year: '2015' ... --- _id: '11786' abstract: - lang: eng text: "In this paper, we develop a dynamic version of the primal-dual method for optimization problems, and apply it to obtain the following results. (1) For the dynamic set-cover problem, we maintain an \U0001D442(\U0001D4532)-approximately optimal solution in \U0001D442(\U0001D453⋅log(\U0001D45A+\U0001D45B)) amortized update time, where \U0001D453 is the maximum “frequency” of an element, \U0001D45B is the number of sets, and \U0001D45A is the maximum number of elements in the universe at any point in time. (2) For the dynamic \U0001D44F-matching problem, we maintain an \U0001D442(1)-approximately optimal solution in \U0001D442(log3\U0001D45B) amortized update time, where \U0001D45B is the number of nodes in the graph." alternative_title: - LNCS article_processing_charge: No author: - first_name: Sayan full_name: Bhattacharya, Sayan last_name: Bhattacharya - first_name: Monika H full_name: Henzinger, Monika H id: 540c9bbd-f2de-11ec-812d-d04a5be85630 last_name: Henzinger orcid: 0000-0002-5008-6530 - first_name: Giuseppe F. full_name: Italiano, Giuseppe F. last_name: Italiano citation: ama: 'Bhattacharya S, Henzinger MH, Italiano GF. Design of dynamic algorithms via primal-dual method. In: 42nd International Colloquium on Automata, Languages and Programming. Vol 9134. Springer Nature; 2015:206-218. doi:10.1007/978-3-662-47672-7_17' apa: 'Bhattacharya, S., Henzinger, M. H., & Italiano, G. F. (2015). Design of dynamic algorithms via primal-dual method. In 42nd International Colloquium on Automata, Languages and Programming (Vol. 9134, pp. 206–218). Kyoto, Japan: Springer Nature. https://doi.org/10.1007/978-3-662-47672-7_17' chicago: Bhattacharya, Sayan, Monika H Henzinger, and Giuseppe F. Italiano. “Design of Dynamic Algorithms via Primal-Dual Method.” In 42nd International Colloquium on Automata, Languages and Programming, 9134:206–18. Springer Nature, 2015. https://doi.org/10.1007/978-3-662-47672-7_17. ieee: S. Bhattacharya, M. H. Henzinger, and G. F. Italiano, “Design of dynamic algorithms via primal-dual method,” in 42nd International Colloquium on Automata, Languages and Programming, Kyoto, Japan, 2015, vol. 9134, pp. 206–218. ista: 'Bhattacharya S, Henzinger MH, Italiano GF. 2015. Design of dynamic algorithms via primal-dual method. 42nd International Colloquium on Automata, Languages and Programming. ICALP: International Colloquium on Automata, Languages, and Programming, LNCS, vol. 9134, 206–218.' mla: Bhattacharya, Sayan, et al. “Design of Dynamic Algorithms via Primal-Dual Method.” 42nd International Colloquium on Automata, Languages and Programming, vol. 9134, Springer Nature, 2015, pp. 206–18, doi:10.1007/978-3-662-47672-7_17. short: S. Bhattacharya, M.H. Henzinger, G.F. Italiano, in:, 42nd International Colloquium on Automata, Languages and Programming, Springer Nature, 2015, pp. 206–218. conference: end_date: 2015-07-10 location: Kyoto, Japan name: 'ICALP: International Colloquium on Automata, Languages, and Programming' start_date: 2015-07-06 date_created: 2022-08-11T09:28:49Z date_published: 2015-01-01T00:00:00Z date_updated: 2023-02-10T09:13:31Z day: '01' doi: 10.1007/978-3-662-47672-7_17 extern: '1' external_id: arxiv: - '1604.05337' intvolume: ' 9134' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1604.05337 month: '01' oa: 1 oa_version: Preprint page: 206 - 218 publication: 42nd International Colloquium on Automata, Languages and Programming publication_identifier: isbn: - '9783662476710' issn: - 0302-9743 publication_status: published publisher: Springer Nature quality_controlled: '1' scopus_import: '1' status: public title: Design of dynamic algorithms via primal-dual method type: conference user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 9134 year: '2015' ... --- _id: '11845' abstract: - lang: eng text: "Phylogenetic diversity (PD) is a measure of biodiversity based on the evolutionary history of species. Here, we discuss several optimization problems related to the use of PD, and the more general measure split diversity (SD), in conservation prioritization.