17 research outputs found
Freedom, Anarchy and Conformism in Academic Research
In this paper I attempt to make a case for promoting the courage of rebels within the citadels of orthodoxy in academic research environments. Wicksell in Macroeconomics, Brouwer in the Foundations of Mathematics, Turing in Computability Theory, Sraffa in the Theories of Value and Distribution are, in my own fields of research, paradigmatic examples of rebels, adventurers and non-conformists of the highest caliber in scientific research within University environments. In what sense, and how, can such rebels, adventurers and non-conformists be fostered in the current University research environment dominated by the cult of 'picking winners'? This is the motivational question lying behind the historical outlines of the work of Brouwer, Hilbert, Bishop, Veronese, Gödel, Turing and Sraffa that I describe in this paper. The debate between freedom in research and teaching, and the naked imposition of 'correct' thinking, on potential dissenters of the mind, is of serious concern in this age of austerity of material facilities. It is a debate that has occupied some of the finest minds working at the deepest levels of foundational issues in mathematics, metamathematics and economic theory. By making some of the issues explicit, I hope it is possible to encourage dissenters to remain courageous in the face of current dogmasNon-conformist research, economic theory, mathematical economics, 'Hilbert's Dogma', Hilbert's Program, computability theory
Shibboleth and the challenge of authentication in multiple servers on a e-learning environment
L' objectiu dâaquest treball Ă©s lâestudi, implementaciĂł i prova d'un sistema de
autentificaciĂł compartida per a mĂșltiples servidors. Encara que des d'un principi es
sabia que es treballaria amb Shibboleth tambĂ© sâhan tingut en compte altres possibles
solucions. Shibboleth Ă©s un projecte desenvolupat per els membres de les universitats
que formen el consorci Internet2 amb lâ objectiu de desenvolupar un nou middleware
per a realitzar les funcions dâautentificaciĂł compartida en mĂșltiples servidors i pensat
especĂficament per facilitar la col·laboraciĂł entre institucions i lâaccĂ©s a continguts
digitals.
Shibboleth Ă©s una soluciĂł complerta ja que contempla des de lâautentificaciĂł ,
autoritzaciĂł i accounting, fins al sistema de login i els atributs a emprar. La qual cosa fa
que es converteixi en un entorn de treball molt segur perĂČ amb lâavantatge dâaportar
privacitat als usuaris.
El primer objectiu ha estat identificar les peculiaritats i requeriments dels entorns de elearning
distribuĂŻts, per aixĂČ sâha estudiat conceptes especĂfics de seguretat aixĂ com la
manera dâadaptar-los a lâentorn requerit. DesprĂšs sâha fet una comparativa de les
solucions existents al mercat amb una funcionalitat similar a Shibboleth, per tal de
presentar els avantatges i desavantatges de Shibboleth vers aquests.
Posteriorment, el treball ha consistit en entendre la estructura i els principis de
funcionament de Shibboleth, quin tipus de requeriments tenia, el funcionament i
objectius de cada part, estudiar els requeriments de lâentorn especĂfic per al qual ha
estat dissenyat (e-learning) i donar una idea general de com sâ hauria de fer la
implementaciĂł. TambĂ© sâhan estudiat totes les tecnologies i requeriments necessaris
per desenvolupar Shibboleth.
Una vegada estudiat Shibboleth i l'entorn especĂfic en el que sâhauria dâintegrar, sâha
muntat un escenari per a la posada en marxa i proves dâaquest, provant especĂficament
cada part i entenent amb les proves reals el funcionament. Amb lâescenari en
funcionament, la idea era integrar Shibboleth amb Sakai i Blackboard, els CMS (Course
Management System) utilitzats a on-campus, el campus virtual de la Fachhochschule
LĂŒbeck.
Per a finalitzar i a mode de conclusions s'ha fet una petita explicaciĂł dels resultats
obtinguts, una valoraciĂł de com Shibboleth resoldria les necessitats plantejades i
algunes propostes de millora
The information rate and other parameters of probabilistic context free grammars and their parsers
Probabilistic context-free languages are defined by giving predetermined probabilities (preprobabilities) for the choices that their grammars make when generating.
Chapter 1 shows how to carry out the above definition, and how to calculate some parameters or the language; for instance: average length or work, mean square length, digraph probabilities, entropy.
Chapter 2 introduces generating ffunctions related to grammars. It uses them to derive a condition for which preprobabilities give rise to well-fformed probability spaces. Two ffunctions, the length and entropy generating ffunctions are studied in detail. They are algebraic ffunctions, can in general only be defined implicitly, but can be used to give unified explicit methods or calculating all the parameters or chapter I (and more).
