PIDSIA Seminar by Franz Berto (7.6)
by Announcements of talks＠IDSIA
*Speaker:
Franz Berto (U. St Andrews & ILLC, U. Amsterdam)
*Title:
Half Empty vs Half Full: Belief Revision and the Framing Effect
*Abstract:
The dominant logical theory of belief revision, AGM (Alchourron, Gärdenfors and Makinson), imposes an amount of idealisation on cognitive agents revising their beliefs in the light of new information: their belief states are perfectly consistent, closed under the full force of classical logic, and they know all logical truths. Humans are not like that: they can hold inconsistent beliefs; their belief states are not classically closed; and they can be subject to framing effects, revising their beliefs in different ways when presented with logically equivalent options (‘If you apply for the job, you have 40% chances of making it’ vs ‘… you have 60% chances of failing’). Behavioural economics has shown the momentous consequences of framing in social choice and decision theory, where presenting the same situation positively (‘glass half full’) or negatively (‘glass half empty’) can lead to dramatically different beliefs and choices. In this talk, I present a semantics for a belief revision operator which is hyperintensional, that is, capable of modelling distinctions more fine-grained than classical logical equivalence, and in particular, framing effects and inconsistent beliefs. Unlike most approaches to belief revision for non-ideal agents, my semantics does not resort to non-classical logics. The framework combines, instead, a standard semantics for propositional modal logic with a simple mereology of contents.
*Bio:
Franz Berto is the chair of logic and metaphysics at the university of St Andrews and a research chair at the Institute for Logic, Language and Computation at the university of Amsterdam. He works more or less on anything nonclassical: non-standard ontology, non-classical modal and epistemic logic, and the philosophy of parallel computation. He has written a number papers on these topics, and books with Oxford University Press, Blackwell, King’s College, Synthese Library, Bloomsbury. He has held research positions at the Institute for Advanced Study at the University of Notre Dame, at the Sorbonne and CNRS in Paris, at the University of Aberdeen, and at the Netherlands Institute for Advanced Study.
*When:
Thursday 7th of June 2018, 12:00-13:00
*Location:
Manno, Galleria 1, 2nd floor, room G1-204
*Registration:
Pizza (or alternative food) and drinks will be offered at the end of the talk. If you plan to attend, please register in a timely fashion at the following link so that we will have no shortage of food:
https://doodle.com/poll/24yvbd6rgs68zarx
7 years
PIDSIA Seminar by Marilena Oita [23.5]
by Announcements of talks＠IDSIA
Title: Creative AI: bridging the Semantic Gap
Speaker: Marilena Oita (IDSIA)
Abstract: This presentation brainstorms on how creativity can be algorithmically forged and eased through Design. A multi-dimensional parallel between semantics and deep learning outlines the complementarity of these AI approaches. Assuming an architecture which eases the communication between the two paradigms, I propose ways in which semantics could solve three fundamental flaws of Deep Learning: narrow focus, opacity and incapacity to build on what we already know.
When: Wednesday, 23d of May 2018, 12:00-13:00
Location: Manno, Galleria 1, 2nd floor, room G1-204
Registration: Pizza (or alternative food) and drinks will be offered at the end of the talk. If you plan to attend, please register in a timely fashion at the following link so that we will have no shortage of food:
https://doodle.com/poll/szwfsfwe2k4heyhy
7 years, 1 month
Fwd: PIDSIA Seminar by Przemyslaw Uznanski
by Announcements of talks＠IDSIA
Dear all,
The talk below is cancelled.
Sorry for the inconvenient.
Regards,
Fabrizio
---------- Forwarded message ----------
From: Fabrizio Grandoni <fabrizio(a)idsia.ch>
Date: Wed, May 2, 2018 at 12:54 PM
Subject: Fwd: PIDSIA Seminar by Przemyslaw Uznanski
To: IDSIA Talks <talks(a)idsia.ch>
Speaker: Przemyslaw Uznanski, ETH Zurich
Title: A Framework for Searching in Graphs in the Presence of Errors
Abstract:
We consider two types of searching models, where the goal is to design
an adaptive algorithm that locates an unknown vertex in a graph by
repeatedly performing queries. In the vertex-query model, each query
points to a vertex v and the response either admits that v is the
target or provides a neighbor of von a shortest path from v to the
target. This model has been introduced for trees by Onak and Parys
[FOCS 2006] and by Emamjomeh-Zadeh et al. [STOC 2016] for arbitrary
graphs. In the edge-query model, each query chooses an edge and the
response reveals which endpoint of the edge is closer to the target,
breaking ties arbitrarily.