\r\nDepending on the conservation goal and the information available about species, one can construct optimization routines that incorporate various conservation constraints. We demonstrate how this information can be used to select sets of species for conservation action. Specifically, we discuss the use of species' geographic distributions, the choice of candidates under economic pressure, and the use of predator–prey interactions between the species in a community to define viability constraints.\r\nDespite such optimization problems falling into the area of NP hard problems, it is possible to solve them in a reasonable amount of time using integer programming. We apply integer linear programming to a variety of models for conservation prioritization that incorporate the SD measure.\r\nWe exemplarily show the results for two data sets: the Cape region of South Africa and a Caribbean coral reef community. Finally, we provide user-friendly software at http://www.cibiv.at/software/pda." article_processing_charge: No article_type: original author: - first_name: Olga full_name: Chernomor, Olga last_name: Chernomor - first_name: Bui Quang full_name: Minh, Bui Quang last_name: Minh - first_name: Félix full_name: Forest, Félix last_name: Forest - first_name: Steffen full_name: Klaere, Steffen last_name: Klaere - first_name: Travis full_name: Ingram, Travis last_name: Ingram - first_name: Monika H full_name: Henzinger, Monika H id: 540c9bbd-f2de-11ec-812d-d04a5be85630 last_name: Henzinger orcid: 0000-0002-5008-6530 - first_name: Arndt full_name: von Haeseler, Arndt last_name: von Haeseler citation: ama: Chernomor O, Minh BQ, Forest F, et al. Split diversity in constrained conservation prioritization using integer linear programming. Methods in Ecology and Evolution. 2015;6(1):83-91. doi:10.1111/2041-210x.12299 apa: Chernomor, O., Minh, B. Q., Forest, F., Klaere, S., Ingram, T., Henzinger, M. H., & von Haeseler, A. (2015). Split diversity in constrained conservation prioritization using integer linear programming. Methods in Ecology and Evolution. Wiley. https://doi.org/10.1111/2041-210x.12299 chicago: Chernomor, Olga, Bui Quang Minh, Félix Forest, Steffen Klaere, Travis Ingram, Monika H Henzinger, and Arndt von Haeseler. “Split Diversity in Constrained Conservation Prioritization Using Integer Linear Programming.” Methods in Ecology and Evolution. Wiley, 2015. https://doi.org/10.1111/2041-210x.12299. ieee: O. Chernomor et al., “Split diversity in constrained conservation prioritization using integer linear programming,” Methods in Ecology and Evolution, vol. 6, no. 1. Wiley, pp. 83–91, 2015. ista: Chernomor O, Minh BQ, Forest F, Klaere S, Ingram T, Henzinger MH, von Haeseler A. 2015. Split diversity in constrained conservation prioritization using integer linear programming. Methods in Ecology and Evolution. 6(1), 83–91. mla: Chernomor, Olga, et al. “Split Diversity in Constrained Conservation Prioritization Using Integer Linear Programming.” Methods in Ecology and Evolution, vol. 6, no. 1, Wiley, 2015, pp. 83–91, doi:10.1111/2041-210x.12299. short: O. Chernomor, B.Q. Minh, F. Forest, S. Klaere, T. Ingram, M.H. Henzinger, A. von Haeseler, Methods in Ecology and Evolution 6 (2015) 83–91. date_created: 2022-08-16T06:43:49Z date_published: 2015-01-01T00:00:00Z date_updated: 2023-02-17T09:30:08Z day: '01' ddc: - '570' doi: 10.1111/2041-210x.12299 extern: '1' external_id: pmid: - '25893087' file: - access_level: open_access checksum: 880e78f09f0ac99cb351c48dc97623b6 content_type: application/pdf creator: asandaue date_created: 2022-08-16T06:52:53Z date_updated: 2022-08-16T06:52:53Z file_id: '11846' file_name: 2015_MethodsInEcologyAndEvolutionChernomor.pdf file_size: 411415 relation: main_file success: 1 file_date_updated: 2022-08-16T06:52:53Z has_accepted_license: '1' intvolume: ' 6' issue: '1' language: - iso: eng month: '01' oa: 1 oa_version: Published Version page: 83-91 pmid: 1 publication: Methods in Ecology and Evolution publication_identifier: eissn: - 2041-210X publication_status: published publisher: Wiley quality_controlled: '1' scopus_import: '1' status: public title: Split diversity in constrained conservation prioritization using integer linear programming tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 6 year: '2015' ...