1,951 research outputs found
Selective Migration in New Towns: Influence on Regional Accountability in Early School Leaving
In an attempt to stop the rampant suburbanization, which countries experienced after World War II, a 'new town' policy was enrolled. As a major objective, and related to its origins, new towns were effective in attracting low and medium income households. Nowadays, cities and municipalities experience an increased accountability in which incentives are provided by 'naming and shaming'. This paper focuses on an issue where both historical and local policy come together: early school leaving. Using an iterative matching analysis, it suggests how to account for differences in population and regional characteristics. In other words, how to compare and interpret early school leaving in new towns in a more `fair' way. The results point out that (statistically) mitigating historical differences is necessary, even though this does not necessarily means that 'naming' is replaced by 'shaming'.Urban Economics; New Town; Early School Leaving; Naming and Shaming; Iterative Matching, Urban Planning
Non-strict Interventionism: The Case Of Right-Nested Counterfactuals
The paper focuses on a recent challenge brought forward against the interventionist approach to the meaning of counterfactual conditionals. According to this objection, interventionism cannot account for the interpretation of right-nested counterfactuals, the problem being its strict interventionism. We will report on the results of an empirical study supporting the objection. Furthermore, we will extend the well-known logic of intervention with a new operator expressing an alternative notion of intervention that does away with strict interventionism (and thus can account for some critical examples). This new notion of intervention operates on the valuation of the variables in a causal model, and not on their functional dependencies.</p
Comparison between hybrid and fully kinetic models of asymmetric magnetic reconnection: coplanar and guide field configurations
Magnetic reconnection occurring in collisionless environments is a
multi-scale process involving both ion and electron kinetic processes. Because
of their small mass, the electron scales are difficult to resolve in numerical
and satellite data, it is therefore critical to know whether the overall
evolution of the reconnection process is influenced by the kinetic nature of
the electrons, or is unchanged when assuming a simpler, fluid, electron model.
This paper investigate this issue in the general context of an asymmetric
current sheet, where both the magnetic field amplitude and the density vary
through the discontinuity. A comparison is made between fully kinetic and
hybrid kinetic simulations of magnetic reconnection in coplanar and guide field
systems. The models share the initial condition but differ in their electron
modeling. It is found that the overall evolution of the system, including the
reconnection rate, is very similar between both models. The best agreement is
found in the guide field system, which confines particle better than the
coplanar one, where the locality of the moments is violated by the electron
bounce motion. It is also shown that, contrary to the common understanding,
reconnection is much faster in the guide field system than in the coplanar one.
Both models show this tendency, indicating that the phenomenon is driven by ion
kinetic effects and not electron ones.Comment: 11 pages, 8 figures, accepted in Physics of Plasma
Classification of Message Spreading in a Heterogeneous Social Network
Nowadays, social networks such as Twitter, Facebook and LinkedIn become
increasingly popular. In fact, they introduced new habits, new ways of
communication and they collect every day several information that have
different sources. Most existing research works fo-cus on the analysis of
homogeneous social networks, i.e. we have a single type of node and link in the
network. However, in the real world, social networks offer several types of
nodes and links. Hence, with a view to preserve as much information as
possible, it is important to consider so-cial networks as heterogeneous and
uncertain. The goal of our paper is to classify the social message based on its
spreading in the network and the theory of belief functions. The proposed
classifier interprets the spread of messages on the network, crossed paths and
types of links. We tested our classifier on a real word network that we
collected from Twitter, and our experiments show the performance of our belief
classifier
ES8 COST-EFFECTIVENESS OF DARUNAVIR/R IN HIGHLY TREATMENT-EXPERIENCED HIV/AIDS PATIENTS IN DIFFERENT EUROPEAN HEALTH CARE SETTINGS
Large-scale molecular interaction data sets have the potential to provide a comprehensive, system-wide understanding of biological function. Although individual molecules can be promiscuous in terms of their contribution to function, molecular functions emerge from the specific interactions of molecules giving rise to modular organisation. As functions often derive from a range of mechanisms, we demonstrate that they are best studied using networks derived from different sources. Implementing a graph partitioning algorithm we identify subnetworks in yeast protein-protein interaction (PPI), genetic interaction and gene co-regulation networks. Among these subnetworks we identify cohesive subgraphs that we expect to represent functional modules in the different data types. We demonstrate significant overlap between the subgraphs generated from the different data types and show these overlaps can represent related functions as represented by the Gene Ontology (GO). Next, we investigate the correspondence between our subgraphs and the Gene Ontology. This revealed varying degrees of coverage of the biological process, molecular function and cellular component ontologies, dependent on the data type. For example, subgraphs from the PPI show enrichment for 84%, 58% and 93% of annotated GO terms, respectively. Integrating the interaction data into a combined network increases the coverage of GO. Furthermore, the different annotation types of GO are not predominantly associated with one of the interaction data types. Collectively our results demonstrate that successful capture of functional relationships by network data depends on both the specific biological function being characterised and the type of network data being used. We identify functions that require integrated information to be accurately represented, demonstrating the limitations of individual data types. Combining interaction subnetworks across data types is therefore essential for fully understanding the complex and emergent nature of biological function
Wikipedia vandalism detection: combining natural language, metadata, and reputation features
Wikipedia is an online encyclopedia which anyone can edit.
