Combinatorial Scoring Auctions

This paper is concerned with a combinatorial, multi-attribute procurement mechanism called combinatorial scoring auction. In the setting that we analyze, private information of the suppliers is multi-dimensional. The buyer wants to procure several items at once. Subsets of these items are characterized by a price as well as by a number of non-monetary attributes called quality (e.g. completion time). The suppliers submit offers specifying prices and quality levels for these subsets. These offers are evaluated according to a quasilinear scoring rule. Based on the resulting scores suppliers win contracts for the delivery of certain items. Such a contract only specifies the set of items a supplier has to deliver and a score that he has to meet. The decision about the specific price-quality combination yielding this contracted score is at the discretion of the supplier who aims at optimizing his own profit. We analyze the equilibria in such auctions and show the link between combinatorial scoring auctions and combinatorial price-only auctions. We demonstrate how this link can be used to employ preexisting knowledge about the equilibrium behavior in regular price-only auctions in the strategic analysis of combinatorial scoring auctions. Our results are the multi-item extension to the results of Asker and Cantillon (2007).mathematical economics;

The Impact of Concept Representation in Interactive Concept Validation (ICV)

Large scale ideation has developed as a promising new way of obtaining large numbers of highly diverse ideas for a given challenge. However, due to the scale of these challenges, algorithmic support based on a computational understanding of the ideas is a crucial component in these systems. One promising solution is the use of knowledge graphs to provide meaning. A significant obstacle lies in word-sense disambiguation, which cannot be solved by automatic approaches. In previous work, we introduce \textit{Interactive Concept Validation} (ICV) as an approach that enables ideators to disambiguate terms used in their ideas. To test the impact of different ways of representing concepts (should we show images of concepts, or only explanatory texts), we conducted experiments comparing three representations. The results show that while the impact on ideation metrics was marginal, time/click effort was lowest in the images only condition, while data quality was highest in the both condition

China's and India's emerging energy foreign policy

"This article aims at analyzing the changing energy foreign policies of the Anchor countries China and India. Both countries' economies are growing at an unprecedented pace. Due to high economic growth based on rapid industrialisation the energy consumption of both countries is rising fast. Against this background it is explored how the quest for energy security has transformed both countries' foreign policies. In fact, energy and, to an increasing extent, climate change, have become defining elements of both countries' foreign policy as well as of the international context in which they find themselves. A new 'energy foreign policy' which transforms the character of existing geopolitical rivalries is emerging. Outside actors such as the European Union must react to these developments when shaping their policy responses. International institutions and governance structures have to adapt to take into account the growing weight of China, India and other emerging economies. Last but not least, energy security and climate change considerations should be merged into an integrated sustainable energy policy." (author's abstract

Tracking, exploring and analyzing recent developments in German-language online press in the face of the coronavirus crisis: cOWIDplus Analysis and cOWIDplus Viewer

The coronavirus pandemic may be the largest crisis the world has had to face since World War II. It does not come as a surprise that it is also having an impact on language as our primary communication tool. We present three inter-connected resources that are designed to capture and illustrate these effects on a subset of the German language: An RSS corpus of German-language newsfeeds (with freely available untruncated unigram frequency lists), a static but continuously updated HTML page tracking the diversity of the used vocabulary and a web application that enables other researchers and the broader public to explore these effects without any or with little knowledge of corpus representation/exploration or statistical analyses.Comment: 13 pages, 6 figures, 1 table, 3852 word

Veränderung der leistungsabhängigen Schwerverkehrsabgabe in Abhängigkeit der Streckenbelastung

Die bisherige Diskussion bezüglich Straßennutzungsgebühren konzentrierte sich überwiegend auf mögliche Verlagerungseffekte auf andere Verkehrsträger. Eine ver-kehrssteuernde Wirkung im Straßennetz ist durch die kilometer- und typabhängige Entrichtung der Maut vernachlässigt worden. In diesem Beitrag wird ein Modell vor-geschlagen, das durch eine monetäre Steuerung eine gleichmäßige Auslastung des Schweizer Autobahnnetzes im Nord-Süd-Gütertransitverkehr unter Berücksichtigung von Opportunitätskosten der Zeit berücksichtigt. Die Ergebnisse des hier behandelten Sonderfalls zeigen, dass insbesondere die Wahl der Opportunitätskosten der Zeit immensen Einfluss auf die Höhe der Maut - und damit auf die vom Spediteur zu verrechnenden Kosten - hat. The present discussion concerning road pricing aims predominantly on modal-shift due to concentrating on distance- and vehicle-type-dependent road toll. Thus, a regulating effect on equal distribution of the transport volume in freight-transit has been neglected widely. Here we present a mathematical model which concerns different sets of value of time (VOT) and guarantees an average utilisation of road capacity in this specific case study of Switzerland. The results show that the value of time has signifi-cantly high impact on the amount of the road toll and hence on the total costs for the transportation companies. --

