Two games in town: a comparison of dealer and auction prices in contemporary visual arts markets     

Michael Hutter  Christian Knebel  Gunnar Pietzner  Maren Schäfer 《Journal of Cultural Economics》2007,31(4):247-261

The article tests a couple of hypotheses relating to markets where demand is not taken as a given, but subject to sophisticated and encompassing price-building strategies. The study uses a data set that provides quoted dealer prices for medium-sized works of 100 leading visual artists from 1970 to 2004. These data are compared with auction price results for works by the same artists. The study reports significant discrepancies with respect to the relationship between the age of artists and prices paid for their works in the two markets, and with respect to general price developments in the two markets as measured by indices.

Michael HutterEmail:

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Das MINERVA-Projekt: Datenbankselektion für Peer-to-Peer-Websuche     

Matthias Bender  Sebastian Michel  Gerhard Weikum und Christian Zimmer 《Informatik - Forschung und Entwicklung》2005,20(3):152-166

Zusammenfassung In diesem Artikel wird MINERVA pr?sentiert, eine prototypische Implementierung einer verteilten Suchmaschine basierend auf einer Peer-to-Peer (P2P)-Architektur. MINERVA setzt auf die in der P2P-Welt verbreitete Technik verteilter Hash-Tabellen auf und benutzt diese zum Aufbau eines verteilten Verzeichnisses. Peers in unserem Ansatz entsprechen v?llig autonomen Benutzern mit ihren lokalen Suchm"oglichkeiten, die bereit sind, ihr lokales Wissen und ihre lokalen Suchm?glichkeiten im Rahmen einer Kollaboration zur Verfügung zu stellen. Wir formalisieren unsere Systemarchitektur und beschreiben das zentrale Problem einer effizienten Suche nach vielversprechenden Peers für eine konkrete Anfrage innerhalb des Verbundes. Wir greifen dabei auf existierende Methoden zurück and passen diese an unseren Systemkontext an. Wir pr?sentieren Experimente auf realen Daten, die verschiedene dieser Ans?tze vergleichen. Diese Experimente zeigen, dass die Qualit?t der Ans?tze variiert und untermauern damit die Wichtigkeit und den Einfluss einer leistungsstarken Methode zur Auswahl guter Datenbanken. Unsere Experimente deuten an, dass eine geringe Anzahl sorgf?ltig ausgew?hlter Datenbanken typischerweise bereits einen Gro?teil aller relevanten Ergebnisse des Gesamtsystems liefert.

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This paper presents the MINERVA project that protoypes a distributed search engine based on P2P techniques. MINERVA is layered on top of a Chord-style overlay network and uses a powerful crawling, indexing, and search engine on every autonomous peer. We formalize our system model and identify the problem of efficiently selecting promising peers for a query as a pivotal issue. We revisit existing approaches to the database selection problem and adapt them to our system environment. Measurements are performed to compare different selection strategies using real-world data. The experiments show significant performance differences between the strategies and prove the importance of a judicious peer selection strategy. The experiments also present first evidence that a small number of carefully selected peers already provide the vast majority of all relevant results.

CR Subject Classification H.4,H.3.3,H3.4  相似文献   

Das MINERVA-Projekt: Datenbankselektion für Peer-to-Peer-Websuche     

Matthias Bender  Sebastian Michel  Gerhard Weikum  Christian Zimmer 《Informatik - Forschung und Entwicklung》2005,12(5):152-166

In diesem Artikel wird MINERVA pr?sentiert, eine prototypische Implementierung einer verteilten Suchmaschine basierend auf einer Peer-to-Peer (P2P)-Architektur. MINERVA setzt auf die in der P2P-Welt verbreitete Technik verteilter Hash-Tabellen auf und benutzt diese zum Aufbau eines verteilten Verzeichnisses. Peers in unserem Ansatz entsprechen v?llig autonomen Benutzern mit ihren lokalen Suchm"oglichkeiten, die bereit sind, ihr lokales Wissen und ihre lokalen Suchm?glichkeiten im Rahmen einer Kollaboration zur Verfügung zu stellen. Wir formalisieren unsere Systemarchitektur und beschreiben das zentrale Problem einer effizienten Suche nach vielversprechenden Peers für eine konkrete Anfrage innerhalb des Verbundes. Wir greifen dabei auf existierende Methoden zurück and passen diese an unseren Systemkontext an. Wir pr?sentieren Experimente auf realen Daten, die verschiedene dieser Ans?tze vergleichen. Diese Experimente zeigen, dass die Qualit?t der Ans?tze variiert und untermauern damit die Wichtigkeit und den Einfluss einer leistungsstarken Methode zur Auswahl guter Datenbanken. Unsere Experimente deuten an, dass eine geringe Anzahl sorgf?ltig ausgew?hlter Datenbanken typischerweise bereits einen Gro?teil aller relevanten Ergebnisse des Gesamtsystems liefert.  相似文献   

Selective search, sectoral patterns, and the impact on product innovation performance     

Christian Köhler 《Research Policy》2012,41(8):1344-1356

The shift toward more open and interconnected innovation activities has been a major topic in recent academic and practitioner discussions. Firms must connect their in-house R&D activities with external partners, such as leading customers or universities, to increase the effectiveness of their innovation activities. Hence, management needs to define where to search for valuable knowledge in its environment. In this paper we argue that knowledge search has to reflect the heterogeneity of various knowledge sources with regard to the knowledge they can provide and how these sources can be activated. We hypothesize that search strategies driven by science, suppliers and the product market will contribute differently to innovation success with new-to-market versus imitated products. Moreover, we explore the effect of these types of knowledge search within different sectoral patterns of innovation. Our empirical analysis rests on a sample of almost 5000 firms from five Western European countries. The results support our hypotheses and highlight the potentials and shortcomings of different types of knowledge search.  相似文献   