While most edits are constructive, about 7% are acts of vandalism. Such
behavior is characterized by modifications made in bad faith; introducing
spam and other inappropriate content.
In this work, we present the results of an effort to integrate three of the
leading approaches to Wikipedia vandalism detection: a spatio-temporal
analysis of metadata (STiki), a reputation-based system (WikiTrust),
and natural language processing features. The performance of the resulting
joint system improves the state-of-the-art from all previous methods
and establishes a new baseline for Wikipedia vandalism detection. We
examine in detail the contribution of the three approaches, both for the
task of discovering fresh vandalism, and for the task of locating vandalism
in the complete set of Wikipedia revisions.The authors from Universitat PolitĂšcnica de ValĂšncia thank also the MICINN research project TEXT-ENTERPRISE 2.0 TIN2009-13391-C04-03 (Plan I+D+i). UPenn contributions were supported in part by ONR MURI N00014-07-1-0907. This research was partially supported by award 1R01GM089820-01A1 from the National Institute Of General Medical Sciences, and by ISSDM, a UCSC-LANL educational collaboration.Adler, BT.; Alfaro, LD.; Mola Velasco, SM.; Rosso, P.; West, AG. (2011). Wikipedia vandalism detection: combining natural language, metadata, and reputation features. En Computational Linguistics and Intelligent Text Processing. Springer Verlag (Germany). 6609:277-288. https://doi.org/10.1007/978-3-642-19437-5_23S2772886609Wikimedia Foundation: Wikipedia (2010) [Online; accessed December 29, 2010]Wikimedia Foundation: Wikistats (2010) [Online; accessed December 29, 2010]Potthast, M.: Crowdsourcing a Wikipedia Vandalism Corpus. In: Proc. of the 33rd Intl. ACM SIGIR Conf. (SIGIR 2010). ACM Press, New York (July 2010)Gralla, P.: U.S. senator: Itâs time to ban Wikipedia in schools, libraries, http://blogs.computerworld.com/4598/u_s_senator_its_time_to_ban_wikipedia_in_schools_libraries [Online; accessed November 15, 2010]Olanoff, L.: School officials unite in banning Wikipedia. Seattle Times (November 2007)Mola-Velasco, S.M.: Wikipedia Vandalism Detection Through Machine Learning: Feature Review and New Proposals. In: Braschler, M., Harman, D. (eds.) Notebook Papers of CLEF 2010 LABs and Workshops, Padua, Italy, September 22-23 (2010)Adler, B., de Alfaro, L., Pye, I.: Detecting Wikipedia Vandalism using WikiTrust. In: Braschler, M., Harman, D. (eds.) Notebook Papers of CLEF 2010 LABs and Workshops, Padua, Italy, September 22-23 (2010)West, A.G., Kannan, S., Lee, I.: Detecting Wikipedia Vandalism via Spatio-Temporal Analysis of Revision Metadata. In: EUROSEC 2010: Proceedings of the Third European Workshop on System Security, pp. 22â28 (2010)West, A.G.: STiki: A Vandalism Detection Tool for Wikipedia (2010), http://en.wikipedia.org/wiki/Wikipedia:STikiWikipedia: User: AntiVandalBot â Wikipedia, http://en.wikipedia.org/wiki/User:AntiVandalBot (2010) [Online; accessed November 2, 2010]Wikipedia: User:MartinBot â