How many people constitute a crowd and what do they do? Quantitative analyses of revisions in the English and German wiktionary editions

Wiktionary is increasingly gaining influence in a wide variety of linguistic fields such as NLP and lexicography, and has great potential to become a serious competitor for publisher-based and academic dictionaries. However, little is known about the "crowd" that is responsible for the content of Wiktionary. In this article, we want to shed some light on selected questions con-cerning large-scale cooperative work in online dictionaries. To this end, we use quantitative analy-ses of the complete edit history files of the English and German Wiktionary language editions. Concerning the distribution of revisions over users, we show that — compared to the overall user base — only very few authors are responsible for the vast majority of revisions in the two Wiktion-ary editions. In the next step, we compare this distribution to the distribution of revisions over all the articles. The articles are subsequently analysed in terms of rigour and diversity, typical revision patterns through time, and novelty (the time since the last revision). We close with an examination of the relationship between corpus frequencies of headwords in articles, the number of article vis-its, and the number of revisions made to articles.Keywords: User-Generated Content, Online Dictionary, Wiktionary, Revision, Edit, Frequency, Collaboration, Wisdom of The Crow

The Na+ cycle in Acetobacterium woodii: identification and characterization of a Na+ translocating F1F0-ATPase with a mixed oligomer of 8 and 16 kDa proteolipids

AbstractThe homoacetogenic bacterium Acetobacterium woodii relies on a sodium ion current across its cytoplasmic membrane for energy-dependent reactions. The sodium ion potential is established by a yet to be identified primary, electrogenic pump connected to the Wood-Ljungdahl pathway. Reactions possibly involved in Na+ export are discussed. The electrochemical sodium ion potential generated is used to drive endergonic reactions such as flagellar rotation and ATP synthesis. Biochemical and molecular data identified the Na+-ATPase of A. woodii as a typical member of the F1F0 class of ATPases. Its catalytic properties and the hypothetical sodium ion binding site in subunit c are discussed. The encoding genes were cloned and, surprisingly, the atp operon was shown to contain multiple copies of genes encoding subunit c. Two copies encode identical 8 kDa proteolipids, and a third copy arose by duplication and subsequent fusion of two genes. Furthermore, the duplicated subunit c does not contain the ion binding site in hair pin two. Biochemical and molecular data revealed that all three copies of subunit c constitute a mixed oligomer. The evolution of the structure and function of subunit c in ATPases from eucarya, bacteria, and archaea is discussed

OPTIMIZING SERVER CONSOLIDATION FOR ENTERPRISE APPLICATION SERVICE PROVIDERS

In enterprise application environments, hardware resources show averagely low utilization rates due to a provisioning practice that is based on peak demands. Therefore, the consolidation of orthogonal workloads can improve energy efficiency and reduce total cost of ownership. In this paper, we address existing workload consolidation potential by solving a bin packing problem, where the number of servers is to be minimized. Since dynamic workloads, gathered from historical traces, and priorities of running services are considered, we formulate the Dynamic Priority-based Workload Consolidation Problem (DPWCP) and develop solution algorithms using heuristics and metaheuristics. Relevance is pointed out by an analysis of service resource demands and server capacities across four studied cases from productively operating enterprise application service providers. After a classification of related work, seven algorithms were developed and evaluated regarding their exploited optimization potential and computing time. Best results were achieved by a best-fit approach that uses a genetic algorithm to optimize its input sequence (GA_BF). When applying the GA_BF onto the four studied cases, average utilization rates could be increased from 23 to 63 percent within an average computing time of 22.5 seconds. Therefore, the overall server capacity was reduced significantly by up to 83%

Integrated Optimization of IT Service Performance and Availability Using Performability Prediction Models

Optimizing the performance and availability of an IT service in the design stage are typically considered as independent tasks. However, since both aspects are related to one another, these activities could be combined by applying performability models, in which both the performance and the availability of a service can be more accurately predicted. In this paper, a design optimization problem for IT services is defined and applied in two scenarios, one of which considers a mechanism in which redundant components can be used both for failover as well as handling overload situations. Results show that including such aspects affecting both availability and performance in prediction models can lead to more cost-effective service designs. Thus, performability prediction models are one opportunity to combine performance and availability management for IT services