7,361 research outputs found
Data from 617 healthy participants performing the Iowa gambling task: a "many labs" collaboration
This data pool (N = 617) comes from 10 independent studies assessing performance of healthy participants (i.e., no known neurological impairments) on the Iowa gambling task (IGT) - a task measuring decision making under uncertainty in an experimental context. Participants completed a computerized version of the IGT consisting of 95 - 150 trials. The data consist of the choices of each participant on each trial, and the resulting rewards and losses. The data are stored as .rdata, .csv, and .txt files, and can be reused to (1) analyze IGT performance of healthy participants; (2) create a "super control group"; or (3) facilitate model-comparison efforts
Applying Biomedical Ontologies on Semantic Query Expansion
*1- Introduction*

The interpretation of a question (or information need) depends, among other things, of a series of lexicalsemantic relations that complement and help the cognitive process of answering that information need. Despite this fact, currently used information retrieval mechanisms take few advantages of the semantic interpretation of users’ information needs (usually specified through keywords). In most of the cases, those mechanisms are based on keyword matching, and thus are excessively dependant on the query and document terms.

There are several past results showing that, in general, information retrieval based on domain knowledge decreases the accuracy of keyword based search engines. We believe this approach deserves further discussion and experimentation, looking for more strong evidences that these negative results can really be generalized. Moreover, there are some questions left unanswered by previous work that our experiment is addressing:

(_i_) Using a scientific ontology, with formal construction and maintenance processes, such as the OBO ontologies, would produce better results? 

(_ii_) Are there more efficient query expansion techniques using available domain knowledge?

(_iii_) Is a scientific ontology complete enough to fulfill the information retrieval researchers’ needs, in general?

*2- Semantic Query Expansion*

To try to answer some of these questions, we run a query expansion experiment using the Gene Ontology (GO) as domain knowledge. As the document repository, we used an extraction of 10 years of PubMed publications (from 1994 to 2004), which contains approximately 4.6 Million documents. This dataset is a test collection used by the information retrieval community, called Genomic TREC.

*3- Results*
To evaluate our ontology-based semantic query expansion technique, we measured the effectiveness of the information retrieval mechanism with and without expansion. In a nutshell, the average result showed an increase of 28% on synonyms relations and a small decrease on other relations.

Our results show a lot of consistence with past related work. In fact, if the expansion strategy does not selectively choose when and how to expand, only synonym relations are worth to be used. However, looking further, it is possible to find several opportunities to try other expansion strategies. For example, the problem with query expansion using generalization/specialization relationships is that, if it is always applied, the bad results are more frequent than the good ones. But, if the strategy is to be selective on when to use these relations for expansion, the increasing on accuracy can be outstanding. As shown by our experiment, there was a query with 98% increment on effectiveness. 

*4- Conclusion*
We strongly believe that it is premature to assume that semantics-based query expansion is, in general, a recall-enhancing, precision-degrading technique. Our experiments suggest that by using scientific based ontologies (like OBO ontologies) with formal relations, it is possible to increase both recall and precision. Our group is currently revising this first experiment towards a better semantic query expansion strategy.

*5- Acknowledgements*
This work was partially funded by CAPES and CNPq research grants 311454/2006-2, 306889/2007-2 and 484713/2007-8.

*References*
_Fox E. Lexical relations enhancing effectiveness of information retrieval systems. SIGIR Forum, New York, v.15, n.3, p.5-3._