Wikipedia (2010), http://en.wikipedia.org/wiki/User:MartinBot [Online; accessed November 2, 2010]Wikipedia: User:ClueBot â Wikipedia (2010), http://en.wikipedia.org/wiki/User:ClueBot [Online; accessed November 2, 2010]Carter, J.: ClueBot and Vandalism on Wikipedia (2008), http://www.acm.uiuc.edu/~carter11/ClueBot.pdf [Online; accessed November 2, 2010]RodrĂguez Posada, E.J.: AVBOT: detecciĂłn y correcciĂłn de vandalismos en Wikipedia. NovATIca (203), 51â53 (2010)Potthast, M., Stein, B., Gerling, R.: Automatic Vandalism Detection in Wikipedia. In: Macdonald, C., Ounis, I., Plachouras, V., Ruthven, I., White, R.W. (eds.) ECIR 2008. LNCS, vol. 4956, pp. 663â668. Springer, Heidelberg (2008)Smets, K., Goethals, B., Verdonk, B.: Automatic Vandalism Detection in Wikipedia: Towards a Machine Learning Approach. In: WikiAI 2008: Proceedings of the Workshop on Wikipedia and Artificial Intelligence: An Evolving Synergy, pp. 43â48. AAAI Press, Menlo Park (2008)Druck, G., Miklau, G., McCallum, A.: Learning to Predict the Quality of Contributions to Wikipedia. In: WikiAI 2008: Proceedings of the Workshop on Wikipedia and Artificial Intelligence: An Evolving Synergy, pp. 7â12. AAAI Press, Menlo Park (2008)Itakura, K.Y., Clarke, C.L.: Using Dynamic Markov Compression to Detect Vandalism in the Wikipedia. In: SIGIR 2009: Proc. of the 32nd Intl. ACM Conference on Research and Development in Information Retrieval, pp. 822â823 (2009)Chin, S.C., Street, W.N., Srinivasan, P., Eichmann, D.: Detecting Wikipedia Vandalism with Active Learning and Statistical Language Models. In: WICOW 2010: Proc. of the 4th Workshop on Information Credibility on the Web (April 2010)Zeng, H., Alhoussaini, M., Ding, L., Fikes, R., McGuinness, D.: Computing Trust from Revision History. In: Intl. Conf. on Privacy, Security and Trust (2006)McGuinness, D., Zeng, H., da Silva, P., Ding, L., Narayanan, D., Bhaowal, M.: Investigation into Trust for Collaborative Information Repositories: A Wikipedia Case Study. In: Proc. of the Workshop on Models of Trust for the Web (2006)Adler, B., de Alfaro, L.: A Content-Driven Reputation System for the Wikipedia. In: WWW 2007: Proceedings of the 16th International World Wide Web Conference. ACM Press, New York (2007)Belani, A.: Vandalism Detection in Wikipedia: a Bag-of-Words Classifier Approach. Computing Research Repository (CoRR) abs/1001.0700 (2010)Potthast, M., Stein, B., Holfeld, T.: Overview of the 1st International Competition on Wikipedia Vandalism Detection. In: Braschler, M., Harman, D. (eds.) Notebook Papers of CLEF 2010 LABs and Workshops, Padua, Italy, September 22-23 (2010)Hall, M., Frank, E., Holmes, G., Pfahringer, B., Reutemann, P., Witten, I.: The WEKA Data Mining Software: An Update. SIGKDD Explorations 11(1) (2009)Breiman, L.: Random Forests. Machine Learning 45(1), 5â32 (2001)Davis, J., Goadrich, M.: The relationship between Precision-Recall and ROC curves. In: ICML 2006: Proc. of the 23rd Intl. Conf. on Machine Learning (2006
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