Institutional Struggles for Recognition in the Academic Field: The Case of University Departments in German Chemistry     

Richard Münch  Christian Baier 《Minerva》2012,50(1):97-126

This paper demonstrates how the application of New Public Management (NPM) and the accompanying rise of academic capitalism in allocating research funds in the German academic field have interacted with a change from federal pluralism to a more stratified system of universities and departments. From this change, a tendency to build cartel-like structures of allocating symbolic capital resulting in oligopolistic structures of appropriating research funds has emerged. This macro level structure is complemented by the strengthening of the traditional oligarchic structures of research, carried out by an increasing number of assistants under the direction of a professor on the meso level. The outcome of this institutional setting is a significant gap between the appropriation of research funds according to the allocation of symbolic capital and the production of knowledge in publications. The application of NPM therefore needs to be explained more as a result of the normative pressure of a globally established model of “rational” administration, and less as a result of its functional effectiveness. This is demonstrated by an empirical analysis with simple and multiple regressions using data on the allocation of research grants and publication records of German chemistry departments.  相似文献   

Transferwirkungen künstlerischer Tätigkeiten. Ihre kritische Kommentierung durch eine umfassende Theorie ästhetischer Bildung     

Christian Rittelmeyer 《Zeitschrift für Erziehungswissenschaft》2013,16(3):217-231

Transfer research examines how artistic activities can have an impact outside of the realm of art itself. The article concludes that this research can be carried out in a meaningful way, only within the framework of a comprehensive theory of aesthetic education. This theory would encompass the structural analysis of artistic activity, as well as biographical reports about artistic experiences. The elucidation of the concepts or themes relevant to the theory would include the notion of aesthetic experience, the understanding of immediate, aesthetic experiences, the analysis of artistic processes, and the outcomes of scientifically evaluated applications of aesthetic education.  相似文献   

Approaches for Effective Vocationalisation of Secondary School Agriculture in Nigeria: The Views of Agricultural Science Teachers in Delta State,Nigeria     

Dr Canice N. Ikeoji  Christian C. Agwubike 《The Journal of Agricultural Education and Extension》2013,19(3):213-222

Abstract

This paper describes a random sample of serving agricultural science teachers in Delta State, Nigeria, as a background to understanding their views on four selected approaches for effective vocationalisation of secondary school agriculture. These approaches were used to develop a 23-item questionnaire based on current literature. A five-point Likert-type scale was used to determine how well the views of the respondents corresponded with the items in the questionnaire. Results showed, among others, that the average teaching experience of the 322 sampled teachers was 12.9 years; 50.6 % of the respondents were BSc(Ed) degree holders; 38.8% had Nigerian Certificate in Education (NCE), while 10.6% were Higher National Diploma (HND) holders. The respondents agreed that the identified approaches were necessary for effective vocationalisation of secondary school agriculture. The paper therefore recommends that the identified approaches should be pursued by the Nigerian government to ensure that vocational agriculture in secondary schools achieves the goals of the National Policy on Education.  相似文献   

Robots Teaching Other Little Robots: Neoliberalism,CCSS, and Teacher Professionalism     

Jason L. Endacott  Ginney P. Wright  Christian Z. Goering  Vicki S. Collet  George S. Denny  Jennifer Jennings Davis 《Review of Education, Pedagogy & Cultural Studies》2013,35(5):414-437

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Assistant Teachers in Prekindergarten Programs: What Roles Do Lead Teachers Feel Assistants Play in Classroom Management and Teaching?     

Laura Stout Sosinsky  Walter S. Gilliam 《Early education and development》2013,24(4):676-706

Assistant teachers are a ubiquitous yet virtually overlooked part of the early education workforce. Assistant teacher education level and its relationship to various classroom characteristics and the roles lead teachers feel assistants play in classroom management and teaching were examined in a nationally representative sample of 3,191 state-funded prekindergarten classes. Research Findings: Most classrooms had at least 1 paid assistant teacher, and classrooms with multiple assistants were more likely to be in Head Start. Lead teachers in public schools were more likely to have a bachelor's degree or higher, to be paired with an assistant with a high school degree, and to report fewer release hours for planning (alone or shared with assistants) than teachers in Head Start. Hierarchical multiple regression indicated that assistant teachers were rated as most useful to teaching duties when the classroom was in a Head Start setting, when the discrepancy between the lead and assistant teachers’ education was smaller, and when there were more shared release hours for planning. Practice and Policy: Implications focus on future prekindergarten teacher workforce needs, the need for more shared planning time and guidance in its use, and the need for more attention to and support for the training and roles of assistant teachers.  相似文献   

Supporting Content-Based Feedback in On-Line Writing Evaluation with LSA     

Peter W. Foltz  Sara Gilliam  Scott Kendall 《Interactive Learning Environments》2013,21(2):111-127

This paper describes tests of an automated essay grader and critic that uses Latent Semantic Analysis. Several methods which score the quality of the content in essays are described and tested. These methods are compared against human scores for the essays and the results show that LSA can score as accurately as the humans. Finally, we describe the implementation of the essay grader/critic in an undergraduate course. The outcome showed that students could write and revise their essays on-line, resulting in improved essays. Implications are discussed for the use of the technology in undergraduate courses and how it can provide an effective approach to incorporating more writing both in and outside of the classroom.  相似文献