Chapter 3 defines and shows how to calculate the information rate or a language. As a by-blow, Macmillan's theorem is extended (for a small class or processes) to an analogue or the Central Limit Theorem.
Chapter 4 tries to compare the efficiencies or different parsing algorithms. In a reasonable sense, all deterministic parsers take equal average time to parse, any backtracking parser is slower, but there is no general algorithm for calculating the speed or a backtracking parser
Shibboleth and the challenge of authentication in multiple servers on a e-learning environment
L' objectiu dâaquest treball Ă©s lâestudi, implementaciĂł i prova d'un sistema de
autentificaciĂł compartida per a mĂșltiples servidors. Encara que des d'un principi es
sabia que es treballaria amb Shibboleth tambĂ© sâhan tingut en compte altres possibles
solucions. Shibboleth Ă©s un projecte desenvolupat per els membres de les universitats
que formen el consorci Internet2 amb lâ objectiu de desenvolupar un nou middleware
per a realitzar les funcions dâautentificaciĂł compartida en mĂșltiples servidors i pensat
especĂficament per facilitar la col·laboraciĂł entre institucions i lâaccĂ©s a continguts
digitals.
Shibboleth Ă©s una soluciĂł complerta ja que contempla des de lâautentificaciĂł ,
autoritzaciĂł i accounting, fins al sistema de login i els atributs a emprar. La qual cosa fa
que es converteixi en un entorn de treball molt segur perĂČ amb lâavantatge dâaportar
privacitat als usuaris.
El primer objectiu ha estat identificar les peculiaritats i requeriments dels entorns de elearning
distribuĂŻts, per aixĂČ sâha estudiat conceptes especĂfics de seguretat aixĂ com la
manera dâadaptar-los a lâentorn requerit. DesprĂšs sâha fet una comparativa de les
solucions existents al mercat amb una funcionalitat similar a Shibboleth, per tal de
presentar els avantatges i desavantatges de Shibboleth vers aquests.
Posteriorment, el treball ha consistit en entendre la estructura i els principis de
funcionament de Shibboleth, quin tipus de requeriments tenia, el funcionament i
objectius de cada part, estudiar els requeriments de lâentorn especĂfic per al qual ha
estat dissenyat (e-learning) i donar una idea general de com sâ hauria de fer la
implementaciĂł. TambĂ© sâhan estudiat totes les tecnologies i requeriments necessaris
per desenvolupar Shibboleth.
Una vegada estudiat Shibboleth i l'entorn especĂfic en el que sâhauria dâintegrar, sâha
muntat un escenari per a la posada en marxa i proves dâaquest, provant especĂficament
cada part i entenent amb les proves reals el funcionament. Amb lâescenari en
funcionament, la idea era integrar Shibboleth amb Sakai i Blackboard, els CMS (Course
Management System) utilitzats a on-campus, el campus virtual de la Fachhochschule
LĂŒbeck.
Per a finalitzar i a mode de conclusions s'ha fet una petita explicaciĂł dels resultats
obtinguts, una valoraciĂł de com Shibboleth resoldria les necessitats plantejades i
algunes propostes de millora
StudentsÂŽ language in computer-assisted tutoring of mathematical proofs
Truth and proof are central to mathematics. Proving (or disproving) seemingly simple statements often turns out to be one of the hardest mathematical tasks. Yet, doing proofs is rarely taught in the classroom. Studies on cognitive difficulties in learning to do proofs have shown that pupils and students not only often do not understand or cannot apply basic formal reasoning techniques and do not know how to use formal mathematical language, but, at a far more fundamental level, they also do not understand what it means to prove a statement or even do not see the purpose of proof at all. Since insight into the importance of proof and doing proofs as such cannot be learnt other than by practice, learning support through individualised tutoring is in demand.
This volume presents a part of an interdisciplinary project, set at the intersection of pedagogical science, artificial intelligence, and (computational) linguistics, which investigated issues involved in provisioning computer-based tutoring of mathematical proofs through dialogue in natural language. The ultimate goal in this context, addressing the above-mentioned need for learning support, is to build intelligent automated tutoring systems for mathematical proofs. The research presented here has been focused on the language that students use while interacting with such a system: its linguistic propeties and computational modelling. Contribution is made at three levels: first, an analysis of language phenomena found in studentsÂŽ input to a (simulated) proof tutoring system is conducted and the variety of studentsÂŽ verbalisations is quantitatively assessed, second, a general computational processing strategy for informal mathematical language and methods of modelling prominent language phenomena are proposed, and third, the prospects for natural language as an input modality for proof tutoring systems is evaluated based on collected corpora