_Voorhees E. Query expansion using lexicalsemantic relations. In: ACM SIGIR conference on research and development in information retrieval, Proceedings, Dublin:17, p.61–69, 1994
Grand Challenge of Psychopathology in the Years to Come
SCOPUS: no.jinfo:eu-repo/semantics/publishe
Electrical conductivity of parylene F at high temperature
The electrical conductivity of both as-deposited and annealed poly(α,α,αâČ,αâČ-tetrafluoro-p-xylylene) (PA-F) films has been investigated up to 400°C. The static conductivity (Ï DC) values of PA-F measured between 200°C and 340°C appear to be âŒ2.5 orders of magnitude lower for annealed films than for as-deposited ones. This change is attributed to a strong increase in the crystallinity of the material occurring above 340°C. After annealing at 400°C in N2, the Ï DC value measured at 300°C, for instance, decreased from 3.8 Ă 10â12 Ωâ1 cmâ1 to 7.5 Ă 10â15 Ωâ1 cmâ1. Physical interpretations of such an improvement are offered
Los antropĂłnimos femeninos latinos de origen griego de la PenĂnsula IbĂ©rica
La presencia de nombres propios de origen griego en las inscripciones latinas de la PenĂnsula IbĂ©rica es notable. Abarca ademĂĄs un amplio perĂodo cronolĂłgico que se extiende en el tiempo como demuestra la documentaciĂłn medieval procedente de iglesias y centros religiosos. El artĂculo muestra que la adaptaciĂłn fonĂ©tica y morfolĂłgica de estos nombres en latĂn se produjo de forma limitada, lo que justifica que la variedad de las formas de estos nombres griegos no conociera una expansiĂłn fuera del cĂrculo cerrado de individuos que los llevaron en su momento.The presence of Greek Personal Names in the Latin in inscriptions coming from the Iberian Peninsula is considerable. Furthermore, from the evidence found in religious centres it is clear that these inscriptions comprise a broad chronological period reaching to Medieval times. This paper shows that the Phonetic and Morphological adaptation of these names was very limited in Latin. Consequently, the fact that the various forms of these Greek names did not expand outside the closed community which bore them is justified.El texto de este artĂculo fue presentado como comunicaciĂłn en el XXIV Congreso
Internacional de ICOS sobre Ciencias OnomĂĄsticas, Barcelona, 5-9 de septiembre de 2011
y se enmarca dentro del proyecto de investigaciĂłn FFI2010-21807
HEURISTICS USED BY HUMANS WITH PREFRONTAL CORTEX DAMAGE: TOWARD AN EMPIRICAL MODEL OF PHINEAS GAGE
In many research contexts it is necessary to group experimental subjects into behavioral âtypes.â Usually, this is done by pre-specifying a set of candidate decision-making heuristics and then assigning each subject to the heuristic that best describes his/her behavior. Such approaches might not perform well when used to explain the behavior of subjects with prefrontal cortex damage. The reason is that introspection is typically used to generate the candidate heuristic set, but this procedure is likely to fail when applied to the decision-making strategies of subjects with brain damage. This research uses the type classification approach introduced by Houser, Keane and McCabe (2002) to investigate the heuristics used by subjects in the gambling experiment (Bechara, Damasio, Damasio and Anderson, 1994). An advantage of our classification approach is that it does not require us to specify the nature of subjectsâ heuristics in advance. Rather, both the number and nature of the heuristics used are discerned directly from the experimental data. Our sample includes normal subjects, as well as subjects with damage to the ventromedial (VM) area of the prefrontal cortex. Subjects are âclusteredâ according to similarities in their heuristic, and this clustering does not preclude some normal and VM subjects from using the same decision rule. Our results are consistent with what others have found in subsequent experimentation with VM patients.experiments, heuristics, neuroeconomics, behavioral economics
The dynamics of the CBC Mode of Operation
In cryptography, the Cipher Block Chaining (CBC), one of the most commonly
used mode in recent years, is a mode of operation that uses a block cipher to
provide confidentiality or authenticity. In our previous research work, we have
shown that this mode of operation exhibits, under some conditions, a chaotic
behaviour. We have studied this behaviour by evaluating both its level of
sensibility and expansivity. In this paper, we intend to deepen the topological
study of the CBC mode of operation and evaluate its property of topological
mixing. Additionally, other quantitative evaluations are performed, and the
level of topological entropy has been evaluated too.Comment: Nonlinearity, IOP Publishing, 2016. arXiv admin note: text overlap
with arXiv:1601.0813
But First, Coffee
University of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/156364/1/Final_IP_PDF_Maalouf.pd
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