Our goal is to analyze solutions to these problems assuming that some
responses may be erroneous. We develop a scheme for tackling such
noisy models with the following line of arguments: For each of the two
models, we analyze a generic strategy that assumes a fixed number of
lies and give a precise bound for its length via an amortized
analysis. From this, we derive bounds for both a linearly bounded
error rate, where the number of errors in T queries is bounded by r*T
for some r<1/2, and a probabilistic model in which each response is
incorrect with some probability p<1/2. The bounds for adversarial case
turn out to be strong enough for non-adversarial scenarios as well.
We obtain thus a much simpler strategy performing fewer vertex-queries
than one by Emamjomeh-Zadeh et al. For edge-queries, not studied
before for general graphs, we obtain bounds that are tight up to logΔ
factors in all error models. Applying our graph-theoretic results to
the setting of edge-queries for paths, we obtain a number of
improvements over existing bounds for searching in a sorted array in
the presence of errors, including an exponential improvement for the
prefix-bounded model in unbounded domains.
Bio:
Przemyslaw Uznanski received a PhD from INRIA Bordeaux in 2013. He is
a postdoc at ETH Zurich since 2015. He works on distributed computing,
biological algorithms, graph algorithms and text processing (with
emphasis on algebraic methods in algorithms).
When:
Friday 11th of May 2018, 12:00-13:00
Location:
Manno, Galleria 1, 2nd floor, room G1-204
Registration:
Pizza (or alternative food) and drinks will be offered
at the end of the talk. If you plan to attend, please register in a
timely fashion at the following link so that we will have no shortage of food:
https://doodle.com/poll/cvwfze59xayg2rkk
7 years, 1 month
Fwd: PIDSIA Seminar by Przemyslaw Uznanski
by Announcements of talks＠IDSIA
Speaker: Przemyslaw Uznanski, ETH Zurich
Title: A Framework for Searching in Graphs in the Presence of Errors
Abstract:
We consider two types of searching models, where the goal is to design
an adaptive algorithm that locates an unknown vertex in a graph by
repeatedly performing queries. In the vertex-query model, each query
points to a vertex v and the response either admits that v is the
target or provides a neighbor of von a shortest path from v to the
target. This model has been introduced for trees by Onak and Parys
[FOCS 2006] and by Emamjomeh-Zadeh et al. [STOC 2016] for arbitrary
graphs. In the edge-query model, each query chooses an edge and the
response reveals which endpoint of the edge is closer to the target,
breaking ties arbitrarily.
Our goal is to analyze solutions to these problems assuming that some
responses may be erroneous. We develop a scheme for tackling such
noisy models with the following line of arguments: For each of the two
models, we analyze a generic strategy that assumes a fixed number of
lies and give a precise bound for its length via an amortized
analysis. From this, we derive bounds for both a linearly bounded
error rate, where the number of errors in T queries is bounded by r*T
for some r<1/2, and a probabilistic model in which each response is
incorrect with some probability p<1/2. The bounds for adversarial case
turn out to be strong enough for non-adversarial scenarios as well.
We obtain thus a much simpler strategy performing fewer vertex-queries
than one by Emamjomeh-Zadeh et al. For edge-queries, not studied
before for general graphs, we obtain bounds that are tight up to logΔ
factors in all error models. Applying our graph-theoretic results to
the setting of edge-queries for paths, we obtain a number of
improvements over existing bounds for searching in a sorted array in
the presence of errors, including an exponential improvement for the
prefix-bounded model in unbounded domains.
Bio:
Przemyslaw Uznanski received a PhD from INRIA Bordeaux in 2013. He is
a postdoc at ETH Zurich since 2015. He works on distributed computing,
biological algorithms, graph algorithms and text processing (with
emphasis on algebraic methods in algorithms).
When:
Friday 11th of May 2018, 12:00-13:00
Location:
Manno, Galleria 1, 2nd floor, room G1-204
Registration:
Pizza (or alternative food) and drinks will be offered
at the end of the talk. If you plan to attend, please register in a
timely fashion at the following link so that we will have no shortage of food:
https://doodle.com/poll/cvwfze59xayg2rkk
7 years, 1 month